JPS6131246Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve that reduces the pressure of, for example, high-pressure fluid to an appropriate constant pressure.

This type of control valve has a cylindrical valve seat connected to a communication hole that communicates the inflow and outflow passages with each other on the inflow passage side of the valve box, and the communication hole can be opened and closed within this valve seat. It consists of a valve body that is slidably inserted in the axial direction.
This valve body is always urged in the closing direction by a coil spring, and is reciprocated within the valve seat by a piston that operates in accordance with the pressure difference between the inflow passage and the outflow passage. There is.

By the way, since the above-mentioned valve body is reciprocated within the valve seat while being slidably guided by the inner surface of the valve seat, there is a risk that both of them will wear out due to the above-mentioned sliding movement during long-term use. In this situation, the valve body tends to vibrate within the valve seat, which significantly impedes smooth reciprocating movement of the valve body, adversely affecting the shutoff performance when fully closed and reducing durability. There is a problem. Moreover, with such a structure, it is almost impossible to adjust the closing force of the valve body, and the opening/closing structure of the valve body is also complicated, which not only increases the number of parts but also requires time and effort to assemble. However, there are disadvantages such as cost disadvantages.

The present invention was developed based on these circumstances, and its purpose is to enable the valve body to operate stably over a long period of time, simplify the structure, and, in this case, reduce the cut-off time when fully closed. It is an object of the present invention to provide a control valve that can easily adjust the force.

The present invention will be explained below based on an embodiment shown in the drawings.

FIG. 1 shows a pilot-operated pressure reducing valve, and 1 is a valve box. A primary passage 2 on the high pressure side and a secondary passage 3 on the low pressure side are provided in the valve box 1.
Both passages 2 and 3 are separated by a partition wall 4. This partition wall 4 is provided with a communication hole 5 for communicating the primary passage 2 and the secondary passage 3, and a valve seat 6 is attached to the communication hole 5 from the secondary passage 3 side. This valve seat 6 is constructed by integrally molding a large-diameter flange portion 8 on the upper edge of a base 7 that has a substantially cylindrical shape. The flange part 8 is connected to the 2nd part of the communication hole 5.
By being locked to the peripheral edge on the side of the secondary passage, the lower half of the base 7 is fixed in a state protruding toward the primary passage 2 side. A recess 10 is formed in the lower end surface of the base 7 facing the primary passage 2, and a plurality of fluids are provided in the base 7 along the axial direction to communicate the recess 10 and the secondary passage 3. Flow passages 11 are formed on the same circumference at intervals. The peripheral edge of the base 7 facing the recess 10 forms a valve closing surface 12 . A valve body 13 that is in close contact with the valve closing surface 12 so as to be able to come into contact with and separate from the valve closing surface 12 is disposed coaxially and oppositely to the lower end side of the base portion 7 . That is, this valve body 13 has a substantially cylindrical shape, and the upper half of this valve body 13 is formed with a slightly narrower diameter, and the lower half outer circumference of this valve body 13 and the lower half outer circumference of the base 7 of the valve seat 6. A spiral groove 14 is formed on the surface. This valve body 13 has a spiral groove 14 of this valve body 13.
and the spiral groove 14 of the base 7.
5, it is connected coaxially to and away from the valve seat 6 by the tensile force of this coil spring 15. Normally, the tensile force of this coil spring 15 causes the upper surface of the valve body to close the valve. It is crimped onto the surface 12. Further, a stem 16 is slidably inserted on the axis of the valve seat 6. One end of this stem 16 passes through the recess 10 and is fitted into a positioning recess 17 at the center of the upper surface of the valve body 13, and the other end protrudes a predetermined length into the secondary passage 3 from the upper surface of the valve seat 6. has been done. Note that a large diameter portion 18 for preventing slippage is provided at the other end of the stem 16.

On the other hand, the upper opening of the valve box 1 is closed by a valve top 19, and a cylinder 20 is attached within this opening. This cylinder 2
0 is present in the secondary passage 3 and is located concentrically above the communication hole 5. A piston 21 having a cylindrical shape with a bottom is housed inside the cylinder 20 so as to be slidable in the axial direction, and the upper part of the piston 21 and the valve top 19
A pressure receiving chamber 22 is formed between the two. Further, a pressing protrusion 23 protrudes from the center of the bottom of the piston 21 toward the valve seat 6, and the tip of the protrusion 23 abuts the upper surface of the large diameter portion 18 of the stem 16. Also, on the primary passage 2 side in the valve box 1, there is a 1
A primary pressure introduction passage 25 is formed that communicates the secondary passage 2 with a supply passage 24 in the valve top 19, and a communication passage 26 between the secondary passage 3 and the valve top 19 is formed on the secondary passage 3 side. A secondary pressure introduction path 27 is formed for communication. The communication passage 26 communicates with a recess 28 on the upper surface of the valve top 19, and a mounting hole 29 is formed in the center of the recess 28 and connected to the supply passage 24 on the inner side surface thereof. A circumferentially extending annular groove 30 is formed on the inner peripheral surface of the intermediate portion of the mounting hole 29, and this annular groove 30 communicates with the pressure receiving chamber 22 via a pressure communication passage 31. Mounting hole 29 like this
A pilot sheet 32 is screwed into the opening. This pilot seat 32 has a through hole 33 along the axis, and also has a communication hole 34 on the threaded end side that communicates the through hole 33 with the annular groove 30. A pilot valve body 3 that opens and closes this through hole 33
5 is mounted so as to be slidable in the axial direction. This pilot valve body 35 is biased in the closing direction by a coil spring 36, and a large diameter head 37 provided at one end is pressed against the opening periphery of the through hole 33, and the other end is in contact with the opening periphery of the through hole 33. 28. Further, a spring case 38 is attached to the upper part of the valve top 19, and a diaphragm 39 is clamped and fixed between the spring case 38 and the valve top 19. This diaphragm 39 covers the upper opening of the recess 28,
The other end of the pilot valve body 35 is in contact with the lower surface thereof, and a pressure chamber 40 is formed within the recess 28. Further, an adjuster screw 41 is screwed into the center of the upper part of the spring case 38, and a diaphragm valve body 42 which comes into contact with the diaphragm 39 is attached to the lower part of the spring case 38. And this diaphragm valve body 42
An adjusting spring 44 is stretched between the adjusting screw 41 and a spring case 43 connected to the tip of the adjusting screw 41. The other end of the pilot valve body 35 is pressed into contact with the other end of the pilot valve body 35.

Next, the operation of the above configuration will be explained.

When this pressure reducing valve is still attached to the piping, the adjusting spring 44 is in a pre-loosened state, and in this case, the biasing force of the compression coil spring 15 is applied to the valve body 13 so that the valve closing surface 12 of the valve seat 6 In addition, the head 37 of the pilot valve body 35 is also pressed against the opening periphery of the through hole 33 by the biasing force of the coil spring 36, and both are in the closed position. Then, when the stop valve on the upstream side of the piping is opened and high pressure fluid flows into the primary passage 2, a check force acts on the valve body 13, and a part of this high pressure fluid is transferred to the primary pressure introduction passage 25 and the supply passage. 24 into the mounting hole 29, and therefore a check force acts on the pilot valve body 35 as well. Next, when the adjusting screw 41 is turned in the direction of arrow A to compress the adjusting spring 44, the diaphragm body 4
2 is pressed against the diaphragm 39, and the diaphragm 39 is bent so as to bulge into the recess 28. Then, the pilot valve body 35 is pushed down,
Since the head 37 separates from the opening periphery of the through hole 33, the through hole 33 is opened and the high pressure fluid that has reached the inside of the mounting hole 29 flows into the annular groove 30 and the pressure communication path 3.
1 and flows into the pressure receiving chamber 22. This applies pressure to the upper side of the piston 21, so the piston 21 is pushed down. As a result, as shown in FIG.
The valve body 13 is slid downward against the urging force of
is pushed down by a distance l from the valve closing surface 12, and the upper surface of the valve body is separated from the valve closing surface 12. At this time, the compression coil spring 15 is expanded and changes to a free length L ₁ ' or L+l. As a result, the recessed portion of the valve seat 6 and the fluid flow passages 11 are opened, and the high-pressure fluid in the primary passage 2 flows into the secondary passage 3 from here.

A part of the fluid that has flowed into the secondary passage 3 side flows into the pressure chamber 40 through the secondary pressure introduction passage 27 and the communication passage 26. And this pressure chamber 40
When the internal pressure increases, 2
Since the pressure on the side of the next passage 3 acts, the diaphragm valve body 42 is pushed back upwards and comes to rest at a place where this force and the biasing force of the adjusting spring 44 are balanced. At the same time, the pilot valve body 35 is biased in the closing direction by the coil spring 36, so that the degree of opening of the through hole 33 is limited, and the pressure of the high pressure fluid flowing into the pressure receiving chamber 22 is controlled to be constant. In this case, the pressure difference between the upper and lower sides of the piston 21, that is, the pressure difference between the pressure receiving chamber 22 and the secondary passage 3, causes a downward force that causes the effective area of the piston 21, and the pressure difference between the front and rear of the valve body 13 causes the valve body to When the upward force obtained by adding the tensile force of the compression coil spring 15 to the force multiplied by the effective area of the closing surface of the valve body 13 balances each other, the valve body 13 remains at a predetermined position, and the inside of the primary passage 2 The high-pressure fluid is reduced to a constant pressure and supplied into the secondary passage 3.

Therefore, when the fluid pressure or flow rate in the primary passage 2 changes from such a balanced state, the pressure in the pressure chamber 40 on the lower surface of the diaphragm 39 also changes. Therefore, the balanced position between the diaphragm valve body 42 and the adjuster spring 44 changes, and the pilot valve body 35 comes to rest at the new balanced position. As a result, the pressure applied to the pressure receiving chamber 22, that is, the upper side of the piston 21 changes, and the resting position of the valve body 13 also changes, so that the fluid pressure on the secondary passage 3 side is automatically adjusted to a predetermined value. That will happen.

However, according to the pressure reducing valve having such a configuration, the valve body 13 is coaxially connected to the valve seat 6 by using the tensile force of the compression coil spring 15, and the reciprocating motion of the valve body 13 is controlled by the coil spring 15. Since it has a guiding function, there is no need to provide a special guide part for slidingly guiding the valve body 13 on the valve body 1 side as in the conventional case. Reliable and smooth operation can be achieved throughout. Moreover, since this coil spring 15 has the function of closing the valve body 13 in addition to the above-mentioned function, it is possible to expand the functions of the parts, thereby reducing the number of parts and simplifying the opening/closing structure of the valve body 13. In addition, it eliminates the need for valve seats that conventionally required high processing precision, which is of course extremely advantageous in terms of manufacturing.
Cost reduction can be achieved.

Moreover, if the amount of screwing of the coil spring 15 into each spiral groove 14 of the valve body 13 and valve seat 6 is changed,
The effective number of windings and the pitch of the intermediate portion of the coil spring 15 that is not wound around the valve body 13 and the valve seat 6 can be arbitrarily changed, so that the tension of the coil spring 15 can be used to close the coil spring 15 when it is fully closed. The force can be freely increased or decreased depending on the type of liquid and purpose of use.

Note that the control valve of the present invention is not limited to a self-controlled pressure reducing valve as shown in the above embodiment, but can be implemented similarly even if it is an externally controlled pressure reducing valve, and can also be applied to other safety valves. It can also be applied to safety relief valves, etc.

As described above, the present invention is equipped with a valve seat equipped with a fluid communication hole that communicates the inflow side primary passage and the outflow side secondary passage in the communication hole in the valve box. A coil spring is wound between the circumferential surface of the valve body and the circumferential surface of the valve seat, and a valve body that closes to one end face so as to be able to come into contact with and separate from the valve body to freely open and close the fluid circulation hole is provided. It is connected coaxially to the valve seat using a tensile force and biased coaxially toward the valve seat. According to this, since the reciprocating motion of the valve body is guided by the tensile force of the coil spring, there is no need to provide a guide part for guiding the valve body on the valve body side. There are no sliding parts, ensuring reliable and smooth operation over a long period of time. In this case, the coil spring also has the function of closing the valve body, so it is possible to expand the functions of the parts, thereby reducing the number of parts and simplifying the opening and closing structure of the valve body. This eliminates the need for a valve seat that requires precision, which is extremely advantageous in terms of manufacturing and reduces costs. Furthermore, by changing the amount of threading of the coil spring into the valve body and valve seat, the effective number of turns and pitch of the intermediate portion of the coil spring that is not wound around the valve body and valve seat can be arbitrarily changed. Therefore, excellent practical effects are achieved, such as the ability to easily and freely adjust the valve body closing force when fully closed due to the tensile force of the coil spring, depending on the type of fluid and the purpose of use.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an overall sectional view, Fig. 2 is an enlarged sectional view showing the valve closed state, and Fig. 3 is an enlarged sectional view showing the valve open state. be. 1...Valve box, 2...Inflow side primary passage, 3...Outflow side secondary passage, 5...Communication hole, 6...Valve seat, 11
...Fluid flow path, 13...Valve body, 15...Coil spring, 35...Pressure balance mechanism (pilot valve body).

Claims (1)

[Scope of utility model registration request] A primary passage on the inflow side and a secondary passage on the outflow side are provided in the valve box, and a communication hole is provided for communicating these two passages with each other, and the communication hole is provided with a valve seat having a fluid communication hole that communicates with both the passages. A valve body is mounted on the valve seat, and a valve body that is in close contact with one end surface of the valve seat so as to be able to come into contact with and separate from it and close the fluid communication hole so as to open and close the fluid passage hole is provided between the circumferential surface of the valve body and the circumferential surface of the valve seat. By winding a coil spring around the coil spring, the tensile force of the coil spring is used to connect the valve seat in a coaxial manner and biased toward the valve seat, and the valve body is connected to the valve seat on the inflow side. A control valve characterized in that the control valve is reciprocated in a direction toward and away from the valve seat by a pressure balancing mechanism that operates in response to pressure fluctuations in the primary passage or the outflow side secondary passage.