JPS623351B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure regulating valve device that controls valve operation based on the duty of a coil excitation signal to obtain a predetermined control pressure.

In conventionally well-known devices of this kind, when driven at a high frequency, the coil generates heat due to the reactance of the coil, the resistance value of the coil increases, and the current flowing through the coil decreases, so the excitation operation time of the coil decreases even with the same duty. As a result, if the coil generates heat, a predetermined pressure regulation cannot be obtained.

Therefore, in order to eliminate the above-mentioned drawbacks, the present invention controls the voltage applied to the coil according to the heat generation of the coil to make the excitation current of the coil a constant current, so that even if the coil generates heat, the excitation current is constant. It is an object of the present invention to provide a pressure regulating valve device which can regulate a predetermined pressure by making the coil current, that is, the excitation operation time of the coil the same, if the signals have the same duty.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the apparatus of the present invention will be described below with reference to the drawings.

10 shows the entire pressure regulating valve device, case 11
Vacuum is introduced through a port 14 and atmospheric air is introduced through a port 15 into the chamber 13 which is kept airtight by a cover 12 and a cover 12 . Reference numeral 16 indicates a valve drive unit located within the chamber 13, 17 a coil, and 18
19 is a magnetic core; 19 is a magnetic yoke; 20 is a movable plate that is supported by the yoke 20 and tilts about the supporting position; A flapper made of magnetic material; 22 is a valve provided at one end of the flapper 21 and capable of closing the port 14; 23 is a valve provided at the other end of the flapper 21 and capable of closing the port 15; 24 is a valve provided at the other end of the flapper 21 and capable of closing the port 15; 1, a spring biases the coil 17 in the counterclockwise direction; 25, a cord for energizing the coil 17; and 26, a thermistor disposed close to the coil 17. As shown in the second diagram, the excitation control circuit for the coil 17 includes a transistor 27 to which a voltage pulse, which is an excitation signal, is applied to the base.
The emitter is connected to the power source B via the coil 17 and the thermistor 26 connected in series with the coil 17. Further, a resistor 28 is connected in parallel to the thermistor 26. 29 is a diode for preventing back electromotive force. The emitter of transistor 27 is grounded. In the operation of the pressure regulating valve device, the coil 17 is repeatedly energized and de-energized in accordance with the duty of a voltage pulse, which is an excitation signal, applied to the base of the transistor 27. That is, the transistor 27 is turned on when the voltage pulse is at a "high" level and turned off when the voltage pulse is at a "low" level. When the transistor 27 is turned on, the coil 17 is connected to the coil 1.
7. An excitation current determined by the resistance values of the thermistor 26 and the resistor 28 flows, and the attraction of the core 18 due to the excitation of the coil 17 causes the movable plate 20 and flapper 21 to move from the state shown in the first figure to the attachment of the spring 24. The valve 22 rotates clockwise using the yoke 19 as a fulcrum against the force, and the valve 22 closes the port 1.
4, the valve 23 comes into contact with the port 15, and the chamber 13 is cut off from communication with the atmosphere, and the valve 23 is separated from the port 14.
Bakyum was introduced from. Also transistor 2
7 is turned off, the valves 22 and 23 return to the state shown in the first figure due to the biasing force of the spring 24, closing the port 14 and opening the port 15 to communicate the chamber 13 with the atmosphere. Therefore, the pressure regulating valve device 10
By controlling communication between the ports 14 and 15 and the chamber according to the excitation signal, a control pressure corresponding to the duty of the excitation signal is obtained in the chamber 13, and the control pressure is transmitted from the port 30 communicating with the chamber 13. It can be extracted as output.

Even if the coil 17 generates heat due to energization and its resistance value increases, the coil 17
The heat generated by the coil 17 is detected by the thermistor 26, and since the resistance value of the thermistor 26 decreases as the temperature rises due to its characteristics, the thermistor 26 can control the voltage applied to the coil 17 according to the heat generated by the coil 17. Even if the coil 17 generates heat, the excitation current of the coil 17 is made constant, and if the excitation signals have the same duty, the excitation operation time of the coil 17 is made the same, and a predetermined pressure regulation can be maintained.

Furthermore, if another example of the excitation control circuit is shown in FIG. 3, a voltage divided by a thermistor 26 and a resistor 31 whose resistance value decreases in accordance with the heat generation of the coil 17 is applied to the transistor 32. transistor 32
The voltage applied to the coil 17 is controlled according to the heat generation of the coil 17 by changing the degree of conductivity of the coil 17, and the excitation current of the coil 17 is made constant, and its function is exactly the same as the circuit shown in the second figure.

As explained above, according to the device of the present invention, the excitation current of the coil is made constant, so even if the coil generates heat due to the excitation current and its resistance value changes, if the excitation signal has the same duty, the coil will be excitation This provides excellent practical effects such as being able to adjust the pressure to a predetermined value according to the duty of the excitation signal while keeping the operating time the same.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the device of the present invention;
FIG. 2 is an electric circuit diagram showing one example of the excitation control circuit according to the present invention, and FIG. 3 is an electric circuit diagram showing another example of the excitation control circuit according to the present invention. 10: Pressure regulating valve device, 22, 23: Valve,
17: Coil, 26: Thermistor.

Claims (1)

[Claims] 1. In a pressure regulating valve device that controls the opening and closing operation of a valve by an excitation control circuit that controls the duty of an excitation signal of a coil to obtain a control pressure according to the duty, the pressure regulating valve device is inserted in the excitation control circuit, and
A thermistor is disposed close to the coil and increases or decreases the voltage applied to the coil in response to an increase or decrease in the resistance of the coil as the temperature of the coil increases or decreases. A pressure regulating valve device characterized by a constant pressure.