Method and system for measuring discharged load, and transport vehicle

Abstract

To provide a method for measuring an unloading amount capable of suitably grasping an unloading amount, a measuring system, and a truck.SOLUTION: A method for measuring an unloading amount comprises: grasping a relation value of a loading amount during lifting operation of a loading platform and a relation value of a loading amount during lowering operation of the loading platform following the lifting operation; and when it is determined that the loading platform is in a loading state from the relation value of the loading amount during the lifting operation, and when it is determined that the loading platform is in an unloading state from the relation value of the loading amount during the lowering operation, integrating the loading amount during the lifting operation of the loading platform as an unloading amount.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method and a system for measuring the amount of cargo discharged from a transport vehicle having a loading platform, and to a transport vehicle equipped with said system. [Background technology]

[0002] At construction sites and the like, earth and sand are transported by transport vehicles, and in that case, technologies proposed for grasping the operating status of the transport vehicles include those described in, for example, the following Patent Documents 1 and 2. Patent Document 1 describes a technology for measuring the load on the platform of an off-road transport vehicle. Patent Document 2 describes a technology for counting the number of movements of the platform of a transport vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-190055 A [Patent Document 2] Japanese Utility Model Application Publication No. 61-160570 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, if it were possible to grasp the total amount of cargo transported by a certain transport vehicle during a certain period (accumulated transport amount), it would be useful for managing the transport vehicle and the work related to construction. The accumulated transport amount can be grasped, for example, by recording the load amount before unloading using a technology such as that described in Patent Document 1 and accumulating it when unloading (note that with regard to a transport vehicle such as a dump truck, the operation of tilting the loading platform to unload the loaded soil is generally called "unloading soil", but in this specification, the operation of unloading the load is referred to as "unloading" in consideration of the fact that the load of the transport vehicle is not necessarily soil). However, performing such work every time unloading is very troublesome for the operator of the transport vehicle, and may affect the efficiency of the transport work itself.

[0005] Therefore, for example, a method can be considered in which the technologies described in Patent Documents 1 and 2 above are combined to count the lifting of the loading platform while automatically accumulating the load immediately before each lifting. However, when driving a transport vehicle, lifting the loading platform does not necessarily result in unloading. In a method that simply links the lifting of the loading platform with unloading, the unloading amount may be accumulated even when the loading platform is raised or lowered in an empty state or when the lifting angle is shallow and the unloading amount is zero or small, making it difficult to accurately grasp the cumulative transport amount.

[0006] In view of the above circumstances, the present invention provides a method, a system and a transport vehicle for measuring the amount of discharged cargo, which can appropriately grasp the amount of discharged cargo. [Means for solving the problem]

[0007] The present invention relates to a method for measuring the amount of loaded material discharged, which is characterized by grasping a relational value of the load amount during the lifting operation of the loading platform and a relational value of the load amount during the lowering operation of the loading platform following the lifting operation, and when it is determined that the loading platform is in a loaded state from the relational value of the load amount during the lifting operation and when it is determined that the loading platform is in an unloaded state from the relational value of the load amount during the lowering operation, the loading amount during the lifting operation of the loading platform is accumulated as the amount of loaded material discharged.

[0008] In the method for measuring the amount of unloaded cargo of the present invention, in response to an input for raising the loading platform from a lowered state, extension control is performed with a constant control amount on the lifting device that raises and lowers the loading platform, and the load amount can be calculated based on the pressure value of the lifting device at the stage when the loading platform is lifted by extension control of the lifting device with the constant control amount.

[0009] The present invention also relates to a load-unloading amount measurement system comprising a loading platform attached to a transport vehicle, a lifting device for raising and lowering the loading platform, a pressure sensor for measuring the pressure generated in the lifting device, and a contact sensor for detecting contact between the loading platform and a frame that forms the body of the transport vehicle, wherein the lifting and lowering operations of the loading platform are grasped by the contact sensor, and a load-unloading amount related value on the loading platform is grasped by the measurement value of the pressure sensor, and when it is determined that the loading platform is in a loaded state from the load-unloading amount related value during the lifting operation and when it is determined that the loading platform is in an unloaded state from the load-unloading amount related value during the lowering operation of the loading platform following the lifting operation, the load amount calculated based on the measurement value of the pressure sensor during the lifting operation of the loading platform is accumulated as the unloaded amount.

[0010] In the discharge volume measurement system of the present invention, the loading condition of the loading platform during the loading platform raising operation can be determined based on the measurement value of the pressure sensor obtained at the time the contact sensor detects that the loading platform has lifted off the frame, and the loading condition of the loading platform during the loading platform lowering operation can be determined based on the measurement value of the pressure sensor obtained at the time the contact sensor detects that the loading platform has come into contact with the frame.

[0011] In the discharged load measurement system of the present invention, the load amount during the lifting operation of the loading platform can be calculated based on the measurement value of the pressure sensor obtained at the time the contact sensor detects that the loading platform has lifted off the frame.

[0012] The discharged load measurement system of the present invention can be configured to perform extension control of the hoisting device with a constant control amount in response to an input for raising the loading platform from a state in which the loading platform is lowered relative to the frame, and to calculate the load amount based on the measurement value of the pressure sensor obtained at the time the contact sensor detects that the loading platform has floated relative to the frame.

[0013] The present invention also relates to a transport vehicle equipped with the above-mentioned discharged load measuring system. Effect of the Invention

[0014] According to the discharged load measuring method, measuring system, and transport vehicle of the present invention, it is possible to obtain the excellent effect of appropriately grasping the discharged load. [Brief description of the drawings]

[0015] [Figure 1] 1 is a side view showing an example of a form of a transporter to which the present invention is applied. [Diagram 2] 1 is a block diagram showing an example of the configuration of a discharge amount measurement system according to an embodiment of the present invention. [Diagram 3] 4 is a flowchart showing an example of a measurement procedure in a method for measuring an amount of discharged cargo according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0017] Fig. 1 shows an example of a transport vehicle equipped with a discharged load measurement system according to the present invention, and Fig. 2 shows an example of the configuration of the measurement system. As shown in Fig. 1, the transport vehicle 1 has a platform 3 attached to the rear of a vehicle body 2 and configured to carry a load C such as soil and sand, and crawlers 4 attached to both the left and right sides as traveling devices.

[0018] A fluid pressure cylinder 6 is provided between the upper surface of the frame 5 constituting the vehicle body 2 and the lower surface of the loading platform 3 as a lifting device for raising and lowering the loading platform 3. The fluid pressure cylinder 6 is rotatably attached at its base end to the upper surface of the frame 5 and at its tip end to the lower surface of the loading platform 3. The fluid pressure cylinder 6 is extended and retracted between the frame 5 and the loading platform 3, thereby raising and lowering the loading platform 3 relative to the vehicle body 2.

[0019] In addition, a contact sensor 7 that detects contact between the loading platform 3 and the frame 5 is attached between the upper surface of the frame 5 and the loading platform 3. In this embodiment, the attachment position of the contact sensor 7 is forward of the installation position of the fluid pressure cylinder 6 on the upper surface of the frame 5. Note that, although a physical contact type switch is assumed as the contact sensor 7 here, the configuration of the contact sensor 7 is not limited to this, and any device that can detect contact between the frame 5 and the loading platform 3 may be used. For example, an optical sensor or the like may be used.

[0020] The extension and retraction of the fluid pressure cylinder 6 is controlled by a control device 9 via a fluid pressure device 8 (see Figure 2). The control device 9 is an information processing device that monitors and controls the operating status of each piece of equipment that makes up the transporter 1 (see Figure 1). The fluid pressure device 8 inputs fluid pressure to the extension side (bottom side) of the fluid pressure cylinder 6 in response to a command signal input from the control device 9. The fluid pressure cylinder 6 expands and contracts due to this fluid pressure, and also supports the weight of the loading platform 3.

[0021] A pressure sensor 10 is attached in the middle of the circuit that inputs fluid pressure from the fluid pressure device 8 to the fluid pressure cylinder 6, and is adapted to measure the pressure generated in the fluid pressure cylinder 6 when it supports the weight of the platform 3 and performs the raising and lowering operation.

[0022] A memory unit 14 for storing various data is connected to the control device 9, and data related to the operation of the system, such as the amount of control input to each device and the measured values ​​of instruments such as the pressure sensor 10, is recorded in an appropriate format as necessary. The memory unit 14 may be provided as a part of the functions of the control device 9, or may be connected to an information terminal device (not shown) and used as the memory unit 14.

[0023] The driver's seat of the transporter 1 (see FIG. 1) is provided with a display device 11 (see FIG. 2; not shown in FIG. 1). The display device 11 is a display that displays various visual information in response to image signals input from the control device 9, and is capable of displaying, for example, the operating state of the loading platform 3, the pressure value detected by the pressure sensor 10, and the load amount of the cargo C calculated based on the pressure value.

[0024] In addition, the driver's seat of the transporter 1 is provided with an operation device 13 for inputting operation commands to the control device 9. The operation device 13 is a device for a person to operate the transporter 1, and is configured to allow input of operations related to operations such as travel by the crawlers 4 and raising and lowering the loading platform 3 by the fluid pressure cylinder 6.

[0025] Next, the method for measuring the discharged load according to the present embodiment will be described with reference to the flow chart of FIG.

[0026] In this embodiment, when the loading platform 3 is raised or lowered, the state of the loading platform 3 (whether the loading platform 3 is floating above the frame 5 or not) is confirmed based on the presence or absence of an input to the contact sensor 7, and the measured value of the pressure sensor 10 is also referred to, and based on these, it is determined whether or not a load has been discharged. At that time, the load amount before discharge is calculated based on the measured value of the pressure sensor 10 at a specific timing (specifically, the timing when the loading platform 3 is floating above the frame 5, which is grasped based on the presence or absence of an input to the contact sensor 7), and when it is determined that a load has been discharged based on the above-mentioned determination of whether or not a load has been discharged, the calculated load amount is accumulated as the discharged amount.

[0027] The specific procedure will be described below. When an operation to raise the loading platform 3 is input to the operation device 13 from a state in which the loading platform 3 is lowered, the control device 9 increases the pressure in the fluid pressure cylinder 6 and starts the lifting operation of the loading platform 3 (step S1). At this time, it is preferable that the control amount input from the control device 9 to the fluid pressure cylinder 6 is constant (for example, 50% of the maximum value) (the reason will be described later).

[0028] While increasing the pressure in the fluid pressure cylinder 6 with a constant control amount, it is determined whether or not there is an input to the contact sensor 7 (step S2). If the input to the contact sensor 7 is on, the determination in step S3 is made again, and this is repeated until the platform 3 leaves the contact sensor 7.

[0029] When the input to the contact sensor 7 is turned off, the process proceeds to step S3, where the measurement value of the pressure sensor 10 is obtained and the load amount is calculated based on this. Here, once the measurement value of the pressure sensor 10 has been obtained, the control device 9 ends the control of the fluid pressure cylinder 6 with a fixed control amount, and performs control according to the operation input amount to the operation device 13. For example, if the operation input amount to the operation device 13 by the operator regarding the operation of raising the platform 3 is 100% at this point, the control input amount to the fluid pressure cylinder 6 is increased from the previous 50% to 100%.

[0030] Next, a determination is made as to whether or not the loading platform 3 is in a loaded state. The determination is made by referring to the measurement value of the pressure sensor 10 and judging whether or not a value related to the load amount grasped by the measurement value (load amount related value) is equal to or greater than a threshold value set in advance as a reference (step S4).

[0031] Here, the "load amount related value" grasped from the measurement value of the pressure sensor 10 is, for example, the measurement value (pressure value) of the pressure sensor 10 itself, or, instead of the pressure value, the load value in the fluid pressure cylinder 6 calculated based on the pressure value or the load amount of the cargo C calculated in the previous step S3 can be used. As the threshold value used as the criterion for judgment, a value suitable for judging whether the platform 3 is in a loaded state or not is set in advance according to the type of value used as the load amount related value (pressure value, load value, load amount, etc.) (a reference value that can be conveniently regarded as indicating that the platform 3 is in a loaded state if the value is above that, and in an unloaded state if the value is below that. Note that the "unloaded state" refers to a state in which the cargo has been unloaded and the load amount is zero or sufficiently reduced).

[0032] In step S4, if the load amount relational value is less than the threshold, it can be determined that the platform 3 is already in an unloaded state when the platform 3 is raised, so the unloaded amount is not added and the process ends. If the measured value of the pressure sensor 10 is equal to or greater than the threshold, it can be determined that the platform 3 is in a loaded state, so the load amount calculated in the previous step S3 is held here (step S5).

[0033] Thereafter, when the lifting operation of the loading platform 3 is completed, the lowering operation is started (step S6). When the lowering operation of the loading platform 3 is started, the process waits while judging whether or not the contact of the loading platform 3 has been input to the contact sensor 7 (step S7). In step S7, if the contact sensor 7 is off, the process repeats the judgment, and when the input to the contact sensor 7 is turned on, the process proceeds to the next step S8. That is, when the lowering operation of the loading platform 3 is performed and the loading platform 3 descends onto the frame 5 and comes into contact with the contact sensor 7, this is detected in step S3, and the process proceeds to step S8.

[0034] In step S8, it is determined whether or not the loading platform 3 is in an unloading state. The determination is made by comparing the load amount related value at this time with a threshold value set in advance as a criterion. The threshold value used here is a value set in advance as a criterion for determining whether or not the loading platform 3 is in a loaded state, and may be the same as the threshold value used in step S4, or a different value may be set.

[0035] In step S8, if the load amount relational value is equal to or greater than the threshold value, it can be determined that the platform 3 is in a loaded state, i.e., no unloading has been performed during the previous lifting operation, so the unloading amount is not calculated and the process ends. If the load amount relational value is less than the threshold value, it can be determined that the platform 3 is in an unloaded state and unloading has been performed by the lifting operation, so the process proceeds to step S9, where the load amount held in the previous step S5 is calculated as the unloading amount. The unloading amount calculated in this way is recorded in the memory unit 14 and is also displayed on the display device 11 as necessary.

[0036] According to the measurement procedure using the above-mentioned system, it is possible to more reliably determine whether or not substantial unloading has occurred with the operation of the platform 3, and to accumulate the amount of unloaded cargo only when unloading has actually occurred, so that it is possible to accurately measure the amount of unloaded cargo in accordance with the actual situation. For example, if the number of unloading attempts is made based only on the on / off state of the contact sensor 7, it will be determined that one unloading has been performed even though the actual amount of unloading is zero or close to zero when the platform 3 is raised and lowered in an empty state, or when the platform 3 is raised slightly but not tilted significantly and is lowered without unloading any cargo (or after unloading only a small amount of cargo). In this embodiment, in addition to the on / off state of the contact sensor 7, the measured value of the pressure sensor 10 is used as a condition for determining whether or not unloading has actually occurred, so that it is possible to accurately grasp whether or not unloading has actually occurred.

[0037] Here, to determine whether or not the load has been substantially discharged with the raising and lowering of the platform 3, it is possible to compare the load amount relationship value during the raising operation and the lowering operation, and determine that the load has been discharged if the load amount relationship value during the lowering operation is smaller than the load amount relationship value during the raising operation, but such a method may not be able to accurately determine whether or not the load has been discharged, particularly when the load amount relationship value is grasped by the pressure value of the fluid pressure cylinder 6. This is because the pressure value of the fluid pressure cylinder 6 varies depending on the load amount of the load C, the attitude of the platform 3 and the fluid pressure cylinder 6, the position of the center of gravity P of the load C on the platform 3, the operating speed of the fluid pressure cylinder 6, and the like, and therefore the measured value of the pressure sensor 10 and the load amount calculated based on it do not necessarily reflect the actual load amount in the same way during the raising operation and the lowering operation. That is, for example, even if no unloading is performed and there is no change in the actual load amount between the raising operation and the lowering operation, the load amount relationship value acquired during the lowering operation may be smaller than that during the raising operation, or conversely, there may be a case where no significant difference is observed in the load amount relationship value between the lowering operation and the raising operation even though unloading is performed, in which case the number of unloadings may be counted even though no unloading is performed, or the number of unloadings may not be counted even though unloading is performed. As in this embodiment, if the load amount relationship value during the raising operation and the lowering operation are compared with a threshold value to determine whether the loading platform 3 is in a loaded state, it is possible to more accurately determine whether unloading has been performed.

[0038] The timing for acquiring the relational value of the load amount during the lifting operation of the loading platform 3 is particularly suitable when the contact sensor 7 detects that the loading platform 3 has been lifted from the frame 5. At this stage, the loading platform 3 is in a state of being lifted at a slight angle from the frame 5, and the loading platform 3 is supported from the frame 5 only by the fluid pressure cylinder 6 and the fulcrum at the rear thereof, and its posture is almost horizontal. In this state, the load of the loading platform 3 is not distributed to the frame 5, and since the loading platform 3 is almost horizontal, the loaded load C does not move under its own weight, and further, it is expected that the position of the center of gravity P of the load C is not significantly different from the expected position (although it may of course shift forward, backward, left, and right depending on the loading method), so that it is easy to acquire the relational value that correctly reflects the load amount. In this embodiment, the measured value of the pressure sensor 10 at the time when the loading platform 3 has been lifted from the contact sensor 7 is acquired, and this is used to judge the loading state, thereby enabling a more accurate judgment (steps S2 and S4).

[0039] Similarly, the timing for acquiring the relational value of the load amount during the lowering operation of the loading platform 3 is particularly suitable when the contact sensor 7 detects that the loading platform 3 has come into contact with the frame 5. In the process of lowering the loading platform 3 to the frame 5 by reducing the fluid pressure in the fluid pressure cylinder 6 to contract the fluid pressure cylinder 6, there is a time lag between when the loading platform 3 comes into contact with the frame 5 and the contact sensor 7 and when the load from the loading platform 3 applied to the fluid pressure cylinder 6 is distributed to the frame 5. Therefore, if the measured value of the pressure sensor 10 is referred to when the input to the contact sensor 7 is turned on, a pressure value sufficient for determining whether the loading platform 3 is in a loaded state or not can be obtained. At this point, the loading platform 3 floats at a slight angle close to horizontal with respect to the frame 5, and the loading platform 3 is supported only by the fluid pressure cylinder 6 and the fulcrum behind it with respect to the frame 5, so that it is easy to acquire the relational value that correctly reflects the load amount. In this embodiment, the measurement value of the pressure sensor 10 at the time when the loading platform 3 contacts the contact sensor 7 is obtained and used to determine the loading status, making it possible to more accurately determine the loading status even when the loading platform 3 is being lowered (steps S7 to S8).

[0040] Also, calculating the load amount based on the pressure values ​​acquired at the above-mentioned timings (steps S2 to S3) is advantageous from the viewpoint of calculating the load amount as accurately as possible. First, by limiting the timing of acquiring the pressure values ​​on which the load amount is based, the pressure can be always measured under the same conditions for the posture of the platform 3 and the fluid pressure cylinder 6. The relationship between the load amount of the cargo C on the platform 3 and the pressure in the fluid pressure cylinder 6 is naturally positively correlated, but the coefficient varies depending on the angles of the platform 3 and the fluid pressure cylinder 6. Therefore, if the pressure values ​​referenced for calculating the load amount are limited to pressure values ​​at the time when the platform 3 and the fluid pressure cylinder 6 are in a specific posture, the relationship between the load amount and the pressure value can be considered to be approximately constant, and the load amount can be calculated by appropriate calculation.

[0041] Furthermore, it is particularly suitable for calculating the load weight to limit the timing of obtaining the reference pressure value to "the point in time when it is determined by the contact sensor 7 that the platform 3 is floating above the frame 5," i.e., "the point in time when the input to the contact sensor 7 is turned off" (step S2). As described above, at this stage, the platform 3 is floating above the frame 5 at an angle close to horizontal, making it easier to obtain a pressure value that correctly reflects the load weight.

[0042] In this state, the relationship between the pressure value in the fluid pressure cylinder 6 and the load amount on the loading platform 3 varies depending not only on the weight of the load C but also on the position of the center of gravity P of the load C, but when calculating the load amount from the pressure value in the fluid pressure cylinder 6, if the calculation is performed assuming that the center of gravity P is in an appropriate position, the load amount can be calculated with sufficient accuracy for practical purposes. In particular, if the pressure value obtained at the specific timing as described above is used as the basis, it can be expected that the position of the center of gravity P of the load C will not deviate significantly from the assumed position because the loading platform 3 is almost horizontal, and more accurate calculations are possible.

[0043] Here, the relationship between the pressure value and the load amount is affected not only by the posture of the platform 3 and the fluid pressure cylinder 6 at that time, but also by the operating speed of the fluid pressure cylinder 6. In this embodiment, from the start of the lifting operation of the platform until the input to the contact sensor 7 is turned off (steps S1 to S2), the pressure in the fluid pressure cylinder 6 is increased at a constant control amount regardless of the input amount of the operation to the operating device 13. Then, the pressure value at the time when the input to the contact sensor 7 is turned off is obtained and used to calculate the load amount (steps S2 to S3). In other words, the pressure value in a state where the operating speed of the fluid pressure cylinder 6 is within a certain range is used to calculate the load amount. In this way, by aligning the conditions for obtaining the pressure value that is the basis for calculating the load amount, the calculation for calculating the load amount can be performed more appropriately.

[0044] Furthermore, when control is performed using a fixed amount of control in this manner, after the operator begins to input the lifting operation, the amount of operation input from the operator and the control amount of the fluid pressure cylinder 6 by the control device 9 will not match for a while. However, this does not mean that the lifting operation of the platform 3 itself is not performed, so the operator will not feel any control delay, or if he does feel it, it will be very slight.

[0045] In addition, when taking measurements, the load amount is automatically measured and the discharged amount is accumulated each time the loading platform 3 is raised, provided that the contact input to the contact sensor 7 is turned off, without the operator having to perform any special operations. This means that there are no missed measurements of the load amount or discharged amount, and it is convenient for the operator as there is no need to perform any operations every time.

[0046] The procedure for measuring the load amount described above is merely an example, and may be modified as appropriate as long as the load amount can be suitably measured and accumulated. For example, the pressure value in the pressure sensor 10 may be acquired every moment regardless of whether the contact sensor 7 is on or off, and the pressure value at the time when the input to the contact sensor 7 is turned off may be extracted and used to calculate the load amount. Also, the order of execution of each step described above may be changed, or another step may be added.

[0047] The data on the amount of unloaded cargo thus obtained can be used as an operating history of the transport vehicle 1 or for monitoring the status of work related to the transportation of cargo.

[0048] As described above, in the method for measuring the amount of discharged cargo in this embodiment, the relational value of the load amount at the time of the lifting operation of the platform 3 and the relational value of the load amount at the time of the lowering operation of the platform 3 following the lifting operation are grasped, and when it is determined that the platform 3 is in a loaded state from the relational value of the load amount at the time of the lifting operation and when it is determined that the platform 3 is in an unloaded state from the relational value of the load amount at the time of the lowering operation, the load amount at the time of the lifting operation of the platform 3 is integrated as the amount of discharged cargo. In this way, it is possible to more reliably determine whether or not substantial discharge of cargo has occurred with the operation of the platform 3, and by integrating the amount of discharged cargo only when substantial discharge of cargo has been performed, the amount of discharged cargo can be measured accurately in accordance with the actual situation.

[0049] Furthermore, in the method for measuring the amount of discharged cargo in this embodiment, in response to an input for raising the loading platform 3 from a lowered state, the hoisting device (fluid pressure cylinder) 6 for raising and lowering the loading platform 3 is extended with a constant control amount, and the load amount is calculated based on the pressure value of the hoisting device 6 at the stage when the loading platform 3 is lifted by the extension control of the hoisting device 6 with the constant control amount. In this way, the pressure value when the loading platform 3 and the hoisting device 6 are in a constant attitude and the operating speed of the hoisting device 6 is within a constant range is always used to calculate the load amount, so that the load amount can be calculated by an appropriate calculation.

[0050] The measurement system for the amount of discharged load of this embodiment includes a platform 3 attached to the transport vehicle 1, a lifting device 6 for lifting and lowering the platform 3, a pressure sensor 10 for measuring the pressure generated in the lifting device 6, and a contact sensor 7 for detecting the contact between the platform 3 and the frame 5 constituting the body 2 of the transport vehicle 1. The lifting and lowering operations of the platform 3 are detected by the contact sensor 7, and the load-related value of the platform 3 is detected by the measurement value of the pressure sensor 10. When it is determined that the platform 3 is in a loaded state from the load-related value during the lifting operation, and when it is determined that the platform 3 is in an unloaded state from the load-related value during the lowering operation of the platform 3 following the lifting operation, the load calculated based on the measurement value of the pressure sensor 10 during the lifting operation of the platform 3 is accumulated as the amount of discharged load. In this way, it is possible to more reliably determine whether or not substantial discharge of load has occurred with the operation of the platform 3, and to accumulate the amount of discharged load only when the load has been substantially discharged, thereby making it possible to accurately measure the amount of discharged load according to the actual situation.

[0051] Furthermore, in the discharge amount measurement system of this embodiment, the load state of the platform 3 during the lifting operation of the platform 3 is determined based on the measurement value of the pressure sensor 10 acquired at the time when the contact sensor 7 detects that the platform 3 has lifted off the frame 5, and the load state of the platform 3 during the lowering operation of the platform 3 is determined based on the measurement value of the pressure sensor 10 acquired at the time when the contact sensor 7 detects that the platform 3 has come into contact with the frame 5. In this way, the pressure value when the platform 3 and the hoisting device 6 are in a constant attitude and the operating speed of the hoisting device 6 is within a constant range is always used to calculate the load amount, so that the load state can be determined more accurately.

[0052] Furthermore, in the discharged load measurement system of this embodiment, the load amount during the lifting operation of the platform 3 is calculated based on the measurement value of the pressure sensor 10 acquired at the time when the contact sensor 7 detects that the platform 3 has been lifted off the frame 5. In this way, the load amount can be calculated by an appropriate calculation, by always using the pressure value when the platform 3 and the hoisting device 6 are in a constant position and the operating speed of the hoisting device 6 is within a constant range.

[0053] Furthermore, in the discharged load measurement system of this embodiment, in response to an input for raising the loading platform 3 from a state in which the loading platform 3 is lowered relative to the frame 5, the hoisting device 6 is extended with a constant control amount, and the load amount is calculated based on the measurement value of the pressure sensor 10 obtained at the time when the contact sensor 7 detects that the loading platform 3 has been lifted off the frame 5. In this way, the load amount can be calculated by an appropriate calculation, by always using the pressure value when the loading platform 3 and the hoisting device 6 are in a constant attitude and the operating speed of the hoisting device 6 is within a constant range.

[0054] Furthermore, the transporter 1 of this embodiment is provided with the above-mentioned discharged load measuring system, and therefore can achieve the same advantageous effects.

[0055] Therefore, according to the present embodiment, the discharged load can be appropriately grasped.

[0056] Incidentally, the discharged load measuring method, measuring system and transport vehicle of the present invention are not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0057] 1 Transport vehicle 2. Body 3 Cargo platform 5 Frames 6. Lifting device (fluid pressure cylinder) 7 Contact Sensor 10 Pressure Sensor

Claims

1. The relationship value of the load amount when the loading platform is raised, A relational value of a load amount during a lowering operation of the loading platform following the raising operation is obtained, The loading state of the platform is determined based on the load amount relationship value during the lifting operation, and When it is determined that the platform is in an unloading state based on the load amount relationship value during the lowering operation, The load amount during the lifting operation of the loading platform is calculated as the discharge amount. A method for measuring discharged load, comprising:

2. In response to an input of an operation to raise the loading platform from a state in which the loading platform is lowered, an extension control is performed with a constant control amount on a lifting device that raises and lowers the loading platform; Calculating the load amount based on the pressure value of the lifting device at the stage where the platform is lifted by the extension control of the lifting device with the constant control amount. The method for measuring the discharged load according to claim 1, further comprising the steps of:

3. A carrier attached to the transport vehicle; A lifting device for lifting the loading platform; A pressure sensor for measuring a pressure generated in the lifting device; a contact sensor that detects contact between the platform and a frame that constitutes a body of the transport vehicle; The lifting and lowering operations of the loading platform are detected by the contact sensor, A value related to the load amount in the loading platform is obtained based on the measurement value of the pressure sensor; The loading state of the platform is determined based on the load amount relationship value during the lifting operation, and When it is determined that the loading platform is in an unloading state based on the load amount relationship value during the lowering operation of the loading platform following the lifting operation, The load amount calculated based on the measurement value of the pressure sensor during the lifting operation of the loading platform is integrated as the unloading amount. A discharge amount measurement system comprising:

4. The load state of the loading platform during the lifting operation of the loading platform is determined based on the measurement value of the pressure sensor acquired at the time when the contact sensor detects that the loading platform has been lifted from the frame, The load state of the loading platform during the lowering operation of the loading platform is determined based on the measurement value of the pressure sensor obtained at the time when the contact sensor detects that the loading platform has come into contact with the frame.

4. The discharged load measuring system according to claim 3,

5. The load amount during the lifting operation of the loading platform is calculated based on the measurement value of the pressure sensor obtained at the time when the contact sensor detects that the loading platform has been lifted from the frame.

5. The discharged load measuring system according to claim 3 or 4, characterized in that:

6. In response to an input of a lifting operation of the loading platform from a state in which the loading platform is lowered relative to the frame, the lifting device is extended by a constant control amount; The load amount is calculated based on the measurement value of the pressure sensor obtained at the time when the contact sensor detects that the loading platform is floating relative to the frame.

6. The discharged load measuring system according to claim 5,

7. A transport vehicle comprising the discharged load measuring system according to any one of claims 3 to 6.

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