Measurement method for loading capacity, measurement system, and transport vehicle

Abstract

To provide a method for measuring a loading amount capable of suitably grasping a loading amount of loading, a measuring system and a truck.SOLUTION: A method for measuring a loading amount comprises: in response to input of operation to lift a loading platform from a state where the loading platform is lowered, performing elongation control at a constant control amount with respect to a lifting / lowering device that lifts and lowers the loading platform; and calculating a loading amount based on a pressure value of the lifting / lowering device at a stage when the loading platform is lifted by the elongation control of the lifting / lowing device by the constant control amount. Further, it is preferable to calculate the loading amount based on the pressure value of the lifting / lowering device acquired after the lapse of time when the pressure value of the lifting / lowering device is considered to be stable after the loading platform is lifted.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method and a system for measuring the loading amount of a load on a loading platform of a transport vehicle, and a transport vehicle equipped with the system.

Background Art

[0002] At a construction site or the like, earth and sand are transported by a transport vehicle. At this time, it is effective to grasp the loading amount of the load on the loading platform of the transport vehicle for preventing overloading and grasping the transport situation of earth and sand. As a document describing a technique for grasping the loading amount in such a transport vehicle, for example, there is Patent Document 1 below. In the rough terrain transport vehicle described in Patent Document 1, after the start of the arithmetic processing of the loading mass, the vessel cylinder that raises and lowers the vessel is extended for a specified time (for example, about 2 seconds), and the load is calculated based on the pressure generated in the vessel cylinder during that time.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the measurement method described in Patent Document 1 above, there is a possibility that the measurement accuracy may vary depending on the measurement timing and the operating state of the vessel cylinder at the time of measurement. This is because the relationship between the loading amount of the load on the loading platform and the pressure generated in the vessel cylinder varies depending on the angle of the loading platform, and the pressure generated with the operation of the vessel cylinder also varies depending on the operating speed of the vessel cylinder.

[0005] In view of such circumstances, the present invention aims to provide a measurement method, a measurement system, and a transport vehicle that can suitably grasp the loading amount of a load.

Means for Solving the Problem

[0006] The present invention relates to A method for measuring the load capacity using a loading platform attached to a transporter, 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 forming the vehicle body of the transporter, detecting with respect to the frame the inputting an operation of raising the loading platform from a state where the loading platform has descended, irrespective of the input force for the raising operation of the loading platform, the performing extension control on the lifting device with a certain control amount, when the contact sensor detects that the loading platform has floated with respect to the frame, obtaining the measured value of the pressure sensor and ending the control with a constant control amount of the lifting device, subsequently starting the extension control of the lifting device according to the input force for the raising operation of the loading platform and performing a series of operations of raising the loading platform to the input force, calculating the load capacity of the load on the loading platform from the obtained measured value of the pressure sensor and is characterized in that it relates to a method for measuring the loading capacity.

[0007] In the method for measuring the loading capacity of the present invention, after the loading platform floats, the loading capacity can be calculated based on the pressure value of the lifting device obtained when a time sufficient for the pressure value of the lifting device to be considered stable has elapsed.

[0008] Further, the present invention includes 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 forming the vehicle body of the transport vehicle. inputting an operation of raising the loading platform from a state where the loading platform has descended with respect to the frame, detecting, irrespective of the input force for the raising operation of the loading platform, performing extension control on the lifting device with a certain control amount, when the contact sensor determines that the loading platform has floated with respect to the frame, before recording the measured value of the pressure sensor obtaining and ending the control with a constant control amount of the lifting device, subsequently starting the extension control of the lifting device according to the input force for the raising operation of the loading platform and performing a series of operations of raising the loading platform to the input force, calculating the load capacity of the load on the loading platform from the obtained measured value of the pressure sensor and is characterized in that it is configured as such, and relates to a loading capacity measurement system.

[0009] In the loading amount measurement system of the present invention, in the raising operation of the loading platform, the contact sensor is configured to detect that the loading platform has floated when a time has elapsed such that the measured value of the pressure sensor can be regarded as having stabilized after the loading platform has floated, and the calculation of the loading amount can be performed based on the measured value of the pressure sensor obtained when the contact sensor detects that the loading platform has floated in the raising operation of the loading platform.

[0010] In the loading amount measurement system of the present invention, the contact sensor is a physical contact type switch installed such that contact is input from the loading platform while the loading platform is descending onto the frame, and the input of contact from the loading platform is turned off while the loading platform is floating from the frame. In the raising operation of the loading platform, the contact sensor is arranged such that the input of contact from the loading platform is turned off when a time has elapsed such that the measured value of the pressure sensor can be regarded as having stabilized after the loading platform has floated. The calculation of the loading amount can be performed based on the measured value of the pressure sensor obtained when the input of contact to the contact sensor is turned off in the raising operation of the loading platform.

[0011] Further, the present invention relates to a transport vehicle characterized by including the above-described loading amount measurement system.

Effects of the Invention

[0012] According to the loading amount measurement method, measurement system, and transport vehicle of the present invention, an excellent effect of suitably grasping the loading amount of the cargo can be achieved.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0015] FIG. 1 shows an example of a transport vehicle equipped with a loading capacity measurement system according to the implementation of 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 is attached to the rear part of the vehicle body 2 and includes a loading platform 3 configured to load a load C such as earth and sand, and crawlers 4 as traveling devices attached to both the left and right sides.

[0016] Between the upper surface of the frame 5 forming the vehicle body 2 and the lower surface of the loading platform 3, a hydraulic cylinder 6 is provided as a lifting device for lifting the loading platform 3. The hydraulic cylinder 6 has its base end portion rotatably attached to the upper surface of the frame 5 and its tip end portion rotatably attached to the lower surface of the loading platform 3, and expands and contracts between the frame 5 and the loading platform 3 to lift the loading platform 3 with respect to the vehicle body 2.

[0017] Also, a contact sensor 7 for detecting the contact between the upper surface of the frame 5 and the loading platform 3 is attached therebetween. In the case of this embodiment, the attachment position of the contact sensor 7 is in front of the installation position of the fluid pressure cylinder 6 on the upper surface of the frame 5. As the contact sensor 7, a physical contact type switch can be used. In that case, contact is input from the loading platform 3 while the loading platform 3 is descending onto the frame 5, and by installing it such that the input of contact from the loading platform 3 turns off while the loading platform 3 is floating from the frame 5, the contact between the loading platform 3 and the frame 5 can be detected. Note that the contact sensor 7 is not limited to such a physical contact type switch, and any device can be adopted as long as it can detect the contact between the frame 5 and the loading platform 3. For example, an optical sensor or the like can also be used.

[0018] The expansion and contraction of the fluid pressure cylinder 6 are controlled by a control device 9 via a fluid pressure device 8 (see FIG. 2). The control device 9 is an information processing device that monitors and controls the operating states of the various devices of the transport vehicle 1 (see FIG. 1). The fluid pressure device 8 is configured to input fluid pressure to the extending 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 by this fluid pressure and also supports the weight of the loading platform 3.

[0019] A pressure sensor 10 is attached in the middle of the circuit for inputting fluid pressure from the fluid pressure device 8 to the fluid pressure cylinder 6, and it is configured to measure the pressure generated in the fluid pressure cylinder 6 when supporting the weight of the loading platform 3 and performing the lifting and lowering operation.

[0020] A display device 11 is provided in the driver's seat of the transport vehicle 1 (see FIG. 1; not shown in FIG. 1). The display device 11 is a display that displays various visual information in response to an image signal input from the control device 9, and can display, for example, the operating state of the loading platform 3, the value of the pressure detected by the pressure sensor 10, the loading amount of the cargo C calculated based thereon, and the like.

[0021] In addition, an alarm device 12 is provided at an appropriate position of the transporter 1. The alarm device 12 is a device that alarms people according to the load amount calculated in the process of measuring the load amount described later. The alarm is issued, for example, on the condition that the load amount reaches a preset threshold value (for example, the allowable upper limit value of the load amount, or a value set lower than that for safety).

[0022] In the case of this embodiment, as shown in FIG. 1, a lamp is provided at the outer rear part of the driver's cab as the alarm device 12, and the alarm is issued as light to the personnel outside the vehicle. In addition to what is shown here, various configurations and arrangements can be adopted as the alarm device 12. For example, the function of the alarm device 12 can be combined with the display device 11, and an alarm can be issued to the driver of the transporter 1 as visual information through the display device 11, or the alarm device 12 can be provided as a buzzer or a speaker that issues the alarm as auditory information.

[0023] In addition, an operating device 13 for inputting an operation command to the control device 9 is provided on the driver's seat of the transporter 1. The operating device 13 is a device for a person to operate the transporter 1, and can input operations related to operations such as traveling by the crawler 4 and raising and lowering the loading platform 3 by the hydraulic cylinder 6.

[0024] Next, the load amount measuring method according to the above-described embodiment will be described with reference to the time chart of FIG. 3.

[0025] In this embodiment, the timing at which the loading platform 3 floats from the frame 5 is grasped based on the presence or absence of input to the contact sensor 7, and the load amount is calculated based on the pressure value (measurement value of the pressure sensor 10) in the hydraulic cylinder 6 obtained at this timing. Further, at this time, by making the control amount input to the hydraulic cylinder 6 constant regardless of the operation input from the operator, the acquisition conditions of the measurement value of the pressure sensor 10 used for calculating the load amount are made uniform, so that the load amount can be grasped accurately.

[0026] In the timing chart of FIG. 3, it is assumed that the operator inputs an operation to raise the loading platform 3 to the operation device 13 at time t0, and in response, the extension control of the fluid pressure cylinder 6 is performed, and the raising operation of the loading platform 3 is carried out.

[0027] In the initial state, the loading platform 3 is lowered with respect to the frame 5 (loading platform angle is zero) and is in contact with the contact sensor 7 (contact sensor ON). No control signal is input to the fluid pressure cylinder 6 (fluid pressure cylinder control amount is zero), and the pressure value of the fluid pressure cylinder 6 (measurement value of the pressure sensor 10) is also zero.

[0028] From here, the operator starts the operation input by tilting the lever of the operation device 13 at time t0. The input amount of the operation to raise the loading platform 3 to the operation device 13 increases from 0% to 100% from time t0 to time t1, and is kept constant (100%) until the loading platform 3 is fully raised.

[0029] When the control device 9 detects the input of the operation to raise the loading platform 3 at time t0, first, regardless of the input amount of the operation to the operation device 13, the extension control of the fluid pressure cylinder 6 is performed with a constant control amount. Here, as the control amount input to the fluid pressure cylinder 6, an appropriate value (for example, 50% of the maximum value) within the range from zero to the maximum value may be set in advance.

[0030] The fluid pressure cylinder 6 increases the internal fluid pressure according to a constant control amount input from the control device 9. When the fluid pressure increases, at the timing (time t2) when the force due to the fluid pressure exceeds the load applied from the loading platform 3, the loading platform 3 starts to float from the frame 5, and eventually the input of contact from the loading platform 3 to the contact sensor 7 becomes OFF (time t3).

[0031] When the control device 9 detects that the input to the contact sensor 7 has become OFF, it ends the control of the fluid pressure cylinder 6 with a constant control amount and starts the control based on the operation input amount from the operator to the operation device 13. In the case of the example shown here, the control amount for the fluid pressure cylinder 6 is increased to 100%.

[0032] The loading platform 3 increases its inclination from time t2 and will rise to the maximum angle by the extension of the fluid pressure cylinder 6 at some point.

[0033] In this series of operations, the measured value (pressure value) of the pressure sensor 10 varies as follows, for example. First, when the extension control of the fluid pressure cylinder 6 starts at time t0, as the pressure in the fluid pressure cylinder 6 rises, the load of the loading platform 3 that was dispersed and supported on the frame 5 concentrates on the fluid pressure cylinder 6, and the pressure value continues to rise until time t2. When the loading platform 3 leaves the frame 5 and the inclination starts at time t2, the pressure value turns downward with this as the peak. When the discharge of the load C from the loading platform 3 starts, the pressure value further decreases accordingly.

[0034] During this period, the measured value of the pressure sensor 10 is input to the control device 9. The control device 9 calculates the loading amount of the load C on the loading platform 3 based on the pressure value at time t3 when the loading platform 3 floats from the frame 5 and the input to the contact sensor 7 turns off.

[0035] There are several advantages to limiting the timing of obtaining the pressure value used as the basis for the loading amount in this way. First, by limiting the timing itself, the pressure can be measured under always the same conditions regarding the postures of the loading platform 3 and the fluid pressure cylinder 6. Although the relationship between the loading amount of the load C on the loading platform 3 and the pressure in the fluid pressure cylinder 6 is positively correlated, of course, the coefficient varies depending on the angles of the loading platform 3 and the fluid pressure cylinder 6. Therefore, if the pressure value referred to for calculating the loading amount is limited to the pressure value when the loading platform 3 and the fluid pressure cylinder 6 are in a specific posture, the relationship between the loading amount and the pressure value can be regarded as generally constant, and the loading amount can be calculated by appropriate calculations.

[0036] Furthermore, if the timing of obtaining the pressure value to be referred to is limited to the point in time when "the loading platform 3 is detected by the contact sensor 7 as having floated relative to the frame 5", that is, "the point in time when the input to the contact sensor 7 turns off" (time t3), it is particularly suitable for calculating the load capacity. At this stage, the loading platform 3 is floating at a slight angle relative to the frame 5. That is, the loading platform 3 is supported by the fluid pressure cylinder 6 and only at the fulcrum behind it (the right side in FIG. 1) relative to the frame 5, and its posture is also substantially horizontal. In this state, the load of the loading platform 3 is not dispersed to the frame 5, and since the loading platform 3 is substantially horizontal, the loaded cargo C does not move under its own weight.

[0037] Incidentally, in such a state, the relationship between the pressure value in the fluid pressure cylinder 6 and the load capacity on the loading platform 3 varies not only depending on the weight of the cargo C but also on the position of the center of gravity P of the cargo C. However, when calculating the load capacity from the pressure value in the fluid pressure cylinder 6, if it is assumed that the center of gravity P is at an appropriate position and the calculation is performed, the load capacity can be calculated with practically sufficient accuracy. In particular, based on the pressure value obtained at the specific timing as described above, since the loading platform 3 is substantially horizontal, it can be expected that the position of the center of gravity P of the cargo C does not deviate significantly from the assumed position, and a more accurate calculation is possible.

[0038] Here, for some time after the moment (time t2) when the loading platform 3 floats from the frame 5, due to the vibration associated with the floating of the loading platform 3, the pressure value in the fluid pressure cylinder 6 becomes unstable. The pressure values obtained during this period lack reliability as a basis for calculating the load capacity. Therefore, assuming in advance the existence of such a time when the pressure value becomes unstable, after the loading platform 3 floats, it is advisable to use the pressure value obtained at the point when this time has elapsed and the pressure value seems to have stabilized for calculating the load capacity. More specifically, the contact sensor 7 is configured to detect that the loading platform has floated at the point when a time sufficient for the measured value of the pressure sensor 10 to be considered stable has elapsed since the loading platform 3 floated, and the measured value of the pressure sensor 10 obtained when the contact sensor 7 detects that the loading platform has floated is used for calculating the load capacity. When the contact sensor 7 is a physically contacting switch, the contact sensor 7 may be arranged at a position where the loading platform 3 separates from the contact sensor 7 at a point when the loading platform 3 further rises slightly after the loading platform 3 floats from the frame 5. Then, if the pressure value at the point when the input to the contact sensor 7 turns off is used for calculating the load capacity, it is possible to calculate the load capacity with high accuracy based on the stable pressure value. Note that the "time sufficient for the pressure value of the fluid pressure cylinder 6 to be considered stable after the loading platform 3 floats" can be appropriately set by, for example, a test such as measuring the change in the pressure value while actually performing the raising operation of the loading platform 3. Depending on the result of this test, for example, when extension control is performed on the fluid pressure cylinder 6 with a certain control amount, the installation position of the contact sensor 7 may be adjusted to a position where the loading platform 3 separates from the contact sensor 7 2 seconds after the loading platform 3 floats from the frame 5. Note that when actually calculating the load capacity along with the raising operation of the loading platform 3, at the point when the loading platform 3 separates from the contact sensor 7, the pressure value does not necessarily have to be completely stable. For the purpose of calculating the load capacity from the pressure value, it is sufficient that the pressure value is stable to the extent that it can be considered stable for convenience.

[0039] In addition, regarding the relationship between the pressure value and the loading amount, not only the postures of the loading platform 3 and the hydraulic cylinder 6 at that time but also the operating speed of the hydraulic cylinder 6 have an impact. In the case of this embodiment, regardless of the amount of input operation to the operating device 13, the pressure in the hydraulic cylinder 6 is increased with a constant control amount from when the raising operation of the loading platform 3 is input until the input to the contact sensor 7 turns off. Therefore, the pressure value in a state where the operating speed of the hydraulic cylinder 6 is within a certain range will be used for calculating the loading amount. In this way, by aligning the acquisition conditions of the pressure value used as the basis for calculating the loading amount, the calculation for calculating the loading amount can be performed more appropriately.

[0040] In addition, when performing control with a constant control amount in this way, after the operator starts inputting the raising operation, for a while, the amount of input operation from the operator and the control amount of the hydraulic cylinder 6 by the control device 9 will not match. However, since the raising operation of the loading platform 3 itself is not stopped, the operator will not feel a control delay, or if they do, it will be only slight.

[0041] Also, when measuring the loading amount, without any special operation by the operator, weighing is automatically performed on the condition that the contact input to the contact sensor 7 turns off each time the loading platform 3 is raised. Therefore, there is no omission in measuring the loading amount, and it is convenient for the operator as there is no need for each operation. Moreover, as described above, the pressure value used as the basis for the loading amount is acquired at a timing suitable for measuring the loading amount, so measurement with high accuracy is possible.

[0042] FIG. 4 shows, as a reference example of the present invention, a time chart of the operation of each device and the measured values when the above-described control is not performed. When the operator inputs a raising operation of the loading platform 3 from time t0, the control device 9 performs control to increase the pressure on the hydraulic cylinder 6 following this. At this time, the control amount is increased in accordance with the amount of input operation from the operator. At a point in time slightly after the input of the raising operation (time t4), the loading platform 3 floats from the frame 5, and thereafter, the inclination angle of the loading platform 3 increases and the load C is discharged.

[0043] During this period, the pressure value in the fluid pressure cylinder 6 varies as shown in the third row of FIG. 4. If, during the raising operation of the loading platform 3, the operator performs a weighing operation at an arbitrary time point and calculates the loading amount based on the pressure value at that time point, then any of these greatly varying pressure values will be applied to a fixed mathematical formula, and depending on the timing, the actual loading amount and the calculated loading amount may differ significantly. If, as in the present embodiment, the loading amount is calculated at a determined timing using the contact sensor 7, a more suitable grasp of the loading amount is possible.

[0044] The method for measuring the loading amount as described above can be summarized in a flowchart as shown in FIG. 5, for example.

[0045] First, the control device 9 determines whether an input for raising the loading platform 3 has been received from the operating device 13 (step S1). If no raising operation input has been received, it waits while repeating the determination in step S1. If an input for raising the loading platform 3 has been received, it proceeds to step S2, increases the pressure in the fluid pressure cylinder 6, and starts extension control. At this time, the control amount input from the control device 9 to the fluid pressure cylinder 6 is constant.

[0046] While increasing the pressure in the fluid pressure cylinder 6 with a constant control amount, it determines whether there is an input to the contact sensor 7 (step S3). If the input to the contact sensor 7 is on, the determination in step S3 is performed again, and this is repeated until the loading platform 3 moves away from the contact sensor 7.

[0047] When the input to the contact sensor 7 turns off, it proceeds to step S4 and acquires the measured value of the pressure sensor 10. After acquiring the pressure value, it ends the control with a constant control amount for the fluid pressure cylinder 6 and starts control according to the input amount of the raising operation to the operating device 13 (step S5). It calculates the loading amount based on the pressure value acquired in the previous step S4 (step S6) and ends the procedure for measuring the loading amount.

[0048] The calculated load is appropriately recorded in the control device 9 and an information terminal device (not shown) connected thereto, and is displayed on the display device 11 or the like as needed for the operator to refer to. Also, when the load is too large and there is a risk of overloading, an alarm can be issued from the display device 11 or the alarm device 12.

[0049] Note that the above-described load measurement procedure is merely an example, and appropriate changes may be made as long as the load can be suitably measured. For example, the pressure value in the pressure sensor 10 may be continuously acquired at all times regardless of the on / off state of the contact sensor 7, and the pressure value at the time when the input to the contact sensor 7 turns off may be extracted and used for calculating the load. Alternatively, steps S5 and S6 may be executed in parallel.

[0050] As described above, in the load measurement method of this embodiment, in response to an input of a raising operation of the loading platform 3 from the state where the loading platform 3 has descended, extension control is performed on the lifting device (fluid pressure cylinder) 6 that raises and lowers the loading platform 3 with a certain control amount. Based on the pressure value of the lifting device 6 when the loading platform 3 floats due to the extension control of the lifting device 6 with the certain control amount, the load is calculated. In this way, by always using the pressure value in a state where the loading platform 3 and the lifting device 6 are in a certain posture and the operating speed of the lifting device 6 is within a certain range for calculating the load, the load can be calculated by appropriate calculation.

[0051] Also, in the load measurement method of this embodiment, after the loading platform 3 floats, the load is calculated based on the pressure value of the lifting device 6 acquired at the time when a time sufficient for the pressure value of the lifting device 6 to be considered stable has elapsed. In this way, it is possible to calculate the load with high accuracy using a stable pressure value.

[0052] In addition, the loading capacity measurement system of this embodiment includes a loading platform 3 attached to the transport vehicle 1, a lifting device 6 for lifting and lowering the loading 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 loading platform 3 and the frame 5 forming the vehicle body 2 of the transport vehicle 1. In response to an input for raising the loading platform 3 from a state where the loading platform 3 has descended with respect to the frame 5, the lifting device 6 is controlled to extend with a certain control amount. Based on the measured value of the pressure sensor 10 obtained when the contact sensor 7 determines that the loading platform 3 has floated with respect to the frame 5, the loading capacity is calculated. In this way, by always using the pressure value in a state where the loading platform 3 and the lifting device 6 are in a certain posture and the operating speed of the lifting device 6 is within a certain range for calculating the loading capacity, the loading capacity can be calculated by appropriate calculation.

[0053] Also, in the loading capacity measurement system of this embodiment, the contact sensor 7 is configured to detect that the loading platform 3 has floated at the point in time when a certain amount of time has elapsed since the loading platform 3 has floated until the measured value of the pressure sensor 10 can be regarded as stable during the raising operation of the loading platform 3. The calculation of the loading capacity is performed based on the measured value of the pressure sensor 10 obtained when the contact sensor 7 detects that the loading platform 3 has floated during the raising operation of the loading platform 3. In this way, it is possible to calculate the loading capacity with high accuracy based on the stable pressure value.

[0054] Further, in the loading capacity measurement system of the present embodiment, the contact sensor 7 is a physical contact type switch installed such that contact is input from the loading platform 3 while the loading platform 3 is descending to the frame 5, and the input of contact from the loading platform 3 is turned off while the loading platform 3 is floating from the frame 5. The contact sensor 7 is arranged such that, in the raising operation of the loading platform 3, the input of contact from the loading platform 3 is turned off when a time period has elapsed such that the measured value of the pressure sensor 10 can be regarded as having stabilized after the loading platform 3 has floated. The calculation of the loading capacity is performed based on the measured value of the pressure sensor 10 obtained when the input of contact to the contact sensor 7 is turned off in the raising operation of the loading platform 3. In this way, by using the contact sensor 7 with a simple configuration, a stable measured value can be obtained as the pressure value used for calculating the loading capacity.

[0055] Further, since the transport vehicle 1 of the present embodiment is provided with the above-described loading capacity measurement system, the same operational effects as described above can be achieved.

[0056] Therefore, according to the present embodiment, the loading capacity of the cargo can be suitably grasped.

[0057] Note that the loading capacity measurement method, measurement system, and transport vehicle of the present invention are not limited only to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

Description of Reference Numerals

[0058] 1 Transport vehicle 2 Vehicle body 3 Loading platform 5 Frame 6 Lifting device (hydraulic cylinder) 7 Contact sensor 10 Pressure sensor

Claims

1. A method for measuring the load capacity using a loading platform attached to a transporter, 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 forming the vehicle body of the transporter, comprising: detecting an input for raising the loading platform from a state where the loading platform is lowered with respect to the frame, and performing extension control on the lifting device with a constant control amount regardless of the input amount of the raising operation of the loading platform; acquiring the measured value of the pressure sensor when it is grasped by the contact sensor that the loading platform has floated with respect to the frame, and ending the control with a constant control amount of the lifting device; subsequently starting the extension control of the lifting device according to the input amount of the raising operation of the loading platform, and performing a series of operations of raising the loading platform to the input amount; calculating the load capacity on the loading platform from the measured value of the acquired pressure sensor, wherein the method for measuring the load capacity is characterized by this.

2. performing the calculation of the load capacity based on the pressure value of the lifting device acquired at the time when a time sufficient for the pressure value of the lifting device to be considered stable has elapsed after the loading platform has floated. The method for measuring the load capacity according to claim 1, characterized by this.

3. A load capacity measurement system comprising a loading platform attached to a transporter, 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 forming the vehicle body of the transporter, detecting an input for raising the loading platform from a state where the loading platform is lowered with respect to the frame, and performing extension control on the lifting device with a constant control amount regardless of the input amount of the raising operation of the loading platform; acquiring the measured value of the pressure sensor when it is grasped by the contact sensor that the loading platform has floated with respect to the frame, and ending the control with a constant control amount of the lifting device; subsequently starting the extension control of the lifting device according to the input amount of the raising operation of the loading platform, and performing a series of operations of raising the loading platform to the input amount; calculating the load capacity on the loading platform from the measured value of the acquired pressure sensor, wherein the load capacity measurement system is characterized by being configured in this way.

4. The contact sensor is configured to detect that the loading platform has floated at the time when a time sufficient for the measured value of the pressure sensor to be considered stable has elapsed after the loading platform has floated during the raising operation of the loading platform. The calculation of the loading amount is configured to be performed based on the measured value of the pressure sensor obtained when the contact sensor detects that the loading platform has floated during the raising operation of the loading platform. The measurement system for the loading amount according to claim 3, characterized in that.

5. The contact sensor is a physical contact type switch installed such that while contact is input from the loading platform in a state where the loading platform is lowered to the frame, the input of contact from the loading platform is turned off in a state where the loading platform has floated from the frame. The contact sensor is arranged such that during the raising operation of the loading platform, the input of contact from the loading platform is turned off when a time period has elapsed such that the measured value of the pressure sensor can be regarded as having stabilized after the loading platform has floated. The calculation of the loading amount is configured to be performed based on the measured value of the pressure sensor obtained when the input of contact to the contact sensor is turned off during the raising operation of the loading platform. The measurement system for the loading amount according to claim 4, characterized in that.

6. A transport vehicle, characterized in that it is equipped with the measurement system for the loading amount according to any one of claims 3 to 5.

Images