JPH0535579U - Pivot shaft support structure for motorcycles - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a motorcycle in which the ride comfort can be easily set even if the course or driver changes. [Structure] A swing arm 24 is rotatably attached around a pivot shaft 7 fixed to a body frame 6. The body frame 6 is provided with a support hole (not shown) penetrating in the width direction of the vehicle body. An annular support member 10 that penetrates and supports the pivot shaft 7 is detachably attached to the support hole.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a support structure for a pivot shaft that rotatably supports a swing arm of a motorcycle.

[0002]

[Prior Art]

 Generally, the rear wheel of a motorcycle is attached to the rear end of a swing arm (see, for example, Japanese Utility Model Publication No. 51-47721). A front end portion of the swing arm is rotatably attached around a pivot shaft, and is elastically supported by a body frame by a rear suspension. By setting the initial load and spring constant of the spring of the above rear suspension to a predetermined value, a ride comfort that suits the tastes of general drivers can be obtained.

[0003]

[Problems to be solved by the device]

 However, in the case of a motorcycle for racing, for example, the riding comfort changes as the course on which the vehicle travels changes. In such a case, there is no problem in adjusting the initial load of the spring or replacing the spring itself or changing the damping force for each course. Is extremely troublesome. In addition, the riding comfort changes depending on the weight of the driver, riding style, and preferences in addition to the course, so it is difficult to set the initial load of the above springs and so on to adjust to the optimal riding comfort. is there.

The present invention has been made in view of the above problems of the prior art, and provides a support structure for a pivot shaft of a motorcycle, which allows the ride comfort to be easily set even when the course to be driven or the driver changes. The purpose is to provide.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a support hole penetrating in the width direction of the vehicle body in a vehicle body frame, and attaches an annular support member penetrating and supporting a pivot shaft to the support hole in a detachable manner. There is.

[0006]

[Action]

 According to this invention, since the annular support member that penetrates and supports the pivot shaft is detachably attached to the support hole of the vehicle body frame, a plurality of types of support members having different positions of the through holes in the support member are prepared in advance. Then, by exchanging these supporting members, the position of the axial center of the pivot shaft can be changed. Therefore, the magnitude of the moment applied to the rear suspension around the pivot shaft can be changed, and the ride comfort tailored to the course and the driver can be obtained.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 showing a first embodiment of the present invention, a drive sprocket 2 connected to an output shaft of an engine (not shown) is provided at the center of a vehicle body 1 of a motorcycle. The drive sprocket 2 is connected to a driven sprocket 5 of the rear wheel 4 via an endless drive chain 3. As shown in FIG. 2, a body frame 6 near the drive sprocket 2 is provided with a mounting portion 8 for a pivot shaft 7 in a portion surrounded by the drive chain 3.

As shown in the plan sectional view of FIG. 3, the attachment portion 8 of the pivot shaft 7 is provided with a support hole 9 penetrating in the width direction W of the vehicle body in each of the two forked vehicle body frames 6. Has been. The cylindrical portion 12 of the annular first support member 10 is fitted in the support hole 9 without a gap. The cylindrical portion 12 of the first support member 10 has a through hole 11 through which the pivot shaft 7 penetrates, and supports the pivot shaft 7.

The pivot shaft 7 is composed of a long bolt 7a with a seat and a nut 7b, and is fixed to the vehicle body frame 6. In the case of this embodiment, this pivot shaft 7 penetrates through a hollow sleeve 20, and a pivot pipe 21 provided on the outer circumference of this sleeve 20 is inserted through three needle bearings 22 and one ball bearing 23. , Rotatably supported.

Although not shown, the pivot pipe 21 has a structure integrally welded with the swing arm 24 shown in FIG. 1. Therefore, the swing arm 24 is rotatable around the pivot shaft 7. ing. The swing arm 24 constitutes a link mechanism together with a rear suspension 25 attached to the vehicle body frame 6, a bell crank 26 and an arm 27, and is elastically supported by the vehicle body frame 6 by the rear suspension 25.

As shown in FIG. 4 (b), the above-mentioned first support member 10 has an integral mounting seat portion 13 in the cylindrical portion 12. In the first support member 10, the cylindrical portion 12 and the through hole 11 are concentrically provided. Four bolt holes 14 through which a mounting bolt 15 (see FIG. 2) penetrates are formed in the mounting seat portion 13 of FIG. 4A. The mounting seat portion 13 has a quadrangular shape as shown in FIG. 4C, and is positioned and fixed to the vehicle body frame 6 by the mounting bolt 15 shown in FIG. The mounting seat 13 is fitted in a rectangular mounting recess 9a formed in the vehicle body frame 6 as shown in FIG.

FIG. 5 shows a second supporting member 10A prepared in advance. The second support member 10A is to be replaced with the first support member 10 shown in FIG. 4 according to the preference of the course and the driver. As shown in FIG. 5B, in the second support member 10A, the center C1 of the through hole 11 is vertically eccentric from the center C2 of the cylindrical portion 12 by a distance e. The other configurations of the above second support member 10A are similar to those of the first support member 10, and the same portions or corresponding portions will be denoted by the same reference numerals and detailed description thereof will be omitted. Note that third to fourth support members (not shown) having different eccentricity e from the second support member 10A of FIG. 5 are prepared in advance.

Next, the principle of this invention will be described with reference to FIG. In FIG. 6, the force applied during acceleration is indicated by a thick solid line arrow, and the force applied during deceleration is indicated by a thick broken line arrow. The moment applied to the rear suspension around the pivot center O of the swing arm 24 during acceleration is expressed by the following equation (1). _{M = F1 · H GP -F1 ·} H P + F C 1 · H C 1 ... (1) where the direction to reduce the rear suspension as positive. F1: driving force (force in the forward acting force or the rear wheels 4 of the rearward acting on the center of gravity G) H _GP: distance from the pivot center O to the center of gravity G H _P: distance from the ground to the pivot center O F _C 1 : Tension of drive chain 3 during acceleration H _C 1: Distance from pivot center O to the upper part of drive chain 3

Here, the tension F _C 1 of the drive chain and the forward force F 1 acting on the rear wheel 4 have the relationship of the following equation (2). F _C 1 = F1 · (R / r) (2) where R is the radius of the rear wheel r is the radius of the sprocket 5 From the above equations (1) and (2), the rear suspension around the pivot center O at the time of acceleration The moment M applied to is expressed by the following equation (3). _{M = F1 · {H GP -H} P + (R / r) · H C 1} ... (3)

Similarly, the moment M applied to the rear suspension around the pivot center O during deceleration is expressed by the following equation (4). _{M = -F2 · {H GP -H} P + (R / r) · H C 2} ... (4) where, F2: braking force (rearward acting force or the rear wheels 4 of the forward acting on the center of gravity G Force) H _C 2: Distance from the center O of the pivot to the bottom of the drive chain 3.

Here, when the moment M in the above equations (3) and (4) is close to zero, an extra force is not applied to the rear suspension 25 (FIG. 1) by the acceleration or deceleration operation, so that the posture change of the vehicle body is changed. It's natural and gives a comfortable ride. The magnitude of this moment M changes depending on the position of the pivot center O, as can be seen from the equations (3) and (4).

Further, when the moment M becomes positive during acceleration, the rear suspension 25 (FIG. 1) contracts, and the posture change of the vehicle body increases. On the contrary, when the moment M becomes negative, a force (extra force) for extending the rear suspension 25 (FIG. 1) is exerted under the spring of the rear suspension 25 (FIG. 1), and it becomes difficult to follow the tread change.

On the other hand, when the moment M becomes positive during deceleration, the braking force F 2 applied to the rear wheels 4 causes the rear suspension 25 (FIG. 1) to contract, so that when the vehicle enters a corner, the front suspension is also combined with the front brake. The nose dive is reduced because the car body sinks in parallel with the 25A contraction. Therefore, the riding comfort is better than when the moment M is zero. Further, when the moment M becomes negative during deceleration, the force for extending the rear suspension 25 (FIG. 1) acts excessively, and the nose dive increases.

From the above, it can be seen that the ride comfort can be selected by changing the position of the pivot center O depending on whether the weight is placed during acceleration or deceleration according to the course and the driver's preference.

Here, in this motorcycle, as shown in FIGS. 4 and 5, a plurality of types of support members 10 and 10 A in which the positions of the through holes 11 are different from the cylindrical portion 12 are prepared. Therefore, since the position of the pivot shaft 7 in FIG. 3 can be changed by exchanging the support members 10 and 10A, the distance from the pivot center O in FIG. 6 to the drive chain 3 can be arbitrarily changed to The moment M can be changed. Therefore, the ride comfort of each of the support members 10 and 10A (FIGS. 4 and 5) is tested in advance, and the support member 10 of FIG. 3 is replaced for each course and driver, so that the course and the driver can be replaced. You can choose the ride comfort to suit your taste.

Next, a method of replacing the first support member 10 will be described. First, the mounting bolt 15 (FIG. 2) of the first support member 10 is loosened, then the nut 7b of the pivot shaft 7 is loosened, and the first support member 10 is removed together with the long bolt 7a. After this removal, the pair of second support members 10A (FIG. 5) are attached to the support holes 9 of the vehicle body frame 6, and the long bolts 7a are attached to the through holes 11 and the sleeve of the second support member 10A (not shown). After passing through the inside 20, tighten the nut 7b. Thus, by exchanging the support members 10 and 10A, the position of the pivot center O of the swing arm 24 in FIG. 6 changes up and down. Therefore, the conventional adjustment of the initial load and the spring itself are exchanged. Ride comfort can be set more easily than with work.

Further, as in the conventional method, the method of adjusting the initial load of the spring and replacing the spring itself is inferior in reproducibility of resetting to a predetermined state. On the other hand, in the present invention, the ride comfort can be adjusted simply by exchanging the support members 10 and 10A (FIGS. 4 and 5), so that the ride comfort previously obtained can be easily reproduced. it can.

By the way, in order to change the position of the center O of the pivot, the support member 10 of FIG. 3 is not replaced, but the support member 10 is supported by adjusting bolts and the mounting position of the support member 10 is changed. It is also possible to let them do. However, since a large impact force is applied to the pivot shaft 7, the method of supporting the support member 10 with the adjusting bolt is not preferable. On the other hand, according to the present invention, the position of the pivot center O (FIG. 6) is changed by replacing the support member 10 fitted in the vehicle body frame 6, so that the pivot shaft 7 can be firmly fixed. Can withstand large loads.

FIG. 7 shows a second embodiment. The pivot shaft 7A in FIG. 7 is a hollow shaft, and is formed by integrally forming the pivot shaft 7 and the sleeve 20 in FIG. At the left end of the pivot shaft 7A shown in FIG. 7, a male screw 7c that is screwed into the female screw 11a of the support member 10B is provided. The other structure of the second embodiment is similar to that of the first embodiment, and the same portions or corresponding portions will be denoted by the same reference numerals and detailed description thereof will be omitted.

In each of the above embodiments, the through hole 11 of the support member 10A shown in FIG. 5 is eccentric in the vertical direction with respect to the cylindrical portion 12, but it may be eccentric in the longitudinal direction A of the vehicle body of FIG. , Moment M can be changed slightly, and is included in the present invention.

[0026]

[Effect of the device]

 As described above, according to the present invention, the annular support member that supports the pivot shaft through it is detachably attached to the support hole that penetrates in the width direction of the vehicle body frame. By preparing multiple types of support members with different hole positions and replacing these support members, the position of the pivot shaft axis can be changed. Therefore, the magnitude of the moment applied to the rear suspension around the pivot shaft generated by the acceleration / deceleration operation can be changed, and the ride comfort tailored to the course and driver can be obtained. In addition, the ride comfort can be changed by exchanging the support members prepared in advance, so that adjustment work is easy and the ride comfort that suits the course can be easily reproduced, and the pivot shaft to which a large load is applied can be easily adjusted. It can be firmly supported.

[Brief description of drawings]

FIG. 1 is a side view of a motorcycle according to a first embodiment of the present invention.

FIG. 2 is a side view of a main portion showing a mounting portion of a pivot shaft.

FIG. 3 is a plan sectional view of a pivot shaft, a mounting member and the like.

FIG. 4 is a front view, a cross-sectional view, and a rear view of a first mounting member.

5A and 5B are a front view, a cross-sectional view, and a rear view of a second mounting member.

FIG. 6 is a side view showing a force applied to the center of the pivot.

FIG. 7 is a plan sectional view of a pivot shaft, a mounting member and the like in a second embodiment.

[Explanation of symbols]

6 ... Body frame, 7 ... Pivot shaft, 9 ... Support hole, 10, 10A, 10B ... Support member, 24 ... Swing arm, W ... Width direction.

Claims (1)

[Scope of utility model registration request] 1. A support structure for a pivot shaft of a motorcycle, wherein a swing arm is rotatably attached around a pivot shaft fixed to a body frame, wherein a support hole penetrating the body frame in a width direction of the body. And a ring-shaped support member that penetrates and supports the pivot shaft and is detachably attached to the support hole.