JPS63236827A - Controller for excavator - Google Patents

Abstract

PURPOSE:To lessen setting error of target value, raise the accuracy of control, and enhance response of controller by using a controller having a bucket lever neutral sensor, an inclination angle sensor, a target value setter, and three arithmetic units. CONSTITUTION:A bucket lever neutral sensor 47, an inclination angle sensor 48, and a target value setter 54 to set up a detected value of bucket inclination angle as a target value during the neutral period from the sensor 47 are provided. A controller 5 which has first, second, and third arithmetic units 51, 52, and 53 and serving to control the supply and discharge of pressure oil to and from bucket cylinder 41 according to deviation between the target value and actual inclination angle is provided. An arm 3 is rotated only by operating arm lever 32, and at the same time the tilting angle of the boom 2 is automatically controlled in such a way as to tilt the bucket 4 at a fixed inclination angle to a reference level, permitting excavation to be made in parallel with the ground surface at given excavating angle and depth.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an M'llJ device for an excavator, which effectively controls the inclination angle of a bucket.

(Prior art) In order to excavate parallel to the ground, an excavator moves the bucket parallel to the ground while rotating the arm while controlling the bucket so that the angle of inclination with respect to the ground remains constant (for example, a special excavator). (Kokai No. 58-47833) is known.

However, in the conventional device, the operator manually sets the target tilt angle of the bucket each time when the bucket starts moving in parallel.
11 settings, it is necessary to recognize the actual bucket inclination angle, which is very troublesome to recognize and manually set, and requires a high degree of skill and experience, which can lead to setting errors. This has the disadvantage that it is difficult to control with high precision. In addition, in the past, feedback control was performed only based on the deviation between the manually set target value and the actual tilt angle detected by the bucket tilt angle detector, so the arm lever was not operated before the arm lever was operated. The control valve, the arm cylinder, and the arm are sequentially actuated, resulting in a change in the bucket inclination angle, and then the bucket inclination angle is detected, and the bucket IIIll valve is actuated based on the deviation between the inclination angle and the target value, The bucket cylinder is activated and the bucket inclination angle is 1111'
Therefore, especially at the start of control, there is a mechanical delay, mainly a response delay in the hydraulic system, from when the arm lever is operated until the bucket is controlled to a predetermined target value, which impairs control accuracy. The problem was that it was bad.

(Object of the Invention) The present invention has been made to solve such problems, and its first purpose is to enable easy and accurate setting of target values, and to prevent setting errors from occurring. Without,
The purpose is to enable highly accurate control, and a second purpose is to roughly improve the responsiveness at the start of control, thereby improving control accuracy.

(Structure of the Invention) The first gist of the present invention is a working machine consisting of a boom, an arm, and a bucket, a boom cylinder, an arm cylinder, and a bucket cylinder for operating these working machines, and a boom lever, an arm lever, and a bucket lever. This w1vss position of an excavator is equipped with a work equipment oil supply device that controls the supply of pressure oil to the boom cylinder, arm cylinder, and bucket cylinder according to each operation, and the w1vss position of the excavator is such that the neutral position of the bucket lever is controlled. A bucket lever neutral detection means for detecting, an inclination angle detection means for detecting an inclination angle of the bucket with respect to a predetermined reference plane, and an inclination angle detection means when a bucket lever neutral signal is output from the bucket lever neutral detection means. target value setting means for setting the detected value of the bucket inclination angle as a target value; and a target value setting means for setting the detected value of the bucket inclination angle as a target value; The bucket inclination angle is kept constant by supplying and discharging pressure oil to
The present invention is characterized in that it is equipped with a control means for controlling iIII.

With this configuration, the bucket inclination angle immediately after returning the bucket lever to the neutral position is automatically and accurately set as the target value. Therefore, there is no need for the operator to set the target value one by one, and there is no possibility of a setting error occurring. After the target value is automatically set, the tilt angle of the bucket is smoothly controlled to be constant based on the deviation between the target value and the detected bucket tilt angle detected by the tilt angle detection means. , control accuracy is improved.

Further, the second gist is that in the above configuration, the bucket tilt angle control signal is calculated according to the deviation between the target value outputted from the target value setting means and the bucket tilt angle outputted from the tilt angle detection means. 1 calculation means, a second P14w means for calculating the bucket tilt angle υ1611 signal according to the operation amount of the arm lever, and &111 from both of the above calculation means.
vjI11 which controls the supply and discharge of pressure oil to and from the bucket cylinder based on the g signal to keep the bucket inclination angle constant;
It is equipped with means.

With this configuration, at the start of 171111, when the arm lever is operated, the correction required tilt angle of the bucket is calculated by the second calculation means according to the amount of operation, and the angle of inclination of the bucket relative to the reference plane is calculated according to the amount of operation of the arm lever. Feedforward with a constant inclination angle i,++ m s is started, and the arm and bucket are operated almost simultaneously, eliminating any response delay. Also after that,
When the bucket starts moving, the first calculation means calculates 14 g.
The correction required tilt angle of the bucket is calculated according to the deviation between the target value set in the value setting means, the tilt angle, and the limit tilt angle detection value detected by the detection means, and the reference plane of the bucket is calculated according to the deviation. Feedback 1iIII control is performed to keep the inclination angle constant. In this way, proper control is performed at the same time as the arm is operated, and IIIwJ accuracy is greatly improved.

<Embodiment> FIG. 3 shows an example of an excavator. In this excavator, a boom 2 is supported on the excavator body 1 via a shaft 11 so as to be able to move up and down freely, and a shaft 12 is attached to the tip of the boom 2. A bucket 4 is rotatably supported at the tip of the arm 3 via a port 13, the boom 2 is lifted up and down by a boom cylinder 21, and the arm 3 is The bucket 4 is rotated by the cylinder 31, and the bucket 4 is rotated by the bucket cylinder 41.

In this excavator, for example, when the arm cylinder 31 is extended and contracted to rotate only the arm 3, the angle between the arm 3 and the bucket 4 remains constant, and the bucket 4 also rotates around the axis 12 together with the arm 3. It is rotated and excavation is performed in an arc shape around the shaft 12.

On the other hand, when excavating parallel to the ground 14 at a certain depth, the reference plane (for example, horizontal plane) 15
It is necessary to correct by rotating the bucket 4 so that the angle α of the bucket 4 with respect to the angle α becomes constant, and the following control device is provided for this correction.

FIG. 1 is a block diagram of the control device, and FIG. 2 is its hydraulic-electrical circuit diagram. In these figures, 22 is a boom lever, 23 is a boom operation valve, 24 is an electromagnetic proportional pressure reducing valve, 2
5 is a selection means, 26 is a boom 1lltll valve, and 3
2 is arm lever, 33 is arm & Il 10 valve, 35
is a means for detecting the amount of operation of the arm lever 32. Also, 4
2 is a bucket lever, 43 is a bucket operating valve, 44 is an electromagnetic proportional pressure reducing valve, 45 is a selection means, 46 is a bucket 111
11 valve, 47 neutral detection means for bucket lever 42, 4
8 is an inclination angle detection means for the bucket 4, 5 is a controller, and 51, 52, 53 are first . Second. 54 is a target value setting means, 55 and 56 are amplifiers, and 57 is a mode changeover switch for selecting manual or automatic mode.

The above-mentioned levers 22, 32, 42 and mode changeover switch 57 are provided in the operator's cab of the carpet cutting machine main body 1 shown in FIG. As shown in Fig. 2, primary pressure is input to the boom operation valve 23.7, the boom operation valve 33, and the bucket operation valve 43 from the pilot oil pressure Ij61 on the primary side, and each lever 22.32゜42 is input on the secondary side. A pair of variable pressure reducing valves 23B, 23b and 338 that output pilot pressure according to the amount of operation
331) and 43a and 43b are used. Boom control valve 26, arm tIqlil valve 34, bucket tI
A pilot type directional control valve is used for each of the III valves 46.

The boom electromagnetic proportional pressure reducing valve 24 and the bucket electromagnetic proportional pressure reducing valve 44 are operated by respective calculation means 51, 52 of the controller 5,
It outputs a hydraulic signal (pilot pressure) to the secondary side in proportion to the electric signal input from 53 through amplifiers 55 and 56. The selection means 25 includes an electromagnetic selection valve 25a and a pressure selection valve 25b.

25c, and the selection means 45 is configured by the electromagnetic selection valve 4.
6a and high pressure selection valves 45b and 46G. The electromagnetic selection valves 25a, 46a are switched by electrical signals from the controller 5.

The arm lever 32 is attached with an operation amount detection means 35 constituted by a potentiometer or the like. The neutral detection means 47 of the bucket lever 42 is connected to the bucket operating valve 43.
Provided in pilot pipe 648.64b on the secondary side of
The high pressure selection valve 47a and the pressure switch 47b constitute the high pressure selection valve 47a and the pressure switch 47b.

Note that, similar to the operation amount detection means 35 of the arm lever 32, a detection means made of a potentiometer or the like may be attached to the bucket lever 42 to electrically detect the neutral state of the bucket lever 4'2.

For example, a pendulum sensor equipped with a potentiometer is attached to the bucket 4 as an inclination angle detection means 48.
This detecting means 48 detects the J! of the bucket 4! An inclination angle d with respect to the quasi-meat surface 15 is detected.

In FIG. 2, 26a, 26b, 34''a, 34b.

44a, 44b, 62a, 62b, 63a, 63b, 6
4a, 64b, 6gb, and 65b are pilot pipes.

Next, the effect will be explained.

When performing excavation work, when the bucket lever 42 is operated in the direction of the arrow in FIG. 2 with the mode selector switch 57 set to automatic, the variable pressure reducing valve 43 of the bucket operating valve 43 is
b is activated, and a pilot pressure corresponding to the amount of lever operation is applied from the secondary side to the pilot pipe 64b and the high pressure selection valve 46c.
The bucket control valve 44 is switched to the right position. Along with this, the main hydraulic power source 6
Pressure oil from the bucket cylinder 41 is guided to the head side oil chamber of the bucket cylinder 41, the cylinder 41 is extended, and the bucket 4 is rotated clockwise.

During this movement of the bucket 4, the pilot pipe 64
The bypass pressure guided to the pressure switch 47.b passes through the high pressure selection valve 47a. b, the switch 47b is activated (for example, turned on), and its activation signal, that is, the signal indicating that the bucket is being operated, is input to the controller 5. Also,
The inclination angle α of the bucket 4 is detected by the inclination angle detection means 48, and the detected value is sequentially input to the controller 5.

Incidentally, the inclination angle α of the bucket 4 detected by the inclination angle detection means 48 may be displayed on a meter in the operator's cab.

After rotating the bucket 4 to a desired digging angle, when the bucket lever 42 is returned to neutral, pilot pressure is no longer introduced to the pipe line 64b, the bucket control valve 44 is returned to neutral, and the bucket cylinder 41 is The bucket 4 is stopped, and the rotation of the bucket 4 is stopped, and the pressure switch 47b is
is stopped (for example, turned off), and the inclination angle α of the bucket 4 that was detected by the inclination angle detection means 48 at the time of Ia1 is changed to the target value setting means 54 of the controller 5.
is set as the target value Vo. That is, the inclination angle α of the bucket 4 immediately after the bucket lever 42 is returned to the neutral position is automatically set as the target value Vo in the target angle setting means 54. Therefore, there is no need for the operator to manually input the target setting angle one by one as in the conventional case, facilitating the operation and eliminating the risk of setting errors.

Next, when the arm lever 32 is operated in eight directions, the variable pressure reducing valve 33a of the arm operation valve 33 is operated, and pilot pressure corresponding to the lever operation amount is guided from the secondary side to the pilot pipe 34a, and the arm control valve 33a is operated. At the same time as the valve 34 is switched to the right position, pressure oil from the main oil pressure 1lI6 is guided to the head side oil chamber of the arm cylinder 31, the cylinder 31 is extended, and the arm 3 in FIG. 3 is rotated clockwise. Ru.

At this time, the controller 5 performs a first calculation based on the target IVo set in the target value setting means 54 and the actual inclination angle @v1 of the bucket 4 detected by the inclination angle detection means 48 of the bucket 4. A deviation is calculated by the means 51, and an output signal VO corresponding to the deviation is calculated.
1 is calculated.

Vcn -Kt (Vt -Vo), K1 Nigain Also, at the same time as the arm lever 32 is operated, the operation amount is detected by the operation amount detection means 35 and inputted to the second calculation means 52 of the controller 5.
The type correction inclination angle of the bucket 4 corresponding to the rotation of the arm 3 predicted by the operation of the arm lever 32 is calculated. That is, when the arm lever 32 is in the neutral position (immediately before the start of the intransitive word wJIJll), the inclination angle signal of the bucket 4 detected by the bucket inclination angle detection means 48 and inputted to the second calculation means 52 is set to 3, and the arm lever 32 is operated. The inclination angle signal of the bucket 4 corresponding to the amount of rotation of the arm 3 predicted according to the amount of rotation is set as v2, and the output signal V 0 corresponds to the correction required inclination angle of the bucket 4 based on both signals V2 and v3.
2 is calculated.

VO2- to 2 (V2-V3), K2 Nigain, then upper 8c! The output signal Vo+ based on the deviation and the output signal vO2 based on the arm operation are crushed to obtain the bucket control signal Vc, and the control signal VC is amplified by the amplifier 55 and output to the electromagnetic proportional pressure reducing valve 44. .

Vc-VO1+VO2 When the control signal Vc is VC≧O, an ON signal is output from the calculation means 52 to the electromagnetic selection station valve 46a of the selection means 45, and when VC<O, the calculation means 52 outputs an ON signal to the electromagnetic selection station valve 46a of the selection means 45. An OFF signal is output to the selection valve 46a.

Then, in response to the control signal VC, the N magnetic proportional pressure reducing valve 45
Pilot pressure is released on the secondary side of the

Furthermore, since this excavation is arm pulling work, the electromagnetic selection valve 45a is turned off and held at the position shown. Therefore, the pilot pressure output from the electromagnetic proportional pressure reducing valve 45 is guided to the pipe 44a via the pipe 65a and the high pressure selection valve 46b, the bucket mw valve 44 is switched to the left position, and the pressure from the main hydraulic pressure source 6 is Oil is guided to the rod side oil chamber of the bucket cylinder 41, the cylinder 41 is contracted, the bucket 4 is rotated counterclockwise, and the inclination angle α of the bucket 4 is tsmed to be constant.

In this case, the deviation of the inclination angle of the bucket 4 is 0 from when the arm lever 32 is operated until the arm 3 rotates, so the output signal VDI based on the deviation is O among the 1lIvA signals VC, The output signal @ V 02 based on the operation amount of the arm lever 32 will be output as the control signal Vc, and this l1llj @ signal VC (-Vez
>, the inclination angle of the bucket 4 is 1ljlIt (feedforward control).

That is, when the arm lever 32 is operated, the arm operation valve 33, the arm control valve 34, and the arm cylinder 31 are sequentially operated by the hydraulic system on the one hand to rotate the arm 3, and on the other hand, the operation amount detection means of the arm lever 32 is activated. Based on the electrical signal from 35
The electromagnetic proportional pressure reducing valve 45 is activated by the Il signal VC (-VO2).
is operated, and the pilot pressure from the electromagnetic proportional pressure reducing valve 45 sequentially operates the bucket 1ljixl valve 44 and the bucket cylinder 41 to rotate the bucket 4, and the arm 3 and bucket 4 are rotated almost simultaneously. ,
Therefore, the control can be properly started without causing a response delay like the feedback III II in the conventional case due to only the deviation of the bucket inclination angle.

Thereafter, when the inclination angle α of the bucket 4 changes with the rotation of the 7-arm 3 and the bucket 4, the inclination angle is detected by the inclination angle detection means 48, and the detected value and the above an output signal Vot based on the deviation from the target value set in the target value setting means 54;
The w4 control signal VC (-VO1 + VO2) added to the output signal based on the operation amount of the arm lever 32 is output, and the electromagnetic proportional pressure reducing valve 45 is operated by the Kono t4 signal. Bucket v4Ill valve 44, bucket cylinder 41 by pilot pressure
are activated sequentially, the bucket 4 is rotated, and the @ of the arm 3 is rotated.
The bucket 4 is rotated by an amount corresponding to the movement, and its inclination angle α is
is controlled so that it is constant.

Further, when controlling the bucket 4, the boom elevation amount is calculated by the third control means 53 in the controller 5 based on the detection signal from the operation amount detection means 35 of the arm lever 32 as necessary. boom all II
The I signal passes through the amplifier 56 to the boom electromagnetic proportional pressure reducing valve 24.
1! Magnetic selection valve 25a is 0N-O
FFilJllIll is done. And the electromagnetic proportional pressure reducing valve 2
4 outputs a pilot pressure according to the boom control signal, and this pilot pressure switches the boom 141111 valve 26 to the left or right position, and the pressure oil from the main hydraulic pressure 16 is guided to the boom cylinder 21. is extended and retracted, and the boom 2 is automatically raised and raised.

As a result, the arm 31 is rotated simply by operating the arm lever 32, and at the same time, the bucket 4 is automatically υJilted so that it has a constant inclination angle α with respect to the reference plane 15, and the elevation angle of the boom 2 is adjusted. Under automatic control, excavation work parallel to the ground 14 is performed at a constant excavation angle and a constant depth. Note that the boom 2 may be operated manually.

During the self-control described above, if there is a large stone or tree root on the ground 14, for example, if the bucket lever 42 is greatly operated in the direction of arrow C in FIG.
A pilot pressure higher than the pilot pressure led from the electromagnetic proportional pressure reducing valve 45 to the pipe 65a is guided from the variable pressure reducing valve 43a of No. 3 to the pipe 64a, and this variable pressure reducing valve 4
The pilot pressure from 3a is guided to the conduit 44a via the high pressure selection valve 46b, and as a result, the switching of the bucket control valve 44 to the left position (spool opening degree) increases, and the bucket cylinder 41 A large flow of pressurized oil is supplied to the 0-side oil chamber, the bucket cylinder 41 is rapidly retracted, and the bucket 4 is prevented from suddenly rotating counterclockwise and colliding with the stones, tree roots, etc. mentioned above. That is, even during the automatic control described above, if the bucket lever 42 is operated greatly, manual control is given priority, and the bucket 4 is quickly rotated in a safe direction to avoid danger.

In addition, if the mode changeover switch 57 is switched to manual mode, by operating each lever 22, 32, 42 individually, each cylinder 21. , Bucket rotation can be performed individually or in combination depending on the lever operation.

Furthermore, even when the bucket 4 is moved to the load release position after excavation, the tilt angle of the bucket 4 is automatically controlled to be constant by simply operating the arm lever 32 in the same manner as described above, thereby preventing the load from spilling. It moves smoothly to the specified position.

In this case, the boom system may or may not be automatically controlled.

By the way, in the above embodiment, after the inclination angle of the bucket 4 is feedforward controlled according to the operation amount of the arm lever 32, the feedforward control is performed according to the operation amount of the arm lever 32, and the inclination angle is controlled according to the deviation of the bucket inclination angle. Although the feedback lIIwJ is performed, the first objective can be achieved in →-min only by feedback control according to the deviation.

In the above embodiment, pilot lines 63a, 63b and 65a, 65b for automatic control of the boom system and the bucket system
are provided with one electromagnetic proportional pressure reducing valve 24.45 and one electromagnetic selection valve 258.46a each, but the electromagnetic selection valves 25a, 4
6a may be omitted and the secondary side of the electromagnetic proportional pressure reducing valve may be connected to each of the pilot pipes 63a, 63b and 65a, 65b.

Furthermore, the control of the boom 2 is not limited to the control according to the amount of operation of the arm lever 32; for example, the control of the boom cylinder 2
The pressure in the holding side, that is, the head side oil chamber of No. 1 may be detected, and the pressure may be controlled to be constant. Also, boom 2
The automatic control of the boom 2 is performed as necessary, and therefore the automatic control of the boom 2 may be omitted.

(Effects of the Invention) As described above, according to the present invention, the bucket inclination angle immediately after returning the bucket lever to the neutral position can be automatically and accurately set as a target value in the target value setting means. Therefore, there is no need for the operator to set the target value one by one, and there is no possibility of a setting error occurring. The advantage is that by simply operating the arm lever, the tilt angle of the bucket with respect to the reference plane can be automatically controlled to be constant, improving control accuracy.

Further, according to the second invention, when the arm lever is operated at the start of the control, feedforward control is started to maintain a constant inclination angle of the bucket with respect to the reference plane according to the amount of the operation, and the arm and the bucket are approximately aligned. They can be operated at the same time, and there is no response delay like in conventional feedback control caused only by the deviation of the bucket inclination angle, and appropriate control can continue to be performed afterwards, greatly improving control precision. .

[Brief Description of the Drawings] Fig. 1 is a block diagram of a control device showing an embodiment of the present invention;
FIG. 2 is an electric-hydraulic circuit diagram thereof, and FIG. 3 is a side view showing an example of a hydraulic excavator equipped with the equipment of the present invention. DESCRIPTION OF SYMBOLS 1... Excavator body, 2... Boom, 3... Arm, 4... Bucket, 5... Controller, 21...
・Boom cylinder, 22...Boom lever, 23...
・Boom operation valve, 24... Solenoid proportional pressure reducing valve, 25...
- Selection means, 26...Boom control valve, 31...Arm cylinder, 32...Arm lever, 33...Arm operation valve, 34...Arm control valve, 35...Arm operation amount detection Means, 41... Bucket cylinder, 42.
... Bucket lever, 43 ... Bucket operation valve, 44
... Solenoid proportional pressure reducing valve, 45... Selection means, 46...
・Bucket $410 valve, 47...Bucket lever neutral detection means, 48...Inclination angle detection means, 51...First
Calculating means, 52... second calculating means, 53... third calculating means, 54... target value setting means. Patent applicant: Kobe Steel, Ltd. Agent
Patent Attorney Etsushi Kotani Patent Attorney Chief 1
) Masamukai Patent Attorney Yasuo Itaya Figure 1

Claims (1)

[Claims] 1. A working machine consisting of a boom, an arm, and a bucket, a boom cylinder, an arm cylinder, and a bucket cylinder that operate these working machines, and a boom lever, an arm lever, and a bucket lever that operate according to each operation. A control device for an excavator, comprising: a hydraulic system for a working machine that controls the supply and discharge of pressure oil to and from the boom cylinder, arm cylinder, and bucket cylinder; bucket lever neutrality detection means for detecting neutrality of the bucket lever; , an inclination angle detection means for detecting the inclination angle of the bucket with respect to a predetermined reference plane, and a bucket inclination angle detection value by the inclination angle detection means when a bucket lever neutral signal is output from the bucket lever neutrality detection means to a target value. a target value setting means for setting a target value, and controlling the supply and discharge of pressure oil to and from the bucket cylinder according to the deviation between the target value outputted from the target value setting means and the bucket inclination angle outputted from the inclination angle detection means. 1. A control device for an excavator, comprising: control means for controlling a bucket inclination angle to a constant value. 2. A work machine consisting of a boom, an arm, and a bucket, a boom cylinder, an arm cylinder, and a bucket cylinder that operate these work machines, and the above-mentioned boom cylinder and arm cylinder according to each operation of the boom lever, arm lever, and bucket lever. , a control device for an excavator, comprising: a hydraulic system for a work machine that controls the supply and discharge of pressure oil to and from a bucket cylinder; bucket lever neutrality detection means for detecting neutrality of the bucket lever; Inclination angle detection means for detecting the inclination angle of the bucket; and target value setting for setting the bucket inclination angle detection value by the inclination angle detection means as a target value when a bucket lever neutral signal is output from the bucket lever neutrality detection means. means, first calculation means for calculating a bucket tilt angle control signal according to the deviation between the target value output from the target value setting means and the bucket tilt angle output from the tilt angle detection means, and the arm. a second calculating means for calculating a bucket inclination angle control signal according to the amount of operation of the lever; and a second calculating means for calculating a bucket inclination angle control signal according to the amount of operation of the lever, and controlling supply and discharge of pressure oil to and from the bucket cylinder based on control signals from both of the above-mentioned calculating means to adjust the bucket inclination angle. 1. A control device for an excavator, comprising: control means for constant control.