| Title of Invention | "FORE AND AFT INTERLOCKING BRAKING DEVICE FOR MOTORCYCLE" |
|---|---|
| Abstract | [Subject] To provide a fore and aft interlocking braking device in which brake operating forces of an interlocking brake lever are transmitted through an operational force distributing lever to brake cables for transmitting the brake operating forces to front and rear wheel brakes, which is capable of eliminating the initial adjustment at least between the interlocking brake lever and the operational force distributing lever; suitably controlling a nose-dive amount upon operation of an interlocking brake lever so as to improve riding comfortability, without exerting adverse effect on a front wheel braking force and brake operational feeling obtained by operation of a front wheel brake lever; and allowing a braking force applied to the front wheel brake to be made different from that applied to the rear wheel Drake upon operation of the interlocking brake lever with a simple structure and to extend the applicability of the braking device to a conventional motorcycle. [Solving Means] A casing 56 is~ disposed at a position adjacent to an interlocking brake lever 32 along the longitudinal direction of a steering handlebar 45. A braking force exhibited by a front wheel brake only upon operation of an interlocking brake lever is controlled by a braking force control means 110. The brake cables 34 and 35 are connected to the operational force distributing lever 33 at positions different in distance from a connecting position of the interlocking brake lever to the operational force distributing lever 33, so that brake operational forces distributed from an operational force distributing lever 33 to both brake cables 34 and 35 in accordance with operation of an interlocking brake lever are made different from each other. |
| Full Text | [Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a fore and aft interlocking braking device, which allows brake operating forces of an interlocking brake lever to be transmitted through an operational force distributing lever to brake cables for transmitting the brake operating forces to front and rear wheel brakes; allows only a front wheel brake to exhibit a braking force upon operation of a front wheel brake lever and allows the front and rear wheel brakes to generate braking forces in interlocking with each other upon operation of the interlocking brake lever; and also allows traction forces to be applied from the operational force distributing lever to the brake cables provided correspondingly to the front and rear wheel brakes by action of the operational force distributing lever in accordance with operation of the interlocking brake lever. [Related Art] The interlocking braking device of this type has been known, for example, from Japanese Patent Laid-open No. Hei 7-196069. [Problem to be Solved by the Invention] The above-described related art braking device, however, is configured that a brake operating force from an interlocking brake lever is transmitted to an operational force distributing lever located at a position being relatively apart from the interlocking break lever, and accordingly, a transmission cable between the interlocking brake lever and the operational force distributing lever must be adjusted for initial adjustment of brake operating forces which are transmitted from the operational force distributing lever to front and rear wheel brakes through respective brake cables in accordance with operation of the interlocking brake lever. Incidentally, upon interlocking braking by operation of an interlocking brake lever, it is desired to suitably control the amount of a nose-dive in which a front portion of a motorcycle is dived and hence to improve the riding comfortability. In this regard, however, the above-described braking device has only a mechanism of distributing a braking 'force to front wheel and rear wheel brakes upon operation of the interlocking brake lever, and is not provided with a mechanism for controlling the nosedive amount. Further, the above related art braking device is configured that each of front and rear wheel brakes exhibits the same braking force in accordance with an interlocking brake lever. As a result, assuming the same operational amount of the brake lever, the brake feeling of a motorcycle having such an interlocking braking device is inevitably different from that of a conventional motorcycle having no interlocking braking device. Therefore, it is expected to develop a fore and aft interlocking braking device, which is capable of ensuring a brake feeling near that of a conventional motorcycle having no interlocking braking device by allowing one of front and rear wheel brakes to exhibit a braking force larger than that of the other one in accordance with operation of an interlocking brake lever. Additionally, according to the above-described related art braking device, tensions of both the brake cables must be simultaneously set because a change in tension of one brake cable exerts an effect on a change in tension of the other one. As a result, there arises a problem that a complicated work is required for setting tensions of the brake cables. In view of the foregoing, the present invention has been made, and a first object of the present invention is to provide a fore and aft interlocking braking device capable of eliminating the initial adjustment at least between, an. interlocking brake lever and an operational force distributing lever. A second object of the present invention is to provide an interlocking braking device for suitably controlling a nose-dive amount upon operation of an interlocking brake lever so as to improve riding comfortability, without exerting adverse effect on a front wheel braking force and brake operational feeling obtained by operation of a front wheel brake lever. A third object of the present invention is to provide a fore and aft interlocking braking device capable of making braking forces of front and rear wheel brakes different from each other upon operation of an interlocking brake lever with a simple structure, thereby extending the applicability of the braking device to a conventional motorcycle. A fourth object of the present invention is to provide a fore and aft interlocking braking device capable of individually setting tensions of both brake cables, thereby facilitating setting of tensions of the brake cables. [Means for Solving the Problem] To achieve the first object, according to an invention described in—claim 1 there is provided a fore and aft interlocking braking device for a motorcycle, including: a front wheel brake lever for allowing a front wheel brake to exhibit a braking force; an interlocking brake lever turnably supported on a holder fixed on one end portion of a steering handlebar and allowing the front wheel brake and a rear wheel brake to exhibit braking forces in interlocking with each other; brake cables for individually transmitting brake operating forces to the front and rear wheel brakes; an operational force distributing lever for connecting the interlocking brake lever to the brake cables in such a manner as to allow traction of each of the brake cables in accordance with braking operation of the interlocking brake lever; and a stationary casing in which the operational force distributing lever is movably contained; wherein the casing is disposed at a position adjacent to the interlocking brake lever along the longitudinal direction of the steering handlebar. With the configuration of the invention in claim 1 the interlocking brake lever and the operational force distributing lever, which are close to each other, can be directly connected to each other at a high rigidity without need of adjustment. As a result, it is possible to eliminate the initial adjustment between the interlocking brake lever and the operational force distributing lever, and to improve the adjustment accuracy of an interlocking braking force by preventing occurrence of deviation in adjustment between the interlocking brake lever and the operational force distributing lever. According to an invention described -in— claims 2, in addition to the configuration of the invention described in claim 1, the casing is disposed in front of the steering handlebar in a posture in which the brake cables are connected to the operational force distributing lever at positions separated from each other in the vertical direction. Accordingly, the casing can be formed in a vertically elongated shape in which the length along the vertical direction is longer than the length along the longitudinal direction of the motorcycle. As a result, the casing can be effectively disposed in a limited space on one end side of the steering handlebar in such a manner as not to exert adverse effect on operation of the steering handlebar and to prevent interference with the handle cover covering the steering handlebar. According to an invention in addition to the configuration of the invention described in claim 1 or 2, a braking force holding means for holding at least one of the brake cables in a traction state is provided to the casing in such a manner that an operating lever as a component of the braking force holding means projects from the casing; the steering handlebar is covered with a handle cover having an opening portion from which one end portion of the steering handlebar and the interlocking brake lever project; and the operating lever extends outward from the opening portion. As a result, the braking force holding means can be provided to the casing without the necessity of provision of a specialized opening portion for arranging the operating lever of the braking force holding means. Thus, the interlocking braking device can be newly applied to a motorcycle having no interlocking braking device without replacement of the handle cover. Further, since it is not required to provide any opening potion other than the opening portion for one end portion of the steering handlebar and the interlocking brake lever, it is possible to keep the external appearance of the handle cover at a level comparable to that of the conventional one. According to an invention described in claim 5, in addition to the configuration of the invention described-in any one-of claims 3 to-4, part of the casing is formed integrally with the holder. Accordingly, it is possible to reduce the number of parts, and to improve the assembling performance since part of the casing is assembled with the steering handlebar by assembling the holder with the steering handlebar. According to an invention -described -In clddHrt-e', in addition to the configuration of the invention described in claim 3 or 4, the casing formed in a vertically elongated shape in which the length along the vertical direction is larger than the length along the longitudinal direction of the motorcycle, is disposed in front of the steering handlebar; and the operating lever projecting from the front surface of the casing is disposed in front of the interlocking brake lever. Accordingly, the casing and the operating lever can be covered with the handle cover even if the swelled amount of the handle cover toward the front side of the steering handlebar is set to be relatively small. As a result, it is possible to avoid enlargement of the handle cover, and to enhance the degree of freedom in design of the handle cover. " To achieve the above second object, according -ta an invention described in claims -7, in addition to the configuration of the invention described in claim 1, there is further provided a braking force control means for controlling a braking force exhibited by the front wheel brake only upon operation of the interlocking brake lever. With this configuration, it is possible to suitably control the nose-dive amount by controlling a front wheel braking force upon operation of the interlocking brake lever while keeping an effective braking force and a brake operational feeling obtained by operation of the front wheel brake lever, resulting in the improved riding comfortability. According to an invent iondescribed in claim. 8, in addition to the configuration of the invention described in claim 7, the braking force control means is configured to restrict the upper limit of a braking force exhibited by the front wheel brake in accordance with operation of the interlocking brake lever. Accordingly, when the interlocking brake lever is largely moved, it is possible to suitably adjust the nose-dive amount by suppressing a front wheel braking force while ensuring a large rear wheel braking force. According to an invention described in claims-9 in addition to the configuration of the invention described in claim 7 or 8, the braking force control means is configured to suppress a braking force of the front wheel brake at the initial stage of operation of the interlocking brake lever. Accordingly, at the initial stage of operation of the interlocking brake lever, it is possible to generate a nose-dive only by a braking force on the rear wheel side and hence to obtain a desirable nose-dive feeling by compensating for the increment of the front wheel shared load due to a load applied by the rider. It is effective to suitably control the nose-dive amount since the initial stage of operation of the interlocking brake lever. To achieve the above third object, according to an invention deacribed-Jji claim KX, in addition to the configuration of the invention described in claim 1, the brake cables are connected to the operational force distributing lever at positions different in distance from a connecting position of the interlocking brake lever to the operational force distributing lever so that brake operating forces distributed from the operational force distributing lever to the brake cables in accordance with operation of the interlocking brake lever are different from each other. With the configuration of the invention described in claim 10, braking forces of the front and rear wheel brakes are made different from each other upon operation of the interlocking brake lever only by providing a simple structure in which both the brake cables are connected to the operational force distributing lever at positions different in distance from the connecting position of the interlocking brake lever to the operational force distributing lever. As a result, the braking device of the present invention can be applied to a conventional motorcycle having no interlocking braking device while avoiding the braking operation feeling from being different from that having obtained by the conventional motorcycle. According to an invention in addition to the configuration of the invention described in claim 10, a diameter of the brake cable to which a large brake operational force is applied from the operational force distributing lever is set to be larger than a diameter of the brake cable to which a small brake operational force is applied from the operational force distributing lever. As a result, the rigidity of the rear wheel brake cable on the side where the brake operational force becomes larger, that is, a traction amount becomes larger can be set to be higher than the rigidity of the front wheel brake cable on the side where the brake operational force becomes smaller;that is, a traction amount becomes smaller, so that the moved amount of the operational force distributing lever can be suitably adjusted by matching the expansion amounts of both the brake cables with the traction amounts thereof. According to an invention -described in cldint-12, in i addition to the configuration of the invention described in claim 10 or 11, the operational force distributing lever is movably contained in the stationary casing; the brake cables are connected to the operational force distributing lever at points which are positioned on both sides of a connecting portion of the interlocking brake lever to the operational force distributing lever and which are different in distance from the connecting portion; a locking portion is provided at an end portion of the operational force distributing lever on the side of one of the brake cables which is small in distance from the connecting portion of the interlocking brake lever; and a braking force holding means to be removably engaged with the locking portion is "provided on the casing in such a manner that the means, when being engaged with the locking portion, is allowed to hold the one brake cable in a traction state but to make the other of the brake cables in a non-traction state, with this configuration, the braking force holding means is engaged with" the operational force distributing lever on the side where the lever is relatively largely moved in accordance with operation of the interlocking brake lever, so that it is possible to make relatively small the operated amount of the interlocking brake lever upon operation of the braking force holding means. To achieve the above fourth object, according to an invention UesciibyU iTl Claim 13, in addition to the configuration of the invention described in claim 1 , the operational force distributing lever is contained in the stationary casing in such a manner as to be movable between a position at which the lever is brought in contact with an initial contact surface provided in the casing upon a non-operation state of the interlocking brake lever and a position at which the lever is separated from the initial contact surface in accordance with operation of the interlocking brake lever. With this configuration of the invention itrclaiiri 13, it is possible to avoid mutual effect of both the brake cables by bringing the operational force distributing lever in contact with the initial contact surface in the non-operation state of the interlocking brake lever, and hence to indivldtraily set tensions of both the brake cables. It is effective to easily set the tensions of the brake cables. The present invention relates to a fore and aft interlocking braking device for a motorcycle, comprising: a front wheel brake lever for allowing a front wheel brake (BF) to exhibit a braking force; an interlocking brake lever turnably supported on a holder fixed on one end portion of a steering handlebar and allowing said front wheel brake (BF) and a rear wheel brake (BR) to exhibit braking forces in interlocking with each other; brake cables for individually transmitting brake operating forces to said front and rear wheel brakes (BF, BR); an operational force distributing lever for connecting said interlocking brake lever to said brake cables in such a manner as to allow traction of each of said brake cables in accordance with braking operation of said interlocking brake lever; and a stationary casing in which said operational force distributing lever is movably contained; wherein said casing is disposed at a position adjacent to said interlocking brake lever along the longitudinal direction of said steering handlebar. [Brief Description of the Drawings) [Fig. 1] A view showing the entire configuration of a fore and aft interlocking braking device for a motorcycle. [Fig. 2] A side view seen from the left side of the motorcycle. [Fig. 3] A plan view seen along arrow 3 of Fig. 2. [Fig. 4] A plan view of a left end portion of a steering handlebar in a state in which a handle cover is removed. [Fig. 5] A front view seen from arrow 5 of Fig. 4. [Fig. 6} A sectional view taken on line 6-6 of Fig. 4. [Fig. 7] An enlarged view seen from arrow 7 of Fig. 5. [Fig. 8) An enlarged view showing essential portions shown in Fig. 5 in a state in which a cover plate of a casing is removed. [Fig. 9] An enlarged sectional view taken on line 9-9 of Fig. 5. [Fig. 10] An enlarged sectional view taken on line 10-10 of Fig. 8, showing an operational force distributing lever. [Fig. 11] An enlarged sectional view taken on line 11-11 of Fig. 8, showing the operational force distributing lever. [Fig. 12] A view, similar to Fig. 7, showing an operating state of a braking force holding means. [Fig. 13] A plan view of ~a right end portion of a steering handlebar. [Fig. 14] A front view seen along arrow 14 of Fig. 13. [Fig. 15] A sectional view taken on'line 15-15 of Fig. 13. [Fig. 16] An enlarged view seen from arrow 16 of Fig. 14, with parts partially cutaway. [Fig. 17] A sectional view taken on line 17-17 of Fig. 15. [Fig. 18] A sectional view taken on line 18-18 of Fig. 15. [Fig. 19] An enlarged sectional view taken on line 19-19 of Fig. 16. [Fig. 20] An enlarged sectional view taken on line 20-20 of Fig. 16. [Fig. 21] A sectional view, similar to Fig. 18, showing a state in which a front wheel brake lever is operated in a non-operation state of an interlocking brake lever. [Fig. 22] A sectional view, similar to Fig. 21, showing a state in which the interlocking brake lever is operated in a non-operation state of the front wheel brake lever. [Fig. 23] A sectional view, similar to Fig. 22, showing a state in which the interlocking brake lever and the front wheel brake lever are both operated. [Fig. 24] A view seen along line 24-24 of Fig. 14, showing a state prior to assembly. [Fig. 25] A sectional view taken on line 25-25 of Fig. 24. [Fig. 26] A graph showing a braking force distributing [Embodiment of the Invention] Hereinafter, one preferred embodiment of the present invention will be described with reference to the accompanying drawing. Figs. 1 to 26 show the embodiment of the present invention, in which: Fig. 1 is a view showing the entire configuration of a fore and aft interlocking braking device for a motorcycle; Fig. 2 is a side view, seen from the left side, of a front portion of the motorcycle; Fig. 3 is a plan view seen along arrow 3 of Fig. 2; Fig. 4 is a plan view of a left end portion of a steering handlebar in a state in which a handle cover is removed; Fig. 5 is a front view seen from arrow 5 of Fig. 4; Fig. 6 is a sectional view taken on line 6-6 of Fig. 4; Fig. 7 is an enlarged view seen from arrow 7 "of Fig. 5; Fig. 8 is an enlarged view showing essential portions shown in Fig. 5 in a state in which a cover plate of a casing is removed; Fig. 9 is an enlarged sectional view taken on line 9-9 of Fig. 5; Fig. 10 is an enlarged sectional view taken on line 10-10 of Fig. 8, showing an operational force distributing lever; Fig. 11 is an enlarged sectional view taken on line 11-11 of Fig. 8, showing the operational force distributing lever; Fig. 12 is a view, similar to Fig. 7, showing an operating state of a braking force holding means; Fig. 13 is a plan view of a right end portion of a steering handlebar; Fig. 14 is a front view seen along arrow 14 of Fig. 13; Fig. 15 is a sectional view taken on line 15-15 of Fig. 13; Fig. 16 is an enlarged view seen from arrow 16 of Fig. 14, with parts partially cutaway; Fig. 17 is a sectional view taken on line 17-17 of Fig. 15; Fig. 18 is a sectional view taken on line 18-18 of Fig. 15; Fig. 19 is an enlarged sectional view taken on line 19-19 of Fig. 16; Fig. 20 is an enlarged sectional view taken on line 20-20 of Fig. 16; Fig. 21 is a sectional view, similar to Fig. 18, showing a state in which a front wheel brake lever is operated in a non-operation state of an interlocking brake lever; Fig. 22 is a sectional view, similar to Fig. 21, showing a state in which the interlocking brake lever is operated in a non-operation state of the front wheel brake lever; Fig. 23 is a sectional view, similar to Fig. 22, showing a state in which the interlocking brake lever and the front wheel brake lever are both operated; Fig. 24 is a view seen along line 24-24 of Fig. 14, showing a state prior to assembly; Fig. 25 is a-sectional view taken on line 25-25 of Fig. 24; and Fig. 26 is a graph showing a braking force distributing characteristic. Referring first to Fig. 1, a fore and aft interlocking braking device for a motorcycle includes a front wheel brake lever 31, and an interlocking brake lever 32. The front wheel brake lever 31 actuates a hydraulic type front wheel brake BF on the basis of a braking operation. The interlocking brake lever 32 is capable of actuating a mechanical type rear wheel brake BR in interlocking with the front wheel brake BF on the basis of the brake operation. The interlocking brake lever 32 is connected to an approximately central portion of an operating force distributing lever 33. One end portion of a front wheel brake cable 34 and one end portion of a rear wheel brake cable 35 are connected to both end portions of the operating force distributing lever 33. The front wheel brake cable 34 is adapted to transmit a brake operating force to the front wheel brake Br, and the rear wheel brake cable 35 is adapted to transmit a brake operating force to the rear wheel brake BR. The rear wheel brake B^is—a drum brake including a brake drum 37, a pair of brake shoes 40, a cam 41, a brake cam arm 42, a fixed arm 43, and a spring 44. The brake drum 37 is rotatably supported on an axle 36 of a rear wheel. The brake shoes 40 are pivotably supported on a brake panel 38 through a pin 39 and are allowed to be frictionally engaged with an inner peripheral surface of the brake drum 37. The cam 41 is pivotably supported on the brake panel 38 in such a manner as to make both the brake shoes 40 in press-contact with the inner peripheral surface of the brake drum 37. The brake cam arm 42 extends outward from the brake drum 37 with a base end thereof being connected to the cam 41. The fixed arm 43 is provided on the brake panel 38 opposite to the brake cam arm 42. The spring 44, which is contractedly provided between the brake cam arm 42 and the fixed arm 43, acts to bias the brake cam arm 42 in the direction where both the brake shoes 40 are close to each other. The rear wheel brake BR exhibits a brake force corresponding to an operational force inputted from the rear wheel brake cable 35 to the brake cam arm 42. Referring to additionally to Figs. 2 to 7, a steering handlebar 45 is provided on a front portion of a body of a scooter type motorcycle-r~ A grip portion 46 to be held by the left hand of a driver is provided at a left end of the steering handlebar 45. A holder 47 is mounted on the steering handlebar 45 at a position inward from the grip portion 46. An arcuate mounting portion 47a corresponding to an approximately lower half circumferential portion of the steering handlebar 45 is integrally provided on the holder 47, and an arcuate mounting stay 48 corresponding to an approximately remaining half circumferential portion of the steering handlebar 45 is provided such that one end thereof is engaged with the mounting portion 47a and the other end thereof is fastened to the holder 47 with a screw member 49. The holder 47 is thus fixed to the steering handlebar 45. A base end portion of the interlocking brake lever 32 is turnably supported on the holder 47 through a bolt as a supporting shaft 50, so that the interlocking brake lever 32 can be operated for braking by the left hand holding the grip portion 46. Additionally, a return spring or a torsion spring 51 is provided between the holder 47 and the interlocking brake lever 32, and the interlocking brake lever 32 is elastically biased by a spring force of the return spring 51 in the direction where it is separated from the grip portion 46. An intermediate portion of the steering handlebar 45 in the longitudinal direction is covered with a handle cover 53. The handle cover 53 is composed of front and rear cover halves 53a and 53b which are made from synthetic resin and connected to each other. The grip portion 46 at the left end portion of the steering handlebar 45 and the interlocking brake lever 32 project outward from an opening portion 54 provided in a left side portion of the handle cover 53. Referring additionally to Figs. 8 and 9, a casing 56 for operably containing the operational force distributing lever 33 is fixed at a position being adjacent to the inner side of the interlocking brake lever 32 along the longitudinal direction of the steering handlebar 45 and being in front of the steering handlebar 45. The casing 56 includes a box-like case portion 57 integrated with the holder 47 and opened forward, and a cover plate 58 connected to the case portion 57 in such a manner as to cover an opening end of the case portion 57. On end of a connecting rod 59 is connected to the base end portion of the interlocking brake lever 32 with a screw member 60. The connecting rod 59 movably passes through a side wall 57a of the case portion 57 of the casing 56 on the interlocking brake lever 32 side and is inserted in the casing 56. Between the side wall 57a of the casing 56 and an intermediate portion of the connecting rod 59 in the casing 56, is provided a boot 61 for preventing permeation of dust from the insertion portion of the connecting rod 59 into the casing 56. / As will be apparent from Figs. 10 and 11, the operational force distributing lever 33 has a pair of flat plate portions 33a and 33b vertically extending longer in parallel to each other. The flat plate portions 33a and 33b are connected to each other by connecting portions 33c, at two vertically spaced portions on the side wall 57a side. The other end of the connecting rod 59 is connected through a connecting pin 62 to an intermediate portion of the operational force distributing lever 33 along the longitudinal direction. In order to operably contain the operational force distributing lever 33 extending longer in the vertical direction, the casing 56 is formed into a vertically elongated shape in which the length thereof along the longitudinal direction of the motorcycle is longer than the length thereof along the vertical direction of the motorcycle. In the case portion 57 of the casing 56, outer cables 34a and 35a of the front and rear wheel brake cables 34 and 35 are fixedly provided in parallel to each other at vertically spaced positions of a side wall 57b opposed to the side wall 57a. Specifically, on one end side of the front wheel brake cable 34, which is composed of the outer cable 34a and an inner cable 34b movably inserted in the outer cable 34a, the outer cable 34a is fixed to the side wall 57b of the case portion 57, and a locking element 64, which is provided on the end portion of the inner cable 34b projecting from the outer cable 34a and inserted in the casing 56, is engaged and connected to the lower portion of the operational force distributing lever 33. Beside, on one end side of the rear wheel brake cable 35, which is composed of the outer cable 35a and an inner cable 35b movably inserted in the outer cable 35a, the outer cable 35a is fixed to the side wall 57b of the case portion 57 in parallel to the front wheel brake cable 34, and a locking element 65, which is provided on the end portion of the inner cable 35b projecting from the outer cable 35a, is connected to the upper portion of— the operational force distributing lever 33. Incidentally, a brake operational force is applied from the interlocking brake lever 32 to the operational force distributing lever 33 through the connecting rod 59 and is distributed from the operational force distributing lever 33 to both the brake cables 34 and 35. Here, to make components of the brake operational force distributed from the operational force lever 33 to both the brake cables 34 and 35 different from each other, both the brake cables 34 and 35 are connected to the operational force distributing lever 33 at positions different in distance from the connecting position of the connecting rod 59 to the operational force distributing lever 33. In this embodiment, letting Lr be a distance between the connecting position of the connecting rod 59 to the operational force distributing lever 33 and the connecting position of the front wheel brake cable 34 to the operational force distributing lever 33,'and also LR be a distance between the connecting position of the connecting rod 59 to the operational force distributing lever 33 and the connecting position of the rear wheel brake cable 35 to the operational force distributing lever 33, a relationship of Lp->LR is given. — Here, letting F be a force inputted from the interlocking brake lever 32 to the operational force distributing lever 33 through the connecting rod 59, Fr be a traction force applied from the operational force distributing lever 33 to the front wheel brake cable 34, and FR be a traction force applied from the operational force distributing lever 33 to the rear wheel brake cable 35, both the traction forces FF and FR are expressed by the following equations ( 1 ) and ( 2 ) .(Equations Removed ) In the equations (1) and (2), FR>FF is given because LF>LR. That is, the brake operating force applied from the operational force distributing lever 33 to the rear wheel brake cable 35 becomes larger than that applied from the operational force distributing lever 33 to the front wheel brake cable 34. With respect to both the brake cables 34 and 35, a diameter DR of the brake cable to which a large brake operating force is applied from the operational force distributing lever 33, that is, the rear wheel brake cable 35 is set to be larger than a diameter Dr of the front wheel brake cable 34-to which a small brake operating force is applied. In other words, the bending rigidity of the front wheel brake cable 34 is set to be relatively small, and accordingly, when a head lamp is mounted to the handle cover 53, the front wheel brake cable 34 can be easily disposed in a state that it bypasses the upper or lower side of the head lamp. Even when the front wheel brake cable 34 is disposed in such a state, the inner cable 34b can be smoothly moved through the front wheel brake cable 34 with less friction therebetween. An intermediate portion of the front wheel brake cable 34 is supported by the rear wheel brake cable 35 by means of a fastener 66 so that the front wheel brake cable 34 is partially disposed along the rear wheel brake cable 35. An initial contact surface 67, which faces the operating force distributing lever 33, is formed on the side wall 57b of the casing 56. The operating force distributing lever 33 has contact plate portions 33d, 33e, and 33f to be brought in contact with the initial contact surface 67. The contact plate portion 33d is bent from the flat plate portion 33a onto the flat plate portion 33b side at a position substantially corresponding to a connecting portion of the connecting rod 59 with respect to the operational force distributing lever 33. The contact plate portion 33e is bent from the flat plate portion 33a onto the side opposed to the flat plate portion 33b at a position substantially corresponding to a connecting portion of the front wheel brake cable 34 with respect to the operating force distributing lever 33. The contact plate portion 33f, which is located lower than the contact plate portion 33e, is bent from the flat plate portion 33b onto the side opposed to the flat plate portion 33a. The casing 56 has a stop switch 68 with a probe 68a facing the initial contact surface 67. The stop switch 68 detects whether or not the interlocking brake lever 32 is operated. In the non-operation state of the interlocking brake lever 32, the contact plata-portion 33d of the operational force distributing lever 33 is brought in contact with the initial contact surface 67, and the probe 68a is depressed by the contact plate portion 33d. When the contact plate portion 33d is separated from the initial contact surface 67 by action of the operational force distributing lever 33 depending on operation of the interlocking brake lever 32, the probe 68a is released from the pressing force applied from the contact plate portion 33d. It is preferred to make relatively wide the area of the flattened contact plate portion 33d for certainly bringing the contact plate portion 33d in contact with the probe 68a of the stop switch 68 even if the position of the operational force distributing lever 33 is offset somewhat in the non-operation state of the interlocking brake lever 32. The casing 56 is provided with a braking force holding means 70. In the non-operation state of the interlocking brake lever 32, the braking force holding means 70 is capable of holding the rear wheel brake cable 35 in a traction state while making the front wheel brake cable 34 in a non-traction state. The braking force holding means 70 includes a braking force holding arm 71 contained in the casing 56, an operating lever 72, and a return spring 73. When the operational force distributing lever 33 is located at an operational position in accordance with the braking operation of the interlocking brake lever 32, the braking force holding arm 71 can be moved between an engagement position where it is engaged with the operational force distributing lever 33 and a non-engagement position where it is disengaged from the operational force distributing lever 33. The operating lever 72, which is connected to the braking force holding arm 71, is allowed to operate the braking force holding arm 71 from outside the casing 56. The return spring 73 is adapted to elastically bias the braking force holding arm 71 on the side where the braking force holding arm 71 is disengaged from the operational force distributing lever 33. The braking force holding arm 71 includes an arm plate portion 74, an arm plate portion 75, a connecting plate portion 76, and an engagement pin 77. A base end of the arm plate portion 74 is integrally formed with a supporting cylinder 74a having a leading end being brought in sliding-contact with an inner surface of the cover plate 58 of the casing 56. The arm plate portion 74 faces the inner surface of the cover plate SS~ The arm plate portion 75 is disposed opposite to the arm plate portion 74 with a gap put therebetween. A base end of the arm plate portion 75 has a supporting hole 75a corresponding to an inner periphery of the supporting cylinder 74a. The connecting plate portion 76 connects one side of an intermediate portion of the arm plate portion 74 to that of the arm plate portion 75. The engagement pin 77 is provided for engaging leading end portions of the arm plate portions 74 and 75 with each other. The gap put between both the arm plate portions 74 and 75 is set at a value allowing the leading end portions of the arm plate portions 74 and 75 to hold the operational force distributing lever 33. A shaft portion 78 is integrally provided on the case portion 57 of the casing 56 at a position near the side wall 57a, with a leading end thereof being brought in contact with the inner surface of the cover plate 58. The shaft portion 78 is made to pass through the supporting cylinder 74a and the supporting hole 75a of the braking force supporting arm 71 so that the braking force supporting arm 71 is turnably supported by the shaft portion 78. The return spring 73 is provided between the braking force holding arm 71 and the case portion 57 while surrounding the shaft portion 78. As shown in Fig. 12, locking portions 79 are provided on both the flat plate portions 33a and 33b at the end portion of the operational force distributing lever 33 on the side of the rear wheel brake cable 35 having a small distance from the connecting portion of the connecting rod 59. The engagement pin 77 of the braking force holding arm 71 is engaged in the locking portions 79 when the operational force distributing lever 33 is separated from the initial contact surface 67 by operation of the interlocking brake lever 32. The operating lever 72 includes a shaft portion 72a and an operating portion 72b. The shaft portion 72a is fixed to the braking force holding arm 71 in parallel to the shaft portion 78 of the casing 56. The operating portion 72b is integrated with the shaft portion 72a and is disposed in front of the casing 56. The shaft portion 72a of the operating lever 72 passes through both the arm plate portions 74 and 75 of the braking force holding arm 71, and one end of the shaft portion 72a is welded to the arm plate portion 75. The cover plate 58 has a through-hole 80 extending longer in an arcuate shape centered on the axial line of the shaft portion 78.. The-other end of the shaft portion 72a passing through the though-hole 80 and projecting forward from the casing 56 is integrated with the operating portion 72b positioned forward from the interlocking brake lever 32 in front of the casing 56. A rubber made cover member 81 formed in a flat shape is brought in sliding-contact with a front surface or an outer surface of the cover plate 58 in such a manner as to cover the through-hole 80. A base portion of the cover member 81 is held between a spacer 82 and the cover plate 58 in such a manner as to be turnable around the axial line of the shaft portion 78. The spacer 82 is fixed on the outer surface of the cover plate 58 by means of a screw member 83 passing through the cover plate 58 and coaxially screwed in the shaft portion 78. The other end of the shaft portion 72a of the operating lever 72 is penetrated in and engaged with the cover member 81. Accordingly, when the shaft portion 72a is turned around the shaft portion 78 along the though-hole 80 by operation of the operating lever 72, the cover member 81 is turned around the axial line of the shaft portion 78 while usually covering the through-hole 80. The operating portion 72b~of the operating lever 72, which extends outward along the longitudinal direction of the steering handlebar 45 on the front side of the casing 56 and the interlocking brake lever 32, further extends outward from the opening portion 54 provided in the handle cover 53. In addition, the grip portion 45 at the left end of the steering handlebar 45 and the interlocking brake lever 32 also project from the opening portion 54. Referring again to Fig. 1, the front wheel brake BF is a disk brake to which a master cylinder 87 is connected through a pipe line 88. The master cylinder 87 outputs a hydraulic pressure based on a pressing operation of an auxiliary operating lever 86. Referring additionally to Figs. 13 to 15, a grip portion 89 held by the right hand of the driver is provided at the right end portion of the steering handlebar 45. The master cylinder 87 integrated with a reservoir 90 is mounted on the steering handlebar 45 at a position inward from the grip portion 89. Specifically, a mounting portion 91 being in contact with a nearly front half circumference of the steering handlebar 45 is integrally provided on the master cylinder 87 and a holding member 92 being in contact with a nearly rear half circumference of the steering handlebar 45 is fastened to the mounting portion 91 with a pair of bolts 93. The master cylinder 87 is thus mounted to the steering handlebar 45. Referring further additionally to Figs. 16 to 18, brackets 94 and 95, spaced in the vertical direction, are integrally provided on the master cylinder 87. A base portion of the front wheel brake lever 31 operable by the right hand holding the grip portion 89 and the auxiliary operating lever 86 are supported by the brackets 94 and 95 in such a manner as to be turnable around a supporting shaft 96. The supporting shaft 96 has an extended diameter head portion 96a at its upper end, an engagement stepped portion 96b engaged with an upper surface portion of the bracket 95 at its intermediate portion, and a small diameter screw shaft portion 96c at its lower end. The screw shaft portion 96c of the supporting shaft 96 having passed through the bracket 94 projects downward from the bracket 95, and a nut 97 is screwed with the portion of the screw shaft portion 96c projecting from the bracket 95, so that the supporting shaft 96 is fixed on both the brackets 94 and 95. In such a fixed statey-the extended diameter head portion 96a is spaced upward from the upper surface of the bracket 94. The auxiliary operating lever 86 includes a turning plate portion 86a, a connecting portion 86b, and an arm portion 86c. The turning plate portion 86a is relatively turnably supported by the supporting shaft 96 together with the base portion of the front wheel brake lever 31 between both the brackets 94 and 95. The connecting portion 86b is formed in a semi-circular shape in cross-section so as to surround the bracket 95 and extends downward from the turning plate portion 86a. The arm portion 86c is connected to the lower end of the connecting portion 86b and extends substantially in parallel to the turning plate portion 86a. At the connecting area between the connecting portion 86b and the arm portion 86c, is formed a circular opening portion 98 allowing fastening and loosening of the nut 97 to and from the screw shaft portion 96c. As clearly shown in Fig. 18, a piston 100 is slidably fitted in the master cylinder 87. In a hydraulic pressure chamber 101 to which a front end surface (left end surface in Fig. 18) of the piston 100 faces, is contained a spring 102 for biasing the piston-100 rearward (rightward in Fig. 18). A piston rod lOOa, which is provided coaxially and integrally with the piston 100, projects from the rear end of the master cylinder 87. A boot 103 covering the piston rod lOOa is provided between a rear end portion of the piston rod lOOa and the master cylinder 87. A pressing portion 104 is integrally provided on the turning plate portion 86a of the auxiliary operating lever 86. The pressing portion 104 is brought in contact with the rear end of the piston rod lOOa for applying a pressing force to the piston rod lOOa. An engagement portion 105 engageable with the pressing portion 104 is provided on the base portion of the front wheel brake lever 31. The engagement portion 105 is engaged with the pressing portion 104 in accordance with the braking operation of the front wheel brake lever 31, causing the pressing portion 104 to apply an operating force to the piston rod lOOa. Also, in the non-operation of the front wheel brake lever 31, the pressing portion 104 is allowed to press the piston rod lOOa by turning of the auxiliary operating lever 86 while leaving the engagement portion 105 of the front wheel brake lever 31 as it is. A return spring 106, whieh— functions as a torsion spring surrounding the supporting shaft 96 between the bracket 94 and the extended diameter head portion 96a, is provided between the front wheel brake lever 31 and the bracket 94. The front wheel brake lever 31 is biased by a spring force of the return spring 106 in the direction where it is separated from the grip portion 89, that is, in the direction where the engagement portion 105 is separated from the pressing portion 104. A restricting surface portion 107 for restricting a turning end of the front wheel brake lever 31 in the direction where it is biased by the return spring 106, is provided on the master cylinder 87 at a position between both the brackets 94 and 95. In a state in which the front wheel brake lever 31 is brought in contact with the restricting surface portion 107, the auxiliary operating lever 86 in a state being not applied with an external force is located at a turning position where the pressing portion 104 is engaged with the engagement portion 105 by the spring force of the spring 102 in the master cylinder 87. A stop switch 108 is mounted on the master cylinder 87. A detecting portion 109 allowed to be brought in contact with a probe 108a of the stop switch 108, is integrally provided on the connecting portion 86b of the auxiliary operating lever 86. The stop switch 108 detects whether or not the auxiliary operating lever 86 is operated, that is, whether or not the front wheel brake Br is actuated. When the auxiliary operating lever 86 is not applied with an external force, the probe 108a is depressed by the detecting portion 109. Besides, when the auxiliary operating lever 86 is turned to depress the piston rod lOOa through the pressing portion 104, the probe 108a is released from being applied with the pressing force from the detecting portion 109. Referring additionally to Figs. 19 and 20, with respect to the front wheel brake cable 34, one end portion thereof is connected to the operational force distributing lever 33, and the other end portion thereof is connected to the arm portion 86c of the auxiliary operating lever 86 through a braking force control means 110 capable of controlling a braking force exhibited by the front wheel brake Bf only upon operation of the interlocking brake lever 32. The braking force control means 110 includes a cable holder 111, a cable joint 112, and a restricting spring 113. The cable holder l11— is fastened to the master cylinder 87. The cable joint 112 is connected to the arm portion 86c of the auxiliary operating lever 86 in such a manner as to be allowed to be close to or separated from the cable holder 111. The restricting spring 113 is adapted to exhibit a spring force biasing the cable joint 112 in the direction where it is separated from the cable holder 111, and is provided between the cable holder 111 and the cable joint 112. The cable holder 111 is formed in a cylindrical shape having an axial line substantially in parallel to the master cylinder 87 and being opened at both ends thereof, and is fastened to the master cylinder 87 with a pair of screw members 114. The cable holder 111 has a mounting hole 115 opened on one end side thereof, and also has a spring containing hole 116 opened on the other end side thereof, that is, on the cable joint 112 side. The mounting hole 115 and the spring containing hole 116 are coaxial with each other. The cable holder 111 also has a flange portion 117 projecting radially inward between both the holes 115 and 116. At the other end portion of the front wheel brake cable 34, a screw cylinder 118 having a male thread provided on its outer surface is fixed at the other end of the outer cable 34a, and an adjusting nut 119 and a lock nut 120 are screwed in the screw cylinder 118. The screw cylinder 118 is inserted in the mounting hole 115 with the adjusting nut 119 being brought in contact with one end of the cable holder 111. Further, the inner surface of the mounting hole 115 is provided with engagement flat surface portions 115a opposed to each other along the diameter line of the mounting hole 115 and extending along the axial line thereof, and the outer surface of the screw cylinder 118 is provided with flat engagement surface portions 118a facing the engagement surface portions 115a. When the screw cylinder 118 is inserted in the mounting hole 115, the engagement surfaces portions 115a are engaged with the engagement surface portions 118a, whereby rotation of the screw cylinder 118 around the axial line in the mounting hole 115 is prevented. The loose movement length of the front wheel brake cable 34 is adjusted by changing forward /backward movement of the adjusting nut 119 and the lock nut 120 along the axial line of the screw cylinder 118. Since rotation of the screw cylinder 118 around the axial line in the mounting hole 115 is prevented, itr~is possible to eliminate of necessity of holding the outer cable 34a upon rotation of the adjusting nut 119 and the lock nut 120. That is, the loose movement length of the front wheel brake cable 34 can be easily adjusted only by rotating the adjusting nut 119 and the lock nut 120. The cable joint 112 has at one end thereof an end plate 112a facing the other end of the cable holder 111, and is substantially U-shaped on the other end side thereof in such a manner as to hold the leading end of the arm portion 86c of the auxiliary operating lever 86. Slots 121 extending along the extension of the axial line of the cable holder 111 are provided on both sides of the cable joint 112. The cable joint 112 is connected to the arm portion 86c of the auxiliary operating lever 86 through a connecting pin 122 having both ends which are engaged in both the slots 121 movably along the slots 121. At the other end of the front wheel brake cable 34, the inner cable 34b projecting from the other end of the outer cable 34a passes through the cable holder 111 and extends on the cable joint 112 side, and a locking piece 123 provided on the other end of the inner cable 34a is engaged with an end plate 112a of the cable joint 112. The restricting spring 113 has a coil shape surrounding the inner cable 34b. One end side of the restricting spring 113 is contained in the spring containing hole 116 of the cable holder 111, with one end thereof being received by the flange portion 117. The other end of the restricting spring 113 is brought in contact with the end plate 112a of the cable joint 112. When both the front wheel brake lever 31 and the interlocking brake lever 32 are not operated, the connecting pin 122 is located in the slots 121 at an opposed end portion to the end plate 122a of the cable joint 112, and the end plate 112a of the cable joint 112 is spaced from the other end of the cable holder 111 at a specific gap. According to such a braking force control means 110, when the front wheel brake lever 31 is operated for braking in the non-operation state of the interlocking brake lever 32, that is, in a state in which the front wheel brake cable 34 is not applied with any traction force, the engagement portion 105 of the front wheel brake lever 31 presses the pressing portion 104 to apply a pressing force to the piston rod lOOa of the master cylinder 87 as shown in Fig. 21, thereby causing the front wheel brake Br to exhibit a braking force. In this case, the connecting pin 122 is only moved along the slots 121 in accordance with the turning of the auxiliary operating lever 86. Accordingly, the spring force of the restricting spring 113 is applied to the cable joint 112; however, it is not applied to the front wheel brake lever 31. This makes it possible to obtain a braking force of the front wheel brake BF which is comparable to a braking force obtained by operation of a front wheel brake lever of a conventional motorcycle having no interlocking braking device. When the interlocking brake lever 32 is operated for braking in the non-operation state of the front wheel brake lever 31, a brake operational force is also applied to the front wheel brake cable 34 by action of the operational force distributing lever 33 in accordance with operation of the interlocking brake lever 32. In this case, the cable joint 112 is not moved in the direction where the end plate 112a thereof is close to the cable holder 111 until the brake operational force exceeds a set load of the restricting spring 113-r- Accordingly, the force from the front wheel brake cable 34 is not applied to the auxiliary operating lever 86. That is, at the initial stage of braking operation of the interlocking brake lever 32, a pressing force is not applied to the master cylinder 87 until a force corresponding to the set load of the restricting spring 113 is applied from the operational force distributing lever 33 to the front wheel brake cable 34, so that the braking force of the front wheel brake Br is suppressed at the initial stage of operation of the interlocking brake lever 32 As the force corresponding to the set load of the restricting spring 113 is applied from the operational force distributing lever 33 to the front wheel brake cable 34, the inner cable 34b of the front wheel brake cable 34 allows traction of the cable joint 112 such that the end plate 112a is close to the cable holder 111. As a result, the auxiliary operating lever 86 is turned to depress the piston rod lOOa by the "pressing portion 104, whereby the front wheel brake Br exhibits a braking force. •> After that, when the end plate 112a of the cable joint 112 is brought in contact with the other end of the cable holder 111 as shown in Pig.-22, the movement of the cable joint 112 is restricted and thereby the movement of the auxiliary operating lever 86 is restricted even if a larger brake operational force is applied to the front wheel brake cable 34. In other words, the upper limit of the braking force exhibited by the front wheel brake BF by operation of the interlocking brake lever 32 is restricted by contact of the end plate 112a of the cable joint 112 with the cable holder 111. When the interlocking brake lever 32 and the front wheel brake lever 31 are both operated, the movement of the cable joint 112 is restricted by contact of the end plate 112a with the cable holder 111 but the connecting pin 122 along the slots 121 can be moved as shown in Fig, 23, the front wheel brake lever 31 can be turned while pressing the pressing portion 104 of the auxiliary operating lever 86 by the engagement portion 105. Thus, an operating force can be applied to the piston rod lOOa of the master cylinder 87 so that the front wheel brake BF exhibits a braking force more than the upper limit, of the braking force of the front wheel brake Br in accordance with operation of the interlocking brake lever 32. Incidentally, it requires—«u complicated work to engage the locking element 123 at the end portion of the inner cable 34b with the end plate 112a of the cable joint 112 while compressing the restricting spring 113 for the purpose of connecting the front wheel brake cable 34 to the auxiliary operating lever 86 through the braking force control means 110. To cope with such an inconvenience, as shown in Figs. 24 and 25, a pair of set pins 126 are mounted on the other end side of the cable holder 111 for facilitating the work by holding the restricting spring 113 in a compressed state before assembly. In order to mount these set pins 126, two pairs of holes 125, parallel to the diameter line of the cable holder 111, are provided on the other end side of the cable holder 111. The set pin 126 includes a straight engagement shaft portion 126a to be inserted in the corresponding holes 125, a circular holding portion 126b continuous to one end of the engagement shaft portion 126a, and an engagement portion 126c formed in a corrugated shape and continuous to the holding portion 126b. The engagement portion 126c is adapted to be elastically engaged with an outer periphery of the cable holder 111. One end of the restricting spring 113, which is contained in the spring containing hole 116 in a compressed state with the other end being brought in contact with the flange portion 117, is received by the engagement shaft portions 126a of both the set pins 126. In a state in which the restricting spring 113 is compressed by mounting of the set pins 126, the locking element 123 at the end portion of the inner cable 34b of the front wheel cable 34 is engaged with the end plate 112a of the cable joint 112. Then, the set pins 126 are pulled off from the cable holder 111, and thereby the restricting spring 113 is extended and is brought in contact with the end plate 112a of the cable joint 112. Accordingly, it is possible to facilitate the work of connecting the front wheel brake cable 34 to the auxiliary operating lever 86 through the braking force control means 110. ^0002] Next, the function of the embodiment will be described. Upon braking operation of only the front wheel brake lever 31 in the non-operation state of the interlocking brake lever 32, the master cylinder 87 is pressed by the auxiliary operating lever 86 engaged with the front wheel brake lever 31, so that the front wheel brake Br is actuated to exhibit a braking force. Upon braking operation of the interlocking brake lever 32 in the non-operation state of the front wheel brake lever 31, the operational force distributing lever 33 is moved in an operational position by the operating force of the interlocking brake lever 32, to allow traction of the front wheel brake cable 34 and the rear wheel brake cable 35. In this case, the front wheel brake cable 34 is connected to the auxiliary operating lever 86 capable of applying a pressing force to the master cylinder 87 through the braking force control means 110 capable of controlling the braking force of the front wheel brake Br only upon operation of the interlocking brake lever 32. The braking force control means 110 can suppress the braking force of the front wheel B,. at the initial stage of brakina operation of the interlocking brake lever 32 and so restrict the upper limit of the braking force of e front wheel brake Br by operation of the interlocking bra Accordingly, a braking force distributing characteristic in accordance with operation of the interlocking brake lever 32 is as shown in Fig. 26. As is apparent from this graph, at the initial stage of operation of the interlocking brake lever 32, it is possible to generate a nose-dive only by the braking force on the rear wheel side and hence to obtain a desirable nose-dive feeling by compensating for the increment of the front wheel shared load due to a load applied by the rider. It is effective to suitably control the nose -dive amount since the initial stage of operation of the interlocking brake lever 32. After the front wheel brake Br starts to exhibit a braking force, the braking force of the rear wheel brake BR is set to be larger than the braking force of the front wheel brake BP. As a result, it is possible to avoid the braking operation feeling from being different from that obtained by a rear wheel brake through operation of a rear wheel brake lever of a conventional motorcycle having no interlocking braking device, and hence to extend the applicability of the interlocking braking device in this embodiment to conventional motorcycles. Also, the upper limit of the braking force exhibited by the front wheel BF in accordance with operation of the interlocking brake lever 32 is restricted, and accordingly, when the interlocking brake lever 32 is largely moved, it is possible to suitably adjust the nosedive amount by suppressing the braking force of the front wheel BF, while allowing the rear wheel brake BR to exhibit a large braking force. T0007] In this way, by controlling the braking force exhibited by the front wheel brake BP upon operation of the interlocking brake lever 32 using the braking force control means 110, the braking force of the front wheel BF can be controlled to suitably adjust the nose-dive amount while keeping the braking effect and braking feeling due to operation of the front wheel brake- lever 31, resulting in the improved riding comfortability. Incidentally, the rear wheel brake cable 35 to which a large brake operational force is transmitted from the operational force distributing lever 33 has the diameter larger than that of the front wheel brake cable 34 to which a small brake operational force is transmitted, so that the rigidity of the rear wheel brake cable 35 in which the traction amount is larger is higher than that of the front wheel brake cable 34 in which the traction amount is smaller. As a result, the rigidity of the rear wheel brake cable 35 having a large traction amount can be set to be higher than the rigidity of the front wheel brake cable 34 having a small traction amount, so that the movement amount of the operational force distributing lever 33 can be suitably adjusted by matching the expansion amounts of both the brake cables 34 and 35 with the traction amounts thereof . The braking force holding means 70 is operated by turning the operating lever 72 in a state in which the interlocking brake lever 32 is operated. Specifically, as shown in Fig. 12, upon turning of the operating lever 72, the braking force holding arm 71 is moved against the spring force of the return spring 73 from the disengagement position to the engagement position, and the engagement pin 77 of the braking force holding arm 71 is engaged in the locking portions 79 of the operational force distributing lever 33 moved at the operational position. When the operating force of the interlocking brake lever 32 is released, the operational force distributing lever 33 is moved to the braking force holding position where it makes the rear wheel brake cable 35 in a traction state but makes the front wheel brake cable 34 in a non-traction state. In this state, only the rear wheel brake BR is actuated and the front wheel brake Br is not actuated. Such a braking force holding state of the operational force distributing lever 33 is detected by the stop switch 68. That is, upon holding the braking force, rubber parts such as a hose and a seal as components of the hydraulic front wheel brake Br are not applied with any hydraulic pressure, to thereby increase the service life of each of the rubber parts. Further, the locking portions 79 are provided to the operational force distributing lever 33 on the side of the brake cable having a small distance from the connecting portion of the interlocking brake lever 32, that is, the rear brake cable 35, so that the engagement pin 77 of the braking force holding means 70 is engaged with the operational force distributing lever 33 on the side where the lever 33 is relatively largely moved in accordance with operation of the interlocking brake lever 32. As a result, it is possible to make relatively small the operated amount of the interlocking brake lever 32 upon operation of the braking force holding means 70. The above braking force holding state is released only by turning the interlocking brake lever 32. At this time, the braking force holding arm 71 is moved by the spring force of the return spring 73 from the engagement position to the disengagement position, to release the engagement between the braking force holding arm 71 and the operational force distributing lever 33. Accordingly, by returning the interlocking brake lever 32 to the original state, the operational force distributing lever 33 is returned to the disengagement position and thereby the rear wheel brake BR comes to be in the rest state. The operating lever 72 as one component of the braking force holding means 70, projecting from the stationary casing 56, further projects outward from the opening portion 54 which is provided in the handle cover 53 for allowing the grip portion 46 at the left end of the steering handlebar 45 and the interlocking brake lever 32 to pass therethrough. As a result, it is possible to eliminate the necessity of provision of a specialized opening portion for the operating lever 72 in the handle cover 53. With this configuration, the interlocking braking device in this embodiment can be newly applied to a motorcycle having no interlocking braking device without replacement of the handle cover 56, and also, since it is not required to provide any opening potion other than the opening portion 53 for the grip portion 46 of the steering handlebar 56 and the interlocking brake lever 32, it is possible to keep the external appearance of the handle cover 3 at a level comparable to that of the conventional one. The casing 56 movably containing the operational force distributing lever 33, is fixed on the steering handlebar 45 along the% longitudinal direction of the steering handlebar 45 at a position inward from and close to the interlocking brake lever 32. Hence, the interlocking brake lever 32 and the operational force distributing lever 33, which are close to each other, can be directly connected to each other by means of the high rigidity connecting rod 59. As a result, it is possible to eliminate the initial adjustment between the interlocking brake lever 32 and the operational force distributing lever 33, and to improve the adjustment accuracy of an interlocking braking force by preventing occurrence of deviation in adjustment between the interlocking brake lever 32 and the operational force distributing lever 33 The casing 56 is fixed on the front portion of the steering handlebar 45 in a posture in which the front wheel brake cable 34 and the rear wheel brake cable 35 are connected to the operational force distributing lever 33 at positions separated from each other in the vertical direction. In other words, the casing 56 is elongated in the vertical direction, that is, it has the vertical length longer than the length along the longitudinal direction of the motorcycle. As a result, the casing 56 can be effectively disposed in a limited space on the left end side of the steering handlebar 45 in such a manner as not to exert adverse effect on operation of the steering handlebar 45 and to prevent interference with the handle cover 53 covering the steering handlebar 45. In addition, since the casing 56 has as one component the case portion 57 integrated with the holder 47 mounted to the steering handlebar 45, it is possible to reduce the number of parts, and to improve the assembling performance because part of the casing 56 is assembled with the steering handlebar 45 through the holder 47. Since the vertically elongated casing 56 is disposed in front of the steering handlebar 45 and the operating lever 12 of the braking force holding means 70 projecting from the front side of the casing 56 is disposed in front of the interlocking brake lever 32, the casing 56 and the operating lever 72 can be covered with the handle cover 53 even if the swelled amount of the handle cover 53 toward the front side of the steering handlebar 45 is set to be relatively small. Accordingly, it is possible to avoid enlargement of the handle cover 53, and to enhance the degree of freedom in design of the handle cover 53. Incidentally, since the casing 56 is provided with the initial contact surface 67 to be brought in contact with the operational force distributing lever 33 contained in the casing 56 in the non-operation state of the interlocking brake lever 32, it is possible to avoid mutual effect of the front wheel brake cable 34 and the rear wheel brake cable 35 by bringing the operational force distributing lever 33 in contact with the initial contact surface 67 of the casing 56 in the non-operation state of the interlocking brake lever 32, and hence to individually set tensions of the brake cables 34 and 35. it is effective to easily set the tensions of both the brake cables 34 and 35. j.0077]- While the preferred embodiment of the present invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that may changes in design may be made without departing from the scope of the claims. For example, in the above-described embodiment, the connecting rod 59 continuous to the interlocking brake lever 32 is connected to the central portion of the operational force distributing lever 33, and the front wheel brake cable 34 and the rear wheel brake cable 35 are connected to the positions which are located on both sides of the connecting rod 59 and which are different in distance from the connecting rod 59; however, there may be adopted another configuration in which a member continuous to the interlocking brake lever 32 is connected to one end side of the operational force distributing lever with the other end side thereof being turnably supported on the casing 56, and the front wheel and rear wheel brake cables 34 and 35 are connected to the operational force distributing lever at positions different in distance from the member. In addition, there may be adopted a further configuration in which the rear wheel brake cable 35 is connected to the operational force distributing lever at a position apart from a connecting point of the interlocking brake lever 32 to the operational force distributing lever/ and the front wheel brake cable 34 is connected to the operational force distributing lever at a position near the above connecting point so that the brake operational force on the front wheel brake cable 35 side becomes larger than the brake operational force on the rear wheel brake cable 35 side. '[0079] [Effect of the Invention] As described above, according to the invention described in claim 1, the interlocking brake lever and the operational force distributing lever, which are close to each other, can be directly connected to each other at a high rigidity without need of adjustment. As a result, it is possible to eliminate the initial adjustment between the interlocking brake lever and the operational force distributing lever, and to improve the adjustment accuracy of an interlocking braking force by preventing occurrence of deviation in adjustment between the interlocking brake lever and the operational force distributing lever. According to the invention described in claim 2, the casing can be formed in a vertically elongated shape in which the length along the vertical direction is longer than the length along the longitudinal direction of the motorcycle. As a result, the casing can be effectively disposed in a limited space on one end side of the steering handlebar in such a manner as not to exert adverse effect on operation of the steering handlebar and to prevent interference with the handle cover covering the steering handlebar. ^•0000 ] According to the invention described in claim 3 or 4, the braking force holding means can be provided to the casing without the necessity of provision of a specialized opening portion for arranging the operating lever of the braking force holding means. Thus, the interlocking braking device can be newly applied to a motorcycle having no interlocking braking device without replacement of the handle cover. Further, since it is not required to provide any opening potion other than the opening portion for one end portion of the steering handlebar and the interlocking brake lever, it is possible to keep the external appearance of the handle cover at a level comparable to that of the conventional one. According to the invention described in claim 5, it is possible to reduce the number of parts, and to improve the assembling performance since part of the casing is assembled with the steering handlebar by assembling the holder with the steering handlebar. According to the invention described in claim 6, the casing and the operating lever can be covered with the handle cover even if the swelled amount of the handle cover toward the front side of the steering handlebar is set to be relatively small. As a result, it is possible to avoid enlargement of the handle cover, and to enhance the degree of freedom in design of the handle cover. As described above, according to the invention described in claim 7, it is possible to suitably control the nose-dive amount by controlling a front wheel braking force upon operation of the interlocking brake lever while keeping an effective braking force and a brake operational feeling obtained by operation of the front wheel brake lever, resulting in the improved riding comfortability . According to the invention described in claim 8, when the interlocking brake lever is largely moved, it is possible to suitably adjust the nose-dive amount by suppressing a front wheel braking force while ensuring a large rear wheel braking force. According to the invention described in claim 9, at the initial stage of operation of the interlocking brake lever, it is possible to generate a nose-dive only by a braking force on the rear wheel side and hence to obtain a desirable nose-dive feeling by compensating for the increment of the front wheel shared load due to a load applied by the rider. It is effective to suitably control the nose-dive amount since the initial stage of operation of the interlocking brake lever. According to the invention described in claim 10, braking forces of the front and rear wheel brakes are made different from each other upon operation of the interlocking brake lever only by providing a simple structure in which both the brake cables are connected to the operational force distributing lever at positions different in distance from the connecting position of the interlocking brake lever to the operational force distributing lever. As a result,"the braking device of the present invention can be applied to a conventional motorcycle having no interlocking braking device while avoiding the braking operation feeling from being different from that having obtained by the conventional motorcycle. According to the invention described in claim 11, the rigidity of the rear wheel brake cable on the side where the brake operational force becomes larger, that is, a traction amount becomes larger can be set to be higher than the rigidity of the front wheel brake cable on the side where the brake operational force becomes smaller, that is, a traction amount becomes smaller, so that the moved amount of the operational force distributing lever can be suitably adjusted by matching the expansion amounts of both the brake cables with the traction amounts thereof. According to the invention described in claim 12, the braking force holding means is engaged with the operational force distributing lever on the side where the lever is relatively largely moved in accordance with operation of the interlocking brake lever, so that it is possible to make relatively small the operated amount of the interlocking brake lever upon operation of the braking force holding means. According to the invention "described in claim 13, it is possible to avoid mutual effect of both the brake cables by bringing the operational force distributing lever in contact with the initial contact surface in the non- operation state of the interlocking brake lever, and hence to individually set tensions of both the brake cables. It is effective to easily set the tensions of the brake cables. [Reference Numerals] 31: front wheel brake lever as front wheel brake operational element 32: interlocking brake lever as interlocking brake operational element 33: operational force distributing lever 34: front wheel brake cable 35: rear wheel brake cable 45: steering handlebar 47: holder 53: handle cover 54: opening portion 56: casing 67: initial contact surface 70: braking force holding means 72: operating lever 79: locking portion 110: braking force control means BP: front wheel brake BR: rear wheel brake We claim; 1. A fore and aft interlocking braking device for a motorcycle, comprising: a front wheel brake lever (3,1) for allowing a front wheel brake (BF) to exhibit a braking force; an interlocking brake lever (32) turnably supported on a holder (47) fixed on one end portion of a steering handlebar (45) and allowing said front wheel brake (BF) and a rear wheel brake (BR) to exhibit braking forces in interlocking with each other; brake cables (34, 35) for individually transmitting brake operating forces to said front and rear wheel brakes (BF, BR); an operational force distributing lever (33) for connecting said interlocking brake lever (32) to said brake cables (34, 35) in such a manner as to allow traction of each of said brake cables (34, 35) in accordance with braking operation of said interlocking brake lever (32); and a stationary casing (56) in which said operational force distributing lever (33) is movably contained; wherein said casing (56) is disposed at a position adjacent to said interlocking brake lever (32) along the longitudinal direction of said steering handlebar (45). 2. A fore and aft interlocking braking device for a motorcycle as claimed in claim 1, wherein said casing (56) is disposed in front of said steering handlebar (45) in a posture in which said brake cables (34, 35) are connected to said operational force distributing lever (33) at positions separated from each other in the vertical direction. 3. A fore and aft interlocking braking device as claimed in claims 1 or 2, wherein a braking force holding means (70) for holding at least one of said brake cables (34, 35) in a traction state is provided to said casing (56) in such a manner that an operating lever (72) as a component of said braking force holding means (70) projects from said casing (56); said steering handlebar (45) is covered with a handle cover (53) having an opening portion (54) from which one end portion of said steering handlebar (45) and said interlocking brake lever (32) project; and said operating lever (72) extends outward from said opening portion (54). 4. A fore and aft interlocking braking device as claimed in any one of claims 1 to 3, wherein part of said casing (56) is formed integrally with said holder (47). 5. A fore and aft interlocking braking device as claimed in claim 3 or 4, wherein said casing (56) formed in a vertically elongated shape in which the length along the vertical direction is larger than the length along the longitudinal direction of the motorcycle, is disposed in front of said steering handlebar (45); and said operating lever (72) projecting from the front surface of said casing (56) is disposed in front of said interlocking brake lever (32). 6: A fore and aft interlocking braking device for a motorcycle as claimed in claim 1, wherein a braking force control means (110) is provided for controlling a braking force exhibited by said front wheel brake (Bp) only upon operation of said interlocking brake lever (32). 7. A fore and aft interlocking braking device for a motorcycle as claimed in claim 1, wherein said brake cables (34, 35) are connected to said operational force distributing lever (33) at positions different in distance from a connecting position of said interlocking brake lever (32) to said operational force distributing lever (33) so that brake operating forces distributed from said operational force distributing lever (33) to said brake cables (34, 35) in accordance with operation of said interlocking brake lever (32) are different from each other. 8. A fore and aft interlocking braking device for a motorcycle as claimed in claim 7, wherein a diameter of said brake cable (35) to which a large brake operational force is applied from said operational force distributing lever (33) is set to be larger than a diameter of said brake cable (34) to which a small brake operational force is applied from said operational force distributing lever (33). 9. A fore and aft interlocking braking device for a motorcycle as claimed in claims 7 or 8, wherein said operational force distributing lever (33) is movably contained in said stationary casing (56); said brake cables (34, 35) are connected to said operational force distributing lever (33) at points which are positioned on both sides of a connecting portion of said interlocking brake lever (32) to said operational force distributing lever (33) and which are different in distance from said connecting portion; a locking portion (79) is provided at an end portion of said operational force distributing lever (33) on the side of one (35) of said brake cables (34, 35) which is small in distance from said connecting portion of said interlocking brake lever (32); and a braking force holding means (70) to be removably engaged with said locking portion (79) is provided on said casing (56) in such a manner that said means (70), when being engaged with said locking portion (79), is allowed to hold said one brake cable (35) in a traction state but to make the other (34) of said brake cables (34, 35) in a non-traction state. 10. A fore and aft interlocking braking device for a motorcycle as claimed in claim 1, wherein said operational force distributing lever (33) is contained in said stationary casing (56) in such a manner as to be movable between a position at which said lever (33) is brought in contact with an initial contact surface (67) provided in said casing (56) upon a non-operation state of said interlocking brake lever (32) and a position at which said lever (33) is separated from said initial contact surface (67) in accordance with operation of said interlocking brake lever (32). 11. A fore and aft interlocking braking device for a motorcycle substantially as herein described with reference to and illustrated in the accompanying drawings. |
|---|
3547-del-1997-correspondenc-others.pdf
3547-del-1997-correspondenc-po.pdf
3547-del-1997-description (complete).pdf
3547-del-1997-petition-137.pdf
3547-del-1997-petition-138.pdf
| Patent Number | 215200 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Indian Patent Application Number | 3547/DEL/1997 | ||||||||||||||||
| PG Journal Number | 10/2008 | ||||||||||||||||
| Publication Date | 07-Mar-2008 | ||||||||||||||||
| Grant Date | 21-Feb-2008 | ||||||||||||||||
| Date of Filing | 10-Dec-1997 | ||||||||||||||||
| Name of Patentee | HONDA GIKEN KOGYO KABUSHIKI KAISHA | ||||||||||||||||
| Applicant Address | 1-1 MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO, JAPAN | ||||||||||||||||
Inventors:
|
|||||||||||||||||
| PCT International Classification Number | G05G 7/00 | ||||||||||||||||
| PCT International Application Number | N/A | ||||||||||||||||
| PCT International Filing date | |||||||||||||||||
PCT Conventions:
|
|||||||||||||||||