Automated Cargo Vehicle

Abstract

To provide a freight automobile capable of dumping operation and sliding operation of a cargo box and that facilitates work for turning a tail gate, keeps the tail gate from being damaged in loading and unloading a vehicle such as a construction machine onto / from a cargo box, and can improve work efficiency of loading and unloading in both the operations.SOLUTION: A freight automobile 1 includes a hydraulic cylinder 21 that can turn a tail gate 15 between a closed position at which the tail gate erects from a base plate 11 of a cargo box 10 and an opening position at which it extends backward from the base plate 11. After a sliding operation and when the cargo box 10 is in contact with the ground, a passage 18 continuous with an upper surface 11U of the base plate 11 of the cargo box 10 is formed by an inner surface 15U of the tail gate 15 by the hydraulic cylinder 21 turning the tail gate 15 to the opening position.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a truck capable of performing a dumping operation to tilt a cargo box and a sliding operation to slide the cargo box rearward and place it on the ground. [Background technology]

[0002] Conventionally, there has been known a freight vehicle that can perform a dumping operation to tilt a cargo box and a sliding operation to slide the cargo box backward to land on the ground. For example, Patent Document 1 describes such a freight vehicle.

[0003] A conventional truck capable of both dumping and sliding motions is equipped with a tailgate that forms the rear wall of the cargo box and pivots to open the cargo box rearward. In such trucks, the tailgate is configured to be pivotable around both its upper and lower ends. An upper metal fitting is provided at the upper end of the tailgate that can be manually attached to the side wall of the cargo box, and a lower metal fitting is provided at the lower end of the tailgate that can be detached from the bottom plate of the cargo box.

[0004] When dumping the soil or sand stored in the cargo box, the lower metal fittings are released from the bottom plate of the cargo box, and the cargo box is tilted to perform a dumping operation. As the cargo box tilts, the tailgate pivots rearward around its upper end. This opens the tailgate, and the soil or sand stored in the cargo box is dumped rearward.

[0005] When loading or unloading a vehicle such as construction equipment into or from the loading box, the loading box is slid backward to land on the ground. After sliding the loading box backward to land on the ground, the upper fittings are released from the side walls of the loading box, and the tailgate is rotated backward around its lower end. This opens the tailgate and spans between the bottom plate of the loading box and the ground. A worker can load or unload a vehicle such as construction equipment into or from the loading box through the tailgate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-133850 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, conventional freight vehicles are designed to allow both the discharge of soil and sand and the loading and unloading of construction equipment. In particular, the tailgate pivots rearward around the upper bracket in conjunction with the dumping operation for discharging soil and sand, and the rear of the cargo box is completely opened by releasing the upper bracket's fastenings for loading and unloading construction equipment. However, while these two operations are possible, loading and unloading vehicles such as construction equipment requires manual work to release the upper bracket from the side wall of the cargo box and then pivot the tailgate rearward around its lower end. However, because the tailgate is a relatively heavy component, this work places a considerable burden on the worker. Furthermore, when vehicles such as construction equipment are loaded or unloaded into the cargo box by driving over the tailgate, there is a risk that the construction equipment may run over the upper bracket of the tailgate, causing deformation or damage to the upper bracket. In such cases, the securing force for securing the tailgate in the normal upright position is reduced, and the support force for the upper end of the tailgate during dumping is also reduced, which may affect the discharge of soil and sand. Furthermore, with such conventional freight vehicles, when the tailgate is rotated around its lower end, a gap is created between the bottom plate of the cargo box and the tailgate, both vertically and horizontally. This makes it difficult for workers to smoothly load and unload vehicles such as construction machinery.

[0008] The present invention has been made in consideration of these points, and its purpose is to make it easy to rotate the tailgate in a freight vehicle capable of dumping and sliding the cargo box, to make the tailgate less likely to be damaged when loading or unloading vehicles such as construction machinery into the cargo box, and to improve the efficiency of loading and unloading operations for both operations. [Means for solving the problem]

[0009] The truck according to the present invention comprises a chassis frame, a slide frame tiltably mounted relative to the chassis frame, and a cargo box slidably supported by the slide frame, and is capable of a dumping operation in which the cargo box and the slide frame are tilted together, and a sliding operation in which the cargo box is slid relative to the slide frame. The cargo box has a bottom plate and a tailgate having a base connected to the rear end of the bottom plate so as to be pivotable forward and backward. The truck is also equipped with a tailgate actuator that can pivot the tailgate between a closed position in which the tailgate stands up from the bottom plate and an open position in which the tailgate extends rearward from the bottom plate. After the sliding operation, when the cargo box is in contact with the ground, the tailgate actuator pivots the tailgate to the open position, thereby forming a passageway between the inner surface of the tailgate and the upper surface of the bottom plate of the cargo box.

[0010] In the above-described freight vehicle, the tailgate is driven by a tailgate actuator and rotates between a closed position and an open position. An operator does not need to manually rotate the tailgate, thereby reducing the burden on the operator. Furthermore, in the above-described freight vehicle, the upper end of the tailgate does not have a detachable upper bracket attached to the side wall of the cargo box. Therefore, when a construction machine or the like drives over the tailgate during loading or unloading, the upper bracket is not stepped on and damaged. Therefore, the tailgate is less likely to be damaged during loading or unloading of the construction machine or the like into the cargo box. Furthermore, in the above-described freight vehicle, after the sliding operation and when the cargo box is on the ground, the tailgate actuator rotates the tailgate to the open position, thereby forming a passageway with the inner surface of the tailgate connected to the upper surface of the bottom plate of the cargo box. Therefore, the operator can smoothly move the construction machine or the like from the passageway to the bottom plate of the cargo box and from the bottom plate of the cargo box to the passageway. Therefore, the operator can smoothly load and unload the construction machine or the like.

[0011] When the tailgate is in the open position, it is preferable that the inner surface of the base of the tailgate and the rear edge of the upper surface of the bottom plate of the cargo box are at the same position in a direction perpendicular to the upper surface of the bottom plate of the cargo box. This eliminates any step between the inner surface of the base of the tailgate and the upper surface of the bottom plate of the cargo box, allowing workers to load and unload construction machinery and the like more smoothly.

[0012] When the tailgate is in the open position, it is preferable that no gap is formed between the base of the tailgate and the bottom plate of the cargo box when viewed from a direction perpendicular to the upper surface of the bottom plate of the cargo box, thereby allowing workers to load and unload construction machinery and the like more smoothly.

[0013] The tailgate actuator may be a hydraulic cylinder having a cylinder body and a rod slidable relative to the cylinder body, wherein one of the cylinder body and the rod may be connected to the bottom plate of the cargo box, and the other may be connected to the tailgate.

[0014] The truck may include a dump actuator that tilts the slide frame, a slide actuator that slides the cargo box relative to the slide frame, and a control device that controls the tailgate actuator, the dump actuator, and the slide actuator. The control device may be configured to execute control to start driving the tailgate actuator so that the tailgate rotates from the closed position to the open position after stopping driving of the slide actuator to terminate sliding of the cargo box relative to the slide frame.

[0015] The control device may be configured to execute control to start driving the tailgate actuator so that the tailgate rotates from the closed position toward the open position, and then to start driving the dump actuator so that the slide frame tilts. [Effects of the Invention]

[0016] According to the present invention, in a freight vehicle capable of dumping and sliding cargo boxes, the operation of rotating the tailgate can be simplified, making it less likely that the tailgate will be damaged when loading or unloading vehicles such as construction machinery into the cargo box, and improving the efficiency of loading and unloading operations for both operations. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a side view of a freight vehicle according to an embodiment. [Figure 2] FIG. 4 is a side view of the truck after dumping. [Figure 3]FIG. 10 is a side view of the truck after the sliding operation. [Figure 4] FIG. 1 is a side view showing a partial cutaway of the rear of the cargo box when the tailgate is in a closed position. [Figure 5] FIG. 1 is a side view showing a partial cutaway of the rear of the cargo box when the tailgate is in an open position. [Figure 6] FIG. 1 is a rear view of a portion of the cargo box with the tailgate in a closed position. [Figure 7] FIG. 1 is a view of a portion of the rear of the cargo box when the tailgate is in the open position, viewed from a direction perpendicular to the bottom wall of the cargo box. [Figure 8] FIG. 1 is a block diagram of a control system for a truck. [Figure 9] 10 is a flowchart showing the flow of processing when discharging earth and sand from a packing box. [Figure 10] 10 is a flowchart showing the flow of processing when loading a construction machine into a packing box. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the present invention will now be described with reference to the drawings, in which: Fig. 1 is a side view of a freight vehicle 1 according to this embodiment.

[0019] As shown in FIG. 1, a truck 1 includes a chassis frame 5, a cab (driver's compartment) 2 supported by the chassis frame 5, a slide frame 8 supported by the chassis frame 5, and a cargo box 10 slidably supported by the slide frame 8. The slide frame 8 is rotatably supported at the rear end of the chassis frame 5 by a hinge shaft 7 extending in the vehicle width direction. The chassis frame 5 may be formed of a single frame or multiple frames. For example, the chassis frame 5 may have a main frame and a subframe supported by the main frame. Front wheels 3 and rear wheels 4 are supported on the chassis frame 5. A driver's seat (not shown) is provided inside the cab 2. In the following description, unless otherwise specified, the terms front, rear, left, right, top, and bottom refer to the front, rear, left, right, top, and bottom, respectively, as seen from the driver sitting in the driver's seat.

[0020] As shown in FIG. 2, the truck 1 is capable of dumping by tilting the cargo box 10 together with the slide frame 8 without sliding it relative to the slide frame 8. The chassis frame 5 and the slide frame 8 are connected by a hoist mechanism 50. The hoist mechanism 50 includes a lift arm 52, a tension link 53, and a hydraulic cylinder 51. When the hydraulic cylinder 51 is contracted, the slide frame 8 is horizontal, as shown in FIG. 1, and the cargo box 10 maintains a horizontal position. As shown in FIG. 2, when the hydraulic cylinder 51 is extended, the front of the slide frame 8 is lifted, and the slide frame 8 rotates around the hinge shaft 7, causing it to tilt. As a result, the cargo box 10 tilts backward. In this embodiment, the hydraulic cylinder 51 constitutes a dump actuator that tilts the slide frame 8. Although not shown, the truck 1 may also be provided with a locking mechanism that prevents the cargo box 10 from sliding relative to the slide frame 8. A well-known locking mechanism conventionally used in trucks can be used as the locking mechanism. When such a locking mechanism is provided, the locking mechanism is turned on during a dumping operation, and the cargo box 10 is prevented from sliding.

[0021] As shown in FIG. 3, the truck 1 is capable of sliding the cargo box 10 relative to the slide frame 8. Note that the hoist mechanism 50 (see FIG. 2) is not shown in FIG. 3. The truck 1 is equipped with a hydraulic cylinder 61 that slides the cargo box 10 back and forth. Note that the hydraulic cylinder 61 is not shown in FIGS. 1 and 2. The hydraulic cylinder 61 constitutes a slide actuator that slides the cargo box 10 relative to the slide frame 8. The front end of the hydraulic cylinder 61 is connected to the slide frame 8, and the rear end of the hydraulic cylinder 61 is connected to the cargo box 10. When sliding the cargo box 10 rearward, the slide frame 8 is tilted by the hoist mechanism 50. Furthermore, the locking mechanism is turned OFF, allowing the cargo box 10 to slide relative to the slide frame 8. Then, the hydraulic cylinder 61 is extended to push the cargo box 10 rearward. As a result, the cargo box 10 slides rearward along the slide frame 8.

[0022] As shown in Figure 1, the cargo box 10 has a bottom plate 11, a front plate 12 extending upward from the front end of the bottom plate 11, a left side plate 13 extending upward from the left end of the bottom plate 11, a right side plate (not shown) extending upward from the right end of the bottom plate 11, and a tailgate 15 rotatably connected to the rear end of the bottom plate 11. The tailgate 15 is connected to the rear end of the bottom plate 11 so as to be rotatable forward and backward. The cargo box 10 also has a ground contact portion 14 extending downward from the rear end of the bottom plate 11. When the cargo box 10 slides rearward, the ground contact portion 14 comes into contact with the ground, thereby supporting the cargo box 10 (see Figure 3).

[0023] As shown in FIG. 4, the cargo box 10 has a connecting shaft 16 provided at the rear end of the bottom plate 11. The connecting shaft 16 is disposed behind the bottom plate 11 and extends in the vehicle width direction (in other words, the left-right direction). The tailgate 15 has a tubular portion 15A (see FIG. 6) through which the connecting shaft 16 is inserted, and a plate portion 15B fixed to the tubular portion 15A. The tubular portion 15A is rotatably engaged with the connecting shaft 16. The tubular portion 15A forms the base portion of the tailgate 15. The base portion of the tailgate 15 is connected to the rear end of the bottom plate 11 by the connecting shaft 16 so as to be rotatable back and forth.

[0024] As shown in FIG. 4, when the tailgate 15 is raised relative to the bottom plate 11, the rear of the cargo box 10 is closed by the tailgate 15. Hereinafter, the position in which the tailgate 15 is raised relative to the bottom plate 11 will be referred to as the closed position. As shown in FIG. 5, when the tailgate 15 rotates rearward about the connecting shaft 16, the cargo box 10 is opened rearward. Hereinafter, the position in which the tailgate 15 extends rearward from the bottom plate 11 will be referred to as the open position. Note that the open position may be a position in which the inner surface 15U of the tailgate 15 coincides with an extension surface 11US obtained by extending the upper surface 11U of the bottom plate 11 rearward, or may be a position slightly inclined relative to the extension surface 11US (for example, a position in which the angle formed between the inner surface 15U of the tailgate 15 and the extension surface 11US is within 15 degrees).

[0025] As shown in FIG. 4, the truck 1 is equipped with a hydraulic cylinder 21. The hydraulic cylinder 21 is an example of a tailgate actuator that can rotate the tailgate 15 between a closed position and an open position. The hydraulic cylinder 21 is provided in the cargo box 10. The hydraulic cylinder 21 has a cylinder body 21A and a rod 21B that can slide relative to the cylinder body 21A. The rod 21B extends rearward from the cylinder body 21A. The hydraulic cylinder 21 expands and contracts as the rod 21B slides back and forth. The cylinder body 21A is connected to the bottom plate 11 via a bracket 22. The rod 21B is connected to the tailgate 15 via a bracket 23. When the hydraulic cylinder 21 expands, the tailgate 15 moves to the closed position, and the tailgate 15 is closed. When the hydraulic cylinder 21 contracts, the tailgate 15 moves to the open position, and the tailgate 15 is opened, as shown in FIG. 5.

[0026] The hydraulic cylinder 21 is disposed below the bottom plate 11. FIG. 6 is an enlarged rear view of the left half of the cargo box 10. The symbol CL in the figure is a line (center line) indicating the center position in the vehicle width direction. The hydraulic cylinder 21 is disposed to the left of the center line CL. The aforementioned hydraulic cylinder 61 (i.e., the hydraulic cylinder 61 that slides the cargo box 10 back and forth) is disposed on the center line CL. The hydraulic cylinder 21 is disposed to the left of the hydraulic cylinder 61 so as not to interfere with the hydraulic cylinder 61. Note that the hydraulic cylinder 21 may be disposed to the right of the hydraulic cylinder 61 to avoid interference with the hydraulic cylinder 61. The hydraulic cylinder 61 may also be disposed to the right of the center line CL. Furthermore, the hydraulic cylinder 21 may be disposed on the center line CL as long as the hydraulic cylinder 21 and the hydraulic cylinder 61 do not interfere with each other. In this embodiment, the number of hydraulic cylinders 21 that rotate the tailgate 15 is one, but the number of hydraulic cylinders 21 is not limited to one. The cargo vehicle 1 may be provided with multiple hydraulic cylinders 21.

[0027] In this embodiment, as shown in Fig. 5, when the tailgate 15 is in the open position, there is no step between the upper surface 11U of the bottom plate 11 of the cargo box 10 (hereinafter referred to as the bottom plate upper surface) and the inner surface 15U of the tailgate 15. Note that "no step" here means that there is no step to the extent that vehicles such as construction machinery can be smoothly loaded and unloaded, and includes not only a completely no step but also a slight step of 30 mm or less (preferably 20 mm or less, for example, about 10 mm). In this embodiment, when the tailgate 15 is in the open position, the inner surface 15Au of the base of the tailgate 15 and the rear edge 11Ub of the bottom plate upper surface 11U of the cargo box 10 are at the same position in the direction Z perpendicular to the bottom plate upper surface 11U of the cargo box 10 (hereinafter simply referred to as the vertical direction). Note that "being in the same position" as used here not only refers to being in the exact same position, but also includes a case where there is a slight deviation of 30 mm or less (preferably 20 mm or less, for example, about 10 mm) in the vertical direction Z. In this embodiment, when the tailgate 15 is in the open position, the upper end of the tubular portion 15A and the rear edge 11Ub of the bottom plate upper surface 11U are located at the same height in the vertical direction Z.

[0028] Figure 7 is a view of a portion of the rear of the cargo box 10 as viewed from the vertical direction Z when the tailgate 15 is in the open position. As shown in Figure 7, when the tailgate 15 is in the open position, as viewed from the vertical direction Z, there is no gap between the base of the tailgate 15 and the bottom plate 11 of the cargo box 10. When the tailgate 15 is in the open position, as viewed from the vertical direction Z, there is no gap between the tubular portion 15A of the tailgate 15 and the bottom plate 11 of the cargo box 10. When the tailgate 15 is in the open position, as viewed from the vertical direction Z, the bottom plate 11 of the cargo box 10, the tubular portion 15A of the tailgate 15, and the plate portion 15B of the tailgate 15 are continuous with no gaps.

[0029] As shown in Fig. 8, the truck 1 is equipped with a control device 30 that controls the hydraulic cylinder 21, the hydraulic cylinder 51, and the hydraulic cylinder 61. Although not shown, the truck 1 is equipped with a hydraulic circuit incorporating the hydraulic cylinder 21, the hydraulic cylinder 51, the hydraulic cylinder 61, a hydraulic pump, and a plurality of solenoid valves. The control device 30 is configured to control the extension and retraction operations of the hydraulic cylinder 21, the hydraulic cylinder 51, and the hydraulic cylinder 61 by appropriately switching the solenoid valves in response to an input operation by an operator or by executing a computer program.

[0030] Next, an example of the operation of the freight vehicle 1 will be described.

[0031] For example, when earth and sand loaded in the cargo box 10 is to be discharged, a dumping operation is performed. In this case, as shown in FIG. 9, first, in step S1, the tailgate 15 is opened. Specifically, the control device 30 starts driving the hydraulic cylinder 21 to rotate the tailgate 15 from the closed position to the open position. Next, in step S2, the control device 30 starts driving the hydraulic cylinder 51 to tilt the cargo box 10. Note that step S2 may be started after the tailgate 15 reaches the open position, before it reaches the open position, or simultaneously with it reaching the open position. The control device 30 may start driving the hydraulic cylinder 51 after stopping the driving of the hydraulic cylinder 21, may start driving the hydraulic cylinder 51 before stopping the driving of the hydraulic cylinder 21, or may start driving the hydraulic cylinder 51 simultaneously with stopping the driving of the hydraulic cylinder 21. When the tailgate 15 is opened and the cargo box 10 is tilted (see FIG. 2), the earth and sand loaded in the cargo box 10 is discharged rearward (step S3). After the soil and sand have been discharged, the control device 30 contracts the hydraulic cylinder 51 to return the cargo box 10 from the tilted state to a horizontal state (step S4), and then extends the hydraulic cylinder 21 to rotate the tailgate 15 from the open position to the closed position, thereby closing the tailgate 15 (step S5). The processing of step S5 may be started after, before, or simultaneously with the completion of the processing of step S4.

[0032] For example, when loading a vehicle such as a construction machine (e.g., a power shovel) into the cargo box 10, a sliding operation is performed. In this case, as shown in FIG. 10, after releasing the locking mechanism that locks the cargo box 10 to the slide frame 8, the control device 30 drives the hydraulic cylinder 51 to tilt the slide frame 8 and the cargo box 10 (step S11). The control device 30 also drives the hydraulic cylinder 61 to slide the cargo box 10 rearward (step S12). Note that the processing of step S12 may be started after the processing of step S11, before the processing of step S11 ends, or simultaneously with the processing of step S11 ends. When the cargo box 10 slides rearward, the ground contact portion 14 of the cargo box 10 touches the ground, and the rear of the cargo box 10 is supported on the ground (see FIG. 3). After stopping the driving of the hydraulic cylinder 61, the control device 30 starts the driving of the hydraulic cylinder 21 to rotate the tailgate 15 from the closed position to the open position. That is, the control device 30 drives the hydraulic cylinder 21 to open the tailgate 15 after the sliding operation and when the cargo box 10 is in contact with the ground.

[0033] As shown in FIG. 3, when the tailgate 15 is rotated to the open position while the cargo box 10 is on the ground, the inner surface 15U of the tailgate 15 forms a passageway 18 that is continuous with the upper surface 11U (see FIG. 5) of the bottom plate 11 of the cargo box 10. As described above, when the tailgate 15 is in the open position, there is no step between the upper surface 11U of the bottom plate 11 of the cargo box 10 and the inner surface 15U of the tailgate 15. Furthermore, when viewed from the direction Z perpendicular to the bottom plate upper surface 11U, there is no gap between the bottom plate upper surface 11U and the inner surface 15U of the tailgate 15. The bottom plate upper surface 11U of the cargo box 10 and the inner surface 15U of the tailgate 15 are continuous with no step or gap. Therefore, when the tailgate 15 is rotated to the open position while the cargo box 10 is on the ground, there is a passageway 18 that is continuous with the bottom plate 11 of the cargo box 10 without any step or gap. The worker loads the construction machine into the packing box 10 by driving the construction machine from the ground onto the bottom plate 11 of the packing box 10 through this passage 18 (step S14). Since there are no steps or gaps between the passage 18 and the bottom plate 11 of the packing box 10, the worker can load the construction machine into the packing box 10 smoothly.

[0034] After the construction machine is loaded into the cargo box 10, the control device 30 drives the hydraulic cylinder 21 to rotate the tailgate 15 from the open position to the closed position. This closes the tailgate 15 (step S15). Thereafter, the control device 30 drives the hydraulic cylinder 61 to slide the cargo box 10 forward (step S16), and drives the hydraulic cylinder 51 to return the cargo box 10 to a horizontal position (step S17). In this way, the construction machine can be loaded into the cargo box 10 of the truck 1.

[0035] As described above, the freight vehicle 1 according to this embodiment is provided with the hydraulic cylinder 21 that can rotate the tailgate 15 between the closed position and the open position. Although the tailgate 15 is a relatively heavy component, the worker does not need to open the tailgate 15 manually, which reduces the workload. The worker can rotate the tailgate 15 using the hydraulic cylinder 21. Therefore, the worker can easily rotate the tailgate 15.

[0036] Furthermore, in the freight vehicle 1 according to this embodiment, the tailgate 15 is not configured to rotate around its upper end, and no upper fitting that can be attached to or detached from the side wall of the cargo box 10 is provided at the upper end of the tailgate 15. Therefore, when a construction machine travels over the tailgate 15 to be loaded, the upper fitting will not be stepped on and damaged. Therefore, the tailgate 15 is unlikely to be damaged when the construction machine is loaded or unloaded into the cargo box 10.

[0037] Furthermore, with the freight truck 1 according to this embodiment, when the cargo box 10 is on the ground after the sliding operation, the hydraulic cylinder 21 rotates the tailgate 15 to the open position, and the inner surface 15U of the tailgate 15 forms a passage 18 that is continuous with the upper surface 11U of the bottom plate 11 of the cargo box 10. When moving the construction machine from the passage 18 onto the bottom plate 11 of the cargo box 10, and when moving the construction machine from the bottom plate 11 of the cargo box 10 to the passage 18, the worker can smoothly move the construction machine. Therefore, the worker can smoothly load and unload the construction machine through the passage 18.

[0038] According to this embodiment, when the tailgate 15 is rotated to the open position, there is no step between the inner surface 15Au of the base of the tailgate 15 and the upper surface 11U of the bottom plate 11 of the cargo box 10, allowing workers to load and unload construction machinery more smoothly.

[0039] Furthermore, according to this embodiment, when the tailgate 15 is rotated to the open position, there is no gap between the base of the tailgate 15 and the bottom plate 11 of the cargo box 10 when viewed from the direction Z perpendicular to the upper surface 11U of the bottom plate 11 of the cargo box 10, so that workers can load and unload construction machinery more smoothly.

[0040] While one embodiment of the present invention has been described above, the above embodiment is merely an example, and the present invention can be embodied in various other forms.

[0041] In the above embodiment, the slide frame 8 is tilted during the sliding operation, and the cargo box 10 slides along the inclined slide frame 8 while remaining in an inclined position. However, the configuration for sliding the cargo box 10 and the manner of the sliding operation are not particularly limited. For example, in another embodiment, rollers (cargo box rollers) may be provided below the front end of the cargo box 10, and a path for the cargo box rollers may be provided in the slide frame 8. In such an embodiment, the slide frame 8 does not tilt during the sliding operation. When the hydraulic cylinder 61 (slide actuator) is extended during the sliding operation, the cargo box rollers pass through the path, thereby lifting the front end of the cargo box 10. This allows the cargo box 10 to tilt rearward without tilting the slide frame 8. Even in such an embodiment, the rear of the cargo box 10 can be placed on the ground by sliding the cargo box 10 backward along the slide frame 8. Note that, for example, the configuration described in Japanese Patent No. 6,867,923 can be used as an example of such an embodiment.

[0042] In the above embodiment, the passage 18 is formed by rotating the tailgate 15 to the open position after the sliding operation and when the cargo box 10 is on the ground, but there is no particular limitation on the timing for forming the passage 18. The passage 18 may also be formed by rotating the tailgate 15 to the open position during the sliding operation or when the cargo box 10 is not on the ground.

[0043] 7, in the embodiment, the tubular portion 15A of the tailgate 15 is formed in a part of the tailgate 15 in the vehicle width direction, but it may be formed over the entire tailgate 15 in the vehicle width direction. The tubular portion 15A is preferably formed in a position where caterpillars, wheels, etc. of a construction machine or the like pass, and is preferably formed over as wide an area as possible in the vehicle width direction of the tailgate 15, but this is not particularly limited.

[0044] The tailgate actuator, dump actuator, and slide actuator are not limited to hydraulic cylinders as long as they generate driving force, and at least one of the tailgate actuator, dump actuator, and slide actuator may be, for example, an electric motor.

[0045] When the tailgate 15 is in the open position, the inner surface 15Au of the base of the tailgate 15 and the rear edge 11Ub of the upper surface 11U of the bottom plate 11 of the cargo box 10 may be slightly misaligned with respect to the direction Z perpendicular to the upper surface 11U of the bottom plate 11 of the cargo box 10. There may be a slight step between the inner surface 15U of the tailgate 15 and the bottom plate 11 of the cargo box 10.

[0046] When the tailgate 15 is in the open position, a small gap may be formed between the base of the tailgate 15 and the bottom plate 11 of the cargo box 10 when viewed from a direction Z perpendicular to the upper surface 11U of the bottom plate 11 of the cargo box 10.

[0047] There is no particular limitation on the configuration of the tailgate 15. The tailgate 15 does not necessarily have to have the cylindrical portion 15A.

[0048] The front-to-rear direction of the hydraulic cylinder 21 may be reversed. In the above embodiment, the cylinder body 21A of the hydraulic cylinder 21 is connected to the bottom plate 11 of the cargo box 10, and the rod 21B is connected to the tailgate 15. However, the cylinder body 21A may be connected to the tailgate 15, and the rod 21B may be connected to the bottom plate 11. [Explanation of symbols]

[0049] 1 lorry 5 Chassis frame 8 Slide Frame 10 packing boxes 11 Bottom plate Top of 11U base plate 15 Tailgate 15A Tube part (base part) 15B Board part 15U Inside of tailgate 16 Connecting shaft 18 aisles 21 Hydraulic cylinder (tailgate actuator) 21A Cylinder body 21B Rod 30 Control device 51 Hydraulic cylinder (dump actuator) 61 Hydraulic cylinder (slide actuator)

Claims

1. The chassis frame and a slide frame tiltably provided with respect to the chassis frame; a packing box slidably supported by the slide frame; and a truck capable of a dumping operation in which the cargo box and the slide frame are tilted together without sliding the cargo box relative to the slide frame, and a slide operation in which the cargo box is slid relative to the slide frame, The cargo box has a bottom plate and a tailgate having a base portion connected to a rear end portion of the bottom plate so as to be pivotable forward and backward, a tailgate actuator that can rotate the tailgate between a closed position in which the tailgate stands up from the bottom plate and an open position in which the tailgate extends rearward from the bottom plate; a dump actuator that tilts the slide frame; a control device for controlling the tailgate actuator and the dump actuator, After the sliding operation and when the cargo box is in contact with the ground, the tailgate actuator rotates the tailgate to the open position, whereby an inner surface of the tailgate forms a passageway that is continuous with an upper surface of the bottom plate of the cargo box, The control device is configured to execute control to start driving the tailgate actuator so that the tailgate rotates from the closed position to the open position during the dumping operation, and then start driving the dump actuator so that the slide frame tilts.

2. 2. The truck according to claim 1, wherein when the tailgate is in the open position, an inner surface of the base portion of the tailgate and a rear edge of the upper surface of the bottom plate of the cargo box are at the same position in a direction perpendicular to the upper surface of the bottom plate of the cargo box.

3. 3. The truck according to claim 1, wherein when the tailgate is in the open position, no gap is formed between the base of the tailgate and the bottom plate of the cargo box when viewed from a direction perpendicular to the upper surface of the bottom plate of the cargo box.

4. the tailgate actuator is a hydraulic cylinder having a cylinder body and a rod slidable relative to the cylinder body, 4. The truck according to claim 1, wherein one of the cylinder body and the rod is connected to the bottom plate of the cargo box, and the other is connected to the tailgate.

5. A slide actuator is provided to slide the packing box relative to the slide frame, the control device controls the tailgate actuator, the dump actuator, and the slide actuator; The truck according to any one of claims 1 to 4, wherein the control device is configured to execute control to stop driving the slide actuator during the sliding operation to end the sliding of the cargo box relative to the slide frame, and then start driving the tailgate actuator so that the tailgate rotates from the closed position toward the open position.

6. The tailgate is not configured to pivot around its upper end, 6. The truck according to claim 1, wherein an upper end of the tailgate is not provided with an upper metal fitting that is detachable from a side wall of the cargo box.

Images