Dumper

Abstract

A vehicle body frame (14) of a dump truck (1) is provided with an operation cabin supporting part (28E) for supporting a rear side part (9A) of an operation cabin (9), a front side supporting component (30) which is arranged between the vehicle body frame (14) and the operation cabin (9) and supports a front side part (9B) of the operation cabin (9), and a reinforcing component (31) for connecting the front side supporting component (30) and the operation cabin supporting part (28E). A frame-side bracket (29) provided to an operation cabin support section (28E) and a reinforcing member-side bracket (33) provided to a reinforcing member (31) are connected via a connecting pin (36), and a spherical bearing (34) is provided between the frame-side bracket (29) and the connecting pin (36).

Description

Technical Field

[0001] The present disclosure relates to a dump truck suitable for transporting crushed rocks excavated in mines. Background Art

[0002] A dump truck for transporting crushed rocks and the like excavated in a mine includes a body frame on which wheels are mounted, a cargo box disposed so as to be tiltable relative to the body frame, and a cab disposed on the body frame in front of the cargo box and dividing a cab. The rear portion of the cab is supported by a cab support portion disposed on the body frame, and the front portion of the cab is supported by a front support member disposed on the front side of the body frame.

[0003] Since the front side support member bears the load from the cab, which is a heavy object, and a large load is applied due to vibration when the dump truck is traveling, a large strength is required. In contrast, a dump truck is disclosed in which a reinforcement member is provided between the upper part of the front side support member (cabin) and the vehicle body frame in a state inclined relative to the up-down direction (vehicle height direction), thereby improving the strength of the front side support member (Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-43481 Summary of the invention

[0007] However, since dump trucks usually travel on uneven roads (uneven ground) such as mines, the body frame is subjected to torsional deformation during travel. Therefore, when a reinforcement member is provided between the front support member and the body frame as in Patent Document 1, a load caused by the torsional deformation of the body frame acts on the connection portion between the reinforcement member and the body frame, thereby reducing the support strength of the cab.

[0008] In contrast, a method of increasing the rigidity of the vehicle body frame to suppress torsional deformation or a method of increasing the strength of the reinforcing member to increase the strength of the connection between the reinforcing member and the vehicle body frame may be considered. However, in the case of adopting either method, there is a problem of increased vehicle body weight.

[0009] An object of the present invention is to provide a dump truck capable of improving the supporting strength of a cab without increasing the weight of the vehicle body.

[0010] The dump truck of the present invention comprises: a body frame, which extends in the front-rear direction and is equipped with wheels; a cargo box, which is tiltably arranged relative to the above-mentioned body frame and loads the transported objects; and a cab, which is arranged on the above-mentioned body frame at the front side of the above-mentioned cargo box and divides the cab. The above-mentioned dump truck is characterized in that a cab support part supporting the rear part of the above-mentioned cab is provided on the above-mentioned body frame, a front support component arranged between the above-mentioned body frame and the above-mentioned cab and supporting the front part of the above-mentioned cab, and a reinforcement component connecting the above-mentioned front support component and the above-mentioned cab support part, and a spherical bearing is provided at a connection part of at least one of the connection part between the above-mentioned cab support part and the above-mentioned reinforcement component and the connection part between the above-mentioned front support component and the above-mentioned reinforcement component.

[0011] According to the present invention, the load acting on the front support member during driving can be reduced by the reinforcing member connecting the cab support portion supporting the rear portion of the cab and the front support member supporting the front portion of the cab. Furthermore, even if the vehicle body frame is torsionally deformed due to the dump truck driving on uneven ground, the torsion deformation of the vehicle body frame can be absorbed by the spherical bearing provided at least one of the connecting portion between the cab support portion and the reinforcing member and the connecting portion between the front support member and the reinforcing member. Thus, the load caused by the torsion deformation of the vehicle body frame acting on the connecting portion between the cab support portion and the reinforcing member or the connecting portion between the front support member and the reinforcing member can be suppressed, thereby improving the supporting strength of the cab without increasing the weight of the vehicle body. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a left side view of the dump truck which shows the embodiment of this invention.

[0013] Figure 2 This is the front view of the dump truck.

[0014] Figure 3 It is a perspective view showing a vehicle body frame and a cockpit.

[0015] Figure 4 It is a perspective view showing a connection portion between a cockpit support portion of a vehicle body frame and a reinforcement member.

[0016] Figure 5 It is a left side view showing the connection portion between the cockpit support portion and the reinforcement member.

[0017] Figure 6 is from Figure 5 A cross-sectional view of the connection portion between the cockpit support portion and the reinforcement component as viewed in the direction of arrows VI-VI. DETAILED DESCRIPTION

[0018] Hereinafter, an embodiment of the dump truck of the present invention will be described in detail with reference to the accompanying drawings. In the embodiment, the traveling direction of the dump truck is described as the front-rear direction, and the direction orthogonal to the traveling direction is described as the left-right direction.

[0019] In the figure, a dump truck 1 is configured to include a self-propelled vehicle body 2 having left and right front wheels 3 and left and right rear wheels 4, and a cargo box 5 described below that is tiltably (up and down) mounted on the vehicle body 2. The dump truck 1 loads the transported objects such as crushed stones excavated from a mine into the cargo box 5 for transport. The vehicle body 2 of the dump truck 1 is configured to include a cabin 7, a deck 8, a cab 9, a vehicle body frame 14, etc. described below.

[0020] The left and right front wheels 3 are rotatably provided on the front side of the vehicle body 2, and constitute steering wheels. The front wheels 3 are supported by the vehicle body frame 14 via a front wheel side suspension (not shown), and the vibration transmitted from the front wheels 3 to the vehicle body 2 is mitigated. The left and right rear wheels 4 are rotatably provided on the rear side of the vehicle body 2, and are rotationally driven by a travel device (not shown) having an electric motor. The travel device of the rear wheel 4 is supported by the vehicle body frame 14 via a rear wheel side suspension (not shown), and the vibration transmitted from the rear wheel 4 to the vehicle body 2 is mitigated.

[0021] The cargo box (cargo box) 5 is mounted on the vehicle body frame 14 so as to be tiltable (able to rise and fall). The cargo box 5 is formed as a large container with a bottom for loading a large amount of minerals excavated by a hydraulic excavator (not shown), for example. The rear bottom of the cargo box 5 is connected to the left and right rear end brackets 24 provided on the vehicle body frame 14 via a connecting pin 5B so as to be tiltable. An eaves 5A extending horizontally from the upper part thereof toward the front is integrally provided on the front side of the cargo box 5. The eaves 5A of the cargo box 5 extends to the front end side of the table 8 in a state of covering the cab 9 from the upper side.

[0022] The tipping cylinders 6 are arranged in pairs between the vehicle body frame 14 and the cargo box 5 in the left-right direction (only the left side is shown). The tipping cylinders 6 are composed of, for example, hydraulic cylinders, which allow the front side of the cargo box 5 to tilt up and down relative to the vehicle body frame 14. One end side (lower end side) of the tipping cylinder 6 is rotatably mounted on the cylinder support shaft 26 described below, and the other end side (upper end side) of the tipping cylinder 6 is rotatably mounted on the lower surface side of the cargo box 5. Therefore, by extending or shrinking the tipping cylinder 6, the front side (eaves 5A side) of the cargo box 5 rotates (rises and falls) in the up-and-down direction with the connecting pin 5B as a fulcrum. As a result, the cargo box 5 can be tilted to the soil discharge position where the front side is lifted upward, and the transported objects loaded in the cargo box 5 can be discharged.

[0023] The compartment 7 is provided on the front side of the vehicle body 2. The compartment 7 is formed in a rectangular frame shape surrounded by left and right side panels and an upper surface panel, and defines a machine room for accommodating onboard equipment (none of which are shown) such as an engine, a generator, and a hydraulic pump.

[0024] The platform 8 is provided on the upper side of the left pillar 22, the right pillar 23 and the cabin 7 of the vehicle body frame 14, so as to be located in front of the cargo box 5. The platform 8 is formed into a rectangular flat plate shape that is long in the left-right direction, and is supported from the lower side by the upper cross beam 28 and the cabin 7 described below. The platform 8 is arranged above the left and right front wheels 3 and extends in the horizontal direction, and the cockpit 9, the control cabinet 10 and the like are mounted on the platform 8. In addition, the upper surface of the platform 8 becomes a flat passage surface for the operator and the like to pass through, and the outer periphery of the platform 8 is surrounded by a plurality of handrails 8A.

[0025] The cab 9 is arranged on the vehicle body frame 14 at the front side of the cargo box 5 and is covered from the upper side by the eaves 5A. The cab 9 is composed of a box body surrounded by a front surface, a rear surface, left and right side surfaces, an upper surface, and a lower surface, and is divided into a cab for the operator of the dump truck 1 to get on and off. The rear side portion 9A of the cab 9 is supported from the lower side by the cab support portion 28E of the upper cross beam 28, and the front side portion 9B of the cab 9 is supported from the lower side by the front side support member 30 described below. Inside the cab 9, a driver's seat, an accelerator pedal, a brake pedal, a steering wheel for steering, and a plurality of operating levers (none of which are shown in the figure) are provided.

[0026] The radiator 11 is provided at the front end side of the vehicle body frame 14. The radiator 11 is arranged at the front side of the cabin 7, and cools the engine cooling water and the like of the engine (not shown) stored in the machine room divided by the cabin 7. Fenders 12 extending to the left and right directions from the left and right side panels of the cabin 7 are provided on the left and right sides of the radiator 11. Air filters 13 are respectively mounted on the left and right fenders 12. The air filter 13 captures dust contained in the outside air at the work site such as a mine, and supplies clean air (intake air) to the engine.

[0027] The vehicle body frame 14 becomes the base of the vehicle body 2 and constitutes a strong supporting structure. Figure 3 As shown, the vehicle body frame 14 is constituted to include a main frame 15 extending in the front-rear direction and a front bumper 27 integrally fixed to the front side of the main frame 15. The main frame 15 is composed of a left frame 16, a right frame 17, a front frame 18, a rear frame 19, an upper plate 20, a lower plate 21, a left pillar 22, a right pillar 23, an upper cross member 28, and the like.

[0028] The left frame 16 is arranged on the left side of the vehicle body frame 14 and extends in the front-rear direction. The left frame 16 is configured to include left and right side panels 16A facing each other in the left-right direction, an upper panel 20 closing the upper ends of the left and right side panels 16A, and a lower panel 21 connecting the lower ends of the left and right side panels 16A. The right frame 17 is arranged on the right side of the vehicle body frame 14 and extends in the front-rear direction. The right frame 17 is configured to include left and right side panels 17A facing each other in the left-right direction, an upper panel 20 closing the upper ends of the left and right side panels 17A, and a lower panel 21 connecting the lower ends of the left and right side panels 17A.

[0029] The front frame 18 connects the front end of the left frame 16 and the front end of the right frame 17. The front frame 18 is configured to include a front plate 18A and a rear plate (not shown) facing each other in the front-rear direction, an upper plate 20 that blocks the upper ends of the front plate 18A and the rear plate, and a lower plate 21 that blocks the lower ends of the front plate 18A and the rear plate. The left end of the front frame 18 is joined to the front end of the left frame 16 by welding, and the right end of the front frame 18 is joined to the front end of the right frame 17 by welding.

[0030] The rear frame 19 connects the rear end of the left frame 16 and the rear end of the right frame 17. The rear frame 19 is configured to include a front plate and a rear plate (neither of which is shown) facing each other in the front-rear direction, an upper plate 20 that blocks the upper ends of the front plate and the rear plate, and a lower plate 21 that blocks the lower ends of the front plate and the rear plate. The left end of the rear frame 19 is joined to the rear end of the left frame 16 by welding, and the right end of the rear frame 19 is joined to the rear end of the right frame 17 by welding.

[0031] The upper plate 20 blocks the upper ends of the left frame 16, the right frame 17, the front frame 18, and the rear frame 19, and connects the left frame 16 and the right frame 17. The front side of the upper plate 20 forms a forked branch portion 20A that blocks the upper ends of the left frame 16 and the right frame 17. The front end of the branch portion 20A is connected by a front side connecting portion (not shown), and the front side connecting portion blocks the upper end of the front frame 18.

[0032] The lower plate 21 blocks the lower ends of the left frame 16, the right frame 17, the front frame 18, and the rear frame 19 in a state facing the upper plate 20 in the vertical direction, and connects the left frame 16 and the right frame 17. The front side of the lower plate 21 forms a bifurcated branch portion 21A similar to the upper plate 20. The front end of the branch portion 21A is connected by a front side connecting portion 21B, and the front side connecting portion 21B blocks the lower end of the front frame 18.

[0033] The left support 22 and the right support 23 are provided at the front side of the center portion of the vehicle body frame 14 in the front-rear direction and face each other in the left-right direction. The left support 22 and the right support 23 are formed of a hollow sheet metal structure in a mountain shape. The left support 22 is provided to protrude upward from the upper plate 20 constituting the left frame 16, and the right support 23 is provided to protrude upward from the upper plate 20 constituting the right frame 17. Flat plate-shaped mounting flanges (only the mounting flange 22A of the left support 22 is shown) are fixed to the upper ends of the left support 22 and the right support 23, respectively. An upper cross member 28 is mounted to the mounting flange 22A of the left support 22 and the mounting flange of the right support 23 (not shown).

[0034] The rear end of the main frame 15 is provided with left and right rear end brackets 24. The rear end brackets 24 protrude rearward from the rear ends of the upper plates 20 constituting the left frame 16 and the right frame 17, respectively, and face each other in the left-right direction. The left and right rear end brackets 24 support the bottom surface of the cargo box 5 rotatably via the connecting pin 5B.

[0035] Left and right cylinder brackets 25 are provided at the lower side of the middle part in the front-rear direction of the main frame 15. The left and right cylinder brackets 25 protrude downward from the lower plate 21 constituting the left frame 16 and the right frame 17, and are opposed to each other in the left-right direction. A cylinder support shaft 26 extending in the left-right direction is fixed to the protruding end side of the cylinder bracket 25, and the lower end side of the hoist cylinder 6 is rotatably mounted on the cylinder support shaft 26.

[0036] The front bumper 27 is integrally fixed to the front side of the front frame 18 constituting the main frame 15 by welding or other methods. The front bumper 27 has a U-shaped cross-sectional shape composed of a front frame portion 27A, a left frame portion 27B, and a right frame portion 27C, and is formed as a frame body bent into a U-shape as a whole. The front frame portion 27A is opposed to the front frame 18 in the front-to-back direction and extends in the left-to-right direction. The left frame portion 27B connects the left end of the front frame portion 27A to the left end of the front frame 18. The right frame portion 27C connects the right end of the front frame portion 27A to the right end of the front frame 18.

[0037] The upper cross beam 28 is mounted on the upper end side of the left support 22 and the right support 23, and extends in the left-right direction. The upper cross beam 28 is formed of a square cylinder having a quadrilateral cross-sectional shape surrounded by a front surface 28A, a rear surface 28B, an upper surface 28C, and a lower surface 28D. The lower surface 28D of the upper cross beam 28 is fixed to the mounting flange 22A of the left support 22 and the mounting flange of the right support 23 (not shown). The left end side of the upper cross beam 28 becomes a cockpit support portion 28E, and the rear side portion 9A of the cockpit 9 is mounted on the upper surface 28C of the cockpit support portion 28E. Thus, the cockpit support portion 28E of the upper cross beam 28 supports the rear side portion 9A of the cockpit 9 from the bottom. In addition, the portion of the upper cross beam 28 located to the right of the cockpit support portion 28E supports the table 8 from the bottom together with the cabin 7.

[0038] A frame side bracket 29 is provided on the front surface 28A of the cockpit support portion 28E. Figures 4 to 6 As shown, the frame side bracket 29 has a quadrilateral base plate 29A and a protruding plate 29B protruding forward from the center portion of the base plate 29A in the left-right direction. The base plate 29A is fixed to the front surface 28A of the upper cross beam 28 using a plurality of bolts 29C. Figure 6 As shown, a bearing mounting hole 29D penetrating in the left-right direction is formed in the protruding plate 29B of the frame side bracket 29. An outer ring 34A of a spherical bearing 34 described below is mounted in the bearing mounting hole 29D.

[0039] The front support member 30 is provided between the vehicle body frame 14 and the cockpit 9. The front support member 30 is formed into a trapezoidal frame body having an upper frame portion 30A, a left frame portion 30B, a right frame portion 30C and an oblique frame portion 30D by joining, for example, a square tube-shaped tube using a method such as welding. The upper frame portion 30A extends in the left-right direction. The left frame portion 30B hangs down from the left end of the upper frame portion 30A. The right frame portion 30C has a larger length dimension than the left frame portion 30B and hangs down from the right end of the upper frame portion 30A. The oblique frame portion 30D connects the lower end of the left frame portion 30B and the lower end of the right frame portion 30C, and extends obliquely downward from the left frame portion 30B toward the right frame portion 30C.

[0040] A quadrilateral mounting base plate 30E is provided at a joint portion (lower end of the front support member 30) between the right frame portion 30C and the oblique frame portion 30D of the front support member 30. The mounting base plate 30E is fixed to the side plate 16A at the front end side of the left frame 16 constituting the vehicle body frame 14 by bolts or the like. The front side portion 9B of the cockpit 9 is mounted to the upper frame portion 30A of the front support member 30. Thus, the front side portion 9B of the cockpit 9 is supported from the lower side by the front support member 30.

[0041] Here, a side panel (not shown) constituting the left side of the cabin 7 is mounted on the right frame portion 30C of the front support member 30, and the front support member 30 constitutes a part (support member) of the cabin 7. Thus, the number of components for forming the cabin 7 can be reduced. In addition, a left fender 12 is fixed to the front surface of the upper frame portion 30A, the left frame portion 30B, and the right frame portion 30C constituting the front support member 30, and an air filter 13 is mounted on the fender 12.

[0042] The reinforcement member 31 is provided between the cockpit support portion 28E of the upper cross beam 28 and the front support member 30, and extends in the front-rear direction. The reinforcement member 31 is formed using a square cylinder having a quadrilateral cross-sectional shape, and a mounting flange (not shown) is provided at one end side (front end side) in the longitudinal direction of the reinforcement member 31. The mounting flange serves as a front side connection portion between the front end side of the reinforcement member 31 and the front support member 30. The mounting flange is fixed to the upper side portion of the front support member 30 (the upper end side of the upper frame portion 30A or the left frame portion 30B) using a fastening member such as a bolt.

[0043] On the other hand, the other end side (rear end side) in the longitudinal direction of the reinforcing member 31 is connected to the cockpit support portion 28E of the upper cross beam 28 by a rear side connecting portion 32. The rear side connecting portion 32 is configured to include a frame side bracket 29 provided on the cockpit support portion 28E, a reinforcing member side bracket 33 provided on the reinforcing member 31, and a connecting pin 36 described below.

[0044] Two reinforcing member side brackets 33 are provided on the other end side (rear end side) in the longitudinal direction of the reinforcing member 31. The reinforcing member side brackets 33 are fixed to the bracket mounting plate 31A using a plurality of bolts 33A in a state where they are opposed in the left-right direction with the bracket mounting plate 31A integrally provided on the rear end side of the reinforcing member 31 sandwiched therebetween. The rear end of the reinforcing member side bracket 33 protrudes rearward from the bracket mounting plate 31A, and a pin insertion hole 33B penetrating in the left-right direction is formed on the protruding end side. The two reinforcing member side brackets 33 sandwich the protruding plate 29B of the frame side bracket 29 from the left-right direction, and the pin insertion holes 33B of the reinforcing member side brackets 33 and the bearing mounting holes 29D of the protruding plate 29B are arranged to be concentrically aligned. Furthermore, the two reinforcing member side brackets 33 are connected to the protruding plate 29B of the frame side bracket 29 via the connecting pins 36 inserted in the pin insertion holes 33B and the spherical bearings 34.

[0045] The spherical bearing 34 is provided at the rear connecting portion 32 between the cockpit supporting portion 28E of the upper cross beam 28 and the reinforcing member 31. Figure 6 As shown in FIG. 1 , the spherical bearing 34 is configured to include an outer ring 34A mounted on the frame side bracket 29 and an inner ring 34B mounted on the connecting pin 36. The inner peripheral surface of the outer ring 34A is a concave spherical surface 34C, and the outer peripheral surface of the inner ring 34B is a convex spherical surface 34D that slidably contacts the concave spherical surface 34C of the outer ring 34A. The outer ring 34A is inserted into the bearing mounting hole 29D formed in the protruding plate 29B of the frame side bracket 29. The outer ring 34A is fixed to the protruding plate 29B in a state where both sides of the axial direction are sandwiched by two hole retaining rings 35.

[0046] The connecting pin 36 is inserted through the two reinforcing member side brackets 33 and the inner ring 34B of the spherical bearing 34. Specifically, the middle portion of the connecting pin 36 in the axial direction is fitted with the inner ring 34B of the spherical bearing 34, and both sides of the connecting pin 36 in the axial direction are respectively inserted into the pin insertion holes 33B of the two reinforcing member side brackets 33. A pin hole 36A is formed on one end side of the connecting pin 36, which passes through the center of the connecting pin 36 and penetrates in a direction orthogonal to the axial direction.

[0047] A cylindrical member 37 is fixed to the outer side surface of one of the two reinforcing member side brackets 33 concentrically with the pin insertion hole 33B. A through hole 37A is formed in the cylindrical member 37, which passes through the center and penetrates in the radial direction. One end side of the connecting pin 36 formed with the pin hole 36A is arranged on the inner circumference side of the cylindrical member 37 fixed to the one reinforcing member side bracket 33. And the stopper bolt 38 is inserted through the through hole 37A of the cylindrical member 37 and the pin hole 36A of the connecting pin 36. Thereby, the connecting pin 36 fitted with the inner ring 34B of the spherical bearing 34 is stopped relative to the reinforcing member side bracket 33 and prevented from coming off in the axial direction.

[0048] Annular spacers 39 are provided between the two axial ends of the inner ring 34B constituting the spherical bearing 34 and the two reinforcing member side brackets 33. The spacers 39 are inserted through the connecting pins 36 to adjust the gap A formed between the protruding plate 29B of the frame side bracket 29 and the reinforcing member side bracket 33. Thus, the reinforcing member side bracket 33 and the frame side bracket 29 are connected to each other so as to be relatively rotatable within the range of the gap A with the inner ring 34B of the spherical bearing 34 as the center.

[0049] Thus, the cab support portion 28E of the upper cross beam 28 supporting the rear portion 9A of the cab 9 is connected to the front support member 30 supporting the front portion 9B of the cab 9 by the reinforcing member 31. Thus, the load acting on the front support member 30 during the travel of the dump truck 1 can be reduced.

[0050] Furthermore, the frame side bracket 29 provided on the cab support portion 28E and the reinforcement member side bracket 33 provided on the reinforcement member 31 are connected via a connection pin 36. A spherical bearing 34 is provided between the connection pin 36 and the frame side bracket 29 (protruding plate 29B). Thus, even if the body frame 14 is torsionally deformed due to the dump truck 1 running on an uneven ground, the reinforcement member side bracket 33 and the frame side bracket 29 relatively rotate around the inner ring 34B of the spherical bearing 34. Thus, the torsion deformation of the body frame 14 can be absorbed. Therefore, the load caused by the torsion deformation of the body frame 14 acting on the connection portion between the cab support portion 28E and the reinforcement member 31 can be suppressed.

[0051] The dump truck 1 of this embodiment has the above-mentioned structure. When the dump truck 1 is used to transport crushed stones in a mine or the like, the operator riding in the cab 9 starts the engine. As a result, the engine drives the hydraulic pump, the generator, etc. (all not shown). The electric power from the generator is supplied to the electric motor of the travel device, and the rear wheel 4 is driven to rotate, so that the dump truck 1 travels to the gravel field. Then, the cargo box 5 of the dump truck 1 stopped at the gravel field is loaded with crushed stones excavated using a large hydraulic excavator or the like (not shown). After the dump truck 1 loaded with crushed stones travels to the collection site, the dump tank 5 is tilted by the dump cylinder 6 to discharge the crushed stones to the collection site.

[0052] Since the dump truck 1 travels on a road surface (uneven ground) with large bumps in a mine or the like, the body frame 14 is torsionally deformed. As a result, a load caused by the torsion deformation of the body frame 14 acts on the reinforcing member 31 connecting the cab support portion 28E of the upper cross member 28 and the front support member 30. In contrast, in the present embodiment, a spherical bearing 34 is provided between the cab support portion 28E and the rear connecting portion 32 of the reinforcing member 31, that is, between the frame side bracket 29 and the reinforcing member side bracket 33 connected via a connecting pin 36.

[0053] Therefore, even if the body frame 14 is torsionally deformed, the reinforcing member side bracket 33 and the frame side bracket 29 relatively rotate around the inner ring 34B of the spherical bearing 34, thereby absorbing the torsion of the body frame 14. As a result, the load caused by the torsion of the body frame 14 acting on the connection portion between the cab support portion 28E and the reinforcing member 31 can be suppressed. As a result, the dump truck 1 of the present embodiment does not need to increase the rigidity of the body frame 14 or the strength of the reinforcing member 31 in order to suppress the torsion of the body frame 14, and can improve the support strength of the cab 9 without increasing the weight of the body.

[0054] Thus, in the embodiment, the dump truck 1 includes a vehicle body frame 14 along the front-rear direction and on which wheels are mounted, a cargo box 5 which is tiltably arranged relative to the vehicle body frame 14 and on which the transported objects are loaded, and a cab 9 which is arranged on the vehicle body frame 14 at the front side of the cargo box 5 and divides the cab. In the dump truck 1, a cab support portion 28E which supports the rear portion 9A of the cab 9, a front support component 30 which is arranged between the vehicle body frame 14 and the cab 9 and supports the front portion 9B of the cab 9, and a reinforcement component 31 which connects the front support component 30 and the cab support portion 28E are provided on the vehicle body frame 14. A spherical bearing 34 is provided on at least one of the connecting portion (rear connecting portion 32) between the cab support portion 28E and the reinforcement component 31 and the connecting portion (front connecting portion) between the front support component 30 and the reinforcement component 31.

[0055] According to this structure, even if the body frame 14 is torsionally deformed during the travel of the dump truck 1, the reinforcement member side bracket 33 of the reinforcement member 31 and the frame side bracket 29 of the cab support portion 28E connected via the connection pin 36 relatively rotate around the inner ring 34B of the spherical bearing 34. Thus, the torsion deformation of the body frame 14 can be absorbed. Therefore, the load caused by the torsion deformation of the body frame 14 acting on the cab support portion 28E and the rear side connection portion 32 of the reinforcement member 31 can be suppressed, and the support strength of the cab 9 can be improved without increasing the weight of the body 2.

[0056] In the embodiment, the frame side bracket 29 is provided in the cab support portion 28E, the reinforcing member side bracket 33 connected to the frame side bracket 29 via the connecting pin 36 is provided in the reinforcing member 31, and the spherical bearing 34 includes an outer ring 34A mounted on the frame side bracket 29 and having a concave spherical surface 34C, and an inner ring 34B mounted on the connecting pin 36 and having a convex spherical surface 34D that is in sliding contact with the concave spherical surface 34C of the outer ring 34A. According to this structure, even if the body frame 14 is torsionally deformed during the travel of the dump truck 1, the reinforcing member side bracket 33 and the frame side bracket 29 relatively rotate around the inner ring 34B of the spherical bearing 34, thereby absorbing the torsion deformation of the body frame 14.

[0057] In the embodiment, the front support member 30 constitutes a part of the cabin 7 that partitions the machine room on the front side of the vehicle body frame 14. According to this structure, since the front support member 30 supporting the front portion 9B of the cab 9 also serves as a part of the cabin 7, the number of components for forming the cabin 7 can be reduced.

[0058] In the embodiment, a case where a spherical bearing 34 is provided between the rear end of the reinforcing member 31 and the rear connecting portion 32 of the cockpit support portion 28E is exemplified. However, the present invention is not limited thereto, and for example, a spherical bearing may be provided between the front end of the reinforcing member 31 and the front connecting portion of the front supporting member 30. Furthermore, a spherical bearing may be provided between the rear end of the reinforcing member 31 and the rear connecting portion 32 of the cockpit support portion 28E and between the front end of the reinforcing member 31 and the front connecting portion of the front supporting member 30, respectively.

[0059] Explanation of symbols

[0060] 1—dump truck, 2—body, 3—front wheel, 4—rear wheel, 5—cargo box, 9—cockpit, 9A—rear part, 9B—front part, 14—body frame, 28—upper cross beam, 28E—cockpit support part, 29—frame side bracket, 30—front side support member, 31—reinforcement member, 32—rear side connecting part (connecting part), 33—reinforcement member side bracket, 34—spherical bearing, 34A—outer ring, 34B—inner ring, 34C—concave spherical surface, 34D—convex spherical surface.

Claims

1. A dump truck having: a vehicle body frame extending in the front-rear direction and having wheels mounted thereon; a cargo box which is tiltably arranged relative to the vehicle body frame and is loaded with transported objects; and A driver's cabin is provided on the vehicle body frame at the front side of the cargo box and divides the driver's cabin. The above dump truck is characterized in that: The vehicle body frame is provided with a cockpit support portion for supporting a rear portion of the cockpit, a front support member disposed between the vehicle body frame and the cockpit and supporting a front portion of the cockpit, and a reinforcement member connecting the front support member and the cockpit support portion. A spherical bearing is provided at at least one of a connection portion between the cockpit support portion and the reinforcement member and a connection portion between the front support member and the reinforcement member.

2. The dump truck according to claim 1, characterized in that: The cockpit support is provided with a frame side bracket. The reinforcing member is provided with a reinforcing member side bracket connected to the frame side bracket via a connecting pin. The spherical bearing includes an outer ring mounted on the frame-side bracket and having a concave spherical surface, and an inner ring mounted on the connecting pin and having a convex spherical surface in sliding contact with the concave spherical surface of the outer ring.

3. The dump truck according to claim 1, characterized in that: The front support member constitutes a part of a compartment that defines a machine room on the front side of the vehicle body frame.

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