JPS58221781A - Hydraulic shock absorber for trailing axle type two-wheel barrow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic shock absorber for a trailing axle type two-wheeled vehicle.

As hydraulic shock absorbers for supporting the front wheels of two-wheeled vehicles, a center axle type shock absorber 1 shown in FIG. 1 and a leading axle type shock absorber 2 shown in FIG. 2 are the mainstream.

The center axle type shock absorber 1 has its axis line fixed so that it intersects with the center of the wheel 3 and the shoulder shaft axis 4, and has good maneuverability because there is little change in the trail while driving. The disadvantage is that the operating friction due to the angle (which occurs in response to the inclination of the axis of the loose cylinder with respect to the vertical line) is large.

The leading axle type shock absorber 2 shown in FIG. 2 is suitable for off-road vehicles because the effective stroke of the shock absorber can be long, but the operating friction is still large as described above.

These operating frictions are caused by the load reaction force from the bearing part of the shock absorber (the bearing part at the upper end of the cylinder that supports the piston rod, and the sliding contact of the piston with respect to the cylinder) and the ground surface in the direction perpendicular to the shock absorber axis. It also occurs based on component force. In the above case, the moments based on the lateral loads generated in these two bearings act in the same direction, so
In order to balance these and reduce strain caused by lateral loads, the multi-current shock absorber should be protruded significantly downward from the axle 4, which is the input point of the load reaction force, to change the direction of the moment in the two bearings. This has many practical problems due to interference between the shock absorber and the road surface.

The present invention was proposed in order to solve these problems, and focused on hydraulic shock absorbers for trailing axle manufacturers where the shock absorber's axis line passes in front of the center of the axle. By setting the line of action of the vertical reaction force from a point to pass between the two bearing parts of the shock absorber, moments in different directions are applied to the two bearing parts, and the bearing part The purpose is to reduce as much as possible the sliding friction and strain caused by lateral loads.

Embodiments of the present invention will be described below based on the drawings.

FIG. 3 shows the operating principle, and FIG. 4 shows its specific structure. In FIG. 4, the inner chain 11 is housed inside the outer tube 10 so as to be freely slidable.

The inner chain f11 and the actor tube 10 are supported in sliding contact with each other by a bearing metal 13 provided at the tip of the inner tube and a bearing metal 14 provided at the upper end of the outer tube 10. The distance varies depending on the stroke amount of the inner tube 11.

A cylinder 15 is disposed in sliding contact with the inner periphery of the inner tube 11 via a male stone portion 16, and this cylinder 15 is fixed to the lower end of the outer tube 10.

As the inner tube expands and contracts by 1°, hydraulic oil moves in and out between the oil chamber and the oil reservoir chamber between the inner tube 11 and the outer tube 10, and at this time, resistance is imparted to the movement of the hydraulic oil. , a predetermined damping force is generated, but since this point is well known, the explanation will be omitted.

A laterally protruding bracket 17 is fixed to the lower part of the outer tube 10, and the support hole 1 of the f racket 17 is fixed to the lower part of the outer tube 10.
An axle 19 is pivotally supported at 8.

In this embodiment, this support hole 1 is
8 (the axis of the inner tube 11 is installed inclined by a predetermined caster angle) is placed on the side of the bracket 17 so that the vertical line passing through the center of the inner tube 11 passes largely between the bearings A and B. Set the offset amount (overhang amount) to

In other words, the line connecting the center of the lower bearing part B and the center of the support hole is set to intersect with a line parallel to the axis of the inner chain 11 at a caster angle θ.

When set in this way, as will be explained in detail later, the moment based on the lateral load applied to the bearings A and B is lost, resulting in a change in the ground reaction force applied to the shock absorber during pressure side operation. This makes it possible to suppress an increase in frictional force.

This will now be explained based on FIG.

When the mounting angle (caster angle) of the shock absorber is θ and the load reaction force received from the ground surface is W, the axial load P and lateral load (load perpendicular to the axial direction) Q acting on the shock absorber are as follows. It is determined by the formula.

p-w(2)0 ・・・・・・・・・・・・・・・
・(1) Q-W blood 0 ・・・・・・・・・・・・
...(2) Based on this Q, the load in the direction perpendicular to the axis generated on the bearing part A is 81. Similarly, the load applied to the bearing part B is R.
Then, R-Q+S ・・・・・・・・・・・・・・・
(3) becomes.

The balance of the moment at the point 00 times where it passes through the center of the support hole and intersects with the shock absorber axis is L S + HP ” 4 R・・・・・・・・・・・・
...(4). (However, L is the distance between the 0 point and the A point, 1. is the distance between the 0 point and the B point, and H is the distance from the 0 point to the center of the support hole, that is, the offset amount of the bracket) Above (
3), (4) formula, LS+HP=Sil (,Q+8) 8 (L4) = 4Q HPLIQ H
P S-□ ・・・・・・・・・・・・(5) L! The condition that the reaction force S, which causes strain etc. in the bearing part, is minimum (t9, S proverbial 0) is At Q -HP Therefore, the condition that the bearing reaction force of the bearing part A is zero is:
- In the case of -m#, under this condition, 1° is s R"'IQ" *W * θ from equation (3).If the sliding friction coefficient of the shock absorber is μ, then its sliding The dynamic resistance depends on the load R on the bearing part B only, and is expressed as fT - μR - μW (
7).

By the way, the above t1 differs depending on the operating stroke of the inner tube 11 (referred to as tlz).
, if the offset amount H is determined so as to satisfy the above equation (6) when tlK is at its maximum (tlmlLX'), then -tIX≦t1mlLX and the condition of AtzQ -HP≦0 is established during normal metrelation. do.

Therefore, according to equation (6), pl is obtained, and the bearing reaction force S has a gap or a negative value.

When S becomes negative, it means that the direction of the force is reversed, and in equation (3), it is expressed as 8=-8', R-Q-8', and R+8'
- There is no problem considering it as Q.

Therefore, when the force S is negative, the bearing friction force is 1fT-
p (R+S') = /JQ HxsWdnθ ・-
(9) Therefore, even if t varies with the stroke, the sliding resistance will not increase more than μWgtnθ, as shown in equations (7) and (8). In other words, to satisfy this condition, Hz, 4 maz-θ ・・・・・・・・・・・・
If the offset amount of the bracket is determined so that Ql, the sliding resistance of the shock absorber is only based on the lateral component Q, and the bearing reaction force does not increase with the stroke.

By the way, if we consider this point in comparison with the center axle type shock absorber shown in FIG. 1 above, we will see the following.

For center axle type, offset bar) quantity bar k”4 (H
-0), so according to equation (4), L S = 4 R
= 4 (Q + 8) ”'・・' ”・Ql
)(L−1鵞) s −tIQ (Lz+)”'zm, so 4 Se= 4 Q Equations (8) and (6), now, substituting equation (2) into equation (9). Substituting, then, in general, t, within t!, so f' = within 3 μW...
......00. Therefore, (7)
From equation 6, f' -3f, ...
・・・・・・・・・・・・(To) Therefore, compared to the center axle type, the sliding resistance is significantly reduced.

Incidentally, the offset amount ■ of the bracket 17 protruding outward from the inner circumference of the outer tube 10 is calculated by assuming that the outer diameter of the inner tube 11 is d. By the way, in the above embodiment, the carrying load is equal to the no load (vehicle weight). However, in reality, the offset of the bracket 17' is calculated based on the relationship with the position of the lower bearing part B in the stationary state at that time, in anticipation of the amount of depression of the buffer 6 when the driver gets on the vehicle. You may also set the amount.

FIG. 5 shows the case where K is set in this way, and the amount of rearward protrusion (offset amount) of the bracket 17' can be made smaller than that in FIG. 4.

In this case, when the inner tube 11 moves from its rest position to the extension side, the vertical line passing through the center of the support hole of the bracket 17 does not pass below the bearing part B, and both bearing parts A
Although it deviates from the condition of being between , H,
1. When the shock absorber is in operation, the load W applied to the shock absorber is in the decreasing direction, so even if the bearing load <S> of the bearing part A occurs, the strain is significantly smaller than that on the compression side, and therefore, it is difficult to use in practical use 1.
This will be within a range where there will be no public welfare issues.

Therefore, in the present invention, when the offset amount of the bracket 17 is set to 1 in a stationary state (IG state) with an average load, a vertical line passing through the center of the support hole of the bracket 17 is in the vertical direction of the outer periphery of the lower bearing part B. This will work if you set it so that it passes through the center of .

As described above, according to the present invention, in a trailing axle type shock absorber, in a stationary state where an average load is applied, the extension of a vertical line passing through the center of the support hole of the bracket is between the inner tube and the outer chineap. Since the bracket is offset so that it passes between both bearings, the load (lateral load) on the bearing is reduced, the sliding friction resistance (operation friction) is minimized, and the telescopic operation is greatly improved.゜It is possible to improve this and reduce sliding noise.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic installation diagrams of a conventional hydraulic shock absorber and a dual shock absorber, respectively. FIG. 3 is a diagram of the operating principle of the present invention, and FIGS. FIG. 3 is a cross-sectional view of the second embodiment. DESCRIPTION OF SYMBOLS 10... Outer tube, 11... Inner tube, 13.14... Bearing metal, 15... Cylinder, 17... Bracket, 18... Support hole, 19...
...Axle, A, B...' bearing part. Patent Applicant: Kayaba Kogyo Co., Ltd. Procedural Amendments Mr. Kazuo Wakasugi, Commissioner of the Patent Office 1, Indication of the Case, Patent Application No. 102547, filed in 1982, Name of the Invention: Hydraulic shock absorber for trailing axle type motorcycles 3, Person making the amendment Case and Relationship with Patent applicant Address: World Trade Center Building, 2-4-1 Hamamatsucho, Minato-ku, Tokyo Name (09'2) Kayaba Kogyo Co., Ltd. 4, Agent address: 10-8, Ginza 8-chome, Chuo-ku, Tokyo 104 No. Ginza 8-10 Building 3rd Floor (1) On page 2, line 14 of the specification, the phrase ``...sliding contact of the piston'' has been corrected to ``...the sliding bearing portion of the piston.'' (2) In the 2nd to 4th lines of page 10, the phrase ``In addition, if the above d...'' is corrected as follows. ``The above is an analysis that ignores the diameter of the inner tube 11, and in reality, the above relational expression is satisfied on the sliding bearing surface between the inner tube 11 and the 7th outer tube 1O, that is, the lower bearing part B Since the line of action of the load 7JW should pass through the actual sliding surface of , the actual offset amount n considering the diameter d of the inner tube 11 is " 1B position" is corrected to "B digit 11: xJ. (4) "H'" in the 11th line of the same page is corrected to "n'". (6) "Bracket 17" on the 16th line of the same page, and the 5th and 7th lines of the 11th page, respectively. Figure 5 is revised in the attached sheet.

Claims (1)

[Claims] In a two-wheeled vehicle equipped with a shock absorber in which an inner tube is freely slidably housed in an outer tube and a bracket for supporting an axle is provided at the bottom of the outer tube protruding toward the rear of the vehicle body, at least in a stationary state where an average load is applied,
The extension of the vertical line passing through the center of the bracket's axle support hole is
A hydraulic shock absorber for a trailing axle type two-wheeled vehicle, characterized in that the bracket is offset so that it passes between the upper and lower bearing parts of the inner tube and the outer tube.