JPS5829866B2 - Bourdon tube pressure gauge safety device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a technology for improving the safety of buttons on, for example, primary side pressure gauges of pressure regulators and other Bourdon tube pressure gauges used to measure fluid pressure in various fluid pipelines.

For example, when taking out oxygen, etc. from a high-pressure cylinder by dropping it to the desired pressure by 1, the container valve must be opened gradually in accordance with the regulations, but even so, the high-pressure fluid is suddenly released due to the large diameter of the valve. When the valve is opened, a large pressure is momentarily applied to the pressure gauge on the high pressure side of the pressure regulator, which may damage the Bourdon tube inside the pressure gauge.

Moreover, since the opening operation of such container valves tends to be quick, the actual risk is even higher, and if the valve is opened rapidly due to such use, it will directly lead to an accident that breaks the Bourdon tube. Easy and extremely dangerous.

Also, for example, backfire may occur during welding work and abnormal pressure is applied to the oxygen or acetylene pipeline, or the downstream pipeline may be blocked due to the pipeline being bent or being trampled by a heavy object. If the fluid pressure in the pipeline rises abnormally, such as in the event of an accident, there is a risk that a similar Bourdon tube breakage accident will occur in the pressure gauge attached to the pipeline.

For this reason, as illustrated in FIG. 3, a so-called insect 01 is attached to the starting end of the pressure fluid introduction path 06 of the Bourdon tube pressure gauge 05A to buffer the introduction pressure when the container valve is opened. Although some considerations have been made, there is a limit to the cross-sectional area of the crest formed on Mushi 07 due to the manufacturing process, and in practice, the limit is to provide a through hole with a diameter of 0.1m77L. Therefore, as described later, the pressure buffering effect is
This is insignificant compared to the case where 7 is not included, and it is not only insufficient as a measure to prevent damage to the Bourdon tube, but also
Even if such measures are taken, in the unlikely event that the cylinder falls over or collides with another object and the Bourdon tube is destroyed, a large amount of gas will not be able to escape from the broken point. However, no consideration was given to safety in this aspect.

The safety device for the Bourdon tube pressure gauge according to the present invention has been developed in view of the current situation. It is located in a state where it is divided into two compartments, and as the pressure rises inside the coal chamber, a pressure difference occurs between the compartments, so that it presses against the end of the pressure fluid introduction path to the Bourdon tube and temporarily blocks this introduction path. In this closed state, the pressure fluid flows from the primary chamber to the secondary chamber through the small gap formed between the fluid introduction channel and the end of the fluid introduction channel. A membrane body that is displaced and returned to be spaced apart from the end and released from the closed state is stretched, and a fluid is applied to an appropriate position of this membrane body excluding a portion facing the open end of the introduction channel in the closed state. It is characterized by the provision of micro holes for passage.

Therefore, even if the pressure fluid introduction channel is not manufactured to be extremely narrow, when the valve is opened or when abnormal high pressure fluid flows into the pipe for some reason during pressure measurement,
- The membrane body that partitions the coal chamber and the secondary chamber is displaced by the pressure difference on both sides of the membrane body, blocking the pressure fluid introduction path and leaving only a minute gap, causing the minute hole provided in the membrane body to become displaced. Pressure fluid entering the secondary chamber passes through the minute gap and gradually flows into the Bourdon tube, exerting a remarkable pressure buffering effect.
This prevents damage to the Bourdon tube due to instantaneous pressure increases.
In addition, even if the Bourdon tube is destroyed due to an external cause such as contact with another object, the membrane will become occluded due to the pressure difference, functioning as a safety valve to prevent fluid from ejecting from the broken point, ensuring safety. can be ensured.

In addition, when the pressure in the primary and secondary chambers is equalized due to the inflow of fluid through the micropores in the membrane and the microgap in the closed state, the membrane returns to its displacement and becomes blocked due to the differential pressure. Since the condition is released, or at least the biasing force holding the valve in the closed position is released, the pressure fluid inside the Bourdon tube can be released immediately when the valve is closed or when the cause of the abnormal square rise is removed. It is something that

The valve according to the present invention is constructed so that the valve action is performed by the membrane body, and the membrane surface is separated from the end of the pressure fluid introduction path, so the processing of the valve body itself is not necessary. Compared to machining such as drilling a minute hole in a metal valve body, it is extremely easy to manufacture as it is only necessary to provide a relatively rough minute hole away from the part facing the pressure fluid introduction path. Moreover, since the valve body that frequently comes into contact with and separates from the pressure fluid introduction path that serves as the valve seat is a membrane body, wear and damage to the valve seat can be extremely reduced, and it can be manufactured relatively easily and at low cost. It is also advantageous in that the durability of the Bourdon tube pressure gauge can be maintained at a good level simply by periodically replacing the membrane body.

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment in which the present invention is applied to a high-pressure side pressure gauge of a pressure regulator for a high-pressure gas container will be described based on the drawings.

FIG. 1 shows an example of a pressure regulator, in which 1 is a handle for mounting on a pressure vessel such as an oxygen cylinder, 2 is a pressure adjustment handle, 3 is a handle for opening/closing a container valve (not shown), and 4 is a pressure fluid handle. The outlet 5A is a Bourdon tube pressure gauge communicating with the high pressure side of the pressure regulator, and 5B is a Bourdon tube pressure gauge communicating with the low pressure side.

In this example, the above-mentioned pressure gauge 5A is installed in a space within the branch flow path of the pressure regulator main body, which is an example of the branch pipe 9.
By tensioning and fixing the membrane body 7 which is partitioned into a charcoal chamber 10 and a secondary chamber 11, the membrane body 7 is moved to the secondary chamber 1 side due to the generation of differential pressure between the compartments 10 and 11 due to the rise in pressure inside the charcoal chamber 10. The pressure fluid introduction path 6 is pressed against the end of the pressure fluid introduction path 6 to the Bourdon tube, and the introduction path 6 is temporarily closed.

In the membrane body 7, in the closed state, fluid passage microholes 12 are provided at appropriate positions other than those facing the open end of the pressure fluid introduction path 6. When the charcoal chamber 10 is open, the pressure fluid in the charcoal chamber 10 flows into the secondary chamber 11 through this microhole 12,
In addition, in the above-mentioned closed state, the pressure fluid in the primary chamber 10 flows into the secondary chamber 11 through the minute gap formed between the membrane body 7 and the end surface of the introduction channel 6, and as a result, the compartment 1
When the pressure difference between 0 and 11 is eliminated, the membrane body 7 is displaced and returned to the primary chamber 10 side, and the closed state is automatically released.

8 in the figure is a filter. According to the above embodiment,
When the pressure regulator is installed with the pointer of the pressure gauge 5A facing upward, by opening the container valve, the membrane body 7 will be displaced toward the secondary chamber 11 side, as shown in Figure 2, A1. A part of the pressure fluid introduction path 6 comes into close contact with the periphery of the starting end of the pressure fluid introduction path 6 and closes the pressure fluid introduction path 6, so that the pressure fluid is prevented from flowing into the Bourdon tube side.

However, a minute gap is always formed between the starting end surface of the pressure fluid introduction path 6 and the upper surface of the membrane body 7 in the case of general machining, and The pressure fluid enters the secondary chamber 11 from the coal chamber 10 through the micropores 12, and further passes through the micropores 12 between the membrane body 7 and the end face of the introduction channel 6. Introductory path 6 from the gap
The pressure gradually flows into the Bourdon tube through the pressure gauge 5A, and the pointer of the pressure gauge 5A slowly rises, and the pressure on both sides of the membrane body 7 is equalized, and the pressure gauge 5A increases.
When the pointer becomes stationary at a predetermined value, the membrane 7 returns to the charcoal chamber 10 side and releases the closed state, as shown in FIG. 2C.

When the work is finished and the container valve is closed, if the pressure gauge has the insect 01 inserted as shown in Figure 3, the flow path will be blocked, which will prevent the release of the pressure fluid inside the pressure gauge. However, in the case of this embodiment, the membrane body 7 is displaced and returned to the charcoal chamber 10 side. When the container valve is closed, the pressure fluid in the pressure gauge 5A flows out into the secondary chamber 11, which has a larger volume, and is further discharged to the outside through the microholes 12 and the coal chamber 10. The pointer can quickly return to zero.

The membrane used in the present invention may be a simple membrane as shown in FIG. 4A, for example.

The operation of this has already been described.

In this case, if a hemispherical or conical protrusion 13 is provided on the surface of the membrane body 7 on the secondary chamber 11 side, as shown by the dotted line, the pressure fluid introduction path 6 will be more effectively blocked. The fluid flow rate passing through the minute gap can be made very small.

The one shown in FIG. 4 uses a bellows 14 as the membrane body.

If the cap of the high-pressure gas container is opened or there is an abnormal pressure rise in the piping, the pressure gauge installation divided by the bellows 14 will be disconnected from the secondary chamber 11 when it flows into the coal chamber 10 in the branch pipe 9. The bottom surface 15 is pressed against the end surface of the pressure fluid introduction path 6, and the introduction path 6
occlude.

Since the bottom surface 15 is provided with micro holes 12, the fourth
Similar to the embodiment shown in Figure (a), the pressure in the coal chamber 10, the secondary chamber 11, the introduction passage 6, and the Bourdon tube are balanced by the inflow of pressurized fluid through the minute hole 12 button and the minute gap in the closed state. When the differential pressure is resolved, the pressure on the bottom surface 15 is released and the closed state is released.

In this case, if the pressure gauge is mounted with the pointer section upward, the bellows 14 will return to its original displacement so as to contract under its own weight, opening the pressure fluid introduction path 6 wide.

Even in the case of bellows, if a protrusion is provided at the center of the bottom surface 15 as in the previous embodiment, the closed state can be made even better.

For the present invention, the inflow speed of the pressure fluid into the Bourdon tube can be arbitrarily changed depending on the volumes of the coal chamber 10 and the secondary chamber 11, the micropores 12, and the cross-sectional areas of the pressure fluid introduction path 6. When a pressure regulator is attached to a gas container, the time required for the pointer of the pressure gauge to indicate the pressure inside the container from the time the container cap is opened is an appropriate time (generally around 3 seconds is considered appropriate). It is a good idea to set these values so that

In this way, in the present invention, the micropores 12 provided in the membrane body 7
Since there are two ridges of minute gaps formed in a closed state between the membrane body 7 and the end faces of the introduction channel 6, the inflow speed of the pressure fluid into the Bourdon tube becomes minute, and the Bourdon is caused by rapid inflow. There is no damage to the pipe.

In addition, even if the pressure gauge is damaged due to a fall of the container or a collision with another object and the Bourdon tube is destroyed, the membrane 7 will similarly block the introduction path, so there is a danger that high-pressure gas will continue to blow out. accidents can be prevented.

On the other hand, when the pressure fluid in the charcoal chamber 10 is released by closing the cap of the container and the pressure in the secondary chamber 11 becomes higher, the membrane body 7 is reversed to the charcoal chamber 10 side. Since the introduction passage 6 is displaced and opened widely, the pressure fluid in the Bourdon tube flows into the secondary chamber 11 whose volume has increased, and further flows into the microhole 12.
Since the charcoal is discharged through the charcoal chamber 10, the pointer on the pressure gauge quickly returns to zero.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the safety device for a Bourdon tube pressure gauge according to the present invention, and FIG. 1 is a plan view of a pressure regulator for a container;
2A to 2C are longitudinal sectional views of the main parts, FIG. 3 is a longitudinal sectional view of the main parts showing a conventional example, and FIG. 4A. The mouth is an enlarged longitudinal sectional view of the main part of the device of the present invention. 6... Pressure fluid introduction path, 7... Membrane body, 9... Branch pipe for installation, 10... - Charcoal chamber, 11... Secondary chamber, 12...
...Minor holes for fluid passage.

Claims (1)

[Claims] 1. The Bourdon tube pressure gauge is installed in the branch pipe 9, and this fall material is located in a state that divides the space in the branch pipe 9 into a primary chamber 10 and a secondary chamber 11, and - the pressure rise in the coal chamber 10. Due to the pressure difference generated between the compartments 10 and 11 due to this, the pressure fluid is pressed against the end of the pressure fluid introduction path 6 to the Bourdon tube and is displaced so as to temporarily block this introduction path 6, and the fluid is introduced in this closed state. Road 6
The primary chamber 10 through the micro gap formed between the end portion
compartment 10°1 due to the inflow of pressure fluid from to the secondary chamber 11
A membrane body 7 which is displaced and returned to the fluid introduction passage 6 so as to be separated from the end of the fluid introduction passage 6 and released from the closed state when the pressure difference between A safety device for a Bourdon tube pressure gauge, characterized in that microholes 12 for fluid passage are provided at appropriate positions except for locations facing the open end of the passage 6.