JP2010014035A - Variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement compressor having structure with no sleeve and capable of preventing the generation of noise caused by the looseness of an oscillation member. <P>SOLUTION: In the variable displacement compressor, by adjusting crank chamber pressure which is the back pressure of each piston, an inclination angle can be varied by oscillating the oscillation member 12 comprising a journal 13 and a swash plate 15 around a connection link 14, and a reciprocation stroke of each piston can be varied by varying the inclination angle of the swash plate 15. A cam face 18a is formed on a rotor 11 and a cam sliding part 19 moved following the cam face 18a is formed on the journal 13. The cam face 18a is set to have a planar shape for regulating the oscillation trajectory of the oscillation member 12 so that the side on the inner face of a drive shaft through-hole 17 and a distant from the connection link 14 is made to abut on the outer peripheral face of a drive shaft 4 at all of the inclination angles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a variable displacement compressor that varies a discharge capacity of a piston according to an inclination angle of a swing member.

  A conventional variable displacement compressor of this type is disclosed in Patent Document 1.

  The variable displacement compressor 100 includes a housing 101 as shown in FIG. The housing 101 is assembled by assembling a cylinder block 101a, a front head 101b disposed on one end side of the cylinder block 101a, and a rear head 101c disposed on the other end side of the cylinder block 101a via a valve plate 102. It is mainly composed.

  A drive shaft 103 is disposed at the center of the cylinder block 101a and the front head 101b. Both end sides of the drive shaft 103 are rotatably supported by a radial bearing portion 104 and a radial bearing portion 105.

  In the cylinder block 101a, a plurality of cylinder bores 106 are formed on the circumference around the drive shaft 103, and pistons 107 are slidably disposed in the cylinder bores 106, respectively. A crank chamber 108 communicating with the plurality of cylinder bores 106 is formed in the front head 101b. The crank chamber 108 is provided with a rotor 109 fixed to the outer periphery of the drive shaft 103 and a swash plate 113 that is a swing member inserted into the drive shaft 103. Each piston 107 is engaged with the outer periphery of the swash plate 113 via a pair of shoes 114.

  A first spring S1 is disposed at one end of the swash plate 113, and the swash plate 113 is returned to the initial drive position after the operation is stopped by the spring force of the first spring S1.

  The rotor 109 and the swash plate 113 are connected by connecting means 115. The connecting means 115 includes a guide hole 115a provided in the rotor 109 and a guide sphere 115b provided in the swash plate 113 and inserted into the guide hole 115a. The rotation of the rotor 109 is transmitted to the swash plate 113 by the connecting means 115, and the inclination angle of the swash plate 113 can be varied.

  When the drive shaft 103 rotates, each piston 107 reciprocates in the cylinder bore 106 by the rotor 109, the swash plate 113, and the like, and the reciprocating stroke of each piston 107 is varied by the inclination angle of the swash plate 113.

  A suction chamber 120 and a discharge chamber 121 are formed in the rear head 101c.

  A valve plate 102 interposed between the cylinder block 101 a and the rear head 101 c partitions the plurality of cylinder bores 106 from the suction chamber 120 and the discharge chamber 121.

  In the above configuration, when the drive shaft 103 is driven to rotate, the swash plate 113 swings and each piston 107 reciprocates. In the suction stroke of each piston 107, the refrigerant is supplied from the suction chamber 120 into the cylinder bore 106, and the supplied refrigerant is compressed in the compression stroke of the piston 107 and discharged to the discharge chamber 121. The discharged refrigerant circulates in the refrigeration cycle, is used for cooling or the like, and returns to the variable capacity compressor 100 again.

  When the variable capacity compressor 100 is driven and the heat load of the refrigeration cycle increases, the pressure in the crank chamber 108 is adjusted to the low pressure side. As a result, the balance between the counterclockwise moment caused by the crank chamber pressure, which is the back pressure of each piston 107, and the spring force of the first spring S1, and the clockwise moment caused by the front pressure of each piston 107 are lost, and the inclination angle of the swash plate 113 is increased. The swash plate 113 is tilted in the direction of arrow a in FIG. 6 until the position where both moments are balanced, and the tilt angle of the swash plate 113 is increased. As the inclination angle of the swash plate 113 increases, the reciprocating stroke of each piston 107 increases, the refrigerant discharge capacity increases, and the cooling capacity and the like increase.

  Further, when the heat load of the refrigeration cycle is reduced, the pressure in the crank chamber 108 is adjusted to the high pressure side. As a result, the balance between the counterclockwise moment caused by the crank chamber pressure, which is the back pressure of each piston 107, and the spring force of the first spring S1, and the clockwise moment caused by the front pressure of each piston 107 are lost, and the inclination angle of the swash plate 113 is reduced. The swash plate 113 tilts in the direction of the arrow b in FIG. 6 to a position where both moments balance, and the tilt angle of the swash plate 113 decreases. When the inclination angle of the swash plate 113 is reduced, the reciprocating stroke of each piston 107 is reduced, the refrigerant discharge capacity is reduced, and the cooling capacity and the like are reduced. The variable displacement compressor 100 saves power by such operation.

  The conventional variable displacement compressor 100 has a structure in which the swash plate 113 is swung without providing a sleeve for sliding the drive shaft 103, that is, a sleeveless structure. There is an advantage of becoming.

  7A shows the state of the minimum inclination angle of the swash plate 113 in the conventional variable displacement compressor 100. In the state of the minimum inclination angle, the restriction protrusion 103a of the drive shaft 103 receives the restriction receiving of the swash plate 113. FIG. When the surface 113a abuts, the angle is not less than the minimum inclination angle.

FIG. 7B shows the state of the maximum inclination angle of the swash plate 113 in the conventional variable displacement compressor 100. In the state of the maximum inclination angle, the restriction surface 113b of the swash plate 113 is in contact with the restriction surface 109a of the rotor 109. The contact does not exceed the maximum inclination angle. In the state of the minimum inclination angle shown in FIG. 7A and the state of the maximum inclination angle shown in FIG. 7B, the inner surface of the drive shaft through-hole 116 of the swash plate 113 is in contact with the outer peripheral surface of the drive shaft 103. It is set not to touch. Accordingly, even in an intermediate state between the minimum inclination angle and the maximum inclination angle, it does not contact the outer peripheral surface of the drive shaft 103.
JP-A-11-257216

  However, in the state of the minimum inclination angle shown in FIG. 7A and the state of the maximum inclination angle shown in FIG. 7B, the restriction receiving surface 113 a and the restriction surface 113 b of the swash plate 113 contact the rotor 109 and the drive shaft 103. Because of the contact, the backlash of the swash plate 113 is reduced. In other states, the backlash of the swash plate 113 is not suppressed because the swash plate 113 is not in contact with the rotor 109 or the drive shaft 103. There is a problem that abnormal noise occurs due to looseness.

  Further, in the state of the minimum inclination angle shown in FIG. 8A and the state of the maximum inclination angle shown in FIG. 8B, the inner surface of the drive shaft through-hole 116 of the swash plate 113 (the place indicated by 116a in the drawing). A conventional example in which the shape of the drive shaft through-hole 116 is set so that the portion indicated by the reference numeral 116b and the outer peripheral surface of the drive shaft 103 contacts the outer peripheral surface of the drive shaft 103 has also been proposed. However, when the shape of the drive shaft through-hole 116 is set in this way, there is a gap between the inner surface of the drive shaft through-hole 116 of the swash plate 113 and the outer peripheral surface of the drive shaft 103 at an intermediate inclination angle. it can. In the state of the intermediate inclination angle shown in FIG. 8C, the gap is particularly large. Therefore, it is impossible to prevent the generation of abnormal noise due to the backlash of the swash plate 113 in all the tilt angles.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a variable capacity compressor that has a sleeveless structure and can prevent the generation of abnormal noise due to backlash of a swinging member.

  According to the first aspect of the invention for achieving the above object, a plurality of cylinder bores and a crank chamber communicating with the cylinder bore are provided in the housing, and a drive shaft passing through the crank chamber is rotatably provided in the housing. The rotor is fixed, has a drive shaft through hole inserted into the drive shaft, is provided with a swing member disposed in the crank chamber, and is provided with a connecting means for connecting the swing member and the rotor. Are provided with a plurality of pistons that reciprocate in a plurality of cylinder bores, and by adjusting the crank chamber pressure, which is the back pressure of each piston, the swash plate oscillates around the connecting means, thereby tilting the angle. In the variable capacity compressor in which the reciprocating stroke of each piston is varied by varying the tilt angle of the swing member, a cam surface is provided on either the rotor or the swing member. A cam sliding part that moves following the cam surface is provided, and the cam surface is the inner surface of the drive shaft through-hole and the outer surface of the drive shaft with all the inclined angles on the side far from the connecting means. The surface shape is set so as to regulate the swing locus of the swing member so as to come into contact.

  The invention according to claim 2 is the variable capacity compressor according to claim 1, wherein the swing member is composed of a journal having a drive shaft through hole and a swash plate fixed to the outer periphery of the journal. Features.

  According to the first aspect of the present invention, the inner surface of the drive shaft through-hole of the swing member is not only the state of the maximum tilt angle and the minimum tilt angle but also the intermediate tilt angle of the swing member. Therefore, no gap is generated between the drive shaft and the swing member at all inclination angles. Therefore, in the variable capacity compressor having the sleeveless structure, it is possible to prevent the generation of noise due to the backlash of the swing member.

  According to the invention of claim 2, the same effect as that of the invention of claim 1 can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 5 show an embodiment of the present invention, FIG. 1 is an overall sectional view of a variable displacement compressor, FIG. 2 (a) is a side view of a rotor, FIG. 2 (b) is a sectional view of a journal, FIG. (C) is an enlarged view of the cam inclined portion, FIG. 3 is a cross-sectional view of the main part when the swash plate is at the minimum inclination angle state, FIG. It is principal part sectional drawing of an inclination angle state.

  As shown in FIG. 1, the variable displacement compressor 1 has a housing 2. The housing 2 is assembled with a cylinder block 2a, a front head 2b disposed on one side surface of the cylinder block 2a, and a rear head 2c disposed on the other side surface of the cylinder block 2a via a valve body 3. Is made up of.

  The cylinder block 2a and the front head 2b are provided with a drive shaft 4 that penetrates a crank chamber 10 described below. The drive shaft 4 is rotatably supported by the cylinder block 2a and the front head 2b by supporting both ends of the drive shaft 4 with radial bearing portions 5 and 6. One end of the drive shaft 4 protrudes outward from the front head 2b, and a pulley (not shown) that receives the rotation of the engine is fixed to the protruding portion. The drive shaft 4 is configured to rotate by receiving a driving force from the pulley fixed to one end side in this way.

  A plurality of cylinder bores 8 are formed in the cylinder block 2a. The plurality of cylinder bores 8 are formed at equal intervals on the circumference around the drive shaft 4. A piston 9 is slidably disposed in each cylinder bore 8.

  A crank chamber 10 communicating with the plurality of cylinder bores 8 is formed in the front head 2b. The crank chamber 10 includes a rotor 11 fixed to the outer periphery of the drive shaft 4, a swing member 12 disposed in a penetrating manner in the drive shaft 4, and a connecting means for connecting the rotor 11 and the swing member 12. A connecting link 14 is provided.

  The swing member 12 includes a journal 13 having a drive shaft through hole 17 inserted into the drive shaft 4 and a swash plate 15 fixed to the outer periphery of the journal 13. First and second springs S1 and S2 are arranged at both ends of the journal 13, and the swash plate 15 is moved to the initial drive position (after the operation is stopped) by the balance of the spring force of the first and second springs S1 and S2. The discharge capacity is returned to a position of about 5% to 10%. The rear end side of each piston 9 is engaged with the outer periphery of the swash plate 15 via a pair of shoes 16.

  The connection link 14 is rotatably connected to the rotor 11 by the first rotation fulcrum portion 14a and to the journal 13 by the second rotation fulcrum portion 14b.

  When the drive shaft 4 rotates, the rotation is transmitted to the swash plate 15 by the rotor 11, the connecting link 14, and the journal 13, and each piston 9 reciprocates in the cylinder bore 8. Further, the stroke of each piston 9 is varied depending on the inclination angle of the swash plate 15, and the discharge capacity of the refrigerant is varied. The mechanism by which the inclination angle of the swash plate 15 is adjusted will be described in the place of action.

  A refrigerant gas suction chamber 20 and a discharge chamber 21 are formed in the rear head 2c. The suction chamber 20 is connected to the outlet side of the evaporator of the refrigeration cycle. The discharge chamber 21 is connected to the inlet side of the condenser of the refrigeration cycle. The suction chamber 20 and the discharge chamber 21 are partitioned by the cylinder bores 8 via the valve bodies 3. A suction hole (not shown) with a suction valve and a discharge hole 22 with a discharge valve are formed in the valve body 3 partitioning both chambers.

  In addition, a bleed passage (not shown) that is in continuous communication is formed between the crank chamber 10 and the suction chamber 20. An air supply passage (not shown) is formed between the crank chamber 10 and the discharge chamber 21. A pressure control valve 24 is disposed in the supply passage. The pressure of the crank chamber 10 can be adjusted by controlling the opening of the pressure control valve 24.

  As shown in detail in FIGS. 2A and 2B, the rotor 11 is integrally provided with a cam inclined portion 18 that protrudes toward the journal 13 side. The journal 13 is provided with a cam sliding portion 19 that protrudes toward the rotor 11 side. A cam sliding portion 19 is in contact with the cam surface 18 a of the cam inclined portion 18. In the swinging member 12, the cam sliding portion 19 moves following the cam surface 18 a in the swinging process of changing the swash plate 15 and the tilt angle. The cam surface 18a is the inner surface of the drive shaft through-hole 17 and the rocking member 12 so that the side farther from the connecting link 14 (the lower surface side in the drawing) is in contact with the outer peripheral surface of the drive shaft 4 at all inclination angles. Is set to a surface shape that regulates the swing trajectory. Specifically, as shown in FIG. 2 (c), it is formed in a curved surface protruding in an arc shape outward with respect to a flat surface (indicated by a one-dot chain line in FIG. 2 (c)).

  Here, the inner surface processing of the drive shaft through hole 17 and the curved surface processing of the cam surface 18a will be described. First, the drive shaft through hole 17 is processed as follows. That is, as shown in FIGS. 3 to 5, the side close to the connecting link 14 (the upper half side of the drawing) is in the state of all inclination angles of the swing member 12 and there is a gap between the drive shaft 4. Process to a diameter that can be done. The side farther from the connection link 14 (the lower half side of the drawing) is in the state of the minimum inclination angle and the first contact surface 17a contacts, and in the state of the maximum inclination angle, the second contact surface 17b contacts. Process to diameter. As a result, an edge-shaped intermediate contact surface 17c is formed at the boundary between the first contact surface 17a and the second contact surface 17b.

  Next, the cam surface 18a is configured such that the drive shaft 4 contacts the first contact surface 17a and the second contact surface 17b of the drive shaft through-hole 17 in the state of the minimum inclination angle and the maximum inclination angle of the swash plate 15, respectively. The drive shaft 4 is processed into a curved surface that is in contact with the intermediate contact surface 17c of the drive shaft through-hole 17 in all intermediate states of the minimum inclination angle state and the maximum inclination angle state. .

  In the above configuration, when the drive shaft 4 rotates, the rotational force causes the swash plate 15 to rotate, and the plurality of pistons 9 reciprocate in the cylinder bore 8. In the suction stroke of the piston 9 (stroke moving from the top dead center to the bottom dead center), a suction hole (not shown) is opened by the pressure reduction in the cylinder bore 8. As a result, the refrigerant gas is supplied from the suction chamber 20 to the cylinder bore 8.

  In the compression stroke of the piston 9 (stroke moving from the bottom dead center to the top dead center), the suction hole (not shown) is closed, and the refrigerant gas in the cylinder bore 8 is compressed by the piston 9. The compressed high-temperature and high-pressure refrigerant gas is discharged from the discharge hole 22 to the discharge chamber 21. The high-temperature and high-pressure refrigerant discharged into the discharge chamber 21 is discharged out of the variable capacity compressor 1 through a discharge port (not shown). The discharged refrigerant circulates in the refrigeration cycle, is used for cooling or the like, and returns to the variable capacity compressor 1 again.

  When the variable capacity compressor 1 is driven and the heat load of the refrigeration cycle increases, the pressure in the crank chamber 10 is adjusted to the low pressure side. Then, the balance between the counterclockwise moment due to the crank chamber pressure as the back pressure of each piston 9 and the spring force of the first spring S1 and the clockwise moment due to the front pressure of each piston 9 and the spring force of the second spring S2 is lost. The clockwise moment in the direction of increasing the inclination angle of the swash plate 15 about the second rotation fulcrum portion 14b with respect to the integral member of the swash plate 15 and the journal 13 increases, and the swash plate 15 reaches a position where both moments are balanced. Is inclined in the direction of arrow a in FIG. 1, and the inclination angle of the swash plate 15 is increased. When the inclination angle of the swash plate 15 increases, the reciprocating stroke of each piston 9 increases, the refrigerant discharge capacity increases, and the cooling capacity and the like increase.

  Further, when the heat load of the refrigeration cycle is reduced, the pressure in the crank chamber 10 is adjusted to the high pressure side. Then, the balance between the counterclockwise moment due to the crank chamber pressure as the back pressure of each piston 9 and the spring force of the first spring S1 and the clockwise moment due to the front pressure of each piston 9 and the spring force of the second spring S2 is lost. The counterclockwise moment in the direction of decreasing the inclination angle of the swash plate 15 about the second rotation fulcrum portion 14b with respect to the integral member of the swash plate 15 and the journal 13 increases, and the swash plate reaches a position where both moments balance. 15 inclines in the direction of the arrow b in FIG. When the inclination angle of the swash plate 15 is reduced, the reciprocating stroke of each piston 9 is reduced, the refrigerant discharge capacity is reduced, and the cooling capacity and the like are reduced. The variable displacement compressor 1 saves power by such operation.

  In the above-described swinging process of the swash plate 15, the cam slide portion 19 of the journal 13 moves along the cam surface 18 a of the rotor 11 and the inclination angle of the swash plate 15 is varied. The inner surface of the drive shaft through hole 17 of the journal 13 is the inner surface of the drive shaft 4 in all of the minimum tilt angle state shown in FIG. 3, the intermediate tilt angle state shown in FIG. 4, and the maximum tilt angle state shown in FIG. There is no gap between the drive shaft 4 and the swing member 12 in contact with the outer peripheral surface and at all inclination angles. Therefore, in the variable capacity compressor 1 having the sleeveless structure, it is possible to prevent the generation of noise due to the backlash of the swing member 12.

  Further, the cam surface 18a is in contact with the outer peripheral surface of the drive shaft 4 with the inner surface of the drive shaft through-hole 17 and the side farther from the connecting link 14, that is, the lower half side in the drawing at all inclination angles. The surface shape is set to regulate the swing locus of the swing member 12. Therefore, the lower half of the inner surface of the drive shaft through hole 17 of the journal 13 contacts the drive shaft 4, but the upper half does not contact the drive shaft 4. It is only necessary to surface the half side.

  In this embodiment, the swing member 12 is composed of a journal 13 having a drive shaft through hole 17 and a swash plate 15 fixed to the outer periphery of the journal 13. A single swash plate may be used.

  In this embodiment, the cam surface 18 a is provided on the rotor 11 and the cam slide portion 19 is provided on the swing member 12. Conversely, the cam surface 18 a is provided on the swing member 12 and the cam slide portion 19 is provided on the rotor 11. It may be provided.

  In this embodiment, the connecting means is the connecting link 14, but a structure in which either one of the rotor 11 and the swinging member 12 is provided with a guide groove and the other is provided with a guide pin that moves in the guide groove (Kidney type). It may be.

1 is an overall cross-sectional view of a variable displacement compressor according to an embodiment of the present invention. 1A and 1B show an embodiment of the present invention, in which FIG. 1A is a side view of a rotor, FIG. 2B is a cross-sectional view of a journal, and FIG. FIG. 3 is a cross-sectional view of a main part of the swash plate according to an embodiment of the present invention with a minimum inclination angle. FIG. 3 is a cross-sectional view of a main part of the swash plate in an intermediate inclination angle state according to the embodiment of the present invention. FIG. 3 is a cross-sectional view of a main part of the swash plate according to an embodiment of the present invention with a maximum inclination angle. It is a whole sectional view of a variable capacity compressor of a conventional example. A prior art example is shown, (a) is a cross-sectional view of a main part in a state where the swash plate is at a minimum inclination angle, and (b) is a cross-sectional view of a main part in a state where the swash plate is at a maximum inclination angle. Other conventional examples are shown, (a) is a cross-sectional view of the main part when the swash plate is at the minimum tilt angle state, (b) is a cross-sectional view of the main part when the swash plate is at the maximum tilt angle state, It is principal part sectional drawing of an angle state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable capacity compressor 2 Housing 4 Drive shaft 8 Cylinder bore 9 Piston 10 Crank chamber 11 Rotor 12 Swing member 13 Journal 14 Connection link (connection means)
15 Swash plate 17 Drive shaft through hole 18a Cam surface 19 Cam sliding part

Claims (2)

A plurality of cylinder bores (8) and a crank chamber (10) communicating with the cylinder bores (8) are provided in the housing (2), and a drive shaft (4) passing through the crank chamber (10) rotates in the housing (2). The rotor (11) is fixed to the drive shaft (4) and has a drive shaft through hole (17) to be inserted into the drive shaft (4), and is disposed in the crank chamber (10). And a connecting means (14) for connecting between the swinging member (12) and the rotor (11). A plurality of swinging members (12) are provided by swinging the swinging member (12). A plurality of pistons (9) that reciprocate in the cylinder bore (8) are provided,
By adjusting the crank chamber pressure, which is the back pressure of each piston (9), the swash plate (15) swings about the connecting means (14), so that the tilt angle is varied, and the swing In the variable displacement compressor (1) in which the reciprocating stroke of each piston (9) is varied by varying the inclination angle of the member (12),
One of the rotor (11) and the swing member (12) is provided with a cam surface (18a), and the other is provided with a cam sliding portion (19) that moves following the cam surface (18a). The cam surface (18a) is in contact with the outer peripheral surface of the drive shaft (4) with the inner surface of the drive shaft through-hole (17) and the side farther from the connecting means (14) being at all inclination angles. The variable displacement compressor (1) is characterized in that it is set to a surface shape that regulates the swing locus of the swing member (12). Variable displacement compressor (1) according to claim 1,
The swing member (12) is composed of a journal (13) having the drive shaft through hole (17) and a swash plate (15) fixed to the outer periphery of the journal (13). A variable displacement compressor (1).

Images