JPH0389086A - Safety valve - Google Patents

Abstract

PURPOSE:To make fine adjustment of urging forces of an elastic body on a closing piece possible by the operation of an adjustment screw by setting the direction of urging the closing piece different from the direction of arrangement of a pressure receiving port and a discharge port. CONSTITUTION:When a pressure beyond a specified value from a pressure receiving part 5 is applied on a closing piece (steel ball) 3, the closing piece 3 resisting the urging force of an elastic body (coil spring) 4 moves toward the other side of a valve body 1, and the pressure receiving port 5 is connected via an inner passage 2 of the valve body 1 to a discharge port 6. Working pressure increases as an adjustment screw 11 is screwed in and vice versa. With the direction of the urging force of the elastic body 4 different from the direction of arrangement of the pressure receiving port 5 and the discharge port 6 in this way, magnitude of the urging force on the closing piece 3 by the elastic body 4 may finely adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a safety valve that opens due to overpressure.

Prior Art A conventional safety valve is constructed as shown in FIG. A steel ball 3 and a coil spring 4 are housed in an internal passage 2 of the valve body 1. Usually, the coil spring 4 presses the steel ball 3 against a pressure receiving port 5 formed at one end of the valve body 1. Therefore, the space between the pressure receiving port 5 and the internal passage 2 is in a closed state. When the pressure P acting on the pressure port 5 becomes an excess pressure higher than the specified pressure, the steel ball 3 is pushed against the bias of the coil spring 4 as shown in FIG. 2 is in communication with the valve body 1, and the pressure acting on the pressure receiving port 5 is released to the atmosphere, for example, as shown by arrow A, via the release port 6 at the other end of the valve body 1.

Note that the other end of the valve body 1 is "caulked".

Problems to be Solved by the Invention In such a conventional configuration, the pressure value at which the safety valve operates is determined by the performance of the coil spring 4, resulting in a low yield when mass producing safety valves according to certain specifications. There is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a safety valve having a structure that allows adjustment of variations in operating performance to achieve a target operating pressure value.

Means for Solving the Problems The safety valve of the present invention has a pressure receiving port at one end that communicates with an internal passage formed from one end to the other end, and a discharge port that communicates with the internal passage formed on the peripheral surface. an obturator inserted into the internal passage of the valve body; an adjusting screw that engages with the other end of the valve body to move in and out of the internal passage of the valve body; The present invention is characterized in that an elastic body is provided between the obturators and urges the obturators in a direction to close the pressure receiving port. As the elastic body, in addition to a coil spring, a tip made of rubber or a synthetic resin having elasticity can be used.

According to this configuration, when a pressure exceeding a specified pressure is applied to the obturator from the pressure receiving port, the obturator moves toward the other end of the valve body against the bias of the elastic body, and the internal passage of the valve body is closed. The pressure receiving port communicates with the discharge port via the pressure receiving port.

Tightening the adjustment screw increases the operating pressure, and loosening it decreases it.

Embodiments Hereinafter, embodiments of the present invention will be explained based on FIGS. 1 to 3. Components having the same functions as those in FIG. 4 showing the conventional example will be described with the same reference numerals.

FIG. 1 shows an embodiment of the safety valve of the present invention. A pressure receiving port 5 is bored at one end of the valve body 1, and a female thread 7 is formed on the inner peripheral surface of the other end. Furthermore, the peripheral surface 8 of the valve body 1
A discharge port 6 communicating with the internal passage 2 is bored in the.

A valve seat sealing material 9 is stored in contact with the pressure receiving port 5 in the internal passage 2 of the valve body 1. Next to the valve seat sealing material 9 is a steel ball 3 as an obturator, and then a steel ball 3 as an elastic body. It is assembled by housing the synthetic resin chip IO and screwing the adjustment screw II into the female screw 7.

The synthetic resin chip 10 is used by molding synthetic resin into a cylindrical shape with a hardness according to the intended specifications. FIG. 2 shows the safety valve thus constructed in use. The safety valve is set inside the lower casing 12 and the upper casing 13. 14°15 and 16 are sealing materials,
The flange portion 17 on the one end side of the valve body 1 is held and positioned between the lower casing 12 and the upper casing 13.

With this configuration, the inlet 18 of the upper casing I3
When the pressure of the piping route to be protected (not shown) connected to the pipe is lower than the specified pressure, the steel ball 3
The pressure receiving port 5 is maintained in a closed state by being pressed against the valve seat sealing material 9 by an elastic force of zero.

When the pressure in the piping route becomes excessive, the steel ball 3 is pushed against the elastic force of the synthetic resin chip 10 as shown in FIG. 2, and the steel ball 3 is separated from the valve seat sealing material 9. Therefore, the pressure receiving port 5 and the discharge port 6 communicate through the internal passage 2,
A flow of pressure fluid is generated as shown by arrow B, passes between the circumferential surface of the valve body 1 and the inner circumferential surface 19 of the lower casing 12, and is discharged to the atmosphere from the outlet 20. When the pressure in the piping route to be protected returns to normal, the steel ball 3 is inserted into the synthetic resin chip I.
It is pushed back to the desired position shown in FIG. 1 by the elastic force of O, and automatically closes the piping route to be protected and the discharge route from the atmosphere.

In order to obtain a safety valve with the desired operating pressure value, 5 kg + 10
The hardness, cross-sectional area, etc. of the synthetic resin chip IO are adjusted according to the intended working pressure range, such as 20 kg or 20 kg.
Further adjustment screws after assembly! By adjusting the position of l in the valve body 1, it is possible to more accurately approach the target operating pressure value, and the yield during mass production is improved.

In the above embodiment, a synthetic resin chip IO was used as the elastic member 9, but even if the coil spring 4 is used as shown in FIG. can be compensated.

In each of the above embodiments, the synthetic resin chip 10 is used as the elastic body.
Although we have explained the case where the 1° synthetic resin chip is used and the case where the coil spring 4 is used, it has been confirmed through experiments that the change over time in the hardness of a 1° synthetic resin chip is smaller than the change over time in the elasticity of the coil spring 4. A safety valve using a synthetic resin chip IO can be expected to operate more stably over a long period of time.

In the above embodiment, a synthetic resin chip IO is used as the elastic body, but a natural rubber chip or a synthetic rubber chip (for example, urethane rubber) may also be used.

Effects of the Invention As described above, according to the present invention, a pressure receiving port communicating with the internal passage formed from one end to the other end is provided at the one end, and a discharge port communicating with the internal passage is provided in the peripheral surface. an obturator inserted into the internal passage of the valve body; an adjusting screw that engages with the other end of the valve body to move in and out of the internal passage of the valve body; An elastic body is provided between the obturators and biases the obturator in a direction to close the pressure receiving port, and the direction in which the obturator is biased by the elastic body and the direction in which the pressure receiving ports and the discharge ports are arranged are set. Since they are made different, it is possible to finely adjust the magnitude of the biasing force exerted on the obturator by the elastic body by operating the adjustment screw.

Therefore, a safety valve having a desired operating pressure value can be manufactured at a good yield.

Furthermore, by using a rubber or elastic synthetic resin tip as the elastic body, it is possible to reduce the variation in operating pressure values compared to when a coil spring is used as the elastic body, and it also has a long lifespan with less deterioration over time. Stable operation can be achieved over a period of time.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of one embodiment of the safety valve of the present invention, Fig. 2 is a longitudinal sectional view of the device in use, Fig. 3 is a longitudinal sectional view of another embodiment, and Fig. 4 is a longitudinal sectional view of a conventional safety valve. FIG. 5 is a longitudinal sectional view of a conventional safety valve in an operating state. t... Valve body, 2... Internal passage, 3... Steel ball [obturator], 4... Coil spring [elastic body], 5...
・Pressure port, 6...Discharge port, 7...Female thread, 10...
・Synthetic resin tip (elastic body), 11...adjustment screw.

Claims (1)

[Scope of Claims] 1. A valve body having a pressure receiving port at one end that communicates with an internal passage formed from one end to the other end, and a discharge port that communicates with the internal passage formed on the peripheral surface. an obturator inserted into the internal passage of the valve body; an adjusting screw that engages with the other end of the valve body to move in and out of the internal passage of the valve body; and between the adjusting screw and the obturator. A safety valve including an interposed elastic body that urges an obturator in a direction to close the pressure receiving port. 2. The safety valve according to claim 1, wherein the elastic body is a coil spring. 3. The safety valve according to claim 1, wherein the elastic body is a chip of rubber or a synthetic resin having elasticity.