JP2000064360A - Load measuring device for hydraulic backhoe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load measuring device for a construction machine, by which an operator is not burdened as the depressing of a button during operation and a spot, where load is measured, is discriminated automatically while operation can be detected without a mistake. SOLUTION: An article to be carried is scooped up and rotated and transferred to another place in the load measuring device for the hydraulic backhoe. Pressure detecting means 123, 124 measuring the differential pressure of pressure on the bottom side and pressure on the rod side of a boom cylinder at the time of slewing operation carrying the article after the scooping up of the article to be carried, a differential-pressure storage means 19, in which differential pressure immediately before bucket damp operation when or after the integral value of a slewing operating time reaches a predetermined value is stored, and a load measuring means, by which the load of the article to be carried is computed from differential pressure immediately before stored bucket damp operation, are installed to the device.

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 for a construction machine such as a hydraulic excavator, and more particularly, a construction machine such as a hydraulic excavator for scooping earth and sand installed and carried on a hoisting ship and transferring it to a hopper or the like. Load measuring device.

[0002]

2. Description of the Related Art FIG. 1 is a diagram showing an example of a working mode of a hydraulic excavator operating on a hoisting ship.

In the figure, 11 is a boom of the hydraulic excavator 1, 12 is a boom cylinder, and 13 is a bucket.
As shown in the figure, a hoisting ship 2 working at sea is composed of at least one hydraulic excavator 1, a hopper 4 into which earth and sand are loaded by the hydraulic excavator 1, and a pressure-feeding pump 5 that pressure-feeds the deposited earth and sand. To be done. A barge ship 3 that has carried sand and sand is laterally attached to the unloading ship 2, and the hydraulic excavator 1 scoops earth and sand from the barge ship 3 and turns it into the hopper 4. When a predetermined amount of earth and sand is put into the hopper 4, it is mixed with cement in the hopper 4 and is sent under pressure by a pump 5 to a planned landfill site. At this time, it is necessary to measure the amount of earth and sand in order to put a proper amount of earth and sand into the hopper 4 with respect to the amount of cement that is put into the hopper 4.

Conventionally, in order to measure the load scooped by a construction machine such as a hydraulic excavator, an operator pushes a button when the front posture of the hydraulic excavator is in a certain posture, and the load is calculated at that timing. .

Further, Japanese Patent Laid-Open No. 6-10378 discloses that
A method for measuring the load before the bucket dump is disclosed.

[0006]

However, as in the conventional hydraulic excavator described above, pressing the button to count when the front posture has a certain fixed posture places a burden on the operator.

Further, in the above-mentioned Japanese Patent Laid-Open No. 6-10378, the load is simply measured before the bucket dump is performed, and the load is generated except for the predetermined work of excavating and dumping. Sometimes a bucket dump operation is detected incorrectly.

It is an object of the present invention to automatically determine a load measurement point without burdening an operator such as pressing a button during work, and to detect a work without error. To provide a measuring device.

[0009]

The present invention employs the following means in order to achieve the above object.

In a load measuring device for a hydraulic excavator that scoops and transports a transported object to another location, the pressure on the bottom side and the pressure on the rod side of the boom cylinder at the time of a swiveling operation for transporting after scooping the transported object. A pressure detection means for measuring a pressure difference between the pressure control means and a differential pressure storage means for storing the pressure difference immediately before or after a bucket dump operation when the integrated value of the turning operation time reaches a predetermined value. And a load measuring means for calculating the load of the transported object from the differential pressure immediately before the bucket dump operation.

Further, in the load measuring device for a hydraulic excavator according to claim 1, an angle detecting means for measuring a boom angle of the hydraulic excavator is provided, and the measured boom angle is set at a start point of the measurement of the turning operation time. It is characterized in that it starts when it reaches a predetermined value or more.

Also, in the load measuring device for a hydraulic excavator according to any one of claims 1 and 2, the turning operation time is from the turning operation time in one turning direction to the other turning direction. It is characterized in that it is calculated by subtracting the turning operation time.

In the load measuring device for a hydraulic excavator according to any one of claims 1 to 3, the differential pressure immediately before the bucket dump operation stored in the differential pressure storage means is the pressure. It is characterized in that it is an average differential pressure of the differential pressures detected in a predetermined period immediately before the bucket dump operation by the detection means.

Further, in a load measuring device for a hydraulic excavator that scoops and transports a transported object to another place, a swiveling operation in one swivel direction for transporting the transported object, a bucket dump operation, and not transporting the transported object. An operation order detecting unit that detects each operation order of the turning operation in the other turning direction,
The pressure detecting means for measuring the differential pressure between the pressure on the bottom side and the pressure on the rod side of the boom cylinder of the hydraulic excavator during the one turning operation, and the detected operation sequence are operated in a predetermined operation sequence. At this time, a load measuring means for calculating the load of the transported object from the differential pressure immediately before the bucket dump operation is provided.

Further, in a load measuring device for a hydraulic excavator that scoops and transports a transported object to another location, a swiveling operation in one swivel direction for transporting the transported object, a bucket dump operation, and not transporting the transported object. An operation order detecting unit that detects each operation order of the turning operation in the other turning direction,
Pressure detecting means for respectively measuring the differential pressure between the pressure on the bottom side and the pressure on the rod side of the boom cylinder of the hydraulic excavator during the one turning operation and the other turning operation, and the detected operation sequence. When operated in a predetermined operation sequence, and the pressure difference of each of the measured differential pressures is a certain value or more, from the differential pressure immediately before the bucket dump operation between the one turning operation and the other turning operation. Load measuring means for calculating the load of the transported object is provided.

Further, in the load measuring apparatus for the hydraulic excavator according to claim 6, while the boom of the hydraulic excavator is rotated by a predetermined angle or more, the end of the turning operation of the one is detected and the other one is detected. A turning operation confirming means for detecting the start of a turning operation in a turning direction is provided, the load measuring means operates the detected operation order in a predetermined operation order, and the turning operation checking means performs the end and the When the start is detected and the pressure difference of each of the measured differential pressures is equal to or more than a certain value, the load of the transported object is determined from the differential pressure immediately before the bucket dump operation in the turning operation in the one turning direction. It is characterized by calculating.

Further, in the load measuring apparatus for a hydraulic excavator according to any one of claims 5 to 7, the differential pressure immediately before the bucket dump operation is the one turning operation in the pressure detecting means. It is an average differential pressure of the differential pressures detected in a predetermined period immediately before the bucket dump operation.

Further, in the load measuring device for a hydraulic excavator according to any one of claims 5 to 8, the operation sequence detecting means includes a turning operation in the one turning direction and a turning operation in the other. It is characterized in that operation determining means for determining that each of the turning operations has been performed when the operation time of each of the turning operations of the direction continues for a predetermined time is provided.

Further, in the load measuring apparatus for a hydraulic excavator according to any one of claims 1 to 9, the load measuring means scoops and conveys the transported object to another place. It is characterized in that a work number measuring means for measuring the number of times of work and a load integrating means for integrating the load for each work number are provided.

Further, in the load measuring device for a hydraulic excavator according to any one of claims 1 to 10, the load measuring device is arranged at a location remote from a load measuring device main body of the hydraulic excavator. It is characterized in that a management means for receiving, processing and displaying the measured data is provided.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
From now on, description will be made with reference to FIG.

FIG. 2 is a block diagram showing a load measuring device and a managing device for a hydraulic excavator according to this embodiment.
The same parts as those shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 121 is a boom cylinder 1.
2 is a bottom chamber, 122 is a rod chamber of the boom cylinder 12, 123 is a pressure sensor that measures the pressure of pressure oil in the bottom chamber 121, 124 is a pressure sensor that measures the pressure of pressure oil in the rod chamber 122, and 14 is a hydraulic excavator. 1 hydraulic pump,
Reference numeral 15 is a hydraulic oil tank, and 16 is a control valve interposed between the hydraulic pump 14 and the boom cylinder 12.

Reference numeral 17 is a bucket operation lever, 18 is a turning operation lever, 171 is a pressure switch for detecting the pilot pressure when the bucket is operated in the dumping direction, 1
Reference numeral 81 is a pressure switch for detecting the pilot pressure when the hydraulic excavator 1 is turned left, and 182 is a pressure switch for detecting the pilot pressure when turning the right shovel. Note that 171, 181, and 182 can be replaced by pressure sensors. In that case, the load measuring device main body 19
A pressure threshold value for detecting the operation of the operation lever is provided inside, and the presence or absence of the operation is determined by comparing with the measured pressure.
Further, not only the pressure switch and the pressure sensor but also the electric signal may be used when the turning operation or the bucket dump operation is operated by the electric lever. Further, a sensor for detecting the turning angle and the turning angle of the bucket may be attached and the output thereof may be used as the right turning signal, the left turning signal and the bucket dump signal. Further, the output of the stroke sensor that measures the stroke of the bucket cylinder may be used as the bucket dump signal.

Reference numeral 19 is a load measuring device main body for calculating and measuring the earth and sand scooped by the bucket 13 based on various input data, and 20 is a rotation angle sensor for measuring the rotation angle of the pin at the base of the boom 11. , 21 is a teaching start button for starting teaching, 22 is a boom boundary angle teaching button for teaching the boom boundary angle of the boom 11, 2
Reference numeral 3 is a turning time teaching button for teaching the turning time.

In the load measuring device main body 19, a right turn signal S1 of the pressure switch 182, a left turn signal S2 of the pressure switch 181, and a bucket dump signal S of the pressure switch 171.
3, pressure signal S4 from the pressure sensor 123, pressure signal S5 from the pressure sensor 124, angle sensor signal S6 from the rotation angle sensor 20, teaching start signal S7 from the teaching start button 21, and boom boundary angle teaching button 22 Each signal of the teaching command signal S8 and the teaching command signal S9 from the turning boundary time teaching button 23 is input, the work determination and the load at that time are calculated, and the number of works is integrated.

The data of the load and the number of works calculated by the load measuring device main body 19 are transmitted via the radio device 24 to, for example, a management station which is installed in another place and which includes the radio device 26 and the management device 25. . The received data is taken into the computer 27 and output to the display device 28. In the present embodiment, the management device 25 is placed in an office that adjusts the amount of cement, and in the office, the amount of earth and sand to be put in by the hydraulic excavator and the number of operations should be grasped and put in based on the data displayed on the display device 28. Determine the amount of cement.

FIG. 3 shows the load measuring device body 19 shown in FIG.
It is a block diagram of.

The load measuring device main body 19 is mainly composed of a computer, 191 is an input interface which has an A / D converter and inputs various signals, 192 is a central processing unit (CPU) which executes various calculations and controls,
193 is a timer for outputting a time signal, 194 is a random access memory (R
AM), 195 is a read only memory (ROM) for storing various processing programs of the CPU 192, 19
Reference numeral 6 denotes an output interface for outputting the data calculated by the load measuring device main body 19 to the management device 25.
The ROM 195 stores a start program 195a, a work detection program 195b, a position teaching program 195c, and a turning boundary time teaching program 195d, which will be described in detail later.

As the work detection program 195b, as will be described in detail later, either the work detection program (1) or the work detection program (2) is stored and the work detection process is executed. The turning boundary time teaching program 195d is used when the work detection program (1) is used.

FIG. 4 is a view for explaining the boom boundary angle α which is used and preset when the load measuring device main body 19 is subjected to arithmetic processing.

The boom boundary angle α is set to a predetermined angle in the lower direction from the horizontal position of the hydraulic excavator 1, and is set based on the angle sensor signal S6 detected by the boom angle sensor 20 by the teaching process described later. The load measuring device main body 19 detects the work in which the hydraulic excavator 1 scoops earth and sand from the barge ship 3 and puts it into the hopper 4 based on the set boom boundary angle α. That is, if the boom boundary angle α is passed from above, the work of scooping out of the barge ship 3 with the bucket 13 is performed, and if the boom boundary angle α is passed from below and the boom boundary angle α is passed, a bucket containing dirt and sand is entered. 1
It can be determined that this is an operation of moving the 3 to the hopper 4.

FIG. 5 is a diagram showing waveforms of various signals input to the load measuring device main body 19 and waveforms of various signals arithmetically processed therein.

A is the set boom boundary angle α and the angle sensor signal S6 detected by the boom angle sensor 20.
In contrast, the boom boundary angle detection signal detected when the boom 11 crosses the boom boundary angle α, ΔPrb is the pressure difference between the bottom chamber 121 of the boom cylinder 12 and the rod chamber 122. The pressure difference ΔPrb may be replaced with the pressure difference between the bottom chamber 121 of the boom cylinder 12 and the rod chamber 122, and the pressure difference of the bottom chamber 121 may be used.

In this embodiment, when the output of the boom angle sensor 20 of the boom 11 passes through the boom boundary angle α, the boom angle sensor 20 is turned on to output the boom boundary angle detection signal a, and the output of the boom angle sensor 20 is again changed to the boom boundary angle α. It is designed to be turned off when it passes through and becomes smaller than the boom boundary angle α.

Further, as shown in the figure, when the boom boundary angle detection signal a is turned off, since there is no sediment in the bucket 13, ΔPrb shows a small value. Further, when the boom boundary angle detection signal a is detected again, the bucket 13 contains dirt and sand, and ΔPrb shows a large value. Further, when the boom boundary angle detection signal a is turned on, the right turn signal S1 is turned on and continues for a fixed time. This can be regarded as turning to the hopper 4.
If it is too short, it can be said that it is not an erroneous operation or a turning operation to the hopper 4. Next, the bucket dump signal S
When 3 is turned on, it indicates that the hydraulic excavator 1 has put earth and sand into the hopper 4. Next, when the left turn signal S2 is turned on and continues for a certain period of time, this indicates that the hopper 4 is turning to the barge ship 3. In this state, since the bucket 13 is empty, ΔPrb has a small value. That is,
If the differential pressure ΔPw between the pressure ΔPrb when the rightward turning signal S1 is detected and the pressure ΔPrb when the leftward turning signal S3 is detected is equal to or more than a certain pressure difference that actually causes a pressure change due to the sediment. The differential pressure ΔPrb immediately before the first bucket dump operation after the boundary angle detection signal is turned ON at a certain time is fetched. The load of earth and sand can be detected by multiplying this pressure difference ΔPrb by the pressure-weight conversion coefficient.

According to the present embodiment, since the bucket dump position does not change so much and the posture does not change, it is not necessary to make a correction at the time of load measurement, but the posture is determined by using the arm angle sensor or the bucket angle sensor. You may calculate and calculate load.

Next, the processing procedure of the position teaching program 195c of the load measuring device main body 19 will be described with reference to the flowchart shown in FIG.

This position teaching process is executed to teach the boom boundary angle and store it in the RAM 194 of the load measuring device body 19.

First, prior to the teaching process, when the operator of the hydraulic excavator 1 starts the engine (or pushes the dedicated button) to start the work of scooping out the soil from the barge ship 3 to the hopper 4, the operation shown in FIG. The shown start program 195a is executed. The start program 195a initializes various parameters.
For example, the flag information such as the detection flag Sr of the right turning operation, the left turning detection flag Sl, the bucket dump detection flag Bd, the signal S4 indicating that the boom boundary angle α has been passed, and the signals of S1, S2, S3, etc. The storage memory, boom cylinder pressure storage memory, etc. are initialized. This time,
The boom boundary angle α and the pressure-weight conversion coefficient are not initialized.

Next, when the operator in the cab of the hydraulic excavator 1 pushes the teaching start button 21 to perform the teaching process, the signal S7 is input to the load measuring device main body 19,
The position teaching program 195c shown in FIG. 3 is started.
In the teaching process, as shown in FIG. 4, an operating lever (not shown) is operated to lower the boom 12 toward the barge ship 3, and when the tip of the bucket 13 comes close to the barge ship 3, the boom shown in FIG. The boundary teaching button A22 is pressed. In step 1 of FIG. 6, it is determined whether or not the boom boundary angle teaching button 22 is pressed, and when it is pressed, the signal S6 detected by the boom angle sensor 20 at that time is sent to the load measuring device main body 19 in step 2. The boom angle is input, and the boom angle is fetched and stored as a boom boundary angle α.
Next, in step 3, since the boom boundary angle α has been set, the boom boundary setting flag Aup is turned on and the teaching is ended.

Next, the processing procedure when the work detection program (1) is used as the work detection program 195b stored in the load measuring device main body 19 will be described with reference to the flow charts shown in FIGS.

This work detection processing is executed to calculate various kinds of input data and measure the load and the number of works of the earth and sand scooped and transferred by the hydraulic excavator.

First, in step 11, in addition to the turning measurement time Tsw, various count values m, i, which will be described later,
n is initialized. Next, at step 12, it is determined whether or not the boom boundary angle detection signal a has changed (rised) from OFF to ON. Here, at the timing of turning on, as shown in step 13, the turning measurement time Ts
In addition to w, count values m and i are initialized. Next, in step 14, it is determined whether or not a rightward turning operation is being performed. If the operation is in progress, the measured tumbling time ΔTs is added to the turning measurement time Tsw as in step 15.
After that, in step 16, it is compared with a preset turning boundary time Tswref. Turning boundary time Ts
The wref is a time during which the hydraulic excavator is turning from when the boom boundary angle detection signal a is turned on to immediately before discharging the earth and sand. Here, when Tsw ≧ Tswref, the process proceeds to step 17, and the turning passing time Tpass at that time is taken out from the timer 198 and stored in the RAM 194. If the rightward turning operation is not being performed at step 14, it is determined at step 18 whether or not the leftward turning operation is being performed. At this time, if the turning operation in the left direction is being performed, the measurement sampling time ΔTs is subtracted from the turning measurement time Tsw as shown in step 19. By providing the processing of step 19, for example, when there is a dumping position in the right direction and a turning operation is performed in the left direction for some reason during the turning in the right direction and the turning is performed in the right direction again, it is more accurate. The turning measurement time Tsw can be measured. Next, in step 20, it is determined whether there is a bucket dump operation. If there is a bucket operation, the bucket operation start time Tbckt in step 21.
As (m), it is read from the timer 193 and stored in the RAM 194. Here, m represents the number of bucket dump operations, and the bucket dump operation in step 20 is not limited to the originally planned bucket dump operation (m = 3), as shown in the bucket dump signal S3 in FIG. Bucket operation that should not be measured for detection Dump operation (m = 1, 2)
Can be. Next, in step 22, after saving the boom cylinder pressure immediately before the bucket dump operation start time Tbckt (m) (for example, the average boom cylinder pressure PRrbb for a predetermined time ΔT immediately before Tbckt), step 23
And add 1 to the count value m. Next, in step 24, it is determined whether or not the boom boundary angle detection signal a changes from ON to OFF (falls). If it has changed, the processing from step 25 is performed. Here, the bucket dump operation that occurs within the elapsed time from the time when the boom boundary angle detection signal a changes from OFF to ON to the time when the boom boundary angle detection signal a changes from OFF to ON is for dumping soil. It is determined whether the operation is a bucket dump operation. First, in step 25, for each bucket operation number m measured in step 20, which bucket operation is the bucket operation for dumping is searched. Here, i represents the number of counts used in the process for searching the bucket dump for dumping, and for each bucket operation count m, the bucket dumb operation start time Tbckt (m) saved in step 21 is equal to the step 17. It is determined whether it is equal to or larger than the turning passage time Tpass stored in. If it is smaller, it is not judged as a predetermined bucket dump operation, and 1 is added to i in step 26 and the judgment is made again in step 25. If it is larger here, for example, in the case of m = 3 in FIG. 5, it is determined that the bucket 13 is on the hopper 4, and it is considered to be just before the soil is discharged. Therefore, in step 27, the average boom cylinder pressure ΔPRrbb for the predetermined time ΔT immediately before the bucket dump operation start time saved in step 22 is calculated, and the bucket dump attitude for each earthing does not change so much. The value multiplied by the coefficient k is taken as the load. Alternatively, an arm angle sensor, a bucket rotation angle, a bucket cylinder stroke sensor, or the like may be prepared, and the posture at the bucket dumping position may be measured to calculate the load. Then, step 28
At 1, the work count value n is incremented by 1 and stored as an integrated value of the number of works.

As described above, according to the present embodiment, since the bucket dump position is estimated based on the turning time, it is possible to prevent a bucket dump operation on a place other than on the hopper from being erroneously determined to be a dumping operation. The accuracy of the number of times of work can be improved.

Here, the turning boundary time (Tswre
The processing procedure by the turning boundary time teaching program used for setting f) will be described with reference to the flowchart shown in FIG.

When the teaching start button 21 is operated by the operator of the hydraulic excavator, the turning boundary time teaching program 195d starts execution. First, step 30
At, it is determined whether or not the turning boundary time teaching button 23 is ON. If ON, the operator turns the turning boundary time teaching button 2 immediately before dumping the bucket from the time when the boom angle passes the boom boundary angle α in step 31.
The turning time until 3 is pressed is the turning boundary time (Tswr
ef) is stored in the RAM 194. According to this setting method, the turning boundary time is automatically set by a simple operation,
The turning boundary time can be easily adjusted even if the turning angle of discharging the soil into the hopper 4 after scooping the soil changes.

Further, when the soil amount is calculated, the load measuring device main body 19 transmits the soil amount and the number of work to the management device 25 provided in the management department or the like via the wireless devices 23 and 26, and the transmitted data is , Necessary processing is performed by the computer and displayed on the display device 28. The display device 28 displays the time when the work is fixed, the amount of soil, the number of works, etc., so that the amount of soil scooped and the number of works can be grasped at a glance.

Next, FIG. 10 and FIG. 11 show the processing procedure when the work detection program (2) is used as the work detection program 195b stored in the load measuring device main body 19.
An explanation will be given using the flow chart shown in. This work detection process is also executed in order to calculate various kinds of input data and to measure the load and the number of works of the earth and sand scooped and transferred by the hydraulic excavator.

First, in step 41, various count values h, i, j described later are initialized.

Next, at step 42, it is judged if there is a right turn operation. Here, it is assumed that the right turn operation is performed in the right turn operation for 2 seconds. Therefore, in steps 43 and 44, it is determined whether the count value h has reached the preset value K1. As shown in step 45, the difference between the pressure PRr (th) of the bottom chamber 21 of the boom cylinder 14 and the pressure PRb (th) of the rod chamber 22 of the boom cylinder 14 is calculated for each count value h, and ΔPRr
The data is stored in the RAM 194 as b (th). When the count value h is a predetermined value K1, that is, 2 seconds have elapsed, S1
In 6, the right turn detection flag Sr is set to 1.

Next, at step 47, it is judged if there is a left turn. Similar to the case of turning to the right, in steps 48 and 49, it is determined whether or not the count value has reached the preset value K2. As shown in step 50, the difference between the pressure PLr (ti) of the bottom chamber 21 of the boom cylinder 14 and the pressure PLb (ti) of the rod chamber 22 of the boom cylinder 14 is calculated for each count value i, and ΔPLrb
The data is stored in the RAM 194 as (ti). When the count value i is the predetermined value K2, that is, when 2 seconds have elapsed, S51
The left turn detection flag Sl is set to 1.

Next, at step 52, it is judged whether or not there is a bucket operation. In steps 53 and 54, it is determined whether the count value has reached a preset value K3. If the count value j is the predetermined value K3, the bucket dump operation here is relatively fast, so operation for 1 second is regarded as bucket operation, and 1
When the second has elapsed, the bucket dump operation detection flag Bd becomes 1 in S55.

Next, at S56, a right turn detection flag S
It is determined whether all of r, the left turn detection flag Sl, and the bucket dump detection flag Bd are 1. If all the flags are 1, the process proceeds to step 57, and if not, S42.
Return to.

If YES in step 56, the process proceeds to step 57 and the generation order of signals is determined. That is, when the flag becomes 1 in the order of the right turn signal S1 → the bucket dump signal S3 → the left turn signal S2 as shown in FIG. 5, the process proceeds to “A” of the flowchart shown in FIG. By performing the determination in step 57, it is possible to accurately detect the work of scooping and turning the earth and sand of the hydraulic excavator to transfer it to another place.

Since the generation time of each operation read from the timer 193 is stored in the RAM 194, the generation order of the signals can be easily performed by comparing them. If the order of occurrence does not match, step 5
8, the right turn detection flag Sr and the left turn detection flag S
l and the bucket dump detection flag Bd are all set to zero. Further, in step 57, the generation order of the signals of right turn → bucket dump → left turn is determined, but it may be determined in the order of generation of left turn → bucket dump → right turn signals. In that case, the average value ΔPLrb and the average value ΔP
The difference from Rrb is obtained, and it is determined whether this difference is smaller than the predetermined value Pref.

If the occurrence order matches, step 59.
In, it is determined whether the boundary angle detection signal a is ON at the operation end time of the right turn or the left turn. That is, it can be determined whether or not the bucket 13 is turning in a state where the bucket 13 is filled with earth and sand.

If YES in step 59, it is determined in step 60 whether the boundary angle detection signal a has been turned off after the turning operation in the direction opposite to the first turning direction.

If YES in step 60, step 6
1, the average value ΣΔPRrb (th) / K of ΔPRrb (th) detected during the right turn in step 45.
1 and ΔP detected when turning left in step 50
The difference between the average value ΣΔPLrb (ti) / K2 of Lrb (ti) is obtained, and it is determined whether or not this difference is smaller than a predetermined value Pref. By this processing, the bucket 13 turns with no soil contained therein. It can be determined and excluded. Note that the processing of step 63 may be omitted although the work detection accuracy is somewhat lowered. Next, at step 64, the bucket dump operation start time Tbck
Average boom cylinder pressure PRr for a predetermined time ΔT immediately before t
Find bb. In step 65, the average boom cylinder pressure PRrbb is multiplied by a predetermined pressure-weight conversion coefficient k, and the amount of soil W (n) carried by the bucket 13 per time,
And soil volume ΣW accumulated by transporting soil volume W (n) n times
Find (n). In step 66, the number of operations is incremented each time one cycle of operation is performed. In the present embodiment, since the earth releasing attitude of the hydraulic excavator 1 during the bucket dump does not change so much, it is not necessary to make the correction when calculating the earth mass, but the attitude is obtained using the arm angle sensor or the bucket angle sensor. The load may be calculated by

If none of steps 59, 60, and 63 is satisfied, the process returns to step 58 of "B" of the flowchart shown in FIG. 10, all flags are set to zero, and the process returns to step 42. Further, every time the work detection is completed, the process returns to the step 41 of “C” and the work detection processing is repeated.

Note that step 59 and step 60
May be omitted, but the processing of these steps may be omitted.

As described above, according to the present embodiment, the work of dumping is accurately detected automatically with a relatively simple structure based on the operation by the operator or the sensor signal. Will never detect your work.

When the work is further decided, the load measuring device main body 19 transmits the data of the amount of soil and the number of works to the management device 25 provided in the management office or the like via the radios 23 and 26,
The transmitted data is processed by a computer and displayed on the display device 28. Since the time when the work is fixed, the amount of soil, the number of times of work, etc. are displayed on the display device 28, the amount of scooped-out soil and the number of times of work can be grasped at a glance.

[0064]

As described above, according to the present invention, the work of scooping a transported object and transferring it to another place is automatically determined to measure the load of the transported object. Compared with, the other work that should not be subjected to load measurement is not erroneously detected, and the accuracy of the accumulated soil volume to be transferred is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a work form of a hydraulic excavator operating on a hoisting ship.

FIG. 2 is a block diagram showing a load measuring device and a display device of a hydraulic excavator according to an embodiment of the present invention.

3 is a configuration diagram of a load measuring device body 19 shown in FIG.

FIG. 4 is an explanatory diagram of a boom boundary angle used in calculation of the load measuring device body 19 shown in FIG.

5 is a diagram showing various signal waveforms input to the load measuring device main body 19 shown in FIG. 2 and various signal waveforms internally processed.

FIG. 6 is a position teaching program 195 according to this embodiment.
It is a flow chart which shows the processing procedure of c.

FIG. 7 is a work detection program (1) according to the present embodiment.
It is a flow chart which shows the processing procedure of 195b.

FIG. 8 is a work detection program (1) according to the present embodiment.
It is a flow chart which shows the processing procedure of 195b.

FIG. 9 is a flow chart showing a processing procedure of a turning boundary time teaching program 195d according to the present embodiment.

FIG. 10 is a flow chart showing a processing procedure of a work detection program (2) 195b according to the present embodiment.

FIG. 11 is a flow chart showing a processing procedure of a work detection program (2) 195b according to the present embodiment.

[Explanation of symbols]

1 hydraulic excavator 2 unloading ship 3 barge 4 hoppers 5 pressure pump 11 boom 12 boom cylinder 121 Bottom chamber 122 Rod chamber 123,124 Pressure switch 13 buckets 17 Bucket operating lever 18 Turning operation lever 19 Load measuring device body 195b Work detection program 195c Position teaching program 195d Turning boundary time teaching program 20 Boom angle sensor 21 Teaching start button 22 Boom boundary angle teaching button 23 Turn boundary time teaching button 24, 26 radio 25 management device 27 Computer 28 Display

Continued front page    (72) Inventor Yasuo Tanaka             Hitachi Construction Machinery Co., Ltd.             Ceremony Company Tsuchiura Factory F-term (reference) 2D003 AA01 AB03 AB04 AC00 BA03                       BA04 BA06 BB07 DB01 DB02                       DB04 DB05 FA02

Claims (11)

[Claims] 1. A load measuring device for a hydraulic excavator that scoops and transports a transported object to another location, wherein a bottom side pressure and a rod side of a boom cylinder during a swiveling operation for transporting the transported object after scooping. Pressure detection means for measuring a differential pressure with respect to the pressure, differential pressure storage means for storing the differential pressure immediately before or after the bucket dump operation when the integrated value of the turning operation time reaches a predetermined value, and A load measuring device for a hydraulic excavator, comprising: load measuring means for calculating a load of the transported object from the stored differential pressure immediately before a bucket dump operation. 2. The angle detection means for measuring a boom angle of a hydraulic excavator according to claim 1, wherein the turning operation time measurement start time is when the measured boom angle reaches a predetermined value or more. A load measuring device for a hydraulic excavator, which starts at. 3. Any one of claims 1 and 2
5. The load measuring device for a hydraulic excavator according to claim 5, wherein the turning operation time is calculated by subtracting the turning operation time in the other turning direction from the turning operation time in one turning direction. 4. Any one of claims 1 to 3
In one claim, the differential pressure immediately before the bucket dump operation stored in the differential pressure storage means is an average differential pressure of the differential pressures detected by the pressure detection means during a predetermined period immediately before the bucket dump operation. Load measuring device for hydraulic excavators. 5. A load measuring device for a hydraulic excavator that scoops and transports a transported object to another place, wherein a swing operation in one swing direction of transporting the transported object, a bucket dump operation, and not transporting the transported object. Operation sequence detection means for detecting each operation sequence of the turning operation in the other turning direction, and measuring the differential pressure between the pressure on the bottom side and the pressure on the rod side of the boom cylinder of the hydraulic excavator during the one turning operation. And a load measuring means for calculating the load of the transported object from the differential pressure immediately before the bucket dump operation when the detected operation order is operated in a predetermined operation order. A characteristic load measuring device for hydraulic excavators. 6. A load measuring device for a hydraulic excavator that scoops and transports a transported object to another location, wherein a swing operation in one swing direction for transporting the transported object, a bucket dump operation, and not transporting the transported object. Operation order detection means for detecting each operation order of the turning operation in the other turning direction, and pressure on the bottom side and rod side pressure of the boom cylinder of the hydraulic excavator during the one turning operation and the other turning operation If the pressure detection means for measuring the respective differential pressure between and, the detected operation order is operated in a predetermined operation order, and the pressure difference of each of the measured differential pressure is a certain value or more, the one Load measuring means for calculating the load of the transported object from the differential pressure immediately before the bucket dump operation between the turning operation and the other turning operation. Load measuring device of pressure excavator. 7. The end of the one turning operation is detected while the boom of the hydraulic excavator is rotated by a predetermined angle or more, according to claim 6,
A turning operation confirming means for detecting a start of a turning operation in the other turning direction is provided, and the load measuring means operates the detected operation order in a predetermined operation order, and the turning operation checking means When the end and the start are detected, and the pressure difference of each of the measured differential pressures is equal to or more than a certain value, the transported object is changed from the differential pressure immediately before the bucket dump operation in the turning operation in the one turning direction. A load measuring device for a hydraulic excavator, which is characterized by calculating the load. 8. Any one of claims 5 to 7
In one claim, the differential pressure immediately before the bucket dump operation is an average differential pressure of the differential pressures detected by the pressure detection means during a predetermined period immediately before the bucket dump operation during the one turning operation. A characteristic load measuring device for hydraulic excavators. 9. Any one of claims 5 to 8
In one claim, the operation sequence detecting means performs the respective turning operation when the respective operation times of the turning operation in the one turning direction and the turning operation in the other turning direction are continued for a predetermined time. A load measuring device for a hydraulic excavator, which is provided with an operation determining means for determining. 10. The work according to any one of claims 1 to 9, wherein the load measuring means measures the number of times of work of scooping and rotating the transported object to another place. A load measuring device for a hydraulic excavator, characterized in that it is provided with a number-of-times measuring means and a load accumulating means for accumulating a load for each number of times of work. 11. The measurement data according to any one of claims 1 to 10 which is arranged at a remote location from a load measuring device main body of the hydraulic excavator and receives measurement data measured by the load measuring means. A load measuring device for a hydraulic excavator, which is provided with management means for processing and displaying.