JP2000038987A - Manufacture of piston for compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bond a cylindrical part with a lid part, and fix them to each other inexpensively in a short time. SOLUTION: A piston 22 comprises both a head part 40 to be housed in a cylinder bore 12a and a neck part 42 to be connected with a swash plate 20, set so as to be continuous thereto. The head part 40 which is a separate body from the cylindrical part 41, and is composed of a cylindrical part 41 in a covered cylindrical shape, and of a lid part 43 blocking the inner space of the cylindrical part 41. The lid part 43 is formed up integrally with the neck part 42. The cylindrical part 41 is joined with and fixed to the neck part 42 by means of a friction welding process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a piston of a compressor applied to, for example, a vehicle air conditioning system.

[0002]

2. Description of the Related Art A piston of this type is mounted on a metal head housed in a cylinder bore formed in a housing of a compressor and a driving portion of the compressor (for example, a swash plate in the case of a swash plate type compressor). The metal neck to be connected is connected.
The head is composed of a cylindrical portion having a closed cylindrical shape, and a lid portion separate from the cylindrical portion and for closing an inner space of the cylindrical portion. The lid is formed integrally with the neck.

[0003] A piston having such a configuration is called a "hollow piston" and is lighter in weight than a "solid piston" having a solid head, which is effective for reducing the weight of a compressor. From another point of view, a solid piston can be molded integrally with the head and neck by casting or the like, but since a hollow piston is hollow, the head is divided into a cylindrical part and a lid part, and later molded. There was no other way but to join and fix them.

[0004]

However, conventionally, the fixing of the cylindrical portion and the neck portion (lid portion) has been performed by, for example, electron beam welding. In the electron beam welding, a welding portion is irradiated with an electron beam accelerated at a high speed in a vacuum welding chamber to perform welding. Therefore, the following problem has occurred.

(1) The electron beam welding machine is provided with a vacuum vessel forming a welding chamber and an electron gun chamber, an exhaust device, an electron gun, a high voltage power supply, a control device, and the like. That is, the electron beam welding requires a large-scale facility, and the manufacturing cost of the piston has been increased.

(2) Since the cylindrical portion and the neck portion are joined and fixed in an annular region, the electron beam must be sequentially irradiated along this annular region. Therefore, there is a problem that it takes time to join and fix the cylindrical portion and the neck portion.

(3) During welding, a high temperature acts near the joint between the cylindrical portion and the neck portion. For example, bubbles formed in the metal material forming the cylindrical portion and the neck portion are ruptured (blow-out) by vacuum evacuation. Sometimes. If the blow-out is to form a recess in it, the corners will catch on the inner surface of the cylinder bore and damage it, or the strength of the joint between the cylinder and the neck will decrease, and if used directly as a compressor, There have been problems such as breakage of the joint.

The present invention has been made in view of the problems existing in the above prior art.
It is an object of the present invention to provide a method for manufacturing a piston of a compressor, which can inexpensively and quickly fix a cylindrical portion and a lid portion.
It is an object of the present invention to provide a method of manufacturing a piston of a compressor which can achieve the first object and can fix and fix a cylindrical portion and a lid portion without applying a high temperature in a vacuum atmosphere.

[0009]

According to a first aspect of the present invention, there is provided a method of manufacturing a piston in which a cylindrical portion and a lid are joined and fixed by a friction welding method. .

[0010] To achieve the second object, a second aspect is provided.
According to the invention, there is provided a method of manufacturing a piston in which the cylindrical portion and the lid portion are joined and fixed by using a plastic flow coupling method. Claim 3
According to the second aspect of the present invention, in the method for manufacturing a piston according to the second aspect, an adhesive is used in combination with the cylindrical portion and the lid portion for fixing.

According to the fourth aspect of the present invention, the brazing material is interposed between the joining surface of the cylindrical portion and the lid, and the brazing material is diffused by plastically flowing the joining surface of the cylindrical portion and the lid by pressing. This is a method for manufacturing a piston for joining and fixing a cylindrical portion and a lid portion.

In the invention according to claim 5, the heat of the melting point or more is applied to the brazing material during the pressing. (Operation) In the first aspect of the present invention, the cylindrical portion and the lid portion are relatively rotated, and are brought into pressure contact with each other in the annular region with their joined end faces. After a predetermined time, the relative rotation between the cylindrical portion and the lid portion is stopped, so that a kind of seizure phenomenon occurs between the joining end surfaces of the two, and the two are joined and fixed.

According to the second aspect of the present invention, a plastic flow (metal flow) is generated by applying pressure to one of the cylindrical portion and the lid as the member to be connected. Accordingly, the metal material forming one of the cylindrical portion and the lid portion flows into the coupling groove formed on the other of the cylindrical portion or the lid portion as the coupling member, and the two are joined and fixed by engagement via the coupling groove. .

According to the third aspect of the present invention, the joint and fixing of the cylindrical portion and the lid portion are further strengthened by the combined use of the adhesive. According to the fourth aspect of the present invention, the plastic working is generated at the joining surface of the cylindrical portion and the lid by the press working, so that the brazing material interposed between the joining surfaces is diffused, and the cylindrical portion and the lid are joined and fixed. Is done.

In the fifth aspect of the present invention, the heat of the melting point or more is applied to the brazing material at the time of the press working, so that the brazing material becomes a liquid phase diffusion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to third embodiments in which the present invention is embodied in a piston of a variable displacement compressor applied to a vehicle air conditioning system will be described. In addition,
In the second embodiment, only the differences from the first embodiment will be described, and the same members will be denoted by the same reference numerals and description thereof will be omitted. In the third embodiment, only differences from the second embodiment will be described, and similar members will be assigned the same reference numerals and description thereof will be omitted.

(First Embodiment) As shown in FIG. 1, a front housing 11 is joined and fixed to a front end of a cylinder block 12. The rear housing 13 is joined and fixed to the rear end of the cylinder block 12 via a valve / port forming body 14. The crank chamber 15 is defined by being surrounded by the front housing 11 and the cylinder block 12.

The rotating shaft 16 is rotatably supported between the front housing 11 and the cylinder block 12 so as to pass through the crank chamber 15. The rotating shaft 16 is connected to a vehicle engine (not shown) as an external drive source via a clutch mechanism such as an electromagnetic clutch. Therefore, the rotating shaft 16 is driven to rotate by the connection of the clutch mechanism during the operation of the vehicle engine.

The rotation support 19 is fixed to the rotation shaft 16 in the crank chamber 15. The swash plate 20 includes the rotating shaft 1
6 is supported so as to be slidable and tiltable in the direction of the axis L thereof. The hinge mechanism 21 is interposed between the rotation support 19 and the swash plate 20. The swash plate 20
With the interposition of the hinge mechanism 21, the hinge mechanism 21 can tilt with respect to the rotation shaft 16 and can rotate integrally with the rotation shaft 16. When the radial center of the swash plate 20 moves toward the cylinder block 12, the inclination angle of the swash plate 20 decreases, and when it moves toward the rotary support 19, the inclination angle of the swash plate 20 increases.

The cylinder bore 12a is the cylinder block 1.
2 is formed through. One end of the single-headed piston 22 is housed in the cylinder bore 12 a at one end, and the other end is moored to the outer peripheral portion of the swash plate 20 via the shoe 23. The piston 22 moves the cylinder bore 1
It is reciprocated back and forth within 2a.

The suction chamber 24 and the discharge chamber 25 are formed in the rear housing 13 respectively. Suction port 2
6, the suction valve 27, the discharge port 28, and the discharge valve 29 are formed on the valve / port forming body 14, respectively. Then, the refrigerant gas in the suction chamber 24 is sucked into the cylinder bore 12a through the suction port 26 and the suction valve 27 by moving from the top dead center side of the piston 22 to the bottom dead center side. The refrigerant gas sucked into the cylinder bore 12a
Is moved to the predetermined pressure by moving from the bottom dead center side to the top dead center side, and the discharge port 28 and the discharge valve 29 are compressed.
Through the discharge chamber 25.

The bleed passage 30 comprises a passage 30a formed in the axis of the rotary shaft 16, and a through hole 30b formed in the cylinder block 12 and the valve / port forming body 14. The bleed passage 30 connects the crank chamber 15 and the suction chamber 24. The air supply passage 31 connects the discharge chamber 25 and the crank chamber 15. The capacity control valve 32 which is an electromagnetic valve is connected to the air supply passage 31.
Is interposed on top. The capacity control valve 32 is connected to the solenoid 3
2a, and a valve body 32b that opens and closes the air supply passage 31 by exciting and demagnetizing the solenoid 32a. The solenoid 32a is excited and demagnetized under the control of a computer (not shown) according to the cooling load and the like. Therefore, the air supply passage 3
1 is adjusted by the valve body 32b, and the crank chamber 15
Is changed, and the difference between the pressure in the crank chamber 15 acting before and after the piston 22 and the pressure in the cylinder bore 12a is adjusted. As a result, the inclination angle of the swash plate 20 is changed, the stroke amount of the piston 22 is changed, and the discharge capacity is adjusted.

That is, when the solenoid 32a is demagnetized, the air supply passage 31 is opened by the valve body 32b and the discharge chamber 25 is opened.
And the crank chamber 15 are communicated. Therefore, the discharge chamber 25
High-pressure refrigerant gas is supplied through the air supply passage 31 to the crank chamber 15.
And the pressure in the crank chamber 15 is increased. When the pressure in the crank chamber 15 rises, the inclination angle of the swash plate 20 becomes minimum, the stroke amount of the piston 22 becomes small, and the discharge capacity becomes minimum. When the solenoid 32a is excited, the air supply passage 31 is closed by the valve body 32b, and the pressure in the crank chamber 15 decreases based on the pressure released through the bleed passage 30. When the pressure in the crank chamber 15 decreases, the swash plate 2
The inclination angle of 0 becomes maximum, the stroke amount of the piston 22 becomes large, and the discharge capacity becomes maximum.

As described above, the piston 22 slides smoothly in the cylinder bore 12a with respect to the swash plate 20 whose inclination angle is to be changed according to the fluctuation of the pressure in the crank chamber 15, that is, the fluctuation of the cooling load. You need to follow it.
In the hollow piston described in detail later, the inertial force due to the reciprocating motion is small due to its light weight. Therefore, the control of the inclination angle of the swash plate 20 is hardly affected, which is preferable.

Next, the structure of the piston 22 will be described in detail. As shown in FIG. 1 and FIG.
Has a head portion 40 accommodated in the cylinder bore 12a, and a neck portion 42 connected to the outer peripheral portion of the swash plate 20 as a driving portion via the shoe 23. Head 40 and neck 42
Are connected in the direction of the axis S of the piston 22. The cylindrical portion 41 constituting the head portion 40 has a closed cylindrical shape in which the back side of the cylinder bore 12a (the valve / port forming body 14 side) is the lid side. The neck portion 42 has a concave portion 42a on the inner peripheral side,
A pair of front and rear spherical receiving surfaces 42b are provided in the concave portion 42a.
Are formed. The pair of shoes 23 hold the front and rear surfaces of the outer peripheral portion of the swash plate 20 and are accommodated in the concave portions 42a, and are spherically received by the corresponding receiving surfaces 42b.

The lid 43 constituting the head 40 has a disk shape centered on the axis S. The lid 43 is a cylindrical part 41
, And is integrally formed at a connection portion with the head portion 40 at the neck portion 42. The connecting cylinder 43a has a cylindrical shape with the axis S as a center, and is integrally formed on the lid 43 so as to protrude from the outer edge of the rear end face. The outer diameter of the connecting cylinder 43a is the same as the outer diameter of the cylindrical portion 41, and the inner diameter is the same as the inner diameter of the cylindrical portion 41. The cylindrical portion 41 and the neck portion 42 are each manufactured by casting, forging, or the like using an aluminum-based metal material.

In this embodiment, a friction welding method is used for joining and fixing the cylindrical portion 41 and the neck portion 42 (lid portion 43). That is, as shown in FIG.
And the neck portion 42 are arranged in a state where the axes S are coincident with each other, that is, in a state where the joint end surface 41b of the cylindrical portion 41 and the joint end surface 43b of the connecting cylinder 43a in the neck portion 42 face each other. Then, as shown in the time chart of FIG.
In this state, the cylindrical portion 41 and the neck portion 42 are rotated relative to each other about the axis S, and the two 41 and 42 are moved closer to each other and brought into contact with each other in the toroidal belt-like region through the joint end surfaces 41b and 43b.

The first pressure P1 is applied to the cylindrical portion 41 and the neck portion 42 in the contact state to make a pressure contact state, and this pressure contact state is continued for a predetermined time. The cylindrical portion 41 and the neck portion 42 that are relatively rotated in the pressed state generate heat at a high temperature by sliding between the joint end surfaces 41b and 43b of the two 41 and 42.
After continuing the relative rotation in the pressure contact state for a predetermined time, the cylindrical portion 4
1 and the relative rotation of the neck 42 are stopped.
1, 42 are pressed against each other by applying a second pressure P2 greater than the first pressure P1. Therefore, a kind of seizure phenomenon occurs between the joining end surfaces 41b and 43b of the cylindrical portion 41 and the neck portion 42,
Both 41 and 42 are fixed by welding.

The above-mentioned operation of joining and fixing the cylindrical portion 41 and the neck portion 42 is performed in an air atmosphere. Therefore, even when a high temperature is applied, bubbles formed in the metal material do not blow out.

The present embodiment having the above configuration has the following effects. (1) The joint between the cylindrical portion 41 and the neck portion 42 is fixed using a friction welding method. Therefore, a large-scale facility such as the electron beam welding described in the related art is not required, and the manufacturing cost of the piston 22 can be reduced. In addition, cylindrical part 4
1 (joining end face 41b) and the neck 42 (joining end face 43b) are brought into pressure contact with each other while being relatively rotated, so that the annular regions can be joined and fixed at the same time. Therefore, it is possible to reduce the time required for the work of joining and fixing the cylindrical portion 41 and the neck portion 42.

(2) After the relative rotation of the cylindrical portion 41 and the neck portion 42 in the pressed state (first pressure P1) is stopped,
1, 42 are pressed against each other at a second pressure P2 greater than the first pressure P1. Therefore, a seizure phenomenon occurs remarkably between the joint end surfaces 41b and 43b of the cylindrical portion 41 and the neck portion 42, and the joint fixation of the two portions 41 and 42 becomes stronger.

(Second Embodiment) FIGS. 4, 5A and 5B show a second embodiment. In this embodiment, the outer diameter of the connecting cylinder 43a is set to be substantially the same as the inner diameter of the cylindrical portion 41. The plurality of (two in the present embodiment) coupling grooves 43c are formed in an annular shape around the axis S of the piston 22 on the outer peripheral surface of the connecting cylinder 43a.

In this embodiment, a plastic flow bonding method and an adhesive are used for joining and fixing the cylindrical portion 41 and the neck portion 42 (lid portion 43). That is, the adhesive (not shown) is applied to the outer peripheral surface of the connecting cylinder 43a including the inner surface of the coupling groove 43c in the lid 43 and the outer peripheral side of the connecting cylinder 43a on the rear end surface of the lid 43, respectively. Apply. Examples of the adhesive include a resin adhesive such as epoxy, polyamide, and vinyl acetate.

With the adhesive applied, the inner space 41a of the cylindrical portion 41 is closed by the lid portion 43, and the cylindrical portion 41 and the neck portion 42 are integrated to form the piston work 22. At this time, the connecting cylinder 43a of the lid 43 is
Is inserted into the inner space 41a of the cylindrical portion 41 and overlapped with the vicinity of the opening end of the cylindrical portion 41 and the inner peripheral side thereof, and the rear end surface of the lid portion 43 is brought into contact with the joining end surface 41b of the cylindrical portion 41.

As shown in FIGS. 5A and 5B, the cylindrical portion 41 and the lid 43 of the piston work 22 are formed.
Is passed through a die 201 having an inner diameter smaller than the outer diameter of the two. Therefore, the cylindrical portion 41 as the member to be coupled is connected to the connecting cylinder 43a of the neck portion 42 as the coupling member.
The overlapped portion with the pressure is subjected to a radially inward pressure by this die passing. As a result, the metal material forming the cylindrical portion 41 flows into each connection groove 43b by plastic flow,
In addition to the above-mentioned curing of the adhesive, the cylindrical portion 41
And the neck 42 are fixed. In FIG. 5A, the difference between the inner diameter of the die 201 and the outer diameter of the cylindrical portion 41 and the lid portion 43 is exaggerated.

The present embodiment having the above configuration has the following effects in addition to the same effects as (1) of the first embodiment. (1) As described above, the cylindrical portion 41 and the neck portion 42 can be joined and fixed without applying a high temperature in a vacuum atmosphere. Therefore, unlike the case where the two members 41 and 42 are joined and fixed by electron beam welding, there is no problem of a decrease in joining strength due to blowout or a problem that the formed concave portion and the inner surface of the cylinder bore 12a are caught.

(2) Cylindrical part 41 using plastic flow coupling method
An adhesive is also used for joining and fixing the and the neck 42. Therefore, the joint between the cylindrical portion 41 and the neck portion 42 is firmly fixed. (3) A plurality of coupling grooves 43c are formed. Accordingly, the engagement structure between the cylindrical portion 41 and the neck portion 42 via the coupling groove 43c becomes complicated, and the joining and fixing of the two portions 41 and 42 become stronger.

(Third Embodiment) FIGS. 6A and 6
(B) shows a third embodiment. The difference between the present embodiment and the second embodiment is that the coupling groove 43c is
3a, and as shown in the enlarged circle of FIG. 6A, when joining and fixing the cylindrical portion 41 and the neck portion 42, a low melting point alloy (the cylindrical portion 41) is used instead of the adhesive. And a brazing material R made of an alloy whose melting point is lower than that of the material forming the neck portion 42.
In that it is interposed between the joining surfaces of In the preparation stage before the joining and fixing work, the brazing material R is fused to the joining surface of the cylindrical portion 41 or the connecting tube 43a, coated with a powdery material, or fitted, that is, It is simply placed.

In the present embodiment, the same die passing as in the second embodiment is performed as the pressure processing. Here, as described above, the connecting cylinder 43 of the neck 42
Since a does not have the coupling groove 43c, the joining surfaces of the cylindrical portion 41 and the neck portion 42 are pressed against each other by piercing, and plastic flow occurs at each joining surface. Therefore, the cylindrical portion 41 and the neck 4
At the bonding surface of No. 2, lattice defects occur in the metal molecules constituting each, and a large number of atomic vacancies are formed.
As a result, the metal atoms of each other enter the atomic vacancies of the cylindrical portion 41 and the neck portion 42.

Further, the brazing material R diffuses between the joining surfaces due to the pressure applied to the respective joining surfaces of the cylindrical portion 41 and the neck portion 42 when the die is passed through and the heat generated during the pressing. Both atoms 41 and 42 enter the vacancies. At this time, heat from the melting point or higher is applied to the brazing material R by the external heating, in addition to the processing heat described above. Therefore,
When the brazing material R is melted, the above-mentioned diffusion is liquid phase diffusion.

As described above, the cylindrical portion 41 and the neck portion 42
6 has an alloy layer G (FIG. 6) made of a metal material constituting each of the cylindrical portion 41, the neck portion 42, and the brazing material R.
(Shown in the image in the enlarged circle of (b)) is formed, and the cylindrical portion 41 and the neck portion 42 are joined and fixed via the alloy layer G as if there is no joining line.

Here, in the above-mentioned die passing, the compressive strain generated on each joint surface between the cylindrical portion 41 and the neck portion 42 is 3% to 3%.
The inner diameter of the die, that is, the cylindrical portion 4
1 and the pressure applied to the neck 42 are set. For example, since the lattice deformation is small and the atomic vacancies are hardly formed by the pressure processing at a low pressure at which the compressive strain of the joining surface is less than 3%, the metal atoms of the cylindrical portion 41 and the neck portion 42 are not formed. Since the penetration is reduced and the diffusion of the brazing material R is not performed well, the joining strength between the two 41 and 42 is reduced. Under low pressure, the brazing material R
Is spread, so that it takes time to pass through the dice. On the other hand, by pressurizing at a high pressure such that the compressive strain of the joint surface exceeds 15%, the dimensions of the piston 22 change greatly, and the outer shape is greatly collapsed. It becomes troublesome without being.

The cylindrical portion 41 and the neck portion 4 having passed through the die
The heat treatment is performed again on the joint portion 2. The temperature applied to the bonding interface at the time of reheating is preferably equal to or higher than the melting point of the alloy layer G formed at the bonding portion. Due to this reheating and the processing stress from the time of passing the die, the alloy layer G at the joint portion is formed.
Are diffused to the cylindrical portion 41 side and the neck portion 42 side, respectively, so that the joining and fixing of the two 41 and 42 are further strengthened. This reheating may be performed locally on the joint portion between the cylindrical portion 41 and the lid portion 43 by a laser heater, an electron beam heater, or the like,
The entire piston 22 may be placed in a heating furnace or the like.

The cylindrical portion 41 and the neck portion 42
After being manufactured by forging, casting, or the like, each is subjected to a quenching process, further subjected to a tempering process, and then subjected to die passing. However, by performing the above-described reheating process on the joint portion, for example, by putting the entire piston 22 into a heating furnace, the reheating process can also serve as a tempering process on the cylindrical portion 41 and the neck portion 42. Therefore, the tempering process of the cylindrical portion 41 and the neck portion 42 before the die is passed can be omitted.

Now, the cylindrical portion 41 and the neck portion 42 of this embodiment
And aluminum alloys (for example, JIS standards A2017, A2014, A4032, A6063, A606
1, A7075 and ADC12, A390, the brazing material R suitable for joining and fixing the same alloy or different alloys) is zinc as a first main component, tin as a second main component, and aluminum as a third main component. Copper, chromium and beryllium added, tin as a first main component and zinc as a second main component, aluminum, copper and beryllium added and tin as a first main component and zinc As the second main component, one obtained by adding aluminum, copper, chromium, and beryllium, the one obtained by adding tin as the first main component, zinc as the second main component, and copper or silver, or the second One obtained by adding cadmium, copper, titanium and beryllium with one main component, aluminum as a second main component, and tin as a third main component, or zinc as a first main component and tin as a second main component. Minor, copper and cadmium added, zinc as a first main component, aluminum as a second main component, silicon, copper and titanium added, zinc as a first main component and aluminum as a first main component As a second main component, one obtained by adding titanium, beryllium and copper, one obtained by adding zinc as a first main component, aluminum as a second main component and added titanium, cadmium and copper, Examples thereof include those obtained by adding copper, chromium, magnesium, and tin as one main component and aluminum as the second main component.

In each of the brazing materials R, (weight% of the first main component) ≧ (weight% of the second main component) ≧ (weight% of the third main component), and The weight% is negligible compared to the main component.

In this embodiment having the above-described structure, the same effect as (1) of the first embodiment is obtained, and the brazing material is formed by plastically flowing the joint surfaces of the cylindrical portion 41 and the neck portion 42 through the die. Because the diffusion of R is promoted,
Compared to simple brazing (without pressure processing)
Bonding fixation of 1, 42 becomes strong.

For example, the following embodiments can be carried out without departing from the spirit of the present invention. ○ FIGS. 7A to 7
As shown in (c), the second embodiment is modified, and the roller 202 is pressed against the overlapping portion of the cylindrical portion 41 with the connecting tube 43a while rotating the piston work 22 about the axis S, whereby the radius is increased. Applying an external force inward in the direction to generate a plastic flow in the cylindrical portion 41.

7A to 7C, when the surface of the cross section of the roller 202 is a flat surface parallel to the center of rotation as shown in FIG. FIG. 7 (b) shows a curved surface, and FIG.
It is conceivable that the tapered surface is formed as shown in FIG.

First, the cylindrical portion 41 is formed on the flat surface shown in FIG.
Is pressed in a plane to cause the two materials to flow, so that a large amount of frictional heat is generated and the plastic flow of the material is small. Therefore, the brazing material R, which has been coated in advance, is likely to be simultaneously diffused during the operation of plastic flow. If the cross-sectional length of the plane is too large, plastic flow occurs to an unnecessary surface and needless processing energy is required. If it is too small, the plastic flow becomes small and an effective joint surface cannot be obtained.

In the case of pressing by a curved surface shown in FIG. 7B, by forming an optimum curved surface on the surface of each part, plastic flow can be performed most efficiently and processing energy can be minimized. The point is the radius of curvature R1 of the surface, the radius of curvature of the corner
R2 may be chamfered. If R1 is too large, it approaches the above-mentioned FIG. 7 (a). If R1 is too small, the plastic flow becomes small and it becomes impossible to join.

In the case of pressing on the tapered surface shown in FIG. 7C, a taper angle θ is provided in the direction opposite to the direction of rotation or rubbing, and plastic flow is effectively generated, but heat generation during processing is reduced. . Therefore, although the processing energy is small, the diffusion of the brazing material R at the time of joining is not so large because the processing heat is small. If the taper angle θ is too small, FIG.
As in (a), the heat generated during processing increases, but the amount of plastic flow decreases. On the other hand, when the angle is larger than the predetermined angle, an external force for causing plastic flow escapes, and effective plastic flow does not occur.

The techniques shown in FIGS. 7A to 7C may be applied to the press working of the third embodiment. In the second embodiment, no adhesive is used for joining and fixing the cylindrical portion 41 and the neck portion 42. That is, the cylindrical portion 41
And the neck 42 are fixed by using only the plastic flow bonding method.

In the cylindrical portion 41, the cylindrical portion and the lid portion are separated from each other, and the two portions are joined and fixed by the joining and fixing method as in the above embodiments.
In this case, the cylindrical portion of the cylindrical portion 41 may be separate from the neck 42 as in the above embodiments, or may be integrally formed with the neck 42.

In the third embodiment, no external heat is applied when the dies are passed through the die, and therefore, only the processing heat is applied to the brazing material R. In this case, the diffusion of the brazing material R is solid-phase diffusion.

At least one of the cylindrical portion 41 and the neck portion 42 is made of a metal material other than aluminum, for example,
To be made of iron or copper metal material. ○ To be embodied in the piston of a wave cam compressor. In this case, the driving unit is a wave cam.

The present invention is embodied in a double-headed piston applied to a double-headed piston compressor. In this case, the heads are connected to both sides of the neck, respectively, and the joint fixing method as in each of the above embodiments is adopted between the neck and the cylindrical portion of each head.

As another compressor, the present invention is embodied in a piston of an air compressor or a reciprocating type internal combustion engine. When embodied in a reciprocating internal combustion engine, the drive is a connecting rod connected to the crankshaft.

The technical ideas that can be grasped from the above embodiment will be described. (1) In the friction welding method, the cylindrical portion 41 and the lid portion 43 are relatively rotated in a pressure-contact state, and after the relative rotation in the pressure-contact state is continued for a predetermined time, the cylindrical portion 41 and the lid portion 43 are rotated. 2. The method for manufacturing a piston according to claim 1, wherein a step of stopping relative rotation with the piston is adopted.

In this manner, the cylindrical portion 41 and the lid 43
Can be fixed inexpensively and in a short time. (2) The relative pressure is applied between the cylindrical portion 41 and the lid 43 after the relative rotation of the cylindrical portion 41 and the lid 43 is stopped, and the cylinder 41 and the lid 43 are pressed against each other by applying a higher pressure P2. Manufacturing method of piston.

In this manner, the cylindrical portion 41 and the lid 43
Is more firmly fixed. (3) In the plastic flow coupling method, an external force is applied to one of the cylindrical portion 41 or the lid portion 43 which is a member to be coupled in a portion where the cylindrical portion 41 and the lid portion 43 overlap to generate plastic flow,
4. The method according to claim 2, wherein the metal material forming one of the cylindrical portion 41 and the lid portion 43 is caused to flow into a coupling groove 43 c formed on the other of the coupling members. 5.

In this way, the cylindrical portion 41 and the lid 43
Can be fixed inexpensively and in a short time.
Further, the cylindrical portion 41 and the lid portion 43 can be formed without applying a high temperature.
Can be fixed.

(4) A head 40 accommodated in a cylinder bore 12a formed in the housing 12 of the compressor is connected to a neck 42 connected to the drive unit 20 of the compressor. In a piston of a compressor including a cylindrical portion 41 and a lid 43 which is separate from the cylindrical portion 41 and closes an opening of the cylindrical portion 41, the cylindrical portion 41 and the lid 43 are joined by friction welding. A fixed piston.

In this way, the manufacturing cost of the piston 22 can be reduced. (5) The head 40 housed in the cylinder bore 12a formed in the housing 12 of the compressor, and the driving unit 20 of the compressor
And a neck 42 connected to the head 40
In a piston of a compressor comprising a cylindrical portion 41 and a lid 43 which is separate from the cylindrical portion 41 and closes an opening of the cylindrical portion 41, the cylindrical portion 41 and the lid 43 A piston joined and fixed by joining.

In this way, the manufacturing cost of the piston 22 can be reduced. (6) The head 40 accommodated in the cylinder bore 12a formed in the housing 12 of the compressor, and the driving unit 20 of the compressor
And a neck 42 connected to the head 40
Is a method for manufacturing a piston of a compressor comprising a cylindrical portion 41 and a lid 43 which is separate from the cylindrical portion 41 and closes an opening of the cylindrical portion 41. The brazing material R is interposed between the joining surfaces of the cylindrical portion 41, and the joining surface of the cylindrical portion 41 and the lid portion 43 is plastically flowed by press working to diffuse the brazing material R, thereby joining and fixing the cylindrical portion 41 and the lid portion 43. Manufacturing method of piston.

In this way, the manufacturing cost of the piston 22 can be reduced.

[0067]

According to the present invention having the above-described structure, it is possible to join and fix the cylindrical portion and the lid portion at low cost and in a short time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a variable displacement compressor.

FIG. 2 is an exploded perspective view of a piston.

FIG. 3 is a time chart showing an operation of joining and fixing a cylindrical portion and a neck portion.

FIG. 4 is an enlarged sectional view of a main part of a variable displacement compressor according to a second embodiment.

FIGS. 5 (a) and 5 (b) are views for explaining a die passing through a piston work.

FIG. 6 is a view showing a third embodiment, in which (a),
(B) is a figure explaining the threading of a piston work with a die.

FIGS. 7A to 7C are diagrams showing another example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Front housing which comprises the housing of a compressor, 12 ... The same cylinder block, 12a ... Cylinder bore, 13 ... Rear housing which comprises the housing of a compressor, 20 ... Swash plate as a drive part, 22 ... Piston, 4
0: head, 41: cylinder, 42: neck, 43: lid.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masato Takamatsu 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Takahiro Sugioka 2-1-1 Toyota-cho, Kariya-shi, Aichi Stock Inside the Toyota Industries Corporation (72) Inventor Tsunehisa Sekiguchi 1-60, Ono-cho, Oguchi-machi, Niwa-gun, Aichi Prefecture Higashihisa Co., Ltd. Inside the corporation

Claims (5)

[Claims] 1. A head accommodated in a cylinder bore formed in a housing of a compressor, and a neck connected to a driving unit of the compressor are connected to each other. In a method for manufacturing a piston of a compressor, which is a separate body and a lid for closing an opening of a cylindrical portion, the joint of the cylindrical portion and the lid is fixed by using a friction welding method. Production method. 2. A head accommodated in a cylinder bore formed in a housing of the compressor, and a neck connected to a drive unit of the compressor are connected to each other. In a method for manufacturing a piston of a compressor, which is a separate body and comprises a lid for closing an opening of a cylindrical portion, the piston fixed by joining and fixing the cylindrical portion and the lid using a plastic flow coupling method. Manufacturing method. 3. The method for manufacturing a piston according to claim 2, wherein an adhesive is used for jointing and fixing the cylindrical portion and the lid portion. 4. A head accommodated in a cylinder bore formed in a housing of the compressor, and a neck connected to a drive unit of the compressor are connected to each other, and the head has a cylindrical portion, a cylindrical portion, In a method for manufacturing a piston of a compressor, which is a separate body and a lid portion for closing an opening of a cylindrical portion, a brazing material is interposed between joining surfaces of the cylindrical portion and the lid portion, A method of manufacturing a piston for joining and fixing a cylindrical portion and a lid by plastically flowing a joint surface between the cylindrical portion and a lid to diffuse a brazing material. 5. The method for manufacturing a piston according to claim 4, wherein heat is applied to the brazing material at a temperature higher than its melting point during the pressing.