Dump truck

Abstract

To provide a dump vehicle that can reduce the need to redo a work when a loaded object cannot be discharged due to an obstacle above a cargo box.SOLUTION: A dump vehicle 1 includes: a vehicle body 1A; a cargo box 30; a dumping device 25 for tilting the cargo box 30; a detection device 45 for detecting a vertical position of an obstacle existing above the cargo box 30; a first processing device that determines an angle of the cargo box 30 at which a loaded object placed in the cargo box 30 can be discharged based on a repose angle of the loaded object; a second processing device that determines an angle by which the cargo box 30 can be tilted based on a position of the obstacle detected by the detection device 45; and a determining device that determines that the loaded object can be discharged from the cargo box 30 when the angle determined by the second processing device is more than the angle determined by the first processing device and determines that the loading object cannot be discharged from the cargo box 30 when the angle is smaller than the angle determined by the first processing device.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a dump vehicle. [Background technology]

[0002] Patent Document 1 discloses a dump trailer that is provided with a sensor on the frame surrounding the loading platform that detects obstacles above. According to the dump trailer in Patent Document 1, when the sensor detects an obstacle, an alarm is generated in an alarm device, so that the driver can be notified. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6009626 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the dump vehicle described in Patent Document 1, a sensor that detects obstacles above can reduce the risk of colliding with an obstacle above when dumping a cargo box. However, if the cargo box is tilted at an angle that prevents it from colliding with an obstacle above, the cargo loaded in the cargo box may not slide off and may not be dumped from the cargo box. In such cases, the cargo box must be reseated, the dump location changed, and the same operation must be repeated.

[0005] The present invention has been made in view of the above points, and its object is to provide a dump vehicle that can reduce the need for redoing work when the load cannot be discharged due to an obstacle above the cargo box. [Means for solving the problem]

[0006] The dump vehicle of the present invention comprises a vehicle body, a cargo box tiltably supported on the vehicle body, a dumping device that tilts the cargo box, a detection device that detects the vertical position of an obstacle above the cargo box, a first processing device that determines the angle of the cargo box at which cargo loaded in the cargo box can be discharged based on the angle of repose of the cargo, a second processing device that determines the angle at which the cargo box can be tilted based on the position of the obstacle detected by the detection device, and a determination device that determines that the cargo can be discharged from the cargo box if the angle determined by the second processing device is equal to or greater than the angle determined by the first processing device, and determines that the cargo cannot be discharged from the cargo box if the angle determined by the second processing device is smaller than the angle determined by the first processing device.

[0007] With the dump vehicle, it is possible to determine whether the load can be discharged at the planned discharge point without actually tilting the loading box. Therefore, if the load cannot be discharged, the work of tilting the loading box and reseating it can be omitted. This reduces the need for redoing work when the load cannot be discharged due to an obstacle above the loading box.

[0008] According to a preferred embodiment of the present invention, the dump vehicle further includes an input device for inputting the type of load, and a storage device in which the type of load and the angle of repose for each load are stored. The first processing device is configured to read from the storage device the angle of repose of the load input to the input device, and to determine an angle of the loading box at which the load can be discharged based on the read angle of repose.

[0009] According to the dump vehicle, even if the types of loads are varied, it is possible to determine the tilt angle of the cargo box at which the loads can be discharged.

[0010] According to a preferred aspect of the present invention, the dump vehicle further includes a weight acquisition device that acquires the weight of a load loaded in the loading box, an imaging device that acquires an image of the inside of the loading box, a volume estimation device that estimates the volume of the load loaded in the loading box from the image acquired by the imaging device, a density estimation device that calculates an estimated density of the load from the weight of the load acquired by the weight acquisition device and the volume of the load estimated by the volume estimation device, and a storage device that stores a correspondence table between the density and the angle of repose of the load. The first processing device is configured to read the angle of repose of the load from the correspondence table in the storage device based on the estimated density calculated by the density estimation device, and to determine an angle of the loading box at which the load can be unloaded based on the read angle of repose.

[0011] The angle of repose of a load can vary depending on factors related to the load density, such as the moisture content and particle size. The dump vehicle described above can accommodate differences in the required inclination angle of the loading box depending on the load density.

[0012] According to a preferred aspect of the present invention, the dump vehicle further includes a storage device in which the maximum tilt angle of the cargo box possible with the dump device is stored, and a dump control device that, when it is determined that the load can be discharged from the cargo box and the angle determined by the second processing device is equal to or less than the maximum tilt angle stored in the storage device, drives the dump device to tilt the cargo box to the angle determined by the second processing device, and, when it is determined that the load can be discharged from the cargo box and the angle determined by the second processing device is greater than the maximum tilt angle, drives the dump device to tilt the cargo box to the maximum tilt angle.

[0013] According to the dump vehicle, if the tiltable angle of the cargo box is not limited by an obstacle above the cargo box, the cargo box is tilted to the maximum tilt angle of the cargo box, and if the tiltable angle of the cargo box is limited by an obstacle above the cargo box, the cargo box is tilted to the angle determined by the second processing device. In other words, the cargo box is tilted to the maximum angle possible depending on the situation. This allows the load to be discharged more quickly.

[0014] According to a preferred aspect of the present invention, the dump vehicle further includes a discharge point setting device that sets a discharge point for the load, and an automatic driving device that drives the vehicle body to the discharge point set by the discharge point setting device. The discharge point setting device is configured to change the discharge point if it is determined that the load cannot be discharged from the shipping box at the set discharge point.

[0015] According to the dump vehicle, even in the case of automatic driving, it is possible to determine whether or not the load can be discharged, and if the load cannot be discharged, the discharge point can be changed.

[0016] According to a preferred aspect of the present invention, the dump vehicle further includes a warning device that issues a warning when the difference between the angle determined by the second processing device and the angle of the cargo box becomes smaller than a predetermined angle.

[0017] According to the dump vehicle, for example, it is possible to reduce the possibility of the cargo box coming into contact with an obstacle due to a driver's error. [Effects of the Invention]

[0018] According to the dump vehicle of the present invention, it is possible to reduce the need for redoing work when the load cannot be discharged due to an obstacle above the loading box. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a side view of a dump truck with a cargo box in a seated position. [Figure 2] FIG. 2 is a plan view of the dump truck. [Figure 3] FIG. [Figure 4] FIG. 1 is a side view of a dump truck when a cargo box is in a tilted state. [Figure 5] FIG. 2 is a circuit diagram of the main parts of a hydraulic circuit. [Figure 6] FIG. [Figure 7] FIG. 2 is a block diagram of a discharge determination system. [Figure 8] 10 is an example of a table showing the relationship between the type of load and the angle of repose. [Figure 9] 10 is a flowchart of a load unloading process. [Figure 10] FIG. 10 is a side view of a dump truck according to a second embodiment. [Figure 11] FIG. 10 is a block diagram of a discharge determination system according to a second embodiment. [Figure 12] FIG. 10 is a block diagram of a load discharge system according to a third embodiment. [Figure 13] 10 is a flowchart showing the discharge of a load by a dump truck according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] [First embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a dump truck 1 according to this embodiment. Fig. 2 is a plan view of the dump truck 1, and Fig. 3 is a rear view of the dump truck 1.

[0021] As shown in FIG. 1, the dump truck 1 includes a chassis frame 2, a cab (driver's compartment) 3 supported by the chassis frame 2, front and rear wheels 5 and 6 supported by the chassis frame 2, a subframe 7 disposed behind the cab 3 and on the chassis frame 2, and a cargo box 30 supported by the subframe 7. The dump truck 1 also includes an engine 9 as a drive source for generating power, and a power take-off device (hereinafter referred to as PTO) 10. In this embodiment, the front wheels 5 or the rear wheels 6 are an example of wheels that rotate upon receiving power from the drive source. The chassis frame 2, the cab 3, the subframe 7, the engine 9, and the PTO 10 constitute a vehicle body 1A. A driver's seat (not shown) is provided inside the cab 3. In the following description, unless otherwise specified, the terms front, rear, left, right, up, and down refer to the front, rear, left, right, up, and down as viewed from the driver sitting in the driver's seat.

[0022] The cargo box 30 is supported by the vehicle body 1A so as to be tiltable. As shown in FIG. 1, the rear portion of the cargo box 30 is rotatably supported at the rear end of the subframe 7 by a hinge shaft 8 extending in the vehicle width direction. The vehicle body 1A has a rotation support portion 13 that rotatably supports the rear portion of the cargo box 30. FIG. 4 is a side view of the dump truck 1 when the cargo box 30 is tilted. The dump truck 1 is equipped with a dump device 25 that tilts the cargo box 30. The dump device 25 is equipped with a hydraulic cylinder 26 and a link mechanism 27. The link mechanism 27 is connected to the vehicle body 1A and the cargo box 30. The hydraulic cylinder 26 is connected to the link mechanism 27. The hydraulic cylinder 26 rotates the cargo box 30 via the link mechanism 27.

[0023] As shown in Fig. 5, the dump truck 1 is provided with a hydraulic circuit 20 incorporating a hydraulic cylinder 26. In addition to the hydraulic cylinder 26, the hydraulic circuit 20 has an oil tank 21, a hydraulic pump 22, and a changeover valve (not shown). The PTO 10 extracts power from the engine 9 and transmits the power to the hydraulic pump 22. In the hydraulic circuit 20, by appropriately switching the changeover valve, oil pressurized by the hydraulic pump 22 is supplied to the hydraulic cylinder 26. This drives the hydraulic cylinder 26, causing the cargo box 30 to rotate around the hinge shaft 8 (see Fig. 4).

[0024] 1 and 2, the cargo box 30 has a bottom plate 31, a front wall 32 standing from the front end of the bottom plate 31, a left wall 33 standing from the left end of the bottom plate 31, a right wall 34 standing from the right end of the bottom plate 31, and a tailgate 35. The front wall 32 extends upward from the front end of the bottom plate 31. The front wall 32 extends upward to a position higher than any of the left wall 33, the right wall 34, and the tailgate 35. As shown in FIG. 1, for example, the front wall 32 extends upward to a position higher than the top end of the cab 3.

[0025] The tailgate 35 is rotatable about a hinge shaft 37 extending in the left-right direction. The tailgate 35 can rotate between a closed position in which it stands up from the rear end of the bottom plate 31 and an open position inclined or perpendicular to the closed position. In FIG. 4 , the tailgate 35 in the closed position is represented by a solid line, and the tailgate 35 in the open position is represented by a phantom line. When the tailgate 35 is in the closed position, the rear of the cargo box 30 is closed. When the tailgate 35 is in the open position, the cargo box 30 is opened rearward. When cargo is to be unloaded from the cargo box 30, the cargo box 30 tilts and the tailgate 35 rotates to the open position. This opens the cargo box 30 rearward, allowing the cargo to be smoothly unloaded from the cargo box 30. The cargo may be any suitable cargo. Examples of cargo include soil, gravel, metal powder, ceramic powder, ash, coal, beans, and other food items. The condition may also vary depending on, for example, the particle size and moisture content of the powder.

[0026] FIG. 6 is a rear view of the cargo box 30. However, the front wall 32 is not shown in FIG. 6. As shown in FIG. 6, a hook 39 is provided on the rear surface of the bottom plate 31 of the cargo box 30. The tailgate 35 is provided with a locking bar 38 extending in the left-right direction, to which the hook 39 can be locked. The hook 39 is connected to a lever (not shown). An operator can manually operate the lever to lock or unlock the hook 39 to the locking bar 38. When the hook 39 is locked to the locking bar 38, the tailgate 35 cannot rotate around the hinge shaft 37, and the tailgate 35 is held in the closed position. When the hook 39 is released from the locking bar 38, the tailgate 35 can be rotated from the closed position to the open position. The hook 39 and the locking bar 38 constitute a manual locking mechanism 36 that holds the tailgate 35 in the closed position.

[0027] As shown in FIG. 1, the vehicle body 1A has a seat 11 that supports the bottom of a cargo box 30. The seat 11 is provided on a subframe 7. As shown in FIG. 1, when the cargo box 30 is in a horizontal position, the bottom of the cargo box 30 is supported by the seat 11. More specifically, the cargo box 30 is provided with a bottom plate 31 and a main beam 31a that reinforces the bottom plate 31, and the main beam 31a is supported by the seat 11. On the other hand, as shown in FIG. 7, when the cargo box 30 is tilted by rotating it around the hinge shaft 8, the bottom of the cargo box 30 moves away from the seat 11.

[0028] As shown in FIG. 4 , the dump truck 1 is equipped with a weighing scale 40 that measures the weight of the load placed in the loading box 30 (hereinafter referred to as the load weight). The weighing scale 40 according to this embodiment measures the weight of the loading box 30 with the load placed therein (i.e., the sum of the weight of the loading box 30 itself and the weight of the load), and calculates the weight of the load by subtracting the weight of the loading box 30 itself from the weight of the loaded item. The weight of the loading box 30 itself is specified in advance. Therefore, measuring the weight of the loading box 30 with the load placed therein and measuring the load weight are technically equivalent matters. In this specification, measuring the load weight includes measuring the load weight itself and measuring a weight that is correlated with the load weight (in the above example, the weight of the loading box 30 with the load placed therein). In other words, measuring the load weight includes measuring any weight that can identify the load weight.

[0029] In this embodiment, the weighing scale 40 is a load cell type weighing scale or a weighing scale that calculates the load weight based on the hydraulic pressure of the hydraulic cylinder 26. However, there are no limitations on the type or configuration of the weighing scale 40, and any weighing scale that has conventionally been used to measure the load weight of a cargo box on a dump truck can be used.

[0030] The dump truck 1 is equipped with an upper sensor 45 that detects the vertical position of an obstacle above the loading box 30. In this embodiment, the upper sensor 45 is an ultrasonic sensor that is configured to emit ultrasonic waves and measures the distance to the obstacle based on the time it takes for the ultrasonic waves reflected by the obstacle to reach the dump truck 1. However, the type of upper sensor 45 is not particularly limited, and any conventionally used obstacle sensor can be used. The upper sensor 45 may be, for example, a camera that is configured to acquire an image above the loading box 30 and estimates the distance to the obstacle based on the image. The upper sensor 45 may be, for example, a photoelectric sensor or millimeter-wave radar that can detect the distance to the obstacle.

[0031] Above the location where the dump truck 1 rotates the loading box 30 to unload a load, there may be obstacles such as a building ceiling, bridge piers, overhead wires, and traffic lights that could collide with the loading box 30. The upper sensor 45 is intended to prevent the loading box 30 from colliding with such obstacles above the loading box 30. As shown in FIG. 1 , the upper sensor 45 is disposed on the upper edge of the front wall 32 of the loading box 30. For example, if the front wall 32 has a recess for accommodating a seat, the upper sensor 45 may be disposed within the recess. For example, the upper sensor 45 may be supported by a stay provided on the front wall 32 so as to extend toward the side (forward) of the cab 3. However, the location where the upper sensor 45 is installed is not particularly limited. The upper sensor 45 may be disposed in the cab 3, for example.

[0032] The dump truck 1 further includes an inclination sensor 50 that detects the inclination angle of the cargo box 30. In this embodiment, the inclination sensor 50 is an acceleration sensor that detects the direction of gravity (vertical direction). As shown in FIG. 4, the inclination sensor 50 is attached to the cargo box 30 and tilts together with the cargo box 30. The inclination sensor 50 is preferably attached to the vehicle body 1A and is used together with another sensor that measures the inclination of the vehicle body 1A. However, in most cases, the location where the dump truck 1 tilts the cargo box 30 is close to horizontal. Therefore, another sensor that measures the inclination of the vehicle body 1A does not need to be used. The configuration of the inclination sensor 50 is not particularly limited. For example, the inclination sensor 50 may be configured to measure the position of the rod of the hydraulic cylinder 26 and calculate the inclination angle of the cargo box 30 from that position.

[0033] The dump truck 1 is also equipped with a parking brake 12. Loading work of earth and sand into the cargo box 30 may be performed with the parking brake 12 OFF (for example, in asphalt stripping work, loading is performed while traveling alongside a road cutter), but there may be cases where it is preferable to do the work while the truck is stopped, and the work may be performed with the parking brake 12 ON. When the parking brake 12 is ON, the dump truck 1 is maintained in a stopped state. On the other hand, when the dump truck 1 is traveling, the parking brake 12 is OFF. As shown in FIG. 1, the dump truck 1 according to this embodiment is equipped with a parking brake detection device 55 that detects whether the parking brake 12 is ON or OFF.

[0034] As described above, when work is performed using the hydraulic pump 22, the power of the engine 9 is transmitted to the hydraulic pump 22 via the PTO 10. That is, the PTO 10 extracts the power of the engine 9 and transmits it to the hydraulic pump 22. In the following, when the PTO 10 extracts the power of the engine 9, it is said that the PTO 10 is ON, and when the PTO 10 does not extract the power of the engine 9, it is said that the PTO 10 is OFF. When the hydraulic pump 22 is driven, the PTO 10 is turned ON. When the dump truck 1 is traveling, the power of the engine 9 is transmitted to the front wheels 5 or the rear wheels 6, and is not transmitted to the hydraulic pump 22. When the dump truck 1 is traveling, the PTO 10 is turned OFF.

[0035] In this embodiment, the dump truck 1 is equipped with a discharge determination system 100 that determines whether a load loaded in a loading box 30 can be discharged from the loading box 30. Fig. 7 is a block diagram of the discharge determination system 100. As shown in Fig. 7, the discharge determination system 100 is equipped with an input device 101 that can input the type of load, a memory 102 that stores the type of load and the angle of repose for each load, a required tilt angle calculation device 103 that calculates the angle of the loading box 30 at which the load can be discharged (hereinafter also referred to as the required tilt angle) based on the angle of repose of the load, a possible tilt angle calculation device 104 that calculates the angle at which the loading box 30 can be tilted (hereinafter also referred to as the possible tilt angle) based on the position of an obstacle detected by the upper sensor 45, a determination device 105 that determines whether the load loaded in the loading box 30 can be discharged from the loading box 30, and a notification device 106 that notifies the driver of the determination result made by the determination device 105.

[0036] The configuration of the emission determination system 100 is not particularly limited. The emission determination system 100 may include, for example, a central processing unit (hereinafter referred to as a CPU), a ROM in which programs executed by the CPU are stored, and a RAM. Each unit of the emission determination system 100 may be configured by software or by hardware. Furthermore, each unit may be a processor or a circuit.

[0037] The input device 101 is provided, for example, in the cab 3. The type of load is input to the input device 101 by, for example, the driver of the dump truck 1. The input device 101 may be configured to allow one load to be selected from pre-registered types of load. The input device 101 does not have to be one that is input by the driver of the dump truck 1 or the like. The input to the input device 101 may be performed automatically, for example, by receiving information from a system that manages the schedule of the dump truck 1 or the like.

[0038] The memory 102 stores the type of load and the angle of repose for each load. Figure 8 shows an example of a table showing the relationship between the type of load and the angle of repose. The angle of repose is the maximum angle at which the piled powder will not slide. If the angle of repose is exceeded, the pile of load will collapse and begin to slide. If the loading box 30 is tilted beyond the angle of repose, the load can be discharged from the loading box 30.

[0039] The required tilt angle calculation device 103 is configured to read from the memory 102 the angle of repose of the load input to the input device 101, and calculate the required tilt angle (the angle of the cargo box 30 at which the load can be unloaded from the cargo box 30) based on the read angle of repose. The required tilt angle may be equal to the angle of repose of the load stored in the memory 102. In this case, the required tilt angle calculation device 103 may simply read from the memory 102 the angle of repose of the load input to the input device 101. However, the required tilt angle may be set to be larger than the angle of repose of the load stored in the memory 102. The memory 102 may store in advance an angle obtained by adding a predetermined angle to the angle of repose of the load, and the required tilt angle calculation device 103 may read this angle from the memory 102. The required tilt angle calculation device 103 may be configured to calculate the required tilt angle by adding the predetermined angle to the angle of repose of the load read from the memory 102. Alternatively, the required inclination angle calculation device 103 may be configured to calculate the required inclination angle by, for example, adding an angle that varies depending on the surrounding environment to the angle of repose of the load read from the memory 102. The variable angle may vary depending on, for example, the ambient humidity. When the ambient humidity is high, the load becomes wet and the pile of load is less likely to collapse. In this case, the dump truck 1 may be equipped with a hygrometer that measures humidity. In this way, "determining" the required inclination angle includes using the angle of repose of the load read from the memory 102 as the required inclination angle as is, and calculating the required inclination angle using the angle of repose of the load read from the memory 102.

[0040] The possible tilt angle calculation device 104 is configured to calculate the possible tilt angle (the angle at which the cargo box 30 can be tilted) based on the position of the obstacle detected by the upper sensor 45. The possible tilt angle is, for example, the angle of the cargo box 30 at which the top end of the cargo box 30 is positioned a predetermined distance below the obstacle detected by the upper sensor 45.

[0041] The determination device 105 is configured to determine that the load can be unloaded from the cargo box 30 if the possible tilt angle calculated by the possible tilt angle calculation device 104 is equal to or greater than the required tilt angle calculated by the required tilt angle calculation device 103. The determination device 105 also determines that the load cannot be unloaded from the cargo box 30 if the possible tilt angle calculated by the possible tilt angle calculation device 104 is smaller than the required tilt angle calculated by the required tilt angle calculation device 103. In other words, the determination device 105 determines that as the cargo box 30 is tilted, the cargo box 30 will come into contact with an obstacle above before the load slides off the cargo box 30. The determination device 105 may, for example, have an operating terminal in the cab 3 that starts the determination operation.

[0042] The notification device 106 is provided, for example, inside the cab 3. The notification device 106 may display whether the load loaded in the cargo box 30 can or cannot be discharged from the cargo box 30. Alternatively, the notification device 106 may display this only when the load loaded in the cargo box 30 cannot be discharged from the cargo box 30. The method of display by the notification device 106 is not particularly limited. The notification device 106 may, for example, be equipped with a lamp that displays whether the load can or cannot be discharged from the cargo box 30. The notification device 106 may, for example, be configured to respond by voice whether the load can or cannot be discharged from the cargo box 30.

[0043] In this embodiment, the discharge determination system 100 is equipped with a warning device 107 that issues a warning when the angle of the cargo box 30 approaches the possible tilt angle calculated by the possible tilt angle calculation device 104. The warning device 107 issues a warning when the difference between the possible tilt angle and the angle of the cargo box 30 becomes smaller than a predetermined angle. The angle of the cargo box 30 is measured by the tilt sensor 50. The type of warning is not particularly limited, but may be, for example, an audible warning. The discharge determination system 100 also includes a limiting device 108 that prohibits the cargo box 30 from being tilted beyond the possible tilt angle.

[0044] FIG. 9 is a flowchart of discharging a load. In this embodiment, the load is discharged by the driver of the dump truck 1. In step S01, the driver inputs the type of load into the input device 101. In step S02 of discharging the load, the dump truck 1 is parked at the planned point where the load is to be discharged. The order of steps S01 and S02 may be reversed. In the following step S03, it is determined whether the load can be discharged from the loading box 30. If the result of step S03 is YES (if it is determined that the load can be discharged from the loading box 30), the driver is notified in step S04A that the load can be discharged. If the result of step S03 is NO (if it is determined that the load cannot be discharged from the loading box 30), the driver is notified in step S04B that the load cannot be discharged.

[0045] When the driver is notified in step S04A that the load can be unloaded, the driver turns on the PTO 10 in step S05. In step S06, the driver tilts the cargo box 30 and unloads the load from the cargo box 30. Control of the angle of the cargo box 30 is up to the driver, but a warning is issued when the angle of the cargo box 30 approaches the allowable tilt angle. This lets the operator know that further tilting of the cargo box 30 requires confirmation that the cargo box 30 will not come into contact with an obstacle. Furthermore, rotation of the cargo box 30 is stopped when the angle of the cargo box 30 reaches the allowable tilt angle.

[0046] When the driver is notified in step S04B that the load cannot be discharged, the driver moves the dump truck 1 to another candidate discharge point in step S07. The movement in step S07 may be a short movement of, for example, within a few meters. After step S07, the operator stops the dump truck 1 at another discharge point again in step S02, and then makes the determination in step S03 again. The flow from step S03 is the same as described above.

[0047] When the unloading of the load in step S06 is completed, in step S08 the worker seats the packing box 30. In step S09, the worker turns off the PTO 10 to make the dump truck 1 ready to travel.

[0048] As described above, the dump truck 1 according to this embodiment is equipped with an upper sensor 45 that detects the vertical position of an obstacle above the cargo box 30, a required tilt angle calculation device 103 that calculates the angle of the cargo box 30 (required tilt angle) at which the load loaded in the cargo box 30 can be discharged, a possible tilt angle calculation device 104 that calculates the angle at which the cargo box 30 can be tilted (possible tilt angle) based on the position of the obstacle detected by the upper sensor 45, and a determination device 105 that determines that the load can be discharged from the cargo box 30 if the possible tilt angle calculated by the possible tilt angle calculation device 104 is equal to or greater than the required tilt angle calculated by the required tilt angle calculation device 103, and determines that the load cannot be discharged from the cargo box 30 if the possible tilt angle calculated by the required tilt angle calculation device 103 is smaller than the required tilt angle calculated by the required tilt angle calculation device 103. With this dump truck 1, it is possible to know whether the load can be discharged at a planned discharge point without actually tilting the cargo box 30. Therefore, with conventional dump trucks, it is possible to omit some of the redoing work required when the load cannot be discharged, which involves tilting the loading box, and if the load cannot be discharged, seating the loading box and moving the dump truck.In other words, it is possible to shorten the redoing work by determining in advance whether the load can be discharged, and moving the dump truck 1 if it is determined that the load cannot be discharged.

[0049] The dump truck 1 according to this embodiment includes an input device 101 that can input the type of load, and a memory 102 that registers the types of load and the angles of repose for each load, and the required inclination angle calculation device 103 is configured to read from the memory 102 the angles of repose of the load input to the input device 101 and determine the required inclination angle based on the read angles of repose. With this dump truck 1, the required inclination angle can be determined even if the types of load are diverse.

[0050] The dump truck 1 according to this embodiment is equipped with a warning device 107 that issues a warning when the difference between the possible tilt angle and the angle of the cargo box 30 becomes smaller than a predetermined angle. The warning device 107 can reduce the risk of the cargo box 30 coming into contact with an obstacle due to a driver error.

[0051] The dump truck 1 may be configured to disable driving of the dumping device 25 when the determination device 105 determines that the load cannot be discharged from the loading box 30. For example, the dump truck 1 may be configured to turn off the PTO 10 when the determination device 105 determines that the load cannot be discharged from the loading box 30. According to such a dump truck 1, it is possible to prevent the loading box 30 from starting to rotate due to driver error or the like, even though it has been determined that the load cannot be discharged from the loading box 30.

[0052] [Second embodiment] In the second embodiment, the method for determining the required tilt angle is different from that in the first embodiment. In the following description of the second embodiment and other embodiments, components that perform the same functions as those in the first embodiment will be designated by the same reference numerals as those in the first embodiment. Furthermore, duplicated descriptions will be omitted or simplified as appropriate.

[0053] FIG. 10 is a side view of a dump truck 1 according to a second embodiment. FIG. 11 is a block diagram of a discharge determination system 100 according to the second embodiment. As shown in FIG. 10, the dump truck 1 according to the second embodiment includes a cargo box camera 60 that acquires images of the interior of the cargo box 30. Here, the cargo box camera 60 is provided on the front wall 32 of the cargo box 30 and is configured to capture images of the rear. However, the position of the cargo box camera 60 is not particularly limited. As shown in FIG. 11, in this embodiment, the discharge determination system 100 includes a weight acquisition device 109 that acquires the weight of the cargo loaded in the cargo box 30 from a weighing scale 40, a volume estimation device 110 that estimates the volume of the cargo loaded in the cargo box 30 from the image acquired by the cargo box camera 60, and a density estimation device 111 that calculates an estimated density of the cargo from the weight of the cargo acquired by the weight acquisition device 109 and the volume of the cargo estimated by the volume estimation device 110. The volume of the load is estimated, for example, by measuring the height of the load in the loading box 30. The bottom area of ​​the loading box 30 is known in advance. Note that the weight acquisition device 109 may be configured to acquire the weight of the load measured not from the weighing scale 40 but from another device, for example, an external weighing scale external to the dump truck 1. In this case, the dump truck 1 does not need to be equipped with the weighing scale 40.

[0054] A correspondence table between the density of the load and the angle of repose is stored in the memory 102 according to this embodiment. The required tilt angle calculation device 103 according to this embodiment is configured to read the angle of repose of the load from the correspondence table in the memory 102 based on the estimated density calculated by the density estimation device 111, and to calculate the angle of the shipping box 30 (required tilt angle) at which the load can be discharged based on the read angle of repose.

[0055] The angle of repose of a load may vary depending on factors related to density, such as moisture content and particle size, even if the load type is the same. This embodiment can accommodate factors other than the type of load. The angle of repose of a load may be registered in association with both the type and density of the load.

[0056] [Third embodiment] In the third embodiment, the dump truck 1 is automatically driven to a planned discharge point for the load and automatically discharges the load. At that time, it is automatically determined whether the load can be discharged from the packing box 30.

[0057] FIG. 12 is a block diagram of a load discharge system 100A according to a third embodiment. As shown in FIG. 12, the load discharge system 100A according to this embodiment includes a discharge point setting device 112 that sets a load discharge point, and an automatic driving device 113 that drives the vehicle body 1A to the discharge point set by the discharge point setting device 112. The discharge point setting device 112 is configured to change the discharge point if it is determined that the load cannot be discharged from the cargo box 30 at the set discharge point. In this embodiment, the memory 102 stores the maximum tilt angle of the cargo box 30 that can be achieved by the dump device 25. The maximum tilt angle of the cargo box 30 that can be achieved by the dump device 25 is not particularly limited, but is, for example, between 45 and 55 degrees. Here, the maximum tilt angle of the cargo box 30 is set to an angle at which all of the loads whose angles of repose are stored in the memory 102 can be discharged. The dump truck 1 further includes a dump control device 114 that drives the dump device 25 to tilt the cargo box 30 to the possible tilt angle when the determination device 105 determines that the load can be discharged from the cargo box 30 and the possible tilt angle calculated by the possible tilt angle calculation device 104 is equal to or smaller than the maximum tilt angle stored in the memory 102. The dump control device 114 is configured to drive the dump device 25 to tilt the cargo box 30 to the maximum tilt angle when it determines that the load can be discharged from the cargo box 30 and the possible tilt angle calculated by the possible tilt angle calculation device 104 is larger than the maximum tilt angle stored in the memory 102.

[0058] FIG. 13 is a flowchart of a load discharge by a dump truck 1 according to the third embodiment. As shown in FIG. 13, in the load discharge operation according to this embodiment, a load discharge point is set in step S11. In step S11, a plurality of candidate discharge points may be set together with their priorities. In step S12, the dump truck 1 travels to the load discharge point by automatic driving and stops. In step S13, a vehicle speed sensor (not shown) confirms that the dump truck 1 has stopped. In step S14, the parking brake 12 is turned on. The fact that the parking brake 12 has been turned on is detected by the parking brake detection device 55. In the example shown here, the PTO 10 is turned on later, but it may also be turned on immediately after the parking brake 12 is turned on.

[0059] In step S15, it is determined whether the load can be discharged from the cargo box 30. This determination method may be any of the methods described above. If the result of step S15 is YES (if it is determined that the load can be discharged from the cargo box 30), the PTO is turned on in step S16. In the following step S17, it is determined whether the possible tilt angle calculated by the possible tilt angle calculation device 104 is equal to or less than the maximum tilt angle of the cargo box 30. If the possible tilt angle is equal to or less than the maximum tilt angle of the cargo box 30 (if the result of step S17 is YES), in step S18A, the tilt angle of the cargo box 30 is set to the calculated possible tilt angle. In step S19A following step S18A, the cargo box 30 is rotated to the possible tilt angle, and the load is automatically discharged.

[0060] If the result of step S17 is NO (if the possible tilt angle is greater than the maximum tilt angle of the cargo box 30), then in step S18B the tilt angle of the cargo box 30 is set to the maximum tilt angle of the cargo box 30. In step S19B following step S18B, the cargo box 30 is rotated to the maximum tilt angle, and the load is automatically discharged. This control allows the cargo box 30 to tilt to the maximum angle possible depending on the situation (the maximum tilt angle of the cargo box 30 if the possible tilt angle of the cargo box 30 is not limited by an obstacle above the cargo box 30, or the possible tilt angle calculated by the possible tilt angle calculation device 104 if the possible tilt angle of the cargo box 30 is limited by an obstacle above the cargo box 30), so that the load can be discharged quickly.

[0061] If the result of step S15 is NO (if it is determined that the cargo cannot be discharged from the shipping box 30), the discharge point is changed to the second candidate point in step S20. After step S20, step S12 is performed again. The flow from step S12 is the same as that described above.

[0062] When the unloading of the load in step S19A or S19B is completed, the loading box 30 is seated in step S21. At this time, it may be determined whether the unloading of the load is completed based on the weight of the loading box 30 measured by the weighing scale 40. In step S22, the PTO 10 is turned OFF. This enables the dump truck 1 to travel.

[0063] According to this embodiment, it is possible to omit some of the redoing work when the load cannot be discharged in the automatically driven dump truck 1. In the automatically driven dump truck 1, the driver does not check whether the load has started to slide off the loading box 30. Therefore, the technology for determining whether the load can be discharged from the loading box 30 before the discharge work is effective even in the automatically driven dump truck 1.

[0064] Several embodiments of the present invention have been described above. However, the above-described embodiments are merely examples. The present invention can be embodied in various other forms. For example, the type of cargo may be identified by artificial intelligence (AI) based on an image of the cargo captured by a camera or the like. Unless otherwise specified, the embodiments do not limit the present invention. [Explanation of symbols]

[0065] 1. Dump truck (dump vehicle) 1A Vehicle body 25 Dump device 30 packing boxes 40 Weight scale 45 Upper sensor (detection device) 60 Cargo box camera (imaging device) 101 Input Device 102 Memory (storage device) 103 Required tilt angle calculation device (first processing device) 104 Possible tilt angle calculation device (second processing device) 105 Judgment device 107 Warning device 109 Weight acquisition device 110 Volume estimation device 111 Density estimation device 112 Discharge point setting device 113 Automatic driving device 114 Dump control device

Claims

1. The vehicle body, a luggage box tiltably supported on the vehicle body; a dump device that tilts the cargo box; a detection device for detecting the vertical position of an obstacle above the packing box; a first processing device that determines an angle of the packing box at which the load loaded in the packing box can be discharged based on the angle of repose of the load; a second processing device that determines an angle at which the container can be tilted based on the position of the obstacle detected by the detection device; The dump vehicle is provided with a determination device that determines that the load can be discharged from the loading box if the angle determined by the second processing device is equal to or greater than the angle determined by the first processing device, and determines that the load cannot be discharged from the loading box if the angle determined by the second processing device is smaller than the angle determined by the first processing device.

2. an input device capable of inputting the type of cargo; Further provided is a storage device in which the type of load and the angle of repose for each load are stored, The first processing device is configured to read from the storage device the angle of repose of the load input to the input device, and calculate an angle of the packing box at which the load can be discharged based on the read angle of repose. The dump vehicle according to claim 1 .

3. a weight acquisition device that acquires the weight of the load loaded in the packing box; an imaging device for capturing an image of the inside of the packing box; a volume estimation device that estimates the volume of the cargo loaded in the shipping box from the image acquired by the imaging device; a density estimation device that calculates an estimated density of the load from the weight of the load acquired by the weight acquisition device and the volume of the load estimated by the volume estimation device; a storage device storing a correspondence table between the density of the load and the angle of repose; The first processing device is configured to read an angle of repose of the load from the correspondence table in the storage device based on the estimated density calculated by the density estimation device, and to determine an angle of the packing box at which the load can be discharged based on the read angle of repose. The dump vehicle according to claim 1 .

4. a storage device storing the maximum tilt angle of the container that can be achieved by the dump device; a dump control device that drives the dump device to tilt the cargo box to the angle determined by the second processing device when it is determined that the load can be discharged from the cargo box and the angle determined by the second processing device is equal to or smaller than the maximum tilt angle stored in the storage device, and drives the dump device to tilt the cargo box to the maximum tilt angle when it is determined that the load can be discharged from the cargo box and the angle determined by the second processing device is larger than the maximum tilt angle. The dump vehicle according to claim 1 .

5. a discharge point setting device for setting a discharge point for the loaded object; an automatic driving device that drives the vehicle body to the discharge point set by the discharge point setting device, The discharge point setting device is configured to change the discharge point when it is determined that the load cannot be discharged from the packing box at the set discharge point. The dump vehicle according to claim 1 .

6. The system further includes a warning device that issues a warning when the difference between the angle determined by the second processing device and the angle of the packing box becomes smaller than a predetermined angle. The dump vehicle according to claim 1 .

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