JPH0684756B2 - Rotary compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a compressor used in a household electric appliance such as a cooler, and more particularly to a compressor in which materials of rollers and vanes are improved.

[Prior Art] At present, rotary compressors used for household electric appliances are required to be lightweight and downsized, and also to be improved in materials for forming respective parts because of demands for cost reduction and high performance. That is, the rotary compressor is the first
As shown in the figure, it is composed of a case 10, a housing 11, a vane 12 housed in a groove of the housing, a roller 13, and the like. Among these, the vane 12 and the roller 13 are particularly required to have wear resistance. Is.

Currently, roller materials are generally Ni-Cr-Mo cast iron, FC cast iron, eutectic graphite cast iron, and iron-based solid-phase sintered alloys, whereas vane materials are hardable cast iron, SKH9 material, and iron-based solid-phase alloys. Sintered alloy is used.

[Problems to be Solved by the Invention] However, when the vane material is formed of hardnable cast iron or SKH9 material, scuffing and wear occur under high load, and the number of processing steps is large and the cost is high.

In addition, since vanes made of iron-based solid-phase sintered alloy have many continuous pores, there is a problem due to contamination due to oil quenching, grinding fluid, residual abrasive particles, etc., and lubricating oil escapes from the pores during sliding to form an oil film. It is necessary to perform a sealing treatment because it has a bad effect such as being hard to be opened. Further, the material strength was low and the wear resistance was poor.

Therefore, an object of the present invention is to provide a vane that exhibits excellent performance in combination with a roller, particularly a vane that has excellent wear resistance, scuffing resistance, and high strength, and has a low manufacturing cost.

[Means for Solving Problems] In order to achieve the above object, according to the present invention, the roller is made of Ni.
-Cr-Mo cast iron, FC cast iron, eutectic graphite cast iron, or one of iron-based sintered alloys, the vane used in combination with the roller is 0.5 to 4.0 wt% carbon other than iron, chromium 5.
Nb, T, which is a carbide forming element, containing 0 to 30.0% by weight.
20% by weight or less of one or more of i, V and W,
Also, it contains 10% by weight or less of any one or more of Ni, Mo, Co, Cu and Mn which are matrix strengthening elements, and further 1250 ° C.
A rotary compressor made of a sintered alloy containing 0.1 to 5.0% by weight of one or more of P, B, and Si for performing liquid phase sintering below, and having 0.2 to 10% by volume of sintering holes. Will be provided.

In addition, the scuffing resistance can be further improved by subjecting the vane to a nitriding treatment on its tip or side surface.

The reasons for limiting the numerical values of the components in the vane material of the present invention are as follows.

Carbon strengthens the matrix, precipitated hard phase (Cr carbide containing Fe)
Is an element necessary for producing wear resistance and having wear resistance.
The reasons for limiting the carbon content of the alloy component are as follows. If it is less than 0.5% by weight, the amount of precipitated hard phase is insufficient and it is difficult to withstand high load wear, and a base material with high strength cannot be obtained. If it exceeds 4.0% by weight, the amount of precipitated hard phase is large and it grows large, resulting in embrittlement.

Liquid phase sintering can be performed by sintering at a higher temperature, but it is necessary to generate a sufficient liquid phase at 1250 ° C. or lower due to the durability problem of the sintering furnace. Phosphorus, boron, silicon, etc. are effective as they are elements that perform liquid phase sintering at 1250 ° C. or less, and if the amount of the liquid phase is too small, the strength cannot be improved, and the amount of the liquid phase is large. If too much, a sintered body with high dimensional accuracy cannot be obtained.

Therefore, based on the above reason, one or more of phosphorus, boron and silicon are used in the range of 0.1 to 5.0% by weight.
Here, the addition amount and the sintering temperature have an inversely proportional correlation.

Cr is an important element to strengthen the matrix and combine with carbon to form a precipitated hard phase. Here, the addition amount of Cr is 5.0
If it is less than 10% by weight, it is related to the amount of one or more of Nb, Ti, V, and W to be described below added in an amount of 20% by weight or less. I can not get sex. If it exceeds 30% by weight, no significant improvement in wear resistance is observed, which only causes an increase in price.
Moreover, the machinability deteriorates.

Nb, Ti, V, W are added for the purpose of improving wear resistance and scuffing resistance by precipitating these fine carbides in the matrix, but if it exceeds 20% by weight, However, since the precipitation of these carbides becomes excessively large, the counterpart material is significantly worn.

With respect to the porosity, if the porosity exceeds 10% by volume, the sintering is insufficient, the inter-particle bond strength is weak, and fatigue fracture easily occurs, so pitting wear is easily induced and mechanical strength deteriorates.
Limited to 10% or less. On the other hand, if it is less than 0.2% by volume, the amount of oil retained is small, the oil retaining property is poor, and scuff wear easily occurs. Further, if the porosity is within this range, it can be used without performing the sealing treatment.

Further, any one or more of Ni, Mo, Co, Cu and Mn is contained in an amount of 10% by weight or less in order to strengthen the matrix structure. The addition of 10% by weight or less can sufficiently achieve the purpose of strengthening the base structure, and the addition of more than 10% by weight is inconvenient in terms of economy.

Further, in the present invention, after sintering, it is possible to strengthen the matrix structure by the mating roller material used mainly in combination with pearlite. As a method of strengthening the matrix structure, a heat treatment after sintering can be applied to obtain a structure mainly of bainite or mainly martensite. In this case, the pitting resistance is further improved. 87 after sintering
After heating to 0 ℃ and heat treatment at about 400 ℃ salt bath for about 10 to 40 hours, the matrix structure becomes bainite. When heated to 870 ° C and heat treated with water or oil at room temperature, the matrix becomes martensite.

INDUSTRIAL APPLICABILITY The sintered alloy material of the present invention is extremely excellent in that relatively large chromium carbides and fine chromium carbides and fine one or more carbides of Nb, Ti, V, W are precipitated in the matrix. Exhibits wear resistance and scuffing resistance. Also, since one or more of Ni, Mo, Co, Cu, Mn are added and liquid phase sintering is performed, the matrix is strengthened. Therefore, under severe operating conditions such as high surface pressure reduction. Also has excellent wear resistance.

The vane material whose content has been adjusted as described above is hardened and then subjected to nitriding treatment to increase the surface hardness and further reduce the wear amount of the mating material, as well as scuffing resistance, fatigue resistance, and corrosion resistance. Can be improved. In this case, the thickness of the nitrided layer at the tip of the vane after the nitriding treatment is adjusted to be 2 μm or more from the surface.

Furthermore, in order to make the wear resistance of the vane material of the present invention effective, the mating roller material is selected from Ni-Cr-Mo cast iron, FC cast iron, eutectic graphite cast iron, or iron-based sintered alloy. . As a result, the amount of wear of both the vane and the roller can be significantly reduced.

[Examples] The results of the performance confirmation test of the present invention will be described below based on Examples and Comparative Examples.

As shown in Table 1, a sintered alloy having the composition, surface hardness, and porosity of No. 1 to 8 as the vane material of the present invention was press-formed into a powder with a pressing surface pressure of 5.0 t / cm ² and then decomposed with ammonia. It was obtained by putting it in a furnace in a gas atmosphere and sintering at a temperature of 1100-1180 ° C. for 1 hour. For Nos. 4, 6 and 8, gas nitriding treatment was further performed for 5 hours after sintering at 550 ° C. to form a nitride layer having a thickness of 5 μm from the surface.

As a comparative vane material, a material having No. 9 to 12 composition, hardness and porosity was obtained. In this case, No. 9 is hardnable cast iron, No. 10 is SUP9 steel, No. 11 is SKH9 steel, and No. 12 is solid phase sintered material.

As described above, the vanes Nos. 1 to 12 were subjected to the Amsler wear test. The vane material is used as the fixing pieces in the plane contact side wear tester, and these fixing pieces are used as the mating material, that is, Ni-Cr-
The disc-shaped sample made of Mo cast iron was pressed, and the disc-shaped sample was rotated while constantly supplying lubricating oil to the pressed surface.

The test conditions are as follows.

Load… 100Kg, peripheral speed 1.1m / s, lubricating oil… SUNISO 4GS, oil temperature…
room temperature.

The scuffing occurrence time was measured for each sample by the above test method. As shown in Table 1,
The material of the present invention showed a significantly longer scuffing generation time than the comparative material.

[Effect of the Invention] As described above and as shown by the test, the vane material in the compressor of the present invention has excellent wear resistance and high strength as compared with the conventional material, and has a low cost. Can be manufactured in.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the structure of the rotary compressor of the present invention. 12 ... Vane, 13 ... Laura.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-40476 (JP, A) JP-A-59-100257 (JP, A)

Claims (2)

[Claims] 1. A roller of a rotary compressor is Ni-Cr-
Made of Mo cast iron, FC cast iron, eutectic graphite cast iron, or one of iron-based sintered alloys, and the vane used in combination with the roller has 0.5 to 4.0% by weight of carbon in addition to iron and 5.0 to 3 of chromium.
Nb, Ti, V, W containing 0.0 wt% and further carbide forming elements
20% by weight or less of one or more of the above, and
Of P, B and Si which contain 10% by weight or less of any one or more of Ni, Mo, Co, Cu and Mn which are matrix strengthening elements and which can perform liquid phase sintering at 1250 ° C or less A rotary compressor made of a sintered alloy containing 0.1 to 5.0% by weight of one or more kinds and having 0.2 to 10% by volume of sintered pores. 2. A rotary compressor according to claim 1, wherein the vanes are nitrided.