JPS6326587Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hydraulic shock absorber equipped with temperature compensation for correcting fluctuations in damping force due to changes in oil temperature and a mechanism for adjusting damping force by manual external operation. .

Conventionally, as shown in FIG. 1, as a temperature compensation mechanism for a hydraulic shock absorber, a piston rod 1 is provided with an oil passage 3 that crosses the piston 2, and a bush 4 inserted into the oil passage 3 is heated to absorb heat in the oil chamber. The area of the orifice hole 6 of the oil passage 3 is changed by sliding the expansion oil 5, and the change in the hole area changes the damping force characteristic due to the decrease in oil viscosity as the oil temperature rises. There are devices that compensate for the decrease in damping force, but although these types of devices compensate for the temperature of the damping force, they do not adjust the damping force on the rebound side depending on the road conditions, such as shock absorbers for motorcycles, etc. However, it is not possible to adjust the rebound damping force from the outside.

The present invention has been made in view of the above-mentioned drawbacks, and aims to provide a hydraulic shock absorber that can compensate for the temperature of the damping force due to oil expansion and that can easily adjust the rebound damping force from the outside. .

Hereinafter, one embodiment of the hydraulic shock absorber of the present invention will be explained with reference to Figs. 2 to 4. Fig. 2 is a partially cutaway front view, and Figs. 3 and 4 are enlarged views of the main parts. FIG.

11 is a cylindrical cylinder with a bottom, and a piston 12 is inserted into the cylinder 11 airtightly and slidably, and a pipe rod 14 is screwed and fixed to the inner end of the cylinder 11 with a nut 13. It protrudes from the shaft hole of the end member 15 fixed to the mouth end, and
A dust seal 16, a sliding bearing 17, and a bump rubber 18 are fixed to the inside of the end member 15. A locking plate 20 is loosely fitted to the lower end of the mounting bracket 19 that is screwed and fixed to the outer end of the pipe rod 14, and is spaced between the locking ring 21 screwed onto the outer periphery of the midsection of the cylinder 11 and the locking plate 20. The pipe rod 14 is elastically biased in the protruding direction by a coil spring 22 loaded in the piston 12, and the upper chamber A and lower chamber B of the cylinder divided by the piston 12 are filled with hydraulic oil. It consists of

Reference numeral 23 denotes a check valve inserted between one end of the oil passage hole 24 drilled in the piston 12 and the valve stopper 23a, and when the shock absorber contracts, the piston 12 moves downward from the lower chamber B to the upper chamber A.
It opens only in the direction in which the hydraulic oil flows, and closes when the shock absorber extends.

The damping force adjustment and temperature compensation mechanism 25 includes a needle valve 28 sharply provided at the lower end of the operating rod 27 inserted airtightly and slidably into the shaft hole 26 of the pipe rod 14, and a needle valve 28 provided at the lower end of the shaft hole 26. The valve hole 30 of the bush 29 is inserted airtightly and slidably into the valve hole 30 of the bush 29.
It is constructed by an orifice 31 constructed by the bush 29, the lower end of the shaft hole 26, and the lower end of the pipe rod 14, and the cap 23 is screwed onto the lower end of the pipe rod 14 via a sealing member 32. The thermal expansion chamber C is filled with a thermal expansion material 34 made of liquid or gas having a large thermal expansion coefficient, and the bush 29 is expanded by the expansion and contraction action of the thermal expansion material 34.
It consists of sliding displacement in the axial direction.

The upper end of the operating rod 27 protrudes from the upper end of the pipe rod 14, and the upper end of the operating rod 27 protrudes from the upper end of the pipe rod 14.
A screw shaft portion 36 is screwed into a female screw 35 screwed into the screw shaft portion 9, and a gear member 37 is inserted and fixed in the vicinity of the screw shaft portion 36, and a gear member 37 is rotatably installed in the mounting bracket 19. A gear shaft 38 is meshed with the gear shaft 38, and a rebound damping force adjustment knob 39 is fixed to the outer end of the gear shaft 38.

Reference numeral 40 denotes a steel ball elastically biased in the inner radial direction by a coil spring 41, and the gear member 37
The gear member 37 engages with locking grooves 42 formed at equal intervals on the outer periphery of the boss portion, and engages with each other at the rotational position. The operating rod 27 rotates, and the operating rod 27 slides within the shaft hole 36 due to the screwing action of the threaded shaft portion 36 and the female thread 35.

Reference numerals 43 and 44 indicate oil passages drilled in the pipe rod 14 so as to sandwich the piston 12 and communicate the shaft hole 26 with the upper chamber A and the lower chamber B, respectively. and the needle valve 28 , and the lower oil passage 43 opens at a circumferential groove 44 communicating with the valve hole 30 of the bush 29 .
The upper chamber A and the lower chamber B of 1 are connected to each other.

In the figure, reference numeral 45 denotes a mounting ring protruding from the lower end of the cylinder 11.

The hydraulic shock absorber having the above configuration has a piston 1 at the time of compression.
When the piston 12 is pushed down, the check valve 23 opens and the hydraulic oil in the lower chamber B moves through the oil passage hole 24 to the upper chamber A. When the piston 12 is pulled up during extension,
Since the check valve 23 is closed, the hydraulic oil in the upper chamber A flows through the orifice 3 of the damping force adjustment and temperature compensation mechanism 25.
Since the pressure moves to the lower chamber B via the pressure sensor 1, a desired damping force can be obtained.

That is, the damping force on the rebound side can be adjusted manually, and when the adjustment knob 39 is rotated, the operating rod 27 rotates together with the gear member 37 that meshes with the gear shaft 38. Screw shaft part 3
6 and the female thread 35 of the mounting bracket 19, the operating rod 27 slides within the pipe rod 14, and the needle valve 28 moves in and out of the valve hole 30 of the bush 29.

This displacement causes the orifice 31 between the needle valve 28 and the valve hole 30 to expand, thereby adjusting the amount of restriction.

Further, when the oil temperature increases and the viscosity of the hydraulic oil decreases, the bush 29 is slid in the direction of the needle valve 28 due to the increase in volume of the thermal expansion material 34 in the thermal expansion chamber C as the temperature rises. .

Due to this displacement, the orifice 31 formed by the needle valve 28 and the valve hole 30 is throttled, and the amount of throttle is commensurate with the decrease in the viscosity of the hydraulic oil, so that even if the oil temperature fluctuates, the orifice 31 is throttled. will maintain power. Furthermore, in the present invention, since the push rod and the needle valve are integrated, the number of parts is small, the assembly work is easy, and there is a great cost advantage.

As mentioned above, the hydraulic shock absorber of the present invention has a temperature compensation mechanism to compensate for fluctuations in damping force due to a decrease in the viscosity of hydraulic oil due to changes in oil temperature, and a mechanism to adjust the rebound damping force from the outside. It has the feature of easy adjustment operation, and is particularly useful as a shock absorbing force adjustable hydraulic shock absorber for motorcycles traveling on rough or flat roads. The effect is extremely large.

[Brief explanation of drawings]

The drawings show one embodiment of the hydraulic shock absorber of the present invention, in which Fig. 1 is a front sectional view of the main part showing a conventional mechanism, Fig. 2 is a half-cut front sectional view of the present invention, Fig. 3 is an enlarged sectional view of the control mechanism, and Fig. 4 is an enlarged sectional view of the extension side damping force adjustment part. 11...cylinder, 12...piston, 14...
... pipe rod, 15... end member, 19... mounting bracket, 22... coil spring, 23... check valve, 24... oil passage hole, 25... temperature compensation mechanism, 2
7: Operating rod, 28: Needle valve, 29:
... bushing, 34 ... thermal expansion material, 37 ... gear member, 38 ... gear shaft, 39 ... adjustment knob, 43,
44...Oil passage.

Claims (1)

[Scope of utility model registration request] In a hydraulic shock absorber, an oil chamber is defined by a piston inserted into a cylinder, and the piston has a valve for generating a damping force. A pusher is inserted, a thermal expansion chamber filled with a thermal expansion material is formed at one end of the pusher, and a valve hole having an approximately L-shaped cross section is bored at the other end, and one end of the valve hole is connected to a cylinder. The seat part is opened through an oil passage into the lower chamber of the shaft hole, and the other end thereof faces a needle valve integrated with an axially adjustable push rod inserted from one end of the shaft hole to form a throttle passage. A hydraulic shock absorber characterized by: