JP2000193127A - Integrated three-way switching valve and fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To synchronously switch a plurality of fluids by a small-sized and inexpensive device and improve the reliability in operation by connecting one driving means and a plurality of valve elements of three way switching means, and operating a plurality of valve elements by the driving means in interlocking with one another. SOLUTION: An integrated three-way switching valve effectively used in a fuel cell system supplying a fuel gas and an oxidant gas to a fuel cell stack, integrally comprises two three-way switching valves 21, 22, and they are simultaneously switched by the operation of a motor 51 through a decelerating part 100 comprising a worm 52 and a worm wheel 53, and a rotation linear motion converting part 200. The three way switching valves 21, 22 are respectively formed by the valve main bodies 68, 69 respectively comprising two valve seats 68a, 68b; 69a, 69b, the valve elements 61, 62, the lid parts 66, 67 and the like. The rotation-linear motion converting part 200 is formed by both nut parts 70 and screw parts 63, 64 fitted to a center of the worm wheel 53, and the valve elements 61, 62 are axially displaced by the rotation of both nut parts 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an integrated three-way switching valve and a fuel cell system.

[0002]

2. Description of the Related Art In order to reduce air pollution as much as possible, it is important to take measures against exhaust gas from automobiles, and as one of the measures, electric vehicles are used. Has not been reached.

[0003] Fuel cells are attracting attention as clean power generation devices that generate electricity by an electrochemical reaction using hydrogen and oxygen and do not emit any waste other than water. It is seen as a clean car. Among the above fuel cells, a solid polymer electrolyte fuel cell operates at a low temperature and is most promising for automobiles.

[0004] A solid polymer electrolyte fuel cell system includes:
In general, a fuel in which a stack composed of a large number of cells in which an electrolyte-electrode assembly sandwiching a solid polymer electrolyte membrane sandwiched between two electrodes (a fuel electrode and an oxidant electrode) is sandwiched between separators is sandwiched between pressure plates. The fuel cell system includes a battery stack, fuel gas supply means for supplying fuel gas to the fuel electrode side, oxidant gas supply means for supplying oxidant gas to the oxidant electrode side, and various gas pipes, and a control device for controlling them. ing.

FIG. 3 is a diagram of a general fuel cell system for mounting on a vehicle such as an automobile. In this fuel cell system, methanol and water as fuels are reformed in a reformer and used as a fuel gas containing hydrogen as a main component. Air is used as the oxidizing gas.

The fuel cell system includes a methanol tank 1, a water tank 2, a reformer 3, and a fuel cell stack 13.
It is composed of

[0007] The methanol tank 1 is for storing methanol, which is the fuel of the fuel cell, and the water tank 2 is for storing water, which is also the fuel of the fuel cell.

The reformer 3 is a device for producing a fuel gas containing hydrogen as a main component from methanol and water. An evaporator 32 for evaporating methanol and water and a combustion for burning the methanol to heat the evaporator 32 are provided. Unit 31 and the evaporation unit 32
A reforming unit 33 for reforming the methanol and water evaporated in the process into a fuel gas containing hydrogen as a main component, and a CO reducing unit 34 for reducing CO from the fuel gas coming out of the reforming unit 33. ing.

The fuel cell stack 13 has a structure in which a large number of cells having a structure in which an electrolyte is sandwiched between two electrodes (a fuel electrode and an oxidant electrode) are stacked, and the fuel gas and the air compressor are stacked. Electric power is generated by an electrochemical reaction using the air sent from 10.

The methanol supplied from the methanol tank 1 to the combustion section 31 is burned using the air supplied by the blower 4 as an auxiliary agent.

The methanol and water supplied from the methanol tank 1 and the water tank 2 to the evaporator 32 are
The fuel is vaporized by the heat of combustion of the fuel, becomes gas, is mixed with air sent from the air compressor 10 via the flow control valve 5a, and the fuel containing hydrogen as a main component by a catalyst (eg, a Cu—Zn catalyst) in the reforming unit 33. Reformed into gas.

The fuel gas contains 0.3 to 1% of CO, and when sent to the fuel cell stack 13 as it is, it poisons the electrode catalyst of the fuel cell stack 13 and significantly reduces the power generation performance of the fuel cell. The fuel gas discharged from the reforming section 33 is sent to a CO reducing section 34. CO reduction unit 3
In 4, the air is mixed with air sent from the air compressor 10 via the flow control valve 5b and oxidized and reduced by a catalyst (for example, a Pt catalyst) to reduce the CO concentration to 10 pp.
m or less and discharged to the fuel gas line 9a. The fuel gas pipe 9a is connected to the three-way switching valve 8.

Immediately after the start-up, the temperature of the reformer 3 has not risen sufficiently and the CO concentration has not dropped below 10 ppm even after passing through the CO reduction section 34. The fuel gas is sent to the unused fuel gas pipe 9c via the fuel gas bypass pipe 9b, and burns in the combustion section 31.

At this time, the air sent from the air compressor 10 is also switched to the unused air line 9f via the air bypass line 9e by switching the three-way switching valve 11, and
1 is a combustion aid.

When the CO concentration in the fuel gas drops to 10 ppm or less, the fuel gas is sent to the fuel gas line 9d by switching the three-way switching valve 8, and is sent to the fuel cell stack 1
Sent to 3.

At the same time, the air sent from the air compressor 10 is also sent to the air line 9g by switching the three-way switching valve 11 and sent to the fuel cell stack 13.

The fuel cell stack 13 generates power by an electrochemical reaction at electrodes using hydrogen in fuel gas and oxygen in air.

The hydrogen in the fuel gas is not completely used in the fuel cell stack 13 and its utilization is about 80%. Unused fuel gas not used in the fuel cell stack 13 is sent to the combustion unit 31 through the unused fuel gas pipe 9p, the pressure regulating valve 14, and the unused fuel gas pipe 9c, and is used as combustion energy.

Since the oxygen in the air is supplied in an amount larger than that required for the reaction, the oxygen is not completely used in the fuel cell stack 13. The fuel cell stack 13
Unused air that has not been used in the unused air line 9q,
It is sent to the combustion section 31 via the pressure regulating valve 15 and the unused air pipe 9f, and is used as a combustion aid for combustion.

The pressure regulating valve 14 and the pressure regulating valve 15 are set to the same set pressure (for example, 1.5 atm), and when the fuel gas or air pressure discharged from the fuel cell stack 13 is lower than the set pressure, the fuel gas Alternatively, the air is shut off, and when the pressure becomes equal to or higher than the set pressure, a part of the fuel gas or air is discharged to the unused fuel gas pipe 9c or the unused air pipe 9f, and the fuel gas or air in the fuel cell stack 13 is discharged. It has a function to stabilize the pressure to the set pressure.

In a steady operation state in which the fuel gas, that is, the air is stably sent, there is no problem since the fuel gas and the air pressure are maintained at the same set pressure. However, a problem arises in an unsteady state in which one of the fuel gas and the air becomes lower than the set pressure.

The three-way switching valve 8 and the three-way switching valve 11
Are simultaneously switched, but it is extremely difficult to supply the fuel gas and the air to the fuel cell stack 13 at the same time due to the operation time, the length of the pipe, etc., and there is a time difference, and the fuel gas is supplied to each electrode of the fuel cell stack 13. As a result, the timing of the supply of air and the supply of air will be shifted, and a difference will occur between the fuel gas and the air pressure.

When the pressure difference between the fuel gas and the air is repeatedly applied, the electrolyte serving as a diaphragm between the fuel gas and the air is damaged, and the performance of the fuel cell is reduced.

Referring to FIGS. 4 and 5, the mechanism by which the electrolyte is damaged by the pressure difference between the fuel gas and the air will be described in detail.

FIG. 4 is a one-side cross-sectional view of a solid polymer electrolyte fuel cell electrode when the fuel gas pressure P2 and the air pressure P1 are substantially the same. FIG. FIG. 4 is a one-side cross-sectional view illustrating a solid polymer electrolyte fuel cell electrode part when it is large.

The solid polymer electrolyte membrane 46 is sandwiched between the fuel electrode 47 and the oxidant electrode 48 to form the electrode section 40. A seal 42 seals a peripheral portion 46 a of the solid polymer electrolyte membrane extending from the electrode end 41 of the fuel electrode 47, that is, the oxidant electrode 48.
The fuel gas on the fuel electrode side and the air on the oxidant electrode side are sealed with a seal 43 interposed therebetween.

As shown in FIG. 4, when the fuel gas pressure P2 and the air pressure P1 are substantially the same, a mechanical stress hardly occurs in the solid polymer electrolyte membrane peripheral portion 46a.

On the other hand, when the air pressure P1 is higher than the fuel gas pressure P2 as shown in FIG. 5, the solid polymer electrolyte membrane 46 swells to the fuel gas side because it is as thin as 20 to 130 μm, and the solid polymer electrolyte membrane 46 A large elongation and a large mechanical stress are generated in the peripheral portion 46a. When this is repeated, the peripheral portion 46a of the solid polymer electrolyte membrane is damaged. The same applies when the fuel gas pressure P2 is higher than the air pressure P1.

In order to avoid this problem, it is necessary to prevent a difference between the fuel gas pressure and the air pressure.
As a prior art, Japanese Patent Laid-Open Publication No.
Detect fuel gas pressure and air pressure and calculate the differential pressure,
A differential pressure control method for releasing a gas having a higher pressure into the atmosphere by opening a release control valve is disclosed.

[0030]

However, the prior art requires a plurality of release control valves and a plurality of pressure detectors, that is, a computing device, so that the system becomes complicated and large,
There was a problem that the cost was high.

The present invention has solved the above-mentioned problems. By devising an integrated three-way switching valve which can switch in conjunction with one driving means, it is possible to synchronize a plurality of fluids at a small size and at low cost. Provided is an integrated three-way switching valve that can be switched by switching, and a small, low-cost, highly reliable fuel cell system.

[0032]

In order to solve the above technical problems, the technical means (hereinafter referred to as first technical means) taken in claim 1 of the present invention is one driving means. And a valve body of a plurality of three-way switching means, and the driving means can move the plurality of valve bodies in an interlocked manner.

The effects of the first technical means are as follows.

That is, since a plurality of fluids can be switched at the same time in conjunction with one drive means, an integrated three-way switching valve which is small and inexpensive and can always switch a plurality of fluids synchronously can be obtained. Having.

In order to solve the above-mentioned technical problem, the technical means (hereinafter referred to as second technical means) taken in claim 2 of the present invention is that the driving means and the valve body are decelerating means. 2. The method according to claim 1, wherein the connection is made through
It is an integrated three-way switching valve as described.

The effects of the second technical means are as follows.

That is, since the fluid can be switched slowly, there is an effect that a plurality of fluids can be switched simultaneously with the same differential pressure.

In order to solve the above technical problem, the technical means (hereinafter referred to as the third technical means) taken in claim 3 of the present invention is that the driving means and the valve element are rotated. 2. The integrated three-way switching valve according to claim 1, wherein the three-way switching valve is connected via a rotary linear motion converting means for converting the linear motion into a linear motion.

The effects of the third technical means are as follows.

That is, since the valve element can be moved using the rotating drive means, a general and inexpensive drive means can be used as the drive means.

In order to solve the above-mentioned technical problem, the technical means (hereinafter referred to as fourth technical means) taken in claim 4 of the present invention is that the three-way switching means makes the inside of the valve body the above-mentioned. A valve body that linearly moves by a driving means, two valve seats are provided on the valve body, a seal portion that can abut on the valve seat is provided on the valve body, and a fluid is provided between the two valve seats. An intermediate communication portion through which the valve body can flow, a communication hole communicating with the outside in the middle of the two valve seat portions, and two communication holes communicating with the outside outside the two valve seat portions of the valve body. The integrated three-way switching valve according to claim 1, wherein:

The effects of the fourth technical means are as follows.

That is, since the switching means is a three-way switching means that can be switched by the linear movement of the valve body, the structure is simple, and the size and cost can be reduced.

In order to solve the above-mentioned technical problem, the technical means (hereinafter referred to as a fifth technical means) of the present invention, which is adopted in claim 5, is an integrated three-way device according to claims 1 to 4. A fuel cell system using a switching valve to supply a fuel gas and an oxidizing gas to a fuel cell stack.

The effects of the fifth technical means are as follows.

That is, since an integrated three-way switching valve is used which is small in size and low in cost and can switch a plurality of fluids in a synchronized manner, it is small in size and low in cost and has a small differential pressure applied to the electrolyte. A high fuel cell system is possible.

In order to solve the above technical problem, the technical means (hereinafter referred to as the sixth technical means) adopted in claim 6 of the present invention is that the integrated three-way switching valve includes the fuel cell. The fuel cell system according to claim 5, wherein the fuel cell system is provided adjacent to the stack.

The effects of the sixth technical means are as follows.

That is, since the integrated three-way switching valve and the fuel cell stack are integrally formed, a small fuel cell system can be obtained.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is a sectional view of an integrated three-way switching valve according to an embodiment of the present invention. This integrated three-way switching valve includes two three-way switching valves (three-way switching means) 21 and 22, a motor 51 as a driving means, a reduction section 100 as a reduction section, and a rotary linear motion conversion section 200 as a rotary linear motion conversion section. It is composed of

The three-way switching valve 21 includes a valve body 68 and a valve body 6.
1, a lid 66. The valve body 68 is provided with two valve seats 68a and 68b. The valve body 61 is provided with seal portions 61a and 61b that can contact the valve seat portions 68a and 68b. Between the two valve seats 68a, 68b, there is provided an intermediate flow part 75 through which a fluid can flow.

The valve seats 68a, 68 of the valve body 68
b, a fluid supply hole 55 which is a communication hole communicating with the outside in the middle of
Is provided. Further, fluid discharge holes 56 and 57, which are communication holes communicating with the outside, are provided outside the valve seat portions 68a and 68b of the valve body 68. A guide part 64 is provided on the lid part 66 side of the valve body 61. A guide projection 71 is provided upright on the lid 66, and the guide projection 71 and the guide section 64 are fitted so that the valve element cannot rotate but can slide.

The three-way switching valve 22 includes a valve body 69 and a valve body 6.
2. It is composed of a lid 67. The valve body 69 is provided with two valve seats 69a and 69b. The valve body 62 is provided with seal portions 62a and 62b that can contact the valve seat portions 69a and 69b. An intermediate flow passage 76 through which fluid can flow is provided between the two valve seats 69a and 69b.

The valve seats 69a, 69 of the valve body 69
b, a fluid supply hole 58 which is a communication hole communicating with the outside in the middle of
Is provided. Further, fluid discharge holes 59 and 60, which are communication holes communicating with the outside, are provided outside the valve seat portions 69a and 69b of the valve body 69. A guide portion 65 is provided on the lid 67 side of the valve body 62. A guide projection 72 is provided upright on the lid 67, and the guide projection 72 and the guide 65 are fitted so that the valve body cannot rotate but can slide.

The speed reducer 100 includes a worm 52 and a worm wheel 53. The worm 5
2 is coupled to the shaft of the motor 51. The worm wheel 53 is engaged with the worm 52,
The rotation speed of the motor 51 is reduced.

The rotary linear motion converting section 200 is composed of both nuts 70 and screw sections 63 and 64. The two nuts 70 are fitted to the worm wheel 53 at the same center. The two nuts 70 have nut portions 70 at both ends.
a, 70b, and the nut portions 70a, 70b are screwed with the screw portions 63, 64, respectively. One of the screw portions 63 is a right-hand screw, and the other screw portion 64 is a left-hand screw. The screw portion 63 is connected to the valve body 61 on the side opposite to the lid 66 side. The screw portion 64 is a cover 67 of the valve body 62.
Combined with the opposite side.

In the state shown in the figure, the fluid supply hole 55 and the fluid discharge hole 56 of the three-way switching valve 21 communicate with each other through the intermediate flow portion 75, and the fluid supplied from the fluid supply hole 55 passes through the intermediate flow portion. The fluid is discharged to the fluid discharge hole 56 through the flow portion 75. On the other hand, the fluid supply hole 58 and the fluid discharge hole 59 of the three-way switching valve 22 communicate with each other via the intermediate flow portion 76, and the fluid supplied from the fluid supply hole 58 is
6 and is discharged to the fluid discharge hole 59.

When the motor 51 rotates rightward, the speed is reduced by the relationship between the worm 52 and the worm wheel 53, and the worm wheel 53 rotates leftward when viewed from the three-way switching valve 22. In conjunction with the worm wheel 53, the nut portions 70 also rotate to the left as viewed from the three-way switching valve 22.

Since the rotation of the valve element 61 is restricted by the guide projection 71, the valve element 61 moves in the direction of the lid 66 due to the relationship between the nut 70 a of the two nuts 70 and the screw 63. The valve element 61 stops when the seal portion 61b of the valve element 61 contacts the valve seat 68b of the valve body 68. As a result, the valve port 73b is closed and the fluid supply hole 55 is
The flow of fluid to 6 is blocked. On the other hand, the valve port 73a between the seal portion 61a of the valve body 61 and the valve seat portion 68a of the valve body 68 opens, and the fluid supply hole 55 and the fluid discharge hole 5 are formed.
7 communicate with each other through the intermediate flow portion 75.

Since the rotation of the valve body 62 is restricted by the guide projection 72, the valve body 62 moves toward the lid 67 due to the relationship between the nut 70 b of the nut 70 and the screw 64. The valve element 62 stops when the seal portion 62b of the valve element 62 contacts the valve seat 69b of the valve body 69. Thereby, the valve port 73b is closed and the fluid supply hole 58 is
The flow of fluid to 9 is blocked. On the other hand, the valve port 74a between the seal portion 62a of the valve body 62 and the valve seat portion 69a of the valve body 69 opens, and the fluid supply hole 58 and the fluid discharge hole 6 are opened.
0 communicates via the intermediate flow part 76.

Thus, the switching from the fluid discharge holes 56 to 57 of the three-way switching valve 21 and the switching from the fluid discharge holes 59 to 60 of the three-way switching valve 21 can be performed simultaneously. When the motor 51 rotates leftward, the switching of the three-way switching valve 21 from the fluid discharge holes 57 to 56 and the switching of the three-way switching valve 21 from the fluid discharge holes 60 to 59 can be simultaneously performed.

According to the structure of the present invention, since two three-way switching valves are combined and driven by one motor, the size and cost are reduced. In addition, when it is necessary to switch the flow direction of two fluids at the same time, there is no time difference because they are driven by one motor, and there is also a problem that only one fluid is switched due to failure etc. do not do. Since the flow direction of the fluid can be switched slowly by the deceleration means of the worm and the worm wheel having the configuration of the present invention, it is possible to prevent a sudden rise in pressure due to the switching of the fluid.

In this embodiment, the communication hole in the middle of the two valve seats is used as the supply hole, and the two communication holes outside the two valve seats are used as the discharge holes. The communication hole of the latter can be used as a supply hole as a discharge hole.

FIG. 2 is a diagram of a fuel cell system for mounting on an automobile or the like according to an embodiment of the present invention. Since it is the same as the general fuel cell system shown in FIG. 3 except that the integrated three-way switching valve of the present invention is used as the three-way switching valve, the same reference numerals are used for the same components and the description is omitted.

The integrated three-way switching valve 18 is connected adjacent to the gas inlet side of the fuel cell stack 13. The connection between the gas pipes of the fuel cell stack 13 and the integrated three-way switching valve 18 is made by an L-shaped pipe of the same size. The positional relationship of the integrated three-way switching valve 18 is such that FIG. 1 shows a cross section parallel to the connecting surface between the fuel cell stack 13 and the integrated three-way switching valve 18.

The carbon monoxide reducing section 34 of the reformer 3 is connected to the fluid supply hole 58 of one of the three-way switching valves 22 of the integrated three-way switching valve 18 via the fuel gas pipe 9h. The air compressor is connected to the fluid supply hole 55 of the other three-way switching valve 21 of the integrated three-way switching valve 18 via the air pipes 9j and 9k.

One fluid discharge hole 5 of the three-way switching valve 22
Numeral 9 is connected to an unused fuel gas line 9c via a fuel gas bypass line 9i. The other fluid discharge hole 60 is connected to the fuel gas inlet of the fuel cell stack 13 via the L-shaped tube. One fluid discharge hole 56 of the three-way switching valve 21 is connected to an unused air line 9f via an air bypass line 9m. The other fluid discharge hole 57 is
It is connected to the air inlet of the fuel cell stack 13 via a pipe.

Immediately after the start-up, the temperature of the reformer 3 has not risen sufficiently and the CO concentration has not dropped to 10 ppm or less even after passing through the CO reduction section 34. The fuel gas is sent from the hole 59 to the unused fuel gas pipe 9c via the fuel gas bypass pipe 9i, and is burned in the combustion unit 31. At the same time, air compressor 10
The air sent from the fluid outlet 5 of the three-way switching valve 21
6 through an air bypass line 9m and an unused air line 9
f and becomes a combustion aid in the combustion section 31.

When the CO concentration in the fuel gas has dropped to 10 ppm or less, the motor 51 is rotated clockwise to change the fuel gas discharge destination of the three-way switching valve 22 from the fluid discharge holes 59 to 6.
0, and at the same time, the air discharge destination of the three-way switching valve 21 is switched from the fluid discharge holes 56 to 57. This allows
Fuel gas and air are simultaneously supplied to the fuel cell stack 13. The fuel cell stack 13 generates power by an electrochemical reaction at electrodes using hydrogen in fuel gas and oxygen in air.

The three-way switching valves 21 and 22 are simultaneously switched by one motor 51, and the pipe lengths between the three-way switching valves 21 and 22 are the same, so that fuel gas and air can be supplied simultaneously. Further, abrupt pressure changes of the fuel gas and the air can be avoided by the worm and the speed reducing means of the worm wheel. Thereby, the mechanical stress applied to the solid polymer electrolyte membrane having the role of a fuel gas and air diaphragm can be reduced, and the reliability of the fuel cell can be increased.

In this embodiment, the integrated three-way switching valve 18 is provided adjacent to the fuel cell stack 13. If the length of the pipe between the fluid discharge hole 57 and the air inlet of the fuel cell stack 13 is the same, the integrated three-way switching valve 18 may be separated from the fuel cell stack 13. However, when they are provided adjacent to each other as in this embodiment, space can be saved and the fuel cell system can be downsized. Further, a delay in pressure change inside the fuel cell stack 13 due to the piping is less likely to occur.

[0073]

As described above, the present invention is characterized in that one drive means and a plurality of three-way switching means are connected to each other, and the plurality of valve bodies can be moved in conjunction with each other by the drive means. The fuel cell system is characterized in that the fuel gas and the oxidizing gas are supplied to the fuel cell stack using the integrated three-way switching valve and the integrated three-way switching valve. Integral three-way switching valve that can always switch fluids synchronously and small size,
A low-cost and highly reliable fuel cell system can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of an integrated three-way switching valve according to an embodiment of the present invention.

FIG. 2 is a diagram of a fuel cell system for mounting on an automobile or the like according to an embodiment of the present invention

FIG. 3 is a diagram of a general fuel cell system for a vehicle such as an automobile.

FIG. 4 is an explanatory one-side sectional view of a solid polymer electrolyte fuel cell electrode portion when the fuel gas and the air pressure are substantially the same.

FIG. 5 is an explanatory one-side sectional view of a solid polymer electrolyte fuel cell electrode portion when the air pressure is higher than the fuel gas pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 13 ... Fuel cell stack 18 ... Integrated three-way switching valve 21, 22 ... Three-way switching valve (three-way switching means) 51 ... Motor 52 ... Worm 53 ... Worm wheel (reduction means) 55, 58 ... Fluid supply hole (communication hole) 56 ..., 57, 59, 60 ... fluid discharge holes (communication holes) 61, 62 ... valve bodies 61a, 61b, 62a, 62b ... seal portions 68, 69 ... valve bodies 68a, 68b, 69a, 69b ... valve seat portions

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H063 AA08 BB32 CC02 DA14 GG03 GG11 3H067 AA14 AA32 BB02 BB12 CC32 DD03 DD32 DD43 EA32 FF11 GG02 GG21 5H027 AA06 MM02

Claims (6)

[Claims] 1. An integrated three-way switching valve, wherein one driving means is connected to valve bodies of a plurality of three-way switching means, and the driving means can move the plurality of valve bodies in an interlocked manner. 2. The integrated three-way switching valve according to claim 1, wherein said drive means and said valve element are connected via a speed reduction means. 3. An integrated three-way switching valve according to claim 1, wherein said drive means and said valve element are connected via rotary linear motion converting means for converting rotary motion into linear motion. 4. The valve body, wherein the three-way switching means is a valve body which linearly moves inside the valve body by the driving means, wherein the valve body is provided with two valve seats, and a seal part which can abut on the valve seats is provided. Provided in the valve body, providing an intermediate communication portion through which fluid can flow between the two valve seats, providing a communication hole communicating with the outside in the middle of the two valve seats, 2. The integrated three-way switching valve according to claim 1, wherein two communication holes communicating with the outside are provided outside the valve seat. 5. A fuel cell system, wherein a fuel gas and an oxidizing gas are supplied to a fuel cell stack using the integrated three-way switching valve according to claim 1. 6. The fuel cell system according to claim 5, wherein the integrated three-way switching valve is provided adjacent to the fuel cell stack.