JP5809967B2 - Pressure regulator for fuel cell system - Google Patents

Description

  The present invention relates to a regulating valve that regulates the pressure of a fluid.

  As a fluid pressure regulating valve, there is known a valve that decompresses high-pressure gas in a tank before being supplied to a fuel cell, such as a regulating valve used in a fuel cell system. Such a pressure regulating valve includes a housing having a primary port into which high-pressure gas flows, a secondary port for supplying gas to the outside, and a flow passage cross-sectional area of a communication path between the primary port and the secondary port in the housing. 2. Description of the Related Art A piston-type pressure regulating valve including a valve body that controls the pressure is known.

  By the way, in the piston type pressure regulating valve, a seal member is disposed between the valve body and the housing so that the fluid flowing in from the primary port does not flow out of the housing through a portion other than the communication path. For example, Patent Document 1 includes a seal member having a relatively small sliding resistance for ensuring durability and a seal member having a relatively large sliding resistance for securing a damper action. Moreover, in patent document 2, the lip seal for ensuring a sealing performance and the O-ring for preventing that a piston moves excessively are arrange | positioned.

JP 2006-172123 A JP 2006-185103 A

  By the way, when the hydrogen in the high-pressure tank is depressurized and supplied to the fuel cell as in the fuel cell system, the pressure in the primary port decreases as the amount of hydrogen in the high-pressure tank decreases. As the pressure in the primary port decreases, the stroke amount of the piston with the same pressure adjustment amount increases. For this reason, under low pressure, a member that prioritizes sealing performance over reduction of sliding resistance, such as a sealing member for securing a damper action in Patent Document 1 and a lip seal in Patent Document 2, becomes a resistance, and a valve body As a result, the gas flow rate cannot be controlled with high accuracy. Moreover, there is a possibility that the member giving priority to the sealing property is worn by sliding, and the sealing property cannot be secured. On the other hand, when the sliding resistance of each seal member is reduced by giving priority to the operability of the valve body over the sealability, wear can be suppressed, but the sealability under high pressure is reduced.

  Therefore, an object of the present invention is to provide a pressure adjusting device that can achieve both high-pressure sealing performance and low-pressure control accuracy.

  The fuel cell pressure regulator of the present invention includes a housing having a primary port connected to a hydrogen tank and a secondary port connected to a fuel cell stack. In addition, the communication area between the primary port and the secondary port is increased by moving the shaft part in the valve port provided in the housing with a stroke according to the amount of hydrogen supplied from the primary port to the secondary port and the pressure in the hydrogen tank. A valve body to be controlled is provided. Furthermore, the sealing member arrange | positioned so that the outer peripheral part of the shaft part of a valve body may contact the wall surface of a valve port is provided. The stroke characteristics determined by the design of the valve body and the seat portion on which the valve body is seated are such that at least the pressure in the hydrogen tank is elastically deformed in the region on the high pressure side and the seal member does not slide between the valve port. It has an elastic region. Further, at least the pressure in the hydrogen tank has a sliding region in a region on the low pressure side, which is a stroke in which the seal member slides between the valve port.

  According to the present invention, since the hydrogen tank internal pressure has an elastic region having a stroke characteristic in a region on the high pressure side, sealing performance under high pressure can be ensured. In addition, since the internal pressure of the hydrogen tank has a sliding region with stroke characteristics in the region on the low pressure side, control accuracy under low pressure can be ensured. That is, according to the pressure adjusting device of the present invention, it is possible to achieve both high sealing performance under high pressure and control accuracy under low pressure.

1 is a configuration diagram of a fuel supply system according to a first embodiment of the present invention. It is a block diagram which shows an example of the assembly of a control valve and a solenoid. FIG. 3 is an enlarged view of the vicinity of a seal member in FIG. 2. It is a figure which shows the stroke characteristic of the valve body of 1st Embodiment. It is a figure which shows the stroke characteristic of the valve body of 2nd Embodiment. It is a figure which shows the relationship between the primary pressure and carrier frequency of 3rd Embodiment. It is a flowchart which shows the control routine of 1st Embodiment. It is a flowchart which shows the control routine of 2nd Embodiment. It is a flowchart which shows the control routine of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram of a fuel supply system 40 for a fuel cell according to the first embodiment.

  The fuel supply system 40 is a system that supplies hydrogen to the fuel cell stack 1, and includes a hydrogen tank 2, a hydrogen supply passage 3, a control valve 4, pressure sensors 7 and 8, and a controller 6.

  The hydrogen tank 2 is provided on the upstream side of the hydrogen supply passage 3. The hydrogen tank 2 stores the hydrogen supplied to the fuel cell stack 1 in a high pressure state of, for example, 70 MPa. The hydrogen tank 2 includes an on-off valve 5 that controls the communication state with the hydrogen supply passage 3. The on-off valve 5 is electromagnetically operated and shuts off the communication between the hydrogen tank 2 and the hydrogen supply passage 3 when the power is off.

  The control valve 4 operates electromagnetically, adjusts the amount of hydrogen supplied from the hydrogen tank 2 to the fuel cell stack 1, and controls the supply hydrogen pressure. The structure of the control valve 4 will be described later.

  In the hydrogen supply passage 3, the hydrogen tank 2 side (hereinafter referred to as upstream side) from the control valve 4 is low-pressure on the high-pressure pipe 3 </ b> A, and the fuel cell stack 1 side (hereinafter referred to as downstream side) from the control valve 4 is low-pressure. It is formed by the pipe 3B.

  The controller 6 is a device that controls the entire fuel cell system including the fuel supply system 40, and includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). ). The controller 6 is connected to a pressure sensor 8 that detects a pressure in the low-pressure pipe 3B (hereinafter referred to as downstream pressure) and a wiring 9 that supplies a control current to the control valve 4.

  FIG. 2 is a sectional view showing an example of an assembly including the control valve 4 and a solenoid 100 for driving the control valve 4.

  First, the configuration of the solenoid 100 will be described.

  The solenoid 100 includes a solenoid coil 101, a movable member 102, a bearing member 103, and a casing 104. The casing 104 is attached to the housing 10 of the control valve 4. The casing 104 communicates with a valve passage 16 formed in the housing 10, and a solenoid coil 101, a movable member 102 and a bearing member 103 are accommodated in the casing 104.

  The solenoid coil 101 includes a bobbin 105 and a coil 106. The bobbin 105 is fitted in the casing 104, and has outward flanges 105a and 105b projecting outward at one end and the other end in the axial direction of the outer periphery thereof. Between these two outward flanges 105a and 105b, a coil 106 configured by winding a coil wire is provided. The solenoid coil 101 configured in this manner has one end in the axial direction in contact with the bottom 104a of the casing 104, and a yoke 107 is provided at the other end.

  The yoke 107 is made of a magnetic material such as electromagnetic stainless steel, and is fitted in the casing 104. The yoke 107 is pushed into the casing 104 by mounting the casing 104 on the housing 10 of the control valve 4, and sandwiches the solenoid coil 101 together with the bottom 104a. A movable member 102 is inserted through the yoke 107 and the solenoid coil 101.

  The movable member 102 is made of a magnetic member, for example, electromagnetic stainless steel, and has an insertion portion 102a and a rod 102b. The insertion portion 102a is inserted into the solenoid coil 101. One end portion (right end portion in FIG. 2) of the insertion portion 102 a in the axial direction protrudes from the solenoid coil 101 and is inserted into an insertion hole 104 b formed in the bottom portion 104 a of the casing 104. The insertion hole 104b passes through the bottom 104a of the casing 104, and the outer opening is closed by the lid 104c. A compression coil spring 109 is provided between one end in the axial direction of the insertion portion 102 a and the lid body 104 c, and the insertion portion 102 a is urged toward the yoke 107 by the compression coil spring 109. A rod 102b is integrally provided at the other axial end portion (left end portion in FIG. 2) of the insertion portion 102a. The outer diameter of the rod 102b is smaller than the outer diameter of the insertion portion 102a.

  The other end of the insertion portion 102a has a larger diameter than the inner hole of the yoke 107 and faces the yoke 107, and a rod 102b provided there passes through the yoke 107 and the valve passage 16 of the control valve 4. It extends to. The tip of the rod 102b is in contact with a valve body 14 of the control valve 4 to be described later, and receives a force from the valve body 14 to separate the insertion portion 102a from the yoke 107. That is, the movable member 102 receives a force against each other from the compression coil spring 109 and the valve body 14. As a result, the insertion portion 102a is separated from the lid body 104c by the first predetermined distance d1, and from the yoke 107 by the second predetermined distance d2. The first predetermined distance d1 is approximately three times or more the second predetermined distance d2. Therefore, when a current is passed through the coil 106, the yoke 107 is magnetized and the insertion portion 102 a is attracted to the yoke 107.

  Further, a guide member 108 is provided in the insertion portion 102a. The guide member 108 is made of a nonmagnetic material such as austenitic stainless steel such as SUS316L, and is fitted in the central portion of the outer peripheral portion of the insertion portion 102a. The outer peripheral surface of the guide member 108 is flush with the outer peripheral surface of the insertion portion 102 a, and the outer diameter of the guide member 108 is smaller than the inner diameter of the solenoid coil 101. Therefore, an annular gap 110 is formed between the guide member 108 and the solenoid coil 101. A bearing member 103 is disposed in the gap 110.

  The bearing member 103 is a rolling bearing, and is a ball guide in the present embodiment. However, it is not limited to a ball guide, and may be a ball bearing. The bearing member 103 is externally mounted on the guide member 108 in a state where a lubricant such as grease is applied, and is interposed between the guide member 108 and the solenoid coil 101. The bearing member 103 supports the movable member 102 so as to be slidable in the axial direction, reduces a frictional force generated between the solenoid coil 101 and the guide member 108, and makes the movable member 102 move smoothly. Thus, the 1st and 2nd diaphragm 111,112 is each provided in the both sides of the bearing member 103 which makes the movement of the movable member 102 smooth.

  The first and second diaphragms 111 and 112 are annular seal members, are arranged on both sides in the axial direction of the bearing member 103, and are fixed so as to be bridged between the insertion portion 102a and the solenoid coil 101. As a result, both axial sides of the bearing member 103 are closed. That is, the gap between the back pressure chamber 114 and the gap 110 is sealed by the first diaphragm 111, and the gap between the gap 110 and the pressure chamber 115 is sealed by the second diaphragm 112. Note that the back pressure chamber 114 is a space defined by the casing 104 and the end of one side in the axial direction of the movable member 102, and is a space on one side in the axial direction from the gap 110. The pressure chamber 115 is a space defined by the yoke 107 and the end of the movable member 102 on the other side in the axial direction, and is a space located on the other side in the axial direction from the gap 110.

  A communication path 113 is formed inside the movable member 102 so as to connect the back pressure chamber 114 and the pressure chamber 115 thus defined. The communication passage 113 has a first opening 113a at one end (right end in FIG. 2) in the axial direction of the insertion portion 102a, and has second and third openings 113b and 113c on the outer periphery of the rod 102b, respectively. ing. The communication path 113 connects the first opening 1113a and the second and third openings 113b and 113c, and connects the back pressure chamber 114 and the pressure chamber 115 to each other. Since the pressure chamber 115 is connected to the valve passage 16 of the control valve 4, the back pressure chamber 114 communicates with the valve passage 16 of the control valve 4 through the communication passage 113.

  Next, the configuration of the control valve 4 will be described.

  A primary port 11, a valve chamber 18, a passage 16, a secondary port 12, a pressure equalizing passage 17, a spring chamber 19, a valve port 20, and a solenoid 100 are integrally formed in the housing 10 of the control valve 4.

  The valve chamber 18 communicates with the high-pressure pipe 3 </ b> A through the primary port 11, and communicates with the low-pressure pipe 3 </ b> B through the passage 16 and the secondary port 12.

  The pressure equalizing passage 17 is a branch of the passage 16 and connects the passage 16 and the spring chamber 19.

  The primary port 11 is connected to the high pressure pipe 3A, and the secondary port 12 is connected to the low pressure pipe 3B.

  Inside the valve chamber 18, a valve body 13 for controlling the communication state between the valve chamber 18 and the passage 16 is arranged. The valve body 13 has a taper portion along the seat portion 16 </ b> A provided at the end portion of the passage 16 on the valve chamber 18 side.

  A shaft 14 is formed integrally with the valve body 13, and the shaft 14 is disposed so as to be able to advance and retract within the valve port 20. The shaft 14 also serves as a plunger rod of the solenoid 100, and moves in the left-right direction in the figure according to the magnitude of the energized current. When the power is turned off, the tapered surface of the valve body 13 and the seat portion 16A are in close contact with each other. The communication between the valve chamber 18 and the passage 16 is blocked. On the other hand, the communication between the valve chamber 18 and the spring chamber 19 is blocked by a seal member 30 described later.

  A spring 15 is disposed in the spring chamber 19. The elastic force of the spring 15 acts so as to press the valve body 13 toward the passage 16 side.

  Further, in order to reduce the primary pressure effect on the valve body 13, the seat diameter of the valve body 13, that is, the diameter D2 of the end of the seat portion 16A on the valve chamber 18 side is equal to the sliding seal diameter D1 of the valve body 13. Equivalent.

  According to the above configuration, when the valve body 13 is opened, the hydrogen flowing into the valve chamber 18 from the high pressure pipe 3A via the primary port 11 is transferred to the low pressure pipe 3B via the passage 16 and the secondary port 12. Flowing. The flow rate to the low pressure pipe 3B is determined by the positional relationship between the valve body 13 and the seat portion 16A in accordance with the differential pressure across the valve body 13, and the positional relationship is determined by the electromagnetic force for moving the valve body 13. That is, the stroke amount of the valve body 13 can be controlled by changing the electromagnetic force.

  FIG. 3 is an enlarged view of the vicinity of the seal member 30 of FIG. The seal member 30 is an O-ring housed in a groove-like recess 14 </ b> A provided on the outer periphery of the shaft 14. A so-called D-ring having a D-shaped cross section may be used.

  The seal member 30 is pressed and crushed by the bottom surface of the recess 14 </ b> A and the inner peripheral surface of the valve port 20, thereby ensuring a sealing property between the valve chamber 18 and the spring chamber 19.

  By the way, in the configuration in which the hydrogen gas supplied from the hydrogen tank 2 is reduced to the pressure to be supplied to the fuel cell stack 1 only by the control valve 4 as in the fuel supply system 40 shown in FIG. Sealability in a high pressure environment is required. That is, as the amount of hydrogen stored in the hydrogen tank 2 increases, the pressure in the primary port 11 increases. Therefore, even in such a high pressure environment, a sealing performance that can reliably block the communication between the valve chamber 18 and the spring chamber 19 is required. Is done.

  Further, as the amount of hydrogen stored in the hydrogen tank 2 decreases, the pressure in the primary port 11 decreases, and the amount of movement of the valve body 13 for adjusting the pressure increases. For this reason, in order to increase the accuracy of pressure control, the seal member 30 is required to have a lower sliding resistance.

  However, high sealing performance and low sliding resistance are contradictory performances. If priority is given to sealing properties, sliding resistance increases, sliding properties deteriorate, and the amount of wear during sliding increases. As wear progresses, the sealing performance deteriorates. Such deterioration of the sealing performance becomes more prominent as the number of actuations of the valve body 13 increases.

  In this respect, the above-described problem can be reduced if the system is configured to reduce pressure in multiple stages from the hydrogen tank 2 to the fuel cell stack 1 via a plurality of pressure reducing valves as in the prior art. That is, it is possible to use a seal member that prioritizes sealing performance on the high pressure side and a seal member that prioritizes sliding performance on the low pressure side. In addition, the use of a plurality of pressure reducing valves can reduce the number of operations of each pressure reducing valve, thereby eliminating the problem of wear.

  On the other hand, when the pressure is reduced with only one control valve 4, it is necessary to achieve both high sealing performance and low sliding resistance with one sealing member 30. Furthermore, since the number of times of operation of the control valve 4 is increased as compared with the case where a plurality of pressure reducing valves are used, it is necessary to solve the problem of wear.

  Therefore, in the present embodiment, the control valve 4 and the seal member 30 are configured as described below.

  FIG. 4 is a diagram illustrating the static frictional force characteristics of the seal member 30 and the stroke characteristics of the valve body 13. The vertical axis indicates the stroke of the valve body 13, and the horizontal axis indicates the primary pressure, that is, the pressure in the hydrogen tank 2 detected by the pressure sensor 7. A solid line A in the figure shows an example of stroke characteristics of the valve body 13.

  A broken line F (hereinafter referred to as a static friction force line F) in the figure indicates a maximum stroke at which the seal member 30 does not slide when the valve body 13 is moved at the primary pressure. In the static friction force line F, the static friction force decreases as the primary pressure decreases. That is, the sliding resistance decreases as the primary pressure decreases.

  If the stroke of the valve body 13 is a region below the static frictional force line F in FIG. 4 (hereinafter referred to as an elastic region), the contact portion between the seal member 30 and the valve port 20 does not move, and the seal member 30 is elastic. The movement of the valve body 13 is followed only by deformation. On the other hand, if the stroke of the valve body 13 is a region above the static frictional force line F in FIG. 4 (hereinafter referred to as a sliding region), the contact portion between the seal member 30 and the valve port 20 moves.

  The static frictional force line F depends on the design of the seal member 30, that is, hardness, size, initial crushing allowance, material, and the like.

  For example, when the seal member 30 is an O-ring, the seal member 30 is elastically deformed in the elastic region when the formula (1) is established.

    Friction coefficient x (π x O-ring outer diameter) x (O-ring wire diameter) x inlet pressure> stroke x elastic modulus (1)

  However, the friction coefficient is the friction coefficient of the sliding surface of the valve port 20, the inlet pressure is the pressure of the primary port 11, and the elastic coefficient is the elastic coefficient of the seal member 30.

  The stroke characteristics of the valve body 13 depend on the shapes of the valve body 13 and the seat portion 16A, the carrier frequency for operating the valve body 13, and the like.

  The flow rate of hydrogen that flows into the secondary port 12 in order to set the pressure in the secondary port 12 to the target value (hereinafter referred to as the target hydrogen flow rate) is the cross-sectional area of the flow path, the valve opening time and the number of valve openings. It is obtained by the product of.

  The cross-sectional area of the flow path is the area of the gap between the valve body 13 and the seat portion 16A, and is a function of the stroke. How much the cross-sectional area of the flow path is determined by the stroke depends on the design of the valve body 13 and the seat portion 16A.

  The number of valve openings decreases as the carrier frequency decreases, and increases as the carrier frequency increases. The valve opening time depends on the carrier frequency, that is, the number of times of valve opening and the flow path cross-sectional area. For example, the smaller the number of valve opening times or the smaller the channel cross-sectional area, the longer the valve opening time necessary to achieve the target hydrogen flow rate. In the carrier frequency region where the valve body 13 cannot follow, it depends only on the flow path cross-sectional area determined by the stroke of the valve body 13 and not the number of valve openings. Therefore, it depends only on the cross-sectional area of the flow path regardless of the valve opening time.

  Therefore, the valve body 13, the seat portion 16A, and the carrier frequency are set so that the stroke characteristics of the valve body 13 become a solid line A (hereinafter referred to as stroke characteristic line A).

  A stroke characteristic line A indicates the stroke characteristic at the rated output. Therefore, the stroke is smaller than the stroke characteristic line A when the load is small and the amount of hydrogen supplied to the fuel cell stack 1 is smaller than that at the rated output, such as when traveling at a constant speed or idling.

  If the stroke characteristic line A and the static friction force line F are set as shown in FIG. 4, the seal member 30 does not slide if the primary pressure is equal to or higher than PA1, which is the intersection of the stroke characteristic line A and the static friction force line F. On the other hand, when the primary pressure is lower than PA1, when the stroke exceeds the static frictional force line F, the seal member 30 slides, and when it does not exceed, the seal member 30 does not slide. In this embodiment, the carrier frequency is constant.

  As described above, in the region where the primary pressure is high, when the valve body 13 moves, the seal member 30 only elastically deforms and does not slide. Since the wear of the seal member 30 can be suppressed by not sliding, durability can be improved while securing the sealability using a material having excellent sealability.

  On the other hand, the seal member 30 slides in a region where the sliding resistance is relatively low, but the wear of the seal member 30 is less than that in a case where the seal member 30 slides under a high pressure, so that a decrease in durability can be suppressed. . Further, when the control current of the valve body 13 is changed, hysteresis is generated in the secondary port pressure, but it is known from experiments that the hysteresis is smaller when the stroke is in the sliding region than in the elastic region. If the hysteresis is small, the control accuracy is naturally increased.

  That is, by sliding the seal member 30 in a region where the primary pressure is low, the control accuracy of the valve body 13 can be improved, and as a result, the control accuracy of the hydrogen supply amount can be improved. Furthermore, wear of the seal member 30 due to sliding can be suppressed.

  The static friction force line F and the stroke characteristic line A are set based on how the fuel supply system 40 is used. For example, what is the service life required for the fuel supply system 40, what kind of primary pressure the vehicle on which the fuel supply system 40 is mounted travels frequently, and how much the primary pressure becomes sliding This should be set in consideration of whether priority should be given to improving control accuracy over wear due to wear. In order to improve control accuracy under low pressure, the stroke is set so that the stroke is equal to or greater than the static friction force line F even in the idling region in the region where the primary pressure is lower than PA1.

  As described above, the valve body 13 moves back and forth with a stroke characteristic in which at least the primary pressure has an elastic region in the high pressure side region and at least the primary pressure has a sliding region in the low pressure side region. As a result, even when there is only one control valve 4 between the hydrogen tank 2 and the fuel cell stack 1, it is possible to achieve both the sealing performance under high pressure and the control accuracy of the hydrogen supply amount under low pressure.

  Further, by setting the region where the primary pressure is PA1 or higher as the elastic region, it is possible to suppress wear of the seal member 30 as compared to the case where sliding is performed in all regions.

  FIG. 7 is a flowchart showing a control routine executed by the controller 6 in the present embodiment.

  The controller 6 sets the value of PA1 in step S101 as described above, and measures the primary pressure Px in step S102. In step S103, the primary pressure Px and PA1 are compared. If the primary pressure Px is equal to or higher than PA1, the process of step S104 is executed. If the primary pressure Px does not exceed PA1, the process of step S105 is executed.

  In step S104, the controller 6 determines to control the control valve 4 in the elastic region. In this region, the stroke of the control valve 4 is controlled.

  In step S105, the controller 6 determines to control the control valve 4 in the sliding area. In the sliding area, the valve opening time of the control valve 4 is controlled.

  In step S106, the controller 6 controls the control valve 4 by the control method determined in step S104 or S105.

  Even if the stroke is controlled in the region where the primary pressure Px does not exceed PA1, the stroke of the control valve 4 may increase depending on the hydrogen supply amount, and may enter the sliding region. That is, even if the stroke is controlled regardless of the primary pressure Px, the control is performed in the elastic region if the stroke is small, and the control is performed in the sliding region if the stroke is large, and a desired control state is obtained. Therefore, the stroke may always be controlled without switching the control method according to the primary pressure Px.

(Second Embodiment)
In the second embodiment, the basic configuration of the fuel supply system 40 and the control valve 4 is the same as that of the first embodiment. The difference from the first embodiment is the relationship between the primary pressure used for the determination of switching between sliding and non-sliding of the seal member 30, the static friction force line F, and the stroke characteristic line A. In this embodiment, the carrier frequency is constant. However, in a region where the primary pressure is PA2 or less, which will be described later, the stroke is set to a carrier frequency that can be set to a maximum value or a value close thereto.

  FIG. 5 is a view showing the static frictional force characteristics of the seal member 30 and the stroke characteristics of the valve body 13 in the same manner as FIG. The static friction force line F is the same as in the first embodiment.

  The stroke characteristic line A is basically set in the same manner as in the first embodiment. However, in the region where the primary pressure is lower than PA2, the stroke of the sliding region is made by controlling the valve opening time by the controller 6 as the switching means.

  FIG. 8 is a flowchart showing a control routine executed by the controller 6 in the present embodiment.

  The controller 6 sets a value of PA2 described later at step S201, and measures the primary pressure Px at step S202. In step S203, the primary pressure Px and PA2 are compared. If the primary pressure Px is equal to or greater than PA2, the process of step S204 is executed, and if the primary pressure Px is lower, the process of step S205 is executed.

  In step S204, it is determined to control the control valve 4 in the elastic region. In this region, the stroke of the control valve 4 is controlled. In step S205, it is determined to control the control valve 4 in the sliding region. In this region, the valve opening time of the control valve 4 is controlled. In step S206, the control valve 4 is controlled by the control method determined in step S204 or step S205. That is, in a region where the primary pressure Px is lower than PA2, the seal member 30 slides regardless of the magnitude of the load.

  As described above, the hydrogen supply amount is represented by the product of the stroke, the valve opening time, and the number of times of opening. Therefore, when the carrier frequency is constant, that is, when the number of times of opening of the valve is constant, the hydrogen supply amount is determined by the valve opening time and the stroke. Therefore, the valve opening time is controlled so that the target hydrogen flow rate can be achieved by fixing the stroke to the size of the sliding region. As described above, the control accuracy is improved by sliding the seal member 30.

  The primary pressure PA2 is set to, for example, a primary pressure at which a hydrogen remaining amount warning lamp is lit to warn that the amount of hydrogen in the hydrogen tank 2 is low. In the case of a 70 MPa tank, the pressure is about 8-10 MPa.

  The estimated travelable distance based on the amount of hydrogen remaining in the hydrogen tank 2 is a judgment material when the driver determines whether or not to supply hydrogen. In particular, in a state in which the remaining hydrogen warning light is turned on, it is desired that the predicted accuracy of the predicted travelable distance is high in order to supply hydrogen before traveling becomes impossible.

  The fuel cell system stops when there is no hydrogen in the hydrogen tank 2, but the threshold used to determine whether or not to stop is that hydrogen is supplied even if there is a detection error of the pressure sensor or an error in the hydrogen supply amount. Set so that it is possible to reliably avoid driving in a state where it is not performed. For this reason, the system is actually stopped even though hydrogen remains in the tank. In this case, as the amount of hydrogen remaining in the tank (hereinafter referred to as an invalid remaining amount) increases, the travelable distance of the vehicle becomes shorter. Therefore, it is desirable that the invalid remaining amount be smaller. Therefore, it is desired that the control accuracy of the hydrogen supply amount be higher in the region where it is determined whether or not to stop the fuel cell system.

  That is, the region where the remaining hydrogen warning light is turned on is a region where highly accurate hydrogen supply amount control is particularly desired for predicting the travelable distance, determining whether the system is stopped, etc., and sliding the seal member 30. The effect of improving the control accuracy is great. Therefore, in the region where the hydrogen remaining amount warning lamp is lit, the valve opening time is controlled so as to be a sliding region even if it is an elastic region in terms of stroke characteristics.

  Note that if the stroke in the region where the primary pressure is lower than PA2 is set to the maximum possible value in terms of mechanism, the stroke amount per adjustment amount of the hydrogen supply amount increases, so that the control accuracy can be further increased.

  In the above description, the primary pressure PA2 is the primary pressure at which the hydrogen remaining amount warning lamp is lit, but the present invention is not limited to this. For example, the primary pressure may be the same as the primary pressure PA1 of the first embodiment.

  As described above, in the region where the primary pressure is lower than PA2, the stroke of the valve body 13 is increased to the sliding region, so that the control accuracy under a low pressure can be further increased.

  Further, since the stroke of the valve body is increased by shortening the valve opening time of the valve body 13, it is possible to secure the hydrogen supply amount while increasing the stroke.

  The primary pressure PA2 is an internal pressure at which a hydrogen remaining amount warning light is lit to warn the driver that the remaining amount of hydrogen in the hydrogen tank 2 is low, so that it meets the demand in a region where higher control accuracy is required. Can do.

(Third embodiment)
In the third embodiment, the basic configuration of the fuel supply system 40 and the control valve 4 is the same as that of the first embodiment. The difference from the first embodiment is the content of the sliding / non-sliding switching control of the seal member 30.

  FIG. 6 is a diagram showing the relationship between the primary pressure and the carrier frequency. The vertical axis is the carrier frequency, and the horizontal axis is the primary pressure. In the region where the primary pressure is PA3 or lower, the carrier frequency is H1, and in the region higher than PA3, the carrier frequency is H2 higher than H1. Such control of the carrier frequency is performed by the controller 6 as switching means. The opening time of the valve body 13 is constant even if the carrier frequency changes.

  The primary pressure PA3 is set to a pressure at which the hydrogen remaining amount warning lamp is turned on, as in the second embodiment. For example, it is set to about 10 MPa.

  The carrier frequency H1 is set to such a magnitude that the valve body 13 can operate following the ON / OFF switching of the control current, for example, 100 Hz. In addition, the seal member 30, the valve body 13, etc. are designed so that the stroke of the seal member 30 becomes a sliding region at the carrier frequency H1.

  That is, in the case of the carrier frequency H1, the valve body 13 opens and closes according to the ON / OFF of the control current, and at this time, the seal member 30 slides. Therefore, compared to the case where the seal member 30 does not slide, the hysteresis of the change in the opening degree of the valve body 13 when the control current is changed is reduced, and the control accuracy is increased.

  On the other hand, the carrier frequency H2 is set to such a magnitude that the valve body 13 cannot operate following the ON / OFF switching of the control current, for example, 500 Hz. At such a carrier frequency H2, since the ON / OFF switching of the control current is fast, it becomes a state equivalent to that a constant current continues to flow. And the valve body 13 stops at the opening according to the magnitude | size of the electric current. That is, in the case of the carrier frequency H2, the seal member 30 does not slide. Therefore, wear of the seal member 30 can be suppressed.

  The controller 6 sets the carrier frequency to H2 when the hydrogen tank 2 is fully filled, and switches the carrier frequency to H1 when the primary pressure decreases to PA3 due to a decrease in hydrogen.

  FIG. 9 is a flowchart showing a control routine executed by the controller 6 in the present embodiment.

  The controller 6 sets a value of PA3 described later in step S301, and measures the primary pressure Px in step S302. In step S303, the primary pressure Px and PA3 are compared. If the primary pressure Px is equal to or higher than PA3, the process of step S304 is executed. If the primary pressure Px is lower, the process of step S305 is executed.

  In step S304, it is determined to control the control valve 4 in the elastic region by setting the carrier frequency to H2 on the higher side. In this region, the stroke of the control valve 4 is controlled. In step S305, it is determined that the control valve 4 is controlled in the sliding region by setting the carrier frequency to the lower H1. In this region, the valve opening time of the control valve 4 is controlled. In step S306, the control valve 4 is controlled at the carrier frequency determined in step S304 or step S305. The higher carrier frequency H2 is desirably 200 Hz or higher, and the lower carrier frequency H1 is desirably 100 Hz or lower. Thereby, the seal member 30 does not slide in a relatively high pressure region, and the seal member 30 slides in a relatively low pressure region, for example, a region where a hydrogen remaining amount warning lamp is lit.

  Therefore, also in this embodiment, it is possible to achieve both sealing performance under high pressure and control accuracy under low pressure.

  As described above, since the stroke of the valve element 13 is increased by lowering the carrier frequency, it is possible to secure the hydrogen supply amount while increasing the stroke.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.

DESCRIPTION OF SYMBOLS 1 Fuel cell stack 2 Hydrogen tank 3 Hydrogen supply passage 4 Control valve 5 On-off valve 6 Controller 7 Pressure sensor 8 Pressure sensor 10 Housing 11 Primary port 12 Secondary port 13 Valve body 14 Shaft 15 Spring 16 Passage 17 Pressure equalization passage 18 Valve chamber DESCRIPTION OF SYMBOLS 19 Spring chamber 20 Valve port 30 Seal member 40 Fuel supply system 100 Solenoid 101 Solenoid coil 102 Movable member 103 Bearing member 104 Casing 105 Bobbin 106 Coil 107 Yoke 108 Guide member 109 Compression coil spring 110 Gap 111 1st diaphragm 112 2nd Diaphragm 113 Communication path 114 Back pressure chamber 115 Pressure chamber

Claims (6)

A housing comprising a primary port connected to the hydrogen tank and a secondary port connected to the fuel cell stack;
The primary port and the secondary port are moved forward and backward by a stroke corresponding to the amount of hydrogen supplied from the primary port to the secondary port and the pressure in the hydrogen tank in the valve port provided in the housing. A valve body that controls the communication area of
A seal member disposed on the outer periphery of the shaft portion of the valve body so as to contact the wall surface of the valve port;
In a pressure adjustment device of a fuel cell system comprising:
The stroke characteristic of the valve body has at least an elastic region in which the pressure in the hydrogen tank is a stroke that does not slide between the valve port only by elastically deforming the seal member in a region on the high pressure side, The pressure adjustment device for a fuel cell system, wherein the pressure in the hydrogen tank has a sliding region in a region on a low pressure side, which has a stroke in which the seal member slides between the valve port and the valve member.   2. The pressure adjustment device for a fuel cell system according to claim 1, wherein the elastic region is an entire region in which the pressure in the hydrogen tank is equal to or greater than a predetermined value.   3. The fuel according to claim 2, further comprising stroke switching means for increasing the stroke to the sliding region when the pressure in the hydrogen tank is lower than the predetermined value and the stroke based on the stroke characteristic is in the elastic region. Battery system pressure regulator.   The pressure adjusting device for a fuel cell system according to claim 3, wherein the stroke switching means increases the stroke of the valve body by shortening a valve opening time of the valve body. The valve body opens and closes by electromagnetic force,
The pressure adjusting device for a fuel cell system according to claim 3, wherein the stroke switching means increases the stroke of the valve body by lowering a carrier frequency for generating electromagnetic force.   6. The fuel cell according to claim 2, wherein the predetermined value is a pressure in the hydrogen tank at which a hydrogen remaining amount warning lamp that warns a driver that the remaining amount of hydrogen in the hydrogen tank is low. System pressure regulator.

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