WO2003095833A1

WO2003095833A1 - Compressor and method of manufacturing piston used for the compressor

Info

Publication number: WO2003095833A1
Application number: PCT/JP2003/005728
Authority: WO
Inventors: Hiromichi Tanabe; Hiroyuki Ishida
Original assignee: Zexel Valeo Climate Control Corporation
Priority date: 2002-05-13
Filing date: 2003-05-07
Publication date: 2003-11-20
Also published as: JPWO2003095833A1

Abstract

A variable displacement swash plate type compressor and a method of manufacturing pistons used for the compressor, the pistons (7) comprising cylindrical head parts (71) and bridge parts (72) connecting the head parts (71) to a swash plate (10), wherein hollow parts (73) and holes (74) allowing the hollow parts (73) to communicate with the outside are formed in the head parts (71); the method comprising the steps of casting the pistons (7) using fluidizable cores and discharging the fluidized cores from the holes (74).

Description

Satsuki Itoda β

Compression: Method of manufacturing the line-up

TECHNICAL FIELD The present invention relates to a variable displacement swash plate type compression and a method for manufacturing bistons used for the compression.

Conventionally, as a variable displacement swash plate type compressor, a cylinder block formed with a plurality of cylinder bores, a shaft rotatably supported at the center of the cylinder block, and a sliding shaft A swash plate mounted so as to be swingable and swingable, a crank chamber for accommodating the swash plate, and a biston connected to the swash plate and reciprocating in the cylinder bore as the swash plate swings. What is done is known.

In this type of variable displacement swash plate compressor, the inclination angle of the swash plate changes in accordance with the change in the pressure in the crankcase, thereby changing the stroke of the piston.

Most pistons of variable capacity swash plate type compressors are hollow inside to reduce weight. If the weight of the piston is reduced, the inertia of the piston is reduced, and the entire compressor is also reduced in weight.

As a method for producing such hollow screws, for example, as disclosed in Japanese Patent Application Laid-Open No. 2001-289163, a method of welding two members, a bottomed cylindrical member and a closing member, is disclosed. In addition, Japanese Patent Application Laid-Open No. 2001-221214 discloses that a hollow piston is manufactured integrally using a deformable core made of rubber or the like when manufacturing the hollow piston. A method is disclosed.

However, in the production of hollow pistons, two parts are welded In this case, not only did the number of parts increase, but also the welding process and the pre- and post-processing steps required for it could not be omitted, making it difficult to reduce costs.

On the other hand, when a hollow piston is integrally formed using a core whose shape is deformable, it is not suitable for manufacturing a high-precision one, and it is difficult to reduce the wall thickness. When a mirror-making method such as a cast or squeeze cast is adopted, the core may be deformed or damaged by high pressure.

The present invention has been made in view of such circumstances, and provides a variable displacement type swash plate type compressor in which the weight and cost of the piston are reduced, and a method of manufacturing the piston used in the compressor. Purpose. Disclosure of the invention

The invention according to claim 1 provides a cylinder opening formed with a plurality of cylinder bores, a shaft rotatably supported at a center portion of the cylinder opening, and a slidable and swingable shaft. A swash plate movably mounted, a crank chamber for accommodating the swash plate, and a piston connected to the swash plate and reciprocating in the cylinder bore as the swash plate swings, In a variable displacement swash plate type compressor in which the inclination angle of the swash plate changes in accordance with the pressure change in the chamber and the stroke amount of the biston changes, the piston has a cylindrical head. And a bridge portion connecting the head portion and the swash plate, wherein the head portion is formed with a hollow portion, and a hole communicating the hollow portion with the outside. The piston is integrally formed by the structure The structure uses a fluidizable core, and the hole of the piston is formed using a core capable of fluidizing the piston. , The fluidized core is discharged The present invention provides a variable displacement swash plate type compressor characterized in that the core is solid, and after the biston is manufactured in a solid state, the core is fluidized to make a piston. The hollow portion of the piston is formed by discharging from the hole formed in the hole.

As described above, according to the present invention, since the hollow piston is integrally formed using the fluidizable core, the welding process can be omitted, and the weight and cost of the piston can be reduced. Thus, it is possible to provide a variable displacement type swash plate type compressor which achieves the above.

Note that “fluidizable” means that the state can be changed from a solid state to a state of a fluid (including a powder). In addition, “fabrication” is a process in which a molten material is poured into a mold and solidified, and the material is not limited to a metal, but widely includes a resin and the like.

The invention according to claim 2 is the invention according to claim 1, wherein the core melts at a temperature lower than a melting point of a constituent material of the piston. Machine.

For example, a core made of a material that melts at a temperature lower than the melting point of the piston constituent material, such as a resin core when the bistone constituent material is aluminum, is suitable as a fluidizable core. is there. According to the inventor's experiments, the resin core does not melt before the melt solidifies even if the temperature rises due to conduction heat from the melt poured into the mold.

Then, after the molten metal solidifies, the piston containing the core is removed from the mold, and when it is heated, the core melts before the piston, so the molten core is removed from the hole. be able to. The removed core can be reused by placing it in a mold and hardening it.

The invention according to claim 3 is the invention according to claim 1, wherein the core is a soluble core. It is a swash plate type compressor.

“Soluble” means soluble in water or other solvents. Such a soluble core is suitable as a fluidizable core. For example, if a core is formed with a water-soluble salt such as sodium chloride, the core can be dissolved by injecting water, and this can be easily removed. In addition, the “soluble core” in this claim includes a sand core solidified with a binder soluble in water or another solvent.

The invention according to claim 4 is the variable displacement type swash plate compressor according to claim 1, wherein the core is a collapsible core.

For example, a disintegrating core such as a sand core that easily disintegrates into a powder form by vibration or impact is suitable as a fluidizable core.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the hole is formed at a bottom dead center when the stroke amount of the piston is at least two-thirds of the maximum. And a variable displacement swash plate type compressor provided at a position communicating with the crank chamber.

When the stroke of the piston becomes larger than a certain amount (two-thirds of the maximum), the inertia force becomes a problem. However, according to the present invention, the lubricating oil flowing from the hole is discharged into the crankcase. In addition, the lubricating oil can be prevented from accumulating in the hollow portion and increasing the inertia of the rubber.

The invention according to claim 6 is the variable displacement type swash plate compressor according to claim 5, wherein at least two of the holes are provided.

According to the present invention, since at least two holes are provided, when the fluidized core is discharged from the biston, one of the holes is formed. By using it as an air hole, the fluidized core can be discharged smoothly. Also, when the piston is mounted on the compressor, one hole becomes the inlet for refrigerant gas and lubricating oil, and the other hole becomes the outlet, so that the flow is smooth and the lubricating oil collects in the hollow part. Thus, the inertia force of the piston can be prevented from increasing.

An invention according to claim 7 is a method for manufacturing a piston used for a variable displacement swash plate type compressor, wherein the piston is integrally formed by a structure in which a core is mounted in a mold. A hollow portion inside, and a hole communicating the hollow portion with the outside. The core includes a main body corresponding to the hollow portion, and a main body corresponding to the hole. And a supporting portion for supporting the portion in the mold. After the core is mounted in the mold, a molten metal is poured to form a piston material, and the molten metal is solidified. After that, the piston material is taken out from the mold, the core is fluidized, and the fluidized core is discharged from the hole to form a hollow piston. This is a method of manufacturing a piston.

In the present invention, in the method for producing a piston, after producing the piston in a state where the core is in a solid state, the core is fluidized and discharged from a hole formed in the piston. The hollow part of the piston is formed.

As described above, according to the present invention, since the hollow piston is integrally formed using the fluidizable core, the welding process can be omitted, and the weight and cost of the piston can be reduced. The invention according to claim 8 is the method for manufacturing a piston according to claim 7, wherein the fluidization of the core is performed by putting the core into a core melting furnace and melting the core. The feature of the piston It is a manufacturing method.

According to a ninth aspect of the present invention, in the method for manufacturing a piston according to the eighth aspect, the core discharged from the hole is poured into a core mold to form a core again. This is a method for producing a piston, characterized in that another piston is formed by using a core that has been made.

According to the invention described in claims 8 and 9, the core can be melted by being put into the core melting furnace, so that the core material can be reused. By reusing such core materials, economic efficiency will be improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view showing a variable displacement swash plate type compressor according to a specific example of the present invention.

FIG. 2 is a plan view showing a bistone material according to a specific example of the present invention.

FIG. 3 is a front view showing a piston material according to a specific example of the present invention.

FIG. 4 is a sectional view taken along line A—A in FIG.

FIG. 5 is a sectional view taken along line B—B in FIG.

FIG. 6 is a cross-sectional view showing a manufacturing process of a bismuth material according to a specific example of the present invention.

FIG. 7 is a cross-sectional view showing a mirror-making process of a rubber material according to a specific example of the present invention.

FIG. 8 is a cross-sectional view showing a manufacturing process of a bismuth material according to a specific example of the present invention.

FIG. 9 is a cross-sectional view illustrating a manufacturing process of a bismuth material according to a specific example of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a variable displacement swash plate type compressor according to one embodiment of the present invention.

One end of the cylinder block 1 of this variable displacement type swash plate compressor has a head 3 via a valve plate 2 and the other end of the cylinder block 1 has a front head 4 , Respectively, are fixed.

The cylinder block 1 is provided with a plurality of cylinder bores 6 at predetermined intervals in the circumferential direction around the shaft 5. In each of these cylinder bores 6, a stone 7 is slidably accommodated.

A crank chamber 8 is formed in the front head 4, and a swash plate 10 is accommodated in the crank chamber 8. The swash plate 10 is slidably and slidably mounted on the shaft 5 via the hinge ball 9.

The swash plate 10 is connected to the piston 7 via a pair of hemispherical showers 50. The shroud 50 is rotatable relative to the front-side sliding surface 10b and the lary-side sliding surface 10a of the swash plate 10 so that the bridge 7 of the piston 7 can rotate. Supported by two.

In the head 3, a discharge chamber 12 and a suction chamber 13 located around the discharge chamber 12 are formed.

The discharge chamber 12 and the crank chamber 8 communicate with each other via a gas introduction passage (not shown). A control valve 81 is provided in the middle of the gas introduction passage, and the flow rate of the refrigerant from the discharge chamber 12 to the crank chamber 8 is controlled by the control valve 81.

Suction chamber 13 and crankcase 8 are installed in cylinder block 1. It communicates via a passage 58.

The valve plate 2 has a discharge port 15 communicating the compression chamber 14 of the cylinder bore 6 with the discharge chamber 12, and a suction port 1 communicating the compression chamber 14 of the cylinder bore 6 with the suction chamber 13. 6 and are provided at predetermined intervals in the circumferential direction. The discharge port 15 is opened and closed by a discharge valve 17, and the suction port 16 is opened and closed by a suction valve 18.

A thrust flange 40 for transmitting the rotation of the shaft 5 to the swash plate 10 is fixed to a front end portion of the shaft 5, and the thrust flange 40 is provided with a thrust bearing 33. Through the inner wall surface of the front head 4 so as to be rotatable.

The thrust flange 40 and the swash plate 10 are connected via a link mechanism 41 so that even when the inclination angle of the swash plate 10 changes, the top dead center of the biston 7 becomes constant. , Is set.

The piston 7 has a cylindrical head portion 71 fitted into the cylinder bore 6, and a flange connecting the head portion 71 and the swash plate 10 via a shoe 50. And a bridge 72. The bridge 72 is provided integrally with the head 71.

The head portion 71 has a hollow portion 73 for reducing the weight and a hole 74 for communicating the hollow portion 73 with the outside. A shower receiving portion 75 that supports the shower 50 so as to be able to roll is formed in the page portion 72.

The hole 74 is provided at a position communicating with the crank chamber 8 at the bottom dead center when the stroke amount of the piston 7 is at least two-thirds of the maximum.

Next, the operation of the variable displacement type swash plate type compressor will be described. When the rotational power of the vehicle engine (not shown) is transmitted to the shaft 5, the rotating force of the shaft 5 is changed to the thrust flange 40 and the link. The swash plate 10 is transmitted to the swash plate 10 via the locking mechanism 41, and the swash plate 10 rotates. The rotation of the swash plate 10 causes the shafts 50 and 50 to relatively rotate on the sliding surfaces 10a and 10b of the swash plate 10, so that the rotation force from the swash plate 10 is fixed. This is converted to a linear reciprocating motion of 77.

The piston 7 reciprocates in the cylinder bore 6, and as a result, the volume of the compression chamber in the cylinder bore 6 changes, and the suction, compression, and discharge of the refrigerant gas are sequentially performed due to the change in the volume, and the oblique movement occurs. A high-pressure refrigerant gas having a capacity corresponding to the inclination angle of the plate 10 is discharged.

At the time of suction, the suction valve 18 opens, and low-pressure refrigerant gas is sucked from the suction chamber 13 into the compression chamber 14 in the cylinder bore 6 via the suction port 16, and at the time of discharge, the discharge valve 1 開き opens. The high-pressure refrigerant gas is discharged from the compression chamber 14 to the discharge chamber 12 via the discharge port 15.

When the heat load is reduced, the cross-sectional area of the gas introduction passage is increased by the control valve 81. Therefore, high-pressure refrigerant gas flows from the discharge chamber 12 to the crank chamber 8 through the gas introduction passage, the pressure in the crank chamber 8 increases, and the inclination angle of the swash plate 10 decreases.

On the other hand, when the heat load increases, the control valve 81 reduces the cross-sectional area of the gas introduction passage. Therefore, the inflow of high-pressure refrigerant gas from the discharge chamber 12 to the crank chamber 8 is suppressed, the pressure in the crank chamber 8 decreases, and the inclination angle of the swash plate 10 increases.

The lubricating oil that has flowed into the hollow part 3 from the hole 74 is discharged to the crank chamber 8 when the hole 74 communicates with the crank chamber 8, so that the lubricating oil accumulates in the hollow part 73 and the piston The inertial force of ン 7 does not increase.

Next, the piston will be described in detail.

When manufacturing piston 7, as shown in Figs. 2 and 3, two 8

10 A stainless steel material 60 in which single-headed stones are connected in a double-headed shape is made, and this piston material 60 is connected to the connecting portion (the position indicated by the two-dot chain line in FIGS. 2 and 3). In, two single-headed pistons are obtained. The receiving portion 75 is formed by cutting after fabrication.

4 and 5 are cross-sectional views of the piston material 60. FIG. As shown in the figure, each piston is provided with two oblong holes 74.

The construction of the piston material 60 is performed as follows.

First, a core 91 is set in a mold 90 as shown in FIG. The core 91 in this example is a soluble core such as a resin and melts at a temperature lower than the melting point of the piston constituent material. The core 91 has a main body 91a corresponding to the hollow portion Ί3, a support portion 91b corresponding to the hole 74 and supporting the main body 91a in the mold 90. Become. In this example, the main body 91a has a columnar shape. Next, as shown in FIG. 7, a molten metal 92 is poured into a mold 90. In this example, the material of the piston material 60 is an aluminum-based material.

After the molten metal 92 has solidified, the mold is opened as shown in FIG. 8, and the biston material 60 containing the core 91 is taken out and put into a core melting furnace (not shown).

When heated in the core melting furnace, the core 91 is melted, and the melted core 91 is discharged from the hole 74 as shown in FIG. The discharged core 91 can be reused as described later by pouring it into a core mold (gravitational structure).

After the core 91 is removed, sufficient strength can be obtained by subjecting the piston material 60 to a heat treatment such as JIS “T 6”. The heat treatment of JIS “T6” refers to the one that performs an artificial aging treatment after the solution treatment, and performs the solution treatment at about 480 to 50 ° C. Then, it is quenched with water at room temperature, etc., and is aged at about 150 to 180 ° C until the required strength is obtained. Thereby, excellent strength can be obtained without performing cold working.

When the above-mentioned meltable core is used, the core 91 is mounted in the mold 90, and then the molten metal is poured to form the bistone material 60. By taking out the piston material 60 from 90 and heating it, the core 91 is melted, and the melted core is discharged from the hole 74 to remove the hollow piston. To form.

In such a method for manufacturing a piston, the core discharged from the hole 74 is poured into a core mold (not shown) to form a core again, and the core thus formed is used. , Other pistons can be formed. In other words, the core can be melted by being put into the core melting furnace, so that the core material can be reused. Reuse of core material improves economics.

In this example, the sickle was made in the state of the piston material 60 in which two pistons 7 were connected. However, the piston 7 may be manufactured alone, or in a state in which three or more are connected. It may be made.

Further, in this example, a meltable core that is soluble as the core 91 was used, but a water-soluble core such as sodium chloride or a disintegratable core such as a sand core may be used. Good.

Furthermore, in this example, two oval holes 74 are provided on the peripheral wall of the head portion 71, but the number, position, and shape of the holes are not limited to those of this example. However, regarding the position, avoid the wall facing the compression chamber 14 or the part where stress is applied. When the number of holes is one or two are provided coaxially, it is advisable to avoid a true circular hole to prevent the core set in the mold from rotating. Les ゃ If the strength is insufficient due to the reduced thickness of the head 71, ribs or struts may be provided inside the head 71. Industrial applicability

The present invention provides a variable-capacity swash plate compressor having a swash plate housed in a crank chamber and a piston reciprocating in a cylinder bore as the swash plate swings, and a method of manufacturing bistons used for the compressor. It is suitable for refrigeration cycles mounted on automobiles, especially because it can reduce the weight and cost of pistons.

Claims

3 Range

1. A cylinder mouth having a plurality of cylinder bores formed therein, a shaft rotatably supported at the center of the cylinder mouth, and a slidable and swingable shaft. A swash plate mounted thereon, a crank chamber for accommodating the swash plate, and a piston connected to the swash plate and reciprocating in the cylinder bore as the swash plate swings; In the variable displacement type swash plate type compressor, in which the inclination angle of the swash plate changes according to the pressure change and the stroke amount of the biston changes.

The piston includes a cylindrical head portion, and a bridge portion connecting the head portion and the swash plate. The head portion has a hollow portion, and the hollow portion has an outer portion. And a hole communicating with the core is formed. The piston is integrally formed by a structure, and the structure uses a fluidizable core. The variable capacity, wherein the hole of the piston is a hole for discharging the fluidized core when the piston is manufactured using a fluidizable core. Type swash plate type compressor.

2. The variable displacement swash plate type compressor according to claim 1, wherein the core is melted at a temperature lower than a melting point of a constituent material of the piston.

3. The variable displacement swash plate compressor according to claim 1, wherein the core is a soluble core.

4. The variable displacement swash plate compressor according to claim 1, wherein the core is a collapsible core.

5. The hole is provided at a position communicating with the crank chamber at a bottom dead center when a stroke amount of the piston is at least two-thirds of a maximum. The variable displacement type swash plate type compressor according to any one of claims 1 to 4, wherein

6. The variable displacement type swash plate compressor according to claim 5, wherein at least two holes are provided.

7. In a method of manufacturing a piston used for a variable displacement swash plate type compressor,

The piston is integrally formed by a structure in which a core is mounted in a mold, has a hollow portion inside, and has a hole communicating the hollow portion with the outside.

The core includes a main body corresponding to the hollow portion, and a support corresponding to the hole and supporting the main body in the mold.

After mounting the core in the mold, a molten metal is poured to form a piston material,

After the molten metal is solidified, the biston material is taken out of the mold, the core is fluidized, and the fluidized core is discharged from the hole to form a hollow piston. A method for producing a piston, characterized by the following.

8. The method for producing bistons according to claim 7,

The method for producing bistons, wherein the fluidization of the core is performed by placing the core in a core melting furnace and melting the core.

9. The method for producing bistone according to claim 8, wherein

Manufacturing the biston, wherein the core discharged from the hole is poured into a core mold to form a core again, and another piston is formed using the formed core. Method.