JPS5813162Y2 - Double-tube shock absorber that separates oil and gas - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dual-tube shock absorber that separates oil and gas.

In general, the oil chamber and gas chamber are not separated in double-tube gas-filled shock absorbers that have an outer razor per tube that forms the gas chamber and an inner pressure tube that forms the oil chamber. Gas enters from the oil hole in the upper bearing, and the seal becomes a gas shaft seal instead of an oil shaft seal, which makes it easy for gas to escape to the outside, resulting in disturbances in the damping force waveform.

Additionally, as the piston rond moves up and down, gas enters the bearing guide, mixes with oil in the cylinder, and causes aeration, which disrupts the damping force waveform and causes play in the operation, causing noise. .

For this reason, as two methods for solving such problems, an oil damper as seen in, for example, Japanese Utility Model Publication No. 48-25495 is known.

In this type, a lip is provided integrally with the seal portion to allow the flow of oil and gas from the cylinder to the gas chamber, while blocking the flow of gas from the gas chamber to the cylinder.

However, with this structure, unexpected pressure is applied to the main lip of the seal to confine the jet flowing from the guide of the bearing part in a local space, and high-temperature hydraulic oil generated from thermal energy due to the generation of damping force is unavoidable. As a result, the product was poured onto the lip while it was still warm, which inevitably resulted in a decrease in the durability of the seal itself.

In addition, the piston rod always bends during operation, generating a twisting moment, and the main lip of the seal needs to follow this movement, but this movement is restricted due to the lip provided on the seal, preventing twisting, etc. This is something that can be seen occurring.

For this reason, the applicant has installed a flexible check valve independent of the seal in the middle of the passage connecting the cylinder and the gas chamber in order to separate the oil and gas, improve the damping force waveform, and prevent noise, thereby increasing the durability of the seal. Taking this into consideration, we have developed a dual-tube shock absorber and have applied for a patent.

However, this device discharges the gas between the cylinders and the mixture of gas and oil, and prevents gas from being sucked into the cylinders, and the check valve is oriented either from the top to the bottom or from the bottom to the top. The valve body was a steel plate with rubber baked into it.

However, this valve body has a conical shape with a tapered tip.
The entire tip has a check function, but as the temperature of the shock absorber hydraulic oil increases and changes over time, the tip becomes flattened or becomes less durable, causing it to open and reduce the check function. There are drawbacks.

Therefore, the purpose of this invention is to provide a shock absorber using a check valve that is sensitive and durable by providing vertical ribs made of the same material as the valve body, preventing shape deformation at the tip, and partially opening and closing the tip. The purpose is to provide an absorber.

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

In FIG. 1, the shock absorber has a bearing 2 fixed to the upper end of the cylinder 1, and a piston rod 3 is slidably inserted into the center of the bearing 2.
An oil chamber 4 is partitioned inside.

A cover 5 is fixed above the bearing 2.
A piston rod 3 passes through the center of the piston rod, and an oil seal 6 is disposed inside the piston rod.The inner ring 7 of this oil seal 6 slides on the outer periphery of the piston rod 3 to prevent oil leakage and to prevent oil from leaking. -5 Prevents dust from entering from outside.

A check valve 8 is disposed facing upward between the upper end of the bearing 2 and a banking retainer 19 on the lower surface of the oil seal 6, and this check valve 8 is connected to the upper surface of the bearing 2 by a spring 15 interposed between the upper end of the bearing 2 and the banking retainer 19 on the lower surface of the oil seal 6. The inner surface of the check valve 8, the lower surface of the oil seal 6, the piston rod 3, and the upper surface of the bearing 2 define an oil retaining chamber 9, and the outer surface of the check valve 8, the lower surface of the banking retainer 19, the inner surface of the cover 5, and the bearing 2 A liquid chamber 14 is defined by the upper surface.

Furthermore, the cover 5 has an outer f-'- coaxial with the cylinder 1.
-7''IQ is fixed, a gas chamber 11 is defined within this outer tube 710, and gas and oil are separated by isolating the gas chamber 11 and the oil chamber 4.

However, the lower part of the gas chamber 10 is filled with oil.

A through hole 12 is bored in the bearing 2, and the through hole 12 allows the liquid chamber 14 and the gas chamber 11 to communicate with each other.

In this case, the tip valve tongue of the check valve 8 is the backing presser 1.
9, the gas from the gas chamber 11 acts in the direction of closing the check valve 8 and does not flow into the oil chamber 9. However, when the internal pressure of the oil chamber 9 increases, By bending the tip valve tongue of the check valve 8, the oil in the oil retaining chamber 9 flows out into the gas chamber 11 through the through hole 12 and drips down to the oil level below the gas chamber 11.

As shown in FIGS. 2 and 3, the check valve 8 is constructed by uniformly covering the outer periphery or upper surface of the core metal 16 with a cone-shaped valve body 20 made of rubber or other similar material and baking the valve body 20. The tip valve tongue portion 21 of the valve body 20 is formed thin, and a plurality of vertical ribs 22 extending from the tip to the bottom are formed of the same material on the outer periphery of the valve body 20, so that the position of the vertical ribs 22 is made thicker. 20 is reinforced.

The valve body 20 has a distal valve tongue portion formed of a thick wall portion and a thin wall portion,
The valve tongue 21 normally comes into elastic contact with the tip of the banking presser 19, but when the internal pressure of the oil retaining chamber 9 increases, the thin wall portion of the valve tongue flexes to discharge oil toward the liquid chamber 14.

Note that it can be used without the backing presser 19, and it can also be used even if the tongue portion of the check valve 8 is brought into direct contact with the lower surface of the seal 6.

Also, as shown in other embodiments in FIGS. 4 and 5, the valve body 20
It is also possible to use it by forming the tip a relatively thick, forming only the thin tongue portion of the tip 21a to be thin in a plurality of places, and forming a plurality of vertical ribs 22a between the thin portions.

In short, it is only necessary to form a thin wall part and a thick wall part in the distal valve tongue part while reinforcing the valve body, and to bend the thin wall part 1-1 so that the valve can be opened and closed.

In the shock absorber of the present invention, oil in the oil chamber 4 leaks into the oil chamber 9 through the gap 13 between the bearing 2 and the piston wand 3 as the piston rod 3 slides, and this leaked oil is temporarily stored in the oil chamber 9. However, the thin tongue part of the valve body tip 21 of the check valve 8 is flexible and comes into contact with the banking presser 19 or the lower surface of the seal 6 under a minute load. When the oil stored in the oil storage chamber 9 is filled and the internal pressure rises above the cent load of the check valve 8, the thin walled portion of the tip 21 of the check valve 8 bends outward and opens, draining the oil in the oil storage chamber 9. It is discharged into the chamber 14, and further through the through hole 1.
2 to the gas chamber 11.

At this time, since the check valve 8 has a core metal 16 built inside and a vertical rib 22° 22a is formed on the outer periphery, not only the lower part of the check valve 8 but also the valve tongue which is the tip of the valve body always maintains a constant strength. This material is reinforced with aluminum and has good followability and durability even after long-term use.

As described above, in the shock absorber of the present invention, the tip 21, 218 of the check valve has a thin wall portion and a thick vertical rib 22.2.
It can be formed from 2a, and the thin wall part performs the opening and closing operation, and the vertical rib part reinforces the valve body, so there is no shape deformation at the tip, making it durable, and the thin wall part allows the opening and closing operation to be performed partially. By doing so, the operation becomes more sensitive and it is possible to prevent the check function from deteriorating due to temperature rise and aging.

Furthermore, in the Shonkuapunba of this invention, the seal member and check valve are each independent, so even if a bending or twisting moment occurs in the seal, the check valve will not follow the movement of the seal.Note that the check valve will not be twisted. I live without.

Also, the jet pressure against the lip of the seal can be reduced without being confined within the same chamber.

The material of the flexible part of the check valve, such as rubber hardness, can be selected regardless of the seal, and the opening pressure can be freely controlled. By synchronizing the increase in ejection volume and the decrease in rubber hardness due to high temperatures, the pressure applied to the seal can be optimally controlled.

Furthermore, by removing the check valve, it can be easily configured as a standard non-gas-filled shock absorber.

Furthermore, since the jet flow toward the lip of the seal is stored in the oil storage chamber, which has a large space, a cooling effect can be expected in terms of temperature, and the jet pressure can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway vertical side view of Shosoku Abunuba according to an embodiment of the present invention, FIG. 2 is a perspective view of a check valve, and FIG. 3 is a partially vertical side view of FIG. 2. FIG. 4 is a perspective view of a check valve according to another embodiment, and FIG. 5 is a partially vertical side view of FIG. 4. 8... Check valve, 19... Banking foot, 20.20a... Hull, 21.21a.
...Tip, 22.22a...I follow.

Claims (4)

[Scope of utility model registration request] (1) In a shock absorber equipped with a check valve that opens above the cylinder oil chamber and the cylinder outside gas chamber by extension action and closes by compression action, the valve body of the check valve is formed into a truncated conical shape, A dual-tube shock absorber that separates oil and gas by forming a plurality of vertical ribs on the outer periphery of the valve body, with a thin wall part and a thick inner part at the tip. (2) A dual-tube shock absorber that separates oil and gas according to claim (1) of the utility model registration, in which the vertical rib extends from the tip to the bottom. (3) A dual-tube shock absorber in which oil and gas are separated, as set forth in claim (1) of the utility model registration, in which a thin wall portion is formed only near the tip. (4) A dual-tube shock absorber that separates oil and gas as set forth in claim (1) of the utility model registration, in which the valve body is disposed upward and its tip is brought into contact with a banking presser.