JP2006012584A - Hermetic sealing method and hermetic sealing fixture for wiring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve pressure resistance of a hermetic seal by equalizing the whole thickness of insulated sealing glass around a lead wire. <P>SOLUTION: The lead wire 9 is arranged in a cylindrical lead-wire insertion hole 11 formed in a metal board 10 along the center axial line of the lead-wire insertion hole 11. Granulated glass 13 is filled in the lead-wire insertion hole 11 around the lead wire 9. Both open ends of the lead-wire insertion hole 11 are covered with plugs 14, 15 inserted around the lead wire 9 respectively, and the lead wire 9 is hermetic sealed with the insulated sealing glass 12 formed by baking the granulated glass 13 in the status. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hermetic sealing method for electrical wiring and a hermetic sealing jig.

In order to take out the lead wire for driving the solenoid wired in the high-pressure fuel in the fuel injection valve to the outside, the cylindrical lead wire insertion hole formed in the metal base is aligned with the central axis of the lead wire insertion hole. 2. Description of the Related Art A fuel injection valve is known in which lead wires are disposed, powder glass is filled in lead wire insertion holes around the lead wires, and the lead wires are hermetically sealed by firing the powder glass (for example, (Refer nonpatent literature 1).
Toyota Technological Collection, issue number 14838, issue date 20th June 2003

  However, when the powder glass is simply fired, the thickness of the insulating sealing glass formed by firing is considerably different around the lead wire, and sufficient pressure resistance cannot be secured for the hermetic seal under a high pressure fuel exceeding 10 MPa or 100 MPa. There is a problem.

  In order to solve the above problems, according to the present invention, a lead wire is disposed in a cylindrical lead wire insertion hole formed in a metal base so as to extend along the central axis of the lead wire insertion hole, and around the lead wire. The lead wire insertion hole is filled with powder glass, and both open ends of the lead wire insert hole are covered with plugs inserted around the lead wire, and both open ends of the lead wire insert hole are covered with plugs. Powdered glass is fired so that the electrical wiring is hermetically sealed.

  Further, according to the present invention, the hermetic sealing jig for carrying out this hermetic sealing method comprises a casing that can be divided into upper and lower parts, and a lead wire insertion hole extends in the vertical direction in this casing. A metal base can be accommodated, and a plug is formed on the bottom surface of the inner chamber of the housing to cover the lower opening end of the lead wire insertion hole, and a plug insertion hole is formed on the upper wall of the inner chamber of the housing. In the plug insertion hole, a plug that covers the upper opening end of the lead wire insertion hole is inserted with a gap.

  The thickness of the insulating sealing glass around the lead wire can be made uniform over the whole, whereby the pressure resistance of the hermetic seal can be improved.

  Referring to FIG. 1 showing the upper part of the fuel injection valve, 1 is a fuel injection valve body, 2 is a needle valve, 3 is a core having a solenoid, 4 is a spacer, and 5 is fixed to the upper end of the fuel injection valve body 1. An upper casing, 6 is a fuel supply path, and 7 is a power supply connector. A hermetic seal terminal 8 is fitted in a recess formed on the lower side surface of the upper casing 5, and a lead wire 9 for supplying power to the solenoid is connected to the connector 7 via the hermetic seal terminal 8. Has been.

  Referring to FIGS. 2 and 3, the hermetic seal terminal 8 comprises a disk-shaped metal base 10 having a uniform thickness. In the embodiment shown in FIGS. 2 and 3, four cylindrical shapes are formed on the metal base 10. A lead wire insertion hole 11 is formed. In each lead wire insertion hole 11, a lead wire 9 is disposed along the central axis of each lead wire insertion hole 11, and the lead wire insertion hole 11 around each lead wire 9 is formed by firing powder glass. It is filled with the formed insulating sealing glass 12. The lead wire 9 is hermetically sealed by the insulating sealing glass 12.

  FIG. 4 shows a conventional hermetic sealing method conventionally performed. In this hermetic sealing method, powder glass is first solidified by press molding to form a hollow cylindrical powder glass, and this solid powder glass 13 is formed in the lead wire insertion hole 11 as shown in FIG. Inserted into. Next, the lead wire 9 is inserted into the central hole of the powder glass 13. Next, when the entire metal substrate 10 is heated to about 1000 ° C., the powdered glass is melted and contracted to become an insulating sealing glass 12 as shown in FIG.

  By the way, when the powder glass 13 is heated, the metal oxide in the metal substrate 10 chemically reacts with the powder glass 13 and these are chemically bonded. As a result, the powder glass 13 is restrained and cannot contract. In this case, the timing of the chemical reaction between the metal oxide and the powdered glass 13 varies depending on the position of the inner wall surface of the lead wire insertion hole 11 due to the temperature distribution of the inner wall surface of the lead wire insertion hole 11, etc. When it occurs, the powder glass 13 does not shrink so much, and when the chemical reaction occurs at a late time, the powder glass 13 is restrained after being considerably contracted, so that as shown in FIG. The thickness of the insulating sealing glass 12 in the longitudinal direction is greatly different.

  However, if the thickness in the longitudinal direction of the insulating sealing glass 12 differs greatly around the lead wire 9 as described above, the insulating sealing glass 12 having the smaller thickness when a high voltage is applied to one side of the insulating sealing glass 12. A large stress is generated at the outer peripheral edge of the insulating sealing glass 12 having a small coupling area with the inner wall surface of the lead wire insertion hole, that is, with the inner wall surface of the lead wire insertion hole, thereby reducing the pressure resistance of the hermetic seal. End up.

  On the other hand, FIG. 5 shows a hermetic sealing method according to the present invention. Also in the hermetic sealing method according to the present invention, powder glass is first solidified by press molding to form a hollow cylindrical powder glass, and this solid powder glass 13 is inserted into a lead wire as shown in FIG. It is inserted into the hole 11. Next, both open ends of the lead wire insertion hole 11 are covered with plugs as indicated by reference numerals 14 and 15 in FIG. Next, the lead wire 9 is disposed. In more detail, the metal substrate 10 is disposed so that the lead wire insertion hole 11 extends in the vertical direction, the lower open end of the lead wire insertion hole 11 is covered with a plug 14, and the upper open end of the lead wire insertion hole 11 is Covered by plug 15. Next, the lead wire 9 is disposed.

  Each plug 14, 15 has a through hole 16, 17 extending along the central axis, and a lead wire 9 is passed through the through hole 16, 17. The external shapes of the plugs 14 and 15 are made of a rotating body around the central axis of the lead wire insertion hole 11, that is, around the central axis of the through holes 16 and 17, and the tip surfaces of the plugs 14 and 15 facing each other are radially inward. A protrusion having an arcuate cross section is formed between the end and the radially outer end. Each of the plugs 14 and 15 is formed of a heat-resistant material that does not react with the glass constituting the metal substrate 10, for example, an iron alloy containing cobalt Co and nickel Ni, and the glass constituting the powder glass 13. The plugs 14 and 15 are made of carbon C.

  The lower plug 14 is fitted into the lead wire insertion hole 11. On the other hand, the lead plug insertion hole 11 is provided so that the weight of the plug 15 continues to be applied to the top surface of the powder glass layer 13 during the initial to intermediate period of the firing of the powder glass 13, that is, during the firing shrinkage period of the powder glass 13. It is inserted with a gap in it. That is, the weight of the upper plug 15 is supported by the top surface of the powder glass layer 13. Therefore, even if the start time of the chemical reaction between the powder glass 13 and the metal substrate 10 varies depending on the location during the firing of the powder glass 13, the insulating sealing glass 12 is shown in FIG. As shown in FIG. 5C, when the plugs 14 and 15 are removed after the firing is completed, the insulating sealing glass 12 is shaped so that the thickness in the longitudinal direction is uniform around the lead wire 9. The thickness in the longitudinal direction is uniform around the lead wire 9. As a result, a large stress is not locally generated in the insulating sealing glass 12, and thus a hermetic seal excellent in pressure resistance can be formed by the insulating sealing glass 12.

  FIG. 6 shows a hermetic sealing jig used for carrying out the hermetic sealing method according to the present invention. The hermetic sealing jig is composed of a carbon C housing 20 which is composed of a lower body 21 and an upper lid 22 and can be divided into upper and lower portions, and an inner chamber 23 is formed in the housing 20. The metal base 10 is accommodated in the housing 20 so that the lead wire insertion hole 11 extends in the vertical direction, and a lower opening end of the lead wire insertion hole 11 is provided on the bottom surface of the inner chamber 23 of the housing 20. The covering plug 14 is formed integrally with the lower main body 21.

  On the other hand, a plug insertion hole 24 is formed in the upper wall of the inner chamber 23 of the housing 20, that is, in the upper lid 22, and the upper opening end of the lead wire insertion hole 11 is covered in these plug insertion holes 24. The plug 15 is inserted with a gap. When the powder glass 13 is fired, the metal substrate 10 is heated in a furnace in a state of being accommodated in a housing 20 as shown in FIG. 6 in order to heat the entire metal substrate 10 as uniformly as possible. .

It is side surface sectional drawing of the upper part of a fuel injection valve. It is an expanded side sectional view of a hermetic terminal. It is an enlarged plan view of a hermetic terminal. It is a figure which shows the conventional hermetic sealing method. It is a figure which shows the hermetic sealing method by this invention. It is side surface sectional drawing of a hermetic sealing jig | tool.

Explanation of symbols

8 Hermetic seal terminal 9 Lead wire 10 Metal base 11 Lead wire insertion hole 12 Insulating sealing glass 13 Powdered glass 14, 15 Plug 20 Housing 21 Lower body 22 Upper lid 23 Internal chamber 24 Plug insertion hole

Claims (4)

  In the cylindrical lead wire insertion hole formed in the metal substrate, the lead wire is disposed along the central axis of the lead wire insertion hole, and the lead wire insertion hole around the lead wire is filled with powder glass, Hermetic seals for electrical wiring in which both open ends of the lead wire insertion holes are covered with plugs inserted around the lead wires, and powder glass is baked with both open ends of the lead wire insertion holes covered with plugs Method.   Arrange the metal base so that the lead wire insertion hole extends in the vertical direction, and the weight of the plug covering the upper opening end of the lead wire insertion hole continues to be applied to the top surface of the powder glass layer during the firing shrinkage of the powder glass The hermetic sealing method according to claim 1.   The hermetic sealing method according to claim 1, wherein the outer shape of the plug is a rotating body around the central axis of the lead wire insertion hole.   It is composed of a casing that can be divided into upper and lower parts, and a metal base can be accommodated in the casing such that a lead wire insertion hole extends in a vertical direction. A lead wire insertion hole is formed on the bottom surface of the inner chamber of the casing. A plug is formed to cover the lower opening end of the housing, and a plug insertion hole is formed in the upper wall of the inner chamber of the housing, and the upper opening end of the lead wire insertion hole is covered in the plug insertion hole. A hermetic sealing jig used for carrying out the hermetic method according to claim 1, wherein the plug is inserted with a gap.

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