JP2629500B2 - Sliding member of hermetic compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding part of a hermetic compressor used for refrigeration and air conditioning.

[0002]

2. Description of the Related Art FIG.
Is a sliding member (vane) of a conventional vane type compressor in which a boron hardened layer is formed on the surface of an iron-based metal, in which reference numeral 101 denotes a base material, 102 denotes a boron hardened layer, and 102a denotes a boron hardened layer. Micropores provided on the surface of the boron hardened layer.

[0003] The sliding parts having the hardened boron layer 2 have a high hardness of 1200 to 1800 HV on the surface of the hardened boron layer 2 and have excellent lubricating performance due to lubricating oil entering the micropores 2a. It is excellent in performance and can prevent wear of the partner material, prolong the life of the compressor and prevent seizure.

[0004]

For the sliding parts of a hermetic compressor, in order to reduce leakage loss, mating dimensions of mating parts such as vanes and vane slots, shafts and bearings are controlled by several μm. is necessary. For this reason, when performing surface treatment on a sliding component, a dimensional change before and after the surface treatment becomes a serious problem. If there is no dimensional change due to the surface treatment, the surface treatment can be performed after the finish processing and used as it is. However, in the case of the boron treatment in which boron B is penetrated into Fe of the surface layer, the thickness of the boron hardened layer is reduced. Due to the treatment temperature of 800 to 1000 ° C. together with the boron swelling of the boron hardened layer of about 1/10, depending on the heat treatment state before the boron treatment of the base material, a large dimensional change may occur due to structural change of the base material, stress release, and the like. Yes, when used as sliding parts for hermetic compressors, surface hardness after boron treatment is 1500
A finishing process must be applied to the hardened boron layer of about HV. In a conventional example, boron is immersed by a solid method, and a surface of about 30 μm-thick FeB (first boride) is applied.
A hardened boron layer 200 having a thickness of about 100 μm, comprising two layers of an iron (Fe) layer and a Fe ₂ B (ferric boride) layer having a thickness of about 70 μm.
This boron hardened layer is processed by diamond lapping for lapping and finishing with GC abrasive grains of about several tens μm. At this time, the hardness of the boron hardened layer is 1500
Since the HV is extremely high, a special grindstone for finishing and special equipment are required, and there is a problem that the processing is more difficult and costly as compared with the case of finishing an existing iron-based material. Further, a long processing time of 3 to 10 hours is required to form a boron cured layer having a thickness of about 100 μm, which is not practical, and the processing time can be reduced from the viewpoint of reducing the cost of boron processing. Was desired. in addition,
When the boron-treated layer is made as thin as necessary for the purpose of shortening the treatment time and eliminating the above-mentioned processing after the boron treatment, there is also a problem that the boron layer is peeled off during use.

The present invention has been made in order to solve the above-mentioned problems. The dimensional change before and after the boron treatment is small, and it is possible to perform finishing before the boron treatment and use it as it is. It is an object of the present invention to obtain an economical and highly reliable sliding member of a hermetic compressor having a short processing time and a small possibility of peeling even in a thin boron hardened layer.

[0006]

SUMMARY OF THE INVENTION A sliding member of a hermetic compressor according to the present invention is formed by quenching / tempering and finishing a ferrous material having a low content of alloying elements such as Cr, Mo, W and V. Thereafter, a boron hardened layer composed of a single layer of Fe ₂ B is immersed in part or all of the surface.

[0007]

The sliding member of the hermetic compressor according to the present invention comprises:
The hardness of the base material after tempering, which is determined by the amount of C contained in the base material, is kept at the minimum hardness that can be finished, and the dimensional change of the base material due to the structural change due to heating and the stress release during the boron treatment. Since the quenching and tempering temperatures are controlled to minimize the thickness and the thickness of the boron hardened layer made of a single layer of Fe ₂ B is made thinner compared to the conventional example, the dimensional change before and after the boron treatment is reduced. ,
Finish processing can be performed before boron treatment and used as it is. In addition, a boron immersion treatment in which the Fe ₂ B single layer is penetrated into the surface thinly by a molten salt immersion method as compared with the conventional example, and in addition, an iron-based material having a low content of alloying elements such as Cr, Mo, W, and V is used. Since the alloy is used, the boron treatment time does not increase due to the inclusion of the alloy, and the boron treatment can be performed in a short time of 2 to 3 hours. Also, Cr, Mo, W, V
Mainly because it is a ferrous material with a low content of alloying elements such as
Since the phenomenon that suppresses the effect of forming the wedge-shaped boron compound at the boundary between the boron-hardened layer and the base material layer caused by the inclusion of r and the like does not occur, and a boron-processed product is generated in a wedge-like shape, the boron-hardened layer is thinner than before. However, the possibility of peeling is reduced.

[0008]

[Embodiment 1] One embodiment of the present invention will be described below with reference to FIG. 1 where, for example, the base material is SK-5. In FIG.
1 is a base material of SK-5. SK-5 has a C content of 0.
8% carbon tool steel, alloy Cr 0.30% or less, Ni
0.25% or less, Cu 0.25% or less, Mo, W, V are killed steels not containing. Base material is 850 ℃ 40
After quenching for a minimum of 550 ° C. for 2 hours, a material having a hardness of about HRC37 by tempering at 2 hours is finished. 2 is a boron cured layer having a thickness of about 30μm by Fe ₂ B monolayer, the boundary between the base material is generated by the wedge-shaped boron additive compound 3. The boron treatment in this embodiment is a molten salt immersion method at a treatment temperature of 800 ° C. and a treatment time of 2 to 3 hours.

In the case of the present embodiment, the hardness of the base material 1 according to the tempering temperature after quenching, the heating at 800 ° C. during the boron treatment, and the boron treatment for blistering due to the formation of the boron layer, from the characteristics of the SK-5K metal material. The amount of dimensional change before and after is governed by the tempering temperature and has a relationship as shown in FIG. In FIG. 2, the point at a tempering temperature of 230 ° C. is for comparison under the same conditions as in the present boron treatment, and the base material is SUJ-2. The minimum hardness required for finish processing is generally about HRC30, and in this embodiment, the temper temperature is 550 to 600 ° C and the HR is
C35-40, and HRC60 in SUJ-2 for comparison
And both have a hardness that allows finishing. However, the dimensional change after the boron treatment is as large as about 3 μm in the present embodiment, whereas the dimensional change in the comparative SUJ-2 is as large as about 30 μm. This is based on the dimensional change characteristics of eutectoid carbon steel with respect to tempering as shown in FIG.
(Point X), the base material 1 may be heated at about 800 ° C. during boron treatment (point D).
2 returns to the point X and almost no dimensional change occurs.
As shown in FIG.
As a result, only a dimensional change of 3 μm is caused as blisters of / 10. On the other hand, SUJ-2 for comparison has a tempering temperature of 230 ° C. and is treated at the Y point. When heated at 800 ° C. during the boron treatment, the temperature returns to the Z point. As a change, about 30 μm is generated. Moreover, in the case of SK-5 embodiment, since almost no content of alloying elements, since does not occur up boron processing time by containing alloy, and a thin boron hardened layer of approximately 30 [mu] m, boron processing time Are 3 to 10 of the conventional example.
Compared to the time, it can be significantly reduced to 2-3 hours. At this time, since the base material contains almost no alloying elements, especially Cr, etc., a sufficient amount of a wedge-shaped boron compound is formed at the boundary between the boron hardened layer and the base material layer. However, the possibility of peeling has become smaller, and reliability has been improved.

[0010]

As described above, the sliding member of the hermetic compressor according to the present invention can be used for an iron-based material having a low alloy element content.
Which was a boron hardened layer consisting of Fe ₂ B monolayer during quenching and tempering and finishing was immersed in a part or whole of the surface, small dimensional change before and after boron treatment, subjected to finishing before the boron treatment, An economical and highly reliable sliding member of a hermetic compressor that can be used as it is, has a short boron treatment time, and has a small possibility of peeling even in a thin boron hardened layer can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a sliding component according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a tempering temperature and hardness of a sliding component and a dimensional change before and after boron treatment according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a dimensional change characteristic of a sliding component according to an embodiment of the present invention with respect to tempering of eutectoid carbon steel.

FIG. 4 is a sectional view of a main part of a conventional sliding component (vane).

[Explanation of symbols]

Base material 2 Fe ₂ B boron cured layer 2a micropores 3 wedge-shaped boron compounds according monolayer by low iron-based material 1 alloying element content

Claims (1)

(57) [Claims] An iron-based material having a low alloying element content, and a hardened boron layer made of a single layer of Fe ₂ B immersed on the surface of the iron-based material after quenching / tempering and finishing. A sliding member for a hermetic compressor.