Dump truck.

Abstract

This dump truck comprises: drive wheels; a vehicle body which is supported on the drive wheels; a dump body which is supported on the vehicle body; an electric motor for rotating the drive wheels; and a first duct through which air supplied from the electric motor to an internal flow channel of the dump body flows.

Description

Dump truck

[0001] The present disclosure relates to a dump truck.

[0002] A dump truck has a dump body on which cargo is loaded. When discharging cargo from the dump body, the dump truck performs a dumping operation of the dump body. When the dumping operation is performed, the cargo is discharged from the dump body due to the action of gravity. If the cargo contains water or oil and is wet, or if the outside air temperature is low, even when the dumping operation is performed, at least a portion of the cargo may remain attached to the inner surface of the dump body and not be discharged from the dump body. A technique for heating the dump body to prevent the cargo from adhering to the inner surface of the dump body is known. Currently, a technique for heating the dump body using engine exhaust is commonly used. Heating the dump body prevents the cargo from freezing or the oil from hardening, and the cargo dries. This prevents the cargo from adhering to the inner surface of the dump body. Patent Document 1 discloses a dump truck having a resistor that converts electric power generated by retarder brake operation into thermal energy, a cooling fan that cools the resistor, and a duct that guides the warm air blown from the cooling fan and heated by the resistor. In Patent Document 1, the warm air heated by the resistor is supplied to a loading platform (dump body), thereby heating the loading platform.

[0003] JP 2012-201227 A

[0004] In the case of a dump truck without an engine, the dump body cannot be heated by the engine's exhaust. Also, if the dump body is heated by air heated by a retarder brake (resistor), when the dump truck is traveling uphill or on a flat road, the retarder brake does not generate enough heat, making it difficult to supply high-temperature air from the retarder brake to the dump body. As a result, the dump body may not be heated sufficiently.

[0005] The present disclosure aims to heat a dump body with air heated by an electric motor.

[0006] According to the present disclosure, there is provided a dump truck comprising drive wheels, a vehicle body supported by the drive wheels, a dump body supported by the vehicle body, an electric motor that rotates the drive wheels, and a first duct through which air flows that is supplied from the electric motor to an internal flow path of the dump body.

[0007] According to the present disclosure, the dump body is heated by air heated by an electric motor.

[0008] FIG. 1 is a side view showing a dump truck according to a first embodiment. FIG. 2 is a schematic view of the dump truck according to the first embodiment as seen from the rear. FIG. 3 is a side view of the dump truck according to the first embodiment. FIG. 4 is a view showing a dump body according to the first embodiment. FIG. 5 is a side view of the dump truck according to the first embodiment. FIG. 6 is a view showing the dump body according to the first embodiment. FIG. 7 is a schematic view of the dump truck according to a second embodiment as seen from the rear. FIG. 8 is a schematic view of the dump truck according to a third embodiment as seen from the rear. FIG. 9 is a side view of a dump truck according to a fourth embodiment. FIG. 10 is a side view of the dump truck according to the fourth embodiment. FIG. 11 is a view showing the dump body of the dump truck according to a fifth embodiment.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] First Embodiment A first embodiment will be described.

[0011] <Dump Truck> FIG. 1 is a side view showing a dump truck 1A according to this embodiment. In this embodiment, the dump truck 1A is a rigid frame dump truck. The dump truck 1A is also an electrically driven dump truck. No engine is mounted on the dump truck 1A. The dump truck 1A does not emit exhaust gas. The dump truck 1A has a storage battery or a fuel cell as a power source. The dump truck 1A may also be driven by power supplied from a contact wire.

[0012] As shown in FIG. 1 , the dump truck 1A includes a vehicle body 2 , front wheels 3 , rear wheels 4 , a dump body 5 , a hoist cylinder 6 , a retarder brake 7 , and an electric motor 8 .

[0013] The vehicle body 2 includes a chassis and supports a dump truck body 5. A cab 9 is provided on the upper front portion of the vehicle body 2.

[0014] The front wheels 3 and the rear wheels 4 each support the vehicle body 2. The front wheels 3 are steering wheels. The rear wheels 4 are driving wheels. Tires 10 are mounted on the front wheels 3 and the rear wheels 4. The dump truck 1A travels as the front wheels 3 and the rear wheels 4 rotate.

[0015] The dump body 5 is loaded with a load. An example of the load that can be loaded on the dump body 5 is earth and sand. The dump body 5 is rotatably supported by the vehicle body 2.

[0016] The hoist cylinder 6 generates power to rotate the dump body 5. A lower end of the hoist cylinder 6 is connected to the vehicle body 2. An upper end of the hoist cylinder 6 is connected to the dump body 5.

[0017] The dump body 5 changes between a loaded position and an upright position by the extension and contraction of the hoist cylinder 6. The loaded position refers to a position in which the dump body 5 is lowered so as to be closest to the vehicle body 2 within its movable range. The upright position refers to a position in which the dump body 5 is raised so as to be farthest from the vehicle body 2 within its movable range. When the dump body 5 is in the loaded position, a load is loaded onto the dump body 5. The dump truck 1A travels when the dump body 5 is in the loaded position. When the dump body 5 is loaded with a load, the dump body 5 changes from the loaded position to the upright position, and the load is discharged from the dump body 5 by the action of gravity. In this embodiment, the operation of changing the dump body 5 from the loaded position to the upright position when the dump body 5 is loaded with a load is referred to as a dump operation as appropriate.

[0018] A dumping operation of the dump body 5 is performed, whereby a load is discharged from the dump body 5. In this embodiment, the dumping operation of the dump body 5 includes an operation of rotating the dump body 5 rearward. That is, in this embodiment, the dump body 5 discharges a load rearward by a rear dump method.

[0019] The retarder brake 7 is disposed behind the cab 9. The retarder brake 7 is housed in a brake housing 11.

[0020] 2 is a schematic diagram of the dump truck 1A according to the embodiment as viewed from the rear. The rear wheels 4 include a first rear wheel 4 disposed on the left (one side) of the center of the vehicle body 2 in the left-right direction (vehicle width direction) and a second rear wheel 4 disposed on the right (other side).

[0021] The electric motors 8 are connected to the rear wheels 4. The electric motors 8 rotate the rear wheels 4. A pair of electric motors 8 are provided. The pair of electric motors 8 are arranged in the left-right direction. The electric motors 8 include a first electric motor 8 that rotates the left rear wheel 4 and a second electric motor 8 that rotates the right rear wheel 4. The left electric motor 8 is connected to the left rear wheel 4. The right electric motor 8 is connected to the right rear wheel 4.

[0022] The electric motor 8 is housed in a motor case 12. The electric motor 8 is housed in a motor housing 13 via the motor case 12. The electric motor 8 is disposed inside the motor housing 13 while housed in the motor case 12. The motor housing 13 is disposed between the left rear wheel 4 and the right rear wheel 4. The motor housing 13 functions as a rear axle case. The motor housing 13 is substantially cylindrical. The motor housing 13 houses the left electric motor 8 and the right electric motor 8, respectively.

[0023] The electric motor 8 has a stator 14, a rotor 15, and an output shaft 16. The stator 14 includes a stator core 14A and a coil 14B attached to the stator core 14A. The stator 14 is fixed to the motor case 12. The rotor 15 is disposed inside the stator 14. The output shaft 16 is fixed to the rotor 15. The rotor 15 and the output shaft 16 rotate relative to the stator 14. One end of the output shaft 16 on the outer side in the vehicle width direction is connected to the rear wheel 4.

[0024] <Dump body> Fig. 3 is a side view showing the dump truck 1A according to this embodiment. Fig. 4 is a view showing the dump body 5 according to this embodiment.

[0025] The dump body 5 has a front plate 5F, a bottom plate 5B connected to the lower end of the front plate 5F, a left plate 5L connected to the left end of the front plate 5F and the left end of the bottom plate 5B, a right plate 5R connected to the right end of the front plate 5F and the right end of the bottom plate 5B, and a protector plate 5P connected to the upper end of the front plate 5F.

[0026] The front plate 5F, bottom plate 5B, left plate 5L, right plate 5R, and protector plate 5P are integral with each other, and are each made of steel.

[0027] When the dump body 5 is in the loaded position, the protector plate 5P is disposed above the cab 9. The rear end of the protector plate 5P is connected to the upper end of the front plate 5F. The lower end of the front plate 5F is connected to the front end of the bottom plate 5B.

[0028] The right plate 5R is disposed to the right of the center of the dump body 5 in the left-right direction and is connected to the right end of the front plate 5F and the right end of the bottom plate 5B. The left plate 5L is disposed to the left of the center of the dump body 5 in the left-right direction and is connected to the left end of the front plate 5F and the left end of the bottom plate 5B.

[0029] In the dump body 5, a loading space in which cargo is loaded is defined between the rear surface of the front plate 5F, the upper surface of the bottom plate 5B, the right surface of the left plate 5L, and the left surface of the right plate 5R. The cargo comes into contact with at least a portion of the rear surface of the front plate 5F, the upper surface of the bottom plate 5B, the right surface of the left plate 5L, and the left surface of the right plate 5R. In this embodiment, the rear surface of the front plate 5F, the upper surface of the bottom plate 5B, the right surface of the left plate 5L, and the left surface of the right plate 5R of the dump body 5 that come into contact with the cargo are collectively referred to as the inner surface of the dump body 5, as appropriate.

[0030] The dump body 5 has a first inlet 17 through which air flows in from the electric motor 8, a second inlet 18 through which air flows in from the retarder brake 7, an internal flow path 19 through which air flowing in from at least one of the first inlet 17 and the second inlet 18 flows, and an outlet 20 through which air that has flowed through the internal flow path 19 is discharged.

[0031] The first inlet 17 is provided on the underside of the bottom plate 5B. The first inlet 17 is provided in the center of the bottom plate 5B in the left-right direction. The first inlet 17 may be provided at a position shifted to the left or right of the center of the bottom plate 5B in the left-right direction. The first inlet 17 is provided in the rear of the bottom plate 5B.

[0032] The second inlet 18 is provided on the front surface of the front panel 5F. The second inlet 18 is provided on the right side of the upper part of the front surface of the front panel 5F. The second inlet 18 may also be provided on the left side of the upper part of the front surface of the front panel 5F, or in the center.

[0033] The outlet 20 is provided at the rear of the left surface of the left plate 5L. The outlet 20 may also be provided in the right plate 5R.

[0034] The internal flow passage 19 is provided inside the dump body 5. The internal flow passage 19 includes a first flow passage 19A provided at the boundary between the bottom plate 5B and the right plate 5R, a second flow passage 19B provided at the boundary between the front plate 5F and the bottom plate 5B, and a third flow passage 19C provided at the boundary between the bottom plate 5B and the left plate 5L. At least a portion of the first flow passage 19A is provided at the right end of the bottom plate 5B. At least a portion of the second flow passage 19B is provided at the lower end of the front plate 5F. At least a portion of the third flow passage 19C is provided at the lower end of the left plate 5L. Cargo tends to adhere to the above-mentioned boundary portions of the dump body 5. For this reason, the internal flow passage 19 is provided at the boundary portions of the dump body 5. Note that the internal flow passage 19 may also be provided on a flat portion of the dump body 5.

[0035] The first flow path 19A, the second flow path 19B, and the third flow path 19C are connected to one another. The first inlet 17 is connected to the first flow path 19A. The second inlet 18 is connected to the second inlet 18. The outlet 20 is connected to the third flow path 19C.

[0036] <First Duct and Second Duct> The dump truck 1A includes a first duct 21 through which air supplied from the electric motor 8 to the internal flow path 19 of the dump body 5 flows. The first duct 21 is arranged to connect the motor housing 13 and the first inlet 17 of the internal flow path 19. A lower end of the first duct 21 is connected to a center part of the motor housing 13 in the left-right direction. Note that the lower end of the first duct 21 may be connected to a left part or a right part of the motor housing 13. An upper end of the first duct 21 is connected to the first inlet 17.

[0037] The dump truck 1A includes a second duct 22 through which air flows that is supplied from the retarder brake 7 to the internal flow path 19 of the dump body 5. The second duct 22 is arranged to connect the brake housing 11 and the second inlet 18 of the internal flow path 19. When the dump body 5 is in the loaded position, the second duct 22 and the second inlet 18 are connected. When the dump body 5 is in the upright position, the second duct 22 and the second inlet 18 are disconnected.

[0038] <Air flow> As indicated by the arrows in Figures 3 and 4, air around the electric motor 8 is supplied to the first inlet 17 via the first duct 21. The air that flows from the first inlet 17 into the internal flow path 19 of the dump body 5 flows through the internal flow path 19 and is then discharged from the outlet 20. For example, when the dump truck 1A travels uphill (on an uphill road) or on a flat road, the electric motor 8 is driven, and as a result, the electric motor 8 generates heat. The air heated by the electric motor 8 is supplied to the internal flow path 19, thereby heating the dump body 5.

[0039] FIG. 5 is a side view showing a dump truck 1A according to this embodiment. FIG. 6 is a view showing a dump body 5 according to this embodiment. As indicated by the arrows in FIGS. 5 and 6 , air around the retarder brake 7 is supplied to the second inlet 18 via the second duct 22. The air that flows from the second inlet 18 into the internal flow path 19 of the dump body 5 flows through the internal flow path 19 and is then discharged from the outlet 20. For example, when the dump truck 1A travels downhill (on a downhill road), the retarder brake 7 is activated, and as a result, the retarder brake 7 generates heat. The air heated by the retarder brake 7 is supplied to the internal flow path 19, thereby heating the dump body 5.

[0040] In the present embodiment, the supply of air from the electric motor 8 to the internal flow path 19 and the supply of air from the retarder brake 7 to the internal flow path 19 may be switched between when the dump truck 1A is traveling uphill or on a flat road and when it is traveling downhill. When traveling uphill or on a flat road, air may be supplied from the electric motor 8 to the internal flow path 19, and when traveling downhill, air may be supplied from the retarder brake 7 to the internal flow path 19. This allows the dump body 5 to be constantly heated when traveling uphill, on a flat road, and downhill, respectively.

[0041] Note that, when the on-board controller of the dump truck 1A cannot determine whether the dump truck 1A is traveling on an uphill road, a flat road, or a downhill road, the on-board controller may detect the operating status of each of the electric motor 8 and the retarder brake 7, and, based on the detected operating status, switch between supplying air from the electric motor 8 to the internal flow path 19 and supplying air from the retarder brake 7 to the internal flow path 19. Furthermore, when a first temperature sensor that detects the temperature around the electric motor 8 and a second temperature sensor that detects the temperature around the retarder brake 7 are provided, the on-board controller may perform control so that air is supplied from the electric motor 8 to the internal flow path 19 when the detection value of the first temperature sensor is equal to or greater than a first predetermined value, and air is supplied from the retarder brake 7 to the internal flow path 19 when the detection value of the second temperature sensor is equal to or greater than a second predetermined value.

[0042] <Effects> As described above, in this embodiment, the dump truck 1A includes the rear wheels 4 which are drive wheels, the vehicle body 2 supported by the rear wheels 4, the dump body 5 supported by the vehicle body 2, the electric motor 8 which rotates the rear wheels 4, and the first duct 21 through which air supplied from the electric motor 8 to the internal flow path 19 of the dump body 5 flows. The air heated by the electric motor 8 is supplied to the internal flow path 19 of the dump body 5 via the first duct 21, so that the dump body 5 is heated. This prevents the cargo from adhering to the inner surface of the dump body 5. In particular, when the dump truck 1A travels uphill or on a flat road, the amount of heat generated by the electric motor 8 increases, so that the dump body 5 is heated effectively.

[0043] The dump truck 1A includes a motor housing 13 that houses the electric motor 8. The first duct 21 is arranged to connect the motor housing 13 and the first inlet 17 of the internal flow path 19. Because the electric motor 8 is housed in the motor housing 13, air heated by the electric motor 8 is efficiently supplied to the internal flow path 19.

[0044] The motor housing 13 accommodates the left electric motor 8 and the right electric motor 8. The first duct 21 is connected to the center of the motor housing 13 in the left-right direction. This allows the air heated by the left electric motor 8 and the air heated by the right electric motor 8 to be efficiently supplied to the internal flow path 19.

[0045] The first inlet 17 is provided in the bottom plate 5B of the dump body 5. This prevents the first duct 21 from becoming too long.

[0046] The dump truck 1A includes a retarder brake 7 and a second duct 22 through which air flows that is supplied from the retarder brake 7 to the internal flow path 19 of the dump body 5. The air heated by the retarder brake 7 is supplied to the internal flow path 19 of the dump body 5 via the second duct 22, thereby heating the dump body 5. This prevents the cargo from adhering to the inner surface of the dump body 5. In particular, when the dump truck 1A travels downhill, the amount of heat generated by the retarder brake 7 increases, so that the dump body 5 is heated effectively.

[0047] The dump truck 1A includes a brake housing 11 that houses a retarder brake 7. The second duct 22 is arranged to connect the brake housing 11 and the second inlet 18 of the internal flow path 19. Because the retarder brake 7 is housed in the brake housing 11, air heated by the retarder brake 7 is efficiently supplied to the internal flow path 19.

[0048] The second inlet 18 is provided in the front plate 5F of the dump body 5. This prevents the second duct 22 from becoming too long.

[0049] Second Embodiment A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0050] Fig. 7 is a schematic diagram of the dump truck 1B according to this embodiment, as seen from the rear. As shown in Fig. 7, the dump truck 1B includes a blower fan 23 disposed inside the motor housing 13. The blower fan 23 rotates so that air is supplied from the electric motor 8 to the internal flow path 19 of the dump body 5. The blower fan 23 is rotated by the electric motor 8. In this embodiment, the blower fan 23 is connected to the output shaft 16. The rotation of the output shaft 16 causes the blower fan 23 to rotate.

[0051] The blower fan 23 is disposed at a position closer to the center of the motor housing 13 in the left-right direction than the electric motor 8. In other words, the blower fan 23 is disposed at a position closer to the first duct 21 than the electric motor 8. The blower fan 23 is connected to the other end of the output shaft 16 which is closer to the center of the motor housing 13 in the left-right direction. As in the above-described embodiment, one end of the output shaft 16 is connected to the rear wheel 4.

[0052] The blower fans 23 are connected to the left electric motor 8 and the right electric motor 8, respectively. The blower fans 23 include a first blower fan 23 rotated by the left electric motor 8 and a second blower fan 23 rotated by the right electric motor 8.

[0053] As described above, in this embodiment, the dump truck 1B includes the blower fan 23 disposed inside the motor housing 13. The blower fan 23 rotates so that air is supplied from the electric motor 8 to the internal flow path 19 of the dump body 5. As a result, air heated by the electric motor 8 is efficiently supplied to the internal flow path 19 via the first duct 21.

[0054] Third Embodiment A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0055] Fig. 8 is a schematic diagram of a dump truck 1C according to this embodiment as seen from the rear. As shown in Fig. 8, the dump truck 1C includes a blower fan 24 disposed inside the first duct 21. The blower fan 24 rotates so that air is supplied from the electric motor 8 to the internal flow path 19 of the dump body 5. The blower fan 24 is rotated by a motor (not shown) separate from the electric motor 8.

[0056] The blower fan 24 rotates so that air is supplied from the electric motor 8 to the internal flow path 19 of the dump body 5 when the dump truck 1C is traveling uphill or on a flat road, and does not rotate when the dump truck 1C is traveling downhill. This is because the electric motor 8 is driven and generates heat when the dump truck 1C is traveling uphill or on a flat road, but the electric motor 8 is not driven when the dump truck 1C is traveling downhill. Note that the blower fan 24 may rotate when the temperature of the electric motor 8 is equal to or higher than a predetermined first predetermined value, and may not rotate when the temperature of the electric motor 8 is below the first predetermined value. For example, if a first temperature sensor (not shown) is provided to detect the temperature around the electric motor 8, the blower fan 24 may rotate when the detected value of the first temperature sensor is equal to or higher than the first predetermined value, and may not rotate when the detected value of the first temperature sensor is below the first predetermined value.

[0057] As described above, in this embodiment, the dump truck 1C includes the blower fan 24 disposed inside the first duct 21. The blower fan 24 rotates so that air is supplied from the electric motor 8 to the internal flow path 19 of the dump body 5. In this way, air heated by the electric motor 8 is efficiently supplied to the internal flow path 19 via the first duct 21.

[0058] A retarder fan that rotates so that air is supplied from the retarder brake 7 to the internal flow path 19 of the dump body 5 may be provided. The retarder fan may be disposed inside the brake housing 11. The retarder fan rotates so that air is supplied from the retarder brake 7 to the internal flow path 19 of the dump body 5 when the dump truck 1C is traveling downhill, and may not rotate when the dump truck 1C is traveling uphill or on a flat road. This is because the retarder brake 7 operates and generates heat when the dump truck 1C is traveling downhill, but the retarder brake 7 does not operate when the dump truck 1C is traveling uphill or on a flat road. The retarder fan may rotate when the temperature of the retarder brake 7 is equal to or higher than a predetermined second predetermined value, and may not rotate when the temperature of the retarder brake 7 is less than the second predetermined value. For example, if a second temperature sensor (not shown) is provided to detect the temperature around the retarder brake 7, the retarder fan may rotate when the detected value of the second temperature sensor is greater than or equal to a second predetermined value, and may not rotate when the detected value of the second temperature sensor is less than the second predetermined value.

[0059] [Fourth Embodiment] A fourth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0060] 9 and 10 are side views showing a dump truck 1D according to this embodiment. The dump truck 1D includes an exhaust duct 25 connected to the first duct 21, a first valve 27 that opens and closes the flow path of the first duct 21, and a second valve 28 that opens and closes the flow path of the exhaust duct 25. The exhaust duct 25 is arranged to branch off from the first valve 27 between the motor housing 13 and the first inlet 17. One end of the exhaust duct 25 is connected to the first valve 27. An outlet 26 is provided at the other end of the exhaust duct 25.

[0061] The supply of air from the electric motor 8 to the internal flow path 19 and the supply of air from the retarder brake 7 to the internal flow path 19 are switched between when the dump truck 1D is traveling uphill or on a flat road and when it is traveling downhill. When traveling uphill or on a flat road, air is supplied from the electric motor 8 to the internal flow path 19, and when traveling downhill, air is supplied from the retarder brake 7 to the internal flow path 19.

[0062] 9 shows the states of the first valve 27 and the second valve 28 when the dump truck 1D is traveling uphill or on a flat road. As shown in FIG. 9, the first valve 27 opens the flow path of the first duct 21 when the dump truck 1D is traveling uphill or on a flat road. The second valve 28 closes the flow path of the exhaust duct 25 when the dump truck 1D is traveling uphill or on a flat road. Air supplied from the electric motor 8 to the internal flow path 19 is discharged from the outlet 20. In this way, air is supplied from the electric motor 8 to the internal flow path 19 when the dump truck 1D is traveling uphill or on a flat road.

[0063] Fig. 10 shows the states of the first valve 27 and the second valve 28 when the dump truck 1D travels downhill. As shown in Fig. 10, the first valve 27 closes the flow path of the first duct 21 when the dump truck 1D travels downhill. The second valve 28 opens the flow path of the exhaust duct 25 when the dump truck 1D travels downhill. As a result, air is supplied from the retarder brake 7 to the internal flow path 19 when the dump truck 1D travels downhill. The air supplied from the retarder brake 7 to the internal flow path 19 is not supplied to the electric motor 8, but is discharged from the outlet 20. In this way, air is supplied from the retarder brake 7 to the internal flow path 19 when the dump truck 1D travels downhill. The air from the electric motor 8 is not supplied to the internal flow path 19, but is discharged to the periphery of the dump truck 1D via the exhaust duct 25.

[0064] As described above, in this embodiment, the dump truck 1D is provided with the first valve 27 that opens and closes the flow path of the first duct 21. When the dump truck 1D is traveling uphill or on a flat road, the flow path of the first duct 21 is opened, and air heated by the electric motor 8 is supplied to the internal flow path 19. When the dump truck 1D is traveling downhill, the flow path of the first duct 21 is closed, and air heated by the retarder brake 7 is supplied to the internal flow path 19. As a result, the dump body 5 is always heated when traveling uphill, on a flat road, and downhill.

[0065] The dump truck 1D is equipped with an exhaust duct 25 branching off from the first duct 21, and a second valve 28 that opens and closes the flow path of the exhaust duct 25. When the flow path of the first duct 21 is open while the dump truck 1D is traveling uphill or on a flat road, the flow path of the exhaust duct 25 is closed. This allows air heated by the electric motor 8 to be efficiently supplied to the internal flow path 19. When the flow path of the first duct 21 is closed while the dump truck 1D is traveling downhill, the flow path of the exhaust duct 25 is opened. This allows air from the electric motor 8 to be discharged to the periphery of the dump truck 1D via the exhaust duct 25.

[0066] In this embodiment, when the dump truck 1D travels downhill, the electric motor 8 does not operate, and the blower fan 23 and the blower fan 24 do not operate either. In other words, when the dump truck 1D travels downhill, air is not supplied from the electric motor 8 to the internal flow path 19 of the dump body 5. Therefore, the exhaust duct 25 may be omitted.

[0067] Fifth Embodiment A fifth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0068] 11 is a view showing the dump body 5 of the dump truck 1E according to this embodiment. As in the above-described embodiment, the dump body 5 includes a bottom plate 5B, a left plate 5L, a right plate 5R, a front plate 5F, and a protector plate 5P.

[0069] In this embodiment, the internal flow path of the dump body 5 includes a first internal flow path 191 and a second internal flow path 192 that is separated from the first internal flow path 191. The first internal flow path 191 and the second internal flow path 192 do not intersect. The first internal flow path 191 and the second internal flow path 192 are separate internal flow paths. Air flowing through the first internal flow path 191 is not supplied to the second internal flow path 192. Air flowing through the second internal flow path 192 is not supplied to the first internal flow path 191.

[0070] The first duct 21 is connected to the first inlet 170 of the first internal flow path 191. Air from the electric motor 8 is supplied to the first inlet 170 via the first duct 21. The air that flows into the first inlet 170 flows through the first internal flow path 191 and is then discharged from the outlet 201 of the first internal flow path 191. The first inlet 170 is provided in the center of the underside of the bottom plate 5B in the left-right direction. The first inlet 170 is provided in the rear part of the bottom plate 5B. The outlet 201 is provided in the front part of the right surface of the right plate 5R.

[0071] The second duct 22 is connected to the second inlet 180 of the second internal flow path 192. Air from the retarder brake 7 is supplied to the second inlet 180 via the second duct 22. The air that flows into the second inlet 180 flows through the second internal flow path 192 and is then discharged from the outlet 200 of the second internal flow path 192. The second inlet 180 is provided on the front surface of the front panel 5F. The second inlet 180 is provided on the upper right part of the front surface of the front panel 5F. The outlet 200 is provided on the rear part of the left surface of the left panel 5L.

[0072] At least a portion of the first internal flow passage 191 is provided in the center of the bottom plate 5B in the left-right direction (vehicle width direction). The second internal flow passages 192 are provided at the boundary between the bottom plate 5B and the front plate 5F, the boundary between the bottom plate 5B and the left plate 5L, and the boundary between the bottom plate 5B and the right plate 5R.

[0073] In this embodiment, the first internal flow path 191 includes a first flow path 191A provided inside the bottom plate 5B, and a second flow path 191B and a third flow path 191C provided inside the front plate 5F. The first flow path 191A is provided in the center of the bottom plate 5B in the left-right direction. In this embodiment, the first flow path 191A is provided so as to extend in the front-rear direction. Two first flow paths 191A are provided with a gap in the left-right direction. The second flow path 191B is provided in the center of the front plate 5F in the left-right direction. In this embodiment, the second flow path 191B is provided so as to extend in the up-down direction. Two second flow paths 191B are provided with a gap in the left-right direction. The front end of the left first flow path 191A is connected to the lower end of the left second flow path 191B. The front end of the right first flow path 191A is connected to the lower end of the right second flow path 191B. The third flow path 191C is provided to extend in the left-right direction. The upper ends of the left and right second flow paths 191B are connected to the third flow path 191C. The right end of the third flow path 191C is connected to the outlet 201. Air from the first inlet 170 flows into the rear end of the left first flow path 191A and the rear end of the right first flow path 191A. The air that flows into the first flow path 191A flows through the first flow path 191A, the second flow path 191B, and the third flow path 191C, and is then discharged from the outlet 201.

[0074] In the present embodiment, the second internal flow path 192 includes a fourth flow path 192B provided inside the front plate 5F, a fifth flow path 192A provided inside the right plate 5R, and a sixth flow path 192C provided inside the left plate 5L. The fourth flow path 192B is connected to the second inlet 180. At least a portion of the fourth flow path 192B is provided at the lower end of the front plate 5F. At least a portion of the fourth flow path 192B is provided at the boundary between the bottom plate 5B and the front plate 5F. At least a portion of the fifth flow path 192A is provided at the lower end of the right plate 5R. At least a portion of the fifth flow path 192A is provided at the boundary between the bottom plate 5B and the right plate 5R. At least a portion of the sixth flow path 192C is provided at the lower end of the left plate 5L. At least a portion of the sixth flow path 192C is provided at the boundary between the bottom plate 5B and the left plate 5L. The fourth flow path 192B, the fifth flow path 192A, and the sixth flow path 192C are connected to each other. The air that flows into the fourth flow path 192B from the second inlet 180 flows through each of the fifth flow path 192A and the sixth flow path 192C, and then is discharged from the outlet 201.

[0075] As described above, in the present embodiment, the air from the electric motor 8 flows through the first internal flow path 191, and the air from the retarder brake 7 flows through the second internal flow path 192, which is separate from the first internal flow path 191. As a result, when the dump truck 1E is traveling uphill or on a flat road, the dump body 5 is effectively heated by the air flowing through the first internal flow path 191, and when the dump truck 1E is traveling downhill, the dump body 5 is effectively heated by the air flowing through the second internal flow path 192. Furthermore, since the first internal flow path 191 and the second internal flow path 192 are separated, the air from the electric motor 8 is prevented from being supplied to the retarder brake 7, and the air from the retarder brake 7 is prevented from being supplied to the electric motor 8.

[0076] In this embodiment, at least a portion of the second internal flow passage 192 is provided at the boundary between the bottom plate 5B and the front plate 5F, the boundary between the bottom plate 5B and the left plate 5L, and the boundary between the bottom plate 5B and the right plate 5R. On the inner surface of the dump body 5, cargo is likely to adhere to the boundary (corner) between the top surface of the bottom plate 5B and the rear surface of the front plate 5F, the boundary (corner) between the top surface of the bottom plate 5B and the right surface of the left plate 5L, and the boundary (corner) between the top surface of the bottom plate 5B and the left surface of the right plate 5R. Furthermore, the air from the retarder brake 7 is likely to be at a higher temperature than the air from the electric motor 8. Because high-temperature air is supplied to the boundary between the bottom plate 5B and the front plate 5F, the boundary between the bottom plate 5B and the left plate 5L, and the boundary between the bottom plate 5B and the right plate 5R, cargo adhesion to the inner surface of the dump body 5 is effectively suppressed.

[0077] [Other Embodiments] In the above-described embodiment, the rear wheels 4 are the drive wheels. However, the front wheels 3 may be the drive wheels, or both the front wheels 3 and the rear wheels 4 may be drive wheels. Furthermore, the rear wheels 4 may be steered.

[0078] In the above-described embodiment, the dump truck (1A, etc.) is of a rigid frame type. However, the dump truck (1A, etc.) may be of an articulated type.

[0079] In the above-described embodiment, the dump truck (1A, etc.) is a rear dump truck. However, the dump truck (1A, etc.) may be a side dump truck in which a load is discharged from the dump body 5 by tilting the dump body 5 to the left or right.

[0080] 1A...dump truck, 1B...dump truck, 1C...dump truck, 1D...dump truck, 1E...dump truck, 2...vehicle body, 3...front wheels, 4...rear wheels (drive wheels), 5...dump body, 5F...front plate, 5B...bottom plate, 5L...left plate, 5R...right plate, 5P...protector plate, 6...hoist cylinder, 7...retarder brake, 8...electric motor, 9...cab, 10...tire, 11...brake housing, 12...motor case, 13...motor housing, 14...stator, 14A...stator core, 14B...coil, 15...rotor, 16...output shaft, 17... 1 inlet, 18...second inlet, 19...internal flow path, 19A...first flow path, 19B...second flow path, 19C...third flow path, 20...outlet, 21...first duct, 22...second duct, 23...blower fan, 24...blower fan, 25...exhaust duct, 26...outlet, 27...first valve, 28...second valve, 170...first inlet, 180...second inlet, 191...first internal flow path, 191A...first flow path, 191B...second flow path, 191C...third flow path, 192...second internal flow path, 192A...fifth flow path, 192B...fourth flow path, 192C...sixth flow path, 200...outlet, 201...outlet.

Claims

1. A dump truck comprising: drive wheels; a vehicle body supported by the drive wheels; a dump body supported by the vehicle body; an electric motor that rotates the drive wheels; and a first duct through which air flows that is supplied from the electric motor to an internal flow path of the dump body.

2. The dump truck according to claim 1, further comprising a motor housing that houses the electric motor, wherein the first duct is arranged to connect the motor housing and a first inlet of the internal flow path.

3. A dump truck as described in claim 2, wherein the drive wheels include a first drive wheel arranged on one side of the center of the vehicle body in the vehicle width direction and a second drive wheel arranged on the other side, the electric motor includes a first electric motor that rotates the first drive wheel and a second electric motor that rotates the second drive wheel, the motor housing accommodates the first electric motor and the second electric motor, and the first duct is connected to a central portion of the motor housing in the vehicle width direction.

4. The dump truck according to claim 2, wherein the first inlet is provided in a bottom plate of the dump body.

5. The dump truck according to claim 3, further comprising a blower fan disposed inside the first duct.

6. The dump truck according to claim 3, further comprising a blower fan disposed inside the motor housing.

7. The dump truck according to claim 5, wherein the blower fan is rotated by the electric motor.

8. The dump truck according to claim 7, wherein the blower fan includes a first blower fan rotated by the first electric motor and a second blower fan rotated by the second electric motor.

9. The dump truck according to claim 1, comprising: a retarder brake; and a second duct through which air supplied from the retarder brake to the internal flow path of the dump body flows.

10. The dump truck according to claim 9, further comprising a brake housing that houses the retarder brake, wherein the second duct is disposed so as to connect the brake housing and a second inlet of the internal flow path.

11. The dump truck according to claim 10, wherein the second inlet is provided in a front plate of the dump body.

12. The dump truck according to claim 9, further comprising a first valve that opens and closes the flow path of the first duct, the first valve opening the flow path of the first duct when traveling uphill or on a flat road, and closing the flow path of the first duct when traveling downhill.

13. The dump truck according to claim 12, further comprising: an exhaust duct connected to the first duct; and a second valve that opens and closes the flow path of the exhaust duct, wherein the second valve closes the flow path of the exhaust duct when traveling uphill or on a flat road, and opens the flow path of the second duct when traveling downhill.

14. A dump truck as described in claim 9, comprising: a blower fan that rotates so that air is supplied from the electric motor to the internal flow path of the dump body when traveling uphill or on a flat road; and a retarder fan that rotates so that air is supplied from the retarder brake to the internal flow path of the dump body when traveling downhill.

15. A dump truck as described in claim 9, comprising: a blower fan that rotates so that air is supplied from the electric motor to the internal flow path of the dump body; a retarder fan that rotates so that air is supplied from the retarder brake to the internal flow path of the dump body when traveling downhill; a first temperature sensor that detects the temperature around the electric motor; and a second temperature sensor that detects the temperature around the retarder brake, wherein the blower fan rotates when the detected value of the first temperature sensor is equal to or greater than a first predetermined value, and the retarder fan rotates when the detected value of the second temperature sensor is equal to or greater than a second predetermined value.

16. A dump truck according to claim 9, wherein the internal flow path of the dump body includes a first internal flow path and a second internal flow path partitioned from the first internal flow path, the first duct is connected to a first inlet of the first internal flow path, and the second duct is connected to a second inlet of the second internal flow path.

17. A dump truck as described in claim 16, wherein the dump body includes a bottom plate, a front plate, a left plate, and a right plate, at least a portion of the first internal flow path is provided in the center of the bottom plate in the vehicle width direction, and the second internal flow path is provided at each of the boundary between the bottom plate and the front plate, the boundary between the bottom plate and the left plate, and the boundary between the bottom plate and the right plate.

18. A dump truck according to claim 9, wherein the supply of air from the electric motor to the internal flow path and the supply of air from the retarder brake to the internal flow path are switched between when traveling uphill and when traveling downhill, so that when traveling uphill, air is supplied from the electric motor to the internal flow path, and when traveling downhill, air is supplied from the retarder brake to the internal flow path.

19. A dump truck comprising: drive wheels; a vehicle body supported by the drive wheels; a dump body supported by the vehicle body; an electric motor that rotates the drive wheels; a first duct through which air flows that is supplied from the electric motor to an internal flow path of the dump body; a blower fan that rotates so that air is supplied from the electric motor to the internal flow path of the dump body; and a first temperature sensor that detects the temperature around the electric motor, wherein the blower fan rotates when the detected value of the first temperature sensor is equal to or greater than a first predetermined value.

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