JP2007092567A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve performance or durability, in a compressor in which a piston has a silencer function. <P>SOLUTION: In the compressor, a cylinder housing has a cylinder bore 6, a first suction chamber, and a first communication hole 17 communicating with the first suction chamber and opened to an inner circumferential face of the cylinder bore. A piston 8 is slidably disposed in the cylinder bore 6, and is provided with a second suction chamber 20 and a second communication hole 21 communicating with the second suction chamber 20 and opened to a side circumferential face of the piston 8. At a suction stroke of the piston 8, the first suction chamber communicates with the second suction chamber 20 through the first communication hole 17 and second communication hole 21, and refrigerant gas is supplied from the second suction chamber 20 into the cylinder bore 6 through a suction hole 22. A peripheral part of an opening of the second communication hole 21 of the piston 8 is depressed to the inside, and a clearance d between the peripheral part of the opening of the second communication hole 21 and an inner peripheral face of the cylinder bore 6 is wider than the other portion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a compressor having a refrigerant gas suction chamber in a piston.

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

  As shown in FIG. 6, the compressor 100 includes a cylinder housing 101. The cylinder housing 101 is mainly configured by assembling a cylinder main body 101a, a front head 101b, and a rear head 101c. A drive shaft 102 is rotatably supported at the center of the cylinder housing 101. In the cylinder housing 101, a plurality of cylinder bores 103 disposed at equal intervals on the circumference and a crank chamber 104 communicating with the plurality of cylinder bores 103 are formed.

  A piston 105 is slidably disposed in each cylinder bore 103. In the crank chamber 104, a rotor 106 and a swash plate 107 through which the drive shaft 102 passes are arranged. The rotor 105 is fixed to the drive shaft 102. The swash plate 107 is supported so as to be movable in the axial direction of the drive shaft 102, and is connected to the rotor 106 via a connecting pin 108. That is, the swash plate 107 rotates with the rotor 106 by the rotation of the drive shaft 102, and the swing angle is variable by the movement in the axial direction. An engaging portion 105 a of the piston 105 is engaged with the outer peripheral portion of the swash plate 107 via a shoe 109. The piston 105 reciprocates in the cylinder bore 103 by the rotation of the swash plate 107, and its stroke is changed by the swing angle of the swash plate 107.

  On the other hand, on the rear head 101c side of the cylinder housing 101, a first suction chamber 110, a first communication hole 111, and a discharge chamber 112 for the refrigerant gas are formed. The first communication hole 111 communicates with the first suction chamber 110 and is opened on the inner peripheral surface of the cylinder bore 103. The discharge chamber 112 is partitioned by a cylinder bore 103 via a valve body 113. A discharge hole 114 with a discharge valve is formed in the valve body 113.

  A second suction chamber 115 and a second communication hole 116 are formed in the piston 105. The second communication hole 116 communicates with the second suction chamber 115 and is opened on the side peripheral surface of the piston 105. Also, a suction hole 117 with a suction valve is formed in the tip wall of the piston 105.

  In the above configuration, in the suction stroke of the piston 105 (stroke moving from the top dead center to the bottom dead center), the first suction chamber 110 is transferred to the second suction chamber 115 via the first communication hole 111 and the second communication hole 116. The suction hole 117 is opened by the communication and the decompression in the cylinder bore 103. As a result, the refrigerant gas is supplied from the second suction chamber 115 to the cylinder bore 103.

  In the compression stroke of the piston 105 (stroke moving from the bottom dead center to the top dead center), the refrigerant gas in the cylinder bore 103 is adiabatically compressed by the piston 105. The compressed refrigerant gas is discharged from the discharge hole 114 to the discharge chamber 112.

Since the compressor 100 of the conventional example has the first suction chamber 110 in the cylinder housing 101 and the second suction chamber 115 in the piston 105, the total suction volume is large. Therefore, even if the refrigerant gas is supplied into the cylinder bore 103 during the compression stroke of the piston 105, the pressure fluctuation on the suction chamber side can be suppressed to a small level, and there is an advantage that noise caused by the pressure fluctuation can be reduced. That is, the piston 105 is structured to have a silencer function.
JP 2002-364528 A

  However, in the compressor 100 of the conventional example, during the compression stroke of the piston 105, a large compressive force acts on the side peripheral wall of the piston 105 due to the pressure increase in the cylinder bore 103. Due to this compressive force, the opening peripheral edge of the second communication hole 116 that is most likely to be elastically deformed on the side peripheral wall of the piston 105 bulges outward, and the swollen opening peripheral edge may locally contact the inner peripheral surface of the cylinder bore 103. When the piston 105 is in local contact with the inner peripheral surface of the cylinder bore 103, the performance and durability of the compressor 100 are deteriorated.

  Therefore, the present invention provides a compressor having a piston with a silencer function, which can improve performance and durability by preventing the piston from locally contacting the inner peripheral surface of the cylinder bore. The purpose is to do.

  According to a first aspect of the present invention for achieving the above object, the cylinder housing is provided with a cylinder bore, a first suction chamber, and a first communication hole that communicates with the first suction chamber and opens on the inner peripheral surface of the cylinder bore. A piston is slidably disposed in the cylinder bore, and the piston is provided with a second suction chamber, a second communication hole that communicates with the second suction chamber, and opens to a side circumferential surface of the piston. In the suction stroke, the first suction chamber communicates with the second suction chamber via the first communication hole and the second communication hole, and the refrigerant gas from the second suction chamber enters the cylinder bore through the suction hole of the piston. In the compression stroke of the piston, in the compressor that compresses the refrigerant gas in the cylinder bore by the piston, the interval between the opening peripheral edge of the second communication hole and the inner peripheral surface of the cylinder bore is changed to another Number And wherein the set wider.

  A second aspect of the present invention is the compressor according to the first aspect, wherein the distance between the opening peripheral edge of the second communication hole and the inner peripheral surface of the cylinder bore is the peripheral edge of the opening of the second communication hole. Widely formed by crushing the part inward.

  A third aspect of the present invention is the compressor according to the first aspect, wherein an interval between a peripheral edge portion of the opening of the second communication hole and the cylinder bore cuts a peripheral edge portion of the opening of the second communication hole. It is characterized by being widely formed.

  According to the first aspect of the present invention, even if the opening peripheral edge of the second communication hole bulges outward during the compression stroke of the piston, the gap between the inner peripheral surface of the cylinder bore is wide, so the opening peripheral edge of the second communication hole is There is no local contact with the inner peripheral surface of the cylinder bore. As described above, the piston having a silencer function can prevent the piston from locally contacting the inner peripheral surface of the cylinder bore and improve performance and durability.

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

  According to the invention of claim 3, the same effect as that of the invention of claim 1 can be obtained.

  Hereinafter, an embodiment 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 compressor 1, FIG. 2 is a partially cutaway side view of a piston 8, and FIG. 3 is a sectional view taken along line AA in FIG. 4 is an enlarged view of a portion B in FIG. 3, and FIG. 5 is a cross-sectional view of the main part showing the compression force acting on the piston 8 in the compression stroke of the piston 8.

  As shown in FIG. 1, the compressor 1 is a so-called swash plate type variable capacity compressor, and includes a cylinder housing 2. The cylinder housing 2 is assembled with a cylinder body 2a, a front head 2b disposed on one side surface of the cylinder body 2a, and a rear head 2c disposed on the other side surface of the cylinder body 2a via a valve body 3. It is configured by being.

  A drive shaft 5 is rotatably supported at the center of the cylinder housing 2 via a bearing 4. In the cylinder housing 2, a plurality of cylinder bores 6 disposed at equally spaced positions on the circumference and a crank chamber 7 communicating with the plurality of cylinder bores 6 are formed.

  A piston 8 is slidably disposed in each cylinder bore 6. In the crank chamber 7, a rotor 10, a sleeve 11, a journal 12, and a swash plate 13 through which the drive shaft 5 passes are arranged. The rotor 10 is fixed to the drive shaft 5 and is rotated integrally with the drive shaft 5. The sleeve 11 is supported so as to be movable in the axial direction of the drive shaft 5. The journal 12 is configured to vary the swing angle according to the position of the sleeve 11 in the axial direction, and is fixed to the rotor 10 via a connecting link 14. The swash plate 13 is fixed to the journal 12. In other words, the swash plate 13 rotates with the rotor 10 by the rotation of the drive shaft 5, and the swing angle is varied by the axial movement of the journal 12. An engaging portion 8 a of the piston 8 is engaged with the outer peripheral portion of the swash plate 13 via a shoe 15. As described above, the piston 8 reciprocates in the cylinder bore 6 by the rotation of the swash plate 13, and its stroke is varied depending on the swing angle of the swash plate 13.

  On the other hand, on the rear head 2c side of the cylinder housing 2, a first suction chamber 16, a first communication hole 17, and a discharge chamber 18 for the refrigerant gas are formed. The first suction chamber 16 is connected to the outlet side of the evaporator of the refrigeration cycle. The first suction chamber 16 is divided and arranged into a compartment 16a in the rear head 2c and a compartment 16b in the cylinder body 2a, and the compartments 16a and 16b communicate with each other through the communication hole 3a of the valve body 3. The first communication hole 17 communicates with the first suction chamber 16 and is opened on the inner peripheral surface of the cylinder bore 6. The discharge chamber 18 is connected to the inlet side of the condenser of the refrigeration cycle. The discharge chamber 18 is partitioned by each cylinder bore 6 via the valve body 3. A discharge hole 19 with a discharge valve is formed in each part of the valve body 3 that partitions both chambers.

  The piston 8 is formed with a second suction chamber 20, a second communication hole 21, and a suction hole 22 with a suction valve. The second suction chamber 20 is disposed inside the piston 8. The second communication hole 21 communicates with the second suction chamber 20 and is opened on the side peripheral surface of the piston 8. The suction hole 22 is formed in the tip wall of the piston 8. A suction valve housing recess is formed on the end face of the tip wall of the piston 8. A suction valve 27 is disposed in the suction valve housing recess, and opens and closes the suction hole 22. The suction valve 27 is supported by a valve pin 25 that passes through a holding hole 27a provided in the central portion. The valve pin 25 passes through a pin hole 27 a provided in the tip wall of the piston 8, and toward the tip wall of the piston 8 together with the suction valve 27 by a valve spring 26 disposed on the back side of the tip wall of the piston 8. Energized and held.

  Moreover, the opening peripheral part of the 2nd communicating hole 21 is dented inside, as shown in detail in FIGS. That is, the entire side peripheral surface of the piston is a perfect circle as indicated by the imaginary line BL in FIGS. 3 and 4, but only the opening peripheral edge of the second communication hole 21 is a perfect circle imaginary line BL. On the other hand, it is a recessed surface 23 recessed inward. The recessed surface 23 is formed by applying an external force to the peripheral edge of the opening of the second communication hole 21 and crushing it. As described above, the gap d (shown in FIG. 5) is set wider than the other portions between the peripheral edge of the opening of the second communication hole 21 of the piston 8 and the inner peripheral surface of the cylinder bore 6.

  In addition, an extraction passage (not shown) that is in continuous communication is formed between the crank chamber 7 and the first suction chamber 16. An air supply passage (not shown) in which a pressure control valve (not shown) is interposed is formed between the crank chamber 7 and the discharge chamber 18. By adjusting the pressure in the crank chamber 7 by the pressure control means, the inclination angle of the swash plate 13 can be adjusted, and the discharge capacity of the refrigerant can be varied.

  In the above configuration, when the drive shaft 5 rotates, the rotational force causes the swash plate 13 to rotate, and the plurality of pistons 8 reciprocate within the cylinder bore 6. In the suction stroke of the piston 8 (stroke moving from the top dead center to the bottom dead center), the first suction chamber 16 communicates with the second suction chamber 20 via the first communication hole 17 and the second communication hole 21. In addition, the suction hole 22 is opened by the reduced pressure in the cylinder bore 6. As a result, the refrigerant gas is supplied from the second suction chamber 20 to the cylinder bore 6.

  In the compression stroke of the piston 8 (stroke moving from the bottom dead center to the top dead center), the suction hole 22 is closed, and the refrigerant gas in the cylinder bore 6 is adiabatically compressed by the piston 8. The compressed refrigerant gas is discharged from the discharge hole 19 to the discharge chamber 18.

  In the compression stroke of the piston 8 described above, as shown in FIG. 5, a large compression force acts on the side peripheral wall of the piston 8 due to the pressure increase in the cylinder bore 6. With this compressive force, as shown by an arrow a in FIG. 4, the opening peripheral edge of the second communication hole 21 of the piston 8 expands outward. Here, since the gap between the opening peripheral edge of the second communication hole 21 and the inner peripheral surface of the cylinder bore 6 is formed at a wider interval d than the other parts, the opening peripheral edge of the second communication hole 21 bulging outward. The portion does not make local contact with the inner peripheral surface of the cylinder bore 6. As described above, the piston 8 having the silencer function can prevent the piston 8 from being in local contact with the inner peripheral surface of the cylinder bore 6 and improve the performance and durability.

  In this embodiment, the recessed surface 23 is formed by crushing by applying an external force to the opening peripheral edge of the second communication hole 21, but may be formed by cutting the opening peripheral edge of the second communication hole 21. . Also, as shown by phantom lines in FIG. 4, it is preferable to form the reinforcing rib 30 on the inner side of the opening peripheral edge of the second communication hole 21, so that deformation to the outer side of the opening peripheral edge can be prevented more effectively.

  In this embodiment, a gap d between the opening peripheral edge of the second communication hole 21 of the piston 8 and the inner peripheral surface of the cylinder bore 6 is set to be wider than other portions by the recessed surface 23 on the piston 8 side. However, the predetermined interval d may be set by forming a recessed surface on the cylinder bore 6 side or a recessed surface on both members. However, processing is easier if the recessed surface 23 is formed on the piston 8 side as in the embodiment.

1 is an overall cross-sectional view of a compressor according to an embodiment of the present invention. 1 shows an embodiment of the present invention and is a partially broken side view of a piston. FIG. FIG. 3 shows an embodiment of the present invention and is a cross-sectional view taken along line AA in FIG. 2. FIG. 4 shows an embodiment of the present invention and is an enlarged view of a portion B in FIG. 3. It is principal part sectional drawing which shows one Embodiment of this invention, and is in the compression stroke of a piston, and shows the compression force which acts on a piston. It is whole sectional drawing of the compressor of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Cylinder housing 6 Cylinder bore 8 Piston 16 1st suction chamber 17 1st communication hole 20 2nd suction chamber 21 2nd communication hole 22 Suction hole d The opening peripheral part of a 2nd communication hole, and the internal peripheral surface of a cylinder bore Interval between

Claims (3)

A cylinder housing (2) communicates with a cylinder bore (6), a first suction chamber (16), and the first suction chamber (16), and a first communication hole (opened on the inner peripheral surface of the cylinder bore (6)) ( 17), and a piston (8) is slidably disposed in the cylinder bore (6). The piston (8) communicates with the second suction chamber (20) and the second suction chamber (20). And providing a second communication hole (21) opening in the side peripheral surface of the piston (8),
In the suction stroke of the piston (8), the first suction chamber (16) communicates with the second suction chamber (20) through the first communication hole (17) and the second communication hole (21). The refrigerant gas is supplied from the second suction chamber (20) into the cylinder bore (6) through the suction hole (22) of the piston (8). In the compression stroke of the piston (8), the piston (8) In the compressor (1) for compressing the refrigerant gas in the cylinder bore (6) by
The compressor (1) characterized in that an interval (d) between an opening peripheral edge of the second communication hole (21) and an inner peripheral surface of the cylinder bore (6) is set wider than other portions. A compressor (1) according to claim 1, comprising:
The distance (d) between the opening peripheral edge of the second communication hole (21) and the inner peripheral surface of the cylinder bore (6) crushes the peripheral edge of the opening of the second communication hole (21) inward. A compressor characterized by being widely formed by. The compressor according to claim 1,
The distance (d) between the peripheral edge of the opening of the second communication hole (21) and the cylinder bore (6) is formed wide by cutting the peripheral edge of the opening of the second communication hole (21). Compressor characterized by.

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