JP4367160B2 - Pressure regulating valve - Google Patents

Description

  The present invention relates to a pressure regulating valve that regulates fluid flowing into a primary side flow path and discharges it to a secondary side flow path, and is particularly suitable for being disposed in a hydrogen supply pipe for supplying hydrogen to an anode of a fuel cell. Related to a pressure regulating valve.

  A fuel cell has a structure in which an anode and a cathode are arranged with an electrolyte membrane in between. A fuel gas containing hydrogen contacts the anode, and an oxidizing gas containing oxygen such as air contacts the cathode, and electricity is supplied to both electrodes. A chemical reaction occurs and an electromotive force is generated. In a conventional fuel cell system equipped with such a fuel cell, generally, fuel gas supplied from a high-pressure hydrogen tank is supplied to the anode of the fuel cell, and air taken in by a compressor is supplied to the cathode.

In the conventional fuel cell system, the pressure of air supplied to the cathode is adjusted to a pressure corresponding to the required output of the fuel cell by controlling the amount of air supplied by the compressor. On the other hand, the pressure of the fuel gas supplied to the anode is adjusted to a pressure corresponding to the air pressure supplied to the cathode by a pressure adjusting valve provided in the fuel gas supply line, as described in Patent Document 1, for example. . The pressure regulating valve described in Patent Document 1 is a pneumatic proportional pressure control valve, which uses the pressure of air supplied from the compressor as a signal pressure, and the outlet pressure of the pressure regulating valve corresponds to the signal pressure. Thus, the pressure of the fuel gas is controlled to be reduced.
JP 2002-373682 A

  However, in the pressure regulating valve as in the above prior art, it is necessary to connect a path for supplying air pressure to the pressure regulating valve from the cathode side, which complicates the apparatus configuration. In particular, in the case of an in-vehicle fuel cell system, it is desirable to simplify the device configuration as much as possible due to installation space limitations. Moreover, since there is a possibility that impurities such as fats and oils may be mixed in the air taken in from the outside, the pressure regulating valve may break down due to the accumulation of impurities. Furthermore, in the conventional pressure regulating valve, the air flow rate is adjusted according to the change in the required output of the fuel cell, and the pressure of the fuel gas is adjusted after the air pressure changes due to the adjustment of the air flow rate. There will be a time delay from when the required output of the battery changes until the fuel gas pressure is adjusted.

  The above disadvantages in the conventional pressure regulating valve are caused by using the pressure of the air supplied to the cathode as a control pressure for controlling the pressure regulation value of the pressure regulating valve. If a pressure regulating valve capable of controlling the pressure regulation value independently without using supply air to the cathode can be realized, the above disadvantages can be avoided. However, if the operation performance of the fuel cell is taken into consideration, it is desired to obtain a pressure regulation characteristic that the pressure regulation value increases as the flow rate of the fuel gas increases. This is because such a pressure regulation characteristic makes it possible to improve the power generation efficiency and durability of the fuel cell as compared with the case where the pressure is always controlled to be constant. Further, there is an advantage that the diameter of the flow path of the fuel gas can be reduced by increasing the pressure at a high flow rate. In addition, the flow rate of the fuel gas increases when purging with the exhaust valve open, but the pressure adjustment value at that time increases, so that even a small exhaust valve can purge the required amount of fuel gas within the required time. There is also an advantage that it becomes possible. As a pressure regulating valve that satisfies the above requirements, an electromagnetic valve that can electrically control the pressure regulation value is conceivable. However, from the viewpoint of the reliability of the device, such an electrical means is not used. It is desirable that the pressure regulation value can be controlled only by mechanical means.

  The present invention has been made to solve the above-described problems, and has a pressure regulation characteristic in which the pressure regulation value increases as the flow rate increases without requiring the supply of control pressure from the outside. An object of the present invention is to provide a mechanical pressure regulating valve that can be realized independently.

In order to achieve the above object, the first invention provides a pressure regulating valve that regulates the fluid flowing into the primary side flow path and discharges it to the secondary side flow path.
A valve seat provided in an opening between the primary side flow path and the secondary side flow path;
A valve body arranged to be displaceable with respect to the valve seat;
A spring connected to the valve body and acting on the valve body with thrust in an opening direction according to a displacement amount of the valve body;
A diaphragm connected to the valve body and receiving a pressure of a fluid in the secondary-side flow path to cause a thrust in a closing direction to act on the valve body;
A balance chamber that is provided separately from the primary side flow path and the secondary side flow path and causes the pressure of the internal fluid to act on the valve body as thrust in the closing direction;
A throttle formed in the primary flow path;
A communication path for communicating the throttle part and the balance chamber;
It is characterized by having.

In order to achieve the above object, the second invention provides a pressure regulating valve that regulates the fluid flowing into the primary channel and discharges it to the secondary channel,
A valve seat provided in an opening between the primary side flow path and the secondary side flow path;
A valve body arranged to be displaceable with respect to the valve seat;
A spring connected to the valve body and acting on the valve body with thrust in an opening direction according to a displacement amount of the valve body;
A pressure chamber provided separately from the primary channel and the secondary channel;
A diaphragm connected to the valve body and receiving a pressure of fluid in the pressure chamber to apply a thrust in the closing direction to the valve body;
A throttle formed in the secondary channel,
A communication path for communicating the throttle part and the pressure chamber;
It is characterized by having.

According to a third aspect of the present invention, in order to achieve the above object, in the pressure regulating valve for regulating the fluid flowing into the primary side flow path and discharging it to the secondary side flow path,
A valve seat provided in an opening between the primary side flow path and the secondary side flow path;
A valve body arranged to be displaceable with respect to the valve seat;
A spring connected to the valve body and acting on the valve body with thrust in an opening direction according to a displacement amount of the valve body;
A diaphragm connected to the valve body and receiving a pressure of a fluid in the secondary-side flow path to cause a thrust in a closing direction to act on the valve body;
A balance chamber that is provided separately from the primary side flow path and the secondary side flow path and causes the pressure of the internal fluid to act on the valve body as thrust in the closing direction;
A throttle formed in the secondary channel,
A communication path for communicating the throttle part and the balance chamber;
It is characterized by having.

According to a fourth aspect of the present invention, there is provided a fuel cell system including a fuel cell that generates power by receiving a supply of a fuel gas containing hydrogen, and a fuel gas passage for supplying fuel gas to an anode of the fuel cell.
A pressure regulating valve according to any one of the first to third inventions is arranged in the fuel gas passage.

  According to the first aspect of the present invention, when the flow rate of the fluid flowing into the primary channel increases, the fluid flow rate in the throttle portion increases, whereby the fluid in the balance chamber communicated with the throttle portion by the communication path. The pressure drops. The valve body is displaced to a position where the thrust in the opening direction received from the spring, the thrust in the closing direction received from the fluid in the secondary flow path via the diaphragm, and the thrust in the closing direction received from the fluid in the balance chamber are balanced. The valve body is driven in the opening direction due to a decrease in the thrust in the closing direction received from the fluid in the balance chamber, and thereby the pressure of the fluid in the secondary side flow path increases. As described above, according to the first aspect of the present invention, it is necessary to provide a pressure regulation characteristic in which the pressure regulation value increases with an increase in the flow rate by mechanical means, and further, it is necessary to supply a control pressure from the outside. It can be realized alone.

  According to the second invention, when the flow rate of the fluid flowing into the primary flow path increases, the flow rate of the fluid discharged to the secondary flow path also increases, and the flow velocity of the fluid at the throttle portion increases. Thus, the pressure of the fluid in the pressure chamber communicating with the throttle portion by the communication path is reduced. The valve body is displaced to a position where the thrust in the opening direction received from the spring balances the thrust in the closing direction received from the fluid in the pressure chamber via the diaphragm, so that the thrust in the closing direction received from the fluid in the pressure chamber via the diaphragm is reduced. Due to the decrease, the valve body is driven in the opening direction, whereby the pressure of the fluid in the secondary side channel increases. As described above, according to the second aspect of the present invention, it is necessary to provide a pressure regulation characteristic in which the pressure regulation value increases with an increase in the flow rate by mechanical means, and further, it is necessary to supply a control pressure from the outside. It can be realized alone.

  According to the third invention, when the flow rate of the fluid flowing into the primary side flow path increases, the flow rate of the fluid discharged to the secondary side flow path also increases, and the flow velocity of the fluid at the throttle portion increases. As a result, the pressure of the fluid in the balance chamber communicating with the throttle portion by the communication path is reduced. The valve body is displaced to a position where the thrust in the opening direction received from the spring, the thrust in the closing direction received from the fluid in the secondary flow path via the diaphragm, and the thrust in the closing direction received from the fluid in the balance chamber are balanced. The valve element is driven in the opening direction due to a decrease in the thrust in the closing direction received from the fluid in the balance chamber, whereby the pressure of the fluid in the secondary flow path increases. As described above, according to the third aspect of the invention, it is necessary to provide a pressure regulation characteristic in which the pressure regulation value increases with an increase in the flow rate by mechanical means, and also requires the supply of the control pressure from the outside. It can be realized alone.

  According to the fourth aspect of the invention, a highly reliable fuel cell system can be realized by arranging the mechanical pressure regulating valve as described above in the fuel gas passage. In addition, since the pressure regulating valve has a pressure regulating characteristic that the pressure regulating value increases as the flow rate increases, the power generation efficiency and durability of the fuel cell are compared to the case where the pressure is constantly controlled at a constant pressure. There is also an advantage that it is advantageous in the operation of the fuel cell, such as being able to improve the performance.

Embodiment 1 FIG.
The first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a schematic cross-sectional view showing a configuration of a pressure regulating valve 2A as Embodiment 1 of the present invention. The pressure regulating valve 2A has a first casing 4 and a second casing 6 that constitute an outer shell. A diaphragm 10 is sandwiched between the first casing 4 and the second casing 6, and internal spaces 14 and 38 formed by the first casing 4 and the second casing 6 are partitioned by the diaphragm 10.

  A space 14 formed by the first casing 4 and the diaphragm 10 is a back pressure chamber into which atmospheric pressure is introduced. A spring 16 is disposed in the back pressure chamber 14 and connects the first casing 4 and the diaphragm 10. The spring 16 is used to set a reference value for the pressure regulation value of the fluid, and biases the diaphragm 10 to the side opposite to the back pressure chamber 14.

  On the other hand, the space 38 formed by the second casing 6 and the diaphragm 10 constitutes a secondary flow path for the fluid to be regulated. The secondary channel 38 is connected to a fluid outlet 39 formed on the side surface of the second casing 6. A force due to a differential pressure between the fluid pressure in the secondary side flow path 38 and the atmospheric pressure in the back pressure chamber 14 acts on the diaphragm 10 as a thrust force that displaces the diaphragm 10.

  The second casing 6 is also formed with a primary flow path 30 of the fluid to be regulated. The primary channel 30 is provided on the side opposite to the back pressure chamber 14 with respect to the secondary channel 38. The primary side flow path 30 and the secondary side flow path 38 are partitioned by a partition wall 36, but the partition wall 36 is formed with an opening 34 that communicates the primary side flow path 30 and the secondary side flow path 38. Has been. The primary-side flow path 30 is connected to a fluid inlet 32 formed on the side surface of the second casing 6, and the fluid that has flowed into the primary-side flow path 30 from the fluid inlet 32 passes through the opening 34 and becomes a secondary-side flow path. 38 is discharged from the fluid outlet 32 to the outside.

  Further, the second casing 6 is provided with a valve mechanism for regulating the pressure of the fluid flowing from the primary side flow path 30 into the secondary side flow path 38. The valve mechanism includes a valve seat 24 formed in the opening 34 and a valve body 8 that can be displaced with respect to the valve seat 24. The valve seat 24 is formed on the peripheral edge of the opening 34 on the primary flow path 30 side, and the valve body 8 is supported by the second casing 6 on the bearing 22 so that the valve seat 8 can approach / separate from the primary flow path 30 side. Is supported through. The bearing 22 supports the valve body 8 so as to be movable in the axial direction, and the displacement of the valve body 8 relative to the valve seat 24, that is, the opening degree of the valve body 8 is changed by the movement of the valve body 8 in the axial direction. It has become.

  The valve body 8 is provided with a connecting rod 12 extending to the valve seat 24 side. The connecting rod 12 passes through the opening 34 and is connected to the central portion of the diaphragm 10 facing the secondary channel 38. As a result, the valve body 8 and the diaphragm 10 are integrated, and the urging force of the spring 16 and the force that the diaphragm 10 receives from the fluid in the secondary flow path 38 act on the valve body 8 via the connecting rod 12. .

  Further, a balance chamber 18 is formed in the second casing 6 on the side opposite to the primary flow path 30 with respect to the valve body 8. The valve body 8 is exposed in the balance chamber 18 on the surface opposite to the surface in contact with the valve seat 24. The balance chamber 18 is filled with a fluid, and the pressure of the fluid acts on the valve body 8 as a thrust for driving the valve body 8 in the closing direction. Further, a spring 20 is disposed in the balance chamber 18 and connects the second casing 4 and the valve body 8. The spring 20 is used to adjust the reference value of the pressure regulation value of the fluid, and urges the valve body 8 in the closing direction. Since the spring 20 is provided to adjust the urging force that the spring 16 acts on the valve body 8, the spring 20 can be omitted depending on the design such as setting of the spring constant of the spring 16. is there.

  The balance chamber 18 is configured as a sealed space isolated from the primary side flow path 30 and the secondary side flow path 38. A communication passage 42 for introducing pressure is connected to the balance chamber 18, and an end portion on the opposite side of the communication passage 42 is connected to the primary flow path 30. More specifically, an orifice (throttle portion) 40 having a reduced flow area is formed in the primary flow path 30, and the communication path 42 is connected to the orifice 40 and is used for fluid passing through the orifice 40. Static pressure is introduced into the balance chamber 18. Therefore, if the static pressure in the orifice 40 changes, the fluid pressure in the balance chamber 18 also changes, and the thrust in the closing direction acting on the valve body 8 from the fluid in the balance chamber 18 also changes.

  With the above-described configuration, the valve body 8 has an opening direction thrust received from the spring 16, a closing direction thrust received from the fluid in the secondary side flow path 38 via the diaphragm 10, and a closing direction thrust received from the spring 20. And the thrust of the closing direction received from the fluid of the balance chamber 18 acts. In the spring 16 and the spring 20, since the spring force of the spring 16 is larger, the valve body 8 has a thrust (elastic force) having a magnitude corresponding to the spring force difference between the springs 16 and 20 and the displacement amount of the valve body 8. ) Acts in the opening direction. By balancing these thrusts acting on the valve body 8, the pressure regulating valve 2A is provided with an automatic pressure regulating function for maintaining the pressure of the fluid in the secondary side flow path 38 at a substantially constant pressure. For example, when the pressure of the fluid in the secondary side flow path 38 decreases, the force that the diaphragm 10 receives from the fluid in the secondary side flow path 38 decreases, so the thrust in the closing direction of the valve body 8 decreases and the valve The body 8 is driven in the opening direction. As a result, the pressure of the fluid in the secondary side flow path 38 increases as the opening of the valve body 8 increases, and is maintained at a constant pressure again. Conversely, when the pressure of the fluid in the secondary side flow path 38 increases, the valve body 8 is driven in the closing direction as the force that the diaphragm 10 receives from the fluid in the secondary side flow path 38 increases. The pressure of the fluid in the secondary flow path 38 decreases as the opening of the valve body 8 decreases, and is maintained at a constant pressure again.

  In addition to the automatic pressure regulating function, the pressure regulating valve 2A configured as described above also has a function of changing the pressure regulation value in accordance with the flow rate. More specifically, when the flow rate of the fluid flowing into the primary side flow path 30 increases, the flow velocity of the fluid at the orifice 40 increases, and the static pressure at the orifice 40 decreases accordingly. Since the orifice 40 is connected to the balance chamber 18 by the communication path 42, the fluid pressure in the balance chamber 18 decreases when the static pressure in the orifice 40 decreases. The valve body 8 has an opening direction thrust received from the springs 16, 20, a closing direction thrust received from the fluid in the secondary side flow path 38 via the diaphragm 10, and a closing direction thrust received from the fluid in the balance chamber 18. Since it is displaced to a balanced position, the valve body 8 is driven in the opening direction due to a decrease in thrust in the closing direction received from the fluid in the balance chamber 18, and the fluid pressure in the secondary side flow path 38 increases the opening of the valve body 8. It rises with.

  Thus, according to the pressure regulating valve 2A according to the present embodiment, it is possible to realize a pressure regulation characteristic (a pressure regulation characteristic that rises to the right) such that the pressure regulation value increases as the flow rate increases. In addition, high reliability is ensured by using purely mechanical means without using electrical means such as solenoid valves, and it is possible to supply control pressure from the outside as in the prior art. Since it is not necessary, it can be expected to improve reliability by simplifying the device configuration.

  The use of the pressure regulating valve 2A according to the present embodiment is preferably used as a fuel gas pressure regulating means supplied to the anode of the fuel cell in the fuel cell system. FIG. 2 is a schematic diagram showing a configuration of a fuel cell system to which the pressure regulating valve 2A according to the present embodiment is applied.

  The fuel cell system includes a fuel cell stack 80 configured by stacking a plurality of single cells of a fuel cell. A fuel gas supply pipe 92 for supplying a fuel gas containing hydrogen to the anode of each single cell is connected to the fuel cell stack 80. A hydrogen supply device (not shown) such as a hydrogen tank or a reformer is connected to the upstream side of the fuel gas supply pipe 92. The pressure regulating valve 2A is disposed in the fuel gas supply pipe 92, and the fuel gas supplied from the hydrogen tank or the like is decompressed by the pressure regulating valve 2A and adjusted to a desired pressure before being supplied to the fuel cell stack 80. The fuel cell stack 80 is connected to an air supply pipe 94 for supplying air to the cathode of each single cell. An air pump 82 is disposed in the air supply pipe 94, and air is taken into the air supply pipe 94 from the outside and supplied to the cathode by the operation of the air pump 82.

  The flow rate of the fuel gas flowing through the fuel gas supply pipe 92 varies depending on the power generation load of the fuel cell stack 80. Although the flow rate of the fuel gas increases at a high load, the pressure regulating valve 2A having a pressure-rising characteristic that rises rightward is disposed in the fuel gas supply pipe 92, so that the fuel gas stack 80 is supplied with an increase in the flow rate. The pressure of the generated fuel gas will increase. This makes it possible to supply high-pressure fuel gas at high output, and improve the power generation efficiency and durability of the fuel cell stack 80 as compared to the case of always supplying constant-pressure fuel gas as in the prior art. It becomes possible. Further, the diameter of the fuel gas supply pipe 92 can be reduced by increasing the pressure when the fuel gas flow rate is high.

  Further, although not shown, there is a fuel cell system in which an exhaust valve (shutoff valve) is provided in a passage of fuel off-gas discharged from the anode. In such a system, control is performed to open (purge) the fuel off-gas outside the system by opening an exhaust valve when a predetermined time has come to discharge impurities accumulated in the anode system. At this time, the flow rate of the fuel gas is increased by opening the exhaust valve. However, if the pressure regulating valve 2A is provided, the pressure regulation value at that time increases. There is also an advantage that the fuel gas can be purged within the required time.

  By the way, in the fuel cell system, in order to avoid damage to the electrolyte membrane of the fuel cell, a differential pressure between the pressure of the fuel gas supplied to the anode and the pressure of the air supplied to the cathode is defined. It is necessary to drive while keeping the value below. In the fuel cell system according to the present embodiment, the fuel gas pressure is mechanically regulated by the pressure regulating valve 2A. Therefore, the air pressure needs to be controlled in order to adjust the inter-electrode differential pressure.

  The air pressure is controlled by controlling an air pump 82 by an ECU (Electronic Control Unit) 90. The ECU 90 sets the target air pressure according to the map shown in FIG. 3 based on the temperature detected by the thermometer 84 that detects the inlet temperature of the pressure regulating valve 2A. In the map, the relationship between the power generation current of the fuel cell stack 80 and the target air pressure is set for each temperature. More specifically, the target air pressure is set so as to increase as the generated current increases, and the target air pressure increases as the inlet temperature of the pressure regulating valve 2A increases. The ECU 90 controls the rotation speed of the air pump 82 so that the air pressure detected at the outlet of the air pump 82 becomes the target air pressure.

By performing the control as described above, the inter-electrode differential pressure of the fuel cell is managed so as not to exceed the specified pressure, and the electrolyte membrane is reliably prevented from being damaged. Instead of the thermometer 84 that detects the inlet temperature of the pressure regulating valve 2A, a thermometer 88 that detects the atmospheric temperature may be provided, and the target air pressure may be set based on the atmospheric temperature. Further, the target air pressure may be obtained by the following mathematical formula instead of the map. In the following formula, C1, C2, and C3 are constants, and T is a detected temperature.
Target air pressure = C1 x (1 + C2 x T) ^C3

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 4 is a schematic cross-sectional view showing a configuration of a pressure regulating valve 2B as Embodiment 2 of the present invention. 4, the same parts as those of the pressure regulating valve 2A according to the first embodiment of FIG. 1 are denoted by the same reference numerals.

  The pressure regulating valve 2B has a first casing 4 and a second casing 6 that constitute an outer shell. A diaphragm 10 is sandwiched between the first casing 4 and the second casing 6, and internal spaces 14 and 54 formed by the first casing 4 and the second casing 6 are partitioned by the diaphragm 10.

  A space 14 formed by the first casing 4 and the diaphragm 10 is a back pressure chamber into which atmospheric pressure is introduced. A spring 16 is disposed in the back pressure chamber 14 and connects the first casing 4 and the diaphragm 10. The spring 16 is used to set a reference value for the pressure regulation value of the fluid, and biases the diaphragm 10 to the side opposite to the back pressure chamber 14.

  On the other hand, a space 54 formed by the second casing 6 and the diaphragm 10 is a pressure chamber filled with a pressure fluid. A force due to a differential pressure between the pressure of the fluid inside the pressure chamber 54 and the atmospheric pressure of the back pressure chamber 14 acts as a thrust force that displaces the diaphragm 10.

  The second casing 6 is formed with a primary side flow path 30 through which the fluid to be regulated flows and a secondary side flow path 60 through which the regulated fluid flows. In the present embodiment, the secondary flow path 60 is provided on the side opposite to the back pressure chamber 14 with respect to the pressure chamber 54. A partition wall 58 partitions the pressure chamber 54 and the secondary channel 60. The primary channel 30 is provided on the opposite side of the pressure chamber 54 with respect to the secondary channel 60. The primary channel 30 and the secondary channel 60 are separated by a partition wall 36, but the partition wall 36 is formed with an opening 34 that allows the primary channel 30 and the secondary channel 60 to communicate with each other. Has been. The primary-side flow path 30 is connected to a fluid inlet 32 formed on the side surface of the second casing 6, and the fluid that has flowed into the primary-side flow path 30 from the fluid inlet 32 passes through the opening 34 and becomes a secondary-side flow path. 60, and is discharged from the fluid outlet 32 to the outside.

  Further, the second casing 6 is provided with a valve mechanism for adjusting the pressure of the fluid flowing from the primary side flow path 30 into the secondary side flow path 60. The valve mechanism includes a valve seat 24 formed in the opening 34 and a valve body 8 that can be displaced with respect to the valve seat 24. The valve seat 24 is formed on the peripheral edge of the opening 34 on the primary flow path 30 side, and the valve body 8 is supported by the second casing 6 on the bearing 22 so that the valve seat 8 can approach / separate from the primary flow path 30 side. Is supported through. The bearing 22 supports the valve body 8 so as to be movable in the axial direction, and the displacement of the valve body 8 relative to the valve seat 24, that is, the opening degree of the valve body 8 is changed by the movement of the valve body 8 in the axial direction. It has become.

  The valve body 8 is provided with a connecting rod 12 extending to the valve seat 24 side. The connecting rod 12 passes through the opening 34, passes through the partition wall 58, and is connected to the central portion of the diaphragm 10 facing the pressure chamber 54. The through portion through which the connecting rod 12 penetrates the partition wall 58 is sealed so that pressure does not leak between the pressure chamber 54 and the secondary side flow path 60. Further, a bearing 56 is provided in the penetrating portion of the partition wall 58, and the connecting rod 12 is supported by the bearing 56 so as to be movable in the axial direction. As a result, the valve body 8 and the diaphragm 10 are integrated, and the urging force of the spring 16 and the force that the diaphragm 10 receives from the fluid in the pressure chamber 54 act on the valve body 8 via the connecting rod 12. ing.

  Further, a balance chamber 62 is formed in the second casing 6 on the side opposite to the primary flow path 30 with respect to the valve body 8. In the present embodiment, atmospheric pressure is introduced into the balance chamber 62. A spring 20 is disposed in the balance chamber 62 and connects the second casing 4 and the valve body 8. The spring 20 is used to adjust the reference value of the pressure regulation value of the fluid, and urges the valve body 8 in the closing direction.

  The pressure chamber 54 is configured as a sealed space isolated from the primary channel 30 and the secondary channel 60. A communication passage 52 for introducing pressure is connected to the pressure chamber 54, and an end portion on the opposite side of the communication passage 52 is connected to the secondary side flow path 60. More specifically, an orifice (throttle portion) 50 having a reduced flow area is formed in the secondary flow path 60, and the communication path 52 is connected to the orifice 50 to reduce the static pressure in the orifice 50. It is introduced into the pressure chamber 54. Therefore, if the static pressure in the orifice 50 changes, the pressure of the fluid in the pressure chamber 54 also changes, and the thrust acting on the diaphragm 10 from the fluid in the pressure chamber 54 also changes.

  With the above-described configuration, the valve body 8 is subjected to the opening thrust received from the spring 16, the closing thrust received from the fluid in the pressure chamber 54 via the diaphragm 10, and the closing thrust received from the spring 20. . In the spring 16 and the spring 20, since the spring force of the spring 16 is larger, the valve body 8 has a thrust (elastic force) having a magnitude corresponding to the spring force difference between the springs 16 and 20 and the displacement amount of the valve body 8. ) Acts in the opening direction. By balancing these thrusts acting on the valve body 8, the pressure regulating valve 2A is provided with an automatic pressure regulating function for maintaining the pressure of the fluid in the secondary side flow path 60 at a substantially constant pressure. For example, when the fluid pressure in the secondary flow path 60 decreases, the static pressure in the orifice 50 also decreases, and the fluid pressure in the pressure chamber 54 also decreases. As a result, the force that the diaphragm 10 receives from the fluid in the pressure chamber 54 is reduced, so that the thrust in the closing direction of the valve body 8 is reduced and the valve body 8 is driven in the opening direction. As a result, the pressure of the fluid in the secondary side flow path 60 increases as the opening of the valve body 8 increases, and is maintained at a constant pressure again. Conversely, when the pressure of the fluid in the secondary side flow path 60 increases, the valve body 8 is driven in the closing direction as the force received by the diaphragm 10 from the fluid in the pressure chamber 54 increases. The pressure of the fluid in the flow path 60 decreases as the opening degree of the valve body 8 decreases, and is maintained at a constant pressure again.

  In addition to the automatic pressure regulating function described above, the pressure regulating valve 2B configured as described above also has a function of changing the pressure regulating value according to the flow rate, similar to the pressure regulating valve 2A according to the first embodiment. It is equipped. More specifically, when the flow rate of the fluid flowing into the primary side flow path 30 increases, the flow rate of the fluid discharged from the primary side flow path 30 to the secondary side flow path 60 increases. As a result, the flow velocity of the fluid at the orifice 50 increases, and the static pressure at the orifice 50 decreases as the flow velocity increases. Since the orifice 50 is connected to the pressure chamber 54 by the communication passage 52, the fluid pressure in the pressure chamber 54 decreases when the static pressure in the orifice 50 decreases. Since the valve element 8 is displaced to a position where the thrust in the opening direction received from the springs 16 and 20 and the thrust in the closing direction received from the fluid in the pressure chamber 54 via the diaphragm 10 are balanced, the valve body 8 is closed in the closing direction received from the fluid in the pressure chamber 54. The valve body 8 is driven in the opening direction by the reduction of the thrust, and the pressure of the fluid in the secondary side flow path 60 increases as the opening degree of the valve body 8 increases.

  Thus, according to the pressure regulating valve 2B according to the present embodiment, as with the pressure regulating valve 2A according to the first embodiment, the pressure regulating characteristic (right shoulder) such that the pressure regulating value increases as the flow rate increases. Can be realized). Moreover, like the pressure regulating valve 2A according to the first embodiment, high reliability is ensured by using only purely mechanical means without using electrical means such as a solenoid valve, Since the supply of control pressure from the outside is not required unlike in the prior art, an improvement in reliability can be expected by simplifying the device configuration.

  The pressure regulating valve 2B according to the present embodiment is also suitable for use as a fuel gas pressure regulating means supplied to the anode of the fuel cell in the fuel cell system, like the pressure regulating valve 2A according to the first embodiment.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIG.

  FIG. 5 is a schematic cross-sectional view showing a configuration of a pressure regulating valve 2C as the third embodiment of the present invention. 5, the same parts as those of the pressure regulating valve 2A according to the first embodiment of FIG. 1 are denoted by the same reference numerals. Detailed description of the same parts as those of the pressure regulating valve 2A according to the first embodiment will be omitted.

  The pressure regulating valve 2 </ b> C according to the present embodiment is different from the pressure regulating valve 2 </ b> A according to the first embodiment in an introduction source for introducing pressure into the balance chamber 18. In the pressure regulating valve 2A, the balance chamber 18 communicates with the orifice 40 formed in the primary channel 30. However, in the pressure regulating valve 2C according to the present embodiment, the balance chamber 18 is connected to the secondary channel 38. It is connected. More specifically, an orifice (throttle portion) 70 having a reduced flow area is formed in the secondary flow path 38, and the balance chamber 18 is connected to the orifice 70 by a communication path 72. The communication path 72 introduces the static pressure of the fluid flowing through the orifice 70 into the balance chamber 18. Therefore, if the static pressure in the orifice 70 changes, the pressure of the fluid in the balance chamber 18 also changes, and the thrust in the closing direction that acts on the valve body 8 from the fluid in the balance chamber 18 also changes.

  With such a configuration, the pressure regulating valve 2C according to the present embodiment also has a function of changing the pressure regulation value according to the flow rate. More specifically, when the flow rate of the fluid flowing into the primary side flow path 30 increases, the flow rate of the fluid discharged from the primary side flow path 30 to the secondary side flow path 38 increases. As a result, the fluid flow rate at the orifice 70 increases, and the static pressure at the orifice 70 decreases as the flow rate increases. Since the orifice 70 is connected to the balance chamber 18 by the communication path 72, the fluid pressure in the balance chamber 18 decreases when the static pressure at the orifice 70 decreases. The valve body 8 has an opening direction thrust received from the springs 16, 20, a closing direction thrust received from the fluid in the secondary side flow path 38 via the diaphragm 10, and a closing direction thrust received from the fluid in the balance chamber 18. Since it is displaced to a balanced position, the valve body 8 is driven in the opening direction due to a decrease in thrust in the closing direction received from the fluid in the balance chamber 18, and the fluid pressure in the secondary side flow path 38 increases the opening of the valve body 8. It rises with.

  Thus, according to the pressure regulating valve 2C according to the present embodiment, as with the pressure regulating valve 2A according to the first embodiment, the pressure regulating characteristic (right shoulder) such that the pressure regulating value increases as the flow rate increases. Can be realized). Moreover, like the pressure regulating valve 2A according to the first embodiment, high reliability is ensured by using only purely mechanical means without using electrical means such as a solenoid valve, Since the supply of control pressure from the outside is not required unlike in the prior art, an improvement in reliability can be expected by simplifying the device configuration.

  The pressure regulating valve 2C according to the present embodiment is also suitable for use as a fuel gas pressure regulating means supplied to the anode of the fuel cell in the fuel cell system, similarly to the pressure regulating valve 2A according to the first embodiment.

  Since the fluid in the secondary side flow path 38 is depressurized with respect to the fluid in the primary side flow path 30, the pressure introduced from the orifice 70 into the balance chamber 18 is changed from the orifice 40 to the balance chamber in the first embodiment. 18 is smaller than the pressure introduced. For this reason, the thrust which acts on the valve body 8 from the fluid in the balance chamber 18 is larger in the pressure regulating valve 2A according to the first embodiment than in the pressure regulating valve 2C. Therefore, the pressure adjustment valve 2A according to the first embodiment can take a larger adjustment allowance for the pressure adjustment value with respect to the change in the flow rate of the fluid flowing into the primary channel 30 than the pressure adjustment valve 2C.

  When comparing the pressure regulating valve 2B and the pressure regulating valve 2C according to the second embodiment, the pressure chamber 54 or the balance chamber 18 is changed from the orifices 50 and 70 formed in the secondary flow paths 60 and 38, respectively. Introducing static pressure. However, the area of the exposed surface in the pressure chamber 54 of the diaphragm 10 in the pressure regulating valve 2B is larger than the area of the exposed surface in the balance chamber 18 of the valve body 8 in the pressure regulating valve 2C. The thrust acting on 8 is larger in the pressure regulating valve 2B according to the second embodiment. Therefore, the pressure adjustment valve 2B according to the second embodiment can have a larger adjustment allowance for the pressure adjustment value with respect to the change in the flow rate of the fluid flowing into the primary channel 30 than the pressure adjustment valve 2C.

Others.
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the following modifications may be made.

  In the second and third embodiments, the orifices 50 and 70 are formed in the secondary flow paths 60 and 38 in the pressure regulating valves 2B and 2C, and static pressure is introduced into the pressure chamber 54 or the balance chamber 18. The place where the orifice is provided is not limited to the pressure regulating valve. For example, as shown in FIG. 6, when the pressure regulating valve 2D is arranged in the fuel gas supply pipe 92 of the fuel cell system and the fuel gas circulates through the ejector 96, the circulation type system is used. The orifice inside the ejector 96 and the pressure chamber of the pressure regulating valve 2D or the balance chamber may be communicated with each other by a pressure introduction pipe (communication path) 98. Further, in the case of a non-circulation type system in which the fuel gas does not circulate, an orifice 100 is provided at the outlet of the fuel cell stack 80 as shown in FIG. 7, and the static pressure of the fuel off-gas flowing through the orifice 100 is increased by the pressure introduction pipe 102. You may make it introduce | transduce into the pressure chamber of the adjustment valve 2E, or a balance chamber. However, when the configuration shown in FIGS. 6 and 7 is adopted, a hydrophobic filter for removing moisture contained in the fuel off-gas is provided in the pressure introduction pipes 98 and 102. As the pressure regulating valves 2D and 2E, either the pressure regulating valve 2B according to the second embodiment or the pressure regulating valve 2C according to the second embodiment can be used.

It is a schematic sectional drawing which shows the structure of the pressure regulating valve as Embodiment 1 of this invention. It is a schematic block diagram of the fuel cell system to which the pressure control valve of FIG. 1 is applied. 3 is a map for setting a target air pressure in the fuel cell system of FIG. 2. It is a schematic sectional drawing which shows the structure of the pressure regulating valve as Embodiment 2 of this invention. It is a schematic sectional drawing which shows the structure of the pressure regulating valve as Embodiment 3 of this invention. FIG. 5 is a schematic configuration diagram of a fuel cell system showing a modification of the second or third embodiment. FIG. 5 is a schematic configuration diagram of a fuel cell system showing a modification of the second or third embodiment.

Explanation of symbols

2A, 2B, 2C, 2D, 2E Pressure regulating valve 4 First housing 6 Second housing 8 Valve body 10 Diaphragm 12 Connecting member 14 Pressure chamber 16, 20 Pressure setting spring 18 Balance chamber 22, 56 Bearing 30 Primary gas flow path 38, 60 Secondary gas flow path 40, 50, 70 Orifice 42, 52, 72 Communication path 54 Pressure chamber 58 Bulkhead 82 Pump 84, 88 Thermometer 86 Pressure gauge 90 ECU
92 Fuel gas supply pipe 94 Air supply pipe 96 Ejector

Claims (3)

In the pressure regulating valve that regulates the fluid flowing into the primary flow path and discharges it to the secondary flow path,
A valve seat provided in an opening between the primary side flow path and the secondary side flow path;
A valve body arranged to be displaceable with respect to the valve seat;
A spring connected to the valve body and acting on the valve body with thrust in an opening direction according to a displacement amount of the valve body;
A diaphragm connected to the valve body and receiving a pressure of a fluid in the secondary-side flow path to cause a thrust in a closing direction to act on the valve body;
A balance chamber that is provided separately from the primary side flow path and the secondary side flow path and causes the pressure of the internal fluid to act on the valve body as thrust in the closing direction;
A throttle formed in the primary flow path;
A communication path for communicating the throttle part and the balance chamber;
A pressure regulating valve comprising: In the pressure regulating valve that regulates the fluid flowing into the primary flow path and discharges it to the secondary flow path,
A valve seat provided in an opening between the primary side flow path and the secondary side flow path;
A valve body arranged to be displaceable with respect to the valve seat;
A spring connected to the valve body and acting on the valve body with thrust in an opening direction according to a displacement amount of the valve body;
A diaphragm connected to the valve body and receiving a pressure of a fluid in the secondary-side flow path to cause a thrust in a closing direction to act on the valve body;
A balance chamber that is provided separately from the primary side flow path and the secondary side flow path and causes the pressure of the internal fluid to act on the valve body as thrust in the closing direction;
A throttle formed in the secondary channel,
A communication path for communicating the throttle part and the balance chamber;
A pressure regulating valve comprising: In a fuel cell system comprising a fuel cell that generates power by receiving a supply of a fuel gas containing hydrogen, and a fuel gas passage for supplying fuel gas to the anode of the fuel cell,
A fuel cell system, wherein the pressure regulating valve according to claim 1 or 2 is arranged in the fuel gas passage.

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