Dump truck

Abstract

A dump truck (1) comprises: a vehicle body frame (5) to which front wheels (3) and rear wheels (4) are attached; an electric motor (25) that drives the rear wheels (4); a battery apparatus (26) that is mounted on the vehicle body frame (5) and that supplies power to the electric motor (25); and an electric device that includes a converter (34) disposed on the rear side of the battery apparatus (26). The battery apparatus (26) is configured by including a battery frame (27) supported by the vehicle body frame (5), and a battery module (33) attached to the battery frame (27). The battery frame (27) is provided with a refrigerant pipe line accommodation unit (32) that accommodates a first refrigerant pipe line (45) through which a refrigerant for cooling the battery module (33) flows and a second refrigerant pipe line (50) through which a refrigerant for cooling the electric device flows.

Description

Dump truck

[0001] The present disclosure relates to a dump truck that is suitable for use in transporting crushed stone excavated from, for example, an open-cut mining site, a mine, or the like.

[0002] Generally, in open-cut mining sites, mines, and the like, hydraulic excavators are used to excavate crushed material such as minerals, and large amounts of the excavated material are loaded onto dump trucks for transport to a designated unloading area. Dump trucks are configured to include a vehicle body to which front and rear wheels are attached, and a loading platform (vessel) attached so as to be rotatable up and down around the rear of the vehicle body as a fulcrum.

[0003] Dump trucks are equipped with electric motors as a power source for rotating the left and right drive wheels. In recent years, dump trucks have been proposed that are equipped with batteries instead of engine-driven generators, and that use the electricity stored in the batteries to drive the electric motors. The batteries in dump trucks are composed of multiple battery modules to increase the driving distance, and the dump trucks are equipped with cooling systems for cooling the multiple battery modules and other electrical equipment (see Patent Document 1).

[0004] EP 3480050 A1

[0005] The cooling system installed in the dump truck described above has multiple refrigerant pipes through which a refrigerant for cooling the multiple battery modules flows. Therefore, the refrigerant pipes occupy a large amount of space required for mounting the onboard equipment on the body frame. This limits the space available for mounting additional battery modules even if the dump truck's travel distance is increased.

[0006] The present invention has been made in consideration of the problems of the conventional technology described above, and an object of the present invention is to provide a dump truck in which refrigerant pipes for cooling battery modules, etc. are arranged so that they can be compactly mounted on the vehicle frame.

[0007] The present invention relates to a dump truck comprising a body frame to which wheels are attached, an electric motor that drives the wheels, a battery device that is mounted on the body frame and supplies power to the electric motor, and electrical equipment including a converter that is arranged behind the battery device, wherein the battery device includes a battery frame supported by the body frame and battery modules attached to the battery frame, the battery frame is provided with a refrigerant pipe accommodating section that accommodates a first refrigerant pipe through which a refrigerant that cools the battery modules flows and a second refrigerant pipe through which a refrigerant that cools the electrical equipment flows, the battery frame has a plurality of support frame bodies stacked in multiple stages in the vertical direction, the battery modules are attached to the plurality of support frame bodies respectively, and the refrigerant pipe accommodating section is provided in at least one of the plurality of support frame bodies.

[0008] According to the present invention, a plurality of battery modules are attached to a battery frame, and a first refrigerant pipe and a second refrigerant pipe are housed in a refrigerant pipe housing provided in the battery frame. This allows the first refrigerant pipe and the second refrigerant pipe to be housed compactly using the battery frame. As a result, the space occupied by the first refrigerant pipe and the second refrigerant pipe is reduced, allowing a larger number of battery modules to be mounted on the vehicle frame.

[0009] FIG. 1 is a left side view showing a dump truck to which an embodiment of the present invention is applied. FIG. 2 is a perspective view showing a body frame alone. FIG. 3 is a plan view showing electrical equipment such as a battery mounted on the body frame. FIG. 4 is a front view of the dump truck from which the current collector has been removed. FIG. 5 is a perspective view showing a battery device, a first refrigerant pipe, and a second refrigerant pipe. FIG. 6 is a perspective view of the battery device, the first refrigerant pipe, and the second refrigerant pipe as seen from below. FIG. 7 is a partially cutaway perspective view showing a first support frame, the first refrigerant pipe, and the second refrigerant pipe. FIG. 8 is a left side view showing the connection state between a plurality of pipes constituting the first refrigerant pipe and a plurality of battery modules. FIG. 9 is an explanatory view schematically showing the first refrigerant pipe and the second refrigerant pipe from the underside of the body frame.

[0010] Hereinafter, a detailed description will be given of an embodiment of the present invention, taking a trolley-type dump truck as an example, with reference to the accompanying drawings. In the embodiment, the traveling direction of the dump truck is defined as the front-rear direction, and the direction perpendicular to the traveling direction is defined as the left-right direction.

[0011] 1, a trolley-equipped dump truck 1 travels by supplying power from a trolley overhead line installed in a mine or the like to an electric motor for traveling via a current collector (trolley). The dump truck 1 includes a self-propelled vehicle body 2 having left and right front wheels 3 and left and right rear wheels 4, and a loading platform 19 (described below) mounted on the vehicle body 2 so as to be tiltable (raise and lower). Minerals mined by a hydraulic excavator or the like (not shown) are loaded onto the loading platform 19 and transported. The vehicle body 2 of the dump truck 1 includes a vehicle frame 5, a deck 22, a cab 23, etc. (described below).

[0012] The left and right front wheels 3 are rotatably mounted on the front side of the vehicle body 2 and constitute steered wheels. The front wheels 3 are supported by the vehicle body frame 5 via front-wheel-side suspensions, which dampen vibrations transmitted from the front wheels 3 to the vehicle body 2. The left and right rear wheels 4 are rotatably mounted on the rear side of the vehicle body 2 and are rotationally driven by running devices 24 equipped with electric motors 25 (described later). The running devices 24 for the rear wheels 4 are attached to the vehicle body frame 5 via rear-wheel-side suspensions, which dampen vibrations transmitted from the rear wheels 4 to the vehicle body 2.

[0013] The body frame 5 is a strong support structure that forms the base of the body 2 and extends in the fore-and-aft direction. As shown in Figure 2, the body frame 5 includes a left frame 6, a right frame 7, a front frame 8, a rear frame 9, an upper plate 10, a lower plate 11, etc., which will be described later.

[0014] The left frame 6 is disposed on the left side of the body frame 5. The left frame 6 is configured to include left and right side panels 6A that face each other in the left-right direction, an upper panel 10 that closes the upper ends of the left and right side panels 6A, and a lower panel 11 that connects the lower ends of the left and right side panels 6A, and has a box structure with a rectangular cross section that extends in the front-to-rear direction. The right frame 7 is disposed on the right side of the body frame 5. The right frame 7 is configured to include left and right side panels 7A that face each other in the left-to-right direction, an upper panel 10 that closes the upper ends of the left and right side panels 7A, and a lower panel 11 that connects the lower ends of the left and right side panels 7A, and has a box structure with a rectangular cross section that extends in the front-to-rear direction.

[0015] The left frame 6 and the right frame 7 extend in the front-to-rear direction while facing each other with a gap left and right, and the gap between the left frame 6 and the right frame 7 in the front and rear directions is set larger than the gap at the rear of the body frame 5. A left rear end bracket 6B is provided at the rear end of the left frame 6, and a right rear end bracket 7B is provided at the rear end of the right frame 7, with the left rear end bracket 6B and the right rear end bracket 7B facing each other in the left and right directions.

[0016] The front frame 8 is disposed on the front side of the body frame 5. The front frame 8 has a box structure extending in the left-right direction, including front and rear side plates 8A, an upper plate 10, and a lower plate 11 that face each other in the front-rear direction, and connects the front end of the left frame 6 to the front end of the right frame 7. The rear frame 9 is disposed on the rear side of the body frame 5. The rear frame 9 has a box structure extending in the left-right direction, including front and rear side plates 9A, an upper plate 10, and a lower plate 11 that face each other in the front-rear direction, and connects the rear end of the left frame 6 to the rear end of the right frame 7.

[0017] The upper plate 10 is provided on the upper ends of the left frame 6, right frame 7, front frame 8, and rear frame 9. The upper plate 10 closes the upper ends of the left frame 6, right frame 7, front frame 8, and rear frame 9, and also connects the left frame 6 and the right frame 7. The upper plate 10 is provided with a front opening 10A and a rear opening 10B located between the left frame 6 and the right frame 7.

[0018] The lower plate 11 is provided at the lower ends of the left frame 6, right frame 7, front frame 8, and rear frame 9, facing the upper plate 10 in the vertical direction. The lower plate 11 closes the lower ends of the left frame 6, right frame 7, front frame 8, and rear frame 9, and connects the left frame 6 and the right frame 7. The lower plate 11 is provided with a front opening 11A and a rear opening 11B at positions corresponding to the front opening 10A and rear opening 10B of the upper plate 10.

[0019] The left support pillar 12 and the right support pillar 13 are located forward of the center of the body frame 5 in the longitudinal direction and face each other in the left-right direction. The left support pillar 12 and the right support pillar 13 each have a mountain-shaped hollow box structure. The left support pillar 12 protrudes upward from the upper plate 10 that constitutes the left frame 6, and the right support pillar 13 protrudes upward from the upper plate 10 that constitutes the right frame 7. A deck 22 and the like are attached to the upper ends of the left support pillar 12 and the right support pillar 13.

[0020] The left cylinder bracket 14 and the right cylinder bracket 15 are provided rearward from the midpoint in the fore-and-aft direction of the body frame 5 and face each other in the left-right direction. The left cylinder bracket 14 protrudes downward from the lower plate 11 that constitutes the left frame 6, and the right cylinder bracket 15 protrudes downward from the lower plate 11 that constitutes the right frame 7. A cylinder support shaft 16 extending in the left-right direction is inserted through the lower ends of the left cylinder bracket 14 and the right cylinder bracket 15. The lower ends of hoist cylinders 20, which will be described later, are attached to both left-and-right ends of the cylinder support shaft 16.

[0021] Left and right front brackets 17 are provided near the left front corner where the left frame 6 and the front frame 8 intersect, and near the right front corner where the right frame 7 and the front frame 8 intersect. These left and right front brackets 17 face each other in the left-right direction, sandwiching the front opening 10A of the upper plate 10 therebetween, and left and right front extension plates 28D of the battery frame 27, which will be described later, are attached to them. In addition, left and right rear brackets 18 are provided on the left frame 6 and the right frame 7, located rearward of the left and right front brackets 17. These left and right rear brackets 18 face each other in the left-right direction, sandwiching the front opening 10A of the upper plate 10 therebetween, and left and right rear extension plates 28E of the battery frame 27 are attached to them.

[0022] The loading platform (vessel) 19 is mounted on the body frame 5 so as to be tiltable (raise and lower). The loading platform 19 is formed as a large, bottomed container for carrying crushed material such as minerals mined by a hydraulic excavator or the like. The rear bottom of the loading platform 19 is tiltably connected to the left rear end bracket 6B of the left frame 6 and the right rear end bracket 7B of the right frame 7 via connecting pins 19A. A eaves portion 19B is integrally formed on the front side of the loading platform 19, extending horizontally forward from the top. The eaves portion 19B of the loading platform 19 extends to the front end of the deck 22, covering the cab 23 from above.

[0023] The hoist cylinders 20 are provided in pairs in the left-right direction between the body frame 5 and the loading platform 19 (only the left side is shown). The hoist cylinders 20 are, for example, hydraulic cylinders, and tilt the front side of the loading platform 19 up and down relative to the body frame 5. One end (lower end) of the hoist cylinders 20 is attached to the cylinder support shaft 16, and the other end (upper end) of the hoist cylinders 20 is attached to the underside of the loading platform 19. Therefore, by extending the hoist cylinders 20, the front side (eaves portion 19B side) of the loading platform 19 is lifted upward around the connecting pin 19A, allowing minerals and the like loaded on the loading platform 19 to be discharged rearward.

[0024] The building 21 is provided on the front end side of the body frame 5. The building 21 is formed in a frame shape surrounded by left and right side panels, a front panel (grill), etc., and a battery device 26 and the like are housed inside the building 21. The building 21, together with the left support column 12 and right support column 13 of the body frame 5, also serves to support the deck 22 and the like from below.

[0025] The deck 22 is located forward of the loading platform 19 and is provided above the building 21. The deck 22 is formed in the shape of a rectangular flat plate that is long in the left-right direction, and extends horizontally while being supported from below by the left support pillars 12 and right support pillars 13 of the body frame 5 and the building 21. A cab 23, a control cabinet 38 (described later), and the like are mounted on the deck 22, and the upper surface of the deck 22 forms a flat walkway surface for operators and the like to pass through.

[0026] The cab 23 is provided on the upper left side of the deck 22 and defines a cab for an operator. Inside the cab 23, a driver's seat, a steering wheel, a start switch, an accelerator pedal, a brake pedal, and control levers (none of which are shown) are provided.

[0027] A rear-wheel-side traveling device 24 is provided on the rear side of the body frame 5. The traveling device 24 is attached to the body frame 5 via a rear-wheel-side suspension device. The traveling device 24 is provided with left and right electric motors 25 for traveling, and the rotation of these left and right electric motors 25 is transmitted to the left and right rear wheels 4 via speed reducers (not shown).

[0028] Next, the battery device 26 mounted on the body frame 5 will be described with reference to FIGS.

[0029] The battery device 26 is located below the deck 22 and mounted on the front portion of the body frame 5. The battery device 26 stores power to be supplied to electrical equipment mounted on the dump truck 1, such as the electric motor 25 for traveling. As shown in FIGS. 5 and 6 , the battery device 26 is configured to include a multi-stage battery frame 27 and a plurality of battery modules 33. The battery frame 27 has a plurality of support frame bodies stacked in the vertical direction and is supported by the body frame 5. The plurality of battery modules 33 are individually attached to the support frame bodies of the battery frame 27.

[0030] The battery frame 27 has a first support frame body 28 arranged at the bottom, a second support frame body 29 detachably attached above the first support frame body 28, a third support frame body 30 detachably attached above the second support frame body 29, and a fourth support frame body 31 detachably attached above the third support frame body 30. In this way, the battery frame 27 has four tiers of support frame bodies (the first support frame body 28, the second support frame body 29, the third support frame body 30, and the fourth support frame body 31) stacked vertically.

[0031] The first support frame 28, serving as the lowest support frame, includes a rectangular frame body 28A extending in the front-to-rear direction, left and right front legs 28B disposed at the front end of the frame body 28A, and left and right rear legs 28C disposed at the rear end of the frame body 28A. A plurality of battery modules 33 are mounted to the frame body 28A in a line in the front-to-rear direction. Front extension plates 28D extending laterally from the front legs 28B are provided at vertically intermediate portions of the left and right front legs 28B, respectively. These left and right front extension plates 28D are attached to the left and right front brackets 17 of the body frame 5. Rear extension plates 28E extending laterally from the rear legs 28C are provided at vertically intermediate portions of the left and right rear legs 28C, respectively. These left and right rear extension plates 28E are attached to the left and right rear brackets 18 of the body frame 5.

[0032] The frame main body 28A of the first support frame 28 is formed into a rectangular frame shape by a front plate 28F, a rear plate 28G, a left plate 28H, a right plate 28J, a lower plate 28K, and an upper plate 28L. The front plate 28F and the rear plate 28G face each other with a gap in the front-to-rear direction, and the left plate 28H and the right plate 28J face each other with a gap in the left-to-right direction. A frame-shaped lower plate 28K is fixed to the lower ends of the front plate 28F, the rear plate 28G, the left plate 28H, and the right plate 28J. A frame-shaped upper plate 28L is fixed to the upper ends of the front plate 28F, the rear plate 28G, the left plate 28H, and the right plate 28J. The lower plate 28K and the upper plate 28L face each other in the vertical direction.

[0033] The second support frame 29 is formed in a rectangular frame shape extending in the front-rear direction, similar to the frame main body 28A of the first support frame 28. The second support frame 29 is detachably attached to the first support frame 28 using fasteners such as bolts. A plurality of battery modules 33 are attached to the second support frame 29, lined up in the front-rear direction.

[0034] The third support frame 30 includes a rectangular frame body 30A extending in the front-to-rear direction, left and right front legs 30B disposed at the front end of the frame body 30A, and left and right rear legs 30C disposed at the rear end of the frame body 30A. The lower ends of the left and right front legs 30B are detachably attached to the upper ends of the front legs 28B of the first support frame 28 using fasteners such as bolts. The lower ends of the left and right rear legs 30C are detachably attached to the upper ends of the rear legs 28C of the first support frame 28 using fasteners such as bolts. As a result, the third support frame 30 is disposed on the second support frame 29, and a plurality of battery modules 33 are attached to the frame body 30A in a line in the front-to-rear direction.

[0035] The fourth support frame 31 includes a rectangular frame body 31A extending in the front-to-rear direction, left and right front legs 31B disposed at the front end of the frame body 31A, and left and right rear legs 31C disposed at the rear end of the frame body 31A. The lower ends of the left and right front legs 31B are detachably attached to the upper ends of the front legs 30B of the third support frame 30 using fasteners such as bolts. The lower ends of the left and right rear legs 31C are detachably attached to the upper ends of the rear legs 30C of the third support frame 30 using fasteners such as bolts. As a result, the fourth support frame 31 is disposed on the third support frame 30, and a plurality of battery modules 33 are attached to the frame body 31A in a line in the front-to-rear direction.

[0036] The refrigerant pipe accommodating section 32 is provided inside the frame body 28A of the first support frame 28. Specifically, the refrigerant pipe accommodating section 32 is configured as a rectangular parallelepiped space surrounded by the front side plate 28F, rear side plate 28G, left side plate 28H, and right side plate 28J that constitute the frame body 28A. The refrigerant pipe accommodating section 32 of the battery frame 27 accommodates a plurality of pipes that constitute a first refrigerant pipe 45 (described below) and a plurality of pipes that constitute a second refrigerant pipe 50. A plurality of pipe insertion holes 28M are formed in the front side plate 28F of the frame body 28A, aligned in the left-right direction. A plurality of pipe insertion holes 28N are formed in the left side plate 28H, aligned in the front-rear direction, and a plurality of pipe insertion holes 28P are formed in the right side plate 28J, aligned in the front-rear direction. The multiple pipes that make up the first refrigerant pipeline 45 and the multiple pipes that make up the second refrigerant pipeline 50 are attached to the first support frame 28 while being inserted into these pipe insertion holes 28M, 28N, and 28P.

[0037] The battery modules 33 are individually attached to the battery frame 27. Each battery module 33 is made of rechargeable batteries such as lithium-ion batteries and is formed in the shape of a rectangular parallelepiped block extending in the left-right direction. The battery modules 33 supply power to electrical devices such as the electric motor 25 for traveling.

[0038] For example, five battery modules 33 are detachably attached to each of the first support frame 28, the second support frame 29, the third support frame 30, and the fourth support frame 31 using fasteners such as bolts. This results in a large-capacity battery device 26 in which a total of 20 battery modules 33 are integrated into a single battery frame 27. The left and right front extension plates 28D of the battery frame 27 (first support frame 28) are attached to the front brackets 17 of the body frame 5, and the left and right rear extension plates 28E are attached to the rear brackets 18 of the body frame 5. As a result, the battery device 26 is supported by the body frame 5 while being disposed between the left frame 6 and the right frame 7.

[0039] The battery modules 33 generate heat as they charge and discharge power. Therefore, a water jacket (not shown) through which a refrigerant, such as cooling water, flows is provided inside the battery modules 33. Each battery module 33 is provided with a refrigerant inlet 33A through which the refrigerant flows into the water jacket and a refrigerant outlet 33B through which the refrigerant flows out of the water jacket. Supply-side pipes 45A, 45C, and 45E, which will be described later, are connected to the refrigerant inlet 33A provided in each of the battery modules 33, and discharge-side pipes 45B, 45D, and 45F, which will be described later, are connected to the refrigerant outlet 33B.

[0040] Electrical devices such as a converter 34, a reactor 35, a hydraulic pump drive motor 36, and a pump drive inverter 37 are arranged behind the battery device 26. The converter 34 is located between the right front wheel 3 and rear wheel 4 and is attached to the right frame 7 of the body frame 5. The converter 34 is a DC / DC converter and converts the voltage of the DC power supplied from the battery device 26 to the electric motor 25 for traveling. The converter 34 has a water jacket (not shown) through which coolant flows, a refrigerant inlet 34A through which the coolant flows in, and a refrigerant outlet 34B through which the coolant flows out (see FIG. 9 ).

[0041] The reactor 35 is located behind the battery device 26 and mounted between the left frame 6 and the right frame 7 of the body frame 5. The reactor 35 is electrically connected between the battery device 26 and the converter 34, and includes an LC filter for removing high-frequency noise, a circuit breaker for protecting the battery device 26, and the like. The reactor 35 has a water jacket (not shown) through which coolant flows, a refrigerant inlet 35A through which the coolant flows in, and a refrigerant outlet 35B through which the coolant flows out.

[0042] The hydraulic pump drive motor 36 is located rearward of the reactor 35 and mounted between the left frame 6 and the right frame 7 of the vehicle body frame 5. The hydraulic pump drive motor 36 is an electric motor that drives a hydraulic pump (not shown) using power from the battery device 26. This causes hydraulic oil to be supplied from the hydraulic pump to hydraulic devices such as the hoist cylinder 20 and the power steering device (not shown). The hydraulic pump drive motor 36 has a water jacket (not shown) through which cooling water flows, a refrigerant inlet 36A through which the cooling water flows in, and a refrigerant outlet 36B through which the cooling water flows out.

[0043] The pump drive inverter 37 is located rearward of the hydraulic pump drive motor 36 and is mounted between the left frame 6 and the right frame 7 of the body frame 5. The pump drive inverter 37 controls the power supplied to the hydraulic pump drive motor 36, and controls the operation of the hydraulic pump drive motor 36. The pump drive inverter 37 has a water jacket (not shown) through which cooling water flows, a refrigerant inlet 37A through which the cooling water flows in, and a refrigerant outlet 37B through which the cooling water flows out.

[0044] The control cabinet 38 is mounted on the upper side of the deck 22, next to the right side of the cab 23. The control cabinet 38 is configured to include an inverter that controls the electric motor 25 for traveling. The hydraulic oil tank 39 is attached to the left frame 6 that constitutes the body frame 5. The hydraulic oil tank 39 is attached to the left frame 6, located between the front wheel 3 and rear wheel 4 on the left side, and stores hydraulic oil to be supplied to hydraulic equipment such as the hoist cylinder 20 mounted on the body frame 5.

[0045] The current collector 40 is provided on a pantograph support 41 mounted on the front end of the body frame 5 (see FIG. 1). The current collector 40 collects electric power from a trolley overhead line (not shown) installed along the travel path of the dump truck 1 in a mine or the like, and supplies the power to the electric motor 25 for traveling, the battery device 26, etc. The current collector 40 has a pantograph 42 provided so as to be extendable and contractible between the pantograph support 41 and the trolley overhead line, and a current collector shoe 42A that comes into sliding contact with the trolley overhead line as the pantograph 42 extends.

[0046] Next, we will explain the first cooling system 43 that cools each battery module 33 of the battery device 26 and the second cooling system 48 that cools the electrical equipment (converter 34, reactor 35, hydraulic pump drive motor 36, pump drive inverter 37) located behind the battery device 26.

[0047] The first cooling system 43 cools the plurality of battery modules 33 that make up the battery device 26. The first cooling system 43 includes a cooling water tank 44, a cooling water pump (not shown), a first refrigerant pipe 45, and a left radiator 46.

[0048] The cooling water tank 44 is located forward of the building 21 and is attached to the front end of the body frame 5. The cooling water tank 44 stores cooling water to be supplied to the water jackets of the plurality of battery modules 33. The plurality of battery modules 33 (water jackets) and the cooling water tank 44 are connected via a first refrigerant pipe 45. The left radiator 46 is disposed adjacent to the left side of the building 21 and below the deck 22. The cooling water tank 44 and the left radiator 46 are connected via a radiator pipe 47, and a circulation pump (not shown) is provided midway along the radiator pipe 47.

[0049] A cooling water pump constituting the first cooling system 43 discharges cooling water stored in a cooling water tank 44 and supplies the cooling water to a cooling water inlet 33A of the battery module 33 through a first refrigerant pipe 45. The cooling water supplied from the refrigerant inlet 33A to the water jacket of the battery module 33 cools the battery module 33, and then flows back to the cooling water tank 44 from the refrigerant outlet 33B through the first refrigerant pipe 45. Meanwhile, the cooling water stored in the cooling water tank 44 is supplied to the left radiator 46 by a circulation pump, and flows back to the cooling water tank 44 after having dissipated heat in the left radiator 46. In this way, when the dump truck 1 is in operation, the multiple battery modules 33 constituting the battery device 26 are cooled by the first cooling system 43.

[0050] 6 to 9 , the first refrigerant pipe 45 is configured by an assembly of multiple pipes. Specifically, the first refrigerant pipe 45 is configured by three supply-side pipes 45A, 45C, and 45E and three discharge-side pipes 45B, 45D, and 45F. One end (front end) of the supply-side pipe 45A is connected to the cooling water tank 44. The other end (rear end) of the supply-side pipe 45A is connected to the cooling water tank 44. The other end (rear end) of the supply-side pipe 45A is connected to the cooling water tank 44. The other end of the discharge-side pipe 45B is connected to the cooling water tank 44. The other end of the discharge-side pipe 45B is connected to the cooling water tank 44.

[0051] One end of the supply-side pipe 45C is connected to the cooling water tank 44. The other end of the supply-side pipe 45C is connected to the refrigerant inlet ports 33A of the eight battery modules 33 that are arranged second and third from the back among the plurality of battery modules 33. One end of the discharge-side pipe 45D is connected to the cooling water tank 44. The other end of the discharge-side pipe 45D is connected to the refrigerant outlet ports 33B of the eight battery modules 33 that are arranged second and third from the back among the plurality of battery modules 33.

[0052] One end of the supply-side pipe 45E is connected to the cooling water tank 44. The other end of the supply-side pipe 45E is connected to the refrigerant inlet ports 33A of the eight battery modules 33 that are arranged fourth and fifth from the back among the plurality of battery modules 33. One end of the discharge-side pipe 45F is connected to the cooling water tank 44. The other end of the discharge-side pipe 45F is connected to the refrigerant outlet ports 33B of the eight battery modules 33 that are arranged fourth and fifth from the back among the plurality of battery modules 33.

[0053] As a result, the cooling water stored in the cooling water tank 44 is supplied to the refrigerant inlet 33A of the battery module 33 through the supply-side pipes 45A, 45C, and 45E, and cools the battery module 33 while flowing through the water jacket. After cooling the battery module 33, the cooling water returns to the cooling water tank 44 through the discharge-side pipes 45B, 45D, and 45F from the refrigerant outlet 33B of the battery module 33. The cooling water that has returned to the cooling water tank 44 has its heat dissipated by the left radiator 46 and is then supplied again to the battery module 33.

[0054] Here, intermediate portions of the supply-side pipes 45A, 45C, and 45E and the discharge-side pipes 45B, 45D, and 45F that constitute the first refrigerant pipeline 45 are housed in a refrigerant pipeline housing 32 provided inside the first support frame 28 that constitutes the battery frame 27. The supply-side pipes 45A, 45C, and 45E and the discharge-side pipes 45B, 45D, and 45F have intermediate portions that are bent in an inverted L shape when viewed from above. One ends of the supply-side pipes 45A, 45C, and 45E and the discharge-side pipes 45B, 45D, and 45F extend from the coolant tank 44 into the refrigerant pipeline housing 32 through pipe insertion holes 28M formed in the front side plate 28F of the first support frame 28 (frame main body 28A). The other ends of the supply side pipes 45A, 45C, 45E and the discharge side pipes 45B, 45D, 45F bend to the left within the refrigerant pipe line accommodating section 32 and extend to the outside of the refrigerant pipe line accommodating section 32 through pipe insertion holes 28N formed in the left side plate 28H of the first support frame 28 (frame main body 28A).

[0055] The supply-side pipes 45A, 45C, 45E and the discharge-side pipes 45B, 45D, 45F that constitute the first refrigerant pipeline 45 are attached to the first support frame 28 in a state where their intermediate portions are inserted through a pipe insertion hole 28M provided in the front plate 28F of the first support frame 28 and a pipe insertion hole 28N provided in the left plate 28H of the first support frame 28. As a result, the supply-side pipes 45A, 45C, 45E and the discharge-side pipes 45B, 45D, 45F are compactly housed in the refrigerant pipeline housing 32 surrounded by the front plate 28F, rear plate 28G, left plate 28H, and right plate 28J of the first support frame 28 in a state where they are arranged in parallel in the horizontal direction.

[0056] The second cooling system 48 cools the electrical devices arranged behind the battery device 26, such as the converter 34, the reactor 35, the hydraulic pump drive motor 36, and the pump drive inverter 37. The second cooling system 48 includes a cooling water tank 49, a cooling water pump (not shown), a second refrigerant line 50, and a right radiator 51.

[0057] The cooling water tank 49 is attached to the front end of the body frame 5 adjacent to the cooling water tank 44 that constitutes the first cooling system 43. The cooling water tank 49 stores cooling water to be supplied to the converter 34, the reactor 35, the hydraulic pump drive motor 36, and the pump drive inverter 37. The converter 34, the reactor 35, the hydraulic pump drive motor 36, and the pump drive inverter 37 are connected to the cooling water tank 49 via second refrigerant pipes 50. The right radiator 51 is disposed adjacent to the right side of the building 21 and below the deck 22. The cooling water tank 49 and the right radiator 51 are connected via a radiator pipe 52, and a circulation pump (not shown) is provided in the middle of the radiator pipe 52.

[0058] A cooling water pump constituting the second cooling system 48 discharges cooling water stored in a cooling water tank 49. This cooling water is supplied to the converter 34, the reactor 35, the hydraulic pump drive motor 36, and the pump drive inverter 37 through a second refrigerant pipe 50, cools these, and then returns to the cooling water tank 49 through the second refrigerant pipe 50. Meanwhile, the cooling water stored in the cooling water tank 49 is supplied to the right radiator 51 by a circulation pump, and returns to the cooling water tank 49 after having dissipated heat in the right radiator 51. In this way, when the dump truck 1 is in operation, the converter 34, the reactor 35, the hydraulic pump drive motor 36, and the pump drive inverter 37, which are arranged behind the battery device 26, are cooled by the second cooling system 48.

[0059] The second refrigerant line 50 is composed of an assembly of multiple pipes. Specifically, the second refrigerant line 50 is composed of three supply-side pipes 50A, 50C, and 50E and three discharge-side pipes 50B, 50D, and 50F. One end (front end) of the supply-side pipe 50A is connected to the cooling water tank 49. The other end (rear end) of the supply-side pipe 50A is connected to the refrigerant inlet 35A of the reactor 35 (water jacket). One end of the discharge-side pipe 50B is connected to the cooling water tank 49. The other end of the discharge-side pipe 50B is connected to the refrigerant outlet 35B of the reactor 35.

[0060] One end of the supply-side pipe 50C is connected to the cooling water tank 49. The other end of the supply-side pipe 50C is connected to the refrigerant inlet 36A of the hydraulic pump drive motor 36 and the refrigerant inlet 37A of the pump drive inverter 37. One end of the discharge-side pipe 50D is connected to the cooling water tank 49. The other end of the discharge-side pipe 50D is connected to the refrigerant outlet 36B of the hydraulic pump drive motor 36 and the refrigerant outlet 37B of the pump drive inverter 37. One end of the supply-side pipe 50E is connected to the cooling water tank 49. The other end of the supply-side pipe 50E is connected to the refrigerant inlet 34A of the converter 34. One end of the discharge-side pipe 50F is connected to the cooling water tank 49. The other end of the discharge-side pipe 50F is connected to the refrigerant outlet 37B of the converter 34.

[0061] As a result, the cooling water stored in the cooling water tank 49 is supplied through supply-side pipes 50A, 50C, and 50E to the reactor 35, the hydraulic pump drive motor 36, the pump drive inverter 37, and the refrigerant inlet ports 35A, 36A, 37A, and 34A of the converter 34. The cooling water cools the reactor 35, the hydraulic pump drive motor 36, the pump drive inverter 37, and the water jackets of the converter 34 while flowing therethrough, and then returns to the cooling water tank 49 from the refrigerant outlet ports 35B, 36B, 37B, and 34B through discharge-side pipes 50B, 50D, and 50F. The cooling water returned to the cooling water tank 49 has its heat dissipated by the right radiator 51 and is then supplied again to the reactor 35, the hydraulic pump drive motor 36, the pump drive inverter 37, and the converter 34.

[0062] Here, the intermediate portions of the supply-side pipes 50A, 50C, and 50E and the discharge-side pipes 50B, 50D, and 50F that constitute the second refrigerant pipeline 50 are housed in the refrigerant pipeline housing 32 of the battery frame 27 (first support frame 28), similar to the first refrigerant pipeline 45. The intermediate portions of the supply-side pipes 50A, 50C, and 50E and the discharge-side pipes 50B, 50D, and 50F are bent in an L-shape when viewed from above. One ends of the supply-side pipes 50A, 50C, and 50E and the discharge-side pipes 50B, 50D, and 50F extend from the coolant tank 49 into the refrigerant pipeline housing 32 through pipe insertion holes 28M formed in the front side plate 28F of the first support frame 28 (frame main body 28A). The other ends of the supply side pipes 50A, 50C, 50E and the discharge side pipes 50B, 50D, 50F bend to the right within the refrigerant pipe line accommodating section 32 and extend to the outside of the refrigerant pipe line accommodating section 32 through pipe insertion holes 28P formed in the right side plate 28J of the first support frame 28 (frame main body 28A).

[0063] The supply-side pipes 50A, 50C, and 50E and the discharge-side pipes 50B, 50D, and 50F that constitute the second refrigerant pipeline 50 are attached to the first support frame 28 with their intermediate portions inserted through a pipe insertion hole 28M provided in a front plate 28F of the first support frame 28 and a pipe insertion hole 28P provided in a right side plate 28J of the first support frame 28. As a result, the supply-side pipes 50A, 50C, and 50E and the discharge-side pipes 50B, 50D, and 50F are arranged in parallel in the horizontal direction and compactly housed within the refrigerant pipeline housing 32 that is surrounded by the front plate 28F, rear plate 28G, left side plate 28H, and right side plate 28J of the first support frame 28. In this way, the second refrigerant pipeline 50 can be housed compactly using the battery frame 27 that aggregates the multiple battery modules 33.

[0064] The dump truck 1 according to this embodiment has the configuration described above, and the following describes the operation of transporting minerals mined in a mine using the dump truck 1.

[0065] The dump truck 1 loads minerals mined by a hydraulic excavator onto a loading platform 19 in a loading area, transports the minerals to a dumping area located away from the loading area, and dumps them. Generally, the loading and dumping areas are flat, and the dumping area is set at a higher position than the loading area. Therefore, the travel path from the loading area to the dumping area is an uphill road. When traveling on an uphill road, for example, the dump truck 1 drives the traveling electric motor 25 with power from the trolley overhead line, and when traveling on a road without a trolley overhead line, such as a flat road, the dump truck 1 drives the traveling electric motor 25 with power from the battery device 26.

[0066] First, in a loading area, the dump truck 1 loads minerals excavated by a hydraulic excavator (not shown) onto the loading platform 19. Since the loading area is usually on a flat road that does not require a large amount of power, the electric motor 25 for traveling is driven by power from the battery device 26, and the dump truck 1 travels on the flat road within the loading area.

[0067] When the dump truck 1 travels uphill from the loading area to the soil dumping area, the pantograph 42 of the current collector 40 provided at the front end of the body frame 5 is extended, and the current collector shoe 42A of the pantograph 42 is brought into sliding contact with the trolley wire installed on the uphill road. As a result, the electric motor 25 for traveling is driven by power from the trolley wire, and the dump truck 1 travels uphill toward the soil dumping area.

[0068] When the dump truck 1 traveling on an uphill road reaches the dumping area, which is a flat road, the dump truck 1 travels within the dumping area using power from the battery device 26. When the dump truck 1 reaches the dumping area, the hydraulic pump drive motor 36 drives the hydraulic pump (not shown), and the hydraulic pump discharges pressure oil to extend the hoist cylinder 20. This causes the loading platform 19 to tilt about the connecting pin 19A, enabling the minerals loaded on the loading platform 19 to be discharged into the dumping area.

[0069] After the minerals loaded on the loading platform 19 have been discharged into the dumping area, the dump truck 1 travels toward the loading area to load new minerals. Because the dumping area is located higher than the loading area, the travel route from the dumping area to the loading area is a downhill road. Because a large amount of power is not required on the downhill road, the electric motor 25 for travel is driven by power from the battery device 26, and the dump truck 1 travels downhill toward the loading area.

[0070] In this way, the dump truck 1 travels between the loading area and the dumping area while appropriately selecting the power from the trolley overhead line and the power from the battery device 26 depending on the road surface on which it is traveling. The dump truck 1 then repeats the operation of transporting the minerals loaded onto the loading platform 19 in the loading area to the dumping area and discharging them into the dumping area.

[0071] The dump truck 1 according to this embodiment includes a first refrigerant pipe 45 through which a refrigerant (cooling water) for cooling each battery module 33 of the battery system 26 flows, and a second refrigerant pipe 50 through which a refrigerant (cooling water) for cooling electrical equipment (converter 34, reactor 35, hydraulic pump drive motor 36, pump drive inverter 37) arranged behind the battery system 26 flows. A battery frame 27 constituting the battery system 26 is provided with a refrigerant pipe housing 32, which houses supply-side pipes 45A, 45C, 45E and discharge-side pipes 45B, 45D, 45F constituting the first refrigerant pipe 45, and supply-side pipes 50A, 50C, 50E and discharge-side pipes 50B, 50D, 50F constituting the second refrigerant pipe 50. In this manner, the first refrigerant pipe 45 and the second refrigerant pipe 50 can be housed compactly using the battery frame 27 to which the multiple battery modules 33 are attached. As a result, the space occupied by the first refrigerant pipe 45 and the second refrigerant pipe 50 mounted on the body frame 5 can be reduced, allowing a larger number of battery modules 33 to be mounted on the body frame 5 accordingly.

[0072] In this case, the supply-side pipes 45A, 45C, 45E and the discharge-side pipes 45B, 45D, 45F of the first refrigerant pipeline 45 and the supply-side pipes 50A, 50C, 50E and the discharge-side pipes 50B, 50D, 50F of the second refrigerant pipeline 50 are arranged in parallel in the horizontal direction and are housed in the refrigerant pipeline housing 32 surrounded by the front side plate 28F, the rear side plate 28G, the left side plate 28H, and the right side plate 28J of the first support frame 28. This reduces the vertical space required for the refrigerant pipeline housing 32, thereby minimizing the height of the entire battery device 26 and improving the stability of the dump truck 1 during travel.

[0073] Furthermore, the refrigerant pipe housing 32 is formed inside the first support frame 28, which is located at the lowest level of the battery frame 27. The first support frame 28 has a front side plate 28F, a rear side plate 28G, a left side plate 28H, and a right side plate 28J that are spaced apart and face each other horizontally, and has high rigidity. Therefore, even if pipe insertion holes 28M, 28N, and 28P are formed in the front side plate 28F, the left side plate 28H, and the right side plate 28J, respectively, to insert the multiple supply pipes and discharge pipes that make up the first refrigerant pipe 45 and the second refrigerant pipe 50, the strength of the battery frame 27 can be ensured.

[0074] Thus, the dump truck 1 according to the embodiment includes a body frame 5 to which the front wheels 3 and the rear wheels 4 are attached, an electric motor 25 that drives the rear wheels 4, a battery device 26 that is mounted on the body frame 5 and supplies power to the electric motor 25, and electrical equipment including a converter 34 that is arranged on the rear side of the battery device 26. The battery device 26 is configured to include a battery frame 27 that is supported on the body frame 5 and a plurality of battery modules 33 that are attached to the battery frame 27. A refrigerant pipe accommodating section 32 is provided to accommodate a first refrigerant pipe 45 through which a refrigerant for cooling the battery module 33 flows, and a second refrigerant pipe 50 through which a refrigerant for cooling the electrical equipment flows.The battery frame 27 has a plurality of support frame bodies (a first support frame body 28, a second support frame body 29, a third support frame body 30, and a fourth support frame body 31) stacked in multiple stages in the vertical direction, and the battery modules 33 are respectively attached to the plurality of support frame bodies, and the refrigerant pipe accommodating section 32 is provided in at least one of the plurality of support frame bodies.

[0075] According to this configuration, a plurality of battery modules 33 are attached to the battery frame 27, and the first refrigerant pipe 45 and the second refrigerant pipe 50 are housed in the refrigerant pipe housing 32 provided in the battery frame 27. This allows the first refrigerant pipe 45 and the second refrigerant pipe 50 to be housed compactly using the battery frame 27. As a result, the space occupied by the first refrigerant pipe 45 and the second refrigerant pipe 50 is reduced, and by mounting a large number of battery modules 33 on the body frame 5, the traveling distance of the dump truck 1 can be increased.

[0076] Furthermore, with this configuration, the refrigerant pipe accommodating portion 32 can be provided in the most appropriate support frame from among the first support frame 28, the second support frame 29, the third support frame 30, and the fourth support frame 31 depending on the routing paths of the first refrigerant pipe 45 and the second refrigerant pipe 50, and the first refrigerant pipe 45 and the second refrigerant pipe 50 can be accommodated in this refrigerant pipe accommodating portion 32. As a result, the degree of freedom in routing the first refrigerant pipe 45 and the second refrigerant pipe 50 can be increased.

[0077] In this embodiment, the first refrigerant pipe 45 and the second refrigerant pipe 50 are each formed by an assembly of a plurality of pipes (supply-side pipes 45A, 45C, 45E, 50A, 50C, and 50E, and discharge-side pipes 45B, 45D, 45F, 50B, 50D, and 50F), and the refrigerant pipe housing 32 accommodates the plurality of pipes (supply-side pipes 45A, 45C, 45E, 50A, 50C, and 50E, and discharge-side pipes 45B, 45D, 45F, 50B, 50D, and 50F) arranged in parallel in the horizontal direction. This configuration reduces the vertical space required for the refrigerant pipe housing 32 to accommodate the first refrigerant pipe 45 and the second refrigerant pipe 50. As a result, the overall height of the battery device 26 can be reduced, improving the stability of the dump truck 1 during travel.

[0078] In this embodiment, the lowermost support frame (first support frame 28) located at the lowermost position among the plurality of support frames constituting the battery frame 27 has a plurality of side plates (front side plate 28F, rear side plate 28G, left side plate 28H, right side plate 28J) facing each other in the horizontal direction at an interval, a lower plate 28K fixed to the lower ends of the plurality of side plates, and an upper plate 28L fixed to the upper ends of the plurality of side plates and to which the battery module 33 is attached, and the refrigerant pipe accommodating portion 32 is surrounded by the plurality of side plates. The first refrigerant line 45 and the second refrigerant line 50 are configured by an enclosed space, and the plurality of pipes (supply-side pipes 45A, 45C, 45E, 50A, 50C, 50E, and discharge-side pipes 45B, 45D, 45F, 50B, 50D, 50F) are attached to the first support frame 28 by being inserted through pipe insertion holes 28M, 28N, 28P provided in the side plates (front side plate 28F, left side plate 28H, right side plate 28J) that configure the first support frame 28.

[0079] With this configuration, the first support frame 28 has a front side plate 28F, a rear side plate 28G, a left side plate 28H, and a right side plate 28J that are spaced apart and horizontally opposed to each other, and has high rigidity. Therefore, even if pipe insertion holes 28M, 28N, and 28P are formed in the front side plate 28F, the left side plate 28H, and the right side plate 28J, respectively, to insert the multiple supply pipes and discharge pipes that make up the first refrigerant pipe line 45 and the second refrigerant pipe line 50, the strength of the battery frame 27 can be ensured.

[0080] In the embodiment, the battery frame 27 is illustrated as having support frames stacked in four levels, including a first support frame 28, a second support frame 29, a third support frame 30, and a fourth support frame 31. However, the present invention is not limited to this, and may be configured to use a battery frame having support frames stacked in two levels, three levels, five levels, or more.

[0081] Furthermore, in the embodiment, the refrigerant pipe accommodating portion 32 is provided inside the first support frame 28, which is the lowest support frame of the battery frame 27. However, the present invention is not limited to this, and the refrigerant pipe accommodating portion may be provided inside any one of the second support frame 29, the third support frame 30, and the fourth support frame 31, or inside two or more of the first support frame 28, the second support frame 29, the third support frame 30, and the fourth support frame 31.

[0082] Furthermore, in the embodiment, the battery device 26 having the battery frame 27 is mounted on the trolley-type dump truck 1 equipped with the current collector 40. However, the present invention is not limited to this, and can also be applied to a dump truck that does not have the current collector 40, for example.

[0083] REFERENCE SIGNS LIST 1 Dump truck 3 Front wheels 4 Rear wheels 5 Vehicle frame 25 Electric motor 26 Battery device 27 Battery frame 28 First support frame (lowest support frame) 29 Second support frame 30 Third support frame 31 Fourth support frame 32 Refrigerant pipe accommodating section 33 Battery module 45 First refrigerant pipe 45A, 45C, 45E, 50A, 50C, 50E Supply side pipe 45B, 45D, 45F, 50B, 50D, 50F Discharge side pipe 50 Second refrigerant pipe

Claims

1. A dump truck comprising: a body frame to which wheels are attached; an electric motor for driving the wheels; a battery device mounted on the body frame and supplying power to the electric motor; and electrical equipment including a converter arranged to the rear of the battery device; wherein the battery device includes a battery frame supported by the body frame and a battery module attached to the battery frame, the battery frame is provided with a refrigerant pipe accommodating section for accommodating a first refrigerant pipe through which a refrigerant for cooling the battery module flows and a second refrigerant pipe through which a refrigerant for cooling the electrical equipment flows, the battery frame has a plurality of support frame bodies stacked in multiple stages in the vertical direction, the battery modules are attached to the plurality of support frame bodies respectively, and the refrigerant pipe accommodating section is provided in at least one of the plurality of support frame bodies.

2. The dump truck described in claim 1, characterized in that the first refrigerant pipeline and the second refrigerant pipeline are each composed of an assembly of a plurality of pipes, and the refrigerant pipeline accommodating section accommodates the plurality of pipes arranged in parallel in the horizontal direction.

3. The dump truck described in claim 2, characterized in that the lowest support frame body, which is located at the lowest level among the multiple support frame bodies that constitute the battery frame, has multiple side plates that are horizontally opposed to each other with a gap between them, a lower plate fixed to the lower ends of the multiple side plates, and an upper plate that is fixed to the upper ends of the multiple side plates and to which the battery module is attached, the refrigerant pipe accommodating section is formed by a space surrounded by the multiple side plates, and the multiple pipes that constitute the first refrigerant pipe line and the second refrigerant pipe line are attached to the lowest support frame body by being inserted into pipe insertion holes provided in the side plates that constitute the lowest support frame body.

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