JPS61206803A - Control device for hydraulic actuator - Google Patents

Abstract

PURPOSE:To enable smooth starting and stop of an actuator, by a method wherein a computing control device, which computes the optimum opening and closing speed of a control valve to output it to a control valve, is located between a joy stick and a control valve. CONSTITUTION:A computing control device 13 is located between a joy stick 6 and a control valve 5. The device 13 computes the optimum opening and closing speed of the control valve 5 computes within an opening and closing lag time of the control valve 5 from the size and differential value of an input signal from the joy stick 6, an optimum stop time, and data, such as opening of the control valve 5 within a real time, and based on the computation, controls the control valve 5. This, even if the lever of the joy stick 6 is irregularily and rapidly controlled, enables proper control of the opening and closing speed of the control valve 5, resulting in the possibility to smoothly start and stop an actuator 1.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a control device for a hydraulic actuator.

(Prior Art) An example of a conventional hydraulic circuit is shown in FIG. 5, in which 1 is a hydraulic actuator for driving a load 2, and 5 is a hydraulic actuator for controlling the supply and discharge of pressure oil to the hydraulic actuator L. A control valve with 3 positions and 4 ports sends a control current proportional to the lever swing angle θ of the joystick 6 to the solenoid 5leS via an electric transmission line 7.8! It operates by applying a current to the control current, and occupies the opening degree according to the control current. 9 is an Imp, 11 is a tank, and 12 is a pressure control valve.

When the joystick 6 lever is in the neutral position 1.
The control valve 5 occupies the illustrated neutral position 5a, and the pressure oil sucked from the tank 11 and pressurized by the pump 9 flows through the oil path 10. It is discharged into the tank 11 via the pressure control valve 12. Therefore, the hydraulic actuator 1 is stopped.

For example, when the lever of the joystick 6 is tilted to the left by an angle θ as shown in the figure, a control current proportional to the swing angle θ is applied to the solenoid S1 via the electric transmission line 7, and the control valve 5 is at the swing angle 5b at position 5b. The opening degree corresponds to θ. Then, the pressure oil discharged from the bomb f9 flows into the pipe 10.
, control valve 5, and piping 3 into the pushing side chamber la of the hydraulic actuator 1 to drive the load 2 to the right at a predetermined speed, and at the same time, the oil in the pulling side chamber lb flows through the piping 4 and the control valve 5. It is discharged into the tank 11 through the process.

(Problems to be Solved by the Invention) In the conventional device described above, when the lever of the joystick 6 is rapidly operated, the port of the control valve 5 is also rapidly opened and closed, and accordingly, pressure is applied to the hydraulic actuator 1. Load 2 is because oil is being rapidly supplied and will be discharged.

Smooth starting and stopping may not be possible, and the hydraulic actuator 1 may vibrate, or abnormal pressure may be generated in the pipes 3, 4, and 10, causing them to be damaged.

(Means for Solving the Problems) The present invention is intended to solve the above problems, and its gist is to use a joystick to operate a control valve that controls the supply and discharge of liquid to a hydraulic actuator. The control device for the hydraulic actuator is installed in an open-loose manner between the joystick and the control valve, and receives an input signal from the joystick and receives an input signal from the joystick to control the opening/closing delay time of the control valve. The optimum opening/closing speed of the control valve is calculated in real time based on data such as the magnitude of the input signal from the joystick and its differential value, the optimum stop time, and the opening range of the control valve. A control device for a hydraulic actuator characterized by having an arithmetic control device that outputs output to a valve.

(Example) The present invention will be specifically described with reference to an example shown in FIGS. 1 to 4.

In Fig. 1, 1 is a hydraulic actuator, 2 is a load,
3.4 is the piping, 5 is the control valve, 6 is the joystick, 7 and 8 are the electric transmission lines, 9 is the pump, 10 is the piping,
11 is a tank, 12 is a pressure control valve, and the above is the same as the conventional one shown in FIG.

Reference numeral 13 denotes an arithmetic and control unit, into which the control current generated by the joystick 6 is inputted via a power transmission line 14t-, which is subjected to arithmetic processing and then outputted to the solenoid 51pS2 of the control valve 5 through a power transmission line 7.8. Now, as shown by the solid line in Figure 2.

Consider the case where the lever of the stick 6 is operated in a step manner. In order to smoothly drive the hydraulic actuator 1 in response to such a sudden input signal, the control valve 5 opens at a low speed in the opening range of 0 to a, as shown by the dashed line in FIG. The actuator 1 is started smoothly, and the range of the opening degree a % b is opened at high speed to accelerate the hydraulic actuator 1 , and the range of the opening degree b % c near the stop is set to a low speed and the hydraulic actuator 1 is driven at a steady speed. Similarly, when the hydraulic actuator 1 is to be stopped, the speed is set in the range of opening 6-y l), the range of opening b% Ik is high speed, and the range of opening ao is slow and stopped slowly. is desirable.

However, the input signal actually generated by the joystick 6 and input to the arithmetic and control unit 13 changes irregularly as shown by the solid line in FIG. It has t2#t=.

The arithmetic and control unit 13 uses this time delay to determine the optimum opening degree of the control valve 5 in real time, and controls this in an open loop.

FIG. 4 shows signal processing in the arithmetic and control unit 13.

When the input signal X generated by the joystick 6 is inputted to the arithmetic and control unit 13 in step (2), the optimum stopping time T when stopping at the input time t is calculated in step (2). Next, in step (2), the differential value of the input signal X is calculated. The sign of this differential value π is compared in step ■, and if the x differential value π is 0, it is determined that the valve opening is increasing, and if the dx differential value π is 0, it is determined that the valve opening is decreasing. do.

dx If the differential value π>0, it is determined in step (2) whether the differential value is larger than a reference value (which can be set arbitrarily), that is, whether speed control is required. If NO, the current differential value is maintained at step (2).

This is the case when the hydraulic actuator 1 is opened at a slow speed. In the case of y@s, it is determined in step ■ whether the input time t is within the speed control range Δ shown in FIG. 2, and if it is within the speed control range Δ, the hydraulic actuator 1 at step The opening speed shall be set to dL. If NO, step■
The current position, that is, the magnitude of the input signal X is the valve opening degree of 0 in Fig.
~a~b~C is determined, and the speed -@, -o*Do is selected according to each opening degree. When the differential value π<0 and the valve opening is on the decreasing side, the same logic is used; at step 0, it is determined whether or not to control the speed; if NO, at step 0, the speed is controlled so that the current differential value is maintained. If the valve is closed and the answer is YES, it is determined in step 0 whether or not the time t is within the speed control range Δ. If YES, set the closing speed to 7- in step [phase],
If NO, the current position of the input signal is determined in step O, and the optimum opening/closing speed of the control valve is controlled based on the respective current times.

(Operations and Effects of the Invention) The present invention includes an open loop between a joystick and the control valve, and receives an input signal from the joystick and controls the control valve within the opening/closing delay time of the control valve in response to an input signal from the joystick. , the optimum opening/closing speed of the control valve is calculated in real time based on data such as the magnitude of the input signal from the Istick, its differential value, the optimum stop time, and the opening range of the control valve. Since it has an arithmetic and control device that outputs
Even when the joystick lever is operated irregularly and rapidly, the opening/closing speed of the control valve is selected according to the input signal from the joystick, the state of the control valve at the input time, etc., and the hydraulic actuator is operated without shock. The vehicle can be started and stopped smoothly. Therefore, when the hydraulic actuator is vibrated as in the past, the liquid piping will not be damaged, and the operator will not feel uncomfortable. Moreover, since this arithmetic and control device is installed in an open loop between the joystick and the control valve, it can be manufactured at low cost.

[Brief explanation of drawings]

1 to 4 show one embodiment of the present invention, FIG. 1 is a system diagram, and FIG. 2 is a typical input signal from a joystick and the corresponding time diagram of the opening of the control valve. Figure 3 is a diagram showing the actual input signal from the joystick and the corresponding change over time in the opening of the control valve. Figure 4 is a flowchart showing signal processing in the arithmetic control unit. It is. FIG. 5 is a system diagram showing an example of a conventional hydraulic actuator control device. Hydraulic actuator...1, control valve...5
, Joystick...6, Arithmetic control unit, 13° Fig. 1 Fig. 2 Fig. 4

Claims (1)

[Claims] In a control device for a hydraulic actuator that controls a control valve in charge of supplying and discharging liquid to a hydraulic actuator by operating a joystick, the control valve is interposed in an open loop between the joystick and the control valve, and In real time, the magnitude of the input signal from the joystick and its differential value, the optimum stop time, the opening range of the control valve, etc. are determined within the opening/closing delay time of the control valve in response to the input signal from the joystick. A control device for a hydraulic actuator, comprising: a calculation control device that calculates an optimum opening/closing speed of the control valve and outputs the calculated speed to the control valve.