JPH01175589A - Rear wheel suspension device for motorcycle - Google Patents

Abstract

PURPOSE:To prevent the twist of a rear wheel support part by connecting a rear wheel shaft bush part at the opposite side of a swing case and a crunk case with a torque link, inserting a rear wheel suspension unit between bodies, and arranging each pivotally interconnected part of the shaft bush part and the suspension unit on the same vertical surface. CONSTITUTION:A unit swing type engine is composed with the whole of an engine 1, a crank case 2, and a rear wheel 4 made freely oscillatory to a body frame 5. A rear wheel shaft 10 in the opposite side of a swing case 3 is pivotally supported to a shaft bush bracket 12 via a shaft bush 11, and the bracket 12 and the case 2 are linked with a torque link 14. On the other hand, moreover one more rear wheel suspension unit 13 is inserted between the bracket 12 and a rear frame 5a, and each upper and lower pivotally support parts 13a and 13b of the shaft bush 11 of the rear wheel shaft and the unit 13 are arranged so as to be positioned on the same vertical surface. This enables the overhang of a rear wheel support part to be zero, and twist to be prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention provides an automatic two-way
This invention relates to a rear wheel suspension system for a wheeled vehicle.

(Prior Art) In a small two-wheeled motor vehicle such as a scooter as shown in FIG. 7, a unit swing type engine is used to suspend the rear wheel. That is, as shown in FIGS. 5 and 6, a swing case 3 extending rearward from the crank case 2 of the engine 1 is provided in series, and the rear wheel 4 is pivotally supported inside the rear part of the swing case 3 to be integrated with the crank case 2. 2 is pivotally supported on the frame 5 at the front lower part, and a rear cushion unit 6 is interposed between the rear upper part of the swing case 3 and the rear frame 5a.

In this case, the rear wheel 4 becomes cantilevered, and twisting is likely to occur due to the couple between it and the rear suspension unit 6.
A swing arm 7 is often provided integrally with the opposite crankcase 2a, pivotally supporting the opposite end of the rear axle 8, and suspending another rear cushion unit 6a.

However, since the muffler 9 is placed on the opposite side of the swing arm 7, the swing arm 7 is placed in a narrow space between the rear wheel 4 and the muffler 9. The muffler 9 is required to have a large capacity for engine function, and therefore the swing arm 7 is moved as close to the rear wheel 4 as possible to ensure the capacity of the muffler 9. Therefore, there is a problem in that the vertical line portion 7a of the swing arm 7 that connects the pivot portion of the rear cushion unit 6a and the pivot portion of the rear axle 8 greatly overhangs to the side, causing torsion on the bearing and resulting in a lack of durability.

(Problems to be Solved by the Invention) As described above, with the conventional unit swing type engine in which a swing arm and a rear cushion unit are added on the opposite side, it is difficult to secure the capacity of the muffler, and the rear axle shaft support and rear cushion unit are In view of the problem that the vertical line connecting the parts overhangs to the side and reduces the durability of bearings, the present invention proposes a system in which the rear axle shaft support part and the rear traction support part on the opposite side are arranged on a vertical plane. To provide a rear wheel suspension system for a two-wheeled motor vehicle, which can secure a required muffler capacity while preventing twisting.

[Structure of the invention]

(Means for Solving the Problems) For the above purpose, the rear wheel suspension system for a motorcycle of the present invention includes a swing case extending rearward from one side of the engine crankcase, and a swing case extending rearward from one side of the engine crankcase. In a unit swing engine, the rear wheel is integrally supported on a protruding rear axle, the front lower part of the crankcase is pivotally supported on the frame, and a rear cushion unit is interposed between the rear upper surface of the swing case and the upper rear frame. The end of the rear axle on the opposite side of the swing case is pivotally supported by a bearing bracket connected to the crankcase on the same side by a torque link, and another rear cushion unit is interposed between this bearing bracket and the rear frame. The rear cushion unit has a configuration in which the pivot part with the rear frame, the pivot part with the bearing bracket, and the axis joint part with the bearing bracket and rear axle are all located on the same vertical plane orthogonal to the rear axle. be.

(Function) With this configuration, the bearing bracket, the support part of the rear cushion unit, and the rear axle shaft support are on the same vertical plane, and the overhang is 0 and the bearing part is not twisted, improving durability. do.

Instead of the swing arm type, which tends to be large, we have adopted a structure with a cast bearing bracket and a torque link to prevent rotation, making it more compact and making it easier to shape the torque link to avoid interference with the muffler. Muffler capacity can be expanded.

Also, it is easy to attach the muffler and rear fender to the bearing bracket.

(Example) DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings showing embodiments of the present invention will be explained below.

The configuration of the engine 1, crankcase 2, swing case 3, rear wheel 4, frame 5, rear frame 5a, rear cushion unit 6, etc. remains unchanged.

A rear axle 10 protruding from the inside of the swing case 3 extends roughly beyond the rear wheel 4. A bearing bracket 12 formed around a bearing 11 is disposed at the tip of the rear axle 10, and the rear axle 10 is pivotally supported by the bearing 11. do.

A lower end of a rear cushion unit 13 is pivotally supported above the bearing 11, and an upper end thereof is pivotally supported on the rear frame 5a. In this case, the rear axle 10 supporting bearing 11 and the upper and lower pivot parts 13a and 13b of the rear cushion unit 13 are all arranged on the same vertical plane orthogonal to the rear axle 10.

The tail end of a torque link 14 is connected to the front upper part of the bearing bracket 12, and the front end of the torque link 14 is connected to the opposite crankcase 2a to firmly hold the bearing bracket 12 so that it does not rotate. The center portion of this torque link 14 is curved toward the rear wheel 4.

Further, the bearing bracket 12 holds the rear fender 15 and also holds the muffler 16.

The muffler 16 is recessed at the center to avoid interference with the bearing bracket 12, but since the torque link 14 is curved at the front and there is a space at the rear, it bulges inward to meet the required volume ω. are sufficiently secured.

FIG. 4 is an enlarged view of the bearing bracket 12, and the axis of the bearing 11 is the vertical pivot portion 13a of the rear cushion unit 13.
, 13b, it is shown that it extends slightly ahead of the line xx connecting the axes of 13b.

When the rear cushion units 13 and 6 work and the rear wheel 4 swings up and down, the line X-X is displaced, but even at its layer pressure, the line X-x is in front of the axis of the bearing 11. It is set so that it does not appear.

〔Effect of the invention〕

As described above, the rear wheel suspension system for a motorcycle according to the present invention includes a swing case extending rearward from one side of the engine crankcase, and the rear wheel is pivoted on the rear axle that protrudes inward from the rear end of the swing case. In a unit swing engine, the front lower part of the crankcase is pivotally supported to the frame, and a rear cushion unit is interposed between the upper rear surface of the swing case and the upper rear frame. , is rotatably supported by a bearing bracket connected to the crankcase on the same side by a torque link, and another rear cushion unit is interposed between this bearing bracket and the rear frame, and the rear cushion unit and the rear frame are connected to each other. The pivot part, the pivot part with the bearing bracket, and the axial joint part between the bearing bracket and the rear axle are all set to be located on the same vertical plane perpendicular to the rear axle. It is located on the surface and does not twist, increasing the durability of the bearing and ensuring sufficient muffler capacity, which has the effect of improving engine performance.

[Brief explanation of the drawing]

FIG. 1 is a left side view of a rear wheel suspension system for a motorcycle showing an embodiment of the present invention, FIG. 2 is a rear view of the rear wheel suspension system,
Figure 3 is a plan view of the rear wheel suspension system, Figure 4 is an enlarged left side view of the bearing bracket, Figure 5 is a left side view of the conventional rear wheel suspension system, and Figure 6 is the same as Figure 5. FIG. 7 is a right side view showing an example of a motorcycle equipped with a unit swing type engine. 1...Engine, 2...Crankcase, 3...
Swing case, 4... Rear wheel, 5... Frame, 5
a... Rear frame, 6... Rear cushion unit, 10... Rear axle, 11... Bearing, 12...
...Bearing bracket, 13...Rear cushion unit, 13a. 13b... Pivotal portion, 14... Torque link. Figure 2 Figure 6

Claims (1)

[Claims] A swing case extending rearward from one side of the engine crankcase is connected, and the rear wheel is pivotally supported and integrated with the rear axle that protrudes inside the rear end of the swing case, and the front lower part of the crankcase is pivoted to the frame and swings. In a unit swing engine with a rear cushion unit interposed between the rear upper surface of the case and the upper rear frame, the rear axle end on the opposite side of the swing case is pivotally supported on a bearing bracket connected to the crankcase on the same side with a torque link. , another rear cushion unit is interposed between this bearing bracket and the rear frame, and the rear cushion unit is pivoted with the rear frame, with the bearing bracket, and with the bearing bracket and the rear axle. The automatic 2 is characterized in that the parts are all located on the same vertical plane perpendicular to the rear axle.
Rear wheel suspension system for wheeled vehicles.