JPH05296364A - Controller for current-carrying of solenoid valve - Google Patents

Abstract

PURPOSE:To install a solenoid valve inside a compressor suppressing the temperature rise of the coil of the solenoid valve. CONSTITUTION:Selecting means 12-14 are arranged, and after operation is surely completed by applying a power source voltage directly to a solenoid valve 15 immediately after current-carrying, the supplied voltage is lowered to the necessary min. voltage value for maintaining an operation state and applied to the solenoid valve 15, and the temperature rise of the coil of the solenoid valve 15 can be reduced exceedingly. Accordingly, the installation of the solenoid valve 15 in the discharged coolant gas flow passage of a compressor is enabled, which was impossible because of the temperature rise of the coil in the conventional refrigerator, and the compact compressor can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator, an air conditioner,
The present invention relates to a solenoid valve energization control device incorporated in a refrigerant compressor applied to a car air conditioner, a refrigeration system, and the like.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a conventional refrigerant compressor equipped with a control solenoid valve. The compressor shown in FIG. 9 is a compressor for a car air conditioner and is provided with a solenoid valve for controlling a capacity control mechanism (not shown) incorporated inside the compressor. In FIG. 9, 1 is a compressor body, 2 is a solenoid valve,
A switch 3 controls the energization of the solenoid valve 2. Reference numeral 4 is a compressor driving clutch.

In the conventional device, the voltage supplied to the solenoid valve 2 was the voltage generated by the alternator battery of the vehicle.

[0004]

In the conventional device,
The mounting position of the solenoid valve to the compressor is most preferably built in the compressor in order to make the compressor compact, but when the solenoid valve is arranged in the intake refrigerant gas passage, it obstructs the flow of the refrigerant, In the case where it is arranged in the discharge gas passage, since the ambient temperature is high, the temperature of the electromagnetic coil exceeds the allowable value when the solenoid valve is continuously energized, so that it cannot be practically incorporated.

When the solenoid valve is externally mounted, there is a clutch on the front side, and the outer periphery interferes with the engine, auxiliary machinery, etc., so that the mounting position is limited to the rear surface, and at least the solenoid coil portion of the solenoid valve. Was projected to the outside of the compressor, significantly impairing the mountability.

The present invention is intended to solve the above problems.

[0007]

[Means for Solving the Problems]

(1) The solenoid valve energization control device of the present invention supplies a power supply voltage to the solenoid valve energization control circuit at the start of energization, and supplies a voltage having a release voltage value of the solenoid valve as a lower limit after the solenoid valve operation is completed. It is characterized in that a switching means is provided.

(2) The solenoid valve energization control device of the present invention is characterized in that the switching means described in the above-mentioned invention (1) is composed of a parallel circuit of a voltage dividing resistor and a normally closed contact of the timer.

(3) In the solenoid valve energization control device of the present invention, the switching means described in the above-mentioned invention (1) comprises a normally closed contact of the timer, a constant voltage circuit and a diode, and a constant voltage is provided on the output side of the normally closed contact. It is characterized in that the output side of the circuit is connected via a diode.

(4) The solenoid valve energization control device according to the present invention is characterized in that the switching means described in the above-mentioned invention (1) comprises a positive temperature coefficient thermistor.

(5) The solenoid valve energization control device according to the present invention is for controlling a refrigerator, and has the above-mentioned invention (1) in the energization control circuit for the solenoid valve for control incorporated in the refrigeration compressor.
It is characterized in that the switching means described in (2), (3) or (4) is provided.

[0012]

In the above invention (1), when the energization of the solenoid valve is started, the power supply voltage is applied to the solenoid valve through the energization control circuit, and the solenoid valve starts operating.

After the operation of the solenoid valve is completed, the state can be maintained at a low supply voltage. Therefore, the switching means releases the voltage applied to the solenoid valve from the energization control circuit after a lapse of a predetermined time. Lower to the value.

As described above, since the supply voltage of the solenoid valve decreases in the holding state after the operation is completed, it is possible to suppress the temperature rise.

In the above invention (2), the power source voltage is applied to the solenoid valve through the normally closed contact of the timer at the start of energization of the solenoid valve, and after the elapse of a predetermined time, the normally closed contact is opened and the power source voltage is increased. Is reduced to the release voltage value by the voltage dividing resistor and applied to the solenoid valve, and the effect of the above invention (1) is produced.

In the above invention (3), the power source voltage is applied to the solenoid valve through the normally closed contact of the timer at the start of energization of the solenoid valve, and after a lapse of a predetermined time, the normally closed contact is opened and the constant voltage is maintained. A voltage having a release voltage value is applied to the solenoid valve from the circuit, and the effect of the invention (1) is produced. Since the diode is provided on the output side of the constant voltage circuit, current does not flow from the normally closed contact to the output side of the constant voltage circuit when the normally closed contact is closed.

In the above invention (4), a power supply voltage is applied to the solenoid valve via a positive temperature coefficient thermistor and is energized. Since the positive temperature coefficient thermistor has a characteristic that its resistance value increases as the temperature rises, its resistance value rapidly increases due to self-heating when the energization is started.

Therefore, when the solenoid valve is energized, the resistance value of the positive temperature coefficient thermistor is small, and a voltage close to the power supply voltage is applied to the solenoid valve, but the temperature rises with time and the positive temperature coefficient thermistor Since the resistance value increases, the voltage applied to the solenoid valve lowers and saturates at the release voltage value, which brings about the effect of the invention (1).

In the above invention (5), the switching means of the above invention (1), (2), (3) or (4) is used in an energization control circuit for a solenoid valve for controlling a refrigerator, and the temperature of the solenoid valve is controlled. Controls the rise. Therefore, it becomes possible to incorporate an electromagnetic valve in the discharge refrigerant gas flow path of the compressor, which was impossible in the conventional refrigerator due to the temperature rise of the coil, and the compressor can be made compact.

[0020]

FIG. 1 shows a first embodiment of the present invention. In the present embodiment shown in FIG. 1, a control switch 11 and a timer 12 connected in series between the positive side and the negative side of a power supply, and a timer 1 whose one end is connected to a connecting portion of the control switch 11 and the timer 12.
2 includes a parallel circuit of the normally closed contact 13 and the voltage dividing resistor 14, and a solenoid valve 15 connected between the other end of the parallel circuit and the negative side of the power supply. Piezoresistive 1
A switching means is formed by 4.

In the above, when the control switch 11 is closed by the energization command to the solenoid valve 15, the voltage Vs is supplied to the circuit constituted by the timer 12, the voltage dividing resistor 14 and the solenoid valve 15. The contact 13 is a normally closed contact and is opened when the timer 12 is supplied with power and a set time has elapsed. Therefore, when the control switch 11 is closed, the voltage dividing resistor 14
Is short-circuited by the contact 13, and the solenoid valve 15 has
As shown in, the power supply voltage Vs is applied as it is.

When the set time of the timer 12 has elapsed, the contact 13 is opened and the solenoid valve 15 is connected in series with the voltage dividing resistor 14. As a result, as shown in FIG. 2, the voltage Vc obtained by dividing the power supply voltage by the ratio of the resistance value of the solenoid valve coil (33 in FIG. 3) and the resistance value of the voltage dividing resistor 14 is applied to the solenoid valve 15.

A method of setting the voltage Vc will be described below.

FIG. 3 shows an example of the structure of the solenoid valve 15 used in this embodiment. 31 is an air gap, 32 is a coil housing, 33 is a coil, 34 is a spring, 35 is a fluid inlet hole, and 36 is a fluid inlet hole. Movable iron core, 37 is solenoid valve body, 3
Reference numeral 8 is a fluid outlet hole. The broken line in the figure shows the flow of magnetism when the coil 33 is energized, and the material forming the magnetic path is all iron-based magnetic material, and the operation of the solenoid valve 15 is well known, so its explanation is omitted. To do.

The coil 33 generates magnetism when a voltage is applied, and its magnetomotive force is the product of the current value and the number of turns of the wire constituting the coil 33, and is a function of the applied voltage.
The attracting force generated in the air gap 31 is a function of the magnetic flux with respect to the applied magnetomotive force, but since the magnetic force and magnetic flux characteristics of the magnetic body have hysteresis as shown in FIG. Similarly, hysteresis occurs.

Assuming that the force required to operate the solenoid valve 15 is Fi and the minimum force capable of maintaining the operated state is Fc, the voltage that generates the required force is Vi when the voltage rises, and when the voltage drops. It becomes Vc. Therefore, the voltage to be generated by the circuit of FIG. 1 is a value with the above Vc as the lower limit value. This Vc is generally called a release voltage and is 10 to 10% of the power supply voltage.
It is about 20%.

The amount of heat generated by the coil 33 is equivalent to the input power and is approximately proportional to the square of the applied voltage. Therefore, by setting the supply voltage to the above Vc, it is possible to suppress the amount of heat generation and the temperature increase of several% when the power supply voltage is supplied.

From the above, the solenoid valve to be controlled is
In the holding state after the operation is completed, the supply voltage drops and the temperature rise is suppressed, so it is possible to install a solenoid valve in the discharge refrigerant gas flow path of the compressor, which was not possible in the past. Became possible.

A second embodiment of the present invention is shown in FIG. In the present embodiment shown in FIG. 5, instead of the voltage dividing resistor in the first embodiment, a constant voltage circuit 51 connected in parallel to the series circuit of the contact 13 and the solenoid valve 15, and the connection between the contact 13 and the solenoid valve 15. And a diode 52 connected between the output terminal of the constant voltage circuit 51 and the output terminal of the constant voltage circuit 51. The constant voltage circuit 51 includes a transistor Tr as shown in detail in FIG.
It is formed of an operational amplifier OP and the like.

In the above description, when the control switch 11 is closed as in the first embodiment, first, the power supply voltage Vs is supplied to the solenoid valve 15, and then the timer 12 times up and the contact 13 is opened. Vc is supplied from the constant voltage circuit 51, and the same effect as that of the first embodiment is produced. The diode 52 is for preventing the current from flowing from the contact 13.

A third embodiment of the present invention is shown in FIG. In this embodiment shown in FIG. 6, the power source includes a control switch 11 and a solenoid valve 15.
Further, a positive temperature coefficient thermistor 61 that is connected in series and forms a switching unit is provided.

In the above, when the control switch 11 is closed as in the first and second embodiments, the positive temperature coefficient thermistor 61 is opened.
The power supply voltage Vs is supplied to the solenoid valve 15 via the. At this time, since the temperature of the positive temperature coefficient thermistor 61 is low, its resistance value is small as shown in FIG. 7, and a voltage close to Vs is supplied to the solenoid valve 15. After that, the positive temperature coefficient thermistor 61
Self-heating causes the temperature to rise rapidly and become saturated. Therefore, the resistance value of the thermistor 61 also increases, and the solenoid valve 1
The voltage supplied to 5 decreases as shown in FIG. 8 and eventually becomes saturated with the voltage Vc, and the same effect as in the first and second embodiments is produced.

[0033]

The solenoid valve energization control device of the present invention is provided with a switching means for immediately maintaining the operating state after the power source voltage is directly applied to the solenoid valve to surely complete the operation. By lowering the supply voltage to the required minimum voltage value and applying it to the solenoid valve, the temperature rise of the solenoid valve coil can be made extremely low, which was impossible with the conventional refrigerator due to the coil temperature rise. A solenoid valve can be built in the discharge refrigerant gas flow path of the compressor, and the compressor can be made compact.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control circuit according to a first embodiment of the present invention.

FIG. 2 is an operation explanatory view of the control circuit according to the first embodiment.

FIG. 3 is a structural diagram of a solenoid valve according to the first embodiment.

FIG. 4 is a relationship diagram of voltage and generated force of the solenoid valve according to the first embodiment.

5A and 5B show a configuration of a control circuit according to a second embodiment of the present invention, FIG. 5A is an overall view, and FIG. 5B is a detailed view of a constant voltage circuit.

FIG. 6 is a configuration diagram of a control circuit according to a third embodiment of the present invention.

FIG. 7 is a temperature resistance characteristic diagram of the positive temperature coefficient thermistor according to the third embodiment.

FIG. 8 is an operation explanatory view of the control circuit according to the third embodiment.

FIG. 9 is an outline of a conventional refrigerant compressor.

[Explanation of symbols]

 11 Control Switch 12 Timer 13 Contact 14 Voltage Dividing Resistance 15 Solenoid Valve 51 Constant Voltage Circuit 52 Diode 61 Positive Characteristic Thermistor

Claims (5)

[Claims] 1. A switching means for supplying a power supply voltage to a solenoid valve energization control circuit at the start of energization and for supplying a voltage having a release voltage value of the solenoid valve as a lower limit after completion of operation of the solenoid valve. Characteristic solenoid valve energization control device. 2. The solenoid valve energization control device according to claim 1, wherein the switching means comprises a parallel circuit of a voltage dividing resistor and a normally closed contact of a timer. 3. The switching means comprises a normally closed contact of a timer, a constant voltage circuit and a diode, and the output side of the normally closed contact is connected to the output side of the constant voltage circuit through a diode. 1. The solenoid valve energization control device according to 1. 4. The solenoid valve energization control device according to claim 1, wherein the switching means comprises a positive temperature coefficient thermistor. 5. A refrigeration compressor characterized in that the switching means according to claim 1, 2, 3 or 4 is provided in an energization control circuit for a control solenoid valve incorporated in the refrigeration compressor. Solenoid valve energization control device for control of.