JPH0343475Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a one-way shock absorber mainly used for controlling gear shift operation time in automobiles.

(Prior art and its problems) In a conventional one-way shock absorber, for example, as shown in FIG. A ball valve 32 is arranged in the valve hole 20 portion as a valve body.

However, the ball valve type check valve has a problem in that the responsiveness of opening and closing the valve to the movement of the rod is slow. Furthermore, since the ball valve 32 is disposed inside the thick piston 33, the check valve itself is heavy and the structure of the check valve itself is complicated.

(Means for solving the problem) In order to solve the above problem, the present invention seals a buffer fluid in a damper case and arranges a piston plate movably, and the piston plate is connected via an appropriate connection mechanism. The piston plate is connected to an external operating member, the piston plate and the inner peripheral surface of the case are connected by a rubber diaphragm, and the inside of the case is divided into first and second chambers, and the piston plate is provided with a valve hole and a small diameter orifice. A flexible film-like valve body for a check valve is formed integrally with the diaphragm at the inner circumferential end of the rubber diaphragm, and the valve body is seated on the first chamber side surface of the valve hole. When the pressure in the chamber is higher than that in the second chamber, the pressure difference causes the valve body to remain closed, and when the pressure in the second chamber is higher than in the first chamber, the pressure difference causes the valve body to open.

(Example) Fig. 1 shows an example in which the one-way shock absorber of the present invention is connected to a gear switching rod 8 for switching between two-wheel drive and four-wheel drive of a four-wheel drive vehicle. , the damper case 1 consists of a pair of front and rear cylindrical case members 1a and 1b, a boss part 2 is fixed to the front case member 1a, and a bearing cylinder 3 and an O-ring 4 are attached to the inner periphery of the boss part 2. A rod 5 is inserted through the rod 5 so as to be movable back and forth (axially). Air is sealed in the case 1 as a buffer fluid. Boss part 2 is transmission case 6
The front and rear parts of the rod 5 protrude into the transmission case 6 and abut against the gear switching rod 8.

The rear end of the rod 5 extends into the case 1, and a circular piston plate 11 and a circular back plate 12 are fixed to the rear end of the rod 5. Both plates 11 and 12 have their inner peripheral ends connected to the rod 5.
It is sandwiched between the collar 17 and the retaining ring 14. The inner circumferential ends of both plates 11 and 12 are in pressure contact with each other, but the intermediate portions in the radial direction are separated from each other in the front and rear, forming an intermediate chamber 19. Cylindrical diaphragm guide portions 11a and 12b are formed at the outer peripheral ends of both plates 11 and 12, respectively.

An annular rubber diaphragm 10 has its inner peripheral end sandwiched between the outer peripheral ends of both plates 11 and 12. Further, an annular recess 12a is formed at the outer peripheral end of the back plate 12.
includes an annular bulge 1 at the inner peripheral end of the diaphragm 10;
0a is engaged. The outer peripheral end of the diaphragm 10 is sandwiched between flanges of both case members 1a and 1b.

The interior of the case 1 is divided by the above-mentioned plates 11, 12 and the rubber diaphragm 10 into a first chamber 25 on the rear side and a second chamber 26 on the front side.
A conical return coil spring 16 is disposed within the spring 5 . A return coil spring 16 is compressed between the back plate 12 and the rear wall of the case 1, and urges both plates 11, 12 and the rod 5 forward.

In order to circulate air between the two chambers 25 and 26, the piston plate 11 is formed with a plurality or one check valve hole 20 and a plurality or one small-diameter orifice 21.
2 has a communication hole 23 formed therein. The orifice 21 constantly communicates between the two chambers 25 and 26 via the intermediate chamber 19 and the communication hole 23, and the valve hole 20 can be opened and closed by the flexible valve body portion 18.

According to the present invention, the valve body portion 18 is formed integrally with the inner circumferential end of the rubber diaphragm 10.
A valve hole 20 extends radially inwardly within the intermediate chamber 19 .
is closed from the intermediate chamber 19 side (first chamber 25 side), and can be bent rearward. Although the valve body portion 18 is formed in an annular shape around the entire circumference, it may be formed only at a location corresponding to the valve hole 20 portion.

(Function) During gear shift operation, the cam surface 8 of the switching rod 8
When rod 5 is pushed backward by a, both plates 1
1 and 12 are pushed backward against the spring 16. As a result, the first chamber 25 is pressurized to a higher pressure than the second chamber 26, and the closed state of the valve body portion 18 is maintained as shown in FIG. Therefore, the air in the first chamber 25 gradually flows into the second chamber 26 through the communication hole 23 and the orifice 21. That is, the rod 5 is cushioned so that it does not move suddenly backward, and the operation time is controlled.

When the rod 5 returns to the front, the piston plate 11 etc. move forward due to the elastic force of the spring 16, but at this time the second chamber 26 is pressurized and has a higher pressure than the first chamber 25. The pressure difference causes the valve body portion 18 to open as shown in FIG. Therefore, the second chamber 2
6 passes through both the valve hole 20 and the orifice 21 and returns from the intermediate chamber 19 to the first chamber 25 through the communication hole 23. That is, the piston plate 11 and the rod 5 quickly return to the front.

Note that by changing the hole diameter or number of orifices 21, the degree of buffering can be adjusted as desired.

(Another Embodiment) Oil can also be included as a buffer fluid.

(Effects of the invention) As explained above, according to the invention: (1) Since the inside of the case 1 is partitioned using the rubber diaphragm 10 and the piston plate 11, it is difficult to use a thick piston as shown in FIG. O body
Compared to a structure that fits through a ring, weight reduction can be achieved.

(2) Since the valve body 18 for the check valve is formed using a part of the diaphragm 10, the number of parts is reduced and the structure is simpler than when using a conventional ball valve. be.

(3) Since the valve body 18 for the membrane check valve is formed using a part of the flexible diaphragm 10, the responsiveness of the check valve to pressure changes in both chambers 25 and 26 is improved. good.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of the one-way shock absorber according to the present invention, Figure 2 is a partial vertical cross-sectional view during the buffer stroke, Figure 3 is a partial vertical cross-sectional view during the return stroke, and Figure 4 is a partial vertical cross-sectional view of the conventional shock absorber. FIG. DESCRIPTION OF SYMBOLS 1... Damper case, 10... Rubber diaphragm, 11... Piston plate, 18... Valve body part, 20... Valve hole for check valve, 21... Orifice, 25, 26... First, second Room.

Claims (1)

[Scope of utility model registration request] A damper case is filled with a buffer fluid and a piston plate is movably arranged, the piston plate is connected to an external actuating member via an appropriate connection mechanism, and the piston plate and the inner peripheral surface of the case are connected by a rubber diaphragm. The interior of the case is divided into first and second chambers, a valve hole and a small-diameter orifice are formed in the piston plate, and a flexible membrane-like check valve body is attached to the inner peripheral end of the rubber diaphragm. The valve body part is formed integrally with the diaphragm, and the valve body part is seated on the surface of the first chamber side of the valve hole, and when the pressure in the first chamber is higher than that in the second chamber, the valve body part is in a closed state due to the pressure difference. , and when the pressure in the second chamber is higher than that in the first chamber, the valve body portion opens due to the pressure difference.