JPS5912437Y2 - Gas-filled cylinder device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a gas-filled cylinder device used, for example, in a gas spring.

Generally, a gas spring is attached to the rear luggage compartment door of a passenger car.

To explain this gas spring, as shown in FIG. 1, a piston/piston rod assembly 4 consisting of a piston 2 and a piston rod 3 is fitted into a cylinder 1.

A slit 5 is provided in the piston 2.

A bottom plate 6 is provided at the lower end of the cylinder 1, and an eye 7 is fixed to the lower surface of the bottom plate 6.

Further, a rod guide 8 for guiding the vertical movement of the piston rod 3 and a packing 10 for sealing the pressure gas 9 sealed in the cylinder 1 are fitted into the upper part of the cylinder 1.

The rod guide 8 is fixed to the upper end of the cylinder 1.

The piston rod 3 is fitted into a rod guide 8 and a packing 10.

An eye 11 is fixed to the tip of the piston rod 3.

Further, a hole is formed in the outer circumferential wall 12 of the cylinder 1, and a plug 13 is provided in this hole.

Then, the pressure gas 9 is supplied to the cylinder 1 from this plug 13.
After flowing into the cylinder 1, the plug 13 is welded to the outer peripheral wall 13, and the pressure gas 9 is sealed inside the cylinder 1.

The gas spring constructed as described above is used as a kind of spring, for example, by attaching the eye 7 to the body of a passenger car and the eye 11 to the luggage compartment door hinged to the luggage compartment of the passenger car. .

That is, when the luggage compartment door is closed, the pressure gas 9 in the cylinder 1 is compressed.

Furthermore, when the luggage compartment door is opened, the piston rod 3 is projected from the cylinder 1 by the expansion force of the pressure gas, thereby urging the luggage compartment door to open.

However, in the conventional gas spring, for example, when the piston/piston rod assembly 4 enters the cylinder 1 beyond the final limit of its contraction stroke, or when the temperature of the gas spring rises abnormally due to being placed at a fire site, etc. This is dangerous because the gas pressure inside the cylinder 1 becomes abnormally high, and as a result, the piston rod 3 may fly out, the cylinder 1 may break, or in severe cases, the gas spring may explode.

For this reason, some gas springs have a thin notch in the outer circumferential wall 12 of the cylinder 1 to weaken the extent of the explosion, but this also causes the gas pressure inside the cylinder 1 to rise abnormally. If this happens, the notch will break and cause a kind of explosion, which is still dangerous.

Further, in the event that the gas spring breaks down or is no longer needed, it is necessary to dispose of the cylinder 1 by drilling a hole in the cylinder 1 to vent gas in order to prevent danger, which is troublesome.

This idea was made in view of the above circumstances, and by providing a safety valve on a gas-filled cylinder, it is possible to prevent dangers such as explosions, cylinder destruction, or piston rods popping out. To provide a gas-filled cylinder device which is safe even if the cylinder is carelessly discarded without making any changes when disposing of the cylinder.

An embodiment of this invention will be described below with reference to FIGS. 2 and 3.

In this embodiment, parts that are substantially the same as those in the conventional example are given the same reference numerals, and their explanations will be omitted.

In this embodiment, a communication hole 23 is formed in the lower part of the outer circumferential wall 22 of the cylinder 21 .

Further, a stud 24 is installed in the center of the upper surface of the bottom portion 6.

At the upper end of this stud 24 is a valve body 25 which is constructed by stacking a required number of discs that can be freely bent.
is fixed.

A sealing member 26 for sealing the gap between the valve body 25 and the outer peripheral wall 22 is fitted to the outer peripheral edge of the valve body 25 .

A safety valve 28 is constituted by the outer peripheral wall 22, the communication hole 23, the stud 24, the valve body 25, and the seal member 26.

Note that the pressure gas 9 does not flow into the valve chamber 27 defined by the outer peripheral wall 22, the valve body 25, and the bottom plate 6, and the pressure is maintained at approximately atmospheric pressure.

The valve body 25 is located below the piston 2 (on the opposite side of the piston rod 3) when the piston/piston rod assembly 4 is inserted into the cylinder 21 to the final limit of its contraction stroke.
The outer peripheral edge of the valve body 25 is actuated downward by the gas pressure set slightly higher than the gas pressure of the pressure gas 9, that is, the safety valve adjustment pressure, and thereby the sealing member 26
is lowered to open the communication hole 23, and as a result, the cylinder 2
It is constructed so that the inside and outside of 1 are in communication.

Therefore, for example, the piston/piston rod assembly 4
When the cylinder 21 is allowed to enter the cylinder 21 beyond the final limit of its contraction stroke, or when the cylinder is placed at a fire site and the temperature rises abnormally, the gas pressure of the pressure gas 9 inside the cylinder 21 increases.

When this gas pressure reaches the set gas pressure (safety valve adjustment pressure), the outer peripheral edge of the valve body 25 is pushed down by this gas pressure, and the seal member 26 is thereby lowered and communicated {L2
Open 3.

As a result, the pressure gas 9 in the cylinder 21 is discharged to the outside through the communication hole 23.

As a result, the cylinder internal pressure above the valve body 25 in the cylinder 21 decreases, and the valve body 25 returns to its original state.

Therefore, even if the temperature of a gas spring placed there rises abnormally, such as at the scene of a fire, the gas spring may explode, various parts of the gas spring may be damaged, or the piston rod 3 may fly out. There's nothing to do.

Therefore, it is safe even if the gas spring of this embodiment breaks down or becomes unnecessary and is carelessly discarded.

The valve body 25 is designed to appropriately increase or decrease the number of discs constituting the safety valve 28 in accordance with the magnitude of the set pressure of the safety valve 28.

Next, another embodiment of this invention will be described based on FIG. 4.

In this embodiment, parts that are substantially the same as those in the previous embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

This embodiment is a shock absorber used, for example, to dampen vibrations in automobiles.

In this embodiment, a free piston 31 is fitted below the piston 2.

Further, the upper and lower portions of the piston 2 are filled with oil 32.

The piston 2 and piston rod 3 constitute a piston/piston rod assembly 33.

Moreover, the gas chamber 3 between the free piston 31 and the valve body 25
4 is filled with a pressure gas 35 of 20 to 30 kg/gas.

Air exists between the valve body 25 and the bottom plate 6 and is at approximately atmospheric pressure.

The safety valve 28 is operated at a gas pressure (safety valve When the adjustment pressure is reached, the outer peripheral edge of the valve body 25 is actuated downward, thereby lowering the sealing member 26 and opening the communication hole 23. As a result, the gas chamber 34 is configured to communicate with the outside of the cylinder. It has been.

Therefore, if the shock absorber of this embodiment is placed at a fire site, for example, and the temperature rises abnormally, the gas pressure of the pressure gas 35 in the gas chamber 34 will rise.

When this gas pressure reaches the set pressure, the peripheral edge of the valve body 25 is pushed down by this gas pressure, thereby lowering the sealing member 26 to open the communication hole 23.

Therefore, the pressure gas 35 in the gas chamber 34 is transferred to the communication hole 23.
is released to the outside of the cylinder 21.

As a result, the gas pressure in the gas chamber 34 decreases and the valve body 25 returns to its original state.

In the above embodiment, the safety valve 28 is constituted by the outer peripheral wall 22, the communication hole 23, the stud 24, the valve body 25, and the seal member 26, but the safety valve 28 is not limited to this, and is generally attached to a boiler or pneumatic piping line. A safety valve having the same structure as the safety valve may be used.

As explained above, this invention includes a cylinder, a piston/piston rod assembly provided in the cylinder,
A gas sealed in a cylinder so as to cause the piston rod of the piston/piston rod assembly to protrude outside the cylinder, an outer circumferential wall of the cylinder, a communication hole drilled in the lower part of the outer circumferential wall, and a predetermined distance from the bottom of the cylinder. A valve body is made of a stack of flexible discs which are spaced apart from each other in a cylinder and whose center part is fixed by a single fixing means, and the valve body is fitted onto the outer peripheral edge of the valve body, and usually the communication hole is inserted into the valve body. and a sealing member that opens the communicating hole to the atmosphere when the gas pressure in the cylinder reaches the set pressure by actuation of the valve body. When the gas pressure in the upper chamber reaches the set pressure, the valve body bends and the sealing member opens the communication hole in the cylinder outer peripheral wall, allowing the gas inside the cylinder to be released outside the cylinder, causing the gas pressure inside the cylinder to rise abnormally. Therefore, the risk of explosion, destruction of various parts such as the cylinder, or the piston rod flying out is prevented, and it is safe.

In addition, even if a gas-filled cylinder breaks down or is carelessly discarded because it is no longer needed, the safety valve will operate when the gas pressure in the cylinder reaches the set pressure, as described above, and the gas in the cylinder will be released. It is safe because it is released.

Moreover, the safety valve has a valve body made of a laminate of flexible discs (
Because it uses a disc valve, it is possible to change the set pressure by simply changing the number of laminated flexible discs.Furthermore, the disc valve can obtain a large spring force even though it is thin. , the length of the safety valve in the axial direction can be made extremely small, and the cylinder device as a whole can be made compact.Moreover, this safety valve has a communication hole drilled in the outer peripheral wall of the cylinder, which is connected to the valve provided inside the cylinder. Since the safety valve is opened and closed by a thin member on the outer periphery of the body, there is no need to separately provide a housing for guarding the safety valve, which has advantages such as being economical.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a conventional gas spring, Fig. 2 is a longitudinal sectional view showing an embodiment of this invention, and Fig. 3 is a vertical sectional view of a conventional gas spring.
FIG. 4 is a longitudinal sectional view showing another embodiment of this invention. 3...Piston rod, 4,33...
Piston/piston rod structure, 9, 35...
・Gas, 21...Cylinder, 22...
Outer peripheral wall, 23...Communication hole, 24...Stud (fixing means), 25...Valve body, 26...
... Seal member, 28 ... Safety valve.

Claims (1)

[Scope of utility model registration request] a cylinder, a piston/piston rod assembly provided within the cylinder, a gas sealed within the cylinder so as to cause the piston rod of the piston/piston rod assembly to protrude outside the cylinder, and an outer peripheral wall of the cylinder;
a communication hole drilled in the lower part of the outer circumferential wall; a valve body made of a stack of flexible discs whose center portion is fixed within the cylinder at a predetermined distance from the bottom of the cylinder; a sealing member that is fitted onto the outer peripheral edge of the valve body, normally closes the communication hole, and opens the communication hole to the atmosphere by actuation of the valve body when the gas pressure in the cylinder reaches a set pressure; A gas-filled cylinder device comprising: the safety valve for gas release as described above.