JP2018152181A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system in which inoperability of a movable mechanism due to freeing can be restrained.SOLUTION: A fuel cell system includes an electrically-driven turbine 30 for recovering exhaust energy of air discharged from a fuel cell stack. The electrically-driven turbine 30 includes a turbine chamber 50, a communication passage 53 connecting between a suction chamber 52, a diaphragm 61 facing the communication passage 53, a movable mechanism 70 for deforming a diaphragm 61 elastically, and a housing chamber 60 housing the movable mechanism 70. The housing chamber 60 is isolated from the communication passage 53 by means of the diaphragm 61. Furthermore, the diaphragm 61 and a turbine housing 34 are sealed by a first weld zone 62a and a second weld zone 62b.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel cell system mounted on a vehicle.

  A vehicle equipped with a fuel cell system having a fuel cell stack that generates electricity by chemically reacting hydrogen and oxygen in the air has been put into practical use. In the fuel cell system, there is a technique for recovering the exhaust energy of the air discharged from the fuel cell stack by rotating a turbine wheel provided in the regenerator.

  In the fuel cell system, the pressure of the air supplied to the fuel cell stack is adjusted in order to adjust the humidity in the fuel cell stack. The pressure adjustment of the air supplied to the fuel cell stack is performed by adjusting the flow path cross-sectional area of the flow path connected to the turbine chamber that houses the turbine wheel in the regenerator.

  For example, as disclosed in Patent Document 1, in a fuel cell system provided with a variable nozzle type turbocharger as a regenerator, a flow passage cross-sectional area is adjusted by a nozzle. Specifically, the exhaust gas introduced from the exhaust gas inlet of the turbocharger is introduced into the turbine wheel through a plurality of nozzles. Each nozzle includes a vane for changing the opening degree. The vane includes a moving blade integrated with a rotating shaft, and the rotating shaft is rotatably supported at a position away from the turbine wheel by a predetermined distance. Each vane can be driven by a control device. When the opening of the nozzle is adjusted by rotating the vane by the control device, the pressure of the air supplied to the fuel cell stack is adjusted.

JP 2000-315510 A

  Incidentally, in the fuel cell system, moisture generated in the fuel cell stack by power generation is discharged from the fuel cell stack together with air. In Patent Document 1, moisture contained in the discharged air may enter between the rotating shaft of the vane in the nozzle and the shaft support portion of the rotating shaft. When the fuel cell system is stopped in this state and the fuel cell system is placed in a sub-freezing environment, moisture that has entered between the rotating shaft of the vane and the shaft support portion of the rotating shaft freezes, and the vane rotates. It may become impossible. Then, when the fuel cell system is started at a low temperature (starting below freezing point), the nozzle does not rotate and pressure adjustment by the nozzle cannot be performed.

  The objective of this invention is providing the fuel cell system which can suppress that a movable mechanism becomes inoperable by freezing.

  A fuel cell system for solving the above problems includes a compressor for compressing air, a fuel cell to which air compressed by the compressor is supplied, and exhaust energy of air discharged from the fuel cell. A regenerator, wherein the regenerator is provided in the housing, and an intake port provided in the housing for taking air discharged from the fuel cell into the housing; A turbine wheel pivotally supported by the housing and rotated by air taken into the housing from the suction port; a turbine chamber partitioned in the housing and containing the turbine wheel; partitioned in the housing; A communication passage constituting at least a part of an air flow path connecting the turbine chamber and the suction port, and supplied to the fuel cell. A pressure adjusting unit that adjusts a pressure of air to be adjusted, and the pressure adjusting unit adjusts a cross-sectional area of the communication path and an elastic member provided in the housing in a state of partitioning the communication path For this purpose, a movable mechanism that elastically deforms the elastic member and a housing chamber that is partitioned in the housing and accommodates the movable mechanism, the housing chamber and the communication path are separated by the elastic member, The gist is that the storage chamber is sealed by a seal portion provided between the elastic member and the housing.

  According to this, the pressure of the air supplied from the compressor to the fuel cell is adjusted by elastically deforming the elastic member by the movable mechanism and adjusting the cross-sectional area of the communication path by the elastic member. The air discharged from the fuel cell flows into the air flow path of the regenerator provided with such a pressure adjusting unit. The air exhausted from the fuel cell contains moisture generated by the fuel cell, but the air that has flowed into the air flow path can be prevented from entering the accommodation chamber from the communication path by the sealing by the seal portion. For this reason, it is suppressed that a movable mechanism is exposed to the air containing a water | moisture content, and it can suppress that a water | moisture content adheres to a movable mechanism. As a result, even when the fuel cell is placed in a sub-freezing environment after the operation of the fuel cell system is stopped, it is possible to prevent the movable mechanism from becoming inoperable due to freezing of moisture. Therefore, when the fuel cell system is started at a low temperature (starting below freezing point), the pressure can be adjusted by operating the movable mechanism and the elastic member.

In the fuel cell system, the seal portion may be formed by welding the metal housing and the metal elastic member.
According to this, the fixing of the elastic member to the housing and the formation of the seal portion can be performed together.

In the fuel cell system, the elastic member may be a diaphragm.
According to this, since the diaphragm has a thin plate shape, the housing and the diaphragm are easily welded, and the seal portion is easily formed.

  According to the present invention, it is possible to prevent the movable mechanism from becoming inoperable due to freezing.

1 is a schematic configuration diagram of a fuel cell system in an embodiment. The fragmentary sectional view showing the electric turbine in an embodiment. The fragmentary sectional view which shows a movable mechanism, a diaphragm, and a seal | sticker part. The fragmentary sectional view which shows the state which narrowed down the communicating path. The fragmentary sectional view which shows the electric turbine which employ | adopted the bellows as an elastic member. The fragmentary sectional view which shows another example of a communicating path.

Hereinafter, an embodiment embodying a fuel cell system will be described with reference to FIGS. The fuel cell system of this embodiment is mounted on a vehicle (fuel cell vehicle).
As shown in FIG. 1, the fuel cell system 10 includes a fuel cell stack 11 as a fuel cell, and a compressor 12 that compresses the air supplied from the suction port 12a and discharges it from the discharge port 12b. The compressor 12 is a turbo electric compressor that is driven by an electric motor. The fuel cell stack 11 is configured by stacking a plurality of cells in series. The fuel cell stack 11 generates electricity by chemically reacting hydrogen supplied from a hydrogen supply unit (not shown) and oxygen in the air supplied by the compressor 12.

  The fuel cell stack 11 is electrically connected to a travel motor (not shown). The traveling motor is driven by using the fuel cell stack 11 as a power source. The power of the travel motor is transmitted to the axle via a power transmission mechanism (not shown), and the fuel cell vehicle travels at a vehicle speed corresponding to the accelerator opening.

  As shown in FIG. 2, the fuel cell system 10 includes an electric turbine 30 as a regenerator. In the electric turbine 30, exhaust energy of the air discharged from the fuel cell stack 11 is taken out as mechanical energy, and the electric motor M of the electric turbine 30 functions as a generator to generate regenerative power in the electric motor M. The regenerative power generated in the electric motor M is stored in a battery (not shown), and is used, for example, as a power source for the travel motor.

  As shown in FIG. 1, the fuel cell system 10 includes a compressor pipe 20 into which air flows from the outside. The compressor pipe 20 is connected to the suction port 12 a of the compressor 12. In addition, the fuel cell system 10 includes a first pipe 21 that connects the discharge port 12 b of the compressor 12 and the fuel cell stack 11. The fuel cell system 10 also includes a connection pipe 25 that connects the fuel cell stack 11 and the intake port 30 a of the electric turbine 30. The suction port 30 a of the electric turbine 30 is an inlet for air discharged from the fuel cell stack 11 in the electric turbine 30. The fuel cell system 10 also includes a second pipe 22 connected to the discharge port 30 b of the electric turbine 30.

As shown in FIG. 2, the electric turbine 30 includes a housing 32, an electric motor M, a turbine wheel 31, and a pressure adjustment unit 29.
The electric turbine 30 constitutes an outline of the electric turbine 30 and includes a housing 32 in which an electric motor M, a turbine wheel 31 and a pressure adjusting unit 29 are accommodated. The housing 32 has, for example, a substantially cylindrical shape (in detail, a cylindrical shape) as a whole.

  The housing 32 includes a motor housing 33 in which the electric motor M is accommodated, a turbine housing 34 having a discharge port 30b through which air is discharged, and a plate 35 provided between the motor housing 33 and the turbine housing 34. It is equipped with. The discharge port 30 b is provided at one end of the housing 32 in the axial direction. The turbine housing 34, the plate 35, and the motor housing 33 are arranged in this order in the axial direction of the housing 32 when viewed from the discharge port 30b. The motor housing 33, the plate 35, and the turbine housing 34 are made of metal, for example, aluminum.

  The turbine housing 34 has a boss 34e protruding from one end surface 34a opposite to the plate 35 side in the main body 34d. The boss 34e is erected from the peripheral edge portion of the through hole 41 of the main body portion 34d. The discharge port 30 b is an opening formed by the boss 34 e and communicates with the through hole 41.

  The turbine housing 34 includes an annular storage chamber recess 54 on the radially outer side of the through hole 41. Further, the turbine housing 34 includes an annular suction chamber 52 on the radially outer side than the storage chamber recess 54. The suction chamber 52 communicates with the suction port 30 a of the electric turbine 30. In the turbine housing 34, a diaphragm 61 as an elastic member is joined to the other end surface 34 b in the axial direction to close the storage chamber recess 54, and the storage chamber 60 is defined by the storage chamber recess 54 and the diaphragm 61. ing. Further, the electric turbine 30 includes a communication path 53 defined by a turbine housing 34 in a state where the diaphragm 61 is joined and a plate 35 assembled to the turbine housing 34. The communication path 53 communicates with the suction chamber 52.

  The plate 35 has a disk shape, and the first plate surface 35a is located on the motor housing 33 side and the second plate surface 35b is located on the turbine housing 34 side among the two plate surfaces 35a and 35b in the axial direction. doing. The plate 35 includes a recess 36 that is recessed in a circular shape in the axial direction from the second plate surface 35b.

  Further, the plate 35 includes a rotation shaft insertion hole 35 c that penetrates the plate 35 in the axial direction at the recess 36 and communicates the inside of the motor housing 33 and the inside of the turbine housing 34. The rotary shaft 39 is inserted through the rotary shaft insertion hole 35c. A part of the rotating shaft 39 is disposed in the turbine housing 34 via the rotating shaft insertion hole 35c. A seal member 40 is provided between the inner peripheral surface that defines the rotary shaft insertion hole 35 c and the peripheral surface of the rotary shaft 39.

  The turbine wheel 31 has an insertion hole 31 c that extends in the direction of the rotation axis of the turbine wheel 31 and through which the rotation shaft 39 is inserted. The turbine wheel 31 is attached to the rotary shaft 39 so as to rotate integrally with the rotary shaft 39 in a state where a portion of the rotary shaft 39 protruding into the through hole 41 is inserted into the insertion hole 31c.

  The turbine wheel 31 is disposed in the through hole 41 and is accommodated in a turbine chamber 50 defined by the inner wall surface 42 of the through hole 41 and the second plate surface 35 b of the plate 35. That is, the housing 32 has a turbine chamber 50 in which the turbine wheel 31 is accommodated. The turbine chamber 50 and the discharge port 30b communicate with each other. Further, the turbine chamber 50 and the suction port 30 a are connected by a suction chamber 52 and a communication path 53. Therefore, the suction chamber 52 and the communication path 53 constitute an air flow path 55 that connects the turbine chamber 50 and the suction port 30a.

  The turbine housing 34 includes a cylindrical first partition wall 37 that separates the storage chamber recess 54 and the through hole 41, and a second partition wall 38 that separates the storage chamber recess 54 and the suction chamber 52. .

  The turbine housing 34 has an annular first end surface 37c on the tip end surface of the first partition wall 37 in the other end surface 34b. The turbine housing 34 has an annular second end surface 38c on the tip end surface of the second partition wall 38 in the other end surface 34b. The first end surface 37 c and the second end surface 38 c are at the same position in the axial direction of the turbine housing 34.

  As shown in FIG. 2 or FIG. 3, the accommodation chamber 60 has a shape that is recessed in a cylindrical shape from the other end surface 34 b of the turbine housing 34. The storage chamber 60 is partitioned by closing the storage chamber recess 54 with a diaphragm 61. The diaphragm 61 as an elastic member is made of a thin metal plate and has a disk shape. The diaphragm 61 has an opening 61a at the center. The inner peripheral edge 61b of the diaphragm 61 and the first end surface 37c of the turbine housing 34 are joined by a first weld 62a. The first welding portion 62 a welds the inner peripheral edge portion 61 b of the diaphragm 61 and the first end surface 37 c of the first partition wall 37 over the entire circumference around the rotation shaft 39. The first weld 62a is annular.

  Further, the outer peripheral edge 61c of the diaphragm 61 and the second end surface 38c of the turbine housing 34 are joined by a second weld 62b. The second welding portion 62 b welds the outer peripheral edge portion 61 c of the diaphragm 61 and the second end surface 38 c of the second partition wall 38 over the entire circumference around the rotation shaft 39. The second welded portion 62b is annular. The diaphragm 61 and the turbine housing 34 are welded, and as a result, the storage chamber 60 is partitioned from the communication path 53. The storage chamber 60 is hermetically sealed by the first welded portion 62a and the second welded portion 62b. In the present embodiment, the first welded portion 62 a and the second welded portion 62 b are seal portions provided between the turbine housing 34 and the diaphragm 61.

  The communication path 53 is a flow path defined by the other end surface 34 b of the turbine housing 34 including the diaphragm 61 and the second plate surface 35 b of the plate 35. A part of the communication path 53 is partitioned by a diaphragm 61. The communication path 53 is disposed on the radially outer side of the turbine wheel 31 with respect to the turbine chamber 50, and is formed in an annular shape (specifically, an annular shape) so as to surround the turbine wheel 31. In the diaphragm 61, the entire flow path forming surface 61d faces the second plate surface 35b. In the present embodiment, the second plate surface 35 b of the plate 35 functions as a flow path forming surface provided in the housing 32, and defines the communication path 53 together with the flow path forming surface 61 d of the diaphragm 61. The diaphragm 61 is interposed between the storage chamber 60 and the communication path 53 in the axial direction of the turbine housing 34, and separates the storage chamber 60 and the communication path 53.

  In the electric turbine 30, the air discharged from the fuel cell stack 11 flows into the suction chamber 52. The air that has flowed into the communication passage 53 from the suction chamber 52 flows into the turbine chamber 50. The turbine wheel 31 is rotated by the air flowing into the turbine chamber 50, and the exhaust energy of the air is taken out as mechanical energy. The air that has flowed into the turbine chamber 50 is discharged from the discharge port 30b.

  Next, the pressure adjustment unit 29 built in the electric turbine 30 will be described. The pressure adjusting unit 29 includes the above-described storage chamber 60, the communication path 53, the diaphragm 61, and the movable mechanism 70 that elastically deforms the diaphragm 61.

  The movable mechanism 70 included in the electric turbine 30 is accommodated in the accommodation chamber 60. The movable mechanism 70 elastically deforms the diaphragm 61 in order to adjust the flow path cross-sectional area of the communication path 53. The movable mechanism 70 includes a stepping motor 71. The stepping motor 71 includes a cylindrical stator 72 fixed to the inner peripheral surface 38 a of the second partition wall 38, and a cylindrical rotor 73 disposed on the inner peripheral side of the stator 72.

  The stator 72 has a cylindrical stator core and a coil wound around a tooth formed on the stator core. The rotor 73 has a constant inner diameter from the one end surface 73 a facing the bottom surface 54 a of the storage chamber recess 54 to the other end surface 73 b facing the diaphragm 61. The rotor 73 has a constant outer diameter from one end surface 73a to an intermediate position in the axial direction, and faces the inner peripheral surface of the stator 72 up to this intermediate position. The rotor 73 includes a thread groove 74 on the outer peripheral surface from the midway position to the other end surface 73b.

  The movable mechanism 70 includes a cylindrical pressing member 75 screwed into a thread groove 74 of the rotor 73 via a ball (not shown). The pressing member 75 includes a screw groove 75a on the inner peripheral surface. Further, the pressing member 75 is prevented from rotating in a state in which the pressing member 75 can move in the axial direction of the turbine housing 34 by a rotation preventing mechanism (not shown). When the rotor 73 is rotated by energizing the coil of the stator 72, the rotational motion of the rotor 73 is converted into a linear motion of the pressing member 75 via the ball, and the pressing member 75 is prevented from rotating by a rotation preventing mechanism. While moving, it moves in the axial direction of the turbine housing 34. The front end surface 75 b of the pressing member 75 is in contact with the pressing surface 61 e on the opposite side of the flow path forming surface 61 d of the diaphragm 61.

  As shown in FIG. 3, when the front end surface 75 b of the pressing member 75 is on the same plane as the first end surface 37 c of the first partition wall 37 and the second end surface 38 c of the second partition wall 38, the diaphragm formed by the pressing member 75 There is no pressing of 61, and the diaphragm 61 is flat. In a state where the diaphragm 61 is not pressed by the pressing member 75, the flow passage cross-sectional area of the communication passage 53 is maximized in the air flow passage 55. Note that the flow passage cross-sectional area of the communication passage 53 is opposed to the flow passage formation surface 61d of the diaphragm 61 and the flow passage formation surface 61d when the communication passage 53 is viewed in a cross section along the axial direction of the housing 32. It is a cross-sectional area of the communication path 53 formed between the second plate surface 35b.

  In the present embodiment, when the rotor 73 is rotated in the first direction, the pressing member 75 moves toward the diaphragm 61. As shown in FIG. 4, when the diaphragm 61 is pressed by the pressing member 75, the diaphragm 61 is elastically deformed. As a result, the flow path forming surface 61 d of the diaphragm 61 approaches the second plate surface 35 b of the plate 35. Then, the flow path cross-sectional area of the communication path 53 becomes small. By controlling the number of rotations of the rotor 73 and the amount of protrusion of the pressing member 75, the amount of protrusion of the diaphragm 61 toward the second plate surface 35b is controlled, and the flow path cross-sectional area of the communication path 53 is adjusted. .

  When the rotor 73 is rotated in the second direction opposite to the first direction with the diaphragm 61 protruding toward the second plate surface 35 b, the pressing member 75 that presses the diaphragm 61 is separated from the diaphragm 61. Move towards As shown in FIG. 3, when the distal end surface 75 b of the pressing member 75 moves to the same plane as the first end surface 37 c of the first partition wall 37 and the second end surface 38 c of the second partition wall 38, the pressing member The pressing of the diaphragm 61 by 75 is released. Then, the diaphragm 61 returns to the original shape, and the flow path cross-sectional area of the communication path 53 is maximized.

  As shown in FIG. 1, the fuel cell system 10 includes a control device 80. The control device 80 controls the stepping motor 71 of the movable mechanism 70. The control device 80 calculates the pressure of the air supplied to the fuel cell stack 11 based on the humidity in the fuel cell stack 11. Then, the control device 80 controls the movable mechanism 70 to adjust the cross-sectional area of the communication passage 53 so that the calculated air pressure is obtained.

  For example, when the humidity of the fuel cell stack 11 is high, the pressure of the air supplied to the fuel cell stack 11 is lowered. In this case, the flow path cross-sectional area of the communication path 53 is increased. The control device 80 controls the stepping motor 71 to rotate the rotor 73 in the second direction, and reduces the amount of pressing of the diaphragm 61 by the pressing member 75.

  On the other hand, when the humidity of the fuel cell stack 11 is low, the pressure of the air supplied to the fuel cell stack 11 is increased. In this case, the flow path cross-sectional area of the communication path 53 is reduced. The control device 80 controls the stepping motor 71 to rotate the rotor 73 in the first direction, and increases the pressing amount of the diaphragm 61 by the pressing member 75.

Next, the operation of the fuel cell system 10 will be described.
In the fuel cell system 10, moisture generated in the fuel cell stack 11 by power generation is discharged from the fuel cell stack 11 together with air. The moisture-containing air reaches the electric turbine 30 through the connection pipe 25, is taken into the housing 32 from the suction port 30 a that is the inlet of the air flow path 55, and flows into the communication path 53 through the suction chamber 52. The accommodating chamber 60 that accommodates the movable mechanism 70 is isolated from the communication path 53 by the diaphragm 61, and a portion where the diaphragm 61 and the turbine housing 34 are joined is sealed by the first welding portion 62a and the second welding portion 62b. . For this reason, it is suppressed that the air containing a water | moisture content penetrate | invades into the storage chamber 60.

According to the above embodiment, the following effects can be obtained.
(1) Air that has flowed into the communication path 53 can be prevented from entering the storage chamber 60 from the communication path 53, and moisture can be prevented from adhering to the movable mechanism 70. As a result, even when the operation of the fuel cell system 10 is stopped and placed in a sub-freezing environment, it is possible to prevent the movable mechanism 70 from becoming inoperable due to freezing. Therefore, when the fuel cell system 10 is started at a low temperature (starting below freezing point), the movable mechanism 70 is operated, and the pressure adjustment by the diaphragm 61 and the movable mechanism 70 becomes possible.

  (2) The diaphragm 61 made of a thin metal plate is used as the elastic member. For this reason, the 1st end surface 37c and the 2nd end surface 38c of the turbine housing 34 which are metal can be joined to the diaphragm 61 by the 1st welding part 62a and the 2nd welding part 62b. Therefore, the fixing of the diaphragm 61 to the turbine housing 34 and the formation of the first welded portion 62a and the second welded portion 62b can be performed together. Further, since the gap between the diaphragm 61 and the turbine housing 34 can be sealed by welding, a structure for providing a sealing property can be easily formed.

  (3) A part of the communication path 53 is partitioned between the flow path forming surface 61 d of the diaphragm 61 and the second plate surface 35 b of the plate 35. Therefore, a part of the communication path 53 is directly partitioned by the diaphragm 61. For this reason, the flow passage cross-sectional area of the communication passage 53 can be directly adjusted by the protrusion and depression of the diaphragm 61, and the air pressure adjustment is easy to adjust.

In addition, you may change the said embodiment as follows.
The diaphragm 61 and the turbine housing 34 may be sealed by a method other than welding. For example, O between the inner peripheral edge 61 b of the diaphragm 61 and the first end surface 37 c of the first partition wall 37 and between the outer peripheral edge 61 c of the diaphragm 61 and the second end surface 38 c of the second partition wall 38. The diaphragm 61 may be fixed to the turbine housing 34 with a seal member such as a ring interposed, and the O-ring may be used as a seal portion. In this case, an annular groove is formed in the first end surface 37c and the second end surface 38c, and the diaphragm 61 is joined to the turbine housing 34 with an O-ring attached to the groove.

  Alternatively, the inner peripheral edge 61b and the outer peripheral edge 61c of the diaphragm 61 are coated with rubber, and the portions coated with the rubber contact the first end surface 37c of the first partition wall 37 and the second end surface 38c of the second partition wall 38. In this state, screws or the like are screwed into the first end surface 37c and the second end surface 38c from the diaphragm 61. As a result, the diaphragm 61 is fixed to the turbine housing 34 with the rubber-coated portion pressed against the turbine housing 34. The rubber coating portion may be used as the seal portion.

  As long as the diaphragm 61 can be elastically deformed to adjust the cross-sectional area of the communication passage 53, the configuration of the movable mechanism 70 may be changed as appropriate. For example, the movable mechanism 70 may be a mechanism that converts the rotational motion of the rotor 73 in the stepping motor 71 into a linear motion via a cam and a lever.

  Alternatively, instead of the stepping motor 71 of the movable mechanism 70, a fluid pressure cylinder may be built in the accommodation chamber 60, and the diaphragm 61 may be pressed and elastically deformed by a rod that can be projected and retracted with respect to the cylinder tube of the fluid pressure cylinder.

  The elastic member may be a metal bellows 90 instead of the diaphragm 61. As shown in FIG. 5, the bellows 90 includes an annular isolation portion 91 that isolates the storage chamber 60 from the communication path 53, and a bellows portion 92 that is erected from the inner periphery of the isolation portion 91. The bellows portion 92 of the bellows 90 has a tip portion 92 a joined to the outer peripheral surface of the first partition wall 37 by a first welded portion 90 a. The first welded portion 90 a is formed over the entire circumferential direction of the bellows portion 92 and the first partition wall 37. Further, the outer peripheral edge portion of the isolation portion 91 is joined to the second end surface 38 c of the second partition wall 38 by the second welding portion 90 b. The second welded portion 90 b is formed over the entire circumferential direction of the second partition wall 38.

  The separating portion 91 of the bellows 90 includes a flow path forming surface 91a on the surface facing the second plate surface 35b of the plate 35, and includes a pressing surface 91b on the opposite side of the flow path forming surface 91a. A communication path 53 is defined between the flow path forming surface 91 a of the bellows 90 and the second plate surface 35 b of the plate 35. The storage chamber 60 is isolated from the communication path 53 by the bellows 90 and is hermetically sealed by the first welded portion 90a and the second welded portion 90b. Therefore, the 1st welding part 90a and the 2nd welding part 90b become a seal part.

  In this embodiment, when the rotor 73 is rotated in the first direction, the pressing member 75 moves toward the separating portion 91 of the bellows 90. When the separating portion 91 is pressed by the pressing member 75, the flow path forming surface 91 a of the separating portion 91 approaches the second plate surface 35 b of the plate 35. At this time, the bellows portion 92 extends. Then, the flow path cross-sectional area of the communication path 53 becomes small.

  When the rotor 73 is rotated in the second direction opposite to the first direction with the separating portion 91 protruding, the pressing member 75 pressing the separating portion 91 moves in a direction away from the separating portion 91. At the same time, the extended bellows portion 92 contracts. When the distal end surface 75b of the pressing member 75 moves to the same position plane as the first end surface 37c of the first partition wall 37 and the second end surface 38c of the second partition wall 38, the separation portion 91 of the pressing member 75 is moved. Pressing is released. As a result, the cross-sectional area of the communication path 53 is maximized.

  The elastic member is embodied as a metal thin plate diaphragm 61 or bellows 90, but the elastic member may be rubber or a flexible resin diaphragm or bellows. In this case, the diaphragm or bellows may be joined to the turbine housing 34 by fusion or the like, and the fusion part may be used as a seal part.

  In the embodiment, a part of the communication path 53 is defined by the flow path forming surface 61d of the diaphragm 61 and the second plate surface 35b of the plate 35, but is not limited thereto. For example, as shown in FIG. 6, the suction chamber 52 may be partitioned within the thickness of the plate 35, and the suction chamber 52 and the turbine chamber 50 may be connected by a communication path 53 partitioned within the plate 35. In this case, the communication path 53 is formed in a truncated cone shape around the rotation shaft 39, and a part of the diaphragm 61 faces near the end of the communication path 53 on the turbine chamber 50 side. Further, an air flow path 55 is constituted by the communication path 53 and the suction chamber 52. Furthermore, it is preferable to change the turbine wheel 31 to a mixed flow turbine. With such a configuration, the inflow of air from the suction chamber 52 to the turbine chamber 50 becomes smooth.

  In the embodiment, the electric turbine 30 is embodied as a regenerator, but is not limited thereto. For example, the regenerator is configured not to include the electric motor M, and the compressor wheel is integrated with an end portion of the rotating shaft 39 opposite to the end portion with which the turbine wheel 31 is integrated. Then, the air discharged from the fuel cell stack 11 is compressed by a compressor wheel that rotates together with the turbine wheel 31, and the compressed air is supplied to the compressor 12 to assist the compressor 12 in compressing the air. Also good.

  In the embodiment, the communication path 53 is a part of the air flow path 55. For example, when there is no suction chamber 52, the suction port 30a and the turbine chamber 50 are connected by the communication path 53, and the entire air flow path is formed. The communication path 53 may be used.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) The seal portion is a welded portion where the elastic member and the housing are welded.
(B) The regenerator is an electric turbine.

  (C) The movable mechanism includes a stepping motor and a pressing member that contacts and separates from the elastic member by rotation of a rotor of the stepping motor.

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell system, 11 ... Fuel cell stack as fuel cell, 12 ... Compressor, 29 ... Pressure adjustment part, 30 ... Electric turbine as regenerator, 30a ... Inlet, 31 ... Turbine wheel, 32 ... Housing, DESCRIPTION OF SYMBOLS 50 ... Turbine chamber, 53 ... Communication path, 55 ... Air flow path, 60 ... Storage chamber, 61 ... Diaphragm as an elastic member, 90 ... Bellows as an elastic member, 62a, 90a ... 1st welding part as a seal part, 62b, 90b ... 2nd welding part as a seal part, 70 ... movable mechanism.

Claims (3)

A compressor for compressing air;
A fuel cell supplied with air compressed by the compressor;
A regenerator that recovers exhaust energy of air discharged from the fuel cell, and a fuel cell system comprising:
The regenerator is
A housing;
An inlet provided in the housing for taking in air exhausted from the fuel cell into the housing;
A turbine wheel pivotally supported by the housing and rotated by air taken into the housing from the suction port;
A turbine chamber defined in the housing and containing the turbine wheel;
A communication path which is partitioned in the housing and forms at least a part of an air flow path connecting the turbine chamber and the suction port;
A pressure adjusting unit that adjusts the pressure of the air supplied to the fuel cell,
The pressure adjusting unit is
An elastic member provided in the housing in a state of partitioning the communication path;
A movable mechanism for elastically deforming the elastic member in order to adjust the flow path cross-sectional area of the communication path;
A housing chamber partitioned in the housing and housing the movable mechanism;
The storage chamber and the communication path are separated by the elastic member, and the storage chamber is sealed by a seal portion provided between the elastic member and the housing. .   The fuel cell system according to claim 1, wherein the seal portion is formed by welding the metal housing and the metal elastic member.   The fuel cell system according to claim 2, wherein the elastic member is a diaphragm.