JP7741562B2 - solenoid valve - Google Patents

Description

The present invention relates to a solenoid valve.

A two-stage pilot-operated solenoid valve is disclosed in which a main body member having an inlet and an outlet is provided with a pilot-operated first valve element and a pilot-operated second valve element for operating the first valve element (see Patent Document 1).

Japanese Patent Application Laid-Open No. 2015-224649

The above-mentioned conventional example is a so-called block-type solenoid valve, in which the valve element is incorporated into a main body having an inlet and outlet, and the overall design can be changed depending on the specifications. On the other hand, there are also cartridge-type solenoid valves that are prepared separately from the main body and can be attached to a main body of any specification.

However, a long hole (first pilot main passage) is formed along the axial direction of the first valve body located in the second stage, and simply changing from a block type to a cartridge type would likely result in an increase in size due to the long hole.

The purpose of this invention is to reduce the size of cartridge-type solenoid valves.

The solenoid valve according to the first aspect is a cartridge-type solenoid valve that is attached to a flow path block having an inlet and an outlet, and is used by being attached to the flow path block. The solenoid valve comprises a valve body that is cylindrically configured so as to be insertable into the flow path block, has a through hole formed in the axial direction, and has a first flow path that communicates with the inlet when attached to the flow path block, and a second flow path that communicates with the outlet, and a main valve chamber having a main valve seat between the first flow path and the second flow path; an attractor attached to the valve body on the opposite side of the second flow path in the axial direction; a plunger that is magnetized and attracted by the magnetized attractor; The valve body includes a pilot-operated main valve element that is provided in the main valve chamber and moves axially to contact or separate from the main valve seat; a holder that is provided on the opposite side of the through hole from the main valve seat and that has a sub-valve chamber that is in communication with the main valve chamber and has a sub-valve seat; and a pilot-operated sub-valve element that is provided in the sub-valve chamber and has a port that is opened and closed by the plunger and moves axially to contact or separate from the sub-valve seat when the port is opened. A relief flow path that releases pressure in the sub-valve chamber to the outlet when the port is open is provided radially outside the main valve element in the valve body.

This solenoid valve is a double-pilot solenoid valve with a pilot-operated main valve element and a pilot-operated sub-valve element. It can be of either a normally closed type, in which the main valve element is closed when the attractor is not attracting the plunger, or a normally open type, in which the main valve element is open when the attractor is not attracting the plunger. Taking the normally closed type as an example, when the plunger is attracted by the attractor, a port is opened and the pilot-operated sub-valve element separates from the sub-valve seat. Fluid in the sub-valve chamber flows to the outlet through the relief flow path. As a result, the pressure on the holder side of the main valve element in the main valve chamber becomes lower than the pressure on the first flow path side that communicates with the inlet, causing the main valve element to separate from the main valve seat. When the attractor stops attracting the plunger, the plunger blocks the port, causing the sub-valve element to abut against the sub-valve seat due to the increase in pressure in the sub-valve chamber, and a further increase in pressure in the main valve chamber causes the main valve element to abut against the main valve seat.

In this solenoid valve, a relief flow path that releases pressure from the sub-valve chamber to the outlet when the port is open is located radially outside the main valve element in the valve body, making it possible to reduce the size of the cartridge-type solenoid valve.

In a second aspect, in the solenoid valve according to the first aspect, a guide member is provided on the main valve chamber side of the holder, within which the main valve body slides, and at least a portion of the relief flow path is formed between the guide member and the inner surface of the valve body.

In this solenoid valve, at least a portion of the relief flow path is formed between the guide member and the inner surface of the valve body, making it easier to manufacture and reduce its size compared to when the relief flow path is drilled into the valve body.

In a third aspect, in the solenoid valve according to the first or second aspect, the holder is provided with an internal flow passage that extends from the port toward the main valve chamber and further extends radially outward to communicate with the relief flow passage, and a communication hole that avoids the internal flow passage and connects the sub-valve chamber and the main valve chamber.

In this solenoid valve, the communication hole in the holder that connects the sub-valve chamber and the main valve chamber is formed so as to avoid the internal flow path that leads to the relief flow path, which helps prevent the holder from becoming too large, and in turn helps prevent the solenoid valve from becoming too large.

In a fourth aspect, in the solenoid valve according to any one of the first to third aspects, the relief flow path opens on the side opposite the holder in the axial direction of the valve body, which is forward in the insertion direction into the flow path block.

In this solenoid valve, the relief flow path opens on the opposite side of the holder in the axial direction of the valve body, which is forward in the direction of insertion into the flow path block. Therefore, when the cartridge-type solenoid valve is attached to the flow path block, the relief flow path can easily be connected to the outlet of the flow path block, which is forward in the direction of insertion.

In this solenoid valve, the attractor and plunger are magnetized by an electromagnetic coil, allowing the plunger to be attracted to the attractor.

A fifth aspect is a solenoid valve according to any one of the first to fourth aspects, further comprising an electromagnetic coil that generates a magnetic field that magnetizes the attractor.

This invention makes it possible to reduce the size of cartridge-type solenoid valves.

1 is a cross-sectional view showing a solenoid valve according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of part A in FIG. 1 . FIG. 4 is a cross-sectional view of the valve body taken along the line 4-4 in FIG. 3. 1A is a cross-sectional view showing a state in which a coil is not energized in a solenoid valve, and FIG. 1B is a cross-sectional view showing a state in which a plunger is attracted to an attractor by energizing the coil. 1A is a cross-sectional view showing a state in which the sub-valve element is separated from the sub-valve seat (valve open state), and FIG. 1B is a cross-sectional view showing a state in which the main valve element is separated from the main valve seat (valve open state).

The following describes an embodiment of the present invention with reference to the drawings. Components designated with the same reference numerals in each drawing are identical or similar components. Note that duplicated descriptions and reference numerals may be omitted in the embodiments described below. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships and ratios of each element shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships and ratios of each element between multiple drawings do not necessarily correspond to the actual ones.

In Figures 1 and 2, the solenoid valve 10 according to this embodiment is a double-pilot solenoid valve used, for example, in the refrigeration cycle of an automotive air conditioner. The solenoid valve 10 according to this embodiment is a so-called normally closed solenoid valve, which is closed when the solenoid coil 18 is not energized. The solenoid valve 10 is a cartridge-type solenoid valve that is attached to a flow path block 16 (Figures 5 and 6) having an inlet 12 and an outlet 14. The solenoid valve 10 includes a valve body 21, an attractor 20, a plunger 24, a main valve element 26, a holder 22, and a sub-valve element 36. The solenoid valve 10 may further include an electromagnetic coil 18 that generates a magnetic field that magnetizes the attractor 20.

(Valve body)
The valve body 21 is configured in a cylindrical shape that can be inserted into the flow path block 16, and has a through hole 21A formed in the axial direction. The valve body 21 has a first flow path 31 and a second flow path 32 formed therein.

As shown in Figures 3 and 4, the first flow paths 31 are flow paths that communicate with the inlets 12 when the solenoid valve 10 is attached to the flow path block 16 (Figures 5 and 6), and are formed at eight locations, for example, evenly spaced circumferentially. This is so that even when the solenoid valve 10 is screwed into the flow path block 16, at least one of the first flow paths 31 is positioned at the inlet 12 of the flow path block 16, allowing fluid to flow from the inlet 12 into the first flow paths 31. Two O-rings 28, for example, are attached to the outer periphery of the valve body 21. The first flow paths 31 are formed between the two O-rings 28 in the axial direction of the valve body 21.

The second flow path 32 is an opening located at the end of the through-hole 21A opposite the plunger 24 (the lower end in Figure 1), and is designed to communicate with the outlet 14 of the flow path block 16 when the solenoid valve 10 is inserted and attached to the flow path block 16.

The first flow path 31 and the second flow path 32 are connected to each other. A main valve chamber 40 having a main valve seat 42 is provided between the first flow path 31 and the second flow path 32.

A male thread 21B is provided on the outer periphery of the valve body 21, which screws into the flow path block 16. A plurality of recesses 21C are formed circumferentially on the outer periphery of the end of the valve body 21 on the plunger 24 side (the upper end in Figure 1). The recesses 21C are, for example, notches with a generally rectangular cross section, for holding a tool that rotates the valve body 21 axially. A female thread 21D, which screws into the holder 22, is provided on the inner periphery of the end of the valve body 21 on the plunger 24 side (the upper end in Figure 1).

(Attractor)
The attractor 20 is attached to the valve body 21 on the axial side opposite to the second flow path 32. Specifically, the attractor 20 is made of a soft magnetic material such as magnetic stainless steel, and is fitted, for example, to one end (the upper end in FIG. 1 ) of the pipe 38. The other end (the lower end in FIG. 1 ) of the pipe 38 is supported by a pipe holder 30, which will be described later.

(electromagnetic coil)
The electromagnetic coil 18 is configured with a winding and is disposed so as to be sandwiched between an upper plate 48U and a lower plate 48L of the housing 48. Furthermore, the electromagnetic coil 18 magnetizes the attractor 20, the plunger, etc. when a current flows through the winding. A pipe 38 passes through the housing 48 and the electromagnetic coil 18, and the upper plate 48U of the housing 48 is fastened to the attractor 20 by, for example, a screw 44. In this way, the housing 48 and the electromagnetic coil 18 are fixed to the pipe 38. The electromagnetic coil 18 is provided with a connector 46 for supplying power.

(plunger)
The plunger 24 is a soft magnetic member that is magnetized by the electromagnetic coil 18 and attracted to the magnetized attractor 20. Specifically, the plunger 24 is arranged axially slidably within the pipe 38. A compression spring 50 is provided between the attractor 20 and the plunger 24. The compression spring 50 biases the plunger 24 toward the sub-valve body 36 (the lower side in FIG. 1). A protrusion, for example, of a substantially conical shape, is provided on the end of the plunger 24 on the sub-valve body 36 side (the lower end in FIG. 1) so as to be able to close the port 36A of the sub-valve body 36.

(Main valve body)
The main valve element 26 is a pilot-operated valve element, and together with the main valve seat 42, constitutes the main valve 70. The main valve element 26 is provided in the main valve chamber 40 and moves axially to contact or separate from the main valve seat 42. Specifically, the main valve element 26 is disposed inside a guide member 52 (described below) and is arranged to be axially slidable relative to the guide member 52. A piston ring 54 is attached to the side wall of the main valve element 26, adjusting the area of the gap between the main valve element 26 and the inner wall of the guide member 52. A passage 26A (pressure equalizing hole) communicating one axial side and the other axial side is formed in the main valve element 26.

A main valve packing 56 is attached to the portion of the main valve body 26 that axially faces the main valve seat 42. A compression spring 58 is provided between the main valve body 26 and the holder 22. The compression spring 58 biases the main valve body 26 toward the main valve seat 42 (the lower side in Figure 1). When the main valve packing 56 comes into close contact with the main valve seat 42, the main valve 70 is closed.

(holder)
The holder 22 is provided on the opposite side of the through hole 21A of the valve body 21 from the main valve seat 42. The central axis of the holder 22 coincides with the central axis of the through hole 21A. The outer periphery of the holder 22 is provided with a male threaded portion 22D that threadably mates with the female threaded portion 21D of the valve body 21. The holder 22 is attached to the valve body 21 by threading the male threaded portion 21D with the female threaded portion 22D. In addition, an O-ring 64 is attached to the outer periphery of the holder 22, closer to the main valve element 26 than the male threaded portion 22D. The O-ring 64 seals the gap between the valve body 21 and the holder 22.

A pipe holder 30 is attached to the holder 22, supporting one end (the lower end in Figure 1) of the pipe 38. The pipe holder 30 is a cylindrical member attached to the holder 22, for example by screwing, from the axial opposite side of the main valve body 26. The central axis of the pipe holder 30 coincides with the central axis of the holder 22 (the central axis of the through-hole 21A). An O-ring 66 seals the gap between the pipe holder 30 and the holder 22.

The holder 22 is provided with a sub-valve chamber 60 that communicates with the main valve chamber 40 and has a sub-valve seat 62. The sub-valve chamber 60 is located primarily inside the pipe holder 30. The sub-valve element 36 is disposed in the sub-valve chamber 60 so that it can slide axially.

A guide member 52, within which the main valve element 26 slides, is provided on the main valve chamber 40 side of the holder 22. The guide member 52 is, for example, a cylindrical pipe. The end of the guide member 52 on the second flow path 32 side is fitted and fixed into the valve body 21. The mating portion between the inner surface of the guide member 52 and the pipe support portion 21E of the valve body 21 is sealed with an O-ring 74. The O-ring 74 is held in place by a retainer 82 crimped to the holder 22 so that it does not come off toward the holder 22 (upper side in Figure 1).

The outer diameter of the guide member 52 is smaller than the inner diameter of the valve body 21 at the location where the guide member 52 is disposed, and a relief flow path 68 is formed between the guide member 52 and the inner surface of the valve body 21. The relief flow path 68 is a flow path that allows the pressure in the sub-valve chamber 60 to flow to the outlet 14 when port 36A is open, and is formed, for example, over the entire circumferential direction between the guide member 52 and the inner surface of the valve body 21.

The holder 22 is provided with an internal flow path 22A and a communication hole 22B. The internal flow path 22A has a first section formed axially, for example, at the center of the holder 22, extending from a port 36A of the sub-valve element 36 (described later) toward the main valve chamber 40, and a second section formed radially outward and communicating with the relief flow path 68. In this embodiment, the internal flow path 22A branches radially from the center of the holder 22 to both sides and penetrates the diameter. In other words, the internal flow path 22A is formed in a T-shape. However, the shape of the internal flow path 22A is not limited to this, and it may branch out further to avoid the communication hole 22B and open to the outer periphery of the holder 22.

The communication holes 22B are formed to avoid the internal flow path 22A and connect the sub-valve chamber 60 and the main valve chamber 40. To avoid the internal flow path 22A, the communication holes 22B are not within the cross section of Figure 1, and are therefore shown in imaginary lines in Figure 1. As an example, the communication holes 22B are located on both radial sides of the portion of the internal flow path 22A that extends in the diametrical direction.

The relief flow path 68 opens axially on the side opposite the holder 22, which is forward in the insertion direction of the valve body 21 into the flow path block 16. As an example, a portion of the outlet side of the relief flow path 68 is formed as a communication hole 72 with a diameter larger than the gap between the guide member 52 and the inner surface of the valve body 21. The communication holes 72 are formed in two locations, for example, point-symmetrical with respect to the center of the valve body 21, avoiding the first flow path 31. As shown in Figures 5 and 6, when the solenoid valve 10 is attached to the flow path block 16, the second flow path 32 and the relief flow path 68 are connected to the outlet 14 of the flow path block 16.

(Sub-valve)
The sub-valve element 36 is a pilot-operated valve element provided in the sub-valve chamber 60, and constitutes a sub-valve 80 together with the sub-valve seat 62. The sub-valve element 36 has a port 36A that is opened and closed by the plunger 24, and moves axially when the port 36A is opened or closed, causing the sub-valve element 36 to come into contact with or separate from the sub-valve seat 62. The port 36A axially communicates from the plunger 24 side to the internal flow path 22A of the holder 22. A sub-valve packing 76 is attached to a portion of the sub-valve element 36 that faces the sub-valve seat 62 in the axial direction. When the sub-valve packing 76 comes into close contact with the sub-valve seat 62, the sub-valve 80 is closed.

(effect)
This embodiment is configured as described above, and its operation will be described below. The solenoid valve 10 according to this embodiment is a so-called normally closed solenoid valve. In Figures 5 and 6, when the electromagnetic coil 18 is energized to magnetize the attractor 20 and plunger 24, the plunger 24 is attracted to the attractor 20. The plunger 24 then moves toward the attractor 20 against the biasing force of the compression spring 50, opening the port 36A of the sub-valve element 36 (Figure 5(B)). This causes fluid in the sub-valve chamber 60 to escape to the outlet 14 through the port 36A of the holder 22, the internal flow path 22A, and the relief flow path 68. Therefore, the pressure on the plunger 24 side of the sub-valve element 36 in the sub-valve chamber 60 (upper side in Figure 5(B)) becomes lower than the pressure on the communicating hole 22B side (lower side in Figure 5(B)). As a result, the pilot-type sub-valve element 36 moves away from the sub-valve seat 62 (FIG. 2), and the sub-valve 80 opens (FIG. 6(A)).

When the sub-valve 80 opens, fluid on the holder 22 side of the main valve element 26 in the main valve chamber 40 escapes to the outlet 14 through the communication hole 22B, the internal flow path 22A, and the relief flow path 68. This causes the pressure on the holder 22 side of the main valve element 26 in the main valve chamber 40 to become lower than the pressure on the first flow path 31 side, which communicates with the inlet 12. This causes the main valve element 26 to move away from the main valve seat 42 (Figures 1 and 2), opening the main valve 70 (Figure 6(B)).

When the electromagnetic coil 18 is de-energized and the attraction of the plunger 24 by the attractor 20 stops, the force of the compression spring 50 moves the plunger 24 to block port 36A, causing the pressure in the sub-valve chamber 60 to increase and be equalized, causing the sub-valve element 36 to abut against the sub-valve seat 62 and closing the sub-valve 80. Furthermore, the force of the compression spring 58 and the increased and equalized pressure in the main valve chamber 40 cause the main valve element 26 to abut against the main valve seat 42, closing the main valve 70.

In this embodiment, the relief flow path 68, which releases the pressure in the sub-valve chamber 60 to the outlet 14 when port 36A is open, is located radially outside the main valve element 26 in the valve body 21, making it possible to reduce the size of the cartridge-type solenoid valve. Because at least a portion of the relief flow path 68 is formed between the guide member 52 and the inner surface of the valve body 21, manufacturing and miniaturization are easier than when the relief flow path 68 is drilled into the valve body 21.

In addition, in the holder 22, the communication hole 22B that connects the sub-valve chamber 60 and the main valve chamber 40 is formed so as to avoid the internal flow path 22A that leads to the relief flow path 68, which prevents the holder 22 from becoming too large, and further prevents the solenoid valve 10 from becoming too large.

Furthermore, the relief flow path 68 opens on the opposite side of the holder 22, which is forward in the axial direction of the valve body 21 in the insertion direction into the flow path block 16. Therefore, when a cartridge-type solenoid valve is attached to the flow path block 16, the relief flow path 68 can be easily connected to the outlet 14 of the flow path block 16, which is forward in the insertion direction.

In this way, according to this embodiment, the cartridge-type solenoid valve 10 can be made smaller.

Other Embodiments
The above describes one example of an embodiment of the present invention, but the embodiment of the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

The solenoid valve 10 in this embodiment is a normally closed type in which the main valve body 26 is closed when the suction element 20 is not attracting the plunger 24, but it may also be a normally open type in which the main valve body 26 is open when the suction element 20 is not attracting the plunger 24.

In the above description, a guide member 52, against which the main valve element 26 slides, is provided on the main valve chamber 40 side of the holder 22. However, the guide member 52 may not be provided and the main valve element 26 may slide against the inner surface of the valve body 21. The relief flow path 68 is formed in the axial direction within the thickness of the valve body 21. In this case, the relief flow path 68 can be formed, for example, by extending the communication hole 72 to the opening position of the internal flow path 22A.

10 Solenoid valve 12 Inlet port 14 Outlet port 16 Flow path block 18 Electromagnetic coil 20 Attractor 21 Valve body 21A Through hole 22 Holder 22A Internal flow path 22B Communication hole 24 Plunger 26 Main valve body 31 First flow path 32 Second flow path 36 Sub-valve body 36A Port 40 Main valve chamber 42 Main valve seat 52 Guide member 60 Sub-valve chamber 62 Sub-valve seat 68 Relief flow path 72 Communication hole

Claims (4)

A cartridge-type solenoid valve used by being attached to a flow path block having an inlet and an outlet,
a valve body configured in a cylindrical shape that can be inserted into the flow path block, with a through hole formed in the axial direction, with a first flow path communicating with the inlet and a second flow path communicating with the outlet when attached to the flow path block, and with a main valve chamber having a main valve seat provided between the first flow path and the second flow path;
a suction element attached to the valve body on the opposite side of the second flow path in the axial direction;
a plunger that is magnetized and attracted to the magnetized attractor;
a pilot-type main valve element that is provided in the main valve chamber and moves in the axial direction to come into contact with or separate from the main valve seat;
a holder provided with an auxiliary valve chamber that is provided on the opposite side of the through hole from the main valve seat, the auxiliary valve chamber communicating with the main valve chamber and having an auxiliary valve seat;
a pilot-type sub-valve element that is provided in the sub-valve chamber, has a port that is opened and closed by the plunger, and moves in the axial direction in response to opening and closing of the port to come into contact with or separate from the sub-valve seat;
a guide member provided on the main valve chamber side of the holder, the guide member having the main valve element sliding therein;
and
a relief flow path for releasing the pressure in the sub-valve chamber to the outlet when the port is opened is provided on the radially outer side of the main valve element in the valve body ,
an outer diameter of the guide member is smaller than an inner diameter of the valve body at a portion where the guide member is disposed;
At least a portion of the relief flow path is formed cylindrically between the guide member and the inner surface of the valve body . The holder includes:
an internal flow passage formed from the port toward the main valve chamber and further formed radially outward, the internal flow passage communicating with the relief flow passage;
2. The solenoid valve according to claim 1, further comprising a communication hole formed to avoid the internal flow path and communicating the sub-valve chamber with the main valve chamber. The solenoid valve according to claim 1, wherein the relief flow path opens on the side opposite the holder in the axial direction of the valve body, which is forward in the insertion direction into the flow path block. Further, an electromagnetic coil is provided to generate a magnetic field that magnetizes the attractor.
The solenoid valve according to any one of claims 1 to 3 .