JP2013078772A - Spot welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spot welding method in which an operator can mount huge substances to be welded on a long plate-like base table and can easily and continuously weld many spot welding positions present in longitudinal faces of the substances to be welded by operation of a push button with good operation efficiency.SOLUTION: The spot welding method is constituted of the plate-like base table for mounting the substances to be welded, a gun body part for welding the longitudinal face of abutting part of two large substances to be welded with a folded-shape, a gun frame part for supporting the gun body part, and a gun travelling part for laterally moving the gun body part and the gun frame part. Electric wiring by a cable is eliminated, and further a drive motor and a rack are arranged, whereby the operator can automatically move the gun body part by the operation of the button.

Description

  The present invention relates to a spot welding method, and more specifically, proposes a spot welding method in which a worker vertically welds a longitudinal surface of a large workpiece to be welded with a welding gun.

  Conventionally, spot welding has been used for joining various metal plates, in which two workpieces are stacked, sandwiched between two electrodes, and pressurized and energized for welding, such as automobiles and railway vehicles. 2. Description of the Related Art For spot welding of workpieces, a method in which an operator manually welds a welding gun called a portable gun has been widely used.

  However, in many cases, a device called a portable gun is integrally formed of an electrode portion, an air cylinder that pressurizes an object to be welded, and a welding transformer, and the entire portable gun becomes large and has a considerable weight. Therefore, the operator operates the portable gun by reducing the weight of the heavy portable gun by using a hoist or balancer to hang it from the ceiling of the equipment. In addition, the electric wires required for energization make the operation of the suspended portable gun more difficult, and the movement and welding of the portable gun when welding several welding points is a very heavy and time-consuming work. It has become.

  Patent Documents 1 and 2 are conventional examples in which a welding gun called a portable gun is suspended and an operator manually welds a huge workpiece.

  This portable gun is roughly classified into a type in which a welding transformer is separated (Patent Document 3) and an integrated type (Patent Document 4), but each has the following problems.

  In the case of the separated type, the welding transformer is installed elsewhere. Therefore, while the portable gun becomes compact, it is necessary to energize the portable gun from the welding transformer via the conductive cable. This conductive cable on the secondary side of the welding transformer is also called a water-cooled cable, which is composed of a thin copper wire, and the cooling water circulates in the cable, so it has a diameter of about 40 mm and is heavy and highly rigid. It has become. Therefore, it is difficult to operate a suspended portable gun. In addition, the copper wire of the cable may be disconnected due to repeated use over time, and the conductive cable is a consumable item.

  In the case of the integral type, since it is constructed integrally with the welding transformer, the portable gun itself becomes large and has a considerable weight. In addition, a primary electric wire to the welding transformer is also required, which makes it difficult to operate the suspended portable gun.

JP 2010-58153 A JP 09-29448 A Japanese Patent Laid-Open No. 06-142940 Japanese Patent Laid-Open No. 06-190563

  As shown in Fig. 3, even if there are many welds on the vertical surface of the butt of two large bent workpieces as shown in Fig. 3, spot welding is easy to operate and efficient. The problem is to propose a law.

The present invention solves the above problems by the following configuration.
<Configuration 1>
A plate-like base for placing the workpiece, a gun main body for welding the vertical surfaces of the butted portions of the two large workpieces to be bent,
A gun frame that supports the gun body;
Consists of a gun traveling unit that laterally moves the gun body and the gun frame,
The gun body part is a thrust electrode in which a welding tip sandwiches and pressurizes the object to be welded by the operation of an air cylinder disposed, and the energization from the gun part conductor is applied to the through shaft and the side pressure of the leaf spring; A spot welding method comprising a gun tip conductor and a plurality of insulators, and energizing the welding tip attached to the gun tip conductor.

<Configuration 2>
The gun frame portion is equipped with a plurality of plate-like conductors called bus bars,
Two flexible conductors connected to this plate-like conductor are:
The operation of the air cylinders arranged in each of them makes contact with and away from the conductive pipe of the gun traveling part,
The gun frame portion travels in a state where the flexible conductor and the conductive pipe are separated from each other,
The spot according to Configuration 1, wherein a welding current energized from a welding transformer through a connection copper plate is pressed while being pressed by the operation of the air cylinder and dropped from the conductive pipe onto the flexible conductor. Welding method.

<Configuration 3>
The gun traveling part is composed of two conductive pipes through which cooling water circulates, a rack arranged in parallel to the conductive pipes, and a linear motion guide, and a gear of a drive motor provided in the gun frame part. The lateral movement of the gun body and the gun frame automatically runs,
2. The spot welding method according to Configuration 1, wherein spot welding points of the workpiece are continuously formed.

  The present invention is a spot welding method in which an object to be welded is placed on a plate-shaped base, the object to be welded is sandwiched between welding guns, and energized under pressure, and is welded with a plurality of vertical spots on the object to be welded. At the welding location, it is possible to perform welding with high work efficiency, in which the welding gun can be automatically moved laterally and continuously welded by operating the push button while the work piece is placed. Further, it is possible to eliminate the conductive cables and the electric wiring of the welding gun, which are consumables, necessary for the portable gun.

It is a perspective view which shows the whole Example 1 of the spot welding method which concerns on this invention. It is a right view of FIG. 1 (Example 1). They are the perspective view (a) of the example of the big to-be-welded object which carries out the spot welding, and sectional drawing (b) of two butt | matching parts. (A) is a perspective view, (b) is an enlarged view of the right side surface, (c) is a cross-sectional view taken along the line A-A in FIG. It is sectional drawing which shows the cooling structure of a conductor (9) and a welding tip (8). (A) is explanatory drawing of the gun frame part of Example 1, (b) shows the state which the flexible conductor (19) and the conductive pipe (22) spaced apart at the time of lateral movement. It is explanatory drawing of the gun driving | running | working part of Example 1. FIG.

  1 to 6 show an example of a spot welding method according to the present invention and an example of an object to be welded. The embodiment is a spot welding method including a gun main body portion, a gun frame portion, and a gun traveling portion for spot welding the longitudinal surfaces of two workpieces.

  The embodiment will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the whole of the first embodiment of the spot welding method of the present invention, and FIG. 2 is a right side view of FIG.
As shown in FIGS. 1 and 2, the spot welder (1) according to the first embodiment of the present invention has a long plate-like base (30) that is a large work piece (W) having a large number of welds on the vertical surface. Place. A gun body (4), a gun frame (5), and a gun traveling part (6) are provided. The gun body (4) is a bent surface of the work piece (W), that is, a longitudinal surface. A large number of spot welds are continuously welded.

A work procedure in the apparatus according to the first embodiment of the present invention will be specifically described.
First, an object to be welded (W) as shown in FIG. 3 having a large number of welding points on the vertical surface is placed on the plate-like base (30).

Next, the operator moves the gun body (4) laterally to a predetermined welding location on the vertical surface of the workpiece (W). The lateral movement of the gun body (4) is performed with a push button on the operation panel (34) (not shown). The gun body (4) is connected to the gun frame (5) and is automatically operated by the operation of the rack (20) disposed in the gun traveling part (6) and the drive motor (15) provided in the gun frame (5). You can move horizontally from side to side.
In order to reduce the weight of the gun body (4), a welding transformer is installed on the back of the apparatus, and the current sent via the plurality of plate conductors (14) is shown in FIG. By using the gun tip conductor (9) and sending it to the welding tip (8), a thick and highly rigid conductive cable and electric wiring are eliminated, and automatic lateral movement is facilitated. As shown in FIG. 4 (c), the current-carrying structure of the gun body (4) is a through shaft (26), and a thin cylindrical thrust electrode (11), gun tip conductor (9), etc. are integrated into a resin washer. The two poles are separated by an insulator (24, 25) and the like, and a lateral pressure is applied by a leaf spring (13), thereby improving the conductivity from the gun part conductor (10). In the embodiment of FIG. 4 (c), the thrust electrode (11) is composed of four pieces, and is fixed to the side surfaces of the gun tip conductor (9) and the gun section conductor (10) with a flat head screw. In addition, the slidability of rotation is improved, and pressurization and energization in gripping the workpiece (W) by opening and closing the welding tip (8) are ensured.

  In vertical spot welding, the operator determines the left and right positions of the gun body (4) by operating the push button, and when the welding switch is turned on, the air cylinder (12) of the gun body (4) is activated. Then, when the work piece (W) is sandwiched and pressed by the welding tip (8) of the gun body (4), the current under the welding conditions registered in the control unit is dropped, and the welding is completed at one point. .

The current path to the work piece (W) is from two conductive pipes (22) connected to each electrode of a welding transformer (33) disposed on the back of the apparatus via connection copper plates (17, 18). Through the two flexible conductors (19) called ounce copper plates as shown in FIG. 5, the plate-like conductor (14) and thrust electrode (11) each called a plurality of bus bars, each having a different polarity. After that, flow spot welding is performed to the workpiece (W) sandwiched between the pair of welding tips (8) attached to each gun tip conductor (9). The welding tip (8) normally prevents heat generation during welding by circulating the cooling water. Similarly, as shown in FIG. 4 (d), the welding tip (8) is connected via the gun tip conductor (9). ) Is used to prevent heat generation. Further, the energization here eliminates a thick and highly rigid conductive cable and electric wiring, and therefore, it is easy to move sideways automatically. Furthermore, each of the two flexible conductors (19) is equipped with an air cylinder (16), which is brought into contact with and separated from the conductive pipe (22) of the gun traveling part (6) by the operation of the air cylinder (16). As shown in FIG. 5B, the gap H is generated and the flexible conductor (19) and the conductive pipe (22) are separated from each other. When the welding current is dropped, the pressure applied by the air cylinder (16) is applied. It is comprised so that it may contact | abut. In the first embodiment, as shown in FIGS. 2 and 6, a linear motion guide (21) is used for the movement in the left-right direction so that the lateral movement can be performed smoothly.
Next, the operator again operates the push button, repeats the above-described operation, and continuously performs spot welding on the vertical surface.

With respect to the various shapes of the work piece (W), especially in the shape where the side surface perpendicular to the vertical surface to be welded is bent, insertion of the vertical surface to be welded to the gun main body (4), that is, the setting property It is considered that there are many problems that cannot be dealt with only by the above-described contents of the present invention.
Therefore, although not shown, if the following countermeasures are taken, it is possible to deal with various shapes of the workpiece (W) and the problem is solved.

In the case where the side surface of the workpiece (W) is not bent as in the case of FIG. 3, the gun main body (4) is simply moved laterally, and the vertical surface to be spot-welded is the same as that of the gun main body (4). There is no problem because it is sandwiched between the two welding tips (8). However, if the gun body (4) is outside the side bend in a shape with side bends, lateral movement inward is difficult and cannot be inserted. Therefore, as a countermeasure, if any one of a mechanism for raising and lowering the gun body (4) or a mechanism for raising and lowering the plate base (30) is employed, the side surface of the workpiece (W) is bent. The gun main body (4) can be moved laterally without interference and the problem of insertion is solved.
In addition, when a large number of vertical surface positions to be spot welded in various shapes of the workpiece (W) are generated in the front-rear direction, the position of the vertical surface to be spot welded with the gun body (4) is not variable. It is not possible to cope with fixing only the place. Therefore, as a countermeasure, there is a mechanism in which the gun frame part (5) coupled to the tip of the gun body part (4) has a mechanism that moves back and forth, or a mechanism in which the plate base (30) slides back and forth. If you have one, or adopt one of these methods, the problem is solved.
Furthermore, according to the size or shape of the product, that is, the work piece (W), the above countermeasures may be selected to set the specifications of the apparatus. In addition, if the countermeasure is added to the present invention, an apparatus using the present invention that can cope with various shapes of workpieces (W) is completed.

  The welding gun can be moved automatically by pressing the button on the operation panel for spot welding of the bent vertical surface of a large workpiece that is mainly bent. Therefore, it can be used as a welding method that can be easily performed continuously with a welding gun without a cable. In addition, there is no need for conductive cables and electrical wiring, which are consumables associated with portable guns, and durability can be improved.

1 Spot Welder 4 Gun Main Body 5 Gun Frame 6 Gun Traveling 7 Cooling Water Passage
DESCRIPTION OF SYMBOLS 8 Welding tip 9 Gun tip conductor 10 Gun part conductor 11 Thrust electrode 12 Air cylinder 13 Leaf spring 14 Plate-like conductor 15 Drive motor 16 Air cylinder 17 Connection copper plate 18 Connection copper plate 19 Flexible conductor (ounce copper plate)
20 rack 21 linear motion guide 22 conductive pipe 23 gear 24 insulator 25 insulator 26 penetrating shaft
30 Plate Base 33 Welding Transformer 34 Operation Panel 41 Mounting Base H Gap W Workpiece

Claims (3)

A plate-like base for placing the workpiece, a gun main body for welding the vertical surfaces of the butted portions of the two large workpieces to be bent,
A gun frame that supports the gun body;
Consists of a gun traveling unit that laterally moves the gun body and the gun frame,
The gun body part is a thrust electrode in which a welding tip sandwiches and pressurizes the object to be welded by the operation of an air cylinder disposed, and the energization from the gun part conductor is applied to the through shaft and the side pressure of the leaf spring; A spot welding method comprising a gun tip conductor and a plurality of insulators, and energizing the welding tip attached to the gun tip conductor. The gun frame portion is equipped with a plurality of plate-like conductors,
Two flexible conductors connected to this plate-like conductor are:
The operation of the air cylinders arranged in each of them makes contact with and away from the conductive pipe of the gun traveling part,
The gun frame portion travels with the flexible conductor and the conductive pipe separated from each other,
The welding current energized from the welding transformer through the connection copper plate is brought into contact while being pressurized by the operation of the air cylinder, and dropped from the conductive pipe onto the flexible conductor. Spot welding method. The gun traveling part is composed of two conductive pipes through which cooling water circulates, a rack arranged in parallel to the conductive pipes, and a linear motion guide, and a gun of a drive motor mounted on the gun frame part. The body part and the gun frame part automatically move laterally,
The spot welding method according to claim 1, wherein spot welding portions of the workpiece are continuously formed.