JP2008196599A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve capable of economically preventing excess flow, and suppressing fluctuation of closing operation characteristics in regard to a mass flow rate generated by levels of upstream side fluid pressure. <P>SOLUTION: A shutoff valve (solenoid valve) 3 for opening and closing a flow passage when a valve element 17 is electromagnetically driven, is provided with a control part for selecting a holding current value of a coil 18 of the solenoid which maintains an open state of the valve element 17 against a fluid pressure in response to the upstream side fluid pressure (a primary pressure) of the shutoff valve 3. A relative position to a valve seat of a base can be adjusted by the fluid pressure on an upstream side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solenoid valve. More specifically, the present invention relates to a structure of an electromagnetic valve capable of controlling the supply flow rate of a fluid such as gas.

  For example, a fuel cell vehicle that drives a traveling motor with power generated by a fuel cell that generates electricity by an electrochemical reaction between fuel gas and oxidizing gas, or a natural gas (CNG) burned by an internal combustion engine to generate driving force for traveling. In a natural gas vehicle or the like obtained directly, an electromagnetic valve is often used as an on-off valve for a fuel gas tank.

In general, the solenoid valve in this case maintains the valve open state by energizing the coil with a constant current that does not close the valve against the resultant force of the spring force biased in the valve closing direction and the force received from the fluid. Is controlled. In addition, an EFV (overflow prevention device) may be provided in preparation for a case where a gas leak occurs in a component downstream of the solenoid valve. Alternatively, a control device is also proposed in which a flow rate measuring device is installed in the fuel gas flow path, an overflow determination is performed by a separately installed flow rate determination device, and the solenoid valve is de-energized and closed at a specified time. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 10-153136

  However, if a flow rate determiner as described above is provided separately from the solenoid valve, there is a problem that the cost, mass, and the like increase.

  Also, a mechanical type EFV (overflow prevention device) may be provided. However, in a conventional system using such an overflow prevention device, the operating mass flow rate changes depending on the tank pressure, and thus the degree of freedom in design. There is a problem that decreases. That is, in the EFV, the spring that biases the valve body has a structure that keeps the distance between the valve body and the valve seat constant regardless of the level of the primary pressure (fluid pressure upstream of the valve). Therefore, when the primary pressure is high, there is a closing operation characteristic in which the mass flow rate during the closing operation increases (see the map indicated by the symbol X in FIG. 6). In other words, although the volume flow rate of the fuel gas passing through the gap between the valve body and the valve seat is substantially constant regardless of the primary pressure level, the higher the primary pressure, the higher the density of the fuel gas. Along with this, the mass flow rate during the closing operation becomes high.

  The present invention has been made in view of the above circumstances, and can economically prevent overflow and suppress variation in closed operation characteristics with respect to mass flow caused by the level of upstream fluid pressure (primary pressure). The purpose is to provide a possible solenoid valve.

  In order to achieve the above object, the present invention provides an electromagnetic valve comprising a valve body that opens and closes a fluid flow path and a coil that electromagnetically drives and strokes the valve body to resist the fluid pressure of the fluid. The holding current value of the coil that holds the valve element in the open state is controlled by the control device in accordance with the fluid pressure of the fluid.

  According to this configuration, it is possible to control the valve body based on the primary pressure (fluid pressure upstream of the valve), and thus electrically suppress the variation in the closing operation characteristic with respect to the mass flow rate caused by the level of the primary pressure. It becomes possible. In this case, the control device can store in advance a control map representing the relationship between the holding current value and the primary pressure for holding the valve element in the valve open state.

  In such a solenoid valve, the valve body is held in an open state so that the valve body is closed when the holding current value of the coil becomes a substantially constant mass flow rate regardless of the fluid pressure of the fluid. It is preferable that the value is controlled. In such a case, when the fluid reaches a certain mass flow rate, the overflow prevention function of the valve body itself can be activated to close the valve.

  It is also preferable that the coil is controlled so that the holding current value of the coil decreases as the fluid pressure of the fluid increases. According to this, it is also possible to suppress the consumption of current required to hold the valve body.

  Further, the present invention provides an electromagnetic valve comprising a valve body that opens and closes a fluid flow path, and a coil that electromagnetically drives and strokes the valve body, and is supported by a pedestal via a valve body spring. The valve body moves against the urging force of the valve body spring and is seated on the valve seat to close the flow path, and the relative position of the pedestal to the valve seat is adjusted by the upstream fluid pressure It is possible.

  According to this configuration, since the relative position of the pedestal with respect to the valve seat can be adjusted by the upstream fluid pressure (primary pressure), the clearance between the valve body supported by the pedestal via the valve body spring and the valve seat is reduced. It can be made variable according to the level of the primary pressure. Therefore, it is possible to mechanically suppress the variation of the closing operation characteristic with respect to the mass flow rate caused by the level of the primary pressure.

  The pedestal has a fluid pressure receiving portion that receives the fluid pressure in a direction in which the pedestal is movable and a support portion of the valve body spring is separated from the valve seat, and the pedestal receives the fluid pressure. It may be provided with a pedestal spring that is biased in the opposite direction.

  According to this configuration, when the upstream fluid pressure (primary pressure) is high, the pedestal moves in a direction to separate the support portion of the valve body spring from the valve seat against the biasing force of the pedestal spring, and the support portion The clearance between the valve body supported by the valve body spring and the valve seat is reduced. Further, when the upstream primary pressure is low, the pedestal does not move in the direction of separating the support portion of the valve body spring from the valve seat, and the gap between the valve body and the valve seat is increased. Therefore, when the primary pressure is high, the increase in mass flow rate can be suppressed by reducing the volume flow rate by narrowing the gap between the valve body and the valve seat. Can be suppressed.

  Furthermore, the pedestal may include an atmospheric pressure receiving unit that receives atmospheric pressure in a direction opposite to a direction in which the fluid pressure is received.

  According to this configuration, since the pedestal receives the atmospheric pressure in the direction opposite to the pressure receiving direction of the upstream fluid pressure (primary pressure) at the atmospheric pressure receiving portion, the secondary pressure is applied as in the case of receiving the secondary pressure. It is possible to adjust the position of the pedestal while suppressing the influence, that is, the influence due to the operating situation on the downstream side.

  According to the present invention, the valve body closes at a constant mass flow rate regardless of the upstream fluid pressure (primary pressure). That is, it is possible to economically prevent overflow by the electromagnetic valve and to suppress the variation of the closing operation characteristic with respect to the mass flow rate caused by the level of the primary pressure.

<First Embodiment>
FIG. 1 is a schematic view of a high-pressure tank 5 in which a solenoid valve according to this embodiment is used. Note that the high-pressure tank 5 in the present embodiment is a tank that can be used to store high-pressure hydrogen gas in the fuel cell system.

  A shut-off valve (solenoid valve) 3 is provided at the opening of the high-pressure tank 5. Further, a pressure sensor 6 for detecting the pressure of the high-pressure tank 5 and a control device 10 for monitoring the output of the pressure sensor 6 and controlling the shut-off valve 3 are further provided.

  Next, an example of the structure of the shutoff valve 3 is shown in FIG. As shown in the figure, the shut-off valve 3 includes a fluid (for example, hydrogen gas) flow path 15, a body 16 that guides hydrogen gas from the high pressure side to the low pressure side, and an axial direction (fluid flow direction) with respect to the body 16. And a valve body 17 that is accommodated and held movably and opens and closes the flow path 15. The valve body 17 of the shut-off valve 3 is driven by a coil 18 constituting a solenoid to make a stroke. At this time, the current supplied to the coil 18 is controlled by the control device 10 so that the valve body 17 moves (strokes). Further, the valve body 17 is urged against the valve seat 19 by a spring 20 so that the flow path 15 is sealed.

  The opening operation of the shut-off valve 3 and the maintenance of the opened state are performed by the electromagnetic force of the coil 18. As shown in FIG. 3, the spring force and fluid pressure act on the valve body 17 in the valve closing direction, and the control device 10 normally applies the force that the electromagnetic force acts in the valve closing direction. Above, hold the valve open.

  When breakage or the like occurs in the flow path on the downstream side of the shut-off valve 3, the secondary pressure of the shut-off valve 3 (the fluid pressure on the downstream side of the valve) decreases and the flow rate increases. As a result, the fluid force acting on the valve body 17 increases, and when the resultant force of this and the spring force exceeds the electromagnetic force, the valve is closed (FIG. 4).

  Here, as indicated by reference numeral X1 in FIG. 5, if the electromagnetic force by the coil 18 is constant regardless of the pressure, the higher the primary pressure, the higher the mass flow rate during the closing operation (in FIG. 6). Reference X). In this regard, in the present embodiment, the map indicated by reference numeral A1 in FIG. 5 is stored in the storage unit 10a of the control device 10, and the control device 10 stores the current of the coil 18 suitable for the current primary pressure. It is calculated by reading from the map of the unit 10a. This map represents the relationship between the holding current and the primary pressure so that the mass flow rate (working flow rate) at which the valve body 17 is closed is substantially constant regardless of the pressure, as indicated by the symbol A in FIG. It is a thing. That is, the line A1 in FIG. 5 is a map in which the holding current decreases as the pressure increases.

  Thus, according to the shutoff valve 3 of the present embodiment, the valve is closed at a constant mass flow rate regardless of the tank pressure. That is, it is possible to economically prevent overflow by the shutoff valve 3, and it is possible to suppress the variation of the closing operation characteristic with respect to the mass flow caused by the level of the primary pressure. Furthermore, since the holding current of the coil 18 can be optimized, power consumption can be suppressed.

  The solenoid valve holding current may be determined with reference to not only the tank pressure but also the gas temperature. As a result, the accuracy of the valve closing flow rate can be increased, and further improvement in design freedom and reduction in current consumption can be expected. In this case, not only the pressure sensor 6 but also a temperature sensor may be provided in the high-pressure tank 5 so that the output of the temperature sensor is given to the control device 10. Furthermore, the relationship between the primary pressure and the gas temperature at which the operating flow rate is substantially constant can be stored in the storage unit 10a.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. The shutoff valve (solenoid valve) 4 of the present embodiment is provided with an overflow prevention device 27a. Since the main components of the shutoff valve 4 except the overflow prevention device 27a are the same as those of the shutoff valve 3, the description thereof is omitted.

  The overflow prevention device 27a has a casing 31 that constitutes an outer portion of the overflow prevention device 27a. The casing 31 is provided with a first hole portion 32 on the communication side to the high-pressure tank 5 (left side in FIG. 7). A second hole 33 having a smaller diameter than the first hole 32 is formed on the opposite side of the first hole 32 from the high-pressure tank 5.

  The casing 31 is formed with a third hole 34 having a smaller diameter than the second hole 33 on the opposite side of the second hole 33 from the first hole 32. A fourth hole 35 having a diameter larger than that of the third hole 34 is formed on the side opposite to the second hole 33 of 34.

  Further, the casing 31 has a diameter smaller than that of the fourth hole 35 on the side opposite to the third hole 34 of the fourth hole 35 and communicates with a fuel cell (not shown) provided on the downstream side. Five holes 36 are formed. Here, the first hole portion 32 to the fifth hole portion 36 are formed on the same axis.

  In addition, a cylindrical housing space 38 concentric with the first hole 32 to the fifth hole 36 is formed outside the casing 31 so as to surround the fourth hole 35. The intermediate portion in the axial direction of the portion 35 and the accommodation space portion 38 communicates with the communication space portion 39 over the entire circumference. Further, the casing 31 is formed with a branch channel 41 for communicating the end face on the first hole portion 32 side in the axial direction of the accommodation space portion 38 with the first hole portion 32. Circular seal grooves 42 and 43 are formed on the inner diameter sides on both sides of the communication space 39 in the axial direction. In addition, an atmospheric pressure port 44 that is open to the atmosphere is formed in the casing 31 on the fifth hole 36 side of the accommodation space 38.

  The overflow prevention device 27a has an annular sheet member 46 fitted to the inner peripheral surface of the second hole 33. The sheet member 46 includes an inner sheet on the first hole 32 side. A valve seat 47 chamfered on the circumferential side is formed.

  The overflow prevention device 27a has a pedestal 49 that is slidably provided in the casing 31 described above. The pedestal 49 has a cylindrical sliding base portion 50 slidably provided in the accommodation space portion 38 of the casing 31, and extends in an annular shape inward from an axially intermediate portion of the sliding base portion 50 to mainly communicate with the space. An inner flange portion 51 disposed in the portion 39, and the inner peripheral portion of the inner flange portion 51 extends into the fourth hole portion 35. An annular seal groove 52 is formed on the outer peripheral surface of the slide base portion 50 of the pedestal 49.

  Here, the seal groove 42 on the first hole 32 side of the casing 31 is provided with a seal ring 53 that always seals the gap with the pedestal 49 regardless of the sliding position of the pedestal 49, and the fifth hole 36 side. A seal ring 54 that always seals the gap with the pedestal 49 regardless of the sliding position of the pedestal 49 is also provided in the seal groove 43 of the pedestal 49, and the seal groove 52 of the pedestal 49 is also connected to the casing 31 regardless of the position of the pedestal 49. A seal ring 55 for sealing the gap is provided.

  In addition, the overflow prevention device 27 a is a coil interposed in the housing space 38 of the casing 31 between the end surface on the fifth hole 36 side in the axial direction and the sliding base portion 50 of the pedestal 49. A base spring 58 made of a spring is provided. The base spring 58 biases the base 49 toward the first hole 32 in the axial direction.

  Further, the overflow prevention device 27a is fixed to the support portion 60 on the inner peripheral side of the inner flange portion 51 of the base 49, and the other end side passes through the inside of the sheet member 46 and extends to the first hole portion 32 side. And a valve body 17 fixed to the other end side of the valve body spring 61 in the first hole portion 32.

  The overflow prevention device 27a having such a structure is arranged in the discharge flow path 22a with the first hole 32 of the casing 31 facing the high-pressure tank 5 and the fifth hole 36 facing the fuel cell stack side. become. In this state, the overflow prevention device 27a is configured such that the valve body 17 supported by the pedestal 49 via the valve body spring 61 moves against the urging force of the valve body spring 61 and is seated on the valve seat 47. The flow path is closed.

  At this time, the primary pressure acts on the end surface of the sliding base portion 50 of the pedestal 49 on the first hole 32 side via the branch channel 41 so as to move the pedestal 49 in the direction of the pedestal spring 58. As a result, this end surface serves as a primary pressure receiving portion 63 that receives a primary pressure in a direction in which the support portion 60 of the valve body spring 61 is separated from the valve seat 47.

  Further, the end surface of the pedestal 49 opposite to the primary pressure receiving portion 63 of the sliding base portion 50 is an atmospheric pressure receiving portion 64 that receives atmospheric pressure in the direction opposite to the primary pressure receiving direction. The pedestal spring 58 biases the pedestal 49 in the direction opposite to the primary pressure receiving direction.

  According to the overflow prevention device 27a having the above structure, the relative position of the pedestal 49 with respect to the valve seat 47 can be adjusted by the primary pressure on the upstream side. Therefore, the valve body supported by the pedestal 49 via the valve body spring 61. The gap between the valve seat 47 and the valve seat 47 can be varied according to the primary pressure level.

  Specifically, when the upstream primary pressure is high, the pedestal 49 resists the urging force of the pedestal spring 58 by the pressure applied to the primary pressure receiving portion 63 via the branch flow path 41 as shown in FIG. The support portion 60 is moved away from the valve seat 47, and the valve body 17 supported by the support portion 60 via the valve body spring 61 is moved downstream along the axial direction so that the valve body 17 is moved. And the clearance between the valve seat 47 and the valve seat 47 are reduced.

  If the primary pressure on the upstream side is low, the pedestal 49 does not move by the urging force of the pedestal spring 58 even if pressure is applied to the primary pressure receiving portion 63 via the branch flow path 41, and the valve body 17 and the valve seat The gap with 47 is increased. Therefore, when the primary pressure is high, an increase in the mass flow rate can be suppressed by narrowing the gap between the valve element 17 and the valve seat 47 to reduce the volume flow rate. Therefore, as indicated by the symbol A in FIG. The fluctuation of the closed operation characteristic with respect to the mass flow rate caused by the pressure level can be suppressed and can be controlled constant.

  Moreover, since the pedestal 49 receives the atmospheric pressure in the direction opposite to the primary pressure receiving direction at the atmospheric pressure receiving portion 64, the influence of the secondary pressure as in the case of receiving the secondary pressure, that is, the downstream fuel cell The position of the pedestal 49 can be adjusted while suppressing the influence of the driving situation.

  As described above, according to this embodiment, the same effect as that of the above embodiment can be obtained, and the operation flow rate can be mechanically made constant regardless of the pressure. The storage unit 10a) becomes unnecessary and the control logic can be simplified.

  In the above description, the position of the valve seat 47 is fixed and the pedestal 49 can be moved according to the primary pressure. However, it is only necessary that the relative position of the pedestal 49 with respect to the valve seat 47 can be adjusted by the primary pressure on the upstream side. It is also possible to move the valve seat 47 according to the primary pressure while fixing the position 49.

  Further, the casing 31 may not have the first atmospheric pressure port 44 and may not have the seal groove 43 and the seal ring 54 on the fifth hole 36 side of the accommodation space 38. . In this case, the end surface opposite to the primary pressure receiving portion 63 of the pedestal 49 becomes the secondary pressure receiving portion 65 that receives the downstream secondary pressure in the direction opposite to the primary pressure receiving direction.

  In such an embodiment, similarly to the above, it is possible to suppress the variation of the closed operation characteristic with respect to the mass flow rate caused by the level of the primary pressure, and in addition to this, the atmospheric pressure port, the seal ring, and the seal groove are reduced. Therefore, the manufacturing cost and the number of parts can be reduced.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited to this, and various modifications can be made without departing from the scope of the present invention. For example, the shutoff valve (solenoid valve) 3 according to the present invention may be a pilot type and a structure using a small solenoid so as to shut off the gas directly under the tank (the most upstream in the system). The shut-off valve 3 having such a structure will be described as an example as follows.

  FIG. 8 is a cross-sectional view showing the main part in a state in which the shut-off valve 3 made up of an electromagnetic valve is attached to one end (mouth part) of the tank main body constituting the main part of the high-pressure gas tank 30. It rushes into the tank chamber 103 from the outside of the high-pressure gas tank 30, that is, into the high-pressure side.

  The shut-off valve 3 has a cylindrical casing 104, the upper part of the casing 104 is screwed to the mouth constituting wall 101 a of the high-pressure gas tank 30 with screws 105, and the lower part of the casing 104 is placed in the tank chamber 103. The upper end portion protrudes outside the high-pressure gas tank 30.

  A bobbin 107 around which an exciting coil (electromagnetic coil) 106 is wound is disposed in a portion of the housing 104 located in the tank chamber 103, and a cylindrical shape is provided on the inner periphery of the bobbin 107. A guide 108 is provided, and a holding cylinder 109 is fitted on the outer periphery of the bobbin 107. The holding cylinder 109 is inserted into the housing 104.

  A plunger 110 is slidably disposed in the guide 108 in the axial direction, a pilot valve 111 is provided at one end of the plunger 110, and the other end faces the stator 112 so as to be able to contact and separate.

  When the coil 106 is energized, the plunger 110 is attracted to the stator 112 side against the spring 113, the pilot valve 111 is opened away from the pilot seat 114, and the coil 106 is de-energized by the urging force of the spring 113. The pilot valve 111 presses against the pilot seat 114 and closes.

  A main valve 115 having a pilot seat 114 is slidable in the axial direction on the inner peripheral portion of the guide 108 and on the outer peripheral portion of the pilot valve 111, and the housing is opposed to the main valve 115. An annular main seat 116 is disposed on the body 104 side, and a main valve 115 is provided so as to be able to contact and separate from the main seat 116.

  A gas outflow passage 117 is formed at the center of the main seat 116 in the housing 104, the main valve 115 is pressed against the main seat 116 to close the gas outflow passage 117, and the main valve 115 is closed by the spring 118. The gas outflow path 117 is opened by being further separated.

  When the coil 106 is energized, the plunger 110 moves downward in FIG. 2, and the hydrogen gas in the tank chamber 103 flows from the flow path 119 formed in the housing 104 to the gap 130 between the main valve 115 and the guide 108 and the main. The gas flows into the pilot seat 114 through the gap 131 between the valve 115 and the pilot valve 111 and flows out from the hole 132 to the gas outflow passage 117. Further, the differential pressure between the flow passage 119 side and the pilot seat 114 portion side is reduced. When the main valve 115 is separated from the main seat 116 by the biasing force of the spring 118, the fluid in the tank chamber 103 flows out from the gas outflow passage 117 through the gap between the main valve 115 and the main seat 116 from the flow passage 119.

  The housing 104 is made of, for example, stainless steel or aluminum. As shown in FIG. 3, the casing 104 has a gas outflow path (fuel outflow path) 117, a gas inflow path (fuel inflow path) 120, and the like. Are formed at predetermined intervals. The gas inflow path 120 and the gas outflow path 117 are processed by a drilling tool such as a drill.

  Normally, the gas inflow path 120 is maintained in a closed state, but when a pressure higher than a predetermined pressure is applied from the outside, that is, when the gas is filled, communication between the inside of the tank chamber 103 and the outside is permitted. A check valve (not shown) is provided. One end of a harness (wiring) 121 that supplies electric power from the outside of the high-pressure gas tank 30 is connected to the coil 106.

  In the present embodiment, a hermetic seal (seal member) 122 is provided at the upper end opening of the harness passage 120a. In other words, the harness passage 120a is also used from the middle of the gas inflow passage 120, and the hermetic seal 122 is provided at the opening 123a of the harness passage 120a that opens to the outer surface side of the high-pressure gas tank 30.

  The harness 121 is a hermetic seal on the atmosphere side (outside the outer surface of the high-pressure gas tank 30) through the gas inflow passage 120 and the harness passage 120a from the opening 123b of the gas inflow passage 120 that opens inward from the outer surface of the high-pressure gas tank 30. It is pulled out of the tank through 122. The other end of the harness 121 is connected to the connector 124. This connector 124 is connected to an external electric wire.

  As described above, the shutoff valve (solenoid valve) 3 according to the present invention may be a pilot type and a structure using a small solenoid so as to shut off the gas directly under the tank (the most upstream in the system). Even in such a case, it is possible to seal the valve at the time of overflow when the fluid flow rate is equal to or higher than the specified flow rate.

It is the schematic of the high-pressure tank in which the cutoff valve concerning this embodiment is used. It is sectional drawing which showed the structure of the cutoff valve. It is the schematic diagram which showed the force which the same shut-off valve receives in an open state. It is the schematic diagram which showed the force which the same cutoff valve receives at the time of an overflow. It is the figure which showed the relationship between the primary pressure and the holding current of a solenoid in this embodiment and a prior art. It is the figure which showed the relationship between the primary pressure and working mass in this embodiment and a prior art. It is sectional drawing which showed the structure of the cutoff valve concerning 2nd Embodiment. It is sectional drawing which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Shut-off valve (solenoid valve), 4 ... Shut-off valve (solenoid valve), 5 ... High pressure tank, 10 ... Control device, 15 ... Flow path, 17 ... Valve body, 18 ... Solenoid coil, 19 ... Valve seat, 61 ... Valve spring

Claims (6)

In a solenoid valve comprising a valve body that opens and closes a fluid flow path, and a coil that electromagnetically drives and strokes the valve body,
An electromagnetic valve in which a holding current value of the coil that holds the valve body in an open state against the fluid pressure of the fluid is controlled by a control device according to the fluid pressure of the fluid.   The holding current value of the coil is controlled to a value that holds the valve body in an open state so that the valve body is closed when the mass flow rate is substantially constant regardless of the fluid pressure of the fluid. The solenoid valve according to claim 1.   3. The solenoid valve according to claim 1, wherein the solenoid valve is controlled so that a holding current value of the coil decreases as a fluid pressure of the fluid increases. 4. In a solenoid valve comprising a valve body that opens and closes a fluid flow path, and a coil that electromagnetically drives and strokes the valve body,
The valve body supported by the pedestal via the valve body spring moves against the urging force of the valve body spring and is seated on the valve seat to close the flow path, and the valve of the pedestal Solenoid valve whose relative position to the seat can be adjusted by the upstream fluid pressure.   The pedestal is movable, and has a fluid pressure receiving portion that receives the fluid pressure in a direction in which the support portion of the valve body spring is separated from the valve seat. What is the pressure receiving direction of the fluid pressure? The solenoid valve according to claim 4, further comprising a pedestal spring biased in the opposite direction.   The electromagnetic valve according to claim 5, wherein the pedestal includes an atmospheric pressure receiving portion that receives atmospheric pressure in a direction opposite to a pressure receiving direction of the fluid pressure.

Images