JPH11153244A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve which is relatively simple in structure, and easily manufactured at a low cost, capable of switching the flow rate in not less than three stages, and playing a role as both a flow rate switching valve and an expansion valve. SOLUTION: A first valve element 25 of inversely projecting section is slidably fitted into a plunger 20 in the axial direction, an energizing means 72 to energize the first valve element 25 to a valve seat 35 side is built in, a second valve element 41 and a third valve element 42 to be successively pulled up to locking piece parts 26, 27 provided on an intermediate part and a lower end part in an attachable/detachable manner are arranged in a cylindrical leg part 24 projected in the plunger 20, a forward orifice 51 which is opened/ closed by the first valve element 25 and smaller than a rear orifice 36 in the effective sectional passage area, is formed on the second valve element 41, a middle stage orifice 52 which is opened/closed by the second valve element 41 and larger than the forward orifice 51 in the effective sectional passage area, is formed on the third valve element 42, and the rear stage orifice 36 is opened/closed by the third valve element 42.

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 solenoid valve which can serve as both a flow switching valve and an expansion valve. About things.

[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, for example,
In the solenoid valve disclosed in Japanese Patent No. 5739, the flow rate cannot be adjusted only by simply opening and closing the passage.

[0003] This type of solenoid valve will be briefly described below with reference to FIG. The illustrated solenoid valve 2 includes a valve chamber 32,
Valve body 3 having inlet 8, outlet 9, and valve seat 35
0, a plunger 20, and a solenoid 10 arranged on the outer periphery of the plunger 20 to move the plunger 20 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. A predetermined voltage (for example, 5
V and 12 V).

At the center of a valve chamber 32 formed in the valve main body 30, a tapered cylindrical valve seat 35 is protruded, and a refrigerant inlet 8 is provided in connection with the valve chamber 32.
A refrigerant outlet 9 is provided downstream of the rear orifice 36 provided in the valve seat 35. In the guide sleeve 12 of the solenoid 10, a plunger 20 having a first valve body 25 having a conical surface formed in the center of a front end (lower end) and projecting downward is slidably fitted. In the upper part of the plunger 20, there is formed a recess 21 having a substantially sectional concave shape into which a holder 16 having a substantially inverted cross-sectional convex shape projecting from the suction element 15 is slidably fitted. The plunger 20 is constantly biased toward the valve seat 35 (downward) by the coil spring 23 compressed between the plunger 20 and the holder 16.

[0005] A cylindrical second valve body 40 is disposed between the first valve body 25 and the valve seat 35 so as to be lifted away from the valve seat 35 by the plunger 20. On the axis of the body 40, a front-stage orifice 51, which is opened and closed by the first valve body 25 and has an effective passage sectional area smaller than that of the rear-stage orifice 36, is formed. Can be opened and closed.

More specifically, the second valve body 40 comes into contact with and separates from a ring-shaped locking piece 26 provided at the lower end of a cylindrical leg 24 protruding from the front end of the plunger 20. And the first valve body 2 is supported by the plunger 20.
5 is adapted to be lifted with the front-stage orifice 51 in an opened state. The cylindrical leg portion 24 has a predetermined number of transparent refrigerants that guide the refrigerant from the inflow port 8 to a refrigerant chamber S formed between the front end surface of the plunger 20 and the upper surface of the second valve body 40. Holes 37, 37,... Are formed.

In the solenoid valve 2 having such a configuration, when no voltage is applied to the solenoid 10, that is, when the solenoid 10 is not energized and excited (when OFF), as shown in the figure. And plunger 2
0 is pushed down to the valve seat 35 side (downward) by the urging force of the coil spring 23, the first valve body 25 is pressed against the second valve body 40 to close the front-stage orifice 51, and the second valve body 40 is The orifice 36 is pushed down to the side 35 and pressed against it to close the rear-stage orifice 36 to be in a valve-closed state.

On the other hand, when a small voltage (for example, 5 V) is applied to the solenoid 10, the solenoid 10 is energized and turned on, and the plunger 20 is turned on the suction element 15 against the urging force of the coil spring 23 (see FIG. (Upper side), the first valve body 25 is pulled up to the middle (intermediate position), and the second valve body 4
The front orifice 51 is opened apart from 0. This allows
Through holes 37, 3 formed in the cylindrical leg portion 24 from the inflow port 8
, The refrigerant flowing into the refrigerant chamber S formed between the second valve body 40 and the plunger 20 flows out to the refrigerant outlet 9 through the front orifice 51 and the rear orifice 36 and is guided to the evaporator. Since the flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the preceding orifice 51, the flow rate is relatively small, and the cooling power is weak.

When a maximum voltage (for example, 12 V) is applied to the solenoid 10, the attraction force of the attraction element 15 is maximized, and the plunger 20 is moved by the coil spring 2
3 is lifted up to the highest position (a position close to the suction element 15) against the urging force of the third valve body 3 so that the first valve body 25 opens the front-stage orifice 51 and the second valve body 25 is opened. 40 is supported and locked by the locking piece 26 of the cylindrical leg 24 and is pulled up together with the plunger 20,
The second valve body 40 separates from the valve seat 35 and opens the rear-stage orifice 36, whereby refrigerant flowing into the valve chamber 32 from the inflow port 8 flows between the lower surface of the second valve body 40 and the valve seat 35. And flows into the rear-stage orifice 36 through the outlet 9, and is guided from the outlet 9 to the evaporator. Therefore, when the maximum voltage is applied, the flow rate of the refrigerant flowing from the inflow port 8 to the outflow port 9 is greatly increased as compared with when the small voltage is applied, and the cooling power is increased.

[0010]

However, in the conventional solenoid valve as described above, the flow rate of the refrigerant can be switched only in two stages, and it is possible to meet the demand for finer flow rate adjustment. Not be able to
There is a difference in the voltage for exciting the coil between the valve opening direction and the valve closing direction, and setting of the excitation voltage is troublesome.Moreover, it only serves as a flow rate switching valve, and in a refrigeration cycle in which it is incorporated. A separate expansion valve was required.

If a motor-operated valve for rotating a valve body by a stepping motor or the like is incorporated in the refrigeration cycle, it is possible to finely adjust the flow rate. However, the structure and control system of the motor-operated valve are complicated and expensive. Therefore, there is a problem in terms of cost. Incorporating both the solenoid valve and the expansion valve into the refrigeration cycle increases the number of parts, complicates the piping system, and is disadvantageous in cost. The present invention has been made to solve the problems described above,
The purpose is to have a relatively simple structure, to be easily manufactured at low cost, and to be able to switch the flow rate in three or more stages and to act as both a flow switching valve and an expansion valve. It is to provide a solenoid valve adapted to be obtained.

[0012]

In order to achieve the above object,
An electromagnetic valve according to the present invention includes a valve body having a valve seat having a valve chamber, an inlet, an outlet, and a rear-stage orifice, a plunger, and moving the plunger toward and away from the valve seat. A solenoid valve disposed at the outer periphery of the plunger to form a concave hole into which the first valve element having a columnar or inverted convex cross section is slidably fitted in the plunger along the axial direction. The recessed hole is provided with a locking piece for locking the first valve body in the front end opening thereof, and the first valve body is biased toward the valve seat. Biasing means is provided inside the cylindrical leg,
A second valve body and a third valve body which are sequentially pulled up in a direction away from the valve seat by the plunger in a state where the second valve body is detachably engaged with the engagement pieces provided on the intermediate part and the lower end part, respectively.
A valve orifice is disposed, and a front-stage orifice, which is opened and closed by the first valve and has an effective passage sectional area smaller than the rear-stage orifice, is formed in the second valve, and the third valve is
A middle stage orifice, which is opened and closed by the second valve body and has an effective passage cross-sectional area larger than the front stage orifice and smaller than the rear stage orifice, is formed so that the third valve body opens and closes the rear stage orifice. Be done.

[0013] In a preferred aspect of the present invention, the applied voltage to the solenoid is switched between three levels of large, medium and small. When the applied voltage is small, the first valve body opens the front-stage orifice, When the voltage is medium, the first
With the valve body opening the front-stage orifice, the second valve body opens the middle-stage orifice, and when the applied voltage is large, the first valve body and the second valve body close the front-stage orifice and the middle-stage orifice, respectively. While open, the third valve opens the rear orifice, whereby the flow rate of the fluid flowing from the inlet to the outlet is switched in three stages, and further, the voltage applied to the solenoid closes the valve. When applied in a direction, the flow rate is controlled in a stepwise manner so that each of the valve bodies opens each of the orifices sequentially after being brought to a voltage that closes all of the orifices by all of the valve bodies.

[0014] In another preferred embodiment, each of the first valve body and the front-stage orifice, the front-stage orifice and the middle-stage orifice, and the middle-stage orifice and the rear-stage orifice respectively. A front-stage widening opening, a middle-stage widening opening, and a rear-stage widening opening are provided, and the opening area of each of these widenings is made larger than the effective passage cross-sectional area of the subsequent orifice. Are made larger than the difference between the effective passage cross-sectional areas between adjacent orifices.

In a preferred embodiment of the solenoid valve according to the present invention having the above-described configuration, the suction force on the plunger is increased stepwise by increasing the voltage applied to the solenoid in a stepwise manner. The amount of pulling up of the plunger is changed, and three valve bodies that are pulled up integrally with or in association with the plunger are sequentially opened to operate, and are provided in the flow path from the inlet to the outlet, and the effective passage is sequentially provided. The three orifices having a larger cross-sectional area are sequentially opened one by one from the upstream one to switch the flow rate to three or more stages.

Therefore, the solenoid valve of the present invention has a relatively simple structure, can be easily manufactured at low cost, and has a smaller flow rate than a conventional solenoid valve which can switch the flow rate only in two stages. By adjusting the flow passage area of the orifice appropriately, the function of both the flow switching valve and the expansion valve can be provided. Therefore, for example, when the solenoid valve of the present invention is incorporated in the rear-side cooling refrigerant passage of the refrigeration cycle of a car air conditioner, the cost is lower than when an electric valve is incorporated, and the solenoid valve and the expansion valve are expanded in the refrigeration cycle. Compared to a case where both of the valves are incorporated, the number of parts is reduced, and the piping system can be easily arranged, which is advantageous in cost.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 show one embodiment of a solenoid valve according to the present invention. Regarding the solenoid valve 1 of the illustrated embodiment, portions corresponding to the respective portions of the conventional solenoid valve 2 shown in FIG.

The solenoid valve 1 of the present embodiment is also incorporated in the rear-side cooling refrigerant passage of the refrigeration cycle of a car air conditioner, and includes a valve body 32, an inlet 8, an outlet 9, and a valve seat 35. A part 30, a tubular mounting base 33 with a flange screwed to the valve body part 30, a plunger 20,
A solenoid 10 arranged on the outer periphery of the plunger 20 for moving the plunger 20 in the direction of approaching and separating from the valve seat 35.
And

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. A predetermined voltage (for example, three steps of 4 V, 7 V, and 12 V) is applied via the power supply.

The guide sleeve 12 is joined and fixed to the inner periphery of the mount 33 by brazing or the like. An O-ring 34 is mounted between the mount 33 and the valve body 30. At the center of the valve chamber 32 formed in the valve body 30, a tapered cylindrical valve seat 35 is protruded, 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 36 provided.

A plunger 20 is slidably fitted in the guide sleeve 12 of the solenoid 10. A concave portion 21 is formed in an upper portion of the plunger 20, and the plunger 2 is compressed by a coil spring 23 compressed between a bottom surface (lower surface) of the concave portion 21 and the suction element 15.
0 is constantly urged to the valve seat 35 side (lower side). A rubber buffer 19 is interposed between the coil spring 23 and the suction element 15. A communication hole 29 penetrating in the radial direction is formed in the recess 21.

The plunger 20 has a recess 71 at the front end (lower side) of the plunger 20 into which the first valve body 25 having an inverted convex cross section is slidably inserted along the axial direction. A ring-shaped locking piece 74 for locking the first valve body 25 is fixed to the front end opening of the concave hole 71, and the first valve body 25 is attached to the valve seat 35 side. The energizing coil spring 72 is contracted.

A flange is provided between the first valve body 25 and the valve seat 35 so as to be sequentially pulled up by the plunger 20 in a direction away from the valve seat 35 as shown in an enlarged view in FIG. A cylindrical second valve body 41 with a shape portion 41A and a stepped short cylindrical third valve body 42 with a support member 42a externally fitted therein are arranged, and the second valve body 41 is provided with the first valve body. A front-stage orifice 51, which is opened and closed by 25 and has a smaller effective passage sectional area than the rear-stage orifice 36, is formed.
A middle stage orifice 52 having an effective passage cross-sectional area which is larger than the front stage orifice 51 and smaller than the rear stage orifice 36 and is opened and closed by the third valve body 42.
Is formed, and the third orifice is opened and closed by the third valve body.

More specifically, the second valve body 41 is attached to a ring-shaped locking piece 27 fixedly locked to an intermediate portion of a cylindrical leg 24 protruding from the front end of the plunger 20. The first valve body 25 is supported by the plunger 20 so as to be able to come and go together with the front-stage orifice 51 in an opened state. At the upper end of the cylindrical leg 24, a predetermined amount of refrigerant from the inlet 8 is guided to a refrigerant chamber S formed between the front end surface of the plunger 20 and the upper surface of the second valve body 41. Number of through holes 37,
37 are formed.

Further, as can be clearly understood from FIG. 5, the second valve body 41 has four rectangular cross sections at 90-degree intervals so as to penetrate the flange 41A in the thickness direction (vertical direction). Are formed in the through holes 37, 3
, The refrigerant introduced into the refrigerant chamber S from the vertical groove 4
Through 1a, the refrigerant is guided to a refrigerant chamber S 'defined by the second valve body 41, the cylindrical leg 24, and the third valve body 42.

On the other hand, the third valve element 42 is supported by the ring-shaped locking piece 26 fixedly locked to the lower end of the cylindrical leg 24 by caulking so as to be able to contact and separate from the plunger 2.
0, the second valve element 41 is connected to the middle orifice 52
It is designed to be lifted with it when it is open. The ring-shaped locking pieces 74 and 27 for supporting and locking the first valve body 25 and the second valve body 41 are provided at inner end edges of the mounting recesses of the plunger 20 and the cylindrical leg 24. Is fixedly locked by inwardly projecting and inclining by stamping with a cylindrical punch or the like.

The upstream and downstream sides of the front orifice 51 of the second valve body 41 and the upstream side of the rear orifice 36 of the valve seat 35, in other words, the first valve body 25 and the front orifice 51 Between the front orifice 51 and the middle orifice 52, and between the middle orifice 52 and the rear orifice 36, respectively.
b, a rear widening opening 36a is provided, and the opening area of each widening opening 51a, 51b, 36a is made larger than the effective passage cross-sectional area of the subsequent orifices 51, 52, 36, and each adjacent widening The difference in the opening area between the openings, that is, the difference in the opening area between the front widening opening 51a and the middle widening opening 51b, the middle widening opening 51b and the rear widening opening 36a
The difference between the effective passage cross-sectional areas of adjacent orifices, that is, the difference between the effective passage cross-sectional areas of the front orifice 51 and the middle orifice 52,
And the effective orifice cross-sectional area of the rear orifice 36 is larger than the difference.

For example, in the present embodiment, the diameters of the front orifice 51, the middle orifice 52, and the rear orifice 36 are 0.65, 0.8, and 0.9 (mm), respectively.
The diameters of the front widening opening 51a, the middle widening opening 51b, and the rear widening opening 36a are each 0.1 mm.
8, 1.2, and 1.7 (mm).

[Cooling OFF (FIG. 1)] In the 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 excited (OFF
1), the plunger 20 is pushed down to the valve seat 35 side (downward) by the urging force of the coil springs 23 and 72, and the first valve body 25 is pressed against the second valve body 41 as shown in FIG. The first orifice 51 is closed, the second valve body 41 is pushed down to the third valve body 42 side, and is pressed against it to close the middle orifice 52. Further, the third valve body 42 is pushed down to the valve seat 35 side. Then, the rear orifice 36 is closed by being pressed against it, and the valve is closed.

At this time, the separation distance Sz between the lower end surface of the suction element 15 and the upper end surface of the plunger 20 becomes the maximum z ₃ , and the lower end surface of the first valve body 25 and the upper end surface of the second valve body 41 , The distance Sb between the lower end surface of the second valve body 41 and the upper end surface of the third valve body 42, the lower end surface of the third valve body 42 and the upper end surface of the valve seat 35. Are all 0.

[Cooling ON: weak (FIG. 2)] On the other hand, when a small voltage (for example, 4 V) is applied to the solenoid 10, the solenoid 10 is energized and excited to turn on.
As shown in FIG. 2, the plunger 20 is in the middle of the suction element 15 side (upper side) against the urging force of the coil springs 23 and 72 (the position where the locking piece 27 contacts the second valve body 41). ), The first valve body 25 is pulled up to the second valve body 4
The first orifice 51 is opened apart from the first orifice. However, the second valve body 41 and the third valve body 42 remain in the closed state due to the pressure difference between the inside and outside (the inlet side is high and the outlet side is low).

At this time, the separation distance Sz between the lower end surface of the suction element 15 and the upper end surface of the plunger 20 is equal to z when the valve is closed.
Small becomes z ₂ next than _3, distance Sa between the upper surface of the lower end surface and the second valve body 41 of the first valve body 25 is a _1, and the lower end surface and the third of the second valve body 41 The separation distance Sb between the upper end surface of the valve body 42 and the separation distance Sc between the lower end surface of the third valve body 42 and the upper end surface of the valve seat 35 are both 0.
Becomes

As a result, through the through holes 37, 37,... Formed in the cylindrical leg 24 from the inflow port 8 and the valve chamber 32,
The refrigerant flowing into the refrigerant chamber S formed between the second valve body 41 and the plunger 20 flows out to the refrigerant outlet 9 through the front orifice 51 and the rear orifice 36 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 front-stage orifice 51, it is relatively small, and the cooling power is weak.

[Cooling ON: Medium (FIG. 3)] When a medium voltage (for example, 7 V) is applied to the solenoid 10, the solenoid 10 is energized and turned on.
As shown in FIG. 3, the plunger 20 is further raised toward the suction element 15 against the urging force of the coil springs 23 and 72 than when the applied voltage is low, as shown in FIG.
When the valve body 25 separates from the second valve body 41,
While the second valve element 41 is open.
And is lifted up together with the plunger 20 to open the middle orifice 52, but the third valve body 42 remains closed.

[0035] At this time, next z ₁ distance Sz is that the applied voltage between the lower end surface and the upper end surface of the plunger 20 is smaller than z ₂ at the time of the small of the suction element 15, the first valve body 25
Distance Sa between the lower end surface of the second valve body 41 and the upper end surface of the second valve body 41
Is a _1, distance Sb of the upper surface of the lower end surface and the third valve body 42 of the second valve body 41 b _1, and the lower end surface of the third valve body 42 and the valve seat 35 The separation distance Sc from the upper end surface is zero.

.. And through the through holes 37, 37,... Formed in the cylindrical leg portion 24 from the inflow port 8 and the valve chamber 32, and the vertical groove 41a formed in the second valve body 41. The refrigerant flowing into the refrigerant chamber S ′ formed between the leg 24, the second valve element 41, and the third valve element 42 passes between the lower surface of the second valve element 41 and the third valve element 42. The refrigerant flows into the middle orifice 52, flows out to the refrigerant outlet 9 via the rear orifice 36, is expanded, and is guided to the downstream evaporator. The flow rate of the refrigerant at this time is determined by the effective passage cross-sectional area of the middle orifice 52, so that the applied voltage is larger than when the applied voltage is small, and the cooling power is medium.

[Cooling ON: Strong (FIG. 4)] A maximum voltage (for example, 12 V) is applied to the solenoid 10.
Is applied, the attraction force of the attraction element 15 is maximized, and as shown in FIG. 4, the plunger 20 is at the highest position (with respect to the attraction element 15) against the urging force of the coil springs 23 and 72. The first valve body 25 opens the front orifice 51, and the second valve body 41 opens the middle orifice 52. Is supported by the locking piece 26 and lifted up together with the plunger 20 to separate from the valve seat 35 and open the rear-stage orifice 36.

At this time, the separation distance Sz between the lower end surface of the suction element 15 and the upper end surface of the plunger 20 becomes z ₀ smaller than z ₁ when the applied voltage is medium, and the first valve body 25
Distance Sa between the lower end surface of the second valve body 41 and the upper end surface of the second valve body 41
Is a ₁ , the separation distance Sb between the lower end face of the second valve body 41 and the upper end face of the third valve body 42 is b ₁ , and the lower end face of the third valve body 42 and the valve seat 35 distance Sc between the upper end surface of the c _1.

As a result, the refrigerant from the inflow port 8 flows directly between the lower surface of the third valve element 42 and the valve seat 35 into the rear orifice 36, and flows through the rear orifice 36 into the refrigerant outlet 9. And is expanded, and guided to a downstream evaporator. Therefore, when the maximum voltage is applied, the effective voltage is determined by the effective passage cross-sectional area of the rear orifice 36.
The maximum flow rate of the refrigerant flowing through the cooling medium is increased, and the cooling power is increased.

In the solenoid valve 1 of the present embodiment having the above-described structure, the suction force on the plunger 20 is increased stepwise by increasing the voltage applied to the solenoid 10 in three steps. The amount of pulling up of the plunger 20 is changed,
1st valve body 2 which is lifted up integrally with or in conjunction with it
5, three orifices provided in the flow path from the inflow port 8 to the outflow port 9 by sequentially opening the second valve body 41 and the third valve body 42 to increase the effective passage sectional area. 5
1, 52 and 36 are sequentially opened one by one from the upstream side to switch the flow rate in three stages.

On the other hand, with respect to the valve closing operation of the solenoid valve 1 of the present embodiment, the sequential closing operation opposite to the above-described sequential opening operation is not performed, and the voltage applied to the solenoid 10 is closed by all the valve elements. After all the valve bodies are closed by setting the voltage to be valved (for example, 0 V), the above-described sequential valve opening operation is performed in the order of the first valve body 25, the second valve body 41, and the third valve body 42. , The desired flow rate is switched stepwise. This is because the force holding the plunger 20 by the coil 14 due to the occurrence of hysteresis due to magnetism,
The direction differs from the direction in which the plunger 20 is pulled up (the direction from the fully open to the fully closed position of the valve element). Further, the pressure receiving area that each valve element receives from the refrigerant in the fully open state of the valve element is the pressure receiving area that is received in the fully closed state. Since the pressure is different between the valve opening direction and the valve closing direction, the applied voltage in the direction from full opening to full closing of the valve body is smaller than that in the direction from full closing to full opening. Otherwise, the valve closing operation does not occur in the valve body.

FIG. 6 is a diagram showing the relationship between the applied voltage and the position of the valve element accompanying the amount of pulling up of the plunger. As shown by the dashed line in the figure, the valve opening operation is performed by the first valve body 25 and the second valve body 25.
The operation is performed in the order of the valve element 41 and the third valve element 42. First, in FIG. 6, when only the first valve body 25 is desired to be opened [cooling ON:
Weak (FIG. 2)] means that a small voltage (for example, 4 V) is applied,
Only the first valve body 25 is opened. When the first valve element 25 and the second valve element 41 are desired to open [cooling ON: medium (FIG. 3)]
Is applied with a medium voltage (for example, 7 V), and the first valve body 25
And the 2nd valve body 41 is opened. Further, the first valve body 25,
When it is desired that all of the second valve body 41 and the third valve body 42 open (cooling ON: high (FIG. 4)), the maximum voltage (for example, 12
V) is applied, and the first valve body 25, the second valve body 41, and the third
The valve element 42 is opened.

The valve closing operation is performed after all the valve bodies are closed. The above-described state in which the first valve body 25, the second valve body 41, and the third valve body 42 are opened [cooling ON:
When the third valve element 42 is desired to be closed (i.e., when the first valve element 25 and the second valve element 41 are desired to open [cooling ON: middle (FIG. 3)) in FIG. As shown by the solid line in the middle, a minimum voltage (for example, 0 V) that can close all the valve bodies is applied, and all the valve bodies are closed. Then, the subsequent valve opening operation is performed by selecting the valve opening in the order of the first valve body 25 and the second valve body 41 as shown by the one-dot chain line in the drawing, so that the desired first valve body 25 and the second valve body 41 are selected. The two-valve element 41 is opened to control the flow rate. The minimum voltage is also applied when the first valve body 25 and the second valve body 41 are desired to close from the open state (cooling ON: middle (FIG. 3)), and all the valve bodies are closed. After that, the valves are sequentially opened from the first valve body 25.

Next, a flowchart of the control will be described with reference to FIG. When the solenoid 10 is energized and excited,
In step 101, it is determined whether the effective passage sectional area is to be reduced. Then, if the valve opening of only the first valve body 25 is selected, that is, if YES, a small voltage is applied in step 104. In step 101, the first valve body 2
If the valve opening of only 5 is not selected, that is, if NO, it is determined in step 102 whether or not the execution passage cross-sectional area is set to be medium, and the valve opening of the first valve body 25 and the second valve body 41 is selected. That is, if YES, a medium voltage is applied in step 105.

In step 102, the valve opening of the first valve body 25 and the second valve body 41 is not selected.
If it is O, it is determined in step 103 whether or not the effective passage cross-sectional area is to be increased, and all of the first valve body 25, the second valve body 41, and the third valve body 42 are selected, ie, YES If so, the maximum voltage is applied in step 106. If it is determined in step 103 that the effective passage sectional area is not large, the process proceeds to step 107.

In step 107, it is determined whether or not the sectional area of the execution passage is to be changed.
If O, the effective passage cross-sectional area is maintained as it is.
On the other hand, if it is changed, that is, if YES, step
At 08, it is determined whether or not to increase the sectional area of the execution passage, and the increase by opening the valve is selected. That is, if YES, the routine returns to step 101 with the sectional area of the execution passage as it is. Select

If it is not selected in step 108 to increase the sectional area of the execution passage, that is, if NO, in step 109, the minimum voltage is applied and all the valves are closed. Subsequently, the process proceeds to step 110, where it is determined whether or not to continue the energization. If the process is to be continued, that is, if YES, the process proceeds to step 101 while all the valve elements are kept closed.
Returning to step 101, a desired valve opening is selected in order from step 101. In step 110, if the energization excitation is not continued, that is, if NO, the process ends.

Therefore, the solenoid valve 1 of the embodiment has a relatively simple structure and can be easily manufactured at low cost, and can perform finer flow rate adjustment.
By appropriately setting the effective passage cross-sectional area of the orifice, both the functions of the flow switching valve and the expansion valve are provided. Therefore, for example, when incorporating the solenoid valve of the present invention into the rear-side cooling refrigerant passage of the refrigeration cycle of a car air conditioner, the cost may be lower than when the electric valve is incorporated,
Further, as compared with the case where both the solenoid valve and the expansion valve are incorporated in the refrigeration cycle, the number of parts is reduced, and the piping system is easily arranged, which is advantageous in cost.

Further, upstream and downstream of the upstream orifice 51 of the second valve body 41 and upstream of the downstream orifice 36 of the valve seat 35, respectively, a front wide opening 51a, a middle wide opening 51b, and a rear wide opening 51b. An enlarged opening 36a is provided, the opening area of each enlarged opening 51a, 51b, 36a is made larger than the effective passage cross-sectional area of the following orifices 51, 52, 36, and the front enlarged opening 51a and the middle enlarged opening 51a. The difference in the opening area between the opening 51b and the difference in the opening area between the middle-stage widening opening 51b and the rear-stage widening opening 36a is determined by the difference in the effective passage cross-sectional area between the front-stage orifice 51 and the middle-stage orifice 52, and the difference between the middle-stage orifice 52 and the rear-stage. By setting the difference between the effective passage cross-sectional areas of the orifices 36 to be considerably larger, the control voltage width (dead zone) can be increased, and the valve elements 25, 41, 42
The opening and closing operations of the orifices 51, 52, and 36 are stabilized, and even if a slight voltage fluctuation (for example, about 1 V) occurs,
The valve bodies 25, 41, 42 undesirably cause the orifices 51,
Opening and closing of 52 and 36 can be reliably prevented, and reliability is increased.

FIG. 8 shows another embodiment of the solenoid valve. As for the solenoid valve 1 'shown in FIG. 8, parts corresponding to the respective parts of the solenoid valve 1 shown in FIGS. Are denoted by the same reference numerals, and duplicate description will be omitted. Differences will be mainly described. The solenoid valve 1 'of the illustrated embodiment has a structure in which the second valve body 41 is removed from the solenoid valve 1 of the embodiment, and an orifice 52 formed in the third valve body 42 by the first valve body 25'. Is opened and closed. In the electromagnetic valve 1 'having such a structure, similarly to the conventional electromagnetic valve 2, in addition to being able to switch the flow rate in two stages, it can serve as both a flow switching valve and an expansion valve.

[0051]

As will be understood from the above description, the solenoid valve according to the present invention has a relatively simple structure, can be easily manufactured at low cost, and can perform finer flow rate adjustment. By appropriately setting the effective passage cross-sectional area of the orifice, it is possible to provide both functions of a flow switching valve and an expansion valve. When the valve is incorporated, the cost is lower than when the electric valve is incorporated, and the number of parts is reduced as compared with the case where both the solenoid valve and the expansion valve are incorporated in the refrigeration cycle, and the piping system is reduced. It is easy and easy to handle, which is advantageous in terms of cost.

[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 an embodiment of the present invention is 0 V (when the valve is closed).

FIG. 2 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 1 is small.

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

FIG. 4 is a cross-sectional view showing a state when an applied voltage of the solenoid valve shown in FIG. 1 is large.

FIG. 5 is an enlarged sectional view of a main part of the solenoid valve shown in FIG. 1;

FIG. 6 is a diagram showing the relationship between the applied voltage and the amount of pulling up of the plunger in one embodiment of the solenoid valve according to the present invention.

FIG. 7 is a flowchart of an opening / closing operation in one embodiment of the solenoid valve according to the present invention.

FIG. 8 is a cross-sectional view illustrating a state where an applied voltage of an electromagnetic valve according to another embodiment is 0 V (when the valve is closed).

FIG. 9 is a cross-sectional view of an example of a conventional solenoid valve when the valve is closed.

[Explanation of symbols]

 Reference Signs List 1 solenoid valve 8 inflow port 9 outflow port 10 solenoid 12 guide sleeve 15 suction element 20 plunger 23 coil spring 24 tubular leg 25 first valve body 30 valve body 32 valve chamber 35 valve seat 36 rear orifice 41 second valve body 42 Third valve element 51 Front orifice 52 Middle orifice 100 Air conditioner control unit 200 Power supply (battery)

Claims (4)

[Claims] 1. A valve body having a valve seat having a valve chamber, an inlet, an outlet, and a downstream orifice, a plunger, and an outer periphery thereof for moving the plunger toward and away from the valve seat. And a cylindrical hole formed in the plunger into which a first valve body having a columnar shape or an inverted convex cross section is slidably inserted along the axial direction, and a cylindrical leg portion. Is protruded, and in the concave hole,
A locking piece for locking the first valve body is provided at the front end opening, and a biasing means for biasing the first valve body toward the valve seat is provided inside the cylindrical leg. Are a second valve body and a third valve body that are sequentially lifted in a direction away from the valve seat by the plunger in a state of being respectively engaged and disengaged by engagement pieces provided at an intermediate portion and a lower end thereof. A front stage orifice, which is opened and closed by the first valve body and has an effective passage sectional area smaller than the rear stage orifice, is formed in the second valve body.
A middle stage orifice which is opened and closed by a valve body and has an effective passage cross-sectional area larger than the front stage orifice and smaller than the rear stage orifice is formed, and the third valve body is configured to open and close the rear stage orifice. An electromagnetic valve characterized by the above. 2. An applied voltage to the solenoid is high,
When the applied voltage is small, the first valve body opens the front-stage orifice, and when the applied voltage is medium, the first valve body opens the front-stage orifice. The second valve body opens the middle orifice, and when the applied voltage is high, the first valve body and the second valve body keep the front orifice and the middle orifice open, respectively. 2. The solenoid valve according to claim 1, wherein a body opens the rear orifice, whereby a flow rate of the fluid flowing from the inlet to the outlet is controlled in a stepwise manner. 3. When a voltage applied to the solenoid is applied in a direction to close the valve body, after a voltage is applied to close all the orifices by all the valve bodies,
3. The solenoid valve according to claim 2, wherein the flow rate is controlled stepwise so that each of the valve bodies opens the orifice in sequence. 4. A method according to claim 1, further comprising: a step between the first valve element and the front-stage orifice; a step between the front-stage orifice and the middle-stage orifice
A front-stage widening opening, a middle-stage widening opening, and a rear-stage widening opening are provided between the middle-stage orifice and the rear-stage orifice, respectively, and the opening area of each of the widening openings is the effective passage of the subsequent orifice. Larger than the cross-sectional area,
4. The method according to claim 1, wherein a difference in the opening area between the adjacent enlarged openings is larger than a difference in the effective passage area between the adjacent orifices. Solenoid valve.