JPS6019032Y2 - Motorcycle rear wheel shock absorber - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rear wheel shock absorbing device for a motorcycle that uses the torsional force of a torsion bar and the damping force of a rotary lever set damper to buffer vertical movement of the rear wheel due to road surface configuration.

Conventional rear wheel shock absorbers for general motorcycles, which absorb and dampen the vertical movement of the rear wheel due to the road surface arrangement and prevent vibrations from propagating to the vehicle body, consist of a telescoping cylindrical damper and the cylindrical damper. A shock absorber consisting of a coil spring fitted around the outer periphery of the damper was installed between the rear wheel support member and the vehicle body frame. The attached rear wheel support member and the torsion bar disposed on the vehicle body frame are connected through an operating force transmission path using a link mechanism, and a rotary lever set damper is attached to the operating force transmission path, thereby reducing torsion. To provide a rear wheel shock absorbing device for a motorcycle, which buffers the vertical movement of a rear wheel using the torsional force of a bar and the damping force of a rotary lever set damper.

The present invention was developed to further develop the above-mentioned shock absorbing device.

The purpose of this invention is to arrange the torsion bar and rotary lever set damper on the lower surface of the bottom of the body frame on which the engine is mounted, thereby allowing parts and machine height to be placed in other parts of the body frame. In addition to securing space, it also lowers the center of gravity of the vehicle.
In addition, the vehicle height of the motorcycle can be adjusted while effectively using the space at the bottom of the body frame by using a long axis-shaped torsion bar and a rotary lever-equipped damper that has a small operating stroke when generating damping force, unlike a cylindrical damper. To provide a rear wheel shock absorber for a motorcycle that can be assembled to a vehicle body frame while being kept low.

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is an overall side view of a motorcycle to which the device according to the present invention is applied, and FIG. 2 is a bottom view of the main parts of FIG. 1.

A body frame 1 of a motorcycle is formed by a main frame 2, a down tube 3, a bottom frame 4, a rear frame 5, etc., and a front fork 6 for a telescopic front wheel 'tQ is pivotally held at the front end of the body frame 1. A head pipe 7 is fixedly installed.

Further, the front end of a rear fork 9 that supports a rear wheel 8 at its rear end is pivoted to the lower rear portion of the vehicle body frame 1 so as to be able to swing up and down through a pivot shaft 10, and the rear fork 9 serves as a rear wheel support member. There is.

The engine 11 is mounted on the upper surface of the bottom frame 4 that constitutes the bottom part 1a of the vehicle body frame 1, and has shafts 12...
・The torsion bar 13 and rotary lever set damper 14 are connected to the vehicle body frame 1 by the vehicle body frame 1.
The structure of the arrangement is shown in FIG. 2.

There are two bottom frames 4 on the left and right, and two torsion bars 13.13 extend along each bottom frame 4.4 with the longitudinal direction of the vehicle body being the longitudinal direction. It is rotatably supported by brackets 15 and 16 connected to 4.

The front ends of the two torsion bars 13.13 are connected by a preload adjustment means 17, and as shown in FIG. Arm 1
8, and right-handed and left-handed screw rods 2f and 22 whose outer ends are connected to the tips of the left and right adjusting arms 18°18 with pins 19 and 20, and lock nuts 23 and 24, as well as screw rods 21 and 22. This makes the front end of the torsion bar 13 a fixed end, and when the lock nuts 23 and 24 are loosened and the cylindrical nut 25 is rotated, the adjustment arm 18 causes the torsion bar 13 to be rotated. Since the torsion bar 13 is rotated, the preload regarding the spring force of the torsion bar 13 can be changed and adjusted.

The rear end of the torsion bar 13, which is a free end as shown in FIG. Rod 2 connected at the top end
8, a link 30 having a triangular side surface whose rear end is connected to the lower end of the rod 28 by a shaft 29, and an outer end of a link arm 31 whose inner end is inserted into and engaged with the rear end serration of the torsion bar 13. and the front end of the link 30.
2, the connecting portion between the link 30 and the rod 32, and the connecting portion between the link arm 31 and the rod 32 (7) are ball joints 33 and 34, respectively.

There are two links 30, link arms 31, and rods 32 on the left and right sides like the torsion bar 13, and therefore, the operating force transmission path by the link mechanism 26 has two rows on the left and right that use the rod 28 portion as a common path; in the illustrated example, there are two rows on the left and right. Link 3
0.30 is formed as one piece joined at the rear end.

The rotary lever set tamper 14 is arranged between the left and right links 30, 30 at the rear of the torsion bar 13,
Further, the damper 14 is arranged with the axial direction of the operating shaft 35 being the vehicle width direction.

Both shaft ends of the operating shaft 35 are rotatably supported by the mounting bosses 4a, 4a of the left and right bottom frames 4, 4, and the front end bracket 14a of the damper 14 is supported by the mounting bosses 4a, 4a of the left and right bottom frames 4, 4.
The damper 14 is connected to the cross frame 36 that connects the damper 14 to the vehicle body frame 1.

The operating shaft 35 of the damper 14 and the link 30 are connected, and therefore the operating shaft 35 serves as a pivot for the link 30, and when the link 30 rotates, the operating shaft 35 also rotates together. The link 30 also serves as a rotating lever for the damper 14 with a rotating lever set.

Further, by coupling the operating shaft 35 and the link 30, the rotary lever set damper 14 is suspended or attached to the operating force transmission path which connects the torsion bar 13 and the fork 9 and has the link 30 as a constituent member. There will be.

As described above, by arranging the torsion bar 13 and the rotary lever set damper 14 on the lower surface of the bottom 1a of the vehicle body frame 1, as is clear from FIG. It is possible to obtain a large space S in the body frame 1, and it is possible to arrange necessary equipment and parts of the motorcycle, such as an air cleaner, in the space S secured in the body frame 1, and it is also possible to lower the center of gravity of the motorcycle. can.

Furthermore, since the bottom portion 1a of the body frame 1 is long in the longitudinal direction of the vehicle body, it is possible to effectively arrange the long-axis torsion bar 13 and the rotary lever set damper 14 behind the torsion bar 13. By arranging the rotary lever set damper 14 below the pivot point between the vehicle body frame 1 and the rear fork 9 through the pivot shaft 10, the pivot point is located above the bottom portion 1a of the vehicle body frame 1. Therefore, by fitting the upper part of the damper 14 between the left and right bottom frames 4° 4, the length of the damper 14 protruding downward from the bottom part 1a can be reduced, and the operating stroke is reduced by the rotation of the link 30. The rotary lever set damper 14 can be sufficiently spaced from the road surface.

In addition, since the area around the pivot joint is formed with high rigidity in order to pivotally hold the rear fork 9 on the vehicle body frame 1, the rotary lever set damper 14 is installed at a location where a large operating force is applied when damping force is generated. It is suitable as

As shown in FIG. 3, which is a sectional view taken along the line 3-3 in FIG.
b is fitted between the left and right bottom frames 4, 4 and protrudes downward, and recesses 11c, 1 are formed on the left and right side surfaces of the lower portions 11b of the left and right torsion bars 13.13.
1 d and is assembled to the bottom frames 4, 4, the amount of downward protrusion of the torsion bar 13 from the bottom part 1a of the vehicle body frame 1 can be reduced, and therefore the downward protruding length of the rotary lever set damper 14 can be reduced as described above. Although the damper 14 of the torsion bar 13 is arranged on the bottom portion 1a, there is no need to increase the vehicle height of the motorcycle, and the height can be kept low.

The rotary lever damper 14 can be of any type, such as a piston type or a vane type, and FIG. 5 shows the internal structure of the damper 14 used in this embodiment.

The interior of the damper case 38 filled with hydraulic oil is divided by a vertical wall 39 into left and right damping force generating chambers S1 and a piston chamber S2, and the piston chamber S2 is further divided by a horizontal wall 40'' into S3. S
, and is divided into chamber S1 and chamber S3. S4 is the through hole 39a,
39b.

The actuating shaft 35 passes through the rear part of the piston r2, and the actuating shaft 35 and the chamber S3. The pistons 41 and 42 that are slidably housed in the piston arm 43 and the connecting rod 44 are
．． 45.

A guide tube 47 integrated with a lid 46 that is crowned on the top surface of the case 38 is inserted into the damping force generation chamber S1, and a plurality of plate valves 48 made of plate spring material and orifices 49a, 49b are arranged around the outer periphery of the guide tube 47. The plate valve 48 and the plate member 49 are fitted together with the spacer 50, and the cap 51 having an orifice 51a at the tip of the guide tube 47 is screwed together. The base flange portion 47a and the spacer 50 are clamped and fixed.

A slide valve 52 is slidably fitted on the outer periphery of the spacer 50, and a needle 53 is inserted into the internal passage 47b of the guide tube 47, with a tapered tip 53a facing the orifice 51a, and the needle 53 moves back and forth. It is of a screw type that is screwed onto the lid 46 for operation.

The lower surface of the case 38 is covered with a lid 54, the lid 54 has a through hole 55a, and a member 55 is attached to a spring retainer that is fitted onto the outer periphery of the cap 51, and the retainer is received by the member 55. The slide valve 52 is pressed against the plate-shaped member 49 by the elastic force of the spring 56, and as a result, the opening end of the orifice 49b on the chamber S3 side is closed by the plate valve 48, and the opening end of the orifice 494 on the chamber S3 side is closed.
The opening on the side is closed by a slide valve 52.

The spring receiver member 55 is of a screw type that is screwed onto the lid 54 so that it can be moved forward and backward in the same manner as the needle 53.

Next, we will discuss the operation.

When the rear fork 9 swings upward around the pivot shaft 10 in FIG. 1 to cause the rear wheel 8 to move upward, the link 30 rotates counterclockwise around the shaft 35 due to the tensile force of the rod 28. The rotation is transmitted to the torsion bar 13 via the rod 32 and the link arm 31, and the force required to twist the torsion bar 13 with the front end fixed serves as a buffering force against upward movement of the rear wheel 8.

Since the two torsion bars 13.13 provided on the left and right sides are twisted in opposite directions, the directions of the torsional reaction forces are in canceling directions.

Since the fixed front end of the torsion bar 13 is provided with the previously described through-return buckle type preload adjustment means 17, the preload adjustment means 17 can adjust the pre-rotation of the torsion bar 13.

On the other hand, due to the rotation of the link 30, the operating shaft 35 of the rotary lever set damper 14 is also rotated counterclockwise.
As a result, the piston 41 shown in FIG.
The chamber S flows through the b1 orifice 51a1 through holes 55a and 39b.

flows into.

During the flow, the closed area of the orifice 51a is the same as that of the needle 53.
Since the tapered portion 53a is narrowed by being inserted into the orifice 51a, a damping force is generated by the throttling action of the oil flow rate of the orifice 51a, and this damping force is applied to the upward movement of the rear wheel 8. Dynamic lever set damper 14
becomes the repeated bias force.

Since the needle 53 is of a screw type that can be moved forward and backward from the outside, it is possible to set the opening area of the orifice 51a and the magnitude of the damping force determined by the size of the opening area.

When the upward movement speed of the rear wheel 8 is high, the hydraulic pressure in the chamber S3 increases due to the piston 41 sliding at high speed, and the slide valve 52, to which this hydraulic pressure acts via the orifice 49a, resists the elastic force of the spring 56. and retreats while being guided by the guide tube 47, thereby opening the orifice 49a.
Hydraulic oil flows through both the orifice 51a and the orifice 49a, and a damping force corresponding to the upward movement speed of the rear wheel 8 is generated.

The upward movement speed of the rear wheel 8 at which the slide valve 52 retreats is determined by the elastic force of the spring 56, and the elastic force can be adjusted by moving the threaded spring receiver member 55 forward and backward from the outside.

When the rear fork 9 swings downward around the pivot shaft 10 in order to move the rear wheel 8 downward, the torsion bar 13 is twisted to create a buffering force in the same way as when the rear wheel is moving upward. As the piston 42 shown moves forward, the hydraulic oil flows through the through hole 39b.

55a1 orifice 51a1 internal passage 47b1 through hole 39
% in circulation.

flows into. During the flow, the tapered portion 5 from the needle 53
A damping force is generated by the throttling action of the orifice 51a into which the orifice 3a is inserted and whose opening area is narrowed.

When the lowering speed of the rear wheel 8 is fast, the oil pressure in the chamber S4 increases, and the plate valve 48, on which the oil pressure acts through the orifice 49b, bends and deforms, thereby opening the orifice 49b and causing the orifice 49b to Orifice 51
A damping force corresponding to the downward movement speed of the rear wheel 8 is generated by the flow of hydraulic oil to both a.

Next, another embodiment of the present invention will be described.

In the embodiment shown in FIGS. 6 and 7, an engine 71 is mounted on the upper surface of the bottom 61a of the vehicle body frame 61, and a torsion bar 63 is mounted on the lower surface of the bottom 61a, as in the previous embodiment.
, a rotary lever set tamper 64 is arranged, but in order to increase the rigidity of the rear fork 69, which is a rear wheel support member that supports the rear wheel, a truss structure is used with base frames 69b, 69c, etc., and a torsion bar 63 and rear fork 69 are installed. The rod 8 of the operating force transmission path by the link mechanism 86 that connects the
8 was connected to the upper corner of the truss structure.

Further, as shown in FIG. 7, the number of torsion bars 63 is one.

The embodiment shown in FIG. 8 is different from the above embodiments in that the rear fork 99 has a downwardly convex truss structure, and the rod 118 of the operating force transmission path by the link mechanism 116 is connected to the lower corner of the truss structure. , torsion bar 103,
A rotary lever set damper 104 is mounted on the top surface of the engine 101.
The structure arranged on the lower surface of the bottom portion 91a of the vehicle body frame 91 on which is mounted is the same as in each of the above embodiments.

The spring force of the torsion bar is determined by the length of the torsion part, but FIG. 9 shows the same torsion bar 123.
An example will be shown in which an effect on spring force equivalent to that obtained by replacing the torsion bar with a torsion bar of a different length can be obtained while using the torsion bar.

At the front ends of the left and right torsion bars 123, 123, a turnbuckle-type preload adjustment means 127 consisting of an adjustment arm 128, right-handed screw rods, left-handed screw rods 131, 132, etc., as shown in FIG. 4, is provided.
The front end serration part 123a of the torsion bar 123 with which the base of the torsion bar 123 is inserted and engaged is elongated in the axial direction, so that the position of the adjustment arm 128 can be changed by a slide operation.

The engagement position of the adjustment arm 128 is the torsion bar 1
Since the torsion bar 12 becomes the fixed end of 23, it is involved in the spring force when the adjustment arm 128 is slid.
The length of 3 is substantially changed.

As shown in FIG. 10, the front end serration portion 133a of the torsion bar 133 is divided into multiple stages 133b in the axial direction.
, 133c, . . . , so that the position of the adjustment arm can be changed in stages.

FIG. 11 shows a torsion bar preload adjustment means 157 suitable for the case where there is only one torsion bar as in the embodiment shown in FIG.

A threaded rod 151 whose end is swingably connected to the vehicle body frame 141 with a pin 149 is loosely inserted into the tip of the adjustment arm 158 whose base is inserted and engaged with the front end serration portion 153a of the torsion bar 153. arm 158
is tightened and fixed to the screw rod 151 with lock nuts 152 and 153.

When the lock nuts 152 and 153 are loosened to rotate the arm 158 and the lock nuts 152 and 153 are tightened again, the preload of the torsion bar 153 is increased or decreased by the amount of rotation together with the arm 158.

As is clear from the above explanation, according to the present invention, the torsion bar and the rotary lever set damper are arranged on the lower surface of the bottom of the body frame on which the engine is mounted on the upper surface. In addition to securing a large space in which to place various parts and equipment, it is also possible to lower the center of gravity of the vehicle.
In addition, since the bottom of the body frame is long in the longitudinal direction of the vehicle body, a long-axis torsion bar and a rotary lever set damper can be effectively disposed behind the torsion bar, and this arrangement increases the vehicle height of the motorcycle. It has the advantage of being able to be carried out at a low level without any problems.

[Brief explanation of the drawing]

Figure 1 is an overall side view of the motorcycle, Figure 2 is a bottom view of the main parts of Figure 1, Figure 3 is a sectional view taken along line 3-3 in Figure 1, and Figure 4 shows the torsion bar preload adjustment means. Fig. 5 is a diagram showing the internal structure of the rotary lever set damper, Fig. 6 is a front view shown.
The figures are side views of main parts showing another embodiment, Fig. 7 is a bottom view of Fig. 6, Fig. 8 is a side view of main parts of yet another embodiment, and Fig. 9 shows adjusting the spring force of the torsion bar. A bottom view showing an example,
FIG. 10 is a diagram showing another embodiment of FIG. 9, and FIG. 11 is a diagram showing another embodiment of the preload adjusting means. In the drawing, 1, 61, 91, 141 are vehicle body frames, l
a, 61at 91a is the bottom, 8 is the rear wheel, 9.69.9
9 is a rear fork that is a rear wheel support member, 11, 71, 1
01 is the engine, 13,63.103,123,133
, 153 are torsion bars, 14, 64, 104 are rotary lever set dampers, and 26. 86, 116 are link mechanisms.

Claims (1)

[Scope of utility model registration request] A rear wheel support member that supports the rear wheel and is pivotally connected to the vehicle body frame so as to be able to swing up and down, and a torsion bar disposed on the vehicle body frame are connected through an operating force transmission path by a link mechanism, and the operating force is transmitted through a link mechanism. In a rear wheel shock absorbing device for a motorcycle in which a rotary lever set damper is attached to a transmission path, the torsion bar is disposed on the lower surface of the bottom of the body frame on which the engine is mounted on the upper surface, with the longitudinal direction of the vehicle body being the longitudinal direction, and The rotary lever set damper is installed on the lower surface of the bottom of the vehicle body frame behind the torsion bar,
A rear wheel shock absorber for a motorcycle, characterized in that the rear wheel shock absorber for a motorcycle is located below a pivot point between a vehicle body frame and the rear wheel support member.