JPS6119222Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damping force adjusting device in a hydraulic shock absorber, and more particularly to a damping force adjusting device that allows position-dependent and variable adjustment of the compression side damping force of a front fork at the same time.

In general, the compression damping force in the front fork of a motorcycle is determined only by the speed of the compression stroke of the piston, so if the spring constant changes, it is not always possible to match the damping force to the optimum damping value, which affects ride comfort and handling. It was not desirable.

On the other hand, the weight of the person riding the motorcycle, the weight of the luggage,
Depending on the road conditions on which the vehicle is traveling, it is necessary to adjust the damping force to suit the conditions each time according to the rider's preference to improve ride comfort and handling.

Therefore, the purpose of the present invention is to provide a front fork of a two-wheeled vehicle, etc., in which the compression damping force can be variably adjusted according to the running road conditions, etc., and the compression damping force can be automatically adjusted according to the stroke amount of the piston. It is an object of the present invention to provide a damping force adjusting device in a hydraulic shock absorber suitable for use.

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

An inner tube 2 is slidably inserted into the outer tube 1 via a piston 3, and an oil hole rod 4 and a hollow pipe 5 are fixed upright at the center of the lower end of the outer tube 1, and the outer circumference of the upper end of the hollow pipe 5. The piston or piston ring 6 provided in the hollow pipe 5 is in sliding contact with the inner circumference of the inner tube 2.
A spring 7 is interposed between the upper surface and the upper end of the inner tube 2 to constantly urge the inner tube 2 in the direction of extension.

The piston 3 defines two upper and lower liquid chambers 8 and 9 within the outer tube 1 and the inner tube 2, and a rebound damping force generating mechanism 10 is built in the piston 3.

A liquid chamber 11 is defined in the hollow pipe 5, and a gas chamber 35 made of air or the like is defined in the inner tube 2 above the liquid chamber 11.

The lower liquid chamber 9 and the hollow pipe inner liquid chamber 11 communicate with each other via a variable orifice 12 formed at the lower part of the hollow pipe 5, and the upper liquid chamber 8 is opened and closed via the liquid chamber 11 and the piston ring 6. It's summery.

The piston ring 6 also has a check valve function, and is arranged in a groove on the outer circumference of the head of the hollow pipe 5 so as to be able to move up and down, so that when the piston ring 6 rises, it shuts off the liquid chambers 8 and 11, and when it falls, it opens them. It's summery. However, if the piston ring 6 does not have a check valve function, an orifice is bored in the hollow pipe 5, and the two liquid chambers 8 and 11 are connected through this orifice.
It may also be possible to allow it to pass through.

Next, a hollow bolt 13 is screwed into the center of the lower end of the outer tube 1 from the outside toward the inside, and the inner periphery of the lower end of the hollow pipe 5 is screwed onto the outer periphery of the hollow bolt 13, so that the hollow pipe 5 is pushed downward. At this time, the hollow pipe 5 descends inside the oil hole rod 4 and presses the oil hole rod 4, so that the hollow pipe 5 and the oil hole rod 4 are held upright above the lower end of the outer tube 1. There is.

An adjuster star 14 which also serves as a valve is inserted into the lower part of the hollow pipe 5 and into the hollow bolt 13 so as to be movable in the axial and rotational directions.

The adjuster star 14 has an operating rod portion 14a at the lower end.
The outer end of the rod portion 14a protrudes outside the hollow bolt 13 so that it can be rotated from the outside.

A spring seat 15 having an H-shaped cross section is inserted between the outer periphery of the operating rod 14a and the inner periphery of the hollow bolt 13 via a packing 16.
A seal 17 is interposed in the lower part of the spring seat 15 and the seal 17 are supported by a washer 24 held by the bolt 13, and the washer 2
A dust seal 19 is interposed at the lower part of 4.
Valve spring 2 is placed on spring seat 15.
2 is interposed, and the upper end of this spring 22 comes into contact with the lower surface of the large diameter of the adjuster star 14, and always urges the adjuster star 14 upward.

A flange-shaped stopper 25 is formed at the lower part of the large diameter part of the adjuster star 14, and when the adjuster star 14 is pressed upward, the stopper 25 moves to the hollow pipe 5.
The adjuster 14 is hooked onto a lower end step 26 of a thick portion formed on the inner periphery of the adjuster 14, thereby regulating the amount of upward movement of the adjuster 14.

A cover 23 is removably fitted onto the lower end of the hollow bolt 13.

An axial passage 27 and a radial passage 28 are integrally formed in the upper part of the adjuster star 14, and the radial passage 28 faces the orifice 12 on the hollow pipe side. Hollow pipe side passage 11 via 27
It is designed to communicate with A fixed orifice 13 is also bored in the hollow pipe 5 as required, and the two orifices 12 and 13 work together to generate a compression damping force.

The adjuster star 14 is movable in the axial and radial directions, and at this time, the position of the radial passage 28 is shifted and placed in an eccentric position with respect to the variable orifice 12, so that the opening area of the variable orifice 12 with respect to the passage 28 changes. , the damping force can be obtained according to the degree of opening.

A plurality of semicircular grooves 29 cut out in the axial direction are formed at arbitrary intervals on the inner periphery of the thick part of the hollow pipe 5, and on the other hand, holes 3 are formed in the adjuster star 14 in the radial direction.
1, a spring 32 is interposed in this hole 31, a detent ball 30 is attached to the top of this spring 32, and these grooves 29 and the ball 3
0 constitutes a detent mechanism that restricts the movement of the adjuster star 14 in the rotational direction.

Although it is preferable to use the variable orifice 12 and the fixed orifice 33 together, the variable orifice 12 alone can be used, or the fixed orifice 33 side can also be made variable like the variable orifice 12.

Next, we will discuss the operation.

When used as a front fork of a motorcycle,
For example, it is preferable to set the compression side damping force in advance in order to obtain the best ride comfort depending on the weight of the passenger, the weight of luggage, and the uneven conditions of the road on which the vehicle is traveling.

In this case, first remove the cap 23,
Insert a tool such as a screwdriver into the thread groove of the operating rod 14a and rotate it. Then, the adjuster star 14 rotates against the spring 32 of the detent mechanism, the detent ball 30 fits into the desired detent groove 29, and the passage 28 is aligned with the variable orifice 12 in correspondence with this groove 29. The opening degree of the variable orifice 12 with respect to the passage 28 is determined, and the damping force is set according to this opening degree. Similarly, if the weight or road conditions change, use the Ajiasutar 1
4 to another position to adjust the opening degree of the variable orifice 12.

Next, in the state set in this way, in the extension operation, the piston 3 rises, and the compressed hydraulic oil in the upper liquid chamber pushes open the valve inside the piston 3 and flows out into the lower liquid chamber 9. At this time, the rebound damping force is obtained by operating the valve. In addition, the lower liquid chamber 9 is enlarged, and part of the oil is introduced from the upper liquid chamber 8, and part of the oil is introduced from inside the hollow pipe through the passages 27, 28, the variable orifice 12, and the fixed orifice 33 to create a negative pressure. prevent.

Next, in pressure operation, the piston 3 descends, and when the upper liquid chamber 8 is expanded, hydraulic oil is introduced from the piston ring 6, and the lower liquid chamber 9 is contracted, and the discharged oil is passed through the fixed orifice 33 and the variable orifice. 12-
flows into the liquid chamber 11 via the passage 28-27,
At this time, a compression damping force is obtained by the orifices 12 and 33.

By the way, when the piston 3 descends and the hydraulic oil in the lower liquid chamber 9 is discharged into the liquid chamber 11, the internal pressure in the gas chamber 35 above the liquid chamber 11 increases, and as a result, the liquid chamber 1
However, when the internal pressure of the liquid chamber 11 is relatively low, the adjuster star 14 is balanced with the spring 22 and does not move in the axial direction, so that the opening area of the variable orifice 12 is set in advance. within the specified range.

However, as the downward stroke amount of the piston increases, the amount of oil discharged into the liquid chamber 11 also increases, and the internal pressures of the gas chamber 35 and the liquid chamber 11 rise.When this internal pressure overcomes the spring 22, The adjuster star 14 descends. At this time, the detent ball 30 slides along the detent groove 29 in the axial direction.

When the adjuster star 14 descends, the passage 28 is displaced in the axial direction with respect to the variable orifice 12, thereby reducing the opening area of the variable orifice 12 and increasing the compression side damping force.

That is, the internal pressure increases in proportion to the downward stroke amount of the piston 3, which causes the variable orifice 1 to increase.
2 becomes smaller and the compression side damping force can be increased,
A damping force corresponding to the piston stroke can be obtained.
So-called position dependence of the damping force becomes possible.

According to the present invention, the following effects are achieved.

An adjuster is provided inside the hollow pipe so that it can move freely in the axial direction, and a spring is interposed at the end of the adjuster to balance the internal pressure of the liquid chamber inside the hollow pipe, so the internal pressure of the liquid chamber inside the hollow pipe increases when compression is activated. When this happens, the adjuster moves in the axial direction against the spring, and the opening area of the orifice can be automatically changed.

Since the adjuster star is inserted into the hollow pipe so as to be movable in the rotational direction, when the adjuster star is rotated, the opening area of the orifice can be changed, and the compression side damping force can be arbitrarily adjusted according to the running conditions, etc.

A simple structure in which an adjuster is inserted into a hollow pipe so that it can move freely in the axial and rotational directions, and a spring is interposed at the end of the adjuster to balance the internal pressure of the liquid chamber inside the hollow pipe, allowing position-dependent and compression-side damping force adjustment at the same time. I can do it.

Since the adjustment mechanism, the adjuster star and the spring, are set inside the hollow pipe, the basic length can be shortened, it is compact, and it is not easily damaged by external loads.

Since all moving parts are submerged in oil, conditions for rust prevention and operability are good.

If the adjuster is held against the hollow pipe by a detent mechanism, the displacement of the orifice will be small and a reliable damping force will be obtained.

[Brief explanation of the drawing]

The accompanying drawing is a partially cutaway vertical side view of a front fork according to one embodiment of the present invention. 1... Outer tube, 2... Inner tube, 5... Hollow pipe, 12... Orifice,
14...Asia star, 22...Spring, 2
7, 28... passage, 29, 30, 31, 32...
Day tent mechanism.

Claims (1)

[Claims for Utility Model Registration] (1) An inner tube is slidably inserted into an outer tube via a piston, so that the head of a hollow pipe that stands up from the center of the lower end of the outer tube slides inside the inner tube. In a hydraulic shock absorber, an orifice that opens into the liquid chamber below the piston is bored in the hollow pipe, and an adjuster star is inserted into the hollow pipe so as to be movable in the axial and rotational directions, and the orifice is inserted into the adjuster star. A damping force adjustment device in a hydraulic shock absorber, which has a passage communicating with the liquid chamber, and further has a spring interposed at the end of the adjuster opposite to the liquid chamber in the hollow pipe to balance the internal pressure of the liquid chamber in the hollow pipe. . (2) The damping force adjusting device in a hydraulic shock absorber according to claim 1, wherein the adjuster star has a detent mechanism that restricts movement in the rotational direction. (3) The damping force adjusting device in a hydraulic shock absorber according to claim 1, wherein the adjuster star is rotated by an external rotational drive.