Solenoid valve and fluid system

Abstract

The valve body includes an inflow passage for the working fluid, an outflow passage for the working fluid, and a pressure relief passage that bypasses a normally closed valve seat to communicate the inflow passage with the outflow passage. A pressure relief valve is disposed in the pressure relief passage. When the pressure of the working fluid in the outflow passage is lower than the pressure of the working fluid in the inflow passage, equal to the pressure of the working fluid in the inflow passage, and higher than the pressure of the working fluid in the inflow passage and the pressure difference is less than a predetermined pressure relief pressure, the pressure relief valve closes the pressure relief passage. When the pressure of the working fluid in the outflow passage is higher than the pressure of the working fluid in the inflow passage and the pressure difference is above the pressure relief pressure, the pressure relief valve opens the pressure relief passage.

Description

[0001] Cross - reference to related applications

[0002] This application is based on Japanese Patent Application No. 2020 - 44325 filed on March 13, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical field

[0003] The present disclosure relates to a solenoid valve that opens and closes a flow path of a working fluid, a fluid system including the solenoid valve, for example, suitable for controlling a flow path of a cleaning liquid. Background art

[0004] Sometimes, a solenoid valve is used to open and close a flow path of a working fluid. The solenoid valve can be used to switch the flow path of the working fluid. In this case, it is necessary to prevent leakage of the working fluid.

[0005] For example, Patent Document 1 discloses a structure that uses a solenoid valve to switch a flow path of a cleaning liquid. In this technology, the cleaning liquid flows to a window glass in a state where the solenoid valve is not energized, and flows to a rear - view camera when the solenoid valve is energized.

[0006] Prior art documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014 - 66309 Summary of the invention

[0009] For example, downstream of the solenoid valve, the pressure of the working fluid sometimes fluctuates. In this case, it is desirable to prevent leakage of the working fluid. In view of the above viewpoints or other viewpoints not mentioned, it is necessary to further improve the solenoid valve and the fluid system including the solenoid valve.

[0010] An object of the present disclosure is to prevent outflow of an undesired working fluid even when the pressure of the working fluid in a normally - closed pipe rises.

[0011] The first disclosure of the present disclosure includes: a coil that is excited when energized, a core disposed in a magnetic circuit of the coil, a plunger disposed in the magnetic circuit of the coil opposite to the core across a magnetic gap, a valve element that moves with the plunger, and a normally - closed compression spring that presses the valve element toward a normally - closed valve seat. A solenoid valve that moves the valve element by a coil exciting force generated by energization of the coil is normally closed, and the valve seat is closed by the valve element when not energized.

[0012] In addition, the first disclosure also includes a valve body having an inflow passage for the working fluid, an outflow passage for the working fluid, a normally closed valve seat formed between the inflow passage and the outflow passage and abutted by the valve core, and a pressure relief passage that bypasses the normally closed valve seat to connect the inflow passage and the outflow passage. In the first disclosure, even when the normally closed valve seat is closed, the inflow passage and the outflow passage can be communicated through the pressure relief passage.

[0013] In the first disclosure, a pressure relief valve is disposed in the pressure relief passage portion within the valve body. When the pressure of the working fluid in the outflow passage is lower than the pressure of the working fluid in the inflow passage, equal to the pressure of the working fluid in the inflow passage, and higher than the pressure of the working fluid in the inflow passage and the pressure difference is less than a predetermined pressure relief pressure, the pressure relief valve closes the pressure relief passage. And when the pressure of the working fluid in the outflow passage is higher than the pressure of the working fluid in the inflow passage and the pressure difference is above the pressure relief pressure, the pressure relief valve opens the pressure relief passage.

[0014] In the first disclosure, by opening the pressure relief valve, it is possible to prevent the pressure of the working fluid in the outflow passage from rising above a predetermined pressure relief pressure.

[0015] In the second disclosure of the present disclosure, as the outflow passage, there are included two passages, namely a normally closed outflow passage and a normally open outflow passage. Moreover, a normally closed valve seat and a normally open valve seat are formed on the valve body.

[0016] In the second disclosure, when the coil is energized, the working fluid from the inflow passage flows to the normally closed outflow passage, and when the coil is not energized, the working fluid flows to the normally open outflow passage. Thus, the flow of the working fluid can be switched by energizing and de-energizing the coil.

[0017] In the third disclosure of the present disclosure, the cross-sectional area of the pressure relief passage is smaller than the cross-sectional areas of the inflow passage and the outflow passage. The pressure relief passage only needs to be able to release pressure and does not need to flow a large amount of working fluid. By reducing the cross-sectional area, miniaturization of the valve body can be achieved.

[0018] The fourth disclosure of the present disclosure relates to the structure of the pressure relief valve. The pressure relief valve includes a pressure relief valve seat formed in the pressure relief passage, a pressure relief valve core disposed on the inflow passage side of the pressure relief valve seat, and a pressure relief spring that pushes the pressure relief valve core toward the pressure relief valve seat side. Pressure relief can be performed with a simple structure of pushing the pressure relief valve core toward the pressure relief valve seat.

[0019] The fifth disclosure of the present disclosure also relates to the structure of the pressure relief valve. The pressure relief passage is circular tubular, the pressure relief valve core is cylindrical and slides within the circular tubular pressure relief passage, and pressure relief grooves are formed on the circumferential surface of the cylindrical pressure relief valve core.

[0020] Since the pressure relief valve core is guided by the pressure relief passage, the movement of the pressure relief valve core can proceed smoothly. In a state where the pressure relief valve core is separated from the pressure relief valve seat, the pressure of the working fluid can be released by using the pressure relief groove.

[0021] The sixth disclosure of the present disclosure also relates to the structure of a pressure relief valve. As the pressure relief valve, a duckbill valve having a slit formed at the tip is used. The pressure relief valve can be configured with a simpler structure.

[0022] The seventh disclosure of the present disclosure is a fluid system including a solenoid valve. The fluid system includes: a tank for the working fluid; a pump that sucks the working fluid from the tank and discharges the working fluid at high pressure; a pipe through which the working fluid from the pump flows; a stop valve that is disposed in the pipe and opens the pipe when the pressure of the working fluid in the pipe is equal to or higher than the release pressure and blocks the pipe when the pressure of the working fluid in the pipe is less than the release pressure; and the solenoid valve described above. The solenoid valve is disposed between the pump and the stop valve.

[0023] Moreover, the pressure relief pressure of the pressure relief valve of the solenoid valve is set to be less than the release pressure of the stop valve. In this fluid system, the pressure of the working fluid in the pipe can always be made less than the release pressure. As a result, an undesired leakage of the working fluid can be prevented. Description of the Drawings

[0024] Figure 1 is a diagram for explaining the piping structure of the solenoid valve.

[0025] Figure 2 is a sectional view of the solenoid valve according to the first embodiment.

[0026] Figure 3 is Figure 2 a perspective view of the solenoid valve shown.

[0027] Figure 4 is Figure 2 a sectional view taken along line IV-IV of

[0028] Figure 5 is Figure 2 a perspective view of the valve core shown.

[0029] Figure 6 is Figure 2 a top view of the valve core shown.

[0030] Figure 7 is Figure 2 a perspective view of the pressure relief valve core shown.

[0031] Figure 8 is Figure 2 a top view of the pressure relief valve core shown.

[0032] Figure 9It is a cross-sectional view of the solenoid valve of the second embodiment.

[0033] Figure 10 It is a cross-sectional view of the solenoid valve of the third embodiment.

[0034] Figure 11 It is Figure 10 the perspective view of the duckbill valve shown.

[0035] Figure 12 It is a cross-sectional view of the solenoid valve of the fourth embodiment.

[0036] Figure 13 It is Figure 12 the cross-sectional view along line XIII-XIII of

[0037] Figure 14 It is a cross-sectional view of the solenoid valve of the fifth embodiment.

[0038] Figure 15 It is a cross-sectional view of the solenoid valve of the sixth embodiment.

[0039] Figure 16 It is a cross-sectional view of the solenoid valve of the seventh embodiment.

[0040] Figure 17 It is a cross-sectional view of the solenoid valve of the eighth embodiment.

[0041] Figure 18 It is a diagram for explaining other piping structures of the solenoid valve.

[0042] Figure 19 It is a cross-sectional view of the solenoid valve of the ninth embodiment. Detailed implementation mode

[0043] First embodiment

[0044] The first embodiment is Figure 1 the fluid system shown. The fluid system controls the behavior of the working fluid in the piping 102. The fluid system provides a control device that controls the behavior of the working fluid including pressure. Figure 1 It shows the fluid system in the cleaning system of a vehicle. Figure 1 The fluid system shown uses a three-way valve for switching the flow path as the solenoid valve 200 (EMV). In Figure 1 it, the cleaning liquid in the tank 110 is pressurized by the pump 120 and supplied to the solenoid valve 200.

[0045] A shut-off valve 101 that opens under a certain pressure is arranged in front of a nozzle 100 (NZL) that sprays a cleaning liquid. The shut-off valve 101 is arranged in a pipe 102 between a solenoid valve 200 and the nozzle 100. When the pressure of the working fluid in the pipe 102 is equal to or higher than the release pressure, the shut-off valve 101 opens the pipe. When the pressure of the working fluid in the pipe 102 is less than the release pressure, the shut-off valve 101 blocks the pipe. The shut-off valve 101 has a setting member such as a spring for setting the release pressure. By closing the cleaning liquid in the pipe 102 with the shut-off valve 101, the responsiveness during the next operation can be improved.

[0046] The solenoid valve shown in Japanese Patent Application Laid-Open No. 2014-66309 can be used as Figure 1 the solenoid valve 200 shown. The cleaning liquid in a pipe (hereinafter referred to as a normally closed pipe 102a) blocked in a state where the solenoid valve 200 is not energized is closed between the solenoid valve 200 and the shut-off valve 101.

[0047] Therefore, when the temperature of the pipe 102 rises, the air and the cleaning liquid in the normally closed pipe 102a expand, and the internal pressure rises. Regarding the solenoid valve of Japanese Patent Application Laid-Open No. 2014-66309, since the normally closed pipe is connected to a rearview camera, there is a concern that when the internal pressure rises above the release pressure set by the shut-off valve 101, the shut-off valve 101 will open and the cleaning liquid will drip onto the rearview camera.

[0048] On the other hand, Figure 1 the nozzle 100 of the normally closed pipe 102a shown faces the rear window glass 130, and sprays the cleaning liquid onto the rear window glass 130 (RWG). The nozzle of the normally open pipe 102b sprays the cleaning liquid onto a camera 131 (CAM). Different from Japanese Patent Application Laid-Open No. 2014-66309, in the present disclosure, when the solenoid valve 200 is not energized, the cleaning liquid from a pump 120 is sprayed onto the camera 131. The reason is that the usage frequency of the camera 131 is higher than that of the rear window glass 130.

[0049] As Figure 2 、 Figure 3 and Figure 4 shown, in the solenoid valve 200, a coil 205 including copper wires is wound around the periphery of a bobbin 204 made of resin. A stator 211 is arranged on the inner periphery of the bobbin 204 with a sleeve 210 interposed therebetween. In addition, the sleeve 210 is made of a non-magnetic material such as SUS304. On the other hand, the stator 211 is made of a magnetic material such as SUS430.

[0050] In addition, the outer periphery of the bobbin 204 is covered with a housing 220 made of resin. The housing 220 is integrally formed with the connector 202. A pair of terminals 221 are embedded and formed in the connector 202, and the pair of terminals 221 are respectively connected to the positive electrode side and the negative electrode side of the coil 205.

[0051] A core 206 made of a magnetic material is disposed inside the bobbin 204. The core 206 has a cylindrical shape with a closed upper end. The open end of the core 206 has a concave conical shape.

[0052] A plunger 209 is disposed opposite to the conical portion of the core 206. The plunger 209 has a cylindrical shape. The upper end of the plunger 209 has a convex conical shape corresponding to the conical shape of the core 206. The plunger 209 has a shoulder 209a continuous with the upper end of the conical shape, and a washer 208 is engaged with the shoulder 209a. The washer 208 is made of a non-magnetic material such as SUS304, for example. The washer 208 prevents the core 206 made of a magnetic material and the plunger 209 from being attracted to each other due to the residual magnetic force after the power supply to the coil 205 is terminated. In addition, the plunger 209 is guided by the cylindrical portion 211a of the stator 211. The plunger 209 can move in the Figure 2 vertical direction.

[0053] A normally closed compression spring 207 that applies a force in a direction to move the plunger 209 away from the core 206 is disposed inside the core 206. A yoke 201 is disposed on the outer periphery of the housing 220 of the bobbin 204. The yoke 201 is made of a magnetic material, steel. When the coil 205 is energized, a magnetic circuit is formed through the yoke 201, the core 206, the plunger 209, and the stator 211.

[0054] With the above structure, the electromagnetic unit 230 is constituted. The electromagnetic unit 230 is coupled to the flow path unit 240 via an O-ring 213. The flow path unit 240 provides a valve body. The valve body is divided into an upper main body 212 and a lower main body 219.

[0055] An inflow passage 222 and a normally open outflow passage 223 are formed in the upper main body 212. The inflow passage allows high-pressure cleaning liquid from the pump 120 to flow in, and the normally open outflow passage is connected to the normally open pipe 102b leading to the camera 131. The outer periphery of the end of the inflow passage 222 and the outer periphery of the end of the normally open outflow passage 223 have a conical shape to facilitate the connection of the pipe 102. A shoulder 224 is formed at the conical end to prevent the pipe 102 from falling off.

[0056] A valve chamber 225 is formed in the upper main body 212. The valve chamber 225 communicates with the inflow passage 222 via a communication hole 226. The valve chamber 225 communicates with the normally open outflow passage 223 via a normally open valve seat 227.

[0057] On the upper part of the upper main body 212, a connecting portion 241 connected to the electromagnetic portion 230 is formed. The connecting portion 241 is in the shape of a circular tube, and a plunger 209 is arranged inside. In addition, the upper part of the connecting portion 241 expands. The connecting portion 241 provides a surface 242 for receiving the O-ring 213 and a shoulder 243 for engaging with the yoke 201.

[0058] In the lower main body 219, a normally closed outflow passage 228 is formed, and the normally closed outflow passage is connected to a normally closed pipe 102a facing the rear window glass 130. The end portion is in a tapered shape, and a shoulder 224 is formed, which is the same as the above-mentioned inflow passage 222 and normally open outflow passage 223. The inner diameters of the normally closed outflow passage 228, the inflow passage 222, and the normally open outflow passage 223 are all about 3 mm in size.

[0059] In the lower main body 219, a cylindrical normally closed valve seat 229 protruding into the valve chamber 225 is formed. A valve core 214 is arranged in the valve chamber 225 between the normally open valve seat 227 and the normally closed valve seat 229. The valve core 214 is a movable valve core operated by electromagnetic force. The valve core 214 has a three-dimensional shape occupying a predetermined volume. The valve core 214 has two sealing surfaces that can alternatively seat on the normally open valve seat 227 and the normally closed valve seat 229. The valve core 214 is a double-sided valve core having sealing surfaces at both axial ends. The valve core 214 is spherical. In addition, the normally open valve seat 227 and the normally closed valve seat 229 are in a concave tapered shape, and their inner diameters are both slightly smaller than 5 mm.

[0060] As Figure 5 and Figure 6 shown, the valve core 214 is a spherical shape with a diameter slightly larger than 7 mm. The valve core 214 has an annular spring support 214a at the equator portion. The spring support 214a protrudes from the spherical surface of the valve core 214 by slightly less than 1 mm. The valve core 214 and the spring support 214a are integrally formed of water-resistant rubber, and the surfaces of the valve core and the spring support are coated. This rubber material is the same as the O-ring 213. The coating material is a substance such as fluorine and molybdenum that prevents the surface of the rubber from melting and improves the adaptability between the valve core and the mating valve seat.

[0061] An normally open compression spring 231 is arranged on the outer periphery of the cylindrical normally closed valve seat 229. The inner diameter of the normally open compression spring 231 is slightly larger than the outer diameter of the normally closed valve seat 229. The normally open compression spring 231 is held by the normally closed valve seat 229. The normally open compression spring 231 engages with the spring support 214a of the valve core 214 and applies a force to the valve core 214 toward the normally open valve seat 227 side.

[0062] As a result, both the force of the normally closed compression spring 207 applied to the valve spool 214 via the plunger 209 and the force of the normally open compression spring 231 are exerted thereon. Among them, the force of the normally closed compression spring 207 is large enough compared to the force of the normally open compression spring 231. As a result, when the coil 205 is not energized, the valve spool 214 is pressed against the normally closed valve seat 229, thereby closing the normally closed outflow passage 228.

[0063] A pressure relief passage 232 is formed in the lower main body 219, and this pressure relief passage bypasses the normally closed valve seat 229 to connect the inflow passage 222 and the normally closed outflow passage 228. Also, a pressure relief passage 232 is formed in the upper main body 212. The inner diameter of the pressure relief passage 232 is about 2 mm. The pressure relief passage 232 is a circular passage with a circular inner cross-section. The pressure relief passage 232 may also be a circular tube.

[0064] A pressure relief valve 233 for opening and closing the pressure relief passage 232 is disposed in the upper main body 212. The pressure relief valve 233 includes a pressure relief valve seat 218, a pressure relief valve spool 217, and a pressure relief spring 216. The pressure relief valve seat 218 is made of a rubber material coated with fluorine on the surface, the same as the valve spool 214. The pressure relief valve seat 218 is clamped between the upper main body 212 and the lower main body 219.

[0065] The pressure relief valve spool 217 is made of resin. The pressure relief valve spool 217 has a cylindrical shape. The pressure relief valve spool 217 is configured to be movable along a pressure relief guide 234 formed in the upper main body 212. The outer diameter of the pressure relief valve spool 217 and the inner diameter of the pressure relief guide 234 are both slightly larger than 5 mm. The pressure relief valve spool 217 is a pressure-responsive movable valve spool that displaces in response to a pressure difference.

[0066] As Figure 7 and Figure 8 shown, three pressure relief grooves 217a are formed on the outer periphery of the pressure relief valve spool 217. The pressure relief grooves 217a are semi-circular with a radius of about 0.3 mm. On the upper surface of the pressure relief valve spool 217, a pressure relief spring seat 217b for receiving the pressure relief spring 216 protrudes in a cylindrical shape. The pressure relief valve spool 217 is a cylindrical valve spool that slides within the circular pressure relief passage 232. The pressure relief grooves 217a are formed on the outer peripheral surface of the cylindrical pressure relief valve spool 217.

[0067] Therefore, the pressure relief spring 216 is clamped between the pressure relief spring seat 217b and a spring seat formed at the lower end of the pressure relief passage 232 in the upper main body 212. The pressure relief spring 216 presses the pressure relief valve spool 217 toward the pressure relief valve seat 218. The set pressure (pressure relief pressure) of the pressure relief spring 216 is about 5 kPa. The pressure relief spring 216 provides a setting member for setting the pressure relief pressure. The pressure relief pressure is about half of the set pressure (release pressure) of the stop valve 101. Therefore, the pressure relief pressure is less than the release pressure.

[0068] Next, the assembly method of the solenoid valve 200 with the above structure will be described. First, the assembly method of the electromagnetic unit 230 will be described. The assembly method of the solenoid valve 200 includes: (i) the assembly process of the electromagnetic unit 230, (ii) the assembly process of the flow path unit 240, and (iii) the connection process of connecting the electromagnetic unit 230 and the flow path unit 240. These processes can be executed in the order of (i), (iii), (ii).

[0069] In the assembly process of the electromagnetic unit 230, multiple turns of the coil 205 are wound around the outer periphery of the bobbin 204, a pair of terminals 221 are connected to both ends of the coil 205, and in this state, the housing 220 and the connector 202 are molded with resin. As the resin, for example, polyphenylene sulfide (PPS: Polyphenylenesulfide) is used. Next, the core 206 and the stator 211 are assembled inside the bobbin 204 with the sleeve 210 interposed therebetween. After that, the yoke 201 is arranged on the outer periphery of the housing 220. In this way, the electromagnetic unit 230 is assembled.

[0070] In the connection process, an O-ring 213 is arranged on the upper surface 242 of the upper body 212. Next, the lower end of the yoke 201 is placed on the shoulder 243 of the upper body 212. Next, the edge of the lower end of the yoke 201 is riveted to wrap around the shoulder 243 of the upper body 212. Figure 4 The state after the riveting process is shown. The riveting process is performed within an arc range of 180 degrees or more in the edge of the yoke 201 except for the part where the connector 202 is located. As a result, the edge of the yoke 201 wraps around the shoulder 243.

[0071] Through the riveting of the yoke 201, the upper end of the upper body 212 abuts against the lower end of the stator 211. Through the riveting, the O-ring 213 is sandwiched between the lower end of the stator 211 and the upper surface 242 of the upper body 212 and is compressed and deformed.

[0072] The assembly method of the solenoid valve 200 includes the assembly process of the flow path unit 240. The assembly process of the flow path unit 240 includes the process of assembling the pressure relief valve 233 and the process of assembling the magnetically operated valve structure. These two processes are executed by assembly operations in the same direction. In the first process, the pressure relief spring 216 and the pressure relief valve core 217 are arranged in the pressure relief guide 234 of the upper body 212. After that, the pressure relief valve seat 218 is arranged at the opening of the pressure relief guide 234. In the second process, the valve core 214 is arranged on the normally open valve seat 227, and the normally open compression spring 231 is arranged to abut against the spring support 214a. In the first process and the second process, the common process is to combine the upper body 212 and the lower body 219. At this time, the pressure relief spring 216 and the normally open compression spring 231 are in a predetermined compressed state.

[0073] The flange 212a of the upper body 212 and the flange 219a of the lower body 219 are in a state of being in contact with each other. The assembling process includes a welding process of welding between the flange 212a and the flange 219a.

[0074] According to the present disclosure, after the electromagnetic unit 230 is assembled, the flow path unit 240 is assembled. Therefore, the flow path unit 240 can be selected from multiple types of flow path units. As a result, in multiple types of solenoid valves having different flow path units 240, the common electromagnetic unit 230 can be used. For example, the shape of the upper body 212 and subsequent components can be selected, and the commonality of the electromagnetic unit 230 can be achieved. The flow path unit 240 sometimes changes the directions of the inflow passage 222, the normally open outflow passage 223, and the normally closed outflow passage 228, which will be described after the second embodiment. In addition, there is also a case where the normally open outflow passage 223 is removed to form a two-way valve. In this way, even if the type of the flow path unit 240 changes, the same electromagnetic unit 230 can be used in common.

[0075] Next, the fluid system and the operation of the solenoid valve 200 in the present disclosure will be described. In addition, the fluid system may include an electric control circuit that electrically controls the solenoid valve 200 and the pump 120 in response to the operation of the user.

[0076] When it is necessary to spray the cleaning liquid from the nozzle 100 to the camera 131, the solenoid valve 200 is not energized. Therefore, the valve core 214 is subjected to the force of the normally closed compression spring 207 via the plunger 209, so that the normally closed valve seat 229 is closed.

[0077] When the pump 120 starts to operate, the high-pressure cleaning liquid is delivered to the solenoid valve 200 via the pipe 102. The delivered cleaning liquid flows into the inflow passage 222, and then flows out from the normally open outflow passage 223 via the communication hole 226, the valve chamber 225, and the normally open valve seat 227.

[0078] The cleaning liquid of the solenoid valve 200 is sprayed from the nozzle 100 via the normally open pipe 102b. Since the pressure of the cleaning liquid rises to about 400 kPa, it is almost no problem to reach the release pressure (about 10 kPa) of the check valve 101.

[0079] When the cleaning of the camera 131 is completed, the operation of the pump 120 stops. Since the pressure in the pipe 102 becomes atmospheric pressure as the pump stops, the pipe 102 is blocked by the check valve 101. By closing the check valve 101, the liquid can be cut off well at the end of the spraying. In addition, the check valve 101 can prevent air from flowing back and can store the cleaning liquid in the pipe 102. As a result, at the next operation, the cleaning liquid is sprayed quickly. In other words, the responsiveness of the cleaning liquid spraying device can be made good.

[0080] When it is necessary to spray the cleaning liquid onto the rear window glass 130, the solenoid valve 200 is energized. Due to the energization, the coil 205 is magnetized, and a magnetic circuit is formed through the yoke 201, the core 206, the plunger 209, and the stator 211. The magnetic gap between the conical portion of the core 206 and the conical portion of the plunger 209 is narrowed by the magnetic force, and the plunger 209 moves toward the core 206 against the compression force of the normally closed compression spring 207.

[0081] With the movement of the plunger 209, the valve core 214 is pushed upward by the normally open compression spring 231, so that the normally open valve seat 227 is closed. In addition, the above operation of the solenoid valve 200 is performed before the start of the operation of the pump 120. Therefore, the pressure of the high-pressure cleaning liquid from the pump 120 is not applied to the valve core 214, and the movement of the valve core 214 is not hindered.

[0082] The valve core 214 is spherical, and the normally open valve seat 227 is also a concave conical shape corresponding to the valve core 214. In other words, the surface of the valve core 214 and the surface of the normally open valve seat 227 are rotating body surfaces that mutually perform a self-aligning function. Therefore, even if the central axis of the valve core 214 is slightly deviated with the elongation of the normally open compression spring 231, the normally open valve seat 227 can be reliably sealed. In particular, since the valve core 214 is made of rubber, it can be closely attached to the normally open valve seat 227 by its own elasticity, and the sealing performance can be further improved.

[0083] After the solenoid valve 200 is energized to switch the flow path, the operation of the pump 120 is started. The high-pressure cleaning liquid from the pump 120 flows into the inflow passage 222, and then flows out from the normally closed outflow passage 228 via the communication hole 226, the valve chamber 225, and the normally closed valve seat 229. The outflowing cleaning liquid is sprayed from the nozzle 100 to the rear window glass 130 via the normally closed pipe 102a and the check valve 101.

[0084] When the cleaning of the rear window glass 130 is completed, the operation of the pump 120 stops. When the pressure in the normally closed pipe 102a drops below the release pressure of the check valve 101, the check valve 101 also closes. Then, the energization of the solenoid valve 200 also ends. Since the washer 208 made of a non-magnetic material is interposed between the core 206 and the plunger 209, the plunger 209 is pressed down by the normally closed compression spring 207 at the same time as the energization ends.

[0085] Since the acting force of the normally closed compression spring 207 is greater than the acting force of the normally open compression spring 231, the valve core 214 is pressed against the normally closed valve seat 229. Since the normally closed valve seat 229 is also a conical shape corresponding to the spherical shape of the valve core 214, the same as the above-mentioned normally open valve seat 227, reliable sealing can be performed.

[0086] According to this embodiment, the valve core 214 has a three-dimensional shape convex on both sides. In addition, the valve core 214 is configured to be accommodated within the tapered shapes of the normally open valve seat 227 and the normally closed valve seat 229. Therefore, there is no need to provide a guide for the valve core 214, and the assembly operation of the valve core 214 becomes easy. That is, even if the axis of the valve core 214 is slightly deviated due to the influence of the normally open compression spring 231 and the flow of the cleaning liquid, the deviation of the valve core 214 is within the range of the normally open valve seat 227 and the normally closed valve seat 229. Therefore, the valve core 214 is pressed against the normally open valve seat 227 or the normally closed valve seat 229 due to the normally closed compression spring 207 and the cleaning liquid pressure. Since both the normally open valve seat 227 and the normally closed valve seat 229 are tapered, the valve core 214 is guided by the tapered shape. As a result, the valve core 214 abuts against the normally open valve seat 227 or the normally closed valve seat 229 over its entire circumference.

[0087] If the ambient temperature rises when the operation of the pump 120 ends, the cleaning liquid and air in the pipe 102 expand. Although the normally open pipe 102b is blocked by the shut-off valve 101, since the normally open valve seat 227 is open, the pressure generated by the expansion is released to the pump 120 side and does not become too high. However, on the normally closed pipe 102a, both the normally closed valve seat 229 and the shut-off valve 101 are closed. Therefore, the cleaning liquid is sealed in the normally closed pipe 102a. Therefore, there is a possibility that the pressure in the normally closed pipe 102a rises excessively due to the expansion of the cleaning liquid and air.

[0088] If the pressure reaches above the release pressure of the shut-off valve 101, there is a possibility that the cleaning liquid in the normally closed pipe 102a leaks from the nozzle 100 to the rear window glass 130. However, according to this embodiment, since the pressure relief valve 233 opens to release the pressure, the leakage of the cleaning liquid can be reliably prevented.

[0089] When the pressure in the normally closed pipe 102a is higher than the pressure relief pressure, the force of the pressure relief spring 216 is overcome, and thus the pressure relief valve core 217 is lifted. As a result, the pressure relief valve seat 218 opens, and the pressure relief passage 232 opens. The normally closed outflow passage 228 communicates with the inflow passage 222 via the pressure relief groove 217a of the pressure relief valve core 217 and the pressure relief guide 234.

[0090] The pressure relief pressure of the pressure relief valve 233 is about half of the release pressure of the shut-off valve 101. Therefore, the pressure relief valve 233 opens before the shut-off valve 101 opens, thereby suppressing the pressure rise in the normally closed pipe 102a.

[0091] Here, since the pressure relief passage 232 releases the pressure of the enclosed cleaning liquid, a large amount of cleaning liquid does not flow through the pressure relief passage 232. The passage cross-sectional area of the pressure relief passage 232 is smaller than the passage cross-sectional areas of the inflow passage 222 and the outflow passages 223 and 228. Therefore, even if there are parts with a small flow passage cross-sectional area (passage cross-sectional area) such as the pressure relief groove 217a, no malfunction will occur during operation. In Figure 7 , Figure 8 , although there are three pressure relief grooves 217a formed, they are components that are symmetrically shaped around the mandrel to achieve balance. If the required flow passage cross-sectional area can be provided, the number of pressure relief grooves 217a can be one.

[0092] In addition, since the pressure relief valve core 217 is held by the guide member 234, reliable sealing with the pressure relief valve seat 218 can be achieved even if the set pressure of the pressure relief spring 216 is small.

[0093] Second Embodiment

[0094] In the second embodiment, as Figure 9 shown, the pressure relief valve seat 218 is formed on the upper surface of the lower body 219. The pressure relief valve seat 218 is provided not by a special component but by the valve body. Since the lower body 219 is made of a resin such as polyphenylene sulfide, the pressure relief valve core 217 is made of a rubber material to ensure sealing performance. That is, the pressure relief valve core 217 of the second embodiment is made of the same rubber material as the pressure relief valve seat 218 of the first embodiment with a coating treatment on the surface.

[0095] Third Embodiment

[0096] In the third embodiment, as Figure 10 shown, a duckbill valve is used as the pressure relief valve 233. As Figure 11 shown, the duckbill valve has a tapered portion 244 at the upper end of the cylindrical valve body. The duckbill valve has a cylindrical shape with a tapered tip. The duckbill valve has a slit 245 at the tip. The slit 245 can be opened and blocked by the deformation of the cylindrical shape. The duckbill valve is made of a rubber material.

[0097] When the pressure in the inflow passage 222 is higher than the pressure in the normally closed outflow passage 228, the tapered portion 244 is pressured, so that the slit 245 is blocked. On the contrary, if the pressure in the normally closed outflow passage 228 becomes higher, the cleaning liquid is released to the inflow passage 222 side by opening the slit 245, and the pressure rise can be prevented.

[0098] In addition, in the third embodiment, a normally closed outflow passage 228 is formed in parallel with the inflow passage 222 and the normally open outflow passage 223. This gives freedom to the processing of the piping 102.

[0099] In addition, in the third embodiment, the valve core 214 is formed in a disc shape and integrally formed with the plunger 209. A sealing member 246 made of a rubber material that abuts against the normally open valve seat 227 to maintain a seal is disposed on the upper surface of the valve core 214. A sealing member 247 made of a rubber material that abuts against the normally closed valve seat 229 to maintain a seal is disposed on the lower surface of the valve core 214. Since the valve core 214 is integrally formed with the plunger 209, the normally open compression spring 231 used in the first and second embodiments is removed.

[0100] Fourth Embodiment

[0101] As Figure 12 and Figure 13 shown, in the fourth embodiment, the pressure relief passage 232 opens into the valve chamber 225. That is, a part of the guide member 234 is opened to communicate with the valve chamber 225. The valve chamber 225 is formed closer to the inflow passage 222 side than the normally closed valve seat 229. Therefore, when the pressure on the normally closed outflow passage 228 side is higher than the pressure relief pressure, the pressure relief valve 233 opens, and thus the pressure can be released to the inflow passage 222 side.

[0102] The fourth embodiment is also the same as the third embodiment in that the valve core 214 is formed in a disc shape. However, in the third embodiment, the valve core 214 is integrally formed with the plunger 209, whereas in the fourth embodiment, the valve core 214 is formed in a ring shape and riveted and fixed to the plunger 209.

[0103] In addition, in the fourth embodiment, since it is not necessary to open the pressure relief passage 232 into the inflow passage 222, the inflow passage 222 is located on the inner side of the paper surface compared to the Figure 12 section position. And the normally open outflow passage 223 is also located in the Figure 12 inner side direction of the paper surface, and is formed in a shape where the normally open outflow passage 223 is orthogonal to the inflow passage 222. In this way, the processing freedom of the piping 102 is improved.

[0104] Fifth Embodiment

[0105] In the fifth embodiment, as Figure 14 shown, the guide member 234 of the pressure relief valve 233 is formed on the lower main body 219. The pressure relief passage 232 is opened into the normally closed valve seat 229, and the guide member 234 is opened into the valve chamber 225. A pressure relief valve seat 218 is formed around the pressure relief passage 232 of the lower main body 219, and the pressure relief valve core 217 and the pressure relief spring 216 are arranged in the horizontal direction.

[0106] The operation is the same as that of the fourth embodiment. If the pressure on the normally closed outflow passage 228 side is higher than the relief pressure by more than the relief pressure compared to the pressure on the inflow passage 222 side, the cleaning liquid in the normally closed outflow passage 228 flows into the inflow passage 222 side via the relief passage 232, the guide member 234, and the valve chamber 225 to release the pressure.

[0107] Sixth Embodiment

[0108] In the above embodiment, the inflow passage 222 is formed in the upper main body 212, but as Figure 15 shown, in the sixth embodiment, the inflow passage 222 is formed in the lower main body 219. Therefore, the relief passage 232 is also entirely formed by the lower main body 219. The lower main body 219 has a sealing plug 252 for closing the relief passage 232.

[0109] In the sixth embodiment, the guide member 234 is formed in the horizontal direction, and the relief valve seat 218 is formed around the normally closed outflow passage 228 of the lower main body 219. After inserting the relief valve element 217 and the relief spring 216 into the guide member 234, the guide member 234 is closed by the stopper 251 that also serves as a spring seat.

[0110] In addition, in the sixth embodiment, the relief valve element 217 is spherical. Furthermore, the same as the third embodiment, the valve element 214 is integrally formed with the plunger 209. In the sixth embodiment, the upper main body 212 and the lower main body 219 are welded without using a flange.

[0111] Seventh Embodiment

[0112] In the seventh embodiment, as Figure 16 shown, the relief valve seat 218 and the guide member 234 are formed in the lower main body 219. The relief valve element 217 is spherical, and the acting force of the relief spring 216 is applied to the relief valve element 217 via the spring seat 253. In addition, the other end of the relief spring 216 is supported by the upper main body 212.

[0113] The same as the sixth embodiment, the relief valve 233 is arranged in the lower main body 219, but this structure does not use the sealing plug 252 and the stopper 251.

[0114] Eighth Embodiment

[0115] In the eighth embodiment, as Figure 17 shown, the relief valve seat 218 and the guide member 234 are formed in the lower main body 219. In the eighth embodiment, the relief valve element 217 is a cylindrical shape with a circular top end, and a relief groove 217a is formed on its side surface.

[0116] In addition, at the rear end of the pressure relief valve element 217, a stepped shape is formed by a low protruding portion. The stepped shape provides a shoulder that serves as a spring seat 217b for the pressure relief spring 216. The other end of the pressure relief spring 216 is supported by the upper body 212, which is the same as in the seventh embodiment.

[0117] Ninth Embodiment

[0118] The above-described embodiments are three-way valves including a normally closed outflow passage 228 and a normally open outflow passage 223 as outflow passages. However, the ninth embodiment is an on-off two-way valve in which the outflow passage is only the normally closed outflow passage 228. Figure 19 The ninth embodiment is shown in Figure 19 . The structure of the solenoid valve 200 is the same as that of the first embodiment except that the normally open outflow passage 223 is omitted.

[0119] As Figure 18 shown, the two-way valve is effective when used in a fluid system having a plurality of normally closed pipes 102a. This is an example where there are a plurality of sensors to be cleaned with a cleaning liquid. In addition, in Figure 18 Figure 18 , one pipe 102 is used as a normally open pipe 102b so that the cleaning liquid always flows to the nozzle 100 when the pump 120 is operating. Alternatively, the normally open pipe 102b can be removed. Conversely, a plurality of normally open pipes 102b can also be provided.

[0120] In addition, in Figure 18 Figure 18 , the number of normally closed pipes 102a is set to four, but this number can also be increased or decreased according to the application and can be set to one.

[0121] Other Embodiments

[0122] In the above embodiments, the upper body 212 and the lower body 219 are welded, but other fixing methods such as bolt fixing and clip limiting can also be used.

[0123] In addition, the valve body is not limited to a structure including two members, the upper body 212 and the lower body 219. It can also include three or more members.

[0124] In addition, a cleaning liquid is used as the working fluid, but other liquids such as water and oil can also be used as the working fluid.

[0125] The disclosure in this specification, the drawings, etc. is not limited to the listed embodiments. The present disclosure includes the listed embodiments and modified embodiments obtained by those skilled in the art based on them.

[0126] Multiple embodiments described in this specification disclose multiple technical concepts listed below. Technical Concept 1 provides a solenoid valve. The solenoid valve includes: a coil that is excited when energized; a core made of a magnetic material, the core being disposed within a magnetic circuit formed when the coil is energized; a plunger that is disposed opposite the core across a magnetic gap within the magnetic circuit; a valve spool that moves along with the plunger; a valve body that has an inflow passage for the working fluid, an outflow passage for the working fluid, a normally closed valve seat formed between the inflow passage and the outflow passage and against which the valve spool abuts, and a pressure relief passage that bypasses the normally closed valve seat to communicate the inflow passage and the outflow passage; a normally closed compression spring that pushes the valve spool toward the normally closed valve seat side; and a pressure relief valve that is disposed within the pressure relief passage in the valve body, and that closes the pressure relief passage when the pressure of the working fluid in the outflow passage is lower than the pressure of the working fluid in the inflow passage, equal to the pressure of the working fluid in the inflow passage, and higher than the pressure of the working fluid in the inflow passage and the pressure difference is less than a predetermined pressure relief pressure, and that opens the pressure relief passage when the pressure of the working fluid in the outflow passage is higher than the pressure of the working fluid in the inflow passage and the pressure difference is at or above the pressure relief pressure.

[0127] Technical Concept 2 is based on the solenoid valve described in Technical Concept 1, wherein the outflow passage is two passages, a normally closed outflow passage and a normally open outflow passage, and the valve body has: a normally closed valve seat formed between the inflow passage and the normally closed outflow passage, and a normally open valve seat formed between the inflow passage and the normally open outflow passage. Technical Concept 3 is based on the solenoid valve described in Technical Concept 1 or Technical Concept 2, wherein the cross-sectional area of the pressure relief passage is smaller than the cross-sectional areas of the inflow passage and the outflow passage.

[0128] Technical Concept 4 is based on the solenoid valve described in Technical Concepts 1 to 3, wherein the pressure relief valve includes: a pressure relief valve seat formed in the pressure relief passage; a pressure relief valve spool that is disposed on the inflow passage side of the pressure relief valve seat; and a pressure relief spring that pushes the pressure relief valve spool toward the pressure relief valve seat side. Technical Concept 5 is based on the solenoid valve described in Technical Concept 4, wherein the pressure relief passage is circular tubular, the pressure relief valve spool is cylindrical and slides within the circular tubular pressure relief passage, and pressure relief grooves are formed on the circumferential surface of the cylindrical pressure relief valve spool.

[0129] The technical concept 6 is based on the solenoid valve described in any one of the technical concepts 1 to 3. The pressure relief valve is a duckbill valve having a slit formed at the top. When the pressure of the working fluid in the outflow passage is lower than the pressure of the working fluid in the inflow passage, equal to the pressure of the working fluid in the inflow passage, and higher than the pressure of the working fluid in the inflow passage and the pressure difference is less than a predetermined pressure relief pressure, the duckbill valve blocks the slit. When the pressure of the working fluid in the outflow passage is higher than the pressure of the working fluid in the inflow passage and the pressure difference is above the pressure relief pressure, the duckbill valve opens the slit.

[0130] The technical concept 7 is a fluid system including the solenoid valve described in any one of the technical concepts 1 to 6. The fluid system includes: a tank for the working fluid; a pump that sucks the working fluid from the tank and discharges the working fluid at high pressure; a pipe through which the working fluid from the pump flows; a stop valve disposed in the pipe, the stop valve opening the pipe when the pressure of the working fluid in the pipe is above a release pressure and blocking the pipe when the pressure of the working fluid in the pipe is less than the release pressure; and the solenoid valve. The solenoid valve is disposed in the pipe between the pump and the stop valve, and the pressure relief pressure of the pressure relief valve is less than the release pressure of the stop valve.

Claims

1. A solenoid valve, characterized in that, Comprising: A coil that is excited when energized; A core made of a magnetic material, the core being disposed within a magnetic circuit formed when the coil is energized; A plunger, the plunger being disposed opposite to the core across a magnetic gap within the magnetic circuit; A valve spool, the valve spool moving along with the plunger; A valve body, the valve body having an inflow passage for a working fluid, an outflow passage for the working fluid, a normally closed valve seat formed between the inflow passage and the outflow passage and against which the valve spool abuts, and a pressure relief passage that bypasses the normally closed valve seat to communicate the inflow passage with the outflow passage; A normally closed compression spring that urges the valve spool toward the normally closed valve seat side; And A pressure relief valve, the pressure relief valve being disposed within the pressure relief passage in the valve body, the pressure relief valve closing the pressure relief passage when the pressure of the working fluid in the outflow passage is lower than the pressure of the working fluid in the inflow passage, equal to the pressure of the working fluid in the inflow passage, and higher than the pressure of the working fluid in the inflow passage and the pressure difference is less than a predetermined pressure relief pressure, and the pressure relief valve opening the pressure relief passage when the pressure of the working fluid in the outflow passage is higher than the pressure of the working fluid in the inflow passage and the pressure difference is above the pressure relief pressure; The outflow passage is two passages, a normally closed outflow passage and a normally open outflow passage, The valve body has: The normally closed valve seat formed between the inflow passage and the normally closed outflow passage, and a normally open valve seat formed between the inflow passage and the normally open outflow passage.

2. The solenoid valve according to claim 1, characterized in that, The cross-sectional area of the pressure relief passage is smaller than the cross-sectional area of the inflow passage and the cross-sectional area of the outflow passage.

3. The solenoid valve according to claim 1 or 2, wherein The pressure relief valve includes: A pressure relief valve seat formed in the pressure relief passage; A pressure relief valve spool, the pressure relief valve spool being disposed on the inflow passage side of the pressure relief valve seat; and A pressure relief spring that urges the pressure relief valve spool toward the pressure relief valve seat side.

4. The solenoid valve according to claim 3, wherein The pressure relief passage is circular tubular, The pressure relief valve spool is cylindrical and slides within the circular tubular pressure relief passage, A pressure relief groove is formed on the circumferential surface of the cylindrical pressure relief valve spool.

5. The solenoid valve according to claim 1 or 2, wherein The pressure relief valve is a duckbill valve having a slit formed at its tip, The duckbill valve blocks the slit when the pressure of the working fluid in the outflow passage is lower than the pressure of the working fluid in the inflow passage, equal to the pressure of the working fluid in the inflow passage, and higher than the pressure of the working fluid in the inflow passage and the pressure difference is less than a predetermined pressure relief pressure, and the duckbill valve opens the slit when the pressure of the working fluid in the outflow passage is higher than the pressure of the working fluid in the inflow passage and the pressure difference is above the pressure relief pressure.

6. A fluid system, characterized in that, Comprising: A tank for the working fluid; A pump that sucks the working fluid from the tank and discharges the high-pressure working fluid; A pipe through which the working fluid from the pump flows; A stop valve configured in the pipe, the stop valve opening the pipe when the pressure of the working fluid in the pipe is equal to or higher than the release pressure and blocking the pipe when the pressure of the working fluid in the pipe is less than the release pressure; and The solenoid valve according to claim 1 or 2; wherein, The solenoid valve is configured in the pipe between the pump and the stop valve, The pressure relief pressure of the pressure relief valve is less than the release pressure of the stop valve.

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