Title of Invention

"A BRAKE DEVICE FOR A VEHICLE"

Abstract

[OBJECT] The present invention varies the respective braking forces of a pair of wheel brake units by the agency of a single actuator to reduce the cost and the weight in a great measure. [CONSTITUTION] An actuator comprises a planetary.gear mechanism 14 comprising a sun gear 24, a ring gear 25 coaxially surrounding the sun gear 24, a plurality of planet gears 26 in engagement with both the sun gear 24 and the ring gear 25, and a planet carrier 34; and a motor 15 connected to the third component 24 among the components 24, 25 and 34. The respective intermediate parts of a first transmission system 6R and a second transmission system 6F are connected individually to the first component 25 and the second component 34. [SELECTED DRAWING]

Full Text

[Field of Utilization in Industry] The present invention relates to a brake device for a vehicle, comprising a first transmission means capable of mechanically transmitting a brake operating force produced by operating a first brake operating member to a first wheel brake unit, and a second transmission means capable of mechanically transmitting a brake operating force produced by operating a second brake operating member to a second wheel brake unit. t- r-? [Related Art] A brake system of such a kind is disclosed, for example, in Japanese Utility Model Laid-open (Kokai) No. 4-7973. [Problem to be Solved by the Invention] Such a known brake system may employ techniques disclosed in, for example, Japanese Patent Laid-open (Kokai) No. 2-234869 to vary braking force for antilock-braking control. However, a brake system disclosed in Japanese Patent Laid-open (Kokai) No. 2-234869 needs one actuator for one pair of wheel brake units. Therefore this known brake system is costly and heavyweight and is difficult to be used on an inexpensive vehicle, such as a motor scooter. [0 0 0 4] It is difficult for the operator to feel satisfactory resistance to the operation of the brake operating member when the braking force is varied by the actuator if the actuator is provided simply in the transmission system. [0 0 0 5] The present invention has been made in view of the foregoing problems and it is therefore a first object of the present invention to provide a brake system for a vehicle, capable of varying braking force of a pair of wheel brake units with a single actuator and of being fabricated at a reduced cost and in a lightweight construction. [0 0 0 6] A second object of the present invention is to provide a brake system for a vehicle, capable of making the operator feel satisfactory resistance to the operation of the brake operating member when braking force is varied by an actuator. [Means for Solving the Problem] To achieve the first object, the invention provides a brake device for a vehicle, comprising a first transmission means capable of mechanically transmitting a brake operating force produced by operating a first brake operating member to a first wheel brake unit, a second transmission means capable of mechanically transmitting a brake operating force produced by operating a second brake operating member to a second wheel brake unit; wherein there is provided an actuator having a planetary gear mechanism with a sun gear, a ring gear coaxially surrounding said sun gear, a plurality of planet gears engaged with both the sun gear and the ring gear, and a planet carrier supporting the planet gears for rotation; the intermediate parts of said first and said second transmission means being connected individually to the first and the second components among the components; and a reversible motor connected to the third component among the components. The invention further comprises, in addition to the aforementioned components of the invention, an electronic control unit that controls the operation of the motor so that the third component operates in the same direction as the direction of operation of either the first or the second component caused by the operation of either the first or the second brake operating member. The invention still further comprises, in addition an electronic control unit that controls the operation of the motor, when carrying out an antilock-braking control operation in a braking mode when at least either the first or the second brake operating member is operated, by selectively establishing a braking force reducing mode in which braking force is reduced by operating the third component in a direction reverse to the direction of operation of the first or the second component to increase braking force or a braking force enhancing mode in which braking force is enhanced by operating the third component in the same direction as that of operation of the first or the second component to enhance braking force. [0 0 10] To achieve the second object, >i an invention stated in oiLutim '1 provides, in a brake system for a vehicle, comprising a first transmission system capable of mechanically transmitting a brake operating force produced by operating a first brake operating member to a first wheel brake unit, a second transmission system capable of mechanically transmitting a brake operating force produced by operating a second brake operating member to a second wheel brake unit; the improvement comprising an actuator provided individually or in common in the intermediate parts of the first and the second transmission system to vary the braking forces of the first and the second wheel brake, and dampers provided in the first and the second transmission system at positions between the actuator and the first and the second brake operating member, respectively. [0 0 11] [Preferred Embodiments] Preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. [BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS] Fig. 1 is a side view of a motor scooter to which the present invention is applied. Fig. 2 is a diagrammatic view of an actuator. Fig. 3 is a side view of a connecting unit for connecting a first and a second transmission system to a planetary gear mechanism. Fig. 4 is a sectional view taken on line 4-4 in Figure 3. Fig. 5 is a sectional view of a damper. Fig. 6 is a diagrammatic view of assistance in explaining a braking operation in a linked braking mode. Fig. 7 is a graph showing linked braking characteristics when a front brake unit is operated. Fig. 8 is a map of assisting force and traveling speed. Fig. 9 is a graph showing linked braking characteristics for traveling speed. Fig. 10 is a graph showing linked braking characteristics when a rear brake unit is operated. Fig. 11 is a diagrammatic view of assistance in explaining braking force reducing operation for antilock-braking control. Fig. 12 is a diagrammatic view of assistance in explaining braking force enhancing operation for antilock-braking control. Fig. 13 is a graph of assistance in explaining a procedure for determining the direction of rotation of a motor and the values of manipulated variables. Fig. 14 is a diagrammatic view of a second embodiment. Fig. 15 is a longitudinal sectional view of an equalizer. Figs. 1 to 13 illustrate a first embodiment of the present invention, in which Fig. 1 is a side view of a motor scooter incorporating the present invention, Fig. 2 is a diagrammatic view of an actuator, Fig. 3 is a side view of a connecting unit for connecting a first and a second transmission system to a planetary gear mechanism, Fig. 4 is a sectional view taken on line 4-4 in Fig. 3, Fig. 5 is a sectional view of a damper, Fig..6 is a diagrammatic view of assistance in explaining a braking operation in a linked braking mode, Fig. 7 is a graph showing linked braking characteristics when a front brake unit is operated, Fig. 8 is a map of assisting force and traveling speed, Fig. 9 is a graph showing linked braking characteristics for traveling speed, Fig. 10 is a graph showing linked braking characteristics when a rear brake unit is operated, Fig. 11 is a diagrammatic view of assistance in explaining braking force reducing operation for antilock-braking control, Fig. 12 is a diagrammatic view of assistance in explaining braking force enhancing operation for antilock-braking control and Fig. 13 is a graph of assistance in explaining a procedure for determining the direction of rotation of a motor and values of manipulated variables. [0 0 13] Referring to Figs. 1 and 2, the motor scooter has a mechanical rear brake unit BR, i.e., a first wheel brake unit, combined with a rear wheel WR and capable of producing a braking force corresponding to the stroke of an actuating lever 1R, and a mechanical front brake unit BF, i.e., a second brake unit, combined with a front wheel WF and capable of producing a braking force corresponding to the stroke of an actuating lever 1F. A handlebar 3 is joined to a front fork 2 supporting the front wheel WF, and hand grips 3R and 3F are attached to the opposite ends, respectively, of the handlebar 3. A first brake lever 5R, i.e., a first brake operating member, is supported pivotally on the right end of the handlebar 3 so as to be operated by the left hand gripping the hand grip 3R. A second brake lever 5F is supported pivotally on the right end of the handlebar 3 so as to be operated by the right hand gripping the hand grip 3F. [0 0 14] The first brake lever 5R is connected to the actuating lever 1R of the rear brake unit BR by a first transmission system 6R capable of mechanically transmitting a brake operating force produced by operating the first brake lever 5R to the rear brake unit BR, and the second brake lever 5F is connected to the actuating lever 1F of the front brake unit BF by a second transmission system 6F capable of mechanically transmitting a brake operating force produced by operating the second brake lever 5F to the front brake unit BF. [0 0 15] The first transmission system 6R comprises a brake cable 7R having one end connected to the first brake lever 5R, a damper 8R having one end connected to the other end of the brake cable 7R, a brake cable 9R having one end connected to the other end of the damper 8R, a transmission lever 10R connected to the other end of the brake cable 9R/ and a brake cable 11R interconnecting the actuating lever 1R of the rear brake unit BR and the transmission lever 10R. The brake cables 9R and 11R are connected to the transmission lever 10R so that the transmission lever 10R turns to transmit a pull given on the brake cable 9R to the brake cable 11R. The second transmission system 6F, which is similar in construction to the first transmission system 6R, comprises a brake cable 7F having one end connected to the second brake lever 5F, a damper 8F having one end connected to the other end of the brake cable 7F/ a brake cable 9F having one end connected to the other end of the damper 8F, a transmission lever 10F connected to the other end of the brake cable 9F, and a brake cable 11F interconnecting the actuating lever 1F of the front brake unit BF and the transmission lever 10F. [0 0 16] As shown in Fig. 1, the dampers 8R and 8F, an actuator 12, and an electronic control unit 13 for controlling the operation of the actuator 12 are disposed in a space covered with a cowling 4 covering the front part of the motor scooter. The actuator 12 is connected to the respective middle parts of the first transmission system 6R and the second transmission system 6F. [0 0 17] The actuator 12 comprises a planetary gear mechanism 14, and a reversible motor 15 capable of applying a rotative force to the planetary gear mechanism 14 and of rotating freely when no power is supplied thereto. [0 0 18] Referring to Figs. 3 and 4, the actuator 12 has a casing 16 comprising a first case member 17 to which the motor 15 is attached, a second case member 18 joined to the first case member 17 on the side opposite the side on which the motor 15 is disposed, and a third case member 19 joined to the second case member 18 on the side opposite the side on which the second case member 18 is joined to the first case member 17. The planetary gear mechanism 14 is con tained in a gear chamber 21 formed in the casing 16. The transmission levers 10R and 10F in the intermediate parts of the first transmission system 6R and the second transmission system 6F are supported for turning in a lever chamber 22 defined by the third case member 19 and a cover 20 joined to the third case member 19. The motor 15 is fastened to the first case member 17 of the casing 16 with its output shaft 23 extended in a gear chamber 21. [0 0 19] The planetary gear mechanism 14 comprises a sun gear 24, a ring gear 25, a plurality of planetary gears 26 in engagement with both the sun gear 24 and the ring gear 25, and a planet carrier 34 supporting the plurality of planet gears 26. The transmission lever 10R of the first transmission system 6R, the transmission lever 10F of the second transmission system 6F and the output shaft 23 of the motor 15 are connected to the ring gear 25, i.e., a first component, the planet carrier 34, i.e., a second component, and the sun gear 24, i.e., a third"component, respectively. [0 0 2 0] A shaft 27 is disposed in the gear chamber 21 with its axis in parallel to that of the output shaft 23 of the motor 15, and has one end rotatably supported on the first case member 17 of the casing 16 and the other end extending through the third case member 19 into the lever chamber 22 and supported rotatably on the third case member 19. A flange 27a is formed so as to project radially outward from the intermediate part of the shaft 27 extending in the gear chamber 21. The sun gear 24, and a driven gear 29 fixedly joined to the sun gear 24 and engaging with a driving gear 28 mounted on the output shaft 23 of the motor 15 are mounted for rotation relative to the shaft 27 on a part of the shaft 27 between the flange 27a and the first case member 17. Thus, the motor 15 is operatively connected to the sun gear 24 through the driving gear 28 and the driven gear 29. [0 0 2 1] In the lever chamber 22, the transmission lever 10F is fixed to the end of the shaft 27, a sleeve 30 is mounted coaxially with the shaft 27 on a bearing 31 put on a part of the shaft 27 between the transmission lever 10F and the flange 27a. The transmission lever 10R is fixed to the end of the sleeve 30 on the side of the lever chamber 22, and the ring gear 25 is fixed to the end of the sleeve 30 on the side of the gear chamber 21. Thus, the transmission lever IOR is connected operatively through the sleeve 3 0 to the ring gear 25. The ring gear 25 is spaced apart from the transmission lever 10R with a cylindrical spacer 32 coaxially put on the sleeve 30. A bearing 33 is interposed between the spacer 32 and the third case member 19. [0 0 2 2] The planet carrier 34 is fixedly mounted on the flange 27a of the shaft 27 to which the transmission lever 10F is fixed. Thus, the transmission lever 10F is connected operatively through the shaft 27 to the planet carrier 34. [0 0 2 3] Referring to Fig. 5, the damper 8R comprises a bottomed cylindrical member 36 having a bottom wall connected to the brake cable 7R, a shaft 37 coaxially inserted in the bottomed cylindrical member 3 6 and connected to a brake cable 9R, a bearing member 38 having the shape of a bottomed cylinder, having a bottom wall provided with a hole 38a through which the shaft is passed axially slidably, and slidably fitted in the bottomed cylindrical member 36, a seat plate 39 having the shape of a disk, provided with a hole 39a through which the shaft is passed axial]y slidably and fitted slidably in the bottomed cylindrical member 36, a damping spring 40 compressed between the bearing member 38 and the seat plate 39 within the bottomed cylindrical member 36, a retaining ring 41 put on the shaft 37 to limit the movement of the bearing member 38 away from the seat plate 39, a retaining ring 42 put on the shaft 37 to limit the movement of the seat plate 3 9 away from the bearing member 38, and a housing 43 containing those components. The brake cable 7R passed through one end of the housing 43 so as to be movable relative to the housing 43 and connected to the bottomed cylindrical member 36, the brake cable 9R is passed through the other end of the housing 43 so as to be movable relative to the housing 43 and connected to the shaft 37. The damping spring 40 is loaded so that the the damper 8R cannot be contracted by an ordinary brake operating force applied thereto by operating the first brake lever 5R. [0 0 2 4] The damper 8F is constructed similarly to the damper 8R and is interposed between the brake cables 7F and 9F. [0 0 2 5] The electronic control unit 13 receives detection signals from a brake operating force detector 44R for detecting brake operating force produced by operating the first brake lever 5R, a brake operating force detector 44F for detecting brake operating force produced by operating the second brake lever 5F, a wheel speed detector 45R for detecting the rotating speed of the rear wheel WR, and a wheel speed detector 45F for detecting the rotating speed of the front wheel WF. The electronic control unit 13 controls the operation of the motor 15 on the basis of the detection signals provided by the detectors 44R, 44F, 45R and 45F in the following manner. [0 0 2 6] Referring to Fig. 6, when the first brake lever 5R is not operated and the second brake lever 5F is operated, the planet carrier 34 is turned in the direction of the arrow whereby the brake operating force is transmitted by the second transmission system 6F to the actuating lever 1F to apply the front brake BF. When no poser is supplied to the motor 15, the rear brake BR remains inoperative because the sun gear 24 is free to rotate. When the motor 15 is driven for rotation in the normal direction, the sun gear 24 turns in the direction of rotation of the planet carrier 34, so that the ring gear 25 turns in the reverse direction to apply the rear brake BR and the assisting force of the motor 15 acts additionally on the front brake BF. [0 0 2 7] As shown in Fig. 7, the front brake BF produces a braking force corresponding to the sum of the brake operating force produced by operating the second brake lever 5F and the assisting force of the motor 15 and the rear brake BR produces' a braking force corresponding to the force produced by the motor 15. Consequently, a total braking force represented by a vector A is produced. [0 0 2 8] In this case, when the reduction ratio of the ring gear 25 to the sun gear 24 is iR, the reduction ratio of the planet gears 26 to the sun gear 24 is iC, the number of teeth of the ring gear 25 is ZR, and the number of teeth of the sun gear is ZS, the inclination of the vector B representing the assisting force is expressed by: (0029) (Formula Removed) The rear wheel braking force is expressed by (T x is x ZR/ZS) and the assisting force in the front wheel braking force is expressed by {T x is x (ZR + ZS)/ZS}, where T is the output torque of the motor 15, and is is the reduction ratio of the sun gear 24 to the motor 15. [0 0 3 0] A shaded region in Fig. 7 is an ideal braking force distribution region between allowable limit lines on the opposite sides of an ideal braking force distribution curve C that does not lock the front wheel WF and the rear wheel WR when braked. The output torque of the motor 15 is controlled on the basis of the brake operating force detected by the brake operating force detector 44F so that the final braking force P is as near to the ideal braking force distribution region as possible. [0 0 3 1] The output of the motor 15 may be controlled on the basis of the traveling speed of the motor scooter at the moment when the braking operation is executed instead of on the basis of the brake operating force so that the an assisting force as shown in Fig. 8 is produced. When the output of the motor 15 is controlled in such a mode, linked braking force characteristics as indicated by broken lines in Fig. 9 are realized when the traveling speed is low, and linked braking force characteristics as indicated by a continuous line in Fig. 9 are realized when the traveling speed is high. [0 0 3 2] When the first brake lever 5R is operated for braking, the second brake lever 5F is not operated and the motor 15 is driven, the rear brake BR produces a braking force corresponding to the sum of the brake operating force produced by operating the first brake lever 5R and the assisting force of the motor 15 and the front brake BF produces a braking force corresponding to the assisting force of the motor 15 as shown in Fig. 10. [0 0 3 3] When it is decided, on the basis of the wheel speeds detected by the wheel speed detectors 45R and 45? when the braking operation is executed, that there is the high possibility that at least either the rear wheel WR or the front wheel WF is locked, the motor 15 is driven for rotation in a direction reverse to that in which the motor 15 is driven for cooperative braking to turn the sun gear 24 in the direction of the arrow as shown in Fig. 11. Consequently, the planet gears 2 6 rotates turning the ring gear 25 in the direction of the arrow, i.e., the direction for reducing the braking force of the rear brake BR, and the planet carrier 34 is turned in the direction of the arrow, i.e., the direction for reducing the braking force of the front brake BF, by the reaction force of the ring gear 25. Consequently, the braking forces acting on the rear wheel WR and the front wheel WF are reduced to avoid locking the wheels WR and WF. In this state, the planetary-gear mechanism 14 applies a pull to the dampers 8R and 8F cf the first transmission system 6R and the second transmission system 6F whereby the damping springs 40 are compressed. [0 0 3 4] The motor 15 is disconnected from the power supply to increase the braking force again in the antilock-braking control mode. Then, as shown in Fig. 12, the damping spring 40 of the dampers 8R and 8F release the stored energ-. to increase the braking forces of the rear brake BR and the front brake BF. [0 0 3 5] Thus, the rear brake BR and the front brake BF are controlled for antilock-braking control by a single control system, in which control operations for converging, reducing and enhancing force is executed on the bar: is of slip factor distribution to the front wheel side and the rear wheel side. The distribution of increasing or reducing force to the front wheel side and the rear wheel side is dependent on the reduction ratio of the planetary gear mechanism 14, and the connection of the first transmission system 6R, the second transmission system 6F and the motor 15 to the components of the planetary gear mechanism 14. . The control operation using the single control system is able to suppress the reduction of effect more effectively than the control using two control systems for individual control by properly determining the inclination 9 of the assisting force. [0 0 3 6] As shown in Fig. 13, when carrying out the antilock-braking control operation, a straight line L connecting predetermined slip factors XOF and XOR respectively for the front wheel side and the rear wheel side and representing a convergence level is set on a map to demarcate a reducing region above the straight line L and an enhancing region below the straight line L. A reducing control operation is executed when a point specified by a front slip factor XF and a rear slip factor XR is in the reducing region as indicated at D, and an enhancing control operation is executed when a point specified by a front slip factor X? and a rear slip factor XR is in the enhancing region as indicated at E. The direction of rotation and the angular displacement of the output shaft of the motor 15 are determined by the following procedure. The length SX of the perpendicular from the point D or E to the straight line L is calculated by using the following expression. [0 0 3 7] SA. = (AQR • A,f + AQF • A.R — AQF • AOR) / (AOR2 + Aop2) 1/2 The direction of rotation of the output shaft of the motor 15 is determined by using SX > 0 for the perpendicular from the point D to the straight line L and SX [0 0 3 8] The operation of the first embodiment will be described hereinafter. Since the intermediate part of the first transmission system 6R capable of mechanically transmitting a brake operating force produced by operating the first brake lever 5R to the rear brake BR is connected to the ring gear 25 of the planetary gear mechanism 14, the intermediate part of the second transmission system 6F capable of mechanically transmitting a brake operating force produced by operating the second brake lever 5F to the front brake BF is connected to the planet carrier 34 supporting the planet gears 26 of the planetary gear mechanism 14, and the sun gear 24 of the planetary gear mechanism 14 is connected to the motor 15, either the rear brake BR or the front brake BF, for example, the front brake BF produces a braking force corresponding to the sum of the brake operating force and the assisting force of the motor 15 when either the first brake lever 5R or the second brake lever 5F, for example, the second brake lever 5F is operated, and, for example, the rear brake BR produces a braking force corresponding to the assisting force of the motor 15. [0 0 3 9] If there is the possibility that the front wheel is locked, the motor is driven in the direction reverse to, the direction for cooperative operation to reduce the braking forces of the rear brake BR and the front brake BF/ and the braking forces of the rear brake BR and the front brake BF can be enhanced again by driving the motor 15 in the direction for cooperative operation. Thus, the antilock-braking control of both the rear brake BR and the front brake BF can be achieved by the single actuator 12 comprising the planetary gear mechanism 14 and the motor 15. [0 0 4 0] Since the dampers 8R and 8F are interposed between the first brake lever 5R and the part of the first transmission system 6R connected to the ring gear 25 of the planetary gear mechanism 14 and between the second brake lever 5F and the part of the second transmission system 6F connected to the planet carrier 34 of the planetary gear mechanism 14, the resilient energy stored in the dampers 8R and 8F can be used for enhancing the braking forces again in the antilock-braking control mode, and the direct action of the force produced by the actuator 12 on the first brake lever 5R or the second brake lever 5F can be avoided in the antilock-braking control mode to give satisfactory brake operating feeling. [0 0 4 1] The operation of the motor 15 is thus controlled by the electronic control unit 13 to achieve the cooperative actions of the rear brake BR and the front brake BF and the antilock-braking control operation, and the braking force can be distributed properly by selectively determining the gear ratios of the planetary gear mechanism 14 and, consequently, the reduction of the braking force, which is a problem in the integral control of the antilock-braking control operation, can be suppressed. Consequently, the actuator 12 and the electronic control unit 13 can be combined in a simple single control system to reduce the cost and the weight of the brake system in a great measure and to enable the application of the brake system to a low-cost vehicle, such as a motor scooter. [0 0 4 2] Figs. 14 and 15 illustrate a second embodiment of the present invention, in which parts like or corresponding to those of the first embodiment are designated by the same reference characters. [0 0 4 3] Referring to Fig. 14, a first brake lever 5R and the actuating lever 1R of a rear brake BR are interconnected by a first transmission system 6R' capable of mechanically transmitting a brake operating force produced by operating the first brake lever 5R to the rear brake BR, a second brake lever 5F and the actuating lever 1F of a front brake BF are interconnected by a second transmission system 6F' capable of mechanically transmitting a brake operating force produced by operating the second brake lever 5F. [0 0 4 4] The first transmission system 6R' comprises a brake cable 7R having one end connected to the first brake lever 5R, a damper 8R having one end connected to the other end of the cable 7R/ a brake cable 9R having one end connected to the other end of the damper 8R/ a brake cable 47R having one end connected through an equalizer 46R to the other end of the brake cable 9R, a brake cable 49R having one end connected through an equalizer 48R to the other end of the brake cable 47R, and a brake cable 50R having one end connected through the ring gear 25 of a planetary gear mechanism 14 included in an actuator 12 to the other end of the brake cable 49R and the other end connected to the actuating lever 1R of the rear brake BR. The second transmission system 6F" is similar in construction to the first transmission system 6R' . The second transmission system 6F' comprises a brake cable 7F having one end connected to the second brake lever 5F, a damper 8F having one end connected to the other end of the brake cable 7F, a brake cable 9F having one end connected to the damper 8F, a brake cable 47F connected through an equalizer 46F to the other end of the brake cable 9F, a brake cable 49F having one end connected through an equalizer 48F to the other end of the brake cable 47F, and a brake cable 50F having one end connected through the planet carrier 34 supporting the planet gears 26 of the planetary gear mechanism included in the actuator 12 to the other end of the brake cable 47F and the other end connected to the actuating lever 1F of the rear front brake BF. [0 0 4 5] Referring to Fig. 15, the equalizer 46R comprises a holding member 51 connected to the brake cable 9R, a sprocket wheel 52 rotatably supported on the holding member 51, a chain 54 wound around the sprocket wheel 52, and having one end connected to the brake cable 47R and the other end connected to an interlocking cable 53, and a housing 55 containing those components. The equalizer 46R is capable of applying a pull given to the brake cable 9R to both the brake cable 47R and the interlocking cable 53. [0 0 4 6] The equalizer 48R is capable of applying a pull applied to either the brake cable 47R or an interlocking cable 56 to the brake cable 49R. The equalizer 48F is capable of applying a pull given to either the brake cable 47F or the interlocking cable 53 to the brake cable 49F. [0 0 4 8] In the second embodiment, both the rear brake BR and the front brake BF produce braking forces when either the first brake lever 5R or the s'econd brake lever 5F is operated with the motor, not shown, connected to the sun gear 24 of the planetary gear mechanism 14 disconnected from the power supply. .Thus, both the rear brake BR and the front brake BF can be actuated in combination. [0 0 4 9] The antilock-braking control operation can be effected by actuating the sun gear 24 of the planetary gear mechanism 14 to reduce or enhance again the respective braking forces of the rear brake BR and the front brake Bf simultaneously by a manner similar to that carried out by the first embodiment. Accordingly, the rear brake BR and the front brake BF can be controlled for antilock-braking control simply by adding the planetary gear mechanism 14 and the motor for applying force to the planetary gear mechanism 14 to a mechanical brake system capable of linked braking actions. [0 0 5 0] Although the preferred embodiments of the present invention has been described above, the present invention is not limited thereto and various changes may be made in the design without departing from the scope of the present invention as stated in the appended claims. [0 0 5 1] [Effect of the Invention] As mentioned above, the brake system according to the invention comprises the actuator comprising the planetary gear mechanism comprising the sun gear, the ring gear coaxially surrounding the sun gear, che plurality of planet gears engaged with both the sun gear and the ring gear, and the planet carrier rotatably supporting the planet gears, the middle parts of the first and the second transmission systems being connected individually to the first and the second components among the components of the planetary gear mechanism; and the motor connected to the third component among the components of the planetary gear mechanism. Thus, the cost and the weight can be reduced in a great measure and the respective braking forces of the pair of wheel brake units can be varied. [0 0 5 2] The brake system according to the invention stated tfflp SMMOPA comprises, in addition to the components of the invention stated in claim 1, the electronic control unit that controls the operation of the motor so that the third component operates in the same direction as the direction of operation of either the first or the second component caused by the operation of either the first or the second brake operating member. Therefore, the wheel brake units can be actuated in combination by controlling the motor according to the operation of either the first or the second brake operating member. [0 0 5 3] The brake system according to the invention stated fcfc. SHBMPA comprises, in addition to the components of the jkbo/e ^ invention stated flBMB^mMHiSMHS, the electronic control unit that controls the operation of the motor, when carrying out antilock-braking control operation in the braking mode when at least either the first or the second brake operating member is operated, by selectively establishing the braking force reducing mode in which braking force is reduced by operating the third component in a direction reverse to the direction of operation of the first or the second component to increase braking force, or a braking force enhancing mode in which braking force is enhanced by operating the third component in the same direction as that of operation of the first or the second component to enhance braking force. Therefore, both the front wheel brake unit and the rear wheel brake unit can be simultaneously controlled for antilock-braking control operation by controlling the motor. [0 0 5 4] The brake system according to the invention stated ftfc. comprises the actuator provided individually or in common in the intermediate parts of the first and the second transmission system to vary the braking forces of the first and the second wheel brake unit, and dampers provided in the first and the second transmission system at positions between the actuator and the first and the second brake operating member, respectively. Therefore, satisfactory brake operating feeling can be obtained according to the operation of the actuator. [REFERENCE CHARACTERS] 5F Second brake lever [Second brake operating member] 5R First brake lever [First brake operating member] 6F, 6r Second transmission systems. 6R, 6R. First transmission systems. 8F, 8R Dampers 12 Actuator 13 Electronic control unit 14 Planetary gear mechanism 24 Sun gear [Third component of the planetary gear mechanism] 25 Ring gear [First component of the planetary gear mechanism] 34 Planet carrier [Second component of the planetary gear mechanism] BF Front brake [Second wheel brake unit] BR Rear brake [First wheel brake unit]. We claim: - 1. A brake device for a vehicle, comprising a first transmission means [6R, 6R-] capable of mechanically transmitting a brake operating force produced by operating a first brake operating member [5R] to a first wheel brake unit [BR], a second transmission means [6F, 6F'] capable of mechanically transmitting a brake operating force produced by operating a second brake operating member [5F] to a second wheel brake unit [BF]; wherein there is provided an actuator [12] having a planetary gear mechanism [14] with a sun gear [24], a ring gear [25] coaxially surrounding said sun gear [24], a plurality of planet gears [26] engaged with both the sun gear [24] and the ring gear [25], and a planet carrier [34] supporting the planet gears [26] for rotation; the intermediate parts of said first and said second transmission means [6R, 6R'; 6F, 6F-] being connected individually to the first and the second components [25, 34] among the components [24, 25, 34]; and a reversible motor [15] connected to the third component [24] among the components [24, 25, 34]. 2. A brake device for a vehicle as claimed in claim 1 wherein said reversible motor [15] is coupled to an electronic control unit [13] that controls the operation of said motor [15] so that said third component [24] operates in the same direction as the direction of operation of either the first or the second component [25, 34] caused by the operation of either the said first or the said second brake operating member [5R, 5F], said electronic control unit [13] coupled to said reversible motor [15] to control said motor on carrying out an antilock-braking control operation in a braking mode on at least operation of either the first or the second brake operating member {5R, 5F], by selectively establishing a braking force reducing mode in which braking force is reduced by operating the said third component [24] in a direction reverse to the direction of operation of the first or the second component [25, 34] .to increase braking force or a braking force enhancing mode in which braking force is enhanced by operating the said third component [24] in the same direction as that of operating of the first or the second component [25, 34] to enhance braking force. 3. A brake device for a vehicle as claimed in claim 1 wherein said actuator [12] is provided individually or in common in the intermediate parts of the said first and the said second transmissions means [6R, 6R'; 6F, 6F'] as hereinbefore described to vary the braking forces of the said first and the said second wheel brake unit [BR, BF], and dampers [8R, 8F] provided in the first and the second transmission means [6R, 6R>; 6F, 6F'] at positions between the said actuator [12] and the first and the second, brake operating member [5R, 5F], respectively. 4. A brake device for a vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

667-del-1995-abstract.pdf

667-del-1995-claims.pdf

667-del-1995-correspondence-others.pdf

667-del-1995-correspondence-po.pdf

667-del-1995-description (complete).pdf

667-del-1995-drawings.pdf

667-del-1995-form-1.pdf

667-del-1995-form-13.pdf

667-del-1995-form-2.pdf

667-del-1995-form-3.pdf

667-del-1995-form-4.pdf

667-del-1995-form-61.pdf

667-del-1995-form-9.pdf

667-del-1995-gpa.pdf

667-del-1995-petition-others.pdf