JP7132120B2 - airtight terminal - Google Patents

Description

The present invention relates to hermetic terminals.

An airtight terminal is a lead hermetically sealed in an eyelet or an eyelet insertion hole via glass, and is used to supply current to or transmit signals from an electrical device or element housed in an airtight container. It is used when deriving to the outside. For example, as described in Japanese Patent Laying-Open No. 10-214646 (Patent Document 1), an airtight terminal used in refrigerant compressors of refrigerators, air conditioners, etc., has a top plate portion, and extends downward from the outer peripheral end of the top plate portion. an opening (cylindrical portion) extending upward, a flange portion extending obliquely outward from the lower end of this opening, and three small openings forming lead sealing holes extending inward from the top plate portion. eyelets are used. Then, the sealed leads are airtightly sealed in the lead sealing holes of the eyelet via the sealing glass.

In general, GTMS (Glass-to-Metal-Seal) type airtight terminals, in which an eyelet and a lead are sealed with insulating glass, are roughly classified into two types: matching sealing type and compression sealing type. In order to ensure the reliability of hermetic sealing, it is important to appropriately select the thermal expansion coefficients of the metal materials of the eyelets and leads and the insulating glass. For this reason, insulating glass for sealing is selected according to eyelet and lead materials, required temperature profile and its coefficient of thermal expansion. For matched sealing, the sealing material is chosen so that the thermal expansion coefficients of the eyelet and the insulating glass match as closely as possible. On the other hand, in airtight terminals used in refrigerant compressors (compressors) of refrigerators and air conditioners, the compressor is placed in a pressure-resistant container filled with refrigerant. A high withstand voltage is required, and compression-sealed hermetic terminals are exclusively used. Compression-sealed hermetic terminals are designed with a combination of eyelet and insulating glass materials with different thermal expansion coefficients so that the steel eyelet compresses the insulating glass and leads. Conventionally, as shown in FIG. 8, insulating glass for airtight terminals for compressors is required to ensure withstand voltage. The mold or (b) was thickly laid on the reeds in a conical shape. In particular, the insulating glass on the inner side (inner) lead of a pressure-resistant container that has a motor drive part may adhere over time to fine metal powder generated from the sliding parts of metal members, etc., improving tracking resistance. It is said that it is preferable to take a large creepage distance also in the meaning.

Patent document 1: JP-A-10-214646

The airtight terminals used in the compressors of refrigerators mentioned above need to have an appropriate mechanical strength by harmonizing stickiness and elongation. - Leads using chromium alloy materials are often used. As described above, the eyelet strongly compresses the insulating glass and the lead due to the so-called shrink-fitting effect, so cracks are likely to occur in the insulating glass from the edge of the opening of the eyelet to the lead. The occurrence of cracks in the insulating glass is undesirable because it becomes a path for inviting moisture from the outside, leading to loss of insulation between the eyelet and the lead.

The present invention provides an improved hermetic terminal that allows the compressive stress received from the eyelet to be distributed in the insulating glass.

According to the present invention, there is provided an airtight terminal in which a lead is passed through an opening provided in an eyelet, and the eyelet and the lead are hermetically sealed and electrically insulated by insulating glass. The insulating glass extends from the inner edge of the eyelet opening to the peripheral wall of the lead, and the surface shape of the insulating glass on at least the inner side is a catenary fillet. A hermetic terminal is provided which is shaped into an arcuate shape. The surface of the insulating glass to be applied to the leads is formed to have a minimum necessary thickness in a position closer to the leads and in a shape that conforms more closely to the peripheral walls of the leads. By forming the surface of the insulating glass into a catenary fillet, the compressive stress received from the eyelet can be distributed to the arc-shaped curved surface.

Conventionally, as shown in FIG. 8, insulating glasses 86, 96 are extended from openings (cylindrical portions) 84, 94 provided in eyelets 85, 95 to peripheral wall portions of leads 87, 97 to Insulating glasses 86, 96 protrude as large as possible from the lead wall surface in a bell shape as shown in FIG. 8(a) or a conical shape as shown in FIG. It was served thickly. The compressive stresses (hollow arrows) in the eyelets 85,95 are applied to clamp the openings 84,94 so that the insulating glass 86,96 at the ends of the openings 84,94 have an opposing compressive stress. A shear stress (dotted arrow) is generated in the direction (see FIG. 8(a)). In the conventional airtight terminal, the amount of insulation glass applied to the open end is the thickest. However, in the surface shape of the conventional insulating glass, the compressive stress compressing in the radial direction of the openings 84 and 94 is vertically applied to the insulating glass in the bell shape of FIG. Since it was received on a straight 45-degree inclined surface, it was structurally weak and cracks were likely to occur in equilibrium from the opening end of the eyelet.

As shown in FIGS. 7A, 7B, and 7C, the insulating glass of the present invention extends from the inner edge of the opening of the eyelet to the peripheral wall of the lead, thereby increasing the withstand voltage. While securing the necessary creepage distance, the exposed surface of the insulating glass is formed into a catenary-shaped fillet, that is, the cross-sectional profile of the glass is formed into an arc that is recessed toward the opening of the eyelet. It can be received at an angle and with a catenary curved surface consisting of an arc-shaped curve. This suppresses glass cracks 89 and 99 due to compressive stress (white arrows) in the eyelet opening edge region while ensuring a high withstand voltage between the eyelet and the lead.

According to one embodiment of the present invention, glass cracks in the airtight terminal can be suppressed.

1 is a plan view of an airtight terminal 10 of Example 1 according to the present invention; FIG. FIG. 2 is a side view of the airtight terminal 10 of Example 1 according to the present invention and a partial cross-sectional view taken along line AA of FIG. 1; 1 is a bottom view of the airtight terminal 10 of Example 1 according to the present invention; FIG. Fig. 2 is a plan view of an airtight terminal 20 of Example 2 according to the present invention; FIG. 5 is a side view of an airtight terminal 20 of Example 2 according to the present invention and a partial cross-sectional view taken along line AA of FIG. 4; FIG. 4 is a bottom view of the airtight terminal 20 of Example 2 according to the present invention; It is a fragmentary sectional view explaining the shape of the insulating glass of the airtight terminal which concerns on this invention, The shape of an Example is shown to (a), (b) and (c), and the shape of a comparative example is shown to (d). FIG. 10 is a partial cross-sectional view showing the shape of insulating glass in a conventional airtight terminal;

In the airtight terminal of the present invention, a lead made of an iron-based alloy material or a copper-cored iron-based alloy material is passed through an opening provided in an eyelet made of steel material, and the eyelet and the lead are hermetically sealed with insulating glass to provide electrical insulation. In the airtight terminal, at least the inner insulating glass extends from the through hole of the eyelet to the lead, and the surface shape of at least the inner insulating glass is a catenary fillet, that is, the cross-sectional contour of the insulating glass. It is formed in an arcuate shape that is recessed on the side of the opening of the eyelet. Any material can be used for the eyelet as long as the insulating glass and the lead can be compression-sealed, and the material can be welded to a pressure vessel or the like. Carbon steel or stainless steel is suitable, for example, although there is no particular limitation. Any material can be used for the lead material as long as it is a conductive member having excellent sealing properties with glass, and is not particularly limited, but for example, an iron-chromium alloy material or a copper-core iron-chromium alloy material is suitable. Any glass material can be used as the insulating glass material as long as it can electrically insulate and hermetically seal the eyelet and the lead. Although not particularly limited, soda lime glass, soda barium glass, and the like are suitable. The lead is passed through the opening of the eyelet and hermetically sealed with insulating glass to electrically insulate the eyelet from the lead.

As shown in FIGS. 1 to 3, the airtight terminal 10 of Example 1 according to the present invention has an opening (cylindrical portion) 14 provided in an eyelet 15 made of carbon steel and a lead 17 made of an iron-chromium alloy. Then, the eyelet 15 and the lead 17 are hermetically sealed and electrically insulated by an insulating glass 16 made of soda barium glass. The surface of the insulating glass 16a on the inner side is a catenary fillet, that is, the cross-sectional contour of the glass is recessed in an arc toward the opening 14 and is smooth. A compression-sealed hermetic terminal for a compressor of a refrigerator, which is formed in an arcuate shape.

The airtight terminal 10 of Example 1 includes a top plate portion 11, a cylindrical portion 12, a flange portion 13 extending obliquely outward from the outer circumference of the cylindrical portion 12, and three openings (cylindrical portions) 14 integrally formed of carbon. It has a steel eyelet 15 and an iron-chromium alloy lead 17 hermetically sealed to the opening 14 of the eyelet 15 by an insulating glass 16 of soda barium glass, the inner side insulating glass 16a being the opening of the eyelet 15. The insulating glass 16a on the inner side is formed to have a catenary fillet surface shape. As shown in FIGS. 2 and 3, the insulating glass 16a on the inner side extends from the opening 14 of the eyelet 15 to the lead 17 to secure the creepage distance required for high withstand voltage. By forming the surface shape into a catenary fillet, the compressive stress from the eyelet 15 can be received at a shallow angle of less than 45 degrees and at a curved cross section, and can be dispersed and deflected on the arc-shaped curved surface recessed into the opening 14 side. . As a result, the creepage distance between the eyelet 15 and the lead 17 can be ensured, glass cracks in the opening end region can be suppressed, and a decrease in insulation resistance can be prevented. The insulating glass 16b on the outer side (outside) of the pressure container does not have an insulating glass extending portion to the lead 17, but is provided with an insulating rubber coating 18. As shown in FIG.

In the airtight terminal 20 of Example 2 according to the present invention, as shown in FIGS. 4 to 6, an iron-chromium alloy lead 27 is passed through an opening (cylindrical portion) 24 provided in an eyelet 25 made of carbon steel. In addition, the eyelet 25 and the lead 27 are hermetically sealed and electrically insulated by an insulating glass 26 made of soda barium glass. The insulating glass 26a on the inner side and the insulating glass 26b on the outer side extend over a predetermined length from the opening 24 toward the peripheral wall of the lead 27. The surfaces of the insulating glass 26a and the outer insulating glass 26b are catenary fillets, that is, glass. It is a compression-sealed hermetic terminal for a compressor of a refrigerator formed so that the cross-sectional profile is arcuately recessed on the side of the opening 24 to draw a smooth arc.

The airtight terminal 20 of Example 2 includes a top plate portion 21, a cylindrical portion 22, a flange portion 23 extending obliquely outward from the outer circumference of the cylindrical portion 22, and three openings (cylindrical portions) 24 integrally formed of carbon. It has a steel eyelet 25 and an iron-chromium alloy lead 27 hermetically sealed to an opening 24 of the eyelet 25 by an insulating glass 26 of soda barium glass, with an inner side insulating glass 26a and an outer side insulating glass 26b. extends over a predetermined length from the opening 24 of the eyelet 25 toward the peripheral wall of the lead 27, and the surfaces of the inner insulating glass 26a and the outer insulating glass 26b are catenary-shaped. Formed into a fillet. As shown in FIGS. 4 to 6, the inner insulating glass 26a and the outer insulating glass 26b extend from the opening 24 of the eyelet 25 to the lead 27 to secure the creepage distance required for high withstand voltage. At the same time, the surfaces of the insulating glasses 26a and 26b are formed into a catenary fillet, so that the compressive stress from the eyelet 25 is received at a shallow angle of less than 45 degrees and a curved cross section, and the insulating glass 26a and 26b is recessed in an arcuate shape on the side of the opening 24. It can be distributed and warped on an arc-shaped curved surface. As a result, the creepage distance between the eyelet 25 and the lead 27 can be ensured, glass cracks in the opening end region can be suppressed, and a decrease in insulation resistance can be prevented.

As for the shape of the insulating glass of the airtight terminal according to the present invention, as shown in FIGS. It extends from the inner edge to the peripheral wall of the lead, and the surface shape of the insulating glass on at least the inner side is a catenary fillet, that is, the cross section of the insulating glass is formed in an arc shape recessed toward the opening of the eyelet. . The insulating glass extends over a predetermined length from the inner edge of the opening toward the peripheral wall of the lead. The insulating glass is preferably sealed so as to contact only the inner wall surface of the opening of the eyelet. The exposed surface of the insulating glass is formed so that the cross-sectional profile of the glass from the inner edge of the eyelet opening to the predetermined peripheral wall portion of the lead is an arcuate catenary curved surface recessed toward the opening. At this time, the end surface of the insulating glass that contacts the inner edge of the eyelet opening is preferably sealed at an inclination angle of less than 45 degrees with respect to the plane of the top plate portion 71 . For example, the shape of the insulating glass is formed as shown in FIGS. 7(a), 7(b) and 7(c). The shape of the insulating glass in the embodiment (a) of FIG. 7 is such that from the inside of the inner wall of the eyelet opening, a horizontal plane is once drawn with respect to the plane of the top plate, and then the lead wall surface is sealed. The shape of the insulating glass in the embodiment (b) of FIG. 7 is such that the edge of the eyelet opening is once recessed inward of the opening to form a J shape and is sealed to the lead wall surface. The shape of the insulating glass in Example (c) of FIG. 7 is such that a horizontal plane is once drawn from the inner edge of the eyelet opening at an angle of inclination of less than 45 degrees with respect to the plane of the top plate, and then climbs up the lead wall surface. sealed to.

In FIG. 7, the compressive stress 700 of the eyelet 75 is applied so as to tighten the opening, so a shear stress 701 is generated in the insulating glass 76 in the direction opposite to the compressive stress (see FIG. 7(a)). The insulating glass shape of the embodiment shown in FIGS. 7(a), (b) and (c) is such that the insulating glass 76 extends from the inner edge 702 of the opening of the eyelet to the lead peripheral wall 703 to provide a withstand voltage. While ensuring the required creepage distance, the exposed surface of the insulating glass is formed into a catenary fillet, that is, the cross-sectional contour of the glass is recessed toward the opening of the eyelet to form a smooth arc. The compressive stress 700 can be received at a shallow angle of less than 45 degrees and with a catenary curved surface consisting of an arcuate curve. As a result, the compressive stress 700 in the eyelet opening end region is distributed to the suspended curved surface to suppress glass cracks while ensuring the withstand voltage between the eyelet 75 and the lead 77 .

On the other hand, the shape of the insulating glass of the comparative example shown in FIG. is sealed almost perpendicularly to the plane of the top plate 71 (inclination angle of 45 degrees or more with respect to the plane of the top plate). Therefore, parallel cracks tend to occur from the open end to the lead.

INDUSTRIAL APPLICABILITY The present invention can be used for airtight terminals that require high pressure resistance and high insulation properties, and can be used particularly for airtight terminals for compressors of refrigerators.

Airtight terminals 10, 20, top plate portions 11, 21, 71, cylindrical portions 12, 22, flange portions 13, 23, openings (cylindrical portions) 14, 24, 84, 94, eyelets 15, 25, 75, 85 , 95, leads 17, 27, 77, 87, 97, insulating glass 16, 26, 76, 86, 96, inner insulating glass 16a, 26a, outer insulating glass 16b, 26b, insulating rubber coating 18, compression Stress 700, shearing stress 701, eyelet inner edge 702, lead peripheral wall portion 703, protruding portion f, glass cracks 89, 99.

Claims (2)

An eyelet integrally comprising a top plate portion, a cylindrical portion, a flange extending obliquely outward from the outer periphery of the cylindrical portion, and three openings, and a lead hermetically sealed to the opening of the eyelet by insulating glass. and the insulating glass on the inner side of the insulating glass extends longer than the linear distance from the opening of the eyelet to the tip of the glass that extends the peripheral wall portion of the lead toward the lead end . In addition, the surface shape of the insulating glass on the inner side is formed in an arc shape in which the cross-sectional profile of the insulating glass is recessed toward the opening of the eyelet and draws a smooth arc to absorb the compressive stress from the eyelet. A catenary curved surface consisting of an arc-shaped curve at a shallow angle of less than 45 degrees is received, and the compressive stress of the open end region of the eyelet is distributed to the catenary curved surface while ensuring the withstand voltage between the eyelet and the lead. An airtight terminal designed to prevent glass cracks . An eyelet integrally comprising a top plate portion, a cylindrical portion, a flange extending obliquely outward from the outer periphery of the cylindrical portion, and three openings, and a lead hermetically sealed to the opening of the eyelet by insulating glass. and the inner insulating glass and the outer insulating glass of the insulating glass have a linear distance from the opening of the eyelet to the tip of the glass extending from the peripheral wall portion of the lead toward the lead end . The surface shape of the insulating glass on the inner side and the insulating glass on the outer side is such that the cross-sectional contour of the insulating glass is recessed toward the opening of the eyelet and draws a smooth arc. The opening of the eyelet is formed in an arc shape, and the compressive stress from the eyelet is received at a shallow angle of less than 45 degrees and by the catenary curved surface of the arc curve, while ensuring the withstand voltage between the eyelet and the lead. An airtight terminal that disperses the compressive stress in the end region to the catenary curved surface to prevent glass cracks .

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