JPH041425Y2 - - 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. 5 shows the structure of a pilot type solenoid valve disclosed in Japanese Patent Application Laid-Open No. 56-18182. 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 or integrally formed with 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 flowing 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. 5 shows a 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.
Since the through hole 14 is closed and 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 seated on the valve seat 1c between the inflow path 1a and the outflow path 1b. By doing so, you can be sure that it will be closed. When the excitation winding 12 is energized, a magnetic flux is formed using the yoke 10, core 13a, plunger 7, and core 13b as a magnetic path, and the plunger 7 is pulled up and the through hole 14 is opened, so that the pressure in the back pressure chamber 8 is reduced. As the valve lowers, the diaphragm valve 2 is pushed up by the water pressure in the inflow path 1a, and the diaphragm valve 2 separates from the valve seat 1c, thereby establishing electrical communication between the inflow path 1a and the outflow path 1b. When the power to the excitation winding 12 is cut off, the plunger 7 closes the through hole 14 of the diaphragm valve 2 by the force of the spring 16, and the outflow of water from the back pressure chamber 8 to the outflow path 1b is stopped, and the inflow of water is stopped. The water in the passage 1a is 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. Inflow path 1a
and the outflow path 1b are cut off. 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, even with the pilot type solenoid valve configured as described above, there are the following problems. That is, since the diameter of the through hole 15 that communicates between the inflow path 1a and the back pressure chamber 8 is constant, when the pressure in the inflow path 1a gradually increases due to the decrease in flow rate during the valve closing process, the back pressure chamber 8 The speed at which water flows into the valve increases, the speed at which the valve closes 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. 6 is disclosed in Japanese Utility Model Publication No. 59-8052. 1 is the valve housing, 1a
is an inflow path, 1b is an outflow path, 1c is a valve seat, 2 is a diaphragm valve, 5 is a lid body, and 8 is a back pressure chamber, which includes a through hole that communicates the back pressure chamber 8 and the outflow path 1b, and an inflow The structure differs from the structure shown in FIG. 5 in that the through hole communicating the passage 1a and the back pressure chamber 8 is formed not in the diaphragm valve 2 but in the valve housing 1 and the lid 5. The through hole 18 that opens in the valve housing 1, the through hole 20 that opens in the lid body 5, and the passage 19 that communicates the through hole 18 and the through hole 20 are the fifth
Corresponds to the through hole 14 in the configuration of the figure, and the through hole 17,
The passage 19 and the through hole 20 correspond to the through hole 15 in the configuration shown in FIG. Flow occurs in both forward and reverse directions in the passage 19 and the through hole 20, and a flow control valve 21 is disposed between the passage 19 and the through hole 20 and is biased 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. 6 shows the state when the excitation winding 12 is not energized, and the water pressure in the inflow path 1a is
The diaphragm valve 2 contacts the valve seat 1c and blocks 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 through the through hole 20 and the passage 1.
9. The water flows out into the outflow path 1b through the through hole 18, and the diaphragm valve 2 is opened by the water pressure in the inflow path 1a. Next, when the excitation winding 12 is de-energized, the plunger 7 closes the through hole 18, and the water pressure in the inflow path 1a passes through the through hole 17, the passage 19, and the through hole 20 to the back pressure chamber 8.
However, when there is no water hammer in the water pressure in the inflow channel 1a, the flow rate control valve 21 is fully opened by the spring 22, and the flow rate regulated by the through hole 20 is maintained in the back pressure chamber 8. Water flows into the diaphragm valve 2 and approaches the valve seat 1c, but when the water pressure in the inlet passage 1a rises significantly due to water hammer during the valve closing process, the spring 22 is compressed and the flow rate control valve 21 closes to the through hole 20.
comes into contact with. Even in that case, the flow control valve 21
Since water flows into the back pressure chamber 8 through the flow path with a small cross-sectional area formed in Therefore, there is no risk of promoting the occurrence of water hammer.

Although the water hammer prevention valve having the configuration shown in FIG. 6 achieves the water hammer prevention effect, the complicated configuration increases the cost.

[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 path and an outflow path of a valve casing, 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 casing and the valve casing. 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. , a through hole that communicates the inflow path and the back pressure chamber is opened, and the through hole that communicates the back pressure chamber and the outflow path is opposite to the open end of the through hole on the opposite side to the outflow path. In a pilot type solenoid valve in which a plunger is disposed to open and close a through hole by electromagnetic force, an upper end surface and a cylindrical shape are provided on the back pressure chamber side of the through hole that communicates the back pressure chamber and the inflow path. A cylindrical member having a throttle hole opened on each surface is arranged in series, and the inside of the cylindrical member has a cylindrical member that moves upward due to the flow of liquid when the pressure in the inflow channel increases significantly. A valve member is arranged to close a throttle hole opening in the upper end surface.

[Embodiment] Fig. 1 is a vertical cross-sectional view 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 a water outflow path, and 101c is the inflow path 101a. and the outflow path 101b. 102 is the valve seat 101
A diaphragm valve having a valve action in cooperation with c, a flexible diaphragm 103 and the diaphragm 10
3 and a valve body 104 fixed to the valve body 104. 105 is a lid of the valve housing 101, and the outer peripheral edge of the diaphragm valve 102 is held between the valve housing 101 and the lid 105, and the lid 105 and the diaphragm valve 102 are A back pressure chamber 106 is formed in between. 107 is the diaphragm valve 102
This is a through hole that opens at the center of the hole and communicates the back pressure chamber 106 and the outflow path 101b, and is generally called a pilot hole. 108 is the inflow path 101
This is a through hole that communicates between a and the back pressure chamber 106.
109 is a solenoid assembly, and an excitation winding 1 is wound around a bobbin 110 made of a synthetic resin material.
11. Yoke 112 and core 113 forming a magnetic path
a, 113b. 114 is the core 11
The outflow path 101b of the through hole 107 that communicates the back pressure chamber 106 and the outflow path 101b with a plunger that is slidable inside the back pressure chamber 106 and the outflow path 101b.
Open and close the opening end on the opposite side. 115 is a spring that urges the plunger 114 toward the diaphragm valve 102.

A cylindrical member 116 is connected to the back pressure chamber 106 side of the through hole 108 that communicates the inflow path 101a and the back pressure chamber 106, and the upper end surface and the cylindrical surface of the cylindrical member 116 are respectively provided with a cylindrical member 116. Aperture holes 117 and 118
is open, and a valve member 119 is disposed inside the cylindrical member 116. FIG. 2 is a partially enlarged sectional view showing in detail the state in which the tubular member 116 is connected to the through hole 108, and the reference numerals shown in the figure are the same as those shown in FIG. Indicates the content of FIG. 3 shows an embodiment in which a valve member 120 having the cross-sectional shape of FIG. 4 is disposed within the tubular member 116. This invention does not limit the shape of the valve member.

[Operation] In FIG. 1, the excitation winding 111 is de-energized, and the force of the spring 115 causes the plunger 114 to come into contact with the diaphragm valve 102, the pilot hole 107 is closed, and the water pressure in the inlet passage 101a is reduced. It acts on the back pressure chamber 106, and the diaphragm valve 102 is pressed against the valve seat 101c, so that the diaphragm valve 102
is closed. When the excitation winding 111 is energized, the yoke 112, the core 113a, and the plunger 11
4. Magnetic flux is formed in the core 113b and the plunger 1
14 is pulled up, the water in the back pressure chamber 106 flows away from the open end of the through hole 107 into the outflow path 101b, the pressure in the back pressure chamber 106 decreases, and the diaphragm valve 102 and the valve seat 101c are separated. Open the valve apart,
Water flows from the inflow path 101a toward the outflow path 101b. Next, when the excitation winding 111 is de-energized, the plunger 114 and the end of the through-hole 107 come into contact, the through-hole 107 is closed, and the water flowing into the back pressure chamber 106 from the inflow path 101a backs up. Pressure chamber 106
The pressure inside increases and the valve begins to close. Due to a change in the flow rate in the pipe, the pressure in the inflow path 101a increases, and when the flow rate of water flowing into the back pressure chamber 106 through the through hole 108 increases, the valve member 119 or 120 is pushed up and becomes cylindrical. Restriction hole 1 on the upper end surface of member 116
17 (the position of the spherical member 119 at that time is shown by the broken line), and the diaphragm valve 102 is gently seated on the valve seat 101c since water will flow into the back pressure chamber 106 only from the throttle hole 118 on the cylindrical surface. Thus, one water hammer does not cause another water hammer, and the water hammer prevention function is improved.

[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 an embodiment of the pilot type solenoid valve of the present invention, Fig. 2 is a partially enlarged sectional view of Fig. 1 when a spherical valve member is used, and Fig. 3 is Fig. 4. FIG. 4 is a cross-sectional view of the valve member used in the construction of FIG. 3, and FIG. 5 is a partial enlarged sectional view of FIG. FIG. 6 is a vertical sectional view of the pilot type solenoid valve disclosed in Japanese Utility Model Publication No. 59-8052. 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, 107,108...Through hole, 10
9... Solenoid assembly, 110... Bobbin, 111... Excitation winding, 112... Yoke, 1
13a, 113b... Core, 116... Cylindrical member, 117, 118... Throttle hole, 119, 120
...Valve member.

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
Diaphragm valve 102 valving in cooperation with 1c
The outer peripheral edge is the valve housing 101 and the valve housing 10.
The lid body 105 is clamped by the lid body 105 of the lid body 1.
5 and the diaphragm valve 102, a back pressure chamber 106 is defined by the diaphragm valve 102, and the diaphragm valve 102 has a through hole 107 that communicates the back pressure chamber 106 and the outflow path 101b, and a through hole 107 that communicates the back pressure chamber 106 with the outflow path 101b, and A through hole 108 that communicates with the back pressure chamber 106 is open, and is opposed to the open end of the through hole 107 that communicates the back pressure chamber 106 and the outflow path 101b on the side opposite to the outflow path 101b. In a pilot type solenoid valve in which a plunger 114 is disposed to open and close the through hole 107 by electromagnetic force, the back pressure chamber 106 side of the through hole 108 that communicates the back pressure chamber 106 and the inflow path 101a A cylindrical member 116 having aperture holes 117 and 118 opened in an upper end surface and a cylindrical surface, respectively, is provided in succession to the cylindrical member 116.
Valve members 119 and 120 are disposed inside the valve member 119 and 120, which move upward due to the flow of liquid and close the throttle hole 117 opening in the upper end surface when the pressure in the inflow path 101a increases rapidly. A pilot type solenoid valve featuring: