WO2013122066A1 - Stress computation system for dump truck - Google Patents

Stress computation system for dump truck Download PDF

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Publication number
WO2013122066A1
WO2013122066A1 PCT/JP2013/053298 JP2013053298W WO2013122066A1 WO 2013122066 A1 WO2013122066 A1 WO 2013122066A1 JP 2013053298 W JP2013053298 W JP 2013053298W WO 2013122066 A1 WO2013122066 A1 WO 2013122066A1
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WO
WIPO (PCT)
Prior art keywords
stress
dump truck
acceleration
load
calculation system
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Application number
PCT/JP2013/053298
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French (fr)
Japanese (ja)
Inventor
泰樹 北
北口　篤
佐藤　隆之
石原　和典
佐々木　崇
田村　克己
秋野　真司
大輔 丹代
Original Assignee
日立建機株式会社
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Application filed by 日立建機株式会社 filed Critical 日立建機株式会社
Publication of WO2013122066A1 publication Critical patent/WO2013122066A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60P—VEHICLES ADAPTED FOR LOAD TRANSPORTATION OR TO TRANSPORT, TO CARRY, OR TO COMPRISE SPECIAL LOADS OR OBJECTS
    • B60P1/00—Vehicles predominantly for transporting loads and modified to facilitate loading, consolidating the load, or unloading
    • B60P1/04—Vehicles predominantly for transporting loads and modified to facilitate loading, consolidating the load, or unloading with a tipping movement of load-transporting element
    • B60P1/28—Tipping body constructions
    • B60P1/283—Elements of tipping devices

Definitions

  • the present invention relates to a stress calculation system for calculating a temporal change of stress at a predetermined position of a dump truck.
  • the temporal change for example, the temporal change of the stress waveform
  • the predetermined position vehicle evaluation position
  • the temporal change of the stress is calculated, and based on the temporal change of the stress.
  • strength evaluation including life prediction of a dump truck and its component parts.
  • suspension force or acceleration sampled by a pressure sensor attached to a hydraulic suspension cylinder of a dump truck or an acceleration sensor attached to a frame is converted into frequency domain data, and
  • the stress of the vehicle evaluation position in the frequency domain is determined by multiplying the frequency domain data by the transfer function (transfer function in the frequency domain between the suspension force or acceleration and the stress of the vehicle evaluation position) written in the memory. It is described that time domain data (time change) of stress at a vehicle evaluation position is obtained from the stress.
  • the stress of the vehicle evaluation position in the frequency domain is determined by multiplying the sampling data in the frequency domain of the sensor by the transfer function, and the data in the frequency domain is converted to that in the time domain. It is difficult to obtain a highly accurate stress waveform (temporal change of stress). That is, when converting the waveform from the frequency domain to the time domain, the time waveform to be converted is innumerable and not unambiguous, so the accuracy of the finally obtained stress waveform is inferior.
  • the suspension force data or acceleration data alone can not accurately identify the position of the loading platform in operation. It is difficult to calculate the amount of damage in light of the whole: driving ⁇ unloading ⁇ unloading ⁇ loading. That is, when obtaining a stress waveform based on the suspension force (pressure sensor), the cylinder pressure fluctuation for calculating the suspension force includes an error factor of the friction resistance of the cylinder and the oil viscosity, and the road surface inclination and the vehicle vibration are high. It is difficult to measure with accuracy.
  • An object of the present invention is to provide a dump truck stress calculation system capable of calculating with high accuracy the time change of stress occurring at a predetermined position (vehicle evaluation position).
  • the present application includes a plurality of means for solving the above-mentioned problems, for example, storage of data of stress generated at a predetermined position of the dump truck when a plurality of external forces respectively act on the dump truck is mentioned.
  • computing means for estimating temporal changes in stress occurring at the position.
  • the process of converting the frequency domain into the time domain is not included when calculating the time change of the stress of the vehicle evaluation position, the time change of the stress at the vehicle evaluation position can be calculated with high accuracy.
  • BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the dump truck which concerns on embodiment of this invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the carrying platform 101 periphery of the dump truck which concerns on embodiment of this invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the stress calculation system of the dump truck which concerns on embodiment of this invention.
  • FIG. 6 is a view showing an example of a time waveform of acceleration of the vehicle under work detected by the acceleration sensor 110.
  • FIG. 1 is a block diagram of a dump truck according to an embodiment of the present invention
  • FIG. 2 is a block diagram of a periphery of a loading platform 101 thereof.
  • the dump truck shown in FIG. 1 is provided with a frame 102, front wheels 21 rotatably attached at one end to the left and right ends of the front of the frame 102, and two wheels rotatably attached to the left and right ends at the rear of the frame 102.
  • a pair of rear wheels 22 and a loading platform 101 mounted on the frame 102 via a hinge pin 104 so as to be rotatable (reversible) via a hinge pin 104 and for loading a load such as earth and sand or crushed stone are provided.
  • a hoist cylinder 103 connected to the frame 102 and the loading platform 101 is attached.
  • the hoist cylinder 103 extends, the loading platform 101 rises on the frame 102 (stand-up state), and when the hoist cylinder 103 contracts, the loading platform falls on the frame 102 (falling state).
  • the dump truck transports a load such as earth and sand, crushed stone, etc. loaded on the loading platform 101 in the fallen state, then makes the loading platform 101 inclined and lowers the load by transferring the loading platform 101 from the laid down condition to the upright condition. There is. At this time, the tilt angle of the loading platform 101 is measured and monitored by a loading platform tilt sensor (loading platform angle detection means) 112 attached to the vehicle body.
  • a loading platform tilt sensor loading platform angle detection means
  • a cushioning member and a pad 105 are provided which cushion the impact received from the frame 102 when the loading platform 101 falls down.
  • suspension cylinders 23 and 24 are mounted on the dump truck so as to be symmetrical in the left-right direction in order to reduce vibration during traveling.
  • the suspension cylinders 23, 24 are provided with cylinder pressure sensors 43, 44 (see FIG. 3).
  • the cylinder pressure sensors 43 and 44 By means of the cylinder pressure detected by the cylinder pressure sensors 43 and 44, it is possible to estimate the load amount and the load load center position, to monitor the load amount, and to prevent the overload. That is, the cylinder pressure sensors 43 and 44 function as load weight detection means and gravity center position detection means.
  • the dump truck includes an acceleration sensor (acceleration detecting means) 110 for measuring the vibration of the vehicle during work, and a road surface inclination sensor (for measuring the inclination angle of the ground on which the dump truck travels) At least one road surface angle detecting means) 111 is provided.
  • FIG. 3 is a schematic configuration diagram of a dump truck stress calculation system according to the embodiment of the present invention.
  • the stress calculation system includes an arithmetic processing unit (for example, a CPU) 31 as calculation means for executing various programs, and a storage device (for example, a storage means for storing various data including the program).
  • a semiconductor memory such as a ROM, a RAM, and a flash memory
  • a magnetic storage device such as a hard disk drive 32
  • a display device for example, a liquid crystal monitor
  • the arithmetic processing unit 31, the storage unit 32, and the display unit 33 are described as being mounted on the dump truck shown in FIG. 1, these units 31, 32, and 33 are not limited to a plurality of units. It may be mounted on an electronic computer in a control center for managing the operation of dump trucks, and the arithmetic processing unit 31 may execute various processing based on the output from the sensor of each dump truck. The rest may be mounted on the computer in the management center while the unit is mounted on the dump truck. That is, the installation places of the devices 31, 32, and 33 are not particularly limited.
  • the storage device 32 when a plurality of external forces in different directions (for example, vibrations due to the operation of the dump truck, load load) respectively act on the dump truck, predetermined positions of the dump truck (hereinafter, "vehicle evaluation position") Or, data (stress data) of stress occurring in “the evaluation position” may be stored.
  • vehicle evaluation position a load of unit gravitational acceleration (a 1g ) was applied to each of three directions (three axial directions) in the front and rear direction, left and right direction, and vertical direction of the vehicle. Stresses that sometimes occur at the vehicle evaluation position are stored as stress data.
  • the stress data is different for each case where the load load size, the barycentric position of the load, the size of the tilt angle of the load bed 101, and the size of the tilt angle of the traveling road surface of the vehicle are different. Is stored in That is, a plurality of stresses in the above three axial directions having these as parameters are stored in the storage device 32. The stress data is created based on stress measurement results or analysis in an actual machine, and is stored in advance in the storage device 32.
  • the arithmetic processing unit 31 receives output values (detection values) from the bed inclination sensor 112, the cylinder pressure sensors 43 and 44, the acceleration sensor 110, and the road surface inclination sensor 111.
  • the arithmetic processing unit 31 generates stress at the vehicle evaluation position by interpolation or extrapolation based on at least one of the detection values of the various sensors 43, 44, 110, 111, 112 and the stress data stored in the storage unit 32.
  • the process of estimating the time change (time-series stress waveform) of the image is executed (details of the process content will be described later).
  • the display device 33 displays the time change (time-series stress waveform) of the stress of the vehicle evaluation position calculated by the arithmetic processing unit 31 and various information obtained based on this.
  • This type of information includes, for example, the time-series stress waveform at the evaluation position, the maximum stress value, the minimum stress value and the stress amplitude in the stress waveform, the damage amount at the evaluation position, and these statistical values for each worker. Accumulated damage amount at evaluation position, threshold value and target value for stress, good or bad driving operation, road surface condition (whether bad road is generated or not), maintenance time and location (details are described Later).
  • the installation destination of the display device 33 is not particularly limited as described above, in addition to the dump truck and the management center, for example, a loading machine (for example, hydraulic shovel or wheel loader) used when loading a load on the dump truck , It may be installed on a repair machine of the road surface where the dump truck travels.
  • a loading machine for example, hydraulic shovel or wheel loader
  • FIG. 4 is a view showing an example of the load shape of the dump truck.
  • FIG. 4 (a) is a view showing a state in which the load 201 is loaded on the loading platform 101 in an ideal state (when the loading center position is at 5 in FIG. 5 described later)
  • FIG. 4 (b) FIG. 6 is a view showing a state where the load 201 is loaded on the loading platform 101 while being biased forward and left (when the loading center position is at 1 in FIG. 5).
  • a side view is shown on the left, and a cross-sectional view in a plane parallel to the front of the dump truck is shown on the right.
  • the goal is to make the loading shape the ideal condition of (a), but due to the topography of the loading site, mismatching of the loading machine and the transporting machine, the loading operator's ability, etc.
  • the balance of the load before and after, left and right may deviate from the ideal position.
  • FIG. 5 shows a top view of the loading platform 101 of the dump truck.
  • the black dots 1 to 9 in the figure indicate the barycentric position of the load when the load shape is changed.
  • the state of (a) shown in FIG. 4 corresponds to the position 5
  • the state of (b) corresponds to the position 1.
  • the gravity center position of the actual load is indicated by the gravity center mark 11.
  • FIG. 6 is a view showing an example of a stress table of a vehicle evaluation position when unit gravity acceleration (a 1g ) is loaded.
  • the stress table shown in this figure is the one when the loading platform 101 is seated on the frame 102 (loading platform inclination angle: zero), and further, the case where the vehicle is on a flat road surface (road surface inclination angle: zero)
  • a 1g unit gravity acceleration
  • the load 201 is loaded on the inner wall surface of the loading platform 101 when the unit gravitational acceleration (a 1g ) is loaded in the forward direction, the lower direction, and the right direction in the vehicle loaded with the load 201 of the amount (Wmax).
  • the stress of the evaluation position of the vehicle which arises by pressure is shown.
  • the bed inclination angle measured from the sensors 43, 44, 110, 111 and 112 and the load center position. It is characterized in that the time change of the stress of the evaluation part is calculated according to the load amount, the vehicle vibration (acceleration) and the road surface inclination.
  • the arithmetic and control unit 31 shown in FIG. 3 has a primary correction unit 31a for correcting stress based on the bed inclination angle and the load bearing center position, and a secondary correction unit 31b for correcting stress based on the product load amount.
  • the third correction unit 31 c corrects the stress based on the acceleration
  • the fourth correction unit 31 d corrects the stress based on the road surface inclination angle.
  • the storage device 32 stores the stress data of the vehicle evaluation position in advance.
  • the arithmetic and control unit 31 stores in the storage unit 32 the bed inclination angle measured from the bed inclination sensor 112, the current product load core position calculated from the cylinder pressure sensors 43 and 44, and the storage unit 32 in the primary correction unit 31a.
  • a process of calculating primary correction stress is executed by interpolation or extrapolation based on stress data of several points.
  • the stress at the actual barycentric position 11 shifted by zg leftward from the position 5 is given by the following equations (from the stresses ⁇ 1n , ⁇ 2n , ⁇ 4n and ⁇ 5n at the positions 1, 2 and 4, 5 1) Obtained from (2).
  • the following expressions (1) and (2) front, bottom, and right are included in subscript n, and a correction stress is obtained for each of three axial directions.
  • the stress of the load at the actual load center position is It can be estimated as (3).
  • the actual barycentric position 11 is the range of the barycentric position prepared by the stress table (see FIG. If the position 5 is out of the rectangular range defined by the positions 1, 3, 7, 9), it may be obtained by extrapolation approximation. Note that either interpolation or extrapolation may be used for the calculations performed by the secondary correction unit 31 b, the tertiary correction unit 31 c, and the quaternary correction unit 31 d described below. Further, the number of stress data prepared in advance for correction of the load bearing center position is not limited to nine as illustrated, but may be any other number as long as it can be interpolated and extrapolated.
  • the stress table of the actual bed inclination angle is first calculated by correcting the bed inclination angle, and the load table is calculated based on the calculated stress table.
  • the correction based on the above-described load center position may be performed only on the stress.
  • the arithmetic and control unit 31 causes the secondary correction unit 31 b to calculate the secondary correction stress by interpolation or extrapolation based on the product load amount detected by the cylinder pressure sensors 43 and 44 and the primary correction stress.
  • the secondary correction stress is the sum of the stress of the empty load and the load of the load.
  • the load stress of the primary correction stress is the product load amount calculated by the rated maximum load amount (Wmax). Therefore, here, assuming that the actual product load amount calculated from the detection values of the cylinder pressure sensors 43 and 44 is w, the weight coefficient (w / Wmax) obtained by dividing the product load amount w by the rated maximum load amount Wmax is the load Correct by multiplying by stress.
  • the secondary correction stress is a stress obtained by adding the stress of the empty load and the stress of the load corrected by the weight coefficient.
  • the second correction stress takes into consideration the bed inclination angle, the load center position, and the load amount to the stress generated at the vehicle evaluation position when the unit gravitational acceleration (a 1g ) is loaded.
  • the suffix n includes the front, the bottom, and the right, and the correction stress is obtained for each of the three axial directions.
  • the arithmetic and control unit 31 causes the third-order correction unit 31 c to take into account the vehicle vibration generated during vehicle operation by interpolation or extrapolation based on the acceleration detected by the acceleration sensor 110 and the second-order correction stress. Execute processing to calculate the correction stress.
  • FIG. 7 is a view showing an example of the time waveform of the acceleration of the vehicle under work detected by the acceleration sensor 110.
  • the acceleration here considers relative acceleration. That is, only the motion vibration during the operation is considered with reference to the stop state without considering the gravitational acceleration. For example, each of a pre-measured values of the acceleration in the three axial directions at time t 1, a bottom, and a right (see FIG. 7).
  • the third-order correction stress is a stress of a vehicle vibration component during work, and does not include the influence of inertial acceleration due to the road surface inclination described later. If the acceleration to be measured is absolute acceleration, it is possible to simultaneously evaluate the influence of the inertial acceleration due to the road surface inclination, but in order to grasp the traveling road surface condition, it is preferable to separately obtain the influence of the vehicle vibration and the road surface inclination.
  • the arithmetic and control unit 31 causes the fourth-order correction unit 31 d to apply an inertial acceleration applied to the vehicle body due to the road surface inclination by interpolation or extrapolation based on the road surface inclination detected by the road surface inclination sensor 111 and the second correction stress.
  • a process of calculating fourth-order correction stress in consideration of the influence of (for example, gravitational acceleration) is executed.
  • FIG. 8 shows a schematic view when the dump truck travels on a sloped road surface.
  • the vehicle is on the upward slope of the inclination angle ⁇ 1 with respect to the flat road surface (the road surface at the time of stress data calculation), and the inertial acceleration (a G ) indicated by the solid arrow is in the vertical direction It is loaded at an angle theta 2 Te. Therefore, the stress (fourth order correction stress) that this inertial acceleration exerts on the vehicle evaluation position is expressed by the following equation.
  • the arithmetic and control unit 31 finally calculates the stress generated at the evaluation position at the time of the actual operation of the vehicle by adding the third correction stress and the fourth correction stress described above (see equation (7)).
  • the stress at the evaluation position corresponding to the bed inclination angle, the load center position, the load amount, the vehicle body vibration (acceleration), and the road surface inclination at a certain point in operation.
  • the time change of the stress which arises in a vehicle evaluation position can be computed. Therefore, according to the present embodiment, the step of converting the frequency domain into the time domain is not included in calculating the time change of the stress at the vehicle evaluation position, so the time change of the stress at the vehicle evaluation position can be made with high accuracy. It can be calculated.
  • the acceleration sensor 110, the cylinder pressure sensor 43, and the acceleration pressure are treated as variables from the viewpoint of improving the accuracy of the stress finally calculated. 44.
  • the time change of the stress at the vehicle evaluation position was calculated by performing the first to fourth corrections.
  • the remaining one is treated as a constant to simplify the correction and calculate the time change of stress. good.
  • the time change of the stress of the vehicle evaluation position may be calculated by interpolation or extrapolation based on the stress data and at least one of the detection values of the various sensors 110, 111, 112, 43, 44.
  • the first correction, second correction, and fourth correction are omitted by substituting predetermined constants for the load amount, the load center position, the loading angle, and the road surface inclination angle, and only based on the detection value of the acceleration sensor 110.
  • the stress at the vehicle evaluation position may be calculated (that is, only the third-order correction is performed).
  • any one of the load amount, the bed inclination angle and the road surface inclination angle is detected by the sensor and the acceleration is detected by the sensor 110, and for the remaining ones, the stress is calculated by substituting a predetermined constant. (Ie, only one of the first correction, the second correction, and the fourth correction and the third correction may be performed). Furthermore, only the correction based on the position of the center of gravity in the first correction, the second correction, and the third correction may be performed.
  • stress data is used when the vehicle is on a flat road surface
  • the load amount is the rated maximum load amount Wmax
  • the load acceleration is unit gravity acceleration, but other road surface slopes, load loads and load accelerations It goes without saying that a stress table created using it may be used.
  • the stress waveform at the time of load traveling can be calculated by repeating the above-mentioned first correction, third correction and fourth correction.
  • the weight coefficient (w / Wmax) shown in the explanation of the second correction becomes zero and the stress of the load is omitted.
  • the final stress is calculated. That is, also in this case, the stress waveform can be calculated.
  • FIG. 9 shows an example of a stress waveform at a vehicle evaluation position at the time of loading work.
  • the load center position and the amount of load change mainly, and in particular, a large impact load (loading impact) tends to occur at the initial stage of loading (first and second cups).
  • the stress waveform can be calculated by interpolation or extrapolation of the stress data shown above with respect to changes in the load center position and the load amount.
  • the impact vibration given to the vehicle by loading may differ depending on the type of load 201 and the loading amount on the loading platform 101 and the loading and unloading position. Therefore, it is difficult to approximate the actual stress waveform only by interpolation or extrapolation of the stress data.
  • an impact coefficient (first impact coefficient) for calculating a stress generated when loading a load onto the loading platform 101 is used.
  • the relationship between the acceleration waveform by the acceleration sensor 110 at the time of loading and the impact coefficient at the evaluation position is obtained in advance, and the impact coefficient is stored in the storage device 32.
  • the stress at loading is calculated by multiplying the stress at loading (stress value estimated by interpolation or extrapolation of stress data) calculated based on each sensor value by the impact coefficient. .
  • FIG. 10 is a schematic view showing an example of operation at unloading
  • FIG. 11 is an example of a stress waveform at an evaluation position at unloading.
  • the states of the loading platform at times a to e in FIG. 11 correspond to the states a to e shown in FIG.
  • the state of the time c is divided and shown just before earth release and right after earth release.
  • the loading platform 101 Before unloading (time a), the loading platform 101 is seated on the frame 102 in a loading state.
  • the hoist cylinder 103 At the initial unloading stage (time b), the hoist cylinder 103 is extended and the loading platform 101 rotates about the hinge pin 104, and the seating state is gradually shifted to the standing state.
  • the load 201 slips off from the loading platform 101 (time c: immediately after releasing the soil).
  • the loading platform 101 is rotated until the maximum inclination angle is reached (time d).
  • the hoist cylinder 103 is contracted, the loading platform 101 gradually returns from the standing posture to the sitting posture, and finally comes into the sitting state (time e).
  • the stress waveform at the evaluation position before the load at time a to time c starts to drop can be regarded as stress calculation of the load state, it can be calculated by interpolation or extrapolation of the stress data shown above.
  • the stress waveform at the evaluation position from the point of time c when the load is exhausted to the point of time e can also be regarded as an empty load stress, it can be calculated by the method described above.
  • an impact load may occur when a load falls, it is difficult to approximate an actual stress waveform only by interpolation or extrapolation of stress data as in the case of loading. Therefore, here too, the impact coefficient (second impact coefficient) for calculating the stress generated when the load drops from the loading platform 101 is used.
  • the relationship between the acceleration waveform by the acceleration sensor 110 at the time of loading and the impact coefficient at the evaluation position is obtained in advance, and the impact coefficient is stored in the storage device 32.
  • the stress at the time of unloading is calculated by multiplying the said impact coefficient by the stress difference at the time of loading and the empty load at the bed inclination angle of time c.
  • FIG. 12 is a schematic diagram showing one cycle of work (loading, loading travel, unloading and empty travel) by the dump truck
  • FIG. 13 is a stress waveform at the evaluation position when one cycle of work is performed
  • the dump truck repeats the operation of (1) loading ⁇ (2) loading travel ⁇ (3) unloading ⁇ (4) empty loading ⁇ (1) loading ... but during each operation
  • the stress at the evaluation position can be determined by the method described above. This makes it possible to extract a stress waveform corresponding to a work of one cycle from the stress waveform of the evaluation position acquired during the work.
  • maximum stress value, minimum stress value, maximum stress amplitude and damage amount in one cycle can be calculated, stored and managed.
  • the amount of damage in the above can be calculated, for example, using a known method such as stress frequency analysis by rain flow method and cumulative damage rule by minor rule.
  • the arithmetic processing unit 31 calculates at least one of the maximum stress value, the minimum stress value, the stress amplitude and the damage amount at the evaluation position based on the time-series stress waveform obtained by the above method, and further, It is determined whether at least one of the calculated values exceeds a threshold.
  • the display unit 33 displays that effect.
  • the threshold values used here are set to the maximum stress value, the minimum stress value, the stress amplitude and the damage amount, respectively.
  • FIG. 14 is a line graph showing transition of the amount of damage for each cycle of work by the dump truck.
  • Fig. 15 shows the average of the damage amount of the last 5 cycles by the worker currently on board the dump truck, the average value of the damage amount of 1 cycle of other workers, and the work of the transition of the damage amount per cycle It is the figure which showed the average value of the amount of damage for 1 whole of a person by a bar graph.
  • the threshold value of the amount of damage is indicated by an alternate long and short dashed line, and the target value of the amount of damage is indicated by a dotted line.
  • the threshold of the amount of damage for example, there are a threshold for notifying that a bad road exists in the traveling route of the dump truck, and a threshold for notifying an indication of the arrival of a maintenance time.
  • the former threshold is a threshold for the amount of damage for one cycle
  • the latter is a threshold for the cumulative amount of damage from the start of use of the dump truck.
  • the threshold shown in FIG. 14 is the former one.
  • the target value of the amount of damage relates to the operation target and skill evaluation of the worker who is on board, for example, the average value of the amount of damage by a worker having an exemplary skill and the amount of damage for all workers. The average value of is available.
  • the graphs shown in FIGS. 14 and 15 may be displayed on the display device 33, for example, as shown in FIG.
  • the arithmetic processing unit 31 warns the worker. In order to evoke, a process of displaying on the display device 33 that the amount of damage exceeds the target value is executed. In the example shown in FIGS. 14 and 15, since the amount of damage caused by the operator while riding the dump truck exceeds the target value, a warning display 35 (see FIG. 16) that the amount of damage exceeds the target value Is displayed on the display device 33.
  • the arithmetic processing unit 31 It is determined that the road surface condition is deteriorated, and a process of displaying on the display device 33 that a bad road has occurred in the dump truck's passage or that the road surface needs to be repaired is executed. At this time, a portion estimated to be a rough road may be specified from the stress waveform, and the estimated portion may be displayed on the display device 33. In FIGS. 14 and 15, since the damage amount exceeds the threshold in the cycles denoted by 3 and 4 in the drawings, at this time, it is displayed on the display device 33 that a rough road is generated.
  • the arithmetic processing unit 31 executes a process of displaying on the display device 33 that maintenance time has arrived. At this time, a portion requiring maintenance based on the evaluation position may be displayed together with the effect of the maintenance time.
  • reported that the target value and threshold value exceeded was displayed on the display apparatus 33 in the above, was demonstrated, you may alert
  • a series of work cycles including unloading, taking into account vehicle body vibration, loading platform inclination, road surface inclination, loading condition (loading ⁇ loading travel ⁇ unloading ⁇ empty load traveling) It becomes possible to estimate the stress waveform of the middle vehicle body evaluation part with high accuracy. As a result, it is possible to calculate the amount of damage with higher accuracy for each work cycle, and it becomes possible to more accurately compare the operator's driving quality and grasp the rough road surface occurrence situation. Furthermore, based on the accumulated value of the damage amount of the dump truck, it is possible to more accurately notify the remaining life, maintenance time and place of the part etc.
  • 21 front wheel, 22: rear wheel, 23: suspension cylinder (front), 24: suspension cylinder (rear), 31: arithmetic processing unit (computing means), 32: storage unit (storage means), 33: display unit (notification Means: 43, 44: cylinder pressure sensor, 101: cargo bed, 102: frame, 103: hoist cylinder, 104: hinge pin, 110: acceleration sensor, 111: road surface inclination sensor, 112: cargo bed inclination sensor, 201: load

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  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

A stress computation system for a dump truck is provided with: a storage device (32) for storing data on stress created at vehicle evaluation positions on the dump truck when a plurality of external forces are respectively applied to the dump truck; an acceleration sensor (110) for detecting the direction and the magnitude of the external forces applied to the dump truck; and a computation processing unit (31) for estimating the time change in the stress created at the vehicle evaluation positions by using interpolation and extrapolation based on the value detected by the acceleration sensor and the stress data stored in the storage unit. Thereby, the time change in the stress created at prescribed positions (evaluation positions) can be calculated with a high degree of accuracy.

Description

ダンプトラックの応力演算システムDump truck stress calculation system
　本発明は、ダンプトラックの所定位置における応力の時間変化を算出するための応力演算システムに関する。 The present invention relates to a stress calculation system for calculating a temporal change of stress at a predetermined position of a dump truck.
　運搬対象物を運搬するダンプトラックに関する技術としては、ダンプトラックにおける所定位置（車両評価位置）に生じる応力の時間変化（例えば、応力波形の時間変化）を算出し、当該応力の時間変化に基づいてダンプトラック及びその構成部品の寿命予測等を含む強度評価を行うものがある。 As a technique related to the dump truck for transporting the object to be transported, the temporal change (for example, the temporal change of the stress waveform) of the stress generated at the predetermined position (vehicle evaluation position) in the dump truck is calculated, and based on the temporal change of the stress. There are some which perform strength evaluation including life prediction of a dump truck and its component parts.
　この種の技術として、特開平２－１３８８０９号公報には、ダンプトラックの油圧サスペンションシリンダに取り付けた圧力センサ又はフレームに取り付けた加速度センサによってサンプリングしたサスペンション力又は加速度を周波数領域データに変換し、予めメモリに書き込んでおいた伝達関数（サスペンション力または加速度と車両評価位置の応力との間の周波数領域での伝達関数）を当該周波数領域データに掛け合わせることにより周波数領域の車両評価位置の応力を求め、当該応力から車両評価位置の応力の時間領域データ（時間変化）を求めるものが記載されている。 As this type of technology, in JP-A-2-138809, suspension force or acceleration sampled by a pressure sensor attached to a hydraulic suspension cylinder of a dump truck or an acceleration sensor attached to a frame is converted into frequency domain data, and The stress of the vehicle evaluation position in the frequency domain is determined by multiplying the frequency domain data by the transfer function (transfer function in the frequency domain between the suspension force or acceleration and the stress of the vehicle evaluation position) written in the memory. It is described that time domain data (time change) of stress at a vehicle evaluation position is obtained from the stress.
特開平２－１３８８０９号公報JP-A-2-138809
　しかしながら、上記文献の技術のように、センサの周波数領域のサンプリングデータに伝達関数を掛け合わせることで周波数領域の車両評価位置の応力を求め、当該周波数領域のデータを時間領域のものに変換する方法を採用すると、高精度な応力波形（応力の時間変化）を得ることが難しい。つまり、周波数領域から時間領域に波形を変換する場合、変換される時間波形は無数の可能性があり一義には決まらないため、最終的に得られる応力波形の精度は劣ってしまう。 However, as in the technique of the above-mentioned document, the stress of the vehicle evaluation position in the frequency domain is determined by multiplying the sampling data in the frequency domain of the sensor by the transfer function, and the data in the frequency domain is converted to that in the time domain. It is difficult to obtain a highly accurate stress waveform (temporal change of stress). That is, when converting the waveform from the frequency domain to the time domain, the time waveform to be converted is innumerable and not unambiguous, so the accuracy of the finally obtained stress waveform is inferior.
　また、ダンプトラックの特徴的な動作に荷下ろしがあるが、サスペンション力データまたは加速度データだけでは、動作中の荷台位置を正確に把握できないため、ダンプトラックにおける一連の作業サイクル（例えば、積み込み→積荷走行→荷下ろし→空荷走行→積み込み）全体を鑑みた損傷量を計算することは困難である。つまり、サスペンション力（圧力センサ）に基づいて応力波形を得る場合には、サスペンション力を算出するシリンダ圧力変動にシリンダの摩擦抵抗やオイル粘性の誤差因子が入ってしまい、路面傾斜や車体振動を高精度に測定することは困難である。一方、加速度（加速度センサ）に基づいて応力波形を得る場合には、車体振動を高精度に測定可能であるが、積荷のバランスを考慮することは困難である。さらに、積み込み及び荷下ろし時には荷台に衝撃荷重が作用するため、サスペンション力データ及び加速度データだけでは応力を高精度に算出できない。 In addition, although there is unloading as a characteristic operation of the dump truck, a series of work cycles in the dump truck (for example, loading → loading) because the suspension force data or acceleration data alone can not accurately identify the position of the loading platform in operation. It is difficult to calculate the amount of damage in light of the whole: driving → unloading → unloading → loading. That is, when obtaining a stress waveform based on the suspension force (pressure sensor), the cylinder pressure fluctuation for calculating the suspension force includes an error factor of the friction resistance of the cylinder and the oil viscosity, and the road surface inclination and the vehicle vibration are high. It is difficult to measure with accuracy. On the other hand, when obtaining a stress waveform based on acceleration (acceleration sensor), it is possible to measure vehicle body vibration with high accuracy, but it is difficult to consider the balance of the load. Furthermore, since an impact load acts on the loading platform at the time of loading and unloading, stress can not be calculated with high accuracy using only suspension force data and acceleration data.
　本発明の目的は、所定位置（車両評価位置）で生じる応力の時間変化を高精度に算出できるダンプトラックの応力演算システムを提供することにある。 An object of the present invention is to provide a dump truck stress calculation system capable of calculating with high accuracy the time change of stress occurring at a predetermined position (vehicle evaluation position).
　上記課題を解決するために、例えば特許請求の範囲に記載の構成を採用する。本願は上記課題を解決する手段を複数含んでいるが、その一例を挙げるならば、複数の外力がそれぞれダンプトラックに作用したときに当該ダンプトラックの所定位置に生じる応力のデータが記憶された記憶手段と、前記ダンプトラックに作用する外力の方向及び大きさを検出するための検出手段と、前記検出手段による検出値及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって前記所定位置に生じる応力の時間変化を推定する演算手段とを備えるものとする。 In order to solve the above problems, for example, the configuration described in the claims is adopted. Although the present application includes a plurality of means for solving the above-mentioned problems, for example, storage of data of stress generated at a predetermined position of the dump truck when a plurality of external forces respectively act on the dump truck is mentioned. Means, detection means for detecting the direction and magnitude of external force acting on the dump truck, interpolation or extrapolation based on detected values by the detection means and stress data stored in the storage means And computing means for estimating temporal changes in stress occurring at the position.
　本発明によれば、車両評価位置の応力の時間変化を算出する際に周波数領域から時間領域に変換する工程が含まれないので、車両評価位置における応力の時間変化を高精度に算出できる。 According to the present invention, since the process of converting the frequency domain into the time domain is not included when calculating the time change of the stress of the vehicle evaluation position, the time change of the stress at the vehicle evaluation position can be calculated with high accuracy.
本発明の実施の形態に係るダンプトラックの構成図。BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the dump truck which concerns on embodiment of this invention. 本発明の実施の形態に係るダンプトラックの荷台１０１周辺の構成図。BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the carrying platform 101 periphery of the dump truck which concerns on embodiment of this invention. 本発明の実施の形態に係るダンプトラックの応力演算システムの概略構成図。BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the stress calculation system of the dump truck which concerns on embodiment of this invention. ダンプトラックの積荷形状の一例を示す図。The figure which shows an example of the load shape of a dump truck. ダンプトラックの荷台１０１の上方図。The upper view of the loading platform 101 of a dump truck. 単位重力加速度（a1g）が負荷された時の車両評価位置の応力テーブルの一例を示す図。The figure which shows an example of the stress table of a vehicle evaluation position when unit gravity acceleration ( a1g ) is loaded. 加速度センサ１１０により検出された作業中の車両の加速度の時間波形の一例を示す図。FIG. 6 is a view showing an example of a time waveform of acceleration of the vehicle under work detected by the acceleration sensor 110. ダンプトラックが傾斜した路面を走行するときの模式図。The schematic diagram when driving | running | working the road surface which the dump truck inclined. 積み込み作業時における車両評価位置での応力波形の一例を示す図。The figure which shows an example of the stress waveform in the vehicle evaluation position at the time of loading operation. 荷下ろし時の動作例を示す模式図。The schematic diagram which shows the operation example at the time of unloading. 荷下ろし時の車両評価位置の応力波形の一例を示す図。The figure which shows an example of the stress waveform of the vehicle evaluation position at the time of unloading. ダンプトラックによる１サイクル分の作業を示した模式図。The schematic diagram which showed the operation | work for 1 cycle by a dump truck. １サイクル分の作業を行ったときの車両評価位置における応力波形の一例を示す図。The figure which shows an example of the stress waveform in a vehicle evaluation position when the work for 1 cycle is performed. ダンプトラックによる作業の１サイクルごとの損傷量の推移を折れ線グラフで示した図。A line graph showing the transition of the amount of damage for each cycle of work by the dump truck. １サイクルごとの損傷量の推移について、現在ダンプトラックに搭乗中の作業者による直近の５サイクル分の損傷量と、他の作業者の１サイクル分の損傷量の平均値と、作業者全体の１サイクル分の損傷量の平均値とを棒グラフで示した図。Regarding the transition of the amount of damage per cycle, the amount of damage for the last 5 cycles by the worker currently boarding the dump truck, the average value of the amounts of damage for other workers in 1 cycle, and the entire worker The figure which showed with the bar graph the average value of the amount of damage for 1 cycle. 本発明の実施の形態に係る表示装置３３における表示の一例を示す図。The figure which shows an example of the display in the display apparatus 33 which concerns on embodiment of this invention.
　以下、本発明に係る実施の形態について図面を用いて説明する。図１は本発明の実施の形態に係るダンプトラックの構成図であり、図２はその荷台１０１周辺の構成図である。図１に示したダンプトラックは、フレーム１０２と、このフレーム１０２の前部の左右両端に回転可能に一輪ずつ取り付けられた前輪２１と、フレーム１０２の後部の左右両端に回転可能に二輪ずつ設けられた一対の後輪２２と、フレーム１０２にヒンジピン１０４を介して回転可能（起伏可能）に取り付けられ、土砂や砕石等の積荷を積載するための荷台１０１を備えている。 Hereinafter, embodiments according to the present invention will be described using the drawings. FIG. 1 is a block diagram of a dump truck according to an embodiment of the present invention, and FIG. 2 is a block diagram of a periphery of a loading platform 101 thereof. The dump truck shown in FIG. 1 is provided with a frame 102, front wheels 21 rotatably attached at one end to the left and right ends of the front of the frame 102, and two wheels rotatably attached to the left and right ends at the rear of the frame 102. A pair of rear wheels 22 and a loading platform 101 mounted on the frame 102 via a hinge pin 104 so as to be rotatable (reversible) via a hinge pin 104 and for loading a load such as earth and sand or crushed stone are provided.
　フレーム１０２におけるヒンジピン１０４の前方には、フレーム１０２と荷台１０１に連結されたホイストシリンダ１０３が取り付けられている。ホイストシリンダ１０３が伸長するとフレーム１０２上で荷台１０１が起き上がり（起立状態）、ホイストシリンダ１０３が縮短するとフレーム１０２上に荷台が倒れる（倒伏状態）ように構成されている。 At the front of the hinge pin 104 in the frame 102, a hoist cylinder 103 connected to the frame 102 and the loading platform 101 is attached. When the hoist cylinder 103 extends, the loading platform 101 rises on the frame 102 (stand-up state), and when the hoist cylinder 103 contracts, the loading platform falls on the frame 102 (falling state).
　従って、ダンプトラックは、倒伏状態において荷台１０１に積載された土砂や砕石等の積荷を運搬した後、荷台１０１を倒伏状態から起立状態へ移行させることにより、荷台１０１を傾斜させて積荷を降ろしている。この際、荷台１０１の傾斜角度は、車体に取り付けられた荷台傾斜センサ（荷台角度検出手段）１１２で測定・監視している。なお、荷台１０１の下部には、図２に示すように荷台１０１が倒伏する際にフレーム１０２から受ける衝撃を和らげる緩衝部材、パッド１０５が設けられている。 Therefore, the dump truck transports a load such as earth and sand, crushed stone, etc. loaded on the loading platform 101 in the fallen state, then makes the loading platform 101 inclined and lowers the load by transferring the loading platform 101 from the laid down condition to the upright condition. There is. At this time, the tilt angle of the loading platform 101 is measured and monitored by a loading platform tilt sensor (loading platform angle detection means) 112 attached to the vehicle body. In the lower part of the loading platform 101, as shown in FIG. 2, a cushioning member and a pad 105 are provided which cushion the impact received from the frame 102 when the loading platform 101 falls down.
　また、ダンプトラックには、走行中の振動軽減のために、左右対称に前後各２本ずつのサスペンションシリンダ２３、２４が搭載されている。このサスペンションシリンダ２３、２４には、シリンダ圧力センサ４３,４４（図３参照）が設けられている。当該シリンダ圧力センサ４３，４４で検出されるシリンダ圧力により、積荷重量及び積荷重心位置の見積もり、積載量の監視、過積載の防止を行うことができる。すなわち、シリンダ圧力センサ４３，４４は、積荷の重量検出手段と重心位置検出手段として機能している。 In addition, two suspension cylinders 23 and 24 are mounted on the dump truck so as to be symmetrical in the left-right direction in order to reduce vibration during traveling. The suspension cylinders 23, 24 are provided with cylinder pressure sensors 43, 44 (see FIG. 3). By means of the cylinder pressure detected by the cylinder pressure sensors 43 and 44, it is possible to estimate the load amount and the load load center position, to monitor the load amount, and to prevent the overload. That is, the cylinder pressure sensors 43 and 44 function as load weight detection means and gravity center position detection means.
　さらに、本実施の形態に係るダンプトラックは、作業中の車両振動を計測するための加速度センサ（加速度検出手段）１１０と、ダンプトラックが走行する地面の傾斜角を計測するための路面傾斜センサ（路面角度検出手段）１１１とを、それぞれ少なくとも１つ装備している。 Furthermore, the dump truck according to the present embodiment includes an acceleration sensor (acceleration detecting means) 110 for measuring the vibration of the vehicle during work, and a road surface inclination sensor (for measuring the inclination angle of the ground on which the dump truck travels) At least one road surface angle detecting means) 111 is provided.
　図３は本発明の実施の形態に係るダンプトラックの応力演算システムの概略構成図である。この図に応力演算システムは、各種プログラムを実行するための演算手段としての演算処理装置（例えば、ＣＰＵ）３１と、当該プログラムをはじめ各種データを記憶するための記憶手段としての記憶装置（例えば、ＲＯＭ、ＲＡＭおよびフラッシュメモリ等の半導体メモリや、ハードディスクドライブ等の磁気記憶装置）３２と、演算処理装置３１の処理結果等を表示するための表示装置（例えば、液晶モニタ等）３３を備えている。 FIG. 3 is a schematic configuration diagram of a dump truck stress calculation system according to the embodiment of the present invention. In this figure, the stress calculation system includes an arithmetic processing unit (for example, a CPU) 31 as calculation means for executing various programs, and a storage device (for example, a storage means for storing various data including the program). A semiconductor memory such as a ROM, a RAM, and a flash memory, a magnetic storage device such as a hard disk drive 32, and a display device (for example, a liquid crystal monitor) 33 for displaying processing results of the arithmetic processing unit 31. .
　なお、ここでは、演算処理装置３１と、記憶装置３２と、表示装置３３は、図１に示したダンプトラックに搭載されているものとして説明するが、これら装置３１，３２，３３は、複数のダンプトラックの運行管理を行うための管理センタ内の電子計算機に搭載し、各ダンプトラックのセンサからの出力に基づいて演算処理装置３１によって各種処理を実行するように構成しても良いし、一部をダンプトラックに搭載しつつ、残りを管理センタ内の電子計算機に搭載しても良い。すなわち、各装置３１，３２，３３の設置場所は特に限定されない。 Here, although the arithmetic processing unit 31, the storage unit 32, and the display unit 33 are described as being mounted on the dump truck shown in FIG. 1, these units 31, 32, and 33 are not limited to a plurality of units. It may be mounted on an electronic computer in a control center for managing the operation of dump trucks, and the arithmetic processing unit 31 may execute various processing based on the output from the sensor of each dump truck. The rest may be mounted on the computer in the management center while the unit is mounted on the dump truck. That is, the installation places of the devices 31, 32, and 33 are not particularly limited.
　記憶装置３２には、方向の異なる複数の外力（例えば、ダンプトラックの動作に伴う振動や、積荷荷重）がダンプトラックにそれぞれ作用したときに当該ダンプトラックの所定位置（以下、「車両評価位置」又は単に「評価位置」と称することがある）に生じる応力のデータ（応力データ）が記憶されている。詳細は後述するが、本実施の形態の記憶装置３２には、車両の前後方向、左右方向、上下方向の３方向（３軸方向）のそれぞれに単位重力加速度（a1g）の荷重が作用したときに車両評価位置に生じる応力が応力データとして記憶されている。さらに、当該応力データは、積荷荷重の大きさ、積荷の重心位置、荷台１０１の傾斜角の大きさ及び車両の走行路面の傾斜角の大きさのうちいずれかが異なる場合について、それぞれの場合ごとに記憶されている。すなわち、これらをパラメータとして持つ上記３軸方向に係る応力が記憶装置３２に複数記憶されている。応力データは、実機での応力測定結果または解析に基づいて作成されたものであり、予め記憶装置３２に記憶しておくものとする。 In the storage device 32, when a plurality of external forces in different directions (for example, vibrations due to the operation of the dump truck, load load) respectively act on the dump truck, predetermined positions of the dump truck (hereinafter, "vehicle evaluation position") Or, data (stress data) of stress occurring in “the evaluation position” may be stored. Although details will be described later, in the storage device 32 of the present embodiment, a load of unit gravitational acceleration (a 1g ) was applied to each of three directions (three axial directions) in the front and rear direction, left and right direction, and vertical direction of the vehicle. Stresses that sometimes occur at the vehicle evaluation position are stored as stress data. Furthermore, the stress data is different for each case where the load load size, the barycentric position of the load, the size of the tilt angle of the load bed 101, and the size of the tilt angle of the traveling road surface of the vehicle are different. Is stored in That is, a plurality of stresses in the above three axial directions having these as parameters are stored in the storage device 32. The stress data is created based on stress measurement results or analysis in an actual machine, and is stored in advance in the storage device 32.
　演算処理装置３１には、荷台傾斜センサ１１２、シリンダ圧力センサ４３，４４、加速度センサ１１０及び路面傾斜センサ１１１からの出力値（検出値）が入力されている。演算処理装置３１は、これら各種センサ４３，４４,１１０，１１１，１１２の検出値の少なくとも１つと記憶装置３２に記憶された応力データとに基づく内挿又は外挿によって、車両評価位置に生じる応力の時間変化（時系列応力波形）を推定する処理を実行する（処理内容の詳細は後述）。 The arithmetic processing unit 31 receives output values (detection values) from the bed inclination sensor 112, the cylinder pressure sensors 43 and 44, the acceleration sensor 110, and the road surface inclination sensor 111. The arithmetic processing unit 31 generates stress at the vehicle evaluation position by interpolation or extrapolation based on at least one of the detection values of the various sensors 43, 44, 110, 111, 112 and the stress data stored in the storage unit 32. The process of estimating the time change (time-series stress waveform) of the image is executed (details of the process content will be described later).
　表示装置３３には、演算処理装置３１が算出した車両評価位置の応力の時間変化（時系列応力波形）及びこれに基づいて得られる種々の情報が表示される。この種の情報としては、例えば、評価位置の時系列応力波形と、当該応力波形における最大応力値、最小応力値および応力振幅と、評価位置の損傷量と、作業者毎のこれらの統計値と、評価位置の損傷量の累積値と、応力に関する閾値及び目標値と、運転操作の良し悪しと、路面状況（悪路が発生しているか否か）と、メンテナンス時期及び箇所がある（詳細は後述）。表示装置３３の設置先は前述のように特に限定されないが、ダンプトラックや管理センタの他にも、例えば、ダンプトラックに積荷を積み込む際に用いられる積み込み機械（例えば、油圧ショベルやホイールローダ）や、ダンプトラックが走行する路面の補修機械等に設置しても良い。以下、本実施の形態に係るシステムで行われる応力演算処理の詳細について説明する。 The display device 33 displays the time change (time-series stress waveform) of the stress of the vehicle evaluation position calculated by the arithmetic processing unit 31 and various information obtained based on this. This type of information includes, for example, the time-series stress waveform at the evaluation position, the maximum stress value, the minimum stress value and the stress amplitude in the stress waveform, the damage amount at the evaluation position, and these statistical values for each worker. Accumulated damage amount at evaluation position, threshold value and target value for stress, good or bad driving operation, road surface condition (whether bad road is generated or not), maintenance time and location (details are described Later). Although the installation destination of the display device 33 is not particularly limited as described above, in addition to the dump truck and the management center, for example, a loading machine (for example, hydraulic shovel or wheel loader) used when loading a load on the dump truck , It may be installed on a repair machine of the road surface where the dump truck travels. Hereinafter, details of stress calculation processing performed in the system according to the present embodiment will be described.
　まず、形状に応じた積荷の重心位置の変化について説明する。図４はダンプトラックの積荷形状の一例を示す図である。図４（a）は積載物２０１が荷台１０１に理想的な状態で積載されている状態（積荷重心位置が後述する図５中の５にあるとき）を示す図であり、図４（ｂ）は積載物２０１が荷台１０１に前方及び左方に偏って積載されている状態（積荷重心位置が図５中の１にあるとき）を示す図である。なお、各図において、側面図を左に、ダンプトラックの正面に平行な面での断面図を右に示す。実際の積み込みでは、積荷形状を（a）の理想的な状態になるように目指すが、積み込み現場の地形、積み込み機械と運搬機械のミスマッチング、積み込み作業者の能力等を要因として、例えば図４（b）で示すように積荷の前後、左右のバランスが理想的な位置からずれてしまうことがある。 First, the change in the center of gravity of the load according to the shape will be described. FIG. 4 is a view showing an example of the load shape of the dump truck. FIG. 4 (a) is a view showing a state in which the load 201 is loaded on the loading platform 101 in an ideal state (when the loading center position is at 5 in FIG. 5 described later), FIG. 4 (b) FIG. 6 is a view showing a state where the load 201 is loaded on the loading platform 101 while being biased forward and left (when the loading center position is at 1 in FIG. 5). In each of the drawings, a side view is shown on the left, and a cross-sectional view in a plane parallel to the front of the dump truck is shown on the right. In actual loading, the goal is to make the loading shape the ideal condition of (a), but due to the topography of the loading site, mismatching of the loading machine and the transporting machine, the loading operator's ability, etc. As shown in (b), the balance of the load before and after, left and right may deviate from the ideal position.
　図５にダンプトラックの荷台１０１の上方図を示す。図中の１～９の黒丸印は積荷形状を変化させた場合の積荷の重心位置を示す。例えば、図４で示した（a）の状態は位置５に対応し、（b）の状態は位置１に対応している。また、実際の積荷の重心位置を重心マーク１１で示す。 FIG. 5 shows a top view of the loading platform 101 of the dump truck. The black dots 1 to 9 in the figure indicate the barycentric position of the load when the load shape is changed. For example, the state of (a) shown in FIG. 4 corresponds to the position 5, and the state of (b) corresponds to the position 1. Further, the gravity center position of the actual load is indicated by the gravity center mark 11.
　次に記憶装置３２に記憶された応力データについて説明する。ここでは複数の応力データをテーブルの形式でまとめたもの（応力テーブル）を例示して説明する。図６は単位重力加速度（a1g）が負荷された時の車両評価位置の応力テーブルの一例を示す図である。この図に示した応力テーブルは、荷台１０１がフレーム１０２に着座しているとき（荷台傾斜角：ゼロ）のものであり、さらに、車両が平坦路面上にある場合（路面傾斜角：ゼロ）を想定する。 Next, stress data stored in the storage device 32 will be described. Here, a plurality of stress data is summarized in the form of a table (stress table) as an example. FIG. 6 is a view showing an example of a stress table of a vehicle evaluation position when unit gravity acceleration (a 1g ) is loaded. The stress table shown in this figure is the one when the loading platform 101 is seated on the frame 102 (loading platform inclination angle: zero), and further, the case where the vehicle is on a flat road surface (road surface inclination angle: zero) Suppose.
　この図において、空荷の荷台１０１による応力σ０前、σ０下、σ0右は、空荷時の車両の前後方向における前方向、上下方向における下方向、左右方向における右方向のそれぞれに単位重力加速度（a1g）が負荷された場合に車両評価位置で生じる応力を示す。車両評価位置としては、例えば、強度的に弱い箇所や応力変動の激しい箇所などが選択されることがある。 In this figure, before stress σ 0 , σ 0 0 and σ 0 right by the empty bed of the load, in the front direction in the front-rear direction of the vehicle when empty, downward in the vertical direction, and right in the left and right The stress which arises in a vehicle evaluation position when unit gravity acceleration ( a1g ) is loaded is shown. As the vehicle evaluation position, for example, a location weak in strength, a location with severe stress variation, etc. may be selected.
　一方、荷台１０１の積荷による応力σｋ前、σｋ下、σk右（k＝１～９）は、積荷重心位置が図５に示した位置１～９のそれぞれのときについて、定格最大積載量（Wmax）の積載物２０１を積んだ車両における前方向、下方向、右方向のそれぞれに単位重力加速度（a1g）が負荷された場合に、積載物２０１が荷台１０１の内壁面に負荷する圧力によって生じる車両の評価位置の応力を示す。なお、積荷の応力σｋ前、σｋ下、σk右（k＝１～９）における添字の数字は、図５の重心位置１～９に対応している。例えば、σ1前は、位置１に重心があるときの積荷による応力（定格最大積載量）を示す。 On the other hand, the stress σ k before , σ k and σ k right (k = 1 to 9) due to the load of the loading platform 101 is the rated maximum load for each of the load bearing positions 1 to 9 shown in FIG. The load 201 is loaded on the inner wall surface of the loading platform 101 when the unit gravitational acceleration (a 1g ) is loaded in the forward direction, the lower direction, and the right direction in the vehicle loaded with the load 201 of the amount (Wmax). The stress of the evaluation position of the vehicle which arises by pressure is shown. The numbers of the subscripts before the load stress σ k , under σ k and at σ k right (k = 1 to 9) correspond to the barycentric positions 1 to 9 in FIG. For example, before σ1, the stress (rated maximum load capacity) by the load when the center of gravity is at position 1 is shown.
　なお、ここでは、荷台１０１がフレーム１０２に着座した場合（荷台傾斜角：ゼロ）の応力テーブルのみを示したが、荷台１０１がフレーム１０２から起立した数種類の荷台角度（例えば、１０度ごと）に係る応力テーブルが記憶装置３２に記憶されているものとする。 Here, only the stress table is shown when the loading platform 101 is seated on the frame 102 (loading platform inclination angle: zero), but several types of loading platform angles (for example, every 10 degrees) at which the loading platform 101 stands up from the frame 102 It is assumed that such a stress table is stored in the storage device 32.
　本発明では、このように予め求めておいた数種類の応力テーブルの応力値を内挿・外挿することで、センサ４３，４４,１１０，１１１，１１２から計測される荷台傾斜角度、積荷重心位置、積荷重量、車体振動（加速度）、路面傾斜に応じて評価部位の応力の時間変化を算出することを特徴とする。 In the present invention, by loading and extrapolating the stress values of several types of stress tables obtained in advance in this manner, the bed inclination angle measured from the sensors 43, 44, 110, 111 and 112, and the load center position. It is characterized in that the time change of the stress of the evaluation part is calculated according to the load amount, the vehicle vibration (acceleration) and the road surface inclination.
　次に、図３を利用して、ダンプトラック実働時の具体的な評価部応力の算出手順について説明する。図３に示した演算制御装置３１は、荷台傾斜角度及び積荷重心位置に基づいて応力を補正するための１次補正部３１ａと、積荷重量に基づいて応力を補正するための２次補正部３１ｂと、加速度に基づいて応力を補正する３次補正部３１ｃと、路面傾斜角度に基づいて応力を補正する４次補正部３１ｄを備えている。先述のように、記憶装置３２には車両評価位置の応力データが予め保存されている。 Next, with reference to FIG. 3, a concrete calculation procedure of the evaluation unit stress at the time of dump truck operation will be described. The arithmetic and control unit 31 shown in FIG. 3 has a primary correction unit 31a for correcting stress based on the bed inclination angle and the load bearing center position, and a secondary correction unit 31b for correcting stress based on the product load amount. The third correction unit 31 c corrects the stress based on the acceleration, and the fourth correction unit 31 d corrects the stress based on the road surface inclination angle. As described above, the storage device 32 stores the stress data of the vehicle evaluation position in advance.
　演算制御装置３１は、１次補正部３１ａにおいて、荷台傾斜センサ１１２から測定される荷台傾斜角度と、シリンダ圧力センサ４３，４４から計算される現状の積荷重心位置と、記憶装置３２に記憶された数点の応力データとに基づく内挿又は外挿により1次補正応力を算出する処理を実行する。 The arithmetic and control unit 31 stores in the storage unit 32 the bed inclination angle measured from the bed inclination sensor 112, the current product load core position calculated from the cylinder pressure sensors 43 and 44, and the storage unit 32 in the primary correction unit 31a. A process of calculating primary correction stress is executed by interpolation or extrapolation based on stress data of several points.
　まず、積荷重心位置と応力データに基づく応力補正の具体例を示す。図５に示すように、シリンダ圧力センサ４３，４４の検出値から算出される積荷の実際の重心位置１１が、理想的な重心位置５から左にzg、前にxgずれているとする。この場合には、積荷による応力を、実際の重心位置１１に近接する複数の重心位置（具体的には図５における位置１，２，４，５）の応力データの内挿近似により求める。ここでは、図５中に示したように、位置１，４の左右方向における位置が位置５から左にzoだけずれており、位置１，２の前後方向における位置が位置５から前にxoだけずれているとする。 First, a concrete example of stress correction based on the load bearing position and stress data will be shown. As shown in FIG. 5, it is assumed that the actual center of gravity position 11 of the load calculated from the detection values of the cylinder pressure sensors 43 and 44 deviates from the ideal center of gravity position 5 by zg leftward and xg forward. In this case, stress due to the load is obtained by interpolation approximation of stress data at a plurality of barycentric positions (specifically, positions 1, 2, 4, and 5 in FIG. 5) close to the actual barycentric position 11. Here, as shown in FIG. 5, the position in the left-right direction of positions 1 and 4 is shifted left from position 5 by zo, and the position in the front-rear direction of positions 1 and 2 is only xo forward from position 5 Suppose that it is off.
　このとき、位置５から左方向にzgずれている実際の重心位置１１の応力は、位置１，２及び位置４，５の応力σ1n，σ2n，σ4n，σ5nから、それぞれ次式（１）（２）より求まる。なお、下記式（１）（２）における添え字nには、前、下、右が入り、３軸方向ごとに補正応力を求める。
Figure JPOXMLDOC01-appb-I000001
At this time, the stress at the actual barycentric position 11 shifted by zg leftward from the position 5 is given by the following equations (from the stresses σ 1n , σ 2n , σ 4n and σ 5n at the positions 1, 2 and 4, 5 1) Obtained from (2). In the following expressions (1) and (2), front, bottom, and right are included in subscript n, and a correction stress is obtained for each of three axial directions.
Figure JPOXMLDOC01-appb-I000001
Figure JPOXMLDOC01-appb-I000002
Figure JPOXMLDOC01-appb-I000002
　これら式（１）（２）から求まる応力より、さらに重心位置５から前方向にxgずれている位置１１の応力を内挿により求めると、実際の積荷重心位置での積荷分の応力を次式（３）のように見積もることができる。
Figure JPOXMLDOC01-appb-I000003
If the stress at position 11 where xg deviates from the center of gravity position 5 in the forward direction from the stress obtained from these equations (1) and (2) is determined by interpolation, the stress of the load at the actual load center position is It can be estimated as (3).
Figure JPOXMLDOC01-appb-I000003
　なお、ここでは、実際の重心位置１１の応力を位置１，２，４，５の応力データの内挿近似より求めたが、実際の重心位置１１が応力テーブルで用意した重心位置の範囲（図５において位置１，３，７，９で規定される長方形内の範囲）から外れている場合には外挿近似で求めても良い。なお、以下に説明する２次補正部３１ｂ、３次補正部３１ｃ及び４次補正部３１ｄで行われる演算についても内挿及び外挿のいずれを用いても良い。また、積荷重心位置の補正のために予め用意する応力データの数は、図示した９つに限られず、内挿・外挿できる個数であれば他の数でも良い。 Here, although the stress at the actual barycentric position 11 is obtained by interpolation approximation of the stress data at the positions 1, 2, 4, and 5, the actual barycentric position 11 is the range of the barycentric position prepared by the stress table (see FIG. If the position 5 is out of the rectangular range defined by the positions 1, 3, 7, 9), it may be obtained by extrapolation approximation. Note that either interpolation or extrapolation may be used for the calculations performed by the secondary correction unit 31 b, the tertiary correction unit 31 c, and the quaternary correction unit 31 d described below. Further, the number of stress data prepared in advance for correction of the load bearing center position is not limited to nine as illustrated, but may be any other number as long as it can be interpolated and extrapolated.
　次に、荷台傾斜角度と応力データに基づく応力補正の具体例を示す。荷台傾斜角度に基づく補正をした応力を求める場合には、荷台傾斜センサ１１２で実際の荷台傾斜角度を求め、当該実際の傾斜角度に近い角度の応力テーブルを記憶装置３２から複数抽出し、当該抽出した複数の応力テーブル内の応力データの内挿又は外挿近似により求める。なお、後続の２次補正（式（４）参照）で必要になるため、積荷による応力（積荷分の応力）だけでなく、荷台による応力（空荷分の応力）も内挿又は外挿により同様に求めるものとする。また、荷台傾斜角度と積荷重心位置の両方を考慮する場合は、まず荷台傾斜角度の補正を行うことで実際の荷台傾斜角度の応力テーブルを算出し、当該算出した応力テーブルに基づいて、積荷による応力のみに先述の積荷重心位置に基づく補正を行えば良い。 Next, a concrete example of stress correction based on the bed inclination angle and stress data will be shown. When the stress corrected based on the bed inclination angle is determined, the actual bed inclination angle is determined by the bed inclination sensor 112, a plurality of stress tables having angles close to the actual inclination angle are extracted from the storage device 32, and the extraction is performed. It calculates | requires by interpolation or extrapolation approximation of the stress data in several stress tables. It should be noted that not only the stress due to the load (stress for the load) but also the stress due to the loading platform (stress for the empty load) is also interpolated or extrapolated because it will be required in the subsequent secondary correction (see equation (4)) The same shall apply. Moreover, when considering both the bed inclination angle and the load bearing center position, the stress table of the actual bed inclination angle is first calculated by correcting the bed inclination angle, and the load table is calculated based on the calculated stress table. The correction based on the above-described load center position may be performed only on the stress.
　次に、演算制御装置３１は、２次補正部３１ｂにおいて、シリンダ圧力センサ４３，４４で検出される積荷重量と１次補正応力に基づく内挿又は外挿により２次補正応力を算出する処理を実行する。２次補正応力は空荷分と積荷分の応力を合算したものになる。先述のように、１次補正応力のうち積荷分の応力は、積荷重量を定格最大積載量（Wmax）で計算したものである。そこで、ここでは、シリンダ圧力センサ４３，４４の検出値から計算される実際の積荷重量をwとし、当該積荷重量wを定格最大積載量Wmaxで除した重量係数（w/Wmax）を積荷分の応力に乗じることで補正する。したがって、２次補正応力は次式（４）で示すように、空荷分の応力と、重量係数で補正した積荷分の応力とを足し合わせた応力となる。これにより、２次補正応力は、単位重力加速度（a1g）が負荷時の車両評価位置に生じる応力に荷台傾斜角度、積荷重心位置、積荷重量が考慮されたものとなる。なお、ここで添え字nには、前、下、右が入り、３軸方向ごとに補正応力を求める。
Figure JPOXMLDOC01-appb-I000004
Next, the arithmetic and control unit 31 causes the secondary correction unit 31 b to calculate the secondary correction stress by interpolation or extrapolation based on the product load amount detected by the cylinder pressure sensors 43 and 44 and the primary correction stress. Run. The secondary correction stress is the sum of the stress of the empty load and the load of the load. As described above, the load stress of the primary correction stress is the product load amount calculated by the rated maximum load amount (Wmax). Therefore, here, assuming that the actual product load amount calculated from the detection values of the cylinder pressure sensors 43 and 44 is w, the weight coefficient (w / Wmax) obtained by dividing the product load amount w by the rated maximum load amount Wmax is the load Correct by multiplying by stress. Therefore, as shown by the following equation (4), the secondary correction stress is a stress obtained by adding the stress of the empty load and the stress of the load corrected by the weight coefficient. As a result, the second correction stress takes into consideration the bed inclination angle, the load center position, and the load amount to the stress generated at the vehicle evaluation position when the unit gravitational acceleration (a 1g ) is loaded. Here, the suffix n includes the front, the bottom, and the right, and the correction stress is obtained for each of the three axial directions.
Figure JPOXMLDOC01-appb-I000004
　次に、演算制御装置３１は、３次補正部３１ｃにおいて、加速度センサ１１０で検出される加速度と２次補正応力に基づく内挿又は外挿により、車両動作中に生じる車体振動を考慮した３次補正応力を算出する処理を実行する。 Next, the arithmetic and control unit 31 causes the third-order correction unit 31 c to take into account the vehicle vibration generated during vehicle operation by interpolation or extrapolation based on the acceleration detected by the acceleration sensor 110 and the second-order correction stress. Execute processing to calculate the correction stress.
　図７は加速度センサ１１０により検出された作業中の車両の加速度の時間波形の一例を示す図である。ここでの加速度は相対加速度を考える。すなわち、重力加速度分は考慮せず、停止状態を基準とし作業中の動作振動のみ考慮するものとする。例えば、時刻t1の時の３軸方向における加速度の実測値をそれぞれa前、a下、a右とする（図７参照）。この時刻t1時の３次補正応力は、これらの実測加速度a前、a下、a右を単位重力加速度（a1g）でそれぞれ除した加速度係数（aｎ/a1g）を求め、当該加速度係数をそれぞれの２次補正応力に乗じて足し合わせることで補正する（式（５）参照）。
Figure JPOXMLDOC01-appb-I000005
FIG. 7 is a view showing an example of the time waveform of the acceleration of the vehicle under work detected by the acceleration sensor 110. As shown in FIG. The acceleration here considers relative acceleration. That is, only the motion vibration during the operation is considered with reference to the stop state without considering the gravitational acceleration. For example, each of a pre-measured values of the acceleration in the three axial directions at time t 1, a bottom, and a right (see FIG. 7). 3 supplementary stress o'clock this time t 1, these measured accelerations a front, a bottom, obtains an acceleration coefficient obtained by dividing each a right unit gravity acceleration (a 1g) (a n / a 1g), the acceleration The correction is performed by multiplying the respective secondary correction stresses by the coefficients and adding them together (see equation (5)).
Figure JPOXMLDOC01-appb-I000005
　なお、この３次補正応力は作業中の車体振動成分の応力であり、後述する路面傾斜による慣性加速度の影響を含まない。測定する加速度を絶対加速度にすれば路面傾斜による慣性加速度の影響も同時に評価可能であるが、走行路面状況を把握するには、車体振動と路面傾斜の影響を別に求めた方が好ましい。 The third-order correction stress is a stress of a vehicle vibration component during work, and does not include the influence of inertial acceleration due to the road surface inclination described later. If the acceleration to be measured is absolute acceleration, it is possible to simultaneously evaluate the influence of the inertial acceleration due to the road surface inclination, but in order to grasp the traveling road surface condition, it is preferable to separately obtain the influence of the vehicle vibration and the road surface inclination.
　次に、演算制御装置３１は、４次補正部３１ｄにおいて、路面傾斜センサ１１１で検出される路面傾斜と２次補正応力に基づく内挿又は外挿により、路面傾斜による車体に負荷される慣性加速度（例えば、重力加速度）の影響を考慮した４次補正応力算出する処理を実行する。 Next, the arithmetic and control unit 31 causes the fourth-order correction unit 31 d to apply an inertial acceleration applied to the vehicle body due to the road surface inclination by interpolation or extrapolation based on the road surface inclination detected by the road surface inclination sensor 111 and the second correction stress. A process of calculating fourth-order correction stress in consideration of the influence of (for example, gravitational acceleration) is executed.
　図８にダンプトラックが傾斜した路面を走行するときの模式図を示す。この図に示した場合、平坦路面（応力データ算出時の路面）に対して傾斜角度θ1の上り坂に車両があり、実線矢印で示す慣性加速度（aG）が平坦路面の垂直方向に対して角度θ2で負荷されている。そこで、この慣性加速度が車両評価位置に及ぼす応力（４次補正応力）は次式で示される。
Figure JPOXMLDOC01-appb-I000006
FIG. 8 shows a schematic view when the dump truck travels on a sloped road surface. In the case shown in this figure, the vehicle is on the upward slope of the inclination angle θ 1 with respect to the flat road surface (the road surface at the time of stress data calculation), and the inertial acceleration (a G ) indicated by the solid arrow is in the vertical direction It is loaded at an angle theta 2 Te. Therefore, the stress (fourth order correction stress) that this inertial acceleration exerts on the vehicle evaluation position is expressed by the following equation.
Figure JPOXMLDOC01-appb-I000006
　なお、ここでは、車両の前後方向の路面傾斜のみを考慮したが、左右方向の路面傾斜に対しても、また前後方向と左右方向の路面傾斜が重畳する場合に対しても、同様の手法で４次補正応力を算出可能である。 Here, only the road surface inclination in the front and rear direction of the vehicle is considered, but the same method is applied to the case where the road surface inclination in the front and rear direction and the left and right direction is superimposed on the road surface inclination in the left and right direction. The fourth order correction stress can be calculated.
　そして、演算制御装置３１は、最終的に前述した３次補正応力と４次補正応力を足し合わせることにより、車両実働時の評価位置で生じる応力を算出する（式（７）参照）。
Figure JPOXMLDOC01-appb-I000007
Then, the arithmetic and control unit 31 finally calculates the stress generated at the evaluation position at the time of the actual operation of the vehicle by adding the third correction stress and the fourth correction stress described above (see equation (7)).
Figure JPOXMLDOC01-appb-I000007
　以上より、作業中のある時点の荷台傾斜角度、積荷重心位置、積荷重量、車体振動（加速度）、路面傾斜に対応した評価位置の応力を算出することが可能となる。これにより各センサ４３，４４，１１０，１１１，１１２による検出値の時間変化に基づいて、車両評価位置に生じる応力の時間変化を算出することができる。したがって、本実施の形態によれば、車両評価位置の応力の時間変化を算出する際に周波数領域から時間領域に変換する工程が含まれないので、車両評価位置における応力の時間変化を高精度に算出できる。 From the above, it is possible to calculate the stress at the evaluation position corresponding to the bed inclination angle, the load center position, the load amount, the vehicle body vibration (acceleration), and the road surface inclination at a certain point in operation. Thereby, based on the time change of the detection value by each sensor 43, 44, 110, 111, 112, the time change of the stress which arises in a vehicle evaluation position can be computed. Therefore, according to the present embodiment, the step of converting the frequency domain into the time domain is not included in calculating the time change of the stress at the vehicle evaluation position, so the time change of the stress at the vehicle evaluation position can be made with high accuracy. It can be calculated.
　なお、上記の説明では、最終的に算出される応力の精度を向上させる観点から、加速度、積荷重量、荷台傾斜、路面傾斜及び積荷重心位置を変数として扱い、加速度センサ１１０、シリンダ圧力センサ４３，４４、荷台傾斜センサ１１２及び路面傾斜センサ１１１からの入力値に基づいて１次～４次補正を行うことで車両評価位置における応力の時間変化を算出した。しかし、加速度、積荷重量、荷台傾斜、路面傾斜及び積荷重心位置の少なくとも１つを変数として扱いつつ、残りのものを定数として扱うことで上記補正を簡素化して応力の時間変化を算出しても良い。すなわち、各種センサ１１０、１１１、１１２、４３，４４の検出値のうち少なくとも１つと応力データとに基づく内挿又は外挿によって、車両評価位置の応力の時間変化を算出しても良い。例えば、積荷重量、積荷重心位置、荷台傾斜角度および路面傾斜角度に所定の定数を代入することで、１次補正、２次補正及び４次補正を省略し、加速度センサ１１０の検出値のみに基づいて車両評価位置の応力を算出しても良い（すなわち、３次補正のみを行うことになる）。また、積荷重量、荷台傾斜角度及び路面傾斜角度のうちのいずれか１つをセンサで検出するとともに加速度をセンサ１１０で検出し、残りのものについては所定の定数を代入することで応力を算出しても良い（すなわち、１次補正のうち荷台傾斜角による補正、２次補正及び４次補正のうちのいずれか１つと３次補正のみを行うことになる）。さらに、１次補正における重心位置による補正と、２次補正と、３次補正のみを行っても良い。 In the above description, the acceleration sensor 110, the cylinder pressure sensor 43, and the acceleration pressure are treated as variables from the viewpoint of improving the accuracy of the stress finally calculated. 44. Based on the input values from the loading platform inclination sensor 112 and the road surface inclination sensor 111, the time change of the stress at the vehicle evaluation position was calculated by performing the first to fourth corrections. However, even if at least one of the acceleration, the load amount, the bed inclination, the road slope and the load center position is treated as a variable, the remaining one is treated as a constant to simplify the correction and calculate the time change of stress. good. That is, the time change of the stress of the vehicle evaluation position may be calculated by interpolation or extrapolation based on the stress data and at least one of the detection values of the various sensors 110, 111, 112, 43, 44. For example, the first correction, second correction, and fourth correction are omitted by substituting predetermined constants for the load amount, the load center position, the loading angle, and the road surface inclination angle, and only based on the detection value of the acceleration sensor 110. The stress at the vehicle evaluation position may be calculated (that is, only the third-order correction is performed). In addition, any one of the load amount, the bed inclination angle and the road surface inclination angle is detected by the sensor and the acceleration is detected by the sensor 110, and for the remaining ones, the stress is calculated by substituting a predetermined constant. (Ie, only one of the first correction, the second correction, and the fourth correction and the third correction may be performed). Furthermore, only the correction based on the position of the center of gravity in the first correction, the second correction, and the third correction may be performed.
　また、上記の説明では、車両が平坦路面にあり、積荷重量が定格最大積載量Wmax、負荷加速度が単位重力加速度の場合の応力データを用いたが、他の路面傾斜、積荷荷重及び負荷加速度を利用して作成した応力テーブルを利用しても良いことは言うまでもない。 In the above description, stress data is used when the vehicle is on a flat road surface, the load amount is the rated maximum load amount Wmax, and the load acceleration is unit gravity acceleration, but other road surface slopes, load loads and load accelerations It goes without saying that a stress table created using it may be used.
　ところで、演算処理装置３１を用いて上記のように算出した車両評価位置における応力の時間変化のデータを利用すれば、積み込み、積荷走行、荷下ろし及び空荷走行を１サイクルとするダンプトラックの一連の作業における車両評価位置の時系列応力波形（応力の時間変化）を算出・取得できる。次にその具体例を以下に説明する。 By the way, if the data of the time change of stress at the vehicle evaluation position calculated as above using the arithmetic processing unit 31 is used, a series of dump trucks with loading, loading, unloading and empty running as one cycle. It is possible to calculate and acquire a time-series stress waveform (temporal change of stress) of the vehicle evaluation position in the operation of the above. Next, a specific example will be described below.
　ダンプトラックの積荷走行では、路面の凹凸及び車両の加減速に起因した車体振動、路面傾斜、積荷重心位置の変化により評価位置の応力変動が主に生じる。そのため、前述の１次補正、３次補正及び４次補正を繰り返すことで、積荷走行時における応力波形は算出できる。一方、空荷走行（w＝０）では、２次補正の説明箇所で示した重量係数（w/Wmax）がゼロになって積荷分の応力が省略されるので、空荷分の応力のみで最終的な応力が算出される。すなわち、この場合も応力波形は算出できる。 In load traveling of a dump truck, stress fluctuation at an evaluation position mainly occurs due to changes in vehicle body vibration, road surface inclination, and load center position caused by road surface unevenness and vehicle acceleration / deceleration. Therefore, the stress waveform at the time of load traveling can be calculated by repeating the above-mentioned first correction, third correction and fourth correction. On the other hand, in the case of empty load running (w = 0), the weight coefficient (w / Wmax) shown in the explanation of the second correction becomes zero and the stress of the load is omitted. The final stress is calculated. That is, also in this case, the stress waveform can be calculated.
　ダンプトラックへの積み込み作業では、ショベル等の積み込み機械から数回に分けて積載物２０１が積み込まれることで、空荷状態から積荷状態になる。図９に積み込み作業時における車両評価位置での応力波形の一例を示す。この図に示すように、積み込み作業時は主に積荷重心位置と積荷重量が変化し、特に、積み込み初期（1、2杯目）において大きな衝撃荷重（積み込み衝撃）が生じやすい。積荷重心位置及び積荷重量の変化に関しては、先に示した応力データの内挿又は外挿により応力波形を算出できる。しかし、積み込み時の衝撃荷重に関しては、積載物２０１の種類と、荷台１０１への積荷量及び積荷投下位置とによって、積み込みによる車両に与える衝撃振動が異なる場合がある。そのため、応力データの内挿又は外挿だけでは実際の応力波形に近づけることが難しい。 In the loading operation to the dump truck, the loading state is changed from an empty loading state by loading the load 201 in several times from a loading machine such as a shovel. FIG. 9 shows an example of a stress waveform at a vehicle evaluation position at the time of loading work. As shown in this figure, at the time of loading operation, the load center position and the amount of load change mainly, and in particular, a large impact load (loading impact) tends to occur at the initial stage of loading (first and second cups). The stress waveform can be calculated by interpolation or extrapolation of the stress data shown above with respect to changes in the load center position and the load amount. However, with regard to the impact load at the time of loading, the impact vibration given to the vehicle by loading may differ depending on the type of load 201 and the loading amount on the loading platform 101 and the loading and unloading position. Therefore, it is difficult to approximate the actual stress waveform only by interpolation or extrapolation of the stress data.
　そこで、本実施の形態では、荷台１０１に積荷を積み込む際に生じる応力を算出するための衝撃係数（第１衝撃係数）を利用する。具体的には、積み込み時の加速度センサ１１０による加速度波形と評価位置における衝撃係数との関係を予め求めておき、当該衝撃係数を記憶装置３２に記憶しておく。そして、各センサ値に基づいて算出される積み込み時の応力（応力データの内挿又は外挿により推定された応力値）に対して当該衝撃係数を乗じることで積み込み時の応力を算出している。 Therefore, in the present embodiment, an impact coefficient (first impact coefficient) for calculating a stress generated when loading a load onto the loading platform 101 is used. Specifically, the relationship between the acceleration waveform by the acceleration sensor 110 at the time of loading and the impact coefficient at the evaluation position is obtained in advance, and the impact coefficient is stored in the storage device 32. The stress at loading is calculated by multiplying the stress at loading (stress value estimated by interpolation or extrapolation of stress data) calculated based on each sensor value by the impact coefficient. .
　次に荷下ろし作業について図１０及び図１１を用いて説明する。図１０は荷下ろし時の動作例を示す模式図であり、図１１は荷下ろし時の評価位置の応力波形の例である。図１１中の時刻a～eのときの荷台の状態は図１０に示したa～eの状態に対応している。なお、図１０では、時刻ｃの状態を放土直前と放土直後に分けて示している。 Next, the unloading operation will be described using FIGS. 10 and 11. FIG. 10 is a schematic view showing an example of operation at unloading, and FIG. 11 is an example of a stress waveform at an evaluation position at unloading. The states of the loading platform at times a to e in FIG. 11 correspond to the states a to e shown in FIG. In addition, in FIG. 10, the state of the time c is divided and shown just before earth release and right after earth release.
　荷下ろし前（時刻a）は、荷台１０１は積荷状態でフレーム１０２に着座している。荷下ろし初期（時刻ｂ）には、ホイストシリンダ１０３が伸びることで荷台１０１がヒンジピン１０４を中心に回動し、着座状態から徐々に起立状態に移行する。そして、荷台１０１の傾斜角度がある角度に到達した時（時刻c：放土直前）に、荷台１０１から積荷２０１はすべり落ちる（時刻ｃ：放土直後）。そして、荷台１０１を最大傾斜角度に達するまで回動させる（時刻ｄ）。その後、ホイストシリンダ１０３が縮むことで荷台１０１が徐々に起立姿勢から着座姿勢に戻り、最終的には着座状態になる（時刻e）。 Before unloading (time a), the loading platform 101 is seated on the frame 102 in a loading state. At the initial unloading stage (time b), the hoist cylinder 103 is extended and the loading platform 101 rotates about the hinge pin 104, and the seating state is gradually shifted to the standing state. And when the inclination angle of the loading platform 101 reaches a certain angle (time c: just before releasing the soil), the load 201 slips off from the loading platform 101 (time c: immediately after releasing the soil). Then, the loading platform 101 is rotated until the maximum inclination angle is reached (time d). Thereafter, as the hoist cylinder 103 is contracted, the loading platform 101 gradually returns from the standing posture to the sitting posture, and finally comes into the sitting state (time e).
　ここで、時刻aから時刻cの積荷が落ち始める前までの評価位置の応力波形は、積荷状態の応力算出と捉えることができるので、先に示した応力データの内挿又は外挿により算出できる。また、時刻ｃの積荷が落ち切った後から時刻eまでの評価位置の応力波形についても、空荷状態の応力算出と捉えることができるので、先に示した方法で算出できる。しかし、積荷が落ちる際には衝撃荷重が発生することがあるので、積み込みの場合と同様に応力データの内挿又は外挿だけでは実際の応力波形に近づけることが難しい。そこで、ここでも荷台１０１から積荷が落ちる際に生じる応力を算出するための衝撃係数（第２衝撃係数）を利用する。具体的には、積み込み時の加速度センサ１１０による加速度波形と評価位置における衝撃係数との関係を予め求めておき、当該衝撃係数を記憶装置３２に記憶しておく。そして、時刻ｃの荷台傾斜角度での積荷時と空荷時の応力差に当該衝撃係数を乗じることで荷下ろし時の応力を算出している。 Here, since the stress waveform at the evaluation position before the load at time a to time c starts to drop can be regarded as stress calculation of the load state, it can be calculated by interpolation or extrapolation of the stress data shown above. . In addition, since the stress waveform at the evaluation position from the point of time c when the load is exhausted to the point of time e can also be regarded as an empty load stress, it can be calculated by the method described above. However, since an impact load may occur when a load falls, it is difficult to approximate an actual stress waveform only by interpolation or extrapolation of stress data as in the case of loading. Therefore, here too, the impact coefficient (second impact coefficient) for calculating the stress generated when the load drops from the loading platform 101 is used. Specifically, the relationship between the acceleration waveform by the acceleration sensor 110 at the time of loading and the impact coefficient at the evaluation position is obtained in advance, and the impact coefficient is stored in the storage device 32. And the stress at the time of unloading is calculated by multiplying the said impact coefficient by the stress difference at the time of loading and the empty load at the bed inclination angle of time c.
　図１２はダンプトラックによる１サイクル分の作業（積み込み、積荷走行、荷下ろし及び空荷走行）を示した模式図であり、図１３は１サイクル分の作業を行ったときの評価位置における応力波形の一例を示す図である。図１２に示すように、ダンプトラックは、（１）積み込み→（２）積荷走行→（３）荷下ろし→（４）空荷走行→（１）積み込み…という作業を繰り返すが、各作業中の評価位置の応力を前述の方法により求めることができる。これにより、作業中に取得した評価位置の応力波形から、１サイクル分の作業に相当する応力波形を抽出することが可能となる。この抽出した応力波形により、例えば、１サイクル中における最大応力値、最小応力値、最大応力振幅および損傷量を計算し、保存管理することができる。なお、上記における損傷量は、例えば、レインフロー法による応力頻度解析とマイナー則による累積損傷則等の公知の方法を用いて算出できる。 FIG. 12 is a schematic diagram showing one cycle of work (loading, loading travel, unloading and empty travel) by the dump truck, and FIG. 13 is a stress waveform at the evaluation position when one cycle of work is performed Is a diagram illustrating an example of As shown in FIG. 12, the dump truck repeats the operation of (1) loading → (2) loading travel → (3) unloading → (4) empty loading → (1) loading ... but during each operation The stress at the evaluation position can be determined by the method described above. This makes it possible to extract a stress waveform corresponding to a work of one cycle from the stress waveform of the evaluation position acquired during the work. With this extracted stress waveform, for example, maximum stress value, minimum stress value, maximum stress amplitude and damage amount in one cycle can be calculated, stored and managed. In addition, the amount of damage in the above can be calculated, for example, using a known method such as stress frequency analysis by rain flow method and cumulative damage rule by minor rule.
　図１３に示した例では、（１）積み込み作業時は積荷の積み込みによって段階的に応力が上昇しており、（２）積荷走行では車体振動によって応力も振動しており、（３）荷下ろし時には放土に伴い急激に応力が減少しており、（４）空荷走行では積荷走行より振幅の小さい応力が発生している。このように各作業における応力波形には独特の特徴があるため、演算処理装置３１によって応力波形の変化を分析することにより、ダンプトラックによって行われていた作業内容を判別することができ、さらには、１サイクルの開始（積み込みの開始）から終了（次の積み込みの直前）を判別することもできる。 In the example shown in FIG. 13, (1) the stress rises stepwise due to loading of the load at the time of loading operation, (2) the stress also vibrates by the body vibration in the loading operation, and (3) unloading Sometimes the stress decreases rapidly with the release of soil, and (4) in the case of an empty run, a stress with a smaller amplitude than that of a load run is generated. As described above, since the stress waveform in each work has a unique feature, by analyzing the change in the stress waveform by the arithmetic processing unit 31, it is possible to determine the work content being performed by the dump truck, and further, It is also possible to determine the start of one cycle (the start of loading) to the end (immediately before the next loading).
　次に、演算処理装置３１によって、上記の方法で得た応力波形から１サイクルごとの損傷量の推移を算出し、当該算出したデータ及びその関連データを表示装置３３に表示する場合について説明する。ここでは、演算処理装置３１は、上記の方法で得た時系列応力波形に基づいて、評価位置における最大応力値、最小応力値、応力振幅および損傷量のうち少なくとも１つを算出し、さらに、当該算出した値の少なくとも１つが閾値を超えたか否かを判定する。そして、当該算出された最大応力値、最小応力値、応力振幅および損傷量のうち少なくとも１つが当該閾値を超えたと演算処理装置３１に判定された場合には、その旨が表示装置３３に表示されるものとする。なお、ここで利用される閾値は、最大応力値、最小応力値、応力振幅および損傷量のそれぞれに設定されるものとする。 Next, the case where the transition of the amount of damage per cycle is calculated by the arithmetic processing unit 31 from the stress waveform obtained by the above method, and the calculated data and its related data are displayed on the display unit 33 will be described. Here, the arithmetic processing unit 31 calculates at least one of the maximum stress value, the minimum stress value, the stress amplitude and the damage amount at the evaluation position based on the time-series stress waveform obtained by the above method, and further, It is determined whether at least one of the calculated values exceeds a threshold. When it is determined by the arithmetic processing unit 31 that at least one of the calculated maximum stress value, minimum stress value, stress amplitude, and damage amount exceeds the threshold value, the display unit 33 displays that effect. Shall be The threshold values used here are set to the maximum stress value, the minimum stress value, the stress amplitude and the damage amount, respectively.
　図１４はダンプトラックによる作業の１サイクルごとの損傷量の推移を折れ線グラフで示した図である。図１５は１サイクルごとの損傷量の推移について、現在ダンプトラックに搭乗中の作業者による直近の５サイクル分の損傷量と、他の作業者の１サイクル分の損傷量の平均値と、作業者全体の１サイクル分の損傷量の平均値とを棒グラフで示した図である。図１４，１５には、損傷量の閾値が１点鎖線で示されており、損傷量の目標値が点線で示されている。損傷量の閾値としは、例えば、ダンプトラックの走行経路に悪路が存在することを報知するための閾値、メンテナンス時期到来の目安を報知するための閾値がある。前者の閾値は１サイクル分の損傷量の閾値であり、後者のものはダンプトラックの使用開始時からの損傷量の累積値の閾値である。なお、図１４に示した閾値は、前者のものである。一方、損傷量の目標値は、搭乗中の作業者の操作目標や技量評価に関するものであり、例えば、模範的な技量を有する作業者による損傷量の平均値や、全作業者についての損傷量の平均値が利用可能である。図１４，１５に示したグラフは、例えば図１６に示すように表示装置３３に表示されることがある。 FIG. 14 is a line graph showing transition of the amount of damage for each cycle of work by the dump truck. Fig. 15 shows the average of the damage amount of the last 5 cycles by the worker currently on board the dump truck, the average value of the damage amount of 1 cycle of other workers, and the work of the transition of the damage amount per cycle It is the figure which showed the average value of the amount of damage for 1 whole of a person by a bar graph. In FIGS. 14 and 15, the threshold value of the amount of damage is indicated by an alternate long and short dashed line, and the target value of the amount of damage is indicated by a dotted line. As the threshold of the amount of damage, for example, there are a threshold for notifying that a bad road exists in the traveling route of the dump truck, and a threshold for notifying an indication of the arrival of a maintenance time. The former threshold is a threshold for the amount of damage for one cycle, and the latter is a threshold for the cumulative amount of damage from the start of use of the dump truck. The threshold shown in FIG. 14 is the former one. On the other hand, the target value of the amount of damage relates to the operation target and skill evaluation of the worker who is on board, for example, the average value of the amount of damage by a worker having an exemplary skill and the amount of damage for all workers. The average value of is available. The graphs shown in FIGS. 14 and 15 may be displayed on the display device 33, for example, as shown in FIG.
　演算処理装置３１は、ダンプトラックに搭乗中の作業者による損傷量（例えば、１回の損傷量又は直近数回の平均値）が目標値を超えると判定した場合には、当該作業者に注意喚起をするために、損傷量が目標値を超えている旨等を表示装置３３に表示する処理を実行する。図１４，１５に示した例では、ダンプトラックに搭乗中の作業者による損傷量は、目標値を超えているため、損傷量が目標値を超えている旨の警告表示３５（図１６参照）が表示装置３３に表示される。 If it is determined that the amount of damage (for example, the amount of one damage or the average value of the most recent several times) by the worker on board the dump truck exceeds the target value, the arithmetic processing unit 31 warns the worker. In order to evoke, a process of displaying on the display device 33 that the amount of damage exceeds the target value is executed. In the example shown in FIGS. 14 and 15, since the amount of damage caused by the operator while riding the dump truck exceeds the target value, a warning display 35 (see FIG. 16) that the amount of damage exceeds the target value Is displayed on the display device 33.
　また、演算処理装置３１は、直近の数回の損傷量が連続して閾値を超え、または同現場で作業している複数のダンプトラックの損傷量が同様のタイミングで閾値を超える場合には、路面状況が悪化していると認定し、ダンプトラックの通行経路に悪路が発生している旨又は路面補修が必要な旨等を表示装置３３に表示する処理を実行する。このとき、応力波形から悪路と推定される箇所を特定し、当該推定箇所を表示装置３３に表示しても良い。図１４，１５では、図中の３及び４を付したサイクルで損傷量が閾値を超えているので、このときに表示装置３３に悪路が発生している旨が表示される。 Further, when the damage amount of the last several times continuously exceeds the threshold or the damage amount of a plurality of dump trucks working at the same site exceeds the threshold at the same timing, the arithmetic processing unit 31 It is determined that the road surface condition is deteriorated, and a process of displaying on the display device 33 that a bad road has occurred in the dump truck's passage or that the road surface needs to be repaired is executed. At this time, a portion estimated to be a rough road may be specified from the stress waveform, and the estimated portion may be displayed on the display device 33. In FIGS. 14 and 15, since the damage amount exceeds the threshold in the cycles denoted by 3 and 4 in the drawings, at this time, it is displayed on the display device 33 that a rough road is generated.
　さらに、演算処理装置３１は、ダンプトラックの使用開始時からの損傷量の累積値が閾値を超えると判定した場合には、メンテナンス時期が到来した旨を表示装置３３に表示する処理を実行する。このとき、評価位置に基づいてメンテナンスが必要な箇所を、メンテナンス時期到来の旨と合わせて表示しても良い。 Furthermore, when it is determined that the cumulative value of the damage amount from the start of use of the dump truck exceeds the threshold value, the arithmetic processing unit 31 executes a process of displaying on the display device 33 that maintenance time has arrived. At this time, a portion requiring maintenance based on the evaluation position may be displayed together with the effect of the maintenance time.
　なお、上記では、目標値及び閾値が超えた旨を表示装置３３に表示することで報知する場合について説明したが、警告灯や音声等、他の報知手段を用いて報知しても良い。また、これらの報知手段は、表示装置３３と同様にどの場所に設置するかは問わないものとする。 In addition, although the case where it alert | reported that the target value and threshold value exceeded was displayed on the display apparatus 33 in the above, was demonstrated, you may alert | report using other alerting means, such as a warning light and an audio | voice. Further, as with the display device 33, these notification means do not matter at which place they are installed.
　以上のように、本実施の形態によれば、車体振動、荷台傾斜、路面傾斜、積荷状態を考慮し、荷下ろしを含めた一連の作業サイクル（積み込み→積荷走行→荷下ろし→空荷走行）中の車体評価部位の応力波形を高精度に見積もることが可能となる。これにより、より高精度な損傷量を作業サイクル毎で算出することができ、作業者の運転の良し悪し比較や、悪路路面発生状況の把握がより正確にできるようになる。更には、ダンプトラックの損傷量の累積値に基づいて、当該部品等の残存寿命やメンテナンス時期及び箇所をより正確に報知することができる。 As described above, according to the present embodiment, a series of work cycles including unloading, taking into account vehicle body vibration, loading platform inclination, road surface inclination, loading condition (loading → loading travel → unloading → empty load traveling) It becomes possible to estimate the stress waveform of the middle vehicle body evaluation part with high accuracy. As a result, it is possible to calculate the amount of damage with higher accuracy for each work cycle, and it becomes possible to more accurately compare the operator's driving quality and grasp the rough road surface occurrence situation. Furthermore, based on the accumulated value of the damage amount of the dump truck, it is possible to more accurately notify the remaining life, maintenance time and place of the part etc.
　２１…前輪、２２…後輪、２３…サスペンションシリンダ（前）、２４…サスペンションシリンダ（後）、３１…演算処理装置（演算手段）、３２…記憶装置（記憶手段）、３３…表示装置（報知手段）、４３，４４…シリンダ圧力センサ、１０１…荷台、１０２…フレーム、１０３…ホイストシリンダ、１０４…ヒンジピン、１１０…加速度センサ、１１１…路面傾斜センサ、１１２…荷台傾斜センサ、２０１…積載物 21: front wheel, 22: rear wheel, 23: suspension cylinder (front), 24: suspension cylinder (rear), 31: arithmetic processing unit (computing means), 32: storage unit (storage means), 33: display unit (notification Means: 43, 44: cylinder pressure sensor, 101: cargo bed, 102: frame, 103: hoist cylinder, 104: hinge pin, 110: acceleration sensor, 111: road surface inclination sensor, 112: cargo bed inclination sensor, 201: load

Claims (11)

  1. 　複数の外力がそれぞれダンプトラックに作用したときに当該ダンプトラックの所定位置に生じる応力のデータが記憶された記憶手段と、
    　前記ダンプトラックに作用する外力の方向及び大きさを検出するための検出手段と、
    　前記検出手段の検出値及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって前記所定位置に生じる応力の時間変化を推定する演算手段とを備えることを特徴とするダンプトラックの応力演算システム。     A storage unit storing data of stress generated at a predetermined position of the dump truck when a plurality of external forces respectively act on the dump truck;
    Detection means for detecting the direction and magnitude of the external force acting on the dump truck;
    Stress of a dump truck comprising: calculating means for estimating a temporal change of stress generated at the predetermined position by interpolation or extrapolation based on a detected value of the detecting means and stress data stored in the storing means Arithmetic system.
  2. 　請求項１に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、前記複数の外力が前記ダンプトラックに付与する加速度の方向及び大きさと関連付けて記憶されており、
    　前記検出手段として、前記荷台の加速度の方向及び大きさを検出するための加速度検出手段を備えており、
    　前記演算手段は、前記加速度検出手段で検出される加速度及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 1,
    The stress data is stored in association with the direction and magnitude of acceleration applied to the dump truck by the plurality of external forces.
    The detection means includes acceleration detection means for detecting the direction and magnitude of the acceleration of the bed.
    The computing means is characterized by estimating a temporal change of stress generated at the predetermined position by interpolation or extrapolation based on the acceleration detected by the acceleration detecting means and the stress data stored in the storage means. Dump truck stress calculation system.
  3. 　請求項２に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、さらに、前記荷台の積荷荷重の大きさ別に記憶されており、
    　前記検出手段として、前記荷台の積荷重量を検出するための重量検出手段をさらに備え、
    　前記演算手段は、前記加速度検出手段で検出される加速度、前記重量検出手段で検出される積荷重量及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 2,
    The stress data is further stored according to the size of the load of the loading platform,
    The detection means further includes a weight detection means for detecting a load amount of the loading platform.
    The calculation means is a stress generated at the predetermined position by interpolation or extrapolation based on an acceleration detected by the acceleration detection means, a product load amount detected by the weight detection means, and stress data stored in the storage means. A dump truck stress calculation system characterized by estimating a time change of the dump truck.
  4. 　請求項３に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、さらに、前記積荷の重心位置ごとに記憶されており、
    　前記検出手段として、前記積荷の重心位置を検出するための位置検出手段をさらに備え、
    　前記演算手段は、前記加速度検出手段で検出される加速度、前記重量検出手段で検出される積荷重量、前記位置検出手段で検出される重心位置及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 3,
    The stress data is further stored for each center of gravity of the load;
    The detection means further comprises position detection means for detecting the barycentric position of the load;
    The calculation means is an interpolation based on an acceleration detected by the acceleration detection means, a product load amount detected by the weight detection means, a barycentric position detected by the position detection means, and stress data stored in the storage means. Alternatively, a stress calculation system for a dump truck that estimates temporal change in stress generated at the predetermined position by extrapolation.
  5. 　請求項４に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、さらに、前記荷台の傾斜角の大きさ別に記憶されており、
    　前記検出手段として、前記荷台の傾斜角を検出するための荷台角度検出手段をさらに備え、
    　前記演算手段は、前記加速度検出手段で検出される加速度、前記重量検出手段で検出される積荷重量、前記位置検出手段で検出される重心位置、前記荷台角度検出で検出される傾斜角及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 4,
    The stress data is further stored according to the size of the tilt angle of the bed.
    The detecting means further comprises a bed-angle detecting means for detecting an inclination angle of the bed.
    The calculating means may include an acceleration detected by the acceleration detecting means, a product load amount detected by the weight detecting means, a barycentric position detected by the position detecting means, an inclination angle detected by the loading bed angle detection, and the memory A dump truck stress calculation system, comprising: estimating a time change of stress generated at the predetermined position by interpolation or extrapolation based on stress data stored in the means.
  6. 　請求項４に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、さらに、前記ダンプトラックが走行する路面の傾斜角の大きさ別に記憶されており、
    　前記検出手段として、前記路面の傾斜角を検出するための路面角度検出手段をさらに備え、
    　前記演算手段は、前記加速度検出手段で検出される加速度、前記重量検出手段で検出される積荷重量、前記位置検出手段で検出される重心位置、前記路面角度検出で検出される傾斜角及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 4,
    The stress data is further stored according to the inclination angle of the road surface on which the dump truck travels,
    The detection means further includes a road surface angle detection means for detecting an inclination angle of the road surface,
    The calculation means includes an acceleration detected by the acceleration detection means, a product load amount detected by the weight detection means, a barycentric position detected by the position detection means, an inclination angle detected by the road surface angle detection, and the storage A dump truck stress calculation system, comprising: estimating a time change of stress generated at the predetermined position by interpolation or extrapolation based on stress data stored in the means.
  7. 　請求項２に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、さらに、前記荷台の傾斜角の大きさ別に記憶されており、
    　前記検出手段として、前記荷台の傾斜角を検出するための荷台角度検出手段をさらに備え、
    　前記演算手段は、前記加速度検出手段で検出される加速度、前記荷台角度検出で検出される傾斜角及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 2,
    The stress data is further stored according to the size of the tilt angle of the bed.
    The detecting means further comprises a bed-angle detecting means for detecting an inclination angle of the bed.
    The calculation means is a stress generated at the predetermined position by interpolation or extrapolation based on an acceleration detected by the acceleration detection means, an inclination angle detected by the bed-body angle detection, and stress data stored in the storage means. A dump truck stress calculation system characterized by estimating a time change of the dump truck.
  8. 　請求項２に記載のダンプトラックの応力演算システムにおいて、
    　前記応力データは、さらに、前記ダンプトラックが走行する路面の傾斜角の大きさ別に記憶されており、
    　前記検出手段として、前記路面の傾斜角を検出するための路面角度検出手段をさらに備え、
    　前記演算手段は、前記加速度検出手段で検出される加速度、前記路面角度検出で検出される傾斜角及び前記記憶手段に記憶された応力データに基づく内挿又は外挿によって、前記所定位置に生じる応力の時間変化を推定することを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 2,
    The stress data is further stored according to the inclination angle of the road surface on which the dump truck travels,
    The detection means further includes a road surface angle detection means for detecting an inclination angle of the road surface,
    The computing means is a stress generated at the predetermined position by interpolation or extrapolation based on the acceleration detected by the acceleration detecting means, the inclination angle detected by the road surface angle detection, and the stress data stored in the storage means. A dump truck stress calculation system characterized by estimating a time change of the dump truck.
  9. 　請求項１から８のいずれかに記載のダンプトラックの応力演算システムにおいて、
    　前記演算手段は、前記応力データの内挿又は外挿によって推定された応力値に前記記憶手段に記憶した衝撃係数を乗じることで、積み込み時又は荷下ろし時に生じる衝撃荷重による応力を算出することを特徴とするダンプトラックの応力演算システム。     The dump truck stress calculation system according to any one of claims 1 to 8,
    The calculating means may calculate the stress due to the impact load generated at the time of loading or unloading by multiplying the stress value estimated by the interpolation or extrapolation of the stress data by the impact coefficient stored in the storage means. Characteristic of dump truck stress calculation system.
  10. 　請求項９に記載のダンプトラックの応力演算システムにおいて、
    　前記演算手段は、積み込み、積荷走行、荷下ろし及び空荷走行からなる前記ダンプトラックによる作業の１サイクルごとの損傷量を算出し、当該損傷量が目標値を超えたか否かを判定し、
    　前記演算手段によって損傷量が目標値を超えたと判定された場合に、その旨を報知するための報知手段をさらに備えることを特徴とするダンプトラックの応力演算システム。     In the dump truck stress calculation system according to claim 9,
    The calculation means calculates the amount of damage per cycle of the work by the dump truck consisting of loading, loading, unloading and emptying, and determines whether the amount of damage exceeds a target value.
    The dump truck stress calculation system, further comprising notification means for notifying that effect when the calculation means determines that the amount of damage exceeds a target value.
  11. 　請求項９又は１０のいずれかに記載のダンプトラックの応力演算システムにおいて、
    　前記演算手段は、積み込み、積荷走行、荷下ろし及び空荷走行からなる前記ダンプトラックによる作業の１サイクルごとの損傷量又は前記ダンプトラックの損傷量の累積値を算出するとともに、当該損傷量または累積値が閾値を超えたか否かを判定し、
    　前記演算手段によって損傷量または累積値が前記閾値を超えたと判定された場合に、その旨を報知するための報知手段をさらに備えることを特徴とするダンプトラックの応力演算システム。     11. The dump truck stress calculation system according to claim 9, wherein
    The computing means calculates the amount of damage per cycle of the operation by the dump truck consisting of loading, loading, unloading and emptying or the cumulative value of the amount of damage of the dump truck, and the damage amount or cumulative amount. Determine whether the value exceeds the threshold,
    A dump truck stress calculation system, further comprising notification means for notifying that effect when the calculation means determines that the damage amount or the accumulated value exceeds the threshold value.
PCT/JP2013/053298 2012-02-13 2013-02-12 Stress computation system for dump truck WO2013122066A1 (en)

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