JPH10197324A - Load measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load measuring device capable of improving the measurement accuracy of loads. SOLUTION: When the width Pa of pressure fluctuations exceeds a reference value after the loading of goods, the measurement of time T2 is started. After a lapse of the time T2 is equal to or more than a predetermined length of time, pressure is calculated by a pressure sensor and a load is calculated and outputted without adjusting the height level of a load-carrying platform. After the lapse of the time T2 is equal to or more than the above-mentioned predetermined length of time, the values detected by the pressure sensor do not contain vibration components associated with the loading of goods. Thereby, the accuracy of the calculated data and output data of a load to obtain is improved as mentioned above. As improvements in the accuracy of the output data of a load enable the loading of goods extremely close to a maximum load on the platform, it is possible to improve the efficiency of transportation. It is also possible to speed up the detection and output of a load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load measuring device used for a vehicle such as a dump truck to measure the load weight (load) of a carrier.

[0002]

2. Description of the Related Art As an example of a conventional load amount measuring device, after a load is loaded, a loading platform is raised to a predetermined height, an internal pressure is measured in a loading height range in which an internal pressure of a loading cylinder is stabilized, and the internal pressure data is measured. There is a device that calculates the load amount based on the information. In this device, when the load amount of the load is not the desired value, the load is added to compensate for the shortage, or the excess is removed, so that the load amount can be optimized. I have to. In the prior art,
The loading capacity was adjusted each time by returning the carrier to its original state.

[0003]

By the way, in the above-mentioned prior art, there is a possibility that the internal pressure includes a vibration component with the addition or removal of the load, and the measurement accuracy of the load may decrease. In addition, in order to adjust the excess or deficiency of the load, it is necessary to return the carrier to its original state each time, and then to lift the carrier again (tilt) to perform measurement, which requires a lot of time for measurement. Had become something.

[0004] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a load amount measuring device capable of improving the measurement accuracy of the load amount and quickly measuring the load amount.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a load data detecting means for detecting data relating to a load on a bed of a vehicle,
Vibration removing means for removing, from the detection data, a vibration component included in the detection data of the load data detection means at the time of loading or partially removing the load on the loading platform, wherein the vibration component is removed. Based on the detection data, the load amount is continuously detected and output without adjusting the height level of the bed at the time of detection by the load data detection means.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A load measuring device according to a first embodiment of the present invention will be described below with reference to FIGS. In addition, this loading amount measuring device is an example in which the loading platform is used in a vehicle in which a loading platform is tiltably attached to the rear side of a chassis via a rotation supporting member. 1 and 2,
A cylinder 7 is interposed between an undercarriage (not shown) of the vehicle and a carrier (not shown) which is tiltably attached to the rear side of the undercarriage via a rotation support member. As shown in FIG. 1, the cylinder 7 is slidably housed in the cylinder body 13 for housing the oil liquid and slidably housed in the cylinder body 13, and defines the inside of the cylinder body 13 into first and second chambers 14 and 15. The piston 16 is substantially constituted by a piston 16, one end of which is connected to the piston 16, and the other end of which extends outside the cylinder body 13 through the first chamber 14. The cylinder body 13 of the cylinder 7 is rotatably attached to the chassis, and the other end of the piston rod 17 is connected to the lift plate 1.
2 so as to be rotatable.

The first and second chambers 14 and 15 are connected to a pump 22 via first and second pipes 20 and 21. A tank 23 and a pressure sensor (load data detecting means) 24 are branched and connected to the first and second pipes 20 and 21, respectively, for storing the oil liquid and the hydraulic pressure of the second chamber 15 of the cylinder 7 ( Load data).

The pump 22 is connected to an engine (not shown) via a pump clutch 26 connected to a transmission 25. The pump clutch 26 can selectively transmit the torque of the engine to the pump 22 in cooperation with a clutch switch 27 provided in the cab 6. The pump 22 has a built-in switching valve 28, and an oil liquid supply route (hereinafter referred to as an extension oil liquid) to the second chamber 15 of the oil liquid through the second pipe 21 by raising and lowering the switching valve 28. N, 1st
An oil liquid supply route (hereinafter, referred to as a contraction side oil liquid supply route) T for the oil liquid to the first chamber 14 through the pipe 20 is formed,
The extension and contraction of the piston rod 17 can be performed.

The switching valve 28 is connected to a lever mechanism 29 provided in the cab 6 via a cable 30. The lever mechanism 29 includes a lever base 31 fixed to the chassis side.
A lever body 32 rotatably supported by the lever base 31 and having one end connected to the cable 30 and a handle provided at the other end, and selectively rotating and rotating the lever body 32. A release button 34 for unlocking a lock mechanism (not shown) is provided, and a clutch switch 27 provided behind the lever base 31 and operated by an operator (driver, loading operator) is generally configured.

When the clutch switch 27 is turned "ON" to transmit the rotational force of the engine to the pump 22 via the pump clutch 26 and the lever body 32 of the lever mechanism 29 is raised, the switching valve is switched via the cable 30. 28 is raised to form an extension-side oil liquid supply route N, whereby the cylinder 7 is extended and the carrier is inclined, and the height of the carrier (the distance between the front end of the carrier and the chassis) is increased. When the release button 34 of the lever mechanism 29 is operated to lower the lever body 32, the switching valve 28 is lowered via the cable 30 to form the contraction side oil liquid supply route T, whereby the cylinder 7 is moved. Shrink and the height of the loading platform L
Becomes lower. In addition, the clutch switch 27 is set to “OF
F "to operate the pump clutch 26 to cut off the rotational force of the engine, thereby stopping the drive of the pump 22,
Lifting or lowering of the carrier is stopped.

An arithmetic unit 36 is connected to the pressure sensor 24 as shown in FIG. The arithmetic unit 36 includes a display 37, a buzzer 35, a printer 38, a communicable communication device (hereinafter, referred to as a vehicle communication device) 39, a timer 50, and a loading completion switch which is turned on by an operator operation when loading is completed. 55 are connected. Further, at a control center (not shown) outside the dump truck 1, a communication device (hereinafter, referred to as a center communication device) 40 capable of transmitting and receiving to and from the vehicle communication device 39 and a computer connected to the center communication device 40 ( PC) 41 are provided. The computer 41 stores information received by the center-side communication device 40, and causes the display and the printer (not shown) provided in the control center to display and print. The computer 41 is connected to the center communication device 4.
The internal setting data of the arithmetic unit 36 can be changed or the like from a remote location via the communication device 39 and the vehicle-side communication device 39.

The arithmetic unit 36 performs arithmetic processing described later, and outputs information corresponding to each of the display 37, the buzzer 35, the printer 38, and the vehicle-side communication device 39 based on the arithmetic result to operate each member. Like that.

In a dump truck, generally, in order to raise (tilt) the loading platform, oil is supplied to a cylinder for tilting the loading platform (the second chamber 15 of the cylinder 7 in the present embodiment) by keeping the rotation speed of the pump constant. It is known that when a liquid is supplied, it exhibits a hydraulic (pressure) characteristic as shown in FIG. That is, the oil pressure of the cylinder (in this embodiment, the second chamber 15 side) pulsates at a high frequency (densely) while the oil liquid is supplied to the cylinder for tilting the bed and the bed is rising. The waveform is a waveform in which a high-frequency pulsating component having a large amplitude is superimposed on a basic component having a constant value (average value P _A ). (Hereinafter, a region exhibiting a dense pulsating hydraulic pressure is referred to as a region AA for convenience).
Then, when the operation of the pump is stopped in order to stop the lifting of the bed, the dense pulsation of the hydraulic pressure is attenuated. [The time when the approximate damping starts (immediately after the stop of the pump operation) is hereinafter referred to as time A1. ] And a pulsation amplitude smaller than the dense pulsation oil pressure (that is, a waveform in which a low-frequency pulsation component having a small amplitude is superimposed on the basic component; hereinafter, the oil pressure in this portion is referred to as a sparse pulsation oil pressure). )become. After the predetermined time has elapsed (for example, time T _1, which is measured from the time A1 is equal to or greater than a predetermined value), the hydraulic pressure is stable compared to the sparse pulsating hydraulic pressure.

The average hydraulic pressure P _A of the dense pulsating hydraulic pressure when the bed is raised is higher than the average hydraulic pressure of the sparse pulsating oil pressure after the loading bed is stopped. This is because the hydraulic pressure in the cylinder and the load are balanced when the loading bed stops, and the hydraulic pressure in the cylinder is higher than the balanced state when the load is raised.

As described above, when a load such as earth and sand is loaded on the loading platform in a state where the oil pressure is stable after time A1 (for example, at time B1), the oil pressure vibrates, and the vibration component is added to the value detected by the pressure sensor 24. Will be included. Thereafter, a predetermined time has elapsed [e.g., time T ₂ is a predetermined value the pressure fluctuation P _a by the vibration of the hydraulic pressure is measured after the timing when the reference value K ₂ or more set in advance (e.g., time t _m) or more ), The vibration component is almost eliminated and the hydraulic pressure is stabilized. Hereinafter, from time A1 to time B1
Is called an area AB.

As described above, when the load is further loaded on the carrier in a state where the oil pressure is stable after time B1 (for example, at time C1), the oil pressure vibrates, and the value detected by the pressure sensor 24 includes a vibration component. Will be. Thereafter, a predetermined time has elapsed [e.g., time T ₂ (T ₂₁₎ of the pressure fluctuation by the hydraulic vibration P _a (P ₂₁₎ is measured from the time of equal to or greater than the reference value set in advance is higher than a predetermined value ), The vibration component disappears and the hydraulic pressure is stabilized. Hereinafter, the region from the time point B1 to the time point C1 is referred to as a region B.

In the case where the load exceeds the maximum value P ₀ in the area following the area B, excessive load is applied in a state where the hydraulic pressure is stabilized (for example, at time D1 (area D starts at time D1)). Is removed from the carrier, the hydraulic pressure vibrates, and the value detected by the pressure sensor 24 includes a vibration component.
Thereafter, a predetermined time has elapsed [e.g., time T ₂ the pressure fluctuation P _a by the hydraulic vibration (P ₂₂₎ is measured from the time of equal to or greater than the reference value set in advance
(T ₂₂ ) becomes equal to or more than a predetermined value], the vibration component disappears and the hydraulic pressure is stabilized. Hereinafter, the region from the time point C1 to the time point D1 is referred to as a region C.

In FIG. 5, P ₁ is a predetermined rising pressure at which the bed is considered to start rising (the rising does not always start), and t _a is the time when the pressure P reaches the rising pressure P _1. This is the measured time.

[0019] In this embodiment, pre-performed the measurement results based on rising pressure P ₁ from the front point, the time until the rear point (hereinafter, the front time, that the rear side time.) Respectively, 2.5 seconds, It is 6.5 seconds.

The arithmetic unit 36 has a control cycle (measurement time) T
The detection value of the pressure sensor 24 is read every [msec], pressure is measured, and a predetermined number (n) is continuously determined as described later.
Pressure (hereinafter, referred to as array pressure) P _i (i
= 1,2, ..., the average value P _m of n), is the difference between the average values of chronologically successive to compare with a reference value K.
In this case, the average value P _m (hereinafter, the pressure average value before the time is referred to as P _m0 and the average value after the time is referred to as the post-pressure average value P _m1 ) is obtained by the following equation (1). That is, when a new average value is calculated, the new data is set as the post-pressure average value P _m1, and the data indicating the previous pre-pressure average value P _m1 is replaced with the previous pressure average value P _m0. Has become.

P _m = ΣP _i / n (1) (where i = 1, 2,..., N)

Here, the contents of the arithmetic processing of the arithmetic unit 36 will be described with reference to FIGS. When the power supply (not shown) is turned on and the calculation of the calculator 36 is started, first, the internal parameters are initialized (step S1), and the detection value of the pressure sensor 24 is read (step S2). Whether the pressure P read at the next step S3 has reached the rising pressure P ₁ (P
≧ P ₁ ? ) Is determined, the pressure P has not reached the rising pressure P ₁ (P <P ₁₎ case, pressure measurement returns to step S2.

The pressure has reached the rising pressure P ₁ (P ≧ P
P ₁₎ If, by the timer 50 starts to measure the bed of rise time t _a (step S4). Subsequent to step S4, it is determined whether the measurement time T has been reached (step S5). If the measurement time T has been reached, the pressure P is measured (step S5).
6).

In the following step S7, the pressure measurement number i is counted up, and in the next step S8, the measured pressure P is obtained as an array pressure P _i (= P _i , P ₂ ,... P _i , P _n ). In step S9 following step S8, it is determined whether or not the number of pressure measurements i has reached a value n corresponding to the number of samples obtained in advance. If NO is determined, the process returns to step S5, and the processing in steps S5 to S9 On the other hand, if YES is determined, the post-pressure average value P _m1 is calculated based on the n pieces of pressure data as shown in the above equation (1) (step S10).

[0025] Subsequently, it is determined whether the bed of rise time t _a has passed 2.5 seconds which is the front point (step S11
). If YES is determined in step S11 (2.5 seconds have elapsed), the buzzer 35 sounds and an alarm is issued to the operator to notify that the carrier can be stopped (step S12). By generating the buzzer sound of the buzzer 35, the operator
As described above, by turning off the clutch switch 27 and operating the pump clutch 26, the drive of the pump 22 is stopped, whereby the lifting of the bed is stopped. The 2.5 seconds is a time for raising the bed to a height at which the height of the bed does not fall below the minimum measurable height even in the maximum loading state.

In the following step S13, a difference (P _m0 −P _m1 ) between the average value of the rear pressure P _{m1 and} the average value of the front pressure P _m0 is calculated, and whether or not this value is equal to or more than the reference value K (P _m0 −P _m1 ≧ K?) is determined. That is, the judgment in step S13 is based on the fact that the average hydraulic pressure at the time of the lifting of the platform is higher than the average hydraulic pressure after the platform is stopped. It is determined that the lifting stop of the carrier has been detected based on the operation of the operator.

[0027] determines whether or determination is NO in step S11 described above, or if it is determined NO in step S13, has elapsed 6.5 seconds which is the time the rear time t _a (step S21). If YES is determined in step S21, the buzzer 35
Is stopped (measureable notification is stopped) (step S22),
An error message is displayed on the display 37 (step S23), and the process ends. As mentioned above the time t _a has passed 6.5 seconds (YES is determined in step S21.) Performs an error display on the display 37 by (step S23) to cause the operator to perform the stop of the apparatus I can tell you.

[0028] If it is determined NO in step S21, and stores the back pressure the average value for the storage section 48 to the rear pressure average value P _m1 as before average pressure P _m0 (step S24). Next, the number i of pressure measurements is cleared to 0 (step S25), the process returns to step S5, and the above-described processes from step S5 are repeated.

If YES is determined in the step S13, the time T
The measurement ₁ (measurement of time until the vibration when the loading platform stops stopping) is started (step S30). Then, it is determined whether or not the time T ₁ has become equal to or longer than a preset time t ₁ (step S31). If YES is determined in the step S31, information indicating that loading of luggage may be started is output to the display 37 or the buzzer 35 to notify the operator that loading can be started (step S32).

After step S32, the pressure P is measured (step S33). Subsequently, based on the pressure P determined in step S33, the load amount is determined, and a signal indicating the determined load amount is output to the display 37 and the printer 38 to be displayed and printed out. Next, the internal pressure P of the cylinder at the time of the maximum loading capacity registered in advance
_It is determined whether or not ₀ has been reached (step S35). Pressure P
Has reached the internal pressure P ₀ , YES is determined in step S35, and output to the display 37 or the buzzer 35 to notify the operator (step S36). Determining S35 determines NO in the (pressure P has not reached the internal pressure P _0), whether the loading completion switch 55 is depressed (step S37
).

[0031] While the process terminates determines YES in step S37, if it is determined that NO is measured the pressure fluctuation width P _a (step S38). Next, it is determined whether or not the pressure fluctuation width P _a is the value K ₂ or more set in advance (step
S39). If step S39 is determined to be NO, the process returns to step S37 and is performed. If it is determined YES in step S39 starts measuring the time T ₂ (step S40). Time T ₂ at subsequent step S41 is equal to or preset time t _m or more. Determining the time T ₂ is equal to or greater than time t _m at step S41 YES and resets the time T ₂ (step S42), processing returns to step S33, repeated pressure measurement, the processing load display etc. . The time t _m is based on having a hydraulic fluid supply time and hydraulic properties, such as the load weight measuring device is shown in FIG. 5, for example, it has been obtained in advance based on the load weight and load timing and the like for stacking .

[0032] In the loading amount measuring apparatus configured as described above performs a loading of cargo, the pressure fluctuation width P _a is a value K ₂ or more and (judged YES in step S39), the measurement of the time T ₂ started (step S40), after a time T ₂ has passed over the time t _m (determined YES in step S41), performs a measurement of the pressure P at the step S33, and the loading amount of calculation and output of the data in step S34 I do. Then, after a time T ₂ as described above or more has elapsed time t _m does not include a vibration component of the detected value of the pressure sensor 24 associated with the loading of the cargo has become (attenuated) state. For this reason,
Calculated data and output data of the load of the measurement data and the step S34 of the pressure P in step S33 in after the above-mentioned time T ₂ has passed over the time t _m, the higher accuracy. By increasing the accuracy of the output data of the loading amount in this manner, it becomes possible to load the loading amount extremely close to the maximum loading amount on the loading platform, so that the transportation efficiency can be improved.

In this embodiment, after the time T ₂ has passed the time t _m or more (determined as YES in step S41), that is, after the vibration component accompanying the load change has almost disappeared,
The measurement data of the pressure P is obtained (step S33), and the display 39 and the load amount are output (step S34). The processing in step S41 constitutes the vibration removing means.

The arithmetic unit 36 has a speaker (not shown).
May be connected, and voice output may be performed at the time of the output in step S32 or step S36, so that the operator can be surely notified of the content.

In the above-described embodiment, an example is described in which a high-accuracy load amount data is obtained with respect to the vibration that occurs with the first load (time point B1 in FIG. 5) after the loading platform is lifted. However, the present invention is not limited to this, and the same applies to the case of obtaining high-accuracy loading amount data for vibration generated at the time of the second loading (for example, time point C1 in FIG. 5) after the loading platform is lifted. I can deal with it. In this case, the time a comparison reference time is measured T _21, the time t _m
Is determined in advance based on the oil supply time / hydraulic characteristic as shown in FIG. 5, for example, in consideration of the vibration convergence state accompanying the initial loading. Further, it is possible to load or partially remove the load as described above without adjusting the height level of the loading platform required in the related art, thereby adjusting and adjusting the load amount. Can be quickly measured. Further, in the above-described embodiment, the case where the load is added has been described as an example.
The present invention is not limited to this. For example, as shown at time point D1 in FIG. 5, when the load data is removed and the detection data of the pressure sensor 24 includes a vibration component, the same processing as described above is performed. As a result, it is possible to improve the measurement accuracy of the load amount. In the above embodiment, although the value K ₂ set in advance of the pressure fluctuation width is constant, not limited to this, for example, since the fine adjustment in the vicinity of the maximum loading,
When the pressure approaches the maximum loading pressure P ₀ , K ₂ may be reduced, and the loading amount may be frequently measured.

Next, a loading capacity measuring apparatus according to a second embodiment of the present invention will be described with reference to FIG. This load amount measuring apparatus is provided with a low-pass filter (vibration removing means) (not shown) so as to operate on the data of the pressure P in step S33, and the computing unit 36 performs the processing in steps S32 to S42 in FIG. Instead, the processing of steps S32 to S56 in FIG. 6 is different from the loading amount measuring device of the first embodiment. As shown in FIG. 6, the computing unit 36 of the loading amount measuring device of the second embodiment outputs information indicating that loading of luggage may be started in step S32 to the display 37 or the buzzer 35, Notifies the operator that loading can be started and the following steps
In step S33, the pressure P is measured (the pressure P in step S33 is preliminary).

[0037] Then, the low-pass filter acts to pressure P obtained in step S33, the high-frequency vibration components are removed and the average value P _L is calculated (step S50).
Then, based on the average value P _L , the load amount is calculated, and a signal indicating the calculated load amount is output to the display 37 and the printer 38 to be displayed and printed out (step S51).
). Next, the average value P _L obtained in step S50 is equal to the pre-registered internal pressure P ₀ of the cylinder at the time of the maximum load (actually, the data processed by the low-pass filter is delayed with respect to the actual pressure fluctuation. It is determined whether the value has reached a value smaller than P _0. ) (Step S52). If the average value P _L has reached the internal pressure P ₀ , YES is determined in step S52, and the display 37 or the buzzer 3
5 to notify the operator (step S53).
Determining S52 determines NO in the (average value P _L has not reached the internal pressure P _0), whether the loading completion switch 55 is depressed (step S54).

If NO is determined in the step S54, a step S5 is performed.
Returning to 0, the above processing is repeated. YE in step S54
If S is determined, the pressure P is measured (step S55).
Subsequently, based on the pressure P determined in step S55, the load amount is determined, and a signal indicating the determined load amount is output to the display 37 and the printer 38 to be displayed and printed out.

In the load measuring device configured as described above, even if the pressure P data includes a vibration component, the low-pass filter removes the vibration component and outputs the average value P _L. For this reason, the accuracy of the measurement data of the pressure P in step S55 and the calculation data of the load amount in step S56 are excellent, and the output data of the load amount in step S56 is high in accuracy. Further, according to the second embodiment, the load amount can be measured with high accuracy even when a high fluidity is continuously loaded.

Further, in each of the above-described embodiments, an example in which the pressure sensor 24 is used as the load data detecting means has been described. However, the present invention is not limited to this, and the portion supporting the carrier (for example, the piston rod 17 of the cylinder 7) may be distorted. A sensor may be attached as load data detecting means. Further, a load sensor formed of a piezoelectric element or the like may be provided at a mounting portion of the loading platform such as the mounting portion of the cylinder 7. As the characteristics of the strain sensor and the load sensor, substantially the same characteristics as those obtained by replacing the pressure in FIG. 5 with the strain and the load can be obtained, and the same control as in the above-described embodiment can be performed. In the above-described embodiment, the judgment of stopping the loading platform is made when the difference between the preceding pressure average value P _m0 and the subsequent pressure average value P _m1 becomes equal to or less than the predetermined value K. However, the present invention is not limited to this. Any method that can detect that the pump 22 has stopped may be used. For example, the stop of the rotation of the pump 22 may be detected.

[0041]

According to the present invention, the vibration removing means removes the vibration component included in the detection data of the load data detecting means from the detected data when the load is loaded or partially removed from the loading platform. Since the load is detected and output based on the detection data from which the load has been removed, the load can be obtained in a state where the vibration components generated when loading or partially removing the load are eliminated, and the load is measured. Accuracy can be improved. Furthermore, since the accuracy of the output data of the load amount is high and the output can be continuously performed, it is possible to load the load amount extremely close to the maximum load amount on the carrier, and it is possible to improve the transport efficiency. Further, since the load amount is detected and output without adjusting the height level of the loading platform at the time of detection of the load data detecting means, the height of the loading platform is adjusted to obtain the loading volume as compared with the related art. In addition, it is possible to speed up the detection and output of the load amount.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a load capacity measuring device according to a first embodiment of the present invention.

FIG. 2 is a block diagram schematically showing the loading capacity measuring device.

FIG. 3 is a flowchart showing a content of a calculation process of a calculator of the load capacity measuring device.

FIG. 4 is a flowchart showing the content of a calculation process subsequent to step S31 in FIG. 3;

FIG. 5 is a diagram showing an oil liquid supply time / oil pressure characteristic, an oil liquid supply time / package height characteristic of the loading amount measuring device of FIG. 1;

FIG. 6 is a flowchart showing a second embodiment of the present invention.

[Explanation of symbols]

 24 pressure sensor (load data detecting means) 36 computing unit

Claims (1)

[Claims] 1. A load data detecting means for detecting data relating to a load on a bed of a vehicle, and a vibration component included in the detection data of the load data detecting means when a load is loaded or partially removed on the bed. A vibration removing unit for removing from the detection data, based on the detection data from which the vibration component has been removed, without adjusting the height level of the loading platform at the time of detection by the load data detecting unit, continuously A load amount measuring device for detecting and outputting a load amount.