JP2001311477A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve realizing the compactness toward axis direction. SOLUTION: In the solenoid valve, a bellows assembly 10 is provided between a center post 2c and a plunger 2b. It is characterized in that the bellows assembly 10 can induce a thrust against the plunger 2b by shrinking and extending in accordance with an environmental pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve used for controlling a pressure of a fluid, and is applied to, for example, a variable displacement compressor for an air conditioner of a vehicle.

[0002]

2. Description of the Related Art Conventionally, for example, there is a solenoid valve used as a control valve capable of controlling the output of a variable displacement type compressor used for compressing a refrigerant in an air conditioner of a vehicle (so-called car air conditioner).

The details of the basic structure of such a solenoid valve, the connection with the compressor, and the operation of controlling the fluid are described in Japanese Patent Application Laid-Open No. 9-268973 by the present applicant. Pressure of the compressor (P
s), the discharge pressure (Pd) is changed to the crank chamber pressure (Pc).
To change the capacity of the compressor (the angle of the swash plate is changed by adjusting the crank chamber pressure (Pc) to change the stroke of the compression piston).

FIG. 4 is an explanatory view of a sectional configuration of a solenoid valve for controlling a variable displacement compressor as an example of the prior art.

[0005] The solenoid valve 100 generally includes a solenoid part 102, a valve part 103 and a bellows assembly 1.
10.

The solenoid portion 102 is disposed at one end of a substantially cylindrical valve body 104 and is the same as that generally used according to a known technique, and supplies a current to the coil 102a. A magnetic force is generated, and the spring 112 forms the suction surface 102 of the center post 102c.
The solenoid-side rod 102d moves away from c1.
By attracting the plunger 102b urged via the center post 102c to the center post 102c, an urging force (proportionally controlled suction force) having a magnitude corresponding to the current value can be generated.

In the valve section 103, a valve body 103b is disposed in a valve chamber 103a formed inside a valve body 104, and the valve body 103b comes into contact with and separates from a valve seat 103c opening in the valve chamber 103a. , And is configured to be movable in the axial direction in the valve chamber 103a.

Further, the valve body 103b is connected to the center post 10
It is urged in the valve opening direction by a spring 112 via a solenoid-side rod 102d passing through the inner cylinder portion 2c.

A port 103e is connected to the valve chamber 103a of the valve section 103, and a port 103 is connected to the valve seat 103c.
f is connected.

The discharge pressure Pd applied to the port 103e
Is connected to the plunger 10 by the pressure balance path 103g.
2b is input to the plunger chamber in which the valve body 10b is accommodated.
The pressure on 3b is balanced.

The solenoid 102 of the valve body 104
A bellows assembly 110 is disposed at the other end on the opposite side.

The bellows assembly 110 has a hermetic structure, and has a bellows core 110a whose inside is sealed in a vacuum state or a constant pressure, a stopper and a holder for holding both ends of the bellows core 110a, and a bellows core 110a.
A spring or the like is provided to extend inside and provide an urging force.

The bellows assembly 110 is generally housed inside a bellows case or the like, and has a bellows core 110.
The bellows-side rod 110 which expands and contracts in response to the pressure (suction pressure Ps) around
When the valve body 103b is extended to a predetermined length or more (when the suction pressure Ps decreases), the urging force in the valve opening direction is applied to the valve body 103b.

Accordingly, the urging force of the bellows assembly 110 is applied in the direction of opening the valve body 103b to the urging force of the solenoid unit 102 in the valve closing direction, and the valve body 103b is opened.
Of the refrigerant (balance control), and the flow rate control of the refrigerant from the discharge pressure Pd to the crankcase pressure Pc is performed.

The compressor suction pressure Ps, discharge pressure Pd, and crankcase pressure Pc are described in Japanese Patent Application Laid-Open No. 9-268.
Since the details are described in Japanese Patent Application Laid-Open No. 973, a brief description will be given here.

In adjusting the cooling capacity of the compressor (discharge pressure Pd), for example, the temperature of the blown-out air of the cool air passing through the evaporator having the heat absorbing action due to the vaporization of the refrigerant (the amount of the blown-out cold air and the temperature before the cooling is also related). And the suction pressure Ps of the refrigerant of the compressor has a correlation (the suction pressure Ps increases when the temperature of the cold air rises, and the suction pressure Ps decreases when the temperature of the cold air decreases). In order to adjust the output (discharge pressure Pd) of the compressor using the swash plate, the swash plate whose angle changes is set to a predetermined angle (the swash plate changes the inclination angle θ by the crankcase pressure Pc). ing.

[0017]

However, in the case of the above-described prior art, the following problems have occurred.

The solenoid valve is applied to, for example, a variable displacement compressor used in an air conditioner of a vehicle, and is always in an environment where vibration is applied.

As described above, bellows assembly 110
Is disposed at the other end of the valve body 104 on the side opposite to the solenoid portion 102, so that the apparatus main body is large in the axial direction. Conventionally, a movable member is arranged coaxially for the purpose of improving performance, simplifying the configuration, and the like.However, if the device becomes larger in the axial direction, which is the movable direction of the movable member, the weight of the movable portion increases, and vibration resistance increases. It was difficult to improve the performance.

Further, the solenoid valve is mounted in a hole formed in the rear housing of the compressor. However, when the main body of the apparatus becomes large in the axial direction, the hole in the rear housing must be formed deep.

The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a solenoid valve which is made compact in the axial direction.

[0022]

According to the present invention, there is provided a solenoid valve having a plunger magnetically attracted to a center post by an excited coil. In the meantime, a pressure responsive means for generating a thrust to the plunger by expanding and contracting according to the surrounding pressure is provided.

With this configuration, it is possible to eliminate the space for the conventional bellows assembly, so that it is possible to reduce the size in the axial direction.

The plunger has a valve body provided opposite to the tip of a rod fixed to the plunger, the rod moving in the axial direction and performing an opening and closing operation, and the plunger is magnetically attracted to the center post. It is also preferable that the open / close position of the valve can be balance-controlled by cooperating a force and a thrust of the pressure response means.

With this configuration, it is possible to make the solenoid valve compact in the axial direction even in a solenoid valve that performs balance control by cooperating suction force of the solenoid and thrust of the pressure response means.

A first flow path for guiding a fluid around the pressure responsive means through a plunger chamber accommodating the plunger, and a second and a third flow path communicating with an on-off valve portion opened and closed by the valve body. A fluid reservoir chamber provided on the opposite side to the plunger chamber via the on-off valve portion;
A fourth flow path that branches from the flow path and guides the fluid at the same pressure as the first flow path to the fluid storage chamber; a valve body rod provided in the valve body and communicating with the fluid storage chamber; Biasing means for biasing the valve body rod toward the plunger, wherein the diameter of the rod, the diameter of the valve body rod, and the diameter of a valve seat that opens and closes when the valve body comes and goes are the same. It is also preferable to use

With this configuration, the fluid guided to the first flow path is not affected by the fluid guided to the second and third flow paths.

A spring member is disposed between the center post and the plunger, the spring member acting in a direction in which the plunger moves away from the center post, and the spring member moves the plunger when the solenoid exciting current becomes equal to or less than a predetermined value. It is also suitable to pull them away from.

With this configuration, when the solenoid exciting current becomes equal to or less than a predetermined value, the spring member can separate the plunger from the center post. For example, as a result, the opening and closing valve is opened and closed. be able to.

[0030]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, the shape, and the relative arrangement thereof should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, and are not intended to limit the scope of the invention to the following embodiments.

(Embodiment 1) FIG. 1 is a view for explaining a sectional configuration of a solenoid valve 1 according to an embodiment. The solenoid valve 1 uses, for example, a refrigerant suction pressure Ps of a variable displacement compressor used in a vehicle air conditioner as a fluid to be subjected to pressure response.

In the variable displacement compressor, the discharge pressure Pd and the crank chamber pressure Pc are magnetically attracted to the thrust of the bellows assembly 10 as a pressure response means responding to the suction pressure Ps and to the center post 2c of the solenoid unit 2. Plunger 2b
The suction pressure Ps is controlled as a result by controlling the valve unit 3 by balancing (cooperating) with the suction force of the suction valve.

The solenoid valve 1 generally includes a solenoid portion 2, a valve portion 3, and a bellows assembly 10. As a characteristic configuration of the present embodiment, the bellows assembly 10 is provided with a center post of the solenoid portion 2. 2c and the plunger 2b.

The solenoid portion 2 is disposed at one end of the substantially cylindrical valve body 4 and supplies a current to the coil 2a to generate a magnetic force. The spring 12 moves away from the suction surface 2c1 of the center post 2c. By attracting the plunger 2b urged toward the center post 2c, a suction force having a magnitude (proportionally controlled) corresponding to the current value can be generated.

Here, the plunger 2b has a substantially concave cross section.
Are arranged so that the inner bottom of each of the recesses faces the center post 2c having a substantially recessed cross section.
e. Further, when the plunger 2b is sucked by the center post 2c, the suction surface 2c1, which is the opposing surface of the side wall of the cross section of the center post 2c, and the plunger 2
A load is generated in the direction in which the opposing surface 2b1 of the side wall of the cross section concave portion b approaches, and moves to a position that balances the load generated by the pressure applied to the bellows assembly 10 and the rod 2d / valve 3b at that time.

Incidentally, the shape of the opposing surfaces of the side walls of the cross-sectional concave portions of the plunger 2b and the center post 2c is designed to be suitable for proportional control, so that a change in thrust for each current is suppressed even when the plunger moves. In order to obtain various characteristics, a conical shape is also suitable.

In the valve section 3, a valve body 3b is arranged in a valve chamber 3a formed inside a valve body 4, and the valve body 3b comes into contact with and separates from a valve seat 3c opening to the valve chamber 3a. ,
It is configured to be movable in the axial direction in the valve chamber 3a. The valve chamber 3a includes a valve body 3b and an end face 4a of the valve body 4.
The spring 13 is arranged in a compressed state between
The spring 13 urges the valve body 3b in the valve closing direction.
The rod 3d connected to the plunger 2b transmits, to the valve body 3b, the suction force by which the plunger 2b is suctioned to the center post 2c and the thrust by the bellows assembly 10.

The valve chamber 3a of the valve section 3 has a port 3e.
Are connected, and a port 3f is connected to the valve seat 3c. In the figure, the discharge pressure Pd is applied to the port 3e and the crank chamber pressure Pc is applied to the port 3f. However, the crank chamber pressure Pc may be applied to the port 3e, and the discharge pressure Pd may be applied to the port 3f.

As a characteristic configuration of this embodiment, the center post 2c of the solenoid portion 2 and the plunger 2
and a bellows assembly 10 is disposed between the bellows assembly b.

The bellows assembly 10 has a sealed structure and includes a bellows core 10a whose inside is sealed in a vacuum state or a constant pressure, and is disposed between the center post 2c and the plunger 2b in the solenoid chamber 2e. Then, both ends of the bellows core 10a are held at the bottoms of the concave portions of the center post 2c and the plunger 2b, respectively.

In the bellows core 10a, a stopper 10b for restricting the bellows core 10a from contracting due to pressure sensitivity,
And a spring 10c for urging the bellows core 10a in a direction in which the bellows core 10a extends.

The center post 2c and the plunger 2b
A spring 1 for urging the valve body 3b in the valve opening direction
2 are arranged.

The urging force of the spring 12 is determined when the solenoid exciting current is equal to or less than a predetermined value and the suction pressure Ps is equal to or less than a predetermined pressure.
The valve is set to be in an open state.

The spring 12 may be arranged between the bellows assembly 10 and the center post 2c to separate the plunger 2b from the center post 2c together with the bellows assembly 10 when the solenoid exciting current is less than a predetermined value. Good.

In the solenoid chamber 2e, a port 3g to which a suction pressure Ps is applied is connected, and when the bellows core 10a which expands and contracts in response to the suction pressure Ps expands (when the suction pressure Ps decreases), a plunger is formed. The rod 2d abuts on the valve body 3b via 2b, and applies an urging force in the valve opening direction according to the suction pressure Ps.

Therefore, the suction force in the valve closing direction by which the plunger 2b is suctioned to the center post 2c by the solenoid portion 2 and the thrust corresponding to the suction pressure Ps by the bellows assembly 10 cooperate, and the valve body 3b Opening / closing control (balance control) is performed, and flow control of the refrigerant from the discharge pressure Pd to the crankcase pressure Pc is performed.

In this case, by arranging the valve body 3b, the solenoid portion 2 and the bellows assembly 10 coaxially, the configuration of the solenoid valve 1 is not complicated, and the transmission of the urging force is directly performed with a simple configuration. And stable control is performed.

In the adjustment of the cooling capacity (discharge pressure Pd) of the compressor provided with the solenoid valve 1, for example, the temperature at which the cold air blows out through the evaporator having a heat absorbing action due to the vaporization of the refrigerant (the blowing of the cold air) Since the suction pressure Ps of the refrigerant of the compressor has a correlation with the suction pressure Ps (which is also related to the amount and the temperature before cooling) (the suction pressure P
s rises and the suction pressure Ps falls when the temperature of the cool air falls), and the swash plate whose angle changes to adjust the output (discharge pressure Pd) of the compressor using a change in the suction pressure Ps to a predetermined angle. The control is performed to set the angle (the inclination angle θ of the swash plate changes depending on the crankcase pressure Pc).

Next, in addition to the structure in which the solenoid valve 1 is embedded in the rear housing of the compressor, a structure in which the solenoid valve 1 is attached to the rear housing of the compressor by taking advantage of the short axial dimension of the body will be described. .

FIG. 3B is a sectional view showing a state where the bracket 14 is attached to the outer periphery of the valve body 4.
FIG. 3A is a schematic side view of FIG. 3B.

The bracket 14 has three ports 14 b, 14 opening at an end 14 a opposite to the solenoid 2.
c, 14d.

The three ports 14b, 14c, 14d extend in the axial direction from the end 14a and are formed to communicate with the ports 3g, 3f, 3e of the valve body 4, respectively.

By mounting such a bracket 14 to the solenoid valve 1 and then to the rear housing of the compressor, there is no need to form a hole for mounting a solenoid valve as in the prior art. It is only necessary to provide ports that communicate with the four ports 14b, 14c, 14d.

As described above, by arranging the bellows assembly 10 between the center post 2c and the plunger 2b, the space for the conventional bellows assembly can be eliminated, thereby realizing the compactness in the axial direction. Becomes possible.

Further, since the rod can be set shorter by realizing the compactness in the axial direction, it is possible to reduce the weight of the movable part and to improve the vibration resistance.

Also, by realizing the compactness in the axial direction, there is no need to form a hole for mounting a solenoid valve like a rear housing of a conventional compressor.
The rear housing of the compressor need only be provided with ports communicating with the three ports 14b, 14b, 14c of the bracket 14.

(Embodiment 2) FIG. 2 is an explanatory sectional view of a solenoid valve 51 according to Embodiment 2. FIG.

The solenoid valve 51 according to the present embodiment
In the solenoid valve according to the first embodiment, a port to which the suction pressure Ps is applied is provided at an end of the valve body opposite to the solenoid portion, and the pressure receiving area (diameter) of each pressure receiving portion is They are the same.

The valve portion 53 has a valve body 53b disposed in a valve chamber 53a formed inside the valve body 54,
The valve body 53b is opened in the valve chamber 53a so that the valve body 53b comes into contact with and separates from the valve body 53b and the valve seat 53c forming an open valve portion.
It is configured to be movable in the axial direction in the inside 3a.

A fluid reservoir chamber 55 is provided at an end of the valve body 54 opposite to the solenoid portion 2 adjacent to the valve chamber 53a.

The valve body 53b is provided with a valve body rod 53h communicating with the fluid reservoir chamber 55. The valve body rod 53h is compressed in the fluid reservoir chamber 55 with the end face 54a of the valve body 54 by a spring 53. Are arranged to urge the valve body 53b in the valve closing direction. In addition, the rod 2d fixed to the plunger 2b transmits to the valve body 53b the suction force by which the plunger 2b is suctioned to the center post 2c and the thrust by the bellows assembly 10.

Then, a port 53g as a first flow path to which the suction pressure Ps is added communicates with the inside of the solenoid chamber 2e,
Further, a port 53i as a fourth flow path is branched from the first flow path to which the suction pressure Ps is added.
Leads to.

Further, a port 53e as a third flow path
Communicates with the valve chamber 53a, and a port 53f as a second flow path
Communicates with the valve seat 53c.

The diameter of the rod 2d and the valve rod 5
The diameter of 3h and the diameter of the valve seat 53c are set to the same size.

The balance equation of the pressure control by the solenoid valve 51 when the discharge pressure Pd is added to the port 53e and the crank chamber pressure Pc is added to the port 53f is shown in the following equation (1).

Where, F: solenoid thrust f1: urging force of spring 12 f2: urging force of spring 14 FB: bellows assembly set load A: effective pressure receiving area of bellows B: pressure receiving area of rod 2d C: valve seat 53c Pressure receiving area D: pressure receiving area of the valve rod 53h Pc: crankcase pressure Pd: discharge pressure Ps: suction pressure: f2 + PsD-Pd (DC) -Pc (CB) -PsB + PsA-f1 + F = FB (Equation 1)

Here, the diameter of the rod 2d and the valve rod 5
Since the diameter of 3h and the diameter of the valve seat 53c are set to the same size, the rod 2d, the valve seat 53c, and the valve rod 53
Assuming that the pressure receiving area of the portion h is the same,
Assuming that B = C = D, f2-f1 + PsA + F = FB (Formula 2)

Therefore, since the load generated by the pressure applied to each part except the bellows assembly 10 is offset, stable control can be performed even under various changing pressure conditions.

For example, even when the flow rate is small and the ratio between the load of the crank chamber pressure Pc and the load of the suction pressure Ps has a large effect, especially at the time of low Pd, the suction pressure Ps, which is the control pressure, is maintained at the discharge pressure Pd
In addition, since it is not affected by the crank chamber pressure Pc, it is possible to easily secure the opening amount of the valve portion, and it is possible to improve the control performance.

However, since it is difficult to set the pressure receiving area of each part to the same size in manufacturing, it is desirable to set the variation of each pressure receiving area within about ± 10% of the reference area.

In this embodiment, the case is shown where the discharge pressure Pd is applied to the port 53e and the crank chamber pressure Pc is applied to the port 53f. However, the crank chamber pressure Pc is applied to the port 53e and the port 53f is applied to the port 53f. The same is true even when the discharge pressure Pd is applied.

The solenoid valve 51 according to the present embodiment
In this case, the solenoid valve 51 can be attached to the rear housing of the compressor using a bracket similar to the bracket described in the first embodiment. However, in this case, four ports are required in the axial direction.

[0073]

As described above, according to the present invention,
By providing pressure response means between the center post and the plunger, which expands and contracts according to the surrounding pressure to generate a thrust on the plunger, the space for the conventional bellows assembly can be eliminated. It is possible to realize compactness in the axial direction.

Also, a solenoid valve that balances by controlling the suction force of the solenoid and the thrust of the pressure response means in cooperation with each other can be made compact in the axial direction.

Further, the on-off valve portion is formed between the plunger chamber to which the fluid of the same pressure is applied through the first and fourth flow paths and the fluid reservoir chamber, so that the fluid communicates with the on-off valve portion. It is not affected by the fluid guided to the second and third flow paths, so that it is possible to easily secure the opening amount of the valve portion, and it is possible to improve the control performance.

Further, a spring member is provided between the center post and the plunger so as to move the plunger away from the center post, and the spring member separates the plunger from the center post when the solenoid exciting current becomes a predetermined value or less. When the solenoid exciting current becomes equal to or less than a predetermined value, the spring member can separate the plunger from the center post. For example, as a result, it is possible to open the opening / closing valve portion that is opened / closed.

[Brief description of the drawings]

FIG. 1 is a sectional configuration explanatory view of a solenoid valve according to a first embodiment.

FIG. 2 is a sectional configuration explanatory view of a solenoid valve according to a second embodiment.

FIG. 3 is an explanatory view of a bracket of the solenoid valve according to the first embodiment, FIG. 3 (b) is a sectional configuration view,
FIG. 3A is a schematic side view of FIG. 3B.

FIG. 4 is an explanatory view of a cross-sectional configuration of a solenoid valve according to the related art.

[Explanation of symbols]

 1,51 solenoid valve 2 solenoid part 2a coil 2b plunger 2b1 opposed surface 2c center post 2c1 suction surface 2d rod 2e solenoid chamber 3,53 valve part 3a, 53a valve chamber 3b, 53b valve body 3c, 53c valve seat 3e, 3f, 3g, port 4, 54 valve body 4a, 54a end face 10 bellows assembly 10a bellows core 10b stopper 10c, 12, 13, 53 spring 14 bracket 14a end 14b, 14c, 14d port 53e, 53f, 53g, 53i port 53h valve Body rod 55 Fluid reservoir Ps Suction pressure Pd Discharge pressure Pc Crank chamber pressure

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[Procedure amendment]

[Submission Date] May 10, 2000 (2000.5.1)
0)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Noriyoshi Uemura 4-3-1 Tsujido Shinmachi, Fujisawa City, Kanagawa Prefecture Inside NOK Co., Ltd. (72) Inventor Ichiro Hirata 4-3-1 Tsujido Shinmachi, Fujisawa City, Kanagawa Prefecture No. F term in NOK Corporation (reference) 3H056 AA02 BB32 CA06 CA19 CD03 GG13 3H106 DA03 DA22 DB02 DB12 DB22 DB32 DC04 DC18 DD05 EE34 GA15 KK17 KK23

Claims (4)

[Claims] 1. A solenoid valve having a plunger magnetically attracted to a center post by an excited coil, wherein a thrust is applied to the plunger between the center post and the plunger by expanding and contracting according to the surrounding pressure. A solenoid valve comprising pressure response means for generating pressure. 2. A valve body which is provided opposite to a tip of a rod connected or abutted on said plunger, said rod moves in an axial direction and is opened and closed, and said center post is magnetically attracted by said center post. 2. The solenoid valve according to claim 1, wherein the opening / closing position of the valve body can be balance-controlled by cooperating a suction force of the plunger and a thrust force of the pressure response means. 3. 3. A first flow path for guiding a fluid around the pressure responsive means through a plunger chamber accommodating the plunger, and second and third communication paths with an on-off valve portion opened and closed by the valve element. A flow path, a fluid reservoir chamber provided on the opposite side of the plunger chamber via the on-off valve portion, and a fluid that branches off from the first flow path and has the same pressure as the first flow path. A fourth flow path leading to the reservoir, a valve rod provided in the valve, communicating with the fluid reservoir, and biasing means for biasing the valve rod toward the plunger. 3. The solenoid valve according to claim 2, wherein a diameter of the rod, a diameter of the valve body rod, and a diameter of a valve seat that opens and closes when the valve body comes and goes are the same. 4. A spring member is disposed between the center post and the plunger, the spring member acting in a direction in which the plunger moves away from the center post, and the spring member moves the plunger when a solenoid exciting current becomes a predetermined value or less. 4. The solenoid valve according to claim 1, wherein the solenoid valve is separated from the center post.