WELDING EQUIPMENT FOR METALLIC MATERIALS AND METHOD FOR WELDING METALLIC MATERIALS

• US 20110303655A1
• Filed: 09/30/2009
• Published: 12/15/2011
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: National Institute for Materials Science, Neturen Company Limited
• Original Assignee: National Institute for Materials Science, Neturen Company Limited
• Inventors: Ikuta, Fumiaki, Kawasaki, Kazuhiro, Nagai, Kotobu, Itagaki, Takehiko, Kanai, Takahiko, Hatta, Munehisa, Nakanishi, Eizaburo, Yoshida, Tsuyoshi, Hayakawa, Masao
• Granted Patent: US 9,079,266 B2
• Time in Patent Office: Days
• US Class Current: 219/660
• CPC Class Codes: B23K 11/115 by means of two electrodes placed opposite one another on both sides of the welded parts
• CPC Class Codes: B23K 11/24 Electric supply or control circuits therefor
• CPC Class Codes: B23K 11/241 Electric supplies B23K11/248 takes precedence
• CPC Class Codes: B23K 11/26 Storage discharge welding
• CPC Class Codes: B23K 11/312 for several electrodes
• CPC Class Codes: B23K 13/08 Electric supply or control circuits therefor
• CPC Class Codes: B23K 2101/18 Sheet panels
• CPC Class Codes: B23K 2103/04 Steel or steel alloys

Abstract

A welding equipment for metallic materials capable of performing heat treatment such as tempering based on partial heating in spot welding is provided. The welding equipment 1 sandwiches metallic materials 9 with a pair of electrodes 4, 4, and heats different regions of the metallic materials 9 by energization, with the pair of electrodes 4, 4 maintained at the same position with respect to the metallic materials 9. The welding equipment includes a first heating means 6 connected to the pair of electrodes 4, 4 for heating and welding the internal region of the circle defined by projecting the cross-sectional area of the axis of the electrodes on the metallic materials by applying power having a low first frequency, a second heating means 8 for heating a ring-shaped region along the circle by applying power having a second frequency that is higher than the first frequency, and an energization control unit 10 for independently controlling the first and the second heating means 6, 8.

Claims

1. Welding equipment for metallic materials, sandwiching metallic materials with the pair electrodes and heating different regions of the metallic materials by energization with the pair of electrodes maintained at the same position with respect to the metallic materials, comprising:

a first heating means connected to a pair of electrodes for heating a given region of the metallic materials by applying electric power having a first frequency;

a second heating means connected to the pair of electrodes for heating a region of the metallic materials different from the given region by applying electric power having a second frequency; and

an energization control unit for independently controlling the first heating means and the second heating means.

2. The welding equipment for metallic materials according to claim 1, wherein

the inside of the given region of the metallic materials is heated by the first heating means,

a proximity of the given region of the metallic materials is heated by the second heating means, and

the heating by the first heating means and that by the second heating means are independently controlled by the energization control unit.

3. The welding equipment for metallic materials according to claim 2, wherein

the first heating means heats the inside of the region defined by projecting the cross-sectional area of the electrodes on the metallic materials,

the second heating means heats a ring-shaped area along a circumference of the region defined by projecting the cross-sectional area of the electrodes on the metallic materials, and

the heating by the first heating means and the heating by the second heating means are independently controlled by the energization control unit.

4. The welding equipment for metallic materials according to claim 3, wherein the first frequency is lower than the second frequency, and the inside of the circle is welded by applying power having the first frequency to the metallic materials.

5. The welding equipment for metallic materials according to claim 3, wherein the second frequency is higher than the first frequency, and the ring-shaped area undergoes resistance heating or induction heating or both resistance heating and induction heating by applying power having the second frequency to the metallic materials.

6. The welding equipment for metallic materials according to claim 1, wherein

the first heating means is a welding power source for supplying power to the pair of electrodes,

the second heating means is a high-frequency power source for supplying power to the pair of electrodes,

the welding power source and the high-frequency power source are connected to the pair of electrodes in parallel respectively,

an inductance for blocking current is connected between the welding power source and the pair of electrodes,

a capacitor for blocking current is connected between the high-frequency power source and the pair of electrodes,

the inductance blocks the high-frequency current supplied from the high-frequency power source to the pair of electrodes so as not to flow into the welding power source, and

the capacitor blocks the current supplied from the welding power source to the pair of electrodes so as not to flow into the high-frequency power source.

7. The welding equipment for metallic materials according to claim 6, further comprising a gun arm, wherein the spot-welding power source and the high-frequency power source are connected to the pair of electrodes via the gun arm.

8. The welding equipment for metallic materials according to claim 6 or 7, wherein the welding power source is a low-frequency power source or DC power source.

9. The welding equipment for metallic materials according to claim 8, wherein the low-frequency power source is connected to the pair of electrodes via a transformer, and

a bypass capacitor is connected to the winding of the transformer on the side of the pair of electrodes.

10. A method for welding metallic materials by sandwiching the metallic materials with a pair of electrodes and energizing the metallic materials, comprising:

a first step for heating a given region of the metallic materials by a first energization to the pair of electrodes; and

a second step for heating a region different from the region in the first step by a second energization to the pair of electrodes performed with the pair of electrodes maintained at the same position as the first step,

wherein the heating time in the first step and that in the second step are independently controlled.

11. The welding method for metallic plates according to claim 10, wherein

the inside of the given region of the metallic materials is heated by a first heating means,

a proximity of the given region of the metallic materials is heated by a second heating means, and

the heating by the first heating means and that by the second heating are independently controlled.

12. The welding method for metallic plates according to claim 11, wherein

the given region heated by the first heating means is the internal area of a circle defined by projecting the cross-sectional area of the electrodes on the metallic materials,

the different region heated by the second heating means is a ring-shaped proximity region along the circle defined by projecting the cross-sectional area of the electrodes on the metallic materials, and

the heating by the first heating means and that by the second heating means are independently controlled.

13. The welding method for metallic plates according to claim 12, wherein the internal area of the circle is welded by performing the heating by the first heating means at a frequency lower than that of the heating by the second heating means.

14. The welding method for metallic plates according to claim 12, wherein the ring-shaped outer peripheral region undergoes either resistance heating or induction heating or both resistance heating and induction heating by performing the heating by the second heating means at a frequency higher than that of the heating by the first heating means.