JPS633481Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a spring load adjustment mechanism for a hydraulic shock absorber.

In a hydraulic shock absorber for a vehicle, the load of a coil spring is adjusted in order to adjust the vehicle height or to obtain appropriate shock absorbing characteristics depending on road surface conditions.

By the way, the applicant has proposed a spring load adjustment mechanism as shown in FIG. That is, according to this, the spring receiver 1 is rotatably fitted on the outer periphery of the cylinder 1.
An adjuster 18 having a wavy cam surface 18a on the lower surface is fitted into the cam surface 1 of the adjuster 18.
8a is abutted and engaged with stoppers 16, 16 protruding from the sides of the adjuster pipe 15, and a pinion gear 23 rotatably housed inside the adjuster pipe 15 is carved into the lower surface of the spring receiver 17. It was tightly meshed with face gear 17b.

When the pinion gear 23 is rotated, the spring receiver 1 having the face gear 17b that meshes with the pinion gear 23 is rotated.
7 rotates around the outer periphery of the cylinder 1, and accordingly, the adjuster 18 that fits into the spring receiver 17 also rotates, and the rotation of the adjuster 18 causes the cam surface 18a of this
The engagement position with the stoppers 16, 16 changes, and the adjuster 18 moves up and down. This adjuster 1
The set length of the coil spring 19 is changed by the vertical movement of the coil spring 8, and the load of the coil spring 19 is thereby adjusted.

However, in this type of adjustment mechanism, the spring receiver 17 and the adjuster 18 are tightly fitted in the circumferential direction and are configured to rotate together, so the spring bearing 17 and the adjuster 18 are configured to rotate together. When the adjustment is made, the reaction force of the coil spring 19 causes the oblique side of the cam surface 18a of the adjuster 18 to slide against the stoppers 16, 16, and as a result, the adjuster 18 and the spring receiver 17 rotate together, causing the face gear 17b and pinion to rotate. The shaft 22 is rotated through the gear 23 in a direction that weakens the spring load, and if a tool is inserted to turn the nut member 22a fixed to the end of the shaft 22, this tool is also rotated against the user's will at the same time. , it was extremely dangerous.

The present invention has been made to effectively eliminate such inconveniences, and its purpose is to provide a spring load adjustment mechanism for a hydraulic shock absorber which provides circumferential play between the notched groove of the adjuster and the protrusion of the spring holder, so that even if the adjuster rotates due to the reaction force of the coil spring when the initial spring load is reduced, this rotation is absorbed by the above-mentioned play, thereby eliminating or only slightly rotating the shaft of the spring holder, i.e., the pinion gear, thereby improving safety.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

Fig. 1 is a half-cut side view of a hydraulic shock absorber having an adjustment mechanism according to the present invention, Fig. 2 is an enlarged sectional view taken along line 2-2 in Fig. 1, and Fig. 3 is an exploded perspective view of the adjustment mechanism. be.

Reference numeral 1 in FIG. 1 denotes a cylinder, and a piston rod 3 is inserted from above into an inner cylinder 2 provided concentrically inside the cylinder, as shown in the figure. A piston 4 that is vertically slidably fitted is fixed to the piston 4. and,
A plurality of oil holes 4a are bored in the piston 4, and a valve mechanism 5 for opening and closing these oil holes 4a is provided on the upper end surface of the piston 4.

A rod guide 6 and an oil seal 7 that slide on the outer periphery of the piston rod 3 are fitted into the upper interior of the cylinder 1, and these are prevented from coming off by a plate 8 crimped to the inner periphery of the upper end of the cylinder 1. . Furthermore, piston 4 and rod guide 6
A rebound spring 9 is interposed between them as shown.

Therefore, inside the inner cylinder 2, there is an upper working air _S1 by the piston 4.
and a lower working space _S2 , and a reservoir chamber _S3 is formed between the inner cylinder 2 and the cylinder 1.
Hydraulic oil is sealed in S ₁ , S ₂ , and S ₃ , and especially the upper part of reservoir chamber S ₃ is occupied by gas. The lower working chamber S ₂ and the reservoir chamber S ₃ are configured to communicate with each other via a valve mechanism 10 and oil passages 11 provided at the lower part of the inner cylinder 2.

An upper bracket 12 is fixed to the upper end of the piston rod 3, and a spring receiver 13 is fixed to the lower edge of the upper bracket 12. A stop lever 14 is provided on the lower surface side of the upper bracket 12.

Incidentally, a cylindrical adjusting pipe 15 having an open upper part is provided on the outer periphery of the lower part of the cylinder 1, with its lower end fixedly fixed. Oval stoppers 16, 16 are protruded from opposing positions on the outer periphery of the adjusting pipe 15, and a circular hole 15a through which the shaft passes is bored on the outer periphery.

Further, a spring receiver 17 is fitted to the outer periphery of the cylinder 1 so as to be rotatable in the circumferential direction. The spring receiver 17 has a flange 17a in its middle portion, and a face gear 17b is carved on the lower end surface of the spring receiver 17 as shown in FIG. It is in contact with the end face. A cutout groove 17c is bored upward from the flange 17a of the spring receiver 17, and therefore, a rectangular engagement protrusion 17d is integrally erected above the flange 17a. The vertical movement of the spring receiver 17 is restricted by a snap spring (not shown) fitted to the outer periphery of the cylinder 1.

As shown in detail in FIG. 3, in the spring receiver 17, a cylindrical adjuster 18 having a wavy cam surface 18a formed on the lower end surface is inserted into the notch groove 18b provided in the inner peripheral part of the upper end of the spring receiver 17. The engaging protrusion 17d...
is inserted and engaged. As shown in FIG. Therefore, the adjuster 18 and the spring receiver 17 engage with each other with the play ΔC in the circumferential direction, and the adjuster 18 slides vertically relative to the spring receiver 17. They are movably engaged. The adjuster 18 is stationary at a position where its wavy cam surface 18a abuts and engages stoppers 16, 16 protruding from the adjuster pipe 15.

On the other hand, a rotating shaft 22 faces inside the adjusting pipe 15 through a circular hole 15a bored in the pipe 15, and a face gear 17b provided in the spring bearing 17 is attached to the end of the rotating shaft 22. An engaging pinion gear 23 is fitted to rotate together with the rotating shaft 22, and a nut portion 22a is formed at the other end of the rotating shaft 22 that extends outside the adjuster pipe 15.

Next, the operation of the adjustment mechanism described above will be described.

If the rotating shaft 22 is rotated using a tool from the state where the adjuster 18 is located at the lower limit as shown in FIG. It rotates without sliding up and down on the outer circumference of 1. As the spring receiver 17 rotates, the adjuster 18 that engages with it also rotates together with it, and the rotation of the adjuster 18 causes the wavy cam surface 18a provided thereon and the stopper provided protruding from the adjuster pipe 15 to rotate. 16, 16 changes, thereby causing the adjuster 18 to move upward relative to the spring receiver 17 while rotating in the circumferential direction. By this upward movement of the adjuster 18, the coil spring 19 stretched between the adjuster 18 and the spring receiver 17 is compressed, and its spring load is adjusted to be high.

Then, if the rotating shaft 22 is further rotated to move the adjuster 18 downward, the spring load of the coil spring 19 is adjusted to a lower value. It slides against the stoppers 16, 16, and as a result, the adjuster 18 rotates by a circumferential angle corresponding to approximately half the pitch of the cam surface 18a.

Incidentally, since the engagement between the adjuster 18 and the spring receiver 17 in the circumferential direction is achieved by providing a play ΔC corresponding to approximately half the pitch of the cam surface 18a,
Even if the adjuster 18 rotates as described above, this rotation is absorbed by the play ΔC, and the spring receiver 17 does not rotate at all or only rotates slightly. Therefore, the pinion gear 23 and the rotating shaft 22 that mesh with the face gear 17b of the spring receiver 17 do not rotate at all or only rotate slightly. As a result, even when a tool is hung on the nut member 22a during work, the tool will not be swung around, and the safety of the work is sufficiently ensured.

According to the present invention, the above effects can be obtained.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is a half-cut side view of a hydraulic shock absorber having an adjustment mechanism according to the present invention, FIG. 2 is a sectional view taken along the line 2-2 in FIG.
FIG. 3 is an exploded perspective view of the adjustment mechanism. In the drawing, 1 is a cylinder, 15 is an adjustment pipe, 16 is a stopper, 17 is a spring receiver, 17b is a face gear, 17d is an engaging protrusion, 18 is an adjuster, 18a is a wavy cam surface, 19 is a coil spring, 22 is a rotating shaft, and 23 is a pinion gear.

Claims (1)

[Scope of utility model registration request] A spring holder is rotatably fitted around the outer circumference of the cylinder,
This spring receiver has a flange in the middle, a face gear on the lower end surface of the spring holder, and a peripheral wall provided with a plurality of engaging protrusions 17d above the flange. The engagement protrusion 1 of the spring receiver is provided on the inner circumference of the upper surface.
7d, a wavy cam surface is formed on the lower end surface of the peripheral wall, and a cylindrical spring adjuster is fitted on the upper surface of the cam surface to support one end of the coil spring fitted on the outer periphery of the cylinder. In a spring load adjustment mechanism for a hydraulic shock absorber configured to rotate the spring receiver through a gear mechanism, the spring adjuster rotates together and slides in the axial direction. A spring load adjustment mechanism for a hydraulic shock absorber, characterized in that a play equal to a circumferential angle corresponding to approximately half the cam pitch of the spring adjuster is provided between the width of the piece 17d and the width of the notch groove 18b of the spring adjuster.