JPS5848604Y2 - Overpressure prevention set valve type low pressure gauge - Google Patents

Description

[Detailed description of the invention] This invention relates to a set-valve type micro-pressure gauge to prevent filtration pressure, which is designed to measure micro-pressures of 0.1 kg or less, and is used for gas pressure and other various atmospheric pressures, as well as leakage inspections of underground telephone cables. The purpose is to provide a low pressure gauge that is free from damage even when an abnormally high pressure higher than the specified pressure is applied.

A micropressure gauge is a highly accurate measuring instrument designed to measure extremely low pressure, and is extremely vulnerable to abnormal pressures that exceed the specified limit. If abnormal pressure that exceeds the specified limit is applied, it will instantly break and become unusable. Become.

This invention solves the difficulties of the above-mentioned conventional example, and its structure will be explained below with reference to the drawings showing one embodiment.

Reference numeral 1 denotes a case, and a chamber 2 is provided inside the case.

The chamber 2 is configured to be expanded or contracted according to the atmospheric pressure by introducing gas into it, and the movement of the chamber 2 causes the pointer 4 to rotate via the internal sector 3 and the like, and the dial 5 The pressure is read by the position of the pointer 4 at the front.

This micropressure gauge connects the outer threaded part 7 of the stock 6 protruding below the case 1 to piping, etc., and connects the valve chamber 9, the set 10 inlet 11 and the pressure port 8 opened at the bottom end of the stock 6 The pipes 12 are communicated with each other, and the connecting pipe 12 is communicated with the chamber 2.

Next, the valve mechanism constructed within the stock 6 will be explained.

A guide screw 13 is attached to the lower part of the valve chamber 9 with a through hole 14 formed in the center.

Reference numeral 15 denotes a cutoff valve, which has a lock 16 fixed therethrough and is movable up and down, so that the lower part of this rod 16 is loosely fitted into the through hole 14 and inserted into the upper setting chamber 10, and the lower surface of the cutoff valve 15 is inserted. is joined to the upper surface of the guide screw 13.

A set screw 17 is fixed to the lower part of the setting chamber 10, and has the upper part of the rod 16 protruding from a through hole 18 formed in the center, and a spring 19 is disposed therein.

20 is a set valve, which has an inverted T-shaped cross section, and has a flange 21.
and a shaft portion 22, and a stepped portion 23 formed in the set chamber 10.
The flange 21, which is pressed and supported by the spring 19, holds an O-ring 24 made of an elastic material joined to the flange 21.

The valve mechanism with the above structure has a cutoff valve 15 and a set valve 20, 24 inserted into the valve chamber 9 and set chamber 10, but it is not a completely sealed mechanism, and there are gaps that allow slight pressure gas to gradually leak. have.

Therefore, the slightly pressured gas flowing in from the pressurizing port 8 is transferred to the shutoff valve 15.
After entering the valve chamber 9 through the gap between the guide screw 13 and the guide screw 13, it flows into the set chamber 10 through the through hole 18, and then leaks from between the set valve 20, the O-ring 24, and the inner surface of the set chamber 10. The liquid then moves into the inlet 11 and further flows into the chamber 2 via the connecting pipe 12.
This will cause chamber 2 to expand.

Conversely, when the pressurization decreases, the low pressure gas flows into the chamber 2 in the opposite direction, causing the chamber 2 to contract.

The extent to which the inner surface of the chamber 10 is joined to the O-ring 24 and the cellar 1 is set by the pressing force of the spring 19. By adjusting the pressing force of the spring 19, the speed of the passing fluid can be adjusted and sudden pressure can be prevented. Pressure is prevented and the pointer 4 is rotated quietly.

Therefore, due to unforeseen circumstances, 0.1k was applied to the pressurizing port 8.
When an abnormally high pressure exceeding the specified value of g or more is applied, this abnormally high pressure acts on the lower surface of the cutoff valve 15, causing the cutoff valve 15 to rise rapidly.

Then, as the shutoff valve 15 rises, the rod 16 pushes up the set valve 20 and presses the O-ring 24, and as shown in FIG. It will be completely blocked.

Therefore, the abnormally high pressure flowing in from the pressurizing port 8 is prevented from flowing into the connecting pipe 12 due to the O-ring 24, and therefore, there is no risk of damage to the internal mechanisms such as the chamber 2.

When the abnormally high pressure disappears, the valve mechanism will be restored and normal low pressure measurement will continue.

Incidentally, the higher the abnormally high pressure is, the stronger the blocking force by the O-ring 24 becomes, and damage to the chamber 2 and the like can be completely prevented.

This device has the above-mentioned configuration, so even if abnormally high pressure is applied, there is no risk of damage to this micropressure gauge, and it is highly durable and maintains accuracy. This is possible, and the overpressure prevention set valve type micropressure gauge according to this invention has excellent practical effects.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of the overpressure prevention set valve type micropressure gauge according to this invention, and FIG. 2 is a longitudinal sectional view thereof. FIG. 3 is a longitudinal cross-sectional view showing the valve mechanism section under normal conditions. FIG. 4 is a longitudinal sectional view showing a state where abnormally high pressure is applied. 9... Valve chamber, 10... Set chamber, 13
...Guide screw, 15 ...Shutoff valve, 1
6...lot, 19...spring,
20...Set valve, 23...Step part, 24...O ring.

Claims (1)

[Scope of utility model registration request] The cutoff valve 15 through which the rod 16 is fixed is connected to a guide screw 13 attached to the lower part of the valve chamber 9, and an O-ring 24 made of an elastic material is connected to a step 23 formed in the set chamber 10. is held by a set valve 20 which is supported by a spring 19, and the cutoff valve 1
5 receives abnormally high pressure, the set valve 20 is pushed up through the lot 16, and the O-ring 24 is brought into close contact with the inner surface of the set chamber 10.