JP2907915B2 - Manufacturing method of scroll compressor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a scroll compressor applied to a refrigerant compressor such as an air conditioner, and more particularly to an improvement in wear resistance of a sliding portion and a reduction in friction. And a method for manufacturing a scroll compressor.

[Conventional technology]

FIG. 3 shows a cross section of a conventional scroll compressor. The closed casing 1 is filled with the refrigerant mixed oil 2, and the electric motor unit 10 and the machine unit main body are assembled. The mechanical part is composed of a fixed scroll 3, an orbiting scroll 4, an Oldham ring 5, a crankshaft 6, and a block 9. Bearings 7, 7 are provided between the crankshaft 6 and the orbiting scroll 4 and between the crankshaft 6 and the block 9, respectively. 8 are provided. The fixed scroll 3 has a wrap formed by a head plate and an involute standing upright on the head plate or a curve similar to the involute. Further, the orbiting scroll 4 is upright on the mirror plate and the mirror plate, and a wrap having the same curve as the fixed scroll 3 is formed. The Oldham ring 5 is formed with a key portion which is inserted into the key groove of the orbiting scroll 4 and the key groove of the block 9. The Oldham ring 5 is inserted between the two, and the movement of the orbiting scroll 4 is controlled. Restrained. The fixed scroll 3 has a suction hole continuous with the suction port at an outer peripheral portion of the involute wrap, and a discharge hole at the center of the involute shape.

The operation of the scroll compressor configured as described above will be described below. Rotational motion of the crankshaft 6 accompanying rotation of the motor unit 10 is transmitted to the orbiting scroll 4 by the bearing 7, but the orbiting scroll 4 rotates by the action of the Oldham ring 5 inserted between the orbiting scroll 4 and the block 9. Orbiting around the center of the fixed scroll 3 in the involute shape. At this time, the volume of the space decreases and the pressure increases as the two contact points between the wrap of the fixed scroll 3 and the wrap of the orbiting scroll 4 approach the center of the involute shape with the orbital movement of the orbiting scroll 4. With this compression mechanism, the refrigerant sucked from the suction hole is compressed, once discharged into the closed casing 1 through the discharge hole, and then discharged from the discharge port to a cooling system (not shown).

The sliding portions of the fixed scroll 3, the orbiting scroll 4, the Oldham ring 5, and the block 9 of such a scroll compressor have conventionally been constituted by a combination of materials shown in Table 2.

That is, most of the components are made of cast iron or iron-based metal, and there is an example in which some of the components, particularly the orbiting scroll 4 or the Oldham ring 5, are made of an aluminum alloy. Some sliding parts have a surface treatment or a reinforcing material for imparting wear resistance.

[Problems to be solved by the invention]

In the above prior art, as shown in Table 2, the sliding parts of the orbiting scroll and the Oldham ring and the sliding part of the Oldham ring and the block are slid with each other using cast iron or a combination of cast iron and iron-based metal. This is mainly done, and even in that case, one side is subjected to surface treatment. When an aluminum alloy is used for one of the materials, anodized aluminum, a Ni foam metal, or an aluminum alloy containing a reinforcing material is used to avoid direct sliding with cast iron or an iron-based metal. Therefore, sufficient consideration has not been given to the material combination of the sliding member, and the wear resistance or low friction has depended on the surface treatment.

SUMMARY OF THE INVENTION The present invention provides a manufacturing method for producing a high-accuracy combination of materials that achieve wear resistance or low friction in consideration of the main required characteristics of each component of a fixed scroll, an orbiting scroll, an Oldham ring, and a block. Is to provide.

[Means for solving the problem]

In order to achieve the above object, the fixed scroll is made of cast iron, the orbiting scroll is made of aluminum alloy, only the key portion sliding with the orbiting scroll key groove of the Oldham ring is cast iron, the Oldham ring is made of aluminum alloy, and the block is made of cast iron. It was made. Regarding the wear resistance of the aluminum alloy, silicon is 8 to 12%.
An Al-Si-Cu alloy containing 3% by weight of copper and 3-4% by weight of copper and treated so as to exhibit a metal structure in which fine crystal grains of silicon are uniformly dispersed is used. Further, in order to form a cast iron key portion on the Oldham ring, a cast iron key portion was inserted into a predetermined position of the aluminum alloy Oldham ring portion, and the aluminum alloy was plastically fluidized and fixed by a method of fastening. Further, in order to achieve another object, the wrap portion and the end plate portion of the orbiting scroll are subjected to a solid lubricating surface treatment, for example, impregnated with molybdenum disulfide in alumite, or combined with boron nitride.
Ni plating was applied.

[Action]

In sliding between cast iron and an aluminum alloy, the aluminum alloy contains 8 to 12% by weight of silicon and 3 to 4% by weight of copper,
In addition, by setting the silicon crystal grains to have a fine and uniform metal structure of several μm or less, an aluminum alloy having relatively high hardness and uniform hardness among aluminum alloys can be obtained. It has been clarified that the sliding between the aluminum alloy and the cast iron exhibits good wear resistance. This is because of the oil retaining properties of cast iron and the sliding of the aluminum alloy, which has a uniform hardness, a good oil film is formed even at high speeds and high loads within the operating range of the scroll compressor, and metal contact occurs. This is because it has been lost. This eliminates the need for the surface treatment applied to cast iron and aluminum alloy, and enables the sliding of the base surfaces of the respective materials. Considering the characteristics required for the fixed scroll, the orbiting scroll, the Oldham ring, and the block members, the orbiting scroll and the Oldham ring are made of an aluminum alloy in order to reduce the inertial force during high-speed rotation. The other parts are preferably cast iron in terms of strength or in combination with an aluminum alloy. However, a sliding portion between the orbiting scroll and the Oldham ring causes sliding between the aluminum alloys. When sliding between aluminum alloys, the oil film retention between the sliding surfaces is poorer than the combination of cast iron and aluminum alloy, and the sliding conditions between the orbiting scroll and Oldham ring are lower than those of other sliding parts. And harsh. That is, the inflow of oil is non-uniform structurally, and the oil is exposed to a high load. Therefore, a method was found that enables sliding between cast iron and an aluminum alloy when sliding between the orbiting scroll and the Oldham ring. That is,
As a method of installing the cast iron part in the aluminum alloy while maintaining the characteristics of the aluminum alloy of the present invention, the method has been made possible by implementing the plastic flow joining method of the aluminum alloy shown in FIG. Also, when the end plate and the lap slide between the fixed scroll and the orbiting scroll, the end plate of the orbiting scroll made of aluminum alloy and the wrap portion are subjected to a surface treatment having a solid lubricating property in advance, so that the rotation between the orbiting scroll and the fixed scroll can be prevented. The sliding loss, that is, the dynamic friction coefficient can be reduced.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to Table 2 and FIGS. First, Table 1 shows combinations of materials constituting the mechanical part of the scroll compressor and materials of the respective sliding parts.

The fixed scroll is made of cast iron, the orbiting scroll is made of aluminum alloy, the key portion sliding with the orbiting ring key groove of the Oldham ring is cast iron, the other portions are made of aluminum alloy, and the block is cast iron. At this time, as the cast iron, the material of the cast iron such as ordinary cast iron and spheroidal graphite cast iron does not matter, but cast iron containing 2 to 4% by weight of copper in which graphite is uniformly dispersed and sliding characteristics are improved is preferable. Also,
The aluminum alloy contains 8 to 12% by weight of silicon and 3 to 4% by weight of copper, has a crystal grain of silicon of several μm or less, and uses an aluminum alloy dispersed uniformly as a member. Further, the Oldham ring is manufactured by a method shown in FIG. That is, the key portion 11 that slides with the orbiting scroll key groove portion of the Oldham ring and the pin portion 11 'that is fastened to the Oldham ring portion 5' are formed in advance using cast iron. At this time, two or three grooves having a depth of 0.1 to 0.5 mm are formed on the circumference at a position of 0.3 to 1.0 mm from the end face of the pin portion 11 '.
The other part of the Oldham ring is formed of an aluminum alloy, and a hole for receiving the pin 11 'of the cast iron key 11 is formed at a predetermined position. Next, a compressive load is applied to the aluminum alloy on the end face side of the pin portion 11 'using a ring-shaped pressing die (not shown) larger than the outer diameter of the pin portion 11', and the aluminum alloy is locally plastically flowed. The aluminum alloy is pushed into the groove of the cast iron pin 11 'and fastened. With these components, the sliding material of the mechanical part can be a combination of cast iron and an aluminum alloy, and the cast iron part can be provided without impairing the wear resistance of the aluminum alloy, so that good sliding characteristics can be obtained. Can be obtained. A scroll type compressor can be manufactured. As another shape of the cast iron key portion, there is a method shown in FIG. That is, a keyway for fixing a cast iron key portion is formed in a predetermined position of the aluminum alloy Oldham ring 5 in advance, and the aluminum alloy is locally plastically flowed and fastened by the above method. According to this method, even when the cast iron key portion has one side contact, the key portion can be fixed at a fixed position without rotating.

In another embodiment of the present invention, the end plate and the lap portion of the orbiting scroll 4 made of an aluminum alloy are subjected to an anodic oxide film treatment under predetermined conditions, and then a molybdenum disulfide film is formed by an electrodeposition method. Slide with the fixed scroll 3 made of. According to this method, among the sliding characteristics of the fixed scroll and the orbiting scroll, particularly low friction can be achieved.

〔The invention's effect〕

According to the invention, 8 to 12% by weight of silicon, 3 to 4% by weight of copper
In the aluminum alloy contained, by dispersing silicon crystal grains finely and uniformly, good abrasion resistance and low friction can be achieved in sliding with cast iron, and bonding of cast iron and aluminum alloy By using the plastic flow coupling method of aluminum as the method, the mechanical part of the scroll compressor can be composed of a combination of cast iron and aluminum alloy only, so that the performance can be improved and the size and weight can be reduced. Production costs can also be reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view (a) and a side sectional view (b) of an Oldham ring key portion according to one embodiment of the present invention, and FIG. 2 is a front sectional view (a) of another embodiment of the Oldham ring key portion. FIG. 3 is a vertical sectional view of a conventional scroll type compressor. DESCRIPTION OF SYMBOLS 1 ... Closed casing, 2 ... Refrigerant mixed oil, 3 ... Fixed scroll, 4 ... Orbiting scroll, 5 ... Oldham ring, 6 ...
Crankshaft, 7: bearing, 8: thrust bearing, 9: block, 10: electric motor.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideaki Kambara 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. In-house (72) Inventor Joji Okamoto 390 Muramatsu, Shimizu-shi, Shizuoka Pref. Inside the Shimizu Plant of Hitachi Ltd. (56) References JP-A-63-134882 (JP, A) JP-A-60-88226 (JP, A) 2-7390 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F04C 18/02 311

Claims (2)

(57) [Claims] 1. A block for engaging a fixed scroll and an aluminum orbiting scroll each having a wrap formed of a spiral curve on a head plate and fixing the fixed scroll,
A method for manufacturing a scroll compressor comprising: an Oldham ring made of aluminum that makes an orbiting motion without rotating the orbiting scroll with respect to the fixed scroll, wherein a key of the Oldham ring that slides with the orbiting scroll is an iron-based key. A method of manufacturing a scroll compressor, wherein the method is made of a material and fastened by plastically flowing an aluminum alloy of the Oldham ring. 2. A method for manufacturing a scroll compressor according to claim 1, wherein the portion of said orbiting scroll which slides with the fixed scroll is subjected to an electroless Ni-P plating in which boron nitride is compounded or anodized. And applying a molybdenum disulfide by an electrodeposition method.