JPH0519573U - Swash plate type variable capacity compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a swash plate type variable displacement compressor capable of reliably performing displacement control in a high speed range. [Structure] A housing 18 having cylinders 5 and 7, and
Spindle 20 rotatably arranged inside housing 18
And a swash plate 42 having a variable tilt angle on the main shaft 20, and a piston 50 slidably inserted into the cylinders 5 and 7.
And the main shaft 20 by being interposed between the piston 50 and the swash plate 42.
In a swash plate type variable displacement compressor including conversion members 52 and 53 that convert the movement of the swash plate 42 associated with the rotation of the swash plate into reciprocating motion and transmit the reciprocating motion to the piston 50. The moment acting in the direction of decreasing the inclination angle of 42 is equal to or larger than the moment acting in the direction of increasing the inclination angle of the swash plate 42 generated by the reciprocating inertial force of the piston 50 and the conversion members 52, 53. Is characterized by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a swash plate type variable displacement compressor, which is used, for example, in a vehicle air conditioner.

[0002]

[Prior Art]

 This type of swash plate compressor is known, for example, from Japanese Patent Laid-Open No. 63-147977. Further, a fixed capacity type compressor, that is, a swash plate type compressor in which the inclination angle of the swash plate is constant has been known for a long time. In this fixed displacement swash plate compressor, it is also known that the forward and backward inertial force of the piston can be canceled by the rotational inertial force of the swash plate. However, in the fixed capacity swash plate compressor, the purpose was to balance the inertial force in order to reduce the vibration transmitted to the outside of the compressor. Even if the balance of the inertial force is not sufficient because of the weight saving and downsizing of the compressor, the swash plate is completely fixed to the main shaft, and problems other than vibration will occur. There wasn't.

[0003]

[Problems to be solved by the device]

 In recent years, it has reached the stage where practical application of a swash plate type variable displacement compressor is being considered.However, in this case, unlike the fixed displacement type, the inclination angle of the swash plate can be changed freely, so the reciprocating inertia force of the piston and the swash plate If the balance with the rotational inertial force is insufficient, not only unnecessary unbalanced vibration occurs but also the problem that the inclination angle of the swash plate changes due to the unbalanced moment. In particular, when a high-speed operation of the compressor causes a moment in the direction to increase the inclination angle of the swash plate, it becomes difficult to control the inclination angle of the swash plate. Has become a problem.

Therefore, an object of the present invention is to provide a swash plate type variable displacement compressor capable of reliably performing displacement control in a high speed range.

[0005]

According to the present invention, a housing having a cylinder, a main shaft rotatably disposed inside the housing, and a swash plate provided on the main shaft with a variable tilt angle, A piston slidably inserted into the cylinder is interposed between the piston and the swash plate to convert the motion of the swash plate accompanying the rotation of the main shaft into a reciprocating motion to form the piston. In a swash plate type variable displacement compressor including a transmitting conversion member, a reciprocating inertia of the piston and the conversion member is applied to a moment acting in a direction to reduce an inclination angle of the swash plate caused by a rotational inertia force of the swash plate. A swash plate type variable displacement compressor is obtained in which the moment generated by force is equal to or greater than the moment acting in the direction of increasing the tilt angle.

[0006]

[Action]

 In the case of the swash plate type variable displacement compressor of the present invention, when the compressor is in operation, the moment acting in the direction of decreasing the tilt angle of the swash plate caused by the rotating inertia force of the swash plate causes the piston and the conversion member to reciprocate. Since it is equal to or larger than the moment that acts in the direction to increase the inclination angle of the swash plate caused by the inertial force, the moment that affects the inclination angle of the swash plate is not generated during high-speed operation of the compressor. Even if it occurs, it is a moment in the direction of reducing the inclination angle of the swash plate. Therefore, during high-speed operation of the compressor, the swash plate does not generate a moment that affects the tilt angle, or if it does, it reduces the tilt angle. To be done.

[0007]

【Example】

 FIG. 1 is a sectional view of a swash plate type variable displacement compressor according to an embodiment of the present invention. Referring to FIG. 1, a front housing member 1 and a rear housing member 2 are butted with a seal member 3 interposed. The front housing member 1 integrally has a front cylinder block 4. The front cylinder block 4 is formed with a plurality of front side cylinders 5 parallel to a main shaft 20 described later. These cylinders 5 are formed at equal intervals so as to surround the main shaft 20. Similarly, the rear housing member 2 integrally has a rear cylinder block 6. The rear cylinder block 6 is formed with a plurality of rear cylinders 7 parallel to the main shaft 20. These cylinders 7 are formed at equal intervals so as to face the cylinder 5 on the front side and surround the main shaft 20. Further, the rear cylinder block 6 has a projecting portion 8, and a central hole 9 is formed in the central portion of the rear cylinder block 6.

A front cylinder head 11 is attached to one surface of the front housing member 1 with a front valve plate device 10 interposed. The front cylinder head 11 has a suction chamber 12 and a discharge chamber 13. Similarly, a rear cylinder head 15 is attached to one surface of the rear housing member 2 with a rear valve plate device 14 interposed. The rear cylinder head 15 has a suction chamber 16 and a discharge chamber 17. A housing 18 is composed of the front housing member 1, the rear housing member 2, the front cylinder head 11, and the rear cylinder head 15 described above.

The main shaft 20 has a front small diameter portion 21, a large diameter portion 22, and a rear small diameter portion 23. The front small diameter portion 21 is rotatably supported by a radial needle bearing 24 provided in the front cylinder block 4. The rear small diameter portion 23 is rotatably supported by a radial needle bearing 25 provided in the rear cylinder block 6. As a result, the main shaft 20 is rotatably supported in the housing 18.

The front cylinder block 4 is provided with a thrust needle bearing 30, and the end face of the large diameter portion 22 on the side of the front small diameter portion 21 is butted against the thrust needle bearing 30. As a result, the main shaft 20 is thrust-supported. On the other hand, a female screw 32 is formed on the projecting portion 8 of the rear cylinder block 6, and an adjusting screw 33 is screwed onto the female screw 32. By rotating the adjusting screw 33, the adjusting screw 33 moves in the axial direction of the main shaft 20, that is, in the axial direction. Further, since the adjusting screw 33 is abutted against one end of the main shaft 20, it is possible to adjust the axial position of the main shaft 20 by rotating the adjusting screw 33. There is.

A center pin 40 is attached to the main shaft 20. The center line of the center pin 40 is orthogonal to the axis of the main shaft 20. A center ring 41 surrounding the main shaft 20 is rotatably attached to the center pin 40. A disk-shaped swash plate 42 is attached to the centering 41. When the centering 41 and the swash plate 42 are rotatably attached to the center pin 40, the center line of the center pin 40 passes through the center points of the centering 41 and the swash plate 42. Therefore, the swash plate 42 is tiltable with respect to the main shaft 20 around its center point. The swash plate 42 is provided with a substantially triangular arm 43 parallel to the main shaft 20. A pin 44 parallel to the center pin 40 is provided at the tip of the arm 43.

The double-headed piston 50 has one end slidably inserted into the front cylinder 5 and the other end slidably inserted into the rear cylinder 7. A concave portion 51 having a curved surface corresponding to a spherical surface is formed in the central portion of the double-headed piston 50. Two shoes 52 and 53 having a spherical surface are provided in the recess 51. A peripheral portion of the swash plate 42 is slidably sandwiched between the shoes 52 and 53. Therefore, when the swash plate 42 rotates together with the main shaft 20, the double-headed piston 50 reciprocates in the axial direction according to the inclination angle of the swash plate 42 to perform compression operation and suction operation. Thus, in the case of the present embodiment, the movement of the swash plate 42 due to the rotation of the main shaft 20 interposed between the double-headed piston 50 and the swash plate 42 is converted into a reciprocating motion and transmitted to the double-headed piston 50. The conversion member is composed of shoes 52 and 53.

A sleeve 60 is attached to the main shaft 20 so as to be movable in the axial direction. A long hole 61 is formed on the side surface of the sleeve 60. A pin 44 is slidably inserted into the long hole 61. The elongated hole 61 is formed so as to be inclined with respect to the axial direction so as to engage with the pin 44 and rotate the pin 44 around the center pin 40 when the sleeve 60 moves in the axial direction. . Further, the elongated hole 61 limits the rotation range of the pin 44 so that the swash plate 42 has a small inclination angle within a limited range from the maximum inclination angle (the state shown in FIG. 1). Conventionally, in the swash plate type variable displacement compressor of the type in which the swash plate is tilted around its center point, the swash plate tilt angle is changed between the minimum (0 °) and the maximum angle. (See JP-A-58-162780). In this case, when the inclination angle of the swash plate is made small, a dead volume is generated between the piston and the valve plate, resulting in a problem that the compression efficiency is significantly reduced. However, in the case of the present embodiment, the increase of the dead volume is made small by decreasing the inclination angle of the swash plate 42 within a limited range from the maximum, and further, the decrease of the volume efficiency due to this dead volume and the angle increase. The discharge capacity of the compressor can be controlled from 0 to the maximum by making use of the effects of both reduction of stroke due to change. In the case of this embodiment, the maximum inclination angle is 20 ° and the minimum inclination angle is 10 °. A large hole 63 is formed in the main shaft 20, and the large hole 63 prevents the pin 44 from interfering with the main shaft 20 when the pin 44 rotates around the center pin 40.

A recess 70 is formed in the center of the rear cylinder head 15, and an approximately tray-shaped actuator 71 is axially slidably arranged in the recess 70. The valve plate device 14 side of the concave portion 70 forms the suction chamber 16 and the opposite side thereof forms the pressurizing chamber 72 with the actuator 71 as a boundary. A coil spring 73 is provided in the pressurizing chamber 72. The coil spring 73 urges the actuator 71 in a direction of separating the actuator 71 from the valve plate device 14. The pressurizing chamber 72 communicates with the discharge chamber 17 through a communication passage 74. An orifice 75 is provided in the communication passage 74. Therefore, the discharge chamber pressure is reduced and constantly introduced into the pressurizing chamber 72. The fluid introduced from the discharge chamber 17 into the pressurizing chamber 72 is made to escape to the suction chamber 16 via the control valve 76. By controlling the communication between the pressurizing chamber 72 and the suction chamber 16 by the control valve 76, the pressure in the pressurizing chamber 72 is controlled, and as a result, the position of the actuator 71 is controlled.

A plurality of actuating pins 80 are provided at the center of the rear cylinder block 6 so as to be slidable in the axial direction. One end of each of the actuating pins 80 is fixed to the actuator 71. A thrust needle bearing 81 is interposed between the actuating pin 80 and the sleeve 60. The thrust needle bearing 81 is arranged in the central hole 9 of the rear cylinder block 6 so as to be axially movable in the central hole 9. The fixed ring 82 of the thrust needle bearing 81 is fixed to the other end of the actuating pin 80. The rotating wheel 83 of the thrust needle bearing 81 is fixed to the sleeve 60. Therefore, the axial movement of the actuator 71 is transmitted to the sleeve 60 via the actuator pin 80 and the thrust needle bearing 81. As a result, the tilt angle of the swash plate 42 can be controlled by controlling the pressurizing chamber pressure by the control valve 76.

FIG. 2 is an explanatory diagram showing the conceptual relationship of the inertial force in the main part of the embodiment shown in FIG. Referring also to FIG. 2, the swash plate 42 is supported by the center pin 40 so that the tilt angle can be varied with respect to the main shaft 20. When the main shaft 20 rotates, the swash plate 42 also rotates, but due to the tilted mass distribution, inertial forces Fs, −Fs are generated above and below the swash plate 42 in the drawing, which causes a left-handed moment − in the drawing. Fs · L is generated (actually, it is represented by the sum of the product of the inertial force generated by the position of the minute mass in the swash plate 42 and its force-pair distance, but this is simply described here). On the other hand, in the drawing, there is a right-handed moment Fp · r · n generated by the reciprocating inertial force of the double-headed piston 50 (n is the number of pistons). If the latter is large in the two moments of −Fs · L and Fp · r · n, the swash plate 42 is urged in the direction in which the tilt angle further increases. Since this tendency increases in proportion to the square of the number of revolutions, eventually, when the number of revolutions increases, the capacity shifts to the maximum direction, which causes an undesirable characteristic that the capacity becomes maximum at high speed. On the contrary, if -Fs.L is made larger than Fp.r.n as in the case of this embodiment, the characteristic that the swash plate 42 shifts to the capacity reduction is obtained in the high speed range. As described above, by making the moment due to the inertial force of the swash plate 42 equal to or greater than that of the piston 50, the capacity controllability in the high speed range is ensured and the durability due to the capacity reduction effect at the ultra high speed is achieved. Great effects such as improvement, vibration and noise reduction can be obtained.

Although the present embodiment is a swash plate type variable capacity compressor of the type having cylinders on both sides of the housing, the present invention is not limited to this. It is also applicable to a plate type variable displacement compressor.

[0018]

[Effect of the device]

 In the case of the present invention, the moment that influences the inclination angle of the swash plate does not occur during high-speed operation of the compressor, or even if it occurs, it is the moment that decreases the inclination angle of the swash plate. Therefore, during high-speed operation of the compressor, the moment that affects the tilt angle does not occur on the swash plate, or even if it does occur, it is a moment that reduces the tilt angle. Therefore, the present invention can reliably control the capacity in the high speed range. Furthermore, the present invention ensures the capacity controllability in the high speed range, and has a great effect of improving the durability and reducing vibration and noise due to the capacity reducing effect at the ultra-high speed.

[Brief description of drawings]

FIG. 1 is a sectional view of a swash plate type variable displacement compressor according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a conceptual relationship of inertial force in a main part of the embodiment shown in FIG.

[Explanation of symbols]

 5 cylinder 7 cylinder 18 housing 20 main shaft 42 swash plate 50 double-headed piston 52 conversion member 53 conversion member

Claims (1)

[Scope of utility model registration request] 1. A housing having a cylinder, a main shaft rotatably disposed inside the housing, a swash plate provided on the main shaft with a variable inclination angle, and slidably inserted into the cylinder. A swash plate type variable capacity including a piston and a conversion member interposed between the piston and the swash plate to convert the motion of the swash plate accompanying the rotation of the main shaft into a reciprocating motion and transmit the reciprocating motion to the piston. In the compressor, a moment acting in a direction to reduce the inclination angle of the swash plate generated by the rotational inertia force of the swash plate increases the inclination angle of the swash plate generated by the reciprocating inertia force of the piston and the conversion member. A swash plate type variable displacement compressor characterized in that it is equal to or larger than the moment acting in the direction.