JP4640645B2 - Compressor - Google Patents

Description

  The present invention relates to a compressor used in a refrigeration cycle or the like, and more particularly to a structure aimed at improving its sealing performance.

  As a structure for improving the sealing performance in a conventional compressor, there is the following structure. A presser rib that forms a partition partitioning the inner peripheral side of the housing as a suction chamber and the outer peripheral side as a discharge chamber, is located between the suction passages that are drilled in the syringe block and open into the suction chamber, and cooperates with the partition wall Is formed integrally with the housing, and the abutment surface of the presser rib is protruded from the abutment surface of the outer peripheral wall among the abutment surfaces of the housing that sandwich the valve plate (see Patent Document 1). . In a compressor that pumps fluid such as refrigerant, the valve plate tends to bend toward the housing as the fluid is compressed in the bore (compression chamber) of the cylinder block. The present invention aims to improve the sealing performance of the cylinder block end face by suppressing the deformation of the valve plate by a pressing rib having an abutting surface protruding from the abutting surface of the wall.

JP-A-8-200188

However, in order to improve the sealing performance of the cylinder block end face, it is necessary to increase the contact pressure between the cylinder block and the gasket. However, in the technique disclosed in Patent Document 1, the presser rib is used. Since pressure is transmitted to the gasket through the valve plate, it is difficult to transmit to the gasket. For this reason, the contact pressure between the cylinder block and the gasket does not increase so much, and the sealing performance at the end face of the cylinder block is not expected to improve so much.
Then, this invention makes it a subject to improve the sealing performance in the end surface of a cylinder block reliably.

In order to achieve the above object, the present invention provides a cylinder block in which a compression chamber is formed, a cylinder head in which a suction chamber and a discharge chamber are defined to seal an end surface of the cylinder block, the cylinder block, and the cylinder. In the compressor including a valve plate disposed between the heads, the cylinder block, and a gasket disposed between the valve plates, the suction chamber is an end surface of the cylinder block and is formed inside the cylinder head. And a protruding portion protruding to the cylinder head side is formed inside the portion corresponding to the partition wall separating the discharge chamber and the discharge chamber .

  According to the compressor of the present invention, the cylinder block and the gasket are in close contact with each other while the convex portion presses the gasket toward the cylinder head, and toward the cylinder head of the valve plate accompanying the compression of the refrigerant in the compression chamber. Allow bending. In other words, the presence of the convex portion prevents a gap from being formed between the cylinder block and the gasket even when the valve plate is curved toward the cylinder head, so that a good sealing performance can always be ensured.

Further, in the compressor according to the present invention, the convex portion is further formed outside the portion facing the partition wall that is formed inside the cylinder head and separates the suction chamber and the discharge chamber. It is characterized by being.

The above-described bending phenomenon of the valve plate is more likely to occur as the distance from the portion where the fastening member such as a bolt or a pin for fixing the cylinder block, the valve plate, the cylinder head, or the like is provided. The portions corresponding to the inner side and the outer side of the partition wall are the space in which the suction chamber or the discharge chamber is defined, so that the bending phenomenon is likely to occur. Therefore, as in the present configuration, by providing the convex portions on the inner side, the outer side, or both sides of the partition wall, it is possible to cope with the curvature of the valve plate and ensure good sealing performance. .
The above-described configuration is particularly useful when the suction chamber is formed inside the partition and the discharge chamber is formed outside the partition.

Moreover, it is preferable that the height of the convex part formed in the outer side of the said partition is below half of the total thickness of the elastic member of the said gasket.
If the height of the convex portion is too large, the fastening force of the fastening member may be affected, and the contact force between the cylinder block and the gasket may be weakened. Since the elastic member of the gasket allows the convex portion, a decrease in the fastening force can be avoided.

  In addition, the shape of the convex portion should be changed as appropriate according to the use conditions, manufacturing cost, etc. Can be lowered. Further, if the convex portion is streamlined along the actual or predicted curved shape of the valve plate, more excellent sealing performance can be obtained.

  As described above, according to the present invention, the cylinder block and the gasket are strongly in close contact with each other while pressing the gasket toward the cylinder head side by the convex portion, and the cylinder head of the valve plate accompanying the compression of the refrigerant in the compression chamber Since the bending to the side is allowed, it is prevented that a gap is formed between the cylinder block and the gasket, and a good sealing property can be secured at the end face of the cylinder block.

FIG. 1 is a sectional view showing the structure of a compressor according to the present invention. FIG. 2 is a cross-sectional view taken along the line AA of the compressor shown in FIG. FIG. 3 is an explanatory view showing the shape of a cylinder block according to the present invention. FIG. 4 is a partially enlarged sectional view showing the structure of the outer convex portion. FIG. 5 is a partially enlarged sectional view showing the structure of the gasket. FIG. 6 is a graph showing the relationship between the distance (radius) from the center of the valve plate and the amount of displacement of the valve plate or convex portion. FIG. 7 is an explanatory view showing the shape of the convex portion according to the first embodiment of the present invention. FIG. 8 is an explanatory view showing the shape of the convex portion according to the second embodiment of the present invention. FIG. 9 is an explanatory view showing the shape of the convex portion according to the third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. A compressor 1 shown in FIG. 1 constitutes a part of a refrigeration cycle used in a vehicle air conditioner, and pumps a refrigerant. A cylinder block 2, a front cylinder head (hereinafter, front head) 3, A rear cylinder head (hereinafter, rear head) 4, a drive shaft 5, a swash plate mechanism 6, a piston 7, gaskets 8 and 12, a suction valve 9, a valve plate 10, a discharge valve 11 and the like are configured.

  The cylinder block 2 is provided with a plurality of bores 15 into which pistons 7 are slidably fitted. The front head 3 is fixed to one end side of the cylinder block 2 by a predetermined connector, and a hollow crank chamber 20 is defined in the inside thereof. A swash plate mechanism 6 having a swash plate 22, an angle adjusting mechanism 23, and the like is disposed in the crank chamber 20, and the piston 7 is swingably connected to the swash plate 22. Yes. The drive shaft 5 is rotatably held by a bearing or the like provided on the front head 3 and the cylinder block 2 and is connected to the swash plate mechanism 6 so as to transmit a driving force. As a result, the space in the bore 15 becomes a compression chamber 18 whose volume changes as the piston 7 slides.

  The rear head 4 is defined with a suction chamber 16 and a discharge chamber 17. As shown in FIGS. 1 to 3, the suction chamber 16 and the discharge chamber 17 are formed so as to be able to communicate with a compression chamber 18 formed in the cylinder head 2, and are partitioned from each other by a high / low pressure partition wall 13. The discharge chamber 17 and the atmosphere are partitioned by the atmospheric pressure partition 14. Between the cylinder block 2 and the rear head 4, a gasket 8, an intake valve 9, a valve plate 10, a discharge valve 11, and a gasket 12 are sandwiched in order from the cylinder block 2 side, as shown in FIG. The vicinity of the outer edge of the cylinder block 2 and the atmospheric pressure partition 14 of the rear head 4 are fastened by a plurality of bolts 21.

  As shown in FIG. 3, the cylinder block 2 according to the present invention has convex portions 25, 25 'raised on the rear head 4 side on the end face 19 on the rear head 4 side. The valve plate 10 is subjected to a bending force toward the rear head 4 as the refrigerant is compressed in the compression chamber 18. In particular, this bending phenomenon is likely to occur in the region S inside the portion 24 facing the high / low pressure partition wall 13 or the region S ′ outside (see also FIG. 2). The convex portions 25, 25 ′ deal with the bending phenomenon of the valve plate 10, and are formed within the regions S and S ′. Further, the height D of the inner convex portion 25 shown in FIG. 3 is set as appropriate, and the height D ′ of the outer convex portion 25 ′ shown in FIG. 4 is the gasket shown in FIG. Eight elastic members 28, 28 'are set to be less than half of the total thickness (t1 + t2), that is, D'≤ (t1 + t2) / 2. The gasket 8 shown here has a structure in which elastic members 28 and 28 'such as rubber are bonded to both surfaces of the steel plate 27, but the present invention is not limited to the structure of the gasket. Further, the drawings relating to the present case are drawn exaggerating the features of the present invention, and are different from actual dimensional ratios.

  As a result, the cylinder block 2 and the gasket 8 are brought into close contact with each other while pressing the gasket 8 toward the rear head 4 by the convex portions 25 and 25 ′, and the valve plate 10 is compressed along with the compression of the refrigerant in the compression chamber 18. Since bending to the rear head 4 side is allowed, it is possible to prevent a gap from being formed between the cylinder block 2 and the gasket 8, and to ensure good sealing performance at the end surface 19 of the cylinder block 2. Further, the height D ′ of the convex portion 25 ′ formed in the region S ′ is less than half of the total thickness (t1 + t2) of the elastic members 28, 28 ′ of the gasket 8, so that the bolt 21 The fastening force can be sufficiently secured.

  FIG. 6 is a graph showing the relationship between the distance (radius) from the center of the valve plate 10 and the amount of displacement of the valve plate 10 or the convex portion 25. The solid line 30 shows the deformation state of the valve plate 10 during the operation predicted experimentally, has a gentle streamline shape, and has a turning point P of the rate of change thereof. A broken line 31 is a straight line passing through the turning point P and having a different inclination, and the convex portion 25 according to the first embodiment has substantially the same shape as the broken line 31 (see FIG. 7). ). That is, the convex portions 25 and 25 ′ according to the first embodiment are configured by a combination of a plurality of planes including the turning point P. By making the said convex-shaped part 25 into such a shape, cost can be restrained low from the ease of manufacture, ensuring sufficient sealing performance.

  FIG. 8 shows the shape of the convex portions 40 and 40 ′ in the second embodiment. The convex portions 40 and 40 ′ are valve plates indicated by the solid line 30. It has a streamline (polynomial curved surface) shape along 10 curved shapes. Thereby, more excellent sealing performance can be obtained.

  FIG. 9 shows the shape of the convex portions 45 and 45 ′ in the third embodiment. The convex portions 45 and 45 ′ are shown by a one-dot chain line 32 in FIG. The feature of the shape is shown by. This alternate long and short dash line 32 is along the curved shape of the valve plate 10 indicated by the solid line 30 from the center point (radius = 0) to the turning point P. Thus, the change rate does not turn to + (plus), and the displacement amount = 0 is reached with an appropriate change rate continued (R curved surface shape). With such a shape of the convex portion 45, it is possible to obtain a good sealing property while ensuring an appropriate productivity.

Claims (6)

A cylinder block in which a compression chamber is formed; a cylinder head in which a suction chamber and a discharge chamber are defined to seal an end surface of the cylinder block; a valve plate disposed between the cylinder block and the cylinder head; and the cylinder In a compressor including a gasket disposed between a block and the valve plate,
A convex portion that protrudes toward the cylinder head is formed on an end surface of the cylinder block, on the inner side of a portion that is formed on the inner side of the cylinder head and faces a partition wall that separates the suction chamber and the discharge chamber. The compressor characterized by being made. 2. The convex portion is further formed outside a portion facing a partition wall that is formed inside the cylinder head and separates the suction chamber and the discharge chamber. Compressor. The compressor according to claim 1, wherein the suction chamber is formed inside the partition wall, and the discharge chamber is formed outside the partition wall. The compressor according to claim 2, wherein the height of the convex portion formed outside the portion facing the partition wall is not more than half of the total thickness of the elastic member of the gasket. The compressor according to any one of claims 1 to 4, wherein the shape of the convex portion is a combination of a plurality of planes. The compressor according to any one of claims 1 to 4, wherein the shape of the convex portion is streamlined.

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