KR100472277B1 - Compressor piston and process for producing the compressor piston - Google Patents

Abstract

The hollow piston has an end wall that receives the pressure of the cylinder bore of the compressor.

Reinforcing protrusions are formed on the inner terminal surface of the terminal wall.

The contour of the projection from the radially outer portion to the radially inner portion initially approaches the outer end face and is spaced apart from the outer end face.

The piston is therefore lightweight and strong.

Description

Compressor piston and manufacturing method of compressor piston {COMPRESSOR PISTON AND PROCESS FOR PRODUCING THE COMPRESSOR PISTON}

The present invention relates to a compressor piston, and more particularly to a hollow piston and a method for producing the hollow piston.

A representative variable displacement compressor is provided, which is located in the crankcase and whose piston is connected to the rotating tilt plate.

The rotating swash plate converts the rotational motion of the drive shaft into a reciprocating motion of the piston.

The angle of inclination of the rotating swash plate changes with the pressure of the crank chamber.

The angle of inclination of the rotating swash plate controls the stroke of the piston and the capacity of the compressor.

Japanese Patent Laid-Open Nos. 10-281065, 11-294320, and 11-107912 propose hollow hollow pistons for use in compressors.

Hollow pistons are lightweight and have low inertia.

Therefore, if the hollow piston is used in the variable displacement compressor, the influence of the rotational tilt plate for the change of the inclination angle can be minimized so that the capacity of the compressor can be changed to a good response.

The thinner the wall of the piston, the lighter the piston.

However, when the piston compresses the refrigerant gas, the end wall of the piston head is subjected to a high pressure of the compressed refrigerant gas.

If the head end wall is relatively thin, the special piston has a flat head end wall because it cannot withstand the pressure.

In Japanese Patent Laid-Open No. 10-281065 related to the above, it is described to have a recess in the center of the head end wall.

When the piston is machined, the center pin of the machining tool is fixed to the associated recess.

The machining tool cuts the outer surface of the piston while the piston rotates around the axis of rotation.

The recess reduces the strength of the head end wall of the piston.

In order to improve the strength of the head end wall, the wall thickness must be increased.

However, this increases the weight of the piston.

It is an object of the present invention to provide a lightweight and powerful hollow piston and a method for producing the hollow piston.

In order to achieve the above object, the present invention provides a hollow piston used in the compressor.

The piston has a terminal wall that receives the pressure of the cylinder bore of the compressor.

The terminal wall has a substantially flat outer terminal surface and an inner terminal surface opposite to the outer terminal surface.

The contour of the inner end face reaches radially from the outer end first to the outer end face radially towards the inner part and is spaced apart from the outer end face.

The present invention also provides another hollow piston for use in a compressor.

The piston is housed in the cylinder bore of the compressor.

The piston includes an end wall that receives the pressure of the cylinder bore.

The terminal wall has a substantially flat outer terminal surface and an inner terminal surface opposite to the outer terminal surface.

A recess is formed in the outer terminal surface.

In order to reinforce the terminal wall, protrusions are formed on the inner terminal surface.

In addition, the present invention is applied to the manufacturing method of the hollow piston used in the compressor.

The piston includes a head piece and a body piece coupled to the head piece.

The head piece includes a terminal wall that receives the pressure of the cylinder bore of the compressor, and the body piece includes the remainder of the piston.

The terminal wall includes a substantially flat outer terminal surface and an inner terminal surface opposite to the outer terminal surface.

The method includes preparing a mold for forming a head piece, wherein the mold is designed to be a temporary protrusion not present in the finished head piece formed on the inner end face, injecting molten metal into the mold, In order to prevent the formation, pressing the temporary protrusions before the molten metal solidifies, and removing the protrusions after the molten metal solidifies.

Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings, and from the description showing examples of the principles of the invention.

(Example)

A first embodiment will next be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, the variable displacement compressor has a cylinder block 11, a front housing member 12 connected to the front terminal of the cylinder block 11, and a rear housing member connected to the rear terminal of the cylinder block 11. 19).

The front housing member 12 defines a control pressure chamber 121.

The rear housing member 19 defines the suction chamber 191 and the discharge chamber 192.

The drive shaft 13 is supported by the front housing member 12 and the cylinder block 11.

The drive shaft 13 is driven by an external drive source such as an engine, for example.

The rotary support 14 is located in the control pressure chamber 121 and is fixed to the drive shaft 13.

The drive plate or the rotation inclined plate 15 is arranged in the control pressure chamber 121 and is supported by the drive shaft.

The rotation tilt plate 15 is slidable along the drive shaft 13 in the axial direction and may be inclined with respect to a plane perpendicular to the axis of the drive shaft 13.

The pair of guide pins 16 extend from the rotation tilt plate, and are loosely fixed to the pair of guide holes 141 formed in the rotary support 14.

The hinge mechanism including the guide pin 16 and the guide hole 141 drives the rotation tilt plate 15 integrally with the drive shaft.

The hinge mechanism also allows the rotary tilt plate 15 to slide or tilt relative to the drive shaft.

The control pressure chamber 121 communicates with the suction chamber 191 through a discharge passage (not shown).

The discharge chamber 192 communicates with the control pressure chamber 121 through a supply passage (not shown).

The displacement control valve 25 is disposed in the supply passage.

The capacity control valve 25 adjusts the flow rate of the refrigerant gas supplied from the discharge chamber 192 to the control pressure chamber 121 so that the control pressure chamber 121 controls the pressure.

An increase in the amount of refrigerant gas supplied from the discharge chamber 192 to the control pressure chamber 121 increases the pressure in the control pressure chamber 121.

The decrease in the amount of refrigerant gas supplied from the discharge chamber 192 to the control pressure chamber 121 decreases the pressure in the control pressure chamber 121.

The inclination angle of the rotation inclination plate 15 changes depending on the pressure of the control pressure chamber 121.

Increasing the pressure in the control pressure chamber 121 reduces the inclination angle of the rotating tilt plate 15.

The decrease in the pressure of the control pressure chamber 121 increases the inclination angle of the rotating tilt plate 15.

As shown in FIG. 1, when the rotation inclination plate 15 contacts the rotation support body 14, the rotation inclination plate 15 will be located in the position of the largest inclination angle.

When the rotary inclined plate 15 contacts the snap ring 24 fixed on the drive shaft 13, the rotary inclined plate 15 is positioned at the minimum inclination angle position.

The cylinder block 11 accommodates a plurality of cylinder bores 111 (only two cylinder bores are shown in FIG. 1) arranged around the axis of the drive shaft 13.

Each cylinder bore 111 accommodates an aluminum piston 17.

Each piston 17 is connected to the rotating bevel plate 15 via a pair of shoes 18.

The rotation tilt plate 15 converts the rotational movement of the drive shaft 13 into a reciprocating movement of the piston 17.

The angle of inclination of the rotating tilt plate 15 controls the stroke of the piston 17 and the capacity of the compressor.

The port plate 20, the suction valve plate 21, the discharge valve plate 22, and the retainer plate 23 are disposed between the cylinder block 11 and the rear housing member 19.

Formed on the port plate 20 is a suction port 201 and a discharge port 202 for each cylinder bore 111.

The suction valve plate 21 has a suction valve flap 211 for each suction port 201.

The discharge valve plate 22 has a discharge valve flap 221 for each discharge port 202.

The retainer plate 23 has a retainer 231 for each discharge valve flap 221.

When the piston 17 moves from the top dead center to the bottom dead center, the refrigerant gas in the suction chamber 191 flows into the corresponding cylinder bore 111 by the suction valve flap 211 through the suction port 201.

When the piston 17 moves from the bottom dead center to the top dead center, the refrigerant gas is compressed in the corresponding cylinder bore 111, and the compressed refrigerant gas is discharged by the discharge valve flap 221 through the discharge port 202. 192 is discharged into.

Movement of the discharge valve flap 221 is limited by the retainer 231.

The external refrigerant circuit 26 connects the discharge chamber 192 to the suction chamber 191.

The external refrigerant circuit 26 includes a condenser 27, an expansion valve 28, and an evaporator 29.

The refrigerant flowing from the discharge chamber 192 to the external refrigerant circuit 26 flows to the suction chamber 191 through the condenser 27, the expansion valve 28, and the evaporator 29.

As shown in FIG. 2 and FIG. 3, each piston 17 includes a cavity 171.

The piston 17 has an interconnected head piece 31 and a body piece 32.

The head piece 31 has a substantially flat head end wall 30 and an annular rim 35 formed on the rear side of the head end wall 30.

The head end wall 30 receives the pressure of the corresponding cylinder bore 111.

The body piece 32 includes a cylindrical wall 34 defining a cavity 171 and a skirt 33 extending from the rear end of the cylindrical wall 34.

The skirt 33 has a pair of accommodating recesses 331 for accommodating the shoe 18, respectively.

The annular rim 35 is fixed to the open end of the cylindrical wall 34, and the head piece 31 and the main body piece 32 are welded to each other.

The head piece 31 functions as a cap for closing the opening of the main body piece 32.

The inner wall surface 341 and outer wall surface 342 of the cylindrical wall 34 and the inner wall surface 351 and the outer wall surface 352 of the annular rim 35 are coaxial with respect to the axis L of the piston 17.

The head end wall 30 is parallel to the suction valve plate 21 and has an opposite flat outer end face 36.

A positioning recess 361 centered on the axis L is formed on the outer terminal face 36.

As described in Japanese Patent Laid-Open No. 10-281065, the positioning recess 361 is used as a center pin of a processing tool for cutting the outer surface of the piston 17.

In addition, when the piston 17 is not coupled to the cylinder bore 111, the positioning jig is engaged with the positioning recess 361.

The head end wall 30 has an inner end face 37 facing the cavity 171.

The inner end face 37 includes an annular concave portion 371 and a convex portion 372 radially in the concave portion 371.

The annular concave portion 371 and the convex portion 372 define the projection 50 for reinforcing the head end wall 30.

2 is a cross-sectional view of the piston 17 cut along the plane S (see FIG. 4).

As shown in FIG. 2, the outer bow line 373 is a busbar of the annular recess 371.

 That is, the annular recess 371 is formed by rotating the outer bow line 373 around the axis L. As shown in FIG.

As shown in FIG. 2, the internal bow line 374 is the bus bar of the convex portion 372.

That is, the convex portion 372 is formed by rotating the inner bow line 374 around the axis L.

The convex portion 372 is a part of the spherical surface.

The diameter of the outer bow 373 is smaller than that of the inner bow 374.

The outer bow line 373 is smoothly connected to the inner surface of the annular rim 35.

The inner bow line 374 smoothly matches the outer bow line 373.

In other words, the annular concave portion 371 smoothly matches the inner wall surface 351 of the annular forest 35, and the convex portion 372 smoothly coincides with the annular concave portion 371.

Both annular recesses 371 and the convex portions 372 are coaxial with the axis L. As shown in FIG.

The imaginary circle K shown by the dotted line shows the boundary of the annular recessed part 371 and the convex part 372. As shown in FIG.

The annular concave portion 371 is radially an external virtual source K, and the convex portion 372 is radially an internal virtual source K.

The convex portion 372 is coaxial with the positioning groove 361.

In other words, the convex portion 372 is arranged in the positioning groove 361 in the axial direction.

The first embodiment has the following advantages.

The contour of the inner end face 37 of the head end wall 30 from the inner wall face 351 towards the axis L first approaches and is separated from the outer end face 36.

In other words, the annular concave portion 371 is smoothly coupled to the inner wall surface 351 of the annular forest 35, and the convex portion 372 is smoothly coupled to the annular concave portion 371.

This configuration prevents stress concentration between the inner end face 37 of the head end wall 30 and the inner wall face 37 of the annular rim 35.

The annular concave portion 371 and the convex portion 372 define the protrusion 50.

The protrusion 50 has a smooth surface to prevent local stress concentration.

The combination of the annular concave portion 371 and the convex portion 372 is required to form the head terminal wall 30 while providing the required strength while providing excellent stress dispersing effect as compared to a simple flat head terminal wall. The amount of material can be reduced.

This contributes to reducing the weight of the piston 17.

The convex portion 372 is arranged in the positioning groove 361 in the axial direction.

The center of the convex portion arranged axially in the positioning groove 361 is furthest from the outer end face 36.

In other words, the convex portion 372 that most effectively reinforces the portion of the head end wall 30 is located in the positioning groove 361.

Thus, the wall around the positioning groove 361 is strong.

The convex portion 372 is formed in the portion of the head terminal wall 30 that is most strengthened.

This improves the strength and reduces the weight of the head end wall 30.

The head piece 31 is formed by casting, cutting, or press molding.

When the head piece 31 and the main body piece 32 are separated from each other, the inner end face 37 of the head end wall 30 is exposed.

Thus, the two-part structure facilitates the shape of the inner end face 37 of the head end wall 30.

Next, a part different from the embodiment of FIGS. 1 to 4 will mainly be described with reference to FIG. 5.

As shown in FIG. 5, in this embodiment, the head piece 31 is fixed to the main body piece 32 so that the head piece 31 is completely fixed in the cylindrical wall 34.

Next, a part different from the embodiment of Figs. 1 to 4 is mainly described with reference to Fig. 6 of the third embodiment of the present invention.

As shown in FIG. 6, in this embodiment, the cylindrical rim 350 corresponding to the cylindrical wall of FIG. 2 is formed integrally with the head piece 31. As shown in FIG.

The main body piece 32 has an outer rim 38 fixed to the open end of the cylindrical rim 350.

Next, a part different from the embodiment of FIGS. 1 to 4 will mainly be described with reference to FIGS. 7 and 8.

As shown in FIGS. 7 and 8, the inner end face 37 of the head end wall 30 has a first taper face 375 coupled to the inner wall face 351 of the annular rim 35. And a second tapered surface 376 coupled to the first tapered surface 375 and a flat central surface 377 coupled to the second tapered surface 376.

If the piston 17 is cut along the plane S, the tapered surfaces 375 and 376 have a straight outline.

Close to the point on the first tapered surface 375 is the axis L, and the far point is from the external terminal surface.

Next, a part different from the embodiment of Figs. 1 to 4 will mainly be described with reference to Figs. 9 (a) and 9 (b).

In this embodiment, as shown in Fig. 9 (a) and Fig. 9 (b), the head piece 31 has a flat head end wall 40.

The head end wall 40 has an inner end face 41 that is flat and parallel to the outer end face 36.

As shown in Fig. 9B, the inner end surface 41 has a plurality of integrally reinforced ribs 39 (six ribs in this embodiment).

The reinforcing ribs 39 extend radially from the axis L and are arranged at intervals of 60 degrees.

The inner terminal portion 391 of the reinforcing rib 39 is located on the shaft L, and the outer terminal portion 392 of the reinforcing rib 39 is connected to the inner wall surface 351 of the annular rim 35.

The inner terminal portion 391 is arranged in the positioning groove 361 in the axial direction.

The rear surface 393 of each reinforcing rib 39 is parallel to the outer terminal surface 36 of the head terminal wall 40.

In other words, the thickness (measured in the direction of the axis L) of each reinforcing rib 39 is equal to its total length.

This embodiment has the following advantages.

Reinforcing ribs 39 formed on the inner end face 41 increase the surface area on the rear surface of the head end wall 30.

This reduces the stress concentration of the head end wall and limits the weight of the head end wall 40 as compared with the case where the thickness of the head end wall is uniformly increased.

Therefore, this head end wall 40 is stronger and lighter than a simple flat head end wall.

Reinforcing ribs 39 reduce their stress concentration in the longitudinal direction.

The reinforcing rib 39 extends radially from the axis L of the head end wall 40.

This reduces the stress concentration of the head end wall 40.

The connection of all the reinforcing ribs 39 to the inner wall surface 351 of the annular rim 35 reduces the stress concentration between the annular rim 35 and the head end wall 40.

The inner terminal portion 391 of all the reinforcing ribs 39 is located on the shaft L. As shown in FIG.

This improves the strength of the head end wall 40 around the axis L. FIG.

The inner terminal portion 391 is also arranged in the axial direction with the positioning groove 361.

This compensates for the strength loss of the head end wall 40 due to the positioning groove 361.

Reinforcing ribs 39 are arranged around the axis L at equal intervals.

This reduces the concentration of the circumferential stress of the head end wall 40.

The head piece 31 is formed by die casting, cutting, or press molding.

The two-piece structure facilitates the formation of the reinforcing ribs 39 on the inner end surface 41 of the head end wall 40.

Next, a sixth embodiment of the present invention will be mainly described with reference to Figs. 10A and 10B, which are different from the embodiments of Figs. 9A and 9B.

In this embodiment, a plurality of reinforcing ribs 42 are formed on the inner end surface 41 of the head end wall 40.

Each reinforcing rib 42 does not extend from the axis L, but extends from an opposite point from the axis L, and is connected to the inner wall surface 351 of the annular rim 35.

The reinforcing ribs 42 are arranged around the axis L at equal intervals.

The inner end portion 421 of the reinforcing rib 42 defines a rectangular box surrounding the axis L. As shown in FIG.

The piston of the sixth embodiment has the same advantages as the embodiment shown in Figs. 9A and 9B.

Next, a part different from the embodiment of Figs. 9A and 9B will mainly be described with reference to Figs. 11A and 11B.

The piston of this embodiment has only four reinforcing ribs 43 formed on the inner end face 41 of the head end wall 40, and the reinforcing ribs 43 are connected to the inner wall face 351 of the annular rim 35. Same as the embodiment of FIGS. 9 (a) and 9 (b) except that otherwise.

Next, an eighth embodiment of the present invention will be mainly described with reference to Figs. 12A and 12B, which are different from the embodiments of Figs. 9A and 9B.

In this embodiment, the projection 44 is formed on the inner end surface 41 of the head end wall 40.

The projection 44 is centered on the axis L. As shown in FIG.

The protruding portion 44 corresponds only to the inner terminal portion 391 of the reinforcing rib 39 in Fig. 9A.

The projection 44 has a substantially cylindrical shape.

The protrusion 44 is smoothly joined to the inner end surface 41.

Next, a ninth embodiment of the present invention will be mainly described with reference to Figs. 13A and 13B, which are different from those of Figs. 12A and 12B.

In this embodiment, the projection 45 is formed on the inner end surface 41 of the head end wall 40.

The projection 45 has a ring-like shape and is centered on the axis L. As shown in FIG.

Next, the tenth embodiment of the present invention will be mainly described with reference to Figs. 14A and 14B, which are different from the embodiments of Figs. 12A and 12B.

In this embodiment, the protrusion 44 and four reinforcing ribs 46 are formed on the inner end face 41 of the head end wall 40.

The projection 44 is substantially as shown in Fig. 12A.

The reinforcing ribs 46 extend radially from the protrusions 44 and are connected to the inner wall surface 351 of the annular rim 35.

The reinforcing ribs 46 are arranged around the axis L at equal intervals.

The protrusion 44 may be omitted leaving only the reinforcing rib 46.

Next, an eleventh embodiment of the present invention will be mainly described with reference to Figs. 15A and 15B, which are different from the embodiments of Figs. 12A and 12B.

This embodiment is substantially the same as shown in Figs. 12 (a) and 12 (b) except that a plurality of reinforcing ribs 47 are included.

The reinforcing ribs 47 each have a triangular plate shape and are located in the corner formed between the inner end face 41 of the head end wall 40 and the inner wall face 351 of the annular rim 35.

The reinforcing ribs 47 extend radially and are disposed around the axis L at equal intervals.

The protrusion 44 may be omitted leaving only the reinforcing ribs 47.

Next, the twelfth embodiment of the present invention will be mainly described with reference to Figs. 16A and 16B, which are different from the embodiments of Figs. 15A and 15B.

This embodiment differs from the embodiment shown in Figs. 15 (a) and 15 (b) in which the protrusions 44 are replaced by a plurality of reinforcing ribs 48.

The reinforcing ribs 48 have a triangular plate shape, respectively, and extend radially from the axis L at equiangular intervals.

Radial outer reinforcing ribs 47 may be omitted leaving only the inner reinforcing ribs 48 radially.

 Next, the thirteenth embodiment of the present invention will be mainly described with reference to Figs. 17A and 17B, which are different from those in Figs. 9A and 9B.

In this embodiment, the top surface of the reinforcing rib 49 is bent, which is different from that shown in Figs. It is different from the embodiment of.

The rear surface 491 of each reinforcing rib 49 includes a concave surface 492 and a convex surface 493.

The contour of the back surface 491 from the terminal of the inner wall surface 351 towards the axis L first approaches and is separated from the outer terminal surface 36.

Next, a part different from the embodiment of Figs. 1 to 4 will mainly be described with reference to Figs. 18 (a) and 18 (b).

This embodiment differs from the embodiment of FIGS. 1 to 4 in that the projections 50 have flat terminal surfaces.

The projection 50 extends from the annular concave surface 371 that is smoothly joined to the inner wall surface 351 of the annular rim 35.

The annular convex surface 378 is smoothly coupled to the concave portion 371, and the flat surface 379 is smoothly coupled to the annular convex surface 378.

The annular convex surface 378 is part of the spherical surface.

It is the axis L that approaches the point on the annular convex surface 378, and the external terminal face 36 is far from the point.

The flat surface 379 is parallel to the outer terminal surface 36.

Next, a fifteenth embodiment of the present invention will be mainly described with reference to Figs. 19 and 20, which are different from the embodiment of Figs.

This embodiment is substantially the same as the embodiment of FIGS. 1-4 except that a plurality of reinforcing ribs 60 are included.

The reinforcing rib 60 (four ribs in this embodiment) extends radially from the axis L and is connected to the inner wall surface 351 of the annular rim 35.

The rear surface 601 of each reinforcing rib 60 is parallel to the outer terminal surface 36.

The reinforcing rib 60 further improves the strength of the head end wall 30 compared with the embodiment shown in FIGS. 1 to 4.

Next, a sixteenth embodiment of the present invention will be mainly described with reference to Figs. 21 and 22, which are different from the embodiments of Figs. 19 and 20.

This embodiment is substantially the same as the embodiment shown in FIGS. 19 and 20 except that the reinforcing ribs 70 each have a curved backside 701.

The rear surface 701 is curved to conform to the contour of the inner terminal surface 37 of the head terminal wall 30.

This embodiment has reduced the amount of material needed to form the reinforcement ribs 70 compared to the embodiment shown in FIGS. 19 and 20.

Next, the manufacturing method of the head piece 31 shown to FIG. 18 (a) and FIG. 18 (b) is demonstrated with reference to FIG. 23 (a), (23b).

FIG. 23A shows the first mold 51 and the second mold 52 used to cast the head piece 31.

The first mold 51 has a portion that does not match the shape of the inner end face 37 of the head end wall 30.

More specifically, the first mold 51 is designed and formed to form a temporary protrusion 54 on the inner end face 37.

The protrusion 54 does not exist in the finished product.

A pushing rod 53 is fixed to the first mold 51 to move in the axial direction.

The molds 51 and 52 coincide with each other, and in this state, molten metal based on aluminum is injected into the casting space between the molds 51 and 52.

Before the molten metal in the molds 51 and 52 solidifies, the pushing rod 53 is biased in the axial direction Q as shown in FIG.

Thus, the molten metal present in the corresponding portion of the temporary protrusion 54 is pressed by the end terminal of the pushing rod 53.

This prevents the formation of shrinkage cavities in the workpiece 310 that occur after solidification of the molten metal.

After the molten metal solidifies, the work 310 is removed from the molds 51 and 52.

The recess 541 corresponds to the shape of the terminal of the pushing rod 53 and remains on the temporary protrusion 54.

As a result, as shown in Fig. 23B, the temporary protrusion 54 is removed by cutting with a cutting tool such as a terminal grinder.

The portion of the inner end face 37 from which the temporary protrusion 54 is removed forms a flat surface 379 (see FIG. 18A).

According to the manufacturing method described above, the shrinkage cavity of the head piece 31 is prevented.

This improves the strength of the head piece 31.

The temporary protrusion 54 may not be completely cut.

In this case, the remaining temporary projections 54 function as annular reinforcement ribs.

The following examples are within the scope of the present invention.

The curved part of the inner end surface of the head terminal wall 30 of the Example shown to FIGS. 1-4 is not limited to what was shown, and can be modified suitably.

In addition, the inner end surface 37 of the head end wall 30 may be formed by a combination of the curved surface and the tapered surface.

For example, the tapered surface may be located between the annular recess and the inner wall surface 351 of the annular rim 35, or the tapered surface may be located between the annular groove-shaped surface and the convex surface.

In the embodiment of Figs. 1 to 4, the convex portion 372 may not be a part of the spherical surface, and may be any shape as long as it is a smoothly curved surface.

In the embodiment shown in FIG. 7 and FIG. 8, the flat center surface 377 may be replaced by a conical tapered surface having a vertex center on the axis L. As shown in FIG.

As shown in FIG. 7, the concave portion may be formed on the flat central surface 377, or may be formed on the flat surface 379 as illustrated in FIG. 18A.

The first piston member may be connected to the second piston using an adhesive.

The first piston member may be connected to the second piston by friction pressure means.

The first piston member may be connected to the second piston by press fixing means.

In the piston of any of the above embodiments, the positioning recess 361 is formed on the outer end face of the head end wall.

However, the present invention can be applied to a piston having no positioning recess 361.

Light and strong hollow pistons are again obtained in such a case.

The present invention relates to a compressor piston, and more particularly, to a hollow piston and a method for producing the hollow piston.

1 is an overall cross-sectional view of a compressor according to a first embodiment of the present invention.

2 is a cross-sectional view of the piston coupled to the compressor of FIG.

3 is a cross-sectional view taken along line 3-3 of FIG.

4 is a cross-sectional view taken along line 4-4 of FIG. 2;

5 is a sectional view of a piston according to a second embodiment of the present invention;

6 is a sectional view of a piston according to a third embodiment of the present invention.

7 is a sectional view of a piston according to a fourth embodiment of the present invention.

8 is a cross-sectional view taken along line 8-8 of FIG.

9 (a) is a sectional view of a piston according to a fifth embodiment of the present invention;

(B) is sectional drawing along the 9 (b) -9 (b) line | wire of (a).

10 (a) is a sectional view of a piston according to a sixth embodiment of the present invention;

(B) is sectional drawing along the 10 (b) -10 (b) line | wire of FIG. 10 (a).

11 (a) is a sectional view of a piston according to a seventh embodiment of the present invention;

(B) is sectional drawing along the 11 (b) -11 (b) line of FIG. 11 (a).

12 (a) is a sectional view of a piston according to an eighth embodiment of the present invention;

(B) is sectional drawing along the 12 (b) -12 (b) line | wire of (a).

Fig. 13A is a sectional view of a piston according to a ninth embodiment of the present invention.

(B) is sectional drawing along the 13 (b) -13 (b) line | wire of (a).

Fig. 14A is a sectional view of a piston according to a tenth embodiment of the present invention.

(B) is sectional drawing along the 14 (b) -14 (b) line | wire of (a).

Fig. 15A is a sectional view of a piston according to an eleventh embodiment of the present invention.

(B) is sectional drawing along the 15 (b) -15 (b) line | wire of FIG. 15 (a).

Fig. 16A is a sectional view of a piston according to a twelfth embodiment of the present invention.

(B) is sectional drawing along the 16 (b) -16 (b) line | wire of (a).

Fig. 17A is a sectional view of a piston according to a thirteenth embodiment of the present invention.

(B) is sectional drawing along the 17 (b) -17 (b) line | wire of (a).

Fig. 18A is a sectional view of a piston according to a fourteenth embodiment of the present invention.

(B) is sectional drawing along the 18 (b) -18 (b) line | wire of FIG. 18 (a).

19 is a sectional view of a piston according to a fifteenth embodiment of the present invention.

20 is a cross sectional view along line 20-20 of FIG. 19;

21 is a sectional view of a piston according to a sixteenth embodiment of the present invention;

FIG. 22 is a cross-sectional view taken along the line 22-22 of FIG. 21;

Fig. 23A is a cross sectional view showing a state in which molten metal is injected into a mold;

Fig. 23 (b) is a cross-sectional view showing the cutting of the protrusion.

(Explanation of symbols for the main parts of the drawing)

11. Cylinder block 12. Front housing member

13. Drive shaft 14. Rotating support

15. Swivel plate 16. Guide pin

17.Piston 20.Port Plate

21.Suction valve plate 22.Discharge valve plate

23. Retainer Plate 24. Snap Ring

25. Control valve 26. External refrigerant circuit

27. Condenser 28. Expansion valve

29. Evaporator 30. Terminal wall

31.Head piece 32.Main piece

33. Skirt 34. Cylindrical wall

35. Fantastic forest 36. External terminal surface

37. Inner end face 50. Protrusion

Claims (21)

The piston has a terminal wall that receives the pressure of the cylinder bore of the compressor, the terminal wall having a substantially flat outer end face and an inner end face opposite the outer end face, and directed from the radial outer part to the radial inner part. The contour of the inner end face is a hollow piston used in a compressor, characterized in that it initially approaches the outer end face and is later separated from the outer end face. The method of claim 1, The inner end surface comprises a annular concave surface and a convex surface located around the axis of the piston, the convex surface is radially inwardly used in the compressor, characterized in that coupled to the annular concave portion. The method of claim 2, The annular concave surface is a smooth curved surface, the hollow piston used in the compressor, characterized in that the cross section of the concave surface is uniform over the entire circumference around the axis of the piston. The method of claim 3, Hollow piston used in a compressor, characterized in that the cross section of the annular concave surface is curved in a bow shape. The method of claim 2, The convex surface is a smooth curved surface, the hollow piston used in the compressor, characterized in that the cross section of the convex surface is uniform over the entire circumference around the axis of the piston. The method of claim 5, A piston for use in a compressor, characterized in that the cross section of the convex surface is curved in a bow shape. The method according to any one of claims 1 to 6, The convex surface is annular around the piston, the inner end surface of the hollow piston used in the compressor, characterized in that it comprises a flat surface coupled to the radially located inside the convex surface. The method according to any one of claims 1 to 6, The terminal wall includes a plurality of ribs, the ribs are radially extending on the inner end surface and the hollow piston used in the compressor, characterized in that arranged at the same angular intervals. The method according to any one of claims 1 to 6, And a head piece coupled to the head piece, wherein the head piece includes a terminal wall, the body piece includes a remainder of the piston, and an inner end surface is exposed when the head piece and the body piece are separated. Hollow pistons used in compressors. The piston has a terminal wall that receives the pressure of the cylinder bore of the compressor, the terminal wall has a substantially flat outer end face and an inner end face opposite to the outer end face, the outer end face is formed with a recess, and the end wall Hollow piston used in the compressor, characterized in that the projection is formed on the inner end surface to strengthen the. The method of claim 10, Hollow piston used in the compressor, characterized in that the projection is arranged in the axial direction with the recess. The method of claim 10, A hollow piston for a compressor, characterized in that the contour of the projection from the radial outer part to the radial inner part is first approached to the outer end face and then separated from the outer end face. The method of claim 12, The surface of the projection portion includes a annular concave surface and a convex surface located around the axis of the piston, the convex surface is radially inwardly used in the compressor, characterized in that coupled to the annular concave portion. The method of claim 13, A hollow piston for a compressor, characterized in that the concave surface is arranged axially in the concave portion. The method of claim 10, Hollow piston used in a compressor, characterized in that the projection is located on the axis of the piston. The method of claim 10, Hollow piston used in a compressor, characterized in that the projection portion comprises a plurality of ribs. The method of claim 16, Hollow piston used in a compressor, characterized in that the ribs extend radially. The method of claim 17, Hollow piston used in a compressor, characterized in that the ribs are arranged at equal intervals in each direction. The method according to any one of claims 10 to 18, And a head piece coupled to the head piece, wherein the head piece includes a terminal wall, the body piece includes a remainder of the piston, and an inner end surface is exposed when the head piece and the body piece are separated. Hollow pistons used in compressors. The piston includes a head piece and a body piece coupled to the head piece, the head piece including a terminal wall for receiving pressure of a cylinder bore of the compressor, the body piece including a remainder of the piston, and the terminal wall Includes a substantially flat outer end face and an inner end face opposite to the outer end face, and prepares a mold for forming the head piece, wherein the mold has a temporary protrusion inside which is not present in the finished head piece. Designed to be formed on the terminal surface, injecting molten metal into the mold, pressing the temporary protrusion before the molten metal solidifies to prevent the formation of shrinkage cavities, and removing the protrusion after the molten metal solidifies Method for manufacturing hollow piston used in compressor. The method of claim 20, The manufacture of the mold is a method of manufacturing a hollow piston used in a compressor, characterized in that for designing the mold so that the reinforcing protrusions are formed on the inner end surface and the temporary protrusions are formed in the reinforcing protrusions.