JP2009281150A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor capable of maintaining a bearing function of a drive shaft even when a fracture occurs in a rotary valve. <P>SOLUTION: When operation of the compressor is continued when a clearance between a cylinder block 1 and the rotary valve 31 is deformed or when there is foreign matter in the clearance, seizure occurs in a bearing part supported by the cylinder block 1, and the rotary valve 31 becomes nonrotatable. When the rotary valve 31 is fixed, large force in a twisting direction by rotation of the drive shaft 6 is applied to the rotary valve 31. Stress occurring in the rotary valve 31 is concentrated on a cutout part 39. As a result, the rotary valve 31 is fractured at the position of the cutout part 39 and a refrigerant gas supply function is lost. However, the fracture in the cutout part 39 allows a region supported by the cylinder block 1 to remain, both sides of the drive shaft 6 can be supported, and the bearing function can be maintained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a compressor that supplies refrigerant gas to a cylinder bore by rotation of a rotary valve.

  For example, a variable capacity compressor using a rotary valve is disclosed in, for example, Patent Document 1 and is configured as follows.

  The front housing 12, the cylinder block 11 and the rear housing 13 constituting the housing are integrated by bolts (not shown). A rotary shaft 18 disposed in the housing is rotatably supported by the front housing 12 via a radial bearing 16. A rotary valve 26 coupled to the rotary shaft 18 is rotatably supported by the cylinder block 11 and rotates integrally. In the rotary valve 26, a supply passage 30 that communicates with the suction chamber 131 is formed along the direction of the axis 181 of the rotating shaft 18, and an introduction passage 31 that communicates with the supply passage 30 is formed. The cylinder block 11 is formed with a suction passage 32 that communicates the cylinder bore 111 and the introduction passage 31 of the rotary valve 26. Accordingly, the introduction passage 31 intermittently communicates with the suction passage 32 as the rotary shaft 18 and the rotary valve 26 rotate.

  When the cylinder bore 111 is in the suction stroke state (ie, the stroke in which the piston 28 moves from the right side to the left side in FIG. 1), the introduction passage 31 communicates with the suction passage 32 and the refrigerant gas in the supply passage 30 of the rotary valve 26. Is sucked into the compression chamber 112 of the cylinder bore 111 via the introduction passage 31 and the suction passage 32. When the cylinder bore 111 is in the discharge stroke state (ie, the stroke in which the piston 28 moves from the left side to the right side in FIG. 1), the introduction passage 31 is disconnected from the suction passage 32, and the refrigerant gas in the compression chamber 112 is The discharge valve 151 is opened from the discharge port 141 and discharged to the discharge chamber 132. The refrigerant discharged into the discharge chamber 132 flows out to an external refrigerant circuit (not shown).

JP 2004-239116 A

  When the swash plate type variable displacement compressor disclosed in Patent Document 1 is mounted on a vehicle or the like, for example, it is fastened and fixed to the engine bracket by a plurality of bolts. If this fastening is overtightened for some reason, the clearance with the cylinder block 11 that rotatably supports the rotary valve 26 is deformed. For this reason, if the swash plate type variable capacity compressor is used in an excessively tightened state, seizure occurs between the cylinder block 11 and the rotary valve 26, and the rotary valve 26 cannot rotate. As a result, the rotary valve 26 is broken such that the vicinity of the small-diameter connecting portion 261 of the connecting portion between the rotary shaft 18 and the rotary valve 26 is twisted or the connection between the rotary shaft 18 and the rotary valve 26 is released. There is a possibility that both the supply function of the refrigerant gas to the cylinder bore 111 and the bearing function of the rotary shaft 18 may be disabled.

  The rupture of the rotary valve 26 may be caused by foreign matters such as dust rarely mixed during initial assembly of the swash plate type variable capacity compressor or maintenance such as pipe replacement. When foreign matter is present in the refrigerant gas, the foreign matter enters a clearance between the cylinder block 11 and the rotary valve 26 together with a part of the refrigerant gas supplied from the introduction passage 31 to the suction passage 32 during the suction process, and the rotary gas is removed. The rotation of the valve 26 is obstructed. For this reason, the occurrence of seizure in the rotation support portion of the rotary valve 26 may cause the rotary valve 26 to break, and the refrigerant gas supply function and the bearing function of the rotary shaft 18 may be disabled.

  An object of the present invention is to provide a compressor capable of maintaining a bearing function of a drive shaft even when a rotary valve is broken.

  The present invention according to claim 1 has a drive shaft disposed in a housing, a supply passage connected to an end of the drive shaft and opening to a suction chamber, and an introduction hole formed in an outer periphery of the supply passage. In a compressor comprising a rotary valve and a cylinder bore for sucking and compressing refrigerant gas, and supplying the refrigerant gas intermittently to the cylinder bore by rotation of the rotary valve, a part of the drive shaft and the rotary valve A part of the rotary valve is rotatably supported by the housing, and a notch is formed in a region S leading to the introduction hole excluding a part of the rotary support part of the rotary valve located on the connection side with the drive shaft. It is characterized by that.

  According to the first aspect of the present invention, since the fracture position of the rotary valve can be specified, the bearing function of the drive shaft by the rotary valve can be maintained even if the rotary valve breaks. Stable rotation can be guaranteed.

  The present invention according to claim 2 is characterized in that the cut-out portion is formed by a wedge-shaped groove, so that the breaking position of the rotary valve can be set most accurately.

  The present invention according to claim 3 is characterized in that the notch is formed in the inner peripheral wall of the supply passage, and therefore the notch groove is formed without affecting the bearing function of the rotary valve. be able to.

  The present invention can maintain the bearing function of the drive shaft even if the rotary valve breaks in the compressor.

(First embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS.
A front housing 2 is joined to the front end of the cylinder block 1. A rear housing 3 is joined to the rear end of the cylinder block 1 via a discharge valve constituting body 4. The cylinder block 1, the front housing 2, and the rear housing 3 constitute a housing of a swash plate type variable capacity compressor (hereinafter simply referred to as a compressor), and are integrated together with a discharge valve component 4 by fastening a plurality of bolts 5. . In the present specification, the left side of FIG. 1 is described as the front side, and the right side is described as the rear side.

  A drive shaft 6 is rotatably supported in the front housing 2 via a radial bearing 7. A drive shaft 6 that protrudes from the front housing 2 to the outside is connected to a vehicle engine that is an external drive source via a pulley and a belt (not shown). A lip seal type shaft seal device 8 is interposed between the front housing 2 and the drive shaft 6. A lug plate 9 is fixed to the drive shaft 6 and a swash plate 10 is supported so as to be slidable and tiltable in the direction of the central axis of the drive shaft 6. The swash plate 10 is connected to the lug plate 9 by the hinge mechanism 11 and rotated. A thrust bearing 12 is interposed between the lug plate 9 and the front housing 2. The hinge mechanism 11 is configured by inserting and coupling a pair of swash plate arms 13 formed protruding from the swash plate 10 between a pair of lug arms 14 formed protruding from the lug plate 9.

  When the central portion of the swash plate 10 moves on the drive shaft 6 toward the lug plate 9, the tilt angle of the swash plate 10 increases. When the swash plate 10 reaches the maximum tilt angle, the swash plate 10 contacts the lug plate 9 and its position is regulated. Moreover, when the center part of the swash plate 10 moves to the cylinder block 1 side, the inclination angle of the swash plate 10 decreases. The solid line position of the swash plate 10 in FIG. 1 indicates the position where the inclination angle is maximum, and the virtual line position indicates the position where the inclination angle is minimum.

  A cylindrical body 16 is slidably fitted on the drive shaft 6 between the lug plate 9 and the swash plate 10, and a coil spring 15 having a rear side biasing force is provided on the cylindrical body 16. It is wound. Accordingly, the swash plate 10 is always pressed toward the rear side by the urging force of the coil spring 15, that is, in the direction in which the inclination angle of the swash plate 10 decreases (imaginary line position). A coil spring 17 restricted by the cylinder block 1 is wound around the drive shaft 6 on the rear side of the swash plate 10. The coil spring 17 defines the position of the minimum inclination angle of the swash plate 10 and has an auxiliary function for returning the swash plate 10 to the tilting direction when the compressor is switched from the minimum capacity operation to the intermediate capacity operation.

  Pistons 19 are accommodated in a plurality of cylinder bores 18 penetrating the cylinder block 1. The piston 19 reciprocates through the shoe 20 by the rotational movement of the swash plate 10 and slides in the cylinder bore 18. A compression chamber 21 in the cylinder bore 18 is partitioned by a piston 19.

  The rear housing 3 has a first suction chamber 22, a second suction chamber 24 communicated via a communication passage 23, and a discharge chamber 26 communicated to the compression chamber 21 via a discharge port 25 of the discharge valve component 4. Has been. A bracket 28 forming a muffler chamber 27 protrudes from the rear side of the rear housing 3 and is fixed by bolts 29. The muffler chamber 27 communicates with the second suction chamber 24 and with a refrigerant gas inlet 30 connected to an external refrigerant circuit (not shown).

  On the other hand, an aluminum rotary valve 31 that is rotatably supported by the cylinder block 1 is connected to the rear side end of the drive shaft 6. Accordingly, the drive shaft 6 rotates in such a manner that the front side is supported by the drive shaft 6 itself and the rear side is supported by the rotary valve 31. The rotary valve 31 is formed of a cylindrical body composed of a front-side small-diameter portion 32 and a rear-side large-diameter portion 33, and the small-diameter portion 32 is press-fitted into the rear-side cavity 34 of the drive shaft 6. It is integrated. Note that other means may be used as long as the connection between the drive shaft 6 and the rotary valve 31 can be integrally rotated.

  The rotary valve 31 has a refrigerant gas supply passage 35 extending in the central axis direction of the drive shaft 6 in the large diameter portion 33, and a throttle passage 36 having a smaller diameter than the supply passage 35 in the small diameter portion 32. The supply passage 35 opens on the rear side to the first suction chamber 22 and communicates with the throttle passage 36 on the front side. The throttle passage 36 passes through the small diameter portion 32 and opens into the cavity 34 of the drive shaft 6. In addition, an introduction hole 37 that always communicates with the supply passage 35 is formed in a part of the outer peripheral wall of the large-diameter portion 33, and can communicate with the suction passage 38 formed in the cylinder block 1 at a predetermined timing. The suction passage 38 communicates with the cylinder bore 18.

  As shown in an enlarged view in FIG. 2, a notch 39 is formed in the inner peripheral wall of the supply passage 35 of the rotary valve 31. The cutout portion 39 is formed in a region S from the wall surface 40 that forms the boundary between the supply passage 35 and the throttle passage 36 to the front side inner wall portion 41 of the introduction hole 37. The area S is set at a position where the area R on the front side in the large-diameter portion 33 of the rotary valve 31 remains. The region R is a minimum range having a bearing function in which the rotary valve 31 is rotatably supported by the cylinder block 1. The notch 39 in the first embodiment is formed as a wedge-shaped groove at a position adjacent to the wall surface 40 in the region S, and is formed in a part of the inner wall of the supply passage 35. The notch 39 positively defines the position of stress concentration applied to the rotary valve 31.

  An in-shaft passage 42 formed in the drive shaft 6 is opened between the front housing 2 and the lug plate 9 through an opening 43 which is opened in the cavity 34 on the rear side and formed in a direction perpendicular to the drive shaft 6 on the front side. It communicates with the gap 44. The refrigerant gas in the crank chamber 45 flows through the gap 44, the opening 43, the in-shaft passage 42 and the throttle passage 36 while lubricating each part, flows into the supply passage 35, and is supplied to the compression chamber 21 together with other refrigerant gases. .

  Note that the discharge chamber 26 and the crank chamber 45 are connected by a feed passage 47 through which a capacity control valve 46 such as an electromagnetic valve provided in the rear housing 3 is interposed. The capacity control valve 46 adjusts the pressure of the refrigerant gas in the crank chamber 45 and sets the inclination angle of the swash plate 10 to an arbitrary angle between the minimum inclination angle and the maximum inclination angle.

  On the outer peripheral wall of the front housing 2, mounting brackets 49 having bolt holes 48 are provided at two locations in the upper and lower parts of FIG. Similarly, the outer peripheral wall of the rear housing 3 is provided with mounting brackets 51 having bolt holes 50 at two locations on the upper and lower sides. When the compressor is attached to an engine bracket (not shown) of the vehicle, the bolt holes 48 and 50 of the attachment brackets 49 and 51 are tightened and fixed through bolts (not shown). The numbers of the mounting brackets 49 and 51 and the bolt holes 48 and 50 are not particularly limited.

The operation of the first embodiment configured as described above will be described below.
The refrigerant gas is sucked and compressed during the normal operation of the compressor as follows. The rotary valve 31 rotates together with the drive shaft 6. At a predetermined timing, that is, a suction stroke timing when the piston 19 slides to the left in FIG. 1 for suction of the refrigerant gas, the introduction hole 37 communicates with the suction passage 38 and the refrigerant gas in the supply passage 35 is transferred to the cylinder bore. 18 compression chambers 21 are supplied. At the timing of the compression stroke in which the piston 19 slides to the right in FIG. 1, the communication between the introduction hole 37 and the suction passage 38 is blocked, and the high-pressure refrigerant gas in the compression chamber 21 is discharged from the discharge valve structure in the subsequent discharge process. The discharge valve 4 is opened and discharged to the discharge chamber 26 through the discharge port 25. The refrigerant gas discharged into the discharge chamber 26 flows out to an external refrigerant circuit (not shown).

  When the compressor is operated with the clearance between the cylinder block 1 and the rotary valve 31 supported by the bearing being deformed due to excessive tightening when the compressor is attached to the engine frame of the vehicle, or during maintenance such as pipe replacement of the compressor When the foreign matter mixed in the compressor enters the clearance between the cylinder block 1 and the rotary valve 31 and is operated while being accumulated, a large rotational resistance is generated in the rotary valve 31.

  When the operation of the compressor is continued in such a state, the rotary valve 31 is seized in the bearing portion supported by the cylinder block 1 and cannot rotate. When the rotary valve 31 is fixed, a large force in the twisting direction due to the rotation of the drive shaft 6 is applied to the rotary valve 31. For this reason, the stress generated in the rotary valve 31 is concentrated in the notch 39.

  As a result, the rotary valve 31 is broken at the position of the notch 39 as shown by a double oblique line in FIG. 3 and loses the refrigerant gas supply function. However, the rupture at the position of the notch 39 can leave the region R, support the drive shaft 6 with both ends, and maintain the bearing function. Since the compressor is not cooled after the rupture of the rotary valve 31, an abnormality can be detected at an early stage and the operation of the compressor can be stopped for repair.

In the first embodiment of the present invention described above, the following operational effects are obtained.
(1) Since the fracture position of the rotary valve 31 can be set, the bearing function of the drive shaft 6 can be maintained.
(2) Since the notch 39 is formed by a wedge-shaped groove, stress concentration can be easily obtained.
(3) Since only the notch 39 is provided, the configuration is simple.

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications are possible within the scope of the gist of the present invention, and can be implemented as follows.

(1) The notch 39 is not limited to a wedge shape, and can be formed of a U-shaped groove or a U-shaped groove.
(2) The notch 39 may be formed in an annular shape around the entire inner wall of the supply passage 35 of the rotary valve 31.
(3) The notch 39 may be formed partially or annularly on the outer peripheral surface of the large diameter portion 33 of the rotary valve 31.
(4) The cutout portion 39 is not limited to a single groove, and may be formed of a plurality of grooves.

It is a longitudinal cross-sectional view of a swash plate type variable capacity compressor. It is an expanded sectional view showing a rotary valve. It is an expanded sectional view showing fracture of a rotary valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Front housing 3 Rear housing 6 Drive shaft 10 Swash plate 18 Cylinder bore 19 Piston 21 Compression chamber 22 First suction chamber 26 Discharge chamber 31 Rotary valve 32 Small diameter portion 33 Large diameter portion 36 Restriction passage 37 Introduction hole 38 Intake passage 39 Notch 40 Wall 41 Inner wall R, S region

Claims (3)

A rotary shaft having a drive shaft disposed in the housing, a supply passage connected to an end of the drive shaft and opening to the suction chamber, and an introduction hole formed in the outer periphery of the supply passage, and suction and compression of the refrigerant gas are performed. A compressor for supplying the refrigerant gas to the cylinder bore intermittently by rotation of the rotary valve.
A part of the drive shaft and a part of the rotary valve are rotatably supported by the housing, and the introduction hole excluding a part of the rotary support portion of the rotary valve located on the connection side with the drive shaft. A compressor characterized in that a notch portion is formed in a region S leading to.   The compressor according to claim 1, wherein the notch is formed by a wedge-shaped groove.   The compressor according to claim 1, wherein the notch is formed in an inner peripheral wall of the supply passage.

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