JPH05172104A - Control device of proportional electromagnetic valve - Google Patents

Abstract

PURPOSE:To offer a control device for improving responsiveness while keeping overlap at the time of a neutral state and preventing leak thereof, and to prevent generation of vibration in a circuit system. CONSTITUTION:This is a control device of a proportional electromagnetic valve provided with a proportional electromagnetic valve equipped with actuator ports 3, 4, a pump port 1, and a tank pot 2, which closes in keeping overlapped condition at the neutral position while controlling opening thereof in accordance with exciting voltages for solenoids 5, 6. This device is equipped with an output part 7 for outputting this exciting voltage, and a correcting circuit 10 for adding offset voltage of the exciting voltage from the output part and correcting increasing rate of the voltage, in a stage where the exciting voltage is low, with a steep gradient. Moreover, a bypass passage for connecting a pair of passages in an actuator port side to each other is provided and a variable throttle is provided in this bypass passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device optimal for controlling an actuator used for vehicle tilt control, ship movement control, or the like.

[0002]

2. Description of the Related Art A proportional solenoid valve V of a conventional control device shown in FIGS. 5 and 6 has a pump port 1, a tank port 2 and an actuator port 3, while maintaining an overlapping state at a neutral position shown in the drawing. Each of the four is closed. Further, the proportional solenoid valve V is provided with solenoids 5 and 6 so that the solenoid valve V is switched according to the excitation voltage from the output unit 7. Now, when either one of the solenoids 5 or 6 is excited, the pump port 1 and one of the actuator ports communicate with each other, and the other actuator port and the tank port 2 communicate with each other.

Therefore, the pressure oil from the pump P is supplied to the cylinder C via the passage 8 or 9, and the return oil from the cylinder C is passed through the passage 9 or 8 on the opposite side to the tank. Returned to T. The control flow rate supplied to the cylinder C at this time is proportional to the opening degree of the proportional solenoid valve V, that is, the exciting current applied to the solenoids 5 and 6. The reason why the overlap state is maintained at the neutral position as described above is to reduce the leakage amount at the neutral position.

[0004]

In the conventional apparatus as described above, when the exciting current is applied, as shown in FIG. 6, the flow rate Q cannot be secured unless the spool moves by the overlap amount. There was a problem. That is, unless the output voltage becomes equal to or higher than E _{1 in} FIG. 6, the flow rate cannot be secured, and a dead zone occurs at the output voltage E ₁ or lower, and the responsiveness deteriorates accordingly. Therefore, there is a problem that this type of device cannot be used for a device that requires quick control while maintaining the overlap state at the neutral position in order to eliminate leakage at the neutral position. Further, in the conventional case, there is also a problem that as the pressure of the circuit system increases, the entire circuit system vibrates due to, for example, vibration generated when the spool moves. The purpose of the first invention is to
It is an object of the present invention to provide a proportional solenoid valve control device that maintains the responsiveness while maintaining the overlapped state at neutral. A second object of the present invention is to provide a controller for a proportional solenoid valve in which vibration of a circuit system is reduced.

[0005]

According to a first aspect of the present invention, an actuator port, a pump port, and a tank port are formed to maintain an overlap state at a neutral position to close a valve, and at the same time, in accordance with an exciting voltage for a solenoid. It is premised on a proportional solenoid valve control device having a proportional solenoid valve for controlling the opening degree. While assuming the above control device,
The present invention includes an output unit that outputs the excitation voltage, and a correction circuit that adds an offset voltage to the excitation voltage from the output unit to correct the rate of increase of the voltage when the excitation voltage is low to a steep slope. It has a feature in the point.

The second aspect of the invention is based on a controller for a proportional solenoid valve that forms a pair of actuator port, pump port and tank port, and controls the opening of the solenoid port according to the excitation voltage for the solenoid. Is. Based on the above device, the present invention is characterized in that a bypass passage that connects the proportional solenoid valve and the actuator is provided in the middle of the pair of passages, and a variable throttle is provided in the bypass passage. ..

[0007]

Since the first aspect of the present invention is configured as described above, the so-called dead band width can be minimized by applying the output voltage corrected by the correction circuit to the proportional solenoid valve. Further, since the second invention is configured as described above, the pressure oil can be released from the high pressure side passage to the low pressure side passage of the pair of passages communicating with the actuator.

[0008]

According to the control device of the first aspect of the present invention, the dead zone width can be reduced, so that the response of the proportional solenoid valve is improved and the control accuracy of the actuator is improved accordingly. According to the control device of the second invention, the pressure oil on the high pressure side can be released on the low pressure side. Therefore, it is possible to eliminate the rigidity of the circuit system due to the high pressure and prevent the occurrence of vibration.

[0009]

1 to 4, a correction circuit 10 is connected between a conventional proportional solenoid valve V and an output section 7,
And the passages 8 and 9 are communicated with each other by a bypass passage 11, and a variable throttle 12 is provided in the bypass passage 11, and the other configurations are the same as the conventional one. As shown in FIG. 2, the correction circuit 10 adds an offset voltage in a range corresponding to the conventional dead zone to make the increase rate of the output voltage steep. In order to obtain the rate of increase of this steep slope, the correction circuit 10 controls the output voltage E ₀ based on the calculation formula in each step as well as the steps shown in FIG.

Therefore, even if the command voltage is low, the output voltage immediately increases, so that the dead zone as in the conventional case and the responsiveness thereof are not impaired.
Further, since the passages 8 and 9 are connected by the bypass passage 11 and the variable throttle 12 is provided in the bypass passage 11, the pressure oil in the passage on the high pressure side of the passages 8 and 9 is released to the passage on the low pressure side. .. Therefore, the pressure of the circuit system is slightly lowered and the rigidity of the circuit system is reduced, so that the vibration due to the movement of the spool is eliminated.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing characteristics of an input voltage and an output voltage according to the present invention.

FIG. 3 is a flow chart diagram showing steps of programming of the correction circuit of the present invention.

FIG. 4 is a graph showing characteristics of a command voltage and a control flow rate according to the present invention.

FIG. 5 is a circuit diagram of a conventional device.

FIG. 6 is a graph showing a relationship between a conventional command voltage and a control flow rate.

[Code]

 V Proportional solenoid valve 1 Pump port 2 Tank port 3 Actuator port 4 Actuator port 5 Solenod 6 Solenod 7 Output section 8 Passage 9 Passage 10 Compensation circuit 11 Bypass passage 12 Variable throttle

Claims (2)

[Claims] 1. A proportional solenoid valve which forms an actuator port, a pump port, and a tank port, maintains an overlapped state at a neutral position and closes the valve, and controls the opening of the solenoid valve in accordance with the excitation voltage for the solenoid. In the proportional solenoid valve control device provided, an output unit that outputs the above-mentioned excitation voltage and an offset voltage are added to the excitation voltage from the output unit, and the increase rate of the voltage when the excitation voltage is low is corrected to a steep slope. And a control circuit of a proportional solenoid valve having a correction circuit. 2. A pair of passages connecting a proportional solenoid valve and an actuator in a controller for a proportional solenoid valve that forms an actuator port, a pump port, and a tank port, and controls the opening of the solenoid port according to the excitation voltage for the solenoid. A control device for a proportional solenoid valve, in which a bypass passage connecting the passages is provided in the middle of, and a variable throttle is provided in the bypass passage.