JPH041424Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement in a pilot type solenoid valve that is equipped with means for preventing or mitigating the occurrence of water hammer when the flow of water in a pipe is stopped.

[Prior art and its problems] FIG. 2 shows the structure of a pilot type solenoid valve disclosed in Japanese Patent Application Laid-open No. 18182/1982. To explain the outline of its structure and operation, reference numeral 1 is the valve housing 1a.
is an inflow path for water, 1b is an outflow path, and a valve seat 1c is formed between the inflow path 1a and the outflow path 1b. Reference numeral 2 denotes a diaphragm valve which performs a valve action in cooperation with the valve seat 1c, and is composed of a flexible diaphragm 3 and a valve body 4 fixed to the diaphragm 3. Reference numeral 5 denotes a lid of the valve housing 1, which airtightly sandwiches the outer peripheral edge of the diaphragm 3 with the valve housing 1. Reference numeral 6 denotes a cylindrical body that slidably accommodates the plunger 7, and the lid 5 and the cylindrical body 6 are integrally formed. A back pressure chamber 8 is defined by the lid 5 and the diaphragm valve 2. 9 is a solenoid assembly consisting of a yoke 10, an excitation winding 12 wound around a bobbin 11, and cores 13a and 13b. 14 is a through hole that opens in the center of the diaphragm valve 2 and communicates the back pressure chamber 8 with the outflow path 1b; 15 communicates the inflow path 1a with the back pressure chamber 8, and connects the inflow path 1a with the back pressure chamber 8; This is a through hole that regulates the flow rate of water into the pressure chamber 8. A spring 16 urges the plunger 7 in a direction in which the plunger 7 comes into contact with the open end of the through hole 14 . FIG. 2 shows the state when the excitation winding 12 is not energized, and the plunger 7 is pressed by the spring 16 against the open end of the through hole 14 of the diaphragm valve 2, and the through hole 14 is closed. Since the water pressure in the inflow path 1a acts on the back pressure chamber 8 through the through hole 15, the diaphragm valve 2 is securely closed between the inflow path 1a and the outflow path 1b by seating on the valve seat 1c. It is. When the excitation winding 12 is energized, the yoke 10, the core 13a,
A magnetic flux is formed using the plunger 7 and core 13b as a magnetic path, and as the plunger 7 is pulled up and the through hole 14 is opened, the pressure in the back pressure chamber 8 is reduced and the diaphragm valve 2 is activated by the water pressure in the inflow path 1a. The diaphragm valve 2 is moved away from the valve seat 1c, and the inflow path 1a and the outflow path 1b are brought into communication with each other. Excitation winding 1
2 is cut off, the plunger 7 closes the through hole 1 of the diaphragm valve 2 by the force of the spring 16.
4 is closed, the outflow of water from the back pressure chamber 8 to the outflow path 1b is stopped, and the water in the inflow path 1a continues to be regulated by the through hole 15 and gradually flows into the back pressure chamber 8. The pressure in the back pressure chamber 8 increases, and the diaphragm valve 2 and the valve seat 1c gradually come into contact with each other, thereby blocking the inflow path 1a and the outflow path 1b. In a normal solenoid valve, the inflow path and outflow path are instantaneously shut off, which causes water hammer in the piping on the inflow side, but in the pilot type solenoid valve with the above configuration, the inflow path 1a and the outflow path 1b are shut off by a diaphragm. Since the water hammer is gradually applied by the valve 2, the occurrence of water hammer is prevented or alleviated.

However, the pilot type solenoid valve having the above structure has the following problems. That is, since the diameter of the through hole 15 communicating between the inflow path 1a and the back pressure chamber 8 is constant, when the pressure in the inflow path 1a increases significantly, the speed of water flowing into the back pressure chamber 8 increases. The problem is that the valve closing speed increases and the water hammer prevention effect cannot be fully exerted. As a countermeasure against this problem, a water hammer prevention valve having a structure shown in FIG. 3 is disclosed in Japanese Utility Model Publication No. 59-8052. 1 is the valve housing, 1a is the inflow path, 1b is the outflow path,
1c is the valve seat, 2 is the diaphragm valve, 5 is the lid body, 8
is a back pressure chamber, but the through hole that communicates the back pressure chamber 8 and the outflow path 1b and the through hole that communicates the inflow path 1a and the back pressure chamber 8 are not the diaphragm valve 2 but the valve housing 1 and the lid. The structure differs from that shown in FIG. 2 in that it is formed on the body 5. The through hole 18 that opens into the valve housing 1, the through hole 20 that opens into the lid body 5, and the passage 19 that communicates the through hole 18 and the through hole 20 are the through hole 14 in the configuration shown in FIG.
The through hole 17, the passage 19, and the through hole 20 correspond to the second
This corresponds to the through hole 15 in the configuration shown in the figure. aisle 19
A flow in both forward and reverse directions is generated in the through hole 20, and a flow control valve 21 is disposed between the passage 19 and the through hole 20 and is urged in the opening direction by a spring 22. A solenoid assembly 9 is arranged to control opening and closing of the through hole 18 by the plunger 7. FIG. 3 shows the state when the excitation winding 12 is not energized, and the water pressure in the inflow channel 1a is
7. The diaphragm valve 2 acts on the back pressure chamber 8 through the passage 19 and the through hole 20, and contacts the valve seat 1c, thereby blocking the inflow path 1a and the outflow path 1b. When the excitation winding 12 is energized, the through hole 18 opens, and the water in the back pressure chamber 8 flows out into the outflow path 1b through the through hole 20, the passage 19, and the through hole 18, and the water pressure in the inflow path 1a increases. The diaphragm valve 2 is then opened. Next, the excitation winding 12
When the power is cut off, the plunger 7 closes the through hole 18, and the water pressure in the inflow path 1a flows into the back pressure chamber 8 through the through hole 17, the passage 19, and the through hole 20, but the water pressure in the inflow path 1a When no water hammer occurs in the water pressure, the flow rate control valve 21 is fully opened by the spring 22, and water flows into the back pressure chamber 8 at the flow rate regulated by the through hole 20, and the diaphragm valve 2 is closed. As it approaches the valve seat 1c, when the water pressure in the inlet passage 1a increases significantly due to the water hammer that occurs during the valve closing process, the spring 22 is compressed and the flow rate control valve 21 comes into contact with the through hole 20. Even in that case, water flows into the back pressure chamber 8 through the flow path with a small cross-sectional area formed in the flow rate control valve 21, so the speed at which the diaphragm valve 2 approaches the valve seat 1c decreases, and the inflow path There is no risk that water hammer will occur due to an increase in water pressure within 1a.

Although the water hammer prevention valve having the configuration shown in FIG. 3 achieves the water hammer prevention effect, the complicated configuration increases the cost.

FIG. 4 shows that the diaphragm valve 2 is not provided with a through hole 15 that communicates the inflow path 1a and the back pressure chamber 8 and regulates the inflow flow rate of water from the inflow path 1a to the back pressure chamber 8. A passage 23 connects the back pressure chamber 8 and an air chamber 24 is disposed in the middle, and a throttle 25 for regulating the flow rate of water is disposed in the passage 23 between the air chamber 24 and the inflow passage 1a. When the water pressure in the inlet passage 1a increases due to water hammer during the valve closing process, the air chamber 2
By compressing the air in the back pressure chamber 8, the increase in the amount of water flowing into the back pressure chamber 8 is delayed, and one water hammer is prevented from causing the next water hammer.
Since the air and water are in direct contact within the air chamber 24, the air is absorbed by the water and carried away by the flow of water in the passage 23, resulting in a gradual decrease in function. It was hot.

[Purpose of the invention] The object is to provide a pilot type solenoid valve with improved water hammer prevention function without increasing costs.

[Structure of the invention] A valve seat is formed between an inflow passage and an outflow passage of a valve housing, and a diaphragm valve that performs a valve action in cooperation with the valve seat has an outer peripheral edge that is connected to the valve housing and the lid body. A back pressure chamber is defined by the lid and the diaphragm valve, and the diaphragm valve has a through hole that communicates the back pressure chamber and the outflow path. In the pilot type solenoid valve, a plunger is disposed opposite to the opening end of the hole on the side opposite to the outflow path, and opens and closes the through hole by electromagnetic force. A water passage connecting the inflow passage and the back pressure chamber is formed, and an air chamber is disposed in contact with the water passage via a diaphragm, and the diaphragm receives a spring via a piston that is slidable within the air chamber. The water passage is biased toward the water passage, and the water passage has a restriction formed between a portion in contact with the air chamber and an inflow passage to regulate the flow rate of water flowing into the back pressure chamber. The configuration is as follows.

[Example] Fig. 1 is a vertical cross-sectional view showing the configuration of a pilot type solenoid valve of the present invention, in which reference numeral 101 is a valve housing, 101a is a water inflow path, 101b is an outflow path, and 101c is the inflow path 101a and the outflow path. It is a valve seat formed between the passage 101b and the passage 101b. A diaphragm valve 102 performs a valve action in cooperation with the valve seat 101c, and is composed of a flexible diaphragm 103 and a valve body 104 fixed to the diaphragm 103 (diaphragm 1
03 and the valve body 104 may be integrally molded). 105
is a lid of the valve housing 101, the outer peripheral edge of the diaphragm valve 102 is held between the valve housing 101 and the lid 105, and there is a gap between the lid 105 and the diaphragm valve 102. A back pressure chamber 106 is formed. 107 is the diaphragm valve 1
This is a through hole that opens at the center of the 02 and communicates the back pressure chamber 106 and the outflow path 101b, and is generally called a pilot hole. 108 is the through hole 10
7, and is arranged opposite to the opening end on the opposite side to the outflow passage 101b, and the through hole 107 is opened by electromagnetic force.
It is a plunger that opens and closes. A solenoid assembly 109 includes a yoke 110, an excitation winding 112 wound around a bobbin 111, and a core 113. 114 is a cylinder in which the plunger 108 freely slides, and is made of a non-magnetic material. 11
5 connects the plunger 108 to the diaphragm valve 10
It is a spring that biases in two directions. The inflow path 101a and the back pressure chamber 106 include a throttle 116 that regulates the flow rate, a space 117, a through hole 118, and a space 11.
9. A water passage consisting of a through hole 120 is formed, and the space 117 is in contact with an air chamber 122 via a diaphragm 121. The diaphragm 121
The outer peripheral edge is connected to the cover plate 124 via the cylindrical member 123.
The water passage (space 11
7), and when the pressure in the space 117 rises, the spring 126 is compressed and retreats toward the air chamber 122, substantially expanding the volume of the back pressure chamber 106 and closing the diaphragm valve 102. Slow down the valve speed.

[Operation] In FIG. 1, when the excitation winding 112 is not energized, the plunger 108 closes the through hole 107, and the water pressure in the inflow passage 101a acts in the back pressure chamber 106, causing the diaphragm valve 102 to press against the valve seat 101c. It shows a seated state. energize the excitation winding 112,
When the plunger 108 is pulled up and the through hole 107 is opened, the water in the back pressure chamber 106 flows out into the outflow path 101b, the water pressure in the back pressure chamber 106 decreases, and the water pressure in the inflow path 101a acts on the diaphragm valve 102.
is removed from the valve seat 101c, and water flows from the inflow path 101a to the outflow path 101b. Next, the excitation winding 11
When the power to the diaphragm 11 is cut off, the plunger 108 is pressed against the open end of the through hole 107 by the force of the spring 115, closing the through hole 107.
6. The inflow path 101a passes through the water passage consisting of the space 117, the through hole 118, the space 119, and the through hole 120.
The water inside is regulated by the opening area of the throttle 116 and flows into the back pressure chamber 106, and the water flows into the back pressure chamber 106.
2 gradually approaches the valve seat 101c. Inflow path 10
The flow rate of water flowing from 1a toward the outflow path 101b decreases, and some water hammer occurs, causing the inflow path 101
Although the water pressure in the space 117 increases, the rate of increase in the water pressure in the space 117 is due to the throttling action of the restrictor 116 and the diaphragm 1.
Since the water hammer is attenuated by the substantial increase in the volume of the back pressure chamber 106 due to the elastic retraction of the diaphragm valve 21, the water hammer is prevented from increasing the closing speed of the diaphragm valve 102 and causing water hammer. This increases the water hammer prevention effect of the pilot type solenoid valve.

The above-mentioned water passage from the inflow path 101a to the back pressure chamber 106 is formed due to the configuration of the valve housing 101 and the lid 105, and does not necessarily include the aperture 116, the space 117, the through hole 118, the space 119, and the through hole. The passage structure is not limited to the passage configuration consisting of 120, but includes a restriction 116 that regulates the flow rate to attenuate the rate of increase in water pressure in the inflow passage 101a, and a water passage downstream of the restriction 116 (on the back pressure chamber 106 side). an air chamber 1 which is in contact with the water passage and partitioned by a diaphragm 121;
It is an essential requirement that 22 be placed.

[Effect] The water hammer prevention effect of the pilot type solenoid valve can be enhanced without creating a complicated structure that increases costs.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of the pilot type solenoid valve of the present invention, Fig. 2 is a longitudinal sectional view of the pilot type solenoid valve disclosed in Japanese Patent Application Laid-Open No. 18182/1982, and Fig. 3 is a longitudinal sectional view of the pilot type solenoid valve disclosed in Japanese Patent Publication No. 59-8052. FIG. 4 is a schematic cross-sectional view of a pilot-type solenoid valve that was prototyped before devising the pilot-type solenoid valve of the present invention shown in FIG. 1. Explanation of symbols: 101... Valve housing, 101a...
Inflow channel, 101b...Outflow channel, 101c...Valve seat, 102...Diaphragm valve, 103...Diaphragm, 104...Valve body, 105...Lid body, 1
06...Back pressure chamber, 107...Through hole, 108...Plunger, 109...Solenoid assembly, 1
10...Yoke, 111...Bobbin, 112...
Excitation winding, 113...Core, 114...Cylinder, 115...Spring, 116...Aperture, 1
17, 119... Space, 118, 120... Through hole, 121... Diaphragm, 122... Air chamber, 123... Cylindrical member, 124... Lid plate, 12
5... Piston, 126... Spring.

Claims (1)

[Scope of utility model registration request] Inflow path 101a and outflow path 101 of valve housing 101
A valve seat 101c is formed between the valve seat 10
A diaphragm valve 10 that acts in cooperation with 1c
2 has an outer peripheral edge held between the valve housing 101 and the lid 105, a back pressure chamber 106 is defined by the lid 105 and the diaphragm valve 102, and the diaphragm valve 102 has a The back pressure chamber 1
06 and the outflow path 101b communicate with each other.
7 is open, and the outflow path 101b of the through hole 107
In the pilot type solenoid valve, a plunger 108 is disposed opposite to the opening end of the through hole 107 by electromagnetic force, and the valve housing 101 and the lid 105 are provided with the inflow. Road 10
A water passage connecting 1a and the back pressure chamber 106 is formed, and an air chamber 122 is arranged in contact with the water passage through a diaphragm 121, and the diaphragm 121 can freely slide within the air chamber 122. is urged toward the water passage by a spring 126 through a piston 125 of
A pilot type solenoid valve characterized in that a throttle 116 is formed between the back pressure chamber 106 and the back pressure chamber 106 to regulate the flow rate of water flowing into the back pressure chamber 106.