JPH0241380Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a suspension spring adjustment device for a hydraulic shock absorber that arbitrarily adjusts a spring constant depending on the magnitude of a load.

A suspension spring consisting of a main buffer spring and an auxiliary buffer spring is installed in series, and the amount of deflection of the auxiliary buffer spring is limited as necessary to change the spring constant to provide an appropriate damping effect depending on the magnitude of the load. As a hydraulic shock absorber, for example, one disclosed in Japanese Utility Model Publication No. 46-6447 is known.

This hydraulic shock absorber has a guide tube movably inserted into the outer periphery of the cylinder, and this guide tube has an axial groove and a plurality of cam surfaces with different depths at the lower end, and main and auxiliary buffer springs are installed above and below the guide tube. are interposed in series, the guide cylinder is rotated in the rotational direction, a stopper fixed to the cylinder side is selectively opposed to one of the grooves or cam surfaces, and the stopper is suspended depending on the position of the groove or cam surface that it faces. The spring constant of the spring can be adjusted arbitrarily.

However, with such a spring adjustment mechanism, when the guide tube and the stopper are separated, the position of the guide tube in the rotational direction may shift due to twisting, vibration, etc. of the suspension spring.

For example, if the live load is small and the spring constant should be set small, the stopper is placed opposite the groove so that the main and auxiliary springs operate. If the guide tube is located higher up and then compressed, the position of the guide tube may shift due to twisting, deflection, vibration, etc. of the suspension spring, and as a result, the groove and stopper no longer face each other, and the end of the guide tube may hit the stopper. , there is a risk that the set spring constant may change due to contact with one of the cam surfaces.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a suspension spring adjustment device for a hydraulic shock absorber in which the position of the guide cylinder serving as an adjustment cam does not change during operation and the preset spring constant does not change.

In order to achieve this objective, the configuration of the present invention is such that an adjusting cam consisting of two cam pieces facing each other on the outer periphery of the cylinder and a spring seat fixed to the outer periphery of the cam pieces is inserted so as to be movable in the axial and rotational directions. In a hydraulic shock absorber, a through gap is formed between each of the cam pieces, a stopper is provided on the outer periphery of the cylinder facing the through gap, and a main buffer spring and an auxiliary buffer spring are provided above and below the spring seat, The main buffer spring and the auxiliary buffer spring are installed with their respective winding directions reversed, and each cam piece has a tapered surface at its lower end to form a long end surface and a short end surface at both ends, and each tapered surface has one or more Cam surfaces having different depths are provided, and the two cam pieces are arranged such that the long end face of one cam piece faces the short end face of the other cam piece, and the through gap between each cam piece is equal to the long end face. and a short end face, and the long end face of each cam piece is configured to be pressed against the stopper by the expanding action caused by the compression of the main buffer spring and the auxiliary buffer spring. It is.

Embodiments of the present invention will be described below with reference to the drawings.

In the hydraulic shock absorber 1, a piston rod 3 is slidably inserted into a cylinder 2 via a piston, and brackets 4 and 5 are provided at the lower end of the cylinder 2 and the upper end of the piston rod 3, respectively. It has come to be installed between the wheel side and the vehicle body side of automobiles, motorcycles, etc.

A spring seat 6 is held at the lower part of the outer periphery of the cylinder 2 via a locking member 6, and a lower part of an auxiliary buffer spring 7 is supported above the spring seat 6.

Similarly, a guide tube 8 serving as an adjustment cam is inserted into the upper outer periphery of the cylinder 2 so as to be movable in the vertical and rotational directions. Further, stoppers 9 are protruded from the outer periphery of the cylinder 2 at diametrically symmetrical positions opposite to the guide tube 8.

A flange-shaped ring 10 serving as a spring seat is integrally formed on the outer periphery of the guide tube 8, and a cylindrical or other similar adjustment cover 11 is connected to this ring 10 so that it can move in the same direction as the guide tube 8. ing.

The upper end of the auxiliary buffer spring 7 held on the spring seat 6 comes into contact with the lower surface of the ring 10, and constantly pushes the ring 10 and the guide tube 8 upward.

The winding direction of the auxiliary buffer spring 7 is clockwise, and when compressed, it expands in the direction of the arrow.

A cylindrical undercover 12 is in contact with the top surface of the adjustment cover 11, and an upper cover 13 fixed to the top of the other piston rod 3 is disposed on the outside of the undercover 12 so as to be movable up and down. Lower end upper surface and upper cover 13
A main buffer spring 14 is interposed between the upper end and the lower surface.
The winding direction of the main buffer spring 14 is left-handed, and when compressed, it expands in the direction of the arrow.

In short, it is necessary to reverse the winding directions of the main buffer spring 14 and the auxiliary buffer spring 7.

The guide tube 8, which is an adjustment cam, is made up of a plurality of cam pieces formed in succession, for example, as shown in FIGS. 2 and 3, it is made up of two curved cam pieces 15 and 16 facing each other, These cam pieces 15,1
Opposite through gaps 17 and 17 are formed between the holes 6 and 6.

The center of the ring 10 is fixed to the outer periphery of each curved cam piece 15, 16, but it is also possible to fix the ring 10 to the outer periphery of one cylindrical body and then cut out two opposing through gaps in this cylindrical body. good.

Tapered surfaces 18 in opposite directions are formed at the lower ends of each of the cam pieces 15 and 16, and a cam surface 19 is formed on the tapered surfaces 18. However, the number of cams 19 may be one or more, depending on the mode of use.

By forming the tapered surface 18 on each of the cam pieces 15 and 16, the length in the axial direction is different between the left end face a and the right end face b, and a dimensional relationship of a>b is maintained, and the left end of one of the cam pieces 16 The right end surface b of the other cam piece 15 is opposed to the surface a, so that one end surface is always longer in each through gap 17.

Therefore, as shown in FIG. 1, when the through gap 17 faces the stopper 9, the guide tube 8 moves up and down guided by the stopper 9, and at this time, the cam pieces 15, 16 are always on the right end surface of the stopper 9. is in contact with the left end surface a.

Moreover, since the main buffer spring 14 and the auxiliary buffer spring 7 are about to expand in the direction of the arrow when compressed, this force applies a force in the rotational direction to the cam pieces 15 and 16 via the ring 10, thereby causing the long left end The surface is pressed against the right end surface of the stopper 9, and as a result, the guide tube 8
It can prevent the position from shifting during vertical movement.

One or more notches 2 are formed on the outer periphery of the ring 10.
1 is formed, and the adjustment cover 1 is formed in this notch 21.
When the locking piece 20 with the upper end of the ring 1 is bent and the adjustment cover 11 is rotated, the locking piece 20 and the ring 1 are fitted together.
The guide cylinder 8, which is an adjustment cam, rotates in the same direction through the adjustment cam.

Next, we will discuss the operation.

FIG. 1 shows the situation when the load is small and the spring constant is set small. In this case, the through gap 17
The stopper 9 faces the stopper 9, and the cam piece 1 is attached to the stopper 9.
The long end surfaces a of the guide tubes 5 and 16 are brought into contact with each other, and the guide tube 8 is guided by the stopper 9 and moves up and down. That is, when the hydraulic shock absorber 1 operates under an axial load, the main buffer spring 14 and the auxiliary buffer spring 7 compress according to the load, and the spring constant at that time is the sum of the two springs 7 and 14. It's small.

In addition, each spring 7,
Even if 14 expands and contracts and the guide tube 8 moves up and down, the cam piece 1
5 and 16 are guided by the stopper 9, there is no positional shift and the spring constant can be prevented from changing.

Next, when it is desired to set a large spring constant, the ring 10 and the guide tube 8 are rotated in the same direction by forcibly rotating the adjusting cam 11 in the direction opposite to the arrow.

For this reason, the cam surface 18 rides on the top of the stopper 9 from the short end surface b side and engages with an arbitrary cam surface 19 having a different depth.

For this reason, the guide tube 8 is locked by the stopper 9 and does not move below this locked position, so the auxiliary buffer spring 7 is also placed below that position.
Since the spring constant is not compressed and only the main buffer spring 14 operates, the spring constant is that of the main buffer spring 14, and a large spring constant can be set.

At this time, the guide cylinder 8, which is an adjustment cam, is held at the set position by the initial load of the auxiliary buffer spring 7, thereby preventing the guide cylinder 8 from rattling or shifting.

Further, during the adjustment operation, the operating force is also reduced by the amount of reaction force of the auxiliary buffer spring 7 acting on the main buffer spring 14.

As described above, in the present invention, even when the through gap faces the stopper or when the adjusting cam moves up and down, the long end surface on one side of the through gap is guided by the stopper, so the axial and rotational directions of the adjusting cam This prevents displacement of the spring constant, thereby preventing the set spring constant from changing.

Also, when the suspension springs, the main buffer spring and the auxiliary buffer spring, are compressed, the force that tends to expand is applied to the adjustment cam, biasing it in one direction. It is pressed against the side and more effectively prevents the adjustment cam from shifting.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a hydraulic shock absorber according to the present invention, FIG. 2 is a perspective view of an adjusting cam, and FIG. 3 is a developed view of the adjusting cam. 2... Cylinder, 7... Auxiliary buffer spring, 8...
Adjustment cam, 9...Stopper, 10...Spring seat, 11...Adjustment cover, 14...Main buffer spring, 15, 16...Cam piece, 17...Gap, 18
... Tapered surface, 19 ... Cam surface, 21 ... Notch, a ... Long end surface, b ... Short end surface.

Claims (1)

[Claims for Utility Model Registration] (1) An adjusting cam consisting of two cam pieces facing each other on the outer periphery of the cylinder and a spring seat fixed to the outer periphery of the cam pieces is fitted so as to be movable in the axial and rotational directions, In a hydraulic shock absorber, a through gap is formed between each of the cam pieces, a stopper is provided on the outer periphery of the cylinder opposite to the through gap, and a main buffer spring and an auxiliary buffer spring are provided above and below the spring seat. The buffer spring and the auxiliary buffer spring are installed with their respective winding directions reversed, and each cam piece has a tapered surface at its lower end to form a long end surface and a short end surface at both ends, and each tapered surface has one or more deep end surfaces. Cam surfaces of different sizes are provided, and the two cam pieces are arranged such that the long end face of one cam piece faces the short end face of the other cam piece, and the through gap between each of the cam pieces is in line with the long end face. A hydraulic shock absorber characterized in that the long end face of each cam piece is configured to be pressed against the stopper by the expanding action caused by the compression of the main buffer spring and the auxiliary buffer spring. Equipment suspension spring adjustment device. (2) The hydraulic shock absorber according to claim 1 of the utility model registration claim, in which two curved cam pieces are provided facing each other, and two passing gaps are formed that face each other in the diametrical direction of each cam piece. Suspension spring adjustment device. (3) Suspension spring adjustment for a hydraulic shock absorber according to claim 1, wherein a notch is formed on the outer periphery of a ring-shaped spring seat, and an adjustment cover is held in this notch. Device. (4) Utility model registration claim 1 where the main buffer spring is left-handed and the auxiliary buffer spring is right-handed.
Suspension spring adjustment device for a hydraulic shock absorber as described in .