JP2021176133A - Cooling device - Google Patents

Abstract

To provide a cooling device capable of decreasing a temperature of a power storage device so as to be lower than an atmospheric temperature.SOLUTION: A cooling device 100 comprises: a cooler 15 which generates a cooling air by taking in outside air; a supply duct 16 which supplies the cooling air generated by the cooler 15 to a lithium ion secondary battery 12; a temperature sensor 29 which detects a temperature of the lithium ion secondary battery 12; and a controller 30 which controls the cooler 15 so as to operate when the temperature of the lithium ion secondary battery 12 detected by the temperature sensor 29 is higher than or equal to a prescribed temperature. The supply duct 16 extends to a counter weight 13 through the lithium ion secondary battery 12 from the cooler 15. The counter weight 13 is provided with a cooling passage 22 through which the cooling air having passed through the lithium ion secondary battery 12 flows.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cooling device.

For example, Patent Document 1 describes a forklift including a plurality of lithium ion batteries and a battery in which a plurality of counterweights are integrated. The counter weights are arranged between the lithium ion batteries in a state of being thermally coupled to the lithium ion batteries. As a result, the heat generated by the lithium ion battery is released to the counter weight, so that the lithium ion battery can be cooled.

Japanese Unexamined Patent Publication No. 2013-239262

In the above-mentioned conventional technique, the heat of the counterweight is released to the outside air. However, in an environment where the temperature of the outside air (atmospheric temperature) is high, the temperature of the lithium ion battery, which is a power storage device, cannot be lowered below the atmospheric temperature. Therefore, when the forklift is often operated in an environment where the atmospheric temperature is high, the life of the lithium ion battery tends to be shortened.

An object of the present invention is to provide a cooling device capable of lowering the temperature of the power storage device below the atmospheric temperature.

One aspect of the present invention is a cooling device mounted on an industrial vehicle provided with a power storage device and a counter weight arranged around the power storage device to cool the power storage device, and introduces outside air to generate cooling air. The cooler to be operated, the supply duct that supplies the cooling air generated by the cooler to the power storage device, the temperature detection unit that detects the temperature of the power storage device, and the temperature of the power storage device detected by the temperature detection unit are above the specified temperature. The supply duct extends from the cooler through the power storage device to the counter weight, and the counter weight passes through the power storage device. A cooling flow path through which the subsequent cooling air flows is provided.

In such a cooling device, when the temperature of the power storage device is equal to or higher than the specified temperature, the cooler operates to introduce outside air by the cooler and generate cooling air. Then, the cooling air flows through the supply duct and is supplied to the power storage device. Therefore, the power storage device is cooled by heat exchange between the cooling air and the power storage device. The cooling air after passing through the power storage device flows through the supply duct, is supplied to the counterweight, and flows through the cooling flow path of the counterweight. Therefore, the counterweight is cooled by heat exchange between the cooling air and the counterweight. By cooling the power storage device with the cooling air generated from the cooler in this way, the temperature of the power storage device can be lowered below the ambient temperature even in an environment where the temperature of the outside air (atmospheric temperature) is high, for example.

A discharge port for discharging the cooling air flowing through the cooling flow path to the outside air may be provided on the downstream side of the cooling flow path. In such a configuration, the cooling air flowing through the counterweight is discharged to the outside air from the discharge port. Therefore, since it is not necessary to frequently turn on / off the cooler so as not to cool the cooler too much, it is possible to simplify the control of the cooler by the control unit.

The cooling device may further include a discharge fan that forcibly discharges the cooling air flowing through the cooling flow path to the outside air from the discharge port. In such a configuration, the exhaust fan facilitates the flow of the cooling air through the supply duct and the cooling flow path, so that the heat exchange efficiency between the cooling air and the power storage device and the counter weight is improved.

The cooling device may further include a reflux duct that returns the cooling air flowing through the cooling flow path to the cooler. In such a configuration, the cooling air flowing through the cooling flow path is effectively used in the cooler, so that the power consumption of the cooler can be reduced.

The cooling device further includes a circulation fan that circulates the air existing between the power storage device and the counter weight, and the control unit controls when the temperature of the power storage device detected by the temperature detection unit becomes lower than the specified temperature. , The cooler may be controlled to stop the operation of the cooler, and the circulation fan may be controlled to operate. In such a configuration, when the temperature of the power storage device becomes lower than the specified temperature, the operation of the cooler is stopped, the circulation fan is operated, and the circulation fan circulates the air existing between the power storage device and the counterweight. do. Therefore, since the counterweight and the power storage device exchange heat with the circulating air, the temperature rise of the power storage device is suppressed by utilizing the heat capacity of the counterweight. Even if the cooler is not operated in this way, the temperature rise of the power storage device is suppressed. As a result, the operating time of the cooler can be shortened and the power consumption of the cooler can be reduced.

The cooling device further includes an outside air temperature detection unit that detects the outside air temperature around the industrial vehicle, and the control unit is detected by the temperature detection unit while the outside air temperature detected by the outside air temperature detection unit is equal to or higher than the specified value. When the temperature of the power storage device is above the specified temperature, the cooler is controlled to operate, and when the outside air temperature detected by the outside air temperature detector is lower than the specified value, the cooler is not operated. The cooler may be controlled to introduce outside air directly into the supply duct. In such a configuration, when the outside air temperature around the industrial vehicle is lower than the specified value, the cooler does not operate and the outside air is directly introduced into the supply duct. Then, the outside air flows through the supply duct and is supplied to the power storage device. Therefore, the power storage device is cooled by the cold outside air. Since the cooler does not operate in this way, the operating time of the cooler can be shortened and the power consumption of the cooler can be reduced.

The cooling flow path may be spirally formed on the counterweight. In such a configuration, the cooling flow path becomes long, so that the amount of heat exchange between the cooling air and the counterweight increases. Therefore, the counterweight can be sufficiently cooled while simplifying the structure of the cooling flow path.

The cooling flow path may have an uneven shape. In such a configuration, the heat exchange area between the cooling air and the counterweight increases. Therefore, the counterweight can be sufficiently cooled while shortening the cooling flow path.

The counterweight may be covered with insulation. In such a configuration, heat exchange between the counterweight and the surroundings is less likely to occur, so that the counterweight can be effectively cooled.

The power storage device may be a lithium ion secondary battery. Lithium-ion secondary batteries are lighter than, for example, lead-acid batteries. Therefore, for example, it is necessary to arrange a counterweight around the lithium ion secondary battery so that the industrial vehicle does not tip over when lifting the cargo. Therefore, it is effective to apply the present invention to a lithium ion secondary battery.

According to the present invention, the temperature of the power storage device can be lowered below the atmospheric temperature.

It is a side view which shows the forklift which is an industrial vehicle provided with the cooling device which concerns on one Embodiment of this invention. It is sectional drawing which shows the battery pack which includes a part of the cooling apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the cooling flow path of the counterweight shown in FIG. It is a block diagram of the cooler shown in FIG. It is a block diagram of the control system of the cooling apparatus shown in FIG. It is a flowchart which shows the detail of the procedure of the control processing executed by the controller shown in FIG. FIG. 5 is a cross-sectional view showing a battery pack including a partially modified example of the cooling device shown in FIG. It is a schematic diagram which shows the cooling flow path of the counterweight shown in FIG. 7. FIG. 7 is an enlarged schematic cross-sectional view of the counterweight shown in FIG. FIG. 5 is a cross-sectional view showing a battery pack including some other modifications of the cooling device shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a side view showing a forklift which is an industrial vehicle provided with a cooling device according to an embodiment of the present invention. In FIG. 1, the forklift 1 is a counterbalance type electric forklift. The forklift 1 is an industrial vehicle that handles cargo.

The forklift 1 is arranged on the vehicle body 2, a pair of drive wheels 3 arranged at the front portion of the vehicle body 2, a pair of steering wheels 4 arranged at the rear portion of the vehicle body 2, and a front side of the vehicle body 2. It is equipped with a cargo handling device 5. A counterweight 6 for balancing the vehicle body 2 in the front-rear direction is mounted on the rear portion of the vehicle body 2. The cargo handling device 5 has a mast 7 erected at the front end of the vehicle body 2 and a pair of forks 8 attached to the mast 7 via a lift bracket (not shown).

Further, the forklift 1 includes a battery pack 10 arranged inside the vehicle body 2. As shown in FIGS. 2 and 3, the battery pack 10 has a rectangular parallelepiped case 11, a lithium ion secondary battery 12 housed in the case 11, and a counterweight 13.

The lithium ion secondary battery 12 is a power storage device that supplies electric power to an electric device mounted on the forklift 1. The lithium ion secondary battery 12 has, for example, a structure in which cells are modularized.

The counter weight 13 is arranged around the lithium ion secondary battery 12 so as to cover the lithium ion secondary battery 12. The counterweight 13 is coupled to the inner wall surface of the case 11. The counterweight 13 is a member for balancing the forklift 1 so that the forklift 1 does not tip over when the load is lifted by the fork 8 of the cargo handling device 5. The counterweight 13 is made of, for example, the same metal material as the case 11. The lithium ion secondary battery 12 is mounted on the bottom surface of the counterweight 13.

The case 11 and the counterweight 13 are covered with the heat insulating material 14. As the heat insulating material 14, for example, a fiber-based heat insulating material or a foam-based heat insulating material is used. The heat insulating material 14 may be arranged between the case 11 and the counterweight 13.

The cooling device 100 of the present embodiment is a device for cooling the lithium ion secondary battery 12, and is mounted on the forklift 1. The cooling device 100 includes a cooler 15 and a supply duct 16 as shown in FIGS. 1 to 3.

The cooler 15 is a cooler that introduces outside air to generate cooling air. The cooling air is cooled air (cold air). The cooler 15 is arranged on the roof of the vehicle body 2 from the viewpoint of space, for example. The location of the cooler 15 is not limited to the roof of the vehicle body 2 as long as there is space.

As shown in FIG. 4, the cooler 15 includes a compressor 17, a condenser 18, an expansion valve 19, and an evaporator 20. In the cooler 15, the refrigerant circulates and flows in the order of the compressor 17, the condenser 18, the expansion valve 19, and the evaporator 20.

The compressor 17 compresses the refrigerant gas vaporized by the evaporator 20 to a high temperature and a high pressure. The condenser 18 cools and liquefies the high-temperature and high-pressure refrigerant gas compressed by the compressor 17. The condenser 18 cools the high-temperature and high-pressure refrigerant gas by taking in the outside air by the outside air introduction fan 21. The expansion valve 19 expands the high-temperature / high-pressure refrigerant liquefied by the condenser 18 and changes it into a low-temperature / low-pressure refrigerant.

The evaporator 20 vaporizes (evaporates) the low-temperature and low-pressure refrigerant obtained by the expansion valve 19. At this time, the evaporator 20 is cooled by taking away heat from the surroundings when the liquid evaporates. Then, the outside air introduced by the outside air introduction fan 21 is cooled by passing through the evaporator 20, and cooling air is generated.

The supply duct 16 supplies the cooling air generated by the cooler 15 to the lithium ion secondary battery 12. The supply duct 16 extends from the cooler 15 to the inside of the battery pack 10 in the vertical direction of the vehicle body 2. The supply duct 16 extends in the case 11 of the battery pack 10 through the lithium ion secondary battery 12 to the inner surface of the counter weight 13 in a direction perpendicular to the vertical direction of the vehicle body 2.

The counterweight 13 is provided with a cooling flow path 22 through which cooling air flows after passing through the lithium ion secondary battery 12. At the upstream end of the cooling flow path 22, an introduction portion 23 into which the cooling air after passing through the lithium ion secondary battery 12 is introduced is provided. The introduction portion 23 opens on the inner side surface of the counterweight 13 and is connected to the supply duct 16. The introduction unit 23 is arranged below the counter weight 13.

At the downstream end of the cooling flow path 22, a discharge portion 24 for discharging the cooling air flowing through the cooling flow path 22 is provided. The discharge unit 24 is open on the upper surface of the counterweight 13. A discharge port 25 communicating with the discharge portion 24 is provided above the case 11 and the heat insulating material 14. The discharge port 25 is arranged on the downstream side of the cooling flow path 22. The discharge port 25 discharges the cooling air flowing through the cooling flow path 22 to the outside air.

The cooling flow path 22 is spirally formed on the counterweight 13 along the vertical direction. The cooling air after passing through the lithium ion secondary battery 12 spirally flows through the cooling flow path 22 from the lower side to the upper side of the battery pack 10. The cooling flow path 22 is formed so that the cooling air does not mix with the air in the case 11.

Although not shown, the counterweight 13 having such a cooling flow path 22 is manufactured by assembling, for example, a weight outer wall portion and a weight inner wall portion provided with a spiral groove portion.

Further, the cooling device 100 includes a discharge fan 26 arranged outside the case 11 and a circulation fan 27 arranged inside the case 11.

The discharge fan 26 is arranged at a position facing the discharge port 25 outside the case 11. The discharge fan 26 is attached to, for example, the case 11. The discharge fan 26 is a fan that forcibly discharges the cooling air flowing through the cooling flow path 22 of the counterweight 13 from the discharge port 25 to the outside air.

The circulation fan 27 is arranged in the case 11 between the upper surface 12a of the lithium ion secondary battery 12 and the upper surface 13a of the inner wall of the counterweight 13. The circulation fan 27 is attached to, for example, a counterweight 13. The circulation fan 27 is a fan that circulates the air existing in the case 11. That is, the circulation fan 27 circulates the air existing between the lithium ion secondary battery 12 and the counterweight 13.

Further, as shown in FIG. 5, the cooling device 100 includes an outside air temperature sensor 28, a temperature sensor 29, and a controller 30. The outside air temperature sensor 28 is an outside air temperature detection unit that detects the outside air temperature around the forklift 1. The temperature sensor 29 is a temperature detection unit that detects the temperature of the lithium ion secondary battery 12.

The controller 30 is composed of a CPU, RAM, ROM, an input / output interface, and the like. The controller 30 controls to operate the discharge fan 26 when the forklift 1 is started. Further, the controller 30 controls the cooler 15 and the circulation fan 27 based on the outside air temperature around the forklift 1 detected by the outside air temperature sensor 28 and the temperature of the lithium ion secondary battery 12 detected by the temperature sensor 29. It constitutes a control unit.

The controller 30 controls to operate the cooler 15 when the outside air temperature around the forklift 1 is equal to or higher than the specified value and the temperature of the lithium ion secondary battery 12 is equal to or higher than the specified temperature. Further, the controller 30 controls the cooler 15 so as to stop the operation of the cooler 15 and controls the circulation fan 27 to operate when the temperature of the lithium ion secondary battery 12 becomes lower than the specified temperature. Further, when the outside air temperature around the forklift 1 is lower than the specified value, the controller 30 controls the cooler 15 so as to directly introduce the outside air into the supply duct 16 without operating the cooler 15.

FIG. 6 is a flowchart showing the details of the procedure of the control process executed by the controller 30. This process is executed when the forklift 1 is started.

In FIG. 6, the controller 30 first acquires the detected values of the outside air temperature sensor 28 and the temperature sensor 29 (procedure S101). Then, the controller 30 determines whether or not the outside air temperature around the forklift 1 is equal to or higher than a predetermined value based on the detected value of the outside air temperature sensor 28 (procedure S102). When the controller 30 determines that the outside air temperature around the forklift 1 is equal to or higher than the specified value, the controller 30 controls the cooler 15 to be in the ON state (procedure S103).

Subsequently, the controller 30 determines whether or not the temperature of the lithium ion secondary battery 12 is equal to or higher than a predetermined predetermined temperature based on the detected value of the temperature sensor 29 (procedure S104). When the controller 30 determines that the temperature of the lithium ion secondary battery 12 is equal to or higher than the specified temperature, the controller 30 controls the cooler 15 to be maintained in the ON state (procedure S105). Further, the controller 30 controls the circulation fan 27 so as to be in the OFF state (procedure S106).

When the controller 30 determines in the procedure S104 that the temperature of the lithium ion secondary battery 12 is lower than the specified temperature, the controller 30 controls the cooler 15 to be in the OFF state (procedure S107). Further, the controller 30 controls the circulation fan 27 to be in the ON state (procedure S108).

When the controller 30 determines in step S102 that the outside air temperature around the forklift 1 is lower than the specified value, the controller 30 controls the cooler 15 to be in the OFF state (procedure S109).

In the cooling device 100 as described above, when the forklift 1 operates in a high temperature environment and the outside air temperature around the forklift 1 is high and the temperature of the lithium ion secondary battery 12 is high, the cooler 15 operates. .. Then, the outside air is introduced by the cooler 15 to generate cooling air, and the cooling air is supplied to the lithium ion secondary battery 12 through the supply duct 16. Therefore, heat exchange between the cooling air and the lithium ion secondary battery 12 is performed, and the lithium ion secondary battery 12 is cooled.

The cooling air after passing through the lithium ion secondary battery 12 is supplied to the counter weight 13 through the supply duct 16 and flows through the cooling flow path 22 of the counter weight 13. Therefore, heat exchange between the cooling air and the counterweight 13 is performed, and the counterweight 13 is cooled. The cooling air flowing through the cooling flow path 22 is forcibly discharged to the outside air from the discharge port 25 of the case 11 by the discharge fan 26.

After that, when the lithium ion secondary battery 12 is cooled and the temperature of the lithium ion secondary battery 12 becomes low, the cooler 15 stops operating and the circulation fan 27 operates. Then, air circulates in the case 11, and heat exchange between the cooled counter weight 13 and the circulating air of the air is performed, and heat exchange between the circulating air of the air and the lithium ion secondary battery 12 is performed. That is, heat exchange between the counterweight 13 and the lithium ion secondary battery 12 is performed by the circulating air in the case 11. Therefore, the temperature rise of the lithium ion secondary battery 12 is suppressed.

Further, when the outside air temperature around the forklift 1 is low, the cooler 15 does not operate and the cold outside air is directly introduced into the supply duct 16. Then, the cold outside air is supplied to the lithium ion secondary battery 12 through the supply duct 16, and the lithium ion secondary battery 12 is cooled by heat exchange between the cold outside air and the lithium ion secondary battery 12.

As described above, in the present embodiment, when the temperature of the lithium ion secondary battery 12 is equal to or higher than the specified temperature, the cooler 15 operates to introduce outside air by the cooler 15 and generate cooling air. .. Then, the cooling air flows through the supply duct 16 and is supplied to the lithium ion secondary battery 12. Therefore, the lithium ion secondary battery 12 is cooled by heat exchange between the cooling air and the lithium ion secondary battery 12. The cooling air after passing through the lithium ion secondary battery 12 flows through the supply duct 16 and is supplied to the counter weight 13 and flows through the cooling flow path 22 of the counter weight 13. Therefore, the counterweight 13 is cooled by heat exchange between the cooling air and the counterweight 13. By cooling the lithium ion secondary battery 12 with the cooling air generated from the cooler 15 in this way, for example, even in an environment where the temperature of the outside air (atmospheric temperature) is high, the temperature of the lithium ion secondary battery 12 is set higher than the atmospheric temperature. Can be lowered. As a result, the life of the lithium ion secondary battery 12 can be extended.

Further, in the present embodiment, the cooling air flowing through the cooling flow path 22 is discharged to the outside air from the discharge port 25. Therefore, it is not necessary to frequently turn on / off the cooler 15 so as not to overcool the lithium ion secondary battery 12, so that the control of the cooler 15 by the controller 30 can be simplified.

Further, in the present embodiment, the discharge fan 26 for forcibly discharging the cooling air flowing through the cooling flow path 22 of the counterweight 13 from the discharge port 25 to the outside air is provided. Therefore, the exhaust fan 26 facilitates the flow of the cooling air through the supply duct 16 and the cooling flow path 22, so that the heat exchange efficiency between the cooling air and the lithium ion secondary battery 12 and the counter weight 13 is improved.

Further, in the present embodiment, when the temperature of the lithium ion secondary battery 12 becomes lower than the specified temperature, the operation of the cooler 15 is stopped, the circulation fan 27 is operated, and the circulation fan 27 causes the lithium ion secondary battery 12 to operate. The air existing between the counter weight 13 and the counter weight 13 circulates. Therefore, since the counter weight 13 and the lithium ion secondary battery 12 exchange heat with the circulating air, the temperature rise of the lithium ion secondary battery 12 is suppressed by utilizing the heat capacity of the counter weight 13. Even if the cooler 15 is not operated in this way, the temperature rise of the lithium ion secondary battery 12 is suppressed. As a result, the operating time of the cooler 15 can be shortened and the power consumption of the cooler 15 can be reduced. As a result, the operating time of the forklift 1 can be lengthened. Further, the number of times the lithium ion secondary battery 12 is charged can be reduced, and the life of the lithium ion secondary battery 12 can be further extended.

Further, in the present embodiment, when the outside air temperature around the forklift 1 is lower than the specified value, the cooler 15 does not operate and the outside air is directly introduced into the supply duct 16. Then, the outside air flows through the supply duct 16 and is supplied to the lithium ion secondary battery 12. Therefore, the lithium ion secondary battery 12 is cooled by the cold outside air. Since the cooler 15 does not operate in this way, the operating time of the cooler 15 can be further shortened, and the power consumption of the cooler 15 can be further reduced.

Further, in the present embodiment, the cooling flow path 22 is spirally formed on the counterweight 13. Therefore, since the cooling flow path 22 becomes long, the amount of heat exchange between the cooling air and the counterweight 13 increases. Therefore, the counterweight 13 can be sufficiently cooled while simplifying the structure of the cooling flow path 22.

Further, in the present embodiment, the counterweight 13 is covered with the heat insulating material 14. Therefore, heat exchange between the counterweight 13 and the surroundings is less likely to occur, so that the counterweight 13 can be effectively cooled.

FIG. 7 is a cross-sectional view showing a battery pack including a partially modified example of the cooling device shown in FIG. FIG. 8 is a schematic view showing a cooling flow path of the counterweight shown in FIG. 7.

In FIGS. 7 and 8, the cooling flow path 22 of the counterweight 13 in this modification is connected to a flow path portion 22a formed along the periphery of the lithium ion secondary battery 12 and the flow path portion 22a. The counterweight 13 has a flow path portion 22b formed so as to extend in the vertical direction. The flow path portion 22a is formed so as to orbit around the circumference of the lithium ion secondary battery 12 for nearly one round. The flow path portion 22b extends from the downstream end of the flow path portion 22a to the discharge portion 24.

As shown in FIG. 9, such a cooling flow path 22 has an uneven shape that follows the extending direction of the cooling flow path 22. Specifically, the cooling flow path 22 has a plurality of convex portions 35 having a rectangular cross section protruding on both sides in a direction perpendicular to the extending direction of the cooling flow path 22. The protrusions 35 are arranged at equal intervals, for example, along the extending direction of the cooling flow path 22. The convex portion 35 may protrude only on one side in the direction perpendicular to the extending direction of the cooling flow path 22. The shape of the convex portion 35 is not particularly limited to a rectangular cross section, and may be, for example, a triangular cross section or a semicircular cross section.

In this modification, since the cooling flow path 22 of the counterweight 13 has an uneven shape, the heat exchange area between the cooling air and the counterweight 13 increases. Therefore, the counterweight 13 can be sufficiently cooled while shortening the cooling flow path 22.

The present invention is not limited to the above embodiment. For example, in the above embodiment, when the forklift 1 is started, the discharge fan 26 is always operated, but the present invention is not particularly limited to that mode, and the discharge fan 26 may be operated when the cooler 15 is operated. .. Further, the discharge fan 26 may not be particularly provided. Even in this case, the cooling air flowing through the cooling flow path 22 of the counterweight 13 is discharged to the outside air from the discharge port 25.

Further, in the above embodiment, the cooling air after passing through the lithium ion secondary battery 12 flows through the cooling flow path 22 of the counterweight 13 and then is discharged to the outside air, but is particularly limited to such a form. I can't. For example, as shown in FIG. 10, instead of the discharge fan 26 in the above embodiment, a reflux duct 40 may be provided to return the cooling air flowing through the cooling flow path 22 of the counterweight 13 to the cooler 15.

The return duct 40 extends from the discharge port 25 of the battery pack 10 to the cooler 15 in the vertical direction of the vehicle body 2 in parallel with the supply duct 16. The reflux duct 40 may be connected to the discharge portion 24 of the cooling flow path 22 instead of the discharge port 25 of the battery pack 10.

In this case, the cooling air after passing through the lithium ion secondary battery 12 flows through the cooling flow path 22 of the counter weight 13 and then is returned to the cooler 15 as a closed loop by the reflux duct 40. Therefore, since the cooling air flowing through the cooling flow path 22 is effectively used in the cooler 15, the power consumption of the cooler 15 can be reduced.

Further, in the above embodiment, the circulation fan 27 for circulating the air existing between the lithium ion secondary battery 12 and the counterweight 13 is arranged, but such a circulation fan 27 may not be particularly provided. ..

Further, in the above embodiment, when the outside air temperature around the forklift 1 is lower than the specified value, the cooler 15 does not operate and the outside air is directly introduced into the supply duct 16, but the embodiment is particularly limited. Instead, the cooler 15 may be operated even if the outside air temperature around the forklift 1 is lower than the specified value.

Further, in the above embodiment, the counterweight 13 is arranged in the case 11 of the battery pack 10, but the present invention is not particularly limited to that form, and the case 11 may not be provided. That is, the counterweight 13 may also serve as a case for accommodating the lithium ion secondary battery 12. Even in this case, the counterweight 13 may be covered with the heat insulating material 14.

Further, in the above embodiment, the cooler 15 has a compressor 17, a condenser 18, an expansion valve 19, and an evaporator 20, but if it is a cooler that introduces outside air to generate cooling air, the form thereof is particularly suitable. Is not limited and can be variously deformed.

Further, in the above embodiment, the lithium ion secondary battery 12 is mounted on the forklift 1, but the power storage device mounted on the forklift 1 is not particularly limited to the lithium ion secondary battery 12, and for example, a nickel hydrogen battery. , Electric double layer capacitor, lithium ion capacitor and the like.

Further, although the cooling device 100 of the above embodiment is mounted on the forklift 1, the present invention is applicable to any electric industrial vehicle in which a counterweight is arranged around the power storage device.

1 ... Fork lift (industrial vehicle), 12 ... Lithium ion secondary battery (power storage device), 13 ... Counter weight, 14 ... Insulation material, 15 ... Cooler (cooler), 16 ... Supply duct, 22 ... Cooling flow path, 25 ... Discharge port, 26 ... Discharge fan, 27 ... Circulation fan, 28 ... Outside temperature sensor (outside temperature detection unit), 29 ... Temperature sensor (temperature detection unit), 30 ... Controller (control unit), 40 ... Circulation duct , 100 ... Cooling device.

Claims (10)

A cooling device mounted on an industrial vehicle having a power storage device and a counterweight arranged around the power storage device to cool the power storage device.
A cooler that introduces outside air to generate cooling air,
A supply duct that supplies the cooling air generated by the cooler to the power storage device, and
A temperature detection unit that detects the temperature of the power storage device, and
A control unit that controls the operation of the cooler when the temperature of the power storage device detected by the temperature detection unit is equal to or higher than a specified temperature is provided.
The supply duct extends from the cooler through the power storage device to the counterweight.
The counterweight is provided with a cooling flow path through which cooling air flows after passing through the power storage device. The cooling device according to claim 1, wherein a discharge port for discharging the cooling air flowing through the cooling flow path to the outside air is provided on the downstream side of the cooling flow path. The cooling device according to claim 2, further comprising a discharge fan for forcibly discharging the cooling air flowing through the cooling flow path to the outside air from the discharge port. The cooling device according to claim 1, further comprising a reflux duct for returning the cooling air flowing through the cooling flow path to the cooler. Further provided with a circulation fan for circulating air existing between the power storage device and the counterweight.
When the temperature of the power storage device detected by the temperature detection unit becomes lower than the specified temperature, the control unit controls the cooler so as to stop the operation of the cooler and operates the circulation fan. The cooling device according to any one of claims 1 to 4, wherein the cooling device is controlled so as to be operated. Further equipped with an outside air temperature detection unit that detects the outside air temperature around the industrial vehicle,
The control unit cools when the outside air temperature detected by the outside air temperature detection unit is equal to or higher than a specified value and the temperature of the power storage device detected by the temperature detection unit is equal to or higher than the specified temperature. When the outside air temperature detected by the outside air temperature detection unit is lower than the specified value, the outside air is directly introduced into the supply duct without operating the cooler. The cooling device according to any one of claims 1 to 5, which controls the cooler. The cooling device according to any one of claims 1 to 6, wherein the cooling flow path is spirally formed on the counterweight. The cooling device according to any one of claims 1 to 6, wherein the cooling flow path has an uneven shape. The cooling device according to any one of claims 1 to 8, wherein the counterweight is covered with a heat insulating material. The cooling device according to any one of claims 1 to 9, wherein the power storage device is a lithium ion secondary battery.

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