JPS6117379A - Seam welding machine provided with circular electrode - Google Patents

Abstract

PURPOSE:To obtain a titled welding machine that can keep the surface of electrode always clean and can make accurate and efficient welding continuously by cutting off metal adhered on the turning plane of by a cutting device that cuts the turning plane of a disk electrode. CONSTITUTION:In a seam welding machine having a circular electrode 1a that is moved vertically by a cylinder 22 and a disk electrode 2a supported by an electrode supporter 27 on a frame 20, superposed materials 3a, 4a to be welded are pinched between lowered disk electrode 1a and the disk electrode 2a. Welding current is applied to the two electrodes 1a, 2a rotating the electrodes, and seam welding is performed feeding the materials 3a, 4a to be welded. During above- mentioned welding, cutters 30, 30a, rotating at high speed, are brought into contact with rotation plane of above-mentioned disk electrodes 1a, 2a by action of cylinders 27, 27a through cylinder rods 28, 28A, and the turning plane is cleaned by cutting off metal such as zinc etc. adhered on the plane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a seam welding machine equipped with a disc electrode.

[Prior art]

Conventionally, when welding joints of materials to be welded, a seam welding machine that performs electric resistance welding has been used.

However, if the material to be welded is a galvanized steel plate, and the melting temperature of the surface-treated zinc is low, the zinc will melt first and adhere to the electrode during resistance heating.

It also forms an alloy with zinc and iron. As a result, the state of resistance heating inside the steel plate becomes abnormal due to molten zinc adhering to the electrodes, causing an abnormality in the molten state of the iron, and as a result, the thermal conductivity and temperature distribution inside the steel plate become different. This may cause trouble in seam welding.

FIGS. 3 and 4 are explanatory diagrams showing the temperature distribution of galvanized steel sheets when the galvanized steel sheets are seam welded.

Figure 3 is an explanatory diagram showing the temperature distribution inside the galvanized steel sheet during normal seam welding, and Figure 5 shows (
11J2+ is an electrode, (31J41 is a galvanized steel plate, +
51 is the joint of the steel plate (51), and (6) is the molten metal (iron) that was melted centering on the xD joint (5) due to the electric resistance during welding. Also, the symbol on the horizontal axis (Ll is the galvanized steel plate (3)
1, (length in the plate thickness direction of 41?).

The symbol on the vertical axis is galvanized steel plate f31. (Indicates the temperature inside 41. Temperature (Tm) indicates the melting temperature of iron.

During normal seam welding, the electrodes (11, (2+) are powered and the galvanized steel plate (31J41
When the inside is heated and the temperature exceeds the melting temperature (Th) of iron, the iron melts and the joints are welded. At this time, the temperature distribution inside the galvanized steel plate [31, +41 shows the highest temperature at the joint (5), and the heat of the molten iron (6) is transferred to the electrode (1).
Since 1J21 is made of copper and has high thermal conductivity and low temperature, the electrode conducts in the 11J21 direction, so the temperature distribution curve becomes a parabola as shown in Figure 6. In this state, the welding current is cut. Then, the molten iron (5) solidifies and forms a spot weld, maintaining a normal seam weld.

On the other hand, in Figure ^t4, zinc melts first due to resistance heating.
A diagram showing the temperature distribution inside the galvanized steel plate (31, (4+) when it is attached to the electrode (11, +21) is shown below. When resistance heating is performed, the zinc with a lower melting temperature melts first, and the electrode (
Attaches to 1+ and +2+. Therefore, the electrode (i +, 12
+ means that the electrical conductivity and thermal ridge conductivity originally possessed by copper electrodes are significantly reduced. As a result, the resistance increases, and abnormal heat generation also occurs at the contact surface between the galvanized steel plate (31, (41) and the electrodes fi+ and [2+).
+, (2+ due to zinc attached to galvanized steel sheet [31
, (The thermal conductivity between 41 and the electrode +11J21 has decreased, and heat is not conducted toward the electrode (11J21).

Heat is stored inside the steel plate. The result is a galvanized steel sheet (6).

(Iron also melts near the contact surface between 41 and the electrode [11J21.
[It is molten iron near the 2+ contact surface.

This work was carried out under 5 abnormal conditions and galvanized steel plate (31 (
If the temperature distribution curve (Bl) inside 4+ is a single parabola, temperature peaks will occur on both sides. Therefore, a hole is created in the weld.

In order to eliminate such inconveniences, seam welding of disc electrodes has been conventionally performed. FIG. 5 is a partial schematic diagram of a conventional disc electrode seam welding machine. In the figure (Ia), (2a)
is a copper disc electrode with a diameter of D(/J), (3a), (4
A) The material to be welded is a galvanized steel plate with a certain length %L. The diameter of the disc electrodes (1a) and (2a) is the same as the phase to be melted (3
From the relationship with the length L in a) and (4a), a range determined by the following formula is used.

D≧□・・・・・・ ■ π What is the diameter of this 0-formula Eri, disk electrodes (1a) and (2a)?

Its circumference is the length llr of the welded materials (3a) and (4a),
The condition is that the dimension is the same as -8 or longer than l.

This was configured in c5. The conventional disc electrode seam welding machine rotates the disc electrode (ia), (2a)' and -
Weld the seam. l, therefore, the material to be welded (3a),
Since the portions of the disc electrodes (1a) and (2a) that come into contact with (4a) change, the inconvenience described in the explanation of FIG. 4 above does not occur continuously.

Even with the L7 rivet disc electrode (Ia) and (2a), the material to be welded (3
a).

If (4a) is a galvanized steel plate, the molten zinc may remain attached to the transfer surfaces of the disk electrodes (1a) and (2a).If the transfer surface is seam welded again, the transfer surface 'lt should be shaped. The disadvantage was that the surface had to be kept clean. In addition, without shaping the transfer surfaces of the disk electrodes (Ia) and (2a), 1
Even if the seam welding length is too large <LJ:'S,
It was impossible to make the diameter (Dw) of the disk electrodes (Ia) and (2a) larger than necessary due to the machine construction and related equipment, etc. (Thus, long distance seam welding?Continuous [Summary of the Invention] The present invention has been made to solve these drawbacks, and the present invention is to provide a cutting device for cutting the rotating surface of the disk ti. In particular, by removing the metal particles attached to the rotating surface of the disc electrode, the electrode surface is always kept clean, and continuous, accurate and efficient seam welding is possible. Equipped with seam welding machine.

[Embodiments of the invention]

FIG. 1 is an E-side view showing an embodiment of the present invention, and FIG. 2 is a side view thereof. In the figure, (Ia), (2a3), (3a), and (4a) are the same as the conventional seam welding machine equipped with the above-mentioned disk electrode, and (20) is the welding current supply device t21)v. It is a built-in frame, and a cylinder (22) is provided in the upper part and an electrode support (23) is provided in the lower part. (24) is a cylinder rod that hangs down from the cylinder (22), and a mounting part (25) is provided at the end of the cylinder rod. The disc electrode (1a) is rotatably mounted. In addition, a flexible conductor (2
6). (27) is a cylinder installed in the mounting part (25), and at the end of the cylinder rod (28 installed.

The cutter (60) is made of hardened tool steel.

A plurality of cutting blades are arranged on the outer periphery of the cylinder, and the shape of the cutting blades is determined to adapt to the shape of the transfer surface on the outer periphery of the disc electrode (1a). When pressed against the transfer surface of 1a), a sharp groove 5 is formed that bites into the transfer surface.

The disc electrode (2a) is used for welding materials (3a), (4a) 'v
The attachment part (25a) is placed in a position facing the disc electrode (1a) through the electrode support (23), using a mechanism similar to that in which the disc electrode (1a) is sprayed onto the cylinder rod (28).
) is rotatably mounted. The cutter (30ω also has the same mechanism as the cutter (30) above, and the cylinder rod (
The shape of the cutting blade is the same as that of the cutter (30). In addition, cutter (30a
)teeth.

Cutter (30) and materials to be welded (3a), (4a)? They are placed at opposite positions with each other in between.

In a seam welding machine equipped with a disc electrode configured as described above, 1 disc electrode (Ia) is lowered to the Y cylinder (22), and between it and the disc electric switch 2a) whose position is fixed. Pressure is applied to the partially overlapped portion of the plate-shaped materials to be welded (3a) and (4a). Next, welding current is supplied from the welding current supply device (21) to the two disk electrodes (1a), (2a), and the drive device rotates the disk electrodes (1a), (2a), and at the same time, the welding material (3a) is , (4a) is sent. As a result, welded #C
Sea) The joints of the overlapped parts of (4a) are spot welded. At that time, if the materials to be welded (3a) and (4a) were galvanized steel plates, melting occurred on the rotating surfaces of the disc electrodes (Ia) and (2a).
Zinc adheres and solidifies. However, the cutter (30), (
30a) rotates at high speed, disc electrodes (1a), (2a
) and also cut the zinc deposits 1. Keep the rotating surface clean.

〔Effect of the invention〕

As explained above, the great invention is to create a simple structure in which a cutter is attached to the disc electrode.1 The rotating surface of the disc electrode is constantly cleaned and the workpiece can be welded continuously, accurately and efficiently. This has the effect of allowing for smooth seam welding.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the great invention, Fig. 2 is a side view thereof, Fig. 3 is an explanatory diagram showing the temperature distribution inside a normal seam-welded galvanized steel sheet, and Fig. 4 is An explanatory diagram showing the temperature distribution inside a galvanized steel sheet when zinc adheres to the electrode. Figure 5 is a partial explanatory diagram of a seam welding machine equipped with a conventional disc electrode. ) are disk electrodes, (3a) and (4a) are the materials to be welded, (20) is the frame, (21) is the welding current supply device, (22) is the cylinder, (26) is the front pole support, (24) ) is shi11
(25) is the mounting part, (26),
(26a) is a flexible conductor, (27) and (27a) are cylinders, (28) and (28a) are cylinder rods, (2
9) and (29a) are drive motors. (30) and (30a) are cutters. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A seam welding machine equipped with a disc electrode, characterized in that the seam welding machine is equipped with a cutting device for cutting a rotating surface of the disc electrode.