Dump truck

Abstract

To make a converter, which is mounted on a vehicle body frame, lightweight.SOLUTION: A dump truck 1 includes a vehicle body frame 5 to which front wheels 3 and rear wheels 4 are attached, a battery 24 mounted on the vehicle body frame 5, an electric motor 23 that drives the front wheels 3 or rear wheels 4 when electric power is supplied from the battery 24, and a converter 29 that is mounted on the vehicle body frame 5 and converts the voltage of the electric power supplied from the battery 24 to the electric motor 23. A converter frame 36 is attached to the flank of a right frame 7 included in the vehicle body frame 5 and located between the front wheels 3 and rear wheels 4. The converter 29 is supported by a converter frame 36. In this case, the converter 29 is attached to the flank of the vehicle body frame 5 while being supported by the converter frame 36. This obviates the need for augmenting the rigidity of the converter 29 itself. Eventually, the converter 29 can be made lightweight.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Generally, in open-cut mining sites, mines, etc., hydraulic excavators are used to excavate crushed material such as minerals, and large amounts of the excavated crushed material are loaded onto dump trucks and transported to an unloading area such as a port. Dump trucks 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 with the rear side of the vehicle body as a fulcrum.

[0003] A dump truck is equipped with an electric motor for driving the wheels, a battery for storing the power to drive the electric motor for driving, and a converter for converting the power supplied to the electric motor for driving.Here, in the prior art, a configuration is disclosed in which a cabinet constituting the outer shell of the converter is hung and attached to the side wall of the vehicle body (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] CN 212649358U Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, the converter cabinet is suspended from the side wall of the vehicle body, so the rigidity of the cabinet needs to be increased compared to a configuration in which the cabinet is supported from below. This causes a problem of an increase in the weight of the entire converter including the cabinet. Furthermore, when a load acts on the vehicle body from the wheels due to unevenness of the road surface while the dump truck is traveling, the vehicle body is deformed in a twisted manner, and this deformation of the vehicle body causes a load to act on the cabinet suspended from the side wall of the vehicle body. Therefore, there is a problem of an increase in the weight of the entire converter by increasing the rigidity of the cabinet.

[0006] The present invention has been made in consideration of the problems with the conventional technology described above, and an object of the present invention is to provide a dump truck in which a converter mounted on a vehicle frame is positioned so as to reduce its weight. [Means for solving the problem]

[0007] The present invention relates to a dump truck comprising a body frame to which front and rear wheels are attached, a battery mounted on the body frame, an electric motor that drives the front or rear wheels by receiving power from the battery, and a converter mounted on the body frame and converts the power supplied to the electric motor, wherein a converter frame is attached to the side of the body frame between the front and rear wheels, and the converter is supported by the converter frame. Effect of the Invention

[0008] According to the present invention, the converter is attached to the side of the vehicle body frame while being supported by the converter frame, so there is no need to increase the rigidity of the converter itself, and the converter can be made lighter. [Brief description of the drawings]

[0009] [Figure 1]1 is a right side view showing a dump truck to which an embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a perspective view showing the body frame alone. [Diagram 3] FIG. 2 is a plan view showing electrical equipment mounted on the body frame. [Figure 4] 2 is a perspective view showing a converter frame and a converter attached to a vehicle body frame. FIG. [Diagram 5] FIG. 2 is a perspective view showing a converter alone. [Figure 6] FIG. 2 is a perspective view showing the converter frame alone. [Figure 7] 2 is an enlarged right side view showing the body frame, the converter frame, and the converter in FIG. 1. [Figure 8] 8 is a plan view of the body frame, the converter frame, and the converter in FIG. 7, as viewed from above. [Figure 9] 9 is a cross-sectional view of the body frame, the converter frame, and the converter as viewed from the direction of arrows IX-IX in FIG. 8. [Figure 10] 5 is a perspective view of a state in which a mudguard member is attached to a converter frame, taken from a position similar to that of FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a dump truck according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the embodiment, the dump truck will be described assuming that the traveling direction is the front-rear direction and the direction perpendicular to the traveling direction is the left-right direction.

[0011] 1, the dump truck 1 includes a self-propelled vehicle body 2 equipped with left and right front wheels 3 and left and right rear wheels 4, and a loading platform 17 (described later) mounted on the vehicle body 2 so as to be tiltable (raised and lowered), and transports crushed material such as minerals excavated by a hydraulic excavator or the like (not shown) by loading it onto the loading platform 17. The vehicle body 2 of the dump truck 1 includes a vehicle frame 5, a deck 20, a cab 21, etc. (described later).

[0012] The left and right front wheels 3 are rotatably provided at the front of the vehicle body 2 and constitute steered wheels. The front wheels 3 are supported by a vehicle body frame 5 via a front-wheel side suspension (not shown), which reduces vibrations transmitted from the front wheels 3 to the vehicle body 2. The left and right rear wheels 4 are rotatably provided at the rear of the vehicle body 2 and are rotationally driven by a running device equipped with an electric motor 23, which will be described later. The running device for the rear wheels 4 is attached to the vehicle body frame 5 via a rear-wheel side suspension (not shown), which reduces vibrations transmitted from the rear wheels 4 to the vehicle body 2.

[0013] The body frame 5 is the base of the body 2 and is a strong supporting structure extending in the front-rear direction. As shown in Fig. 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 vehicle body frame 5. The left frame 6 is configured to include left and right side plates 6A opposing each other in the left-right direction, an upper plate 10 closing the upper ends of the left and right side plates 6A, and a lower plate 11 connecting the lower ends of the left and right side plates 6A, and has a box structure with a rectangular cross section extending in the front-rear direction. The right frame 7 is disposed on the right side of the vehicle body frame 5. The right frame 7 is configured to include left and right side plates 7A opposing each other in the left-right direction, an upper plate 10 closing the upper ends of the left and right side plates 7A, and a lower plate 11 connecting the lower ends of the left and right side plates 7A, and has a box structure with a rectangular cross section extending in the front-rear direction.

[0015] The left and right frames 6 and 7 extend in the front-rear direction while opposing each other with a gap in the left-right direction, and the left-right gap between the left and right frames 6 and 7 is set larger on the front side than on the rear side of the body frame 5. As a result, as shown in Fig. 3, the left-right width dimension A of the front end of the body frame 5 is larger than the left-right width dimension B of the rear end (A>B). In addition, 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, and these left rear end bracket 6B and right rear end bracket 7B face each other in the left-right direction.

[0016] The front frame 8 is disposed on the front side of the vehicle 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 between the front end of the left frame 6 and the front end of the right frame 7. The rear frame 9 is disposed on the rear side of the vehicle 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 between the rear end of the left frame 6 and 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 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 between 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 provided at a position toward the front from the center in the fore-and-aft direction of the body frame 5, 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 20 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 at a position rearward from the central portion 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 constituting the left frame 6, and the right cylinder bracket 15 protrudes downward from the lower plate 11 constituting 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 a hoist cylinder 18 (described later) are attached to both left-right ends of the cylinder support shaft 16.

[0021] The loading platform (vessel) 17 is mounted on the vehicle body frame 5 so as to be tiltable (able to rise and fall). The loading platform 17 is formed as a large container with a bottom for carrying crushed material such as minerals excavated by a hydraulic excavator or the like. The rear bottom of the loading platform 17 is 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 17A so as to be tiltable. A eaves portion 17B is integrally provided on the front side of the loading platform 17, extending horizontally from the top toward the front. The eaves portion 17B of the loading platform 17 extends to the front end side of the deck 20 while covering the cab 21 from above.

[0022] The hoist cylinders 18 are provided in pairs in the left-right direction between the body frame 5 and the loading platform 17 (only the right side is shown). The hoist cylinders 18 are, for example, hydraulic cylinders, and tilt the front side of the loading platform 17 up and down relative to the body frame 5. One end side (lower end side) of the hoist cylinders 18 is attached to the cylinder support shaft 16, and the other end side (upper end side) of the hoist cylinders 18 is attached to the underside of the loading platform 17. Therefore, by extending the hoist cylinders 18, the front side (eaves portion 17B side) of the loading platform 17 is lifted upward around the connecting pin 17A, and transported goods loaded on the loading platform 17 can be discharged rearward.

[0023] The building 19 is provided on the front end side of the body frame 5. The building 19 is formed in a frame shape surrounded by left and right side panels and a front panel (grill), and a battery 24 and the like are housed inside the building 19. The building 19, together with the left support pillar 12 and right support pillar 13 of the body frame 5, also plays a role in supporting the deck 20 and the like from below.

[0024] The deck 20 is located forward of the loading platform 17 and provided above the building 19. The deck 20 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 19, etc. A cab 21, a control cabinet 28 (described later), etc. are mounted on the deck 20, and the upper surface of the deck 20 forms a flat passageway surface along which the operator and others pass.

[0025] The cab 21 is provided on the upper left side of the deck 20 and defines a cab for an operator. A driver's seat, a steering wheel, a start switch, an accelerator pedal, a brake pedal, and operation levers (none of which are shown) are provided in the cab 21.

[0026] Next, the arrangement of the electric motor 23, the battery 24, the converter 29, etc. mounted on the vehicle body 2 will be described with reference to FIG.

[0027] A rear wheel axle housing 22 is provided on the rear side of the body frame 5. The axle housing 22 is made of a cylindrical body extending in the left-right direction, and is attached to the body frame 5 via a rear wheel suspension device (not shown). An electric motor 23 for driving is provided on each of the left and right sides of the axle housing 22, and rotation of the left and right electric motors 23 is transmitted to the left and right rear wheels 4 via a reduction mechanism (not shown).

[0028] The battery 24 is located below the deck 20 and mounted on the front side of the body frame 5. The battery 24 is disposed between the left frame 6 and the right frame 7, and is attached to the body frame 5 via an anti-vibration mount or the like (not shown). The left and right electric motors 23 drive the left and right rear wheels 4 by receiving power from the battery 24.

[0029] The reactor 25 is located below the deck 20 and mounted on the vehicle body frame 5. The reactor 25 is electrically connected between the battery 24 and a converter 29 (described later), and includes an LC filter for removing high-frequency noise, a circuit breaker for protecting the battery 24, and the like. The reactor 25 is adjacent to the rear side of the battery 24, and is disposed between the left frame 6 and the right frame 7 and attached to the vehicle body frame 5.

[0030] The hydraulic pump drive motor 26 is located rearward of the reactor 25 and is mounted on the vehicle body frame 5. The hydraulic pump 27 is located rearward of the hydraulic pump drive motor 26 and is mounted on the vehicle body frame 5. The hydraulic pump drive motor 26 is an electric motor, and drives the hydraulic pump 27 with electric power from the battery 24. As a result, hydraulic oil is supplied from the hydraulic pump 27 to hydraulic equipment such as the hoist cylinder 18.

[0031] The battery 24, the reactor 25, the hydraulic pump drive motor 26, and the hydraulic pump 27 are disposed between the left frame 6 and the right frame 7, and are housed inside the front openings 10A, 11A of the upper plate 10 and the lower plate 11. In this manner, the battery 24, the reactor 25, the hydraulic pump drive motor 26, and the hydraulic pump 27, which are heavy objects, are disposed in the center of the vehicle body frame 5 in the left-right direction, thereby improving the stability of the dump truck 1 during traveling.

[0032] The control cabinet 28 is mounted on the upper side of the deck 20, aligned to the right of the cab 21. The control cabinet 28 is configured to include an inverter that controls the electric motor 23 for traveling, and the like.

[0033] Converter 29 is located between the right front wheel 3 and rear wheel 4 and is mounted on the body frame 5. Converter 29 is a DC / DC converter, and includes a cabinet 30 forming an outer shell, and various electric devices housed within the cabinet 30. Converter 29 is attached to the body frame 5 via a converter frame 36 (described below) that is attached to the right frame 7 of the body frame 5, and converts the voltage of DC power supplied from the battery 24 to the electric motor 23.

[0034] As shown in FIG. 5, the converter 29 has a cabinet 30 in the shape of a rectangular parallelepiped that is long in the left-right direction. The cabinet 30 is surrounded by a front plate 30A facing the right front wheel 3, a rear plate 30B facing the right rear wheel 4, a left plate 30C, a right plate 30D, an upper plate 30E, and a lower plate 30F. The left plate 30C and the right plate 30D face each other in the left-right direction, and the left plate 30C faces the vehicle body frame 5 (right frame 7). The upper plate 30E closes the upper ends of the front plate 30A, the rear plate 30B, the left plate 30C, and the right plate 30D. The lower plate 30F closes the lower ends of the front plate 30A, the rear plate 30B, the left plate 30C, and the right plate 30D.

[0035] The top plate 30E of the cabinet 30 is provided with two left upper brackets 31 arranged near the corner where it intersects with the left side plate 30C, and two right upper brackets 32 arranged near the corner where it intersects with the right side plate 30D. The two left upper brackets 31 each have a protruding plate 31A protruding upward from the top plate 30E, and these two protruding plates 31A face each other at a fixed interval in the front-to-rear direction. The two right upper brackets 32 each also have a protruding plate 32A protruding upward from the top plate 30E and facing each other at a fixed interval in the front-to-rear direction.

[0036] The bottom plate 30F of the cabinet 30 is provided with three left-lower vibration-isolating members 33, three right-lower vibration-isolating members 34, and three middle-lower vibration-isolating members 35. The left-lower vibration-isolating member 33 is disposed near the corner where the bottom plate 30F and the left side plate 30C intersect. The right-lower vibration-isolating member 34 is disposed near the corner where the bottom plate 30F and the right side plate 30D intersect. The middle-lower vibration-isolating member 35 is disposed in the middle of the bottom plate 30F in the length direction (left-right direction). These vibration-isolating members 33, 34, 35 are formed into a rectangular plate shape using an elastic body such as rubber, and are each fixed to the bottom plate 30F.

[0037] The converter frame 36 is located between the right front wheel 3 and rear wheel 4 and is attached to the right side plate 7A of the right frame 7. The converter frame 36 is attached integrally with the converter 29 to the body frame 5 in a state in which the converter frame 36 supports the converter 29. As shown in Figures 4 and 6, the converter frame 36 is configured to include a frame-shaped frame main body 37 that surrounds the converter 29, and a front reinforcing member 48 and a rear reinforcing member 49 that reinforce the frame main body 37.

[0038] The frame body 37 has a framework structure surrounding the cabinet 30 of the converter 29 from the outside. The frame body 37 has a rectangular lower frame portion 38 that is long in the left-right direction, a left front leg portion 39 erected at the left front corner of the lower frame portion 38, a left rear leg portion 40 erected at the left rear corner of the lower frame portion 38, a right front leg portion 41 erected at the right front corner of the lower frame portion 38, a right rear leg portion 42 erected at the right rear corner of the lower frame portion 38, and a rectangular upper frame portion 43 that connects the upper ends of these four legs 39, 40, 41, 42. Here, the left front leg portion 39 and the left rear leg portion 40 are the vehicle body side legs that are arranged closest to the vehicle body frame 5 among the four legs 39, 40, 41, 42, and a vehicle body frame attachment portion 44 that is attached to the vehicle body frame 5 is fixed to these left front leg portion 39 and left rear leg portion 40.

[0039] The lower frame portion 38 has a front frame member 38A located at the front side in the front-rear direction and extending in the left-right direction, a rear frame member 38B located at the rear side in the front-rear direction and extending in the left-right direction, a left frame member 38C connecting the left ends of the front frame member 38A and the rear frame member 38B, a right frame member 38D connecting the right ends of the front frame member 38A and the rear frame member 38B, and an intermediate frame member 38E connecting the intermediate portions in the length direction of the front frame member 38A and the rear frame member 38B. With the converter 29 supported within the converter frame 36, the left lower vibration isolating member 33 attached to the cabinet 30 abuts against the left frame member 38C, the right lower vibration isolating member 34 abuts against the right frame member 38D, and the intermediate lower vibration isolating member 35 abuts against the intermediate frame member 38E (see FIG. 8).

[0040] A front mounting plate 39A is fixed to the upper end of the left front leg 39, facing the right frame 7 of the body frame 5 in the left-right direction. The front mounting plate 39A is attached to the right side plate 7A of the right frame 7 using fasteners 39B. A rear mounting plate 40A is fixed to the upper end of the left rear leg 40, facing the right frame 7 of the body frame 5 in the left-right direction. The rear mounting plate 40A is attached to the right side plate 7A of the right frame 7 using fasteners 40B. The left front leg 39 and the left rear leg 40 are connected at their intermediate portions in the longitudinal direction (vertical direction) by a body frame mounting portion 44.

[0041] The upper frame 43 is fixed to the upper ends of the left front leg 39, the left hind leg 40, the right front leg 41, and the right hind leg 42. The upper frame 43 is formed in a rectangular frame shape by a front beam 43A connecting the left front leg 39 and the right front leg 41, a rear beam 43B connecting the left hind leg 40 and the right hind leg 42, and a left cross beam 43C and a right cross beam 43D connecting the front beam 43A and the rear beam 43B with a gap in the left-right direction. The left cross beam 43C is disposed near the left front leg 39 and the left hind leg 40, and the right cross beam 43D is disposed near the right front leg 41 and the right hind leg 42.

[0042] The left front leg 39 and the left rear leg 40 constitute the vehicle body side legs that are disposed closest to the vehicle body frame 5 among the four legs 39 to 42. A vehicle body frame attachment part 44 is fixed to the vertical middle part of the left front leg 39 and the left rear leg 40. The vehicle body frame attachment part 44 has a frame body 44A with a rectangular cross section that protrudes leftward from the left front leg 39 and the left rear leg 40. The protruding end face of the frame body 44A faces the right cylinder bracket 15 that constitutes the vehicle body frame 5, and is attached to the right cylinder bracket 15 via a vibration-proof mount 45 described later.

[0043] A plurality of (for example, three) anti-vibration mounts 45 are provided on the frame body 44A of the body frame mounting portion 44. These three anti-vibration mounts 45 are formed using an elastic body such as rubber, and constitute anti-vibration members provided between the body frame 5 and the converter frame 36. The anti-vibration mounts 45 are disposed adjacent to the frame body 44A of the body frame mounting portion 44 in the front-rear direction, and are provided between the right cylinder bracket 15 of the body frame 5 and the body frame mounting portion 44.

[0044] When mounting the converter frame 36 to the body frame 5, as shown in Figures 7 to 9, the front mounting plate 39A of the left front leg 39 and the rear mounting plate 40A of the left rear leg 40 are mounted to the side plate 7A of the right frame 7 using fasteners 39B, 40B, respectively, and the body frame mounting part 44 is mounted to the right cylinder bracket 15 via three vibration-proof mounts 45 provided on the frame body 44A. In this way, by providing three vibration-proof mounts 45 between the right cylinder bracket 15 of the body frame 5 and the body frame mounting part 44, horizontal vibration of the converter frame 36 relative to the body frame 5 is suppressed.

[0045] The upper left vibration isolating member 46 and the upper right vibration isolating member 47 are provided on the upper frame portion 43. The upper left vibration isolating member 46 and the upper right vibration isolating member, together with the lower left vibration isolating member 33, the lower right vibration isolating member 34, and the lower middle vibration isolating member 35 provided on the cabinet 30 of the converter 29, constitute vibration isolating members provided between the converter frame 36 and the converter 29. The upper left vibration isolating member 46 includes a pair (two pieces) of brackets 46A protruding to the right side (right cross beam 43D side) from the left cross beam 43C of the upper frame portion 43, and an elastic body 46B such as rubber fixed to each of the pair of brackets 46A. The upper right vibration isolating member 47 includes a pair of brackets 47A protruding to the left side (left cross beam 43C side) from the right cross beam 43D of the upper frame portion 43, and an elastic body 47B such as rubber fixed to each of the pair of brackets 47A.

[0046] 8, with the converter 29 attached inside the converter frame 36, elastic bodies 46B are disposed between the pair of brackets 46A of the upper left vibration isolating member 46 and the protruding plates 31A of the two upper left brackets 31 provided on the cabinet 30 of the converter 29. In addition, elastic bodies 47B are disposed between the pair of brackets 47A of the upper right vibration isolating member 47 and the protruding plates 32A of the two upper right brackets 32 provided on the cabinet 30.

[0047] In this way, when the converter 29 is supported inside the converter frame 36, the lower left vibration isolating member 33, the lower right vibration isolating member 34, and the lower middle vibration isolating member 35 are provided between the lower frame part 38 of the converter frame 36 and the lower face plate 30F of the cabinet 30, and the upper left vibration isolating member 46 and the upper right vibration isolating member 47 are provided between the upper frame part 43 of the converter frame 36 and the upper face plate 30E of the cabinet 30. This suppresses vertical vibration of the converter 29 relative to the converter frame 36. In addition, the upper left vibration isolating member 46 and the upper right vibration isolating member 47 position the converter 29 in the horizontal direction relative to the converter frame 36.

[0048] The front reinforcing member 48 and the rear reinforcing member 49 are detachably provided on the frame main body 37 except for the portion attached to the vehicle frame 5, and reinforce the frame main body 37. Specifically, the front reinforcing member 48 includes a first arm 48A, a second arm 48B, a third arm 48C, and a fourth arm 48D.

[0049] The first arm 48A is provided between the lower frame portion 38 and the left front leg portion 39 of the frame main body 37. Specifically, one end of the first arm 48A is fixed to the left front leg portion 39 near the vehicle body frame mounting portion 44, and the other end is fixed to the front frame member 38A of the lower frame portion 38, and extends obliquely downward from the left front leg portion 39 toward the lower frame portion 38. The second arm 48B is provided between the upper frame portion 43 and the left front leg portion 39. Specifically, one end of the second arm 48B is fixed to the left front leg portion 39 near the vehicle body frame mounting portion 44, and the other end is fixed to the front beam 43A of the upper frame portion 43, and extends obliquely upward from the left front leg portion 39 toward the upper frame portion 43.

[0050] The third arm 48C is provided between the lower frame portion 38 and the upper frame portion 43. Specifically, one end of the third arm 48C is fixed to the front frame member 38A of the lower frame portion 38, and the other end is fixed to the front beam 43A of the upper frame portion 43, and extends vertically between the lower frame portion 38 and the upper frame portion 43. As a result, the first arm 48A, the second arm 48B, and the third arm 48C are connected in a triangular frame shape, and the distance between the first arm 48A and the second arm 48B increases from the left front leg portion 39 toward the third arm 48C. The fourth arm 48D is provided between the lower frame portion 38 and the upper frame portion 43. Specifically, the fourth arm 48D has one end fixed to the front frame member 38A of the lower frame portion 38 and the other end fixed to the front beam 43A of the upper frame portion 43 near the connection portion with the right front leg portion 41, and extends diagonally upward from the lower frame portion 38 toward the upper frame portion 43.

[0051] The rear reinforcing member 49, like the front reinforcing member 48, is configured to include a first arm 49A provided between the lower frame portion 38 of the frame main body 37 and the left rear leg portion 40, a second arm 49B provided between the upper frame portion 43 and the left rear leg portion 40, and a third arm 49C and a fourth arm 49D provided between the lower frame portion 38 and the upper frame portion 43. The first arm 49A has one end fixed to the left rear leg portion 40 near the vehicle body frame mounting portion 44 and the other end fixed to the front frame member 38A of the lower frame portion 38, and extends obliquely downward from the left rear leg portion 40 toward the lower frame portion 38. The second arm 49B has one end fixed to the left rear leg portion 40 near the vehicle body frame mounting portion 44 and the other end fixed to the rear beam 43B of the upper frame portion 43, and extends obliquely upward from the left rear leg portion 40 toward the upper frame portion 43.

[0052] The third arm 49C has one end fixed to the rear frame member 38B of the lower frame portion 38 and the other end fixed to the rear beam 43B of the upper frame portion 43, and extends vertically between the lower frame portion 38 and the upper frame portion 43. As a result, the first arm 49A, the second arm 49B, and the third arm 49C are connected in a triangular frame shape, and the distance between the first arm 49A and the second arm 49B increases from the left rear leg portion 40 toward the third arm 49C. The fourth arm 49D has one end fixed to the rear frame member 38B of the lower frame portion 38 and the other end fixed to the rear beam 43B of the upper frame portion 43 near the connection portion with the right rear leg portion 42, and extends obliquely upward from the lower frame portion 38 toward the upper frame portion 43.

[0053] In this way, the distance between the first arm 48A and the second arm 48B constituting the front reinforcement member 48 increases from the left front leg 39 to which the body frame mounting portion 44 is fixed toward the third arm 48C. Similarly, the distance between the first arm 49A and the second arm 49B constituting the rear reinforcement member 49 increases from the left rear leg 40 to which the body frame mounting portion 44 is fixed toward the third arm 49C. This allows the load acting on the body frame mounting portion 44 from the body frame 5 during travel of the dump truck 1 to be efficiently transmitted to the entire converter frame 36 via the front reinforcement member 48 and the rear reinforcement member 49, thereby increasing the rigidity of the converter frame 36.

[0054] A front mudguard base 50 extending in the left-right direction while facing the right-side front wheel 3 is fixed to the front frame member 38A of the lower frame portion 38 and the front beam 43A of the upper frame portion 43 that constitute the converter frame 36. A rear mudguard base 51 extending in the left-right direction while facing the right-side rear wheel 4 is fixed to the rear frame member 38B of the lower frame portion 38 and the rear beam 43B of the upper frame portion 43.

[0055] The front mudguard member 52 is attached to the front mudguard base 50 of the converter frame 36. As shown in Fig. 10, the front mudguard member 52 is made of a plurality of (e.g., three) plates formed of an elastic material such as rubber, and is attached to the front mudguard base 50 using bolts or the like, thereby facing the front wheels 3 in the front-rear direction. With the converter 29 supported within the converter frame 36, the front mudguard member 52 is interposed between the front plate 30A of the cabinet 30 and the front wheels 3, and prevents mud and the like scattered from the front wheels 3 when the dump truck 1 is traveling from adhering to the converter 29.

[0056] In addition, a rear mudguard member (not shown) similar to the front mudguard member 52 is attached to the rear mudguard base 51 of the converter frame 36 in a state facing the right rear wheel 4 in the front-rear direction. This rear mudguard member is interposed between the rear plate 30B of the cabinet 30 and the rear wheel 4 in a state in which the converter 29 is supported within the converter frame 36, and prevents mud and the like scattered from the rear wheel 4 when the dump truck 1 is traveling from adhering to the converter 29.

[0057] The hydraulic oil tank 53 is attached to the left frame 6, which is the opposite side of the right frame 7 to which the converter frame 36 is attached, out of the left frame 6 and right frame 7 that constitute the body frame 5 (see FIG. 3). The hydraulic oil tank 53 is located between the left front wheel 3 and rear wheel 4 and attached to the left side plate 6A of the left frame 6, and stores hydraulic oil to be supplied to hydraulic equipment such as the hoist cylinder 18 mounted on the body frame 5.

[0058] In this way, the converter frame 36 that supports the converter 29 and is located between the right-side front wheel 3 and rear wheel 4 is attached to the right frame 7, which is one of the left frame 6 and right frame 7 that make up the body frame 5, and the hydraulic oil tank 53 that stores hydraulic oil and is located between the left-side front wheel 3 and rear wheel 4 is attached to the left frame 6, which is the other. This configuration enables the body frame 5 to maintain a good weight balance in the left-right direction.

[0059] The dump truck 1 according to this embodiment has the configuration described above, and its operation will be described below.

[0060] When using the dump truck 1 to transport crushed rock excavated in a mine or the like, an operator in the cab 21 operates a start switch (not shown). As a result, the power output from the battery 24 is supplied to the left and right electric motors 23 for traveling via the control cabinet 28 in a state where the power is voltage-converted by the converter 29. The left and right rear wheels 4 are driven by the electric motor 23, and the dump truck 1 travels to the quarry.

[0061] Then, crushed stone excavated by a large hydraulic excavator or the like (not shown) is loaded onto the loading platform 17 of the dump truck 1 stopped at the stone pit. After the dump truck 1 loaded with the crushed stone travels to a collection site, the loading platform 17 is tilted by the hoist cylinder 18, and the crushed stone is discharged to the collection site.

[0062] Here, a converter frame 36 is attached to the right side plate 7A of the right frame 7 constituting the body frame 5, positioned between the right front wheel 3 and the right rear wheel 4, and the converter 29 is supported from below inside the converter frame 36 via a left lower vibration isolating member 33, a right lower vibration isolating member 34, and a middle lower vibration isolating member 35. Therefore, the rigidity of the cabinet 30 forming the outer shell of the converter 29 can be kept low, compared to a configuration in which the converter is suspended from the side wall of the body frame, for example. As a result, the weight of the converter 29 including the cabinet 30 can be reduced. Also, the workability in manufacturing the cabinet 30 can be improved.

[0063] On the other hand, the converter 29 is supported in a vibration-isolated state relative to the converter frame 36 via the lower left vibration-isolation member 33, the lower right vibration-isolation member 34, the lower middle vibration-isolation member 35, and the upper left vibration-isolation member, and an upper left vibration-isolation member 46 and an upper right vibration-isolation member 47 are provided between the upper frame part 43 of the converter frame 36 and the cabinet 30 of the converter 29. Therefore, even if vertical vibration occurs when the dump truck 1 is traveling, the vibration is prevented from being transmitted to the cabinet 30, and damage to various electrical devices housed in the cabinet 30 can be prevented, and the converter 29 can be protected.

[0064] Further, the body frame attachment portion 44 constituting the converter frame 36 is attached to the right cylinder bracket 15 of the body frame 5 via three anti-vibration mounts 45 provided on the frame 44A. As a result, horizontal vibration of the converter frame 36 relative to the body frame 5 is suppressed by the anti-vibration mounts 45. Therefore, even if a load acts on the body frame 5 from the front wheels 3 or the rear wheels 4 due to unevenness of the road surface while the dump truck 1 is traveling and the body frame 5 is deformed so as to be twisted by this load, this deformation can be absorbed (suppressed) by the anti-vibration mounts 45. As a result, the load associated with the deformation of the body frame 5 is suppressed from acting on the converter frame 36, and the rigidity of the converter frame 36 can be maintained at a good level.

[0065] Moreover, the converter frame 36 has a frame-shaped frame main body 37 that surrounds the converter 29, and a front reinforcing member 48 and a rear reinforcing member 49 that reinforce the frame main body 37, and the front reinforcing member 48 and the rear reinforcing member 49 are detachably provided to portions of the frame main body 37 excluding the portion that is attached to the body frame 5. As a result, for example, when performing maintenance on the converter 29, the converter 29 can be easily accessed by removing the front reinforcing member 48 or the rear reinforcing member 49 while leaving the converter frame 36 attached to the body frame 5.

[0066] Further, a front mudguard member 52 facing the right front wheel 3 is attached to the front frame member 38A of the lower frame portion 38 and the front beam 43A of the upper frame portion 43 constituting the converter frame 36, and a rear mudguard member (not shown) facing the right rear wheel 4 is attached to the rear frame member 38B of the lower frame portion 38 and the rear beam 43B of the upper frame portion 43. As a result, the front mudguard member 52 and the rear mudguard member prevent mud and the like scattered from the front wheels 3 or rear wheels 4 when the dump truck 1 is traveling from adhering to the converter 29, thereby protecting the converter 29.

[0067] Furthermore, a converter frame 36 that is located between the right front wheel 3 and rear wheel 4 and supports the converter 29 is attached to the right frame 7, which is one of the left frame 6 and right frame 7 that constitute the body frame 5, and a hydraulic oil tank 53 that stores hydraulic oil is attached to the left frame 6, which is the other of the left frame 6. As a result, the weight balance in the left-right direction of the body frame 5 can be maintained well, and the stability of the dump truck 1 during traveling can be improved.

[0068] Thus, the dump truck 1 according to the embodiment includes a vehicle body frame 5 to which the front wheels 3 and rear wheels 4 are attached, a battery 24 mounted on the vehicle body frame 5, an electric motor 23 that drives the front wheels 3 or the rear wheels 4 by receiving power from the battery 24, and a converter 29 mounted on the vehicle body frame 5 and converts the power supplied to the electric motor 23, and a converter frame 36 is attached to a side surface of the vehicle body frame 5 between the front wheels 3 and the rear wheels 4, and the converter 29 is supported by the converter frame 36. According to this configuration, the converter 29 is attached to the side surface of the vehicle body frame 5 while being supported by the converter frame 36, so that there is no need to increase the rigidity of the converter 29 itself, and the weight of the converter 29 can be reduced.

[0069] In the embodiment, the converter frame 36 is configured to include a frame-shaped frame main body 37 that surrounds the converter 29, and a front reinforcing member 48 and a rear reinforcing member 49 that reinforce the frame main body 37, and the front reinforcing member 48 and the rear reinforcing member 49 are detachably attached to portions of the frame main body 37 excluding the portions that are attached to the sides of the body frame 5. With this configuration, the converter 29 can be easily accessed by removing the front reinforcing member 48 or the rear reinforcing member 49 while the converter frame 36 is attached to the body frame 5, thereby improving workability, for example, when performing maintenance on the converter 29.

[0070] In the embodiment, the frame main body 37 of the converter frame 36 has a lower frame portion 38 and an upper frame portion 43, a plurality of legs (left front leg portion 39, left rear leg portion 40, right front leg portion 41, right rear leg portion 42) connecting the lower frame portion 38 and the upper frame portion 43, and a body frame attachment portion 44 fixed to the body side leg portion (left front leg portion 39, left rear leg portion 40) arranged closest to the body frame 5 among the plurality of legs and attached to the body frame 5. One end of the front reinforcing member 48 and the rear reinforcing member 49 is disposed adjacent to the body frame attachment portion 44. The converter frame 36 includes first arms 48A, 49A each having one end fixed to the vehicle body leg near the vehicle body frame mounting portion 44 and the other end fixed to the lower frame portion 38, second arms 48B, 49B each having one end fixed to the vehicle body leg near the vehicle body frame mounting portion 44 and the other end fixed to the upper frame portion 43, and third arms 48C, 49C each having one end fixed to the lower frame portion 38 and the other end fixed to the upper frame portion 43, and the distance between the first arms 48A, 49A and the second arms 48B, 49B increases from the vehicle body leg toward the third arms 48C, 49C. According to this configuration, the load acting on the vehicle body frame mounting portion 44 from the vehicle body frame 5 during the travel of the dump truck 1 can be efficiently transmitted to the entire converter frame 36 via the front reinforcing member 48 and the rear reinforcing member 49, thereby increasing the rigidity of the converter frame 36.

[0071] In the embodiment, vibration-isolating members (lower left vibration-isolating member 33, lower right vibration-isolating member 34, lower middle vibration-isolating member 35, vibration-isolating mount 45, upper left vibration-isolating member 46, and upper right vibration-isolating member 47) are provided between the converter frame 36 and the body frame 5, and between the converter frame 36 and the converter 29. According to this configuration, the vibration-isolating mount 45 supports the converter frame 36 in a vibration-isolating state relative to the body frame 5, and the lower left vibration-isolating member 33, lower right vibration-isolating member 34, lower middle vibration-isolating member 35, upper left vibration-isolating member 46, and upper right vibration-isolating member 47 can support the converter 29 in a vibration-isolating state relative to the converter frame 36.

[0072] In the embodiment, the vibration-proof mount 45 provided between the converter frame 36 and the vehicle body frame 5 suppresses horizontal vibration of the converter frame 36 relative to the vehicle body frame 5, and the lower left vibration-proof member 33, lower right vibration-proof member 34, lower middle vibration-proof member 35, upper left vibration-proof member 46, and upper right vibration-proof member 47 provided between the converter frame 36 and the converter 29 suppress vertical vibration of the converter 29 relative to the converter frame 36. According to this configuration, even if a load acts on the vehicle body frame 5 from the front wheels 3 or the rear wheels 4 during the travel of the dump truck 1 and the vehicle body frame 5 is deformed so as to be twisted by this load, this deformation can be absorbed (suppressed) by the vibration-proof mount 45. As a result, the load associated with the deformation of the vehicle body frame 5 is suppressed from acting on the converter frame 36, and the rigidity of the converter frame 36 can be maintained at a good level. On the other hand, even if vertical vibrations occur when the dump truck 1 is traveling, the vibrations can be prevented from being transmitted to the cabinet 30 by the lower left vibration isolating member 33, the lower right vibration isolating member 34, the lower middle vibration isolating member 35, the upper left vibration isolating member 46, and the upper right vibration isolating member 47. As a result, damage to the various electrical devices housed in the cabinet 30 can be prevented, and the converter 29 can be protected.

[0073] In the embodiment, a front mudguard member 52 and a rear mudguard member (not shown) are attached to the converter frame 36 at locations facing the front wheels 3 and the rear wheels 4. According to this configuration, the front mudguard member 52 and the rear mudguard member prevent mud and the like scattered from the front wheels 3 or the rear wheels 4 when the dump truck 1 is traveling from adhering to the converter 29, thereby protecting the converter 29.

[0074] In the embodiment, the vehicle body frame 5 has a left frame 6 disposed on the left side in the left-right direction and extending in the front-rear direction, and a right frame 7 disposed on the right side in the left-right direction and extending in the front-rear direction, the converter frame 36 is attached to one of the left frame 6 and the right frame 7 (right frame 7), and a hydraulic oil tank 53 is attached to the other of the left frame 6 and the right frame 7 (left frame 6) located between the front wheels 3 and the rear wheels 4. According to this configuration, the hydraulic oil tank 53 and the converter 29, which are heavy objects, are disposed on both the left and right sides of the vehicle body frame 5 between the front wheels 3 and the rear wheels 4, so that the weight balance in the left-right direction of the vehicle body frame 5 can be maintained well, and the stability of the dump truck 1 during traveling can be improved.

[0075] In the embodiment, the converter 29 is attached to the side surface of the right frame 7 that constitutes the body frame 5, and the hydraulic oil tank 53 is attached to the side surface of the left frame 6. However, the present invention is not limited to this, and for example, the hydraulic oil tank may be attached to the side surface of the right frame 7, and the converter may be attached to the side surface of the left frame 6. [Explanation of symbols]

[0076] 1. Dump truck 3 Front wheel 4 Rear Wheel 5 Body frame 6 Left Frame 7 Right Frame 23 Electric Motor 24 Battery 29 Converter 33 Lower left vibration isolation member (vibration isolation member) 34 Lower right vibration isolation member (vibration isolation member) 35 Intermediate lower vibration isolation member (vibration isolation member) 36 Converter Frame 37 Frame body 38 Lower frame part 39 Left front leg (body side leg) 40 Left rear leg (body side leg) 41 Right front leg 42 Right hind leg 43 Upper frame part 44 Body frame mounting part 45 Anti-vibration mount (anti-vibration material) 46 Upper left vibration-proof member (vibration-proof member) 47 Upper right vibration isolator (vibration isolator) 48 Front reinforcing member (reinforcing member) 48A, 49A 1st arm 48B,49B 2nd arm 48C,49C 3rd arm 49 Rear reinforcement member (reinforcement member) 52 Front mudguard member 53 Hydraulic Oil Tank

Claims

1. A vehicle body frame to which front and rear wheels are attached; A battery mounted on the vehicle body frame; an electric motor that drives the front wheels or the rear wheels by receiving electric power from the battery; A converter mounted on the vehicle body frame and configured to convert power supplied to the electric motor. a converter frame is attached to a side surface of the body frame and is located between the front wheels and the rear wheels; The dump truck is characterized in that the converter is supported by the converter frame.

2. The converter frame includes a frame body that surrounds the converter and a reinforcing member that reinforces the frame body, 2. The dump truck according to claim 1, wherein the reinforcing member is detachably attached to a portion of the frame body excluding a portion attached to a side surface of the vehicle body frame.

3. the frame body of the converter frame has a lower frame portion, an upper frame portion, a plurality of legs connecting the lower frame portion and the upper frame portion, and a vehicle body frame mounting portion fixed to a vehicle body side leg of the plurality of legs that is disposed closest to the vehicle body frame and is mounted to the vehicle body frame, the reinforcing member has a first arm having one end fixed to the vehicle body leg near the vehicle body frame mounting portion and the other end fixed to the lower frame portion, a second arm having one end fixed to the vehicle body leg near the vehicle body frame mounting portion and the other end fixed to the upper frame portion, and a third arm having one end fixed to the lower frame portion and the other end fixed to the upper frame portion, 3. The dump truck according to claim 2, wherein a distance between the first arm and the second arm increases from the vehicle body side leg toward the third arm.

4. 2. The dump truck according to claim 1, wherein vibration isolating members are provided between the converter frame and the vehicle body frame, and between the converter frame and the converter.

5. the vibration-isolating member provided between the converter frame and the vehicle body frame suppresses horizontal vibration of the converter frame relative to the vehicle body frame, The dump truck according to claim 4 , wherein the vibration-proof member provided between the converter frame and the converter suppresses vertical vibration of the converter relative to the converter frame.

6. 2. The dump truck according to claim 1, wherein mudguard members are attached to the converter frame at locations facing the front wheels and the rear wheels.

7. the vehicle body frame includes a left frame disposed on the left side in the left-right direction and extending in the front-rear direction, and a right frame disposed on the right side in the left-right direction and extending in the front-rear direction, the converter frame is attached to one of the left frame and the right frame, 2. The dump truck according to claim 1, wherein a hydraulic oil tank is attached to the other of the left frame and the right frame between the front wheels and the rear wheels.

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