JPH04274987A - Fitting construction of rear swing arm for vehicle - Google Patents

Abstract

PURPOSE:To prevent generation of a large space between the front end part of a rear swing arm and a bracket by pinching the front end part of a rear swing arm between the inside member of a nut and a bracket on the opposite side, and pushing and fixing the outer circumferential face of the outside member of the nut to the inner circumferential face of a fitting hole. CONSTITUTION:When a pivot shaft 13 is screwed in, the inside member 39 of a nut 37 is drawn toward the end face of the pivot pipe 12 of a rear swing arm 9, and pressed on the end face of the pivot pipe 12 through the flange part 19b of a bush 18b. When fixing bolts 44 are tightened, an outside member 40 of same length to fitting holes 15b is enlarged in diameter to be pressed on the inner circumferential face of the fitting hole 15b, and the nut 37 is fixed to a swing arm bracket 8b. In this way, generation of a large space between the end face of the pivot pipe 12 and the swing arm bracket 8b can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for attaching a rear swing arm of a vehicle such as a motorcycle to a frame.

0002

2. Description of the Related Art A rear swing arm that supports a rear wheel of a motorcycle has its front end rotatably supported by a bracket of a frame. This frame has a pair of left and right brackets, and the front end of the rear swing arm is interposed between these brackets. A pivot shaft passing through the front end of the rear swing arm is installed between the brackets, and a nut is screwed into one end of the pivot shaft. Therefore, as the nut is screwed in, the front end of the rear swing arm is inserted between the brackets, and the rear swing arm is positioned in the left-right direction with respect to the frame.

By the way, the dimensional tolerances of these brackets and the rear swing arm act between the bracket of the frame and the front end of the rear swing arm, so even when the nut is tightened, the bracket and the rear swing arm do not fit together. There may be a gap between the front end of the Moreover, this gap has different dimensions depending on the product, so
If a collar is simply interposed between the bracket and the front end of the rear swing arm to fill the gap, the gap cannot be completely absorbed, and many types of collars must be prepared.

[0004] For this reason, conventionally, the
89, an adjustment collar whose length can be adjusted in the axial direction of the pivot shaft is interposed between the frame bracket and the front end of the rear swing arm, and the length of this adjustment collar can be varied in a variety of ways. A configuration is disclosed that can be freely changed depending on the size of the gap. This adjustment collar is composed of a first screw member attached to the outer periphery of the pivot shaft, and a second screw member screwed into the outer periphery of the first screw member. By changing the relative screwing amount of the second screw member, it is possible to expand and contract in the axial direction. In this adjustment collar, one end surface of the first threaded member is in contact with the bearing at the front end of the rear swing arm, and one end surface of the second threaded member is in contact with the bracket. Two screw members fill the gap between the bracket and the front end of the rear swing arm.

[0005]

However, according to this conventional configuration, both the first and second screw members are tubular with a thin wall, so that the outer diameter of the entire adjustment collar is smaller than that of the rear swing arm. It is much smaller than the outer diameter of the front end. Therefore, if the gap is particularly large, a ring-shaped space is formed on the outer circumference of the adjustment collar, which is surrounded by the outer peripheral surface of the adjustment collar, the front end of the rear swing arm, and the bracket. Therefore, the end face of the front end of the rear arm cannot be received over a wide area, and the space becomes an obstacle to increasing the rigidity of the attachment portion of the rear swing arm.

The present invention was developed based on the above circumstances, and it is possible to prevent a large space from being created between the front end of the rear swing arm and the bracket, and to increase the mounting rigidity of the rear swing arm. The purpose of the present invention is to provide a mounting structure for a rear swing arm in a vehicle that can be used.

[0007]

[Means for Solving the Problems] Accordingly, in the present invention, the front end of a rear swing arm extending behind the bracket is interposed between a pair of left and right brackets, and the front end of this rear swing arm is pivoted. A pivot shaft passing through the rear swing arm so as to be rotatable in a circumferential direction is spanned between the brackets, and one end of the pivot shaft is tightened with a nut, so that the front end of the rear swing arm is sandwiched between the brackets. In a vehicle, the nut is composed of an inner member into which the pivot shaft is screwed, and a cylindrical outer member that is slidably fitted on the outside of the inner member, and the mutual contact surface between the inner member and the outer member. is an inclined surface that is inclined radially outward as it approaches the front end of the rear swing arm, so that one end of the inner member on the rear swing arm side is formed to have a large diameter, and the inner member The outer members are connected to each other via a plurality of bolts extending in the axial direction of the pivot shaft passing through the inclined surface, and the large diameter end of the inner member is provided with:
A pressing surface is formed between the one bracket and the front end of the rear swing arm, and a slot is formed in the outer member that opens on its outer circumferential surface and on the inner circumferential surface that contacts the inner member. The outer member is configured to be expandable in the radial direction, and the bolt is tightened with the front end of the rear swing arm being sandwiched between the pressing surface of the inner member and one of the brackets. By sliding the outer member in the axial direction, the diameter of the outer member is expanded radially outward along the slope of the inclined surface, and the other bracket located on the nut side is It is characterized in that a fitting hole into which the member fits is formed, and the outer circumferential surface of the expanded outer member is pressed against the inner circumferential surface of the fitting hole and fixed.

[0008]

[Operation] In this configuration, when the nut is fitted into the fitting hole of the bracket and the pivot shaft passing through the front end of the rear swing arm is screwed into the inner member, the pressing surface of the inner member and one bracket The front end of the rear swing arm is inserted between the two from the left and right. When the bolt is tightened in this state, the outer member of the nut slides along the outer peripheral surface of the inner member in a direction toward the rear swing arm. At this time, the mutual contact surfaces of the inner member and the outer member form an inclined surface that expands radially outward as it approaches the rear swing arm.
The outer member is sequentially expanded as the bolts are tightened, and the outer peripheral surface of the outer member is pressed against the inner surface of the fitting hole. As a result, the nut is immovably fixed to the bracket, and the front end of the rear swing arm is firmly clamped between one of the brackets and the inner member of the nut.

Therefore, according to the above structure, since the pressing surface of the inner member of the nut sandwiches the front end of the rear swing arm between the bracket and the front end of the rear swing arm, a large space is created between the front end of the rear swing arm and the bolt. will not occur,
The front end of the rear swing arm can be received over a wider area than in the past.

Furthermore, since the outer circumferential surface of the outer member contacts the inner circumferential surface of the fitting hole, the contact area between the nut and the bracket is also increased compared to the prior art. Therefore, the mounting strength of the nut is improved, the front end of the rear swing arm can be received over a wide area, and the front end of the rear swing arm can be firmly tightened in the axial direction of the pivot shaft.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a motorcycle.

In FIG. 6, the frame designated by numeral 1 is
A steering head pipe 2 is provided at its front end. The front fork 3 is attached to the steering head pipe 2.
is pivotally supported, and a front wheel 4 is supported at the lower end of the front fork 3. A pair of left and right main pipes 5 extending rearward and diagonally downward are connected to the steering head pipe 2. A down tube 6 extending downward is connected to the front lower surface of the main pipe 5, and an engine 7 is mounted between the down tube 6 and the main pipe 5.

A pair of left and right swing arm brackets 8a and 8b extending downward are connected to the rear end of the main pipe 5. Swing arm bracket 8a, 8b
is formed into a thin box shape with a predetermined wall thickness, and a rear swing arm 9 is swingably supported on these swing arm brackets 8a and 8b. The rear swing arm 9 includes a pair of left and right arm members 10 extending toward the rear of the swing arm brackets 8a and 8b. A rear wheel 11 is supported at the rear end portions of these arm members 10. As shown in FIG. 1, the front ends of the arm members 10 are connected by a pivot pipe 12 made of a round pipe. The pivot pipe 12 is located at the front end of the rear swing arm 9, and is interposed between the swing arm brackets 8a and 8b. And this pivot pipe 12 is
It is rotatably supported by swing arm brackets 8a and 8b via a hollow pivot shaft 13, and this pivot structure will be described in detail below.

That is, as shown in FIG. 1, the swing arm brackets 8a, 8b have the pivot shaft 1.
Fitting holes 15a and 15b having a diameter larger than 3 are formed. The fitting holes 15a, 15b are coaxially located, and are opened on the outer and inner surfaces of the swing arm brackets 8a, 8b. The fitting hole 15a located on the right side in the direction of movement of the motorcycle is
The diameter of the swing arm bracket 8a decreases from the outer surface to the inner surface, and the inner circumferential surface of the fitting hole 15a forms a conically inclined surface 16. On the other hand, the fitting hole 15b located on the right side in the direction of movement is formed to have a constant diameter, and the inner circumferential surface of the fitting hole 15b is
It is parallel to the axis X1 of 5a and 15b.

The pivot shaft 13 passes through the pivot pipe 12 from the fitting hole 15a of the left swing arm bracket 8a, and is guided to the fitting hole 15b of the right swing arm bracket 8b. This pivot pipe 12
Needle bearings 17a and 17b that rotatably receive the pivot shaft 13 are mounted on both left and right ends of the shaft. Left and right bushes 18a, 18b are interposed between the needle bearings 17a, 17b and the pivot shaft 13. The bushes 18a, 18b have a thin cylindrical shape, and one ends of these bushes 18a, 18b are led out from both ends of the pivot pipe 12. These bushes 18a,
Flange portions 19a and 19b, which are integrally folded back toward the outside in the radial direction of the pivot shaft 13, are formed at the leading end of the pivot shaft 18b. Flange portion 19a of left bush 18a
is formed to have a larger diameter than the pivot pipe 12, and is in contact with the inner surface of the left swing arm bracket 8a. A thrust bearing 20 is interposed between the flange portion 19a and the pivot pipe 12. This thrust bearing 20 includes a dust cover 21 that extends between the outer peripheral edge of the flange portion 19a and the left opening edge of the pivot pipe 12.
covered by.

[0016] Also, the flange portion 1 of the right bushing 18b
9b is formed to have a slightly smaller diameter than the pivot pipe 12, and a thrust bearing 22 is interposed between the flange portion 19b and the pivot pipe 12. This thrust bearing 22 is covered by a dust cover 23 that spans between the outer peripheral edge of the flange portion 19b and the right opening edge of the pivot pipe 12.

A cylindrical spacer 24 is attached to the outer periphery of the pivot shaft 13 to keep the distance between the bushes 18a and 18b constant, and both ends of this spacer 24 are
It is in contact with the bushes 18a and 18b.

A collar 26 is fitted into the left fitting hole 15a so as to be rotatable around the axis. The outer peripheral surface of the collar 26 is inclined along the inclined surface 16 of the fitting hole 15a, and the collar 26 itself has a truncated cone shape. The collar 26 has a shaft hole 2 through which the pivot shaft 13 is inserted.
7 is formed. The shaft hole 27 is provided at a position offset from the center of the collar 26.
The axis X2 of the fitting hole 15a is eccentric with respect to the axis X1 of the fitting hole 15a. The outer surface of the collar 26 is substantially flush with the outer surface of the swing arm bracket 8a, and the outer surface of the collar 26 has a recess for accommodating the large diameter head 13a at one end of the pivot shaft 13. 28 is formed.

In the case of this embodiment, FIGS. 4 and 5
As shown in , arcuate positioning recesses 29 are formed at four locations on the outer peripheral surface of the collar 26 at equal intervals in the circumferential direction, and these four positioning recesses 29 are
A continuous opening is provided on the outer surface of the collar 26. A fitting recess 30 that faces one of the positioning recesses 29 is formed on the inner circumferential surface of the fitting hole 15 a that is in contact with the outer circumferential surface of the collar 26 . The fitting recess 30 is continuously opened on the outer surface of the swing arm bracket 8a, and
When facing the positioning recess 29, a circular bolt hole 31 is formed. In addition, the fitting recess 30
A screw hole 32 is formed in the bottom surface. Screw hole 32
A fixing bolt 33 made of a socket bolt is screwed into the fixing bolt 33, and a head 33a of the fixing bolt 33 is fitted into the bolt hole 31. Therefore, fixing bolt 3
A part of the head 33a of the collar 26 is located in the positioning recess 2 of the collar 26.
9 and prevents the collar 26 from rotating. This determines the insertion position of the pivot shaft 13 within the fitting hole 15a, and prevents the collar 26 from falling off from the fitting hole 15a.

By the way, as shown in FIG. 1, a threaded portion 36 is formed at the right end portion of the pivot shaft 13. A nut 37 is screwed into the threaded portion 36. This nut 37 is fitted into the fitting hole 15b on the right side so as to be rotatable in the direction around the axis. The nut 37 includes an inner member 39 having a screw hole 38 into which the threaded portion 36 is screwed, and a cylindrical member that coaxially and slidably overlaps the outer periphery of the inner member 39 and fits into the right fitting hole 15b. The overall length of the outer member 40 is approximately equal to the axial length of the fitting hole 15b. Inner member 3
The screw hole 38 of No. 9 is provided at a position offset from the center of the inner member 39, and the axis X3 of this screw hole 38
is eccentric with respect to the axis X1 of the fitting hole 15b. The eccentricity of the screw hole 38 matches the eccentricity of the shaft hole 27, and the screw hole 38 and the shaft hole 27 are located coaxially. The mutual contact surfaces of the inner member 39 and the outer member 40 form an inclined surface 41 that is inclined so as to expand radially outward as it approaches the pivot pipe 12. For this reason, the inner member 39 is formed in the shape of a truncated cone with a larger diameter on the side facing the pivot pipe 12.

The large diameter end surface of the inner member 39 facing the pivot pipe 12 forms a flat pressing surface 42 . The pressing surface 42 is formed to have a larger diameter than the pivot pipe 12, and when the pivot shaft 13 is screwed into the inner member 39 of the nut 37, the pressing surface 42 is in contact with the flange portion 19b of the bushing 18b. Furthermore, a slot 43 is formed in the outer member 40, as shown in FIG. The slots 43 are open to the outer peripheral surface and the inner peripheral surface of the outer member 40, and the presence of the slots 43 allows the outer member 40 to expand in the radial direction.

The inner member 39 and the outer member 40 are connected by four fixing bolts 44 made of socket bolts. The fixing bolt 44 is parallel to the pivot shaft 13, and extends from the outer surface of the outer member 40 to the inclined surface 41.
After passing through the inner member 39, it is screwed into the inner member 39. These four fixing bolts 44 are arranged at equal intervals in the circumferential direction of the nut 37.
The arrangement interval of the positioning recesses 29 is equal to the arrangement interval of the positioning recesses 29. The outer surface of the outer member 40 is connected to the inner member 3
The outer member 40 is provided with a four-piece housing which accommodates the head 44a of the fixing bolt 44 on the outer surface of the outer member 40. Two depressions 45 are formed. These recesses 45 are also continuously opened on the outer circumferential surface of the outer member 40, and the fitting holes 15b are in contact with the outer circumferential surface of the outer member 40.
An engaging recess 46 is formed on the inner circumferential surface of the recess 46 to face any one of the four recesses 45 . The engagement recess 46 is also continuously opened on the outer surface of the swing arm bracket 8b, and is formed at a position corresponding to the engagement recess 30 of the left swing arm bracket 8a.

A ring-shaped anti-rotation member 48 is fitted into one of the four depressions 45, and is fastened together with the fixing bolt 44. A portion of the outer circumferential surface of the detent member 48 enters the engagement recess 46 and engages the nut 37.
This prevents the fitting hole 15b from rotating.
The insertion position of the pivot shaft 13 within is determined. Next, a procedure for assembling the rear swing arm 9 between the swing arm brackets 8a and 8b will be explained.

First, swing arm brackets 8a, 8
A collar 26 and a nut 3 are inserted into the fitting holes 15a and 15b of b.
7. Then, the positioning recess 29 of the collar 26
The collar 26 is prevented from falling off and rotated by aligning one of the collars 26 with the fitting recess 30 and screwing the fixing bolt 33 into the screw hole 32 of the fitting recess 30. Similarly, on the nut 37 side, align one of the recesses 45 of the outer member 40 with the engagement recess 46, tighten the fixing bolt 44 in this state, and move the detent member 48 into the engagement recess 46.
By engaging with the nut 37, the nut 37 is prevented from rotating. This allows the shaft hole 27 of the collar 26 and the nut 37 to
The screw holes 38 are aligned on the same straight line, and the insertion position of the pivot shaft 13 is determined.

Next, the pivot pipe 12 at the front end of the rear swing arm 9 is attached to the swing arm bracket 8a,
8b, and the pivot shaft 13 is inserted from the left fitting hole 15a side. Then, this pivot shaft 13 is passed through the pivot pipe 12 and screwed into the threaded hole 38 of the nut 37 on the opposite side. Then, the nut 37 is inserted into the fitting hole 1.
5b and is pulled toward the pivot pipe 12, the pressing surface 42 of the inner member 39 comes into contact with the flange portion 19b of the right bushing 18b, and the flange portion 19a of the left bushing 18a contacts the swing arm bracket. It comes into contact with the inner surface of 8a. Therefore, the pivot pipe 12 is temporarily fixed in a state where it is inserted between the inner member 39 of the nut 37 and the swing arm bracket 8a via the flange portions 19a and 19b.

Subsequently, the four fixing bolts 44 of the nut 37 are tightened. By this tightening, the outer member 40
is pushed toward the pivot pipe 12, so the outer member 40 is slid on the outer periphery of the inner member 39 in a direction toward the pivot pipe 12. In this case, the mutual contact surfaces of the inner member 39 and the outer member 40 form an inclined surface 41 that is inclined so as to expand toward the pivot pipe 12 side. The outer member 40 is sequentially expanded along the inclination, and the outer circumferential surface of the outer member 40 is pressed against the inner circumferential surface of the fitting hole 15b. As a result, the nut 37 is fixed to the swing arm bracket 8b according to the entire length of the pivot pipe 12.

Finally, the pivot shaft 13 is screwed into the threaded hole 38 of the nut 37 again, and the collar 26 is pressed by the head 13a of the pivot shaft 13. Then color 2
Since the mutual contact surface between 6 and the fitting hole 15a forms a tapered inclined surface 16, the collar 26 bites into the fitting hole 15a, and the pivot shaft 13 is tightened and fixed in the axial direction. be done.

According to this embodiment of the present invention, as the pivot shaft 13 is screwed in, the inner member 39 of the nut 37 is drawn toward the end surface of the pivot pipe 12 of the rear swing arm 9, and the bush 18b Since the end face of the pivot pipe 12 is pressed through the flange portion 19b, it is possible to prevent a large space from being created between the end face of the pivot pipe 12 and the swing arm bracket 8b.

Moreover, the pressing surface 42 of the inner member 39 that presses the pivot pipe 12 has a larger diameter than the pivot pipe 12, and the flange portion 19b interposed between the pressing surface 42 and the pivot pipe 12 also has a diameter larger than that of the pivot pipe 12. , having substantially the same diameter as the pivot pipe 12, the front end of the pivot pipe 12 can be received over a wider area than in the past.

Furthermore, when the fixing bolt 44 is tightened, the diameter of the outer member 40 having the same length as the fitting hole 15b is expanded.
The nut 37 is pressed against the inner peripheral surface of this fitting hole 15b.
is fixed to the swing arm bracket 8b, so the swing arm bracket 8b and the nut 37 are fixed to the swing arm bracket 8b.
This will also increase the contact area with.

Therefore, the mounting strength of the nut 37 is improved, a large space is not created between the end face of the pivot pipe 12 and the swing arm bracket 8b, and the front end of the rear swing arm 9 is attached to the swing arm bracket. 8a and 8b can be firmly tightened, and the rigidity of the attachment portion of this rear swing arm 9 can be increased.

Further, in the case of this embodiment, the shaft hole 27 of the collar 26 and the screw hole 38 of the nut 37 are eccentric with respect to the fitting holes 15a, 15b of the swing arm brackets 8a, 8b. The position of the nut 37 in the fitting holes 15a, 15b can be changed in four steps in the circumferential direction by the fixing bolt 33 and the anti-rotation member 48, so that the insertion position of the pivot shaft 13 can be changed. It can be changed at four locations inside the fitting holes 15a and 15b: front and back, and top and bottom.

Therefore, there is an advantage that the wheel base between the front wheels 4 and the rear wheels 11 and the position of the engine 7 can be freely changed according to the driver's preference or the course conditions of the circuit. Note that the vehicle according to the present invention is not limited to a motorcycle, but can be similarly applied to a four-wheeled vehicle having two rear wheels, for example.

[0034]

According to the present invention described in detail above, the front end of the rear swing arm is sandwiched between the inner member of the nut and the bracket on the opposite side, so that there is a gap between the rear swing arm and the nut. There is no need for a large space, and the front end of the rear swing arm can be received over a large area.

Furthermore, since the nut is fixed to the bracket by pressing the outer circumferential surface of the outer member of the nut against the inner circumferential surface of the fitting hole, the contact area between the nut and the bracket also increases. Improves nut installation strength. Therefore, in addition to being able to receive the front end of the rear swing arm over a wide area, the front end of the rear swing arm can be firmly tightened in the axial direction of the pivot shaft, increasing the rigidity of the attachment part of the rear swing arm. can be increased.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the attachment part of the rear swing arm.

FIG. 2 is a sectional view taken along line A-A in FIG. 3;

3 is a side view of the attachment portion of the rear swing arm as seen from the direction of line B in FIG. 1. FIG.

FIG. 4 is a sectional view taken along line CC in FIG. 5;

5 is a side view of the attachment portion of the rear swing arm as seen from the direction of line D in FIG. 1. FIG.

FIG. 6 is a side view of the motorcycle.

[Explanation of symbols]

8a, 8b...bracket (single arm bracket),
9... Rear swing arm, 12... Front end (pivot pipe), 13... Pivot shaft, 15b... Fitting hole, 37... Nut, 39... Inner member, 40... Outer member, 41... Inclined surface,
42...Press surface, 43...Slot, 44...Bolt (fixing bolt).

Claims (1)

[Claims] Claim 1: A front end of a rear swing arm extending behind the bracket is interposed between a pair of left and right brackets, and a pivot shaft passes through the front end of the rear swing arm so as to be rotatable around the axis. In a vehicle in which the front end of the rear swing arm is inserted between the brackets by extending the front end of the rear swing arm between the brackets and tightening one end of the pivot shaft with a nut, the nut is screwed into the pivot shaft. and a cylindrical outer member that is slidably fitted on the outside of the inner member, and the mutual contact surface of the inner member and the outer member is brought close to the front end of the rear swing arm. Accordingly, one end of the inner member on the rear swing arm side is formed to have a large diameter by forming an inclined surface inclined radially outward, and the inner member and the outer member are connected by penetrating the inclined surface. The inner member is connected to each other via a plurality of bolts extending in the axial direction of the pivot shaft, and a pressing surface is formed at one large diameter end of the inner member to sandwich the front end of the rear swing arm between the inner member and the one bracket. On the other hand, the outer member is configured to have slots that open on its outer circumferential surface and on its inner circumferential surface in contact with the inner member, so that the outer member can be expanded in the radial direction, and the pressing surface of the inner member With the front end of the rear swing arm sandwiched between the front end of the rear swing arm and one of the brackets, tighten the bolt to slide the outer member in the axial direction and move the outer member to the slope of the inclined surface. The other bracket located on the nut side is formed with a fitting hole into which the outer member of the nut fits,
A structure for mounting a rear swing arm in a vehicle, characterized in that the outer circumferential surface of the expanded outer member is pressed and fixed to the inner circumferential surface of the fitting hole.