Title of Invention

"ENGINE STARTER SUPPORT STRUCTURE FOR A TWO WHEELED MOTOR VEHICLE"

Abstract

[Summary] [Solution] In a power unit 1 comprising an engine 2, a transmission case 41 and a cover member 46, a starter 13 attached to the engine 2 comprises a starter motor 61 mounted to the transmission case 41, a support shaft 63 adapted to rotate in interlock with the starter motor 61, and a pinion 65 movable axially on the support shaft 63 and adapted to move into mesh with a ring gear 11 mounted on a crank shaft 12 of the engine 2 to transmit the rotation of the support shaft 63 to the ring gear 11, one end of the support shaft 63 is connected rotatably to the transmission case 41, the opposite end of the support shaft 63 is connected rotatably to a holder 68 which is held by the inner wall of the cover member 46, an elastic member 69 is sandwiched in between the holder 68 and the cover member 46 and held by a fitting engagement with the holder 68 or the cover member 46. [Effect] The number of mounting steps can be kept small and an axial vibration of the holder can be absorbed.

Full Text

The present invention relates to an engine starter support structure for a two-wheeled motor vehicle. [Prior art] As an engine starter support structure there is known, for example, "an engine starter supporting device for a two-wheeled motor vehicle" disclosed in Japanese Utility Model Laid Open No. 42431/95 corresponding to Indian equivalent 1609/DEL/94. The technique disclosed in the said unexamined publication aims at providing an engine starter supporting device for a two-wheeled motor vehicle capable of preventing an axial vibration of a holder without increasing the number of components used. The device disclosed in the above unexamined publication, as shown in Figs. 6 and 7 thereof, comprises a starter motor 101 mounted to a case portion of a transmission case 64, a pinion 105 adapted to rotate in interlock with a rotating shaft of the starter motor 101 and capable of moving into mesh with a ring gear 103 mounted on a crank shaft, a support shaft 104 capable of rotating integrally with the pinion 105, a holder 110 attached to the case portion 61 to support an end portion of the support shaft 104 rotatably, a gasket 62 sandwiched in between the case portion 61 and a case member 63 which is a cover for the transmission case 64, and an elastic support portion 112 formed by molding integrally with the gasket 62 and sandwiched in between the holder 110 and the case member 63. [0004] [Problems to be Solved by the Invention] The elastic support portion 112, which is formed by molding integrally with the gasket 62, possesses flexibility and functions to seal a wide area. At the time of mounting, therefore, it is necessary that the gasket 62 and the elastic support portion 112 be each subjected to positioning. Thus, the improvement of their mounting performance is desired. [0005] In the case where the gasket 62 and the elastic support portion 112 are formed as separate members, it is required that the elastic support portion 112 be fixed to the holder 110 or the case member 63 with an adhesive or the like to prevent its displacement. This results in an increase in the number of mounting steps. Besides, the adhesive may be deteriorated by a secular change, and once it is deteriorated, it is necessary to apply the adhesive again to the elastic support member 112. It is therefore and object to the present invention to provide an engine starter support structure for a two-wheeled motor vehicle capable of being mounted easily and capable of absorbing an axial vibration of a holder. [Means for Solving the Problems] According to the present invention there is an engine starter support structure for a two-wheeled motor vehicle comprising: a power unit of a two-wheeled motor vehicle, comprising an engine, a transmission case adjacent to a crank case of the engine, and a cover member for covering the transmission case: a starter support structure for supporting a starter attached to the engine, said starter comprising a starter motor mounted to the transmission case, a support shaft adapted to rotate in interlock with the starter motor, and a pinion movable axially on said support shaft and adapted to move into mesh with a ring gear mounted on a crank shaft of the engine to transmit the rotation of the support shaft to said ring gear, wherein characterized in that one end of said support shaft being connected rotatably to the transmission case, the opposite end of the support shaft being connected rotatably to a holder which is held by the inner wall of said cover member, an elastic member being sandwiched in between said holder and said cover member and held by a fitting engagement with the holder or the cover member. Since it is not necessary to form the elastic member integrally with a gasket or the like, nor is it necessary to use any special member for fixing the elastic member, the mounting of the elastic member becomes easy and it is possible to keep small the number of mounting steps. Besides, there is no fear of secular deterioration of an adhesive, and it is possible to absorb an axial vibration of the holder. According to claim 2, the elastic member is held by the holder. Since the elastic member can be fixed temporarily to the holder by only fitting without using any adhesive, it is possible keep small the number of mounting steps. If the elastic member is held beforehand by the holder, then in a power unit assembly line for example, a small storage space suffices because the holder-elastic member assembly is small-sized. Moreover, the said assembly can be mounted in a successive manner to each power unit being assembled and carried along the .assembly x line, whereby the mounting performance can be improved. [0009] According to claim 3, the elastic member is held by the cover member. Since the elastic member can be fixed temporarily to the cover member by only fitting without using any adhesive, it is possible to keep small the number of mounting steps. [Brief Description of the Drawings] Fig.l is a side view showing a power unit of a two-wheeled motor vehicle according to the present invention; Fig.2 is a sectional view taken on line 2-2 in Fig.l; Fig.3 is a sectional view taken on line 3-3 in Fig.l; Fig.4 is a perspective view showing a holder and a rubber both used in the present invention; Fig.5 is an explanatory diagram of the rubber; Fig. 6 is a diagram explaining the operation of the rubber; and Fig.7 is a sectional view showing a rubber mounting method according to another embodiment of the present invention. [0010] [Embodiments of the Invention] Embodiments of the present invention will be described hereinunder with reference to the accompanying drawings, which drawings are to be seen in the directions of the reference numerals. Fig.l is a side view showing a power unit of a two-wheeled motor vehicle according to the present invention. The power unit, indicated at 1, comprises an engine 2 and a continuously variable transmission 3 for the transmission of power from the engine 2 to the vehicular wheels. The engine 2 is provided with a starter 13 for rotating a crank shaft 12 through a ring gear. 11. [0011] The transmission 3 is provided with a transmission case 41 integral with the engine 2, a driving pulley 42 mounted on one end of the crank shaft 12 projecting sideways from the front portion (left-hand side in the figure) of the transmission case 41, a driven shaft 43 mounted in the rear portion of the power unit 1 in parallel with the crank shaft 12, a driven pulley 44 mounted on the driven shaft 43, a V belt 45 entrained on both driving pulley 42 and driven pulley 44, and a cover member 46 (see Fig.2) which covers the transmission case 41 sideways. Numeral 4la denotes a cover member mounting surface, and numeral 47 denotes a body frame mounting portion for mounting to a vehicular body frame. [0012] x Fig.2 is a sectional view taken on line 2-2 in Fig.l. The engine 2 is provided with a crank case 16 for supporting the crank shaft 12 rotatably, a generator 17 mounted on the opposite end of the crank shaft 12, a connecting rod 18 connected at one end thereof to the crank shaft 12 through a crank pin 12a, a piston 22 connected to the opposite end of the connecting rod 18 through a piston pin 21, a cylinder block 23 having a cylinder 23a inserted slidably into the piston 22, a cylinder head 21 mounted on the upper portion of the cylinder block 23, and a spark plug 25 attached to the cylinder head 24. The numeral 23b denotes a scavenging passage, numeral 26 denotes a reed valve, numeral 27 an intake pipe, and numeral 28 a bearing. [0013] The driving pulley 42 in the transmission 3 comprises a fixed pulley half 51 fixed to an end portion of the crank shaft 12 and a movable pulley half 52 mounted on the crank shaft 12 axially movably. Numeral 53 denotes a plate fixed to the crank shaft 12. [0014] Numeral 54 denotes a weight disposed between the plate 53 and the movable pulley half 52. As the rotation of the crank shaft 12 increases, the weight 54 moves radially outwards under the action of a centrifugal force, thereby causing the movable pulley half 52 to move toward the fixed pulley half 51, enlarging the diameter of contact of the V belt 45 with both pulley halves 51 and 52 and increasing the change gear ratio of the transmission 3 in a stepless manner to increase the vehicle speed. On the other hand, when the rotation of the crank shaft 12 decreases, the weight 54 moves radially inwards to exert an action reverse to the above, thereby decreasing the vehicle speed. Numeral 55 denotes a kick starter, and numeral 56 denotes a driving wheel. [0015] Fig.3 is a sectional view taken on line 3-3 in Fig.l. In the same figure, a starter motor 61 of the starter 13 is fixed to the transmission case 41 with bolts Bl ...(the dots ... stands for plurality and this applies also in the following), a gear 62 is engaged with a rotating shaft 61a of the starter motor 61, a support shaft 63 is formed integrally with the gear 62, one end of the support shaft 63 is supported rotatably by the transmission case 41 through a bearing 64, a pinion 65 is mounted on the support shaft 63 centrally and movably by a pinion moving means 66, *a stopper 67 is attached to an end portion of the pinion 65, the opposite end of the support shaft 63 is supported by a holder 68 through a bearing 64, and rubber 69 as an elastic member is fitted on an end portion of the holder 68 and is held in place by the cover member 46. The rubber 69 is for absorbing vibrations of the holder 68 generated during movement of the pinion 65 to prevent the vibrations from being transmitted to the cover member 46 and the transmission case 41. [0016] Thus, since the rubber 69 can be fixed temporarily to the holder 68 by only fitting without using any adhesive, it is possible to keep small the number of mounting steps. Moreover, if the rubber 69 is held beforehand by the holder 68, an assembly of holder 68 and rubber 69 requires only a small space because it is small-sized, for example, in an assembly line of the power unit 1 (see Fig.l). Further, the said assembly can be mounted in a successive manner to each power unit 1 being carried and assembled along the assembly line, and thus it is possible to improve the mounting performance. [0017] Fig.4 is a perspective view showing the holder 68 and the rubber 69 both used in this embodiment. The holder 68 has a sectorial hole portion 68a, a columnar portion 68b projecting in the sectorial hole portion 68a, a flange portion 68c adapted to abut the inner surface of the transmission case 41 (see Fig.3) to prevent rotation of the holder 68 around the support shaft 63 (see Fig. 3), and a housing portion 68d for supporting the support shaft 63 through the bearings 64 shown in Fig.3. The holder 68 is kept floated with respect to the transmission case 41. In Fig.4, numeral 68e denotes an outer surface df the holder 68 which outer surface is arcuate in section, numeral 68f denotes an outer surface of the holder which outer surface is rectilinear in section, and numeral 68g denotes an inner surface of the sectorial hole portion. [0018] The rubber 69 has a generally sectorial base portion 69c which is in the shape of a plate and whose outer periphery comprises an arcuate portion 69a and a linear portion 69b (see Fig.5), a generally sectorial upright portion 69d formed on one side of the base portion 69c, a first pawl portion 69e projected to the same side as the upright portion 69d from the arcuate part 69a of the base portion 69c and formed so as to fall down to the upright portion 69d side, and a second pawl portion 69f projected "to the same side as the upright portion 69d from the linear part 69b of the base portion 69c and formed so as to fall down to the upright portion 69d side. [0019] The .upright portion 69d of the rubber 69 is to be inserted into the sectorial hole portion 68a of the holder 68. The first pawl portion 69e presses the outer surface 68e of the holder 68 radially from the exterior, and the second pawl portion 69f presses the outer surface 68f of the holder 68 from the exterior. [0020] Figs.5(a) to (c) are explanatory diagrams of the rubber used in this embodiment, of which (a) is a front view, (b) is a sectional view taken on line b-b in (a), and (c) is a sectional view taken on line c-c in (a) In Fig.5(a), numeral 69g denotes an inner arcuate portion formed at a position close to the center of the upright portion 69d, numeral 69h denotes an outer arcuate portion formed outside the upright portion 69d, and numeral 69j denotes an air vent hole for the escape of air which has been entrapped between the holder 68 and the rubber 69 at the time of fitting the rubber 69 on the holder 68. [0021] In Fig.5(b), the second pawl portion 69f is in a fallen state on the upright portion 69d side and it is brought into an upright state forcibly when the rubber 69 is fitted on the holder 68, so that the outer surface 68f of the holder 68 is urged inwards by the elastic force of the rubber 69. Numeral 69k denotes a thin-wall part of the base portion 69c, which part 69k is not sandwiched in between the holder 68 and the cover member 46. Numeral 69m denotes a thick-wall part, of the base portion 69c and it forms a stepped part 69n for the base portion 69c to effect positioning with respect to the cover member 46. [0022] In Fig.5(c), the first pawl portion 69e is in a fallen state on the upright portion 69d side and it is brought into an upright state forcibly when the rubber 69 is fitted on the holder 68, so that the outer surface 68e of the holder 68 is urged radially inwards by the elastic force of the rubber 69. Thus, the rubber 69 can be fitted and held on the holder 68 by the upright portion 69d, first pawl portion 69e and second pawl portion 69f. [0023] NoV, the operation of the rubber 69 will be described below. Figs.6(a) and (b) are diagrams explaining the operation of the rubber used in the present invention, of which (a) shows a state before movement of the pinion and (b) shows a state after movement of the pinion. In Fig.6(a), when the starter motor 61 (see Fig.3) is off, that is, when the engine is off or is operating, except start-up of the engine, the pinion 65 does not move and is out of mesh with the ring gear 11. [0024] In Fig.6(b), at the time of start-up of the engine, first the pinion moving means 66 operates and the pinion 65 moves into mesh with the ring gear 11. Next, the starter motor 61 operates, the gear 62, support shaft 63, pinion 65 and ring gear 11 rotate, so does the crank shaft 12 (see Fig.3), and the engine 2 (see Fig.2) starts operating. [0025] Upon movement of the pinion 65, the stopper 67 at the front end of the pinion 65 strikes against one end face of the holder 68 to restrict the movement of the pinion 65. Although the holder 68 vibrates upon abutment therewith of the stopper 67, the vibration can be absorbed by the rubber 69 fitted bn the other end face of the holder 68, whereby the holder 68 itself, transmission case 41 and cover member 46 can be prevented from deformation, breakage and generation of noise. [0026] Fig.7 is a sectional view showing a rubber mounting method according to another embodiment of the present invention. According to this method, a rubber 71 is fitted on a cover member 4 6 and is held thereby. Thus, since the rubber 71 can be fixed temporarily to the cover member 46 by only fitting without using any adhesive, it is possible to keep small the number of mounting steps. [0027] Although in the previous embodiment an elastic member is used as the rubber 69, this constitutes no limitation. There may be used a soft resin. Although the rubber 69 is formed with the thin-wall part 69k, the thin-wall part 69k may be removed to form an opening. Further, not only the rubber 69 is fitted on the holder 68 or the cover member 46 but also it may be bonded to the holder 68 or the cover member 46 with use of an adhesive. [0028] [Effects of the Invention] The present invention constructed as above exhibits the following effects. According to the starter support structure for supporting a starter attached to an engine of a two-wheeled motor vehicle, which is defined in claim 1 of the invention, in a power unit of the two-wheeled motor vehicl, comprising the engine, a transmission case adjacent to a crank case of the engine, and a cover member /or covering the transmission case, the starter comprises a starter motor mounted to the transmission case, a support shaft adapted to rotate in interlock with the starter motor, and a pinion movable axially on the support shaft and adapted to move into mesh with a ring gear mounted on a crank shaft of the engine to transmit the rotation of the support shaft to the ring gear, one end of the support shaft is connected rotatably to the transmission case, the opposite end of the support shaft is connected rotatably to a holder which is held by the inner wall of the cover member, an elastic member is sandwiched in between the holder and the cover member and held by a fitting engagement with the holder or the cover member. Therefore, it is not necessary to form the elastic member integrally with a gasket or the like, nor is it "necessary to use any special fixing member for fixing the elastic member. Thus, the mounting operation becomes easier and it is possible to keep small the number of mounting steps. Further, there is no fear of secular deterioration of an adhesive. In addition, it is possible to absorb an axial vibration of the holder. [0029] According to the engine starter supporting structure for a two-wheeled motor vehicle defined 4.n claim 2, since the elastic member is held by the holder, the elastic member can be fixed temporarily to the holder by only fitting without using any adhesive, and hence it is possible to keep small the number of mounting steps. Further, if the elastic member is held beforehand by the holder, then, for example, in a power unit assembly line, a small storage space for an assembly of the holder and the elastic member suffices because the said assembly is small-sized. Additionally, the said assembly can be mounted in a successive manner to each power unit being carried and assembled along the assembly line, whereby the \ x mounting performance can be improved. [0030] According to the engine starter supporting structure for a two-wheeled motor vehicle defined in claim 3, since the elastic member is held by the cover member, the elastic member can be fixed temporarily to the cover member by only fitting without using any adhesive and hence it is possible to keep small the number of mounting steps. [Explanation of Reference Numerals] 1 ... power unit/ 2 ... engine, 11 ... ring gear/ 12 ... crank shaft, 13 ... starter, 16 ... crank case, 41 ... transmission case, 46 ... cover member, 61 ... starter motor, 63 ... support shaft, 65 ... pinion, 68 ... holder, 69 ... elastic member (rubber) WE CLAIM : 1. In a power unit of a two-wheeled motor vehicle, comprising an engine, a transmission case adjacent to a crank case of the engine, and a cover member for covering the transmission case: a starter support structure for supporting a starter attached to the engine, said starter comprising a starter motor mounted to the transmission case, a support shaft adapted to rotate in interlock with the starter motor, and a pinion movable axially on said support shaft and adapted to move into mesh with a ring gear mounted on a crank shaft of the engine to transmit the rotation of the support shaft to said ring gear, one end of said support shaft being connected rotatably to the transmission case, the opposite end of the support shaft being connected rotatably to a holder which is held by the inner wall of said cover member, an elastic member being sandwiched in between said holder and said cover member and held by a fitting engagement with the holder or the cover member. 2. A starter support structure as claimed in claim 1, wherein said elastic member is held by said holder. 3. A starter support structure as claimed in claim 1, wherein said elastic member is held by said cover member. 4. A power unit of a two-wheeled motor vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. 5. A starter support structure substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

3221-del-1997-abstract.pdf

3221-del-1997-claims.pdf

3221-del-1997-correspondence-others.pdf

3221-del-1997-correspondence-po.pdf

3221-del-1997-description (complete).pdf

3221-del-1997-drawings.pdf

3221-del-1997-form-1.pdf

3221-del-1997-form-13.pdf

3221-del-1997-form-19.pdf

3221-del-1997-form-2.pdf

3221-del-1997-form-3.pdf

3221-DEL-1997-Form-4.pdf

3221-del-1997-form-6.pdf

3221-del-1997-gpa.pdf

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