JP7493244B2 - Pressure Control Valve - Google Patents

Description

The present invention relates to a pressure control valve used in pneumatic tools, etc., and in particular to a pressure control valve that reduces the load on the pressure adjustment handle, allowing pressure adjustment and relief settings to be performed with light handle operation.

2. Description of the Related Art Conventionally, there has been known a pressure control valve that is interposed between an air compressor and a pneumatic tool to reduce and adjust the air pressure supplied from the air compressor to a desired air pressure.
As such a pressure control valve, for example, there is a pressure control valve as shown in FIG. 4 (see Patent Document 1).

This pressure control valve comprises a fluid passage formed inside the casing 1, a valve body 3 with a valve spring 31 interposed in the fluid passage and dividing the fluid passage into a primary side 2a passage and a secondary side 2b passage, a cylinder section 4 formed inside the casing 1, a piston 5 slidably arranged in the cylinder section 4, a piston small diameter section 51 extending from the piston 5 toward the valve body 3 and forming a passage 6 through which air flows with its tip as a valve seat 61, a valve chamber 12 in which the valve body 3 is disposed and into which the piston small diameter section 51 is slidably inserted, a pressure adjustment spring 7 that biases the piston 5 in the direction in which the valve seat 61 moves away from the valve body 3, a hollow rod 8' inserted into the piston small diameter section 51 so that its tip abuts against the valve body 3, and a relief passage 9' that opens the secondary side 2b passage to the atmosphere via the rod 8' when the tip of the rod 8' moves away from the valve body 3. The rod 8' is formed integrally with the casing 1, and forms a relief passage 9' at its tip that leads to the outside of the casing 1.

As shown in FIG. 4(a), this pressure control valve compresses the pressure adjustment spring 7 by tightening the pressure adjustment handle 10′ screwed onto the outer periphery of the casing 1, thereby moving the piston 5 backward and separating the valve seat 61 from the valve body 3, thereby introducing compressed air in the passage on the primary side 2a into the passage on the secondary side 2b.
Then, when the pressure in the secondary side passage 2b reaches the set pressure, as shown in FIG. 4(b), the piston 5, which receives the air pressure in the secondary side passage 2b, moves toward the valve body 3 against the pressure adjustment spring 7, and presses the valve seat 61 against the valve body 3, thereby blocking the passage of the primary side 2a and the passage of the secondary side 2b and preventing a pressure increase in the passage of the secondary side 2b.
Next, when the air pressure in the passage on the secondary side 2b drops due to the use of a pneumatic tool or the like, the piston 5 is moved backward again by the pressure adjustment spring 7, as shown in FIG. 4(a), and the valve seat 61 is moved away from the valve body 3, thereby introducing the compressed air in the passage on the primary side 2a into the passage on the secondary side 2b.
Furthermore, if the secondary side pressure rises above the set pressure, or if the pressure adjustment handle 10' is loosened and the compression amount of the pressure adjustment spring 7 is decreased to lower the set pressure, the piston 5 advances and further presses the valve disc 3 due to an increase in the pressure ratio of the secondary side pressure to the spring force, as shown in FIG. 4(c), and moves the valve disc 3 away from the rod 8' of the casing 1 with the passage on the primary side 2a and the passage on the secondary side 2b blocked, and the compressed air in the passage on the secondary side 2b is discharged to the atmosphere through a relief passage 9' of the rod 8'.
Then, as the secondary pressure decreases, the piston 5 moves backward, and when the secondary pressure and the set pressure are in equilibrium, the state returns to that shown in FIG. 4(b).

Incidentally, in this conventional pressure control valve, the set pressure is adjusted by increasing or decreasing the amount of compression of the pressure adjustment spring 7 by rotating the pressure adjustment handle 10'. However, since the pressure adjustment spring 7 has a large spring constant, a large load is applied to the pressure adjustment handle 10', making it difficult to operate the handle and making it difficult to adjust the pressure and set the relief.

Japanese Patent Application Laid-Open No. 11-305843

In consideration of the problems with the conventional pressure control valves described above, the present invention aims to provide a pressure control valve that reduces the load on the pressure adjustment handle, allowing pressure adjustment and relief settings to be performed with lighter handle operation.

In order to achieve the above object, the pressure control valve of the present invention is a pressure control valve that reduces and adjusts a primary side pressure to a desired secondary side pressure by rotating a pressure adjustment handle, and is characterized in that it comprises a first cylinder portion and a second cylinder portion formed inside a casing, a piston slidably arranged in the first cylinder portion and having a passage for flowing air to the secondary side and a relief passage for releasing the secondary side pressure to the atmosphere, a valve chamber into which the tip of the piston is inserted, a pressure adjustment spring that urges the piston in a direction in which the valve body moves away from the valve seat, a rotatable pressure adjustment handle arranged outside the casing, a slide plate that moves in the axial direction by rotation of the pressure adjustment handle and compresses the pressure adjustment spring, and an assist piston slidably arranged in the second cylinder portion, which comes into contact with the slide plate to separate the atmospheric pressure from the secondary side pressure, and which receives the secondary side pressure and presses the slide plate, thereby urging the pressure adjustment spring in a direction to compress it.

In this case, the device is provided with a regulating ring rotatably arranged on the outer periphery of the casing, a set screw arranged in a screw hole penetrating from the outer periphery to the inner periphery of the regulating ring, and a stopper that regulates the rotation of the pressure adjustment handle by the set screw, and the regulating ring can be fixed to the casing by the set screw at the position of the pressure adjustment handle where the maximum pressure that can be set by the pressure control valve is achieved.

According to the pressure control valve of the present invention, there is provided a rotatable pressure adjustment handle, a slide plate which moves axially by rotation of the pressure adjustment handle and compresses the pressure adjustment spring, and an assist piston which is slidably arranged in the second cylinder section and comes into contact with the slide plate to separate the atmospheric pressure from the secondary pressure, and which receives the secondary pressure and presses the slide plate, thereby urging the pressure adjustment spring in the direction of compression. As a result, the load on the pressure adjustment handle can be reduced and pressure adjustment and relief settings can be performed with light handle operation.

The device also includes a regulating ring rotatably arranged on the outer periphery of the casing, a set screw arranged in a threaded hole penetrating from the outer periphery to the inner periphery of the regulating ring, and a stopper that regulates the rotation of the pressure adjustment handle by the set screw. The regulating ring is fixed to the casing by the set screw at the position of the pressure adjustment handle where the maximum pressure that the pressure control valve can be set is reached. This allows the pressure adjustment handle to be set so as not to rotate above the maximum pressure on the secondary side with a simple structure and operation, preventing damage to tools and other equipment connected to the secondary side and greatly improving the ease of adjustment work during production.

1A and 1B show an embodiment of a pressure control valve of the present invention, in which FIG. 1A is an explanatory diagram of the components of the pressure control valve, where (a) is an external view of the casing, (b) is an external view of the slide plate, (c1) is a right side view of the pressure adjustment handle, (c2) is a cross-sectional view of the internal structure, (d1) is a left side view of the regulating ring, and (d2) is a cross-sectional view of the internal structure. FIG. 4 is an explanatory diagram of the operation of the pressure control valve. 1 is an explanatory diagram of the operation of a conventional pressure control valve.

Below, an embodiment of the pressure control valve of the present invention will be described with reference to the drawings.

1 to 3 show an embodiment of a pressure control valve according to the present invention.
This pressure control valve reduces and adjusts the pressure on the primary side 2a to a desired pressure on the secondary side 2b by rotating a pressure adjustment handle 10. The pressure control valve comprises a first cylinder portion 4a and a second cylinder portion 4b formed inside a casing 1, a piston 5 slidably disposed in the first cylinder portion 4a and having a passage 6 for flowing air to the secondary side 2b and a relief passage 9 for releasing the pressure on the secondary side 2b to the atmosphere, a valve chamber 12 into which a hollow tip portion 8 of the piston 5 is inserted, and a valve body 3 biasing the piston 5 in a direction away from a valve seat 11. the pressure adjustment spring 7, a rotatable pressure adjustment handle 10 disposed outside the casing 1, a slide plate 13 which moves axially by rotation of the pressure adjustment handle 10 and compresses the pressure adjustment spring 7, and an assist piston 14 disposed slidably in the second cylinder portion 4b, which comes into contact with the slide plate 13 to separate atmospheric pressure from the pressure on the secondary side 2b and which presses the slide plate 13 under the pressure of the secondary side 2b, thereby urging the pressure adjustment spring 7 in the direction of compression.

The casing 1 has two long hole-shaped through holes 1b formed opposite the hollow shaft portion 1a, and the slide plate 13 connected via the connecting portion 13a is inserted into the through holes 1b.

The pressure adjustment handle 10 is made of a cylinder, and has a double helical groove 10a around its inner surface, into which the tip of the slide plate 13 engages. The pressure adjustment handle 10 is rotatably fitted to the casing 1, and by rotating the pressure adjustment handle 10, the slide plate 13 that engages with the double helical groove 10a is moved in the axial direction.

The pressure adjustment handle 10 is connected to a relief passage 9 that releases the pressure on the secondary side 2b to the atmosphere, forming a passage 10b for releasing air to the atmosphere.

A regulating ring 15 is rotatably arranged on the outer periphery of the casing 1, and has a threaded hole 15a that penetrates from the outer periphery of the regulating ring 15 to the inner periphery. A set screw 16 that is operated through a through hole 10c formed in the pressure adjusting handle 10 is arranged in this threaded hole 15a, and a stopper 10d that restricts the rotation of the pressure adjusting handle 10 by abutting against this set screw 16 is formed on the pressure adjusting handle 10. The regulating ring 15 is fixed to the casing 1 by the set screw 16 at the position of the pressure adjusting handle 10 where the maximum pressure that can be set by the pressure control valve is reached.
The mechanism for restricting the rotation of the pressure adjustment handle 10 restricts the rotation of the pressure adjustment handle 10 to less than one rotation, so that the set pressure increases from 0 to the maximum pressure within one rotation of the pressure adjustment handle 10.
The pressure adjustment handle 10 is provided with a pressure scale 10e.
This allows, with a simple structure and operation, to set the pressure adjustment handle 10 so that it does not rotate beyond the maximum pressure on the secondary side, preventing damage to tools and other equipment connected to the secondary side and greatly improving the ease of adjustment work during production.

The secondary side 2b is constituted by an air coupler 17 which is screwed into the casing 1, and is provided with a valve 19 which is opened when a socket (not shown) on the tool side is inserted through a seal member 18.
The spring 20 , which biases the valve 19 in a direction to close the valve 19 , has the other end abutting against the assist piston 14 , thereby biasing the assist piston 14 at the same time.

Next, the operation of this pressure control valve will be described.
When the pressure adjustment handle 10 is rotated from the initial state (stopped state) shown in FIG. 3(a), the slide plate 13 engaged with the double spiral groove 10a moves axially (to the left in the figure) as shown in FIG. 3(b), and moves the piston 5 axially (to the left in the figure) via the pressure adjustment spring 7.
As the piston 5 moves, its tip 8 presses against the valve body 3, causing the valve body 3 to move away from the valve seat 11 arranged in a fixed position in the casing 1, allowing air to flow from the primary side 2a through the passage 6 to the secondary side 2b.
Here, even when a socket (not shown) on the tool side is inserted into the air coupler 17 and air is supplied to the tool side, the state shown in FIG. 3B is maintained.

At this time, the air flowing to the secondary side 2b acts on the back surface of the assist piston 14, and via the assist piston 14, moves the slide plate 13 in a direction that compresses the pressure adjustment spring 7 (to the left in the figure).
This allows the load applied to the pressure adjusting handle 10 when the pressure adjusting handle 10 is rotated to be reduced, and pressure adjustment and relief settings can be performed with lighter handle operation.

In addition, when the pressure adjustment handle 10 is further rotated to strongly compress the pressure adjustment spring 7 with the slide plate 13 and increase the pressure on the secondary side 2b, the load on the slide plate 13 increases. However, as the pressure on the secondary side 2b increases, the force with which the assist piston 14 pushes the slide plate 13 also increases in proportion to the magnitude of the pressure on the secondary side 2b. This reduces the fluctuation in the force required to move the slide plate 13, and allows the handle to be operated with ease regardless of the magnitude of the pressure on the secondary side 2b that is set.

When the pressure on the secondary side 2b rises to a predetermined pressure set by the pressure adjustment handle 10, as shown in Figure 3(c), the piston 5 moves in the reverse axial direction (to the right in the figure), the pressure on the valve body 3 by its tip 8 is released, and the separated valve body 3 seats on the valve seat 11, stopping the flow of air from the primary side 2a to the secondary side 2b.

In this state, when the pressure adjustment handle 10 is rotated in the reverse direction, as shown in Figure 3 (d), the slide plate 13 engaged with the double spiral groove 10a moves in the reverse axial direction (to the right in the figure), the biasing force of the pressure adjustment spring 7 becomes smaller, and the piston 5 moves in the reverse axial direction (to the right in the figure).
As the piston 5 moves, its tip 8 separates from the valve body 3, and air is released into the atmosphere from the secondary side 2b through the passage 6, the relief passage 9, and the passage 10b formed in the pressure adjustment handle 10.
When the pressure on the secondary side 2b drops to atmospheric pressure, the piston 5 moves axially (to the left in the figure) and returns to the initial state (stopped state) shown in FIG. 3(a).

The pressure control valve of the present invention has been described above based on the embodiments thereof. However, the present invention is not limited to the configurations described in the above embodiments, and the configuration can be appropriately changed without departing from the spirit of the present invention.

The pressure control valve of the present invention has the characteristic that the load on the pressure adjustment handle can be reduced, allowing pressure adjustment and relief settings to be performed with light handle operation, and therefore can be widely used in pressure control valves used in pneumatic tools, etc.

REFERENCE SIGNS LIST 1 casing 1a shaft portion 1b through hole 2a primary side 2b secondary side 3 valve body 4a first cylinder portion 4b second cylinder portion 5 piston 6 passage 7 pressure adjustment spring 8 tip portion of piston 9 relief passage 11 valve seat 10 pressure adjustment handle 10a double helical groove 10b passage 10c through hole 10d stopper 10e pressure scale 12 valve chamber 13 slide plate 13a connecting portion 14 assist piston 15 regulating ring 15a screw hole 16 set screw 17 air coupler 18 seal member 19 valve 20 spring

Claims (2)

A pressure control valve in which a primary pressure is reduced and adjusted to a desired secondary pressure by rotating a pressure adjustment handle,
A first cylinder portion and a second cylinder portion are formed inside the casing,
a piston slidably disposed in the first cylinder portion, the piston having a passage for allowing air to flow to a secondary side and a relief passage for releasing secondary side pressure to the atmosphere;
a valve chamber into which a tip portion of the piston is inserted;
a pressure adjusting spring that biases the piston in a direction in which the valve body moves away from the valve seat;
a rotatable pressure adjustment handle disposed on the outside of the casing;
a slide plate that moves axially in response to rotation of the pressure adjustment handle and compresses the pressure adjustment spring;
a second cylinder portion that is in contact with the slide plate and separates the atmospheric pressure from the secondary pressure, and an assist piston that receives the secondary pressure and presses the slide plate, thereby urging the pressure adjustment spring in a direction to compress the pressure adjustment spring. A restriction ring rotatably disposed on the outer periphery of the casing;
a set screw disposed in a screw hole passing through the restriction ring from its outer periphery to its inner periphery;
and a stopper that restricts the rotation of the pressure adjustment handle by a set screw.
2. The pressure control valve according to claim 1, wherein the regulating ring is fixed to the casing by a set screw at a position of the pressure adjusting handle where the maximum pressure that can be set by the pressure control valve is achieved.

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