JPH0624444Y2 - Control device for boom type work machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a control device for a boom type working machine such as a backhoe.

(Prior Art) A boom-type working machine in which a boom having a working tool at its tip is swingably provided around a vertical axis on a vehicle body, and a predetermined work is performed by the working tool while swinging the boom around the vertical axis during work. Is, for example, a backhoe.

The backhoe is equipped with a swing frame that can be swung around the vertical axis by expanding and contracting the swing cylinder on the machine frame mounted on the vehicle body. This swing frame can be moved up and down around the vertical axis by expanding and contracting the boom cylinder. Is equipped with a boom, the bucket is flexibly pivotally attached to the tip of the boom via an arm, and the swing cylinder, boom cylinder, arm cylinder, and bucket cylinder are
The expansion / contraction is controlled by a control valve that is linked to the operating lever.

(Problems to be solved by the invention) When excavating with a backhoe of this type, after scooping soil into the bucket, swing the boom together with the swing frame to the side soil discharge position for soil removal. There is a need. Therefore, during the excavation work, the boom has to be repeatedly rocked between the excavation position and the earth removal position, and the operation is very complicated by the conventional artificial control by the operation lever, which requires skill. was there.

Especially when the groove width to be excavated is narrow, stopping accuracy when stopping the boom at the excavation position after soil removal is required, but it is difficult to always reliably stop at the intended stop position, that is, the excavation position. is there. Therefore, in the conventional method, the boom is temporarily stopped in the vicinity of the target stop position, and then the boom is rocked from the overrun position or the underrun position to the final target stop position while slightly moving the rocking cylinder again. Was often taken.

When returning the boom to the excavation position, it is necessary to control the arm and bucket to move to the next excavation posture.
There was a drawback that I could not concentrate on controlling the stop position of the boom.

In view of the conventional problems as described above, the present invention can automatically stop the boom at the target position at the time of work by setting the target position at which the boom should be stopped at the start of work. An object of the present invention is to provide a control device capable of smoothly stopping the boom at the target position when the boom swings to the target position and stops, as the boom approaches the target position. To do.

(Means for Solving the Problem) As a means for solving the problems, the present invention provides a boom 16 having a working tool 18 at its tip end on the vehicle body 1 so as to be swingable around a vertical axis 14,
In a control device for a boom type working machine provided with a control valve 60 for controlling the swing of the boom 16, a setting means 89 for setting a target position at which the boom 16 should stop swinging, and a swing position of the boom 16 are detected. Position detecting means 24, a deviation means 90 for obtaining the deviation between the setting signal from the setting means 89 and the detection signal from the position detecting means 24, and the operation direction of the boom 16 is determined by the magnitude of the deviation signal from the deviation means 90. Determining means 115, pulse width modulating means 96 for pulse width modulating the deviation signal, and the pulse signal from the pulse width modulating means 96
And a drive means for driving the control valve 60 in proportion to the deviation signal in the operation direction of the boom 16 determined by the above.

(Operation) When the boom 16 is returned to the digging position at the center of the left and right after the soil is removed, if the target position is set in advance by the setting means 89, the manual / automatic changeover switch 92 is simply pressed to push the boom 16
Automatically stops at the target position.

Since the position detecting means 24 detects the current position of the swing frame 15 and the detection signal from the variable resistor 91 is input to the deviation means 90, the deviation means 90 causes the deviation means 90 to set the signal from the setting means 89 and the position detecting means 24.
Deviation from the detection signal from, and the deviation signal via the changeover switch 92 the discrimination means 115 and the pulse width modulation means 96
Send to. Then, the discriminating means 115 discriminates the left swing command and outputs the left swing signal, and the analog switch 105 is turned on. On the other hand, since the pulse width modulation means 96 pulse width modulates the deviation signal, the left solenoid 61 of the electromagnetic control valve 60 is excited via the analog switch 105 and the driving means 111. Therefore, the electromagnetic control valve 60 is switched to the right swing side at an opening proportional to the deviation signal, and the swing frame 1 and 2 are expanded and contracted to swing the frame 1.
5. The boom 16 swings around the vertical axis 14 to the target position. In this case, the deviation signal becomes smaller as the position approaches the target position, so the deviation signal gradually decreases. When the target position is reached, the deviation signal becomes zero.
60 returns to neutral, and the swing frame 15 and the boom 16 stop smoothly at the target position.

(Example) The drawings illustrate an example in which a front loader and a backhoe are mounted in front of and behind a tractor.

In FIG. 2, 1 is a tractor vehicle body, 2 is a front wheel, and 3 is a rear wheel. 4 is a steering wheel and 5 is a driver's seat.

Reference numeral 6 denotes a front loader mounted on the front part of the tractor vehicle body 1. The masts 7 are attached to both left and right sides of the tractor vehicle body 1, and a boom 8 pivotally attached to an upper end of the mast 7 so as to be vertically movable. It has a boom cylinder 9 for moving the boom 8 up and down, a bucket 10 pivotally attached to the tip of the boom 8, and a bucket cylinder 11 for rotating the bucket 10.

Reference numeral 12 is a backhoe attached to the rear end of the tractor body 1, and includes a machine frame 13 attached to the tractor body 1 and a machine frame 13.
A rocking frame 15 pivotally mounted on the rocking shaft 13 about a vertical axis 14 and a boom 16 pivotally mounted on the rocking frame 15 so as to be vertically movable about the horizontal axis.
And an arm 17 pivotally attached to the tip of the boom 16
And a bucket 18 pivotally attached to the tip of the arm 17
And a control box 19 and a driver's seat 20 provided on the swing frame 15.

As shown in FIG. 4, the swing frame 15 is supported by a pair of upper and lower brackets 21 protruding rearward from the machine frame 13 via a vertical axis 14,
Further, a pair of left and right rocking cylinders 22 and 23 interposed between the machine frame 13 and the rocking frame 15 near the lower bracket 21 perform rocking operation. Position detecting means 24 for detecting the swing position of the swing frame 15 is attached to the swing frame 15. The position detecting means 24 includes a variable resistor 91 so that the detection signal continuously changes depending on the swing position of the swing frame 15.

The boom 16 can be moved up and down by a boom cylinder 25, and the arm 17 can be bent by an arm cylinder 26.
Are rotatably operated by bucket cylinders 27, respectively.

Outriggers 28 and 29 are mounted on the left and right sides of the machine casing 13 as shown in FIG. The outriggers 28, 29 are hydraulic cylinder type, and the cylinder bodies 30, 31 are vertically mounted on the machine frame 13, and the ground plates 34, 35 are attached to the lower ends of the piston rods 32, 33. The outriggers 28, 29 are provided with subsidence amount detection means 36, 37 which are interlocked with the vertical movement of the ground plates 34, 35 and detect the subsidence amount of the ground plates 34, 35. The subsidence amount detection means 36 and 37 are the cylinder bodies 30 and 31.
Cylindrical sensor bodies 38, 39 attached to, and rods 40, 41 vertically slidably inserted into the sensor bodies 38, 39,
With the sensing plates 42a, 43a provided at the lower ends of the rods 40, 41, the relative resistance of the rods 40, 41 relative to the sensor bodies 38, 39, the variable resistance 42, which is incorporated in the sensor bodies 38, 39. The value of 43 changes. Sensing plates 42 and 43 are ground plates 3
It engages with 4, 35 from above and contacts the ground when the ground plates 34, 35 sink.

On the upper surface side of the control box 19, as shown in FIG. 5, two operation levers 44 and 45 that can swing back and forth and left and right around two axes orthogonal to each other, and two that can swing back and forth. And operating levers 46 and 47 are provided. Operating lever 44
The rocking frame 15 swings left and right when it is operated left and right, and the arm 17 bends and extends when it is operated back and forth. When operating the lever 45 left and right, the bucket 18
The boom 16 moves up and down when it is dumped and operated back and forth. Operation levers 46 and 47 are outrigger 2
It is for 8 and 29, and the value of variable resistors 48 and 49 changes when it is operated back and forth.

FIG. 6 shows a hydraulic circuit, and 118 is a hydraulic pump, which is driven by an engine mounted on the tractor body 1. Reference numeral 119 is a flow rate priority valve, and 50 is a steering valve interlocking with the steering wheel 4, which controls the steering operation of the front wheels 2 via the steering cylinder 51. Reference numeral 52 is a boom control valve on the front loader 6 side, 53 is a bucket control valve on the front loader 6 side, and the boom cylinder 9 and the bucket cylinder 11 are controlled by manually operating these control valves 52, 53.

54 and 55 are flow rate proportional electromagnetic control valves for controlling the outriggers 28 and 29.
Have 59. Reference numeral 60 is a flow rate proportional electromagnetic control valve for controlling the swing cylinders 22 and 23, and includes a left solenoid 61 and a right solenoid.
Has 62. Reference numeral 63 is a boom control valve that controls the boom cylinder 25 of the backhoe 12, and is linked to the forward / backward operation of the operation lever 45. Reference numeral 64 is an arm control valve that controls the arm cylinder 26, and is linked to the front-back operation of the operation lever 44. Reference numeral 65 is a bucket control valve for controlling the bucket cylinder 27, which is interlocked with the left / right operation of the operation lever 45. 66-73 relief valve.

The electric circuit for controlling the electromagnetic control valves 54, 55, 60 is constructed as shown in FIG. The variable resistors 42 and 43 are variable resistors for raising / lowering commands of the outriggers 28 and 29, and are adapted to interlock with the forward / backward operation of the operating levers 46 and 47. 74 and 75 are up-and-down discrimination means, which are composed of up-comparison sections 76 and 77 and down-comparison sections 78 and 79, and up-comparison sections 76 and 77 when the command signal from the variable resistors 42 and 43 is larger than the up-reference value. The up signal is output from the down comparator, and the down comparators 78 and 79 output the down signal when the down signal is smaller than the down reference value.

Reference numerals 80 and 81 denote storage means composed of sample and hold circuits.When the switches 82 and 83 at the upper ends of the operating levers 46 and 47 are turned on, the detection signals from the variable resistors 48 and 49 of the squat amount detection means 36 and 37 are used as setting signals. It is designed to be remembered. 84 and 85 are deviation means, which are detection signals from the variable resistors 48 and 49 and storage means 80 and 81.
The deviation signal is obtained by comparing the deviation signal with the setting signal from the above, and when the detection signal is smaller than the setting signal, the deviation signal is output. Reference numerals 86 and 87 are manual / automatic changeover switches, which are adapted to switch and connect the variable resistors 42 and 43 and the deviation means 84 and 85 to the subsequent stage, and these changeover switches 86 and 87 are adapted to interlock with each other. .

Reference numeral 88 is a variable resistance of the swing command means, which is interlocked with the left and right operation of the operation lever 44, and the command signal changes in proportion to the operation amount of the operation lever 44.

89 is a setting means for setting a target position of the swing frame 15 at which it should be stopped, and is constituted by a variable resistor. 90 is a deviation means,
Detection signal from variable resistor 91 of position detecting means 24 and setting means
The deviation from the set signal from 89 is calculated and the deviation signal is output. Reference numeral 92 is a manual / automatic changeover switch for controlling the swing frame 15, which is adapted to switchably connect the variable resistor 88 of the command means and the deviation means 90 to the subsequent stage. The changeover switches 86 and 87 are provided on the upper surface of the control box 19.

A triangular wave oscillator 93 oscillates a triangular wave signal a having a constant frequency as shown in FIG. Reference numeral 115 is a swing determination means, which has left and right comparing units 116 and 117, compares the command signal from the variable resistor 88 with a reference value, and outputs a left swing signal and a right swing signal based on the magnitude relationship. It is like this. 9
Reference numerals 4,95,96 denote pulse width modulation means for pulse-width modulating the signal b from the variable resistors 42,43,88 or the deviation means 84,85,90 with the triangular wave signal a. Comparison section 97,9
It is composed of 8,99,100,101,102. Comparison section 97,98,99
And the inputs of the comparison units 100, 101 and 102 are opposite, and the comparison units 97, 98 and 99 convert the signal b to the triangular wave signal a as shown in FIG.
A pulse signal c which is turned on when the signal b is smaller than the triangular wave signal a and is turned on when the signal b is smaller than the triangular wave signal a and is turned off when the signal b is larger than the triangular wave signal a. Is to occur. Each comparison section 97, 98,
The output side of 99, 100, 101, 102 is analog switch 103-108,
Pulse signals from the comparison units 97, 98, 99, 100, 101, 102 are connected to the solenoids 56, 57, 58, 59, 61, 62 of the electromagnetic control valves 54, 55, 60 via the driving means 109 to 114, respectively. Thus, the electromagnetic control valves 54, 55, 60 are driven in proportion to the signals from the variable resistors 42, 43, 88 or the deviation means 84, 85, 90.

The analog switches 103 to 108 are adapted to be turned on when there is a signal from the comparing section 76, 77, 78, 79, 116, 117 of the discriminating means 74, 75, 115.

Next, the operation of the above configuration will be described. When excavating work with the backhoe 12, the boom 8 of the front loader 6 is lowered to ground the bucket 10, and the ground plates 34, 35 of the outriggers 28, 29 provided on both sides of the machine frame 13 on the backhoe 12 side are grounded. These front loaders 6
Also, the tractor vehicle body 1 is supported by the pair of left and right outriggers 28, 29.

When lowering the pair of left and right outriggers 28 and 29, operating the left and right operation levers 46 and 47 forward reduces the resistance value of the variable resistors 42 and 43 in conjunction with this, and a command signal proportional to the operation amount is generated. Get out. When this command signal is sent to the discriminating means 74, 75, since the command signal is small, the comparing units 78, 79 discriminate the descending command and output the descending signal, and the analog switches 106, 107 are turned on. On the other hand, the command signal b is input to the comparison units 97, 98, 100, 101 of the pulse width modulation means 94, 95 and compared with the triangular wave signal a of the triangular wave oscillator 93. In this case, since the command signal is smaller than the midpoint voltage, the comparison units 100 and 101 compare the two, and the command signal b is the triangular wave signal a, contrary to FIG.
When the pulse signal c is smaller than the comparison signal 100, 10
It occurs from 1. The larger the deviation between the two is, the wider the pulse width of the pulse signal c is.
The drive means 112, 113 operate via 6, 107, and the electromagnetic control valve 5
Energize the descending solenoids 58 and 59 of 4,55. As a result, the electromagnetic control valves 54, 55 are switched to the lower side at an opening proportional to the pulse width and supply hydraulic oil to the cylinder bodies 30, 31 of the outriggers 28, 29. , 35 descends and touches the ground. In this case, since the outriggers 28 and 29 operate at a speed proportional to the operation amount of the operation levers 46 and 47, the outriggers 28 and 29 can descend at any speed.

When the ground plates 34, 35 are in contact with the ground and the tractor body 1 is horizontal, the operation levers 46, 47 are returned to the neutral position and the outrigger 2
The lowering operation of 8,29 is stopped, the manual / automatic changeover switches 86,87 are switched to the automatic side, and the work by the backhoe 12 is started.

If the changeover switches 86 and 87 are set to the automatic side during the work, the tractor body 1 can be maintained substantially horizontal at a predetermined ground clearance. That is, when the ground plates 34, 35 of the outriggers 28, 29 are lowered, the rods 40, 41 of the sinking amount detecting means 36, 37 are lowered,
The resistance values of the variable resistors 48 and 49 change in proportion to the descending amounts of the ground plates 34 and 35. Therefore, when the switches 82 and 83 are turned on when the tractor body 1 becomes substantially horizontal, a signal indicating the current posture is input from the variable resistors 48 and 49 to the storage units 80 and 81 and stored as a setting signal. During work, for example, when the ground plate 34 on the left side sinks into the ground as shown in FIG. 8 in a local soft ground, the sensing plate 42a of the sinking amount detecting means 36 touches the ground and pushes up relatively. Therefore, the resistance value of the variable resistor 48 is reduced by the amount of sinking. Then, this detection signal is the deviation means 84
, The deviation means 84 obtains the deviation between the setting signal and the detection signal, and the deviation signal is sent to the judging means 74 and the pulse width modulating means 94 via the changeover switch 86. Therefore,
Simultaneously with the above-described descent, the descent signal is output from the comparison unit 78 of the determination unit 74, and the deviation signal is pulse-width modulated with the triangular wave signal a from the comparison unit 100 of the pulse-width modulation unit 94 to output the analog switch 106. , The electromagnetic control valve 54 is switched to the lower side via the drive means 112, and the left outrigger
The ground plate 34 of 28 descends by the amount of subsidence. And ground plate
When 34 is lowered by the amount of subsidence, the sensing plate 42a of the subsidence amount detecting means 36 is grounded on the ground and relatively descends, so that the resistance value of the variable resistor 48 becomes large, and the detection signal at that time becomes the set signal. When they coincide, the electromagnetic control valve 54 returns to neutral. As a result, the tractor body 1 is always controlled to be substantially horizontal and is maintained at a predetermined ground clearance.

In the excavation work by the backhoe 12, when the earth and sand in the bucket 18 is discharged to the side earth discharging position, after the boom 16 is raised, the rocking frames 1 and 2 are expanded and contracted by the rocking cylinders 22 and 23.
5. Swing the boom 16 around the vertical axis 14 to the soil discharging position.
That is, when the operation lever 44 is operated to the left, the resistance value of the variable resistor 88 decreases in conjunction with this, and a command signal proportional to the operation amount is output. When this command signal is sent to the determination means 115, the command signal is small, so the comparison unit 117 determines that it is a right swing command, outputs a right swing signal, and turns on the analog switch 108. On the other hand, the command signal b is input to the comparison units 99 and 102 of the pulse width modulation means 96 and compared with the triangular wave signal a of the triangular wave oscillator 93. In this case, since the command signal b is smaller than the midpoint voltage, the comparison unit 102 compares the two, and the pulse signal which is turned on when the command signal b is smaller than the triangular wave signal a contrary to FIG. c is generated by the comparison unit 102. The larger the deviation between the two, the wider the pulse width of the pulse signal c. Therefore, the driving means 1 is driven through the analog switch 108.
14 operates to excite the right solenoid 62 of the electromagnetic control valve 60. As a result, the electromagnetic control valve 60 switches to the right swing side at an opening proportional to the pulse width, and supplies the hydraulic oil to the swing cylinders 22 and 23, so that the swing frame 15 and the boom 16 rotate about the vertical axis 14. Swing to the right. In this case, since the boom 16 swings at a speed proportional to the operation amount of the operation lever 44, the boom 16 can be moved at an arbitrary speed.

When the boom 16 reaches the soil discharging position, the operation lever 44 is returned to the neutral position, the expansion and contraction of the swing cylinders 22 and 23 is stopped, and the swing frame 1
5. After stopping the boom 16 at the soil discharging position, the soil in the bucket 18 is discharged.

When the boom 16 is returned to the digging position in the center of the left and right after soil removal, if the target position is preset by the variable resistance of the setting means 89, the boom 16 can be moved by simply pressing the manual / automatic changeover switch 92. It can be automatically stopped at the target position. Therefore, the operator can concentrate on the operation of the arm 17, the bucket 18, and the like.

That is, the position detection means 24 detects the current position of the swing frame 15,
Since the detection signal from the variable resistor 91 is input to the deviation means 90, the deviation means 90 obtains the deviation between the setting signal from the setting means 89 and the detection signal from the position detecting means 24, and the deviation signal is used as the changeover switch 92. To the discrimination means 115 and the pulse width modulation means 96. Then, in the same manner as described above, the determination means 115
Discriminates the left swing command, outputs a left swing signal, and the analog switch 105 is turned on. On the other hand, since the pulse width modulation means 96 pulse width modulates the deviation signal, the analog switch 10
5, the left solenoid 61 of the electromagnetic control valve 60 via the drive means 111
Is excited. Therefore, the electromagnetic control valve 60 is switched to the right swing side at an opening proportional to the deviation signal, and the swing frame 15 and the boom 16 swing to the target position around the vertical axis 14 by the expansion and contraction operation of the swing cylinders 22 and 23. Move. In this case, since the deviation signal becomes smaller as the target position is approached, the speed gradually decreases. When the target position is reached, the deviation signal becomes zero, so the electromagnetic control valve 60 returns to the neutral position, and the swing frame 15 and the boom 16 stop smoothly at the target position.

It should be noted that this operation is performed only while the changeover switch 92 is continuously pressed, and the rocking frame 15 can be stopped even if the changeover switch 92 is released.

Vehicles and work machines are not limited to tractors and backhoes.

According to the present invention, the setting means 89 for setting the target position at which the boom 16 should stop swinging, the position detecting means 24 for detecting the swinging position of the boom 16, and the setting means 89 are used. Deviation means 90 for finding the deviation between the setting signal and the detection signal from the position detection means 24
A discriminating means 115 for discriminating the operating direction of the boom 16 based on the magnitude of the deviation signal from the deviation means 90, a pulse width modulating means 96 for modulating the pulse width of the deviation signal, and a pulse signal from the pulse width modulating means 96. Since the control means comprises a drive means for driving the control valve 60 in the operating direction of the boom 16 determined by the determination means 115 in proportion to the deviation signal, a target position for stopping the boom 16 at the start of work is set. By doing so, the boom 16 can be automatically stopped at that position when working, and when the boom 16 stops, the swing speed gradually decreases as the boom 16 approaches the target position. The boom 16 can be smoothly stopped at the target position.

Furthermore, the present invention is a command means for issuing a command to swing the boom 16.
Equipped with 88, the command signal from the command means 88 and the deviation means 90
Since the changeover switch 92 for selectively sending the deviation signal from the latter to the discrimination means 115 and the pulse width modulation means 96 in the subsequent stage is provided, the boom 16 is controlled by the command means 88 and stopped at the target position described above. Control and can be arbitrarily selected as required.

[Brief description of drawings]

The drawings illustrate one embodiment of the present invention.
Fig. 2 is an electric circuit diagram of the solenoid valve control circuit, Fig. 2 is a side view of the whole, Fig. 3 is a rear view of the outrigger part, Fig. 4 is a sectional plan view of the swing part, and Fig. 5 is a plan view of the control box. FIG. 6 is a hydraulic circuit diagram, FIG. 7 is a waveform diagram, and FIG. 8 is an operation explanatory diagram. 1 ... tractor body, 6 ... front loader, 12 ... backhoe, 24 ... position detection means, 54, 55, 60 ... electromagnetic control valve, 74, 75, 115 ... discrimination means, 89 ... setting means, 90 ......
Deviation means, 93 ... Triangular wave oscillator, 94,95,96 ... Pulse width modulation means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-6403 (JP, A) JP-A-59-203131 (JP, A) JP-A-59-52031 (JP, A)

Claims (3)

[Scope of utility model registration request] 1. A boom 16 having a working tool 18 at its tip is mounted on a vehicle body 1.
In the control device for the boom type work machine, which is swingably provided around the vertical axis 14 and has the control valve 60 for controlling the swing of the boom 16, the setting for setting the target position at which the boom 16 should stop swinging Means 89, position detecting means 24 for detecting the swing position of the boom 16, setting signal from the setting means 89 and position detecting means 24
Deviation means 90 for obtaining a deviation from the detection signal from the deviation means, a judgment means 115 for judging the operation direction of the boom 16 based on the magnitude of the deviation signal from the deviation means 90, and a pulse width modulation means 96 for pulse width modulating the deviation signal. , The boom 16 discriminated by the discrimination means 115 by the pulse signal from the pulse width modulation means 96.
And a drive means for driving the control valve 60 in proportion to the deviation signal in the direction of the movement of the boom type work machine. 2. A command means 88 for issuing a command for swinging the boom 16 is provided, and a command signal from the command means 88 and a deviation signal from the deviation means 90 are discriminated at a subsequent stage and a pulse width modulation means 9 is provided.
6. The control device for a boom type working machine according to claim 1, further comprising a changeover switch 92 for selectively sending to 6. 3. The pulse width modulating means 96 is a triangular wave oscillating means 93.
And the deviation signal from the deviation means 90 or the command signal from the command means 88 are compared by comparators 89 and 102 to obtain a pulse signal. Boom-type work machine control device described in.