JP2007314101A - Motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft drive type motorcycle capable of increasing the strength of a rear frame. <P>SOLUTION: The motorcycle 1 transmits power from an engine E to a rear wheel 3 through a drive shaft 16 disposed in a front/rear direction of a vehicle body. The drive shaft 16 passes though a recessed portion 10a recessed inward in the vehicle width direction of a pivot frame 10 constituting a vehicle body. An external opening 51 of the recessed portion 10a in a vehicle width direction is closed by a frame cover 12. Above the drive shaft 16, the front portion of a rear frame 37 provided behind the pivot frame 10 is connected to the frame cover 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shaft drive type motorcycle that transmits power from an engine to a rear wheel via a drive shaft disposed in the longitudinal direction of the vehicle body.

  In motorcycles, power is generally transmitted from the engine transmission to the rear wheels by a chain, but there is a shaft drive type that transmits power by a drive shaft arranged in the longitudinal direction of the vehicle body instead of the chain ( For example, see Patent Document 1). According to this shaft drive type, there is an advantage that there is no need to adjust the elongation due to long-term use unlike a chain, the frequency of lubrication is reduced, and the drive efficiency is also improved. However, in the case of a shaft drive type motorcycle, a tail lift phenomenon occurs in which the rear part of the vehicle body is lifted during acceleration due to a reaction of torque, and a tail down phenomenon in which the rear part of the vehicle body sinks during deceleration.

Therefore, in order to reduce such a phenomenon, a para-lever system has been proposed in which two arms that connect the vehicle body frame and the rear wheel are arranged in parallel above and below the drive shaft. According to this paralever system, the intersection point on the extension line of the upper and lower arms becomes a virtual pivot, so that the length of the virtual swing arm that is the distance from the rear wheel to the virtual pivot can be secured long, and the tail lift phenomenon and It becomes possible to suppress the tail-down phenomenon.
Japanese Patent Laid-Open No. 9-109981

  By the way, the seat rail on which the seat for riding the driver is installed extends rearward from the main frame or the pivot frame near the center of the vehicle body, and this seat rail is disposed at the rear of the vehicle body above the drive shaft. It is supported from below by a rod-shaped rear frame. This rear frame has its front part connected to the pivot frame and extends obliquely upward from the front part to the rear, and the rear part is connected to the seat rail to maintain strength.

  However, in the case of the shaft drive type motorcycle adopting the above-described para-lever system, the arm (torque rod) is disposed above the drive shaft along the vehicle longitudinal direction so that the rear frame does not interfere with the arm. The pivot frame is connected to the pivot frame at a position above the arm. As a result, the vertical opening angle between the seat rail and the rear frame is reduced, and the strength of the rear frame is structurally reduced. Therefore, the rear frame diameter and the like must be increased, which increases the weight and cost of the vehicle body. Will be invited.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to increase the strength of a rear frame in a shaft drive type motorcycle without increasing the body weight or the like.

  The present invention has been made in view of the circumstances as described above, and for the motorcycle according to the present invention, the drive shaft passes through a recess recessed inward in the vehicle width direction of the frame constituting the vehicle body, An opening on the outer side in the vehicle width direction of the recess is closed by a frame cover, and a front portion of a rear frame provided behind the frame above the drive shaft is connected to the frame cover. To do.

  In this way, the opening of the frame recess through which the drive shaft passes is closed by the frame cover, and the front part of the rear frame is connected to the frame cover, so the front part of the rear frame is below the vicinity of the drive shaft. Thus, the strength of the rear frame can be structurally improved.

  A seat rail is provided behind the frame having the recess along the front-rear direction of the vehicle body, and the rear frame extends obliquely rearward and upward from a front portion connected to the frame cover. The rear part may be connected to the seat rail.

  In this way, the front portion of the rear frame is extended to a lower position near the drive shaft, and the opening angle between the seat rail and the rear frame can be increased. Therefore, the seat rails arranged in the longitudinal direction of the vehicle body are stably held by the rear frame, and the strength of the seat rail and the rear frame can be structurally improved. Note that the seat rail may directly support a seat serving as a seat or may indirectly support the seat.

  A torque rod is provided between the rear wheel and the frame above the drive shaft between the rear wheel and the vehicle body in a substantially front-rear direction, and the rear frame intersects the torque rod, and a front end portion of the torque rod. It may be connected to the frame cover at a lower position.

  In this way, the rear frame crosses the torque rod, which is the upper arm of the paralever system, so that the front end of the rear frame is connected to the frame cover at a position lower than the front end of the torque rod, and the rear frame is Since it becomes easy to arrange it close to the direction, the strength of the rear frame can be structurally improved.

  The rear frame may pass outside the torque rod in the vehicle width direction and cross the torque rod.

  In this case, since the rear frame is disposed on the outer side in the vehicle width direction, the strength of the rear frame in the vehicle width direction can be improved as compared with the case where the rear frame is disposed on the inner side in the vehicle width direction.

  The frame cover may integrally include a plate-shaped cover main body portion and a step bracket portion that protrudes outward from the cover main body portion in the vehicle width direction and to which a step member for placing a driver's foot is attached. Good.

  For example, when a separate step bracket is bolted to the outer side surface of the cover body in the vehicle width direction, the bolt head may be projected to the inner side surface of the cover body. Since there is a drive shaft (and drive shaft case) on the inside, if the bolt head does not interfere with the drive shaft (and drive shaft case), the frame cover will be arranged in the vehicle width direction accordingly. It will spread outward. If it does so, while a vehicle width will increase and it will enlarge, the position of a step member will spread to the vehicle width direction outer side, and the problem that a riding position becomes uncomfortable will arise.

  Therefore, if a frame cover in which the cover main body part and the step bracket part are integrated as described above is used, there is no bolt for fixing the step bracket on the inner surface in the vehicle width direction of the cover main body part. The frame cover can be disposed on the inner side in the vehicle width direction, and the vehicle width can be reduced to make the riding position comfortable.

  As is clear from the above description, according to the present invention, the opening of the frame recess through which the drive shaft passes is closed by the frame cover, and the front portion of the rear frame is connected to the frame cover. The front part of the frame is extended to a lower position near the drive shaft, and the strength of the rear frame can be structurally improved.

  Embodiments according to the present invention will be described below with reference to the drawings. The direction concept used in the following description is based on the direction seen from a driver (not shown) riding the motorcycle.

  FIG. 1 is a left side view of a motorcycle 1 according to an embodiment of the present invention. As shown in FIG. 1, the motorcycle 1 includes a front wheel 2 and a rear wheel 3, and the front wheel 2 is rotatably supported by a lower end portion of a front fork 4 that extends substantially in the vertical direction. It is supported by a steering shaft (not shown) via an upper bracket (not shown) provided at the upper end portion and an under bracket provided below the upper bracket. The steering shaft is rotatably supported by the head pipe 5. A bar-type steering handle 6 extending to the left and right is attached to the upper bracket. Therefore, the driver can turn the front wheel 2 in a desired direction with the steering shaft as a rotation axis by rotating the steering handle 6. A fuel tank 7 is provided behind the steering handle 6, and a seat 8 for riding the driver and passengers is provided behind the fuel tank 7.

  From the head pipe 5, a pair of left and right main frames 9 (only the left main frame is shown in FIG. 1) constituting the skeleton of the vehicle body extends rearward while slightly tilting downward. A pair of left and right pivot frames 10 and 11 (only the left pivot frame 10 is shown in FIG. 1) are connected to the rear end. A parallel four-cylinder engine E is mounted between the front wheels 2 and the rear wheels 3 while being supported by the main frame 9 and the pivot frames 10 and 11. A cowling 44 is provided so as to cover the engine E and the like from the front of the vehicle body to both sides of the vehicle body.

  FIG. 2 is a rear view of the motorcycle 1 as viewed mainly from the pivot frames 10 and 11. As shown in FIG. 2, the right pivot frame 11 has a substantially flat outer surface in the vehicle width direction, while the left pivot frame 10 has a recess 10a that is recessed inward (center side) in the vehicle width direction when viewed from the front. It has a shape. An opening 51 on the outer side in the vehicle width direction of the concave portion 10a of the left pivot frame 10 is closed with a metal frame cover 12, and the frame cover 12 is fixed to a required position of the left pivot frame 10 with a plurality of bolts 45 and 46. ing. Thus, an insertion space S is formed between the recess 10a and the frame cover 12, and a drive shaft case 15 formed in a cylindrical shape by a case body 27 and a cover 29, which will be described in detail later, is disposed in the insertion space S. ing. A drive shaft 16 is inserted into the drive shaft case 15. Further, the left pivot frame 10 and the right pivot frame 11 are connected to each other by an upper cross member 13 and a lower cross member 14 that extend in the left-right direction.

  In the frame cover 12, a step bracket portion 12b to which a step 32 serving as a footrest for the driver is fixed at a position below the passing position of the drive shaft 16 is integrally directed from the plate-shaped cover main body portion 12a toward the left side of the vehicle body. Projecting. On the other hand, a separate step bracket 33 for fixing the step 35 is attached to the right pivot frame 11 at a required position of the right pivot frame 11. The step bracket 33 has a plate portion 33a and an attachment portion 33b protruding from the plate portion 33a toward the right side of the vehicle body. With the step 35 fixed to the attachment portion 33b, the plate portion 33a is bolts 49, 50. Thus, it is fastened to the right pivot frame 11 from the outside in the vehicle body width direction.

  Further, the upper end portion 40a of the shock absorber 40 is attached to the bracket portions 13a, 13a of the upper cross member 13 connecting the left pivot frame 10 and the right pivot frame 11 via bolts or the like (not shown). A shock absorbing oil reserve tank 47 is provided above the shock absorber 40. A lower end portion 40 b of the shock absorber 40 is connected to a bell crank 41 attached to the lower cross member 14. The bell crank 41 is rotatably connected to the rod 43 through a boss 48 integrated with itself.

  FIG. 3 is a left side view of the main part of the motorcycle 1 mainly showing the rear part of the vehicle body. FIG. 4 is a perspective view of the main part of the motorcycle 1 showing mainly the rear part of the vehicle body. As shown in FIGS. 3 and 4, a drive shaft 16 protected by a cylindrical drive shaft case 15 is inserted in the insertion space S formed between the recess 10 a of the pivot frame 10 and the frame cover 12. It is inserted through. A front end portion of the drive shaft 16 meshes with an output gear (not shown) of the transmission T (FIG. 1) of the engine E. The rear end portion of the drive shaft 16 meshes with a bevel gear (not shown) in a rear gear case 17 attached to the rear wheel 3 to convert the power rotation direction into the wheel rotation direction, thereby converting the rear wheel 3 (FIG. 3, Power is transmitted to FIG.

  As shown in FIG. 3, the rear gear case 17 attached to the rear wheel 3 includes a cylindrical portion 17 a into which the rear end portion of the drive shaft 16 is inserted, a lower bracket portion 17 b that protrudes obliquely downward and forward, and obliquely upward and forward. The upper bracket part 17c which protrudes is provided. The lower bracket portion 17b is pivotally supported by a rear end portion of a substantially arc-shaped swing arm 18 in side view, which will be described in detail later, and the front end portion of the swing arm 18 is inside the pivot frame 10, 11 in the vehicle width direction. It is pivotally supported on the inner surface of the. A rear end portion of the torque rod 19 that is substantially linear in a side view is pivotally supported on the upper bracket portion 17 c, and a front end portion of the torque rod 19 is pivotally supported at a required portion of the left pivot frame 10. That is, in the present embodiment, a para-lever system is adopted in which a suspension unit that connects the pivot frame 10 and the rear wheel 3 is configured by the torque rod 19 and the swing arm 18 arranged side by side vertically.

  The left pivot frame 10 and the right pivot frame 11 (shown only on the left side in FIG. 3) are frame-like in plan view arranged in the longitudinal direction of the vehicle body to support the driver's and passenger's seat 8 (FIG. 1). The front end portion 36a of the seat rail 36 is fixed. As shown in FIG. 1, the front portion of the seat 8 is supported by the rear portion of the tank 7, and the rear portion (passenger seat portion) of the seat 8 is supported by the rear portion of the seat rail 36.

  As shown in FIG. 3, a rear end portion 37 a of a rod-shaped rear frame 37 is welded to the rear portion of the seat rail 36. A front end portion 37 b of the rear frame 37 extending from the rear end portion 37 a toward the front diagonally downward direction is fixed to the frame cover 12 with bolts 39. Specifically, as shown in FIGS. 3 and 4, the rear frame 37 passes through the left outer side in the vehicle width direction, intersects the torque rod 19, and is positioned below the front end portion of the torque rod 19. It is fixed to the inner surface of the cover 12 (the surface on the center side in the vehicle width direction).

  As shown in FIG. 3, a mounting portion 42 projects downward on the lower surface of the swing arm 18, and the bell crank 41 and the mounting portion 42 described above are connected by a rod 43. In this way, the shock absorber 40 is connected between the upper cross member 13 (FIG. 2) and the swing arm 18, and the shock received by the rear wheel 3 from the road surface is absorbed by the shock absorber 40.

  FIG. 5 is an exploded perspective view of the swing arm 18 showing the drive shaft case 15 in an exploded manner. As shown in FIG. 5, the swing arm 18 is made of iron or aluminum metal, and a left arm portion 20 passing in the front-rear direction on the left side of the vehicle body, a right arm portion 21 passing in the front-rear direction on the right side of the vehicle body, and a left arm. The front cylinder part 22 (swing arm support part) which has the axis line of the left-right direction following the front-end part of the part 20 and the right arm part 21, and the intermediate part of the front-back direction of the left arm part 20 and the right arm part 21 are connected. It includes a connecting portion 23 (cross member) in the left-right direction. A through hole 24 in the vertical direction is formed between the front cylinder portion 22 and the connecting portion 23 so that a shock absorber 40 (see FIG. 2 or FIG. 3) passes through. At the rear end portion of the left arm portion 20, a bolt mounting portion 25 pivotally supported by the lower bracket portion 17b of the rear gear case 17 (FIG. 3) is provided, and at the rear end portion of the right arm portion 21, A bolt mounting portion 26 pivotally supported by a bracket (not shown) mounted on the right side of the rear wheel 3 is provided.

  As shown in FIG. 5, a case main body 27 constituting a part of the drive shaft case 15 (see also FIG. 3 and the like) is integrally provided on the left arm portion 20 of the swing arm 18. The case main body 27 is made of the same metal as the swing arm 18 and has a shape obtained by dividing the cylindrical drive shaft case 15 in the axial direction, and has an opening 28 that opens in the left direction of the vehicle body along the axial direction. The opening 28 is formed partway from the front end of the case main body 27 to the rear end in the axial direction, and the case main body 27 is provided with a cylindrical edge 27a at the rear end. In addition, a flat bolting portion 27b in which a bolt hole 27c is formed is provided on the upper surface of the case body 27 at the center in the front-rear direction.

  The opening 28 of the case body 27 is covered and closed with a cover 29, and the cylindrical drive shaft case 15 is formed by the case body 27 and the cover 29. The cover 29 is made of a resin having a substantially semicircular cross section, and has a shape that covers the front end edge of the cylindrical edge portion 27 a from the front end of the case body 27. At the upper end edge of the cover 29, a flange portion 29a covering the upper end edge of the case body 27 from above is projected in an inverted L-shaped cross section. A bolt attachment portion 29b that overlaps the bolt fastening portion 27b of the case body 27 protrudes from the center portion in the front-rear direction of the flange portion 29a, and a bolt hole 29c is provided in the bolt attachment portion 29b. That is, the bolt 29 is fastened to the bolt hole 29c of the cover 29 and the bolt hole 27c of the case main body 27, so that the cover 29 is fixed to the case main body 27 with the opening 28 closed. . As shown in FIG. 3, the drive shaft case 15 assembled in this way is connected to the cylindrical portion 17 a of the rear gear case 17 via a rubber bellows cylindrical body 31.

  With the configuration described above, as shown in FIGS. 3 and 4, the rear frame 37 intersects the torque rod 19 in a side view, and the front end portion 37 a of the rear frame 37 is the recess 10 a of the left pivot frame 10. Since the front end portion 37a of the rear frame 37 is extended to a lower position in the vicinity of the drive shaft 16, the opening between the seat rail 36 and the rear frame 37 is established. The angle θ (FIG. 3) can be increased. Therefore, the seat rail 36 disposed in the longitudinal direction of the vehicle body can be stably held by the rear frame 37 and the strength can be improved.

  Further, the rear frame 37 passes through the outside of the torque rod 19 in the vehicle width direction, and the rear frame 37 is arranged outside the vehicle body. Therefore, when the rear frame 37 is arranged inside the vehicle width direction, In comparison, the strength of the rear frame 37 and the seat rail 36 in the vehicle width direction is improved.

  Further, as shown in FIGS. 2 and 4, the frame cover 12 has a step bracket portion 12b integrally projecting from the cover body portion 12a, so that the back side of the cover body portion 12a (the insertion space S). Side brackets, etc., do not protrude. Accordingly, the insertion space S is widened by the amount of bolts or the like that interfere with the drive shaft case 15 in the insertion space S, and the frame cover 12 can be disposed on the inner side (vehicle body center side) in the vehicle width direction. It is possible to reduce the width and make the riding position comfortable.

  The cover 29 is made of resin, but may be made of metal such as aluminum or iron. Further, the motorcycle of the present invention is not limited to the above-described embodiment, and the configuration can be changed, added, or deleted without departing from the spirit of the present invention.

  As described above, the motorcycle according to the present invention has an excellent effect of structurally improving the strength of the rear frame, and is useful for application to such a shaft drive type motorcycle.

1 is a left side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is a rear view mainly showing a pivot frame of the motorcycle shown in FIG. 1. FIG. 2 is a left side view of a main part mainly showing a rear part of the vehicle body of the motorcycle shown in FIG. FIG. 2 is a perspective view of a principal part mainly showing a rear part of the vehicle body of the motorcycle shown in FIG. 1. Fig. 2 is a perspective view of a swing arm provided with a drive shaft case of the motorcycle shown in Fig. 1.

Explanation of symbols

1 Motorcycle 3 Rear Wheel 8 Seat 10 Pivot Frame (Frame)
12 Frame cover 12a Cover body 12b Step bracket 15 Drive shaft case 16 Drive shaft 18 Swing arm 19 Torque rod 36 Seat rail 37 Rear frame E Engine

Claims (5)

A motorcycle that transmits power from an engine to a rear wheel via a drive shaft arranged substantially in the longitudinal direction of the vehicle body,
The drive shaft passes through a recess recessed inward in the vehicle width direction of the frame constituting the vehicle body, and the opening on the outer side of the recess in the vehicle width direction is closed with a frame cover,
2. A motorcycle according to claim 1, wherein a front portion of a rear frame provided on the rear side of the frame above the drive shaft is connected to the frame cover. It further comprises a seat rail disposed along the front-rear direction of the vehicle body behind the frame having the recess,
The motorcycle according to claim 1, wherein the rear frame has a rear portion extending substantially obliquely rearward and upward from a front portion connected to the frame cover connected to the seat rail. . Further comprising a torque rod bridged in the longitudinal direction of the vehicle body between the rear wheel and the frame above the drive shaft;
The motorcycle according to claim 1 or 2, wherein the rear frame is connected to the frame cover at a position lower than a front end portion of the torque rod so as to intersect the torque rod.   The motorcycle according to claim 3, wherein the rear frame passes outside of the torque rod in the vehicle width direction and intersects the torque rod. The frame cover integrally includes a plate-like cover main body portion and a step bracket portion that protrudes outward from the cover main body portion in the vehicle width direction and to which a step member for placing a driver's foot is attached. The motorcycle according to any one of claims 1 to 4.

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