JPS6113116B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in compressor valve covers.

Conventionally, the valve cover of this type of compressor has been made of a metal material with good thermal conductivity, such as casting, and has a thin partition between the discharge chamber, where the discharge gas, which is the highest temperature of the compressor, flows, and the suction chamber, where the suction gas flows. The heat of the discharged gas heats the suction gas by heat conduction through this partition. Therefore, when the heated suction gas is compressed, the temperature of the discharged gas becomes even higher, decomposing the oil and refrigerant and causing carbon slatch to adhere to the discharge hole of the valve seat plate, which may prevent the valve from operating properly. It was hot.

Furthermore, in order to prevent this suction gas from heating, it is known that the inside of the suction chamber or discharge chamber of the valve cover is covered with a material with poor thermal conductivity, as shown in, for example, Japanese Utility Model Application Publication No. 140003/1983. It is being However, the above method had the following disadvantages.

In other words, in order to obtain a sufficient thermal insulation effect with the covering member (for example, refrigerant-resistant rubber), the thickness should be 3.
It must be formed very thick, ~5 mm.
Therefore, the internal volume of the suction chamber or discharge chamber covered by the cover member becomes significantly smaller, and the effect of reducing pressure pulsations and noise of the refrigerant is reduced, causing the compressor to generate large noise.

It is necessary to attach the cover member to the valve cover, and this attachment adds a new manufacturing process, and since the attachment is done with adhesive or the like, productivity is poor and costs increase.

As the material of the cover member, an expensive material such as refrigerant-resistant rubber must be used, which increases the cost.

The present invention has been made based on the above circumstances, and the entire valve cover is made of sintered metal, making use of the characteristics of sintered metal to achieve good manufacturability and low cost, as well as the contents of the discharge chamber and suction chamber. without reducing the product.
The object of the present invention is to provide a valve cover that can thermally insulate a discharge chamber and a suction chamber.

In the present invention, the entire valve cover is made of sintered metal, the partition wall separating the discharge chamber and the suction chamber is formed with a lower density than other parts, and an impermeable oxide film is formed on at least the surface of the discharge chamber of the valve cover. , the entire partition wall is used as a thermal insulating layer to prevent the temperature of the discharged gas from being conducted to the suction gas.

An embodiment of the present invention will be described below with reference to the drawings.

A piston 2 is slidably provided in a cylinder 1 of the compressor, and a valve seat plate 3 is provided at the end of the cylinder 1.
and valve cover 4 are attached in sequence.

The valve seat plate 3 is provided with a discharge valve 6 for opening and closing the discharge hole 5 and a suction valve 8 for opening and closing the suction hole 7. The valve cover 4 has a discharge chamber 9 surrounding the discharge valve 6 and a suction chamber 10 surrounding the suction hole 7 with sufficient space, which are partitioned by a partition wall 11 .

This valve cover 4 is entirely formed of iron-based sintered metal, and the partition wall 11 is formed with a lower density than other parts to obtain a heat insulating layer having more pores than other parts. Steam oxidation treatment is performed on the inner surface of the discharge chamber 9 facing the inner surface of the discharge chamber 9 to form an impermeable oxide film 12, thereby making the discharge chamber 9 and the suction chamber 10 airtight.
Since the density of the sintered metal can be easily set by adjusting the pressure applied during molding, it does not impair manufacturability in any way. Furthermore, since the impermeable oxide film can be formed by steam oxidation treatment by simply passing the sintered metal through a steam atmosphere, it is highly manufacturable and does not cause a significant increase in cost. Moreover, the thickness of the coating is on the order of microns and does not significantly reduce the internal volume of the discharge chamber.

Note that, since the airtightness of the suction chamber 10 is not so important for its function as a compressor, it is only necessary to increase the sintering density of the portion surrounding the suction chamber 10 other than the partition wall 11. Moreover, an impermeable oxide film may be formed on the entire valve cover 4 as required.

As described above, in the present invention, the entire valve cover having a discharge chamber and a suction chamber is molded from sintered metal, and the partition wall that partitions the discharge chamber and the suction chamber is formed with a lower density than other parts, and at least the discharge chamber and the suction chamber are By forming an impermeable oxide film on the interior surface, the partition wall is provided with a heat insulating layer consisting of pores with more space than other parts.

Therefore, it is possible to provide a valve cover for a compressor that has good manufacturability, is low cost, and can provide sufficient thermal insulation between the discharge chamber and the suction chamber without significantly reducing the internal volume of the discharge chamber. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a compressor equipped with a valve cover according to the present invention, and FIG. 2 is a sectional view showing another embodiment of the valve cover. 4... Valve cover, 9... Discharge chamber, 10... Suction chamber, 11... Partition wall, 12... Impermeable oxide film.

Claims (1)

[Claims] 1. A compressor characterized in that the whole is made of sintered metal, the partition wall separating the discharge chamber and the suction chamber is formed with a lower density than other parts, and an impermeable oxide film is formed on at least the surface of the discharge chamber. Machine valve cover.