KR101124943B1 - Max. Flow Control System of Hydraulic Pump for Excavator - Google Patents

Abstract

The present invention relates to an excavator hydraulic pump maximum flow rate control device, and to control the setting of the maximum discharge flow rate of the hydraulic pump in a number of cases under the same conditions, it is easy to change the maximum flow rate setpoint without errors The present invention provides an excavator hydraulic pump maximum flow rate control device that enables adjustment.

The present invention for achieving the above object is provided with a variable flow type hydraulic pump, a regulator which is respectively installed and operated in a positive control manner to control the discharge flow rate of the variable flow type hydraulic pump and having a control piston, a pilot piston and a spool; Excavator hydraulic pump control device including an electronic proportional control valve for controlling the flow rate and hydraulic pressure of the hydraulic pump, at least one working device operated by receiving the pressure oil of the hydraulic pump, and a pilot gear pump for discharging pilot pressure A variable flow type hydraulic pump is provided by installing a normal open type electronic control valve in a positive signal line connected to a pilot piston of the regulator, adjusting a current value of a normal open type electronic control valve through a CPU, and controlling a positive signal pressure value. That can control the maximum discharge flow rate And as a base.

Hydraulic Pump, Regulator, Normally Open Electronic Control Valve, Positive Signal Line

Description

Excavator Hydraulic Pump Maximum Flow Control System {Max. Flow Control System of Hydraulic Pump for Excavator}

1 is an exemplary view showing a pump hydraulic circuit applied to a general negative system excavator;

2 is an exemplary view showing a pump hydraulic circuit applied to a general positive system excavator;

3 is an exemplary view showing a pump hydraulic circuit for a positive system excavator according to the present invention;

4 is an exemplary view showing the action of the secondary pressure compared to the input current of the normal open-type solenoid control valve according to the present invention,

5 is an exemplary view showing positive flow control through a normal open type electronic control valve according to the present invention;

<Description of the symbols for the main parts of the drawings>

(10): variable flow type hydraulic pump (20): regulator

21: pilot piston 22: spool

23: negative signal line 24: positive signal line

25: control piston

(30): Normally open electromagnetic control valve (40): Electronic proportional control valve

(50): pilot gear pump (60): maximum flow cutoff signal line

70: engine 80: CPU

90: cluster

The present invention relates to an excavator hydraulic pump maximum flow rate control device, and more specifically, the degree of adjustment of the maximum flow rate in accordance with the case of fine operation of a separate work device or a conventional work device that is frequently used according to the driver, the electronically normal open type electronic It is possible to control the maximum flow rate of the hydraulic pump by setting the input current value of the control valve, and to control the maximum flow rate of the excavator hydraulic pump that can be easily selected by the operation of the cluster button in the driver's seat so that the maximum flow rate can be discharged as much as the user wants. In providing a device.

In general, an excavator includes a hydraulic system for driving a device, and the hydraulic system includes a hydraulic pump for pumping hydraulic oil, a hydraulic control valve for controlling the flow direction and flow rate of the hydraulic oil, and various hydraulic actuators for mechanical work. . The hydraulic pump is a variable flow type hydraulic pump is configured to control the discharge flow rate. Hydraulic actuators include boom cylinders, arm cylinders, bucket cylinders and swing motors.

An example of a control system of such a hydraulic pump is a negative control system. An embodiment of the main pump hydraulic circuit used in such a negative system excavator will be described with reference to FIG. 1.

The main pump is largely a variable flow type hydraulic pump 10, a regulator 20 which serves to control the tilt angle of the variable flow type hydraulic pump 10, and the electronics such that the secondary pressure is adjusted by the regulator 20. It is divided into a proportional control valve 40 and a pilot gear pump 50 for deriving a pilot pressure.

At this time, the regulator 20 for controlling the tilt angle of the variable flow type hydraulic pump 10 has a large pressure applied to the magnetic pump, a pressure applied to the relative pump, and an engine 70 and a variable flow type input to the CPU 80. The control piston 25 receives the adjusted secondary pressure after passing through the electromagnetic proportional control valve 40 by adjusting the input current value of the electromagnetic proportional control valve 40 in the CPU 80 according to the load signal value of the hydraulic pump 10. Along the horsepower control portion of the variable flow hydraulic pump 10, which adjusts the tilt angle of the pump as the spool 22 is moved by the movement of s) and also acts along the negative pressure and maximum flow cutoff signal lines 60 of the system. The spool 22 is moved by the pilot piston 21 receiving the signal pressure to be divided into parts that play a role of tilt angle control.

Here, the movement of the pilot piston 21 is restricted when the maximum flow rate cutoff signal pressure is applied, whereby the stroke of the spool 22 is restricted so that the flow rate of the variable flow type hydraulic pump 10 is not maximized. .

Meanwhile, another example of the hydraulic pump control system is a positive control system.

The positive control system controls the discharge flow rate of the variable flow type hydraulic pump 10 through the pilot signal pressure of the joystick that controls each spool of the hydraulic control valve. As shown in FIG. 2, the tilt angle control of the regulator 20 is performed. The front horsepower control portion of the portion is the same as the pump of the negative system as shown in FIG.

The variable flow type hydraulic pump 10 as described above has a maximum flow cut off function when the required flow rate is not required as the maximum discharge flow rate of the pump in a corresponding mode of the equipment, such as when operating a micromanipulator or other separate work device. By applying pressure oil to the maximum flow rate cutoff port of the tilt angle control unit of the regulator 20, the variable flow type hydraulic pump 10 controls the tilt angle of the variable flow type hydraulic pump not to be inclined by a predetermined angle or more. (10) has a function of limiting the maximum discharge flow rate.

However, there is a disadvantage in that the structure of the regulator is complicated to apply the maximum flow rate cutoff function to the positive control hydraulic pump, and even when the maximum flow rate cutoff function is applied, the maximum flow rate in the case of the maximum flow rate in each condition is maximum. In this case, there are only two cases where the maximum flow rate cutoff function is reduced from the maximum flow rate to a certain rate. Therefore, by setting the flow rate at the maximum flow rate cutoff in accordance with the work device or the micro-manipulation which is frequently applied, If you want to install or adjust the maximum flow rate, the default maximum flow rate must be reset manually according to the changed working device or working conditions, and there is a problem that an error occurs due to manual adjustment.

The present invention is created in order to solve the conventional problems as described above, it is possible to control the setting of the maximum discharge flow rate of the hydraulic pump in a number of cases under the same conditions, it is easy to change the maximum flow rate set value It is to provide an excavator hydraulic pump maximum flow rate control device that can be adjusted accurately without error.

In order to achieve the above object, the present invention provides a variable flow type hydraulic pump and a regulator each installed and operated in a positive control manner to control the discharge flow rate of the variable flow type hydraulic pump and having a control piston, a pilot piston, and a spool. And an hydraulic proportional control valve for controlling the flow rate and the hydraulic pressure of the hydraulic pump, at least one working device operated by receiving the pressure oil of the hydraulic pump, and a pilot gear pump for discharging pilot pressure. In the apparatus, a variable flow type hydraulic pressure is provided by installing a normal open type electronic control valve in a positive signal line connected to a pilot piston of the regulator, adjusting a current value of the normal open type electronic control valve through a CPU, and controlling a positive signal pressure value. It is possible to adjust the maximum discharge flow rate of the pump. It shall be.

In addition, the CPU is set in advance the data of the maximum flow restriction degree according to the micro-manipulation of the excavator and the work type is characterized in that the operator can be selectively input by the button operation of the cluster in the driver's seat.

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

3 is an exemplary view showing a pump hydraulic circuit for a positive system excavator according to the present invention,

The hydraulic device of the pump for excavators of the present invention is to control the discharge flow rate of the pair of variable flow type hydraulic pump 10, the engine 70 for driving the same, the variable flow type hydraulic pump 10, respectively A regulator 20 installed and operated in a positive control manner and having a control piston 25, a pilot piston 21 and a spool 22, and an electronic device for controlling the flow rate and oil pressure of the variable flow type hydraulic pump 10. The positive signal line 24 is connected to the proportional control valve 40, the pilot gear pump 50 for discharging the pilot pressure oil, and the positive signal line 24 connected to the pilot piston 21 of the regulator 20 to control the positive signal pressure. Normal open type electronic control valve 30, and the state of the engine 70, the pump and other devices to receive the input, and also the normal open type electronic control valve 30 and electromagnetic proportional control valve (40) Control of other devices, including It is configured to include a CPU (80) for outputting a signal.

A working device such as a boom cylinder, an arm cylinder, a bucket cylinder, a swing motor, and the like is operated by receiving the pressure oil discharged from the variable flow type hydraulic pump 1.

The regulator 20 is operated to control the stroke of the spool 22 to control the discharge flow rate of the variable flow type hydraulic pump 10 by controlling the stroke of the spool 22.

The electromagnetic proportional control valve 40 is operated by a control current according to frequency modulation or pulse width control to control the flow rate and the hydraulic pressure.

The CPU 80 controls the operation state and load of the entire excavator, and input current value of the normal open type electronic control valve 30 according to the maximum flow rate limit for the micro-manipulation and work type to the CPU 80 By variously setting in advance, it is possible to variously adjust the positive signal pressure passing through the normal open-type solenoid control valve 30 so that the maximum flow rate control of the variable flow type hydraulic pump 10 can be variously set. .

In addition, according to the type of work to be performed by the operator to the degree of the maximum flow rate control, it is possible to easily change and adjust the set value of the CPU selectively through the button operation of the cluster in the driver's seat.

Referring to the operation and effects using the configuration of the present invention configured as described above are as follows.

First, when there is no separate input signal when the variable flow type hydraulic pump 10 operates, as shown in FIG. 4, the input current applied to the normal open electronic control valve 30 in the CPU 80 is 0 mA. The flow rate control of the variable flow type hydraulic pump 10 is positive by allowing the positive signal line 24 inlet pressure (primary pressure) entering the valve 30 to be applied to the positive control pilot piston 21 without being decompressed. Adjusted by the positive signal pressure entering line 24.

On the other hand, when the maximum flow rate restriction of the variable flow type hydraulic pump 10 is required, the positive signal line of the regulator 20 is inputted by the CPU 80 by inputting the input current value of the normally open solenoid control valve 30 by a set value. Since the pressure entering the 24 passes through the normal open solenoid valve 30, the pressure is reduced by a predetermined value and the pressure acting on the pilot piston 21 is reduced, so that the pilot piston 21 stops the stroke of the spool 22. It is impossible to move to a section capable of maintaining the maximum swash plate angle, and as a result, the tilt angle of the variable flow type hydraulic pump 10 cannot be maximized, thereby increasing the maximum discharge flow rate of the variable flow type hydraulic pump 10. It will be limited

That is, as shown in FIG. 4, when the input current value of the normally open solenoid control valve 30 is set from the initial 0 mA to “b” mA in the CPU 80, the positive pressure input to the positive signal line 24 is electronic proportional control. After passing through the valve 40, the initial pressure will be reduced to "a" at the initial pressure, where the pump maximum discharge flow rate by the positive signal pressure will be reduced to "c" as shown in FIG.

In the present invention as described above, the current setting value "b" of the normally open solenoid control valve 30 is set in advance in the CPU 80 in various cases, thereby passing through the normally open solenoid control valve 30. Since the value of the differential pressure "a" can be adjusted, the number of cases of the control of the maximum flow rate "c" discharged from the pump at that time varies.

The normal open type electromagnetic control valve 30 configured as described above may be installed in the regulator 20 of each pump to control all of the flow rates of the pair of variable flow type hydraulic pump 10.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

The effect of the present invention can be expected by the configuration and action as described above, the degree of adjustment of the maximum flow rate of the variable flow type hydraulic pump according to the case of fine operation of a separate work device or a conventional work device that is often used according to the driver in the CPU By setting the input current value of the normally open solenoid control valve, the maximum flow rate control of the hydraulic pump can be set in various ways by the pressure control of the positive signal pressure, and by setting such a preset value on the CPU in advance, It can be easily selected in the driver's seat so that the maximum flow rate can be discharged is a very useful invention that is very easy to change the flow rate setpoint, and can be adjusted accurately.

Claims (2)

A variable flow type hydraulic pump and a regulator each installed and operated in a positive control manner to control the discharge flow rate of the variable flow type hydraulic pump and having a control piston, a pilot piston and a spool, and a flow rate and hydraulic pressure of the hydraulic pump In the excavator hydraulic pump control device including an electronic proportional control valve for controlling a, at least one working device that is operated by receiving the pressure oil of the hydraulic pump, and a pilot gear pump for discharging pilot pressure, The normal open type electronic control valve is installed on the positive signal line connected to the pilot piston of the regulator, the current value of the normal open type electronic control valve is adjusted through the CPU, and the positive signal pressure value is controlled to discharge the maximum flow rate of the variable flow type hydraulic pump. Excavator hydraulic pump maximum flow rate control device, characterized in that the flow rate can be adjusted. The method of claim 1, The CPU hydraulic excavator hydraulic pump maximum flow rate control device, characterized in that the operator to selectively set the data of the maximum flow rate limit according to the micro-manipulation and work type of the excavator in the operator's seat.

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