JP2001248748A - Three-stage flow rate control solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge an allowable range against a position deviation of a plunger, a voltage variation and a fluid pressure variation. SOLUTION: A first coil spring 51, a second coil spring 52 and a third coil spring 53 are arranged in parallel so as to urge a plunger 20 to a valve seat 35 side such that a flow rate of a fluid flowing from an inlet 8 to an outlet 9 is switched to three stages by switching an applied voltage against a solenoid 10 to three stages. When the applied voltage against the solenoid 10 is a voltage at the first stage, a first valve element 21 opens a front stage orifice 41. When the applied voltage is a voltage at a second stage, a second valve element 22 opens an intermediate stage orifice 42. When the applied voltage is a voltage at a third stage, a third valve element 23 opens a rear stage orifice 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve suitable for being incorporated in a refrigeration cycle of, for example, a car air conditioner, and more particularly to a function of an expansion valve in addition to a function of a switching valve for switching a flow rate into three stages. The present invention also relates to a three-stage flow control solenoid valve which can also have the same.

[0002]

2. Description of the Related Art For example, in a refrigeration cycle of a car air conditioner, a refrigerant passage is usually branched into a front side (driver's seat side) for cooling and a rear side for cooling, and both paths are provided with evaporators, respectively. An expansion valve is disposed on each of the upstream sides of the evaporators. In particular, on the upstream side of the rear expansion valve, a solenoid valve is provided to open and close the rear refrigerant passage (cooling ON / OFF) as necessary. Are often arranged.

However, conventionally, there has been a problem that the solenoid valve disposed in the refrigerant passage simply cannot open and close the passage but cannot adjust the flow rate. In order to solve the above-mentioned problem, the applicant of the present application has previously arranged a refrigerant passage as described above and switched its flow rate between two stages, that is, switched between a weak stage and a strong stage with the cooling ON state. (See Japanese Utility Model Publication No. 3-5739).

However, even with the proposed solenoid valve, the flow rate of the refrigerant can be switched only in two stages, and the function of the flow rate switching valve cannot be satisfied even more precisely. However, the refrigeration cycle in which the refrigeration cycle is incorporated has a problem that a separate expansion valve is required.

Accordingly, the applicant of the present application has disclosed in
As described in JP-A-1-82801, a valve body having a valve chamber, an inlet, an outlet, and a valve seat, and suction provided on the opposite side of the valve body in the valve body. A solenoid having a valve element, and a plunger slidably disposed between the valve seat of the valve body and the suction element, wherein the plunger is provided with a first valve body and the valve seat A second-stage orifice is formed in the second valve body, and a second valve body and a third valve body that are sequentially lifted by the plunger in a direction away from the valve seat are disposed between the first valve body and the valve seat. Between the suction element and the plunger, the first
A first coil spring for urging the valve body, the second valve body, and the third valve body toward the valve seat via the plunger is provided, and the second valve body is opened and closed by the first valve body. A front orifice having an effective passage cross-sectional area smaller than the rear orifice is formed, and the third valve body is opened and closed by the second valve body. The effective passage cross-sectional area is larger than the front orifice and An intermediate orifice smaller than the orifice is formed, and the rear orifice is opened and closed by the third valve body. By increasing the voltage applied to the solenoid in a stepwise manner, the first valve body is increased. , The second valve body and the third valve body open the front orifice, the middle orifice, and the rear orifice in order, so that the flow rate can be controlled in three stages. It has proposed a control solenoid valve).

[0006]

In the proposed three-stage flow control solenoid valve, the flow rate can be more finely adjusted as compared with the conventional solenoid valve which can switch the flow rate only in two stages. Although the intended purpose of having both functions of the flow switching valve and the expansion valve could be achieved for the time being, there were still the following problems.

That is, in the conventional three-stage flow control solenoid valve, as a biasing means for biasing the plunger in a direction away from the attraction element (stator) of the solenoid, substantially one coil spring (a plurality of coil springs) is used. When a predetermined voltage is applied to the solenoid, the plunger applies a suction force of the solenoid and an urging force (+ fluid) of the coil spring to the suction element when a predetermined voltage is applied to the solenoid. Is lifted up to a position where it is balanced with the back pressure, and is held at that position.

More specifically, when the applied voltage to the solenoid is, for example, 4 volts (first-stage voltage), the plunger is pulled up to the position where the first valve element opens the front-stage orifice. However, when the second valve element is separated from the position where the middle orifice opens, and the applied voltage is, for example, 7 volts (second step voltage), the second valve element is pulled up to the position where the second orifice opens. However, when the third valve body is separated from the position where the rear-stage orifice is opened, and the applied voltage is, for example, 12 volts (third stage voltage), the third valve body is raised to the position where the rear-stage orifice is opened. ing.

In this case, the solenoid valve naturally has its own size, the attraction force (excitation force) of the solenoid, etc., from the viewpoint of the space restrictions of the equipment into which the solenoid valve is incorporated and the magnitude of the power supply voltage. A limit is imposed, and the distance (lift amount) for pulling up the plunger is usually limited to a maximum of about 3 to 4 mm. Therefore, the lift amount for each of the steps is about 0.5 to 2 mm. Extremely high precision is required for flow control.

However, the attraction force of the solenoid and the urging force of the coil spring acting on the plunger may vary due to individual differences due to processing errors in manufacturing the solenoid or the coil spring, and aging (reduction of the exciting force, setting of the spring, etc.). And the like, a variation occurs, and the variation causes a deviation in a position where the suction force and the urging force are balanced, that is, a position in which the plunger is pulled up with respect to the suction element.
The lifting position of the plunger with respect to the suction element also deviates from a desired position due to dimensional errors of component parts (plungers, valve bodies, etc.), assembly errors, and the like. In addition, the applied voltage to the solenoid (the voltage of the vehicle-mounted battery) and the pressure of the fluid (especially the refrigerant) introduced into the valve body also fluctuate.

Therefore, in the conventional three-stage flow control solenoid valve, variations in the suction force and the urging force, dimensional errors,
Due to the displacement of the plunger raised position, the applied voltage, the fluctuation of the fluid pressure, etc., caused by an assembly error, etc., the first stage,
In the second stage and the third stage, the position of the plunger greatly deviates from the position to be taken by the plunger, or the balance is lost due to a slight change in the applied voltage or the fluid pressure, and the position of the plunger fluctuates greatly. In many cases, the flow rate was not properly switched. In other words, in the conventional three-stage flow control solenoid valve, the displacement of the plunger, the voltage fluctuation, the fluid pressure fluctuation, etc. caused by the variation of the attraction force of the solenoid or the urging force of the coil spring, the dimensional error, the assembly error, etc. The range that could be supported (allowed) was narrow.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. An object of the present invention is to reduce the flow rate by 3 while the structure is relatively simple and can be easily manufactured at low cost. You can switch between stages,
It can serve as both a flow switching valve and an expansion valve, and furthermore, the displacement of the plunger, voltage fluctuation, fluid fluctuation due to variation in the attraction force of the solenoid and the biasing force of the coil spring, dimensional error, assembly error, etc. The range that can be countered (allowed) against pressure fluctuations etc. can be expanded,
An object of the present invention is to provide a solenoid valve capable of improving the certainty and reliability of a flow rate switching operation.

[0013]

In order to achieve the above object,
An electromagnetic valve according to the present invention basically includes a valve body having a valve chamber, an inlet, an outlet, and a valve seat, a plunger disposed in the valve body, and the plunger being connected to the valve seat. A solenoid having a suction element that suctions on the opposite side to
A first portion which is sequentially lifted between the plunger and the valve seat in a direction away from the valve seat by the plunger;
A valve element, a second valve element, and a third valve element are arranged,
A first orifice, a middle orifice, which has an effective passage sectional area which is sequentially opened and closed by the first, second and third valve bodies at the second and third valve bodies and the valve seat, respectively; An orifice and a rear-stage orifice are formed, and the plunger is stepped up to the suction element by increasing the applied voltage to the solenoid in a stepwise manner, whereby the first valve body, the second valve A body and a third valve body are configured to sequentially open the front orifice, the middle orifice, and the rear orifice.

A first coil spring, a second coil spring, and a third coil spring are arranged in parallel with the plunger so as to bias the plunger toward the valve seat.
A first movable stopper is disposed between the plunger and the second coil spring, and a second movable stopper is disposed between the plunger and the third coil spring.
When the voltage applied to the solenoid is the first-stage voltage Va, the first coil spring is compressed, the first valve body opens the front-stage orifice, and the second valve stopper is opened via the first movable stopper. When the coil spring is slightly compressed and the applied voltage is the second step voltage Vb, the first coil spring and the second coil spring are both compressed, the second valve body opens the middle orifice, and When the third coil spring is slightly compressed via the second movable stopper, and the applied voltage is the third step voltage Vc, the third coil spring is added to the first and second coil springs. Is also compressed, the third valve element opens the rear orifice, and
It is characterized in that the plunger is brought into contact with the suction element side packing.

In a preferred aspect, the first coil spring is compressed between the plunger and the attraction element, a second coil spring is compressed between the plunger and the first movable stopper, and A third coil spring is contracted between the plunger and the second movable stopper.

In another preferred aspect, the first coil spring is compressed between the plunger and the attraction element, and the second coil spring is compressed between the plunger and the first movable stopper. The second movable stopper and the third coil spring are interposed between the plunger and the first movable stopper, and when no voltage is applied to the solenoid, the first movable stopper and the second movable stopper are connected to each other. A predetermined gap is formed between the movable stopper and the movable stopper.

In still another preferred aspect, the first coil spring is disposed on the plunger side of the attraction element, and the second coil spring, the third coil spring is disposed on a side of the attraction element opposite to the plunger, A first movable stopper and a second movable stopper are provided. In the three-stage flow control solenoid valve according to the present invention, it is preferable that an initial set load of at least one of the first coil spring, the second coil spring, and the third coil spring can be externally adjusted.

In this case, as a preferred specific example, a cylindrical fitting in which a spring receiving member for receiving the second coil spring and the third coil spring is slidably inserted on a side of the suction element opposite to the plunger. A male screw portion is formed on the outer periphery of the cylindrical fitting portion, and the second coil spring and the third coil spring are compressed on the male screw portion via the spring receiving member. And a nut member for adjusting the initial set load of the above.

In addition to the above, in a more specific preferred embodiment of the three-stage flow control solenoid valve according to the present invention in consideration of assemblability, reduction of manufacturing cost, and the like, the plunger is provided with the suction from the valve seat side. Over the child side, the third valve body, the second valve body, the first valve body, the second coil spring, and the first movable stopper are respectively movable along the length direction of the plunger, And it is inserted in series in the state of being in contact sequentially.

In a further preferred aspect, the plunger prevents the first valve body from moving toward the second valve body, but the second valve body is integrally provided with a first locking portion through which the second valve body passes. A second locking portion is integrally provided on the valve seat side of the first locking portion to prevent the second valve body from moving toward the third valve body.

In another preferred embodiment, the fluid from the inflow port is passed directly to the middle orifice without passing through the second valve body, from the second locking portion of the plunger to the third valve body side. A guiding lateral hole is formed. In yet another preferred embodiment, a hemispherical projection for opening and closing the front-stage orifice is integrally provided on the first valve body.

In a preferred embodiment of the three-stage flow control solenoid valve according to the present invention having such a configuration, the flow rate is controlled to 3
In order to switch between the stages, a small voltage Va (for example, 4 volts) is applied to the solenoid in a first stage, a medium voltage Vb (for example, 7 volts) is applied in a second stage,
In the third stage, a large voltage Vc (for example, 12 volts) is applied. Generally, the applied voltage-attraction force characteristic of the solenoid is as shown in FIG. 6, and as shown in the figure, as the applied voltage to the solenoid increases, the attraction force increases,
The increase rate increases as the applied voltage increases.

Here, when the applied voltage to the solenoid is the small voltage Va (first step voltage), the attraction force of the solenoid is Fa, and when the applied voltage to the solenoid is the medium voltage Vb (second step voltage), When the attraction force of the solenoid becomes Fb larger than Fa, and when the voltage applied to the solenoid is the large voltage Vc (third stage voltage), the attraction force of the solenoid becomes Fc much larger than Fb.

On the other hand, in the three-stage flow control solenoid valve of the present invention, the plunger is pulled up by the attraction force of the solenoid, and the first, second and third valve bodies sequentially open each orifice. The first coil spring acts (compresses) in all stages so as to oppose the plunger suction force of the solenoid, and the end of the first stage, the second stage, and the second stage. The second coil spring operates (compressed) in three stages, and the third coil spring operates (compressed) in the end of the second stage and in the third stage. The biasing force (the load on the plunger) increases (as the compression amount increases).

The plunger is pulled up by the attraction force of the solenoid so as to overcome the urging force of each coil spring. In the three-stage flow control solenoid valve of the present invention,
In advance, the attraction forces F1, F2, and F3 of the solenoids required for the first, second, and third valve bodies to open (open each orifice) are respectively equal to the first force.
Step voltage Va, second step voltage Vb, and third step voltage V
It is set so that voltages V1, V2 and V3 smaller than c are sufficient. In other words, the voltages Va, Vb,
When voltages V1, V2, and V3 smaller than Vc and Vc are applied to the solenoid, the first, second, and third valve bodies are opened (opening each orifice) in advance. , A spring constant of each of the coil springs, an initial set load, and the like are set.

For this reason, when the voltage applied to the solenoid is the first-stage voltage Va, the plunger is pulled up by the suction force Fa.
The coil spring is compressed, the first valve body opens the front-stage orifice, and the second coil spring is slightly compressed through the first movable stopper. The coil spring and the second coil spring are stopped and held at the lifting position where the biasing force is balanced.

The voltage applied to the solenoid is equal to the second voltage.
At the step voltage Vb, the plunger is pulled up by the attraction force Fb. At this time, the first coil spring and the second coil spring are both compressed, the second valve body opens the middle orifice, and The third coil spring is slightly compressed, and the plunger is stopped and held at the raised position where the attraction force and the urging forces of the first coil spring, the second coil spring, and the third coil spring are balanced.

Further, the applied voltage is a third step voltage Vc.
In this case, the plunger is pulled up by the suction force Fc, the third coil spring is also compressed in addition to the first coil spring and the second coil spring, and the third valve body opens the rear-stage orifice. In addition, the plunger is stopped and held at a position where the plunger is brought into contact with the suction element-side packing (maximum pulling position).

As described above, in the solenoid valve according to the present invention,
The voltages V1, V2, and V3 at which the first, second, and third valve bodies open (open each orifice) are a first step voltage Va, a second step voltage Vb, and a first step voltage Vb, respectively. Since it is smaller than the three-step voltage Vc, the voltage difference U between them is
“a”, “Ub”, and “Uc” are allowable voltage ranges for absorbing displacement and fluctuation in the direction of pushing down the plunger to the valve seat side such as a voltage drop (see FIG. 6).

On the other hand, at the end of the first stage, the second coil spring is slightly compressed and starts to work,
Further, at the end of the second stage, the third coil spring is slightly compressed so as to start working.
At the stage, the plunger is brought into contact with the suction element side packing and is stopped and held, so that the plunger such as voltage rise is pulled up to the suction element side,
The displacement and the fluctuation can be suppressed very effectively as compared with the conventional three-stage flow control solenoid valve having only one coil spring.

Therefore, the solenoid valve according to the present invention has a relatively simple structure, can be easily manufactured at low cost, can switch the flow rate in three stages, and has a flow switching valve and an expansion valve. Of the plunger, displacement of the plunger, voltage fluctuation, fluid pressure fluctuation, etc. due to the variation of the attraction force of the solenoid or the biasing force of the coil spring, dimensional error, assembly error, etc. The range that can be supported (allowed) can be widened, and as a result, the reliability and reliability of the flow rate switching operation can be improved.

[0032]

Embodiments of the present invention will be described below with reference to the accompanying drawings. [I] First Embodiment FIG. 1 shows a first embodiment of a three-stage flow control solenoid valve according to the present invention. The solenoid valve 1 of the illustrated embodiment is incorporated in a rear-side cooling refrigerant passage of a refrigeration cycle of a car air conditioner, and FIG. 1 shows a state when cooling is OFF.

The solenoid valve 1 of this embodiment has a valve body 30 having a valve chamber 32, an inlet 8, an outlet 9, and a valve seat 35.
A tubular mounting base 33 with a flange screwed to the valve body 30; a plunger 20;
And a solenoid 10 disposed on the outer periphery of the valve seat 35 so as to move toward and away from the valve seat 35.

The solenoid 10 includes a yoke 13, a coil 14, a suction element (stator) 15, a set screw 17, a power cable 18, a guide sleeve 12, and the like. The first step voltage Va, the second step voltage Vb, and the third
A step voltage Vc (for example, three steps of 4 V, 7 V, and 12 V) is applied.

The lower portion of the guide sleeve 12 is joined and fixed to the inner periphery of the mounting table 33 by brazing or the like.
An O-ring 34 is provided between the mounting base 33 and the valve body 30.
Is installed. The valve chamber 32 formed in the valve body 30 is provided with a valve seat 35 having a slightly rounded tip, and a refrigerant inlet 8 is provided so as to be continuous with the valve chamber 32. The refrigerant outlet 9 is provided downstream of the rear orifice 43 provided in the seat 35.

The plunger 20, which is slidably disposed within the guide sleeve 12 of the solenoid 10, has an inverted convex cross section near its center, as can be clearly understood from the enlarged view of FIG. A first valve body 21 holding a ball 21a is slidably fitted at the lower end thereof.
A second valve body 22 having a substantially cross-shaped cross-section and having a stepped front orifice 41 opened and closed by the first valve body 21 is slidably inserted below the second valve body. A main body 23a, which is provided with a middle orifice 42 having an effective passage area larger than that of the front orifice 41, which is opened and closed by the second valve body and is opened and closed by the second valve body, is fixed by caulking. The third valve body 23 formed of the outer peripheral fitting portion 23b is slidably fitted therein. With the third valve body 23, the effective passage cross-sectional area is larger than that of the middle orifice 42 formed in the valve seat 35. The second orifice 43 is opened and closed.

The outer diameter of the lower part of the plunger 20 is slightly smaller than that of the upper part, and between the outer peripheral surface of the lower part and the inner peripheral surfaces of the main body 30, the mounting base 33 and the guide sleeve 12. For guiding fluid (refrigerant) from the inflow port 8 to a space (first valve chamber 32A) formed between the first valve body 21 and the second valve body 22 through the lateral holes 62, 62; An outer peripheral passage portion 60 is formed, and the second valve body 22
Is provided on the outer peripheral portion of the housing for guiding a fluid (refrigerant) from the inflow port 8 to a space (second valve chamber 32B) formed between the second valve body 22 and the third valve body 23. A number of slit-like vertical grooves 25, 25,... Are formed.

The plunger 20 includes a first locking ring 71, a second locking ring 71, and a second locking ring 71 from the top so that the first valve body 21, the second valve body 22, and the third valve body 23 are sequentially pulled up. A ring 72 and a third locking ring 73 are caulked and fixed below the first valve body 21, the second valve body 22, and the third valve body 23, respectively.

In this case, when no voltage is applied to the solenoid 10 (cooling OFF, initial set state), as shown in FIG. 1 and FIG.
Is urged toward the second valve body 22 (downward) by a coil spring 65 interposed on the upper side thereof, and the ball 21a at the tip thereof comes into pressure contact with the second valve body 22 so that the front orifice 41 is moved. Although it is closed, a necessary gap for absorbing an assembly error, a processing error, and the like is formed between the first locking ring 71 and the first locking ring 71. Also, required gaps are formed between the second valve body 22 and the second locking ring 72 and between the third valve body 23 and the third locking ring 73, respectively.

On the other hand, a stepped recess 27 is formed in the upper part of the plunger 20, and an annular spring receiver 45 having a concave cross section fitted to the upper part of the recess 27 and the suction element 15 are formed.
Between the first valve body 21 and the second valve body 2 between the spring receiver 44 serving also as the suction element side packing 44 disposed below
A first coil spring 51 for urging the second and third valve bodies 23 toward the valve seat 35 via the plunger 20 is compressed.

The suction element 15 and the plunger 2
A first movable stopper 50 having a flange-like portion 50a having a substantially cross-sectional shape is slidably interposed between the recess 27 (and the annular spring receiver 45). A second coil spring 52 is compressed between the flange 50a of the movable stopper 50 and the bottom surface of the recess 27 of the plunger 20.

A cylindrical member having an L-shaped cross section is provided on the outer peripheral side of the flange portion 50a of the first movable stopper 50 and the second coil spring 52 and below the annular spring receiver 45. Second movable stopper 54 with stop 54a (FIG. 2)
And a third coil spring 5 is provided between the second movable stopper 54 and the recess 27 of the plunger 20.
3 has been disguised. A lateral hole 29 is formed in the recess 27, and a communication hole 28 communicates between the recess 27 and the hollow portion 26 formed under the first valve body 21. ing.

In the present embodiment, the first coil spring 51, the second coil spring 52, and the third coil spring 53
Is a plunger 20 by the solenoid 10 respectively.
In order to obtain a large elastic force (repulsive force) from the beginning at the time of raising, it is assembled in a compressed state at the time of assembly.

[Cooling OFF, applied voltage V = 0, (FIGS. 1 and 2)] In the three-stage flow control solenoid valve 1 having such a configuration,
When no voltage is applied to the solenoid 10, that is, when the solenoid 10 is not energized and energized (OFF), as shown in FIGS. The urging force of the spring 21 pushes down to the valve seat 35 side (downward), and the first valve body 21
Is pressed against the second valve body 22 to close the front orifice 41, and the second valve body 22 is pushed down to the third valve body 23 side, and pressed against it to close the middle orifice 42, and further the third valve body 23 is pushed down to the valve seat 35 side, presses against it, closes the rear orifice 43, and the entire valve element 21,
The valves 22 and 23 are closed, and no fluid (refrigerant) flows out from the inlet 8 to the outlet 9.

At this time, a maximum gap Lma is provided between the suction element side packing 44 and the upper end surface of the plunger 20.
x is formed. Further, a gap Q is formed between the lower surface of the suction element 15 and the upper end surface of the first movable stopper 50, and further, a flange-shaped portion 50 of the first movable stopper 50 (
a) and the second movable stopper 54 are caused by the urging force of the second coil spring 52 and the third coil spring 53, respectively.
Abutting against the lower surface of the annular spring receiver 45;
A gap S is formed between the flange 50a of the first movable stopper 50 and the locking portion 54a of the second movable stopper 54.

[Cooling ON: weak, applied voltage V = Va (FIG. 3)] On the other hand, when a first-stage voltage Va (for example, 4 volts) is applied to the solenoid 10, the solenoid 10 is energized and turned on. As shown in FIG. 3, the plunger 20 is pulled up halfway toward the suction element 15 against the urging force of the first coil spring 51.
The coil spring 51 is slightly compressed, the first valve body 21 is supported and locked by the first locking ring 71 of the plunger 20, and is pulled up together therewith. Thereby, the first valve body 21
Opens the front-stage orifice 41 away from the second valve body 21,
In addition, the first movable stopper 50 is brought into contact with the attraction element 15, and the second coil spring 52 is slightly compressed. However, the second valve body 22 and the third valve body 2
3 is the pressure difference between inside and outside (the inflow side is high and the outflow side is low)
As a result, the middle orifice 42 and the rear orifice 43 remain closed.

At this time, the maximum gap L is provided between the suction element side packing 44 and (the upper end surface of) the plunger 20.
A gap La smaller than max is formed. Further, there is no gap Q between the first movable stopper 50 and the suction element 15 (the first movable stopper 50 contacts), and the flange 50a of the first movable stopper 50 and the second movable stopper 5
The gap formed between the locking portion 54a and the locking portion 54a
The state of the gap S is maintained at the time of F.

Thus, the refrigerant from the inlet 8 is
The air is guided to a space (first valve chamber 32A) formed between the first valve body 21 and the second valve body 22 through the outer peripheral passage portion 60 and the lateral holes 62, 62, and is connected to the front orifice 41 and the middle stage. It flows out to the outlet 9 through the orifice 42 and the rear-stage orifice 43 to be expanded, and is guided to the downstream evaporator. Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the preceding orifice 41, the flow rate is relatively small, and the cooling power is weak.

[Cooling ON: Medium, applied voltage V = Vb,
(FIG. 4)] When a second step voltage Vb (for example, 7 volts) is applied to the solenoid 10, the solenoid 10 is energized and turned on, and as shown in FIG. The applied voltage V is further raised to the attraction element 15 side when the applied voltage V is the small voltage Va against the urging force of the coil spring 51 and the second coil spring 52, and accordingly, the first voltage is applied.
The coil spring 51 and the second coil spring 52 are both compressed, and the first valve body 21 is separated from the second valve body 22 and the second orifice 41 is opened while the front orifice 41 is open. 2 and is lifted up together with the plunger 20 by the support ring 72, whereby the second valve body 22 opens the middle orifice 42 and the flange 50a of the first movable stopper 50 (2) The third coil spring is slightly compressed by contacting the locking portion 54a of the movable stopper 54, but the third valve body 23 keeps the rear-stage orifice 43 closed.

At this time, the applied voltage V is applied between the suction element side packing 44 and (the upper end surface of) the plunger 20.
Is smaller than when the voltage is small voltage Va.
Further, no gap Q is formed between the first movable stopper 50 and the suction element 15 (the first movable stopper 50 contacts),
The second movable stopper 54 and the first movable stopper 50
The gap S formed between the second movable stopper 54 and the flange 50a is eliminated (the second movable stopper 54 contacts).

As a result, the second valve body 2 is formed from the inflow port 8 through the longitudinal grooves 25 formed in the second valve body 22.
The refrigerant flowing into the second valve chamber 32B formed between the second and third valve bodies 23 flows into the middle orifice 42, flows out to the refrigerant outlet 9 through the rear orifice 43, and is expanded. , To a downstream evaporator. Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the middle orifice 42, the applied voltage V becomes larger than when the first-stage voltage Va, and the cooling power becomes medium.

[Cooling ON: strong, applied voltage V = Vc,
(FIG. 5) When a third-stage voltage Vc (for example, 12 volts) is applied to the solenoid 10, the suction force of the suction element 15 becomes maximum, and as shown in FIG. The first coil spring 51, the second coil spring 52,
The first coil spring 51 and the second coil spring 5 are pulled up to a highest position (a position where the third coil spring 53 comes into contact with the suction element-side packing 44) against the urging force of the third coil spring 53.
The second and third coil springs 53 are compressed together, so that the first valve body 21 is
The third valve 23 is supported and locked by a third locking ring 73 of the plunger 20 in a state where the second valve 22 opens the middle orifice 42 and the plunger 2 is opened.
0 and is lifted away from the valve seat 35 to open the rear orifice 43.

At this time, no gap is formed between the suction element-side packing 44 and the upper end surface of the plunger 20 (the plunger 20 contacts), and the first movable stopper 50 and the suction element 15, there is no gap Q (the first movable stopper 50 contacts), and the second movable stopper 5
There is no gap between the second movable stopper 54 and the flange 50a of the first movable stopper 50 (the second movable stopper 54 contacts).
Since the second movable stopper 54 comes into contact with the first movable stopper 50 and does not move, a gap K is formed between the second movable stopper 54 and the annular spring receiver 45.

As a result, the refrigerant from the inlet 8 flows directly between the lower surface of the third valve body 23 and the valve seat 35 into the rear-stage orifice 43, and flows through the rear-stage orifice 43 into the refrigerant outlet 9. , And is led to a downstream evaporator. Therefore, when the third-stage voltage Vc is applied, the rear-stage orifice 43
, The flow rate of the refrigerant flowing from the inlet 8 to the outlet 9 is maximized, and the cooling power is increased.

As described above, in the solenoid valve 1 according to the present embodiment in which the flow rate is switched between three stages, as described above,
The small voltage Va (for example, 4 volts) is applied to the solenoid 10 in the first stage, and the medium voltage V is applied in the second stage.
b (for example, 7 volts) is applied, and a large voltage Vc (for example, 12 volts) is applied in the third stage. Advantages and reasons thereof compared to a three-stage flow control solenoid valve that is energized only by a coil spring will be described below. In general, the applied voltage-attraction force characteristic of the solenoid 10 is as shown in FIG. 6. As shown in the figure, as the applied voltage to the solenoid 10 increases, the attraction force increases, and the rate of increase increases as the applied voltage increases. growing.

Here, when the voltage V applied to the solenoid 10 is the small voltage Va (first step voltage), the attraction force of the solenoid 10 becomes Fa, and the voltage applied to the solenoid 10 becomes the medium voltage Vb (second step voltage). ), The suction force of the solenoid 10 is higher than Fb.
When the voltage V applied to the solenoid 10 is the medium voltage Vc (third stage voltage), the suction force of the solenoid 10 becomes Fc which is considerably larger than Fb.

On the other hand, in the solenoid valve 1 of this embodiment, three coil springs, that is, a first coil spring 51, a second coil spring 52, and a third coil spring 53 are arranged in parallel with the plunger 20. The solenoid 1
The plunger 20 is pulled up by the suction force of 0,
The first valve body 21, the second valve body 22, and the third valve body 23 are sequentially
Are operated to open the orifices 41, 42 and 43, and the first coil spring 51 works (compresses) in all stages so as to resist the plunger suction force of the solenoid 10, The end of the first stage, the second
The second coil spring 52 operates (compressed) in the third and third stages, and the third coil spring 53 operates (compressed) in the final stage and the third stage of the second stage. The urging force of the members 51, 52, and 53 increases as they are compressed (as the compression amount increases).

The plunger 20 is designed to overcome the urging force (+ fluid back pressure) of each of the coil springs 51, 52, 53.
Is lifted up by the attraction force of the solenoid 10, but in the solenoid valve 1 of the present embodiment, the first valve body 21, the second valve body 22, and the third valve body 23 are previously opened (each orifice 41). , 42, 43), the attraction forces F1, F2, and F3 of the solenoid 10 required to produce the voltages V, Vb, and Vc, respectively, that are smaller than the voltages Va, Vb, and Vc.
1, V2, and V3. In other words, the first step voltage Va, the second step voltage Vb,
By applying voltages V1, V2, and V3 smaller than the third stage voltage Vc to the solenoid 10, the first valve body 2
The spring constants of the coil springs 51, 52, and 53 and the initial set load are set in advance so that the first, second, and third valve bodies 22 and 23 open (open the orifices 41, 42, and 43). Etc. are set.

For this reason, when the voltage V applied to the solenoid 10 is the first step voltage Va, the plunger 20 is pulled up by the attraction force Fa. At this time, the first coil spring 51 is compressed, and The first valve element 21 opens the front-stage orifice 41, and
The first movable stopper 50 is brought into contact with the attraction element 15, the second coil spring 52 is slightly compressed, and the plunger 20 moves the attraction force and the first coil spring 5.
The first and second coil springs 52 are stopped and held at the lifting position where the biasing forces are balanced.

The voltage V applied to the solenoid 10 is
Is the second step voltage Vb, the plunger 20 is pulled up by the attraction force Fb. At this time, the first coil spring 51 and the second coil spring 52 are both compressed, and the second valve body 22 The middle orifice 4
2 and the third coil spring 53 is slightly compressed, and the plunger 20 applies the suction force to the first coil spring 51, the second coil spring 52, and the third coil spring 5.
3 is stopped and held at the lifting position in which the biasing force of 3 is balanced.

Further, the applied voltage V is a third step voltage V
At the time of c, the plunger 20 is pulled up by the suction force Fc, and the third coil spring 53 is also compressed in addition to the first coil spring 51 and the second coil spring 52, so that the third valve body 23 is moved. The rear orifice 43 is opened, and the plunger 20 is
4 and is stopped and held at a position where it is brought into contact with No. 4 (a maximum lifting position).

As described above, in the solenoid valve 1 of the present embodiment, the first valve body 21, the second valve body 22, and the third valve body 2
The voltages V1, V2, and V3 at which the valve 3 opens (opens the respective orifices 41, 42, 43) are the first-stage voltage Va, the second-stage voltage Va,
Since it is smaller than the step voltage Vb and the third step voltage Vc, the voltage differences Ua, Ub, and Uc between them absorb the displacement and fluctuation in the direction of pushing down the plunger to the valve seat side such as a voltage drop. This is the allowable voltage range (see FIG. 6).

On the other hand, at the end of the first stage, the second coil spring 52 is slightly compressed to start working, and at the end of the second stage, the third coil spring 53 is slightly compressed. In the third stage, the plunger 20 is brought into contact with the suction element-side packing 44 so as to be stopped and held. Therefore, the plunger such as a voltage rise is pulled up to the suction element side. Directional displacement and fluctuation can be extremely effectively suppressed as compared with the above-described conventional three-stage flow control solenoid valve having substantially only one coil spring.

Therefore, the solenoid valve 1 according to the present embodiment has a relatively simple structure and can be easily manufactured at low cost, but can switch the flow rate in three stages, and has a flow switching valve and an expansion valve. It is designed to be able to fulfill both roles of the valve, and also to prevent plunger displacement, voltage fluctuations, fluid pressure fluctuations, etc. due to variations in the attraction force of the solenoid or the biasing force of the coil spring, dimensional errors, assembly errors, etc. As a result, the range that can be supported (allowed) can be expanded, and as a result, the reliability and reliability of the flow rate switching operation can be improved.

[II] Second Embodiment FIG. 7 shows a second embodiment of a three-stage flow control solenoid valve according to the present invention. The same functional portions as those of the three-stage flow control solenoid valve 1 of the first embodiment are denoted by the same reference numerals, and a duplicate description thereof will be omitted. In the following, differences will be mainly described.

In the three-stage flow control solenoid valve 1 ′ of the second embodiment, the cross section having a substantially cross-shaped cross section is provided between the suction element 15 and the recess 27 of the plunger 20 (and the annular spring receiver 45). A first movable stopper 50 'having a flange 50a having a larger diameter than that of the first embodiment is slidably interposed, and the flange 50a of the first movable stopper 50' and the plunger 20 A second coil spring 52 is contracted between the bottom of the recess 27 and the second coil spring 5.
A third coil spring 53 is disposed in a natural state in which the third coil spring 53 is not substantially compressed on an outer peripheral side of the second movable stopper 55. A spring receiving member) is mounted.

In the three-stage flow control solenoid valve 1 ′ of the second embodiment, in the three-stage flow control solenoid valve 1 of the first embodiment, the third coil spring 53 is compressed from the beginning by the second movable stopper 54. In contrast, the third coil spring 53 is not substantially compressed at the time of assembling, and is merely placed on the second movable stopper 5 in the form of a ring.
5 is simply placed.

[Cooling OFF, applied voltage V = 0, (FIGS. 1 and 2)] In the solenoid valve 1 having such a configuration, when no voltage is applied to the solenoid 10, A maximum gap Lmax is formed between the packing 44 and (the upper end surface of) the plunger 20.

The first movable stopper 50 ′ is moved by its urging force of the second coil spring 52 so that its flange 50
a is pressed against the lower surface of the annular spring receiver 45, and a gap Q is formed between the upper end (top surface) and the suction element 15. Further, a gap J is formed between the second movable stopper 55 on the third coil spring 53 and the flange 50a of the first movable stopper 50 '.

[Cooling ON: weak, applied voltage V = Va (FIG. 9)] On the other hand, when a first-stage voltage Va (for example, 4 volts) is applied to the solenoid 10, as shown in FIG. 20 is pulled up, the first coil spring 51 is slightly compressed, the first valve body 21 is pulled up together with the plunger 20, and the first valve body 21 is separated from the second valve body 21 to open the front orifice 41. Further, the first movable stopper 50 'is brought into contact with the suction element 15, and the second coil spring 52 is slightly compressed. At this time, a gap La smaller than the maximum gap Lmax is formed between the suction element packing 44 and the (upper end face) of the plunger 20.

Further, there is no gap Q between the first movable stopper 50 ′ and the suction element 15 (the first movable stopper 50 ′ abuts), so that the ring member 54 on the third coil spring 53 and the The gap formed between the first movable stopper 50 'and the flange 50a is the same as the gap J
To maintain the state. Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the preceding orifice 41, the flow rate is relatively small, and the cooling power is weak.

[Cooling ON: Medium, applied voltage V = Vb,
(FIG. 10) A second stage voltage (for example, 7 volts) is applied to the solenoid 10.
Is applied, the plunger 20 is further attracted by the plunger 20 against the urging force of the first coil spring 51 and the second coil spring 52, as shown in FIG. Child 15 side,
The first coil spring 51 and the second coil spring 52 are both compressed, and the first valve element 21 is separated from the second valve element 22 and the second orifice 41 is opened while the front orifice 41 is open. , So that the second valve element 22 opens the middle orifice 42 and the second movable stopper 55 on the third coil spring 53.
Abuts against the flange 50a of the first movable stopper 50 'to slightly compress the third coil spring, but the third valve body 23 keeps the rear orifice 43 closed.

At this time, the applied voltage V is applied between the attraction element side packing 44 and (the upper end surface of) the plunger 20.
Is smaller than the first step voltage Va, a gap Lb is formed. Further, the first movable stopper 50 'and the suction element 15
Does not occur between the first movable stopper 50 ′
), The gap J formed between the second movable stopper 55 on the third coil spring 53 and the flange 50a of the first movable stopper 50 'disappears (the second movable stopper 54 contacts the second movable stopper 54). This). Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the middle orifice 42, the applied voltage V becomes larger than when the small voltage Va is applied, and the cooling power becomes medium.

[Cooling ON: strong, applied voltage V = Vc,
(FIG. 11) When a third-stage voltage Vc (for example, 12 volts) is applied to the solenoid 10, the suction force of the suction element 15 becomes maximum, and as shown in FIG. The first coil spring 51, the second coil spring 5
The second coil spring 51, the second coil spring 52, and the second coil spring 53 are pulled up to the highest position (the position where the second coil spring 53 comes into contact with the suction-side packing 44) against the urging force of the third coil spring 53. The three coil springs 53 are compressed together,
Thereby, the first valve element 21 is connected to the front orifice 4.
1 and the second valve body 22 opens the middle orifice 42 while the third valve body 23 is
To open the rear orifice 43 apart from the valve seat 35.

At this time, no gap is formed between the suction element side packing 44 and (the upper end surface of) the plunger 20 (the plunger 20 contacts), and the first movable stopper 50 ′ is in contact with the first movable stopper 50 ′. There is no gap Q between the child 15 and
(The first movable stopper 50 'is in contact with the first movable stopper 50'), and no gap is formed between the second movable stopper 55 on the third coil spring 53 and the flange 50a of the first movable stopper 50 '. The movable stopper 55 contacts).

Therefore, when the maximum voltage Vc is applied, the flow rate of the refrigerant flowing from the inflow port 8 to the outflow port 9 is maximized since the effective flow passage area of the rear orifice 43 determines the cooling force. In the three-stage flow control solenoid valve 1 'of the second embodiment, substantially the same functions and effects as those of the first embodiment can be obtained.

[III] Third Embodiment FIG. 12 shows a third embodiment of a three-stage flow control solenoid valve according to the present invention. The same functional portions as the respective portions of the three-stage flow control solenoid valve 1 of the first and second embodiments are denoted by the same reference numerals, and the description thereof will not be repeated, and the differences will be mainly described below.

In the three-stage flow control solenoid valve 3 of the third embodiment, the first coil spring 51 is disposed on the side of the plunger 20 in the suction element 15 ', and is opposite to the plunger 20 in the suction element 15'. On the side, the second coil spring 52, the third coil spring 53, a first movable stopper 56 having a cross-sectional shape in cross section, and a second movable stopper 57 provided with an inner peripheral locking portion 57a are arranged.

Further, in order to adjust the initial set load of the second coil spring 52 and the third coil spring 53 from the outside, the suction element 15 ′ is placed on the opposite side (upper side) to the plunger 20. A cylindrical fitting portion 81 into which a spring receiving member 85 having an inverted convex cross section for receiving the second coil spring 52 and the third coil spring 53 is slidably fitted via an O-ring 84 is extended. A male screw portion 82 is formed on the outer periphery of the cylindrical fitting portion 81, and the male screw portion 82 is connected to the second thread via the spring receiving member 85.
By compressing the coil spring 52 and the third coil spring 53 so as to depress them, the female screw portion 91 of the inverted bottomed cylindrical nut member 90 for adjusting the initial set load is screwed together.

More specifically, the coil 1 of the solenoid 10
4. The exterior unit such as the yoke 13 is connected to the guide sleeve 1
2, the external diameter of the male screw portion 82 of the cylindrical fitting portion 81 of the suction element 15 'is
4, smaller than the inner diameter of the exterior unit such as the yoke 13. The exterior units such as the coil 14 and the yoke 13 are fixed so as to be sandwiched between the mount 33 and the C-ring 78 externally fitted and fixed to the tubular fitting portion 81.

The first coil spring 51 is connected to the suction element 1
The first movable stopper 56 is compressed between the suction element side packing 44 disposed below 5 ′ and the spring receiving recess 20a provided on the upper surface of the plunger 20, and the lower half of the first movable stopper 56 is suction element 15 ′. The flange-shaped portion 56a is brought into contact with the bottom surface 15b (the upper surface of the suction element) of the tubular fitting insertion portion 81. The spring receiving member 8
The second coil spring 52 is compressed between the flange 5 and the flange 56a of the first movable stopper 56, and the spring receiving member 8
A third coil spring 53 is contracted between the fifth movable stopper 57 and the second movable stopper 57.

Therefore, in such a configuration, if the nut member 90 is screwed into the tubular fitting portion 81 from the outside after assembly, the male screw portion 82 and the female screw portion 91 are screwed together. The spring receiving member 85 is pushed down, whereby the second coil spring 52 and the third coil spring 53 are simultaneously compressed, and their initial set load is adjusted.

[Cooling OFF, applied voltage V = 0, (FIG. 1
2)] Also in the solenoid valve 3 having such a configuration, when no voltage is applied to the solenoid 10, the suction element-side packing 44 and the spring receiving recess 20 (of the plunger 20).
a), a maximum gap Lmax is formed.

Further, the first movable stopper 56 has its flange-shaped portion 56a provided by the urging force of the second coil spring 52.
Is brought into contact with the bottom surface 15b (the upper surface of the suction element) of the cylindrical fitting portion 81, and the lower end surface thereof is connected to the plunger 20.
Is formed between them. Further, a gap P is formed between the inner peripheral locking portion 57a of the second movable stopper 57 and the flange portion 56a of the first movable stopper 56.

[Cooling ON: weak, applied voltage V = Va (FIG. 13)] On the other hand, when the first step voltage Va (for example, 4 volts) is applied to the solenoid 10, as shown in FIG.
When the plunger 20 is raised, the first coil spring 51
Is slightly compressed, the first valve body 21 is pulled up together with the plunger 20, the first valve body 21 is separated from the second valve body 21 to open the front orifice 41, and the plunger 20 is moved to the first movable position. The second coil spring 52 is slightly compressed by being brought into contact with the stopper 56.

At this time, the maximum gap L is provided between the suction element side packing 44 and (the upper end surface of) the plunger 20.
A gap La smaller than max is formed, and a gap formed between the inner periphery locking portion 57a of the second movable stopper 57 and the flange portion 56a of the first movable stopper 56
The state of the gap P is maintained during the FF. Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the preceding orifice 41, the flow rate is relatively small, and the cooling power is weak.

[Cooling ON: Medium, applied voltage V = Vb,
(FIG. 14) A second stage voltage (for example, 7 volts) is applied to the solenoid 10.
Is applied, the plunger 20 is further attracted by the plunger 20 against the urging force of the first coil spring 51 and the second coil spring 52 as compared with when the applied voltage V is the first step voltage Va, as shown in FIG. Child 15 side,
The first coil spring 51 and the second coil spring 52 are both compressed, and the first valve element 21 is separated from the second valve element 22 and the second orifice 41 is opened while the front orifice 41 is open. With this, the second valve body 22 opens the middle orifice 42, and the inner peripheral locking portion 57 a of the second movable stopper 57 comes into contact with the flange portion 56 a of the first movable stopper 56. Then, the third coil spring is slightly compressed, but the third valve body 23 keeps the rear-stage orifice 43 closed.

At this time, the applied voltage V is applied between the attraction element side packing 44 and the (upper end surface) of the plunger 20.
Is smaller than the first step voltage Va, a gap Lb is formed.

Further, there is no gap R between the first movable stopper 56 and the plunger 20 (the first movable stopper 56 contacts), and the inner peripheral locking portion 5 of the second movable stopper 57
The gap P formed between the first movable stopper 56 and the flange 56a of the first movable stopper 56 is eliminated (the second movable stopper 57
A gap M is formed between the flange portion 56a of the first movable stopper 56 and the bottom surface 15b of the cylindrical fitting portion 81. Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the middle orifice 42, the applied voltage V becomes larger than when the small voltage Va is applied, and the cooling power becomes medium.

[Cooling ON: strong, applied voltage V = Vc,
(FIG. 15) When a third-stage voltage Vc (for example, 12 volts) is applied to the solenoid 10, the attraction force of the attraction element 15 is maximized, and as shown in FIG. The first coil spring 51, the second coil spring 5
The second coil spring 51, the second coil spring 52, and the second coil spring 53 are pulled up to the highest position (the position where the second coil spring 53 comes into contact with the suction-side packing 44) against the urging force of the third coil spring 53. The three coil springs 53 are compressed together,
Thereby, the first valve element 21 is connected to the front orifice 4.
1 and the second valve body 22 opens the middle orifice 42 while the third valve body 23 is
To open the rear orifice 43 apart from the valve seat 35.

At this time, no gap is formed between the suction element side packing 44 and the upper end surface of the plunger 20 (the plunger 20 contacts), and the first movable stopper 56 and the plunger 20 No gap R is generated between
(The first movable stopper 56 contacts), the inner peripheral locking portion 57a of the second movable stopper 57 and the first movable stopper 56
There is no gap between the second movable stopper 56 and the flange 50a. Further, the lower end of the second movable stopper 57 and the bottom surface 15b of the cylindrical fitting portion 81 (the upper surface of the suction element)
Is formed between them.

Therefore, when the maximum voltage Vc is applied, the flow rate of the refrigerant flowing from the inflow port 8 to the outflow port 9 is maximized since the effective flow area of the rear orifice 43 is determined, and the cooling power is increased. In the three-stage flow control solenoid valve 3 of the third embodiment, substantially the same effects as those of the first embodiment can be obtained.

[IV] Fourth Embodiment FIG. 16 shows a main part of a three-stage flow control solenoid valve according to the present invention (when cooling is OFF). Regarding the flow control solenoid valve 4, the first
The same functional portions as those of the three-stage flow control solenoid valves 1 and 1 'of the second embodiment are denoted by the same reference numerals, and the description thereof will not be repeated, and the differences will be mainly described below. . The three-stage flow control solenoid valve 4 of the fourth embodiment
In order to improve assemblability and reduce manufacturing costs,
This is mainly a modification of the plunger 20 in the first and second embodiments around the first valve body 21 and the second valve body 22.

That is, the plunger 20 'is provided with a stepped through hole 20A so as to penetrate the center thereof in the vertical direction.
Are formed in the through hole 20A from the valve seat 35 side (lower side) to the suction element 15 side (upper side) from the valve seat 35 side (lower side) to the suction valve 15 side (upper side). , The second coil spring 52 and the first movable stopper 50 ′ are movable in the longitudinal direction of the plunger 20 (in the vertical direction), and are sequentially inserted in series while being in contact with each other. Have been.

More specifically, the first valve element 21 'has a structure in which a ball 21a for opening and closing the front orifice 41 is fixed by caulking like the first valve element 21 of the first and second embodiments. Instead, a hemispherical projection 21b is integrally provided instead of the ball 21a. Thereby, the manufacturing and assembly costs of the first valve body are reduced. Further, in the first and second embodiments, the coil spring 65 for urging the first valve body 21 downward is required, but is not required in the present embodiment.

The second valve body 22 'is not of a complicated shape having vertical grooves 25, 25,... Like the second valve body 22 of the first and second embodiments. 4
1 has a simple stepped cylindrical shape with an inverted convex cross section. Instead, the refrigerant from the inflow port 8 is supplied directly from the second locking portion 102 of the plunger 20 'to the third valve body 23 side without passing through the second valve body 22'. Side holes 105, 10 leading to
5,... Are formed. Thereby, the second valve body 2
The cost of manufacturing and assembling 2 'and its surroundings is reduced.

Further, the plunger 20 ′ prevents the first valve body 21 ′ from moving toward the second valve body 22 ′. 1,
A first alternative to the first locking ring 71 in the second embodiment
The locking portion 101 is provided integrally, and replaces the second locking ring 72 in the first and second embodiments, which prevents the second valve body 22 ′ from moving toward the third valve body 23. The second locking portion 102 is provided integrally.

With the above structure, the first and second flow control solenoid valves are assembled at the time of assembling the three-stage flow control solenoid valve.
In the embodiment, after the coil spring 65 and the first valve body 21 are sequentially inserted from the lower side of the plunger 20, the first locking ring 71 is inserted and fixed by caulking. The troublesome work of inserting the valve body 22 and then inserting the second locking ring 72 and fixing it by crimping was required. In the present embodiment, however, the plunger 2
From the upper side of 0 ', the first valve body 21', the second coil spring 52 and the third coil spring 53, and the first movable stopper 50 may be sequentially dropped with the second valve body 22 'at the head. This eliminates the need for cumbersome caulking work. Therefore, manufacturing costs and assembly costs are further reduced.

In the first and second embodiments, a required gap is formed between the first valve body 21 and the first locking ring 71 to absorb an assembly error, a processing error, and the like. However, in the present embodiment, the first valve body 21 ′ is
1, the assembly error, the processing error, and the like are absorbed by a gap L ′ formed between the upper end surface of the third body 23b and the lower end surface of the plunger 20 facing the upper end surface. It has become.

The valve body 30 'is provided with a caulking tubular mounting portion 110 in place of the mounting base 33 in the first and second embodiments, and the caulking tubular mounting portion 110 is provided.
A flange 12a formed at the lower end of the guide sleeve 12
Is mounted so as to ride on the O-ring 34, and is caulked and fixed by the upper end of the caulking tubular mounting portion 110 via a mounting ring 112 which is fitted around the lower end of the O-ring 34. This also eliminates the need for threading, brazing, and the like for fixing the guide sleeve 12 and the mounting base 33 in the first and second embodiments, thereby reducing manufacturing costs and assembly costs.

In the three-stage flow control solenoid valve 1 of the first embodiment, the third coil spring 53 is connected to the second movable stopper 54.
In the present embodiment, the third coil spring 53 is not substantially compressed at the time of assembling, as in the second embodiment. Second movable stopper 5 in the embodiment
The role of 5 is performed by the upper end of the third coil spring 53. 3 of the fourth embodiment having such a configuration
Also in the step flow control solenoid valve 4, three-step flow control is performed in the same manner as in the above-described embodiment, and substantially the same operational effects as in the above-described embodiment can be obtained.

[0102]

As will be understood from the above description, the solenoid valve according to the present invention has a relatively simple structure and can be easily manufactured at low cost, and can switch the flow rate in three stages. As well as being able to function as both a flow switching valve and an expansion valve.Moreover, the plunger displacement and voltage caused by variations in the attraction force of the solenoid and the urging force of the coil spring, dimensional errors, assembly errors, etc. It is possible to widen the range that can be supported (allowed) for fluctuations, fluid pressure fluctuations, and the like, and to improve the reliability and reliability of the flow rate switching operation.

By simply adding a simple structure, the initial set load of each coil spring can be adjusted from the outside.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which an applied voltage of an electromagnetic valve according to a first embodiment of the present invention is 0 V (initial set state).

FIG. 2 is an enlarged cross-sectional view showing a plunger and its surroundings of the solenoid valve shown in FIG. 1;

FIG. 3 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 1 is small.

FIG. 4 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 1 is medium;

FIG. 5 is a cross-sectional view showing a state when the applied voltage of the solenoid valve shown in FIG. 1 is large.

FIG. 6 is a graph showing a voltage-attraction force characteristic of a solenoid, which is used for describing the operation and effect of the solenoid valve according to the present invention.

FIG. 7 is a cross-sectional view illustrating a state where an applied voltage is 0 V (initial set state) in a second embodiment of the solenoid valve according to the present invention.

FIG. 8 is an enlarged cross-sectional view showing a plunger and its surroundings of the solenoid valve shown in FIG. 7;

FIG. 9 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 7 is small.

FIG. 10 is a sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 7 is medium;

FIG. 11 is a cross-sectional view showing a state when the applied voltage of the solenoid valve shown in FIG. 7 is large.

FIG. 12 is a cross-sectional view illustrating a state where an applied voltage is 0 V (initial set state) in a third embodiment of the solenoid valve according to the present invention.

FIG. 13 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 12 is small.

FIG. 14 is a sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 12 is medium;

FIG. 15 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 12 is large.

FIG. 16 is a sectional view showing a state where an applied voltage of a main part of an electromagnetic valve according to a fourth embodiment of the present invention is 0 V (initial set state).

[Explanation of symbols]

 Reference Signs List 1 electromagnetic valve 8 inflow port 9 outflow port 10 solenoid 12 guide sleeve 15 suction element (stator) 20 plunger 21 first valve body 22 second valve body 23 third valve body 27 recess 30 valve body 32 valve chamber 32A first Valve chamber 32B Second valve chamber 41 Front orifice 42 Middle orifice 43 Rear orifice 44 Suction element side packing 50 First movable stopper 51 First coil spring 52 Second coil spring 53 Third coil spring 54 Second movable stopper 60 Peripheral passage 81 cylindrical fitting portion 82 external thread portion 85 spring receiving member 90 nut member 91 internal thread portion 100 air conditioner control portion 200 power supply (vehicle battery)

Claims (10)

[Claims] 1. A valve body having a valve chamber, an inlet, an outlet, and a valve seat, a plunger disposed in the valve body, and suction for sucking the plunger to a side opposite to the valve seat. A first valve element, a second valve element, and a third valve element, which are sequentially lifted by the plunger in a direction away from the valve seat, between the plunger and the valve seat. And the second valve body, the third
A first valve body, a second valve body, respectively, in a valve body and a valve seat,
A first orifice, a middle orifice, and a second orifice, which are sequentially opened and closed by the third valve body and have an effective passage sectional area that sequentially increase, are formed by increasing the voltage applied to the solenoid in a stepwise manner. The first valve body, the second valve body, and the third valve body are sequentially raised up to the suction element side, so that
In the three-stage flow control solenoid valve configured to open the front-stage orifice, the middle-stage orifice, and the rear-stage orifice, a first coil spring is provided in parallel with the plunger so as to bias the plunger toward the valve seat. A second coil spring and a third coil spring are arranged, a first movable stopper is arranged between the plunger and the second coil spring, and between the plunger and the third coil spring. When a second movable stopper is provided and the voltage applied to the solenoid is at a first step voltage Va, the first coil spring is compressed, the first valve element opens the front-stage orifice, and (1) The second coil spring is slightly compressed via the movable stopper, and when the applied voltage is the second step voltage Vb, the first coil spring and the second coil spring are compressed. The second spring is compressed together,
When the valve element opens the middle orifice and the third coil spring is slightly compressed via the second movable stopper, and the applied voltage is the third step voltage Vc, the first coil spring and the second In addition to the coil spring, the third
A three-stage flow control solenoid valve characterized in that the coil spring is also compressed so that the third valve body opens the rear orifice and the plunger is brought into contact with the suction element side packing. . 2. The first coil spring is compressed between the plunger and the attraction element, the second coil spring is compressed between the plunger and the first movable stopper, and the plunger is compressed. The three-stage flow control solenoid valve according to claim 1, wherein a third coil spring is contracted between the first movable stopper and the second movable stopper. 3. The first coil spring is compressed between the plunger and the suction element, the second coil spring is compressed between the plunger and the first movable stopper, and the plunger is compressed. The second movable stopper and the third coil spring are interposed between the first movable stopper and the first movable stopper, and when no voltage is applied to the solenoid, the first movable stopper and the second movable stopper 2. The three-stage flow control solenoid valve according to claim 1, wherein a predetermined gap is formed between the solenoid valves. 4. The first coil spring is disposed on the plunger side of the attraction element, and the second coil spring, the third coil spring, a first movable stopper is disposed on a side of the attraction element opposite to the plunger, The three-stage flow control solenoid valve according to claim 1, wherein a second movable stopper and a second movable stopper are provided. 5. The first coil spring, the second coil spring,
The three-stage flow control solenoid valve according to any one of claims 1 to 4, wherein an initial set load of at least one of the first and third coil springs can be externally adjusted. 6. A cylindrical fitting portion on which a spring receiving member for receiving the second coil spring and the third coil spring is slidably fitted on a side of the suction element opposite to the plunger, A male screw portion is formed on the outer periphery of the tubular fitting portion, and the initial set load of the male screw portion is adjusted by compressing the second coil spring and the third coil spring via the spring receiving member. The nut member to be screwed is screwed together.
3. The three-stage flow control solenoid valve according to 1. 7. The third valve body, the second valve body, the first valve body, the second coil spring, and the first movable body in the plunger from the valve seat side to the suction element side. The three-stage according to any one of claims 1 to 3, wherein each of the stoppers is inserted in series so as to be movable along the length direction of the plunger and sequentially in contact with each other. Flow control solenoid valve. 8. A plunger for preventing movement of the first valve body toward the second valve body, wherein a first locking portion through which the second valve body passes is provided integrally with the plunger. 8. The device according to claim 7, wherein a second locking portion that prevents movement of the valve body toward the third valve body is provided integrally. 9.
Step flow control solenoid valve. 9. A side hole which guides fluid from the inflow port directly to the middle orifice without passing through the second valve body is formed on the third valve body side of the plunger with respect to the second locking portion. The three-stage flow control solenoid valve according to claim 7 or 8, wherein 10. The device according to claim 1, wherein a hemispherical protrusion for opening and closing the front orifice is integrally provided on the first valve body.
Step flow control solenoid valve.