JP4071551B2 - Compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressor that adiabatically compresses a refrigerant that is interposed in a refrigeration cycle such as a vehicle air conditioner and vaporized in the refrigeration cycle.
[0002]
[Prior art]
In this type of compressor, a front housing is joined to a front end face of a cylinder block having a cylinder bore to form a crank chamber, and a rear housing is joined to a rear end face of the cylinder block via a valve plate. A suction chamber and a discharge chamber are formed, and the piston in the cylinder bore is reciprocated using the rotation of a drive shaft that is pivotally supported in the crank chamber, whereby the refrigerant gas in the suction chamber is sucked into the cylinder bore and compressed, Some discharge into the discharge chamber.
[0003]
The suction chamber and the discharge chamber are partitioned by a cylindrical partition wall, and either the suction chamber or the discharge chamber is provided inside the partition wall, and the other is provided outside the partition wall.
[0004]
In this type of compressor, there is a problem that the heat of the refrigerant discharged into the discharge chamber at a high temperature and high pressure is transferred to the refrigerant gas in the suction chamber through the partition wall. That is, as the refrigerant gas in the suction chamber expands due to heat from the discharge chamber, the amount of refrigerant gas sucked into the cylinder bore decreases, resulting in a reduction in compression efficiency.
[0005]
As a conventional example for solving this problem, there is one in which heat transfer between the suction chamber and the discharge chamber is suppressed by providing a heat insulating groove on the partition wall (Japanese Patent Laid-Open No. 5-164042).
[0006]
[Problems to be solved by the invention]
However, in this conventional example, since the compression efficiency is lowered due to the reduction of the space area of the discharge chamber and the suction chamber, only a shallow heat insulating groove is provided on the partition wall, and a sufficient heat insulating effect cannot be expected.
[0007]
The present invention has been made based on such a conventional technique, and an object of the present invention is to provide a compressor capable of suitably blocking heat transfer between the suction chamber and the discharge chamber.
[0008]
[Means for Solving the Problems]
As a result of research, the present applicant has found that even if the area of the discharge chamber is reduced, there is almost no decrease in the discharge capacity, and there is almost no decrease in the compression efficiency. Is formed so as to project to the discharge chamber side.
[0009]
In the first aspect of the present invention, a front housing is joined to a front end face of a cylinder block having a cylinder bore to form a crank chamber, and a rear housing is joined to a rear end face of the cylinder block via a valve plate. In a compressor that forms a suction chamber and a discharge chamber and reciprocates a piston using rotation of a drive shaft that is pivotally supported in the crank chamber,
An overhanging wall that protrudes from the partition wall that partitions the suction chamber and the discharge chamber toward the discharge chamber and forms a heat insulating space with the partition wall is provided from the tip of the partition wall ;
The overhanging portion includes a vertical portion that protrudes substantially perpendicularly from the tip of the partition wall and is not in contact with the valve plate, so that the overhanging wall portion is in noncontact with the valve plate. It is a feature. In the present invention, the front end portion of the partition wall is defined as a portion on the front end side from the midpoint of the partition wall.
[0012]
【The invention's effect】
According to the first aspect of the present invention, heat transfer between the suction chamber and the discharge chamber can be sufficiently suppressed by the heat insulating space provided from the tip of the partition wall along the partition wall. In addition, since the overhanging wall portion that forms the heat insulation space between the partition wall and the discharge chamber is provided so as to extend over the suction chamber, the rear housing does not have to be enlarged. There is no reduction in compression efficiency due to a decrease in discharge capacity.
[0013]
In addition, according to the invention described in claim 1, as described above, a protruding wall portion that forms a heat insulating space between the partition wall and the tip of the partition wall can be provided to obtain a sufficient heat insulating effect. However, since the overhanging wall portion is not in contact with the valve plate, there is no concern that the discharge hole is blocked. Therefore, other parts of the existing compressor can be used as they are.
[0014]
Further, according to the first aspect of the invention, by the vertical section to utilize vertical portion forming a stepped portion between the substantially vertically projecting from said section Ekabe from the compartment walls, the rear housing bore and The rear housing can be easily held during processing.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a compressor according to an embodiment of the present invention will be described with reference to the drawings.
[0016]
1 is an overall sectional view of a compressor according to an embodiment of the present invention, FIG. 2 is a rear view of the rear housing of the compressor, FIG. 3 is a front view of the rear housing of the compressor, and FIG. 4 is equipped with a control valve. FIG. 5 is an enlarged sectional view of the rear housing of the compressor, FIG. 6 is a diagram for explaining the rear housing forming process, and is a sectional view showing the original shape of the rear housing by die casting, FIG. It is principal part sectional drawing which shows the modification of this invention.
[0017]
The compressor 1 of this embodiment is a swash plate type variable capacity compressor, and is used, for example, in a cooling cycle of a vehicle air conditioner, and adiabatically compresses refrigerant gas evaporated in a refrigeration cycle.
[0018]
The variable capacity compressor 1 includes a cylinder block 2 having a plurality of cylinder bores 3 arranged at equal intervals in the circumferential direction, and a crank chamber 5 between the cylinder block 2 joined to the front end face of the cylinder block 2. And a rear housing 6 joined to the rear end surface of the cylinder block 2 via a valve plate 9 to form a suction chamber 7 and a discharge chamber 8. The cylinder block 2, the front housing 4 and the rear housing 6 are fastened and fixed by a plurality of through bolts B.
[0019]
The valve plate 9 includes a suction hole 11 that communicates the cylinder bore 3 and the suction chamber 7, and a discharge hole 12 (see FIG. 3) that communicates the cylinder bore 3 and the discharge chamber 8.
[0020]
A valve mechanism (not shown) for opening and closing the suction hole 11 is provided on the cylinder block 2 side of the valve plate 9, while a valve mechanism (not shown) for opening and closing the discharge hole 12 is provided on the rear housing 6 side of the valve plate 9. Is provided. A gasket is interposed between the valve plate 9 and the rear housing 6 to keep the suction chamber 7 and the discharge chamber 8 sealed. In addition, an O-ring is interposed on the joint surface between the rear housing 6 and the cylinder block 2 at the periphery of the valve plate 9 to prevent refrigerant leakage to the outside of the compressor 1.
[0021]
A drive shaft S is pivotally supported through bearings in the support holes 19 and 20 in the center of the cylinder block 2 and the front housing 4, and the drive shaft S is rotatable in the crank chamber 5.
[0022]
In the crank chamber 5, a drive plate 21 fixed to the drive shaft S, a journal 24 slidably connected by a pin 23 to a sleeve 22 slidably fitted to the drive shaft S, and the journal 24 And a wobble plate (swash plate) 26 attached to the boss portion 25 via a bearing. The wobble plate 26 is slidably connected to a restriction plate 35 fixed in the crank chamber 5, thereby preventing rotation and swinging in the axial direction. That is, when the journal 24 rotates by rotating the drive shaft S, the wobble plate 26 swings non-rotatingly and in the axial direction as the journal 24 rotates and swings. The drive plate 21 and the journal 24 are connected to the hinge arms 21h and 24h via arcuate long holes 27 and pins 28, whereby the wobbling plate 26 has a maximum inclination angle and a minimum inclination angle. Is regulated.
[0023]
The pistons 29 accommodated in the cylinder bores 3 are connected to the wobble plate 26 via the piston rod 30 and reciprocate by the swinging of the wobble plate 26. The basic function of the compressor 1 is to compress the refrigerant sucked into the suction chamber 7 → the valve hole 9 of the valve plate 9 → the cylinder bore 3 by the piston movement of the piston 29, and the cylinder bore 3 → the discharge hole 12 of the valve plate 9 → The liquid is discharged into the discharge chamber 8.
[0024]
In order to make this discharge capacity variable, an extraction passage 31 that always connects the crank chamber 5 and the suction chamber 7, an air supply passage 32 that connects the crank chamber 5 and the discharge chamber 8, and the air supply passage 32 A pressure control mechanism including a control valve 33 that opens and closes is provided. When the pressure in the crank chamber 5 is changed by opening and closing the control valve 33, the pressure balance between the crank chamber 5, the suction chamber 7, and the discharge chamber 8 is changed. The inclination angle of the wobble plate 26 changes from (the pressure balance before and after the piston 29), that is, the piston stroke changes, and the discharge capacity of the compressor 1 changes.
[0025]
The bleed passage 31 includes the support hole 19 of the cylinder block 2, the passage 31c of the valve plate 9, the passage 31a of the rear housing 6, the groove 31b of the rear housing, and the passage 31a of the rear housing 6. The air supply passage 32 includes a passage 32a of the cylinder block, a passage 32b of the valve plate 9, a passage 32c of the rear housing 6, and a passage (not shown) that is provided in the control valve 33 and communicates the passage 32 and the discharge chamber 8. It is configured.
[0026]
2 to 4 show the rear housing 6.
[0027]
The rear housing 6 defines a cylindrical partition wall 36, a discharge chamber 8 is formed on the inner peripheral side, and a suction chamber 7 is formed on the outer peripheral side. A suction port 37 that communicates with the chamber 7 via a passage 38 and a discharge port 39 that communicates with the discharge chamber 8 via a passage 40 are provided. The suction port 37 is connected to a low-pressure side pipe that communicates with the evaporator, and the discharge port 39 is connected to a high-pressure side pipe that communicates with a capacitor.
[0028]
The control valve 33 described above is provided across the suction chamber 7 and the discharge chamber 8 and is held by a holding hole 42 formed in the inner peripheral surface of the cylindrical holding wall 41.
[0029]
In the rear housing 6 of this embodiment, a projecting wall 44 that projects from the partition wall 36 toward the discharge chamber 8 and forms a heat insulating space 43 between the partition wall 36 and the rear wall 6 extends from at least the tip 36b of the partition wall 36. This extends to the base end 36 c, whereby the heat of the refrigerant having a high temperature in the discharge chamber 8 is difficult to be transmitted to the suction chamber 7 through the partition wall 36. Further, the overhanging wall portion 44 is not in contact with the valve plate 9, and more specifically, the partition wall 36 at a portion separated from the distal end surface (joint surface with the valve plate 9) 36 a of the partition wall 36. A substantially vertical L-shaped section from a vertical portion 45 projecting substantially vertically from a parallel portion 46 provided substantially parallel to the partition wall 36 and connecting the vertical portion 45 and the bottom wall portion of the rear housing 6. Is provided. In the present invention, the front end portion 36 b of the partition wall 36 is defined as a portion on the front end side from the midpoint of the partition wall 36. In addition, when providing the heat insulation space 43 to the front-end | tip part 36b of the partition wall 36 as mentioned above, since it is necessary to form the heat insulation space 43 avoiding the holding hole 42, the channel | path 40, etc., as shown in FIG. The heat insulation space is formed intermittently.
[0030]
The manufacturing process of the rear housing 6 will be described below. The rear housing 6 is manufactured by first forming an original shape as shown in FIG. 6 by die casting, and then forming a passage 31a, a passage 32c, and a holding hole with a predetermined bit on the die casting original shape. 42, the suction port 37, the passage 38, the discharge port 39, the passage 40, and the like are excavated to obtain the desired rear housing 6 shown in FIG. Here, the vertical portion 45 of the overhanging wall portion 44 becomes a stepped portion with the tip end portion 36b of the partition wall 36, and this stepped portion 45 can easily hold the die cast original shape of the rear housing 6 during excavation processing.
[0031]
As described above, according to the compressor 1 of this embodiment, the protruding wall 44 that protrudes from the partition wall 36 and forms the heat insulating space 43 between the partition wall 36 is provided from the distal end portion 36 b of the partition wall 44. The transfer of heat between the suction chamber 7 and the discharge chamber 8 can be sufficiently suppressed. Moreover, since the overhanging wall portion 44 is provided so as to overhang the discharge chamber 8 side, unlike the case of overhanging the suction chamber 7 side, the overhanging wall portion 44 is sufficiently provided without reducing the discharge capacity without increasing the size of the rear housing 6. A large heat insulating space 43 can be formed.
[0032]
Here, in general, in order to prevent refrigerant leakage from the discharge chamber to the suction chamber, a structure is adopted in which the partition wall and the valve plate are joined with a very large force via a gasket. In this embodiment, since the heat insulating space 43 is formed by providing the overhanging wall portion 44 projecting from the partition wall 36 as described above, the strength of the partition wall 36 is increased and the assembly strength is increased. To be advantageous.
[0033]
Moreover, according to the compressor 1 of this embodiment, since the overhanging wall portion 44 is not in contact with the valve plate 9, there is no fear that the discharge hole 12 is blocked by the overhanging wall portion 44. In particular, in the case of a small compressor, as shown in FIG. 3, the arrangement positions of the partition wall 36, the suction hole 11, and the discharge hole 12 are extremely limited, and this advantage is great. Moreover, there is an advantage that parts of the existing compressor other than the rear housing 6 can be used as they are.
[0034]
Moreover, according to the compressor 1 of this embodiment, since the overhang | projection part 44 is provided with the vertical part 45 protrudingly provided substantially perpendicularly from the division wall 36, this vertical part 45 becomes a step part, and a cutting process etc. When this is done, the die cast original shape of the rear housing 6 can be easily held.
[0035]
In the above-described embodiment, the heat insulating space 43 is configured as an air layer. However, for example, the heat insulating material C may be filled as shown in FIG. In this embodiment, the discharge chamber 8 is provided on the inner peripheral side of the partition wall 36 and the suction chamber 7 is provided on the outer peripheral side. However, the suction chamber is provided on the outer peripheral side and the discharge chamber is provided on the outer peripheral side. Of course, it is applicable.
[Brief description of the drawings]
FIG. 1 is an overall cross-sectional view of a compressor according to an embodiment of the present invention.
FIG. 2 is a rear view of the rear housing of the compressor.
FIG. 3 is a front view of a rear housing of the compressor.
FIG. 4 is a front view of a rear housing equipped with a control valve.
FIG. 5 is an enlarged sectional view of a rear housing, which is a main part of the compressor.
FIG. 6 is a cross-sectional view for explaining a rear housing forming process and showing a rear housing original form by forging.
FIG. 7 is a cross-sectional view of an essential part showing a modification of the present invention.
[Explanation of symbols]
1 Swash plate type variable capacity compressor (compressor)
2 Cylinder block 3 Cylinder bore 4 Front housing 5 Crank chamber 6 Rear housing 7 Suction chamber 8 Discharge chamber 29 Piston 36 Partition wall 36a Partition wall tip surface 36b Partition wall tip 44 Overhang wall S Drive shaft

Claims (1)

A front housing (4) is joined to a front end face of a cylinder block (2) having a cylinder bore (3) to form a crank chamber (5), and a valve plate (9) is attached to a rear end face of the cylinder block (2). ) To form the suction chamber (7) and the discharge chamber (8) by using the rotation of the drive shaft (S) supported in the crank chamber (5). In the compressor (1) for reciprocating the piston (29),
A heat insulating space (43) is formed between the partition wall (36) projecting from the partition wall (36) partitioning the suction chamber (7) and the discharge chamber (8) to the discharge chamber (8) side. An overhang wall (44) is provided from the tip (36b) of the partition wall (36) ,
The overhang portion (44) includes a vertical portion (45) that protrudes substantially perpendicularly from the tip end portion (36b) of the partition wall (36) and is not in contact with the valve plate (9). The compressor (1), wherein the projecting wall (44) is not in contact with the valve plate (9 ).

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