Transport vehicles

Abstract

To provide a transport vehicle that can suppress damage to hoist cylinders. [Solution] The dump truck 1 comprises a vehicle body 2, a vessel 3, and a hoist cylinder 12. A guide plate 31, which serves as a displacement limiting member, is provided between the cylinder mounting portion 16 of the vessel 3 and the hoist cylinder 12. The guide plate 31 is fixed to the cylinder mounting portion 16 and is positioned close to and opposite the groove 32 of the hoist cylinder 12 in the width direction of the vehicle body 2.

Description

Technical Field

[0001] The present disclosure relates to a transport vehicle such as a dump truck that is suitably used for transporting crushed materials mined at, for example, open-pit mines, stone quarries, and mines.

Background Art

[0002] Generally, a transport vehicle such as a dump truck includes a loading platform (bed) that is provided on the frame of the vehicle body so as to be able to rise and fall. The transport vehicle transports a large amount of heavy loads such as crushed materials loaded on the loading platform to the unloading location. At the unloading location, the transport vehicle unloads the loaded goods from the loading platform by raising and lowering the loading platform with a hoist mechanism including a hoist cylinder. Here, if the life of the components of the hoist mechanism is short, it is necessary to frequently replace these components, and the on-site operation rate of the transport vehicle decreases. In particular, for ultra-large transport vehicles, the cost and labor of work stoppage and restart are large. For this reason, there is a demand for reducing wear, damage, and extending the life of the hoist mechanism.

[0003] On the other hand, Patent Document 1 describes a technique for suppressing the sway of the loading platform by opposing a sway-preventing member provided on the loading platform and a contact plate provided on the frame of the vehicle body in the width direction (left-right direction) of the vehicle body. According to this technique, when the loading platform vibrates in the width direction of the vehicle body with respect to the frame, it is suppressed that the loading platform vibrates more than the gap between the sway-preventing member and the contact plate. Thereby, it is considered that the vibration transmitted to the connection pin connecting the loading platform and the hoist cylinder and the hoist cylinder holding this connection pin can be reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technology described in Patent Document 1, when the hoist cylinder is extended to unload cargo such as soil from the cargo bed, the position of the anti-sway member and the backing plate changes as the cargo bed moves away from the vehicle frame, and the anti-sway member and the backing plate no longer face each other in the width direction of the vehicle body. Therefore, when the hoist cylinder is extended to unload cargo from the cargo bed, if the cargo bed vibrates in the width direction of the vehicle body relative to the frame, the anti-sway member and the backing plate will not come into contact, and this vibration may be transmitted to the connecting pin and the hoist cylinder. This vibration may cause damage to the connecting pin and the hoist cylinder.

[0006] The object of the present invention is to provide a transport vehicle that can suppress damage to the hoist cylinder. [Means for solving the problem]

[0007] The present invention preferably relates to a transport vehicle comprising a drivable body, a cargo bed mounted on the body so as to be rotatable in the vertical direction with its rear as a pivot point, and a hoist cylinder mounted between a cylinder mounting portion provided on the cargo bed and the vehicle body, which rotates the cargo bed upward or downward by extending or contracting, wherein a displacement limiting member is provided between the cylinder mounting portion of the cargo bed and the hoist cylinder, fixed to one of the members of the cylinder mounting portion and the hoist cylinder, and positioned in close proximity to the other member in the width direction of the vehicle body, thereby limiting the relative displacement in the width direction between the other member and the one member. [Effects of the Invention]

[0008] According to the present invention, damage to the hoist cylinder can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a left side view showing a transport vehicle according to the first embodiment. [Figure 2] This is a perspective view showing the loading platform in an upright position with the hoist cylinder extended. [Figure 3] This is a perspective view of the cargo bed from the upper left side. [Figure 4] This is an enlarged view of section (IV) in Figure 1. [Figure 5] This is a cross-sectional view taken from the direction of arrow VV in Figure 4. [Figure 6] This is a cross-sectional view taken from the direction indicated by the arrow VI-VI in Figure 5. [Figure 7] This is a cross-sectional view taken from the direction indicated by the arrow VII-VII in Figure 4. [Figure 8] This is a perspective view showing the displacement limiting member as a standalone unit. [Figure 9] This is an enlarged view of the same position as in Figure 4 according to the second embodiment. [Figure 10] This is a cross-sectional view taken from the direction indicated by the arrow XX in Figure 9. [Figure 11] This is a cross-sectional view taken from the direction indicated by the arrow XI-XI in Figure 10. [Figure 12] This is a cross-sectional view taken from the direction indicated by the arrow XII-XII in Figure 10. [Figure 13] This is an enlarged view of the same position as in Figure 4, using a modified example. [Figure 14] This is a cross-sectional view taken from the direction indicated by the arrow XIV-XIV in Figure 13. [Modes for carrying out the invention]

[0010] In the following description, a dump truck used to transport crushed stone, ore, soil, etc., excavated from a mine will be used as an example of a transport vehicle according to the embodiment, and will be explained in detail with reference to the attached drawings.

[0011] In the following description, the traveling direction of the dump truck 1 is defined as the front-rear direction, and the direction orthogonal to the traveling direction is defined as the left-right direction (width direction). For example, the front-rear direction of the dump truck 1 corresponds to the left-right direction in FIG. 1. More specifically, the cab 9 side on the left side in FIG. 1 is the front side of the dump truck 1, and the side opposite to the cab 9 on the right side in FIG. 1 is the rear side of the dump truck 1. Also, the left-right direction of the dump truck 1 corresponds to the front-back direction in FIG. 1. More specifically, the front side (near side) in FIG. 1 is the left side of the dump truck 1, and the back side (far side) in FIG. 1 is the right side of the dump truck 1.

[0012] FIGS. 1 to 8 show the first embodiment. In FIG. 1, a dump truck 1, which is a large transport vehicle, includes a vehicle body 2, a vessel 3 as a loading platform, left and right front wheels 4, and left and right rear wheels 5. The dump truck 1 loads, for example, a transport object such as earth and sand or crushed stones onto the vessel 3 by a hydraulic excavator. In this state, the dump truck 1 transports the transport object to the unloading location. At the unloading location, the dump truck 1 unloads the transport object from the vessel 3 by rotating (shifting) the vessel 3 from the toppled state to the upright state.

[0013] The vehicle body 2 of the dump truck 1 includes a vehicle body frame 6 that serves as the base of the vehicle body 2. The vehicle body frame 6 is configured as a strong support structure extending in the front-rear direction. A pair of front wheels 4 are arranged on the front side of the vehicle body frame 6, and a pair of rear wheels 5 are arranged on the rear side of the vehicle body frame 6. That is, the pair of front wheels 4 are rotatably attached to the left and right sides of the front portion of the vehicle body frame 6. The pair of rear wheels 5 are rotatably attached to the left and right sides of the rear portion of the vehicle body frame 6. The front wheels 4 and the rear wheels 5 are formed, for example, with a tire diameter (outer diameter dimension) ranging from 2 to 4 meters.

[0014] The front wheels 4 correspond to the steering wheels that are steered by the driver of the dump truck 1 (or automatic driving from the outside). A front-wheel side suspension 7 composed of a hydraulic shock absorber is provided between the front part of the vehicle body frame 6 and the front wheels 4. On the other hand, the rear wheels 5 correspond to the drive wheels of the dump truck 1. That is, the rear wheels 5 are rotationally driven by a traveling electric motor (not shown). A rear-wheel side suspension 8 composed of a hydraulic shock absorber is provided between the rear part of the vehicle body frame 6 and the rear wheels 5.

[0015] More specifically, an axle housing (not shown) is provided on the rear part side of the vehicle body frame 6. The axle housing is composed of a cylindrical body extending in the width direction (left-right direction) of the vehicle body 2 and is attached to the vehicle body frame 6 via the rear-wheel side suspension 8. Traveling electric motors are provided on both the left and right sides of the axle housing. The rotation of the left and right traveling electric motors is transmitted to the left and right rear wheels 5 via a reduction mechanism (not shown).

[0016] Also, a cab 9 and a control box 10 are arranged on the upper part of the front side of the vehicle body frame 6. The interior of the cab 9 is a driver's cab. Inside the cab 9, a driver's seat, a start switch, an accelerator pedal, a brake pedal, a steering wheel for steering, and a plurality of operation levers (all not shown) are provided. The control box 10 is configured to include an inverter for controlling the traveling electric motor.

[0017] The hopper 3 is mounted on the vehicle body 2 so as to be able to rise and fall. For this purpose, the hopper 3 is connected to the rear end side of the vehicle body 2 via a connection pin 11 also called a hinge pin so as to be able to rise and fall (tilt). More specifically, the hopper 3 is connected to the vehicle body frame 6 by the connection pin 11 and the hoist cylinder 12. The connection pin 11 is attached to the rear side of the vehicle body frame 6. The hoist cylinder 12 is attached to the front side of the vehicle body frame 6 with respect to the connection pin 11. The hoist cylinder 12 can be extended and contracted.

[0018] The vessel 3 moves up and down (standing and lowering) as the hoist cylinder 12 extends and retracts, and the part connected to the upper end of the hoist cylinder 12 rotates vertically around the connecting pin 11. In other words, the vessel 3 can be moved from a state where the hoist cylinder 12 is retracted and lowered against the vehicle body 2 (lowered position) to a state where the hoist cylinder 12 is extended and the front is raised upward with the rear as the pivot point (upright position). The vessel 3 is formed as a large container with a total length of about 9 to 13 meters in order to carry large quantities of heavy loads (objects to be transported, loads) such as soil, crushed stone, and ore.

[0019] As shown in Figure 2, the vehicle frame 6 is composed of a pair of frame members 6A and 6B (left frame member 6A, right frame member 6B). The frame members 6A and 6B have a frame shape that extends in the front-rear direction and are arranged separately in the width direction (left-right direction) of the vehicle body 2. In contrast, a pair of rail plates 13A and 13B (left rail plate 13A, right rail plate 13B) are provided on the underside of the vessel 3. When the vessel 3 is seated on the vehicle frame 6, the pair of rail plates 13A and 13B of the vessel 3 are placed on the upper surfaces of the pair of frame members 6A and 6B of the vehicle frame 6.

[0020] Furthermore, a pair of bracket portions 6C and 6D (left bracket portion 6C, right bracket portion 6D) are provided at the rear of the vehicle frame 6 (a pair of frame members 6A and 6B). These bracket portions 6C and 6D rotatably support the rear bottom of the vessel 3 via a connecting pin 11. The connecting pin 11 becomes the pivot point (center of rotation) of the vessel 3 when the vessel 3 is raised or lowered, that is, when the front part of the vessel 3 is rotated vertically.

[0021] A pair of hoist cylinders 12 are attached to the vehicle frame 6 in front of the connecting pin 11, connecting the vehicle frame 6 to the vessel 3. In this case, the frame members 6A and 6B of the vehicle frame 6 are provided with mounting portions 6E that protrude downward in a mountain shape. The mounting portions 6E constitute mounting brackets for the hoist cylinders 12. That is, the lower end (for example, the rod side) of the hoist cylinder 12 is attached to the mounting portion 6E. As a result, the hoist cylinders 12 are attached to approximately the center of the vehicle frame 6 in the front-rear direction.

[0022] As shown in Figure 1, a cab 9, which serves as the operator's cabin, is located on the upper left side of the vehicle frame 6 (in other words, above the left front wheel 4). A power unit 14, which includes an engine and generator, is located at the front of the vehicle frame 6. The operator can raise or lower the vessel 3 by driving the hoist cylinder 12 from the cab 9.

[0023] When the vessel 3 is upright, the hoist cylinder 12 is extended. When the hoist cylinder 12 is retracted from this state (the upright position of the vessel 3), the front of the vessel 3 rotates downward around the connecting pin 11. As a result, the vessel 3 assumes a reclined position (see Figure 1) where it is seated on the vehicle frame 6. When the hoist cylinder 12 is extended from this state (the reclined position), the front of the vessel 3 rotates upward around the connecting pin 11. As a result, the vessel 3 assumes an upright position (see Figure 2) where it can release the object being transported.

[0024] Next, we will explain the configuration of Vessel 3 in detail.

[0025] As shown in Figures 2 and 3, the vessel 3 comprises a bottom plate 3A, a front plate 3B, and two side plates 3C and 3D (left side plate 3C, right side plate 3D). The bottom plate 3A, the front plate 3B, and the side plates 3C and 3D are joined together by welding. The vessel 3 has a roughly box-like shape with the top and rear open due to these bottom plate 3A, front plate 3B, and side plates 3C and 3D. As a result, the interior of the vessel 3 forms a loading area for loading objects to be transported.

[0026] Specifically, the front plate 3B is positioned on the front side of the bottom plate 3A in the front-to-back direction (length direction). The side plates 3C and 3D are positioned on both sides of the bottom plate 3A in the left-to-right direction (width direction). By being positioned around the periphery of the bottom plate 3A, the front plate 3B and the side plates 3C and 3D form a peripheral wall with at least one side (the rear in this embodiment) open.

[0027] Thus, the bottom plate 3A, front plate 3B, and side plates 3C, 3D constitute the inner surface of the loading section of the vessel 3. Specifically, the bottom plate 3A constitutes the bottom surface of the loading section. The front plate 3B constitutes the front inner wall surface of the loading section. The side plates 3C, 3D constitute the inner wall surfaces on both sides of the loading section in the left-right direction. As shown in Figure 1, the vessel 3 sits on the vehicle frame 6 of the vehicle body 2 with the bottom plate 3A tilted slightly forward and downward.

[0028] Furthermore, a roughly plate-shaped top plate 3E is attached to the upper part of the front plate 3B. As shown in Figure 1, the top plate 3E protrudes forward from the upper part (upper edge) of the front plate 3B so as to cover the top of the cab 9. In other words, the upper front part of the vessel 3 is the top plate 3E, which acts as an overhang that covers the cab 9 from above. The top plate 3E prevents damage to the cab 9, power unit 14, etc., caused by objects being transported falling from the vessel 3 while the vessel 3 is seated on the vehicle frame 6. Also, as shown in Figure 3, diagonal plates 3F are welded to the corners, which are the joints of the bottom plate 3A, the front plate 3B, and the side plates 3C, 3D, for reinforcement.

[0029] Furthermore, as shown in Figure 2, two rail plates 13A and 13B are provided in the center of the lower surface of the vessel 3 (i.e., the lower surface of the bottom plate 3A), spaced apart in the left-right direction, and extending in the front-rear direction of the vehicle frame 6. The rail plates 13A and 13B are formed, for example, from steel with a roughly U-shaped cross-section. Multiple body pads 15 are provided on the lower surface of the rail plates 13A and 13B, arranged in the front-rear direction. The body pads 15 are made of, for example, an elastic resin material, and when the vessel 3 is seated on the vehicle frame 6, they come into contact with the upper surface of the vehicle frame 6 (the upper surface of the frame members 6A and 6B). The body pads 15 cushion the impact when the vessel 3 is seated on the vehicle frame 6.

[0030] Furthermore, the rear ends of the rail plates 13A and 13B are connected to the vehicle frame 6 by connecting the rear of the vessel 3 to the vehicle frame 6 by connecting parts 13A1 and 13B1 (left connecting part 13A1, right connecting part 13B1). The connecting parts 13A1 and 13B1 are tiltably connected to the bracket parts 6C and 6D of the vehicle frame 6 via connecting pins 11. Also, on the lower surface of the vessel 3 (i.e., the lower surface of the bottom plate 3A), a pair of cylinder mounting parts 16 (only the left cylinder mounting part 16 is shown) are provided, located approximately midway in the front-rear direction of the vessel 3. The cylinder mounting parts 16 are each located outside the rail plates 13A and 13B in the left-right direction and are fixed to the lower surface of the vessel 3 (i.e., the lower surface of the bottom plate 3A) by welding or the like. The upper end (for example, the tube side) of the hoist cylinder 12 is attached to the cylinder mounting part 16.

[0031] Next, we will explain the configuration of the hoist cylinder 12 in detail.

[0032] The hoist cylinders 12 are installed in pairs in the left-right direction between the vehicle frame 6 and the vessel 3. The hoist cylinders 12 are, for example, hydraulic cylinders, and by extending and retracting, they tilt the front side of the vessel 3 up and down relative to the vehicle frame 6. One end (lower end) of the hoist cylinder 12 is attached to the mounting portion 6E of the vehicle frame 6. The other end (upper end) of the hoist cylinder 12 is attached to the lower side (cylinder mounting portion 16) of the vessel 3.

[0033] The hoist cylinder 12 is composed of, for example, a multi-stage (two-stage) hydraulic cylinder. As shown in Figure 2, the hoist cylinder 12 comprises an outer cylinder portion 12A located on the outside (circumferential side), an inner cylinder portion 12B that is extendable and retractable within the outer cylinder portion 12A, and a piston rod 12C that is extendable and retractable within the inner cylinder portion 12B. The piston rod 12C, which is one end (lower end) of the hoist cylinder 12, is attached to the mounting portion 6E of the vehicle frame 6. The outer cylinder portion 12A, which is the other end (upper end) of the hoist cylinder 12, is attached to the lower surface (cylinder mounting portion 16) of the vessel 3.

[0034] The hoist cylinder 12 extends vertically when pressurized oil is supplied from a hydraulic pump (not shown). As a result, the front of the vessel 3 is lifted upward around the connecting pin 11, allowing the cargo loaded on the vessel 3 to be discharged to the rear. For this purpose, as shown in Figure 1, a hydraulic oil tank 17 is mounted on the side of the vehicle frame 6, located below the vessel 3. The hydraulic oil in the hydraulic oil tank 17 is drawn in and discharged by the hydraulic pump, becoming pressurized oil which is then supplied to the hoist cylinder 12. The hydraulic oil in the hydraulic oil tank 17 is also supplied to, for example, the operating cylinder (not shown) for the power steering.

[0035] Incidentally, Patent Document 1, mentioned above, describes a technique for suppressing the swaying of a cargo bed by positioning a sway-preventing member provided on the cargo bed (vessel) and a backing plate provided on the vehicle body frame (vehicle frame) opposite each other in the width direction (left-right direction) of the vehicle body. However, in the technique of Patent Document 1, when the hoist cylinder is extended to unload cargo such as soil from the cargo bed, the position of the sway-preventing member and the backing plate changes as the cargo bed moves away from the vehicle body frame, and the sway-preventing member and the backing plate no longer face each other in the width direction of the vehicle body.

[0036] Therefore, when the hoist cylinder is extended to unload cargo from the cargo bed, if the cargo bed vibrates in the width direction relative to the frame, the vibration may not be transmitted to the connecting pin and hoist cylinder without contact between the anti-vibration member and the backing plate. This vibration may cause damage to the connecting pin and hoist cylinder. In particular, when unloading cargo from the cargo bed, the large movement caused by the rotation of the cargo bed may damage the part of the holding portion of the hoist cylinder that holds the connecting pin, especially the part close to the connection point with the hoist cylinder body (the tube with an oil chamber inside).

[0037] Therefore, in this embodiment, vibrations transmitted to the connecting pin and the hoist cylinder are reduced not only when the hoist cylinder is retracted and the loading platform is resting on the vehicle frame, but also when the hoist cylinder is extended and the loading platform is separated from the vehicle frame. Specifically, in this embodiment, a displacement limiting member (guide plate 31) is provided between the hoist cylinder and the loading platform to limit the relative displacement between the hoist cylinder and the loading platform (relative displacement in the width direction of the vehicle body). The displacement limiting member (guide plate 31) suppresses the application of localized stress to the holding portion of the hoist cylinder.

[0038] In other words, in this embodiment, a displacement limiting member (guide plate 31) is interposed at the connection between the dump truck bed and the hoist cylinder to distribute local stress and suppress damage to the hoist cylinder. In this case, the displacement limiting member (guide plate 31) is configured to maintain a state of being close to and facing the hoist cylinder in the width direction of the vehicle body, even when the hoist cylinder is extended. Therefore, in this embodiment, the displacement limiting member (guide plate 31) reduces vibrations transmitted to the connecting pin and the hoist cylinder even when the hoist mechanism is operated to unload cargo from the bed (when the hoist cylinder is extended). As a result, in this embodiment, wear and damage to the hoist cylinder can be suppressed and the lifespan of the parts can be extended. These points will be explained in detail below.

[0039] Figures 4 to 7 show enlarged views of the mounting area between the cylinder mounting portion 16, which is provided on the lower surface of the vessel 3 (the lower surface of the bottom plate 3A), and the upper end side (tube side) of the hoist cylinder 12. In this case, Figure 4 corresponds to part (IV) in Figure 1. Figure 5 corresponds to the cross-section in the direction of arrow VV in Figure 4. Figure 6 corresponds to the cross-section in the direction of arrow VI-VI in Figure 5. Figure 7 corresponds to the cross-section in the direction of arrow VII-VII in Figure 4. Figure 8 shows the displacement limiting member, i.e., the guide plate 31, provided between the cylinder mounting portion 16 of the vessel 3 and the hoist cylinder 12, as a standalone unit.

[0040] As shown in Figures 4 to 7, the cylinder end face 21, which is the upper end surface in the vertical direction (longitudinal direction) of the hoist cylinder 12, is a plane that extends in a direction perpendicular to the central axis of the hoist cylinder 12. The cylinder end face 21 is provided with a pair of support plates 23A and 23B that protrude upward (towards the vessel 3) from the cylinder end face 21. The support plates 23A and 23B are roughly horseshoe-shaped (roughly U-shaped). The pair of support plates 23A and 23B are each provided with through holes 24A and 24B.

[0041] The central axes of the through holes 24A and 24B extend in the left-right direction of the vehicle body 2. The through hole 24A of one support plate 23A and the through hole 24B of the other support plate 23B are concentric. That is, the central axes of the through holes 24A and 24B provided in the pair of support plates 23A and 23B coincide with each other. A connecting pin 22 is inserted through the through holes 24A and 24B. That is, both ends of the pin 22 are fixed to the pair of support plates 23A and 23B.

[0042] The cylinder mounting portion 16, provided on the lower surface of the vessel 3 (the lower surface of the bottom plate 3A), comprises a plate portion 25 that is roughly horseshoe-shaped (roughly U-shaped) and extends downward (towards the hoist cylinder 12), and a cylindrical portion 27 fixed to the side surface of the plate portion 25. The plate portion 25 is provided with an insertion hole 26 through which a pin 22 is rotatably inserted. The insertion hole 26 and the cylindrical portion 27 are concentric. That is, the central axis of the insertion hole 26 and the central axis of the cylindrical portion 27 coincide. Also, the inner diameter of the insertion hole 26 and the inner diameter of the cylindrical portion 27 coincide. The pin 22 is rotatably inserted through the insertion hole 26 and the cylindrical portion 27.

[0043] A shim ring 28A is provided between the plate portion 25 of the cylinder mounting portion 16 and one support plate 23A of the hoist cylinder 12 facing it. This shim ring 28A makes surface contact with the plate portion 25 and one support plate 23A. Another shim ring 28B is provided between the cylindrical portion 27 of the cylinder mounting portion 16 and the other support plate 23B of the hoist cylinder 12 facing it. This other shim ring 28B makes surface contact with the cylindrical portion 27 and the other support plate 23B. A pin 22 is rotatably inserted inside the shim rings 28A and 28B.

[0044] The hoist cylinder 12 is rotatably supported by the cylinder mounting portion 16 via a pin 22. Specifically, a cylindrical pin 22 is provided between the plate portion 25 and cylindrical portion 27 of the cylinder mounting portion 16 and the pair of support plates 23A and 23B of the hoist cylinder 12. Both ends of the pin 22 are fixed in place by being inserted through the through holes 24A and 24B of the support plates 23A and 23B. The middle portion of the pin 22 is rotatably inserted through the insertion hole 26 of the plate portion 25 and the cylindrical portion 27. As a result, the upper end of the hoist cylinder 12 (i.e., the pair of support plates 23A and 23B) is rotatably supported by the cylinder mounting portion 16 of the vessel 3 via the pin 22.

[0045] Next, the damage suppression mechanism of the hoist cylinder 12 will be described.

[0046] The damage suppression mechanism for the hoist cylinder 12 includes a guide plate 31 as a displacement limiting member fixed to the cylinder mounting portion 16, and a groove 32 provided on the cylinder end face 21 of the hoist cylinder 12.

[0047] As shown in Figures 7 and 8, the guide plate 31 has a three-dimensional shape obtained by rotating a roughly J-shaped cross section around the central axis of the pin 22 by an angle of 90° to 180°. As a result, the guide plate 31 has a roughly fan-shaped overall form. The guide plate 31 comprises a roughly semi-cylindrical inner diameter portion 31A located radially inward, a roughly semi-cylindrical outer diameter portion 31B located radially outward from the inner diameter portion 31A, and a radial connecting portion 31C that connects the inner diameter portion 31A and the outer diameter portion 31B in the radial direction.

[0048] One side of the inner diameter portion 31A in the axial direction (left-right direction in Figure 5) (the side with the plate portion 25 of the cylinder mounting portion 16) is a semi-cylindrical flange portion 31D whose outer diameter is larger than the outer diameter of the inner diameter portion 31A and less than or equal to the width of the plate portion 25 of the cylinder mounting portion 16. In contrast, the other side of the inner diameter portion 31A in the axial direction (the side with the radial connection portion 31C) is connected to the other side of the outer diameter portion 31B in the axial direction via the radial connection portion 31C. That is, the radial connection portion 31C connects the other side of the inner diameter portion 31A and the outer diameter portion 31B in the axial direction (the right side in the left-right direction in Figure 5).

[0049] In this case, the other side surface 31A1 of the inner diameter portion 31A, the other side surface 31B1 of the outer diameter portion 31B, and the other side surface 31C1 of the radial connection portion 31C coincide. That is, the other side surfaces 31A1, 31B1, and 31C1 of the inner diameter portion 31A, the outer diameter portion 31B, and the radial connection portion 31C are on the same plane. These side surfaces 31A1, 31B1, and 31C1 constitute the other side surface of the guide plate 31. Furthermore, the radial dimension A of the other side surface of the guide plate 31 is greater than the radial dimension B of one side surface 31B2 of the outer diameter portion 31B (A > B).

[0050] Furthermore, one side surface 31A2 of the inner diameter portion 31A and one side surface 31D1 of the flange portion 31D also coincide. That is, the side surfaces 31A2 and 31D1 of the inner diameter portion 31A and the flange portion 31D are on the same plane. These side surfaces 31A2 and 31D1 constitute one side surface of the guide plate 31. And one side surface of the guide plate 31, the other side surface of the guide plate 31, and one side surface 31B2 of the outer diameter portion 31B are parallel to each other.

[0051] The flange portion 31D is provided with multiple (for example, three) bolt insertion holes 31E spaced apart in the circumferential direction, through which bolts 33 for fixing the guide plate 31 to the cylinder mounting portion 16 are inserted. Accordingly, the plate portion 25 of the cylinder mounting portion 16 is also provided with bolt insertion holes 25A (see Figure 5) for inserting bolts 33 at positions corresponding to the bolt insertion holes 31E in the flange portion 31D of the guide plate 31.

[0052] The guide plate 31 is positioned relative to the cylinder mounting portion 16 by bringing the inner surface of its inner diameter portion 31A into curved contact with the outer circumferential surface of the cylindrical portion 27 of the cylinder mounting portion 16, and by bringing the side surface 31D1 of the flange portion 31D into surface contact with the plate portion 25 of the cylinder mounting portion 16. In this state, the guide plate 31 can be fixed to the cylinder mounting portion 16 by inserting bolts 33 through the bolt insertion holes 31E of the flange portion 31D and the bolt insertion holes 25A of the plate portion 25, and screwing nuts 34 onto these bolts 33.

[0053] With the guide plate 31 fixed to the cylinder mounting portion 16, a portion of the outer diameter portion 31B in the circumferential direction fits into a groove 32 provided on the cylinder end face 21 of the hoist cylinder 12. That is, the cylinder end face 21 is provided with a groove 32 cut out from the cylinder end face 21 toward the piston rod 12C at a position corresponding radially to the guide plate 31 (in other words, between the pair of support plates 23A and 23B). The groove 32 has a width dimension larger than the width dimension of the outer diameter portion 31B, and its bottom surface 32A is in close proximity to the outer circumferential surface 31B3 of the outer diameter portion 31B.

[0054] That is, the outer peripheral surface 31B3 of the outer diameter portion 31B faces the bottom surface 32A of the groove 32 in parallel with a radial gap 35. Also, the widthwise sides 31B1 and 31B2 of the outer diameter portion 31B face the inner sides 32B and 32C of the groove 32 in parallel with an axial (widthwise) gap 36. The axial gap 36 between the sides 31B1 and 31B2 of the outer diameter portion 31B and the inner sides 32B and 32C of the groove 32 is smaller than the radial gap 35 between the outer peripheral surface 31B3 of the outer diameter portion 31B and the bottom surface 32A of the groove 32.

[0055] The outer circumferential surface 31B3 of the outer diameter portion 31B has a uniform width in the axial direction at all points. That is, when the outer diameter portion 31B is projected from top to bottom, its shape is rectangular. Similarly, the bottom surface 32A of the groove 32 is also rectangular when the groove 32 is projected from top to bottom. Furthermore, with the guide plate 31 fixed to the cylinder mounting portion 16, the axial center of the outer diameter portion 31B and the axial center of the bottom surface 32A of the groove 32 coincide. Also, the axial center of the outer diameter portion 31B and the axial center of the bottom surface 32A of the groove 32 pass through the central axis of the cylinder end face 21 of the hoist cylinder 12 (the central axis of the hoist cylinder 12). In other words, the central axis of the cylinder end face 21 of the hoist cylinder 12 (the central axis of the hoist cylinder 12) passes through a position that bisects the outer diameter portion 31B and the groove 32 in the axial direction.

[0056] Furthermore, in this embodiment, the outer diameter portion 31B is semi-cylindrical in shape so that a portion of it remains inside the groove 32 of the hoist cylinder 12 regardless of the change in the inclination angle of the vessel 3 due to the extension and contraction of the hoist cylinder 12. That is, the outer diameter portion 31B has an angle θ (Figure 8) of 180° between one end face 31B4 and the other end face 31B5 in the circumferential direction. Note that the angle θ of the outer diameter portion 31B only needs to be an angle that allows a portion of the outer diameter portion 31B to always remain inside the groove 32 of the hoist cylinder 12, regardless of whether the hoist cylinder 12 is extended or contracted. For this reason, the angle θ of the outer diameter portion 31B may be less than 180°. For example, the angle θ of the outer diameter portion 31B can be set in the range of 90° to 180°.

[0057] The guide plate 31 is detachable from the cylinder mounting portion 16. In this case, the guide plate 31 can be attached to and detached from the cylinder mounting portion 16 without removing the hoist cylinder 12 from the cylinder mounting portion 16 (without disassembling the surrounding parts). For this purpose, the guide plate 31 is fixed to the cylinder mounting portion 16 using bolts 33 and nuts 34. In this case, the bolt insertion holes 31E in the guide plate 31 (flange portion 31D) and the bolt insertion holes 25A in the cylinder mounting portion 16 (plate portion 25) can be through holes extending parallel to the axial direction of the pin 22.

[0058] Furthermore, the pitch circle centers of the bolt insertion holes 31E and 25A coincide, for example, with the center of the pin 22. It is preferable that there be two or more locations where bolts 33 and nuts 34 are used for fastening. In this embodiment, there are three locations. Although not shown in the figures, either the bolt insertion hole 31E of the guide plate 31 (flange portion 31D) or the bolt insertion hole 25A of the cylinder mounting portion 16 (plate portion 25) may be made into a female threaded hole, and a bolt may be screwed into this female threaded hole. Also, the fixing of the guide plate 31 and the cylinder mounting portion 16 only needs to be such that the guide plate 31 can be removed from the cylinder mounting portion 16 and replaced. For this reason, the fixing of the guide plate 31 and the cylinder mounting portion 16 is not limited to fastening means (engaging means) using bolts 33 and nuts 34, but various detachable fastening means (engaging means) can be used.

[0059] The surface hardness of the guide plate 31 is preferably less than or equal to the surface hardness of the surrounding parts (e.g., the cylinder end face 21) that the guide plate 31 contacts. Furthermore, the Young's modulus of the guide plate 31 is also preferably less than or equal to the Young's modulus of the surrounding parts that the guide plate 31 contacts. This helps to suppress wear on the mating parts that the guide plate 31 contacts. In other words, the replaceable guide plate 31 is the one that wears down. The material of the guide plate 31 can be, for example, resin (synthetic resin), spring steel, etc.

[0060] To summarize, as shown in Figures 1 to 3, the dump truck 1, as a transport vehicle, comprises a body 2, a vessel 3 as a cargo bed, and a hoist cylinder 12. The body 2 comprises, for example, a body frame 6. The body frame 6 is equipped with, for example, front wheels 4 and rear wheels 5. This allows the body 2 to move. The vessel 3 is mounted on the body 2 (more specifically, the body frame 6) so as to be rotatable in the vertical direction with its rear end as the pivot point.

[0061] The vessel 3 is provided with a cylinder mounting portion 16 to which one end (upper end, tube side) of the hoist cylinder 12 is attached. The vehicle body 2 (more specifically, the vehicle body frame 6) is provided with a mounting portion 6E to which the other end (lower end, rod side) of the hoist cylinder 12 is attached. The hoist cylinder 12 is mounted between the cylinder mounting portion 16 of the vessel 3 and the vehicle body 2 (more specifically, the mounting portion 6E of the vehicle body frame 6). The hoist cylinder 12 rotates the vessel 3 upward or downward by extending or retracting.

[0062] Furthermore, a guide plate 31 is provided as a displacement limiting member between the cylinder mounting portion 16 of the vessel 3 and the hoist cylinder 12. The guide plate 31 is fixed to the cylinder mounting portion 16, which is one of the components of the vessel 3 and the hoist cylinder 12. At the same time, the guide plate 31 is positioned in close proximity to the hoist cylinder 12 (more specifically, the groove 32 of the hoist cylinder 12), which is the other component of the vessel 3, in the width direction of the vehicle body 2.

[0063] The guide plate 31 comes into contact with the hoist cylinder 12 (more specifically, the inner surfaces 32B and 32C of the groove 32) when the hoist cylinder 12 and the vessel 3 (cylinder mounting portion 16) are displaced relative to each other in the width direction of the vehicle body 2. As a result, the guide plate 31 limits the relative displacement between the hoist cylinder 12 and the vessel 3 (cylinder mounting portion 16) (relative displacement in the width direction of the vehicle body 2).

[0064] In this case, even when the hoist cylinder 12 extends, the guide plate 31 maintains a state in which it is close to and facing the hoist cylinder 12 (more specifically, the groove 32 of the hoist cylinder 12) in the width direction of the vehicle body 2. That is, even when the rotational position of the vessel 3 changes due to the extension or contraction of the hoist cylinder 12, the guide plate 31 maintains a state in which it is close to and facing the hoist cylinder 12 (more specifically, the inner surfaces 32B, 32C of the groove 32) in the width direction of the vehicle body 2.

[0065] Furthermore, the cylinder mounting portion 16 of the vessel 3 has a cylindrical portion 27 through which a pin 22 is inserted for rotatably supporting the hoist cylinder 12 relative to the cylinder mounting portion 16. On the other hand, the hoist cylinder 12 has a cylinder end face 21 facing the cylindrical portion 27 of the cylinder mounting portion 16, and a pair of support plates 23A and 23B that extend from the cylinder end face 21 toward the cylindrical portion 27 and are attached to both ends of the pin 22, respectively.

[0066] Furthermore, the guide plate 31 is provided between the pair of support plates 23A and 23B of the hoist cylinder 12, and between the cylindrical portion 27 of the cylinder mounting portion 16 and the cylinder end face 21 of the hoist cylinder 12.

[0067] The guide plate 31 comprises an inner diameter portion 31A, an outer diameter portion 31B, a radial connection portion 31C, and a flange portion 31D. The inner diameter portion 31A and the flange portion 31D correspond to fixing portions that are fixed to the cylinder mounting portion 16. The radial connection portion 31C and the outer diameter portion 31B correspond to displacement limiting portions that extend from the inner diameter portion 31A toward the groove 32 provided in the hoist cylinder 12. The displacement limiting portion has two inner surfaces 32B, 32C of the groove 32 and a pair of surfaces that are in close proximity to each other in the width direction of the vehicle body 2, namely the surfaces 31B1, 31B2 of the outer diameter portion 31B.

[0068] The dump truck 1 according to this embodiment has the configuration described above, and its operation will now be explained.

[0069] In quarries and other mining facilities, for example, a large hydraulic excavator (not shown) is used to load the material to be transported (e.g., soil and sand) onto the vessel 3. At this time, the hoist cylinder 12 is retracted, and the vessel 3 is positioned in a transport location seated on the vehicle frame 6. The dump truck 1 travels towards the unloading area with a large amount of material loaded onto the vessel 3. When the dump truck 1, loaded with a large amount of material on the vessel 3, arrives at the unloading area, the hoist cylinder 12 is extended, causing the vessel 3 to rotate upward using the connecting pin 11 as a pivot point. This allows the material loaded onto the vessel 3 to be discharged into the unloading area.

[0070] In this embodiment, a guide plate 31 is provided between the cylinder mounting portion 16 of the vessel 3 and the hoist cylinder 12. The guide plate 31 is a displacement limiting member that limits the relative displacement of the cylinder mounting portion 16 and the hoist cylinder 12 in the width direction of the vehicle body 2. Therefore, the guide plate 31 can suppress damage to the hoist cylinder 12. Furthermore, even when the hoist cylinder 12 extends, the guide plate 31 maintains a state in close proximity to the hoist cylinder 12 (more specifically, the inner surfaces 32B, 32C of the groove 32 of the hoist cylinder 12) in the width direction of the vehicle body 2.

[0071] In other words, not only when the hoist cylinder 12 is retracted, but also when the hoist cylinder 12 is extended, the guide plate 31 comes into contact with the hoist cylinder 12 (the inner surfaces 32B, 32C of the groove 32) when the vessel 3 (cylinder mounting portion 16) and the hoist cylinder 12 are displaced relative to each other in the width direction. As a result, regardless of whether the hoist cylinder 12 is extended or retracted, the guide plate 31 limits the relative displacement of the cylinder mounting portion 16 and the hoist cylinder 12 in the width direction of the vehicle body 2, thereby suppressing damage to the hoist cylinder 12. Consequently, wear and damage to the hoist cylinder 12 can be reduced, and the lifespan of the parts can be extended.

[0072] According to this embodiment, the guide plate 31 is provided between a pair of support plates 23A and 23B of the hoist cylinder 12, and between the cylindrical portion 27 of the cylinder mounting portion 16 and the cylinder end face 21 of the hoist cylinder 12. Therefore, the space between the cylinder end face 21 of the hoist cylinder 12 and the cylindrical portion 27 of the cylinder mounting portion 16 facing it can be effectively utilized as the installation space for the guide plate 31.

[0073] According to the first embodiment, the guide plate 31 includes a radial connecting portion 31C and an outer diameter portion 31B that extend toward a groove 32 provided in the hoist cylinder 12 as a displacement limiting portion. The outer diameter portion 31B has a pair of side surfaces 31B1 and 31B2 that are in close proximity to and facing the inner side surfaces 32B and 32C of the groove 32 in the width direction. Therefore, when the vessel 3 (cylinder mounting portion 16) and the hoist cylinder 12 are displaced relative to each other in the width direction of the vehicle body 2, the side surfaces 31B1 and 31B2 of the guide plate 31 come into contact with the inner side surfaces 32B and 32C of the groove 32, thereby limiting this relative displacement in the width direction.

[0074] Next, Figures 9 to 12 show a second embodiment. The second embodiment is configured such that the hoist cylinder is provided with a protrusion (guide plate support) that is close to and opposite the guide plate in the width direction of the vehicle body. In the second embodiment, the same reference numerals are used for the same components as in the first embodiment described above, and their descriptions are omitted.

[0075] In the first embodiment described above, the damage suppression mechanism for the hoist cylinder 12 is composed of a guide plate 31 fixed to the cylinder mounting portion 16 and a groove 32 provided on the cylinder end face 21 of the hoist cylinder 12. In contrast, in the second embodiment, the damage suppression mechanism for the hoist cylinder 12 is composed of a guide plate 31 fixed to the cylinder mounting portion 16 and a guide plate support 41 as a protrusion provided on the cylinder end face 21 of the hoist cylinder 12.

[0076] The guide plate 31 of the second embodiment, like the guide plate 31 of the first embodiment, includes an inner diameter portion 31A, an outer diameter portion 31B, a radial connection portion 31C, and a flange portion 31D. In the second embodiment, the outer peripheral surface 31B3 of the outer diameter portion 31B is provided with a groove 42 that is recessed radially inward (towards the pin 22) from the outer peripheral surface 31B3 and extends along the circumferential direction of the outer peripheral surface 31B3. The projection 41B of the guide plate support 41 fits into the groove 42.

[0077] A guide plate support 41 is provided on the cylinder end face 21 of the hoist cylinder 12, positioned between a pair of support plates 23A and 23B and forming a protrusion. The guide plate support 41 comprises a mounting flange portion 41A which forms the bottom of the guide plate support 41, and a projection portion 41B which protrudes upward from the mounting flange portion 41A and has a semi-circular concave surface 41B1. The mounting flange portion 41A is attached to the cylinder end face 21 of the hoist cylinder 12 using bolts 43. The projection portion 41B fits into a groove 42 in the outer diameter portion 31B of the guide plate 31, following the groove 42. The concave surface 41B1 of the projection portion 41B of the guide plate support 41 faces the bottom surface 42A of the groove 42 in the outer diameter portion 31B of the guide plate 31.

[0078] Specifically, the bottom surface 42A of the groove 42 of the guide plate 31 (outer diameter portion 31B) faces the concave surface 41B1 of the guide plate support 41 (projection portion 41B) parallel to it with a radial gap 35 in between. Also, the inner surfaces 42B and 42C of the groove 42 of the guide plate 31 (outer diameter portion 31B) face the sides 41B2 and 41B3 of the guide plate support 41 (projection portion 41B) parallel to each other with an axial (widthwise) gap 36 in between. The axial gap 36 between the inner surfaces 42B and 42C of the groove 42 and the sides 41B2 and 41B3 of the projection portion 41B is smaller than the radial gap 35 between the bottom surface 42A of the groove 42 and the concave surface 41B1 of the projection portion 41B.

[0079] The guide plate support 41 is detachable from the cylinder end face 21 of the hoist cylinder 12. In this case, the guide plate support 41 can be attached to and detached from the cylinder end face 21 of the hoist cylinder 12 without removing the hoist cylinder 12 from the cylinder mounting portion 16 (without disassembling the surrounding parts). For example, the guide plate support 41 can be made into a two-part structure that can be separated in the front-rear direction of the vehicle body 2 at the lowest point of the projection 41B.

[0080] Furthermore, the guide plate support 41 is fixed to the cylinder end face 21 of the hoist cylinder 12 using bolts 43. It is sufficient that the guide plate support 41 can be removed from the hoist cylinder 12 and replaced. Therefore, the fixing of the guide plate support 41 to the hoist cylinder 12 is not limited to fastening means (engaging means) using bolts 43, but various detachable fastening means (engaging means) can be used.

[0081] The second embodiment includes the guide plate 31 and guide plate support 41 as described above, and its basic operation is no different from that of the first embodiment described above. That is, in the second embodiment as well, a guide plate 31, which is a displacement limiting member, is provided between the cylinder mounting portion 16 of the vessel 3 and the hoist cylinder 12. Therefore, damage to the hoist cylinder 12 can be suppressed. In addition, even when the hoist cylinder 12 extends, the guide plate 31 (more specifically, the groove 42 of the outer diameter portion 31B) is maintained in close proximity to the hoist cylinder 12 (more specifically, the projection 41B of the guide plate support 41 which becomes the convex portion of the hoist cylinder 12) in the width direction of the vehicle body 2.

[0082] In other words, not only when the hoist cylinder 12 is retracted, but also when the hoist cylinder 12 is extended, if the vessel 3 (cylinder mounting portion 16) and the hoist cylinder 12 are displaced relative to each other in the width direction, the guide plate 31 (inner surfaces 42B, 42C of the groove 42 of the outer diameter portion 31B) comes into contact with the hoist cylinder 12 (side surfaces 41B2, 41B3 of the guide plate support 41). As a result, regardless of whether the hoist cylinder 12 is extended or retracted, the relative displacement of the cylinder mounting portion 16 and the hoist cylinder 12 in the width direction of the vehicle body 2 is limited, and damage to the hoist cylinder 12 can be suppressed. As a result, wear and damage to the hoist cylinder 12 can be suppressed, and the life of the parts can be extended.

[0083] In the second embodiment, the guide plate 31 comprises an inner diameter portion 31A, an outer diameter portion 31B, a radial connection portion 31C, and a flange portion 31D. The inner diameter portion 31A and the flange portion 31D correspond to fixed portions that are fixed to the cylinder mounting portion 16. The radial connection portion 31C and the outer diameter portion 31B correspond to displacement limiting portions that extend from the inner diameter portion 31A toward the guide plate support 41 which is a protrusion provided on the hoist cylinder 12. The displacement limiting portion has two outer surfaces 41B2, 41B3 of the guide plate support 41 (protrusion 41B) and a pair of surfaces that are in close proximity to each other in the width direction of the vehicle body 2, namely the inner surfaces 42B, 42C of the groove 42 of the outer diameter portion 31B.

[0084] Thus, the guide plate 31 is equipped with a radial connection portion 31C and an outer diameter portion 31B that extend toward the guide plate support 41, which is a protrusion on the hoist cylinder 12, and serve as displacement limiting portions. The outer diameter portion 31B is provided with a groove 42 that extends in the circumferential direction. As a result, the outer diameter portion 31B has a pair of side surfaces 42B, 42C that are in close proximity to and facing both outer surface surfaces 41B2, 41B3 of the guide plate support 41 (projection portion 41B) in the width direction of the vehicle body 2. Therefore, when the vessel 3 (cylinder mounting portion 16) and the hoist cylinder 12 are displaced relative to each other in the width direction of the vehicle body 2, the side surfaces 42B, 42C of the groove 42 of the guide plate 31 and the outer surface surfaces 41B2, 41B3 of the guide plate support 41 (projection portion 41B) come into contact, thereby limiting this relative displacement in the width direction.

[0085] In the second embodiment, the mounting flange portion 41A of the guide plate support 41 was described as being configured to protrude outward from the projection 41B in the width direction of the projection 41B. However, the embodiment is not limited to this, and for example, as shown in the modified examples in Figures 13 and 14, the mounting flange portion 51 of the guide plate support 41 may be configured to protrude outward from the projection 41B in the length direction of the projection 41B. In other words, the mounting flange portion of the guide plate support can be made to have a shape that is easy to attach to the cylinder end face of the hoist cylinder.

[0086] In the first embodiment, the guide plate 31 was described using as an example a configuration in which one side of the inner diameter portion 31A and the outer diameter portion 31B in the axial direction is connected by a radial connection portion 31C. However, it is not limited to this configuration, and for example, the guide plate may be configured in which the axial center of the inner diameter portion and the outer diameter portion is connected by a radial connection portion. In this case, the width dimension (axial dimension) of the outer diameter portion and the radial connection portion may be the same. Furthermore, by making the width dimension (axial dimension) of the outer diameter portion, the radial connection portion and the inner diameter portion the same, the guide plate as a whole may be semi-cylindrical. That is, the displacement limiting member (guide plate) only needs to have a configuration in which a portion is fixed to the cylinder mounting portion and a portion that limits the relative displacement in the width direction by being close to and facing the hoist cylinder (groove) in the width direction of the vehicle. The same applies to the second embodiment and its modifications.

[0087] In the first embodiment, the guide plate 31, as a displacement limiting member, was described as being fixed to the cylinder mounting portion 16 and positioned in close proximity to the hoist cylinder 12 (more specifically, the groove 32 on the cylinder end face 21). However, the invention is not limited to this, and the displacement limiting member (guide plate) may be fixed to the hoist cylinder (cylinder end face) and positioned in close proximity to the cylinder mounting portion (for example, a groove provided in the cylindrical portion). That is, the displacement limiting member can be fixed to one of the members, the cylinder mounting portion or the hoist cylinder, and positioned in close proximity to the other member in the width direction of the vehicle body. The same applies to the second embodiment and its modifications.

[0088] In the first embodiment, a rear-wheel-drive dump truck 1 was used as an example of a transport vehicle. However, the invention is not limited to this, and may also be applied to, for example, a front-wheel-drive or four-wheel-drive dump truck. Also, in the first embodiment, a dump truck 1 equipped with an engine was used as an example of a transport vehicle, but the invention is not limited to this, and may also be applied to, for example, a dump truck equipped with a trolley device or an energy storage device. Also, in the first embodiment, a dump truck 1 equipped with wheels (front wheels 4, rear wheels 5) was used as an example of a transport vehicle, but the invention is not limited to this, and may also be applied to, for example, a crawler-type transport vehicle or other transport vehicle without wheels. The same applies to the second embodiment and its modifications.

[0089] Furthermore, although the first embodiment was described using a dump truck 1 having a drive source as an example of a transport vehicle, it may also be applied to transport vehicles that do not have a drive source, such as a towed vehicle (trailer) towed by a towing vehicle (tractor). In addition, it can be broadly applied to various types of transport vehicles, such as articulated transport vehicles. These points also apply to the second embodiment and its modifications. [Explanation of symbols]

[0090] 1. Dump truck (transport vehicle) 2 car bodies 3 Vessel (cargo bed) 12. Hoist cylinder (one component, the other component) 16 Cylinder mounting section (other member, one member) 21 Cylinder end face 22 pins 23A,23B Support plate 27. Cylindrical section (tube section) 31 Guide plate (displacement limiting member) 31A Inner diameter part (fixed part) 31B Outer diameter section (displacement limiting section) 31B1,31B2 Side 31C Radial connection section (displacement limiting section) 31D Flange section (fixing section) 32 grooves 32B,32C inner surface 41 Guide Plate Support 41B2,41B3 Outer surface 42B,42C Inner side (side)

Claims

1. A vehicle body that can be driven, A cargo bed is mounted on the vehicle body so as to be rotatable vertically with the rear as the pivot point, A hoist cylinder is installed between the cylinder mounting portion provided on the cargo bed and the vehicle body, and extends or retracts to rotate the cargo bed upward or downward. In a transport vehicle equipped with, Between the cylinder mounting portion of the cargo bed and the hoist cylinder, a displacement limiting member is provided, which is fixed to one of the members of the cylinder mounting portion and the hoist cylinder, and is positioned in close proximity to the other member in the width direction of the vehicle body, thereby limiting the relative displacement in the width direction between the other member and the one member. A transport vehicle characterized by the following features.

2. The cylinder mounting portion of the loading platform has a cylindrical portion through which a pin is inserted for rotatably supporting the hoist cylinder relative to the cylinder mounting portion. The hoist cylinder has a cylinder end face facing the cylindrical portion of the cylinder mounting section, and a pair of support plates extending from the cylinder end face toward the cylindrical portion and attached to both ends of the pin, respectively. The displacement limiting member is provided between the pair of support plates of the hoist cylinder and between the cylindrical portion of the cylinder mounting part and the cylinder end face of the hoist cylinder. The transport vehicle according to feature 1.

3. The displacement limiting member is A fixing portion fixed to one of the aforementioned members, The device comprises a displacement limiting portion that extends from the fixing portion toward a groove provided in the other member, and has a pair of sides that are adjacent to and facing both inner surfaces of the groove in the width direction, The transport vehicle according to feature 1.

4. The displacement limiting member is A fixing portion fixed to one of the aforementioned members, The fixed portion extends toward a protrusion provided on the other member, and comprises a displacement limiting portion having a pair of sides that are adjacent to and facing both outer surfaces of the protrusion in the width direction, The transport vehicle according to feature 1.

Images