Truck and loading weight measurement system for truck

Abstract

To provide a truck that allows an operator to easily perform loading operations so as not to exceed the maximum loading weight, and a loading weight measurement system for the truck.SOLUTION: A truck comprises a weight measurement device 70 that measures the weight of a cargo box. The weight measurement device 70 has: a measurement unit 71 that measures the loading weight of a loaded material loaded in the cargo box; a storage unit 72 that stores the maximum loading weight; and an operation unit 73 that calculates a loadable weight that is the difference between the maximum loading weight stored in the storage unit 72 and the loading weight measured by the measurement unit 71. The truck further comprises a display 76 that displays the loadable weight calculated by the operation unit 73.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to trucks. [Background technology]

[0002] Conventionally, freight vehicles equipped with a weighing scale that measures the weight of cargo loaded in a cargo box (hereinafter also referred to as load weight) have been known, as described in Patent Document 1. Patent Document 1 discloses a weighing scale that tilts the cargo box using a hydraulic cylinder and calculates the load weight based on the hydraulic pressure of the hydraulic cylinder at that time. Here, the cargo box rotates around a hinge shaft provided at the rear of the cargo box and tilts downward toward the rear.

[0003] The freight vehicle disclosed in Patent Document 1 is equipped with a display installed at the top of the front wall of the cargo box. The display is installed facing rearward and displays the load weight measured by a weighing scale. This allows workers to perform loading work while checking the current load weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-096925 Summary of the Invention [Problem to be solved by the invention]

[0005] When carrying out such loading work, workers must ensure that the load weight does not exceed the maximum load weight of the truck. However, trucks have different equipment, including options, and the weight of the equipment varies from vehicle to vehicle. As a result, the maximum load weight also varies from vehicle to vehicle. Therefore, workers must check the maximum load weight of the vehicle each time they carry out loading work.

[0006] Generally, the maximum load weight of a freight vehicle is often displayed on a plate attached to the rear of the vehicle. However, if the plate is dirty with soil or if work is being done at night, it may be difficult to see the maximum load weight. Even in such cases, it is desirable for workers to be able to instantly determine how much more cargo can be loaded during loading work.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide a freight vehicle and a freight vehicle load weight measurement system that facilitates loading operations so as not to exceed the maximum load weight. [Means for solving the problem]

[0008] The freight truck of the present invention comprises a vehicle body, a cargo box provided on the vehicle body in which cargo is loaded, a weight measuring device having a measuring unit that measures the load weight of the cargo loaded in the cargo box, a memory unit that stores a maximum load weight, and a calculation unit that calculates a loadable weight, which is the difference between the maximum load weight stored in the memory unit and the load weight measured by the measuring unit, and a display that displays the loadable weight calculated by the calculation unit.

[0009] The loadable weight is the difference between the maximum load weight and the current load weight, and indicates how much more weight of cargo can be loaded into the shipping box. According to the above configuration, the loadable weight is displayed on the display, so the worker performing the loading operation can easily determine by looking at the display whether the current load weight exceeds the maximum load weight. This makes it easier to perform loading operations without exceeding the maximum load weight. Furthermore, since it is easier to load cargo up to a weight as close as possible to the maximum load weight without exceeding the maximum load weight, transportation efficiency is improved.

[0010] According to one preferred aspect, the truck includes a hydraulic cylinder that tilts the cargo box, a hydraulic sensor that measures the hydraulic pressure of the hydraulic cylinder, a tilt angle sensor that measures the tilt angle of the cargo box, and a display control device that controls the display. The measurement unit of the weight measuring device is configured to measure the load weight based on the hydraulic pressure of the hydraulic cylinder measured by the hydraulic sensor. The display control device causes the display to display the loadable weight calculated by the calculation unit of the weight measuring device when the tilt angle of the cargo box is less than a predetermined angle. The display control device does not cause the display to display the loadable weight calculated by the calculation unit of the weight measuring device when the tilt angle of the cargo box is equal to or greater than the predetermined angle.

[0011] In a weight measuring device that measures the load weight of a load placed on a cargo box based on the hydraulic pressure value of a hydraulic cylinder that tilts the cargo box, the load weight is measured with the cargo box tilted. It is known that when measuring load weight in this manner, the accuracy of the load weight measurement decreases as the inclination angle of the cargo box increases. Therefore, even if a loadable weight calculated when the inclination angle of the cargo box is large is displayed on the display and a worker performs loading work while looking at the display, it is difficult to load the desired amount of cargo. Furthermore, even if the display does not indicate the maximum load weight, the actual load may exceed the maximum load weight, resulting in an overload condition. According to the above configuration, the loadable weight is not displayed on the display when the inclination angle is greater than a predetermined angle. Not displaying the loadable weight on the display prompts the worker to check the work status, including the inclination angle of the cargo box.

[0012] According to a preferred embodiment, the truck is equipped with a display control device that controls the display. When the load weight measured by the measurement unit of the weight measuring device is equal to or greater than a predetermined weight, the display control device causes the display to display the loadable weight calculated by the calculation unit of the weight measuring device. When the load weight calculated by the measurement unit of the weight measuring device is less than the predetermined weight, the display control device does not cause the display to display the loadable weight calculated by the calculation unit of the weight measuring device.

[0013] When the load weight is small, it is highly likely that the load is unevenly loaded within the box. When the load is unevenly loaded within the box, the center of gravity of the box is shifted, making it difficult to accurately measure the load weight. Furthermore, in normal loading operations, the operator tries to load as much load as possible without overloading, so when the load weight is small, there is little need for the operator to check the display. According to the above configuration, when the load weight is less than a predetermined load weight, the display does not display the available load weight. Therefore, when it is difficult to accurately measure the load weight and there is little need to check the load weight, the display does not intentionally display the available load weight.

[0014] According to a preferred embodiment, the truck includes a display control device that controls the display, and the display control device is configured to be able to switch the display on the display between the loaded weight and the loadable weight.

[0015] This allows the display to show either the loaded weight or the loadable weight, depending on the loading work situation, etc.

[0016] The truck according to the present invention includes a vehicle body, a cargo box mounted on the vehicle body and configured to hold cargo, a hydraulic cylinder for tilting the cargo box, a hydraulic pressure sensor for measuring the hydraulic pressure of the hydraulic cylinder, a tilt angle sensor for measuring the tilt angle of the cargo box, a weight measuring device having a measuring unit for measuring the load weight of the cargo loaded in the cargo box, a display for displaying the load weight measured by the weight measuring device, and a display control device for controlling the display. The display control device causes the display to display information other than the load weight when the tilt angle of the cargo box measured by the tilt angle sensor is equal to or greater than a predetermined angle.

[0017] In a weight measuring device that measures the weight of a load placed on a cargo box based on the hydraulic pressure value of a hydraulic cylinder that tilts the cargo box, the load weight is measured with the cargo box tilted. It is known that when measuring the load weight in this manner, the accuracy of the load weight measurement decreases as the inclination angle of the cargo box increases. Therefore, even if a load weight measured when the inclination angle of the cargo box is large is displayed on a display and a worker performs loading work while looking at the display, it is difficult to load the desired weight of cargo. According to the above configuration, when the inclination angle of the cargo box measured by the inclination angle sensor is equal to or greater than a predetermined angle, the display displays information other than the load weight. Displaying information other than the load weight on the display prompts the worker to check the work status, including the inclination angle of the cargo box. Furthermore, because the display displays information other than the load weight, the worker is not misled into thinking that the weight measuring device or the display is malfunctioning.

[0018] According to a preferred aspect, the display control device causes the display to display the loaded weight when the tilt angle of the packing box measured by the tilt angle sensor is less than the predetermined angle and the loaded weight measured by the weight measuring device is equal to or greater than a predetermined weight. When the tilt angle of the packing box measured by the tilt angle sensor is less than the predetermined angle and the loaded weight measured by the weight measuring device is less than the predetermined weight, the display control device does not cause the display to display the loaded weight.

[0019] When the weight of the load measured by the weight measuring device is small, the load is likely to be unevenly distributed within the loading box, causing the center of gravity of the loading box to shift, making it difficult to accurately measure the loaded weight. On the other hand, when the loading box has a small tilt angle and a large load weight, the loaded weight can be accurately measured. With the above configuration, the load weight is displayed on the display only when the loaded weight can be accurately measured, thereby avoiding unnecessary display. Furthermore, when a freight truck is traveling, the loading box is kept horizontal, not tilted. With the above configuration, when the freight truck is traveling with an empty load, the loaded weight is not displayed on the display. This prevents drivers of vehicles behind a freight truck traveling with an empty load from being drawn to the display.

[0020] According to a preferred embodiment, the weight measuring device includes a storage unit that stores a maximum load weight, and a calculation unit that calculates a loadable weight, which is the difference between the maximum load weight stored in the storage unit and the load weight measured by the measurement unit. The display control device is configured to be able to switch the display on the display between the load weight and the loadable weight.

[0021] This allows the display to show either the loaded weight or the loadable weight, depending on the loading work situation, etc.

[0022] The load weight measurement system for a freight vehicle according to the present invention is a system for measuring the load weight of a freight vehicle, comprising a chassis, a cargo box mounted on the chassis, a hydraulic cylinder for tilting the cargo box, and a hydraulic sensor for measuring the hydraulic pressure of the hydraulic cylinder. The load weight measurement system comprises a weight measuring device having a measuring unit for measuring the load weight of the cargo loaded in the cargo box, a memory unit for storing the maximum load weight of the freight vehicle, and a calculation unit for calculating the loadable weight, which is the difference between the maximum load weight stored in the memory unit and the load weight measured by the measuring unit, a display for displaying the loadable weight calculated by the weight measuring device, and a display control device for controlling the display. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a freight vehicle and a freight vehicle load weight measuring system that facilitates loading operations so as not to exceed the maximum load weight. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a side view of a freight vehicle according to a first embodiment. [Figure 2] FIG. 1 is a plan view of a freight vehicle according to a first embodiment. [Figure 3] FIG. 2 is a rear view of the freight vehicle according to the first embodiment. [Figure 4] FIG. 1 is a side view of a truck when the cargo box is tilted. [Figure 5] FIG. 2 is a circuit diagram of a hydraulic circuit. [Figure 6] FIG. 1 is a side view of a truck with the cargo box in the separated position. [Figure 7] FIG. [Figure 8] 1 is a block diagram of a freight vehicle load weight measurement system according to a first embodiment. [Figure 9] FIG. 10 is a schematic diagram of the display when displaying something other than a numerical value. [Figure 10] FIG. 10 is a schematic diagram of the display when displaying the load weight. [Figure 11] FIG. 2 is a schematic diagram of a display when no display is being performed. [Figure 12] 10 is a table summarizing a method for controlling a display device by a display control device. [Figure 13] FIG. 10 is a block diagram of a cargo vehicle load weight measurement system according to a second embodiment. [Figure 14] 10 is a flowchart showing the procedure for weight measurement by the cargo vehicle load weight measurement system according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] First Embodiment An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a side view of a freight vehicle 1 according to this embodiment. Fig. 2 is a plan view of the freight vehicle 1, and Fig. 3 is a rear view of the freight vehicle 1.

[0026] As shown in FIG. 1, truck 1 includes a chassis frame 2, a cab (driver's compartment) 3 supported by the chassis frame 2, front wheels 5 and rear wheels 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. 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. The chassis frame 2, cab 3, subframe 7, engine 9, and 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 seen from the perspective of a driver sitting in the driver's seat.

[0027] The truck 1 according to this embodiment is a dump truck, and the cargo box 30 is configured to be rotatable between a horizontal position and an inclined position. In this embodiment, the truck 1 can load a maximum of 10 tons of cargo into the cargo box 30. That is, the truck 1 according to this embodiment has a maximum load capacity of 10 tons. However, the maximum load capacity is not limited to this, and is not particularly limited. As shown in FIG. 1 , the rear of the cargo box 30 is rotatably supported on the rear end of the subframe 7 by a hinge shaft 8 extending in the vehicle width direction. FIG. 4 is a side view of the truck 1 when the cargo box 30 is inclined. The truck 1 is equipped with a dump mechanism 26 that rotates the cargo box 30. The dump mechanism 26 includes a hydraulic cylinder 25. The configuration of the dump mechanism 26 is not particularly limited, and a conventional mechanism can be applied. The dump mechanism 26 is connected to the vehicle body 1A and the cargo box 30. The cargo box 30 can be rotated by operating the hydraulic cylinder 25.

[0028] As shown in FIG. 5, the truck 1 is provided with a hydraulic circuit 20 incorporating a hydraulic cylinder 25. In addition to the hydraulic cylinder 25, the hydraulic circuit 20 has an oil tank 21, a hydraulic pump 22, and a switching 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 switching valve, oil pressurized by the hydraulic pump 22 is supplied to the hydraulic cylinder 25. This drives the hydraulic cylinder 25, causing the cargo box 30 to rotate around the hinge shaft 8 (see FIG. 4).

[0029] 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, a tailgate 35, and a tail panel 40. 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. In this embodiment, as shown in FIG. 1, the front wall 32 extends upward to a position higher than the top end of the cab 3.

[0030] 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. 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. 6, when the cargo box 30 is tilted by rotating it about the hinge shaft 8, the bottom of the cargo box 30 is separated from the seat 11. Hereinafter, the position of the cargo box 30 when the bottom of the cargo box 30 is supported by the seat 11 will be referred to as the seating position. Furthermore, the position of the cargo box 30 when the bottom of the cargo box 30 is separated from the seat 11 and the cargo box 30 is tilted will be referred to as the separated position.

[0031] The tailgate 35 is configured to be rotatable about a hinge shaft 37 extending in the left-right direction. The tailgate 35 is rotatable between a closed position and an open position. When the tailgate 35 is in the closed position, the tailgate 35 stands upright from the rear end of the bottom plate 31. In FIG. 4, the state when the tailgate 35 is in the open position is represented by a solid line, and the state when the tailgate 35 is in the closed 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 rear of the cargo box 30 is open. When earth or sand is to be discharged from the cargo box 30, the cargo box 30 tilts, and the tailgate 35 rotates to the open position. This causes the cargo box 30 to open rearward, allowing earth or sand to be smoothly discharged from the cargo box 30.

[0032] FIG. 7 is a rear view of the cargo box 30. However, the front wall 32 is not shown in FIG. 7. As shown in FIG. 7, a hook 39 is provided on the tail panel 40. A locking bar 38 extending in the left-right direction is provided on the tailgate 35, 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 on the locking bar 38. When the hook 39 is locked on 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.

[0033] As shown in FIG. 4, the truck 1 is equipped with a weight measuring device 70 that measures the weight of the cargo loaded in the cargo box 30 (hereinafter also referred to as the load weight). The weight measuring device 70 measures the weight of the cargo box 30 loaded with the cargo (i.e., the sum of the weight of the cargo box 30 itself and the weight of the cargo), and calculates the weight of the cargo by subtracting the weight of the cargo box 30 itself from the weight of the loaded cargo. The weight of the cargo box 30 itself is specified in advance. Therefore, measuring the weight of the cargo box 30 loaded with the cargo 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 cargo box 30 loaded with the cargo). In other words, measuring the load weight includes measuring any weight that can identify the load weight.

[0034] FIG. 8 shows a block diagram of a load weight measurement system 100 for a cargo truck 1 according to this embodiment. The weight measurement device 70 is configured by a microcomputer having a processor and memory. As shown in FIG. 8, the weight measurement device 70 functionally comprises a measurement unit 71, a memory unit 72, and a calculation unit 73. The measurement unit 71 is a processing unit that measures the weight of the cargo box 30. In this embodiment, the measurement unit 71 is communicatively connected to a hydraulic sensor 74 and a tilt angle sensor 75. The hydraulic sensor 74 is a sensor that measures the hydraulic pressure of the hydraulic cylinder 25. The tilt angle sensor 75 is a sensor that measures the tilt angle of the cargo box 30. The tilt angle of the cargo box 30 refers to the tilt angle of the cargo box 30 from its horizontal position. The memory unit 72 pre-stores the relationship between the load weight of the cargo box 30 and the hydraulic pressure value of the hydraulic cylinder 25. The measurement unit 71 references the relationship between the load weight and the hydraulic pressure value stored in the memory unit 72 and calculates the load weight of the cargo box 30 from the hydraulic pressure value measured by the hydraulic pressure sensor 74. As a result, the measuring unit 71 measures the loaded weight of the shipping box 30.

[0035] The memory unit 72 also stores the maximum load weight of the cargo truck 1 (10 tons in this embodiment). The calculation unit 73 calculates the loadable weight by subtracting the load weight of the cargo box 30 measured by the measurement unit 71 from the maximum load weight stored in the memory unit 72. The loadable weight is a numerical value indicating how much more cargo can be loaded into the cargo box 30. If the load weight of the cargo box 30 is less than the maximum load weight of the cargo truck 1, the loadable weight will be a positive value. On the other hand, if the load weight of the cargo box 30 exceeds the maximum load weight of the cargo truck 1, i.e., the cargo box 30 is in an overloaded state, the loadable weight will be a negative value. The calculation unit 73 also calculates the excess weight by subtracting the maximum load weight stored in the memory unit 72 from the load weight of the cargo box 30 measured by the measurement unit 71. The excess weight is a numerical value indicating how much the current load weight exceeds the maximum load weight. If the load weight of the cargo box 30 is less than the maximum load weight of the truck 1, the excess weight will be a negative value. On the other hand, if the truck is overloaded, the excess weight will be a positive value. The absolute value of the loadable weight and the absolute value of the excess weight are equal.

[0036] As shown in FIG. 3 , the truck 1 is equipped with a display 76. The display 76 displays the load weight of the cargo box 30 measured by the measuring unit 71 of the weight measuring device 70 or the loadable weight calculated by the calculation unit 73. The display 76 is communicatively connected to the weight measuring device 70 via a display control device 77, which will be described later. The display 76 is installed on the upper part of the front wall 32 of the cargo box 30. The upper part of the front wall 32 refers to the portion above the middle position of the front wall 32 in the vertical direction. The display 76 is installed to face rearward. More specifically, the display 76 includes a case 78 and a display panel 79. The display panel 79 is provided at the rear of the case 78. In this embodiment, the display 76 is installed at the upper end of the front wall 32 of the cargo box 30. The display 76 is also installed in the center of the front wall 32 of the cargo box 30 in the vehicle width direction, and is positioned on the vehicle centerline. Therefore, the display 76 is placed in a location that is easy to see for the worker performing the loading work behind or to the side of the packing box 30. However, the location where the display 76 is installed is not limited to this, and it may be installed in a location that is visible from behind. Furthermore, the number of display devices 76 is not limited to one, and two or more may be provided. By looking at the display device 76, the worker can perform the loading work of earth and sand, etc., while easily understanding the load weight of the packing box 30 at all times (in other words, in real time).

[0037] As shown in FIG. 8 , the truck 1 includes a display control device 77 that controls a display 76. The display control device 77 is communicatively connected to the weight measuring device 70. The display control device 77 controls the display 76 based on the loaded weight measured by the measuring unit 71 of the weight measuring device 70 and the tilt angle of the container 30 measured by the tilt angle sensor 75. The display control device 77 can switch the display on the display 76 between the loaded weight measured by the measuring unit 71 and the loadable weight calculated by the calculation unit 73. Note that the method for switching the display on the display 76 from the loaded weight to the loadable weight, or from the loadable weight to the loaded weight, is not particularly limited. For example, a selector switch communicatively connected to the display control device 77 may be provided in the cab 3, and the display may be switched by pressing the selector switch. By providing such a selector switch, the truck 1 of this embodiment is configured so that the operator can freely select whether the display 76 displays the loaded weight or the loadable weight. In addition, if the load weight of the container 30 is greater than the maximum load weight and the worker selects to display the loadable weight, the display control device 77 of this embodiment is configured to display the excess weight on the display 76.

[0038] However, when the packing box 30 is supported on the seat 11, a load is applied to the seat 11, and the load applied to the hydraulic cylinder 25 becomes smaller (or is not applied at all). As a result, the weight of the packing box 30 cannot be measured accurately. Therefore, the weight measuring device 70 according to this embodiment measures the loaded weight with the packing box 30 in a slightly tilted state, as shown in FIG. 6. In other words, the weight measuring device 70 measures the loaded weight with the packing box 30 separated from the seat 11.

[0039] When the cargo box 30 is tilted, the load of the cargo box 30 is supported by the hydraulic cylinder 25 and the hinge shaft 8. When the tilt angle of the cargo box 30 is small, the load received by the hydraulic cylinder 25 is relatively small, and the load received by the hydraulic cylinder 25 is relatively large. Therefore, the load of the cargo box 30 can be accurately calculated based on the hydraulic pressure value of the hydraulic cylinder 25. On the other hand, when the tilt angle of the cargo box 30 is large, the load received by the hinge shaft 8 becomes relatively large, and the load received by the hydraulic cylinder 25 becomes relatively small. The larger the tilt angle, the smaller the hydraulic pressure value of the hydraulic cylinder 25. Therefore, when the tilt angle of the cargo box 30 is large, it is difficult to obtain an accurate load weight even if the load weight is measured based on the hydraulic pressure value of the hydraulic cylinder 25.

[0040] Furthermore, when the weight of the load loaded in the packing box 30 is small, if the packing box 30 is tilted to measure the load weight, there is a high possibility that the load will become unbalanced within the packing box 30. If the load is unbalanced within the packing box 30, the center of gravity of the packing box 30 will also be unbalanced, making it difficult to accurately measure the load weight. On the other hand, when the weight of the load loaded in the packing box 30 is large, the load is less likely to become unbalanced within the packing box 30 even if the packing box 30 is tilted. Therefore, as the weight of the load loaded in the packing box 30 increases, it becomes possible to calculate the load weight more accurately.

[0041] As described above, the weight of the cargo loaded in the cargo box 30 and the tilt angle of the cargo box 30 affect the accuracy of weight measurement by the weight measuring device 70. It is difficult to load the desired amount of cargo when loading cargo while referring to a load weight measured in a state where accuracy is likely to be low. Furthermore, even if the actual load weight exceeds the maximum load weight and the truck is overloaded, the display 76 may display a value below the maximum load weight due to low weight measurement accuracy, and the overload condition may not be noticed. Therefore, in this embodiment, the display control device 77 switches the display on the display 76 depending on the tilt angle measured by the tilt angle sensor 75 and the load weight calculated by the measurement unit 71 of the weight measuring device 70.

[0042] As described above, when the tilt angle is large, it is difficult to accurately measure the load weight of the packing box 30. Therefore, when the tilt angle measured by the tilt angle sensor 75 is equal to or greater than a predetermined angle, the display control device 77 causes the display 76 to display information other than numerical values (e.g., letters, symbols, etc.). Here, an angle equal to or greater than a predetermined angle means, for example, 10° or greater. Displaying letters, symbols, etc. other than numerical values here means, for example, displaying a "-" as shown in FIG. 9. Displaying letters and symbols other than numerical values on the display 76 prompts the worker to check the work status, including the tilt angle of the packing box 30. Furthermore, by displaying letters, symbols, etc. other than numerical values, rather than displaying nothing on the display 76, the worker can be informed that the display 76, etc., is not malfunctioning.

[0043] As described above, when the tilt angle is small and the load weight is large, the load weight of the container 30 can be accurately measured. Therefore, when the tilt angle measured by the tilt angle sensor 75 is less than a predetermined angle and the load weight measured by the measurement unit 71 of the weight measuring device 70 is equal to or greater than a predetermined weight, the display control device 77 causes the display 76 to display the load weight or the loadable weight. If the worker selects to display the load weight, the display control device 77 causes the display 76 to display the load weight measured by the measurement unit 71 of the weight measuring device 70. FIG. 10 is a diagram showing the display 76 displaying the load weight. Furthermore, if the worker selects to display the maximum load weight, the display control device 77 causes the display 76 to display the loadable weight. Here, "less than the predetermined angle" means, for example, less than 10°. Furthermore, "equal to or greater than the predetermined weight" means, for example, more than half the maximum load weight, which in this embodiment is equal to or greater than 5 tons.

[0044] As described above, when the tilt angle is small and the load weight is small, the load is likely to be unevenly distributed within the loading box 30, making it difficult to accurately measure the load weight of the loading box 30. Therefore, if the tilt angle measured by the tilt angle sensor 75 is less than a predetermined angle and the load weight calculated by the weight measuring device 70 is less than a predetermined weight, the display control device 77 displays nothing on the display 76. Less than the predetermined angle is, for example, less than 10°. Also, less than the predetermined weight is, for example, less than half the maximum load weight, which in this embodiment is less than 5 tons. Here, displaying nothing on the display 76 means not displaying not only numerical values but also letters, symbols, etc. other than numerical values, as shown in FIG. 11 . When the truck 1 is traveling, the loading box 30 is kept horizontal (i.e., tilt angle 0°). Even if the truck 1 is traveling with no load in the loading box 30 and the display 76 is turned off, nothing is displayed on the display 76. This prevents the driver of a vehicle traveling behind the freight vehicle 1 that has forgotten to turn off the display 76 from being distracted by the display 76.

[0045] When the tilt angle of the container 30 is equal to or less than a predetermined angle and the load weight of the container 30 measured by the measuring unit 71 of the weight measuring device 70 exceeds the maximum load weight, if the worker has selected to have the load weight displayed on the display 76, the display control device 77 causes the display 76 to display the load weight. Also, if the worker has selected to have the display 76 display the maximum load weight, the display control device 77 causes the display 76 to display the excess weight. When displaying the excess weight on the display 76, the display control device 77 displays the excess weight in a color different from the color used to display the load weight, in order to indicate that the numerical value displayed on the display 76 is the excess weight. In this embodiment, the display control device 77 displays the load weight in green and the excess weight in red. Therefore, in the freight truck 1 of this embodiment, for example, if the load weight measured by the measuring unit 71 is 11.0 tons and the excess weight is to be displayed on the display 76, the display control device 77 will display "1.0" in red on the display 76.

[0046] Fig. 12 shows a table summarizing how the display control device 77 controls the display 76 based on the tilt angle of the cargo box 30 and the load weight of the cargo box 30. Note that the values shown in Fig. 12 are merely examples and are not limiting. Furthermore, if the maximum load weight of the vehicle or the like changes, the values shown in Fig. 12 will also be changed appropriately.

[0047] According to this embodiment, the freight vehicle 1 is equipped with a weight measuring device 70 that measures the weight of the cargo loaded in the cargo box 30. The weight measuring device 70 includes a measuring unit 71 that measures the load weight of the cargo box 30, a memory unit 72 that stores the maximum load weight of the freight vehicle 1, and a calculation unit 73 that calculates the loadable weight. The freight vehicle 1 is further equipped with a display 76 that displays the loadable weight calculated by the calculation unit 73. A worker performing loading work can perform the work while checking the loadable weight displayed on the display 76, making it easy to load only the desired weight of cargo as long as it does not exceed the maximum load weight.

[0048] As described above, when the inclination angle of the packing box 30 is large, it is difficult to accurately measure the load weight of the packing box 30. According to this embodiment, when the inclination angle of the packing box 30 is equal to or greater than a predetermined angle, the display 76 does not display the loadable weight, but displays characters or symbols other than numerical values. Displaying characters or symbols other than numerical values on the display 76 prompts the worker to check the work status, including the inclination angle of the packing box 30. Furthermore, because the display 76 displays information other than the load weight, the worker is not misled into thinking that the weight measuring device 70 or the display 76 has malfunctioned.

[0049] As described above, when the load weight of the container 30 is small, it is difficult to accurately measure the load weight of the container 30. In normal loading operations, the worker tries to load as much cargo as possible without overloading, so when the load weight is small, there is little need for the worker to check the display on the display 76. According to this embodiment, when the load weight is less than a predetermined weight, the display control device 77 does not display the loadable weight on the display 76. This makes it possible to avoid unnecessary displays.

[0050] According to this embodiment, the display control device 77 can switch the display on the display 76 between the loaded weight and the loadable weight. This allows the display 76 to display either the loaded weight or the loadable weight, depending on the loading work situation, etc.

[0051] According to this embodiment, when the tilt angle of the cargo box 30 is less than a predetermined angle and the load weight of the cargo box 30 is less than a predetermined weight, the display control device 77 does not display the load weight on the display 76. Here, the display control device 77 does not display anything on the display 76. Because the cargo box 30 is in a horizontal position when the truck 1 is traveling, even if the truck 1 is traveling empty and the display on the display 76 has been forgotten to be turned off, nothing is displayed on the display 76. This prevents the driver of a vehicle traveling behind the truck 1 that is empty and has forgotten to turn off the display 76 from being distracted by the display on the display 76.

[0052] Second Embodiment Next, a second embodiment of the present invention will be described. In the description of the second embodiment, 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, and duplicated descriptions will be omitted or simplified.

[0053] FIG. 13 shows a block diagram of a load weight measurement system 100 according to the second embodiment. In the second embodiment, the weight measurement device 70 is provided in an external server 80. The server 80 is communicably connected to the truck 1. Data is exchanged between the server 80 and the truck 1, for example, via wireless communication. The memory unit 72 of the weight measurement device 70 stores the relationship between the load weight of the cargo boxes 30 of multiple trucks 1 and the hydraulic pressure value of the hydraulic cylinder 25. The memory unit 72 also stores the maximum load weight of multiple trucks 1. The relationship between the load weight of the cargo boxes 30 of each truck 1 and the hydraulic pressure value of the hydraulic cylinder 25 and the maximum load weight are stored, for example, linked to the vehicle serial number.

[0054] FIG. 14 shows a flowchart of weight measurement by the load weight measurement system 100 according to the second embodiment. However, the flowchart shown in FIG. 14 is merely an example, and the weight measurement procedure is not limited to this. In step S01, the hydraulic pressure value of the hydraulic cylinder is measured by the hydraulic sensor. In step S02, the truck 1 transmits the hydraulic pressure value measured in step S01 and the vehicle serial number of the truck 1 to the server 80. In step S03, the measurement unit 71 of the weight measurement device 70 calculates the current load weight based on the vehicle serial number and hydraulic pressure value transmitted in step S02. Here, the load weight is calculated by referring to the relationship between the load weight of the cargo box 30 and the hydraulic pressure value of the hydraulic cylinder 25 stored in the memory unit 72. In step S04, the weight measurement device 70 reads the maximum load weight stored in the memory unit 72 based on the vehicle serial number transmitted in step S02. In step S05, the calculation unit 73 of the weight measuring device 70 calculates the loadable weight based on the maximum load weight read in step S04 and the load weight calculated in step S02. In step S06, the truck 1 receives the loadable weight calculated in step S05 from the server 80. In step S07, the display control device 77 causes the display 76 to display the loadable weight.

[0055] In step S06, the truck 1 may receive the load weight calculated in step S03 instead of the loadable weight. In this case, steps S04 and S05 do not need to be executed. In this case, in step S07, the display control device 77 causes the display 76 to display the load weight.

[0056] Furthermore, in the second embodiment, the display control device 77 is provided in the truck 1, but the display control device 77 may also be provided in an external server 80. Therefore, the display control device 77 may be configured to be able to remotely control the display 76.

[0057] Although the first and second embodiments of the present invention have been described above, these embodiments are merely examples, and various other embodiments are possible.

[0058] In the above embodiment, when displaying the excess weight on the display 76, the display control device 77 displays the excess weight on the display 76 in a color different from the color used to display the load weight, in order to indicate that the numerical value displayed on the display 76 is the excess weight. However, the method of indicating that the numerical value displayed on the display 76 is the excess weight is not limited to this. For example, the display control device 77 may be configured to simply light up the display panel 79 when displaying the load weight or the loadable weight, and to flash the display panel 79 when displaying the excess weight. Furthermore, an alarm device equipped with a speaker may be provided on the freight vehicle 1, and an audio alarm may be issued when the load weight exceeds the maximum load weight.

[0059] In the above embodiment, when the tilt angle of the cargo box 30 is equal to or less than a predetermined angle and the container is overloaded, if the operator selects to have the display 76 display the loadable weight, the display control device 77 displays the excess weight on the display 76. However, instead of the excess weight, the loadable weight may be displayed as a negative value. For example, in a cargo truck 1 with a maximum load capacity of 10 tons, when the load weight measured by the measuring unit 71 is 11.0 tons, the display control device 77 may display "-1.0" on the display 76. When the loadable weight is displayed as a negative value, the color of the loadable weight may be the same as or different from the color used to display the load weight.

[0060] In the above embodiment, the calculation unit 73 calculates the excess weight by subtracting the maximum load weight stored in the memory unit 72 from the load weight of the shipping box 30 measured by the measurement unit 71. However, the method of calculating the excess weight is not limited to this. Because the absolute value of the loadable weight and the absolute value of the excess weight are equal, the calculation unit 73 may be configured to calculate the excess weight by inverting the positive and negative signs of the loadable weight.

[0061] The freight vehicle 1 may be configured to display the loadable weight on the display 76 even when the tilt angle of the cargo box 30 is equal to or greater than a predetermined angle. Also, the freight vehicle 1 may be configured to display the loadable weight on the display 76 even when the load weight is less than a predetermined weight.

[0062] The above embodiment is a truck capable of displaying the load capacity. However, the problem of difficulty in accurately measuring the load weight of the cargo box 30 when the inclination angle of the cargo box 30 is large similarly occurs in trucks other than the truck 1 capable of displaying the load capacity. The truck 1 according to the present invention may be a truck that solves the above problem, regardless of whether or not the load capacity is displayed. Another embodiment of the present invention may be an embodiment in which the above embodiment is modified so that the load capacity is not displayed. The truck 1 may not display the load capacity, and may display information other than the load weight on the display 76 when the inclination angle of the cargo box 30 is equal to or greater than a predetermined angle. This allows the worker to be notified that the inclination angle of the cargo box 30 is not appropriate when measuring the load weight, without misleading the worker into thinking that the weight measuring device 70 or the display 76 is malfunctioning. [Explanation of symbols]

[0063] 1 lorry 1A Vehicle body 8 Hinge axis 25 hydraulic cylinders 30 packing boxes 70 Weight measuring device 71 Measuring part 72 Memory section 73 Arithmetic section 74 Oil pressure sensor 75 Inclination Angle Sensor 76 Display 77 Display Control Device 100 Load Weight Measurement System

Claims

1. The vehicle body, a cargo box provided on the vehicle body and configured to carry cargo; a weight measuring device having a measuring unit for measuring the load weight of the load loaded in the packing box, a memory unit for storing a maximum load weight, and a calculation unit for calculating a loadable weight which is the difference between the maximum load weight stored in the memory unit and the load weight measured by the measuring unit; and a display that displays the loadable weight calculated by the calculation unit.

2. a hydraulic cylinder for tilting the container; a hydraulic pressure sensor for measuring a hydraulic pressure value of the hydraulic cylinder; an inclination angle sensor for measuring the inclination angle of the packing box; a display control device that controls the display device, the measuring unit of the weight measuring device is configured to measure the load weight based on the hydraulic pressure value of the hydraulic cylinder measured by the hydraulic pressure sensor, The display control device When the tilt angle of the packing box is less than a predetermined angle, the loadable weight calculated by the calculation unit of the weight measuring device is displayed on the display, 2. The truck according to claim 1, wherein when the tilt angle of the cargo box is equal to or greater than the predetermined angle, the loadable weight calculated by the calculation unit of the weight measuring device is not displayed on the display.

3. a display control device that controls the display; The display control device When the load weight measured by the measurement unit of the weight measuring device is equal to or greater than a predetermined weight, the loadable weight calculated by the calculation unit of the weight measuring device is displayed on the display; 2. The freight vehicle according to claim 1, wherein when the load weight calculated by the measurement unit of the weight measuring device is less than the predetermined weight, the loadable weight calculated by the calculation unit of the weight measuring device is not displayed on the display.

4. a display control device that controls the display; The truck according to claim 1, wherein the display control device is configured to be able to switch the display on the display between the loaded weight and the loadable weight.

5. The vehicle body, a cargo box provided on the vehicle body and configured to carry cargo; a hydraulic cylinder for tilting the container; a hydraulic sensor for measuring the hydraulic pressure of the hydraulic cylinder; an inclination angle sensor for measuring the inclination angle of the packing box; a weight measuring device having a measuring unit for measuring the load weight of the load loaded in the packing box; a display that displays the loaded weight measured by the weight measuring device; a display control device that controls the display device, The display control device of the freight vehicle causes the display device to display information other than the load weight when the inclination angle of the cargo box measured by the inclination angle sensor is equal to or greater than a predetermined angle.

6. The display control device When the tilt angle of the packing box measured by the tilt angle sensor is less than the predetermined angle and the loaded weight measured by the weight measuring device is equal to or greater than a predetermined weight, the loaded weight is displayed on the display, 6. The truck according to claim 5, wherein when the inclination angle of the cargo box measured by the inclination angle sensor is less than the predetermined angle and the load weight measured by the weight measuring device is less than the predetermined weight, the display does not display the load weight.

7. The weight measuring device is a storage unit that stores the maximum load weight; a calculation unit that calculates a loadable weight that is the difference between the maximum load weight stored in the storage unit and the load weight measured by the measurement unit, The display control device 7. The truck according to claim 5, wherein the display on the indicator is switchable between the loaded weight and the loadable weight.

8. A loading weight measurement system for a freight vehicle, comprising: a chassis; a cargo box provided on the chassis; a hydraulic cylinder for tilting the cargo box; and a hydraulic sensor for measuring a hydraulic pressure value of the hydraulic cylinder, a weight measuring device having a measuring unit that measures the load weight of the load loaded in the packing box, a memory unit that stores the maximum load weight of the truck, and a calculation unit that calculates a loadable weight that is the difference between the maximum load weight stored in the memory unit and the load weight measured by the measuring unit; a display that displays the loadable weight calculated by the calculation unit of the weight measuring device; A freight vehicle load weight measurement system comprising: a display control device that controls the display.

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