JPH04327083A - Pilot type solenoid valve - Google Patents

Abstract

PURPOSE:To eliminate a sudden valve closing operation and prevent the generation of water hammer by utilizing the deformation of a diaphragm generated just before valve closing to reduce the effective passage sectional area of a bleed passage, and reducing the force of lowering a diaphragm valve. CONSTITUTION:A pilot type solenoid valve 1 has a diaphragm valve 23 consisting of a pilot valve 26 having a diaphragm 24 separable from a valve seat 9 on a valve port 8 periphery provided on a bulkhead 7 partitioning primary side and secondary side pressure chambers 4, 6. The pilot port 25 of the pilot valve 26 is rotated by a plunger 34 vertically moved by a solenoid 30. A stepped surface 19 is circumferentially provided through a difference in level on the inner circumferential side of the mounting surface 18 of a cap body 14, and a bleed groove 20 is circumferential provided on the stepped surface 19. A communicating hole 21 is bored in a proper position of the bleed groove 20 to allow the bleed groove 20 to communicate with a pilot chamber 15, and a bleed port 29 is bored in the diaphragm 24 in opposition to the bleed groove 20 of the cap body 14.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot type solenoid valve that prevents water hammer caused by a sudden valve closing.

0002

[Prior Art] Conventionally, a primary pressure chamber a and a secondary pressure chamber b
A pilot valve e having a pilot port d seated on the valve port c is connected to a diaphragm f.
At the same time, a pilot type solenoid valve can be seen that is connected to a plunger h that reciprocates within a solenoid g, and forms a bleed port j that communicates a pilot chamber i above a diaphragm f with a primary pressure chamber a. However, in such a pilot type solenoid valve, the hole diameter of the bleed port j is fixed, so as the degree of valve closure increases, the flow path between the valve port c and the diaphragm f is narrowed, and the primary side Due to the synergistic effect of the rapidly increasing differential pressure between the pressure chamber a and the secondary pressure chamber b and the rising pressure in the pilot chamber i, the diaphragm f seats at the valve port c at high speed, causing impact noise and noise. It had the disadvantage of water hammer.

0003

Problem to be Solved by the Invention The present invention utilizes the deformation of the diaphragm that occurs just before the valve closes to reduce the effective flow cross-sectional area of the bleed passage formed by the bleed groove and the bleed port. The purpose of the present invention is to provide a pilot type solenoid valve that reduces the force of lowering the valve, eliminates the sudden closing of the valve, and prevents the generation of impact noise and water hammer.

0004

[Means for Solving the Problems] In view of the problems caused by impact noise, water hammer, etc. caused by the above-mentioned prior art, the present invention aims to improve the effectiveness of the bleed passage that communicates the primary side pressure chamber and the pilot chamber just before closing the valve. The present invention aims to solve the above-mentioned drawbacks by providing a pilot-type solenoid valve that automatically reduces the cross-sectional area of the flow path and gradually lowers the diaphragm valve.

[0005] The pilot type solenoid valve includes a valve body in which a valve port with a valve seat is provided in a partition wall that partitions an inlet pressure chamber and a secondary pressure chamber, and a diaphragm that can freely move into and out of contact with the valve seat. In a pilot type solenoid valve, the valve body is provided with a diaphragm valve consisting of a pilot valve having a pilot port, and a plunger that is moved up and down in a solenoid that can freely open and close the pilot port of the pilot valve. The peripheral edge of the diaphragm is clamped and fixed between the mounting surfaces of the valve box and the lid body, and a stepped surface is provided around the inner peripheral side of the mounting surface of the lid body via a step, and a bleed is prevented on the stepped surface. A groove is provided around the circumference, and a communication hole is bored at an appropriate position of the bleed groove to communicate the bleed groove and the pilot chamber, while a bleed port is bored in the diaphragm so as to face the bleed groove of the lid body. are doing.

[0006]

[Operation] In the present invention, the pilot port of the pilot valve is closed by the plunger, and the pressure in the primary side pressure chamber is increased in accordance with the degree of closing of the valve port. A diaphragm located between the stepped surface of the valve body and the mounting surface of the valve body is deformed so as to come into close contact with the stepped surface of the lid body, the bleed groove is sealed by this diaphragm, and the bleed port is communicated with the bleed groove. The effective flow cross-sectional area of the bleed flow path that communicates the primary side pressure chamber and the pilot chamber is reduced.

[0007]

[Embodiment] An embodiment of the present invention will be described below based on the drawings. 1 is a pilot type solenoid valve according to the present invention;
The valve body 2 of the pilot type solenoid valve 1 has a primary pressure chamber 4 communicating with an inflow port 3 and a secondary pressure chamber 6 communicating with a discharge port 5.
The partition wall 7 is formed with a valve port 8 that communicates the primary pressure chamber 4 and the secondary pressure chamber 6, and a valve seat 9 is provided above the valve port 8. An insertion hole 11 having a larger diameter than the valve port 8 is formed in the outer wall 10 facing the valve port 8, and a flat mounting surface 12 is formed on the outer wall 10 at the outer periphery of the insertion hole 11. The valve box 13 is formed by the valve body 13.

Reference numeral 14 denotes a lid that constitutes the valve body 2. A cylindrical recess 16 that becomes the pilot chamber 15 when attached to the valve box 13 is formed in the lower part of the lid 14. Solenoid mounting hole 1 passing through the recess 16 at the top
On the other hand, a mounting surface 18 facing the mounting surface 12 of the valve box 13 is formed on the lower end surface of the lid body 14, and a step surface 19 is provided around the inner circumferential side of the mounting surface 18 via a step. The step surface 19 is provided with a bleed groove 20 having a V-shaped cross section opening downward and having a smaller effective flow passage cross-sectional area than a bleed port 29, which will be described later. One communication hole 21 is bored to communicate the bleed groove 20 and the pilot chamber 15.

The shape of the bleed groove 20 is not limited to the above-mentioned shape, and may have a U-shaped cross section, for example.

When the lid 14 is attached to the valve box 13, a gap 22 is formed between the mounting surface 12 of the valve box 13 and the stepped surface 19 of the lid 14.

Reference numeral 23 denotes a diaphragm valve disposed within the valve body 2, and the diaphragm valve 23 has a flexible sheet-like diaphragm 24 whose peripheral edge is attached to the mounting surface 1 of the lid body 14.
8 and the mounting surface 12 of the valve box 13, and are disposed oppositely above the valve port 8, and have a pilot port 25 approximately in the center of the diaphragm 24.
are fixed via a diaphragm receiver 27 and a retainer ring 28.

Reference numeral 29 denotes a bleed port, and the bleed port 29 is located in the gap 22 formed by the lid 14 and the valve box 13, and is located in the bleed groove 20 of the lid 14.
and the communication hole 21 of the bleed groove 20 and the displacement (
In this embodiment, the holes are displaced by approximately 180 degrees).

Further, a piston-shaped plunger 3 is provided in a guide sleeve 31 in a solenoid 30 that is attached to the solenoid mounting hole 17 of the lid body 14, and is pressed downward by a kick spring 32 and has communication slits 33, 33a formed therein.
4 is arranged to be vertically slidable, and the plunger 34 and the pilot valve 26 are connected by a connecting spring 35.

In the drawing, reference numeral 36 denotes a pilot disk fitted inside the lower end of the plunger 34 and pressed downward by a pilot spring 37.

Next, the operation of the pilot type solenoid valve according to the present invention will be explained. First, regarding the valve opening operation, when the solenoid 30 is energized, the plunger 34 is attracted and raised, so that the pilot of the plunger 34 The disk 36 separates from the pilot port 25 and opens the pilot port 25.

The fluid in the pilot chamber 15 above the diaphragm 24 flows out from the pilot port 25 to the secondary pressure chamber 6, reducing the pressure in the pilot chamber 15 and causing the pressure in the primary pressure chamber 4 to open the diaphragm valve 23. is pushed upward to open the valve port 8.

[0017] In this state, the primary pressure chamber 4
Although the fluid inside flows into the pilot chamber 15 from the bleed port 29, since the bleed port 29 has a smaller diameter than the pilot port 25, the pilot chamber 15
This causes the pressure to decrease.

Next, regarding the valve closing operation, solenoid 3
When the excitation of 0 is released, the plunger 34 that was attracted
is pressed downward by the elastic force of the kick spring 32, and the pilot disk 36 of the plunger 34 seats on the pilot port 25 of the pilot valve 26, closing the pilot port 25.

Fluid from the primary pressure chamber 4 flows into the pilot chamber 15 from the bleed port 29 of the diaphragm 24, increasing the pressure in the pilot chamber 15 and pushing the diaphragm valve 23 downward.

Furthermore, as the pressure in the primary pressure chamber 4 increases in accordance with the degree of closure of the valve port 8, the diaphragm 24 in the gap 22 comes into close contact with the stepped surface 19 of the lid body 14 just before the valve closes. The diaphragm 24 seals the bleed groove 20 and brings the bleed port 29 into communication with the bleed groove 20.

As a result, the effective cross-sectional area of the bleed passage formed by the bleed groove 20 and the communication hole 21 communicating from the primary pressure chamber 4 to the pilot chamber 15 can be calculated from the effective cross-sectional area of the opening of the bleed port 29. The bleed groove 20 is narrowed down to the effective cross-sectional area of the bleed groove 20, and in combination with the flow path loss that occurs depending on the length of the bleed groove 20 between the bleed port 29 and the communication hole 21, the bleed appears to be further reduced. The effective flow cross-sectional area of the groove 20 is reduced to limit the flow rate flowing into the pilot chamber 15, thereby slowing down the rate of pressure rise in the pilot chamber 15.

[0022] Also, in such a state, the diaphragm 2
4 is brought into close contact with the step surface 19 of the valve body 13 and also with the diaphragm receiver 27. As a result, the range of the flexible portion of the diaphragm 24 is narrowed, and the diaphragm 2
The flexibility of the diaphragm valve 23 is reduced, which, in conjunction with the above-mentioned effect, further slows down the rate of descent of the diaphragm valve 23.

[0023]

In short, the present invention provides a valve body 2 in which a valve port 8 having a valve seat 9 is provided in a partition wall 7 that partitions a primary pressure chamber 4 and a secondary pressure chamber 6, and a valve body 2 that is in contact with the valve seat 9. A diaphragm valve 23 consisting of a removable diaphragm 24 and a pilot valve 26 having a pilot port 25, and a pilot valve 2
A plunger 34 that is moved up and down in a solenoid 30 that can freely open and close the pilot port 25 of 6 is connected to the valve body 2.
In the pilot type solenoid valve provided inside the valve body 2
Both mounting surfaces 12 and 18 of the valve box 13 and the lid body 14 that constitute the
The peripheral edge of the diaphragm 24 is clamped and fixed, and a step surface 19 is provided around the inner peripheral side of the mounting surface 18 of the lid body 14 via a step, and a bleed groove 20 is provided around the step surface 19. A communication hole 21 is bored at an appropriate position in the bleed groove 20 to communicate the bleed groove 20 and the pilot chamber 15, and a bleed port 29 is bored in the diaphragm 24 so as to face the bleed groove 20 of the lid body 14. Since the pilot port 25 is closed and the pressure in the primary pressure chamber 4 is increased in accordance with the degree of closing of the valve port 8, just before the valve is closed, the step surface 19 of the lid body 14 and the valve box 13 mounting surface 1
The diaphragm 24 is deformed so as to come into close contact with the stepped surface 19 of the lid body 14 due to the pressure in the primary pressure chamber 4 that has increased in the gap 22 formed between the diaphragm 24 and the bleed groove 20. At the same time, by communicating the bleed port 29 with the bleed groove 20 and reducing the effective cross-sectional area of the bleed passage, the flow rate flowing into the pilot chamber 15 from the primary pressure chamber 4 is restricted, and the pressure in the pilot chamber 15 is reduced. The rate of rise is made gentle, the force for lowering the diaphragm valve 23 is reduced, the sudden closing of the valve is eliminated, and the occurrence of impact noise and water hammer can be reliably prevented.

[0024] Furthermore, since the above-mentioned bleed channel that communicates the primary side pressure chamber 4 and the pilot chamber 15 is constituted by the bleed groove 20 and the bleed port 29, its machining is simpler than before, and it can be opened and closed easily. Since the bleed groove 20 is repeatedly sealed and unsealed during valve operation, the bleed passage is not blocked by foreign matter, and the bleed groove 20 is sealed by deforming a part of the flexible portion of the diaphragm 24. By doing so, the range of the flexible portion of the diaphragm 24 is narrowed, which, in conjunction with the original function of the bleed channel, has great practical effects such as being able to further slow down the descending speed of the diaphragm 24. It is what it is.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a pilot type solenoid valve according to the present invention in an open state.

FIG. 2 is a longitudinal cross-sectional view of the pilot type solenoid valve showing an initial closed state.

FIG. 3 is an enlarged sectional view of the main part A in FIG. 2;

FIG. 4 is a longitudinal cross-sectional view of the pilot type solenoid valve showing a mid-stage closed state.

FIG. 5 is an enlarged sectional view of the main part of B in FIG. 4;

FIG. 6 is a longitudinal sectional view of the pilot type solenoid valve showing a state immediately before closing.

FIG. 7 is an enlarged cross-sectional view of C main part in FIG. 6;

FIG. 8 is a longitudinal cross-sectional view of the pilot type solenoid valve showing a state immediately after the valve is closed.

FIG. 9 is an enlarged sectional view of the main part D in FIG. 8;

FIG. 10 is a schematic diagram of the positional relationship between a communication hole and a bleed port in a bleed groove.

FIG. 11 is a longitudinal sectional view of a conventional pilot type solenoid valve.

[Explanation of symbols]

2 Valve body 4 Primary side pressure chamber 6 Secondary pressure chamber 7 Partition wall 8. Oral address 9 Valve seat 12 Mounting surface 13. Bento box 14 Lid body 15 Pilot room 18 Mounting surface 19 Step surface 20 Bleed groove 21 Communication hole 23 Diaphragm valve 24 Diaphragm 25 Pilot port 26 Pilot valve 29 Bleed port 30 Solenoid 34 Plunger

Claims (1)

[Claims] Claim 1: A valve body provided with a valve port having a valve seat in a partition wall that partitions a primary side pressure chamber and a secondary side pressure chamber, a pilot valve having a diaphragm that can freely move into and out of contact with the valve seat, and a pilot port. A pilot type solenoid valve is provided with a diaphragm valve consisting of a diaphragm valve and a plunger that is moved up and down in a solenoid that can freely open and close a pilot port of the pilot valve. The peripheral edge of the diaphragm is clamped and fixed by both mounting surfaces with the body, and a stepped surface is provided around the inner peripheral side of the mounting surface of the lid via a step, and a bleed groove is provided around the stepped surface, A pilot characterized in that a communication hole is bored at an appropriate position in the bleed groove to communicate the bleed groove with the pilot chamber, and a bleed port is bored in the diaphragm so as to face the bleed groove of the lid body. type solenoid valve.