JPH04114144U - Oil lock mechanism of hydraulic shock absorber - Google Patents

Abstract

(57) [Summary] [Purpose] To improve durability and reliability by smoothing the sliding movement of a member that fits into a bottomed cylindrical member. [Structure] At the end of the compression stroke of the piston rod 3, the free piston 21, which is slidably fitted in the bottomed cylindrical member 17, is pressed down by the pressing member 31, thereby locking the oil.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to an oil lock mechanism that prevents a hydraulic shock absorber from bottoming out.

0002

[Conventional technology]

As shown in FIG. 7, a conventional hydraulic shock absorber has a cylinder 1 in an outer tube 101. 02 is set upright, the piston rod 103 is inserted into the cylinder 102, and the piston rod 103 is inserted into the cylinder 102. A piston 104 that slides on the inner peripheral surface of the cylinder 102 is fixed to the lower end of the connecting rod 103. oil passages 105 and 106 for generating damping force are formed in the piston 104, and these Valves 107 and 108 are installed to open and close oil passages 105 and 106.

0003 A bottom valve machine is installed at the bottom of the tube 101 (lower part of the cylinder 102). A bottom valve mechanism 110 is provided, and a bottomed valve facing into the cylinder 102 is provided on the bottom valve mechanism 110. A collar 111, which is a cylindrical member, is provided, and this collar 111 has a cylinder lower chamber and a reservoir. An orifice 113 that communicates with the valve chamber 112 via the bottom valve mechanism 110 is formed. has been completed. On the other hand, the lower end of the piston rod 103 is provided with a collar at the extended portion 103a. - Attach a piece 115 that can be fitted to the inner peripheral surface of 111, and insert a chain into this piece 115. A check valve 116 is provided, and an oil hole 117 is formed in the piece 115.

0004 In the above-mentioned hydraulic shock absorber, the piece is removed at the end of the compression stroke of the piston rod 103. By fitting the piece 115 into the collar 111, the piece 115 and the collar 111 are connected. The hydraulic oil is sealed in between and an oil lock is applied. Then, at the beginning of the extension stroke The hydraulic oil flows from the oil hole 117 of the piece 115 to the collar via the check valve 116. 111.

[0005]

[Problem that the idea aims to solve]

However, in the oil lock mechanism of the conventional hydraulic shock absorber mentioned above, the pin It is necessary to allow a certain amount of mating length between the base and collar, which increases the basic length. Furthermore, P Because the base and collar slide against each other, galling, scratches, and noise may occur, resulting in poor durability. This will reduce reliability, and if the axes of the piece and collar become misaligned, operability will deteriorate. .

[0006]

[Means to solve the problem]

In order to solve the above problems, the present invention uses a spring inside the bottomed cylindrical member to bias it upward. The free piston is slidably fitted and comes into contact with the free piston at the end of the compression stroke. A pressing member for pressing the piston rod was provided at the lower end of the piston rod.

[0007]

[Effect]

At the end of the compression stroke, the pressing member installed on the piston rod comes into contact with the free piston. By pressing against the urging force of the spring, hydraulic oil is sealed inside the bottomed cylindrical member. At this time, the free piston and the bottomed cylindrical member are The mating length is shortened, sliding becomes smoother, and durability and reliability are improved.

[0008]

【Example】

Embodiments of the present invention will be described below with reference to the accompanying drawings. Figure 1 shows the results obtained by applying the present invention. Figure 2 is a sectional view of the main parts of a hydraulic shock absorber equipped with an oil lock mechanism. Figure 3 is an enlarged cross-sectional view of the main part of the same mechanism, and Figure 4 is the main part of the mechanism in the locked state. FIG. 5 is a sectional view of a main part of another embodiment of the present invention.

[0009] A cylinder 2 is installed upright inside the bottomed cylindrical outer tube 1. Insert the piston rod 3 from above and attach the cylinder to the lower end of the piston rod 3. A piston 4 is fixed in sliding contact with the inner circumferential surface of the cylinder 2, and this piston 4 has a damping force generator. It is composed of a plurality of disc valves that form oil passages 5 and 6 and open and close these oil passages 5. A valve 8 consisting of a plurality of disc valves that open and close the oil passage 6 is installed. are doing.

0010 A bottom valve mechanism 10 is installed at the bottom of the tube 1 (lower part of the cylinder 2). The bottom valve mechanism 10 has oil passages 12 and 13 formed in the bottom piece 11. A valve 14 opens and closes these oil passages 12 and a valve 1 opens and closes oil passages 13. I am wearing 5. Then, on the bottom piece 11 of this bottom valve mechanism 10, is provided with a collar 17 which is a cylindrical member with a bottom, and this collar 17 has a cylinder lower chamber and a rim. An oil passage 19 is formed that communicates with the reservoir chamber 18 via the bottom valve mechanism 10. .

[0011] A free piston 21 is slidably fitted into this collar 17, and the bottom It is biased upward by a spring 22 interposed between the two parts. free piston 21 A Teflon ring 24 is fitted onto the outer peripheral surface of the , an oil hole 25 is formed, and a check valve 26 for opening and closing this oil hole 25 is fitted with a locking ring. The check valve is installed by being biased by a spring 28 interposed between the check valve An oil hole 29 is formed in 26. Furthermore, there is a free piston in the upper part of the collar 17. 21 stopper rings 30 are fitted.

0012 On the other hand, the lower end of the piston rod 3 is extended and the piston 2 is free at the end of the compression stroke. 1, and a rubber plate is formed on the lower end surface of this pressing portion 31. 32 is attached. In addition, the shape of the rubber plate 32 may be different from the plate shape as shown in the embodiment. A spherical shape as shown in 6 is also possible.

[0013] The operation of the oil lock mechanism of the hydraulic shock absorber configured as above will be explained. . When the piston rod 3 descends from the state shown in Fig. 1 during the compression stroke, the piston rod 3 Hydraulic oil equivalent to the entering volume flows from the cylinder lower chamber to the oil passage 19 and the bottom valve mechanism 10. The oil flows into the reservoir chamber 18 through the oil passage 12 . At this time, the pressing part 31 is a piston. As the rod 3 descends, it descends and at the end of the compression stroke of the piston rod 3, the 2 and 3, the rubber plate 32 of the pressing member 31 is placed above the free piston 21. The free piston 21 is spun out by further lowering the piston rod 3. Since it is pushed down against the biasing force of the ring 22, the hydraulic oil is sealed inside the collar 17. The oil becomes locked.

[0014] From this state, the piston rod 3 rises in the rebound direction, and the pressing part 3 1 separates from the free piston 21, and the free piston 21 is attached to the spring 22. At this time, the check valve 26 opens and the collar 1 flows through the oil hole 25. 7 is replenished with hydraulic oil.

[0015] Next, in another embodiment shown in FIG. 5, a groove 35 of a predetermined length is formed from the bottom side of the cover. A tapered portion 36 that spreads toward the bottom of the stopper ring 30 at the upper part of the inner circumferential surface of the roller 17 is formed. By doing this, the free piston 21 starts to move. (When the oil lock starts to work), remove the free piston from the groove 35 or tapered part 36. Since the hydraulic oil flows bypassing the piston 21, the pressing part 31 is free piston 21. It is possible to prevent a sudden damping force from being generated at the moment of contact.

[0016]

[Effect of the idea]

As explained above, according to the present invention, the free piston is slid inside the bottomed cylindrical member. By fitting it so that it can move freely and pressing this free piston at the end of the compression stroke. Since the oil lock is applied, the axis of the free piston and the bottomed cylindrical member are aligned. Smooth sliding without slipping, improving durability and reliability.

[Brief explanation of drawings]

[Figure 1] Cross-sectional view of essential parts of a hydraulic shock absorber equipped with an oil lock mechanism to which the present invention is applied

[Figure 2] Cross-sectional view of the main parts of the hydraulic shock absorber in the oil-locked state

[Figure 3] Enlarged sectional view of the main parts of the mechanism

[Fig. 4] Cross-sectional view of main parts of another embodiment of the present invention

[Fig. 5] Cross-sectional view of main parts of still another embodiment of the present invention

[Fig. 6] A diagram showing another example of the shape of the rubber plate.

[Figure 7] Cross-sectional view of main parts of a conventional hydraulic shock absorber

[Explanation of symbols]

1...Tube, 2...Cylinder, 3...Piston rod, 4
... Piston, 10 ... Bottom valve mechanism, 11 ... Bottom piece, 17 ... Collar (bottomed cylindrical member), 21 ... Free piston, 22 ... Spring, 31 ... Pressing part.

Claims (1)

[Scope of utility model registration request] Claim 1: A hydraulic system in which a bottomed cylindrical member is disposed at the bottom of the lower cylinder chamber, and hydraulic oil is sealed in the bottomed cylindrical member to apply an oil lock at the end of the compression stroke of the piston rod. In the oil lock mechanism of the shock absorber, a free piston urged upward by a spring is slidably fitted in the bottomed cylindrical member, and the free piston is pressed against the free piston at the end of the compression stroke. An oil lock mechanism for a hydraulic shock absorber, characterized in that a pressing member is provided at the lower end of the piston rod.