JPS5844322A - Pressure detector - Google Patents

Abstract

PURPOSE:To miniaturize a detector, by a method wherein caps are attached to opposite ends of a bellows contracting through the working of a pressure applied from the outside to form a case, and a device incorporating a pressure sensor is located at the inside of a fluid path. CONSTITUTION:Inert gas L, a microswitch 6 attached to a metal cap 2, and an operating piece 10 set to a metal cap 3 are mounted to the inside of a body case 4 in which the caps 2 and 3 are hermetrically secured to opposite ends of a bellows part 1 made of synthetic rubber. The operation of a device such that, if a pressure of fluid W flowing through the inside of a hot water feed pipe 11 increases, the bellows part contracts, and the operating piece 10 on the cap 3 works in synchronism with said contraction to operate the microswitch 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure detector and a button device for detecting the pressure of a fluid in a container containing a fluid or in a fluid passage.

Conventional pressure detection devices include water pressure responsive valves used in gas water heaters and the like, and wind pressure switch devices used in FF type gas or oil hot air heaters. This water pressure responsive valve uses a diaphragm as a pressure receiving surface and converts the pressure difference between the front and rear surfaces into sliding movement of a valve interlocked with the diaphragm to adjust the degree of opening and control the flow rate of water. Similarly, the wind pressure switch device uses a diaphragm, and when a certain pressure is reached, a microswitch that operates in conjunction with the diaphragm is activated. All of these conventional devices take the fluid to be detected inside and require a large pressure-receiving surface, resulting in a large volume.
In addition, connecting piping was required, and the space required for its installation was large, thus increasing the size of the attached equipment.

Therefore, an object of the present invention is to provide a pressure sensing device that is compact, easy to install, and requires a small installation space.The present invention has a structure including a bellows portion that contracts due to external pressure, and a pressure sensing device provided on one side of the bellows portion. and a cap B provided on the other side of the bellows portion.
The outer case is filled with a fluid at an arbitrarily set pressure, and a pressure sensor is provided to detect fluctuations in the pressure of the fluid.It is small and lightweight, and requires little installation space. The durability and reliability of the pressure sensor can be improved by being small or by protecting the internal pressure sensor with an outer case.

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

In the figure, a metal cap 2 is fixed to one side of a bellows part 1 made of synthetic rubber, and a metal cap B3 is fixed to the other side in an airtight manner. The bellows part 1
, cap A2 and cap B3 constitute an outer case 4. A mounting screw portion 5 is formed on the outer periphery of the cap 2.

A microswitch 6 as a pressure sensor is fixed inside the cap 2 with a fixture 7. The lead wire 8 is taken out from the flat part 9 of the cap 2 while maintaining airtightness with the cap 2. On the other hand, the cap 83 is provided with an operator 1o that comes into contact with the microswitch 6 to operate the microswitch 6 when the bellows portion 1 contracts due to external pressure and a predetermined pressure is detected. The fluid sealed inside is an inert gas in this embodiment, and the pressure of the inert gas is set so that when the bellows part 1 receives pressure Pc from the outside, the operator 1° turns on the micro switch 6. ing.

In the above configuration, the cap 2 is screwed to the wall surface of the hot water supply pipe 11 of the gas water heater using the mounting screw portion 6 as shown in FIG. The gasket 12 is water resistant and heat resistant and prevents leakage of the pipe fluid W from the mounting screw part 6. Although the pipe fluid W heated to 80'C or higher flows through the hot water supply pipe 11, hot water is supplied due to the dry heating phenomenon, etc. When the pressure inside the pipe 11 rises to pressure 16 or higher, the bellows part 1 contracts as shown in the figure, and the operator 1° of the cap B3 is interlocked to operate the micro switch 6 to turn off the electromagnetic force in the gas passage. A valve (not shown) is shut off to stop combustion in a gas burner (not shown).

Therefore, safety is ensured by preventing piping systems such as heat exchangers from burning or exploding.

In the pressure sensing device of this embodiment, since the gas sealed in the bellows portion 1 is an inert gas, the durability of the pressure sensor such as the micro switch 6 can be improved and reliability can be improved. It can be miniaturized and can be installed in passages with little space, such as gas passages, water supply passages, and hot water supply passages. Also, in the unlikely event that the bellows part 1 is damaged,
Even if the sealed structure is destroyed, the sealed fluid or the fluid to be detected will not leak to the outside, and it is possible to prevent the risk of raw gas leaking due to a diaphragm breakage, as in conventional gas governors.

Furthermore, since pressure can be detected just by placing it in the fluid,
Bellows part 1 and capum 2. If a material such as B3 is selected, it can be applied to most fluids such as gas, water, hot water, oil, seawater, etc. Therefore, it is possible to achieve common use and achieve effects such as cost reduction through mass production.

Next, another embodiment of the present invention will be explained based on FIG.

In the figure, the cap 2 has a tightening nut 13 on the flat part 9.
The mounting screw part 6 is short and has a stepped part 15 that comes into contact with a gasket 14 such as an O-ring in the middle.

Instead of the bellows, a heat-resistant and corrosion-resistant wax metal plate, such as a stainless steel plate 16, is used. As a pressure sensor, a strain gauge 17 is used which continuously detects continuous pressure fluctuations.

In this embodiment, the device can be attached and removed from the outside of the container or passageway, making it easy to replace or inspect during maintenance. Also, the stainless steel plate 16 is a weak substitute for bellows.
It can be applied to fluids with high viscosity, high pressure, and high temperature fluids. Furthermore, since a strain gauge is used as a pressure sensor, pressure fluctuations can be continuously detected.

As described above, according to the present invention, all the parts are housed within the device, so it can be assembled into a very compact external shape, and therefore does not require a large space when used, and can be used in various passages such as containers. Can be installed without using piping. Furthermore, the fluid to be sealed can be a fluid that improves the durability of the sensor, such as an inert gas, and the reliability of the internal sensors can be increased. Furthermore, even if the bellows portion is damaged, the fluid inside the container or the passageway will not leak to the outside, thereby providing an excellent pressure sensing device that is safe especially in the case of dangerous fluids.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing how a pressure sensing device according to an embodiment of the present invention is installed, and FIG. 2 is a cross-sectional view showing how a pressure sensing device according to another embodiment of the invention is installed. 1... Bellows part, 2... Capm, 3... Cap B, 4... Body case, 6... Mark pressure sensor, 1o... ...operator,
L...Fluid. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (2)

[Claims] (1) A bellows part that contracts due to external pressure. A cap member provided on one side of the bellows part and a cap B provided on the other side of the bellows part form an outer case. 1. A pressure sensing device, which is filled with a fluid at an arbitrarily set pressure, and is provided with a pressure sensor that senses fluctuations in the pressure of the fluid. (2) The pressure sensing device according to claim 1, wherein the cap member is provided with a mounting screw portion on the outer surface thereof, and an operator for driving the pressure sensor is provided on the inside of the cap B.