JPH06309042A - Pressure reducing valve - Google Patents

Abstract

PURPOSE:To provide the pressure reducing valve which has a protecting function for relieving secondary pressure if the pressure rises abnormally. CONSTITUTION:The opening extent of a valve hole 9 which links a primary side 7 and a secondary side 8 is controlled by a valve body 12 which is connected to a valve shaft 11 and a thrust in a valve opening direction which is applied by a main spring 18 and a thrust in a valve closing direction which is generated by a main diaphragm 17 by receiving secondary-side pressure are transmitted to the valve shaft 11 to control the opening extent of the valve hole 9 by the difference between those thrusts. This pressure reducing valve A is provided with a relief valve 50 which discharges secondary-side liquid to the outside when the secondary pressure reaches a certain value or above. Consequently, when the secondary pressure exceeds the certain value, the relief valve operates to discharge the secondary-side liquid to the outside, so a member which is applied with the secondary side pressure can be prevented from being damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure reducing valve used, for example, when controlling the amount of water sprayed in a snowfall machine or a water sprinkler.

[0002]

2. Description of the Related Art Generally, a snowfall machine used at a ski resort or a water sprinkler used at a golf course controls the amount of water spray depending on weather conditions such as rain, cold, and the like. A pressure reducing valve is installed. As this type of pressure reducing valve, in order to maintain the amount of water sprayed from the spray nozzle at a required flow rate, when the secondary side pressure fluctuates, the opening degree of the valve hole is automatically controlled according to this and a predetermined value is set. A pressure reducing valve is used which functions to maintain the set pressure of.

[0003]

However, if the spray nozzle is clogged for some reason, the secondary pressure of the pressure reducing valve rises, so the valve hole should be throttled in order to maintain this secondary side pressure at the set pressure. Works. Therefore, the flow rate gradually decreases. When the control limit is exceeded, the set pressure cannot be maintained, and the secondary pressure rises and approaches the primary pressure. As a result, the pressure on the secondary side becomes equal to the original pressure on the pump side, and a load acts on the diaphragm for converting the pressure on the secondary side into the thrust in the valve closing direction of the valve shaft. I am worried about problems such as hitting and damage.

The present invention has been made in view of such circumstances, and an object thereof is to provide a protective function for preventing the damage of the diaphragm or the like by releasing this pressure when the secondary side pressure rises excessively. It is intended to provide a pressure reducing valve having the same.

[0005]

According to a first aspect of the present invention, the opening degree of a valve hole communicating between the primary side and the secondary side is controlled by a valve body connected to a valve shaft, and the valve shaft is connected to the main shaft. In the pressure reducing valve that transmits the thrust in the valve opening direction given by the spring and the thrust in the valve closing direction generated by receiving the pressure on the secondary side, and automatically reduces the opening degree of the valve hole by the difference between these thrusts, It is characterized in that a relief valve for escaping the liquid on the secondary side to the outside is provided when the pressure on the secondary side reaches a certain value or more.

According to a second aspect of the present invention, in a pressure reducing valve provided with a drain valve for allowing the residual liquid on the secondary side to flow out to the outside when the secondary pressure falls below a predetermined value, this drain valve is used. It is characterized in that the relief valve is incorporated in the liquid valve, and the spring of the drain valve is shared with the spring of the relief valve.

[0007]

According to the first aspect of the present invention, when the secondary pressure reaches a certain value or more, the relief valve operates to let the liquid on the secondary side escape to the outside. It is possible to prevent damage to the diaphragm and the like.

According to the second aspect of the invention, when the secondary pressure drops below a predetermined value, the drain valve opens and the residual liquid on the secondary side flows out to the outside. For example, it is possible to prevent freezing due to residual water in winter or at a ski resort, and since the spring of the drain valve is also used as the spring of the relief valve, the number of parts can be reduced and the structure is simplified.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. In FIG. 1, A indicates the entire pressure reducing valve, and 1 indicates the valve box of the pressure reducing valve A. The valve box 1 includes a valve box body 2, an inner lid 3, an upper lid 4 and a bottom lid 5.
The valve box body 2 includes a primary-side inflow chamber 7 and a secondary-side outflow chamber 8
Are formed by being partitioned by the partition wall 6. The partition wall 6 is
It has a closed end projecting towards the secondary outflow chamber 8. The partition wall 6 is provided with a valve hole 9 and a sliding hole 10 that have the same opening area and are coaxially opposed to each other. A valve shaft 11 penetrating the valve hole 9 and the sliding hole 10 concentrically is attached to the valve box 1 in a vertically movable manner. Valve stem 1
A valve body 12 that is located in the secondary outflow chamber 8 and adjusts the opening of the valve hole 9 is fixed to the valve 1. The valve body 12 faces the valve seat of the valve hole 9 so as to come into contact with and separate from the valve seat. Further, the valve shaft 11 is provided with a balancing piston 13 slidably fitted in the sliding hole 10, and the balancing piston 13 receives pressure on the primary side and pressure on the secondary side on both surfaces. Even if the pressure of the primary-side inflow chamber 7 fluctuates, the influence thereof is automatically eliminated.

A main drive unit 14 is provided on the inner lid 3. The main drive unit 14 includes a third pressure chamber 15 that is in constant communication with the secondary outflow chamber 8, a fourth pressure chamber 16 that is in communication with the outside, and a main diaphragm 17 that partitions these chambers 15, 16. ing. This main diaphragm 17
The peripheral portion and the central portion are supported by the inner lid 3 and the valve shaft 11, respectively. Between the upper lid 4 and the upper end of the valve shaft 11 that slidably penetrates through and protrudes to the outside, the main spring 1 composed of a compression coil spring for setting a reference pressure is provided.
8 is installed. The main spring 18 pushes the valve shaft 11 down, that is, generates a thrust in a direction in which the valve body 12 separates from the valve hole 9 and the opening degree increases. This main spring 18
The pressing force of, that is, the reference pressure is variably set by the adjusting screw 19.

An auxiliary drive unit 20 is provided between the inner lid 3 and the upper lid 4. The auxiliary drive unit 20 includes an auxiliary diaphragm 21 whose peripheral portion is sandwiched between the inner lid 3 and the upper lid 4 and whose central portion is supported by the valve shaft 11. The auxiliary diaphragm 21 is used for the fourth pressure chamber 1
The fifth pressure chamber 22 communicating with 6 and the sixth pressure chamber 23 are partitioned. The fifth pressure chamber 22 is the fourth pressure chamber 1 described above.
6, and the sixth pressure chamber 23 can be connected to the compressed air source 65 shown in FIG. 3, for example, through the compressed air introducing port 24 for adjusting the reference pressure. . The lower support plate 25 of the auxiliary diaphragm 21 comes into contact with the bottom portion of the fifth pressure chamber 22 so that it can freely come into contact with and separate from the bottom portion of the fifth pressure chamber 22, thereby regulating the amount of movement of the valve shaft 11 in the opening direction.

A shutoff function section 26 for shutting off the pressure reducing valve A is provided on the upper portion of the valve box 1. This blocking function unit 26
Is provided with a shutoff spring 27 that applies thrust to the valve shaft 11 in the valve closing direction. That is, a connecting plate 29 through which the upper end of the valve shaft 11 freely penetrates is attached to the support column 28 erected on the upper lid 4 so that the connecting plate 29 can be raised and lowered. Has been done. A pair of upper and lower spring seats 31 and 32 are respectively supported by the column 28 and the connecting rod 30 so as to be vertically movable. The upper spring seat 31 is restricted from moving upward by a nut 33 screwed with the connecting rod 30, and the lower spring seat 32 is restricted from moving downward by a stopper 34 provided on the support column 28. The breaking spring 27 is stretched between the pair of upper and lower spring seats 31 and 32. The amount of compression of the cutoff spring 27 is set by the nut 33 that is screwed onto the connecting rod 30. The force by which the cutoff spring 27 expands and returns pushes up the upper spring seat 31, and this force is a force that integrally raises the connecting rod 30 and the connecting plate 29. The pulling force is applied to the valve shaft 11 from the connecting plate 29 by the nut body 35 provided at the upper end contacting the connecting plate 30. Therefore, the valve shaft 11
Is subjected to an upward (valve closing direction) thrust force based on the extension restoring force of the cutoff spring 27.

The set pressure of the shut-off spring 27 is the main spring 1
8 is set to a desired reference pressure, and the valve body 12 is set to be in close contact with the valve seat of the valve hole 9 in a state where compressed air is not introduced into the sixth pressure chamber 23 of the auxiliary drive unit 20. .

The pressure reducing valve A is provided with a drain valve 36 for discharging the accumulated liquid in the secondary side outflow chamber 8. The drain valve 36 has a recess 38 formed in the bottom lid 5, and a valve case 39 is provided in the recess 38. Inside the valve case 39, as shown in detail in FIG. The body 40 is configured to be vertically movable. A communication hole 41 that communicates with the secondary pressure chamber 8 through the recess 38 is formed in the lower side wall of the valve case 39, and a discharge hole that is connected to a discharge hole 37 formed in the bottom lid 5 is formed at the bottom. The liquid hole 42 is opened. The drain valve body 40 slidably fitted in the valve case 39 is provided at its lower end surface with a valve seat 43 such as an O-ring that comes into contact with the bottom surface of the valve case 39 so as to come into contact with and separate from it. When the valve seat 43 is in close contact with the bottom surface of the valve case 39, the drainage valve body 40 blocks the conduction between the communication hole 41 and the drainage hole 42, so that the secondary side outflow chamber 8 And the discharge hole 37 are disconnected from each other.

A coil spring 44 is provided between the bottom surface of the valve case 39 and the drainage valve body 40, and the coil spring 44 constantly presses the drainage valve body 40 in a rising direction. When the drainage valve body 40 is lifted by receiving this spring force, the communication hole 41 and the drainage hole 42 are brought into conduction, so that the fluid in the secondary side outflow chamber 8 flows from the recess 38 to the communication hole 41, the drainage hole 42, and the drainage hole 42. It is adapted to be discharged to the outside of the pressure reducing valve A through the discharge hole 37. The upper surface of the drain valve body 40 faces the secondary outflow chamber 8 from the upper end opening end of the valve case 39, and receives the pressure of the secondary outflow chamber 8. The amount of rise of the drainage valve body 40 is regulated by a stopper pin 45 provided at the upper end opening of the valve case 39.

Further, the pressure reducing valve A is provided with a relief valve 50 for releasing the secondary pressure in the secondary outflow chamber 8 when the secondary pressure rises excessively. In the case of the present embodiment, the relief valve 50, as shown in detail in FIG.
The drain valve 36 is installed. That is, a relief hole 51 is opened in the upper surface of the drainage valve body 40, and a relief valve body 52 that opens and closes the relief hole 51 is accommodated in the drainage valve body 40. The relief valve body 52 is the coil spring 44.
The valve seat body 53 such as an O-ring provided on the upper surface of the relief valve body 52 is seated on the valve seat 54 of the drainage valve body 40 by the force of the coil spring 44. It has become. When the secondary pressure in the secondary outflow chamber 8 rises and exceeds the pushing force of the coil spring 44, the relief valve body 5
2 is pushed down, the valve seat body 53 separates from the valve seat 54, and the escape hole 51 is opened. Therefore, the liquid in the secondary outflow chamber 8 passes through the drain hole 51, the inside of the drain valve body 40, and the drain hole 4
2 and the discharge hole 37 to escape to the outside of the pressure reducing valve A. In this case, the drainage valve body 40 is also pushed down by receiving the pressure in the secondary side outflow chamber 8, and the valve seat 43 comes into close contact with the bottom surface of the valve case 39, so the communication hole 41 and the drainage hole 42.
The electrical connection with is cut off. In the case of such a configuration, the coil spring 44 is commonly used for both the opening action of the drainage valve 36 and the blocking action of the relief valve 50.

Next, the operation of the structure of the above embodiment will be described. If the reference pressure is set in the main spring 18 via the adjusting screw 19, the valve shaft 11 is pushed down by the thrust of the main spring 18 in the non-circulation state, and the lower end of the lower support plate 25 moves to the fifth pressure chamber 22. Stop at the position where it abuts the bottom,
The valve body 12 is separated from the valve seat of the valve hole 9 and is in the fully open state shown. That is, this embodiment is a so-called normally open type.

Further, in the drainage valve 36, the drainage valve body 40 is raised by the force of the coil spring 44, and the valve seat 43 is separated from the bottom surface of the valve case 39. It is fully open.

In this state, when the liquid is supplied to the primary side pressure chamber 7, most of the liquid is initially sent from the secondary side pressure chamber 8 through the valve hole 9 to the outside, and the other is supplied to the drain valve 36. It flows out through the communication hole 41, the drainage hole 42, and the discharge hole 37.

When the secondary pressure rises to some extent, the drain valve body 40 of the drain valve 36 receives the secondary pressure and is pushed down against the coil spring 44, so that the valve seat 43 is closed.
Is pressed against the bottom surface of. Therefore, the communication hole 41 is closed.

On the other hand, the pressure in the secondary pressure chamber 8 is transmitted to the third pressure chamber 15, and the secondary pressure introduced into the third pressure chamber 15 causes the valve shaft 1 to pass through the main diaphragm 17.
Give 1 an upward thrust. When this thrust increases and approaches the reference pressure set by the main spring 18, the valve body 12 moves toward the valve shaft 1
When the reaction force of the main spring 18 exceeds the thrust due to the secondary pressure, the valve element 12 is moved in the opening direction together with the valve shaft 11. Then, by balancing these thrust and reaction forces, the secondary side pressure is held at the reference pressure set and adjusted by the main spring 18.

In this state, when the end device connected to the secondary pressure chamber 8 such as the spray nozzle (FIG. 3) is clogged and the flow rate decreases, the secondary pressure rises. The pressure in the pressure chamber 15 increases, and the thrust force that pushes the valve shaft 11 upward via the main diaphragm 17 increases. Therefore, the valve hole 9 is throttled in an attempt to maintain the secondary side pressure at the set pressure, so that the flow rate gradually decreases. When the control limit is exceeded, the set pressure cannot be maintained, and the secondary pressure rises excessively and approaches the primary pressure. However, if the above-mentioned excessive pressure rise occurs in the secondary pressure chamber 8,
The relief valve body 52 of the relief valve 50 is pushed down against the pushing force of the coil spring 44, and the relief hole 51 is opened. Therefore, the liquid in the secondary outflow chamber 8 is discharged from the drain hole 51 through the drain valve body 40.
Through the drainage hole 42 and the drainage hole 37 to the outside. In this case, since the drainage valve body 40 is also pushed down by receiving the pressure in the secondary side outflow chamber 8, the valve seat 43
Comes into close contact with the bottom surface of the valve case 39, and the communication hole 41 and the drainage hole 4
The connection with 2 is cut off. Due to the action of the relief valve 50 as described above, the secondary side pressure is reduced, and thus the abnormal pressure rise can be prevented, and the main diaphragm 17 can be prevented from sagging or being damaged.

In such a pressure reducing valve A, when it is necessary to change the reference pressure set in the main spring 18, compressed air is introduced into the sixth pressure chamber 23 of the auxiliary drive section 20. If introduced from 24, auxiliary diaphragm 21
The downward thrust force applied to the valve shaft 11 via is applied to the reference pressure set by the main spring 18. Therefore,
By appropriately setting the pressure of the compressed air, an effect substantially equivalent to that when the reference pressure preset in the main spring 18 is replaced with a new preset value can be obtained. Further, when the compressed air in the sixth pressure chamber 23 is released, the reference pressure is returned from the new set value to the initial set reference pressure.

When shutting off the supply of the liquid, the compressed air in the sixth pressure chamber 23 of the auxiliary drive unit 20 may be removed. That is, when the pressure in the sixth pressure chamber 23 decreases, the thrust in the valve opening direction with respect to the valve shaft 11 is reduced. The valve body 12 is pressed against the valve seat of the valve hole 9 by the thrust in the direction, and the primary side pressure chamber 7 and the secondary side pressure 8
Communication will be cut off.

When the secondary pressure decreases as a result, the drainage valve body 40 is pushed up by the urging force of the compression spring 44 of the drainage valve 36, moves in the opening direction, and the communication hole 41 is formed.
Is opened. Therefore, the residual liquid on the secondary side flows out from the recess 38 to the outside through the communication hole 41, the drainage hole 42, and the drainage hole 37. Then, when the discharge of the residual liquid is completed, the device returns to the initial state.

When the pressure reducing valve A is applied to a snowfall machine, a water sprinkler, or the like, as shown in FIG. 3, it is individually combined with a desired number of spray nozzles 60 and a water supply pipe 62 connected to a water supply pump 61. In parallel. Further, the compressed air source 65 is connected to a compressed air pipe 67 reaching the introduction port 24 of the pressure reducing valve A and a spray generation air pipe 68 reaching the spray nozzle 60 via the operating portion 66. Then, the main spring 18
The reference pressure set in the above is made to correspond to the minimum pressure of the spray nozzle 60, and the portion exceeding this is compensated by appropriately controlling the compressed air pressure supplied to the auxiliary drive section 20 in the operation section 66. To do so. In addition, H in the figure shows an elevation difference.

Since the pressure reducing valve A of the above embodiment is integrally provided with the auxiliary drive unit 20, the reference pressure set in the main spring 18 can be remotely controlled via the compressed air press-fitted into the auxiliary drive unit 20. In addition, the pressure reducing valve A can be shut off by the shut-off function section 26 only by discharging the compressed air to the outside. Therefore, by combining the compressed air source 65 with an appropriate solenoid valve or the like, it is possible to provide a fail-safe function of shutting off the pressure reducing valve A when the energy source is cut off.

Further, since the pressure reducing valve A is integrally provided with the drainage function part 36 capable of automatically draining, when the secondary pressure drops below a predetermined value after shutting off, the residual liquid in each part is automatically removed. Is leaked to the outside.

Further, this pressure reducing valve A is provided with a secondary pressure chamber 8
Since the relief valve 50 is provided in the secondary side, when the secondary side pressure exceeds a certain pressure and rises excessively, the relief valve 50 is opened and the liquid in the secondary side pressure chamber 8 is discharged to the outside. Since the pressure is rapidly reduced, abnormal pressure rise can be prevented and damage to the main diaphragm 17 and the like can be prevented.

In this case, in this embodiment, the relief valve 50 is incorporated in the drain valve 36, and the compression spring 44 acting in the opening direction of the drain valve 36 is shared by acting in the closing direction of the relief valve 50. Therefore, since the relief valve 50 is incorporated in the drainage valve 36 and the compression spring 44 is shared, the structure is simplified, the number of parts is reduced, and the drainage valve 36 and the relief valve are provided at one place of the valve box 1. The valves 50 can be centrally installed, and the size can be reduced. Further, the drainage valve 36 and the relief valve 50 can be maintained at the same time, which simplifies the work.

Therefore, even for a large number of spray nozzles 60 scattered over a vast site, the water pressure can be variably set and the valves can be shut off by the operation unit 66 all at once, and the water after shutting off can be controlled. Since the residue is also prevented, it is not necessary to go to the installation location of each spray nozzle 60 to individually operate the valve as in the conventional case, and the labor and time of the worker are greatly reduced. It should be noted that the present invention is not limited to the above embodiments, and various modifications and applications are possible within the scope of the gist of the present invention.

[0032]

As described above, according to the present invention, since the relief valve is installed on the secondary side, when the pressure on the secondary side reaches a certain value or more, the relief valve operates and the liquid on the secondary side is activated. Can be released to the outside, and damage to a member that receives the secondary pressure, such as a diaphragm, can be prevented. When the relief valve is incorporated in the drain valve and the spring of the drain valve is also used as the spring of the relief valve, the number of parts can be reduced and the structure is simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the structures of a drain valve and a relief valve of the same embodiment.

FIG. 3 is a system diagram illustrating a case where the same embodiment is applied for watering.

[Explanation of symbols]

A ... Pressure reducing valve 1 ... Valve box 7 ... Primary pressure chamber 8 ... Secondary pressure chamber 9 ... Valve hole 11 ... Valve shaft
12 ... Valve body 14 ... Main drive part 17 ... Main diaphragm 18 ... Main spring 20 ... Auxiliary drive part 24 ... Compressed air introduction port 26 ... Shutoff function part 27 ... Shutoff spring 36 ... Drain valve 37 ... Discharge hole 39 ... Valve case 40 ... Drainage valve body 44 ... Coil spring 50 ... Relief valve 52 ... Relief valve body 60 ... Spray nozzle 61 ... Water pump 65 ... Compressed air source 66 ... Operation part.

Claims (2)

[Claims] 1. An opening degree of a valve hole communicating between the primary side and the secondary side is controlled by a valve body connected to a valve shaft, and the valve shaft is connected to the valve shaft.
In a pressure reducing valve that transmits thrust in the valve opening direction given by the main spring and thrust in the valve closing direction generated by receiving pressure on the secondary side, and automatically adjusts the opening degree of the valve hole by the difference between these thrusts to reduce the pressure. A pressure reducing valve provided with a relief valve that allows the liquid on the secondary side to escape to the outside when the pressure on the secondary side reaches a certain value or more. 2. In a pressure reducing valve provided with a drain valve for allowing residual liquid on the secondary side to flow out to the outside when the secondary pressure drops below a predetermined value, the relief valve is provided with the relief valve. The pressure reducing valve according to claim 1, characterized in that the spring of the drain valve is incorporated and shared with the spring of the relief valve.