JPH10252931A - Solenoid proportional control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid proportional control valve capable of controlling the valve opening with controlling accuracy by correctly detecting the opening of a valve disk arranged in a conduit in which the fluid flows from the conduit with simple constitution, and feeding the detected signal back to the solenoid. SOLUTION: A magnetic member 8 to be jointly operated with a valve disk 3 to be positionally controlled by a solenoid is arranged in a conduit, a primary excitation coil 31 and a plurality of secondary induction coils 32a... are juxtaposed outside the conduit along the moving direction of the magnetic member 8, the position of the magnetic member 8 is detected from the phase difference between the carrier wave of the AC voltage to be applied to the primary excitation coil 31 and the synthesized wave of the induction voltage to be generated in a plurality of secondary induction coils 32a..., and valve opening sensors 30, 40 to detect the opening of the valve disk 3 based thereon are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic proportional control valve in which a flow rate of a fluid passing through a pipeline is controlled by a reciprocating electromagnetic solenoid.

[0002]

2. Description of the Related Art For example, an expansion valve used in a refrigeration cycle of a car air conditioner is one in which the flow rate of refrigerant sent to an evaporator is controlled by an electromagnetic proportional control valve that drives the valve with a reciprocating electromagnetic solenoid. is there.

Heretofore, in such an electromagnetic proportional control type expansion valve, the valve opening has been controlled simply by controlling the current supplied to a solenoid.

[0004]

As described above, it is difficult to perform high-precision valve opening by controlling the valve opening by simply controlling the current supplied to the solenoid. In order to perform the degree control, it is desirable to detect the valve opening and feed back the valve opening signal obtained thereby to the solenoid control.

[0005] However, since it is difficult to accurately detect the opening of the valve element disposed in the pipeline through which the refrigerant flows, such feedback control has not been put to practical use, and high precision Valve opening control could not be performed.

Therefore, the present invention accurately detects the opening of a valve disposed in a conduit through which a fluid flows from outside the conduit with a simple configuration, and feeds back a detection signal to an electromagnetic solenoid to thereby achieve a high level. An object of the present invention is to provide an electromagnetic proportional control valve capable of performing accurate valve opening control.

[0007]

In order to achieve the above object, an electromagnetic proportional control valve according to the present invention controls the position of a valve disposed in a pipe through which a fluid is passed by a reciprocating electromagnetic solenoid. Thereby, in the electromagnetic proportional control valve configured to control the flow rate of the fluid passing through the pipe, the magnetic material cooperating with the valve body is arranged in the pipe, and the magnetic material moves in the moving direction of the magnetic material. A primary excitation coil and a plurality of secondary induction coils are juxtaposed along the outside of the conduit, and a carrier wave of an AC voltage applied to the primary excitation coil and a composite wave of an induced voltage generated in the plurality of secondary induction coils And a valve opening sensor for detecting the position of the magnetic material from the phase difference between the two and detecting the opening of the valve body based on the detected position.

[0008] Solenoid control means for controlling the current supplied to the electromagnetic solenoid is provided.
The detection signal from the valve opening sensor may be fed back to the solenoid control means to control the valve opening.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an expansion valve for controlling a flow rate of a cooling amount to be sent while adiabatically expanding an evaporator (not shown) during a refrigeration cycle of a car air conditioner.
However, the present invention is not limited to the expansion valve, and can be applied to an electromagnetic proportional control valve for controlling the flow rates of various fluids.

Reference numeral 1 denotes a refrigerant passage pipe through which high-pressure refrigerant sent from a liquid tank (not shown) passes.
A valve seat 2 is formed in a flow path portion formed by bending into a crank shape, and a valve body 3 having a variable gap A between the valve seat 2 and the valve seat 2 is disposed.

The valve body 3 is formed to be elongated, and the refrigerant flow pipe 1
Is disposed through the valve seat 2 in a direction perpendicular to the pipe axis, and a gap A between the tapered portion formed opposite the valve seat 2 from the upstream side and the valve seat 2 forms a refrigerant flow. It becomes a throttle portion of the path, and the refrigerant passing therethrough starts adiabatic expansion. The flow rate of the refrigerant is controlled by moving the valve body 3 in the axial direction to change the size of the gap A.

The front half of the valve body 3 projects laterally from the refrigerant flow pipe 1 and is made of a non-magnetic material projecting from the refrigerant flow pipe 1 so that the refrigerant does not leak out. Is inserted in the guide cylinder 4 so as to be able to advance and retreat in the axial direction.

A communication hole 5 is formed in the valve body 3, one end of which opens into the refrigerant flow pipe 1 on the upstream side of the valve seat 2, and the other end of which opens at the protruding end of the valve body 3. The refrigerant pressure is not applied in the axial direction of the valve body 3. In order to obtain the effect, the inner diameter of the guide cylinder 4 is formed to be the same as the diameter of the valve seat 2.

Reference numeral 10 denotes a reciprocating electromagnetic solenoid arranged to control the position of the valve element 3. A movable iron core 12 abutting on an end of the valve element 3 is driven by an electromagnetic coil 11 to rotate the valve element 3. 3 so as to reciprocate in the central axis direction.

The valve element 3 is urged by a compression coil spring 6 from the protruding end side, and the movable iron core 12 is urged by a compression coil spring 13 in the opposite direction. Therefore,
The valve element 3 stops at a position where the urging forces of both the compression coil springs 6 and 13 and the thrust of the movable iron core 12 are balanced.

Therefore, when the solenoid control circuit 20 changes the current flowing through the electromagnetic coil 11 based on the valve opening setting signal input to the solenoid control circuit 20, the valve body 3 moves in the axial direction and its stationary position. Is changed, whereby the area of the gap A between the valve seat 2 and the valve body 3 is changed, so that the flow rate of the refrigerant sent into the evaporator through the refrigerant flow pipe 1 can be changed. 3 shows a fully closed state in which the valve body 3 is in close contact with the valve seat 2, and FIG. 5 shows a fully open state in which the valve body 3 is farthest from the valve seat 2.

A non-magnetic material 7 made of, for example, a brass material is provided on a portion of the valve body 3 projecting laterally from the refrigerant flow pipe 1.
Sandwiching the two magnetic materials 8 made of, for example, iron,
The valve body 3 is fixed along the axial direction.

The non-magnetic material 7 and the magnetic material 8 are both formed in a cylindrical shape, and the outer peripheral surface faces the inner peripheral surface of the guide cylinder 4, and when the valve body 3 moves in the axial direction, the non-magnetic material 7 and the magnetic material 8 move together. The magnetic material 7 and the magnetic material 8 also move.

Outside the guide cylinder 4 in which the non-magnetic material 7 and the magnetic material 8 are arranged, valve opening detectors 30 are provided corresponding to the positions of the non-magnetic material 7 and the magnetic material 8. . The valve opening detection section 30 and the valve opening detection circuit 40 electrically connected thereto detect the position of the valve body 3 from the position of the magnetic material 8,
This constitutes a valve opening detection sensor that detects the opening of the valve body 3 (valve opening).

As shown in FIG. 2 in an enlarged manner, five primary exciting coils 31 and four secondary induction coils 32a and 33 formed in a thin donut shape are provided in the valve opening detecting section 30.
a, 32b and 33b are arranged alternately.

Each of the five primary excitation coils 31 has a structure in which the windings of the coils are continuously wound in the same direction, and one primary excitation coil is dispersedly arranged in five. In addition, the primary excitation coil 31 may be configured collectively.

With such a structure, the primary excitation coil 3
When a constant AC voltage is applied to the first and second induction coils 32, 33a, 32a, and 32b, the magnitude of the secondary induced voltage depends on the positional relationship between the two magnetic materials 8 that pass the magnetic flux well.
3b.

The four secondary induction coils 32a, 33a, 3
2b and 33b are wound in a continuous winding in which every other two are arranged. However, the winding directions of the two secondary induction coils connected by the same winding are opposite.

That is, the first secondary induction coil 32a and the third
Are connected by the same winding with the winding direction reversed, and the second secondary induction coil 33a and the fourth secondary induction coil 33b have the same winding with the winding direction reversed. It is connected by.

Therefore, when a constant AC voltage is applied to the primary excitation coil 31, a voltage value V1 of a difference between the induced voltage of the first secondary induction coil 32a and the induced voltage of the third secondary induction coil 32b is obtained. The voltage value V2 of the difference between the induced voltage of the second secondary induction coil 33a and the induced voltage of the fourth secondary induction coil 33b is output and input to the valve opening detection circuit 40.

The values of the output voltage values V1 and V2 differ depending on the positional relationship between the secondary induction coils 32a, 33a, 32b, 33b and the magnetic material 8. FIG. 4 shows the valve opening detector 30 in a fully closed state, and FIG. 6 shows the valve opening detector 30 in a fully open state.

In the valve opening detection circuit 40, the phase difference between the carrier of the AC voltage flowing through the primary excitation coil 31 and the composite wave of the output voltages V 1 and V 2 from the valve opening detection section 30 is used to determine the magnetic material 8. The position (ie, the position of the valve element 3) is detected,
Based on this, the opening of the valve body 3 is detected. The specific contents are described in "Nikkei Medical 1996.10.14 no.491", pages 49 to 55, etc., and the outline is as follows.

That is, the carrier wave V = A is applied to the primary excitation coil 31.
When an AC voltage of sinωt is applied, a secondary induced voltage of V1 = Bsinωt · sinx V2 = Bsinωt · cosx is obtained. Here, x is a displacement amount of the magnetic material 8 from a reference position (for example, a fully closed state).

Then, V3 = V2 + (1 / ω) · (dV1 / dt) = B (cosωt · sinx + sinωt · cosx) = Bsin (ωt + x)

From the phase difference between the composite wave V3 and the carrier V of the voltage applied to the primary excitation coil 31, the magnetic material 8
Is detected from the reference position, and the position of the valve body 3 and the opening degree of the valve body 3 are detected based on the movement amount.

Returning to FIG. 1, the signal of the valve opening detected by the valve opening detecting section 30 and the valve opening detecting circuit 40 as described above is sent from the valve opening detecting circuit 40 to the solenoid control circuit 20. The electromagnetic solenoid 1 is fed back so that the valve opening coincides with the value input by the setting signal.
The value of the current supplied to the electromagnetic coil 11 of 0 is controlled.

FIG. 7 shows a second embodiment of the present invention. An end portion of a guide cylinder 4 formed by a sleeve serves as a valve seat 2 and a sleeve 1 for guiding a movable iron core 12.
4 is also formed long up to the valve seat 2 portion.

The valve body 3 is formed short, and a magnetic material 8 and a non-magnetic material 7 are fixed to a front portion of an elongated pipe-like connecting member 9 connected to the valve body 3. Are integrally movable in the axial direction.
The configuration of the valve opening detector 30 and the like is the same as in the above-described first embodiment.

[0034]

According to the electromagnetic proportional control valve of the present invention, the position of the carrier of the AC voltage applied to the primary excitation coil provided outside the pipeline and the combined wave of the induced voltages generated in the plurality of secondary induction coils are changed. By providing a valve opening sensor that detects the opening of the valve body from the phase difference, it is possible to accurately detect the opening degree of the valve body arranged in the pipeline through which the fluid flows from outside the pipeline with a simple configuration By feeding back the detection signal to the solenoid, highly accurate valve opening control can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electromagnetic proportional control type expansion valve according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a valve opening sensor portion according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the electromagnetic proportional control type expansion valve according to the first embodiment of the present invention in a fully closed state.

FIG. 4 is a longitudinal sectional view of a valve opening sensor portion in a fully closed state according to the first embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of the electromagnetic proportional control type expansion valve according to the first embodiment of the present invention in a fully opened state.

FIG. 6 is a longitudinal sectional view of a valve opening sensor portion in a fully opened state according to the first embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view of the electromagnetic proportional control type expansion valve according to a second embodiment of the present invention in a fully closed state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerant flow pipe 2 Valve seat 3 Valve body 10 Electromagnetic solenoid 11 Electromagnetic coil 20 Solenoid control circuit 30 Valve opening detection part 31 Primary excitation coil 32a, 32b, 33a, 33b Secondary induction coil 40 Valve opening detection circuit

Claims (2)

[Claims] 1. A reciprocating electromagnetic solenoid controls the position of a valve disposed in a pipe through which a fluid passes.
An electromagnetic proportional control valve configured to control a flow rate of a fluid passing through the pipeline, wherein a magnetic material cooperating with the valve body is disposed in the pipeline, and the magnetic material is moved along a moving direction of the magnetic material. A primary excitation coil and a plurality of secondary induction coils are juxtaposed outside a conduit, and a position of a carrier wave of an AC voltage applied to the primary excitation coil and a composite wave of an induced voltage generated in the plurality of secondary induction coils are arranged. An electromagnetic proportional control valve, comprising: a valve opening sensor that detects a position of the magnetic material from a phase difference and detects an opening of the valve body based on the detected position. 2. A solenoid control means for controlling a current supplied to the electromagnetic solenoid is provided, and a detection signal from the valve opening sensor is fed back to the solenoid control means to control the valve opening. The electromagnetic proportional control valve according to claim 1.