JP7777982B2 - lorry - Google Patents

Description

The present invention relates to a freight vehicle that is capable of performing a dumping operation to tilt the cargo box, and a sliding operation to slide the cargo box backward and onto the ground.

Freight trucks that are capable of performing a dumping operation, in which the cargo box is tilted, and a sliding operation, in which the cargo box is slid backward and placed on the ground, have been known for some time. For example, Patent Document 1 describes such a freight truck.

Conventional freight vehicles capable of both dumping and sliding movements are equipped with a tailgate that forms the rear wall of the cargo box and pivots to open the cargo box rearward. In these freight vehicles, the tailgate is configured to be able to pivot around both its upper and lower ends. An upper fitting is attached to the upper end of the tailgate, which can be manually attached and detached to the side wall of the cargo box, and a lower fitting is attached to the lower end of the tailgate, which can be detached and attached to the bottom plate of the cargo box.

When discharging soil or sand loaded in the cargo box, the lower metal fittings are released from the bottom plate of the cargo box, and the cargo box is tilted, performing 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 loaded in the cargo box is discharged rearward.

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, which is then suspended between the bottom plate of the loading box and the ground. Workers can load or unload vehicles such as construction equipment into or from the loading box through the tailgate.

Japanese Patent Application Laid-Open No. 2021-133850

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 to discharge soil and sand, and the rear of the cargo box is completely opened by releasing the upper bracket's fastenings to load and unload construction equipment. However, while these two operations are possible, loading and unloading construction equipment and other vehicles requires manual labor 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 tailgates are relatively heavy components, this task places a significant burden on the worker. Furthermore, construction equipment and other vehicles are loaded and unloaded into the cargo box by driving over the tailgate, which can potentially cause the construction equipment and other vehicles to step on the upper bracket of the tailgate, deforming or damaging the upper bracket. In such cases, the securing force that secures the tailgate in its normal upright position is reduced, and the support force that supports the upper end of the tailgate during dumping operations is also reduced, which could affect the discharge of soil and sand. Furthermore, with these conventional freight vehicles, when the tailgate is rotated around its lower end, a vertical gap and front-to-back gaps are created between the bottom plate of the cargo box and the tailgate. This makes it difficult for workers to smoothly load and unload vehicles such as construction machinery.

The present invention was made in light of these issues, and its purpose is to make it easier to rotate the tailgate in a freight vehicle capable of dumping and sliding cargo boxes, to make the tailgate less susceptible to damage when loading and unloading vehicles such as construction machinery into the cargo box, and to improve the efficiency of loading and unloading operations for both operations.

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 on the slide frame. The truck 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 slides 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 that it can pivot forward and backward. The truck is equipped with a tailgate actuator that can rotate the tailgate between a closed position in which it stands up from the bottom plate and an open position in which it extends rearward from the bottom plate. After the sliding operation, when the cargo box is in contact with the ground, the tailgate actuator rotates 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.

In the above-mentioned freight vehicle, the tailgate is driven by a tailgate actuator and rotates between a closed position and an open position. There is no need for the worker to manually rotate the tailgate, thereby reducing the burden on the worker. Furthermore, in the above-mentioned 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 construction equipment, etc., drives over the tailgate during loading or unloading, the upper bracket will not be stepped on and damaged. Therefore, the tailgate is less likely to be damaged when loading or unloading construction equipment, etc. into the cargo box. Furthermore, in the above-mentioned 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 top surface of the bottom plate of the cargo box. Therefore, the worker can smoothly move the construction equipment, etc., from the passageway to the bottom plate of the cargo box, and from the bottom plate of the cargo box to the passageway. This allows the worker to smoothly load and unload construction equipment, etc.

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.

When the tailgate is in the open position, it is preferable that no gap be formed between the base of the tailgate and the bottom plate of the cargo box when viewed from a direction perpendicular to the top surface of the bottom plate of the cargo box. This allows workers to load and unload construction machinery and the like more smoothly.

The tailgate actuator may be a hydraulic cylinder having a cylinder body and a rod that is slidable relative to the cylinder body. 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.

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 stop driving the slide actuator to end the sliding of the cargo box relative to the slide frame, and then execute control to start driving the tailgate actuator so that the tailgate rotates from the closed position to the open position.

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, and then start driving the dump actuator so that the slide frame tilts.

This invention makes it easier to rotate the tailgate on a freight vehicle capable of dumping and sliding cargo boxes, making it less likely for the tailgate to 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.

FIG. 1 is a side view of a freight vehicle according to an embodiment. FIG. 4 is a side view of the truck after dumping. FIG. 10 is a side view of the truck after the sliding operation. FIG. 1 is a side view showing a portion of the rear of the cargo box cut away when the tailgate is in a closed position. FIG. 1 is a side view showing a portion of the rear of the cargo box cut away when the tailgate is in an open position. FIG. 1 is a rear view of a portion of the cargo box with the tailgate in a closed position. 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. FIG. 1 is a block diagram of a control system for a truck. 10 is a flowchart showing the flow of processing when discharging earth and sand from a packing box. 10 is a flowchart showing the flow of processing when loading a construction machine into a packing box.

One embodiment of the present invention will now be described with reference to the drawings. Figure 1 is a side view of a freight truck 1 according to this embodiment.

As shown in FIG. 1, the truck 1 comprises 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 composed 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. Unless otherwise specified, in the following description, 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.

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 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 retracted, 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 tilts by rotating around the hinge axis 7. 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 equipped 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. If such a locking mechanism is provided, it will be turned on during dumping, preventing the cargo box 10 from sliding.

As shown in Figure 3, the truck 1 is capable of sliding the cargo box 10 relative to the slide frame 8. The hoist mechanism 50 (see Figure 2) is not shown in Figure 3. The truck 1 is equipped with a hydraulic cylinder 61 that slides the cargo box 10 back and forth. The hydraulic cylinder 61 is not shown in Figures 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. The locking mechanism is also disengaged, allowing the cargo box 10 to slide relative to the slide frame 8. The hydraulic cylinder 61 is then extended to push the cargo box 10 rearward. As a result, the cargo box 10 slides rearward along the slide frame 8.

As shown in FIG. 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 that it can rotate back and forth. 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 FIG. 3).

As shown in Figure 4, the cargo box 10 has a connecting shaft 16 attached to the rear end of the bottom plate 11. The connecting shaft 16 is located 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 Figure 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 of the tailgate 15. The base of the tailgate 15 is connected to the rear end of the bottom plate 11 by the connecting shaft 16 so that it can rotate back and forth.

As shown in Figure 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 Figure 5, when the tailgate 15 rotates rearward around the connecting shaft 16, the cargo box 10 opens 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 the extension surface 11US, which is an extension rearward of the upper surface 11U of the bottom plate 11, or a position slightly inclined relative to the extension surface 11US (for example, a position in which the angle between the inner surface 15U of the tailgate 15 and the extension surface 11US is within 15 degrees).

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 mounted on 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 extends and retracts 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 extends, the tailgate 15 moves to the closed position, and the tailgate 15 is closed. As shown in FIG. 5, when the hydraulic cylinder 21 retracts, the tailgate 15 moves to the open position, and the tailgate 15 is opened.

The hydraulic cylinder 21 is located below the bottom plate 11. Figure 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) that indicates the center position in the vehicle width direction. The hydraulic cylinder 21 is located 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 located on the center line CL. The hydraulic cylinder 21 is located 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 located to the right of the hydraulic cylinder 61 to avoid interference with the hydraulic cylinder 61. The hydraulic cylinder 61 may also be located to the right of the center line CL. Furthermore, the hydraulic cylinder 21 may be located on the center line CL as long as there is no interference between the hydraulic cylinder 21 and the hydraulic cylinder 61. 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 truck 1 may be equipped with multiple hydraulic cylinders 21.

In this embodiment, as shown in Figure 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 loaded and unloaded smoothly. This includes not only a complete lack of step, but also a slight step of 30 mm or less (preferably 20 mm or less, e.g., approximately 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 "in the same position" as used here not only refers to being in the exact same position, but also includes cases 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.

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

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

Next, an example of the operation of truck 1 will be described.

For example, to unload earth and sand loaded in the cargo box 10, 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. By opening the tailgate 15 and tilting the cargo box 10 (see FIG. 2), the earth and sand loaded in the cargo box 10 is dumped rearward (step S3). After the soil and sand have been discharged, the control device 30 retracts the hydraulic cylinder 51 to return the cargo box 10 from its 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). Note that the processing of step S5 may be started after, before, or simultaneously with the completion of the processing of step S4.

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 activates the hydraulic cylinder 51 to tilt the slide frame 8 and the cargo box 10 (step S11). The control device 30 also activates the hydraulic cylinder 61 to slide the cargo box 10 rearward (step S12). Note that the processing of step S12 may be initiated after the processing of step S11, before the processing of step S11 ends, or simultaneously with the completion of the processing of step S11. 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 activates the hydraulic cylinder 21 to rotate the tailgate 15 from the closed position to the open position. In other words, after the sliding operation, when the cargo box 10 is in contact with the ground, the control device 30 drives the hydraulic cylinder 21 to open the tailgate 15.

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 of the cargo box 10 and the inner surface 15U of the tailgate 15. Furthermore, when viewed from the direction Z perpendicular to the upper surface 11U of the bottom plate, there is no gap between the upper surface 11U of the bottom plate and the inner surface 15U of the tailgate 15. The upper surface 11U of the bottom plate 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 no step or gap between the tailgate 15 and the bottom plate 11 of the cargo box 10. 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). Because there are no steps or gaps between the passage 18 and the bottom plate 11 of the packing box 10, the worker can smoothly load the construction machine into the packing box 10.

After the construction equipment 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, thereby closing the tailgate 15 (step S15). The control device 30 then 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 equipment can be loaded into the cargo box 10 of the truck 1.

As described above, the freight vehicle 1 according to this embodiment is equipped with a hydraulic cylinder 21 that can rotate the tailgate 15 between a closed position and an open position. The tailgate 15 is a relatively heavy component, but 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, rotating the tailgate 15 is easy for the worker.

In addition, with the freight truck 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 the side wall of the cargo box 10 is provided at the upper end of the tailgate 15. Therefore, when construction machinery is loaded onto the tailgate 15 and the construction machinery drives over the tailgate 15, the upper fitting will not be stepped on and damaged. Therefore, the tailgate 15 is less likely to be damaged when construction machinery is loaded onto or unloaded from the cargo box 10.

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 an aisle 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 aisle 18 onto the bottom plate 11 of the cargo box 10, and when moving it from the bottom plate 11 of the cargo box 10 to the aisle 18, the worker can smoothly move the construction machine. This allows the worker to smoothly load and unload the construction machine through the aisle 18.

In 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.

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, allowing workers to load and unload construction machinery even more smoothly.

The above describes one embodiment of the present invention, but the above embodiment is merely an example. The present invention can be implemented in various other forms.

In the above embodiment, the slide frame 8 is tilted during the sliding operation, and the cargo box 10 slides along the tilted slide frame 8 while remaining in a tilted position. However, the configuration for sliding the cargo box 10 and the manner of 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, lifting the front end of the cargo box 10. This allows the cargo box 10 to tilt rearward and downward 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 an example of such an embodiment is the configuration described in Japanese Patent No. 6,867,923.

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 the timing for forming the passage 18 is not particularly limited. 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.

As shown in FIG. 7, in the above embodiment, the tubular portion 15A of the tailgate 15 is formed on a portion 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 the caterpillars, wheels, etc. of construction machinery pass through, 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.

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

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 in the direction Z perpendicular to the upper surface 11U of the bottom plate 11 of the cargo box 10. There may also be a slight step between the inner surface 15U of the tailgate 15 and the bottom plate 11 of the cargo box 10.

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.

The configuration of the tailgate 15 is not particularly limited. The tailgate 15 does not have to have the cylindrical portion 15A.

The front-to-back orientation 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.

1 Freight vehicle 5 Chassis frame 8 Slide frame 10 Cargo box 11 Bottom plate 11U Upper surface of bottom plate 15 Tailgate 15A Cylinder portion (base portion)
15B Plate portion 15U Inner surface of tailgate 16 Connecting shaft 18 Passage 21 Hydraulic cylinder (tailgate actuator)
21A Cylinder body 21B Rod 30 Control device 51 Hydraulic cylinder (dump actuator)
61 Hydraulic cylinder (slide actuator)

Claims (6)

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 . The truck of claim 1, wherein when the tailgate is in the open position, 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. A freight vehicle as described in claim 1 or 2, 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. 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. a slide actuator that slides 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. The tailgate is not configured to pivot about 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.