JPH0331865Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a continuously adjustable gas spring, and in particular, the invention is designed to facilitate the work of filling gas at a predetermined pressure into the gas spring and commercializing it as a product. Concerning improvements to continuously adjustable gas springs.

[Conventional technology]

As a stepless adjustable gas spring, for example, there is a proposal related to Japanese Patent Publication No. 18540/1983.

That is, as shown in FIG. 3, the proposal in the above-mentioned publication consists of a piston side pressure chamber A and a rod side pressure chamber B in which a piston part 2 is housed in a cylinder 1 and high pressure gas is sealed in the cylinder 1. The pressure chambers A and B communicate with each other via a side passage C formed between the pressure chambers A and B and an outer cylinder 3 disposed outside the cylinder 1 at an appropriate interval. I'm trying to do what I can. The lower end portion 4a of the piston rod 4, which fixes the piston portion 2 to the upper end thereof, is inserted through the axis of a base member 5 disposed inside the lower end of the outer cylinder 3 and protrudes to the outside.

A cap member 6 is fitted on the upper end sides of the cylinder 1 and the outer cylinder 3.
The axial center of the pressure chamber A and pressure chamber B can be communicated with each other through the side passage C, and the communication can be interrupted. That is, a pin valve 7 that allows opening and closing of the side channel C is slidably housed. The upper end side of the pin valve 7 is an operating rod mounting portion 7a, and an operating rod 8 slidably inserted into the cap member 6 is screwed into the operating rod mounting portion 7a. are integrally connected.

In addition, seal members 9a and 9b arranged in upper and lower stages on the inner circumferential surface of the opposing cap member 6 are adjacent to the outer circumferential surfaces of the lower end side valve body portion 7b and the intermediate sliding portion 7c of the pin valve 7, respectively. When the valve body portion 7b is adjacent to the lower seal member 9b, communication between the piston side pressure chamber A and the side passage C is cut off, and the sliding portion 7c is adjacent to the upper seal member 9a. The pressure chamber A and the side passage C in the cylinder 1 are so formed that communication with the outside is cut off when the pressure chamber A and the side passage C are in the cylinder 1.

Therefore, when the operating rod 8 is at its highest position as shown in the figure, the communication between the pressure chambers A and B via the side passage C is cut off, so that the gas spring does not expand. However, the operating rod 8 is forcibly lowered within the cap member 6 by an external force as shown by arrow P in the figure, and the lower end surface 8a of the operating rod 8 comes into contact with the inner bottom surface 6a of the recess of the cap member 6. At the end of the stroke, the pin valve 7 is forcibly lowered and the valve body 7
B and the lower seal member 9b are no longer adjacent to each other, and the side passage C is opened, and the pressure chambers A and B are brought into communication via the opened side passage C.

In the above state, the pressure receiving area of the gas pressure on the piston side pressure chamber A side with respect to the piston part 2 is greater than the pressure receiving area on the rod side pressure chamber B side, so the piston part 2 in the cylinder 1 In other words, the gas spring is extended with a thrust determined by the product of the sealed gas pressure and the effective pressure-receiving area of the piston rod 4. Then, when the desired extension state is reached, when the external force on the operating stick 8 is released, the pin valve 7 moves up inside the cap member 6 due to the gas pressure in the pressure chamber A, and the valve body part 7b moves to the lower stage. This closes the side passage C, cutting off communication between the pressure chambers A and B, and stops the expansion of the gas spring.

[Problem that the invention attempts to solve]

However, in the conventional gas spring proposed above, when filling gas at a predetermined pressure into the gas spring, as shown in FIG. A chuck rod 10 for sealing is connected by means such as screwing, and by applying an external force to the chuck rod 10 in the direction shown by arrow P in the figure, the pin valve 7 is greatly lowered within the cap member 6, and the pin valve 7 is slid. It is necessary to work to release the adjacency between the moving part 7c and the upper seal member 9a so that the cylinder internal pressure chamber A and the side passage C can communicate with the outside.

After injecting gas at a predetermined pressure into the cylinder 1, the pin valve 7 is housed in the cap member 6 by pulling up the chuck rod 10, and communication between the inside of the cylinder 1 and the outside is cut off. Later, the chuck rod 10 must be removed and the operating rod 8 must be integrally connected to the pin valve 7.

That is, when assembling the gas spring, it is necessary to check the operability of the pin valve 7 with the operation rod 8 connected to it, and when filling gas at a predetermined pressure, the operation rod 8 must be connected once. Remove the chuck rod 10 from the pin valve 7 and connect the chuck rod 10, and after the gas filling operation, remove the chuck rod 10 from the pin valve 7 and connect the operating rod 8 again.
Therefore, when the gas spring is filled with gas to make it into a final product, there is an inconvenience that the workability is greatly reduced.

Therefore, in view of the above-mentioned circumstances, the purpose of the present invention is to provide a new stepless adjustable gas spring that does not reduce the workability of the final product by filling it with gas. shall be.

[Means for solving problems]

In order to solve the above-mentioned problems, the structure of the present invention is such that a cap member is provided at one end of the cylinder, an outer cylinder is provided on the outside of the cylinder, and a piston rod is movably inserted into the cylinder via a piston part. The piston portion defines a piston side pressure chamber and a rod side pressure chamber within the cylinder, and the piston side pressure chamber and the rod side pressure chamber communicate with each other via a cap member and a side passage provided on the outer circumference of the cylinder. In a steplessly adjustable gas spring that communicates with the outside through a port provided in a cap member and is provided with a pin valve in the middle of the side passage so as to freely open and close, the pin valve has a large-diameter valve body portion that shuts off the side passage. , a small-diameter part that allows communication between the side passage, a large-diameter sliding part that blocks the port and the side passage, and a small-diameter operation stick attachment part that allows communication between the port and which are successively connected in series. A large-diameter operating stick is integrally connected to the outer end of the operating stick mounting part, and a spring is disposed between the cap member and the operating stick, so that the end surface of the operating stick does not come into contact with the free end of the spring. When the pin valve is slid within the normal valve stroke range, the valve body and the small diameter part open and close the side passage, and the operating rod overcomes the repulsive force of the spring to allow the pin valve to slide beyond the normal valve stroke range. This feature is characterized in that the side passage is connected to the outside when the system is used.

〔Example〕

Hereinafter, the present invention will be explained based on the illustrated embodiments.

As shown in FIG. 1, the stepless adjustable gas spring according to the most preferred embodiment of the present invention uses a piston section 2 housed in a cylinder 1 to generate pressure on the piston side with gas sealed inside. A chamber A and a rod side pressure chamber B are partitioned. An outer cylinder 3 is disposed outside the cylinder 1 at an appropriate interval, and a gap formed between the outer cylinder 3 and the cylinder 1 is connected to the pressure chamber A. A side passage C allows communication with room B.

The upper end of a piston rod 4 is connected to the piston portion 2, and the lower end 4a of the piston rod 4 is disposed and fixed inside the lower end of the outer cylinder 3 so as to lock the lower end of the cylinder 1 from below. It is inserted through the axis of the base member 5 and protrudes to the outside.

A cap member 6 is disposed at the upper end of the cylinder 1 and fitted inside near the upper end of the outer cylinder 3, and a pin valve 7 is slidably housed in the axial center of the cap member 6. ing. An operating rod 8 is integrally connected to the operating rod mounting portion 7a at the upper end of the pin valve 7, and the operating rod 8 is inserted into the upper end guide portion 3a of the outer cylinder 3.
Further, the outer cylinder 3 is defined below the operating rod 8, that is, by the upper end surface of the cap member 6.
A spring 11 is disposed within the upper end guide portion 3a.

The pin valve 7 includes a valve body portion 7b at the lower end, a small diameter portion 7d continuous above the valve body portion 7b,
The valve body part 7b has a sliding part 7c connected above the small diameter part 7d, and the valve body part 7b passes through the central opening 12a of the valve seat 12 fixed to the central lower end surface of the cap member 6. In addition, the opening 12
It is formed so that it can close a.

The sliding portion 7c passes through the shaft of the upper half of the cap member 6 and is in sliding contact therewith, and is configured to slide in the vertical direction using the cap member 6 as a guide member. A sleeve 13 is disposed at the lower half axis of the cap member 6, and the sleeve 13 has a communication hole 13a and an annular groove 13b forming the side passage C. The small diameter portion 7d is formed to face the communication hole 13a.

At the upper and lower ends of the sleeve 13, seal members 9a and 9b each consisting of an O-ring are provided, and the sliding portion 7c and the valve body portion 7b are adjacent to the upper and lower two-stage seal members 9a and 9b, respectively. When this happens, the so-called sealing function is performed in each of the above parts, and when the small diameter part 7d faces the lower seal member 9b, the valve body part 7b is removed from the valve seat 12.
is removed, its central opening 12a is opened, and the pressure chamber A and side channel C are brought into communication. When the sliding portion 7c comes to be adjacent to the lower seal member 9b, communication between the pressure chamber A and the side passage C is cut off, and the side passage C is reclosed. Furthermore, when the operating rod attachment part 7a of the pin valve 7 is to face the upper and lower seal members 9a and 9b, the pressure chamber A and the side passage C are connected to the outside via the port a provided in the cap part 6. When the outside is used as a gas pressure source, a predetermined gas pressure can be injected into the cylinder 1 (see FIG. 2).

The above-mentioned sliding of the pin valve 7 within the cap member 6, especially its downward movement, involves applying an external force in the direction indicated by the arrow P in the figure to push the operating rod 8 into the guide portion 3a of the outer cylinder 3. It was then approved,
The rise of the lowered pin valve 7 within the cap member 6 is made possible by the gas pressure within the pressure chamber A acting on the valve body portion 7b. and,
By sliding the pin valve 7 within the cap member 6, the side channel C is opened or closed, i.e.
The stroke amount of the pin valve 7 when the valve body portion 7b leaves the valve seat 12 or seats on the valve seat 12 is a constant stroke amount such that the lower end of the operating rod 8 does not come into contact with the upper end of the lower spring 11. When the pin valve 7 is in the moving state within the small stroke l of the range, and when the pin valve 7 is in the moving state exceeding the above-mentioned small stroke l, that is, in the downward state, the side passage C is fully closed and reopened by the pin valve 7. state becomes possible.

Note that the annular groove 13b of the sleeve 13 has
One end of a port 6b bored in the cap member 6 is open, and the other end of the port 6b is open to the outer cylinder 3.
It opens into the gap formed by the cylinder 1 and the cylinder 1.

The operation of the continuously adjustable gas spring according to the present invention formed as described above will be briefly explained.

First, when filling the gas spring with gas at a predetermined pressure, as shown in FIG.
A gas filling chuck 10 is brought into contact with the upper end, and by moving the chuck 10 in the direction shown by the arrow P in the figure, the operating rod 8 is moved by the repulsive force of the spring 11 with a large stroke shown by the symbol L in the figure. Lower it as if to overcome it, and press pin valve 7.
is lowered within the cap member 6 so that the operating rod mounting portion 7a faces the upper and lower two seal members 9a and 9b, allowing communication between the inside of the cylinder 1 and the outside.

From the above state, gas at a predetermined pressure from an external gas pressure source (not shown) is injected into the cylinder 1. After the injection of gas at a predetermined pressure is completed, the chuck rod 10 in contact with the upper end of the operating rod 8 is removed, the pin valve 7 is raised within the cap member 6, and the side channel C is returned to the closed state. At this time, the pin valve 7 is initially raised by the repulsive force of the spring 11, and after the repulsive force of the spring 11 ceases to act, the pin valve 7 is raised by the gas pressure in the pressure chamber A acting on the valve body portion 7b. It will be lifted up.

In addition, in this embodiment, the pin valve 7
The movement of the large stroke L is formed at the end of the stroke of the operation stick 8, and the spring 11 below the operation stick 8 is set to be in the most compressed state at the end of the stroke. .

In order to adjust the gas spring, which is filled with gas at a predetermined pressure, to a desired length as described above, the operation stick 8 must be lowered with a small stroke l, as shown in FIG. do. The above-mentioned small stroke l is the lower end surface 8a of the operation stick 8.
As mentioned above, the spring 11 does not come into contact with the upper end of the spring 11.

By lowering the operation stick 8, the pin valve 7 is
is lowered with a small stroke l, the small diameter portion 7d of the pin valve 7 faces the lower seal member 9b, and the pressure chambers A and B are communicated via the side passage C. As a result, the piston portion 2 descends within the cylinder 1 under the thrust determined by the pressure receiving area difference between the piston side pressure chamber A and the rod side pressure chamber B, that is, the product of the cross-sectional area of the piston rod 4 and the gas pressure. Therefore, the gas spring will be expanded.

As described above, when the gas spring reaches the desired expanded state, when the external force on the operating stick 8 is released, the pin valve 7 is pushed back inside the cap member 6 by the gas pressure in the pressure chamber A. As a result, the side passage C is closed and gas flow between the pressure chambers A and B is blocked, and the expansion of the gas spring is stopped.

In addition, in the above operation, when the gas spring is extended more than desired and needs to be compressed, an external force that exceeds the extension thrust is applied to the outer cylinder 3 while the pin valve 7 is lowered within a small stroke l.
It is sufficient to add it between the piston rod 4 and the piston rod 4.

In this embodiment, when the pin valve 7 descends with a medium stroke, that is, when it descends so that the sliding portion 7c is adjacent to the lower seal member 9b, the small stroke l is The communication between the pressure chamber A and the side channel C during the descent is reclosed, and the expansion of the gas spring is prevented. At this time, the upper end of the operating rod 8 is By locking the gas spring to the guide portion 3a of the outer cylinder 3 using an appropriate locking means, it becomes possible to maintain the compressed state of the gas spring and facilitate its transportation.

[Effect of idea]

According to the present invention, the pin valve is constructed by sequentially connecting in series a large diameter valve body portion, a small diameter portion, a large diameter sliding portion, and a small diameter operating rod mounting portion. A large diameter control stick is connected to the outer end, so
When the valve is slid beyond the normal stroke range, the piston side pressure chamber and the rod side pressure chamber are opened to the outside via the side passage and the port. For this reason, it is possible to fill gas at a predetermined pressure while the operating stick is connected to the top of the pin valve, and when filling gas, the operating stick can be removed from the top of the pin valve, or the operating stick can be attached to the top of the pin valve again. This eliminates the need for installation, greatly simplifies the work required to produce the final product, and enables automatic assembly using machines, making mass production easier.

Further, according to the present invention, it is also possible to prevent an unexpected accident such as elongation during transportation or the like.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a gas spring according to an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view partially enlarging the operating state when gas is filled in, and Fig. 3 is a longitudinal cross-sectional view showing a conventional example. FIG. 4 is a diagram similar to FIG. 1, and FIG. 4 is a diagram similar to FIG. 2, showing the operating state when gas is filled in the conventional example. 1...Cylinder, 2...Piston part, 3...Outer cylinder, 3
a...Guide part, 4...Piston rod, 5...Base member, 6...Cap member, 6b...Port, 7...Pin valve, 7a...Operation rod mounting part, 7b...Valve body part,
7c...Sliding part, 7d...Small diameter part, 8...Operation stick, 9
a, 9b...Seal member, 10...Chuck rod,
11...Spring, 12...Valve seat, 12a
...Central opening, 13...Sleeve, 13a...Port,
13b...Annular groove, A, B...Pressure chamber, C...Side channel, a
…port.

Claims (1)

[Claims for Utility Model Registration] (1) A cap member is provided at one end of the cylinder, an outer cylinder is provided on the outside of the cylinder, a piston rod is movably inserted into the cylinder via a piston part, and the piston part is connected to the cylinder. A piston-side pressure chamber and a rod-side pressure chamber are defined within the cylinder, and the piston-side pressure chamber and the rod-side pressure chamber communicate with each other via a side passage provided on the cap member and the outer periphery of the cylinder, and the side passage is provided on the cap member. In the stepless adjustable gas spring, the pin valve communicates with the outside through a port, and is provided in the middle of the side passage with a pin valve that can be freely opened and closed. a small diameter portion that allows communication;
It consists of a large-diameter sliding part that blocks the port and side passage, and a small-diameter operation stick attachment part that allows communication between the ports, which are connected in series, and the outer end of the operation stick attachment part has a large diameter The operating stick is integrally connected, and a spring is placed between the cap member and the operating stick.
When the pin valve is slid and operated in the normal valve stroke range where the end face of the operating stick does not come into contact with the free end of the spring, the valve body and small diameter part open and close the bypass, and the operating stick overcomes the repulsive force of the spring. A continuously adjustable gas spring characterized in that a side passage is communicated with the outside when the valve is slid beyond the normal valve stroke range. (2) A cap member is provided with two upper and lower seal members, and a pin valve is slidably inserted into the center of the two seal members, and when the valve body part and the sliding part face each seal member, a side passage and a pin valve are inserted into the center of the two seal members. When the port is blocked and the small diameter part faces the lower sealing member, the side passage is opened, and when the sliding part faces the lower sealing member and the operating rod mounting part faces the upper sealing member, the piston side pressure increases. When the chamber is shut off, the rod-side pressure chamber communicates with the outside through the side passage and the port, and when the operating rod mounting portion faces the upper and lower seal members, both the piston-side pressure chamber and the rod-side pressure chamber are connected to the outside through the side passage. The continuously adjustable gas spring according to claim 1, wherein the gas spring is communicated with the outside through a port.