JPH0669792U - Gas pressure detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a gas pressure detector capable of preventing a gas accident by preventing excessive outflow of gas into the atmosphere even if the pressure detecting means is damaged. Has an aim. [Gas pressure detection for detecting gas pressure as a differential pressure from atmospheric pressure by introducing gas to one side of pressure detection means (diaphragm) and opening the other side of the pressure detection means to the atmosphere The device is provided with overflow prevention means (check valve) 3 for preventing the gas from flowing out of the pressure detection means to the atmosphere side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas pressure detector that detects gas pressure as a pressure difference from atmospheric pressure.

[0002]

[Prior art]

 Conventionally, as this type of gas pressure detector, there has been known a gas pressure detector configured to convert a gas pressure into a mechanical displacement by a pressure detecting means such as a diaphragm, and to open and close an electrical contact by the mechanical displacement. There is. Gas is introduced into one side of the pressure detecting means, and the other side of the pressure detecting means is open to the atmosphere. In the gas pressure detector thus configured, the pressure of various gases can be detected as a pressure difference from the atmospheric pressure.

[0003]

[Problems to be solved by the device]

 However, in the above conventional gas pressure detector, since the other side of the pressure detecting means is open to the atmosphere, if the pressure detecting means is damaged, the gas flows into the atmosphere through this pressure detecting means. If there is a large amount of spillage, there is the problem of gas accidents.

The present invention has been made to solve the above-mentioned problems, and the purpose thereof is to prevent a gas accident by preventing excessive outflow of gas into the atmosphere even when the pressure detection means is damaged. It is to provide a gas pressure detector that can be prevented in advance.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention introduces a gas into one side of the pressure detecting means and opens the other side of the pressure detecting means to the atmosphere, so that the gas pressure is different from the atmospheric pressure. A gas pressure detector for detecting pressure as pressure, characterized in that an overflow prevention means for preventing the gas from flowing out from the pressure detection means to the atmospheric side is provided. The overflow prevention means may be provided on one side of the pressure detection means, or may be provided on the other side of the pressure detection means. Further, the excessive outflow prevention means may be constituted by a check valve for preventing the outflow of gas from the pressure detecting means to the atmosphere side, or may be constituted by a throttle for limiting the flow of gas.

[0006]

[Action]

 In the gas pressure detector configured as described above, the pressure detecting means is normally displaced by a change in gas pressure, but since this displacement is extremely small, the gas flow before and after the pressure detecting means is small. It hardly happens. Therefore, the overflow prevention means does not operate, and the gas pressure can be accurately detected by the pressure detection means. However, if the overflow prevention means is provided on one side of the pressure detection means, the overflow prevention means acts as a resistance to gas flow, so the overflow prevention means is provided on the other side of the pressure detection means. As a result, the gas pressure detection speed is reduced, but the gas pressure is not suddenly applied to the pressure detector, so that the durability of the pressure detection means can be improved. For this reason, in order to improve the durability of the pressure detecting means, use one in which the overflow prevention means is provided on one side of the pressure detecting means, and to improve the responsiveness of gas pressure, It is preferable to use the one in which the overflow preventing means is provided on the other side of the pressure detecting means.

Further, if the pressure detecting means is damaged or the like, and the gas may flow out to the atmosphere side from the pressure detecting means, the overflow preventing means is activated to prevent the gas from flowing into the atmosphere. Outflow is prevented. Further, in the case where the overflow prevention means is composed of a check valve, the outflow of gas into the atmosphere can be completely prevented. Therefore, a gas accident can be prevented in advance. Further, in this case, one side and the other side of the pressure detecting means have the same pressure, and the pressure cannot be detected, so that it is possible to immediately discover that the gas pressure detector is out of order. .

Further, in the case where the overflow preventing means is constituted by the throttle that restricts the gas flow, the gas slightly flows out into the atmosphere, but the gas leakage is very small. There is no risk of gas accidents, and gas odors can be easily spotted for gas leaks. Therefore, a gas accident can be prevented. Also in this case, since the pressure becomes substantially the same on one side and the other side of the pressure detecting means by the throttle, it is possible to immediately find out that the gas pressure detector is out of order.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1 and FIG. 2, reference numeral 1 is a housing main body of the gas pressure detector, and inside the housing main body 1, a diaphragm (pressure detecting means) not shown is provided. One side of the diaphragm is connected to a gas outlet of a gas meter (not shown) via a connection pipe 2 and a check valve (overflow prevention means) 3, and the other side of the diaphragm is connected to the other side. The pipe 4 for opening to the atmosphere and the hose (not shown) connected to the pipe 4 are opened to the atmosphere. Further, the displacement of the diaphragm opens and closes an electrical contact (not shown), and the output of this electrical contact can be taken out from the terminals 1a and 1b.

As shown in FIG. 3, in the check valve 3, the connection pipe 2 extends in a closed valve housing 5, and a gas introduction pipe 6 is provided so as to face the connection pipe 2. It has been extended. The inner edges of the pipes 2 and 6 are valve seats 2a and 6a, respectively, and the spherical valve body 7 is provided between the valve seats 2a and 6a. The spherical valve body 7 is placed on the holding pipe 8 so as to come to an intermediate position between the valve seats 2a and 6a, and depending on the flow of gas in the pipes 2 and 6, either the valve seat 2a or the valve seat 6a is selected. Abutting against and completely blocking the flow of gas. The gas introduction pipe 6 is connected to the gas outlet of the gas meter by a hose (not shown) connected to the gas introduction pipe 6.

In the gas pressure detector configured as described above, the displacement of the diaphragm is small during normal gas pressure detection, so that the flow rate of the gas passing through the check valve 3 is very small. The spherical valve body 7 does not come into contact with the valve seats 2a and 6a. Therefore, the diaphragm detects the accurate gas pressure. However, if the spherical valve body 7 can be moved at a slight flow rate by reducing the diameter of the holding pipe 8, the spherical valve body 7 will not move even if the flow rate of the gas is such that the diaphragm is displaced. , 6a. In this case, the check valve 3 becomes a resistance to the flow of gas, so that the gas pressure detection speed is reduced.

Further, when the diaphragm is damaged, the gas flows out into the atmosphere through the damaged part of the diaphragm, so that the flow rate of the gas passing through the check valve 3 increases and the spherical valve body 7 contacts the valve seat 2a. Since the diaphragm side is open to the atmosphere, the spherical valve body 7 is kept pressed against the valve seat 2a by the gas pressure. As a result, the outflow of gas into the atmosphere is completely blocked.

Therefore, according to the gas pressure detector configured as described above, even if the diaphragm is damaged, it is possible to completely prevent the outflow of gas into the atmosphere and prevent a gas accident. Can be prevented in advance. Further, since the check valve 3 is activated, the pressure on one side and the other side of the diaphragm becomes equal to the atmospheric pressure, so that the pressure cannot be detected. You can immediately discover that you are out of order.

In the above embodiment, the diaphragm is shown as the pressure detecting means, but the pressure detecting means may use a piezoelectric element, a strain gauge or the like. Further, although the check valve 3 is provided on one side of the diaphragm, that is, on the side for introducing gas, it goes without saying that the check valve 3 may be provided on the other side of the diaphragm, that is, on the atmosphere side. However, in this case, since the gas pressure directly acts on the diaphragm, the response speed for detecting the pressure is improved, but the durability of the diaphragm is reduced. Therefore, in order to improve the durability of the diaphragm, it is preferable to use the one in which the check valve 3 is located on one side of the diaphragm, and to improve the response speed of gas pressure, the check valve 3 should be used. It is preferred to use the stop valve 3 on the other side of the diaphragm. Also, when the check valve 3 is provided on the other side of the diaphragm, the same pressure is applied before and after the diaphragm due to the gas pressure.

Further, in place of the check valve 3, as shown in FIGS. 4 to 6, filter-shaped throttles 11, 12, 13 for limiting the flow rate of gas may be provided. The diaphragm 11 is composed of a mesh type filter, and the diaphragm 12 is composed of a waterproof and breathable sheet. These throttles 11 and 12 are provided on one side or the other side of the diaphragm (pressure detecting means) so as to limit the outflow of gas to the atmosphere side. The throttle 13 is made of asbestos-like ventilation material, and is provided in the pipe or hose on one side or the other side of the diaphragm (pressure detection means) to limit the outflow of gas to the atmosphere side. It is like this.

When the throttles 11, 12, and 13 as described above are provided, the gas slightly flows out into the atmosphere, but since the gas leak is minute, there is no possibility of causing a gas accident. By the smell of gas, gas leakage can be easily found. Therefore, it is possible to prevent gas accidents. Also in this case, since the pressure on one side and the other side of the diaphragm are almost the same due to the filter or the throttle, it is possible to immediately discover that the gas pressure detector has a failure.

[0018]

[Effect of device]

 According to this invention, even if the pressure detecting means is damaged and the gas flows out to the atmospheric side from the pressure detecting means, the overflow preventing means prevents the gas from flowing into the atmosphere. Outflow can be prevented. Therefore, gas accidents can be prevented. Moreover, since one side and the other side of the pressure detecting means have the same pressure and the pressure cannot be detected, it is possible to immediately discover that the gas pressure detector is out of order.

Then, the same effect as above can be obtained regardless of whether the overflow prevention means is provided on one side of the pressure detection means or the overflow prevention means is provided on the other side of the pressure detection means. However, when the overflow prevention means is provided on one side of the pressure detection means, the overflow prevention means acts as a resistance to the gas flow, so the overflow prevention means is provided on the other side of the pressure detection means. As a result, although the gas pressure detection speed becomes low, the gas pressure does not suddenly be applied to the pressure detector, so that the durability of the pressure detection means can be improved. For this reason, in order to improve the durability of the pressure detection means, it is possible to use an overflow prevention means provided on one side of the pressure detection means, and in the case of improving the responsiveness of the gas pressure. For this, an overflow prevention means provided on the other side of the pressure detection means can be used.

Further, in the case where the overflow prevention means is composed of a check valve, the outflow of gas into the atmosphere can be completely prevented. Furthermore, if the overflow prevention means is composed of a throttle that restricts the flow of gas, the gas will flow out slightly into the atmosphere, but since gas leakage is minute, gas accidents will occur. There is no fear of connection, and gas scents make it easy to spot gas leaks. Therefore, it is possible to prevent a gas accident. Also in this case, since the pressure becomes substantially the same on one side and the other side of the pressure detecting means by the throttle, the trouble of the gas pressure detector can be immediately found.

[Brief description of drawings]

FIG. 1 is a side view of a gas pressure detector shown as an embodiment of the present invention.

FIG. 2 is an end view of the gas pressure detector.

FIG. 3 is a cross-sectional view of a check valve shown as an overflow prevention unit of the gas pressure detector.

FIG. 4 is a perspective view of a throttle shown as an overflow prevention unit of the gas pressure detector.

FIG. 5 is a perspective view showing another example of the diaphragm.

FIG. 6 is a perspective view showing still another example of the diaphragm.

[Explanation of symbols]

 1 Gas pressure detector housing body 3 Check valve 11, 12, 13 Throttle

Claims (5)

[Scope of utility model registration request] 1. A gas pressure detector for detecting gas pressure as a differential pressure from atmospheric pressure by introducing gas to one side of the pressure detecting means and opening the other side of the pressure detecting means to the atmosphere. A gas pressure detector, characterized in that an overflow prevention means for preventing the gas from flowing out from the pressure detection means to the atmosphere side is provided. 2. The gas pressure detector according to claim 1, wherein the overflow preventing means is provided on one side of the pressure detecting means. 3. The gas pressure detector according to claim 1, wherein the overflow preventing means is provided on the other side of the pressure detecting means. 4. The gas pressure according to claim 1, wherein the overflow prevention means is a check valve for preventing the outflow of gas from the pressure detection means to the atmosphere side. Detector. 5. The gas pressure detector according to claim 1, wherein the overflow prevention means is a throttle for limiting the flow of gas from the pressure detection means to the atmosphere side. .