JPS633480Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a damping force adjustment mechanism for a hydraulic shock absorber.
In particular, the present invention relates to an improvement of a dial operation unit that operates a needle valve of a damping force adjustment device.

An oil passage communicating between the upper and lower oil chambers of the piston of the cylinder is formed at the axis of the piston that is slidably fitted into the cylinder, and oil passes through the oil passage by vertical movement of a needle valve inserted into the hollow axis of the piston rod. A hydraulic shock absorber is known in which the damping force can be varied by adjusting the amount.

Conventionally, in the damping force adjustment device of this type of hydraulic shock absorber, the adjuster star that controls the vertical movement of the needle valve is directly exposed to the outside, and there are gaps around the adjuster star, so dust etc. can enter these gaps, making it difficult for the adjuster to operate smoothly. There is a problem in that it becomes impossible to perform rotational operations, and there is a strong desire to improve this problem, especially when it comes to maneuvering under severe conditions such as in motocross races.

The present invention was devised to solve this problem, and aims to provide a damping force adjustment mechanism that prevents dust from entering the dial operating section and ensures smooth operation.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Fig. 1 shows a piston 2 equipped with a damping force generating mechanism slidably fitted into a cylinder 1 filled with oil, and a spring receiver 4a of a piston rod 3 led out of the cylinder 1 and a spring on the side of the cylinder 1. This figure shows a cross section of a hydraulic shock absorber in which a spring 4c is stretched between the bearings 4b, and an oil passage 5 is formed in the axis of the tip end of the piston 2, which communicates between the upper and lower oil chambers of the piston of the cylinder 1. At the same time, a needle valve 6 having a tapered tip is fitted into the hollow shaft core of the piston rod 3 so as to be movable up and down.
The tapered tip of the piston 2 is moved forward and backward into the opening 5' of the oil passage 5 provided in the piston 2 to adjust the amount of oil passing;
This allows the damping force to be adjusted.

In the damping force adjustment mechanism having such a configuration, the present invention is characterized by providing a valve operation mechanism for vertically moving the push rod 6' of the needle valve 6 on the lower metal 7 fixed to the rear end of the piston rod 3;
An adjustment cover 8 which also serves as a dial is rotatably fitted to the outside of the valve operation mechanism, and the rotation of the adjustment cover 8 moves the valve operation mechanism via a key.

That is, a spring receiver 4 is provided at the rear end of the piston valve 3.
Base member 9 and lower metal 7 for supporting a
The lower metal 7 is integrally formed with the cylindrical body part 7, and as shown in FIGS. 2 and 3, the cylindrical body part 7' communicates with the hollow interior of the piston rod 3 and is elongated in the axial direction. Holes 10, 10 are formed opposite to each other, and a thread 11 is formed over a predetermined length on the outer periphery of the elongated hole. As shown in FIGS. 1 and 2, an annular adjusting plate 12 having a concave groove 12' in the groove direction on the outer surface is rotatably screwed onto the thread 11 of the lower metal 7, and It is assembled so that it can be moved up and down in the axial direction of the lower metal 7 by rotating along the lower metal 7. Also,
A pin 13 is loosely fitted between the opposing elongated holes 10, 10 of the lower metal 7, and the lower surface of the pin 13 engages and supports the upper surface of the adjuster plate 12, and the push rod 6' of the needle valve 6 is attached to the upper surface of the pin 13. are arranged so that they are in contact with each other.

Note that the adjuster plate 12 slides on the pin 13 when rotated, but in order to obtain a sense of moderation during rotation, it is preferable to adjust the adjuster plate 12 as shown in FIGS. 1 and 2. A plurality of radial grooves 14 are formed on the pin engagement surface. Reference numeral 15 denotes an annular guide collar fitted on the outside of both ends of the pin 13, and its outer circumferential surface is dimensioned to be flush with the outer circumferential surface of the adjuster plate 12.

Furthermore, as shown in FIGS. 1 and 2, a cylindrical adjuster cover 8 having an axial groove 8' formed in the inner wall surface is rotatably provided on the outside of the adjuster plate 12 and the guide collar 15. At the same time, as shown in FIG. The rotational force of the adjuster cover 8 is applied to the key 1.
7 to the adjusting plate 12. Further, preferably, the lower and upper parts of the adjustment cover 8 are each provided with a seal member 1.
It is in sealing contact with the lower metal 7 or the base member 9 via 8.

In the figure, 19 is a hose that connects to a sub-tank (not shown), 20 is a connection hole on the vehicle body side of the hydraulic shock absorber, and 21 is a connection hole on the wheel axle side.

Next, the operation of the present invention will be explained.

When the adjuster cover 8, which is in sealing contact with the lower metal 7 and the base member 9, is rotated from the outside, the rotational force of the adjuster cover 8 is transmitted to the adjuster plate 12 via the key 17, and the adjuster plate 12 is rotated from the outside. It moves up and down while rotating along the thread 11 of the lower metal 7. The upper surface of the adjuster plate 12 has a long hole 10 in the lower metal 7.
The pin 13 that moves up and down along the
are in contact with each other, the needle valve 6 is vertically displaced by the vertical movement of the adjuster plate 12, that is, the rotation of the adjuster cover 8, and the needle valve 6 is attenuated by adjusting the opening area of the oil passage 5 with its tapered tip. The power will be adjusted.

As described above, in this device, a dial-type adjustment cover is provided on the outer periphery of the operating part of the needle valve, and the rotation of the cover is transmitted to the inside of the operating mechanism via the key, so that all the movable parts that move up and down are covered by the adjustment cover. This eliminates the risk of dust getting in and causing problems with the operation of the adjustment mechanism as in the past, and also improves the service life.
It is particularly effective when used on motorcycles in motocross races.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a hydraulic shock absorber according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line -- in FIG. 1, and FIG. 3 is a side view of the lower metal. 1... Cylinder, 2... Piston, 3... Piston rod, 5... Oil path, 6... Needle valve, 7
...Lower metal, 8...Aziast cover, 10
...Long hole, 12...Adjust plate, 13...
...Pin, 16...Key engagement groove, 17...Key.

Claims (1)

[Scope of utility model registration request] The piston rod of the piston, which is slidably fitted into the cylinder with one end attached to the vehicle body side, is led out of the cylinder and connected to the axle by a lower metal at the end, and the piston rod is connected to the axis of the piston to the upper and lower oil chambers of the cylinder. In a damping force adjustment mechanism for a hydraulic shock absorber, the lower metal 7 and A long hole 10 is formed in the axial direction in the integrally provided cylindrical body part 7'.
A screw thread 11 is formed on the outer periphery of the elongated hole, and the lower metal 7 is fixed to the rear end of the hollow piston rod 3, and an axial groove 12' is formed on the outside.
An annular adjusting plate 12 having a shape formed thereon is screwed onto the thread 11 of the lower metal 7, and the elongated hole 10 of the lower metal 7 is inserted between the rear end of the push rod 6' inserted into the piston rod 3 and the adjusting plate 12. At the same time, the adjustment cover 8 having an axial groove 8' formed on the inner surface is rotatably and hermetically fitted to the outside of the adjustment plate 12, and the adjustment cover 8 concave groove 8' and adjuster plate 12
A damping force adjustment mechanism for a hydraulic shock absorber, characterized in that a key 17 is loosely fitted into a key engagement groove 16 with a concave groove 12' opposed to the key engagement groove 16.