JP2001107902A - Fluid pressure actuator control method and fluid pressure actuator control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early converge residual vibration at stop operation of a fluid pressure actuator in controlling the meter-in and meter-out separable type fluid pressure actuator. SOLUTION: A bridge circuit 17 is formed of meter-in valves 21, 22 to control supply of working fluid to a fluid pressure actuator 11 and meter-out valves 23, 24 to control discharge of working fluid from the fluid pressure actuator 11. A by-pass valve 14 is provided in a by-pass line 40 communicated to a tank 15 from a pump discharge line 13 to supply working fluid to the meter-in valves 21, 22. They are controlled by control boxes 44, 45 and a feed-back control system 46. That is, the meter-out valve 23 or 24 on a side where a crest of pressure vibration generated at the time of operating to stop working of the fluid pressure actuator 11 is produced is slightly opened or the meter-in valve 21 or 22 on a side where a trough of pressure vibration generated at the time of working stop operation is produced is slightly opened, and the by-pass valve 14 is contracted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for controlling a hydraulic actuator in a meter-in / meter-out separated circuit.

[0002]

2. Description of the Related Art FIG. 2 shows a control circuit which is applied to a construction machine such as a hydraulic shovel and controls a fluid pressure actuator 11 by a so-called meter-in / meter-out type bridge circuit.

This control circuit comprises a pump discharge line 13 drawn from a discharge port of a variable displacement pump 12 capable of variably controlling a discharge flow rate by a swash plate.
15 and a bridge circuit 17 via a load hold check valve 16.

The bridge circuit 17 is provided with a pump discharge line
13 two meter-in valves 21 and 22 respectively connected to
And two meter-out valves 23 and 24 connected to the meter-in valves 21 and 22, respectively.

[0005] These meter-out valves 23 and 24 are connected to a tank line 25.
Check valves 26 and 27 for replenishing the working oil as the working fluid from the tank line 25 to the negative pressure generating section in the circuit are connected in parallel to the tanks 23 and 24.

A pipe (shown by a fixed throttle 31) drawn from between the meter-in valve 21 and the meter-out valve 23 shown above the bridge circuit 17 is connected to a rod 33 by a piston 32 of the fluid pressure actuator 11. Is connected to a chamber (hereinafter, referred to as a “rod side chamber”) 34 on which
A pipe drawn from between the meter-in valve 22 and the meter-out valve 24 shown below (shown by a fixed throttle 35)
Is connected to a chamber (hereinafter, referred to as “head-side chamber”) 36 located closer to the head than the piston 32 of the fluid pressure actuator 11.

The bypass valve 14, the meter-in valve 21,
The throttle valve 22 and the meter-out valves 23 and 24 are provided with variable throttle means such as a spool valve or a poppet valve whose opening area can be variably controlled by electromagnetic means or pilot hydraulic means. In the case of the electromagnetic means, the control is directly performed by the output electric signal, and in the case of the pilot hydraulic means, the control is performed by the pilot pressure signal via the electro-hydraulic conversion means.

The hydraulic oil supplied from the pump 12 to one of the rod side chamber 34 and the head side chamber 36 of the fluid pressure actuator 11 and discharged from the other to the tank 15 is
Control is performed by a bridge circuit 17 formed by the two meter-in valves 21 and 22 and the two meter-out valves 23 and 24.

For example, when the fluid pressure actuator 11 is
When the extension operation is performed, the meter-in valve 22 is gradually opened by a command signal from an operation lever (not shown), and the meter-out valve 23 is also opened at the same time. At that time, the meter-in valve 21 and the meter-out valve
24 remains closed. At this time, at the same time, the bypass valve 14 is closed by a command signal from the operation lever, and the discharge flow rate of the pump 12 is also gradually increased to reach a predetermined fluid actuator expansion speed.

Conversely, when the fluid pressure actuator 11 is contracted, the meter-in valve 21 and the meter-out valve 24 are gradually opened in the same manner, and the bypass valve 14 is closed.
The pump discharge flow rate is also gradually increased to reach a predetermined fluid pressure actuator contraction speed. At this time,
The meter-in valve 22 and the meter-out valve 23 remain closed.

When the operation lever is returned to the neutral position from these operating states of the hydraulic actuator to stop the movement of the hydraulic actuator 11, the inertial load driven by the hydraulic actuator 11 and the rod of the hydraulic actuator 11 A spring-mass system is configured for the compressibility of oil existing in the side chamber 34, the head side chamber 36, and the connecting pipe (the volume of which can be changed by pressure change) and the elasticity of the pipe wall. The kinetic energy temporarily changes the pressure in the rod side chamber 34 and the head side chamber 36, as shown in FIG.
And the displacement of the inertial load remains as a vibration phenomenon having a small amplitude for a while until settling.

FIG. 5 is a computer simulation result showing a change in the head side chamber pressure when the operation lever at the cylinder extension operation position (full stroke position) is suddenly returned to the neutral position.

FIG. 3 is a plot of actual measurement data when the operation of the hydraulic cylinder is stopped by the control valve. The stabilizing pressure on the cylinder head side is lower than the stabilizing pressure on the rod side due to gravity acting on the inertial load. It is expensive. The settling pressure on the rod side is closed due to oil tightness of the control valve.However, if it is left for a long time, it gradually decreases to the tank pressure due to the internal leak of the control valve. Go on.

[0014]

As described above, when a construction machine such as a hydraulic excavator is operated and stopped, the residual vibration remaining in the fluid pressure actuator and the pipeline when the construction machine such as a hydraulic excavator is stopped is caused by an operator working in a cab of the construction machine. There is a problem that the operator who feels the vibration often has a discomfort that sometimes causes a symptom similar to seasickness.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in a meter-in / meter-out type fluid pressure actuator control, a fluid pressure actuator control method for early convergence of residual vibration at the time of a fluid pressure actuator stop operation. And a fluid pressure actuator control device.

[0016]

According to the first aspect of the present invention, a meter-in valve for supplying a working fluid to a hydraulic actuator and a meter-out valve for discharging a working fluid from the hydraulic actuator are controlled. When the operation of stopping the operation of the fluid pressure actuator is performed, the pressure vibration generated at the time of the stop operation is detected, and the meter-out valve on the side where the peak of the pressure vibration is generated is slightly opened to obtain the height of the peak. Is a method of controlling a hydraulic actuator that discharges a working fluid so as to reduce the pressure.

If kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the meter-out valve on the side where the peak of the pressure vibration occurs is slightly opened. The working fluid at the time of pressure peak bleeds, and the height of the peak is reduced.

According to a second aspect of the present invention, a meter-in valve for supplying a working fluid to a fluid pressure actuator and a meter-out valve for discharging a working fluid from the fluid pressure actuator are respectively controlled and a meter-in valve is provided. By controlling the bypass valve in the bypass line that communicates with the tank from the pump discharge line that supplies the working fluid to the tank, the fluid pressure actuator is operated, and when the operation of the fluid pressure actuator is stopped, the pressure vibration generated during the stop operation is detected. A fluid pressure actuator that supplies a working fluid to increase the pressure of the pump discharge line and reduce the depth of the valley by slightly opening the meter-in valve on the side where the valley of pressure oscillation occurs and narrowing the bypass valve. It is a control method.

If kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the bypass valve is throttled so that the pressure of the pump discharge line is increased, and the pressure vibration is reduced. Open the meter-in valve on the side where the valley of the
By supplying working fluid to the side where this valley occurs,
Mitigates the valley depression.

According to a third aspect of the present invention, a meter-in valve for supplying a working fluid to a fluid pressure actuator and a meter-out valve for discharging a working fluid from the fluid pressure actuator are controlled, respectively. By controlling the bypass valve in the bypass line that communicates with the tank from the pump discharge line that supplies the working fluid to the tank, the hydraulic actuator is operated. The meter-out valve on the generating side is minutely opened to discharge the working fluid to reduce the height of the peak, and the meter-in valve on the side where the valley of pressure oscillation generated at the time of the stop operation is generated is minutely opened, and the bypass valve Supply of working fluid to increase the pressure of the pump discharge line and reduce the depth of the valley A hydraulic actuator controlling how.

If the kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the meter-out valve on the side where the peak of the pressure vibration occurs is slightly opened. The working fluid at the time of pressure peak bleeds, and the height of the peak is reduced.
At the same time, by narrowing the bypass valve so that the pressure of the pump discharge line becomes high, and by slightly opening the meter-in valve on the side where the valley of pressure oscillation occurs, replenish the working fluid to the side where this valley occurs , Alleviate the valley depression. As a result, the peaks and valleys of the pressure vibration are leveled, and the pressure vibration converges in a shorter time than when no measures are taken.

According to a fourth aspect of the present invention, there is provided the fluid pressure actuator control method according to the second or third aspect,
A fluid pressure actuator control method for feedback-controlling the throttle of the bypass valve so that the pressure of the pump discharge line is higher than the high pressure side of the pressure generated at the actuator connection side of the two meter-in valves by a predetermined margin pressure. is there.

Feedback control for narrowing the bypass valve so that the pump discharge pressure is higher than the high pressure side of the pressure generated on the actuator connection side of the two meter-in valves by a predetermined margin pressure; The working fluid is replenished to the chamber of the fluid pressure actuator in which the valley of the pressure vibration is generated by the minute opening control of the meter-in valve on the side where the pressure occurs.

According to a fifth aspect of the present invention, there is provided a meter-in valve for controlling supply of a working fluid to a hydraulic actuator, a meter-out valve for controlling discharge of a working fluid from the hydraulic actuator, and a hydraulic actuator. And a control means for slightly opening the meter-out valve on the side where a peak of pressure oscillation generated at the time of the operation stop operation is generated to lower the height of the peak.

If the kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the meter-out valve on the side where the peak of the pressure vibration is generated is controlled by the control means. With a small opening, the working fluid at the time of pressure peak bleeds and the height of the peak is reduced.

According to a sixth aspect of the present invention, there is provided a meter-in valve for controlling supply of a working fluid to a hydraulic actuator, a meter-out valve for controlling discharge of a working fluid from the hydraulic actuator, and a meter-in valve. A minute opening of the bypass valve provided in the bypass line communicating from the pump discharge line to the tank to supply the working fluid to the tank, and the meter-in valve on the side where the valley of the pressure vibration generated when the operation of the fluid pressure actuator is stopped occurs. And a control means for increasing the pressure of the pump discharge line by narrowing the bypass valve to supply the working fluid and reduce the depth of the valley.

If the kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the control means narrows down the bypass valve so as to increase the pressure of the pump discharge line. The meter-in valve on the side where the valley of pressure oscillation occurs is slightly opened to supply working fluid to the low-pressure side, thereby reducing the valley drop.

According to a seventh aspect of the present invention, there is provided a meter-in valve for controlling supply of a working fluid to a hydraulic actuator, a meter-out valve for controlling discharge of a working fluid from the hydraulic actuator, and a meter-in valve. The bypass valve provided in the bypass line that communicates with the tank from the pump discharge line that supplies the working fluid to the tank, and the meter-out valve on the side where the peak of the pressure oscillation that occurs when the operation of the fluid pressure actuator is stopped is slightly opened. The hydraulic fluid is discharged to reduce the height of the peak, the meter-in valve on the side where the valley of pressure oscillations generated when the operation of the fluid pressure actuator is stopped is slightly opened, and the bypass valve is throttled to discharge the pump. Control means for increasing the pressure of the line to supply the working fluid and reduce the depth of the valley. It is a Chueta control device.

If the kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the meter-out valve on the side where the peak of the pressure vibration is generated is controlled by the control means. With a small opening, the working fluid at the time of pressure peak bleeds, the height of the peak is reduced, the bypass valve is narrowed down so that the pressure of the pump discharge line is increased, and a meter on the side where a valley of pressure oscillation occurs By slightly opening the in-valve and replenishing the working fluid to the low pressure side to alleviate the drop of the valley, the peaks and valleys of the pressure vibration are evened out, and the pressure vibration converges in a shorter time than when no countermeasures are taken.

According to an eighth aspect of the present invention, the control means of the seventh aspect allows the control means to pass only the natural frequency of the pressure vibration generated at the time of the operation stop operation of the fluid pressure actuator and the vibration components of the frequencies before and after the natural frequency. A high-pass filter that controls the meter-out valve by picking up a positive vibration waveform from the filter and the vibration waveform that passed through the band-pass filter, and a meter-in valve by picking up a negative vibration waveform from the vibration waveform that passed through the band-pass filter And a bypass valve so that the pressure in the pump discharge line becomes higher by a predetermined margin pressure than the high pressure side of the pressure generated on the actuator connection side of the two meter-in valves when a signal is output from the low pass filter. Hydraulic actuator system with feedback control system for narrowing control It is a device.

Utilizing the high degree of freedom of the meter-in / meter-out separation control and the bypass individual control, the residual vibration at the time of the operation of stopping the fluid pressure actuator is passed through only its natural frequency and vibration components of the frequencies before and after the natural frequency. From a band-pass filter, a high-pass filter that picks up the positive vibration waveform and controls the meter-out valve, a low-pass filter that picks up the negative vibration waveform and controls the meter-in valve, and a feedback control system for controlling the pump discharge pressure By converging early by the individual control algorithm of each valve, the operation feeling of the operator is improved.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. The same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof is basically omitted.

The two meter-in valves 21 and 22 for controlling the supply of the working fluid to the hydraulic actuator 11 and the two meter-out valves 23 and 24 for controlling the discharge of the working fluid from the hydraulic actuator 11 include: A bridge circuit 17 for meter-in / meter-out separation control is formed.

The pump discharge line 13 for supplying working fluid to the meter-in valves 21 and 22 is connected to the tank 15 by a bypass line 40, and a bypass valve 14 is provided in the bypass line 40.

The pump discharge line 13 is provided with pressure detecting means 41 for detecting the pressure of the pump discharge line 13, that is, the pump discharge pressure P 1, and is connected to one of the meter-in valve 21 and the meter-out valve 23. Pressure detecting means 42 for detecting the pressures P2 and P3 generated on the actuator connection side of the two meter-in valves 21 and 22, respectively, between the two meter-in valves 22 and the meter-out valve 24. , 43 are provided.

The meter-in valves 21 and 22 and the meter-out valves 23 and 24 are connected to two control boxes 44 and 45 as control means for controlling these valves.

These control boxes 44, 45
Meter-out valve 23 or 24 on the side where a peak of pressure vibration generated at the time of operation stop operation of fluid pressure actuator 11 is generated
A small opening to lower the height of the peak, and a small opening to the meter-in valve 21 or 22 on the side where the valley of pressure vibration generated at the time of operation stop operation occurs, so as to reduce the depth of the valley. Control.

Further, when the meter-in valve 21 or 22 on the side where the valley of pressure oscillation occurs is slightly opened, the pressure of the pump discharge line 13 is increased by narrowing the bypass valve 14 to reduce the depth of the valley. A feedback control system 46 is provided as control means.

One control box 44 is provided with a band pass filter 51 connected to the pressure detecting means 42. The band-pass filter 51 passes only the natural frequency of the pressure vibration generated at the time of the operation stop operation of the fluid pressure actuator 11 and the vibration components of the frequencies before and after the natural frequency, and cuts the DC component. ΩL in the transfer function of the band-pass filter 51 indicates the lower limit, and ωH indicates the angular frequency of the vibration to be passed on the upper limit side. The band-pass filter 51 is connected to a high-pass filter 53 that picks up a positive vibration waveform from the vibration waveform multiplied by the positive gain G1 and controls the meter-out valve 23.

The output signal line of the high-pass filter 53 is connected to a multiplier 54. When the operation lever command, which is a command signal from the operation lever operated by the operator of the construction machine, is in the neutral dead zone, a positive logic output "1" is output. The signal from the operation lever neutral position detection generator 64 that outputs the signal is multiplied by the output signal of the high-pass filter 53 by the multiplier 54. Further, the output signal of the multiplier 54 The signal multiplied by the positive gain G2 via the function 60a that outputs a signal proportional to the signal is added by the adder 55 to become a command signal input to the meter-out valve 23.

Further, the control box 44 has a low-pass filter for picking up a negative vibration waveform from the vibration waveform multiplied by the gain G1 via the band-pass filter 51.
56 are provided. The output signal line of the low-pass filter 56 is connected to a multiplier 57, and the signal from the operating lever neutral position detection generator 64 is multiplied by the output signal of the low-pass filter 56 by the multiplier 57. The output signal of the control lever command, through a function 60b that outputs a signal proportional to the cylinder contraction operation signal in response to a signal obtained by multiplying a positive gain G3 through an inverter 58 that inverts a negative vibration waveform to a positive value Addition, meter-in valve 21
Becomes a command signal to be input to.

Similarly, another control box 45 is provided for the other meter-in valve 22 and meter-out valve 24. The other control box 45 has the same structure as the one control box 44, and a description thereof will be omitted.

The feedback control system 46 is connected to the actuator connection of the two meter-in valves 21 and 22 when the pressure in the pump discharge line 13 is increased when the signal is output from the low-pass filter 56 and the operation lever is in the neutral dead zone. The bypass valve 14 is throttled down to a pressure higher by a predetermined margin pressure than the high pressure side of the pressures P2 and P3 generated on the side, and is output from the low-pass filter 56 of one and the other control boxes 44 and 45. Step signal generators 61 and 62 for outputting a positive logic output “1” in response to the negative signal, and a positive logic output “1” if at least one of the step signal generators 61 and 62 is a positive logic output “1”. OR circuit 63 which outputs a positive logic output "1" when the operating lever command is 0 or in a neutral dead zone near the operating lever command. High pressure side selector for selecting the high pressure side of the pressure P2 and P3 generated at the actuator connection side of the two meter-in valves 21 and 22 detected by the lever neutral position detection generator 64 and the two meter-in valves 21 and 22 detected by the pressure detection means 42 and 43. 65, an adder 67 for adding a constant 66 corresponding to a predetermined margin pressure to an output signal of the high-pressure side selector 65, an output signal of the OR circuit 63, and an output signal of the operation lever neutral position detection generator 64. Are both positive logic outputs "1"
In this case, a value obtained by adding a multiplier 68 that outputs “1” and a margin pressure determined by a constant 66 to the high pressure side of the pressure P2 or P3 is detected by the pressure detection means 41 as a pump discharge pressure target value. A comparator 69 for calculating an error from the actual measured value of the pump discharge pressure fed back, and a comparator 69
PI controller 70 for integrating and proportionally controlling the output signal of 69
And when the output signal of the OR circuit 63 and the output signal of the operating lever neutral position detection generator 64 are both positive logic outputs "1". A multiplier 72 for outputting a signal from the PI controller 70.
A signal obtained by multiplying the output of the multiplier 68 by the output of the multiplier 68 by the output of the multiplier 68 and an operation lever command are added, and the sum is input to a bypass valve opening controller 71 for controlling the opening of the bypass valve 14. The bypass valve 14 is feedback-controlled through the bypass valve opening controller 71.

Next, the operation of the embodiment shown in FIG. 1 will be described.

The pressure P2 generated on the actuator connection side of the meter-in valve 21 connected to the rod-side chamber 34 of the fluid pressure actuator 11 via a pipe (indicated by a fixed throttle 31) is detected by pressure detection means 42, and one of the control boxes
Input to 44.

In this one control box 44, a natural frequency determined by the compressibility of oil in the fluid pressure actuator 11 and the pipeline, elasticity of the pipeline wall surface and inertia load, and a natural frequency before and after the natural frequency are controlled by a band-pass filter 51 in the control box 44. Only the vibration component of the frequency is passed, and further multiplied by a certain positive gain G1, and a positive vibration waveform is picked up by the high-pass filter 53,
When the operation lever is returned to the neutral dead zone, the meter-out valve 23 is minutely opened at a timing at which a peak of pressure vibration occurs when the operation of stopping the operation of the fluid pressure actuator 11 occurs.

Further, the negative vibration waveform is converted to a low-pass filter 56.
Similarly, when the operation lever is returned to the neutral dead zone, the meter-in valve 21 is minutely opened at a timing when a valley of pressure oscillation occurs.

Similarly, the pressure generated on the actuator connection side of the meter-in valve 22 connected to the head side chamber 36 of the fluid pressure actuator 11 via a pipe (indicated by a fixed throttle 35).
P3 is detected by the pressure detecting means 43 and input to the other control box 45, and the other control box 44
Similarly, the other control box 45 controls the meter-in valve 22 and the meter-out valve 24 to be slightly opened.

When the meter-in valves 21 or 22 are minutely opened, the feedback control system 46 operates simultaneously, and when a negative signal is input from the low-pass filter 56, the step signal generator 61 or the step signal generator 61 generates a positive logic output "1". A multiplier 68 multiplies an output signal of the operation lever 62 and an output signal of the operation lever neutral position detection generator 64 that generates a positive logic output “1” when the operation lever command is in the neutral dead zone.
Of the pressures P2 and P3 generated on the actuator connection sides of the meter-in valves 21 and 22 by the high-pressure side selector 65, and a constant (margin pressure) by the adder 67. A multiplier 72 multiplies an output signal obtained by performing PI control by the PI controller 70 with a deviation between the added value and the actual measured value of the pump discharge pressure, and adds the output to an operation lever command signal. It is input to the bypass valve opening controller 71.

That is, when the pressure P2 or P3 generated on the actuator connection side of the meter-in valve 21 or 22 is at the valley of the pressure oscillation even though the operation lever is at the neutral position, these pressures P2 or P3 Is controlled so that the pump discharge pressure approaches a pump discharge pressure target value obtained by adding a margin pressure to the high pressure side of the pump.

That is, the deviation between the pump discharge pressure target value and the actual measured value of the pump discharge pressure detected by the pressure detecting means 41 is calculated by the comparator 69, and the PI is calculated so as to eliminate the deviation.
Feedback control is performed in a direction to narrow the bypass valve 14 by a signal passed through the controller 70 and the bypass valve opening degree controller 71.

When the operation lever is returned to the neutral position in order to stop the operation of the fluid pressure actuator 11 by controlling as described above, the kinetic energy is reduced as shown in FIG. In each of the head-side chambers 36, it is attempted to remain in the form of pressure vibration, but only the positive vibration component is picked up by the band-pass filter 51 and the high-pass filter 53, and a peak of pressure vibration occurs in each chamber. Then, the corresponding meter-out valve 23 or 24 is slightly opened to bleed the hydraulic oil at the time of the pressure peak into the tank line 25 to reduce the height of the peak.

When a valley of pressure oscillation occurs in each of the rod-side chamber 34 and the head-side chamber 36 of the fluid pressure actuator 11, the pump discharge pressure P 1 is reduced to two meter-in valves 2.
Feedback control for narrowing the bypass valve 14 is performed so that the pressure becomes higher by a predetermined margin pressure than the higher one of the pressures P2 and P3 generated on the actuator connection side of the first and second actuators 22, and the band-pass filter 51 and the low-pass Since the meter-in valve 21 or 22 is minutely opened based on the negative vibration waveform picked up by the filter 56, an appropriate amount of hydraulic oil is supplied from the pump 12 to the low-pressure side rod side chamber 34 or the head side chamber 36, which is a valley. Replenishment relieves valley depression.

With these functions, the peaks and valleys of the pressure vibration are equalized, so that the vibration is reduced to the settling pressure in a short time as shown by the waveform shown by the dotted line as compared with the unmeasured state shown by the solid line in FIG. Can converge.

FIGS. 6 and 7 show computer simulations of this situation. These are computer simulation results showing the change in the head side chamber pressure when the operating lever is suddenly returned to the neutral position from the cylinder extension operation position (full stroke operation position) of the fluid pressure actuator 11, and is shown in FIG. G1, G2,
As the gains such as G3, Kp, and Ki are adjusted, the early decay waveform during the gain adjustment shown in FIG. 6 can be attenuated in a shorter time after the optimal gain adjustment, as shown in FIG. I understand.

As described above, by utilizing the high degree of freedom of the meter-in / meter-out separation control and the bypass individual control, the residual vibration at the time of the operation of stopping the fluid pressure actuator is converted into its natural frequency and the vibration component of the frequency before and after the natural frequency. It is possible to improve the operator's operation feeling by converging early by an individual control algorithm of each valve including a band-pass filter 51, a high-pass filter 53, a low-pass filter 56, and a feedback control system 46 of a pump discharge pressure that allows only the passage. it can.

[0057]

According to the first aspect of the present invention, when the kinetic energy remains in the form of pressure vibration in the fluid pressure actuator during the operation of stopping the operation of the fluid pressure actuator,
The meter-out valve on the side where the peak of the pressure oscillation occurs is slightly opened to bleed the working fluid at the time of pressure peak, and the height of the peak is lowered, so that the meter-in / meter-out separated type fluid pressure actuator control At
The residual vibration at the time of stopping the operation of the fluid pressure actuator can converge relatively early.

According to the second aspect of the present invention, if the kinetic energy remains in the form of pressure vibration during the operation of stopping the operation of the fluid pressure actuator, the pressure of the pump discharge line is increased. Meter-in / meter-out separation by narrowing the bypass valve and opening the meter-in valve on the side where pressure oscillation valleys are slightly opened to replenish working fluid to the side where the valleys occur and alleviating the valley drop In the control of the hydraulic actuator of the type, the residual vibration at the time of the operation of stopping the hydraulic actuator can be made to converge relatively early.

According to the third aspect of the present invention, when kinetic energy remains in the form of pressure vibration in the fluid pressure actuator during the operation stop operation of the fluid pressure actuator, the peak of the pressure vibration peak is generated. Open the meter-out valve slightly to bleed the working fluid at peak pressure,
At the same time as lowering the height of the peak, narrow the bypass valve so that the pressure of the pump discharge line increases, and open the meter-in valve on the side where the valley of pressure oscillation occurs slightly,
By replenishing the working fluid to the side where the valley is generated and reducing the drop of the valley, the peaks and valleys of the pressure vibration are leveled and the pressure vibration can be converged in a shorter time than when no countermeasures are taken. That is, in the meter-in / meter-out type fluid pressure actuator control, the residual vibration at the time of the operation of stopping the fluid pressure actuator is made to converge earlier than when no countermeasures are taken, thereby improving the operability.

According to the fourth aspect of the present invention, the bypass valve is throttled so that the pump discharge pressure is higher than the high pressure side of the pressure generated on the actuator connection side of the two meter-in valves by a predetermined margin pressure. By the feedback control and the minute opening control of the meter-in valve on the side where the valley of the pressure vibration occurs, the side where the valley of the pressure vibration occurs can be sufficiently opposed to the side where the valley of the pressure vibration occurs. The working fluid at the pressure can be supplied, and the residual vibration can be quickly converged.

According to the fifth aspect of the present invention, when kinetic energy remains in the form of pressure vibration in the fluid pressure actuator during the operation of stopping the operation of the fluid pressure actuator, the peak of the pressure vibration is reduced by the control means. By slightly opening the meter-out valve on the generating side to bleed the working fluid at the time of pressure peak and reducing the height of the peak, the residual pressure when stopping the fluid pressure actuator in the meter-in / meter-out separated control circuit The vibration can be converged relatively early.

According to the sixth aspect of the present invention, when kinetic energy remains in the form of pressure oscillation in the fluid pressure actuator during the operation stop operation of the fluid pressure actuator, the pressure of the pump discharge line is reduced by the control means. By narrowing the bypass valve so that it becomes higher and opening the meter-in valve on the side where the valley of pressure oscillation occurs slightly, replenish the working fluid to the side where this valley occurs, and alleviate the fall of the valley, The residual vibration at the time of stopping the operation of the fluid pressure actuator in the meter-in / meter-out separated type control circuit can converge relatively early.

According to the seventh aspect of the present invention, when kinetic energy remains in the form of pressure vibration in the fluid pressure actuator during the operation of stopping the operation of the fluid pressure actuator, the peak of the pressure vibration is controlled by the control means. Open the meter-out valve on the generation side slightly, bleed the working fluid at the time of pressure peak, reduce the height of the peak, narrow the bypass valve so that the pressure of the pump discharge line increases, and perform pressure oscillation. Since the meter-in valve on the side where the valley occurs is slightly opened, working fluid is supplied to the side where the valley occurs, and the fall of the valley is reduced, so that the peaks and valleys of the pressure vibration are equalized. Can be converged in a shorter time than when no measures are taken. That is, the residual vibration at the time of stopping the operation of the fluid pressure actuator in the meter-in / meter-out separated control circuit is made to converge earlier than in the case where no countermeasures are taken, thereby improving the operability.

According to the eighth aspect of the present invention, the residual vibration at the time of stopping the operation of the fluid pressure actuator is reduced to its natural frequency and its natural frequency by utilizing the high degree of freedom of the meter-in / meter-out separation control and the bypass individual control. Bandpass filter that passes only the vibration component of the frequency, high-pass filter that picks up the positive vibration waveform and controls the meter-out valve, low-pass filter that picks up the negative vibration waveform and controls the meter-in valve, and pump discharge pressure The convergence can be made early by an individual control algorithm for each valve including a feedback control system for control, and the operability can be improved.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram and a control block diagram showing an embodiment of a fluid pressure actuator control device according to the present invention.

FIG. 2 is a conventional hydraulic circuit diagram showing a meter-in / meter-out separated control circuit.

FIG. 3 is a characteristic diagram showing a vibration continuation state due to pressure vibration conventionally generated at the time of a hydraulic cylinder operation stop operation.

FIG. 4 is a characteristic diagram showing a comparison between pressure set states of a conventional product and a product to which the present invention is applied.

FIG. 5 is a simulated pressure waveform diagram of a conventional example.

FIG. 6 is a simulated pressure waveform diagram during gain adjustment.

FIG. 7 is a simulated pressure waveform diagram after gain adjustment.

[Explanation of symbols]

 11 Fluid pressure actuator 13 Pump discharge line 14 Bypass valve 15 Tank 21, 22 Meter-in valve 23, 24 Meter-out valve 40 Bypass line 44, 45 Control box as control means 46 Feedback control system 51 Band pass filter 53 High pass filter 56 Low pass filter

Claims (8)

[Claims] 1. A hydraulic actuator is actuated by controlling a meter-in valve on the side of supplying hydraulic fluid to the hydraulic actuator and a meter-out valve on the side of discharging hydraulic fluid from the hydraulic actuator, and operating the hydraulic actuator. A method of controlling a fluid pressure actuator, wherein, during a stop operation, a meter-out valve on a side where a peak of pressure oscillation generated at the time of a stop operation is generated is minutely opened to reduce the height of the peak. 2. A pump discharge for controlling a meter-in valve on a supply side of a working fluid to a hydraulic actuator and a meter-out valve on a discharge side of a working fluid from the hydraulic actuator, and supplying a working fluid to the meter-in valve. The fluid pressure actuator is operated by controlling the bypass valve in the bypass line that communicates with the tank from the line.When the operation of stopping the operation of the fluid pressure actuator is stopped, the meter-in valve on the side where the valley of pressure vibration generated at the time of the stop operation occurs is generated. A method of controlling a fluid pressure actuator, comprising increasing the pressure of a pump discharge line by making a minute opening and narrowing a bypass valve to reduce the depth of a valley. 3. A pump discharge for controlling a meter-in valve on a supply side of a working fluid to a hydraulic actuator and a meter-out valve on a discharge side of a working fluid from the hydraulic actuator, and supplying working fluid to the meter-in valve. The fluid pressure actuator is operated by controlling the bypass valve in the bypass line that communicates with the tank from the line.When the operation of stopping the operation of the fluid pressure actuator is stopped, the meter-out valve on the side where the peak of pressure vibration generated at the time of the stop operation is generated The height of the peak is reduced by making a slight opening, and the meter-in valve on the side where the valley of pressure oscillation generated at the time of the stop operation is generated is opened slightly, and the pressure of the pump discharge line is increased by narrowing the bypass valve to increase the valley. A fluid pressure actuator control method, wherein the depth of the fluid is reduced. 4. The throttle control of the bypass valve is feedback-controlled so that the pressure of the pump discharge line is higher than the high pressure side of the pressure generated at the actuator connection side of the two meter-in valves by a predetermined margin pressure. The method according to claim 2 or 3, wherein: 5. A meter-in valve for controlling supply of a working fluid to a fluid pressure actuator, a meter-out valve for controlling discharge of a working fluid from the fluid pressure actuator, and pressure vibration generated when the operation of the fluid pressure actuator is stopped. Control means for slightly opening the meter-out valve on the side where the peak is generated to reduce the height of the peak. 6. A meter-in valve for controlling supply of a working fluid to a hydraulic actuator, a meter-out valve for controlling discharge of a working fluid from the hydraulic actuator, and a pump discharge for supplying a working fluid to the meter-in valve. The bypass valve provided in the bypass line communicating from the line to the tank, and the meter-in valve on the side where the valley of pressure oscillation generated at the time of the operation stop operation of the fluid pressure actuator is slightly opened,
And a control means for increasing the pressure of the pump discharge line by narrowing the bypass valve to reduce the depth of the valley. 7. A meter-in valve for controlling supply of a working fluid to a hydraulic actuator, a meter-out valve for controlling discharge of a working fluid from the hydraulic actuator, and a pump discharge for supplying a working fluid to the meter-in valve. The height of the peak is reduced by slightly opening the bypass valve provided in the bypass line communicating from the line to the tank, and the meter-out valve on the side where the peak of the pressure vibration generated when the operation of the fluid pressure actuator is stopped is generated. At the same time, the meter-in valve on the side where a valley of pressure vibration generated at the time of the operation stop operation of the fluid pressure actuator is generated is slightly opened, and the pressure of the pump discharge line is increased by narrowing the bypass valve to reduce the depth of the valley. A control device for a fluid pressure actuator, comprising: a control unit. 8. A control means includes: a band-pass filter that passes only a natural frequency of pressure vibration generated at the time of an operation stop operation of the fluid pressure actuator and a vibration component of a frequency around the natural frequency; A high-pass filter that picks up the vibration waveform to control the meter-out valve, a low-pass filter that picks up the negative vibration waveform from the vibration waveform that has passed through the band-pass filter, and controls the meter-in valve, and a pump that outputs a signal from the low-pass filter A feedback control system for controlling the bypass valve so that the pressure of the discharge line is higher than the high pressure side of the pressure generated on the actuator connection side of the two meter-in valves by a predetermined margin pressure. 8. The fluid pressure actuator control device according to claim 7, wherein: