JPS6238575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas filling device for a shock absorber, and more specifically, as a means for actively improving the suction performance from the reservoir of a bottom valve, it is possible to improve the damping force characteristics by the gas filling effect. In the so-called gas-filled shock absorber, which can improve abnormal noise by reducing airation,
This invention relates to a gas filling device that allows gas filling to be performed easily.

Unlike conventional strut-type shock absorbers of this type, the gas chamber and oil chamber are not separated, and an oil seal-type packing with a dust seal and lip is incorporated into the upper bearing of the operating cylinder, in sliding contact with the piston rod. In a shock absorber that fills pressure gas, an expensive filling valve that requires precision is installed at an appropriate position in the actuating cylinder. Pressure gas is filled through this filling valve, and after gas filling, the filling valve Either completely fix the parts by welding or other means to prevent pressure gas from leaking to the outside, or provide a special sealing hole or slit in a part of the structure of the shock absorber, and use these holes or slits. After filling the gas with the gas, etc., the lid was put on or the slit was moved. For this reason, it is difficult and troublesome to design, process, and manufacture a special filling valve and to perform hole drilling and welding as described above, and the cost increases and becomes uneconomical.

Therefore, the present invention makes it possible to reliably and easily fill gas by making slight improvements to the existing sealing member, without requiring any special hole drilling, welding or filling valves. Easy and reliable installation to the gas inlet.
Moreover, it is an object of the present invention to provide a gas filling device for a shock absorber that can reliably prevent gas leakage during gas injection.

To achieve this objective, the configuration of the present invention is such that a piston rod is slidably inserted into the center of the bearing.
In the shock absorber, a seal member held by a ring nut is arranged above the bearing, and a reservoir chamber is partitioned below the bearing.
A sealing lip made of an elastic material different from the sealing member is provided inside the main body of the sealing member, and a gas filling hole is bored in the main body of the sealing member, and this gas filling hole is opened and closed by the sealing lip. It is characterized by this.

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

In the shock absorber according to the present invention, a cylinder tube 2 coaxial with the outer tube 1 is inserted into the outer tube 1, and a piston rod 3 is slidably inserted into the cylinder tube 2 via a piston.
A lower oil chamber and a reservoir chamber 4 above it are formed in the outer tube 1, and a cylinder tube 2 is formed inside the outer tube 1.
Inside, an upper oil chamber 5 and a lower oil chamber are partitioned by a piston.

A bearing 6 and a bush 7 on the inner circumference of the cylinder tube 2 are fixed to the upper end of the cylinder tube 2. A piston rod 3 slidably passes through the center of the bush 7 and protrudes to the outside.
A seal 8 is interposed between them to prevent oil and gas from leaking.

An oil chamber 9 is defined in the upper part of the bearing 6, and a through hole 10 is bored in the bearing 6.
0 communicates the oil chamber 9 and the reservoir chamber 4, and also connects the oil chamber 9 to the reservoir chamber 4.
communicates with the upper oil chamber 5 through a gap between the bush 7 and the piston rod 3.

An oil seal assembly is removably installed inside the upper part of the outer tube 1. The oil seal assembly consists of a ring nut 13 screwed into the outer tube 1, a seal member 14 held inside the ring nut 13, and a seal lip 20. The seal member 14 has an upper dust seal lip 11 and a lower dust seal lip 11. The oil seal lip 12 and a main body 16 with an L-shaped cross section or other similar body that holds these lips are integrally formed of an elastic material, and the dust seal lip 11 and the oil seal lip 12 extend in opposite directions. Its inner circumferential surface is in sliding contact with the outer circumference of the piston rod 3, the dust seal lip 11 prevents dust from entering from the outside, and the oil seal lip 12 prevents oil leakage in the oil chamber 5 and reservoir chamber 4. .

The seal lip 20 is made of an elastic material having an L-shaped cross section and has a built-in core metal.The outer periphery of the seal lip 20 fits into the inner periphery of the seal member 14, and opens and closes the mouth end of the gas filling hole 21 formed in the seal member 16. I'm starting to do that.

A flange portion 17 is provided above the ring nut 13, a hole 18 through which the piston rod 3 passes is formed inside the flange portion 17, and a chamber 19 is provided between the flange portion 17 and the sealing member 14.

In the above gas filling device, high pressure gas is introduced through the filling passage hole 21, the seal lip 20 is opened, and the gas is led to the reservoir chamber 4 through the oil chamber 9 and the passage 10. When a predetermined gas is introduced, the internal pressure of the reservoir chamber 4 closes the seal lip. 20 is pressed against the inner surface of the main body of the sealing member 14 to self-seal.

Next, the gas filling process will be explained with reference to FIG.

First, the lower part of the hollow jig 24 is inserted into the outer periphery of the outer tube 1 through the seal 25, and the piston rod 3 is compressed and brought into contact with the stopper 26 of the jig 24. A predetermined high pressure gas can be introduced into the jig 24 from the outside, and the stopper 26 is designed to detect the repulsive force from the piston rod 3 and measure it with an external meter 27.

When high-pressure gas is introduced into the jig 24 from this state, this gas is introduced into the oil chamber 9 through the hole 18, the chamber 19, and the gas filling hole 21 by bending the seal lip 20 downward, and is further introduced into the oil chamber 9 through the passage 10. is supplied to When a predetermined gas is supplied, this gas pressure acts on the piston rod 3 and tries to push it up, so the stopper 26 detects the repulsive force.
Measure with the meter 27, and when the predetermined pressure is reached, the jig 2
Remove 4. At this time, the internal pressure of the reservoir chamber 4 acts on the seal lip 20 from the passage 10 and the oil chamber 9,
This seal lip 20 is pressed against the lower surface of the main body 16 to close the through hole 21 and self-seal, thereby preventing backflow of gas and sealing in a predetermined gas.

In the gas filling device of the present invention, a through hole is bored in the axial direction in the main body of a conventional sealing member, and a seal lip consisting of a sealing member and another elastic member is attached to the main body of the sealing member so as to open and close the end of the through hole. Since it is only provided on the inside, the structure is simple and processing is easy. Furthermore, gas filling can be performed reliably and easily, which is advantageous in terms of cost.

That is, the shock absorber can be reliably and easily attached to the gas injection port, and gas leakage can be reliably prevented during gas injection. Furthermore, the seal lip itself has a check valve function that closes the seal hole when gas is filled in, and since the seal lip itself is installed in a position that is not affected by assembly, it is already integrated as a check valve.
Assembling work becomes easier and assembly accuracy can be improved.

[Brief explanation of the drawing]

The attached drawings relate to one embodiment of the present invention, and show the first embodiment of the present invention.
The figure is a longitudinal side view, and FIG. 2 is a longitudinal side view during the sealing operation. 3...Piston rod, 4...Reservoir chamber, 6
... Bearing, 11 ... Dust seal lip,
12... Oil seal lip, 13... Ring nut, 14... Seal member, 16... Main body, 20
... Seal lip, 21 ... Through hole.

Claims (1)

[Claims] 1. A shock absorber in which a piston rod is slidably inserted into the center of the bearing, a sealing member held by a ring nut is disposed above the bearing, and a reservoir chamber is defined below the bearing. , a shock absorber in which a seal lip made of the seal member and another elastic material is provided inside the main body of the seal member, a gas filling hole is bored in the main body of the seal member, and this gas filling hole is opened and closed by the seal lip. Gas filling device. 2. A gas filling device in a shock absorber according to claim 1, wherein the sealing member comprises a main body, a dust seal lip and an oil seal lip provided on the main body. 3. A gas filling device in a shock absorber according to claim 1, wherein the gas filling hole is bored in the main body of the seal member in the axial direction, and the seal lip is provided along the inside of the main body of the seal member. 4. A gas filling device in a shock absorber according to claim 1, wherein the seal lip is made of an elastic material having an L-shaped cross section.