JPH05263436A - Automatic control device for construction machine - Google Patents

Abstract

PURPOSE:To improve the function by freely setting the target excavation moment in response to the excavation mode such as a deep excavation or a shallow excavation, and controlling an electric/hydraulic converter and a hydraulic drive section. CONSTITUTION:The voltage signal value from a volume operation section 39 is inputted to a target moment reading section 45. The reading section 45 outputs the target excavation moment signal value to an output command signal calculation section 37'. Detection signals from a pressure sensor 34 and a bucket angle sensor 35 are inputted to the excavation moment calculation section 36' of a controller 38, and the calculation result signal is outputted to the calculation section 37'. The calculation section 37' performs the comparison calculation process based on the signals from the reading section 45 and the calculation section 36' and outputs command signals to electromagnetic proportional pressure reducing valves 26-31, a governor 41 adjusting control motor 42, and a variable pump 24 control regulator 43. Pilot selector valves 20, 21, 22 are operated by the pilot secondary pressure guided from the pressure reducing valves 26-31, thus an arm 10, a boom 9, and a bucket cylinder 11 perform expanding/shrinking actions for a deep excavation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic controller for construction machines such as hydraulic excavators and work vehicles.

[0002]

2. Description of the Related Art FIG. 4 is an overall side view of a hydraulic excavator. In the figure, 1 is an upper swing body which is a vehicle body, 2 is a lower traveling body, 3 is a work attachment mounted on the front part of the upper swing body 1, 4 is a boom of the work attachment 3,
Reference numeral 5 is an arm, 6 is a bucket, 7 is a swing motor disposed on the upper swing body 1, 8L and 8R are left and right traveling motors disposed on the lower swing body 2, 9 is a boom cylinder, 10 is an arm cylinder, and 11 is a bucket cylinder. Is. FIG. 5 is a circuit diagram of essential parts showing a conventional automatic control device mounted on a hydraulic excavator. In the figure, reference numerals 10, 9, 11, and 7 denote arm cylinders, boom cylinders, bucket cylinders, swing motors, 12, 13, 1 as typical examples of various hydraulic actuators arranged in a hydraulic excavator.
4 and 15 are for arm, boom, bucket,
The turning hydraulic remote control valve (the hydraulic remote control valve can be operated in the crosswise direction of front, rear, left and right, but is shown divided for convenience of explanation), 16, 17, 18, 19 are hydraulic remote control valves 12, 13 , 14, 15 are operating levers, 20, 21, 22, 23 are directional switching valves for arm, boom, bucket, and swing pilot switching valves, 24 is a variable pump, 25 is a pilot pump,
Reference numerals 26, ..., 31 denote electromagnetic proportional pressure reducing valves which are electro-hydraulic converters, 33 a controller, 34 a pressure sensor which is an action detecting means for detecting an action force for rotating the bucket 6.
Reference numeral 35 is a bucket angle sensor which constitutes a bucket attitude detecting means. For convenience of explanation, the boom and arm angle sensors that constitute the bucket lift control means and the bucket attitude detection means are not shown.

Next, a conventional automatic control device will be described with reference to FIGS. Some hydraulic excavators are equipped with an automatic control device capable of automatically performing general simple excavation called so-called digging or horizontal excavation that requires skilled operation skill. When performing automatic excavation work with this hydraulic excavator, an automatic / manual selection switch (not shown) is automatically switched. As shown in FIG. 4, the excavation reaction force R acting on the bucket 6 is detected, and the detection signals from the pressure sensor 34 and the bucket angle sensor 35 are used as excavation moment calculator 3 of the controller 33.
6 is input. The excavation moment calculation unit 36 performs calculation processing based on the above detection signal, and outputs the command signal to the solenoids of the electromagnetic proportional pressure reducing valves (including the case of an electromagnetic opening / closing valve) 26, ..., 31 via the output command calculation unit 37. Output. The electromagnetic proportional pressure reducing valve operates to apply the adjusted pilot secondary pressure to the pilot pressure receiving portion of the predetermined pilot switching valve via the shuttle valve (any one of the shuttle valves 52, 57, and 57). Let The pilot switching valves (20, 21, 22) are switched, and the hydraulic actuators (9, ..., 1) are operated according to the operation of the pilot switching valves.
Since 1) is activated, the automatic excavation work can be performed based on a predetermined target excavation moment.

[0004]

When a hydraulic excavator equipped with an automatic control device performs an automatic excavation work, deep excavation (excavation of depth H shown in FIG. 4) which is heavy excavation is performed depending on the work content. A shallow excavation (drilling to a depth h shown in FIG. 4) such as stroking the ground must be performed. However, since the hydraulic excavator provided with the conventional automatic control device performs automatic excavation based on a predetermined target excavation moment, it is not possible to adjust and set the form of deep or shallow excavation in advance. An object of the present invention is to provide an automatic control device that can solve the above problems.

[0005]

In the automatic control apparatus of the present invention, the controller is provided with a target moment reading section capable of inputting a signal value of the target excavation moment for bucket rotation control, and a desired target excavation moment is selected. In order to adjust the voltage, a volume operation unit that can output up / down signals is provided, and the voltage signal value from the volume operation unit can be input to the target moment reading unit.When the volume operation unit is set to the required position, By outputting a command signal from the controller to the electro-hydraulic converter and the hydraulic drive unit that perform control, the bucket performs excavation to a depth corresponding to the target excavation moment.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a circuit diagram of essential parts showing an automatic control device of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. 38 is a controller, 39 is a volume operation unit, 40 is the main pump 2
4 and the engine that drives the pilot pump 25, 41
Is a governor of the engine 40, 42 is a control motor such as a stepping motor for adjusting and driving the governor 41, 43 is a regulator for adjusting the tilt angle of the swash plate of the variable pump 24, and 44 is a rotation sensor. FIG. 2 is a chart showing the relationship between the adjustment amount of the volume operation unit 39 and the value of the target excavation moment.

Next, the configuration of the automatic control apparatus of the present invention is shown in FIG.
2 will be described. In the present invention, the controller 38
Is provided with a target moment reading unit 45 capable of inputting a signal value of a target excavation moment for bucket (6) rotation control, and a volume operation unit 39 capable of outputting a voltage adjustment up / down signal to select a desired target excavation moment. Is provided so that the voltage signal value from the volume operating unit 39 can be input to the target moment reading unit 45, and when the volume operating unit 39 is set to a required position, the electromagnetic proportional pressure reducing valve 26, ... , 31, governor (4
1) Control motor 42 for adjustment, and variable pump (24)
By outputting a command signal from the output command calculator 37 'of the controller 38 to the control regulator 43, the bucket 6 excavates to a depth corresponding to the target excavation moment.

Next, the operation of the automatic control device of the present invention will be described. FIG. 3 is a chart showing the magnitudes of the excavating moments when the operation position of the volume operation unit 39 is adjusted to a large position and adjusted to a small position. As shown in FIG. 3, when the volume operation unit 39 is operated to a large position, the target excavation moment is set large, and when the volume operation unit 39 is operated to a small position, the target excavation moment is set small. First, when performing deep digging (deep digging at a depth H as shown in FIG. 4) with a hydraulic excavator, the volume operating unit 39 is operated to a large position to start automatic excavation control. The voltage signal value from the volume operation unit 39 is
It is input to the target moment reading unit 45. The target moment reading unit 45 makes a judgment based on the voltage signal value,
Outputs signal value of target excavation moment Command signal calculation unit 3
Output to 7 '. On the other hand, the detection signals from the pressure sensor 34, the bucket angle sensor 35, and the like (including the boom angle sensor, the engine rotation rotation sensor 44, and the like, which are not shown) are input to the excavation moment calculation unit 36 ′ of the controller 38, The calculation result signal from the excavation moment calculation unit 36 'is output to the output command calculation unit 37'. The output command calculation unit 37 'performs a comparison calculation process based on the signals from the target moment reading unit 45 and the excavation moment calculation unit 36', and the electromagnetic proportional pressure reducing valve 2
6, to 31, a command signal is output to the governor (41) adjustment control motor 42 and the variable pump (24) control regulator 43. The electromagnetic proportional pressure reducing valves 26, ..., 3
Since the pilot switching valves 20, 21, 22 are operated by the pilot secondary pressure derived from 1, the arm cylinder 10, the boom cylinder 9, and the bucket cylinder 11 are expanded / contracted for deep digging. As a result, the excavation form of automatic excavation control becomes a deep excavation pattern, and the variable pump 2
Since the discharge amount of the pressure oil from No. 4 is increased, it is possible to perform deep digging with a large digging moment.

Next, when performing a shallow excavation with a hydraulic excavator (a shallow excavation at a depth h as shown in FIG. 4), the volume operating section 39 is operated to a small position to start automatic excavation control.
Similar to the control sequence in the case of deep digging, the voltage signal value from the volume operating unit 39 is input to the target moment reading unit 45. The target moment reading unit 45 makes a determination based on the voltage signal value and outputs the signal value of the target excavation moment to the output command calculation unit 37 '. On the other hand, detection signals from the pressure sensor 34, the bucket angle sensor 35, and the like (including a boom angle sensor, an engine rotation rotation sensor 44, and the like (not shown)) are input to the excavation moment calculation unit 36 ′ of the controller 38, and The calculation result signal from the excavation moment calculation unit 36 'is output to the output command calculation unit 37'. Output command calculator 3
In 7 ', a comparison calculation process is performed based on the signals from the target moment reading unit 45 and the excavation moment calculation unit 36', and the electromagnetic proportional pressure reducing valves 26 to 31 and the governor (4
1) Output a command signal to the adjustment control motor 42 and the variable pump (24) control regulator 43. Since the pilot switching valves 20, 21, 22 are operated by the pilot secondary pressure derived from the electromagnetic proportional pressure reducing valves 26, ..., 31, the arm cylinder 10, the boom cylinder 9,
The bucket cylinder 11 operates to expand and contract for shallow digging. Accordingly, the excavation form of the automatic excavation control becomes a shallow excavation pattern, and the discharge amount of the pressure oil from the variable pump 24 is reduced, so that the shallow excavation can be performed automatically with a small excavation moment.

[0010]

When a hydraulic excavator having an automatic control device performs an automatic excavation work, heavy excavation such as deep excavation or shallow excavation such as stroking the ground must be performed according to the work content. However, since the hydraulic excavator including the conventional automatic control device performs automatic excavation based on a predetermined target excavation moment, it is impossible to adjust and set excavation forms such as deep excavation or shallow excavation in advance. However, in the automatic control device of the present invention, the controller is provided with a target moment reading unit capable of inputting a signal value of a target excavation moment for bucket rotation control, and a voltage adjustment up / down signal is supplied to select a desired target excavation moment. A volume operating unit capable of outputting is provided, and the voltage signal value from the volume operating unit can be input to the target moment reading unit. Accordingly, when deep excavation or shallow excavation is performed with the hydraulic excavator, the volume operation section is operated to a large position or a small position to start automatic excavation control. The voltage signal value is input from the volume operating unit to the target moment reading unit. On the other hand, the detection signals from the bucket attitude detecting means, the acting force detecting means, etc. are input to the excavating moment calculating section of the controller. The signals from the target moment reading unit and the excavation moment calculation unit are input to the output command calculation unit, and the output command calculation unit outputs command signals to the electro-hydraulic converter and the hydraulic drive unit.
Therefore, in the construction machine equipped with the automatic control device of the present invention, automatic excavation forms such as deep excavation and shallow excavation can be set in advance by adjusting the volume operation section, and economical automatic excavation work that can demonstrate energy saving is performed. be able to.

[Brief description of drawings]

FIG. 1 is a main part circuit diagram showing an automatic control device of the present invention.

FIG. 2 is a chart showing the relationship between the adjustment amount of the volume operating unit and the value of the target excavation moment in the present invention.

FIG. 3 is a table showing the magnitudes of excavating moments when the operation position of the volume operation unit according to the present invention is adjusted and set to a large position and a small position.

FIG. 4 is an overall side view of the hydraulic excavator.

FIG. 5 is a circuit diagram of essential parts showing a conventional automatic control device.

[Explanation of symbols]

 3 Work attachment 6 Bucket 11 Bucket cylinder 24 Variable pump 26, ~, 31 Electromagnetic proportional pressure reducing valve 33, 38 Controller 34 Pressure sensor 35 Bucket angle sensor 36, 36 'Excavation moment calculator 37, 37' Output command calculator 39 Volume control Part 42 control motor 43 regulator 45 target moment reading part

Claims (1)

[Claims] 1. A work attachment is attached to a front portion of a vehicle body, various hydraulic actuators are arranged on the vehicle body and the work attachment, and the various hydraulic actuators can be controlled by a manual operation of an operating lever,
Further, a bucket attitude detecting means for detecting the attitude of the bucket of the work attachment, an acting force detecting means for detecting an acting force for rotating the bucket, and a working moment around the rotation axis of the bucket from the bucket attitude and acting force every moment. A moment calculation means for calculating, a bucket rotation control means for controlling bucket rotation drive based on the calculated excavation moment, and a bucket elevating control means for controlling up and down drive of the bucket based on the excavation moment are provided. An automatic control device capable of automatically controlling a predetermined hydraulic actuator among the various hydraulic actuators, wherein a target excavation moment for bucket rotation control is provided to a controller that commands the bucket rotation control means and the bucket lifting control means. Target moment that can input the signal value of And a volume operating section capable of outputting a voltage adjustment up / down signal to select a desired target excavation moment, and a voltage signal value from the volume operating section can be input to the target moment reading section. When the volume operation section is set to the required position, by outputting a command signal from the controller to the electro-hydraulic converter and the hydraulic drive section that perform automatic control,
An automatic control device for a construction machine, characterized in that a bucket excavates a depth corresponding to a target excavation moment.