Solenoid valve

Abstract

Provided is a recoil-type solenoid valve capable of reducing the number of components, simplifying a manufacturing process, and ensuring a gap between a valve body and a stopper. A plunger (60) of a solenoid valve (1) has a recess (61) formed in an end surface on a pilot valve port (105) side, and a plunger hole (63) extending from an end surface on a suction element (50) side to the recess (61). A stopper (62) is provided in the recess (61). The coil spring (90) is disposed in the hole (63) and biases the valve body (80) toward the stopper (62). The hole (63) has a first hole part (64) at the upper part of the plunger (60) and a second hole part (65) at the lower part of the plunger (60). The inner diameter of the second hole portion (65) is smaller than that of the first hole portion (64). The coil spring is provided with: a plunger biasing section (91) that is disposed in the first hole section (64) and has a diameter that comes into contact with the end surface of the first hole section (64) on the second hole section (65) side; and a valve body biasing section (92) that is smaller than the plunger biasing section (91), is housed in the second hole section (65), and is in contact with the valve body (80).

Description

Technical Field

[0001] The present invention relates to a solenoid valve. Background Art

[0002] For example, there is a known technique of providing a solenoid valve in a flow path of a refrigeration cycle and switching the flow path by opening and closing the solenoid valve. As the solenoid valve, a so-called kick-type solenoid valve is known. The kick-type solenoid valve has the following structure (for example, refer to Patent Document 1).

[0003] That is, in the kick-type solenoid valve, a valve element is disposed in a recess formed in the top surface of a plunger. At the opening of the recess, a stopper such as a rivet or a pressing plate for preventing the valve element from falling off is provided. The dimension of the valve element in the axial direction of the plunger is set such that there is a gap between the valve element and the stopper in a state where the valve element abuts against the bottom surface of the recess. A valve element spring is provided between the bottom surface of the recess and the valve element, and the valve element spring biases the valve element toward the stopper.

[0004] In the kick-type solenoid valve having such a structure, the valve element is pressed against a valve seat by a plunger spring that biases the plunger toward the valve closing side in the valve closed state. The valve element is pressed against the valve seat, so that the valve element spring contracts, and a gap is formed between the stopper and the valve element.

[0005] After the coil of the solenoid valve is energized and the plunger starts to move toward the valve opening side, during the period when the plunger moves by the amount of the gap between the seated valve element and the stopper, the valve element is maintained in the state of being pressed against the valve seat by the acting force of the valve element spring. When the plunger completes the movement of the above-mentioned gap amount, the stopper collides with the valve element. Thus, by using the impact force generated by the collision of the plunger having a speed via the stopper and the valve element, the valve element can be smoothly separated from the valve seat.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-213635

[0009] Technical Problems to be Solved by the Invention

[0010] The above-mentioned kick-type solenoid valve has the following problems. That is, since the solenoid valve has a plunger spring that biases the plunger and a valve element spring that biases the valve element, there is a problem of an increase in the number of parts.

[0011] Furthermore, in order to attach the valve element to the plunger, it is necessary to set the stopper at the opening of the recess while maintaining the state where the valve element presses the valve element spring, and there is a problem that the operation of attaching the valve element to the plunger is troublesome.

[0012] For such a problem, the following structure can also be considered: a hole is formed axially through the plunger, a helical spring is disposed in the hole, and the spool valve is pressed by the helical spring. In the case of this structure, although there is only one spring, since there is no spring pressing the plunger, the plunger is in a free state in its axial direction. Since the plunger is in a free state, there are the following problems: there is a problem that the plunger moves toward the valve opening side due to the installation posture, vibration, etc., resulting in the inability to ensure the gap between the spool valve and the stopper required for the recoil type. Furthermore, there is a problem of abnormal noise generated due to the vibration of the plunger. Summary of the Invention

[0013] An object of the present invention is to provide a recoil type solenoid valve that can reduce the number of parts, simplify the manufacturing process, and ensure the gap between the spool valve and the stopper.

[0014] Technical Means for Solving Technical Problems

[0015] The solenoid valve of the present invention includes a valve body, a pipe, an electromagnetic coil, an attracting element, a plunger, a spool valve, a stopper, and a helical spring. The valve body has a valve port and a valve seat. The pipe has an opening at at least one end and is fixed to the valve body in a posture where the one end faces the valve port. The electromagnetic coil is disposed outside the pipe. The attracting element is fixed inside the pipe. The plunger is disposed on the valve port side with respect to the attracting element inside the pipe. The plunger has a recess formed in a first end face on the valve port side and a plunger hole extending from a second end face on the attracting element side to the recess. The spool valve is housed in the recess and can move in the moving direction of the plunger within the recess. The stopper is provided on the plunger to prevent the spool valve from falling off from the opening of the recess. The helical spring is disposed in the plunger hole, one end of the helical spring abuts against the attracting element, the other end of the helical spring abuts against the spool valve, and the spool valve is biased toward the stopper side. The spool valve can move between a position where it abuts against the stopper and a position where it retreats from the stopper. The plunger hole has a first hole portion and a second hole portion. The first hole portion extends from the second end face of the plunger to a middle portion toward the first end face. The second hole portion extends from the first hole portion to the recess and has an inner diameter smaller than that of the first hole portion. The helical spring has a plunger biasing portion and a spool valve biasing portion. The plunger biasing portion is disposed in the first hole portion and has a diameter that abuts against an end face on the second hole portion side of the first hole portion. The spool valve biasing portion has a smaller diameter than the plunger biasing portion and is housed in the second hole portion and abuts against the spool valve. The spring load of the plunger biasing portion is larger than the spring load of the spool valve biasing portion.

[0016] Effects of the Invention

[0017] According to the present invention, a recoil-type solenoid valve can be provided, which can reduce the number of parts, simplify the manufacturing process, and ensure the clearance between the spool and the stopper. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. 6 is a cross-sectional view showing the energized-off state of the solenoid valve according to the first embodiment of the present invention.

[0019] Figure 2 FIG. 7 is a cross-sectional view showing the energized-on state of the same solenoid valve.

[0020] Figure 3 FIG. 8 is a cross-sectional view showing the state in which the stopper of the plunger of the same solenoid valve collides with the pilot spool.

[0021] Figure 4 FIG. 9 is a cross-sectional view showing the state of the plunger of the same solenoid valve and its periphery in an exploded manner.

[0022] REFERENCE SIGNS

[0023] 1... solenoid valve, 10... valve body, 40... pipe, 50... attracting element, 60... plunger, 61... recess, 62... stopper, 63... hole (plunger hole), 64... first hole portion, 65... second hole portion, 70... electromagnetic coil, 80... pilot spool (spool), 90... spring member (helical spring), 91... plunger biasing portion, 92... spool biasing portion, 105... pilot valve port (valve port), 106... pilot valve seat (valve seat). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Hereinafter, with reference to Figures 1 to 4 the solenoid valve 1 according to the first embodiment of the present invention will be described. The solenoid valve 1 is a so-called recoil-type solenoid valve, and in the present embodiment, an example applied to a pilot-type solenoid valve will be described.

[0025] Figure 1 FIG. 6 is a cross-sectional view showing the solenoid valve 1 in the energized-off state, Figure 2 and FIG. 7 is a cross-sectional view showing the solenoid valve 1 in the energized-on state. The energized-on state means a state in which the electromagnetic coil 70 of the solenoid valve 1 described later is energized, and is a state in which the plunger 60 described later abuts against the attracting element 50. In other words, it is a state in which the plunger 60 rises to the top dead center. Further in other words, the energized-on state is a state in which the plunger 60 moves the pilot spool 80 described later to the upper end of its movement range. The energized-off state means a state in which the electromagnetic coil 70 is not energized.

[0026] Figure 3It is a cross-sectional view showing an intermediate state from the power-off state of the electromagnetic valve 1 to the power-on state where power is supplied to the electromagnetic coil 70, and is a state where the stopper 62 of the plunger 60 collides with the pilot spool 80. Figure 4 It is a cross-sectional view showing the plunger 60 of the electromagnetic valve 1 and its surroundings in an exploded manner, specifically showing the plunger 60, the stopper 62, the pilot spool 80, and the spring member 90.

[0027] Here, for the sake of convenience in explanation, for the valve body 10, the side where the electromagnetic coil 70 is arranged is set as the upper side to define the vertical direction.

[0028] As Figure 1 、 2 、as shown in FIG. 3, the electromagnetic valve 1 includes a valve body 10, a tube holder 20, a housing 30, a tube 40, an attracting element 50, a plunger 60, an electromagnetic coil 70, a pilot spool 80, a spring member 90, and a main spool 100.

[0029] The valve body 10 has, for example, a cylindrical shape. The axis of the valve body 10 is parallel or substantially parallel to the vertical direction. The valve body 10 has a valve chamber 11, an inflow hole 12, an outflow hole 13, a main valve port 14, and a main valve seat 15.

[0030] The valve chamber 11 is divided into a main valve chamber 11a and a pilot valve chamber 11b by the main spool 100.

[0031] There are, for example, a plurality of inflow holes 12 arranged along the circumferential direction of the valve body 10. In this embodiment, six inflow holes 12 are provided as an example. The inflow holes 12 communicate the valve chamber 11 with the outside. The inflow holes 12 allow fluid to flow into the main valve chamber 11a from the outside.

[0032] The outflow hole 13 is, for example, the lower opening of the valve body 10. The outflow hole 13 communicates the valve chamber 11 with the outside. The outflow hole 13 allows the fluid in the valve chamber 11 to flow out to the outside. The opening on the valve chamber 11 side of the outflow hole 13 is the main valve port 14. A main valve seat 15 is formed around the main valve port 14.

[0033] The tube holder 20 is fixed to the inner circumferential surface of the upper opening of the valve body 10. The tube holder 20 has a cylindrical shape. The tube holder 20 is coaxial or substantially coaxial with the valve body 10. The upper opening of the tube holder 20 is a fixing hole 21 to which the tube 40 is fixed.

[0034] The housing 30 is fixed to the upper end of the valve body 10 to cover the electromagnetic coil 70. The housing 30 has a shape with a U-shaped cross-section, having a bottom plate portion 31, a vertical plate portion (not shown), and a top portion 33.

[0035] The pipe 40 has a cylindrical shape with at least one open end, for example, a cylindrical shape with both ends open. The lower end portion of the pipe 40 is fixed, for example, by welding to the inner peripheral surface of the fixing hole 21 of the pipe holder 20. The pipe 40 is coaxial or substantially coaxial with the valve body 10, and the opening at one end of the pipe 40 is located on the side of the pilot valve port 105 described later. The upper end of the pipe 40 is located near the lower surface of the top 33 of the housing 30.

[0036] The attracting element 50 has a bottomed cylindrical shape and is fixed to the upper part inside the pipe 40. The attracting element 50 extends in the vertical direction from the upper end of the pipe 40 to the middle part with its bottom surface facing downward. The attracting element 50 is fixed to the top 33, for example, via a hole 34 passing through the top 33 of the housing 30 and by a threaded member 35.

[0037] As Figure 1 、 2 As shown in FIGS. 3, the plunger 60 has a cylindrical shape, for example, and is disposed below the attracting element 50 inside the pipe 40, that is, on the side of the pilot valve port 105. The plunger 60 has an outer diameter dimension slightly smaller than the inner diameter of the pipe 40 such that it can move inside the pipe 40.

[0038] As Figure 4 shown, a recess 61 is formed on the lower end surface (first end surface) of the plunger 60. The inner peripheral surface of the recess 61 has a cylindrical shape, for example. Here, the cylindrical shape means a shape in which the edge of the cross-section orthogonal to the axis is a circle. A stopper 62 for preventing the detachment of a later-described pilot valve core 80 is provided at the edge portion of the recess 61. The stopper 62 is formed, for example, by fixing a washer to the edge portion.

[0039] The hole (plunger hole) 63 of the plunger 60 has a first hole portion 64 and a second hole portion 65. The first hole portion 64 is a part from the upper end surface (second end surface) of the plunger 60 to the middle part in the axial direction. In the present embodiment, the first hole portion 64 has a frustoconical shape portion and a portion with a constant diameter. The second hole portion 65 is a part from the recess 61 of the plunger 60 to the first hole portion 64. The inner diameter of the second hole portion 65 has a size smaller than the inner diameter of the first hole portion 64. The inner diameter of the recess 61 has a size larger than the inner diameter of the second hole portion 65.

[0040] As Figure 1 、 2 、3 shown, the electromagnetic coil 70 has a cylindrical shape. The electromagnetic coil 70 is disposed around the pipe 40 such that the pipe 40 is disposed inside it.

[0041] The pilot spool 80 is housed in the recess 61 so as to be movable in the moving direction of the plunger 60, i.e., the vertical direction, relative to the recess 61. In the present embodiment, since the inner peripheral surface of the recess 61 has a cylindrical shape, the pilot spool 80 has a cylindrical shape. The outer diameter of the pilot spool 80 has a size slightly smaller than the inner diameter of the recess 61 so that the pilot spool 80 can move axially within the recess 61. The axial length of the pilot spool 80 has, for example, a size substantially the same as the depth of the recess 61.

[0042] The peripheral edge portion 81 of the lower surface of the pilot spool 80 forms an annular stepped portion. Here, the stepped portion means that the height of the peripheral edge portion of the lower surface of the pilot spool 80 is different from the height of the portion closer to the inside than the peripheral edge portion. In other words, the pilot spool 80 has a shape in which a small-diameter cylindrical portion and a large-diameter cylindrical portion larger than the cylindrical portion are coaxially arranged. The peripheral edge portion 81 faces the stopper 62 in the axial direction. In a state where the upper surface of the pilot spool 80 abuts against the bottom surface of the recess 61, there is a gap S1 between the peripheral edge portion 81 and the stopper 62. Here, the bottom surface of the recess 61 means the upper surface of the internal space of the recess 61. The pilot spool 80 is made of, for example, synthetic resin.

[0043] The spring member 90 is a compression coil spring. The spring member 90 is disposed in the hole 63 of the plunger 60. The upper end of the spring member 90 abuts against the lower surface of the attracting element 50, and the lower end of the spring member 90 abuts against the upper surface of the pilot spool 80.

[0044] As Figure 1 、 2 shown in FIGS. 3, the spring member 90 has a plunger biasing portion 91 that biases the plunger 60 and a spool biasing portion 92 that biases the pilot spool 80.

[0045] The plunger biasing portion 91 is disposed in the first hole portion 64 of the plunger 60. The outer diameter of the plunger biasing portion 91 has a size larger than the inner diameter of the second hole portion 65. In addition, the outer diameter of the plunger biasing portion 91 has a size slightly smaller than the inner diameter of the first hole portion 64 so that the plunger biasing portion 91 can expand and contract within the first hole portion 64.

[0046] The lower end 91a of the plunger biasing portion 91 has an annular shape that continuously surrounds the axis of the spring member 90 for one week. Here, the annular shape that continuously surrounds for one week means an annular shape that is completely continuous for one week and an annular shape that is substantially continuous for one week. The lower end 91a is shaped such that the plane including the lower end 91a is orthogonal to the axis of the spring member 90. The lower end 91a of the plunger biasing portion 91 abuts against the end surface of the first hole portion 64.

[0047] The spool biasing portion 92 is disposed in the second hole portion 65 of the plunger 60. The outer diameter of the spool biasing portion 92 has a size slightly smaller than the inner diameter of the second hole portion 65 so that the spool biasing portion 92 can expand and contract within the second hole portion 65.

[0048] The main spool valve 100 has a cylindrical trunk portion 101, an upper flange portion 102 formed on the upper part of the trunk portion 101, and a lower flange portion 103 formed on the lower part of the trunk portion 101. The main spool valve 100 divides the valve chamber 11 into a main valve chamber 11a and a pilot valve chamber 11b. The main spool valve 100 is biased in the valve opening direction by a spring member 90.

[0049] The trunk portion 101 has a hole penetrating in the vertical direction, and the upper part of this hole constitutes a pilot valve port 105. In a state where the main spool valve 100 is seated on the main valve seat 15, the lower end of this hole opens to the main valve port 14. A pilot valve seat (valve seat) 106 is formed around the pilot valve port 105.

[0050] The upper flange portion 102 is disposed inside the pipe holder 20 so as to be movable in the vertical direction. The upper flange portion 102 divides the valve chamber 11 into a main valve chamber 11a and a pilot valve chamber 11b. The upper flange portion 102 has a pressure equalizing passage 107 communicating the main valve chamber 11a and the pilot valve chamber 11b.

[0051] The lower flange portion 103 closes the main valve port 14 by abutting against the main valve seat 15, that is, closes the valve. The valve is opened by the lower flange portion 103 moving away from the main valve seat 15.

[0052] Next, regarding the assembly operation of the plunger 60 of the electromagnetic valve 1, an example of the operation of assembling the pilot spool valve 80 to the plunger 60 will be described.

[0053] First, the pilot spool valve 80 is received in the recess 61 of the plunger 60. Next, a stopper 62 is disposed at the opening edge of the recess 61. Next, as shown in FIGS. Figure 1 、 2 、3, by bending the opening edge of the recess 61 inward, riveting for preventing the stopper 62 from coming off is performed. Next, with the spool valve biasing portion 92 as the tip, the spring member 90 is inserted into the first hole portion 64 of the plunger 60. At this time, the spool valve biasing portion 92 is inserted into the second hole portion 65 so that the tip of the spool valve biasing portion 92 abuts against the pilot spool valve 80. Through such an assembly operation, the pilot spool valve 80 and the spring member 90 are assembled to the plunger 60.

[0054] Next, regarding the operation of the electromagnetic valve 1, the operation of energizing the electromagnetic coil 70 and opening the pilot valve port 105 by the pilot spool valve 80 starting from the state where the pilot valve port 105 is closed by the pilot spool valve 80 in the power-off state will be described.

[0055] As shown in Figure 1As shown, in the power-off state, the plunger 60 is biased toward the main spool valve 100 by the biasing force of the spring member 90. By this biasing force, the pilot spool valve 80 is maintained in the state of being seated on the pilot valve seat 106, that is, the state where the pilot valve port 105 is closed is maintained. In this closed valve state, the upper surface of the pilot spool valve 80 abuts against the bottom surface of the recess 61, and there is a gap S1 between the peripheral portion 81 and the stopper 62.

[0056] As Figure 3 shown, when power is supplied to the electromagnetic coil 70 from the power-off state, the plunger 60 starts to rise. As described above, in the power-off state, since there is a gap S1 between the peripheral portion 81 of the pilot spool valve 80 and the stopper 62, the stopper 62 does not abut against the pilot spool valve 80 until the plunger 60 completes the rise of the amount of the gap S1 after the start of the rise of the plunger 60. Therefore, the state where the pilot spool valve 80 is seated on the pilot valve seat 106, that is, the closed valve state, is maintained.

[0057] When the plunger 60 completes the rise of the amount of the gap S1, the stopper 62 collides with the peripheral portion 81 of the pilot spool valve 80. Due to the impact force generated by this collision, the pilot spool valve 80 separates from the pilot valve seat 106. When the plunger 60 further rises, the pilot spool valve 80 starts to rise by being pressed by the stopper 62. In this way, after the start of the rise of the plunger 60, the plunger 60 collides with the pilot spool valve 80 via the stopper 62 while having a speed, so that the pilot spool valve 80 can be smoothly separated from the pilot valve seat 106 by the impact force generated by this collision.

[0058] In the solenoid valve 1 configured in this way, the spring member 90 includes a plunger biasing portion 91 and a spool valve biasing portion 92. And, since the diameters of both the plunger biasing portion 91 and the spool valve biasing portion 92 are different, the biasing of the plunger 60 and the biasing of the pilot spool valve 80 can be performed by the spring member 90. Therefore, it is not necessary to separately provide a spring member for biasing the plunger 60 and a spring member for biasing the pilot spool valve 80. Therefore, the number of parts of the solenoid valve 1 can be reduced, and a gap S1 can be ensured between the pilot spool valve 80 and the stopper 62 at the time of closing the valve.

[0059] The inner diameter of the second hole portion 65 of the hole 63 of the plunger 60 in which the spool valve biasing portion 92 is disposed is set to a size smaller than the inner diameter of the first hole portion 64 in which the plunger biasing portion 91 is disposed. Further, the inner diameter of the recess 61 of the plunger 60 is set to a size larger than the inner diameter of the second hole portion 95. Therefore, in the state where the pilot spool valve 80 is housed in the recess 61 and the stopper 62 is provided to prevent the pilot spool valve 80 from falling off from the recess 61, by inserting the spring member 90 from the side of the first hole portion 64, the spring member 90 can be assembled to the plunger 60. Therefore, the operation of assembling the pilot spool valve 80 and the spring member 90 to the plunger 60 can be made simple.

[0060] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments. As long as it does not violate the gist of the present invention, structures obtained by those skilled in the art by adding, deleting, or changing the components of the above embodiments, and structures obtained by appropriately combining the features of the embodiments are also included within the scope of the present invention.

Claims

1. A solenoid valve, characterized in that: have: A valve body having a valve port and a valve seat; a tube having an opening at at least one end and fixed to the valve body in a posture where the one end faces the valve port; an electromagnetic coil disposed outside the tube; an attraction element fixed in the tube; a plunger disposed on the valve port side relative to the suction element in the tube, and having a recess formed on a first end surface on the valve port side and a plunger hole extending from a second end surface on the suction element side to the recess; a valve core, which is accommodated in the recess and can move in the recess along the moving direction of the plunger; a stopper, the stopper being arranged on the plunger to prevent the valve core from falling off from the opening of the recess; as well as a coil spring, the coil spring being arranged in the plunger hole, one end of the coil spring being in contact with the attraction element, the other end of the coil spring being in contact with the valve core, and urging the valve core toward the stopper side, The valve element is movable between a position in contact with the stopper and a position retracted from the stopper. The plunger hole includes a first hole portion extending from the second end face of the plunger to a midway portion toward the first end face, and a second hole portion extending from the first hole portion to the recessed portion and having an inner diameter smaller than that of the first hole portion. The coil spring has a plunger force portion and a valve core force portion. The plunger force portion is arranged in the first hole portion and has a diameter that abuts against the end surface of the first hole portion on the second hole portion side. The valve core force portion has a smaller diameter than the plunger force portion and is accommodated in the second hole portion and abuts against the valve core. The spring load of the plunger force portion is greater than the spring load of the valve core force portion.

2. The solenoid valve according to claim 1, characterized in that: A main valve element is provided, the main valve element is accommodated in the valve body, the main valve element divides the valve body into a pilot valve chamber and a main valve chamber, and has a through hole that connects the main valve chamber and the pilot valve chamber. A main valve port and a main valve seat are formed in the valve body. The main valve port is opened and closed by the main valve core, and the main valve seat is for the main valve core to sit on. The valve port is an opening of the through hole on the tube side.

3. The solenoid valve according to claim 1, characterized in that: The inner circumferential surface of the recess is a cylindrical surface, The valve element is cylindrical and has an annular step portion on the outer peripheral portion of the end surface of the valve element on the stopper side.

4. The solenoid valve according to claim 1, characterized in that: The stopper is a washer fixed to the edge of the recessed portion.

5. A method for manufacturing a solenoid valve, the solenoid valve comprising: A valve body having a valve port and a valve seat; a tube having an opening at at least one end and fixed to the valve body in a posture where the one end faces the valve port; an electromagnetic coil disposed outside the tube; as well as The attraction element is fixed in the tube and is characterized in that: The valve element is accommodated in the recessed portion of a plunger which is arranged on the valve port side relative to the suction element in the tube and has a recessed portion and a plunger hole, the recessed portion is formed on the end surface of one end of the plunger, the plunger hole extends from the other end of the plunger to the recessed portion, the plunger hole has a first hole portion and a second hole portion, the first hole portion extends from the other end of the plunger to a midway portion toward the one end, and the second hole portion extends from the first hole portion to the recessed portion and has an inner diameter smaller than that of the first hole portion, A stopper is provided at the opening of the recessed portion to prevent the valve core from falling off the recessed portion. A coil spring is inserted into the plunger hole from the other end side of the plunger, the coil spring having a plunger force applying portion and a valve core force applying portion, the plunger force applying portion being arranged in the first hole portion and having a diameter abutting against an end surface of the second hole portion side of the first hole portion, the valve core force applying portion having a smaller diameter than the plunger force applying portion, being accommodated in the second hole portion and abutting against the valve core, and the spring load of the plunger force applying portion being greater than the spring load of the valve core force applying portion.

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