JP5164679B2 - Variable capacity compressor - Google Patents

Description

  The present invention relates to a swash plate type variable capacity compressor, and more particularly to a variable capacity compressor suitable for use in a vehicle air conditioner or the like with improved swash plate tilt restriction and change mechanisms.

  In a swash plate type variable displacement compressor in which the piston stroke is changed by changing the tilt angle of the swash plate to change the capacity, the swash plate is required to ensure smooth operation near the minimum tilt angle of the swash plate. There is known a structure provided with a minimum inclination defining means (for example, a minimum inclination defining stopper) for defining the minimum inclination angle and an urging means (for example, an inclination increasing spring) for urging the swash plate in the direction of increasing the inclination from the minimum inclination position. (For example, Patent Document 1).

However, in the structure disclosed in Patent Document 1, an inclination increasing spring (coil spring + curved spring) for urging the swash plate in the inclination increasing direction and a minimum inclination defining means (stopper) for defining the minimum inclination of the swash plate. Are composed of parts different from each other, and thus have the following problems.
(1) The structure of this part is relatively complicated, the assembly becomes complicated, and it becomes a factor of productivity deterioration.
(2) Since the tilt increasing spring and the minimum tilt defining means have dimensional tolerances, if the biasing force of the tilt increasing spring increases with respect to the minimum tilt, and if the biasing force is reduced, the tilt is reduced from the minimum tilt. There is a risk that problems such as a delay in capacity recovery due to the increase will occur.
JP 2001-304107 A

  Therefore, the object of the present invention is to focus on the above-mentioned problems in the prior art, and can define the minimum inclination angle of the swash plate with a simple structure, and there is little variation in the urging force of the urging means in the inclination increasing direction. The object is to provide a variable capacity compressor.

  In order to solve the above problems, a variable capacity compressor according to the present invention includes a housing in which a discharge chamber, a suction chamber, a crank chamber, and a cylinder bore are defined, a piston disposed in the cylinder bore, A drive shaft rotatably supported in the housing; and a conversion mechanism including a variable tilt swash plate that converts the rotation of the drive shaft into a reciprocating motion of the piston, and the pressure between the crank chamber and the suction chamber In a variable capacity compressor that adjusts the piston stroke by changing the difference to compress the fluid sucked into the cylinder bore from the suction chamber and discharge the compressed fluid into the discharge chamber, the mechanical minimum inclination angle of the swash plate A minimum inclination angle defining means for regulating the swash plate, an urging means for urging the swash plate in the direction of increasing the inclination angle, and a connecting means for integrally connecting the minimum inclination angle defining means and the urging means. Consisting of those characterized by being equipped with.

  In such a variable capacity compressor, since the minimum inclination defining means and the urging means are integrally connected, both the minimum inclination defining means and the urging means having different functions simply by incorporating this integrated member. Are assembled in a predetermined form in a predetermined positional relationship, and assembling becomes easy, and productivity is improved. Further, it becomes possible to adjust the biasing force of the biasing means on the basis of the minimum tilt angle defined by the minimum tilt angle defining means, and the variation in the biasing force of the biasing means can be reduced. Further, since the minimum inclination angle defining means is integrally connected to the urging means, it can also serve as a regulating means for restricting excessive deflection of the urging means, and excessive stress acts on the urging means. Can be avoided and contribute to ensuring the reliability of the urging means.

  In the variable capacity compressor according to the present invention, for example, the urging means includes a leaf spring, and the leaf spring is formed by pressing from a leaf spring forming material that forms the leaf spring. The minimum inclination angle defining means and the connecting means may be formed in the remaining part other than the leaf spring. In such a configuration, the leaf spring, the minimum tilt angle defining means, and the connecting means can be formed from a single member, which facilitates manufacture and contributes to cost reduction.

  A plurality of urging means can be provided. By using a plurality of urging means, the urging force can be easily adjusted by changing the urging number of the urging means.

  In addition, the connecting means is formed so as to surround the drive shaft, the plurality of urging means are arranged at a predetermined interval, and each tip part urges the swash plate in an inclination increasing direction, The base end portion can be configured to be integrally connected to the connecting means. In such a configuration, the connecting means is formed so as to surround the drive shaft, and a plurality of urging means can be arranged around the drive shaft at a predetermined interval, so that the swash plate can be urged in a stable form.

  If three or more urging means are provided and each urging means is arranged at equal intervals, the swash plate can be urged more stably.

  Further, a positioning structure for positioning the connecting means in the axial direction of the drive shaft may be formed on the connecting means and the drive shaft. With such a configuration, the minimum inclination angle can be more reliably defined, whereby the urging force of the urging means can be more reliably defined to a desired urging force.

  The variable capacity compressor according to the present invention is particularly suitable when the fluid to be compressed is composed of a refrigerant, and is particularly suitable as a compressor used in a vehicle air conditioner.

  According to the variable capacity compressor of the present invention, the minimum inclination defining means for defining the mechanical minimum inclination of the swash plate and the urging means for urging the swash plate in the direction of increasing the inclination are integrally connected by the connecting means. Since it is configured, the minimum inclination angle defining means and the urging means can be easily assembled with a predetermined desired positional relationship simply by incorporating an integrated member, and the minimum inclination angle of the swash plate can be easily constructed. Can be reliably set to a desired inclination angle, and variation in the urging force of the urging means in the direction of increasing the inclination angle can be suppressed, so that a variable capacity compressor having desirable performance can be realized at low cost and with simple assembly work. be able to.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a variable capacity compressor (FIG. 1A) and a capacity control valve (FIG. 1B) for controlling the capacity according to an embodiment of the present invention. In FIG. 1, a variable capacity swash plate compressor 100 as a variable capacity compressor includes a cylinder block 101 having a plurality of cylinder bores 101a, a front housing 102 provided at one end of the cylinder block 101, and a valve plate 103. And a rear housing 104 provided at the other end of the cylinder block 101.

  A drive shaft 106 is disposed across the crank chamber 105 defined by the cylinder block 101 and the front housing 102. The drive shaft 106 is inserted through the swash plate 107. The swash plate 107 is coupled to a rotor 108 fixed to the drive shaft 106 via a connecting portion 109, and is supported so as to be able to rotate together with the drive shaft 106 and to change the tilt angle with respect to the drive shaft 106. A coil spring 110 is disposed between the rotor 108 and the swash plate 107 to urge the swash plate 107 in the direction of decreasing the tilt angle. On the opposite side of the coil spring 110 across the swash plate 107, a plate spring 111 for urging the swash plate 107 in the minimum tilt state in the direction of increasing the tilt angle is disposed. As will be described later, the leaf spring 111 is a stopper as a minimum inclination defining means for defining the mechanical minimum inclination angle of the swash plate 107 and an urging means for urging the swash plate 107 in the direction of increasing the inclination. The plate spring portion is configured as a member integrally connected by a connecting portion as connecting means.

  One end of the drive shaft 106 extends to the outside of the housing through the boss portion 102a of the front housing 102, and is connected to a drive source such as a vehicle engine (not shown) via a belt or the like via a power transmission device (not shown). ing. A shaft seal device 112 is disposed between the drive shaft 106 and the boss portion 102a. The drive shaft 106 is supported in the radial direction and the thrust direction by bearings 113, 114, 115, and 116.

  A piston 117 is disposed in the cylinder bore 101a, and a pair of shoes 118 housed in a recess 117a at one end of the piston 117 sandwich the outer peripheral portion of the swash plate 107 so as to be slidable relative to each other. The rotation of the drive shaft 106 is converted into a reciprocating motion of the piston 117 via the swash plate 107 and the shoe 118.

  A suction chamber 119 and a discharge chamber 120 are formed in the rear housing 104. The suction chamber 119 communicates with the cylinder bore 101a via a suction hole 103a formed in the valve plate 103 and a suction valve (not shown), and the discharge chamber 120 includes a discharge valve (not shown) and a discharge hole 103b formed in the valve plate 103. Is communicated with the cylinder bore 101a. The suction chamber 119 is connected to an evaporator of a vehicle air conditioner (not shown) through a suction port 104a.

  Front housing 102, cylinder block 101, valve plate 103, and rear housing 104 cooperate to drive shaft 106, rotor 108, connecting portion 109, swash plate 107, shoe 118, piston 117, cylinder bore 101a, intake valve, discharge valve. A housing for accommodating a compression mechanism formed by a valve or the like is formed.

  A muffler 121 is disposed outside the cylinder block 101. The muffler 121 is formed by joining a bottomed cylindrical lid member 122 separate from the cylinder block 101 to a cylindrical wall 101b erected on the outer surface of the cylinder block 101 via a seal member. . A discharge port 122 a is formed in the lid member 122. The discharge port 122a is connected to a condenser of a vehicle air conditioner (not shown).

  A communication passage 123 that allows the muffler 121 to communicate with the discharge chamber 120 is formed across the cylinder block 101, the valve plate 103, and the rear housing 104. The muffler 121 and the communication passage 123 form a discharge passage extending between the discharge chamber 120 and the discharge port 122a, and the muffler 121 forms an expansion space arranged in the middle of the discharge passage. Yes. A check valve 200 for opening and closing the inlet of the muffler 121 is disposed in the muffler 121.

  The front housing 102, the cylinder block 101, the valve plate 103, and the rear housing 104 are adjacent to each other through a gasket (not shown), and are integrally assembled using a plurality of through bolts.

  A capacity control valve 300 is attached to the rear housing 104. The capacity control valve 300 adjusts the opening of the communication passage 124 between the discharge chamber 120 and the crank chamber 105, and controls the amount of refrigerant gas discharged into the crank chamber 105. The refrigerant gas in the crank chamber 105 is sucked through a gap between the bearings 115 and 116 and the drive shaft 106, a space 125 formed in the cylinder block 101, and an orifice hole 103 c formed in the valve plate 103. Flows into chamber 119.

  By changing the internal pressure of the crank chamber 105 by the capacity control valve 300, the discharge capacity of the variable capacity swash plate compressor 100 can be variably controlled. The capacity control valve 300 adjusts the energization amount to the built-in solenoid based on the external signal, and the internal pressure of the suction chamber 119 introduced into the pressure sensing chamber of the capacity control valve 300 via the communication path 126 becomes a predetermined value. As described above, the discharge capacity of the variable capacity swash plate compressor 100 is variably controlled, and the communication path 124 is forcibly opened by turning off the energization of the built-in solenoid. Control to a minimum. The capacity control valve 300 can optimally control the suction pressure according to the external environment.

  As shown in FIG. 2, the capacity control valve 300 is formed in the valve housing 301 and has a first pressure sensing chamber 302 communicating with the crank chamber 105 through the communication hole 301 a, and one end opened to the first pressure sensing chamber 302. The valve hole 301c having the other end opened to the valve chamber 303 communicating with the discharge chamber 120 through the communication hole 301b, one end disposed in the valve chamber 303 opens and closes the valve hole 301c, and the other end is a support hole. A cylindrical valve body 304 slidably supported by 301d and the first pressure sensing chamber 302 are disposed, and the crank chamber pressure is received through the communication hole 301a, the inside is evacuated, and a spring is disposed. A bellows assembly 305 that functions as a pressure-sensitive means, a connection portion 306 in which the bellows assembly 305 is detachably connected to one end and the other end is fixed to one end of the valve body 304, and the other end of the valve body 304 is Via the communication hole 301e And a second pressure sensing chamber 307 which communicates with the entrance 119.

  The valve housing 301 is formed with a support hole 301d that slidably supports the other end portion of the valve body 304, and the valve body 304 is supported by the support hole 301d so as to be slidable with a minute gap. The other end is blocked from the valve chamber 303.

  The displacement control valve 300 further includes a solenoid rod 304a integrally formed with the valve body 304 and having a movable iron core 308 press-fitted and fixed to an end portion separated from the valve body 304, and the solenoid rod 304a inserted therein, and the movable iron core is separated by a predetermined gap. A fixed iron core 309 disposed opposite to the 308, a spring 310 disposed between the fixed iron core 309 and the movable iron core 308 and biasing the movable iron core 308 in the valve opening direction, and the fixed iron core 309 and the movable iron core 308 are connected to each other. A cylindrical member 312 made of a non-magnetic material that is inserted and fixed to the solenoid case 311, and an electromagnetic coil 313 that surrounds the cylindrical member 312 and is accommodated in the solenoid case 311.

Regarding the operation of the capacity control valve 300, the bellows effective area Sb of the bellows assembly 305, the pressure receiving area Sv of the crank chamber 105 received from the valve hole 301 c acting on the valve body 304, and the second pressure sensing chamber 307. Since the pressure receiving area Sr of the suction pressure acting on the valve body 304 is set to substantially the same value, the force acting on the valve body 304 is expressed by the equation (1).
Ps = [− (1 / Sb) · F (i) + (F + f) / Sb] (1)
here,
Ps: suction chamber pressure Sb: bellows effective area (= pressure receiving area of crank chamber acting on valve body (Sv) = pressure receiving area of suction chamber acting on valve body (Sr))
f: biasing force F of the spring 310: bellows biasing force F (i): electromagnetic force.

  Further, in the capacity control valve 300, when the suction chamber pressure Ps is lower than the value expressed by the equation (1), the bellows 305a extends, the valve body 304 moves away from the valve seat, and the valve hole 301c is opened. 1 The pressure sensing chamber 302 and the valve chamber 303 are communicated with each other via the valve hole 301c, and the communication passage 124 between the discharge chamber 120 and the crank chamber 105 is opened. The refrigerant in the discharge chamber 120 is supplied to the crank chamber 105 through the communication path 124, the crank chamber pressure increases, the inclination angle of the swash plate 107 decreases, the discharge capacity of the variable capacity compressor 100 decreases, and the suction chamber pressure. Rises. When the suction chamber pressure is higher than the value represented by the expression (1), the bellows of the bellows assembly 305 contracts, the valve body 304 comes into contact with the valve seat, closes the valve hole 301c, and the first pressure sensing chamber 302 Communication with the valve chamber 303 via the valve hole 301 c is blocked, and the communication path 124 between the discharge chamber 120 and the crank chamber 105 is closed. The refrigerant gas in the crank chamber 105 is sucked through the gaps between the bearings 115 and 116 and the drive shaft 106, the space 125 formed in the cylinder block 101, and the orifice hole 103 c formed in the valve plate 103. It flows into the chamber 119 and the crank chamber pressure decreases, the inclination angle of the swash plate 107 increases, the discharge capacity of the compressor 100 increases, and the suction chamber pressure decreases. A pressure-sensitive mechanism constituted by the bellows assembly 305, the connecting portion 306, and the valve body 304 autonomously controls the suction chamber pressure to a value represented by the formula (1). The electromagnetic actuator composed of the solenoid rod 304a, the movable iron core 308, the fixed iron core 309, the spring 310, the solenoid case 311, the cylindrical member 312 and the electromagnetic coil 313 is operated in accordance with the current value i flowing through the electromagnetic coil 313. Change the operating point.

  In the capacity control valve 300, a control characteristic is obtained in which the suction chamber pressure decreases as the energization amount i to the electromagnetic coil 313 increases. In the capacity control valve 300, the pressure sensing mechanism and the electromagnetic actuator drive the valve body 304. Since the capacity control valve 300 has a pressure sensing mechanism, the control accuracy of the suction chamber pressure is improved, and by having an electromagnetic actuator that changes the operating point of the pressure sensing mechanism, the control current i is uniquely controlled. It becomes possible to determine the suction chamber pressure.

  Further, when the energization to the solenoid is turned off, the valve body 304 opens the valve hole 301c by the biasing force of the spring 310, and the refrigerant in the discharge chamber 120 is supplied to the crank chamber 105 through the communication passage 124, and the crank chamber pressure is increased. Increases, the inclination angle of the swash plate 107 decreases, and the discharge capacity of the variable capacity compressor 100 is minimized.

Next, the leaf spring 111 will be described with reference to FIGS.
In this embodiment, as shown in FIGS. 3 and 4, the leaf spring 111 includes three leaf spring portions 111a, three stoppers 111b, three leaf spring portions 111a and three stoppers 111b in the circumferential direction. The connection part 111c formed in the ring shape which connects 2 is integrally connected. That is, the leaf spring 111 has three leaf spring portions 111a as urging means for urging the swash plate 107 in the direction of increasing the inclination angle in the present invention, and a minimum that defines the mechanical minimum inclination angle of the swash plate 107. Three stoppers 111b as the tilt angle defining means are configured as a member integrally connected by a connecting portion 111c as a connecting means. The leaf spring 111 is formed by press molding from a leaf spring forming material (leaf spring forming plate), and a stopper 111b and a connecting portion 111c are formed on the remaining portion other than the leaf spring portion 111a. The three leaf spring portions 111a are arranged at substantially equal intervals around the drive shaft 106 so as to stably bias the swash plate 107.

  As shown in FIG. 4, the leaf spring 111 is positioned in the axial direction when the inner diameter side portion 111 d of the connecting portion 111 c is inserted into the drive shaft 106 and abuts against a step formed on the drive shaft 106, and the snap ring 150. It is fixed by. When the swash plate 107 comes into contact with the tip of the stopper 111b, the minimum inclination angle of the swash plate 107 that is mechanically regulated is defined. For example, as shown in FIG. 5, the minimum inclination angle is, for example, an angle (θmin) in the vicinity of 0 ° when the state where the surface of the swash plate 107 is orthogonal to the axis of the drive shaft 106 is 0 °. The heights of the three stoppers 111b are set aiming at.

  Further, the urging force for urging the swash plate 107 in the direction of increasing the tilt angle is applied when the distal end side of the leaf spring portion 111 a abuts the swash plate 107. Since the stopper 111b and the leaf spring portion 111a are integrally connected via the connecting portion 111c, the height (h) of the tip of the leaf spring portion 111a from the tip of the stopper 111b can be managed, and the attachment of the leaf spring portion 111a is possible. The variation of power is reduced. Since the stopper 111b also serves as a restricting means for restricting excessive bending of the leaf spring portion 111a, excessive stress does not act on the leaf spring portion 111a.

When the swash plate 107 becomes smaller than a predetermined angle θ ₁ , the swash plate 107 is sandwiched between the coil spring 110 and the plate spring 111, and the resultant force of both springs biases the swash plate 107 in the direction of increasing the tilt angle below θ ₂ as shown in FIG. When the force is applied and exceeds θ ₂ , a biasing force is applied to bias the swash plate 107 in the direction of decreasing the tilt angle. Since the urging force of the leaf spring 111 is a resultant force of the urging forces of the plurality of leaf spring portions 111a, the urging force can be adjusted by changing the number of leaf spring portions 111a.

  As described above, the leaf spring 111 has three stoppers 111b as minimum inclination defining means for defining the mechanical minimum inclination angle of the swash plate 107, and urging means for urging the swash plate 107 in the inclination increasing direction. The three plate spring portions 111a are configured as a single member integrally connected by a connecting portion 111c as a connecting means. The minimum inclination defining means and the urging means of the plate 107 can be easily assembled with a predetermined desired positional relationship, and the minimum inclination of the swash plate can be surely set to a desired inclination while having a simple structure and simple assembling work. In addition to being able to define, it is possible to suppress variation in the biasing force of the biasing means in the direction of increasing the tilt angle, and it is possible to easily and inexpensively realize a variable capacity compressor with desirable performance. It made.

  In the above embodiment, the leaf spring portion 111a is formed in the circumferential direction of the drive shaft 106, but the formation of the leaf spring portion 111a is not limited to this. For example, the leaf spring portion 111 a may be formed such that the tip portion thereof is directed toward the axis of the drive shaft 106 or may be formed in a direction away from the drive shaft 106.

  Further, a rotation blocking structure can be provided so that the leaf spring 111 does not rotate with respect to the drive shaft 106. For example, a groove may be formed in the drive shaft 106, and a part of the leaf spring 111 may be engaged with the groove.

  In the case of a structure having a swash plate support such as a sleeve or a hinge ball between the swash plate 107 and the drive shaft 106, the swash plate support may be urged by a leaf spring portion 111a. it can.

  In addition, in an oscillating plate type variable capacity compressor provided with an oscillating plate that does not rotate together with the drive shaft separately from the swash plate, the oscillating plate can be urged by a leaf spring portion 111a.

  In addition, the present invention can be applied to a variable capacity compressor or a clutchless compressor equipped with an electromagnetic clutch, or a variable capacity compressor driven by a motor, for example, a variable capacity compressor with a built-in motor. You can also

  Furthermore, in the said embodiment, although the case where the to-be-compressed fluid was a refrigerant | coolant was demonstrated, another to-be-compressed fluid may be sufficient. In addition, the type of refrigerant as the fluid to be compressed is not particularly limited, and the present invention is commonly applied to variable capacity compressors corresponding to carbon dioxide and other new refrigerants in addition to the case of using R134a as the refrigerant. Is possible.

  The variable capacity compressor according to the present invention can be applied to any compressor having a swash plate with a variable tilt angle, and is particularly suitable as a variable capacity compressor used in a vehicle air conditioner.

It is a longitudinal cross-sectional view (FIG. 1 (A)) of the variable capacity compressor which concerns on one embodiment of this invention, and sectional drawing (FIG. 1 (B)) of the capacity | capacitance control valve for controlling the capacity | capacitance. It is a longitudinal cross-sectional view of the capacity control valve shown in FIG. The leaf | plate spring in the variable capacity compressor of FIG. 1 is shown, (A) is a front view of a leaf | plate spring, (B) is A arrow directional view of FIG. 3 (A), (C) is FIG. 3 (A). FIG. It is a partial expanded sectional view of the variable capacity compressor of FIG. 1 which shows the state which the swash plate is contacting the stopper. FIG. 6 is a relationship diagram between a resultant force of a coil spring and a leaf spring and a swash plate inclination angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Variable capacity compressor 101 Cylinder block 101a Cylinder bore 102 Front housing 103 Valve plate 104 Rear housing 105 Crank chamber 106 Drive shaft 107 Swash plate 108 Rotor 109 Connecting part 110 Coil spring 111 The minimum inclination defining means and the urging means are integrated by the connecting means. Leaf spring 111a as a connected member Leaf spring portion 111b as urging means for urging the swash plate in the inclination increasing direction Stopper 111c as minimum inclination defining means for defining the mechanical minimum inclination of the swash plate Minimum inclination defining means Connecting portion 111d as connecting means between the urging means and the urging means 117 Piston 118 Shoe 119 Suction chamber 120 Discharge chamber 121 Muffler 122 Lid member 123 Communication path 150 Snap ring 200 Check valve 300 Capacity control valve 301 Valve Housing 302 First pressure sensing chamber 303 Valve chamber 304 Valve body 304a Solenoid rod 305 Bellows assembly 307 Second pressure sensing chamber 308 Movable iron core 309 Fixed iron core 311 Solenoid case 313 Electromagnetic coil

Claims (8)

  A housing in which a discharge chamber, a suction chamber, a crank chamber, and a cylinder bore are defined, a piston disposed in the cylinder bore, a drive shaft rotatably supported in the housing, and rotation of the drive shaft And a conversion mechanism including a variable swash plate that converts the reciprocating motion of the piston to adjust the stroke of the piston by changing the pressure difference between the crank chamber and the suction chamber. In a variable capacity compressor that compresses fluid sucked into the cylinder bore and discharges the fluid into the discharge chamber, minimum inclination defining means for defining a mechanical minimum inclination of the swash plate, and attaching the swash plate in an increasing direction of inclination. A variable capacity compressor comprising: an urging unit that urges; and a coupling unit that integrally couples the minimum tilt angle defining unit and the urging unit.   The biasing means comprises a leaf spring, and the leaf spring is formed by press molding from a leaf spring forming material that forms the leaf spring, and the minimum inclination angle defining means is provided on a remaining portion of the leaf spring forming material other than the leaf spring. The variable capacity compressor according to claim 1, wherein the connecting means is formed.   The variable capacity compressor according to claim 1 or 2, wherein a plurality of the biasing means are provided.   The connecting means is formed so as to surround the drive shaft, and the plurality of urging means are arranged at a predetermined interval, and each distal end part urges the swash plate in the direction of increasing the inclination angle, and a proximal end The variable capacity compressor according to claim 3, wherein the portion is integrally connected to the connecting means.   The variable capacity compressor according to claim 3 or 4, wherein three or more urging means are provided, and each urging means is arranged at equal intervals.   The variable capacity compressor according to any one of claims 1 to 5, wherein a positioning structure for positioning the connecting means in the axial direction of the drive shaft is formed on the connecting means and the drive shaft.   The variable capacity compressor according to claim 1, wherein the fluid to be compressed is made of a refrigerant.   The variable capacity compressor according to any one of claims 1 to 7, which is used in a vehicle air conditioner.

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