JPH05144493A - Hermetically sealed terminal cover of nermetic compressor - Google Patents

Abstract

PURPOSE:To prevent attachment of metal dust, etc., to glass surface or the surface of hermetically sealed terminal cover and protect the terminal from destruction by eventual attachment of such metal dust, etc., by making the hermetically sealed terminal cover by means of injectin molding, and forming the outer surface of that part of cover which encloses glass, in approx. a convex spherical surface having a thickness over 0.5mm. CONSTITUTION:A hermetically sealed terminal cover 1 made through injection molding from plastics is installed on the inside of a sealed vessel 10 of the hermetically sealed terminal 4, which is fixed to the vessel 10 and supplied electric power externally, in such a way as tightly attaching to a cylindrical part and a pin of the terminal 4. That portion of the cover 1 outer surface which encloses glass 8 is embodies in approx. convex shperical surface. The thickness of this portion enclosing the glass is made over 0.5mm. This arrangement permits shaping any complexly by changing the wall thickness of the cover 1 so that it is unlikely that metal dust, etc., attaches to the surface of the hermetically sealed terminal glass 8, which leads to preclusion of dielectric destruction of the hermetically sealed terminal part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airtight terminal cover for an airtight terminal of a hermetic compressor.

[0002]

2. Description of the Related Art Generally, a hermetic terminal used in a hermetic compressor is a glass as an insulator which is excellent in refrigerant resistance and oil resistance because a refrigerant and oil are splashed in a hermetic container and can firmly support a terminal pin. Are using.

For example, there is one described in JP-A-62-271975. This will be described with reference to FIG. In FIG. 2, 4 is an airtight terminal. 5 is a through hole, 6
Is a metal outer ring and has cylindrical portions 7 surrounding the through holes 5, respectively. Reference numeral 8 is glass, and 9 is a terminal pin, which is hermetically sealed by the glass 8 in substantially the center of the tubular portion 7. Reference numeral 10 denotes a hermetic container of a hermetic compressor, and the hermetic terminal 4 is welded to the hermetic container 10.

By the way, in the refrigerant or oil in the closed container 10, metal powder such as iron powder or copper powder produced by welding of the container or sliding wear of the piston is mixed. Then, these metal powders are carried by the refrigerant to each part in the container and adhered thereto, and also adhere to the surface of the glass 8 of the airtight terminal. If a large amount of metal powder adheres to the surface of the glass 8 and a large voltage is applied to the terminal when the compressor is restarted, etc., the space between the terminal pin 9 and the cylindrical portion 7 will pass through the adhered metal powder. Sparks fly out, causing an accident such as electric leakage or damage to the terminals.

Further, as a means for dealing with the above problem, there is one described in Japanese Patent Laid-Open No. 62-271975.

This will be described with reference to FIGS. 3 and 4. Reference numeral 11 denotes an insulating plate, which is a disk-shaped plate drawn from polyethylene phthalate (hereinafter referred to as PET) having a thickness of about 250 to 300 μm. 12 is a folded portion of the outer periphery, 13 is a tubular portion,
Reference numeral 14 is a small hole at the center, and the cylindrical portion 13 has a bulging portion 15, a large diameter hole 16 and a small diameter hole 17. The outer diameter of the folded portion 12 of the insulating plate is slightly larger than the inner diameter of the metal outer ring 6, the inner diameter of the bulging portion 15 is slightly smaller than the outer diameter of the tubular portion 7, and the large diameter hole 16 has The diameter is larger than the cylindrical portion 7, and the diameter of the small diameter hole 17 is formed to be slightly smaller than the outer diameter of the terminal pin 9.

In this insulating plate 11, as shown in FIG. 4, the small diameter hole 17 is inserted into the terminal pin 9 and the folded portion 12 is inserted into the metal outer ring 6 in a press-fitted state so that the airtight terminal 4 is formed.
Is attached to. Here, the insulating plate 11 mounted on the airtight terminal 4 has the above-mentioned dimensional relationship, and therefore, between the small diameter hole 17 and the terminal pin 9, between the bulging portion 15 and the tubular portion 7, and between the folded portion 12 and the metal outer ring. 6 and 6 and the gap 18 is formed between the glass 6 and the surface of the glass 8.

In the airtight terminal of the hermetic compressor thus constructed, the insulating plate 11 made of PET is the glass 8
In addition to completely covering the surface of the glass plate, a gap 18 is formed between the insulating plate and the surface of the glass 8, so that the insulating plate 11 should be separated from the surface of the glass 8 having the strongest line of electric force to some extent. The insulating plate 1 can be provided near the tubular portion 7.
Since the amount of the metal powder adsorbed on 1 can be greatly reduced, the spark generated between the terminal pin 9 and the metal outer ring 6 is prevented.

[0009]

However, in the above-mentioned conventional structure, the pressure in the gap 18 is determined by the pressure of the atmosphere at the time of insertion. However, the operation of the hermetic compressor,
Since the pressure in the closed container changes with the stop, the gap can be made to a certain size so that the cover does not move following the pressure difference between the inside and the outside. Therefore, it is impossible to separate more than the glass surface where the electric lines of force are the strongest, and the adhesion of metal powder cannot be completely prevented, and the spark jumps from the surface of the insulating plate between the terminal pin 9 and the metal outer ring 6 to cause electric leakage. Will result in an accident.

Further, when the spark is blown, since it is formed of a thin plate, it has a small heat capacity and melts and loses its part. As a result, it becomes equal to the state of the hermetic terminal without this insulating plate. was there.

The present invention solves the above-mentioned conventional problems, and not only prevents metal powder or the like from adhering to the glass surface or the surface of the airtight terminal cover, but also adheres metal powder or the like to the surface of the airtight terminal cover. An object of the present invention is to provide an airtight terminal cover that does not lead to a very dangerous destruction of the terminal even when there is a problem.

[0012]

In order to achieve the above object, the airtight terminal cover of the present invention is formed by injection molding and is in close contact with the pin and the cylindrical portion of the airtight terminal.

Further, in the airtight terminal cover of the present invention, the outer surface of the portion of the airtight terminal that covers the glass has a substantially convex spherical shape.

Further, the airtight terminal cover of the present invention has a construction in which the thickness of the cover of the airtight terminal covering the glass is 0.5 mm or more.

[0015]

The airtight terminal cover of the present invention can be formed into a complicated shape by changing the wall thickness of the cover by molding by injection molding, and since it is in close contact with the pin and the tubular portion of the airtight terminal. However, it becomes difficult for metal powder or the like to adhere to the surface of the airtight terminal glass where the electric lines of force are strong, and thus it is difficult for the airtight terminal portion to cause dielectric breakdown.

Further, in the airtight terminal cover of the present invention, the outer surface of the cover of the airtight terminal covering the glass is formed into a substantially convex spherical surface so that the surface of the airtight terminal cover from the surface of the airtight terminal cover having the strongest electric line of force. Can be sufficiently separated from each other, and since they have a substantially convex spherical shape, adhesion of metal powder or the like becomes difficult.

Further, in the airtight terminal cover of the present invention, the thickness of the cover is 0.5 mm or more at the portion covering the glass of the airtight terminal, so that the surface of the airtight terminal cover having the strongest line of electric force is removed from the surface of the airtight terminal cover. It is possible to separate the surfaces sufficiently, and even if the insulation is poor, the wall thickness is 0.
Since it is thicker than 5 mm, the terminals will not be destroyed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same configurations as in the related art are denoted by the same reference numerals and detailed description thereof will be omitted.

In FIG. 1, reference numeral 1 denotes an airtight terminal cover, which is made of polybutylene terephthalate (hereinafter referred to as PBT) which is excellent in oil resistance and withstand voltage and which is also a material for clusters, and is formed by injection molding. An outer surface 2 of the airtight terminal cover near the glass 8 has a substantially convex spherical shape. Reference numeral 3 indicates a glass 8 near the airtight terminal, and a thickness of 0.5 mm or more is secured. The airtight terminal cover 1 is closely attached to the pin 9 and the tubular portion 7 of the airtight terminal 4.

In the above structure, the airtight terminal cover 1 of the present invention can be formed into a complicated shape by changing the wall thickness of the cover by injection molding.
Since the pin 9 and the tubular portion 7 of the airtight terminal 4 are in close contact with each other, it becomes difficult for metal powder or the like to adhere to the surface of the glass 8 of the airtight terminal having the strongest line of electric force, and the dielectric breakdown of the airtight terminal 4 occurs. It becomes difficult to remove.

In the airtight terminal cover 1, the outer surface 2 of the airtight terminal that covers the glass is formed into a substantially convex spherical surface, so that the surface of the airtight terminal glass 8 having the strongest line of electric force is removed from the surface of the airtight terminal cover 1. The surfaces can be separated sufficiently, and since the surfaces are substantially convex spherical surfaces, it becomes difficult for metal powder or the like to adhere.

The airtight terminal cover 1 has a portion 3 covering the glass of the airtight terminal with a wall thickness of 0.5 mm or more, so that the airtight terminal glass 8 with the strongest line of electric force can be obtained.
The surface of the airtight terminal cover 1 can be sufficiently separated from the surface of the terminal, and even if the insulation is defective, the terminal is not broken because the thickness is as thick as 0.5 mm or more.

[0023]

As described above, the airtight terminal cover of the present invention can be formed into a complicated shape by changing the wall thickness of the cover by injection molding, and the pin and the tubular portion of the airtight terminal can be formed. Since it adheres to the surface of the airtight terminal, it becomes difficult for metal powder or the like to adhere to the surface of the airtight terminal glass, which has the strongest line of electric force, and it is difficult for the airtight terminal portion to cause dielectric breakdown.

Further, in the airtight terminal cover of the present invention, the outer surface of the cover of the airtight terminal covering the glass is formed into a substantially convex spherical surface, so that the surface of the airtight terminal cover from the surface of the airtight terminal cover having the strongest electric line of force is changed. Can be sufficiently separated from each other, and since they have a substantially convex spherical shape, it becomes difficult for metal powder or the like to adhere.

In the airtight terminal cover of the present invention, the thickness of the cover is 0.5 mm or more at the portion of the airtight terminal that covers the glass, so that the surface of the airtight terminal cover having the strongest line of electric force is removed from the surface of the airtight terminal cover. It is possible to separate the surfaces sufficiently, and even if the insulation is poor, the wall thickness is 0.
Since it is thicker than 5 mm, the terminals will not be destroyed.

[Brief description of drawings]

FIG. 1 is a sectional view of an airtight terminal cover of the present invention.

FIG. 2 is a sectional view of an ordinary airtight terminal.

FIG. 3 is a sectional view of a conventional airtight terminal cover.

FIG. 4 is an assembled sectional view of a conventional airtight terminal and an airtight terminal cover.

[Explanation of symbols]

 1 Airtight terminal cover 2 Outer surface of glass of airtight terminal cover 3 Glass cover of airtight terminal cover 4 Airtight terminal 7 Cylindrical part of airtight terminal 8 Glass of airtight terminal 10 Closed container

Claims (3)

[Claims] 1. A hermetic container having an electric element and a compression element, an airtight terminal for supplying electric power to the electric element from the outside is fixed to the hermetic container, and a resin airtight inside the hermetic container of the hermetic terminal. An airtight terminal cover for a hermetic compressor, characterized in that a terminal cover is attached, the airtight terminal cover is made of a synthetic resin molded by injection molding, and is in close contact with a pin and a cylindrical portion of the airtight terminal. 2. The airtight terminal cover for a hermetic compressor according to claim 1, wherein a portion of the outer surface of the airtight terminal cover that covers the glass of the airtight terminal has a substantially convex spherical shape. 3. The hermetic terminal cover for a hermetic compressor according to claim 1, wherein a thickness of a portion of the hermetic terminal cover that covers the glass of the hermetic terminal is 0.5 mm or more.