JPH1182801A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve capable of switching a flow rate in three or more steps and capable of playing both parts of a flow rate switching valve and an expansion valve, although a structure is comparatively simple, costs are low, and manufacturing is facilitated. SOLUTION: This solenoid valve 1 is provided with a valve body 30 equipped with a valve chamber 32, an inlet 8, an outlet 9 and a valve seat 35, a plunger 20, and a solenoid 10 arranged on the outer periphery in order to move the plunger 20 back and forth in the directions approaching and parting from the seat 35. Plural orifices 51, 52, 36 are formed so that an effective cross section area becomes larger gradually in a passage from the inlet 8 to the outlet 9. Three valve elements are disposed so as to be moved in a direction parting from the valve seat 35 integrally or linking with the plunger 20. The flow rate of fluid flowing from the inlet 8 to the outlet 9 is switched at least in three steps by switching an applied voltage to the solenoid 20 at least in three steps.

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 merely by 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) is applied via the. 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.
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 slidably provided with a first valve body 25 having a conical surface at its front end (lower end) and having a conical surface projecting downward. At the upper part of the plunger 20, there is formed a recess 21 having a substantially concave cross-sectional shape into which a holder 16 having a substantially inverted cross-sectional convex shape projecting from the suction element 15 is slidably inserted. The plunger 20 has a coil spring 23 compressed between the plunger 20 and the holder 16.
, Which constantly urges the valve seat 35 toward the lower side.

A cylindrical second valve element 40 is disposed between the first valve element 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 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 3. 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 FIG. 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 excited to be turned on, and the plunger 20 is turned on the suction element 15 side (upper side) against the urging force of the coil spring 23. The first valve body 25 is lifted halfway (intermediate position) to separate from the second valve body 40 and open the front-stage orifice 51.

As a result, the second valve body 40 is formed from the inflow port 8 through the through holes 37 formed in the cylindrical leg 24.
The refrigerant that has flowed into the refrigerant chamber S formed between the refrigerant 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. At this time, the flow rate of the refrigerant is
, 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 suction force of the suction 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 orifice 36, whereby the 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. Then, it flows into the rear-stage orifice 36 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.

[0011]

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
It only served as a flow switching valve, and a refrigeration cycle in which it was incorporated required a separate expansion valve. In addition, it is possible to finely adjust the flow rate by incorporating an electric valve that rotates a valve body with a stepping motor or the like in the refrigeration cycle, but since the structure and control system of the electric valve are complicated and expensive, There is a problem in cost.

Incorporation of 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 an object to provide a solenoid valve adapted to be obtained.

[0013]

In order to achieve the above object,
An electromagnetic valve according to the present invention basically has a valve body, a valve body, an inlet, an outlet, and a valve seat, a plunger, and a plunger for moving the plunger toward and away from the valve seat. A plurality of orifices are formed in the flow path from the inflow port to the outflow port so that the effective passage cross-sectional area is sequentially increased, and the orifices are opened and closed. To this end, a plurality of valve bodies are provided which are moved integrally with or in association with the plunger in a direction away from the valve seat. By switching the voltage applied to the solenoid, the flow rate of the fluid flowing from the inflow port to the outflow port is controlled stepwise.

In a preferred aspect of the present invention, the plunger is provided with a first valve body, and a second-stage orifice is formed in the valve seat, and the plunger is provided between the first valve body and the valve seat by the plunger. A second valve body and a third valve body that are sequentially lifted in a direction away from the seat are disposed, and the second valve body has an effective passage cross-sectional area that is opened and closed by the first valve body and is smaller than the rear orifice. A front stage orifice is formed, and a middle stage orifice formed in the third valve body and opened and closed by the second valve body and having an effective passage sectional area larger than the front stage orifice and smaller than the rear stage orifice is formed, and The third orifice is opened and closed by three valve bodies, and when the voltage applied to the solenoid is small, the first valve body opens the front orifice, When the applied voltage is medium, the first valve body keeps the front-stage orifice open, the second valve body opens the middle-stage orifice, and when the applied voltage is large, the first valve body and the second valve The third valve body opens the rear orifice with the body opening the front orifice and the middle orifice, respectively, whereby the flow rate of the fluid flowing from the inlet to the outlet is controlled stepwise.

In another preferred embodiment, the plunger is provided with a first valve body, and a second-stage orifice is formed in the valve seat, and the plunger is provided between the first valve body and the valve seat. A second valve body that is lifted in a direction away from the valve seat is arranged, and a front-stage orifice that is opened and closed by the first valve body and that has an effective passage cross-sectional area smaller than the rear-stage orifice is formed in the second valve body. The second orifice is configured to open and close the rear-stage orifice, and when the applied voltage to the solenoid is small, the first valve body opens the front-stage orifice halfway, and the applied voltage is When the first valve element fully opens the front-stage orifice and the applied voltage is large, the first valve element opens the front-stage orifice fully and the second valve element moves forward. Open subsequent orifice, whereby the flow rate of the fluid flowing through the outlet from the inlet 3
It is made to be able to be switched between stages.

In a more specific preferred embodiment, the first valve element has a contact surface with the front orifice formed as a conical surface. Further, the second valve body is supported so as to be able to contact and separate from a locking piece provided at a lower end of a cylindrical leg protruding from the plunger, and the first valve body is moved by the plunger. The front orifice is opened so that it can be pulled up with it.

Further, the third valve element has a bottomed cylindrical shape in which an inwardly projecting locking portion is provided at an upper end edge portion and the middle orifice is formed at a bottom portion. The plunger is supported so as to be able to contact and separate from the lower end surface of a concave groove formed in the peripheral side of the plunger, and the plunger allows the second valve body to be pulled up together with the middle stage orifice in an opened state. Become.

In another preferred embodiment, the plunger is provided with a recess having a convex cross section along the axial direction thereof, and a stopper having a convex cross section is formed in the concave to have a large diameter portion. The compression coil spring is slidably fitted in a state of being located at the large diameter portion of the recess, and a compression coil spring is provided between the large diameter portion of the stopper and the suction element of the solenoid and between the bottom surface of the recess. When the plunger is pulled up with the applied voltage set to a medium level and the plunger is lifted, the stopper comes into contact with the suction element and is stopped, so that the plunger is also stopped there.

In a preferred embodiment of the solenoid valve according to the present invention having the above-described configuration, the suction force to 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 a plurality of valve bodies which are pulled up integrally with or in association with the plunger are sequentially opened to operate the valve body sequentially provided in the flow path from the inlet to the outlet. A plurality of orifices having a larger passage cross-sectional area are sequentially opened, for example, one by one from the upstream side to switch the flow rate to three or more stages.

Therefore, the solenoid valve of the present invention has a relatively simple structure and can be easily manufactured at a low cost, can perform finer flow rate adjustment, and appropriately sets the effective passage sectional area of the orifice. By doing
It has both functions of a flow switching valve and an expansion valve. 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.

[0021]

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 has 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 1
3, coil 14, suction element (stator) 15, set screw 1
7, a power supply cable 18, a guide sleeve 12, and the like. A predetermined voltage (for example, 4V, 7V, 12V) is supplied from an in-vehicle power supply (battery) 200 via the air conditioner control unit 100.
3) is applied.

The lower portion of the guide sleeve 12 has a large diameter and is fixed to the inner periphery of the mounting base 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 a valve chamber 32 formed in the valve body 30, a tapered cylindrical valve seat 3 is provided.
5, a refrigerant inlet 8 is provided so as to be continuous with the valve chamber 32, and a refrigerant outlet 9 is provided downstream of a rear orifice 36 provided in the valve seat 35.

A plunger 20 having a conical first valve body 25 projecting downward at the center of the front end (lower end) is slidably fitted into the guide sleeve 12 of the solenoid 10, and the plunger 20 is slidably inserted therein. A recess 21 is formed in an upper part of the recess 20, and a bottom surface (lower surface) of the recess 21 and the suction element 15 are formed.
The plunger 20 is constantly urged toward the valve seat 35 (downward) by the coil spring 23 compressed between them. A communication hole 29 penetrating in the radial direction is formed in the recess 21.

Further, between the first valve body 25 and the valve seat 35, a stepped cylindrical second valve body 41, which will be described later, is sequentially raised by the plunger 20 in a direction away from the valve seat 35. And a third valve body 42 having a cylindrical shape with a bottom. The second valve body 41 has a front 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 orifice 36. Is formed in the third valve body 42, and an intermediate orifice 52, which is opened and closed by the second valve body 41, has an effective passage cross-sectional area larger than the front orifice 51 and smaller than the rear orifice 36,
Also, the rear orifice 36 is provided by the third valve body 42.
Can be opened and closed.

More specifically, the second valve element 41 is a ring-shaped locking piece fixedly locked by caulking to the lower end of a cylindrical leg 24 protruding from the front end of the plunger 20. The first valve body 25 is lifted by the plunger 20 together with the front orifice 51 in an opened state by the plunger 20. The cylindrical leg 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 3. Holes 37, 37,... Are formed.

Further, the third valve element 42 is provided with a locking portion 42a protruding inward at the upper end edge thereof, and is provided with a tapered cylindrical intermediate valve seat 46 at the center of the bottom. The orifice 52 has a bottomed cylindrical shape with a hole formed with the middle-stage orifice 52, and the locking portion 42a is supported on the lower end surface 27 of the concave groove formed in the peripheral side of the plunger 20 so as to be able to contact and separate therefrom. , By the plunger 20, the second
The valve element 41 is adapted to be pulled up together with the middle orifice 52 in an opened state. In the lower part on the peripheral side of the third valve body 42, the refrigerant is supplied to the inlet 8 and the valve chamber 32.
From the cylindrical leg 24, the second valve body 41 and the third valve body 42
Are formed in a predetermined number of through holes 39, 30,.

[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), as shown in FIG. 1, the plunger 20 is pushed down to the valve seat 35 side (downward) by the urging force of the coil spring 23, and the first valve body 25 is pressed against the second valve body 41 to While closing the orifice 51, the second valve body 41 is pushed down to the third valve body 42 side, and presses against the second valve body 41 to close the middle-stage orifice 52.
The orifice 36 is pushed down to the side 5 and pressed against it to close the rear-stage orifice 36 to be in a valve-closed state.

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 separation distance between the lower end surface of the plunger 20 and the upper end surface of the second valve body 41 is increased. distance Sa is minimum a _0, and the second
The separation distance Sb between the lower end surface of the valve body 41 and the upper end of the intermediate valve seat 46 of the third valve body 42 and the separation distance Sc between the lower end surface of the third valve body 42 and the upper end of the valve seat 35 are: Both become 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 turned on.
As shown in FIG. 2, the plunger 20 moves toward the suction element 15 (upper side) against the urging force of the coil spring 23 as shown in FIG.
(The position where the locking piece 27 contacts the second valve body 41)
The first valve body 25 is separated from the second valve body 41 to open the front-stage orifice 51. 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.
₃ from the small consisting z _2, and the distance Sa is greater than a ₀ when the valve closing a ₁ next to the lower end surface and the upper end surface of the second valve body 41 of the plunger 20, the second valve body 41 The separation distance Sb between the lower end surface of the third valve body 42 and the upper end of the intermediate valve seat 46 of the third valve body 42 and the separation distance Sc between the lower end surface of the third valve body 42 and the upper end of the valve seat 35 are all zero. Becomes

Thus, through the through holes 39, 39,... Formed in the third valve body 42 from the inflow port 8 and the valve chamber 32, and through the through holes 37, 37,. 2
Refrigerant chamber S formed between valve body 41 and plunger 20
Flows into 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 pulled up to the suction element 15 side when the applied voltage is low against the urging force of the coil spring 23, as shown in FIG.
The second valve body 41 is supported and locked by the locking piece 26 of the cylindrical leg portion 24 of the plunger 20 while the front orifice 51 is opened while being separated from the second valve body 41, and the plunger 20 is The middle orifice 52 is lifted together.
Is opened, but the third valve body 42 remains closed.

At this time, the lower end face of the suction element 15 is
The distance Sz from the upper end surface of the jaw 20 is determined by the applied voltage.
Z when small_TwoSmaller z₁And the plunger 2
0 and the upper end surface of the second valve body 41.
a is a_TwoThe lower end face of the second valve body 41 and the third
The separation distance Sb between the valve body 42 and the upper end of the intermediate valve seat 46 is b ₁
And above the lower end surface of the third valve body 42 and the valve seat 35
The distance Sc from the end is zero.

Thus, the cylindrical leg portion 24, the second valve body 41, and the third valve body 41 are formed from the inflow port 8 and the valve chamber 32 through the through holes 39, 30, ... formed in the third valve body 42. The refrigerant flowing into the refrigerant chamber S ′ formed between the second valve body 41
Flows into the middle orifice 52 through the space between the lower surface of the third valve body 42 and the intermediate valve seat 46 of the third valve body 42, flows out to the refrigerant outlet 9 via the rear orifice 36, and is expanded.
It is led to a 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 suction force of the suction element 15 is maximized, and as shown in FIG. 4, the plunger 20 is at the highest position (close to or close to the suction element 15) against the urging force of the coil spring 23. (Abutting position), whereby the first valve body 25 is moved to the front-stage orifice 51.
With the second valve body 41 opening the middle orifice 52, the third valve body 42 is supported and locked on the lower end surface 27 of the concave portion of the plunger 20, and is pulled up together with the plunger 20, The rear orifice 36 is opened apart from the valve seat 35.

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 plunger 2
0 and the upper end surface of the second valve body 41.
a is a ₂ , the lower end surface of the second valve body 41 and the third
The distance Sb between the valve body 42 and the upper end of the intermediate valve seat 46 is b ₁
Next, distance Sc of the lower end surface and the upper end of the valve seat 35 of the third valve body 42 becomes c _1.

As a result, the refrigerant from the inflow port 8 flows directly between the lower surface of the third valve body 42 and the valve seat 35 into the rear-stage orifice 36, and flows through the rear-stage 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 to 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, the second valve body 41 and the third valve body 42 are sequentially opened to provide three passages provided in the flow passage from the inflow port 8 to the outflow port 9, the effective passage areas of which are sequentially increased. The orifices 51, 52, and 36 are sequentially opened one by one from the upstream one to switch the flow rate in three stages.

Accordingly, the solenoid valve 1 of the embodiment has a relatively simple structure and can be easily manufactured at low cost, but has a smaller flow rate than a conventional solenoid valve which can switch the flow rate only in two stages. Thus, the flow rate can be adjusted more finely, and the function of both the flow rate switching valve and the expansion valve can be provided by appropriately setting the effective passage sectional area of the orifice. 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.

FIGS. 5 to 8 show another embodiment of the solenoid valve according to the present invention. The solenoid valve 1 'shown in FIGS. 5 to 8 is shown in FIGS. 9 and 1 to 4 described above. Portions corresponding to the respective portions of the solenoid valves 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted. Differences will be mainly described.

The basic structure of the solenoid valve 1 'of the illustrated embodiment is substantially the same as that of the conventional solenoid valve 2 shown in FIG. 9, and the first valve body 25 is provided on the plunger 20 and the valve seat 35 is provided. A second orifice 36 is formed in the plunger 20 between the first valve body 25 and the valve seat 35.
A second valve body 40 that is lifted up in a direction away from the valve seat 35 is disposed, and the second valve body 40 has an effective passage cross-sectional area that is opened and closed by the first valve body 25 and is smaller than the rear orifice 36. A first orifice 50 is formed, and the second orifice 36 is opened and closed by the second valve body 40. The second orifice 50 is provided in the solenoid valve 1 of the embodiment shown in FIGS. Such a third valve body does not exist.

Here, a concave portion 61 having a convex cross section is formed in the plunger 20 along the axial direction thereof, and a stopper 62 having a convex cross section is formed in the concave portion 61 so that the large diameter portion is formed. The stopper 62 is slidably fitted in a state of being positioned at the large-diameter portion, and between the large-diameter portion of the stopper 62 and the plunger 20 and the suction element 15 and between the bottom surface of the concave portion 61, respectively. When the compression coil springs 63 and 64 are compressed and the applied voltage is set to the middle and the plunger 20 is pulled up, the stopper 62 abuts on the suction element 15 and is stopped, and the plunger 20 is also there. It is designed to be stopped.

[Cooling OFF (FIG. 5)] 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
5), as shown in FIG. 5, the plunger 20 is pushed down to the valve seat 35 side (downward) by the urging force of the coil springs 63 and 64, and the first valve body 25 is pressed against the second valve body 40. While closing the front orifice 50, the second valve body 40 is pushed down to the valve seat 35 side and presses against the second orifice to close the rear orifice 36, 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 separation distance between the lower end surface of the plunger 20 and the upper end surface of the second valve body 40 is increased. distance Sa is minimum a _0, and the second
Separation distance S between the lower end surface of valve body 40 and the upper end of valve seat 35
b becomes 0.

[Cooling ON: weak (FIG. 6)] 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. 6, the plunger 20 is pulled up to a middle position (intermediate position) on the suction element 15 side (upper side) against the urging force of the coil springs 63 and 64, as shown in FIG. The front orifice 50 is opened halfway apart from the valve body 40, but the second valve body 40 remains closed due to a pressure difference between the inside and outside thereof (the inflow side is high and the outflow side is low).

At this time, the 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, the separation distance Sa is larger. A ₁ 'it becomes from a ₀ during the closing of the lower end surface and the upper surface of the second valve body 40 of the plunger 20, the second valve body The separation distance Sb between the lower end surface of the valve seat 40 and the upper end of the valve seat 35 is zero.

Thus, the second valve body 40 is formed from the inflow port 8 through the through holes 37 formed in the cylindrical leg 24.
The refrigerant flowing into the refrigerant chamber S formed between the refrigerant and the plunger 20 flows out to the refrigerant outlet 9 through the front orifice 50 and the rear orifice 36 to be expanded, and is guided to the downstream evaporator. At this time, the flow rate of the refrigerant is relatively small because the front-stage orifice 50 is half-open, and the cooling power is weak.

[Cooling ON: Medium (FIG. 7)] 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. 7, the plunger 20 is further raised to the suction element 15 side when the applied voltage is low against the urging force of the coil springs 63 and 64, as shown in FIG.
The valve body 25 is separated from the second valve body 40 and the front orifice 50
Is fully opened, the stopper 62 abuts on the suction element 15 and is stopped, and the plunger 20 is also stopped there. For this reason, the second valve body 40 remains in the closed state.

[0050] At this time, distance and Sz becomes z ₁ of the applied voltage is smaller than z ₂ when the small between the lower end surface and the upper end surface of the plunger 20 of the suction element 15, the plunger 2
0 and the upper end surface of the second valve body 40.
a becomes a ₂ ′ which is larger than a ₁ ′ when the applied voltage is small, and the separation distance Sb between the lower end surface of the second valve body 40 and the upper end of the valve seat 35 becomes zero.

As a result, the second valve body 40 is formed from the inflow port 8 through the through holes 37 formed in the cylindrical leg 24.
The refrigerant flowing into the refrigerant chamber S formed between the refrigerant and the plunger 20 flows out to the refrigerant outlet 9 through the front orifice 50 and the rear orifice 36 to be expanded, and is guided to the downstream evaporator. At this time, the flow rate of the refrigerant is larger than when the applied voltage is small because the front-stage orifice 50 is completely opened, and the cooling power is medium.

[Cooling ON: Strong (FIG. 8)] 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. 8, the plunger 20 is moved to the highest position against the urging force of the coil springs 63 and 64 (at the highest position). (Or close or abutting position), whereby the first valve body 25 opens the front-stage orifice 50, and the second valve body 40 is moved to the valve seat 35.
And open the latter-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 plunger 2
0 and the upper end surface of the second valve body 40.
a is a ₂ ′, and the separation distance Sb between the lower end surface of the second valve body 40 and the upper end of the valve seat 35 is b ₁ . As a result, the refrigerant from the inlet 8 flows directly between the lower surface of the second valve body 40 and the valve seat 35 into the rear orifice 36, and flows out to the refrigerant outlet 9 via the rear orifice 36. To be expanded and guided to a downstream evaporator. Therefore, when this maximum voltage is applied,
Since it is determined by the effective passage cross-sectional area of the rear orifice 36, the flow rate of the refrigerant flowing from the inflow port 8 to the outflow port 9 is maximized, and the cooling power is increased.

In the solenoid valve 1 ′ of the present embodiment having the above-described structure, the voltage applied to the solenoid 10 is increased in three stages, so that the plunger 20
The suction force for the plunger 20 is gradually increased, thereby changing the amount of pulling up of the plunger 20.
The first valve body 25 and the second valve body 40 which are lifted up integrally or in conjunction with the valve body 0 are sequentially opened, and the effective passages provided in the flow path from the inlet 8 to the outlet 9 are sequentially provided. The upstream orifice 50 of the two orifices 50 and 36 whose cross-sectional area is enlarged is switched between two stages of half opening and full opening, and the downstream orifice 3 on the downstream side.
6 is opened and closed to switch the flow rate in three stages.

Therefore, also in the solenoid valve 1 'of the embodiment, similarly to the above-described embodiment, the structure is relatively simple, and it can be easily manufactured at low cost.
The flow rate can be adjusted more finely than the conventional solenoid valve which could switch the flow rate only in two stages, and by setting the effective passage area of the orifice appropriately, the flow switching valve and the expansion valve can be adjusted. It will have both functions. 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.

When the plunger 20 is pulled up with the applied voltage set to the middle level, the stopper comes into contact with the suction element 15 and is stopped, so that the plunger 20 is also stopped there. As a result, the second valve element 40 is not lifted up with a slight voltage fluctuation, and the state in which the second orifice 36 is closed is maintained. Therefore, the control becomes easy, the flow rate can be adjusted reliably and accurately, and the reliability is improved. Increase.

[0057]

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 has a conventional flow rate of only two stages. In addition to being able to finely adjust the flow rate compared to the solenoid valve that could not be switched, by setting the effective passage cross-sectional area of the orifice appropriately, it has both the functions of the flow rate switching valve and the expansion valve, 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.

[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 a cross-sectional view illustrating a state where an applied voltage is 0 V (when the valve is closed) according to another embodiment of the solenoid valve according to the present invention.

FIG. 6 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 5 is small.

FIG. 7 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 5 is medium.

FIG. 8 is a cross-sectional view showing a state when the voltage applied to the solenoid valve shown in FIG. 5 is large.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 8 Inflow port 9 Outflow port 10 Solenoid 12 Guide sleeve 15 Suction element 20 Plunger 23 Coil spring 24 Cylindrical leg part 25 First valve body 30 Valve main body part 32 Valve room 35 Valve seat 36 Rear-stage orifice 41 Second valve body 42 Third valve body 46 Intermediate valve seat 51 Front orifice 52 Middle orifice 100 Air conditioner control unit 200 Power supply (battery)

Claims (7)

[Claims] 1. A valve body having a valve chamber, an inlet, an outlet, and a valve seat, a plunger, and a solenoid disposed on an outer periphery of the plunger for moving the plunger toward and away from the valve seat. A plurality of orifices are formed in the flow path from the inflow port to the outflow port so that the effective passage cross-sectional area increases sequentially, and the orifices are integrally formed with the plunger to open and close the orifices. Alternatively, in an electromagnetic valve provided with a plurality of valve bodies that are moved in a direction away from the valve seat in association therewith, by switching an applied voltage to the solenoid, a flow rate of a fluid flowing from the inflow port to the outflow port is changed. The solenoid valve is controlled in a stepwise manner. 2. A first valve body is provided on the plunger, and a second-stage orifice is formed on the valve seat, and the plunger is provided between the first valve body and the valve seat in a direction away from the valve seat. A second valve body and a third valve body that are sequentially raised are arranged, and a front-stage orifice that is opened and closed by the first valve body and that has an effective passage cross-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 the second valve body and has an effective passage sectional area larger than the front stage orifice and smaller than the rear stage orifice, is formed by the third valve body; When the rear-stage orifice is opened and closed and the voltage applied to the solenoid is small,
The first valve body opens the front-stage orifice, and when the applied voltage is medium, the second valve body opens the middle-stage orifice while the first valve body keeps the front-stage orifice open.
When the applied voltage is large, the third valve body opens the rear orifice while the first valve body and the second valve body open the front orifice and the middle orifice, respectively, and thereby, from the inflow port. 2. The solenoid valve according to claim 1, wherein the flow rate of the fluid flowing to the outlet is controlled stepwise. 3. A plunger is provided with a first valve body, and a second-stage orifice is formed in the valve seat. The plunger is provided between the first valve body and the valve seat in a direction away from the valve seat. A second valve body to be lifted is disposed, and a front stage orifice that is opened and closed by the first valve body and has an effective passage cross-sectional area smaller than the rear stage orifice is formed in the second valve body, and When the voltage applied to the solenoid is small, the first valve body opens the front-stage orifice halfway, and when the applied voltage is medium, the first valve is opened and closed by the body. When the body fully opens the front stage orifice and the applied voltage is large, the second valve body opens the rear stage orifice while the first valve body fully opens the front stage orifice. 2. The solenoid valve according to claim 1, wherein the flow rate of the fluid flowing from the inflow port to the outflow port is switched in three stages. 4. The solenoid valve according to claim 2, wherein a contact surface of the first valve body with the front orifice is formed as a conical surface. 5. The second valve body is supported by a locking piece provided at a lower end of a cylindrical leg protruding from the plunger so as to be able to contact and separate therefrom, and the first valve is moved by the plunger. The solenoid valve according to any one of claims 2 to 4, wherein the body is adapted to be lifted together with the front-stage orifice in an open state. 6. The third valve element has a bottomed cylindrical shape in which an inwardly projecting locking portion is provided at an upper end edge portion and the middle orifice is formed in a bottom portion. The plunger is supported so as to be able to contact and separate from the lower end surface of a concave groove formed in the peripheral side of the plunger, and the plunger allows the second valve body to be pulled up together with the middle stage orifice in an opened state. The solenoid valve according to claim 2, 4 or 5, wherein: 7. A concave portion having a convex cross section is formed in the plunger along an axial direction thereof, and a stopper having a convex cross section is provided in the concave portion so that a large diameter portion of the concave portion has a large diameter. The compression coil spring is contracted between the large-diameter portion of the stopper and the suction element of the solenoid and the bottom surface of the recess, respectively. 4. The system according to claim 3, wherein when the voltage is set to a medium level, when the plunger is pulled up, the stopper comes into contact with the suction element and is stopped, and the plunger is also stopped there. , 4, or 5
Solenoid valve according to the above.