KR950004023B1 - Method and apparatus for actuator control of excavator - Google Patents

Abstract

The method and apparatus limits the action range of an excavator in order to prevent the excavator from touching surrounded building and obstacles by the simple operation of a manual switch. The apparatus comprises valves(19a,19b) controlling slant plate angle adjustors(20a,20b) adjusting discharge amount of pumps(3,4) and electronic proportional control valve blocks(22a,22b); displacement sensors(23a,...) sensing the displacement amount of an actuator; an electronic controller(24) connected to an operation lever and a pedal(21); a function selection pannel(28); a sensor(27) sensing a slant angle of the excavator frame; and a manual switch(30) with selecting and releasing functions.

Description

Actuator operating range limiter of heavy equipment and its limiting method

1 is a hydraulic circuit diagram of an excavator equipped with the apparatus of the present invention,

2 is a schematic view of a state in which the excavator excavates the ground to a depth below the ground,

3 is a schematic plan view of an excavator for explaining the left and right angle of rotation limitation state of the excavator,

4 is a flowchart illustrating a process of limiting the operating range using the apparatus of the present invention.

5 is a flowchart showing the actual operation of each actuator after limiting the operation range using the apparatus of the present invention.

* Explanation of symbols for the main parts of the drawings

1 engine 2 output shaft

3: pour cylinder 4: second pump

5: third pump 6: left driving motor

7: left driving control valve 8: differential cylinder

9: differential control valve 10: swing motor

11: Swing control valve 12: Right driving motor

13: Right driving control valve 14: Bucket cylinder

15: bucket control valve 16: pour cylinder

17: pour control valve 18: option valve

19a, 19b: Function selector switch 20a, 20b: Swash plate adjustment mechanism

21: operation lever / pedal 22a, 22b: electronic proportional control valve block

23a, 23b, 24c, 23d, 23e, 23f: displacement sensor 24: electronic controller

25a, 25b: amplifier 26: amplifier

27: Self tilting angle sensor 28: Function selection panel

29: function selection switch 30: manual switch

31: traveling crawler 32: bucket

33: Connection pin A / G: Reference selection button

W: Work equipment Left θ / Right θ: Turning angle selection button

Upper / Lower H: Height selection button R: Work radius selection button

N: Numeric Keys

The present invention relates to a working range limiting system of heavy equipment, and more particularly, to an operating range limiting system for limiting the upper, lower, left, and right operating ranges and excavation depths of working equipment attached to an excavator within a required range. .

In general, actuators of heavy equipment such as excavators are designed to operate in response to the driver's operation of the control lever or control pedal. Therefore, if the driver incorrectly manipulates the control lever or operation pedal in a confined space, There are problems such as swelling of the building and destruction of the building, and in the case of excavating the ground to a predetermined depth, there is a case that the water supply pipe, the electric wire cable, etc. buried below the predetermined depth is damaged, causing problems.

Accordingly, an object of the present invention is to provide an actuator operating range limiting system in which the actuator is operated only within a safe range in order to solve the above problems.

In order to achieve the above object, the present invention provides an electronic proportional control valve block and an operation lever / to which the pilot pressure oil discharged from a pump driven by an engine of an excavator controls the sprue movement amount of each actuator control valve. A microcontroller with a built-in microcontroller is installed between the pedals, while the electronic controller has a function selection panel for selecting the upper, lower, left, right, and rotation ranges of the angle sensor and the actuator. By connecting the manual switch for setting and canceling the selection range, and connecting the displacement sensor installed in each actuator to the electronic controller, the selection state of the function and the selection function by the function selection panel and the sensor installed in each actuator The input signal and the electric input signal according to the operation position of the control lever / pedal are transmitted from the electronic controller. The actuator is operated to operate within the range selected by the function selection button.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 schematically shows the overall hydraulic circuit diagram of an excavator adopting the apparatus of the present invention. First, referring to FIG. 1, the overall hydraulic system will be described. The operation of each actuator on the output shaft 2 of the engine 1 will be described. The first and second pumps 3 and 4 for supplying the hydraulic oil and the third dump 5 for supplying the internal pilot pressure oil are respectively connected in series, and the first pump 3 is connected to the left side of the excavator, for example. Supply to the left driving control valve (7) for controlling the flow of the operating pressure oil supplied to the left driving motor (6) in charge, and the cylinder (8) for operating the dipper stick of the excavator boom Deep control valve (9) for controlling the flow of the working pressure oil to be operated, and swing control valve (11) for controlling the flow of operating pressure oil supplied to the swing motor (10) for turning the upper body of the excavator to the lower body ) Are connected in series.

In addition, the second gump 4 includes, for example, a right driving control valve 13 for controlling the flow of the operating pressure oil supplied to the right driving motor 12 for the right driving of the excavator, and the soil directly from the excavator. The bucket control valve 15 for controlling the flow of the operating pressure oil supplied to the cylinder 14 for operating the bucket, which is a part for excavation work, the supply to the cylinder 16 for adjusting the boom overall angle of the excavator up and down A boolean control valve 17 for controlling the flow of the working pressure oil, and an optional valve for controlling the flow of the working pressure oil for operating a predetermined actuator (not shown) attached to other needs or as required by the consumer ( 18) are each connected in series.

On the other hand, while the third pump 5 is smaller than the first and second pumps 3 and 4, the pressurized oil supplied from the third pump 5 is the first and second gums 3 and 4. It is operated by the internal pilot pressure oil for moving the inclined plate (3a, 4a) and the sprue of each control valve (7, 9, 11, 13, 15, 17, 18), that is, the third pump ( 5) The part of the pressurized oil discharged from the swash plate angle adjusting mechanism 20a directly controls the inclined plates 3a and 4a of the pumps 3 and 4 through the swash plate angle adjusting valves 19a and 19b which are electromagnetic proportional valves. 20b), the internal pilot pressure applied to the swash plate angle control mechanism (20a, 20b) is variable according to the degree of adjustment of the swash plate angle control valve (19a, 19b) of the inclined plate (3a, 4a) While adjusting the inclination angle, the remaining portion of the pressure oil discharged from the third guam (5) is electromagnetic proportional valve block (22a, 22b) which is operated by the operation lever / pedal 21 of each actuator through another path By moving the sprue of each of the control valves (7, 9, 11, 13, 15, 17, 18) to the left and right through the variable to change the amount of passage of the operating pressure oil flows to each actuator through the control valve It is supposed to be.

Here, the operation lever / pedal 21 has a number corresponding to the number of each actuator and control valve (7, 9, 11, 13, 15, 17, 18), the electronic proportional control block (22a) 22b) is provided with an electronic proportional control valve (not shown) corresponding to the number of control valves (7, 9, 11 or 13, 15, 17, 18) in charge thereof, so that the operating levers associated with the actuator can be operated. When the pedal 21 is operated, the internal pilot pressure oil discharged from the third palm 5 is controlled while the control valve inside the electromagnetic proportional control valve block 22a or 22b associated therewith is operated proportionally. 7,9,11,13,15,17,18) is supplied to move the sprue of the control valve to the left or right.

The electrical control system is additionally installed in the structure of the hydraulic circuit as described above, and the displacement by operation of each of the actuators, that is, the hydraulic motors 6, 10, 12 and the cylinders 8, 14, 16, respectively. Displacement detection sensors (23a, 23b, 23c, 23d, 23e, 23f) are installed, and the microcontroller with a built-in microcomputer between the operation lever / pedal 21 and the electromagnetic proportional control block (22a, 22b) While the 24 and the amplifiers 25a and 25b are installed and electrically connected to each other, the electronic controller 24 is also electrically connected to the swash plate angle control valves 19a and 19b through the amplifier 26. It is also electrically connected to the displacement detection sensors 23a, ... installed in the actuator.

The control system has a current of a magnitude corresponding to the operation displacement amount of the operation lever / pedal 21 is applied to the electronic controller 24 to be processed, and then amplified by the amplifiers 25a and 25b. Internal pilot pressure oil, which is applied to the proportional control valve blocks 22a and 22b and is pumped from the third pump 5 to the spool of each of the control valves 7, 9, 11, 13, 15, 17 and 18, is controlled. By inputting a signal corresponding to the displacement amount of each actuator detected by each displacement detection sensor (23a, ...) to the electronic controller 24, the microcomputer inside the electronic controller (24) of the actuator The first and second pumps 3 and 4 are in charge of the displacement by calculating the displacement amount to the required load of the load and the operating pressure oil.

In addition, the displacement detection sensors 23a, 23b, 23c, 23d, 23e, and 23f, which detect displacements according to the operation of the actuators 6, 8, 10, 12, 14, and 16, select various types of known sensors. For example, the sensors 23a, 23d, and 23e attached to the boom cylinder 16, the bucket cylinder 14, and the differential cylinder 8, respectively, may use a variable resistance potential meter or magnetic resistor. A sensor that counts the number of magnetic materials and outputs an electrical signal is used, and a sensor attached to the swing motor 10 side uses an absolute encoder that detects the absolute position of the upper frame relative to the lower frame. The sensors 23c and 23d attached to the driving motors 6 and 12, respectively, may be configured as incremental encoders.

In addition, the amplifiers 25a, 25b and 26 connected to the output side of the controller 24 amplify the current signals of the control values computed in the control path 24 and the electronic proportional control blocks 23a and 22b. It is sent to the swash plate adjustment valves 19a and 19b.

On the other hand, the electronic controller 24 has a self inclination angle sensor 27 for detecting its own tilt, and a possible selection panel 28 for selecting the upper, lower, upper, right and rotation ranges of the actuator, The function selection switch 29 for turning on / off the function selection panel 28 and the manual switch 30 for setting or releasing the function selection are respectively connected in parallel.

Here, the function selection panel 28 includes a reference selection button (A / G) for selecting a reference plane based on the absolute slope reference plane or its current position and a rotation reference of the work equipment (W), and the work equipment (W). Turning angle selection button (left θ / right θ) to select left and right turning angle of), height selection button (upper H / bottom H) to select up and down height of work equipment (W), radius of work Work radius selection button (R) and numeric keys (N) for inputting the selected value of each selection button are provided, and the combination of these buttons and the numeric keys (N) to work the work equipment (W) The range is set in advance, or the work equipment W is moved to a predetermined position, and then the position is set by the selection button to the working range.

When the operation range limiting process by the present device configured as described above is blinded with reference to the flowchart of FIG. 4, first, the function selection switch 29 is turned on to limit the operation range of the actuator. Set the reference plane of the operation with the selection switch (A / G), for example, in the case of the "A" mode to work on the basis of the absolute horizontal plane (AL) as shown in Figure 2, "G" If it is set to mode, it will work based on its own horizontal plane (RL) based on the current position of the equipment. Thus, the reference plane setting will limit the operating range of the actuator, which is the selection of the reference plane. This is because the upper and lower working limits and the working radius is changed as shown in FIG.

Then, there are two ways to set the actuator's operating range. One method is to limit the actuator's operating range by using each selection button and the numeric keys (N), and the other is using the numeric keys (N). Instead, move the actuator to the actual operating limit and then set the position using the select button.

In detail for each method, first, the method of setting the actuator by moving the actuator to the direct limit range without using the numeric keys (N), the operation lever / pedal 21 and the corresponding selection button to be set Press to operate the actuator and the working device W reaches the working limit range. Then, the displacement sensor 23 reads the displacement value of each actuator at the position, and the manual switch 30 is in the ON state. The displacement value of the actuator is calculated and stored as a working limit switch, and when the manual switch 30 is in the OFF state, the displacement detection sensors 23a,... Repeat the process of continuously tracking the displacement value of each actuator. do.

Therefore, when the work equipment W reaches the predetermined work limit range, the manual switch 30 is turned on, and the position value of each actuator at that time is set to the work range value.

On the other hand, instead of operating the work equipment (W) directly using the control lever / pedal (21), the work equipment (W) itself remains in place and the driver moves up and down height, right and left turning angle and The working radius can be defined by the selection button and the numeric key (N) only. In this case, press the selection button first and then press the next numeric key (N). For example, when the working height limit is 10m, press the Up button and then enter a value of 10m using the numeric keys (N). At this time, when the current position of the work equipment (W) is outside the setting range, that is, when the displacement value of the actuator detected by each displacement detection sensor 23 is out of the setting range, it is determined that the workable range is set incorrectly. It will give the driver a signal to set the new value again.

As described above, if the reference plane is not selected by using the reference selection button (A / G) in the process of setting the working limit range, it automatically selects the "A" mode, that is, the absolute horizontal plane (AL), and directly the work equipment. In the method of setting the working limit by moving (W), the manual switch 30 used to set the working limit by determining the displacement value of each actuator serves as a setting switch that sets the operating range of each actuator. .

However, there are two standards in the case of limiting the turning angle, that is, the work crawler 31 and the work equipment W of the excavator are arranged in a straight line as shown in the solid line in FIG. When the line along the center of the equipment W is the pivot center line, the "A" mode refers to the absolute pivot reference line (AD), and the string is turned by a predetermined angle from the absolute pivot reference line as shown by the dotted line. The turning center line along the longitudinal direction of the work equipment W at the position is set to the "G" mode with respect to the relative turning reference line RD. Accordingly, when selecting the turning angle, the reference selection button (A / G) is selected in advance. ) Select "A" mode or "G" mode, and then enter the turning angle to set the left and right turning angles around the absolute turning reference line (AD) or the relative turning reference line (RD). Will be. At this time, if the A / G mode is not selected, the relative turning reference line RD is automatically selected as the turning center line.

In the case of setting the limit of the range by actually operating the work equipment W as described above, the displacement detection sensor 23a, ... installed in each actuator detects the displacement value according to the term of the operation. Converting to the angle between each member interconnected by the connecting pin 33 while forming the equipment (W), by calculating the geometric value of the angle and the fixed length of the work-cost member, the entire work equipment (W) is an absolute horizontal plane A height is set for the AL or the self-leveling surface RL, and the depth is defined as the depth where the blade tip of the bucket 32 touches.

Referring to the flowchart of FIG. 5 in the state where the working range is set as described above, first, when the operating lever / pedal 21 is operated, an electrical signal corresponding to the operating angle θi is generated. When the manual switch 30 is applied to the controller 24, the signal processing process is changed according to the ON or OFF relative. In the process of setting the operating range, the manual switch 30 sets the setting value. Once the setting value is set, the manual switch 30 has a selection function for releasing or maintaining the setting value.

Therefore, after the operation range is set, the operation lever / pedal 21 is operated so that a signal corresponding to the operation angle is applied to the controller 24 and the main switch 30 connected to the controller 24 is ON. It is determined that the working range setting value is maintained as it is, and the actuator is operated in accordance with the operation amount of the operation lever / pedal 21, and the instantaneous displacement value is applied to the controller 24 by the displacement detection sensors 23a,... Calculates the upper, lower, left, right, and the work radius of the work equipment 10, and compares the calculated value with the set working position value. If the work equipment W is consistent with the set working range value by sending a warning signal to the driver primarily, the swash plate angle regulating valves 19a and 19b and the electric proportional control valve blocks 22a and 22b are provided. Swash plate angle adjusting mechanism (20a, 20) b) to reduce the discharge volume of the pumps 3 and 4, to eliminate the discharge volume at all, or to adjust the sprue of each control valve so that the working pressure oil is no longer supplied to the corresponding actuator. Do not go beyond the range.

In this way, when operating the work equipment (W) to work, if necessary, that is, when the work around the obstacles are removed, or if you need to work outside of the initial set work range, the manual switch ( If 30) is turned off, the corresponding actuator is operated according to the operation amount of the control lever / pedal 21. Then, if the manual switch is turned on again, the displacement value sensor 23a,… reads the position value of the actuator. Calculate the positions of W, up, down, left, right and working radius. At this time, it is determined whether the position is over the existing limited working range. If the existing working range is within the limited working range, the existing working range is used effectively. If the existing working range is exceeded, the value changed by the actuator is changed. The setting value is entered as the working range value.

For example, if the height of the existing working range (upper height) is 10 m and the last result of working with the manual switch 30 turned off, the height of the work equipment is 1 lm. If it is ON, the reset value is reset to 1lm.

As described above, the present invention is equipped with a function selection panel having up, down, left, right, and work radius selection buttons for setting a working range of work equipment, and an inclination angle detection sensor for detecting its own inclination angle, and a function selection or release function. The manual switch controls the solenoid proportional control valve blocks 22a and 22b for controlling the control valves of the respective actuators with the internal pilot pressure, and the swash plate control valves 20a and 20b for adjusting the discharge amounts of the pumps 3 and 4. The swash plate adjustment valves 19a and 19b for measuring the pressure and the displacement sensor 23a, ... for detecting the displacement of each actuator are additionally provided to the connected electronic controller 24, thereby requiring a working range of the work equipment. Set within the range so that the surrounding facilities or obstacles and work equipment do not come in contact with each other to increase the stability and workability. By operating only one, it is possible to work outside the working range, and the existing working range is reset, thereby improving work efficiency.

Claims (2)

Electronic proportional control valve block (22a, 22b) for controlling and moving the sprue of each control valve for controlling the flow of the hydraulic oil supplied to each actuator of the heavy equipment with the internal pilot pressure oil, and the discharge amount of the pump (3, 4) Swash plate adjusting valves 19a and 19b for controlling the swash plate adjusting mechanisms 20a and 20b, attached to respective actuators, and displacement detection sensors 23a to detect the displacements of the actuators. In the actuator operation control device of heavy equipment equipped with an electronic controller 24 electrically connected to an operation lever / pedal 21 for operating an actuator, the electronic controller 24 limits the working range of the work equipment W. Function selection panel (28) with up, down, left, right working radius and time base selection buttons (A / G, 左 θ / 右 θ, UpH / 下 H, R) and numeric keys (N) for setting , Tilt angle sensor 27 for detecting the tilt angle of itself, and Select / release function gatchun the manual switch 30 is connected to the actuator operating range of the heavy equipment, it characterized in that each device having limited. After selecting the work reference plane of the heavy equipment, set the operating range of the work equipment (W) by using the control lever / pedal (21) and each function selection button or function selection button and numeric keys (N). If it is necessary to work outside the previously set operating range in the course of working with (W), turn off the operating range setting manual switch 30, readjust the working range, and work outside the existing working range. Actuator operating range limiting method of the heavy equipment to reset the working range by turning on the manual switch 30 again after the operation of the equipment (W).