JPH0576684U - Positioning jig for welding - Google Patents

Abstract

(57) [Summary] [Structure] A guide pin 31 made of non-magnetic metal and a ceramic welding positioning member 3 through which the guide pin 31 is inserted.
3 and an electrically insulating insulating member 35 that supports the lower end of the guide pin 31. The welding positioning member is, for example, Al ₂ having an average crystal grain size of 2 μm or less.
It is composed of a sintered body containing O ₃ as a main component. [Effect] The positioning member has excellent durability against any mechanical, electrical, or thermal action on the positioning member during welding, and thus the life of the positioning member can be extended.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a welding positioning jig used for positioning members to be welded during welding.

[0002]

[Prior art]

 BACKGROUND ART Conventionally, as a welding method, for example, a resistance welding method is known in which a welding place of a member to be welded is sandwiched by electrodes and a current is applied between the members to be welded to perform welding. Using this method, for example, a method of welding a member such as a nut to a predetermined position of an iron plate will be described. As shown in FIG. 2, first, a positioning hole 2 which is pre-drilled at a predetermined position of the iron plate 1 is formed. The pin 4 of the welding positioning jig is fitted into the nut 3. Since the pin 4 is biased upward by the spring 5 from below, the iron plate 1 and the nut 3 are positioned and fixed relative to each other. After that, the iron plate 1 and the nut 3 are clamped by the upper electrode 6 and the lower electrode 7, and a current is passed between both electrodes, whereby the iron plate 1 and the nut 3 are welded.

In such a welding method, a welding positioning jig used for positioning a member to be welded has high strength and is excellent in wear resistance because it can withstand an impact due to contact with the member to be welded. It is also required to be a material, and it is also required to be a material with excellent durability that will not cause electrolytic corrosion due to deterioration of insulating properties due to repeated use.

Such positioning jigs for welding have hitherto been prepared by spraying a ceramic insulator such as Al ₂ O _{3 on} the surface of a jig body made of metal, or by adding glass or the like to Al ₂ O _3. A sintered body or the like that has been sintered is used (for example, see JP-A-62-142086).

[0005]

[Problems to be Solved by the Invention] However, in the case where the insulator is sprayed on the jig body, the insulator on the surface is scraped off by the contact with the member to be welded and the insulating property deteriorates. There is a problem that causes food. Further, the Al ₂ O ₃ based sintered body has a problem that it is easily broken due to contact with a member to be welded during welding work because of its low strength.

Therefore, an object of the present invention is to provide a positioning jig for welding which has excellent durability in repeated use in resistance welding and excellent long-term insulation that does not cause electrolytic corrosion or the like. is there.

[0007]

[Means for solving problems]

The present invention comprises a non-magnetic metal guide pin, a ceramic welding positioning member through which the guide pin is inserted, and an electrically insulating insulating member that supports the lower end of the guide pin. The positioning member for welding is composed of a sintered body containing Al ₂ O ₃ having an average crystal grain size of 2 μm or less as a main component in some cases.

Hereinafter, the present invention will be described in detail. The guide pin made of non-magnetic metal is made of, for example, stainless steel or aluminum. As the electrically insulating member, for example, stainless steel coated with Al ₂ O ₃ or other ceramics, high temperature resistant plastic such as polybutylene terephthalate, or the like is used.

Further, as the ceramic welding positioning member, for example, alumina porcelain, silicon nitride, or aluminum nitride may be used, but as described above, it is composed of a sintered body containing Al ₂ O ₃ as a main component. preferable. In terms of composition, this sintered body contains Al ₂ O _{3 in an amount} of 50 to 99.99% by weight, particularly 60 to 90% by weight, and contains 0.01 to 50% by weight, especially 10 to 50% by weight of a grain growth suppressing component. It is preferable to add it in a ratio of about 40% by weight. The grain growth inhibiting component, it forms an action to suppress the grain growth of the particles of _{Al 2 O 3, Al 2 O} 3 crystal particle diameter becomes smaller sinter This ensures. Specifically, the average grain size of Al ₂ O ₃ crystals in the sintered body is preferably 2 μm or less, and particularly preferably 1 μm or less.

As described above, the composition of each component is limited to the above range because if the content of Al ₂ O ₃ is less than 50% by weight, or if the content of the grain growth suppressing component exceeds 50% by weight, the sinterability is increased. In order to decrease the temperature, it is necessary to perform firing at a high temperature, and as a result, grain growth of Al ₂ O ₃ is promoted and the strength and hardness of the sintered body are likely to decrease. Further, when Al ₂ O ₃ exceeds 99.99% by weight or the grain growth suppressing component is less than 0.01% by weight, the grain growth of Al ₂ O ₃ cannot be sufficiently suppressed and the sintered body is This is because the strength, hardness, and durability of are likely to decrease.

Further, the average grain size of the Al ₂ O ₃ crystal is limited to 2 μm or less, because the grain size larger than this lowers the strength and hardness of the sintered body and causes breakage due to contact with the member to be welded. This is because it is easy and problems such as abrasion due to repeated use are likely to occur.

The grain growth suppressing component used in the present invention includes TiC, ZrO _{2 and the} like. If TiN is added, or if a part of carbon of TiC is replaced by nitrogen or the like, the toughness is increased. Since it can also be applied, the durability against impact is improved.

Further, the sintered body used in the present invention preferably has a high density of 95% or more in relative density, and for this reason, it is preferable to use a periodic law such as MgO, TiO ₂ , NiO, SiO ₂ or Y ₂ O _3. A Group 3a oxide or the like may be added as a sintering aid in a proportion of 2% by weight or less. However, addition of a component that deteriorates the insulation of the sintered body should be avoided, and it is desirable to maintain the insulation resistance of the sintered body at 1 × 10 ⁻³ Ω-cm or more.

As a method for producing such a positioning member, Al ₂ O ₃ powder as a raw material powder, a grain growth suppressing component powder, and a sintering aid powder as required are prepared, and these are weighed to the above specific composition. And mix well. After that, the mixed powder is molded into a predetermined positioning member shape. As the molding means, known molding means such as press molding, injection molding, cast molding, extrusion molding can be used.

Next, for example, in the case of Al ₂ O ₃ —TiC system, the above-mentioned molded body is heated to 1600 to 1900 ° C. in the inert atmosphere, and in the case of Al ₂ O ₃ —ZrO ₂ system, 1400 to 1750 in an oxidizing atmosphere such as the atmosphere. Bake at ° C. Fine because each firing temperature effects of the present invention is insufficient densification of the sintered body lower than the above range can not be achieved, when each sintering temperature is too high grain growth of A l ₂ O ₃ is accelerated A fine structure cannot be obtained and excellent properties cannot be exhibited.

In order to further increase the density of the sintered body, it is desirable that the sintered body obtained by the above method be hot isostatically fired at 1350 to 1600 ° C. in an inert atmosphere of 1000 atm or more. .

[0017]

[Action]

 In the welding positioning jig of the present invention, since the guide pin made of a non-magnetic metal is inserted into the welding positioning member, it is possible to replenish the toughness of the welding positioning member and prevent damage or the like. In addition, since the lower end of the guide pin is supported by the electrically insulating insulating member, the insulating property of the jig itself can be secured.

Further, since the welding positioning member is made of ceramic, the characteristics are not deteriorated even when a high current is applied between the members to be welded during welding, and electrolytic corrosion does not occur. In particular, as described above, by being composed of a specific sintered body containing Al ₂ O ₃ as a main component and a grain growth suppressing component added, the sintered body itself has high strength and is broken due to contact with the welded member. In addition, no deterioration of the characteristics occurs even when a high current is applied between the members to be welded during welding, and electrolytic corrosion does not occur at all. Further, even if there is a burr or the like in the positioning hole of the member to be welded during use, it will not be worn due to its high hardness.

Further, it has excellent characteristics such as being less likely to be damaged by thermal shock generated during welding.

[0020]

【Example】

 The welding positioning jig of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a welding positioning jig of the present invention. The welding positioning jig comprises a guide pin 31, a welding positioning member 33, and an insulating member 35. There is.

The guide pin 31 is made of stainless steel which is a non-magnetic metal. The guide pin 31 is composed of a head portion 37 for guiding a positioning hole of a member to be welded such as an iron plate and a leg portion 39 having a diameter smaller than that of the head portion 37, and the lower end portion of the leg portion 39 is a male portion. It is a screw part.

Further, the insulating member 35 is formed in a columnar shape, and the insulating member 35 is formed by covering the stainless steel with Al ₂ O ₃ and has a through hole formed in the center thereof and a female screw portion. Has become.

Then, the male screw portion of the leg portion 39 of the guide pin 31 is screwed into the female screw portion of the insulating member 35, whereby the welding positioning member 33 includes the insulating member 35 and the guide pin 31. It is clamped and fixed by the head portion 37. The guide pin 31 is formed so that the lower end of the leg portion 39 thereof does not protrude below the insulating member 35, whereby the insulation of the welding positioning jig is maintained.

The welding positioning member 33 is formed in a cylindrical shape, and the guide pin 31 is inserted through the inside thereof. The welding positioning member 33 is formed as follows. First, Al ₂ O ₃ powder, TiC powder, TiN powder, ZrO ₂ powder, NiO powder, MgO powder, Dy ₂ O ₃ powder, and Y ₂ O ₃ powder were used as raw material powders, and these are shown in Table 1. After weighing in the indicated proportions, they were mixed by a ball mill and formed into a cylindrical positioning member shape as shown in FIG. 1 together with a molded body for characteristic evaluation by an extrusion molding method. Then, the molded body was cut into a predetermined length, pre-fired, fired under the conditions shown in Table 1, and further hot isostatically fired at 1550 ° C. in an argon atmosphere of 2000 atm. In the table, sample No. 9 is a conventional product.

The density, the average grain size of Al ₂ O ₃ crystals, the flexural strength according to JIS R1601, and the Vickers hardness were measured for the obtained sintered body by using a sintered body for characteristic evaluation. The results are shown in Table 2. In addition, the number of shots until a defect is generated using the positioning member 33 is shown.

[0026]

[Table 1]

[0027]

[Table 2]

[0028] According to Tables 1 and 2, the conventional product had a defect after 10,000 welding shots, whereas the samples to which the grain growth suppressing component was added according to the present invention had excellent durability. showed that. However, with respect to the sample No. 1, in which the guide pin 31 was made of iron, which is a magnetic metal, shunting occurred and the power consumption increased. When the insulation resistance of the samples in Table 1 was measured, they were all 1 × 10 ⁻³ Ω-cm or more.

In the welding positioning jig configured as described above, since the guide pin 31 made of a non-magnetic metal is inserted into the welding positioning member 33, the insufficient toughness of the welding positioning member 33 is supplemented. As a result, it is possible to surely prevent breakage and the like, and it is possible to surely prevent the occurrence of shunting. Therefore, it is possible to reduce power consumption. Further, since one end of the guide pin 31 is supported by the insulating member 35 having an electrically insulating property, the insulating property of the jig itself can be secured.

Further, since the welding positioning member 33 is made of ceramic, the characteristics are not deteriorated even with a high current applied between the members to be welded during welding, and electrolytic corrosion does not occur. In particular, by using a specific sintered body containing Al ₂ O ₃ as a main component and a grain growth suppressing component as described above, it is possible to reliably prevent breakage due to contact with the member to be welded, In addition, the characteristics are not deteriorated even with a high current applied between the members to be welded during welding, and electrolytic corrosion can be completely prevented. Further, even if there is a burr or the like in the positioning hole of the member to be welded during use, it does not wear due to its high hardness, and it is possible to reliably prevent the occurrence of chipping against the thermal shock generated during welding.

Although the welding positioning member 33 is made of a specific sintered body containing Al ₂ O ₃ as a main component and a grain growth suppressing component added in the above embodiment, the present invention is not limited to this. The present invention is not limited to the above embodiment, and the welding positioning member may be formed by another ceramic.

Further, in the above embodiment, an example in which the guide pin 31 made of a non-magnetic metal is made of stainless steel has been described, but the present invention is not limited to this.

Further, in the above-described embodiment, an example in which stainless steel coated with Al ₂ O ₃ is used as the insulating member 35 has been described, but the present invention is not limited to the above-described embodiment, and the insulating member May be anything as long as it has electric insulation and heat resistance.

[0034]

[Effect of the device]

 As described in detail above, according to the present invention, the positioning member has excellent durability against any mechanical, electrical, or thermal action on the positioning member during welding. Can be planned.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a welding positioning jig of the present invention.

FIG. 2 is a diagram for explaining a resistance welding method.

[Explanation of symbols]

 31 Guide Pin 33 Positioning Member for Welding 35 Insulation Member

Claims (2)

[Scope of utility model registration request] 1. A guide pin made of non-magnetic metal, a ceramic welding positioning member through which the guide pin is inserted, and an electrically insulating insulating member supporting a lower end portion of the guide pin. Positioning jig for welding. 2. The positioning member for welding has an average crystal grain size of 2
The welding positioning jig according to claim 1, which is made of a sintered body containing Al ₂ O ₃ having a size of not more than μm as a main component.