JP2007230464A - Cargo vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accomplish power-saving, low noise and miniaturization of a cooling system of a fuel cell. <P>SOLUTION: The fuel cell 5 becomes an energy source for driving a fork lift 1. The cooling system 8 for cooling the fuel cell 5 includes a radiator 6 and a heat sink 7. The heat sink 7 cools a cooling liquid for cooling the fuel cell 5. The radiator 6 further cools the cooling liquid from the heat sink 7 and feeds it to the fuel cell 5. The heat sink 7 is installed so as to be closely adhered to a counter weight 4 such that a heat conduction route from the cooling liquid in a passing route formed at the inside is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cargo handling vehicle using a fuel cell as an energy source.

  Fuel cells are attracting attention as a clean energy source. BACKGROUND ART A fuel cell vehicle that is an automobile that uses a fuel cell as an energy source has a cooling system that cools the fuel cell. The cooling system includes a pump for circulating a coolant for cooling the fuel cell and a radiator for cooling the coolant. In an engine vehicle having an engine, the difference between the temperature of the coolant for cooling the engine and the outside air temperature is large, and the cooling efficiency of the radiator is high. However, in the fuel cell vehicle, the difference between the temperature of the coolant for cooling the fuel cell and the outside air temperature is smaller than that of the engine vehicle, and the cooling efficiency of the radiator is low. For this reason, the radiator of the fuel cell vehicle has a cooling fan with a large capacity, and the coolant is cooled by the air blown from the cooling fan and the traveling wind generated when the fuel cell vehicle travels.

  A cargo handling vehicle rarely travels at a high speed like a general automobile. Further, since handling of a load is mainly performed when traveling is stopped, it is difficult to obtain a cooling effect by traveling wind in a radiator. Therefore, when a cargo handling vehicle uses a fuel cell as an energy source, the size of the cooling fan of the radiator is increased, the number of cooling fans is increased, or the cooling fans are rotated at a higher speed. It is conceivable to further increase the capacity. However, when the size of the cooling fan is increased or the number of cooling fans is increased, the cooling system is increased in size. Further, when the cooling fan is rotated at a higher speed, noise increases. Furthermore, in any case, the power consumption of the cooling system increases.

  On the other hand, in cargo handling vehicles, a technique for cooling a heating element by connecting a heating element such as a controller to a counterweight having a large heat capacity via a thermal conductive agent is known (see Patent Document 1).

Japanese Utility Model Publication No. 5-5681

  However, in the fuel cell, in order to keep the cell temperature uniformly at a temperature suitable for power generation, the coolant circulates inside the fuel cell. Further, the fuel cell is housed in the case via an electrical insulator in order to maintain electrical insulation (high voltage safety) from the outside. Due to such a configuration, a cooling method in which the fuel cell is directly arranged close to the heat capacity body as in the technique described in Patent Document 1 cannot be taken.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a cargo handling vehicle that can achieve power saving, noise reduction, and downsizing of a fuel cell cooling system.

Means and effects for solving the problems

  A cargo handling vehicle according to the present invention is a cargo handling vehicle that uses a fuel cell as an energy source, a radiator that cools a coolant for cooling the fuel cell, and a heat capacity that is a member that forms part of the vehicle body. And a radiator that forms a heat conduction path from the cooling liquid in the passage to the heat capacity body.

  According to the present invention, the cooling liquid is cooled by the radiator and the heat radiating body that radiates heat to the heat capacity body. The fan can be downsized. As a result, it is possible to achieve power saving, noise reduction, and size reduction of the fuel cell cooling system.

  In the present invention, it is preferable that the coolant reaches the radiator from the fuel cell via the passage of the radiator and is supplied to the fuel cell again after being cooled by the radiator. According to this, since the coolant finally cooled by the radiator is supplied to the fuel cell, the temperature of the coolant supplied to the fuel cell can be accurately adjusted by the radiator.

  In the present invention, the heat capacity body may be a counterweight. According to this, it is possible to efficiently cool the coolant in the radiator using a counterweight having a large heat capacity.

  At this time, in the present invention, the radiator has a cooling fan, the counterweight has a ventilation hole in which an exhaust path from the cooling fan is formed, and the radiator has a radiation fin. It is preferable that the heat dissipating fins are disposed in the exhaust path. According to this, since the radiating fin is efficiently cooled by the exhaust from the cooling fan, the coolant in the radiating body can be cooled more efficiently.

  Alternatively, in the present invention, at least one of the heat capacity body and the heat radiating body may have a heat radiating fin. According to this, the cooling liquid in the radiator can be efficiently cooled by the radiation fins.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings.

  FIG. 1 is a side view of a forklift 1 that is a cargo handling vehicle according to the present embodiment. FIG. 2 is a rear view of the forklift 1. As shown in FIGS. 1 and 2, the forklift 1 is configured as, for example, a front wheel drive / rear wheel steering four-wheel vehicle. A front part of the forklift 1 is provided with a lift device 2 for performing a lifting / lowering operation of the load and a tilt device 3 for performing a forward / backward tilting operation of the lift device 2. A counterweight (heat capacity body) 4 is provided at the rear portion of the forklift 1. The counterweight 4 is a member that forms a part of the vehicle body, and is an essential component of the forklift 1. Further, the counterweight 4 is formed with a through hole penetrating from the front to the rear of the vehicle body. This through hole is a ventilation hole 41 in which an exhaust path 42 from a cooling fan 62 of the radiator 6 described later is formed. Further, the forklift 1 has a fuel cell 5 and a cooling system 8 for cooling the fuel cell 5.

  The fuel cell 5 is an energy source for driving the forklift 1, and is disposed near the bottom of the vehicle body. In addition, a coolant for cooling the fuel cell 5 circulates in the fuel cell 5. The cooling system 8 includes a radiator 6, a heat sink (heat radiator) 7, and a water pump (not shown) for circulating the coolant. The water pump is provided between the fuel cell 5 and the heat sink 7 (hose 81). The radiator 6 cools a coolant for cooling the fuel cell 5, and includes a radiator body 61 and a cooling fan 62. A cooling pipe (not shown) through which the cooling liquid passes is disposed in the radiator main body 61, and is disposed so as to face the opening of the vent hole 41 of the counterweight 4. The radiator body 61 is attached with a temperature sensor 21 (see FIG. 6) for detecting the temperature of the coolant in the cooling pipe. The temperature sensor 21 is composed of, for example, a thermocouple. The cooling fan 62 cools the cooling pipe of the radiator main body 61, and is disposed between the radiator main body 61 and the ventilation holes 41. When the cooling fan 62 is driven, the air in the vehicle body passes through the radiator body 61 and is exhausted to the outside through the ventilation holes 41. At this time, the exhaust passage 42 is formed in the ventilation hole 41 as described above. Further, as will be described later, the temperature of the coolant in the radiator 6 is controlled by the temperature control device 10 (see FIG. 6).

  Next, the heat sink 7 will be described with further reference to FIGS. FIG. 3 is a top view of the heat sink 7 (viewed from above in FIGS. 1 and 2). FIG. 4 is a cross-sectional view of the heat sink 7 taken along line IV-IV shown in FIG. The heat sink 7 cools a coolant for cooling the fuel cell 5. As shown in FIGS. 1 and 2, the heat sink 7 has a heat sink body 71 and a large number of heat radiation fins 73 and is installed in the ventilation holes 41 of the counterweight 4. The heat sink main body 71 has a rectangular parallelepiped shape, and as shown in FIG. 4, a passage path 72 through which the cooling liquid passes is formed therein. The passage path 72 is formed so as to circulate throughout the heat sink body 71 and has a continuous S-shape. The heat sink body 71 is made of a metal having high thermal conductivity such as an aluminum alloy, and the heat sink main body 71 is connected to the counterweight 4 so that a heat conduction path from the coolant in the passage path 72 to the counterweight 4 is formed. It is installed in close contact. In other words, the heat of the coolant in the passage path 72 is dissipated to the counterweight 4 so that the coolant is cooled. The heat sink body 71 may be installed on the counterweight 4 via a member having high thermal conductivity such as a heat conductive sheet.

  The heat radiating fins 73 radiate the heat of the heat sink main body 71 to the atmosphere, and are disposed on the upper surface of the heat sink main body 71 (the surface opposite to the surface in contact with the counterweight 4) as shown in FIGS. ing. Therefore, the heat radiating fins 73 are arranged in the exhaust path 42 formed in the ventilation hole 41. The heat radiation fins 73 have a plate shape extending along the exhaust path 42 and are arranged in a direction orthogonal to the extending direction. On the surface of the radiating fin 73, a large number of fine grooves (not shown) formed along the extending direction are formed. Thereby, the surface area of the radiation fin 73 becomes large, and the heat radiation effect can be improved.

  The fuel cell 5 and the heat sink 7 are connected by a hose 81, the heat sink 7 and the radiator 6 are connected by a hose 82, and the radiator 6 and the fuel cell 5 are connected by a hose 83. Then, by being driven by the water pump, the coolant circulates in the fuel cell 5, the radiator 6 and the heat sink 7 via the hoses 81 to 83.

  Next, the flow of the coolant in the cooling system 8 will be described with reference to FIG. FIG. 5 is a diagram illustrating the flow of the coolant in the cooling system 8. As shown in FIG. 5, in the cooling system 8, the coolant in the fuel cell 5 reaches the heat sink 7 via the hose 81. The coolant that has reached the heat sink 7 is cooled through the passage path 72 and then reaches the radiator 6 via the hose 82. The coolant that has reached the radiator 6 is cooled by the cooling fan 62 and then supplied to the fuel cell 5 again through the hose 83.

  Next, the temperature control device 10 that controls the temperature of the coolant in the radiator 6 will be described with reference to FIG. FIG. 6 is a functional block diagram of the temperature control device 10. As shown in FIG. 6, the temperature control device 10 includes a coolant temperature detection unit 11, a coolant temperature control unit 12, and a cooling fan control unit 13. The coolant temperature detection unit 11 detects the temperature of the coolant based on the voltage value output from the temperature sensor 21. The coolant temperature control unit 12 controls the temperature of the coolant in the radiator 6. Specifically, the coolant temperature control unit 12 determines the rotation speed of the cooling fan 62 based on the detection result of the coolant temperature detection unit 11 so that the coolant reaches a predetermined temperature. The cooling fan control unit 13 controls the cooling fan 62 so as to rotate at the rotation speed determined by the coolant temperature control unit 12. As described above, the temperature control device 10 controls the number of rotations of the cooling fan 62, whereby the temperature of the coolant in the radiator 6 can be controlled.

  According to the present embodiment described above, since the coolant is cooled by the radiator 6 and the heat sink 7, the number of revolutions of the cooling fan 62 of the radiator 6 is reduced as compared with the case where the coolant is cooled only by the radiator 6. Or the cooling fan 62 can be downsized. Thereby, power saving, noise reduction, and size reduction of the cooling system 8 can be achieved. In the forklift 1, the fuel cell 5 is installed in the vicinity of the bottom of the vehicle body. However, by installing the heavy fuel cell 5 in the vicinity of the bottom, the center of gravity of the forklift 1 can be lowered.

  Further, the coolant for cooling the fuel cell 5 reaches the radiator 6 from the fuel cell 5 via the passage path 72 of the heat sink 7, is cooled by the radiator 6, and is then supplied to the fuel cell 5 again. That is, the coolant finally cooled by the radiator 6 is supplied to the fuel cell 5. Further, the rotational speed of the cooling fan 62 is controlled by the temperature control device 10 so that the coolant in the radiator 6 has a predetermined temperature. For this reason, the temperature of the coolant supplied to the fuel cell 5 can be accurately adjusted by the cooling fan 62.

  Furthermore, since the heat sink 7 cools the coolant using the counterweight 4 having a large heat capacity, the coolant in the heat sink 7 can be efficiently cooled. Further, by using the counterweight 4 which is an essential component of the forklift 1 for cooling, it becomes unnecessary to newly provide a heavy object having a large heat capacity. For this reason, the cost and weight of the cooling system 8 can be reduced.

  In addition, since the radiating fins 73 of the heat sink 7 are disposed in the exhaust path 42 formed in the ventilation hole 41 of the counterweight 4, the radiating fins 73 are efficiently cooled by the exhaust from the cooling fan 62. . Thereby, the cooling liquid in the heat sink 7 can be cooled more efficiently.

  Next, a modification according to the present embodiment will be described with reference to FIG. FIG. 7 is a partial side view of a forklift 101 which is a modified example according to the present embodiment. In the above-described embodiment, the heat sink 7 is installed in the ventilation hole 41 of the counterweight 4, but the heat sink 7 may be installed in any place of the counterweight 4. For example, as shown in FIG. 7, the heat sink 7 may be installed on the counterweight 104. Note that the exhaust from the cooling fan 62 in the radiator 6 is exhausted from the side surface of the forklift 101. Thereby, it can respond also to the forklift 101 which has the counterweight 104 in which the ventilation hole 41 is not formed.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made as long as they are described in the claims. For example, the following invention can be implemented.

(1) In the above embodiment, in the cooling system 8, the coolant reaches the radiator 6 from the fuel cell 5 via the passage path 72 of the heat sink 7, is cooled by the radiator 6, and then is supplied to the fuel cell 5 again. However, the flow of the coolant is not limited to this. For example, after the coolant is cooled by the radiator 6 from the fuel cell 5, the coolant again passes through the passage 72 of the heat sink 7. The structure supplied to the fuel cell 5 may be sufficient.

(2) In the above embodiment, the heat sink 7 is installed so that the heat conduction path from the coolant in the passage path 72 to the counterweights 4 and 104 is formed. The configuration may be such that a heat conduction path is formed from the coolant in the passage path 72 to another heat capacity body constituting the vehicle body such as a bottom plate of the vehicle body.

(3) Furthermore, in the said embodiment, although the heat sink 7 is the structure which has the radiation fin 73, the structure which does not have the radiation fin 73 may be sufficient. Further, the counterweights 4 and 104 may have heat radiation fins.

(4) In the above embodiment, the coolant temperature controller 12 determines the rotation speed of the cooling fan 62 so that the coolant reaches a predetermined temperature based on the detection result of the coolant temperature detector 11. The cooling fan control unit 13 is configured to control the cooling fan 62 so as to rotate at the determined rotation speed, but is not limited to such a configuration. For example, based on the detection result of the coolant temperature detection unit 11, the coolant temperature control unit determines the rotation speed of the cooling fan 62 such that the coolant reaches a predetermined temperature and the amount of coolant flow in a water pump (not shown). The cooling fan control unit 13 controls the cooling fan 62 so as to rotate at the determined rotational speed, and the separately provided pump control unit uses a water pump so that the coolant flows in the determined amount. The structure which controls this may be sufficient.

(5) Furthermore, in the said embodiment, although the radiator 6 becomes a structure which has the cooling fan 62, the structure where a radiator does not have a cooling fan may be sufficient. At this time, the coolant temperature control unit determines the amount of coolant flow in the water pump so that the coolant reaches a predetermined temperature based on the detection result of the coolant temperature detection unit 11, and the pump control unit The water pump may be controlled so that the coolant flows in a determined amount. In addition, the circulation path of the coolant formed in the radiator body of the radiator can be switched, and the coolant temperature control unit determines the circulation path in the radiator body so that the coolant reaches a predetermined temperature. You may control a radiator main body so that it may become a circulation path.

(6) In addition, in the above embodiment, the example in which the present invention is applied to the forklift 1 has been described. However, the present invention is also applicable to other cargo handling vehicles such as a skid steer loader.

It is a side view of the forklift which is one embodiment concerning the present invention. It is a rear view of the forklift shown in FIG. It is a top view of the heat sink shown in FIG. It is sectional drawing of the heat sink which concerns on the IV-IV line shown in FIG. It is the figure which showed the flow of the cooling fluid in the cooling system shown in FIG. It is a functional block diagram of the temperature control apparatus which controls the temperature of the cooling fluid in the radiator shown in FIG. It is a partial side view of the forklift which concerns on the modification of this embodiment.

Explanation of symbols

1, 101 Forklift (loading vehicle)
4, 104 Counterweight (heat capacity body)
5 Fuel cell 6 Radiator 7 Heat sink (heat sink)
DESCRIPTION OF SYMBOLS 8 Cooling system 10 Temperature control apparatus 11 Coolant temperature detection part 12 Coolant temperature control part 13 Cooling fan control part 21 Temperature sensor 41 Ventilation hole 42 Exhaust path 61 Radiator main body 62 Cooling fan 71 Heat sink main body 72 Passing path 73 Radiation fins 81- 83 hose

Claims (5)

A cargo handling vehicle using a fuel cell as an energy source,
A radiator for cooling a coolant for cooling the fuel cell;
A heat capacity body which is a member forming a part of the vehicle body;
A cargo handling vehicle, comprising: a passage through which the coolant passes; and a heat radiator that forms a heat conduction path from the coolant to the heat capacity body in the passage.   2. The coolant according to claim 1, wherein the coolant reaches the radiator from the fuel cell via the passage of the radiator and is supplied to the fuel cell again after being cooled by the radiator. The listed cargo handling vehicle.   The cargo handling vehicle according to claim 1, wherein the heat capacity body is a counterweight. The radiator has a cooling fan;
The counterweight has a vent hole in which an exhaust path from the cooling fan is formed;
The radiator has a radiating fin;
The cargo handling vehicle according to claim 3, wherein the heat dissipating fins are disposed in the exhaust path.   The cargo handling vehicle according to any one of claims 1 to 3, wherein at least one of the heat capacity body and the heat radiating body has a heat radiating fin.

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