JPH09292098A - Pressure sensing safety device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a safety device with proper pressure unless it is used for a long time. SOLUTION: A check valve 11 in contact with a leading end of a nozzle valve N of a gas vessel and a piston 12 are unitedly movably arranged inside a pressur esensing chamber 14. The piston 12 applies pressure by means of a spring means 19 in a contacting direction with the check valve 11. Movement of the check valve 11 pressed by the nozzle valve N is transmitted to the piston 12 at the time of installation of the gas vessel. A seal means 16 in contact with an inner surface of the pressure sensing chamber 14 is slid together with the piston 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a check valve which can be opened by pushing its nozzle valve when a gas container is attached.
The present invention relates to a pressure sensing safety device for a gas appliance having a structure in which a piston movable due to an abnormal increase in internal pressure of a gas container is incorporated in a pressure sensing chamber via a sealing means.

[0002]

2. Description of the Related Art There is a pressure sensing device using a piston that moves by sensing an abnormal rise in the internal pressure of a gas container and shuts off the flow of gas, which is described, for example, in Japanese Utility Model Publication No. 7-22248 as a piston member. A seal member such as an O-ring is attached to the outer circumference of the piston, as shown in FIG. This seal member keeps the space between the inner peripheral surface of the cylinder-shaped pressure sensing chamber containing the piston and the outer peripheral surface of the piston airtight.

However, it has been found that when the gas appliance having such a piston with a sealing member is not used for a long period of time, the sealing member becomes stuck to the inner peripheral surface of the pressure sensing chamber. As a result, the sliding resistance of the piston increases, and there is a risk that the operating pressure of the pressure sensing safety device will be higher than the reference value.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points. The problem is that the operating pressure does not increase even when it is not used for a long period of time, and the safety device always operates at an appropriate pressure. To get it.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a check valve in contact with the tip of a nozzle valve of a gas container and a piston incorporated in a pressure sensing chamber are integrally movable. At the same time, spring means for pressurizing the piston in the contact direction with the check valve is provided, and the movement of the check valve pushed by the nozzle valve when the gas container is attached is transmitted to the piston, and the sealing means is in contact with the inner surface of the pressure sensing chamber. The means is slid together with the piston to ensure the detection of abnormal pressure.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure sensing safety device according to the present invention has a check valve 11 that can be opened by pushing the nozzle valve N when the gas container B is mounted, and the internal pressure of the gas container B is abnormal. It has a configuration in which the piston 12 movable by rising is incorporated in the pressure sensing chamber 14 via the first and second sealing means 16 and 13.

The pressure sensing chamber 14 is means for allowing the piston 12 to sense the pressure of the gas ejected from the gas container B. The upstream side of the region controlled by the pressure of the jetted gas is the connection port of the nozzle valve N of the gas container B, and the downstream side is the tip side of the piston 12. A sealing means 15 is provided on the upstream side to maintain airtightness. First sealing means 1
6 also serves as a sealing means on the downstream side.

In the illustrated embodiment, the body 10 is provided with a cavity extending therethrough. The hollow portion is on the axis of the mounting direction of the nozzle valve N, one end opening 17 of which serves as a connection port, and the other end opening 18 of which the tip portion of the piston is arranged. A check valve 11 is arranged inside the one end opening 17 so as to oppose the nozzle valve N inserted into the connection port.

The check valve 11 in the present invention is a nozzle valve N.
Is pushed against its built-in spring (not shown). That is, the check valve 11 is pushed and moved by the nozzle valve N in the initial stage of mounting, and when it comes into contact with the support 21, the check valve 11 works to push the nozzle valve N back and open it.

In the illustrated embodiment, the check valve 11 is a support 2
1 is provided so as to be movable in the axial direction. The support body 21 is fixed to the main body 10 by locking the outer peripheral edge of the support body 21 to the locking step portion 22 provided in the hollow portion. Further, the tip end portion of the check valve 11 projects forward from the central passage port 23 and can come into contact with the piston 12. However, although the check valve 11 and the piston 12 need to be movable in the same direction, they do not have to be on the same axis.

Reference numeral 24 is a hole for introducing the gas flow formed in the support 21. The gas flow is once received by the support 21 and flows into the pressure sensing chamber 14 from the introduction hole 24.

In the pressure sensing chamber 14, the piston 12 allows the gas introduced therein to flow downstream while the pressure of the gas is within a normal range, and when the pressure rises abnormally, the piston 12 moves by the pressure to move the gas. Cut off the flow of. That is, the piston 12 operates not only as a pressure sensing means but also as a gas flow opening / closing means.

The second sealing means 13 is provided for this opening / closing means. In the case of the illustrated embodiment, the piston 12 has a cylindrical portion arranged in the pressure sensing chamber 14, and a concave groove is formed on the outer peripheral surface on the upstream side (check valve side) thereof, and the second sealing means is formed therein. 13 is fitted and fixed. Each sealing means may be an O-ring.

A sealing surface 25 is formed on the inner peripheral surface of the pressure sensing chamber 14 as a partner for blocking or passing the gas flow by contacting and separating the second sealing means 13.
In the illustrated embodiment, since the sealing surface 25 is tapered, the piston 12 can slightly move in the axial direction while contacting the inclined surface. Therefore, the second seal means 13 moves in the tapering direction to make the seal more stable.

The through hole 26 for allowing the gas flow from the pressure sensing chamber 14 to the downstream side is located at the downstream side of the sealing surface 25 (second sealing means 13) and on the downstream side of the pressure sensing chamber 14 (first seal). It is formed in an area upstream of the means 16). In the illustrated embodiment, the main body 10 is integrated with a decompressor (also referred to as a governor), and the through hole 26 has a diaphragm 2.
A pressure regulating chamber 28 and a pressure sensing chamber 14 which are partitioned by 7 are provided.

The piston 12 has a sealing means 1 at the second tip.
3 has a shaft-shaped portion 29 thinner than the cylindrical portion provided with
The spring means 19 act here. The spring means 19 in the present invention acts on the nozzle valve N through the piston 12 and the check valve 11 and can push in the nozzle valve N, but the internal pressure of the gas container B rises abnormally and the pressure judged to be dangerous is increased. When exceeding, piston 1 which moves by sensing the pressure
2 has elastic force capable of elastic deformation.

The spring means 19 in the illustrated embodiment comprises a coil spring wound around the shaft-like portion 29, one end of which is supported by the main body side and the other end of which acts on the piston 12. An adjuster 3 capable of axially expanding and contracting one end of the spring means 19.
It can be adjusted so that the device operates within a set pressure range (for example, 4 to 6 kg / cm ² ) by changing the spring length. The illustrated adjuster 30 is screwed into the other end opening 18.

The tip of the shaft-like portion 29 can project from the tip opening 18 of the main body cavity portion, and also serves as an operating portion for resetting or the like. That is, an engaging portion 31 is provided at the tip of the engaging piece 3 which is in contact with the tip of the shaft-like portion by the spring 32.
3 is the piston 12 due to the engaging portion 31 coming to the protruding position.
The cam surface 3 in contact with the shaft end surface 34.
By 5, the reset of pushing the piston 12 back in the valve opening direction can be performed. Reference numeral 36 denotes an operation piece having the engagement portion 31 and the cam surface 35.

In such an apparatus according to the present invention, when the nozzle valve N of the gas container is inserted into the connection port, the nozzle valve N hits the check valve 11 and the piston 12 is pushed by the check valve 11 and moves by a certain amount. To do. At this time, the first sealing means 16 provided on the piston 12 also moves with respect to the inner surface of the pressure sensing chamber 14, so that the first sealing means 16 is immediately released even if it is in a fixed state until then.

By connecting a normal gas container, the nozzle valve N
Opens and gas is ejected. In the lower half of Figure 1,
The check valve 11 moves forward until it comes into contact with its support 21, and the piston 12 also moves forward integrally, but the second sealing means 13 is not in contact with the sealing surface 25 yet. Therefore, the gas flows downstream from the through hole 26, and the gas appliance equipped with the decompressor can be normally used.

When the internal pressure of the gas container rises abnormally and exceeds the upper limit of the pressure value recognized as safe, the piston 12 senses the abnormal high pressure and moves axially against the spring means 19. By moving, the 2nd sealing means 13 comes in close contact with the sealing surface 25, and interrupts the flow of gas. This is the state from the upper half to the lower half of FIG.

The following results were obtained by comparing the changes with time of the conventional pressure sensing safety device and the pressure sensing safety device according to the present invention.

Working pressure during manufacturing Working pressure change after 1 month Conventional type 4.5 6.2 1.7 (38% increase) Invention 5.1 5.1 5.3 0.2 (4% increase) The effect of the invention could be confirmed.
The unit is Kg / cm ² .

[0024]

Since the present invention is constructed and operates as described above, even if the gas appliance is not used for a long period of time, the piston must be pushed and moved by the mounting of the gas container before it is reused. Therefore, the working pressure does not become excessive, and the safety device can always be operated at an appropriate pressure.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a pressure sensing safety device according to the present invention.

FIG. 2 is a sectional view showing an operating state of the next stage of FIG.

FIG. 3 is a plan view of a pressure reducer incorporating the present device.

Claims (6)

[Claims] 1. A check valve that can be opened by pushing a nozzle valve of the gas container when the gas container is mounted, and a piston that is movable due to an abnormal increase in internal pressure of the gas container is incorporated into a pressure sensing chamber via a sealing means. A pressure sensing safety device having the above structure, in which a check valve in contact with the tip of a nozzle valve of a gas container and a piston incorporated in a pressure sensing chamber are arranged so as to be movable integrally, and the piston is also a check valve. Provided with spring means for pressurizing in the contact direction with the piston, the movement of the check valve pushed by the nozzle valve when the gas container is attached is transmitted to the piston, and the sealing means in contact with the inner surface of the pressure sensing chamber slides with the piston. A pressure-sensitive safety device characterized in that 2. The check valve and the piston are movably arranged on the same axis, and the piston is pushed back by spring means against the nozzle valve mounted from the check valve side. The pressure-sensing safety device according to item 1. 3. A check valve which can be opened by pushing the nozzle valve when the gas container is mounted, and a piston movable in response to an abnormal increase in the internal pressure of the gas container is incorporated into the pressure sensing chamber via a sealing means. In the pressure sensing safety device having the above structure, the check valve is pushed by the nozzle valve when the gas container is attached and moves until it comes into contact with the support, and the contact valve pushes the nozzle valve back to open it. Acting on the piston, the piston has first and second sealing means located before and after the through hole for the gas flowing out of the pressure sensing chamber, and the spring means for pressurizing in the contact direction with the check valve. The first seal means is movable in contact with the inner surface of the pressure sensing chamber, and the second seal means is separable from and in contact with the inner surface of the pressure sensing chamber, so that the flow of gas is prevented. Control the
The check valve and the piston are located on the same axis, and when the gas container is mounted, the movement of the check valve is transmitted to the piston so that the first sealing means slides on the inner surface of the pressure sensing chamber. Pressure sensing safety device. 4. The sealing means is an O-ring, and the gas flow is shut off by contacting with a tapered sealing surface forming the inner peripheral surface of the pressure sensing chamber. Described pressure sensing safety device. 5. The pressure sensing safety device according to claim 1, wherein the spring means is a coil spring, and is configured to elastically press the piston from outside the pressure sensing chamber. 6. The pressure-sensing safety device according to claim 1, wherein the spring means is supported by an adjuster capable of expanding and contracting in the axial direction, and the working pressure of the piston is adjusted within a set pressure range.