JP2013160143A - Variable displacement compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive variable displacement compressor, by simplifying a structure of an installation part of a control valve for the variable displacement compressor.SOLUTION: A control valve 23 for a variable displacement compressor is stored in a room 25 of a cylinder head 19, and is fixed to a valve plate 26 by a nut 28 from the side of a cylinder block 15, and a refrigerant inlet 32 is opened in a room 24 communicating with a crank case. The valve plate 26 has the function of a partition wall for separating the crank case and a suction chamber, so that a seal member is obviated. Since a main part of the control valve 23 for the variable displacement compressor is positioned in the room 25 of the cylinder head 19, there is no need to form a complicated shape groove for communicating with the suction chamber 20 of the cylinder head 19 in the cylinder block 15. Thus, cost of the variable displacement compressor 1 can be reduced.

Description

  The present invention relates to a variable capacity compressor, and more particularly, to a variable capacity compressor that constitutes a refrigeration cycle of an automotive air conditioner and includes a control valve for a variable capacity compressor that controls the discharge capacity of a refrigerant.

  Since the compressor used for compressing the refrigerant in the refrigeration cycle of the air conditioner for automobiles uses the engine as a drive source, the rotational speed control cannot be performed. Therefore, in order to obtain an appropriate cooling capacity without being restricted by the engine speed, the variable compression capacity of the refrigerant can be changed according to the engine speed so that the discharge capacity of the refrigerant does not change. A capacity compressor is used.

  In such a variable capacity compressor, a compression piston is connected to a swing plate that is tiltably attached to a rotating shaft driven by an engine, and the stroke of the compression piston is changed by changing the angle of the swing plate. The compression capacity of the refrigerant is changed.

  The angle of the oscillating plate is continuously changed by introducing a part of the compressed refrigerant into the sealed crank chamber, changing the pressure in the crank chamber, and changing the balance of pressure applied to both sides of the compression piston. Can be changed to

  The pressure in the crank chamber is introduced into the crank chamber from the discharge chamber by providing a control valve for the variable displacement compressor between the discharge chamber and the crank chamber of the variable displacement compressor or between the crank chamber and the suction chamber. It is adjusted by changing the flow rate of the refrigerant led out to the suction chamber.

  A control valve that is provided between the crank chamber and the suction chamber of the variable capacity compressor and controls the flow rate of the refrigerant that is led out from the crank chamber to the suction chamber is known as a control valve for a variable displacement compressor that is controlled to be removed. (For example, refer to Patent Document 1). According to the variable displacement compressor described in Patent Document 1, a chamber is formed coaxially with the rotation shaft in the cylinder block in which the bearing of the rotation shaft is installed, and the control for the variable displacement compressor is formed in the chamber. A valve is installed. In this chamber, the bearing side of the rotating shaft communicates with the crank chamber, and the opposite side communicates with a suction chamber formed in the cylinder head. When installing the control valve for the variable capacity compressor in the room, an O-ring is provided around the body of the control valve for the variable capacity compressor so that a gap between the control valve for the variable capacity compressor and the inner wall of the room is provided. The crank chamber on the refrigerant inlet side is isolated from the suction chamber on the refrigerant outlet side. Further, the control valve for the variable capacity compressor has a guide cylinder portion extending through a valve plate disposed between the cylinder block and the cylinder head and screwed on the outer peripheral surface thereof. The nut is screwed into the guide tube portion to be fixed to the valve plate.

Japanese Patent No. 3088527

  However, the conventional variable displacement compressor control valve mounting structure has a problem that the cost increases because an O-ring is provided and sealed on the outer periphery between the refrigerant inlet and the refrigerant outlet. Also, the cylinder block that houses the control valve for the variable capacity compressor has a groove formed in the surface covered with the valve plate, and a passage is formed from the refrigerant outlet to the suction chamber formed in the cylinder head. The shape of the cylinder block was complicated.

  The present invention has been made in view of these points, and an object thereof is to provide a low-cost variable capacity compressor.

  In the present invention, in order to solve the above problems, in a variable capacity compressor having a control valve for a variable capacity compressor that is attached to a portion communicating with a crank chamber and a suction chamber and controls the pressure of the crank chamber, A first chamber formed and communicating with the crank chamber; a second chamber formed in a cylinder head at a position corresponding to the first chamber and communicating with the suction chamber; the cylinder block and the cylinder head A valve plate that is sandwiched between the first chamber and the second chamber, a refrigerant inlet is located in the first chamber, and a refrigerant outlet is located in the second chamber. There is provided a variable capacity compressor comprising the control valve for a variable capacity compressor attached to a valve plate.

  According to such a variable capacity compressor, the valve plate functions as a partition for fixing the control valve for the variable capacity compressor and sealing between the crank chamber and the suction chamber. The mounting structure can be made simple.

  In the variable capacity compressor having the above configuration, the valve plate is used as a partition wall that seals between the refrigerant inlet and the refrigerant outlet of the control valve for the variable capacity compressor. There is an advantage that a compressor can be provided.

  In addition, since the cylinder block only needs to form a chamber for accommodating the control valve for the variable displacement compressor, the shape of the cylinder block can be simplified, and a low-cost variable displacement compressor is provided. Can do.

It is a system block diagram which shows the refrigerating cycle of the air conditioner for motor vehicles. It is a fragmentary sectional view of the variable capacity compressor which shows the principal part of the mounting structure of the control valve for variable capacity compressors.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system configuration diagram showing a refrigeration cycle of an automotive air conditioner.
The refrigeration cycle of the automotive air conditioner includes a variable capacity compressor 1, a condenser 2, a receiver 3, an expansion valve 4, and an evaporator 5. The variable capacity compressor 1 compresses the refrigerant and discharges it as a high-temperature and high-pressure refrigerant. The condenser 2 condenses by exchanging heat of the high temperature / high pressure refrigerant with the outside air. The receiver 3 stores the condensed refrigerant and sends out the liquid refrigerant that has been gas-liquid separated. The expansion valve 4 expands the liquid refrigerant into a low temperature / low pressure vapor refrigerant. The evaporator 5 exchanges heat between the vapor refrigerant and the air in the passenger compartment, and returns the evaporated refrigerant to the variable capacity compressor 1. When the air in the passenger compartment passes through, the evaporator 5 takes heat from the air to make it cold air. The cooled air is dehumidified and sent into the passenger compartment.

  The variable capacity compressor 1 is driven by a driving force transmitted from an engine output shaft to a pulley 11 via a belt, and drives a shaft 13 that is a rotating shaft disposed across the crank chamber 12. The shaft 13 is provided with a swash plate 14 with a variable inclination angle. A plurality of cylinders 16 are formed around the axis of the shaft 13 in the cylinder block 15, and a piston 17 that converts the rotational motion of the swash plate 14 into reciprocating motion is disposed in the cylinder 16. The cylinder 16 is connected to a suction chamber 20 and a discharge chamber 21 formed in the cylinder head 19 by a reed valve 18, respectively. The discharge chamber 21 is connected to the capacitor 2, and the suction chamber 20 is connected to the evaporator 5.

  In the variable capacity compressor 1, an orifice 22 is disposed between the discharge chamber 21 and the crank chamber 12, and a control valve 23 for variable capacity compressor is disposed between the crank chamber 12 and the suction chamber 20. ing. The orifice 22 reduces the discharge pressure Pd of the discharge chamber 21 and sends it to the crank chamber 12. The variable capacity compressor control valve 23 controls the flow rate of the refrigerant extracted from the crank chamber 12 and sent to the suction chamber 20, and the crank chamber 12 has a predetermined value so that the suction pressure Ps of the suction chamber 20 becomes a predetermined value. The crank chamber pressure Pc is controlled. The orifice 22 is provided by forming a throttle part or installing a capillary tube in the cylinder block 15 of the variable capacity compressor 1. The variable capacity compressor control valve 23 is mounted in a chamber 24 formed on the cylinder block 15 on the refrigerant inlet side, and mounted in a chamber 25 formed on the cylinder head 19 on the refrigerant outlet side.

FIG. 2 is a partial cross-sectional view of the variable capacity compressor showing the main part of the mounting structure of the control valve for the variable capacity compressor.
In the variable capacity compressor 1, the cylinder block 15 and the cylinder head 19 are assembled in a state where the valve plate 26 is sandwiched. The cylinder block 15 has, for example, a chamber 24 formed on the axis of the shaft 13 adjacent to the installation position of the bearing of the shaft 13, and the chamber 24 communicates with the crank chamber 12. The cylinder head 19 has a chamber 25 at a position corresponding to the chamber 24 of the cylinder block 15, and the chamber 25 is provided for each of the inlet for introducing the refrigerant into the variable capacity compressor 1 and all the cylinders 16. Communicated with the suction chamber 20 formed. The chamber 24 of the cylinder block 15 communicates with the chamber 25 of the cylinder head 19 via an opening 27 formed in the valve plate 26.

  The variable displacement compressor control valve 23 is disposed in the chamber 24 of the cylinder block 15 and the chamber 25 of the cylinder head 19 through the valve plate 26, and is fixed to the valve plate 26 by nuts 28.

  The control valve 23 for the variable capacity compressor has a valve portion 29 that controls the flow rate of the refrigerant flowing from the crank chamber 12 to the suction chamber 20 and a power that detects the suction pressure Ps of the suction chamber 20 and controls the opening degree of the valve portion. Element 30.

  The valve portion 29 has a cylindrical body 31, and a portion opened into the chamber 24 constitutes a refrigerant inlet 32 for introducing a refrigerant having a crank chamber pressure Pc, and is formed on an end surface on the power element 30 side. The valve seat 33 is formed. The valve portion 29 also has a valve body 34 that is disposed in proximity to or away from the valve seat 33. The valve body 34 has a cup shape, and the end surface on the opening side is disposed to face the valve seat 33 and is urged away from the valve seat 33. In the valve portion 29, a screw thread that is screwed with the nut 28 is formed on the outer periphery of the body 31 on the refrigerant inlet 32 side, and a screw thread that is screwed with the power element 30 is also formed on the outer periphery of the valve seat 33 side. Has been.

  The power element 30 includes housings 35 and 36 and a diaphragm 37 serving as a pressure-sensitive member, and is formed by joining these outer peripheral edges to each other. The housing 35 and the diaphragm 37 form a vacuum chamber, and urging means for pushing the diaphragm 37 from the inside is accommodated therein. The housing 36 has a cylindrical connecting portion formed at the center, and the cylindrical connecting portion is connected to the valve portion 29 by screwing into the body 31 of the valve portion 29. The housing 36 is also provided with a plurality of refrigerant outlets 38, and sends out the refrigerant whose flow rate is controlled by the valve portion 29 to the suction chamber 20. The diaphragm 37 is brought into contact with the central portion thereof by urging the valve body 34 of the valve portion 29 away from the valve seat 33. As a result, the lift amount from the valve seat 33 of the valve body 34 is changed according to the displacement amount of the diaphragm 37 that changes depending on the suction pressure Ps.

  Before assembling the variable displacement compressor 1, the variable displacement compressor control valve 23 passes the body 31 through the opening 27 of the valve plate 26 that partitions the chamber 24 and the chamber 25, and fastens the nut 28 to the body 31. As a result, the valve plate 26 is fixed. At this time, the step portion of the housing 36 and the nut 28 are pressed against the valve plate 26, so that the space between the chamber 24 and the chamber 25 is tightly sealed. When tightening with the nut 28, the variable displacement compressor control valve 23 is fixed to the valve plate 26 with the reed valve seat and the packing forming the reed valve 18 on the suction side and the discharge side being sandwiched together. Yes.

  In the variable capacity compressor 1, the main part including the valve part 29 of the variable capacity compressor control valve 23 and the diaphragm 37 is arranged in the chamber 25 of the cylinder head 19, and the variable capacity compressor control is provided on the valve plate 26. The valve 23 was fixed. As a result, the valve plate 26 functions as a partition wall that naturally separates the refrigerant inlet 32 side and the refrigerant outlet 38 side, so that an O-ring for sealing between the refrigerant inlet 32 and the refrigerant outlet 38 is unnecessary. Thus, the cost of the variable capacity compressor 1 can be reduced. Further, since the power element 30 is accommodated in the chamber 25 of the suction pressure Ps, the cylinder block 15 does not need to form a complicatedly shaped groove for communicating with the suction chamber 20 of the cylinder head 19, so that the variable capacity. The cost of the compressor 1 can be further reduced.

  According to the variable displacement compressor 1 having the above-described configuration, the control valve 23 for the variable displacement compressor has a constant suction pressure Ps when the power element 30 monitors the suction pressure Ps and the suction pressure Ps varies. The opening degree of the valve part 29 is controlled to become. For example, it is assumed that the engine speed increases, the refrigerant discharge capacity increases, and the suction pressure Ps fluctuates in a decreasing direction. At this time, the diaphragm 37 is displaced toward the valve portion 29, and accordingly, the valve body 34 moves in a direction approaching the valve seat 33. As a result, the flow rate of the refrigerant drawn from the crank chamber 12 to the suction chamber 20 is smaller than the refrigerant supplied from the discharge chamber 21 to the crank chamber 12, so that the crank chamber pressure Pc rises and the swash plate 14 moves to the shaft 13. It moves in the direction perpendicular to the rotation axis. Then, the variable capacity compressor 1 is controlled so that the compression capacity is reduced by reducing the stroke of the piston 17 and the refrigerant discharge capacity is restored. Conversely, when the engine speed decreases and the refrigerant discharge capacity decreases and the suction pressure Ps fluctuates in the direction of increasing, the variable capacity compressor control valve 23 decreases the crank chamber pressure Pc. Thus, the refrigerant discharge capacity is controlled to be restored.

DESCRIPTION OF SYMBOLS 1 Variable capacity compressor 2 Capacitor 3 Receiver 4 Expansion valve 5 Evaporator 11 Pulley 12 Crank chamber 13 Shaft 14 Swash plate 15 Cylinder block 16 Cylinder 17 Piston 18 Lead valve 19 Cylinder head 20 Suction chamber 21 Discharge chamber 22 Orifice 23 Variable capacity compressor Control valve 24, 25 chamber 26 valve plate 27 opening 28 nut 29 valve 30 power element 31 body 32 refrigerant inlet 33 valve seat 34 valve body 35, 36 housing 37 diaphragm 38 refrigerant outlet

Claims (4)

In a variable capacity compressor having a control valve for a variable capacity compressor that is attached to a portion communicating with a crank chamber and a suction chamber and controls the pressure of the crank chamber,
A first chamber formed in a cylinder block and communicating with the crank chamber;
A second chamber formed in a cylinder head at a position corresponding to the first chamber and communicating with the suction chamber;
A valve plate that is sandwiched between the cylinder block and the cylinder head to separate the first chamber and the second chamber;
The control valve for the variable displacement compressor attached to the valve plate such that a refrigerant inlet is located in the first chamber and a refrigerant outlet is located in the second chamber;
A variable capacity compressor characterized by comprising:   In the control valve for the variable capacity compressor, a valve portion for controlling the flow rate of the refrigerant flowing from the crank chamber to the suction chamber and a pressure sensitive member for detecting the suction pressure of the suction chamber are installed in the second chamber. The variable capacity compressor according to claim 1, wherein the variable capacity compressor is provided.   The variable capacity compressor according to claim 1, wherein the first chamber is formed on an axis of the shaft adjacent to an installation position of a shaft bearing of the variable capacity compressor. The variable displacement compressor control valve has a valve portion having a cylindrical body having the refrigerant inlet on one end side and a valve seat and a valve body on the other end side, and the other end side of the valve portion A power element coupled to the body and controlling the opening of the valve portion according to the suction pressure of the suction chamber and having the refrigerant outlet,
The body is disposed through an opening provided in the valve plate, the valve plate is sandwiched between a housing of the power element and a nut screwed into the body, and tightened by the nut for the variable capacity compressor. 2. The variable capacity compressor according to claim 1, wherein a control valve is attached to the valve plate.

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