JPS5817277A - Locking and unlocking valve device for expansion lock device - Google Patents

Abstract

PURPOSE:To reduce a pressure difference between before and after a seal ring, by providing a seal ring in a seal ring groove formed in the inside surface of a piston or a valve bore and by providing an auxiliary bypass for the main circular passage. CONSTITUTION:A seal ring groove 18 which is long enough to reach an orifice passage 8 is formed in the inside of a valve bore 9 of a piston section. In this groove 18, a back-up ring 19 is installed. A seal ring 12 is installed in a groove provided between this ring 19 and a side plate 21. And an auxiliary bypass 20 for a main circular passage 17 on the inside diameter side of the seal ring, is defined to connect the outer peripheral section of the back of this seal ring 12 to the orifice passage 8. In the initial period of valve opening operation, therefore, the main circular passage 17 is bypassed to the back pressure side of the outer periphery of the seal ring 12 to cause the initial flow of a pressure fluid to balance the pressure for proper recovery of the seal ring 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is subject to very high pressure fluids and
Regarding an on-off valve device including a seal ring that forms a passage for the pressure fluid with the sliding spool valve member or conversely ensures a sealed state between the sliding spool valve member and the sliding spool valve member, particularly, Defining parts such as piston parts in oil- or gas-filled telescoping locking devices used as support devices for stepless height adjustment of office chairs and desks, or locking devices for adjusting the tilt angle of the backrest of reclining seats. This invention relates to an improved on-off valve device installed in a.

The general structure of the telescoping lock device to which the on-off valve device according to the present invention is applied is, for example, as shown in Figure 1, one cylinder end is sealed. The inner end of the hollow piston rod (4) slidably and airtightly led out from the bearing member (5) is fixed, and the inside of the cylinder is divided into two working chambers 3α, 3.
The piston 2 for partitioning into the cylinder b and the free piston 6 for partitioning and forming the gas chamber 7 for sealing high-pressure gas within the cylinder on the side of the working chamber 3α are slidably fitted into the husband, and the piston 2 The chambers 3a and 3b are filled with hydraulic oil, and the piston portion is provided with an orifice passage 8 and a valve hole 9 for forming a communication passage connecting the two working chambers 3α and 36.
A spool-shaped opening/closing spool valve 1o having a small diameter portion 11c for forming a passage between the large diameter portions 11α and llb at both ends is slidably fitted into the valve hole 9. Seal ring 1 corresponding to portions 11α and 11b, respectively
2 and 13 are provided, and the spoo/L valve xO functions as a self-closing valve due to the pressure of the sealed gas when the inner seal ring 12 and the large diameter portion 11α come into contact, and is inserted into the piston rod 4. When the bushing rod 14 is pushed in, the seal ring 12 and the small diameter portion 116 cooperate to form an annular fluid passageway leading to the orifice passageway 8, thereby opening both working chambers 3α.

3b, and is configured so that the piston 2 and the piston rod 4 can be expanded and contracted and held locked at any position by external operation of the opening/closing screw 4 valve 10. . In addition, 15 in the figure is a piston ring.

In the telescopic lock device as described above, conventionally, a seal ring 1 for the spool valve lo in the piston portion
2.13 is usually used as an O-ring, and the sealing ring of the high-pressure sliding part in this type of equipment, especially the inner side 12.
There were various drawbacks regarding the 0υng.

That is, as shown in detail in Figure 2, when an O-ring is employed in the piston ring groove 16 as the seal ring 12 for the opening/closing spool valve 10 in the piston 2, the groove width regarding the O-ring in line diameter dimension is There is a general agreement between W and groove depth H, and airtightness is maintained under the interference dimension created even when the valve is closed by cooperation with the large diameter part 11α, but in the O-ring groove width direction. There is a gap remaining in the small diameter part 11C.
There is a need to leave an especially large gap radially inward to form a predetermined fluid annular passage 17 when the valve is opened. Extremely different clearance conditions δ and δ for forming fluid passages
Both λ must be satisfied, and it is difficult to design a seal ring that is suitable for any of these gap size relationships, and this tends to become more difficult as the pressure increases.

Then, when the seal ring 12 is subjected to high pressure from one side when the valve is closed, it is pressed against the other side of the ring groove 16 and deforms, and one part of the seal ring 12 is pushed toward the fitting gap δl. Part power; protrude. For this reason, when the spool valve 10 is subsequently opened/closed, when the valve which forms the annular passage 17 in cooperation with the small diameter portion 11C is opened, the working fluid flowing at high speed toward the annular passage 17 and its flow are
Due to the suction effect due to the pressure drop on the back side of the seal ring,
If the seal ring 12 in the above-mentioned protruding deformed state is further deformed into a suction bow 1 toward the inner diameter side and becomes a state as shown by the chain line in FIG. If an attempt is made to close the spool valve 10 in such a state, the large diameter portion 11a may jam the seal ring 12, resulting in an immobile state or damaging the seal ring 12 and impairing its sealing function. There were drawbacks such as.

The present invention solves the drawbacks of the conventional on-off valve device,
It is an object of the present invention to provide an optimal opening/closing valve device with excellent high-pressure sealing function, particularly in a defining part such as a piston part of a telescopic locking device having different clearance conditions.

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

The details of one embodiment of the piston opening/closing valve device included in the telescopic locking device of the present invention are shown in FIG. 3, but the other main components are the same as those in FIG. Reference numerals are given and explanations are omitted. In addition, 22 in the figure is a stopper ring of the spool valve 10.

The feature of the on-off valve device of the present invention is that a ring groove 18 long enough to reach the Oriais passage 8 is bored in the inner periphery of the valve hole 9 of the piston part, and a backup ring 19 with legs is housed in this ring groove 18. At the same time, attach the side plate 21 to the distal end of the valve hole ml, and attach the back-up ring 19 with equal legs.
A ring groove of a predetermined width is formed by the side plate 21 and the seal ring 12 is housed in the ring groove, and the spool valve 10 is
Valve closing effect due to cooperation with large diameter portion 11a and small diameter portion 11G
The seal ring 1
The shape of the legged backup ring 19 is as shown in FIG. 4A. , B, as shown in FIG.
On one side of the plate part 19α, an annular step part 19d is formed below the inner diameter which is slightly larger than that of the plate part 19α, and a cylindrical array leg part 19b is formed by a plurality of radially extending slits 19c. The auxiliary bypass passage 20 is formed by the outer peripheral clearance of the legged backup ring 19, the slit 196, and the annular stepped portion 19d as the inner peripheral clearance, and the auxiliary bypass passage 20 is formed by the outer peripheral clearance of the legged backup ring 19, the slit 196, and the annular step portion 19d as the inner peripheral clearance, and the Oriswiss passage located at any position. It is now possible to secure a bypass path to 8.

Next, to explain the operating state, from the valve closed state as shown in FIG.
During the valve opening operation corresponding to the above, the seal ring 12 is subjected to high pressure and is pushed toward the backup ring 19 from a state in which it tends to go from a state to an initial state of opening the valve as shown in FIG. That is, when the inner circumference of the seal ring 12 is removed from contact with the large diameter portion 11α of the spool valve, the annular passage 17 with the small diameter portion 11G is once affected by the high pressure fluid as in the conventional valve device. However, in the case of the present invention, the auxiliary bypass I (high-pressure hydraulic oil bypasses the inlet passage 20 to the orifice passage 8 As a result, the pressure difference between the front and rear of the seal ring 12 (left and right in Fig. 3) is relaxed and the pressure becomes the same, so the seal ring 12 freely returns to the proper jing state by its own elastic restoring force. Then, as shown in Figure 3B, the spool valve 10
A predetermined main annular passage 17 can be formed and secured by cooperation with the small diameter portion 116 of the seal ring 12 when returning the spool valve 10 to the valve closed state as shown in FIG. 3A. The opening/closing operation of these spool valves 10 is no different from the conventional one, but the opening/closing valve device of the present invention is completely free from the risk of causing damage due to jamming. Advantageously, it can be configured for high-load telescoping locking devices.

In the illustrated embodiment, the main annular passage 1 is located on the back pressure side of the outer circumference of the seal ring 12 at the initial stage of the valve opening operation.
The auxiliary bypass passage 20 is backed up with legs to bypass 7 to generate an initial flow of pressure fluid to create a pressure balance, and to bite under the proper self-restoring force of the seal ring 12 to obtain a deformation prevention effect. Although this is achieved by the ring 19 and the long ring groove 18, the present invention is not limited to the above, and any bypass passage means that generates an initial bypass flow at the time of opening the valve may be used, for example, as shown in FIG. Alternatively, a bypass hole 20α may be formed directly in the piston portion from the back side of the outer circumference of the ring groove 18 on the inner periphery of the valve hole 9 to the orifice passage 8, or a slit-like groove means may be used instead of the hole. An auxiliary bypass passage may be provided, and in this case, the backup ring with legs can be omitted, reducing the number of parts and simplifying the structure.

On the other hand, in the case of using a backup ring as in the above-mentioned embodiment, the sea! It is suitable for use as an on-off valve device for ultra-high pressure applications, since the protrusion of the ring is suppressed. - In addition, in the above embodiment, an example was explained in which an on-off valve device was provided in a piston part that was slidably fitted into a cylinder. In addition, the telescopic locking device itself is not limited to the single cylinder type or the illustrated type.

As shown above, the opening/closing valve device in the telescopic locking device of the present invention has a seal ring groove formed on the inner periphery of the valve hole in the piston or partition wall, which is in close contact with the spool valve outer periphery when the valve is closed, and when the valve is open, the main annular shape is formed in the seal ring groove. An auxiliary bypass passage is provided for accommodating a seal ring that forms a passage, and bypassing the main annular passage by connecting a back pressure side of the seal ring near the outer periphery of the ring groove to an orifice passage that forms a communication passage with the valve hole. Therefore, at the initial stage of opening the valve, an initial flow of high-pressure fluid bypassing the main annular passage can be generated to alleviate the pressure difference before and after the seal ring, thereby ensuring proper self-restoration of the seal ring itself. As a result, it is possible to reliably prevent deformation of the seal ring to its inner diameter side and damage to the seal ring due to jamming, and in addition to ensuring a fluid passage when the valve is opened, it also prevents valve malfunction accidents. In addition, it is possible to obtain an on-off valve device that is suitable for a telescopic lock device for heavy loads that is filled with high-pressure gas, and when equipped with a backup ring.
In addition to being suitable for ultra-high pressure applications, if an auxiliary bypass passage is formed directly in the piston section or partition wall, a high-pressure on-off valve device with a simple structure with a small number of parts should be used, even if it is not suitable for ultra-high pressure applications. It is something that can be done.

[Brief explanation of the drawing]

Figure 1 is a partial sectional view of one embodiment of a telescopic locking device to which the on-off valve device of the present invention is applied;
FIG. 3A is an enlarged sectional view showing the valve closed state in an embodiment of the on-off valve device of the present invention, and FIG. 3B is an enlarged sectional view of the on-off valve device of the present invention. FIG. 4A is an enlarged sectional view showing the valve open state in the example. B is a vertical sectional view and left side view of the legged backup ring in the embodiment shown in FIG. 3, FIG. 5 is a sectional view showing the initial state of the valve opening operation in the embodiment shown in FIG. 3, and FIG. FIG. 3 is a sectional view showing another embodiment of the on-off valve device. 1...Cylinder, 2...Piston, 3α, 3b・1
Working chamber, 4... Piston rod, 8... Orifice passage, 9/1 valve hole, 10... Spool valve, 11α, 1
1b...Large diameter part, llc...Small diameter part, 12, 13
0...Seal ring, 17...Main annular passage, 16,1
8.18...Seal ring groove, 191・Backup ring with legs, 20・S・Auxiliary bypass passage, 20cL
...Bypass hole. Representative Patent Attorney Izumi Amano Page 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] (1) A cylinder filled with high-pressure gas and hydraulic oil, a piston housed in a slidable manner so as to divide the inside of the cylinder into two chambers, and one end of which is fixed to the piston. In a telescopic locking device comprising a piston rod whose other end protrudes in a sealed state from the piston rod, and an opening/closing spool valve disposed in a communication passage of the piston or the partition wall between the two chambers, the piston rod or the valve hole of the partition wall A seal ring is accommodated in the seal ring groove formed on the inner circumference of the spool valve, which is in close contact with the outer circumference of the spool valve when the valve is closed, and forms a main annular passage when the valve is open. An opening/closing valve device in a telescoping lock device, characterized in that an auxiliary bypass passage bypassing the main annular passage is provided to an orifice passage forming a communication passage together with the valve hole. (2) An on-off valve device in a telescoping lock device according to claim 1, wherein the auxiliary bypass passage is comprised of a drilled hole or a notch-like slot. [3] The opening/closing valve device in the telescoping lock device according to claim 1, wherein the auxiliary bypass passage is constituted by a seal ring groove that reaches the orifice passage and a backup ring. (4) An on-off valve device in a telescoping lock device according to claim 2, characterized in that a backup ring is housed in the seal ring groove.