JPH02146201A - Scroll type fluid machine and method for forming scroll member of scroll type fluid machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for forming a scroll member, including a method for surface treatment when manufacturing a scroll-type fluid machine and an orbiting scroll or a fixed scroll from aluminum or an aluminum alloy. .

[Conventional technology]

As a surface treatment method when molding the orbiting scroll or fixed scroll of conventional scroll-type fluid machinery from aluminum, the surface of the scroll is anodized (anodized) as described in JP-A-57-99202. and then Tafram treatment, or
As described in Japanese Patent No. 3-32992, the surface of one of the scrolls was subjected to hard alumite treatment.

[11M to be Solved by the Invention] In the above-mentioned conventional technology, countless cyclopores are generated on the aluminum surface by the alumite treatment. The treatment for sealing these pores is the Taflam treatment disclosed in Japanese Patent Application Laid-Open No. 57-9920.2.

However, in alumite treatment, the hardness of the produced hard alumite film changes depending on the type of aluminum alloy used, so the material of aluminum is limited. Alternatively, there is a problem that the mechanical strength of aluminum is reduced due to the formation of countless cyclopores, which are used in a state where the properties of the film are deteriorated. Further, alumite treatment is a method in which a scroll is formed into a shape of aluminum and then subjected to surface treatment.

A first object of the present invention is to provide a surface treatment method that allows a hard coating to be obtained regardless of the material of aluminum. A second object is to provide a method for molding a scroll member, including a method for surface treatment with high precision in the shape of the scroll. A third object is to provide a surface treatment coating for aluminum or aluminum alloy that can be combined with a cast iron fixed scroll.

[Means to solve the problem]

In order to achieve the above first object, an electroless N3--P plating film is formed on the surface of aluminum or an aluminum alloy, and heat treatment is applied.

Furthermore, in order to achieve the second purpose, organic or
A model of the scroll member is manufactured using an inorganic resin, and electroless Ni-P plating is formed on the model to a predetermined thickness to form a mold, and molten aluminum is poured into the mold and integrated.

[Effect]

Electroless Ni on aluminum or aluminum alloy
-P plating is put into practical use in various fields. Electroless Ni
- Since P plating is a catalytic reaction type, it can be plated even on non-conductive substrates such as plastic glass, and since it is an autocatalytic reaction in which the deposited metal itself acts as a catalyst for the plating reaction, it can be applied to any thickness and can be applied to any thickness. Plating can be controlled with uniform distribution. Furthermore, electroless Ni-P plating is a film that is excellent in corrosion resistance but is not very suitable for wear resistance. This means that the hardness of the simply treated electroless Ni-P plating film is Hv = 50 in micro Vickers hardness.
This is because it is about 0. However, when heat treated at 350'C or higher, it becomes hard to about Hv = l OOO.

Therefore, by using electroless Ni-P plating for surface treatment of aluminum and performing heat treatment, there is no need to limit the material of the aluminum alloy.

However, if heat treatment is performed after electroless Ni--P plating is applied to the surface of aluminum, there is a possibility that the accuracy of the spiral winding shape will be reduced due to thermal deformation of the aluminum material. Therefore, electroless Nj--P plating was formed in advance along the outer contour of the scroll shape to a predetermined thickness to create a small model.
Molten aluminum is cast into it and integrated. According to this method, electroless N2 is produced due to the humidity of molten aluminum.
The i-P plating film is heat treated to make it hard.

The parts of the film that come into contact with molten aluminum are strongly integrated by metal bonding.

〔Example〕

- An explanation will be given by taking a compressor as an example.

FIG. 1 shows a sectional view of the entire structure of a hermetic scroll compressor embodying the present invention.

In FIG. 1, a compressor section 2 is disposed above and an electric motor 3 is disposed below inside a closed container 1, and an oil reservoir 4 for lubrication is formed at the bottom of the closed container 1. The compressor section 2 includes a fixed scroll 5 having a spiral wrap 5a on the end plate, and a spiral wrap 6 on the end plate.
The orbiting scroll 6 having a diameter and the fixed scroll 5 are integrated.

It has a frame 7 that supports an orbiting scroll 6, and has a structure in which the wraps of the fixed scroll 5 and the orbiting scroll 6 are engaged with each other.

Further, an Oldham mechanism 8 is provided between the orbiting scroll 6 and the frame 7 to prevent the orbiting scroll 6 from rotating. The electric motor 3 is press-fitted into the hermetic container 1 and rotates the orbiting scroll 6 via the crankshaft 9. The crankshaft 9 is supported by a main bearing 10 and a lower bearing 11 provided on the frame 7, and its crank pin is fitted into an orbiting bearing 12 provided on the back surface of the orbiting scroll 6.

1 in the crankshaft 9 is the main bearing 10. An oil supply passage 13 is provided that guides lubricating oil to the lower bearing 11 and the swing bearing 12.

In the compressor section 2, when the orbiting scroll 6 is caused to orbit through the crankshaft 9 driven by the electric motor 3, the fluid sucked from the suction port 18 flows through the orbiting scroll 6,
As the space (compression chamber) formed by the fixed scroll 5 moves toward the center of the scroll, its volume is reduced and compressed.

The compressed refrigerant gas is discharged from a discharge port 16 provided at the center of the fixed scroll into an upper space 17 within the closed container, and then is discharged into the cycle through a discharge port 19.

Furthermore, an intermediate pressure chamber 15 is formed on the back surface of the orbiting scroll to which gas for the compression stroke is guided.

The pressure in the intermediate pressure chamber 15 is between the suction pressure and the discharge pressure of the refrigerant gas, and oil supply to the sliding portion of the scroll is performed using the differential pressure between the discharge pressure and the intermediate chamber pressure.

Scroll compressors as described above are known, for example,
This method is disclosed in Japanese Patent Application Laid-Open No. 58-32988.

Furthermore, although a closed scroll compressor has been described, the present invention relates to an open scroll compressor for use in air, etc.

It can also be applied to semi-hermetic scroll phase ratio machines and scroll type expanders for car coolers.

By the way, in the case of scroll-type fluid machines, one technical challenge is to mold them from aluminum in order to reduce the weight of the fluid machine and reduce the centrifugal force of the orbiting scroll. However, if you use the soft aluminum base as is,
Abrasion occurs, and due to lack of oil film, both parts deform and stick together at the contact area. Therefore, conventionally, alumite treatment was performed. However, in the method of subjecting aluminum to alumite treatment, as described above, the hardness of the hard alumite film varies depending on the type of aluminum alloy, so the material of the aluminum is limited. This has the problem of reducing the mechanical strength of aluminum due to the formation of countless micropores.

Therefore, in order to solve the above problems and achieve the first object, the present invention provides a fixed scroll in which a spiral wrap is formed on one surface of an end plate, as shown in FIGS. 2 and 3.
Similarly, the orbiting scroll members having a spiral wrap formed on one surface of the end plate are meshed with each other, and the orbiting scroll members are rotated without rotating on their own axis to form a closed space between the spiral wraps and allow fluid flow. In the scroll-type fluid machine, the orbiting scroll member is moved around the space in accordance with the movement of the orbiting scroll member, and compresses the fluid by reducing the volume, wherein at least the orbiting scroll is made of aluminum. A scroll-type fluid machine was obtained in which the sliding surface was subjected to electroless Ni--P plating treatment and heat treatment. According to this, electroless Ni-P plating is a catalytic reaction type and heat-treated, so it can create a surface treatment layer with excellent corrosion resistance, surface hardening, and wear resistance, regardless of the type of aluminum alloy. As a result, it is possible to obtain a lightweight scroll-type fluid machine that is less susceptible to wear and adhesion due to lack of oil film. Note that if the scroll fluid machine is small and the surface pressure between the scroll members is small, even if only Ni-P plating or Ni plating is applied, 1. ! It may be electrolytically plated. Such surface treatment has the effect of providing a surface layer with no pinholes, a uniform plating layer thickness, and good shape accuracy. Further, it has the effect that a lightweight scroll member with good wear resistance and corrosion resistance can be obtained.

Furthermore, an embodiment showing means for achieving the second objective of molding a scroll while ensuring accuracy will be described with reference to FIG.

First, a model of the scroll member 22 consisting of the spiral body portion 20 and the mirror body portion 21 is molded from organic or inorganic resin, and electroless Ni-P plating is applied thereon to form the outer shell 23 of the scroll member 22. Form. At this time, the plating thickness is determined based on the required specifications of the scroll compressor, but is preferably about 10 to 100 μm. In other words, if the plating film is thin, there is a risk that the plating film will break when molten aluminum is poured into it, and if it becomes thick, there is a concern that the plating film properties (decreased mechanical strength, distortion due to crystallization, etc.) may change. It is.

Then, the organic or inorganic resin model is removed using a method such as a solvent or low-temperature heating, and the scroll member 22 is removed.
Only the outer shell 23 is taken out. Thereafter, a molten metal of aluminium or aluminum alloy is cast into the outer shell 23 and integrated. At this time.

It is desirable that the outer shell 23 be buried in a sand mold or a metal mold. In addition, the temperature of the molten metal is 600°C or higher, preferably 65°C.
The temperature is 0°C or higher, and casting is performed by gravity casting or pressure casting. In this way, the outer shell 23 made of electroless ff4Ni-P plating is applied to aluminum or aluminum alloy.
By casting the electroless N:i-P plating into a metal, it crystallizes and becomes a hard film, and also reacts with aluminum or an aluminum alloy to bond with gold, resulting in high adhesion strength.

In these steps, the method for manufacturing the model of the scroll member 20 is not limited to organic or inorganic resin, but may also be manufactured using plaster mold or other metals.

According to this embodiment, a hard electroless Ni--P plating film can be obtained regardless of the material of aluminum, and a scroll with high shape accuracy can be formed. Furthermore, since the formation of fine cracks accompanying the crystallization of the plating film creates an oil stagnation effect, it also has the effect of improving the sliding characteristics. Thirdly, good wear resistance and durability can be obtained by combining the fixed scroll with cast iron and the orbiting scroll with aluminum material subjected to the above-mentioned surface treatment.

〔Effect of the invention〕

According to the present invention, firstly, the surface of the scroll member formed of aluminum is subjected to electroless Ni-P plating and treatment, so it is not limited to the type of aluminum alloy, and has corrosion resistance, surface hardening, and wear resistance. 1J An excellent surface treatment layer was obtained,
A lightweight and durable scroll-type fluid machine can be obtained. In addition, when the device is small and the surface pressure is low, by using only Ni-P plating, there is no pinhole and the shape accuracy is good, and it is lightweight and durable.

Secondly, electroless plating is applied to the model of the scroll member, and the model is used as a facing mold and molten aluminum alloy is cast into one piece, so amorphous electroless Ni-P is formed.
The plating film can be heat treated at the same time as aluminum or aluminum alloy is cast, and hard electroless N
Not only can an i-P plating film be obtained, but it also reacts with molten aluminum or aluminum alloy to form a strong metal bond, which has the effect of improving adhesion. In addition, the accuracy of the shape of the scroll member can be ensured. Furthermore, since the sliding characteristics and wear resistance of the scroll member can be improved, there is also the effect of improving reliability and performance.

Furthermore, by forming the orbiting scroll from aluminum, centrifugal force can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a hermetic scroll compressor, FIG. 2 is a plan view of a scroll member plated with electroless Ni-P, which is an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view thereof. Fourth
The figure is a longitudinal sectional view for explaining the manufacturing method. DESCRIPTION OF SYMBOLS 1... Airtight container, 2... Compressor part, 3... Electric motor, 4... Oil reservoir, 5... End plate, 5a... Wrap,
6... Casting plate. 6a...Wrap, 7...Frame, 8...Oldham mechanism, 9...Crankshaft, 10...Main bearing, 11
...Lower bearing, 12...Swivel bearing, 13...Oil supply passage, 20...Wrap part, 21...End plate part, 22...
...Scroll member model, 23...outer shell. nth 6α・-lap z5・pa outside

Claims (6)

[Claims] 1. A scroll-type fluid machine in which an orbiting scroll member having a spiral wrap formed on the end plate and a fixed scroll member similarly forming the spiral wrap on the end plate are engaged with each other, and the orbiting scroll is rotated by an anti-rotation mechanism. , the scroll member is formed of an aluminum alloy, and at least a part of its surface is coated with electroless Ni.
- A scroll-type fluid machine characterized by being coated with P plating. 2. The scroll type fluid machine according to claim 1, wherein the plating is Ni plating. 3. The scroll type fluid machine according to claim 1, wherein the plating is electroless plating. 4. 4. The method of forming a scroll member for a scroll-type fluid machine according to claim 1, wherein a heat treatment is performed after the plating treatment. 5. 2. The scroll-type fluid machine according to claim 1, wherein the fixed scroll member is made of cast iron, and only the orbiting scroll member is subjected to electroless Ni-P plating surface treatment and heat treatment. 6. A scroll-type fluid machine in which an orbiting scroll member having a spiral wrap formed on the end plate and a fixed scroll member similarly forming the spiral wrap on the end plate are engaged with each other, and the orbiting scroll is rotated by an anti-rotation mechanism. , the method for forming the scroll member includes (a) applying electroless Ni-P plating to a model of the scroll member, and (b) removing the model to leave an outer shell made of an electroless Ni-P plating layer. (c) A method for forming a scroll member of a scroll compressor, characterized in that the forming step comprises a step of melting and casting an aluminum alloy into the outer shell.