JP4418309B2 - Control valve for variable capacity compressor - Google Patents

Description

  The present invention relates to, for example, a control valve for a variable displacement compressor that constitutes a refrigerant circulation circuit of a vehicle air conditioner and can change a discharge capacity based on a pressure in a crank chamber.

  As this type of control valve, there is one disclosed in Patent Document 1 below. The control valve described in this publication constitutes a refrigerant circulation circuit and is used in a variable displacement compressor capable of changing the discharge capacity based on the pressure in the crank chamber. The suction pressure region between the crank chamber and the refrigerant circulation circuit The valve chamber partitioned in the valve housing to form a part of the extraction passage that connects to the valve housing, and the opening of the extraction passage can be adjusted depending on the position in the valve chamber that is displaceably accommodated in the valve chamber A valve body, a pressure sensitive chamber partitioned in the valve housing, and a pressure sensitive member formed of a bellows disposed in the pressure sensitive chamber and dividing the pressure sensitive chamber into a first pressure chamber and a second pressure chamber. The pressure at the first pressure monitoring point located on the high pressure side is introduced into the first pressure chamber, the pressure at the second pressure monitoring point located on the low pressure side is introduced into the second pressure chamber, The displacement of the pressure-sensitive member based on the pressure difference fluctuation between the two pressure chambers is to cancel the pressure difference fluctuation. In which discharge capacity of the variable displacement compressor is reflected in the positioning of the valve body so as to be changed.

JP 2002-89442 A

However, since the control valve described in the above publication has four refrigerant ports, the configuration of both the variable capacity compressor and the control valve is complicated, and further development of a control valve with a simple configuration has been desired. .
Accordingly, an object of the present invention is to provide a control valve for a variable displacement compressor that has a simple configuration and can quickly reflect the fluctuation in the differential pressure between the discharge side refrigerant pressure and the crank chamber refrigerant pressure in the valve opening. There is to do.

In order to achieve the above problems, the following measures were taken. That is,
The control valve of the variable displacement compressor according to claim 1 is a control valve for a variable displacement compressor that constitutes a refrigerant circulation circuit and can change a discharge capacity based on a pressure difference between the discharge chamber and the crank chamber. A pressure-sensitive part housing chamber 52 defined in the main body housing 51 so as to form a part of an air supply flow path connecting the discharge chamber 4 and the crank chamber 12 of the refrigerant circulation circuit, and the pressure-sensitive part housing chamber 52 And an air supply valve body 65 capable of adjusting the opening degree of the air supply flow path according to the position in the pressure sensing portion housing chamber 52, and partitioned in the pressure sensing portion housing chamber 52. A pressure sensing chamber 64; and a bellows 62 that is disposed in the pressure sensing chamber 64 and divides the pressure sensing chamber 64 into a high pressure chamber 64a and a low pressure chamber 64b together with the air supply valve body 65; Is introduced into the high pressure chamber 64a and the crank chamber is cooled. The pressure Pc is introduced into the low pressure chamber 64b, and the displacement of the bellows 62 based on the pressure difference variation between the high pressure chamber 64a and the low pressure chamber 64b causes the discharge capacity of the variable displacement compressor to be on the side that cancels the pressure difference variation. It is reflected in the positioning of the air supply valve body 65 so as to be changed, and the air supply valve body 65 is formed with a throttle channel 66 through which refrigerant can flow from the high pressure chamber 64a to the low pressure chamber 64b. With this feature, the pressure in the crank chamber is adjusted by control for adjusting the opening of the air supply passage.

The control valve for a variable displacement compressor according to claim 2 is the control valve for a variable displacement compressor according to claim 1, wherein the force applied to the bellows 62 can be changed by external control. further comprising external control means capable of changing a serving as a reference set pressure differential positioning operation of the air supply valve body 65 is characterized by, by such features, have been capable of changing the set differential pressure by the external control means, the Compared to a control valve that does not have an external control means, in other words, that can have only a single set differential pressure, finer air conditioning control is possible.

Control valve variable displacement compressor according to claim 3, in the control valve of the variable displacement compressor according to claim 2, wherein the external control unit, by electrical control from the outside forces applied to the bellows 62 It is characterized by comprising a changeable electromagnetic drive unit, and this feature limits the preferred configuration of the external control means.

The control valve of the variable capacity compressor according to claim 4 is the control valve of the variable capacity compressor according to any one of claims 1 to 3 , wherein the inlet of the throttle channel 66 opens into the high pressure chamber 64a, outlet is characterized by being formed by an opening in the low-pressure chamber 64b, by such features are both simplified refrigerant passage configuration, the variable displacement compressor in a control valve.
In the description of the above-described constituent elements, reference numerals are attached to clarify the correspondence with the following embodiments, but the present invention is not limited to this.

  According to the present invention, there is provided a control valve for a variable displacement compressor that has a simple configuration and can quickly reflect a variation in differential pressure between a discharge side refrigerant pressure and a crankcase refrigerant pressure in a valve opening degree. Can do. In addition, since the present invention has two refrigerant ports communicating with the variable capacity compressor, the configuration of both the control valve and the variable capacity compressor can be simplified.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a control valve used in the variable displacement compressor of the present embodiment, FIG. 2 is a schematic explanatory view of the variable displacement compressor, and FIG. 3 is a state in which the control valve is disposed in the variable displacement compressor. It is a longitudinal cross-sectional view of the control valve. In the following description, upper, lower, left, and right expressions are used. However, this is for convenience of explanation on the drawings, and the actual positional relationship is not limited to this.

First, a variable displacement compressor to which the control valve of the embodiment is applied will be described. In FIG. 2, reference numeral 20 denotes a swash plate type variable capacity compressor, which is used, for example, in an air conditioning refrigeration cycle of an automobile. As the refrigerant, chlorofluorocarbon is used, but the refrigerant may be applied to a refrigeration cycle using carbon dioxide as a refrigerant, and the kind of the refrigerant is not limited. The variable capacity compressor 20 is supported by a front housing 5 and a rear housing 6 integrated with the front housing 5.
In FIG. 2, reference numeral 11 denotes a rotating shaft disposed in an airtight crank chamber 12 (pressure regulating chamber), which is connected to a pulley 13 that is rotationally driven by a driving belt 13a directly connected to the engine. As the rotary shaft 11 rotates, the swing plate 14 disposed in the crank chamber 12 is tilted with respect to the rotary shaft 11 and swings. A piston 17 is disposed in a reciprocating manner in a cylinder 15 disposed in the periphery of the crank chamber 12, and the piston 17 and the swing plate 14 are connected by a rod 18.

  As a result, when the swing plate 14 rotates and swings, the piston 17 reciprocates in the cylinder 15, and a low-pressure (suction refrigerant pressure) refrigerant is sucked into the cylinder 15 from the suction chamber 3. 15 is compressed to a high pressure (discharge refrigerant pressure Pd), and the refrigerant is discharged from the discharge chamber 4. Refrigerant is fed into the suction chamber 3 from the upstream evaporator 30 side via the suction pipe 1, and from the discharge chamber 4 to the downstream condenser 40 side via the discharge pipe 2, the high pressure. The refrigerant is sent out.

  The inclination angle of the swing plate 14 changes depending on the refrigerant pressure in the crank chamber 12 (crank chamber refrigerant pressure Pc), and the stroke length of the piston 17 changes depending on the inclination angle of the swing plate 14. The refrigerant discharge amount (that is, the compression capacity) changes. The amount of discharge is often when the oscillating plate 14 is inclined as indicated by the solid line, and is small when it is not inclined as indicated by the two-dot chain line. When the swing plate 14 is perpendicular to the rotating shaft 11, the discharge amount becomes zero. However, as the swing plate 14 gradually shifts to a state without inclination (a state approaching a two-dot chain line), the minimum flow rate holding spring 19 that is mounted around the rotating shaft 11 is gradually compressed by the swing plate 14. .

  As a result, the reaction force from the minimum flow rate holding spring 19 to the swing plate 14 gradually increases, and the swing plate 14 does not reach the direction perpendicular to the rotary shaft 11, and the discharge amount is the maximum discharge amount. For example, it does not become less than about 3 to 5%.

  Next, the control valve 100 applied to the variable displacement compressor 20 will be described in detail. A control valve 100 shown in FIGS. 1 and 3 is provided on the rear housing 6 side of the variable displacement compressor 20 shown in FIG. 2, and in the control valve space 8 formed in the rear housing 6, an O-ring s1, Arranged in a state where airtightness is maintained via s2.

  As shown in FIG. 1, the control valve 100 is formed by a main body portion 50, a solenoid exciting portion 70 for performing variable compression capacity control by controlling the refrigerant pressure Pc in the crank chamber 12, and a pressure sensitive portion 61. The solenoid excitation unit 70 is disposed below the control valve 100, and the pressure sensing unit 61 is disposed inside the main body 50.

  As shown in FIG. 1, the main body housing 51 that constitutes the main body 50 is a cylindrical body that is long in the vertical direction, and has a hole in the shaft core, that is, an upper large-diameter hole 52a and a small-diameter hole. A pressure-sensitive part housing chamber 52 comprising 52 b and a lower spring chamber 55 are formed in communication with each other, and a crank chamber communication port 54 is formed in a side portion of the spring chamber 55.

  In addition, a bellows receiving ring 63 is fitted to the bottom of the pressure sensing part housing chamber 52, and the pressure sensing part housing 60 holds the O-ring s3 so as to contact the upper surface of the bellows receiving ring 63. Are fitted and mounted. The lower surface of the bellows receiving ring 63 is supported by a receiving step 53 formed in the main body housing 51.

  The pressure-sensitive part housing 60 includes a cylindrical part 60 a and an upper bottom part 60 b, and a lower end part of the cylindrical part 60 a abuts on the bellows receiving ring 63 and is fitted to an inner wall of the main body housing 51. Further, a discharge refrigerant port 60c is bored in the center of the upper bottom 60b, and the discharge refrigerant port 60c communicates with the discharge pipe communication passage 10 as shown in FIG.

  A pressure sensitive chamber 64 having a predetermined length is formed in the pressure sensitive portion housing chamber 52 in the vertical direction. A cylindrical bellows 62 as a whole is disposed in the pressure sensing chamber 64, and a lower portion of the bellows 62 is fixed and supported in an airtight manner on the bellows receiving ring 63, and an upper portion thereof is a circumference of the air supply valve body 65. Fixed to the part in an airtight state. The inside of the bellows 62 communicates with the lower spring chamber 55 as a low pressure chamber 64b, and the outside of the bellows 62 communicates with the discharge refrigerant port 60c as a high pressure chamber 64a. That is, the length (vertical height) of the bellows 62 is determined by the differential pressure between the refrigerant pressure (Pd) acting on the high pressure chamber 64a and the refrigerant pressure (Pc) acting on the low pressure chamber 64b.

The air supply valve body 65 hermetically sealed and fixed to the upper end portion of the bellows 62 is disposed such that the upper portion thereof is separated from and in contact with the air supply valve seat portion 60d formed on the upper bottom portion 60b. That is, when the bellows 62 provided at the lower portion of the air supply valve body 65 extends, the air supply valve body 65 contacts the air supply valve seat portion 60d and closes. When the bellows 62 is reduced, the air supply valve body 65 is separated from the air supply valve seat portion 60d by that amount according to the degree of reduction of the bellows 62. The air supply valve body 65 is formed with a throttle channel 66 for communicating the high pressure chamber 64a and the low pressure chamber 64b.
The flow path of the throttle channel 66 has a small cross-sectional area, and the refrigerant gradually flows from the high pressure chamber 64a to the low pressure chamber 64b. The refrigerant in the low pressure chamber 64b passes through the spring chamber 55 and the crank chamber communication port 54. 2 and 3, it flows into the crank chamber communication passage 9.

  A shaft 80 is attached to the lower part of the air supply valve body 65. The shaft 80 is made of a rod-like body having a circular cross section and a different diameter, and has a narrow diameter portion (upper end portion) 83 attached to the lower portion of the air supply valve body 65, a low pressure chamber 64b, A small-diameter portion 82 located in the spring chamber 55, an attractor sliding contact portion 85 that is continuous to the small-diameter portion 82 and supported by sliding contact with a large-diameter suction member 76, and a plunger coupling portion that is coupled to a plunger 74 described later. 84. Further, a spring receiving step portion 81 is formed between the small diameter portion 82 and the attractor sliding contact portion 85, and a valve opening spring 86 is provided between the spring receiving step portion 81 and the lower surface of the bellows receiving ring 63. Is retracted, and the shaft 80 is repelled downward, that is, the air supply valve body 65 is repelled in the valve opening direction.

A valve opening spring 86 is provided between the shaft 80 and the suction element 76 to urge the plunger 74 in a direction away from the suction element 76 side.
The solenoid excitation unit 70 as an electromagnetic drive unit includes a solenoid housing 71 mounted on the lower portion of the main body housing 51. The solenoid housing 71 moves in the vertical direction by the solenoid 73 and the excitation of the solenoid 73. The plunger chamber 72 having the plunger 74 disposed therein and the plunger 76 disposed therein communicates with the crank chamber communication port 54 provided in the main body housing 51. In addition, a lead wire 91 that can supply an excitation current controlled by a control unit (not shown) is connected to the solenoid 73 via a coil assembly 90.

Next, the operation of the control valve 100 will be described together with the operation of the variable displacement compressor 20. When the variable displacement compressor 20 is in an operating state and the energization of the solenoid exciting unit 70 is off, the supply valve body 65 is in a “fully open” state as shown in FIG. Therefore, in this state, the refrigerant pressure control of the crank chamber refrigerant pressure Pc accompanying the fluctuation of the discharged refrigerant pressure Pd is not performed.
After energization from the lead wire 91 to the solenoid excitation unit 70 and the start of control, the attractor 76 is magnetized according to the energization amount, the plunger 74 is attracted by the attractor 76, and the shaft 80 moves up a predetermined length. The air supply valve body 65 changes from “fully open” to “open”.

  Then, when the value of the energization current to the solenoid 73 is changed to change the magnetic force of the attractor 76, the crank chamber refrigerant pressure Pc changes accordingly, thereby changing the compression capacity (discharge amount) and the crank chamber. The refrigerant pressure Pc is kept constant at different levels.

  That is, when the electromagnetic force of the solenoid exciting portion 70 is reduced, the plunger 74 is moved downward by a predetermined amount by the valve opening spring 86, so that the air supply valve body 65 is moved downward via the shaft 80 (further, "open"). 2) As a result, as shown in FIGS. 2 and 3, the high-pressure refrigerant (discharge refrigerant pressure Pd) flowing into the discharge refrigerant port 60c is between the supply valve seat portion 60d and the supply valve body 65, the high-pressure chamber 64a, the throttle The refrigerant flow rate of the refrigerant flowing to the crank chamber 12 through the transverse flow path 66a and the throttle vertical flow path 66b, the low pressure chamber 64b, the spring chamber 55, the crank chamber communication port 54, and the crank chamber communication passage 9 is increased. The pressure Pc rises quickly, and the swing plate 14 approaches a direction perpendicular to the rotating shaft 11, so that the refrigerant discharge amount decreases rapidly.

  On the contrary, when the electromagnetic force of the control valve 100 is increased, the plunger 74 is moved up by a predetermined amount by the suction force of the suction element 76, the shaft 80 is moved up, and the air supply valve body 65 is moved up (one layer “close” As a result, the refrigerant flow rate from the discharge refrigerant port 60c to the crank chamber decreases, the crank chamber refrigerant pressure Pc rapidly decreases, and the inclination angle of the swing plate 14 with respect to the rotating shaft 11 becomes small, so that the refrigerant flow is reduced. The discharge amount increases quickly.

  In addition, control of the energization current value to the solenoid 73 is performed by inputting detection signals from a plurality of sensors for detecting various conditions such as an engine, a temperature inside and outside the vehicle, an evaporator sensor, and the like to a control unit incorporating a CPU and the like. Then, a control signal based on the calculation result is sent from the control unit to the solenoid 73 and performed. The drive circuit of the solenoid 73 is not shown.

  When the energization of the solenoid 73 is stopped, the supply valve body 65 is separated from the supply valve seat portion 60d and is fully opened by the urging force of the valve opening spring 86 that urges the shaft 80.

  In a state where the current value is constant and the electromagnetic force of the solenoid exciting unit 70 is constant (control state), the air supply valve body 65 has a refrigerant discharged in addition to the downward spring force (valve opening direction) by the valve opening spring 86. A downward refrigerant pressure acts from the port 60c (discharge refrigerant pressure Pd), the crank chamber refrigerant pressure Pc acts on the lower surface of the supply valve body 65, and the crank chamber refrigerant pressure Pc acting on the plunger 74 passes through the shaft 80. An upward (valve closing direction) refrigerant pressure acts, and the bellows 62 has a pressure lower than the discharge refrigerant pressure Pd from the high pressure chamber 64a (an intermediate pressure between the discharge refrigerant pressure Pd and the crank chamber refrigerant pressure Pc). A reducing force due to a differential pressure between the refrigerant pressure and the crank chamber pressure Pc on the low pressure chamber 64b side, that is, a downward force acts.

Both of these forces are due to the pressure difference (Pd−Pc) between the discharge refrigerant pressure Pd and the crank chamber refrigerant pressure Pc. The crank chamber refrigerant pressure Pc is quickly adjusted.
Although the control valve according to the present embodiment has been developed for a variable displacement compressor, it goes without saying that the control valve can be used as another flow control valve.

FIG. 2 is a longitudinal sectional view of a control valve used in the variable capacity compressor according to the first embodiment. Schematic explanatory drawing of the variable capacity compressor. The longitudinal cross-sectional view of the control valve of the state arrange | positioned in the variable displacement compressor.

Explanation of symbols

Pd .. Discharge refrigerant pressure, Pc .. Crank chamber refrigerant pressure,
1 ··· suction pipe, 1a · · · branch pipe, 2 · · discharge pipe, 3 · · suction chamber,
4 .... Discharge chamber, 5 .... Front housing, 6 .... Rear housing,
8 .... Control valve space, 9 .... Crank chamber communication passage, 10 .... Discharge pipe communication passage,
11..Rotating shaft, 12 .... Crank chamber,
13 .... Pulley, 13a ... Drive belt, 14 .... Oscillating plate,
15 ·· cylinder, 17 · · piston, 18 · · rod,
19 .... Minimum flow rate retaining spring, 20 .... Variable capacity compressor, 30 ... Evaporator,

40 ... Condenser, 50 ... Main body, 51 ... Main body housing,
52..Pressure-sensitive part housing chamber, 52a..large diameter hole part, 52b..small diameter hole part,
53 .. Receiving step part, 54 .. Crank chamber communication port, 55 .. Spring chamber,
60..Pressure sensitive housing, 60a..Cylinder, 60b..Upper bottom,
60c ··· Discharge refrigerant port, 60d · · Supply valve seat portion, 61 · · Pressure sensing portion,
62 ... Bellows, 63 ... Bellows ring,
64..Pressure sensitive chamber, 64a..High pressure chamber, 64b..Low pressure chamber,
65 ... Air supply valve body, 66 ... Throttle flow path,
66a .. Restriction horizontal flow path, 66b .. Restriction vertical flow path,

70 .. Solenoid excitation part, 71 .. Solenoid housing,
72-Plunger chamber, 73-Solenoid, 74-Plunger,
75 .. Solenoid support cylinder, 76 .. Suction element,
80 .. Shaft, 81 .. Spring receiving step part, 82 .. Small diameter part,
83 ..Small diameter part, 84 ..plunger connecting part, 85 ..slider sliding contact part,
86..Valve opening spring, 90..Coil assembly, 91..Lead wire,
100 ・ ・ Control valve (for variable capacity compressor)

Claims (4)

A control valve for a variable displacement compressor that constitutes a refrigerant circulation circuit and can change a discharge capacity based on a pressure difference between a discharge chamber and a crank chamber,
A pressure-sensitive part housing chamber defined in a main body housing constituting a part of an air supply flow path connecting the discharge chamber of the refrigerant circulation circuit and the crank chamber, and is housed displaceably in the pressure-sensitive part housing chamber. and air supply valve body adjustable the degree of opening of the inlet channel, depending on the position of the pressure portion housing chamber, a pressure sensitive chamber which is divided into the pressure sensing housing chamber, wherein disposed in said sensitive pressure chamber And a bellows that divides the pressure sensitive chamber into a high pressure chamber and a low pressure chamber together with an air supply valve body , the discharge refrigerant pressure is introduced into the high pressure chamber, and the crank chamber refrigerant pressure is introduced into the low pressure chamber. The displacement of the bellows based on the pressure difference between the low pressure chamber and the low pressure chamber is reflected in the positioning of the air supply valve body so that the discharge capacity of the variable displacement compressor is changed to cancel the pressure difference fluctuation. , wherein the air supply valve body, the low pressure chamber from the high pressure chamber Control valve variable displacement compressor, wherein the refrigerant can flow throttle flow paths are formed. Can change the force applied to the bellows by an external control, billing, characterized in that it comprises an external control means capable of changing a serving as a reference set pressure differential positioning operation of the air supply valve body by the bellows Item 5. A control valve for a variable displacement compressor according to Item 1. The external control unit, a control valve variable displacement compressor according to claim 2, characterized in that comprises a solenoid actuator capable of changing the force applied to the bellows by electrical control from the outside. The inlet of the throttle channel is open to the high pressure chamber, the outlet control variable displacement compressor according to any one of claims 1 to 3, characterized in that it is formed open to the low-pressure chamber valve.

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