JPS6021116B2 - Rear arm mounting structure for motorcycles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the mounting structure of a rear arm in a motorcycle.

-In general, the engine supported by the body frame and the rear arm swingably attached to the body frame must be attached to the body frame using a considerably strong attachment point due to weight and reaction force of the rear wheels. Must be.

Therefore, it is advantageous to integrally attach the engine and rear arm to the vehicle body to reduce the number of attachment parts. For this reason, both the left and right pivot shaft mounting parts at the front end of the rear arm are placed close to both brackets provided on both sides of the frames that make up the vehicle body, and the collars inserted into these two pivot shaft mounting parts are then attached to both pivot shaft crests. With the rear end of the engine disposed between them, both brackets, both pivot shaft mounting portions, and a pivot shaft passing through the rear end of the engine are connected together to both brackets, and these two brackets are connected to each other through the pivot shaft. Therefore, it is conceivable to support the rear end of the engine and to mount the front end of the rear arm so as to be swingable. However, with this motorcycle, when the pivot shaft is pulled out to remove the engine for maintenance,
The rear arms separate from the frames on both sides along with the engine, which is extremely inconvenient for maintenance. The present invention has been made to eliminate the above-mentioned disadvantages and improve maintainability in this type of motorcycle, and the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a motorcycle body to which an engine and a rear arm are attached according to the present invention.

This vehicle body 10 is composed of a diamond-shaped frame, and the front end of a crankcase 21 of an engine 20 is attached to a bracket 1 1 1 provided at the lower end of a down tube 11, and a pair of left and right frames fixed to a main pipe 12 are attached. Brackets 131 (131a, 131) provided at the lower part of the seat pillar tube 13 (13a, 13b)
b) The rear of the crankcase 21 is attached to the engine 20, thereby assembling the engine 20 into the vehicle body.
On the other hand, the rear arm 30' has a triangular shape on its side, and a pair of lower pipes 31 (31a, 31b) on the left and right sides thereof.
Bracket 131 of seat pillar tube 13 at the front end of
Furthermore, the upper ends of the pair of left and right upper pipes 32 are swingably attached to cushion units 14 attached to the main pipe 12, respectively. Therefore, the rear end of the crankcase 21 and the front end of the IJ arm 30 are connected to the second
As shown in the figure and FIG. 3, it is integrally attached to the bracket 131 of the seat pillar tube 13 via the pivot shaft 40, and is attached to the rear end of the crankcase 21.
An insertion hole 211 through which the pivot ball 40 can be inserted is provided.

Further, the pair of left and right lower pipes 31 of the rear arm 30 have bushes 331 (331a, 331
b) A cylindrical pivot shaft attachment device 33 having an inner diameter through which a collar 332 (332a, 332b) can be inserted.
(33a, 33b) are welded. Note that the inner peripheral surface of the bush 331 has a spiral groove 334 (33
4a, 334b) are engraved. On the other hand, the pivot shaft 4 is attached to the bracket 131 of the seat pillar tube 13.
An insertion hole 132 (132a132b) through which a 0 can be inserted is provided. Of these brackets 131, a reinforcing plate 134b having an insertion hole through which the pivot shaft 40 can be inserted is welded to the outside of the left side bracket 131a, and a left side pivot shaft is attached to the inside surface of the left side bracket 131a on the outside of the reinforcement plate 134b. A bolt 51 insertion hole is provided for detachably attaching a plate 50 that supports the portion 33a via the collar 332a independently of the pivot shaft 40.
This plate 5 is provided with an inner hole 52 for supporting the outer peripheral surface of the protruding end of the collar 332a. Furthermore, a reinforcing plate 134b having an insertion hole through which the pivot shaft 40 can be inserted is welded to the inner surface of the right side bracket 131b. In addition, in FIG. 3, the reference numeral 34 indicates a reinforcing pipe for the rear arm 30, the reference numeral 61 indicates a sprocket fixed to the output shaft of the transmission, and the reference numeral 62 indicates a drive chain guide suspended between the sprocket 61 and the sprocket assembled to the rear wheel axle. Reference numeral 63 is a kick rank. By the way, rear arm 3
0 and the rear end of the crankcase 21 to the bracket 131 of the seat pillar tube 13, first, the collar 332 is fitted to the pivot shaft mounting portion 33 of the rear arm 30 via the bush 331.

That is, in the left pivot shaft mounting portion 33a, a collar 332a is inserted into a bush 331a which is iron-bonded from the inside, and one end of the collar 332a is made to protrude.
The inner end of the collar 33a is closed with a push cover 333a having an insertion hole for the pivot shaft 40, and the annular opening at the outer end thereof is closed with a sealing member to form a lubricating oil storage part. The inner hole 52 of the plate 50 is iron-fitted to the outer peripheral surface. In addition, the right pivot shaft mounting part 3
In 3b, bush 331 arrived from both sides.
The collar 332b is iron-inserted into the collar 331b, and shims 335 are installed at both ends of the collar 332b to adjust and position the right pivot shaft mounting portion 33b in the direction of the pivot shaft 40.
Further, both ends of the right pivot shaft mounting portion 33b are closed with bush covers 333b, 333b to form a lubricating oil storage portion between the bushes 331b, 331b. Next, the left and right pivot shaft attachment portions 33 are arranged to face the left and right brackets 131 of the seat pillar tube 13, and the rear end of the crankcase 21 is placed so that its insertion hole 211 faces the pivot shaft attachment portion 33. the insertion hole 1 from the outside of the right side bracket 131b.
Insert the pivot shaft 40 through 32b. As a result, the rear end of the crankcase 21 and the pivot shaft mounting portion 33 are held by the bracket 131. Thereafter, the plate 50 fitted onto the outer peripheral surface of the protruding end of the left collar 332a is attached to the inner surface of the left bracket 131a with bolts 51 regardless of the pivot bracket, and the nut 41 is screwed onto the left protrusion of the pivot shaft 40. and fix it. As a result, the front end of the rear arm 30 is swingably attached to the bracket 131 via the pivot shaft 40, and the rear end of the crankcase o 21 is supported, and the left pivot shaft mounting portion 33a of the rear arm 30 is attached to the collar 332a. It is supported by the inner hole 52 of the plate 50 attached to the left side bracket 131a. When the rear end of the crankcase 21 supported in this manner is to be removed from the bracket 131 of the seat pillar tube 13 for maintenance of the engine 20, the nut 41 screwed onto the protruding end of the pivot shaft 40 is removed and pulled out. Its left end is clipped into collar 332b.

This allows the rear end of the crankcase 21 to be attached to the bracket 1.
It is removed from 31. By the way, in this state, the right pivot shaft mounting portion 33b is held by the right bracket 131b from the pivot shaft 4, and the left pivot shaft mounting portion 33a is connected to the inner hole 52 of the plate 50 via the outer peripheral surface of the protruding end of the collar 332a. It is supported by the department. Therefore, even when the crankcase 21 is removed, the pivot shaft mounting portion 33 is held by the bracket, and the front end of the rear arm 30 does not come off the seat pillar tube 13. It has been removed from the pillar tube 13, and if necessary, the plate 50 can be removed from the left bracket 131a and the pivot shaft 40 can be completely pulled out. In the above embodiment, the plate 50 is attached to the left side bracket 131a.
Although the plate 50 is removably attached to the inner surface of the right bracket 131b and only the left pivot shaft mounting portion 33a is supported via the collar 332a, the plate 50 is also removably attached to the inner surface of the right bracket 131b to support both left and right sides. Pivot shaft mounting part 3
3 may be modified to be supported by collars 332a, 332b.

In this case, even if the pivot shaft 40 is completely pulled out, the front end of the 1' arm 30 will not reach the seat pillar tube 1.
There will be no departure from 3. In summary, in the present invention, in the above-mentioned various motorcycles, a plate having an inner hole is removably attached to at least one of the inner surfaces of the brackets, and the inner hole is attached to the inner surface of at least one of the brackets. The structure is characterized by supporting the outer peripheral surface of at least one protruding end of the collar, which is fitted with iron into both the pivot shaft mounting parts, so that even if the engine is removed, The front end of the rear arm does not come off from both the brackets, and maintainability of the motorcycle can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an example of the body of a motorcycle implementing the present invention, FIG. 2 is an enlarged side view of the main part of FIG. 1, and FIG. It is an enlarged view of a line cross section.

Explanation of symbols 10... Vehicle body, 11... Down tube, 13... (13a, 13b)... Seat pillar tube, 131 (131a, 131b)... Bracket, 20...
Engine, 21... Crank case 30... Rear arm joint 31 (31a, 31b)... Lower pipe, 33 (33
a, 33b) Pivot shaft mounting part, 332 (332a, 3
32b)... Collar, 40... Pivot shaft, 50... Plate, 52... Inner hole.

figure ship Figure 2 Figure 3

Claims (1)

[Claims] 1 Place both the left and right pivot shaft attachment parts at the front end of the rear arm close to both brackets provided on both sides of the frames that make up the vehicle body, and insert the collars fitted into these two pivot shaft attachment parts between these two pivot shaft attachment parts. together with the rear end of the engine disposed in the rear end of the engine, the two brackets, the two pivot shaft mounting portions, and the pivot shaft penetrating the rear end of the engine are jointly fastened to the two brackets, and the two brackets are connected to each other via the pivot shaft, In the motorcycle in which the rear end of the engine is supported and the front end of the rear arm is swingably mounted, a plate having an inner hole is provided on an inner surface of at least one of the brackets, independent of the pivot shaft. A mounting structure for a rear arm, characterized in that the inner hole supports an outer circumferential surface of at least one protruding end of the collar fitted in the pivot shaft mounting portions.