JPH0641968U - Arc spot welding jig - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] When performing arc spot welding of lapped work, the lower holding member should be welded to the welded part even if the plane dimensional accuracy of the work is somewhat poor. An arc which can be brought into contact with the back surface of the workpiece with a sufficient degree of adhesion to prevent sticking of the contact interface due to infiltration of molten metal into the contact interface, and moreover, the welding torch can be easily positioned with respect to the work. Provide spot welding jig. [Structure] The lower arm 1a and the upper arm 1b are assembled into a single-mouth type picking mechanism, and one end of the lower arm on one side of the mechanism is attached to the rear surface of the work to be welded. The lower holding member 6a that abuts on the upper arm is attached to one end of the upper arm, and the upper holding member 6b that abuts around the welded portion on the work surface side is attached to one end of the upper arm. It was attached by facing the inside of the upper holding member.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a jig for use in arc spot welding of overlapping portions of thin plates such as steel plates.

[0002]

[Prior art]

 Conventionally, when spot welding of overlapping parts of thin plates by arc spot welding, the work is placed on a holding plate and the welding torch is positioned at a predetermined position directly above the welded part of the work. The welding torch is operated to generate an arc between the welding electrode and the surface of the welded part, thereby melting the base material of the welded part.

In this arc spot welding, it is known that a hole is preliminarily formed in the upper work of the work overlapping portion, and the base metal portion in and around the hole is melted.

[0004]

[Technology the device is trying to solve]

 However, in the conventional arc spot welding method, since the entire work is placed on the lower holding member, if the plane dimensional accuracy of the work is low, the work back surface and the lower side It is unavoidable that the adhesiveness with the holding member deteriorates and the decrease in adhesion between them is unavoidable.In this case, in the method of forming a hole in the upper work of the welded part in advance, the lower part of the hole is The penetration of the work part deepens, the lower work part that comes into contact with the lower holding member melts, and due to the arc pressure, this molten part has a low adherence to the back surface of the work and the lower protection part. It becomes difficult to remove the work from the lower holding member after the welding by penetrating into the interface with the holding member and the workability is inevitably reduced.

In order to eliminate such a problem, it is possible to correct the work before welding, but the workability is unavoidably deteriorated due to the increase in man-hours. Further, in the conventional arc spot welding method, after placing the work on the holding plate at a predetermined position, the lower end of the welding torch is positioned at a predetermined height immediately above the welded part. Since the positioning is performed so that the positioning is required twice, it is inevitable that the positioning operation and the positioning device are complicated.

An object of the present invention is, when performing arc spot welding of overlapping work, the lower holding member is attached to the back surface of the work to be welded even if the plane dimension accuracy of the work is somewhat poor. An arc spot which can be brought into contact with a sufficient degree of adhesion to prevent the molten metal from infiltrating into the contact interface to prevent the contact interface from sticking, and moreover, the welding torch can be easily positioned with respect to the work. To provide a welding jig.

[0007]

[Means for Solving the Problems]

 In the arc spot welding jig of the present invention, a lower arm and an upper arm are assembled into a single-mouth type picking mechanism, and one end of the lower arm on one side of the mechanism is provided with a wire. -A lower holding member that comes in contact with the back surface of the welded part of the work is attached, and an upper holding member that comes into contact with the periphery of the work to be welded on the work surface side is attached to one end of the upper arm. The structure is characterized in that the chi is attached with its lower end facing the upper holding member.

[0008]

[Action]

 Insert one end of the jig into the welded part of the work and close the picking mechanism to hold the welded part of the work by the upper holding member and the lower holding member, and hold the lower part. The member is brought into close contact with the back surface of the work to be welded, and the lower end of the welding torch is positioned at a predetermined position directly above the work to be welded.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a single-mouth type picking mechanism composed of a lower arm 1a and an upper arm 1b. The lower arm 1a and the upper arm 1b are rear ends. At the intermediate position closer to each other, the ears 2a and 2b projecting inward are rotatably connected by a pin 3, and the rear end of the upper arm 1b is rotatably connected by a pin 5b to a cylinder -4b. A piston rod 4a for the cylinder 4b is rotatably connected to the rear end of the lower arm 1a by a pin 5a.

Reference numeral 6a denotes a lower holding member attached to the tip of the lower arm 1a, which has a flat upper surface 61 that can come into contact with the back surface of the welded portion of the work with sufficient adhesion, A cooling water passage 62 is provided in the. The outer contour of the lower holding member 6a is slightly larger than the outer contour of the arc spot welded portion of the work, and is usually circular. As the material, a metal such as copper, heat-resistant pottery, or the like is used.

An upper holding member 6b is attached to the tip of the upper arm 1b so as to face the lower holding member 6a of the lower arm tip. The upper holding member has a shape, for example, a cylindrical shape, which can abut the periphery of the work-side arc spot welded portion of the work with a sufficient degree of adhesion. The same material as the lower holding member 6a can be used as the material of the upper holding member 6b.

A welding torch 7 is attached to the tip of the upper arm 1b. A support 8 is attached to the arm 1b, and the welding torch 7 is supported by the support 8. The welding electrode at the lower end 71 of the welding torch faces the upper part inside the upper holding member 6b.

The lower holding member 6a may be attached to the lower arm 1a via an elastic member such as a disc spring. In order to perform arc spot welding of a work overlapping portion, for example, a joint portion of a reinforcing bar for construction, by using the jig of the present invention, as shown in FIG. 2, in the X-axis direction and the Y-axis direction. Using a Cartesian coordinate system robot that supports the jig of the present invention so that it can move in the Z-axis direction on the arm 92 on the movable traverse 91, the lower side of the jig can be adjusted by adjusting the movement in the Z-axis direction. The upper surface 61 of the holding member 6a is positioned slightly lower than the lower surface of the work A, and then the movement of the jig in the X-axis direction and the Y-axis direction is adjusted to directly below the spot-welded portion a of the work A. The lower holding member 6a is positioned, and after that, the piston rod 4a of the jig is moved so as to project with respect to the cylinder 4b so that the spot welded portion a of the work is held by the lower holding member 6a and the upper holding member. 6b, and then the welding torch 7 is operated to generate an arc.

A hole is previously formed in the upper work of the spot welded portion, and due to the heat of the arc, the upper and lower work parts around the hole and the lower work in the hole are processed. Even if part of the base material melts, the lower holding member 6a is in contact with the back surface of the spot-welded portion, so that the base material does not fall out and welding can be performed safely.

In this case, since the spot welded portion, which is a very small part of the work, is held between the upper holding member 6b and the lower holding member 6a of the jig, there is some warpage in the entire work. However, the lower holding member can be brought into contact with the back surface of the work with a sufficient degree of adhesion, and even if the lower work inside the hole of the upper work melts to the depth reaching the lower holding member, its melting It can well prevent metal from penetrating into the contact interface. Therefore, it is possible to satisfactorily perform arc pot welding by eliminating the sticking between the work and the lower holding member without correcting the flatness of the work.

After the lower holding member 6a of the jig is positioned immediately below the spot-welded portion of the work, the jig is closed by operating the cylinder-4b, and the welding torch 7 is opened. -It can be naturally positioned at a predetermined position necessary for cup-pot welding and does not require any special means for positioning the welding torch 7 apart from the positioning of the lower holding member 6a.

When using the jig of the present invention to arc-weld a joint portion (plate thickness 2.3 mm) of a building rebar, the pressing force between each holding member and the work is 20 kg. Is sufficient, does not require high pressure (about 1 ton) as in spot welding by resistance welding, does not require sufficient strength to reach the arm and other parts, and has a low cylinder capacity. Therefore, the jig can be made sufficiently small. Moreover, the weight of the jig can be suppressed to about 3 to 4 kg by making it from aluminum (the above resistance welding requires a large current transformer and reaches 500 kg).

Therefore, even in the case of automation by the welding robot, a small robot can be used, and an operator can directly operate the portable robot easily. Of course, it does not require a large current such as resistance welding, so it is possible to avoid operation failures due to voltage drops in peripheral equipment.

[0020]

[Effect of device]

 The arc spot welding jig of the present invention is configured as described above, and is used to hold the spot welded portion, which is a part of the work, by using the lower holding member and the work piece. Since the contact area of the contact surface is small, the contact interface can be sufficiently adhered, the infiltration of the molten metal into the contact interface can be well eliminated, and the work of the contact interface can be performed without correcting the work. Good arc spot welding without sticking.

After the lower holding member is positioned directly below the spot-welded portion of the work, the welding torch can be positioned at a predetermined position simply by closing the jig. Since the welding torch can be positioned by itself and the shaft is small and lightweight, the arc spot welding can be performed with good workability.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing an arc spot welding operation using the jig of the present invention.

[Explanation of symbols]

 1 Clamping mechanism 1a Lower arm 1b Upper arm 3 pin 4a Piston rod 4b Cylinder 6a Lower holding member 6b Upper holding member 7 Welding torch

Claims (1)

[Scope of utility model registration request] 1. A lower arm and an upper arm are assembled into a single mouthed picking mechanism, and one end of the lower arm on one mouth side of the mechanism is attached to the rear surface of the work to be welded. A lower holding member that abuts on the upper arm, and an upper holding member that abuts around the welded portion on the work surface side is attached to one end of the upper arm. An arc spot welding jig characterized by being installed facing inside.