JPH0245540Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a continuously adjustable gas spring, and particularly to a gas spring that maintains the maximum compression state during transportation of the gas spring itself or a product using the gas spring. This invention relates to an improvement of a continuously adjustable gas spring that makes it possible to adjust the gas spring.

[Conventional technology]

An example of a continuously adjustable gas spring is proposed in Japanese Patent Publication No. 58-18540.

That is, as shown in FIG. 6, the proposal according to the above-mentioned publication is that a piston part 2 is housed in a cylinder 1 filled with high-pressure gas, and two pressure chambers A and B are defined therein. The two pressure chambers A and B are made to communicate with each other via a side passage C formed on the inner circumferential side of an outer cylinder 3 disposed outside the cylinder 1 at an appropriate interval. There is. The lower end 4a of the piston rod 4 to which the piston portion 2 is fixed has a bearing member 5 fixed to the inner periphery of the lower end of the outer cylinder 3.
It is inserted through and protrudes to the outside. Further, a cap member 6 is fitted to the upper end sides of the cylinder 1 and the outer cylinder 3, and the axial center of the cap member 6 is connected to the pressure chamber A and the pressure chamber B via the side passage C. A pin valve 7 is slidably housed to allow communication and cutoff, that is, to open and close the side channel C. Furthermore, an operating rod 8 slidably inserted into the cap member 6 is connected to the upper end of the pin valve 7.

Therefore, when the operating rod 8 is at its highest position as shown in the figure, communication between the pressure chambers A and B via the side passage C is cut off, so that the gas spring cannot be expanded or contracted. However, if the operation stick 8 is forcibly lowered to the stroke end by an external force as shown by arrow P in the figure,
Pin valve 7 will also be forcibly lowered,
Pressure chamber A and pressure chamber B are brought into communication via open side path C. At this time, the pressure receiving area for the piston part 2 is larger in the pressure chamber A than in the pressure chamber B by an amount equivalent to the cross-sectional area of the piston rod 4. Therefore, under a thrust corresponding to the product of this pressure receiving area and the internal pressure, The piston part 2 in the cylinder 1 moves down within the cylinder 1, ie the gas spring is extended.

Then, when the desired extension state is reached, when the external force on the operating rod 8 is released, the pin valve 7 is raised within the cap member 6 by the gas pressure within the pressure chamber A, and thereby the side passage C is closed, communication between pressure chamber A and pressure chamber B is cut off, and the expansion of the gas spring is stopped.

If you want to achieve even more compression than the state shown in the figure, push up the operating rod 8, keep the lower end 8a in contact with the inner bottom surface 6a of the cap member 6 at the end of the stroke, and apply a large external force that exceeds the thrust caused by the internal pressure. The gas spring may be forcibly compressed, and when the desired compression state is achieved, the pressing force may be released.

[Problem that the invention attempts to solve]

However, in the case of the gas springs according to the conventional proposals described above, the gas springs are stretched during transportation of the gas springs themselves or products using the gas springs, and for example, break through the cardboard box used as packaging. This may lead to an accident in which the lower end 4a of the piston rod 4 protrudes outside the packaging.

That is, in the conventional proposal mentioned above, the operation stick 8
When the gas spring is pushed into the cap member 6 by the length of the valve body 7a of the pin valve 7, that is, with a slight stroke, communication between the pressure chambers A and B is enabled, and the gas spring expands. Therefore, if the operating rod 8 is pushed into the cap member 6 with a slight stroke during transportation, there is a problem in that the operating rod 8 easily stretches.

Therefore, in view of the above-mentioned circumstances, the present invention is designed to prevent the operating stick from moving and maintain its compressed state even if an external force is applied to the operating stick during transportation or the like. The purpose is to provide a new continuously adjustable gas spring.

[Means for solving problems]

In order to solve the above-mentioned problems, the structure of the present invention is arranged in a side passage that allows communication between two high-pressure pressure chambers A and B in a cylinder partitioned by a piston part. A pin valve formed to allow closing of the side passage by the internal pressure of the pressure chamber A opens the side passage when it slides with a small stroke against the internal pressure of the pressure chamber A. At the same time, it is formed so that the side passage can be reclosed when sliding with a stroke larger than the above stroke, and the reclosed state of the side passage is maintained by an appropriate locking means. It is characterized by being formed so that it can be used.

〔Example〕

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

As shown in FIG. 1, the continuously adjustable gas spring according to an embodiment of the present invention has a piston section 2 housed in a cylinder 1 filled with high-pressure gas, which creates a pressure chamber inside the cylinder 1. A and a pressure chamber B are partitioned. An outer cylinder 3 is disposed outside the cylinder 1 at an appropriate interval.
The inside of the outer cylinder 3 is a side passage C that allows the pressure chambers A and B to communicate with each other. Further, a piston rod 4 is connected to the piston portion 2, and the lower end 4a of the piston rod 4 is inserted through the shaft core of a bearing member 5 fixed to the lower end of the outer cylinder 3 so as to seal the lower end of the cylinder 1. It is slidably protruded to the outside in this manner.

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 disposed within the cap member 6. An operating rod 8 is in contact with the upper end of the pin valve 7, and the operating rod 8 is connected to a guide member 9 fixed inside the upper end of the outer cylinder 3.
It is housed inside.

As shown in FIG. 2, the pin valve 7 is
It has a large diameter valve body part 7a at the lower end, an intermediate small diameter part 7b connected to the large diameter valve body part 7a, and a large diameter part 7c at the upper end side connected to the small diameter part 7b. ,
The large diameter valve body portion 7a is located at a central opening 10 of a valve seat 10 fixed to the lower end surface of the cap member 6.
The large diameter portion 7c passes through the upper half of the shaft core of the cap member 6 and is in sliding contact therewith, and can be slid in the vertical direction using the cap member 6 as a guide member. can do.
A sleeve 11 is interposed in the lower half of the shaft of the cap member 6, and the sleeve 11 has a communication hole 11a and an annular groove 11b forming the side passage C, and also has The small diameter portion 7b is arranged to face the communication hole 11a.

O-rings 12a and 12b are interposed at the upper and lower ends of the sleeve 11, respectively, and the large-diameter portion 7c and the O-ring 12 are connected to the O-ring 12b.
When the large diameter valve body portion 7a is adjacent to a,
The sealing function is exerted and the passage is closed, and the small diameter portion 7 is attached to the lower O-ring 12a.
When the valve body 7a faces the O-ring 12a, as shown in FIG. The chamber A and the side channel C are brought into communication. And the lower O-ring 12a
When the large diameter portion 7c is adjacent to the
As shown in FIG. 4, the O-ring 12a exerts its sealing function again, cutting off communication between the pressure chamber A and the side passage C, and the side passage C is reclosed.

Note that the cap member 6 of the pin valve 7 described above
The sliding movement within the cap member 6, especially the downward movement, is made possible by applying an external force to the operating rod 8, and the upward movement of the descended pin valve 7 within the cap member 6 is made possible by applying an external force to the operating rod 8.
This is due to the internal pressure within the pressure chamber A acting on the pressure.
Further, one end of a port 6b bored in the cap 6 is open in the annular groove 11b of the sleeve 11, and the other end of the port 6b is formed by the outer tube 3 and the cylinder 1. It opens into a side channel C consisting of an annular space.

The operating rod 8 is formed with a so-called step, and the outer periphery of the upper end step of the lower large diameter portion is engaged with a locking portion 9a formed on the inner periphery of the upper end of the guide member 9 by caulking or the like. , are prevented from escaping to the outside. As shown in FIG. 5, a pair of diametrically opposed notches 9b are formed in the locking portion 9a, allowing the locking piece 13 to be inserted therethrough.

After the locking piece 13 is arranged as shown by the broken line in FIG. ), the locking piece 1
The upper surfaces of both ends of the guide member 9 come into contact with the lower end surface of the locking portion 9a, and function as a so-called stopper that prevents the operation stick 8, which has been lowered most of the guide member 9, from rising. (See Figure 4).

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

First, when attempting to adjust the gas spring to a desired length, the operating rod 8 is lowered with a small stroke S as shown in FIG. 3 from the state shown in FIG. 1 or FIG. 2. Through this operation, pressure chamber A and pressure chamber B are brought into communication via side passage C. At this time, since the piston rod 4 is disposed on the pressure chamber B side, the effective pressure receiving surface for the internal pressure is larger in the pressure chamber A, and the piston part 2 directs the working fluid in the pressure chamber B to the pressure chamber A side. The gas spring moves downward in a downward motion, and the gas spring is extended. When the desired extension state is reached, the external force pushing down on the operating rod 8 is released, and the pin valve 7 is pushed back by the internal pressure in the pressure chamber A, allowing it to rise. The diameter valve body portion 7a is brought into a state adjacent to the O-ring 12a, and communication between the pressure chamber A and the side passage C is cut off.

In addition, in the above operation, if the gas spring is stretched more than desired and needs to be compressed, push down the operation stick 8 to bring it into communication (Fig. 3).
By applying an external force between the outer cylinder 3 and the piston rod 4 that exceeds the thrust determined by the internal pressure and the pressure-receiving area of the piston rod 4, the piston rod 4 can be forcibly compressed.

Next, when the gas spring according to the present invention is brought into the most compressed state so that it does not become bulky during transportation, from the state shown in FIG. 1 or FIG. 2,
As shown in FIG. 3, first, with the operation stick 8 being lowered with a small stroke
With communication between the gas spring and the pressure chamber B enabled, an external force that exceeds the thrust determined by the pressure in the pressure chamber and the diameter of the piston rod 4 is applied between the outer cylinder 3 and the piston rod 4 to cause the gas spring to move. Make it the most compressed state. When the compressed state is reached, the operating rod 8 is then further lowered with a stroke L larger than the small stroke S, as shown in FIG. In this embodiment, the sliding movement of the operating stick 8 with a large stroke L occurs at the end of the stroke of the operating stick 8, and at the end of the stroke, the lower end of the operating stick 8 8a is set so as to come into contact with the upper end 6c of the cap member 6.

When the operating rod 8 is in the lowest position of the large stroke L, the large diameter portion 7c of the pin valve 7 is adjacent to the lower O-ring 12a, and communication between the pressure chamber A and the side passage C is interrupted. It will be blocked. At that time, if the locking piece 13 that locks the upper end of the operating stick 8 is locked to the locking portion 9a of the guide member 9, the lifting of the operating stick 8, that is, the pin valve 7 is prevented. , the expansion of the gas spring is prevented, that is, the most compressed state of the gas spring is maintained. To maintain the most compressed state, the locking piece 13 is connected to the locking portion 9 of the guide member 9
This will continue as long as the locking piece 13 is not released from the locking portion 9a during normal transportation, so the gas spring may suddenly expand during transportation. Accidents like this will never occur.

[Effect of idea]

As described above, according to the present invention, communication between both pressure chambers is achieved via a side passage by sliding the operating rod with a small stroke, and the gas spring is adjusted to extend or contract to a desired length in a stepless manner. Of course, when the operation stick is pushed in with a large stroke, that is, at the end of the stroke, the side passage can be closed so as to cut off communication between the two pressure chambers. There is an advantage that the end of the stroke can be held by a simple locking means.

As a result, it is possible to easily prevent unexpected accidents such as sudden expansion of the gas spring during transportation of the gas spring itself or products using it. This has the advantage of reducing storage space and transportation packaging.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing a gas spring according to an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing a pin valve in an enlarged manner, and Fig. 3 is a vertical cross-sectional view showing a state in which the side passage is opened by the pin valve. 4 is a longitudinal sectional view similar to that shown in FIG. FIG. 6 is a plan view of the state shown in FIG. 6, and a vertical cross-sectional view showing the conventional example in the same manner as FIG. 1. 1... Cylinder, 2... Piston part, 3... Outer cylinder, 4... Piston rod, 5... Base member,
6... Cap member, 7... Pin valve, 7a...
...Large diameter valve body part, 7b...Small diameter part, 7c...Large diameter part, 8...Operation stick, 9...Guide member, 9a...
Locking portion, 10... Valve seat, 11... Sleeve, 12a, 12b... O ring, 13... Locking piece, A, B... Pressure chamber, C... Side channel, S... Small stroke, L...Large stroke.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Slidably disposed in a side passage that allows communication between two pressure chambers in a cylinder filled with high-pressure gas separated by a piston part. With,
In a continuously adjustable gas spring having a pin valve formed so as to enable closing of the side passage by the internal pressure of the pressure chamber, the pin valve is pushed in with a small stroke against the internal pressure of the pressure chamber. It is formed so that the side passage can be opened when pushed in, and the side passage can be reclosed when the side passage is pushed in with a stroke larger than the above stroke, and the reclosed state of the side passage is adjusted appropriately. A continuously adjustable gas spring, characterized in that it is formed so as to be maintained by a locking means. (2) The pin valve has a large-diameter valve body, a small-diameter part connected to the large-diameter valve body, and a large-diameter part connected to the small-diameter part. The side passage can be closed when the O-ring is adjacent to the part, and the side passage can be opened when the O-ring faces the small-diameter part, and the O-ring is adjacent to the large-diameter part. The continuously adjustable gas spring according to claim 1, which is capable of occasionally re-closing a side road. (3) The locking means includes a locking piece that locks onto the upper end of the operating rod that comes into contact with the pin valve, and that also engages with the upper end locking portion of the guide member that accommodates the operating rod. A continuously adjustable gas spring according to claim 1 of the utility model registration claim.