solenoid valve

Abstract

To obtain a solenoid valve capable of realizing failure detection of the solenoid valve by detecting a position of a plunger.SOLUTION: A solenoid valve 100 includes: a valve body 30 in which an input 31 and an output 32 of fluid are formed, and a main valve seat 35 (valve seat) and a main valve chamber 33 (valve chamber) are formed therebetween; a pipe 51 disposed in the valve body 30, having an inner part communicated with the main valve chamber 33 side, and blocked from outside air; a main valve element 40 arranged so as to vertically slide in the pipe 51, and capable of approaching / separating to / from the main valve seat 35; a plunger 50 arrange inside the valve body 30, and moving the main valve element 40 in a direction of separating from the main valve seat 35; a solenoid 70 wound with a coil 70a for driving the plunger 50; a magnet 102 fitted to the plunger 50; and a magnetic sensor 108 positioned outside the pipe 51 in the valve body 30 and in the side part of the pipe 51, and detecting a magnetic flux density of the magnet 102.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to solenoid valves. [Background technology]

[0002] BACKGROUND ART Solenoid valves capable of detecting abnormalities or failures in the solenoid valve have been proposed (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-291887 [Patent Document 2] Special Publication No. 52-36287 Summary of the Invention [Problem to be solved by the invention]

[0004] The solenoid valve of Patent Document 1 detects abnormalities by observing the current waveform of the coil that drives the plunger, but does not detect the position of the plunger itself.

[0005] In the solenoid valve of Patent Document 2, an abnormality is detected by a separately provided coil, but the position of the plunger itself is not detected.

[0006] In consideration of the above, the present disclosure aims to provide a solenoid valve that can detect a failure by detecting the position of the plunger. [Means for solving the problem]

[0007] The solenoid valve according to the first aspect includes a valve body having an inlet and an outlet for a fluid, with a valve seat and a valve chamber formed therebetween; a valve element disposed within the valve chamber and capable of moving toward and away from the valve seat; a plunger disposed within the valve body and moving the valve element in a direction toward and away from the valve seat; a solenoid wound with a coil for driving the plunger; a magnet attached to the plunger; and a magnetic sensor provided in the valve body for detecting the magnetic flux density of the magnet.

[0008] In this solenoid valve, by passing current through the solenoid coil, the valve element can be moved in a direction away from the valve seat, thereby allowing fluid to flow from the inlet to the outlet.

[0009] A magnet is attached to the plunger, so when the plunger moves, the distance between the magnet and a magnetic sensor provided in the valve body changes, and the magnetic flux density of the magnet detected by the magnetic sensor changes.

[0010] For example, if the magnet approaches the magnetic sensor as the plunger that moves the valve body moves in the direction that separates the valve body from the valve seat, it can be detected that the plunger has moved in the direction that separates the valve body from the valve seat when the magnetic flux density detected by the magnetic sensor is large, and it can be detected that the plunger has moved the valve body toward the valve seat when the magnetic flux density detected by the magnetic sensor is small. Therefore, in this solenoid valve, failure of the solenoid valve can be detected from the relationship between the energization of the coil and the position of the plunger. This solenoid valve can detect the position of the plunger regardless of whether the coil is energized.

[0011] The solenoid valve according to the second aspect comprises a valve body having an inlet and an outlet for a fluid, with a valve seat and a valve chamber formed therebetween; a valve element disposed within the valve chamber and capable of moving toward and away from the valve seat; a plunger disposed within the valve body and moving the valve element in a direction toward and away from the valve seat; a solenoid wound with a coil for driving the plunger; and a magnetic sensor provided in the valve body and detecting the magnetic flux density of the coil passing through the plunger.

[0012] In this solenoid valve, by passing current through the solenoid coil, the valve element can be moved in a direction away from the valve seat, thereby allowing fluid to flow from the inlet to the outlet.

[0013] When the plunger moves, the distance between the plunger and the magnetic sensor provided on the valve body changes, and the magnetic flux density of the coil that passes through the plunger changes at the location where the magnetic sensor is installed.

[0014] For example, in the case of a solenoid valve in which a plunger that moves a valve element is configured to move in a direction in which the valve element contacts the valve seat and moves away from a magnetic sensor by energizing a solenoid coil, if the magnetic flux density detected by the magnetic sensor is equal to or less than a preset value, it can be detected that the plunger is moving in the direction in which the valve element contacts the valve seat.Also, if the magnetic flux density detected by the magnetic sensor when the coil is energized exceeds a preset value, it can be detected that the plunger is positioned in a direction in which the valve element moves away from the valve seat, i.e., that the plunger is not in the correct position.

[0015] In a third aspect, in the solenoid valve according to the first aspect, the plunger is cylindrical, and the magnet is inserted into and fixed to an upper end portion of a hole in the plunger.

[0016] In this solenoid valve, the plunger is cylindrical and the magnet is inserted into and fixed to the upper end of the plunger hole, making it lighter than a plunger with a cylindrical shape.

[0017] A fourth aspect is an electromagnetic valve according to any one of the first to third aspects, which has a pipe whose interior is connected to the valve chamber side and is isolated from the outside air, the plunger is arranged to slide up and down within the pipe, and the magnetic sensor is arranged outside the pipe.

[0018] Since the plunger is disposed in a pipe that is connected to the valve chamber side and is isolated from the outside air, the fluid in the valve chamber does not leak into the outside air. If a magnetic sensor is placed inside a pipe, a hole must be formed in the pipe to pass the wiring that outputs the magnetic sensor signal, and the gap between the hole and the wiring must be sealed with a sealant or the like to prevent the fluid inside the pipe from leaking into the outside air. However, by placing the magnetic sensor outside the pipe, such a seal is not required, simplifying the configuration.

[0019] In a fifth aspect, in the solenoid valve according to the fourth aspect, there is provided an attractor made of magnetic stainless steel that connects the pipe and the valve body, and a compression coil spring is arranged between the attractor and the plunger.

[0020] When a magnetic stainless steel attractor is provided, energizing the solenoid coil magnetizes the attractor and plunger, generating a magnetic attraction between them and compressing the plunger against the resilience of the compression coil spring. When the solenoid coil is de-energized, the electromagnetic attraction force disappears and the resilience of the compression coil spring returns the plunger to its original position before it was attracted. [Effects of the Invention]

[0021] As described above, according to the solenoid valve of the present disclosure, it is possible to detect a malfunction of the solenoid valve by detecting the position of the plunger. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a vertical cross-sectional view illustrating the configuration of a solenoid valve according to a first embodiment of the present disclosure, showing a fully open state in which both a pilot valve and a main valve are open (a state in which no current is applied to a solenoid). FIG. [Figure 2] 1 is a longitudinal cross-sectional view illustrating the configuration of a solenoid valve according to a first embodiment of the present disclosure, showing a fully closed state (a state in which the solenoid is energized) in which both the pilot valve and the main valve are closed. FIG. [Figure 3] 4 is a flowchart illustrating control of a fault diagnosis of a solenoid valve according to the first embodiment. [Figure 4] FIG. 10 is a vertical cross-sectional view illustrating the configuration of a solenoid valve according to a second embodiment of the present disclosure, showing a fully open state in which both the pilot valve and the main valve are open (a state in which no current is applied to the solenoid). [Figure 5] FIG. 10 is a longitudinal cross-sectional view illustrating the configuration of a solenoid valve according to a second embodiment of the present disclosure, showing a fully closed state (a state in which the solenoid is energized) in which both the pilot valve and the main valve are closed. [Figure 6] FIG. 10 is a vertical cross-sectional view illustrating the configuration of a solenoid valve according to a third embodiment of the present disclosure, showing a fully open state in which both the pilot valve and the main valve are open (a state in which no current is applied to the solenoid). [Figure 7] FIG. 10 is a longitudinal cross-sectional view illustrating the configuration of a solenoid valve according to a third embodiment of the present disclosure, showing a fully closed state (a state in which the solenoid is energized) in which both the pilot valve and the main valve are closed. [Figure 8] 10 is a flowchart illustrating control of a fault diagnosis of a solenoid valve according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] [First embodiment] A solenoid valve 100 according to a first embodiment of the present disclosure will be described with reference to FIGS. Here, Fig. 1 is a diagram for explaining the configuration of a solenoid valve 100 according to this embodiment, showing the fully open state, and Fig. 2 shows the fully closed state. In the following description of the embodiment, the up / down, left / right, and inside / outside directions indicate directions within the plane of Fig. 1 and Fig. 3, and are not to be construed as narrowing the technical scope of the present disclosure.

[0024] The solenoid valve 100 of this embodiment is a pilot-operated solenoid valve that can be used in the refrigeration cycle of an automotive air conditioner, etc., and includes a main valve section 10 and a pilot valve section 20 within a valve body 30. The opening and closing of the main valve section 10 controls the opening and closing of a fluid flow between a fluid inlet 31 and an outlet 32. The inlet 31 and the outlet 32 ​​are formed in the valve body 30, which serves as a valve body. A main valve chamber 33 is provided between the inlet 31 and the outlet 32. As described below, a main valve element 40, which is an example of a valve element of the present disclosure, is housed within the main valve chamber 33 so as to be slidable up and down. The main valve section 10 is formed on one side (lower in the illustrated embodiment) of the sliding direction of the main valve element 40, and the pilot valve section 20 is formed on the other side (upper in the illustrated embodiment). Female threads 30b and 30c are formed in the valve body 30. The valve body 30 and the main valve element 40 are made of an aluminum material, such as aluminum or an aluminum alloy.

[0025] A cylindrical plunger 50, which slides a pilot valve element 60, is disposed in a pipe 51 that is open downwards, at the center of the upper part of the solenoid valve 100. A cylindrical magnet 102 is inserted and fixed in the upper end of the hole in the plunger 50. As an example, the magnet 102 is magnetized with a south pole on one radial side and a north pole on the opposite radial side. The arrow Lm in the figure indicates the magnetic field lines. Since the plunger 50 of this embodiment is formed in a cylindrical shape, it is lighter in weight than a plunger formed in a columnar shape.

[0026] The pilot valve element 60 is connected to the plunger 50 and is configured to slide up and down within the pipe 51 together with the plunger 50. That is, the plunger 50 slides up and down within the pipe 51 by the operation of the solenoid 70. An attractor 80 is provided as a means for driving the plunger 50 by the operation of the solenoid 70. The attractor 80, made of magnetic stainless steel, becomes magnetized when current is applied to the solenoid 70 by appropriate control means (not shown). This magnetizes the plunger 50 by overcoming the resilience of a spring 52, which is a compression coil spring, disposed between the attractor 80 and the plunger 50, thereby attracting the plunger 50 downward. The pipe 51 that houses the plunger 50 is open downward and is fixed to the attractor 80 by appropriate means such as crimping or welding. The solenoid 70 is configured by surrounding a bobbin 70b, around which a coil 70a is wound, with a yoke 70c made of a magnetic material. A protruding portion 70d that protrudes outward is formed on the lower side (valve body side) of the yoke 70c.

[0027] A cover 104 that covers the solenoid 70 is provided on the top of the valve body 30 . The cover 104 has an open top, and the opening at the top is closed by a lid 104A. Inside the cover 104, a control board 106 serving as a control device is provided above the plunger 50 with a gap therebetween.

[0028] As an example, a magnetic sensor 108 that detects the strength of magnetic flux density is provided on the underside of control board 106, and electrical components such as a microcomputer 110 are mounted on the upper surface of control board 106. By arranging magnetic sensor 108 on the outside of pipe 51 in this way, it is not necessary to form a hole in pipe 51 through which wiring that outputs a signal from magnetic sensor 108 passes and to seal the gap between the hole and the wiring with a sealant or the like to prevent the fluid in pipe 51 from leaking to the outside air, thereby simplifying the configuration.

[0029] Although the magnetic sensor 108 in this embodiment is a Hall element, a magnetic sensor other than a Hall element, such as a magnetoresistive element, can also be used.

[0030] The microcomputer 110 can detect the position of the plunger 50 from the strength of the magnetic flux density detected by the magnetic sensor 108. That is, when the magnet 102 is located close to the magnetic sensor 108, the magnetic flux density is strong and the Hall output voltage is high, and when the magnet 102 is located far from the magnetic sensor 108, the magnetic flux density is weak and the Hall output voltage is low; therefore, by measuring the Hall output voltage, it is possible to detect whether the magnet 102 is close or far away, i.e., the position of the plunger 50.

[0031] In this embodiment, the magnetic sensor 108 is located above the plunger 50 in the axial direction. A female connector 112 is provided on the side of the cover 104 for electrically connecting the electrical circuit of the control board 106 with an external device (not shown) of the air conditioning system. One example of the external device is an air conditioner ECU of an automotive air conditioner. Electrical signals are sent and received between the control board 106 and the external device. The control board 106 can control the power supply to the solenoid 70 (for example, by turning it on and off) in response to instructions from the external device.

[0032] The aspirator 80 has an overall multi-stage cylindrical shape with through holes formed at the top and bottom, and the pipe 51 is attached to it. In this state, the aspirator 80 is inserted or screwed into the upper large-diameter hole 30a formed in the valve body 30. Then, the male screw 71 is inserted into the through hole formed in the protruding portion 70d of the solenoid 70 inserted around the outer periphery of the pipe 51, and screwed into the female screw formed in the valve body 30, thereby pressing and fixing the aspirator 80 to the valve body 30. The cylindrical shape of the aspirator 80 roughly consists of an upper small-diameter portion 81 and a lower large-diameter portion 82. The lower open end of the pipe 51 is fixed to the small-diameter portion 81, and the large-diameter portion 82 is fixed to the valve body 30 as described above. The plunger 50 is housed in the pipe 51 fixed to the small-diameter portion 81 so that it can slide up and down.

[0033] A cylindrical main valve element accommodating section (space) 82a is formed inside the large diameter section 82 of the suction element 80, and the main valve element 40 is accommodated in this main valve element accommodating section 82a so that it can slide up and down. The space is divided into upper and lower sections by the main valve element 40, with the lower section serving as the main valve chamber 33 and the upper section serving as the pilot valve chamber 34. The outside of the large diameter section 82 of the suction element 80 is sealed from the valve body 30 by an appropriate O-ring 83, and the inside of the large diameter section 82 is sealed from the outer peripheral surface of the main valve element 40 (the portion that slides with the suction element 80) that slides inside the large diameter section 82 by an appropriate main valve element sealing 43, preventing refrigerant leakage.

[0034] By configuring as described above, the inside of the pipe 51 is in communication with the pilot valve chamber 34 side but is isolated from the outside air.

[0035] In the illustrated embodiment of the present disclosure, the small diameter portion 81 and the large diameter portion 82 of the suction element 80 are integrated into a cylindrical member with a step interposed therebetween as a single member. However, depending on the embodiment, the small diameter portion 81 and the large diameter portion 82 may be formed as separate members and fixed together by appropriate means, although this is not shown. The key is that the suction element 80 must be able to attract and drive the plunger 50 when current is applied to the solenoid 70. In the present disclosure, the member that drives the plunger 50 by attraction and accommodates the main valve body 40 so that it can slide up and down is referred to as the suction element. It does not matter whether the suction element 80 is formed from a single member or multiple members.

[0036] The main valve section 10 is made up of a main valve packing 41 attached to the underside of the main valve element 40 and a main valve seat 35 formed between the inlet 31 and the outlet 32 ​​of the valve body 30, while the pilot valve section 20 is made up of a pilot valve packing 61 attached to the underside of the pilot valve element 60 and a pilot valve seat 42 formed on the upper side of the main valve element 40. A pilot passage 45 and a pressure equalizing hole 44 are formed in the main valve element 40. The pilot valve seat 42 is provided at the end of the pilot passage 45. The pressure equalizing hole 44 communicates between the main valve chamber 33 and the pilot valve chamber 34, and the cross-sectional area of ​​the pressure equalizing hole 44 is smaller than the cross-sectional area of ​​the pilot passage 45.

[0037] The formation of this pressure equalizing hole 44 equalizes the pressure in the main valve chamber 33 and the pilot valve chamber 34, facilitating and smoothing the opening and closing operation of the main valve element 40. Furthermore, when the main valve portion 10 is in the closed state, even if there is a sudden change in pressure from a compressor (not shown) connected to the solenoid valve 100, such as when the compressor is started, the refrigerant in the main valve chamber 33 quickly flows out to the pilot valve chamber 34, preventing the main valve portion 10 from opening or making it difficult to open.

[0038] In this solenoid valve 100, the valve body 30 and the main valve element 40 are made of an aluminum material such as aluminum or an aluminum alloy, and the attractor 80 is made of magnetic stainless steel. The entire main valve element 40, or at least the surface of the main valve element 40 that slides against the main valve element accommodating portion 82a of the attractor 80, is made of an anodized aluminum layer.

[0039] (Action, effect) Next, the operation of the solenoid valve 100 will be described with reference to Figures 1 to 3, taking as an example a case where the solenoid valve 100 is applied to a refrigeration cycle. Figure 1 shows a state where the solenoid 70 (coil 70a) is not energized. In this case, no suction force is generated in the attractor 80, so the spring 52 causes the plunger 50 to be lifted upward within the pipe 51, and the pilot valve portion 20 is in an open state. In addition, the main valve element 40 is lifted upward within the main valve chamber 33 by the spring 46, and the main valve portion 10 is in an open state.

[0040] If the compressor (not shown) is operated in this state, for example, high-temperature, high-pressure refrigerant flows from the inlet 31 through the main valve element 10 that is open in the main valve chamber 33 and through the outlet 32. Furthermore, the amount of refrigerant flowing from the pilot valve chamber 34 to the main valve chamber 33 via the pilot passage 45 is greater than the amount of refrigerant flowing from the main valve chamber 33 to the pilot valve chamber 34 via the pressure equalizing hole 44. Therefore, the pressure in the pilot valve chamber 34 becomes smaller than the pressure in the main valve chamber 33, and an upward force is generated on the main valve element 40. Together with the elastic force of the main valve element spring 46, the main valve element 10 is kept in a sufficiently open state, and the flow from the inlet 31 to the outlet 32 ​​is maintained.

[0041] Next, when the solenoid 70 is energized in the state shown in Fig. 1, the attractor 80 and the plunger 50 are magnetized, generating an electromagnetic attractive force between them, which pulls the plunger 50 down against the resilient force of the spring 52. Because the pilot valve element 60 is fixed integrally to the lower part of the plunger 50, the pilot valve element 60 slides up and down within the pipe 51 in unison with the movement of the plunger 50. The attractive force of the attractor 80 pulls the plunger 50 down, and at the same time, the pilot valve element 60 also slides downward. As a result, the pilot valve packing 61 provided below the pilot valve element 60 abuts against the pilot valve seat 42 formed on the upper side of the main valve element 40, which closes the pilot valve portion 20 as shown in Fig. 2 (i.e., blocks the pilot passage 45).

[0042] When the pilot passage 45 is closed, the only passage connecting the pilot valve chamber 34 and the main valve chamber 33 is the pressure equalizing hole 44, eliminating the pressure difference between the two valve chambers. When the plunger 50 further presses the main valve element 40 downward and slides it to its lowest point, the main valve packing 41 formed on the lower side of the main valve element 40 abuts against the main valve seat 35 formed in the valve body 30, closing the main valve unit 10. As a result, as shown in Figure 2, the main valve unit 10 is also closed, and the flow path of the fluid, such as the refrigerant, is closed, preventing it from flowing from the inlet 31 to the outlet 32.

[0043] Next, when the power supply to the solenoid 70 is stopped in the state shown in FIG. 2, the electromagnetic attraction force of the attractor 80 by the solenoid 70 is lost, the plunger 50 is pushed upward by the elastic force of the spring 52, the pilot valve body 60 moves upward together with the plunger 50, the pilot valve packing 61 separates from the pilot valve seat 42 provided on the upper surface side of the main valve body 40, and the pilot valve portion 20 enters the open state, resulting in the state shown in FIG. 3.

[0044] As a result, the pilot valve chamber 34 is connected to the outlet 32 ​​via the pilot passage 45 provided in the center of the main valve body 40, and the pressure in the pilot valve chamber 34 changes from high to low.

[0045] As a result, the main valve element 40 moves upward, and the main valve packing 41 fixed to the underside of the main valve element 40 separates from the main valve seat 35, resulting in an open valve state, as shown in FIG.

[0046] (Plunger position detection) In the solenoid valve 100 of this embodiment, the plunger 50 moves in response to an instruction from an external device to turn on or off the power supply to the solenoid 70. However, even when the power supply to the solenoid 70 is turned on or off, there are cases where the plunger 50 does not move for some reason.

[0047] In this embodiment, the position of the plunger 50 can be detected as follows, and a fault diagnosis of the solenoid valve 100 can be performed. The fault diagnosis of the solenoid valve 100 will be described below with reference to the flowchart shown in FIG.

[0048] In step 100, the solenoid 70 (coil 70a) is not energized (energization OFF), and the valve is in an open state (see FIG. 1).

[0049] In step 102, it is determined whether the magnetic flux density detected by the magnetic sensor 108 is large (difference). Specifically, if it is determined that the magnetic flux density exceeds a preset value, it is determined that the magnet 102 is approaching the magnetic sensor 108, i.e., the plunger 50 is moving upward, the main valve packing 41 is separated from the main valve seat 35, and the main valve unit 10 is in an open state.

[0050] On the other hand, if it is determined that the magnetic flux density is equal to or less than a preset value, it is determined that the magnet 102 is away from the magnetic sensor 108, and therefore the plunger 50 is not in the correct position when the power supply to the solenoid 70 is stopped. Here, not being in the correct position means, for example, that the plunger 50 has moved downward as shown in Figure 2 (the main valve packing 41 is in contact with the main valve seat 35 formed in the valve body 30, and the main valve section 10 is in a closed state).

[0051] If it is determined in step 102 that the main valve unit 10 is in an open state, the process proceeds to step 104, and if it is determined that the main valve unit 10 is in a closed state, the process proceeds to step 116. In step 116, for example, an external device can use a display device (not shown) or the like to notify the user that the solenoid valve 100 has failed.

[0052] In step 104, the solenoid 70 is energized to change the main valve portion 10 from an open state to a closed state.

[0053] In the next step 106, the magnitude of the magnetic flux density detected by the magnetic sensor 108 is determined. If it is determined that the magnetic flux density is equal to or less than a preset value, it means that the plunger 50 has moved downward, and the process proceeds to step 108. On the other hand, if it is determined that the magnetic flux density exceeds the preset value, it means that the plunger 50 has not moved downward even though the solenoid 70 is energized, and the process proceeds to step 116, where a fault is notified to an external device.

[0054] In the next step 108, the solenoid 70 is de-energized to change the main valve portion 10 from the closed state to the open state.

[0055] In the next step 110, it is determined whether the magnetic flux density detected by the magnetic sensor 108 is large or small. If it is determined that the magnetic flux density exceeds a preset value, it means that the magnet 102 is approaching the magnetic sensor 108, the plunger 50 has moved upward, and the main valve unit 10 is in an open state, so the process proceeds to step 112.

[0056] On the other hand, if it is determined that the magnetic flux density is equal to or less than the preset value, the magnet 102 is separated from the magnetic sensor 108, and the plunger 50 does not move upward even when the power supply to the solenoid 70 is stopped, so that the main valve unit 10 is in a closed state. In this case, the process proceeds to step 116, and a fault is notified to external devices.

[0057] In the next step 112, an instruction to stop the fault diagnosis is received from the external device, and in step 114, it is determined whether or not the instruction to stop the fault diagnosis has been received. If it is determined in step 114 that an instruction to stop the fault diagnosis has been received, the process ends, and if it is determined that an instruction to stop the fault diagnosis has not been received, the process returns to step 100 and the fault diagnosis continues.

[0058] In the solenoid valve 100 of this embodiment, by performing the failure diagnosis described above, the position of the plunger 50 can be detected to detect a failure of the solenoid valve 100, in this case, it is possible to detect the open / closed state of the main valve unit 10. Furthermore, the solenoid valve 100 configured in this embodiment can constantly detect the position of the plunger 50 regardless of whether the solenoid 70 is energized or not, by detecting the magnetic flux density with the magnetic sensor 108.

[0059] Furthermore, in the solenoid valve 100 of this embodiment, a failure of the solenoid valve 100 can be detected with a simple configuration in which the magnetic sensor 108 detects the magnitude of the magnetic flux density of the magnet 102 .

[0060] If the magnetic field lines of the solenoid 70 affect the detection of the magnetic flux density of the magnet 102 by the magnetic sensor 108, as an example, a magnetic shield 116 made of an electromagnetic steel plate or the like may be provided above the solenoid 70, as shown in FIG.

[0061] [Second embodiment] A solenoid valve 100 according to a second embodiment of the present disclosure will be described with reference to FIGS.

[0062] In the solenoid valve 100 of this embodiment, the positions of the control board 106 and the magnetic sensor 108 are different from those of the first embodiment. In this embodiment, the control board 106 is positioned lower than in the first embodiment, and the upper end of the pipe 51 passes through the center of the control board 106.

[0063] The magnet 102 used in the second embodiment is magnetized so that one side in the vertical direction is the south pole and the other side is the north pole, and the magnetic sensor 108 is magnetic field lines Lm is provided at a position close to the side of the pipe 51 so that it passes through the magnetic sensor 108.

[0064] In the solenoid valve 100 of this embodiment, as in the first embodiment, the magnetic flux density of the magnet 102 detected by the magnetic sensor 108 changes depending on the position of the plunger 50, so that a failure of the solenoid valve 100 can be detected in the same manner as in the first embodiment.

[0065] [Third embodiment] A solenoid valve 100 according to a third embodiment of the present disclosure will be described with reference to FIGS. FIG. 6 shows the main valve unit 10 in an open state, and FIG. 7 shows the main valve unit 10 in a closed state.

[0066] Unlike the first and second embodiments, the solenoid valve 100 of this embodiment does not have a magnet 102 provided on the plunger 50, but is configured such that the magnetic sensor 108 detects the magnetic field lines Lm of the solenoid 70, as shown by the arrow in FIG. 6.

[0067] An example of fault diagnosis of the solenoid valve 100 will now be described with reference to the flowchart shown in FIG.

[0068] In step 200, the solenoid 70 is energized (ON) to change the main valve portion 10 from the open state shown in FIG. 6 to the closed state shown in FIG.

[0069] In the next step 202, while the solenoid 70 is energized (ON), the magnitude of the magnetic flux density detected by the magnetic sensor 108 is determined.

[0070] If it is determined that the magnetic flux density exceeds a preset value, the plunger 50 is positioned upward, i.e., the plunger 50 is not in the correct position when the solenoid 70 is energized (ON), and the main valve unit 10 remains in an open state. Therefore, the process proceeds to step 206, where an external device is notified of the malfunction.

[0071] On the other hand, if it is determined that the magnetic flux density is equal to or less than the preset value, the plunger 50 has moved downward and the main valve portion 10 is in a closed state, so the process proceeds to step 204.

[0072] In step 204, the solenoid 70 is de-energized (turned off) to change the main valve portion 10 from a closed state to an open state.

[0073] In the next step 208, it is determined whether or not an instruction to stop the fault diagnosis has been received from an external device. If it is determined that an instruction to stop the fault diagnosis has been received, the process is terminated; if it is determined that an instruction to stop the fault diagnosis has not been received, the process returns to step 200 and the fault diagnosis continues.

[0074] In the solenoid valve 100 of this embodiment, by performing the failure diagnosis described above, it is possible to detect whether or not the plunger 50 has moved to the correct position when the solenoid 70 is energized. Furthermore, in the solenoid valve 100 of this embodiment, a failure of the solenoid valve 100 can be detected with a simple configuration in which the magnetic sensor 108 detects the magnitude of the magnetic flux density of the solenoid 70 that has passed through the plunger 50 .

[0075] [Other embodiments] The above describes one embodiment of the present disclosure, but the present disclosure is not limited to the above, and it goes without saying that various modifications can be made to the present disclosure without departing from the spirit of the present disclosure.

[0076] In the above embodiment, the solenoid valve 100 is a pilot-operated solenoid valve, and the magnet 102 is attached to the plunger 50 of the pilot-operated solenoid valve to detect the position of the plunger 50. However, it is of course possible to attach the magnet 102 to the plunger of a normal solenoid valve that is not provided with a pilot valve, and detect the position of the plunger.

[0077] In addition, the control board 106 as a control device notifies external devices of failures and controls the on / off of the power supply to the solenoid 70. It is also capable of detecting abnormalities such as voltage abnormalities, temperature abnormalities (if a temperature sensor is provided to measure the temperature of the solenoid 70), and coil breaks in the solenoid 70 (compatible with On Board Diagnostics (vehicle self-diagnosis)), and can also reduce power consumption by, for example, lowering the current value that is passed through when the load is low. [Explanation of symbols]

[0078] 30 Valve body 31 Inlet 32 Outlet 33 Main valve chamber 35 Main valve seat (valve seat) 40 Main valve body (valve body) 50 plunger 51 Pipe 52 Spring (compression coil spring) 70 Solenoid 70a coil 80 Aspirator 100 Solenoid valve 102 Magnet 108 Magnetic Sensor

Claims

1. a valve body having an inlet and an outlet for a fluid, and a valve seat and a valve chamber formed therebetween; a pipe provided in the valve body, the inside of which is in communication with the valve chamber and is isolated from the outside air; a valve body that is disposed in the valve chamber and is movable toward and away from the valve seat; a plunger that is arranged to slide up and down within the pipe and moves the valve body in a direction toward and away from the valve seat; a solenoid wound with a coil for driving the plunger; a magnet attached to the plunger; a magnetic sensor located outside the pipe and on a side of the pipe within the valve body, the magnetic sensor detecting the magnetic flux density of the magnet; Equipped with the plunger is cylindrical; The magnet is inserted into and fixed to the upper end of the plunger hole.

2. 2. The solenoid valve according to claim 1, wherein the magnet is magnetized so that one side in the vertical direction is a south pole and the other side is a north pole.

3. a magnetic stainless steel attractor that connects the pipe and the valve body; A compression coil spring is disposed between the attractor and the plunger. The solenoid valve according to claim 1 .

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