JP2014184458A - Multi-point spot welding machine and welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-point spot welding machine which can achieve cost reduction and space saving.SOLUTION: Provided are a holding stage 1 which positions one side workpiece W1, a workpiece setting device 2 which positions and sets another side workpiece W2 on the one side workpiece W1, welding electrodes 3a, 3b which are mounted at each side of the holding stage 1 and the workpiece setting device 2 so that both workpieces face each other and are contact-held with a specified pressure at each point of plural welding points P on both workpieces and form a pair for each welding point P, and an electrification gun 4 which contacts to one side welding electrode 3a mounted at the workpiece setting device 2 side among the plural pairs of welding electrodes and electrifies to weld mutually both workpieces W1, W2 between the other side welding electrode 3b forming a pair with it. Regarding the electrification wiring, although a number of wiring corresponding to the number of welding points is needed in the other side welding electrode side, one wiring connecting to the electrification gun is enough in the one side welding electrode side.

Description

  The present invention relates to a multi-dot spot welding apparatus and a welding method suitable for continuous welding of a plurality of welding points when manufacturing plate-like vehicle parts and the like.

Conventionally, there has been a welding apparatus described in Patent Document 1 as this type of technology.
This is an advancing / retreating drive means that is configured to be able to advance / retreat the lower electrode and fix it at a predetermined advancing position when a plurality of sets of upper electrodes and lower electrodes are provided and sequentially welded to a plurality of welding points. Is a multi-spot welding apparatus.

Japanese Patent Laid-Open No. 05-305448

  However, in the above-described prior art, it is necessary to provide equipment such as a welding power supply wiring for the upper electrode for each of a plurality of welding points (positions). Increase.

  An object of the present invention is to provide a multi-dot spot welding apparatus and method capable of reducing equipment costs and saving space.

The said subject is solved by making the multi-dot spot welding apparatus and the welding method into the structure of each following aspect.
As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the present invention, and the technical features described in this specification and combinations thereof should not be construed as being limited to those described in the following sections. . In addition, when a plurality of items are described in one section, it is not always necessary to employ the plurality of items together, and it is also possible to take out only a part of the items and employ them.

  Of the following items, (1) is in claim 1, (2) is in claim 2, (3) is in claim 3, (4) is in claim 4, (5) The term corresponds to claim 5, and the term (6) corresponds to claim 6.

(1) A holding table for positioning and holding one workpiece, a workpiece setting device for holding and positioning the other workpiece on one workpiece on the holding table, and both positioned workpieces on both workpieces Welding provided in each side of the holding table and the work setting device so as to be opposed to each other at a predetermined pressing force at each point of the plurality of welding points, and to make a pair for each of the plurality of welding points The workpiece is brought into contact with one welding electrode provided on the work setting device side of the plurality of pairs of welding electrodes, and the two workpieces between the one welding electrode and the other welding electrode forming a pair are connected to each other. A multi-dot spot welding apparatus comprising: an energizing gun that energizes to weld a metal.
(2) In the item (1), the one welding electrode is provided with a guide member for guiding the energizing gun when the energizing gun is brought into contact with the one welding electrode. The multi-dot spot welding apparatus as described.
(3) A detection member that detects that the energization gun is guided by the guide member, and a predetermined addition between the detection electrode and the one welding electrode by detecting the energization gun by the detection member. And an actuator for driving the other welding electrode so that pressure is applied. The multi-dot spot welding apparatus according to (2),
(4) A multi-spot spot welding according to any one of (1) to (3), further comprising a robot for sequentially bringing the energizing gun into contact with the one welding electrode. apparatus.
(5) The welding electrode according to any one of (1) to (4), wherein each welding electrode includes a spring mechanism that follows contact with the workpiece in accordance with the shape of the workpiece. A multi-dot spot welding apparatus according to claim 1.
(6) The welding electrodes are arranged in pairs so that the pair of workpieces that are overlapped and positioned and set are opposed to each other at a plurality of welding points on both the workpieces with a predetermined pressing force. In addition, an energizing gun is sequentially brought into contact with the welding electrode on one side of each pair of welding electrodes, and the two workpieces between the welding electrode and the other welding electrode paired with the welding electrode are paired. A multi-dot spot welding method characterized by sequentially energizing and welding.

According to the invention described in the item (1), the number of welding points is required for the other welding electrode side for the energization wiring, but one welding electrode side is connected to the energization gun. Just do it. Therefore, the equipment cost can be reduced and the space can be saved as compared with the prior art that requires wiring for one welding electrode at each welding point.
According to the invention described in item (2), the energizing gun can be reliably brought into contact with the welding electrode.
According to the invention described in the item (3), there is no possibility of deterioration of the welding quality due to the diversion to the lower side welding electrode that is not used for welding.
According to the invention described in the item (4), the multi-spot spot welding can be performed efficiently and fully automated.
According to the invention as described in the item (5), it is possible to reduce the occurrence of the plate gap of the workpiece.
According to the invention as described in the item (6), it is possible to provide a multi-dot spot welding method capable of reducing the equipment cost and saving the space.

It is a figure which shows 1st Embodiment of the multi-dot spot welding apparatus with which the method of this invention was applied in a welding preparation state. It is a figure which shows 1st Embodiment same as the above in the state just before welding. It is a figure which shows 1st Embodiment same as the above in a welding operation state. It is a flowchart which shows the welding procedure by 1st Embodiment same as the above. It is a figure which shows 2nd Embodiment of the multi-dot spot welding apparatus with which the method of this invention was applied in a welding preparation state. It is a figure which shows 2nd Embodiment same as the above in the state just before welding. It is a figure which shows 2nd Embodiment same as the above in a welding operation state. It is a flowchart which shows the welding procedure by 2nd Embodiment same as the above. It is a top view which shows an example of the workpiece | work which has three or more welding points.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol shows the same or an equivalent part between each figure.
The multi-spot spot welding method according to the present invention is a method for performing multi-spot spot welding in the following order.
That is, a pair of workpieces to be welded are positioned and set in advance, and a pair of the above-mentioned set with a predetermined pressing force facing each point of a plurality of welding points on the set of workpieces. A pair of welding electrodes are arranged so as to sandwich the workpiece.
Then, an energizing gun is sequentially brought into contact with the welding electrode on one side of each pair of welding electrodes, and the above-described workpieces between the welding electrode paired with the welding electrode are paired with each other. This is a spot welding method of sequentially energizing and welding.

There are three important conditions for performing welding: pressurizing force, energizing current, and energizing time. In the prior art, these conditions are applied to the workpiece using only a pair of welding electrodes. In the method of the present invention, the functions are divided into a welding electrode in charge of the applied pressure and an energizing gun in charge of the energizing current and energizing time.
As a result, each welding point of the pair of workpieces is given a predetermined pressing force necessary for welding before welding (energization) by a pair of welding electrodes, and the energizing gun is welded on one side. What is necessary is just to contact an electrode. That is, it is not necessary to consider that the pressurization at the time of contact with the welding electrode on one side of the energizing gun is a predetermined pressurizing force necessary for welding.

According to this, wiring from the welding power supply device is required for the number of welding points for the welding electrode on the other side, but the welding electrode for one side is connected to the energizing gun regardless of the number of welding points. One to do is enough. Therefore, the equipment cost can be reduced and the space can be saved as compared with the prior art that requires wiring for the welding electrode on one side at each welding point.
Moreover, the energizing gun need only be brought into contact with the welding electrode on one side, and the pressurizing force required for welding is applied by a pair of welding electrodes. When the gun is held by a robot or the like, the reaction force applied to the robot or the like can be reduced.
Such an operational effect is common to the multi-spot spot welding apparatus described below to which the multi-spot spot welding method according to the present invention described above is applied.

1 to 3 are diagrams showing a first embodiment of a multi-dot spot welding apparatus to which the above-described method of the present invention is applied. FIG. 1 shows a welding preparation state, FIG. 2 shows a state immediately before welding, and FIG. Each welding operation state is shown. FIG. 4 is a flowchart showing a welding procedure in the first embodiment.
Hereinafter, with reference to FIGS. 1-4, the multi-dot spot welding apparatus which concerns on 1st Embodiment of this invention is demonstrated.
As shown in FIGS. 1 to 3, the first embodiment of the apparatus of the present invention includes a holding base 1, a work setting device 2, a pair of welding electrodes 3 and 3, a conduction gun 4 and a welding power supply device 5. Prepare.

The holding table 1 is a table for positioning and holding one of the placed workpieces (workpieces) W, here the lower workpiece W1.
The workpiece setting device 2 is a device that holds the other workpiece W, here the upper workpiece W2, and positions and sets it on the lower workpiece W1 on the holding table 1. In the illustrated example, the upper work W2 made of a steel plate is attracted and held mainly by the magnet 2a and the frame 2b.
Although not shown, the holding base 1 is provided with a proper number of positioning convex portions for the lower workpiece W1, and the lower workpiece W1 is provided with a suitable number of positioning holes. Further, the work set device 2 is provided with a proper number of positioning protrusions for the upper work W2, and the upper work W2 is provided with a suitable number of positioning holes. Then, by passing the positioning hole of the lower workpiece W1 through the positioning convex portion of the holding table 1 and passing the positioning hole of the upper workpiece W2 through the positioning convex portion of the work setting device 2, the lower workpiece W1 is passed. And the upper workpiece W2 is positioned.

The pair of welding electrodes 3 and 3 (upper side welding electrode 3a and lower side welding electrode 3b) are positioned and set, and the lower workpieces W2 and W1 are placed at the respective welding points P on the lower workpieces W2 and W1. It is provided on each side of the holding table 1 and the work setting device 2 so as to be able to be opposed and held with a predetermined pressing force, and forms a pair for each welding point P.
Each welding electrode 3a, 3b may be provided with a spring mechanism that follows the contact with the upper and lower workpieces W2, W1 in accordance with the shapes of the upper and lower workpieces W2, W1. According to this spring mechanism, it is possible to reduce the generation of the plate gap between the upper and lower workpieces W2, W1.
The welding electrode (upper side welding electrode) 3a on the work setting device 2 side is provided with a guide member 3c for guiding the energizing gun 4 when the energizing gun 4 is brought into contact with the upper side welding electrode 3a. ing. The guide member 3c is formed, for example, in a cylindrical shape coaxial with the upper-side welding electrode 3a, and is fixed to the rear end side of the upper-side welding electrode 3a, so that the energizing gun 4 can be inserted and removed.
Cooling water is circulated through the welding electrode (lower welding electrode) 3b on the holding table 1 side and can be cooled.

The energizing gun 4 is brought into contact with the welding electrode (upper side welding electrode) 3a on the work setting device 2 side of the plurality of pairs of welding electrodes 3a and 3b, and lower side welding which makes a pair with the upper side welding electrode 3a. This is a current-carrying tool that is energized to weld the upper and lower workpieces W2, W1 between the electrodes 3b. The energizing gun 4 includes a pressure detector 4a, a start switch 4b, and an energizing electrode 4c.
The welding power supply device 5 includes a welding power supply circuit 5a and a transformer 5b, and is a power supply device for supplying a welding power supply (current) between the upper and lower welding electrodes 3a and 3b.
A wiring 6a is provided between the welding power source device 5 and each lower-side welding electrode 3b. Further, a wiring 6 b is provided between the welding power supply device 5 and the energizing gun 4. As shown in the drawing, the number of wires 6a needs to be equal to the number of lower-side welding electrodes 3b, but the number of wires 6b is one regardless of the number of lower-side welding electrodes 3b.
Note that communication for welding control is possible between the energizing gun 4 and the welding power source device 5.

Next, a welding procedure using the first embodiment will be described with reference to FIG.
First, in step 401, the lower work W1 is positioned and held on the holding table 1. Thereby, lower work W2 contacts lower side welding electrode 3b.
In step 402, the upper work W2 is held mainly by the magnet 2a and the frame 2b of the work setting device 2, and the work setting device 2 is rotated as shown by the arrow a in FIG. 1 with the shaft portion 2c as a fulcrum. Then, the upper work W2 is positioned and set (clamped) on the lower work W1 on the holding table 1. By this clamp, a pressing force necessary for welding them is applied between the upper and lower workpieces W2, W1.
In step 403, the energizing gun 4 is brought into contact with the upper-side welding electrode 3a while being guided by the guide member 3c (see arrow B in FIG. 2). The contact of the energizing gun 4 with the upper welding electrode 3a may be performed by an operator or may be performed by moving the energizing gun 4 by a robot, for example, a 6-axis articulated robot. If the energizing gun 4 is moved by a robot, welding can be performed efficiently and full automation is possible.

In step 404, it is determined whether or not the energizing gun 4 is normally in contact with the upper-side welding electrode 3a. This determination is performed by a pressure detector 4 a provided in the energizing gun 4. If the applied pressure detector 4a detects an applied pressure of a certain value or more, it is determined that the energizing gun 4 is normally in contact with the upper-side welding electrode 3a. Since it is determined whether the contact is correct or not, the constant value is a slight value (necessary for welding given in the second embodiment to be described later, and the value of the applied pressure between the lower workpieces W2 and W1). Remarkably small). Step 404 is repeated until the determination result is YES.
In step 405, the determination result YES in step 404 is received and the ON operation of the start switch 4b is determined. Step 405 is repeated until the determination result is YES.

In step 406, welding power is supplied from the welding power source device 5 to the upper and lower workpieces W2, W1 (welding point P) through the upper and lower welding electrodes 3a, 3b. That is, a welding current is applied between the upper and lower workpieces W2 and W1 (welding point P), and the welding point P is spot-welded (see FIG. 3).
In step 407, the energizing gun 4 is detached from the upper welding electrode 3a. The detachment of the energizing gun 4 from the upper welding electrode 3a is performed by the operator when the operator performs step 403, and is performed by the robot when the robot performs.
In step 408, steps 403 to 407 are sequentially repeated for all the welding points P on the upper and lower workpieces W2 and W1 (two left and right in the first embodiment shown in FIGS. 1 to 3) to complete the welding.

In the first embodiment described above, the pair of welding electrodes 3a and 3b for applying the pressure necessary for welding between the upper and lower workpieces W2 and W1 by the workpiece setting device 2 are provided on the upper and lower workpieces W2 and W1. It arrange | positions at each welding point P. And wiring from one output terminal of the welding power supply device 5 is connected to one of each of the pair of welding electrodes 3a and 3b, here, each of the lower side welding electrodes 3b.
The wiring from the other output terminal of the welding power supply device 5 is connected only to the energizing gun 4, and this energizing gun 4 is moved to sequentially contact the upper side welding electrodes 3 a arranged at the respective welding points P, A welding current was passed between the upper and lower workpieces W2 and W1 through the side and lower side welding electrodes 3a and 3b, and the welding point P was spot welded.

According to this, since the wiring from the output terminal on one side of the welding power supply device 5 has only to be connected to the energizing gun 4, it is possible to reduce equipment costs and save space. Moreover, such reduction in equipment cost and space saving have the effect of increasing as the number of welding points P increases.
In particular, the pressure required for welding was given to the pair of welding electrodes 3a and 3b. According to this, the energizing gun 4 is released from the role of applying the necessary pressure during welding between the upper and lower workpieces W2 and W1 (welding point P), and is simply one welding electrode, here the upper side welding. What is necessary is just to contact the electrode 3a. Therefore, when the contact of the energizing gun 4 with the upper side welding electrode 3a is manually performed, it is possible to suppress the deterioration of the welding quality caused by the variation in the pressure applied to the upper side welding electrode 3a by the operator. Multi-point spot welding can be performed efficiently.
Further, when the energizing gun 4 is held by the robot, the reaction force applied to the robot can be reduced.

Next, a second embodiment will be described with reference to FIGS.
In the second embodiment, a cylinder 7a and a cylinder driving switch 3d are added to the configuration of the first embodiment.
In the second embodiment, the lower side welding electrode 3b rises only when welding by the lower side welding electrode 3b and comes into contact with the lower workpiece W1, and the upper side welding electrode 3a that makes a pair with the lower side welding electrode 3b; The upper and lower workpieces W2 and W1 positioned and set by the workpiece setting device 2 are clamped with a predetermined pressure and welded.
The work setting device 2 positions and sets the upper and lower workpieces W2 and W1 as described above, but does not apply the pressure necessary for welding. The lower side welding electrode 3b that is not actually used for welding does not rise, and the upper side welding electrode 3a paired with the lower side welding electrode 3b can contact the lower and upper workpieces W1, W1 and W1. Is not sandwiched with a predetermined pressure.

That is, as shown in FIGS. 5 to 7, the lower-side welding electrode 3 b is raised by a certain amount at a predetermined time by an actuator provided here, that is, a cylinder 7 a. The upper and lower workpieces W2 and W1 positioned and set by the workpiece setting device 2 are sandwiched between the opposing upper welding electrodes 3a with a predetermined pressure.
Only one cylinder 7a, and therefore only one lower welding electrode 3b raised by this cylinder 7a, contacts and pressurizes the lower workpiece W2. That is, there is no electrical connection between the left and right lower welding electrodes 3b, 3b.

The lower side welding electrode 3b is raised when the energizing gun 4 is brought into contact with the upper side welding electrode 3a facing the lower side welding electrode 3b. That is, the cylinder drive switch 3d that operates when the energization gun 4 is guided by the guide member 3c provided on the upper side welding electrode 3a and contacts the upper side welding electrode 3a (detects the energization gun 4) is turned on. As a result, the lower-side welding electrode 3b rises. When the welded point P of the lower workpieces W2 and W1 is welded after being sandwiched by the raised lower side welding electrode 3b and the upper side welding electrode 3a opposed thereto with a predetermined pressure, the lower side welding electrode 3b is The cylinder 7a moves down with the returning operation and returns to the standby position.
Here, the cylinder driving switch 3d is provided on the guide member 3c. When the guide member 3c is formed in a cylindrical shape as described above and a limit switch is used as the cylinder driving switch 3d, the operating end of the limit switch protrudes from the inner wall of the guide member 3c toward the axis. The limit switch is configured to be turned on / off in accordance with the insertion / removal of the energizing gun 4.

The welding procedure using the second embodiment will be described with reference to FIG.
First, in step 801, the lower work W1 is positioned and held on the holding table 1. At this time, the lower-side welding electrode 3b is not in contact with the lower workpiece W1.
In Step 802, the upper work W2 is held mainly by the magnet 2a and the frame body 2b of the work setting device 2, and the work setting device 2 is rotated as indicated by an arrow A in FIG. 1 with the shaft portion 2c as a fulcrum. Then, the upper work W2 is positioned and set (clamped) on the lower work W1 on the holding table 1. Unlike the first embodiment, this clamp does not apply the pressure required for welding between the upper and lower workpieces W2, W1.
In step 803, the energizing gun 4 is brought into contact with the upper welding electrode 3a while being guided by the guide member 3c (see arrow B in FIG. 6). The contact of the energizing gun 4 with the upper welding electrode 3a may be performed by an operator or may be performed by moving the energizing gun 4 by a robot, for example, a 6-axis articulated robot. If the energizing gun 4 is moved by a robot, welding can be performed efficiently and full automation is possible.

In step 804, it is determined whether or not the cylinder drive switch 3d that detects contact of the energizing gun 4 with the upper welding electrode 3a is ON. Step 804 is repeated until the determination result is YES.
If the decision result in the step 804 becomes YES, a step 805 is executed.
In step 805, the cylinder 7a provided at the lower part of the lower-side welding electrode 3b facing the upper-side welding electrode 3a in which the contact of the energizing gun 4 is detected is actuated to raise the lower-side welding electrode 3b by a certain amount, A welding pressure is applied between the upper and lower workpieces W2, W1.
The cylinder 7a which operates is only one cylinder 7a which raises the lower side welding electrode 3b opposite to the upper side welding electrode 3a where the contact of the energizing gun 4 is detected. The other cylinder 7a does not operate, and the lower welding electrode 3b raised by the other cylinder 7a does not contact the lower workpiece W1.
In step 806, it is determined whether the applied pressure has reached a predetermined value (a predetermined applied pressure necessary for welding). This determination is performed by a pressure detector 4 a provided in the energizing gun 4. This step 806 is repeated until the determination result is YES.
In step 807, the determination result YES in step 806 is received and the ON operation of the start switch 4b is determined. Step 807 is repeated until the determination result is YES.

In step 808, welding power is supplied from the welding power source device 5 to the upper and lower workpieces W2, W1 (welding point P) through the upper and lower welding electrodes 3a, 3b. That is, a welding current is passed between the upper and lower workpieces W2 and W1 (welding point P), and the welding point P is spot-welded (see FIG. 7).
In step 809, the energizing gun 4 is detached from the upper welding electrode 3a. The detachment of the energizing gun 4 from the upper side welding electrode 3a is performed by the operator when the operator performs step 803, and is performed by the robot when the robot performs.
In step 810, the cylinder 7a is operated to lower the lower welding electrode 3b and return to the standby position.
In step 811, steps 803 to 810 are sequentially repeated for all the welding points P on the upper and lower workpieces W2 and W1 (two left and right in the second embodiment shown in FIGS. 5 to 7) to complete the welding.

According to the second embodiment described above, in addition to the same effects as the first embodiment, the following effects are obtained.
That is, in the second embodiment, only one cylinder 7a, and therefore, only one lower-side welding electrode 3b raised by this cylinder 7a contacts and pressurizes the lower workpiece W1. That is, there is no electrical connection between the left and right lower welding electrodes 3b, 3b.
In the first embodiment, the left and right lower welding electrodes 3b, 3b are electrically connected during welding. Therefore, in particular, when the distance between the left and right welding points P, P, that is, the distance between the lower welding electrodes 3b, 3b is short, current flows to the lower welding electrode 3b side that is not used for welding during welding ( (Diversion may occur).
In the second embodiment, there is no fear of this, and there is no possibility of deterioration of the welding quality due to the diversion to the lower side welding electrode 3b that is not used for welding. In addition, the cylinder 7a can apply a pressing force to the welding point P, so that it is possible to avoid the generation of a plate gap due to insufficient pressing force at the time of clamping a thick plate component or the like, thereby reducing the welding quality. Can be prevented.

  In the above-described embodiment (FIGS. 1 to 3 and FIGS. 5 to 7), the case where there are two welding points P has been described. However, the present invention has three welding points P as shown in FIG. It can also be applied to spot welding at more than one spot. The effect of the present invention increases as the number of welding points P increases.

As the cylinder driving switch 3d in the second embodiment (FIGS. 5 to 7), in addition to a mechanical switch such as a limit switch, a minute voltage is applied between the energizing gun 4 and the ground to change the voltage. The electrical switch to be used can be used. The welding conditions (pressing force, energizing current, energizing time, etc.) may be switched for each cylinder driving switch 3d (for each welding point P). According to this, different welding conditions are set for each welding point P. The welding quality can be improved.
When the energizing gun 4 is provided to, for example, a 6-axis articulated robot, the position (coordinates) of the energizing gun 4 is grasped by the robot itself. Accordingly, if the cylinder driving switch 3d is turned on when the robot itself recognizes the position where the energizing electrode 4c contacts the upper welding electrode 3a, the cylinder driving switch 3d can be omitted.

  DESCRIPTION OF SYMBOLS 1: Holding stand, 2: Work setting apparatus, 3: Welding electrode, 3a: Upper side welding electrode, 3b: Lower side welding electrode, 3c: Guide member, 3d: Cylinder drive switch (detection member), 4: For electricity supply Gun, 5; power supply device for welding, 7a: cylinder (actuator), W: workpiece, W1: lower workpiece (one workpiece), W2: upper workpiece (the other workpiece), P: welding point.

Claims (6)

A holding base for positioning and holding one workpiece;
A work setting device for holding and positioning the other work on one work on the holding table;
Provided on each side of the holding table and the work setting device so as to oppose and clamp the two workpieces that have been positioned and set at a predetermined pressing force at each of a plurality of welding points on both workpieces, A welding electrode paired for each of the plurality of welding points;
One of the plurality of pairs of welding electrodes is brought into contact with one welding electrode provided on the work setting device side, and the two workpieces between the welding electrode paired with the other welding electrode are welded to each other. An energizing gun to energize for
A multi-dot spot welding apparatus comprising:   2. The multi-dot according to claim 1, wherein the one welding electrode is provided with a guide member that guides the energizing gun when the energizing gun is brought into contact with the one welding electrode. Spot welding equipment. A detection member for detecting that the energizing gun is guided by the guide member;
An actuator that drives the other welding electrode so that a predetermined pressing force is applied between the welding electrode and the one welding electrode by detecting the energization gun by the detection member;
The multi-dot spot welding apparatus according to claim 2, comprising:   The multi-dot spot welding apparatus according to any one of claims 1 to 3, further comprising a robot for sequentially bringing the energizing gun into contact with the one welding electrode.   The multi-spot spot according to any one of claims 1 to 4, wherein each welding electrode includes a spring mechanism that follows contact with the workpiece in accordance with the shape of the workpiece. Welding equipment. The welding electrodes are arranged in pairs so that the pair of workpieces that are superimposed and positioned and set are opposed to each other at a plurality of welding points on both the workpieces with a predetermined pressing force. To one side of each pair of welding electrodes,
A multi-spot spot welding method comprising sequentially bringing a current-carrying gun into contact with each other and sequentially welding between the workpieces between one welding electrode and the other welding electrode.

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