JP2554561B2 - Pilot type solenoid valve - Google Patents

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 which prevents a water hammer due to a sudden valve closing at the time of valve closing.

[0002]

2. Description of the Related Art Conventionally, a primary pressure chamber a and a secondary pressure chamber b
A pilot valve e having a pilot port d seated at the valve port c and a diaphragm f
The pilot type solenoid valve which is attached to the plunger h and is connected to the plunger h which reciprocates in the solenoid g, and which forms the bleed port j that connects the pilot chamber i above the diaphragm f and the primary side pressure chamber a, is seen. However, in such a pilot type solenoid valve, since the hole diameter of the bleed port j is fixed, the flow path between the valve port c and the diaphragm f is narrowed as the degree of valve closing increases, so that the primary side Due to the synergistic effect of the rapidly expanding differential pressure between the pressure chamber a and the secondary pressure chamber b and the rising pressure of the pilot chamber i, the diaphragm f is seated at the valve opening c at a high speed and an impact noise or It had the drawback of producing water hammer.

[0003]

SUMMARY OF THE INVENTION The present invention utilizes the deformation of the diaphragm that occurs immediately before the valve is closed to reduce the effective flow passage 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 to eliminate the sudden closing valve and prevent the generation of impact noise and water hammer.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems that impact noise, water hammer, etc. are generated based on the above-mentioned prior art, and an effective bleed flow passage that connects the primary side pressure chamber and the pilot chamber immediately before the valve is closed. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks by providing a pilot-type solenoid valve whose main feature is to automatically reduce the cross-sectional area of the flow path to gently lower the diaphragm valve.

As the pilot type solenoid valve, a valve main body having a valve opening having a valve seat on a partition wall for partitioning the primary pressure chamber and the secondary pressure chamber, and a diaphragm capable of coming into contact with and separating from the valve seat are provided. A pilot type solenoid valve having a diaphragm valve including a pilot valve having a pilot port and a plunger that is moved up and down in a solenoid that opens and closes the pilot port of the pilot valve in the valve body. The peripheral edge of the diaphragm is clamped and fixed by both mounting surfaces of the valve box and the lid that compose the above, and the stepped surface is circumferentially provided on the inner peripheral side of the mounting surface of the lid through a step, and the bleed is formed on the stepped surface. Along with surrounding the groove, one communication hole is bored from an appropriate position of the bleed groove to communicate the bleed groove with the pilot chamber, while the bleed port is opposed to the bleed groove of the lid. It has been drilled in the Iyafuramu.

[0006]

According to the present invention, the lid is closed immediately before the valve is closed in the process of closing the pilot port of the pilot valve with the plunger to raise the pressure of the primary side pressure chamber in accordance with the degree of valve closing. The diaphragm located between the step surface of the body and the mounting surface of the valve box is deformed so as to be in close contact with the step surface of the lid, and this diaphragm seals the bleed groove and connects the bleed port with the bleed groove. The effective flow passage cross-sectional area of the bleed flow passage that connects the primary pressure chamber and the pilot chamber is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, in which 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 the inlet 3 and a secondary pressure chamber 6 communicating with the discharge port 5.
Is formed by a partition wall 7, and the partition wall 7 is formed with a valve port 8 for communicating the primary side pressure chamber 4 and the secondary side pressure chamber 6, and a valve seat 9 is formed on the valve port 8 above. And an insertion hole 11 having a larger diameter than the valve opening 8 is formed in the outer wall 10 facing the valve opening 8.
And the outer wall 10 of the outer peripheral portion of the insertion hole 11 is formed.
A valve box 13 is formed by surrounding a flat mounting surface 12 on the.

Reference numeral 14 denotes a lid constituting the valve body 2. A lower portion of the lid 14 is provided with a cylindrical recess 16 which serves as a pilot chamber 15 when the valve body 13 is attached to the valve body 13. A solenoid mounting hole 17 penetrating the concave portion 16 is provided in the upper part, and a mounting surface 18 facing the mounting surface 12 of the valve box 13 is provided on the lower end surface of the lid body 14.
And a step surface 19 is provided on the inner peripheral side of the mounting surface 18 via a step, and the step surface 19 has a downward opening section V.
A bleed groove 20 is formed around the bleed port 29, which is formed in a letter shape and has a smaller effective flow passage cross-sectional area than the bleed port 29 described later, and one communication hole 21 is formed at an appropriate position of the bleed groove 20. Communicates with the pilot room 15.

The groove shape of the bleed groove 20 is not limited to the above-described one, and may be, for example, U-shaped in cross section.

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

Reference numeral 23 is a diaphragm valve disposed in the valve body 2. The diaphragm valve 23 has a flexible sheet-shaped diaphragm 24 at its peripheral portion at the mounting surface 18 of the lid 14 and the valve box 13.
A pilot valve 26 having a pilot port 25 at a substantially central portion of the diaphragm 24 is sandwiched and fixed by a mounting surface 12 of the diaphragm 24 and a diaphragm receiver 27.
And the retainer ring 28.

Reference numeral 29 denotes a bleed port. The bleed port 29 is located in a gap 22 formed by the lid 14 and the valve box 13 and is opposed to the bleed groove 20 of the lid 14 and at the same time. Communication hole 21 and displacement (about 18 in this embodiment)
It has been displaced by 0 degrees).

Further, a kick spring 32 is provided in a guide sleeve 31 in a solenoid 30 fitted in a solenoid mounting hole 17 of a lid body 14.
A piston-shaped plunger 34 having communication slits 33 and 33a is vertically slidably arranged by means of a spring which connects the plunger 34 and the pilot valve 26 together.
It is connected by 35.

Reference numeral 36 in the drawing denotes a pilot disk which is fitted in the lower end of the plunger 34 by a pilot spring 37 so as to be pressed downward.

Next, the operation of the pilot type solenoid valve according to the present invention will be described. First, in the valve opening operation, when the solenoid 30 is excited, the plunger 34 is attracted and rises, 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 from the pilot port 25 to the secondary pressure chamber 6
And the pressure in the pilot chamber 15 is reduced, and the diaphragm valve 23 is pushed upward by the pressure in the primary pressure chamber 4 to open the valve port 8.

In this state, the primary pressure chamber 4
Although the fluid inside also flows into the pilot chamber 15 from the bleed port 29, the bleed port from the pilot port 25
Since 29 has a small diameter, the pressure in the pilot chamber 15 drops.

Next, regarding the valve closing operation, the solenoid 30
When the excitation is released, the plunger 34 that has been attracted is pressed downward by the elastic force of the kick spring 32, and the pilot disk 36 of the plunger 34 sits on the pilot port 25 of the pilot valve 26 and closes the pilot port 25. Speak.

The pilot chamber 15 has a diaphragm.
The fluid in the primary side pressure chamber 4 flows in from the bleed port 29 of 24 to raise the pressure of the pilot chamber 15 and the diaphragm valve.
Push down 23.

Further, the pressure in the primary side pressure chamber 4 rises in accordance with the degree of valve closing of the valve port 8, so that the diaphragm 24 in the gap 22 is brought into close contact with the step surface 19 of the lid 14 immediately before the valve is closed. Then, the diaphragm 24 seals the bleed groove 20, and the bleed port 29 communicates with the bleed groove 20.

As a result, the effective flow passage cross-sectional area of the bleed flow passage constituted by the bleed groove 20 and the communication hole 21 communicating from the primary side pressure chamber 4 to the pilot chamber 15 is calculated from the opening effective cross-sectional area of the bleed port 29. In addition to narrowing down the effective flow passage cross-sectional area of the bleed groove 20, apparently further bleeding in combination with the flow passage loss that occurs depending on the flow passage length of the bleed groove 20 between the bleed port 29 and the communication hole 21. The effective flow passage cross-sectional area of the groove 20 is reduced to limit the flow rate flowing into the pilot chamber 15 to make the pressure increase rate of the pilot chamber 15 gentle.

Further, in such a state, the diaphragm 24
Is closely attached to the stepped surface 19 of the valve box 13 and closely attached to the diaphragm receiver 27. As a result, the range of the flexible portion of the diaphragm 24 is narrowed, so that the flexibility of the diaphragm 24 is reduced, and therefore Together with this, the descending speed of the diaphragm valve 23 is further moderated.

[0023]

In summary, according to the present invention, the valve body 2 provided with the valve opening 8 having the valve seat 9 in the partition wall 7 which divides the primary pressure chamber 4 and the secondary pressure chamber 6 into contact with the valve seat 9. The valve body includes a diaphragm valve 23 including a separable diaphragm 24 and a pilot valve 26 having a pilot port 25, and a plunger 34 that is vertically moved in a solenoid 30 that opens and closes the pilot port 25 of the pilot valve 26. In the pilot type solenoid valve provided in 2, the valve box 13 that constitutes the valve body 2
The peripheral edge of the diaphragm 24 is sandwiched and fixed by both mounting surfaces 12 and 18 of the lid 14 and the lid 14, and a step surface 19 is provided around the inner peripheral side of the mounting surface 18 of the lid 14 via a step. A bleed groove 20 is provided around the surface 19, and one communication hole 21 is bored from an appropriate position of the bleed groove 20 to communicate the bleed groove 20 with the pilot chamber 15, while the bleed port 29 is provided with a lid 14 Since it was bored in the diaphragm 24 so as to face the bleed groove 20 of
Immediately before the valve is closed in the process of closing the pilot port 25 and increasing the pressure of the primary side pressure chamber 4 according to the degree of closing of the valve port 8, the step surface 19 of the lid 14 and the mounting surface of the valve box 13 are closed. The diaphragm 24 is deformed so as to be in close contact with the step surface 19 of the lid body 14 by the pressure of the primary pressure chamber 4 that has risen in the gap 22 formed between the diaphragm 24 and the bleed groove.
Seal 20 and bleed port 29 to bleed groove.
By reducing the effective flow passage cross-sectional area of the bleed flow passage by communicating with 20, the flow rate from the primary pressure chamber 4 to the pilot chamber 15 is limited, and the pressure increase rate of the pilot chamber 15 is made gentle. The force for lowering the diaphragm valve 23 is reduced to eliminate the sudden closing valve, and it is possible to reliably prevent the generation of impact noise and water hammer.

Further, since the bleed passage for connecting the primary pressure chamber 4 and the pilot chamber 15 is constituted by the bleed groove 20 and the bleed port 29, the machining thereof is simpler than the conventional one, and the opening / closing is performed. Since the bleed groove 20 is repeatedly sealed and unsealed during valve operation, foreign matter does not block the bleed flow passage, and the flexible portion of the diaphragm 24 is partially deformed to seal the bleed groove 20. By doing so, the range of the flexible part of the diaphragm 24 is narrowed, so that the lowering speed of the diaphragm 24 can be further slowed down in combination with the original function of the bleed flow path. It will be.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a valve open state of a pilot type solenoid valve according to the present invention.

FIG. 2 is a vertical cross-sectional view of a pilot-type solenoid valve showing a valve closing initial state.

FIG. 3 is an enlarged sectional view of a main part of FIG.

FIG. 4 is a vertical cross-sectional view of a pilot-type solenoid valve showing a valve closing mid-stage state.

5 is an enlarged cross-sectional view of a main part B of FIG.

FIG. 6 is a vertical cross-sectional view of a pilot-type solenoid valve showing a state immediately before valve closing.

FIG. 7 is an enlarged cross-sectional view of the main part C of FIG.

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

9 is an enlarged sectional view of a main part of D in FIG.

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

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

[Explanation of symbols]

 2 Valve body 4 Primary side pressure chamber 6 Secondary side pressure chamber 7 Partition 8 Valve opening 9 Valve seat 12 Mounting surface 13 Valve box 14 Lid body 15 Pilot chamber 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)

(57) [Claims] 1. A valve body having a valve opening having a valve seat on a partition wall that divides the primary pressure chamber and the secondary pressure chamber, and a pilot valve having a diaphragm and a pilot port that can be brought into and out of contact with the valve seat. In a pilot type solenoid valve having a diaphragm valve composed of and a plunger that is moved up and down in a solenoid that opens and closes the pilot port of the pilot valve in a valve body, a valve box and a lid that form the valve body. While sandwiching and fixing the peripheral edge of the diaphragm by both mounting surfaces with the body, a step surface is provided on the inner peripheral side of the mounting surface of the lid through a step, and a bleed groove is provided on the step surface.
A pilot characterized in that one communication hole is bored from an appropriate position of the bleed groove to communicate the bleed groove with the pilot chamber, and one bleed port is bored in the diaphragm so as to face the bleed groove of the lid. Type solenoid valve.