KR20160057763A - Spot welding device - Google Patents

Abstract

Disclosed is a spot welding device. According to the embodiment of the present invention, the spot welding device comprises: a fixing frame integrally having a mounting unit mounted on an arm of a robot, and a mounting plate formed on an opposite side of the mounting unit; a moving welder installed in front of the mounting plate, enabling a moving electrode to reciprocate toward an object to be welded by moving forwards and backwards; an equalizing unit connecting the moving welder and the mounting plate between the moving welder and the mounting plate, formed to reciprocate in front of the mounting plate to provide a pressure in a reverse direction of the weight of the spot welding device in accordance with a position of the moving welder; a valve terminal remote mounted on one side of the fixing frame between the mounting unit and the mounting plate to control an operation pressure supplied to the equalizing unit, and connected to the equalizing unit; and a fixed welder mounted on one side of the lower part of the moving welder by a connection frame. The spot welding device increases a producing speed and improves welding quality. The spot welding device also minimizes an external force applied to a panel when the moving welder comes in contact with the panel.

Description

[0001] SPOT WELDING DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding apparatus, and more particularly, to a spot welding apparatus that adjusts a pressure in a reverse direction of a moving welder according to a position at which a welding operation is performed, And to improve the quality of welding and increase the production speed.

BACKGROUND ART [0002] Generally, during the manufacturing process of an automobile, various structural parts such as a body panel formed by a press are joined together by welding or the like to complete an entire body.

Here, spot welding is often used as a method of welding two sheets of steel sheets formed through press forming. Such spot welding forms an electrical resistance by energizing while providing a pressing force to the surface of the steel sheet, Electric resistance welding.

A spot welding apparatus is applied for such spot resistance welding. The spot welding apparatus is mainly composed of a bidirectional spot welding apparatus comprising a pair of movable electrodes for pressing a base material together with a fixed electrode, and a bi- Welding equipment.

Of these, the bidirectional spot welding apparatus joins body parts composed of two panels, such as a roof, a pillar, a side panel, and an opening flange of a bodywork door.

Fig. 6 is a perspective view of a general spot welding robotic system, and Fig. 7 is a perspective view of a spot welding gun according to the prior art.

Referring to FIG. 6, the spot welding apparatus is a C-type spot welding apparatus installed at the tip of the arm 3 of the spot welding robot 1 in such a manner that the spot welding apparatus is welded by electric resistance while applying a pressing force to the surface of the vehicle body panel. (5).

7, the spot welding gun 5 includes a lower electrode 13 and an upper electrode 15 on a C-type gun body 11, And is connected to a driving cylinder 17 provided at one side of the upper portion of the body 11 and providing a pressing force.

The spot welding gun 5 is positioned at the welding position according to the behavior of the robot 1 in a state where the gun body 11 is mounted on the arm 3 of the robot 1 through the installation frame 19 The spot welding is performed on the workpiece by the operation of the drive cylinder 17. [

Particularly, such spot resistance welding is performed by the robot 1 at the first time in order to automatically and repeatedly weld the spot welding gun 5 to the new welding spot with the spot welding gun 5 attached thereto, The welding position and welding angle of the spot welding gun 5 are determined, and the robot 1 is programmed by setting its welding position and angle.

However, in the conventional spot welding gun 5, the upper electrode 13 is reciprocally moved toward the lower electrode 15 according to the operation of the driving cylinder 17, and the panel is welded. At this time, 13) is contacted with the panel, an external force is exerted by an excessive pressure, so that the panel is damaged and the welding quality is deteriorated.

In addition, when the reciprocating speed of the drive cylinder 17 is slowed to prevent damage to the panel, the overall welding speed of the spot welding gun 5 is lowered, thereby lowering the productivity.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a welding machine capable of adjusting the pressure in the reverse direction of the weight of the moving welding machine, And to provide a spot welding apparatus which minimizes an external force exerted on the panel when the panel is brought into contact with the moving welder which is reciprocated forward and backward toward the gun, thereby improving the welding quality and the production speed.

According to an aspect of the present invention, there is provided a spot welding apparatus comprising: a fixed frame integrally formed with an arm mounted on an arm of a robot and having a mounting plate formed on an opposite side of the mounting portion; A moving welder disposed in front of the mounting plate and reciprocating the moving electrode toward the object to be welded through forward and backward movement; An equalizing mechanism configured to reciprocally move forward of the mounting plate to interconnect the moving welder and the mounting plate between the moving welder and the mounting plate and to provide a pressure in a direction opposite to the self weight of the moving welder, unit; A valve terminal remote mounted on one side of the fixing frame between the mounting portion and the mounting plate to adjust an operating pressure supplied to the equalizing unit and connected to the equalizing unit; And a stationary welder mounted on a lower side of the moving welder through a connecting frame.

The equalizing unit including an actuating rod, an equalizing cylinder mounted on an upper side of the front of the mounting plate; And an equalizer rod connected to an upper end of the actuating rod at a lower portion of the equalizing cylinder and reciprocally mounted in front of the mounting plate, the moving welder being mounted in front of the equalizing rod.

The equalizing cylinder is connected to the valve terminal remotely operated according to the control signal of the controller through a connection pipe, and can be operated by receiving operating pressure through the valve terminal remotely.

The valve terminal remote may adjust the supply amount of the operating pressure supplied from the operating pressure supply to supply the equalizing cylinder.

The equalizing cylinder may be a pneumatic cylinder using its operating pressure as pneumatic pressure.

The equalizer rod may be formed in a rectangular plate shape whose upper and lower lengths are longer than the left and right widths, and the rear side may be connected to one side of the lower portion of the mounting plate through a guide means.

Wherein the guide means comprises at least one guide rail mounted longitudinally in front of the mounting plate; And at least one rail block slidably mounted on the guide rail and connected to the rear of the equalizer rod.

The moving welder may be connected to the equalizing unit through a moving block which is configured to reciprocally move in the screw axis with the moving electrode provided in the moving welder.

The pressure actuator may comprise a roller screw actuator for converting the rotational torque of the driving motor into linear motion through the screw shaft.

Wherein the fixed welding machine comprises: a connection arm having one end connected to the other end of the connection frame, the connection arm having one end connected to a lower side of the pressure actuator; And a fixed electrode mounted on the other end of the connection arm at a position corresponding to the moving electrode.

A transformer is mounted between the mounting portion and the mounting plate, and a lower portion of the transformer is provided with a bus bar and a shunt for passing current through the moving welding machine and the fixed welding machine.

Wherein the equalizing unit adjusts the position of the moving welding gun to adjust a teaching error of each welding tip when a distance between the welding tips is increased by a dressing operation of a welding tip mounted on the moving welding machine and the fixed welding machine, You can compensate.

The mounting plate may be mounted with an angle sensor at a rear end thereof.

As described above, according to the spot welding apparatus according to the embodiment of the present invention, the pressure can be adjusted in the reverse direction of the moving welding machine according to the position where the welding operation is performed, It is possible to minimize the external force applied to the panel when the panel contacts the moving welder, thereby preventing the panel from being damaged and improving the welding quality.

In addition, the amount of pressure is adjusted in the reverse direction of the moving welder's own weight according to the moving speed of the moving welding gun, and when the welding tip is worn, the position of the moving welding gun is changed by performing equalization according to the change in distance between the welding tips due to the welding tip dressing The welding operation can be performed by compensating the teaching error of the welding tips, thereby improving the welding speed, increasing the overall production speed, and improving the productivity.

1 is a perspective view of a spot welding apparatus according to an embodiment of the present invention.
2 is a view showing an operation direction of the equalizing unit when a difference in distance between respective welding tips according to the welding tip dressing occurs in the spot welding apparatus according to the embodiment of the present invention.
3 to 5 are views showing the operation of the equalizing unit according to the welding direction in the spot welding apparatus according to the embodiment of the present invention.
6 is a perspective view of a general robot system for spot welding.
7 is a perspective view of a spot welding gun according to the prior art.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, It should be understood that various equivalents and modifications may be present.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

And throughout the specification, when an element is referred to as " comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

It should be noted that terms such as " ... unit ", " unit of means ", " part of item ", " absence of member ", and the like denote a unit of a comprehensive constitution having at least one function or operation it means.

1 is a perspective view of a spot welding apparatus according to an embodiment of the present invention.

1, a spot welding apparatus 100 according to an embodiment of the present invention includes a fixed frame 110, a moving welder 120, an equalizing unit 130, a valve terminal remote 140, and a fixed And a welder (150).

The stationary frame 110 is integrally formed with a mounting portion 111 mounted on the end of the arm A of the robot R and a mounting plate 113 is integrally formed on the opposite side of the mounting portion 111.

In the present embodiment, the moving welder 120 is disposed in front of the mounting plate 113, and reciprocates the moving electrode 121 toward the welding object through forward and backward movement.

The moving welder 120 is configured such that the pressing actuator 123 mounted on the equalizing unit 130 is movable between a moving electrode 121 provided in the moving welder 120 and a moving block (Not shown).

Here, the pressing actuator 123 is constituted by a roller screw actuator that converts the rotational torque of the driving motor 127 into linear motion through the screw shaft 125.

The roller screw actuator has a structure in which the nut-shaped moving block 127, which is threaded to the threaded portion of the screw shaft 125, moves back and forth while the screw shaft 125 directly connected to the driving shaft of the driving motor 129 is rotated by the motor driving force The configuration of the roller screw actuator, which can be applied as the pressure actuator 123, is a well-known configuration widely used in industry, and thus a detailed description thereof will be omitted.

Here, the driving motor 129 may be a servo motor capable of adjusting the rotational speed and the rotational direction thereof.

That is, the pushing actuator 123 reciprocates the moving electrode 121 forward and backward while the moving block 127 moves forward or backward along the screw shaft 125 during operation.

In this embodiment, the equalizing unit 130 interconnects the moving welder 120 and the mounting plate 113 between the moving welder 120 and the mounting plate 113.

The equalizing unit 130 is configured to be reciprocatable in front of the mounting plate 113 so as to provide a pressure in a direction opposite to the self weight according to the position of the moving welder 120.

The valve terminal remote 140 is mounted on one side of the fixing frame 110 between the mounting portion 111 and the mounting plate 111 to adjust an operating pressure supplied to the equalizing unit 130, Unit 130 is connected.

Here, the equalizing unit 130 includes an equalizing cylinder 131 and an equalizer rod 133.

The equalizing cylinder 131 includes an actuating rod, and the actuating rod is mounted downward from the front of the mounting plate 111 toward the bottom of the mounting plate 113, with reference to FIG.

The equalizing cylinder 131 is composed of a pneumatic cylinder using the operating pressure thereof and connected to the valve terminal remotely 140 which operates in accordance with the control signal of the controller C through a connection pipe 141 to be operated The pressure can be supplied.

The valve terminal remote 140 adjusts the operating pressure supplied from the operating pressure supplier 160 and supplies the operating pressure to the equalizing cylinder 131.

The equalizer rod 133 is connected at the lower end of the equalizing cylinder 131 to an end of the operation rod of the equalizing cylinder 131 and is mounted so as to be reciprocatable in front of the mounting plate 113, A pressing actuator 123 of the moving welder 120 is mounted.

Here, the equalizer rod 133 may be formed in a rectangular plate shape having a longer length than the left and right width, and the rear side may be connected to one side of the lower portion of the mounting plate 113 through the guide unit 135.

The guide means 135 includes a pair of guide rails 137 mounted on the front sides of the mounting plate 113 along the longitudinal direction and slidably mounted on the respective guide rails 137, And at least one or more rail blocks 139 connected to the rear of the equalizer rod 133.

These rail blocks 139 may be connected to the equalizer rod 133 by two on a single guide rail 137.

That is, when the equalizer rod 133 is moved to the upper portion or the lower portion of the mounting plate 113 by the operation of the equalizer cylinder 131, the guide unit 135 having the above- And is slidably moved along the guide rails 137, thereby stably guiding the movement of the equalizer rod 133.

The equalizing unit 130 configured as described above is configured such that when the welding object is welded, the equalizing cylinder 131 operates the equalizer rod 133 in a direction opposite to the self-weight direction according to the position of the moving welder 120, 120 are brought into contact with the surface of the object to be welded, the external force is minimized.

The fixed welder 150 is mounted on a lower side of the pressurizing actuator 123 of the moving welder 120 through a connection frame 151.

The stationary welder 150 includes a connection arm 153 having one end connected to the other end of the connection frame 151 having one end connected to one side of the lower portion of the pressure actuator 123, And a fixed electrode 155 mounted on the other end of the connection arm 153 at a position where the connection arm 153 is positioned.

The movable electrode 121 and the fixed electrode 153 may be mounted with a welding tip T at the tip thereof.

In the present embodiment, the stationary frame 110 is mounted with a transformer 170 between the mounting portion 111 and the mounting plate 112, and the moving welder 120 And a booster bar 171 and a shunt 173 for passing current through the fixed welder 130. [

The mounting plate 113 may be mounted with an angle sensor 180 at a rear end opposite to the equalizing unit 130 and the angle sensor 180 may be connected to the controller C. [

The angle sensor 180 detects the angle of the moving welder 120 and outputs a detection signal to the controller C during the welding operation of the spot welding apparatus 100. The controller C may output a control signal to the valve terminal remotely 140 according to the monitoring signal output from the angle sensor 180 to adjust the operating pressure supplied to the equalizing cylinder 131.

Hereinafter, the operation and operation of the spot welding apparatus 100 according to the embodiment of the present invention will be described.

FIG. 2 is a view showing an operation direction of the equalizing unit when a difference in distance between respective welding tips according to the welding tip dressing occurs in the spot welding apparatus according to the embodiment of the present invention, and FIGS. 3 to 5 are views Fig. 8 is a view showing an operating state of the equalizing unit according to the welding direction in the spot welding apparatus according to the example.

Referring to FIG. 2, the equalizing unit 130 is mounted on the movable electrode 121 and the fixed electrode 155 of the movable welder 120 and the fixed welder 150, It is possible to compensate the teaching error of each welding tip T by adjusting the position of the moving welding gun when the distance between the welding tips T is increased by the dressing operation.

That is, when the unused welding tip T is in an initial state in which the moving welder 120 and the fixed welder 150 of the spot welding apparatus 100 are mounted, as shown in FIG. 2A, (D1), and the equalizing unit 130 is not operated.

In this state, when the spot welding is performed more than 500 times on the object to be welded, the welding tips T are worn. In this case, the dressing operation is performed on the worn out welding tip T.

2B, the distance between the welding tips T subjected to the dressing operation becomes larger than D1, which is the distance between the welding tips T in the initial mounting state, as shown in Fig. 2 (b) do.

At this time, the equalizing unit 130 operates the equalizing cylinder 131 to raise the equalizer rod 133, thereby moving the moving welding gun 120 upward by a certain amount.

The teaching error between the welding tips T is compensated and at the same time the rotational speed of the driving motor 129 of the moving welder 120 is also increased by the control signal of the controller C, So that welding can be performed.

The operation of the equalizing unit 130 according to the welding direction of the spot welding apparatus 100 according to the present embodiment will be described with reference to Figs. 3 to 5. Fig.

First, when the moving welder 120 is vertically erected by the operation of the robot and the moving electrode 121 is positioned downward, the spot welding apparatus 100 is operated by the operation of the controller C The equalizing cylinder 131 is driven by the operating pressure supplied from the valve terminal remote 140 to the equalizer rod 133 toward the opposite side of the moving electrode which is opposite to the self weight of the moving welder 120, .

Conversely, when the moving electrode 121 of the moving welder 120 is positioned upward by the operation of the robot, as shown in FIG. 4, the valve terminal remote 140 is moved in accordance with the operation signal of the controller C, The equalizing cylinder 131 is operated by the operating pressure supplied from the equalizing rod 133 to generate a pressure in the equalizer rod 133 in a direction in which the moving electrode 121 which is opposite to the self weight of the moving welder 120 is positioned .

Accordingly, the equalizing unit 130 may be provided with an equalizer (not shown) that is supplied with an operating pressure in the reverse direction of the self weight of the moving welder 120 when performing spot welding on a welding object positioned between the moving welder 120 and the fixed welder 150. [ When the moving welder 120 contacts the surface of the object to be welded via the rod 133, the external force can be minimized.

5, when the moving welder 120 is horizontal with respect to the ground, the equalizing unit 130 moves the moving welder 120 such that the weight of the moving welder 120 moves along the moving direction of the moving electrode 121 As a result, the supply of the operating pressure from the valve terminal remote 140 is stopped and the operation is stopped.

Here, the angle sensor 180 senses the angle of the moving welder 120 when the direction of the moving welder 120 is different from the upper or lower angle as described above, The amount of operating pressure supplied to the equalizing unit 130 through the valve terminal remote 140 can be adjusted to the angle of the moving welder 120 by outputting a control signal.

Accordingly, by applying the spot welding apparatus 100 according to an embodiment of the present invention configured as described above, it is possible to adjust the pressure in the reverse direction of the weight of the moving welder 120 according to the position at which the welding operation is performed, It is possible to minimize the external force applied to the panel when the moving welder 120 reciprocates forward and backward toward the stationary welding gun 150, thereby preventing the panel from being damaged and improving the welding quality.

In addition, the amount of pressure is adjusted in a direction opposite to the self weight of the moving welder 130 according to the moving speed of the moving welding gun 120, and when the welding tip T is worn, the welding tips T The position of the moving welding gun 120 is changed so that the welding operation can be performed by compensating the teaching error of the welding tips T so that the welding speed can be improved and the overall production speed can be improved So that the productivity can be improved.

The spot welding apparatus 100 according to the present embodiment may further include an operating sensor 140 for detecting the operating pressure supplied from the valve terminal remote 140 to the equalizing cylinder 131 in accordance with the angle of the moving welder 120 sensed through the angle sensor 180. [ The supply amount can be adjusted to suitably vary the operating pressure magnitude, so that a more smooth spot welding operation can be performed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

100: Spot welding device 110: Fixing frame
111: mounting portion 113: mounting plate
120: moving welding machine 121: moving electrode
123: pressure actuator 125: screw shaft
127: moving block 129: drive motor
130: equalizing unit 131: equalizing cylinder
133: Equalizer rod 135: Guide means
137: guide rail 139: rail block
140: Valve terminal remote 141: Connection piping
150: Fixed welder 151: Connection frame
153: connecting arm 155: fixed electrode
160: Operational pressure feeder 170: Transformer
171: Booth bar 173: Shunt
180: Angle sensor C: Controller
R: Robot A: Cancer
T: welding tips

Claims (13)

A fixed frame integrally formed with a mounting portion mounted on the arm of the robot and having a mounting plate formed on the opposite side of the mounting portion;
A moving welder disposed in front of the mounting plate and reciprocating the moving electrode toward the object to be welded through forward and backward movement;
An equalizing mechanism configured to reciprocally move forward of the mounting plate to interconnect the moving welder and the mounting plate between the moving welder and the mounting plate and to provide a pressure in a direction opposite to the self- unit;
A valve terminal remote mounted on one side of the fixing frame between the mounting portion and the mounting plate to adjust an operating pressure supplied to the equalizing unit and connected to the equalizing unit; And
A stationary welder mounted on a lower side of the moving welder through a connecting frame;
And a welding device for welding the spot welding device. The method according to claim 1,
The equalizing unit
An equalizing cylinder including an actuating rod, the equalizing cylinder being mounted on an upper side of the front side of the mounting plate; And
An equalizer rod to which an upper end is connected to the end of the actuating rod at a lower portion of the equalizing cylinder and which is mounted to be reciprocatable in front of the mounting plate and to which the moving welder is mounted;
And a welding device for welding the spot welding device. 3. The method of claim 2,
The equalizing cylinder
Is connected to the valve terminal remotely operated according to the control signal of the controller through a connection pipe, and is operated by receiving operating pressure through the valve terminal remotely. The method of claim 3,
The valve terminal remote
Wherein the supply amount of the operating pressure supplied from the operating pressure supplier is adjusted and supplied to the equalizing cylinder. 3. The method of claim 2,
The equalizing cylinder
And a pneumatic cylinder using the operating pressure as pneumatic pressure. 3. The method of claim 2,
The equalizer load
Wherein the upper and lower lengths are formed in a rectangular plate shape longer than the left and right widths and the rear side is connected to one side of the lower portion of the mounting plate through a guide means. 5. The method of claim 4,
The guide means
At least one guide rail mounted longitudinally in front of the mounting plate; And
At least one rail block slidably mounted on the guide rail and connected to the rear of the equalizer rod;
Wherein the spot welding apparatus comprises: The method according to claim 1,
The moving welder
Wherein the pressing actuator mounted on the equalizing unit is connected to the moving electrode provided on the moving welder through a moving block configured to reciprocate on a screw shaft. 9. The method of claim 8,
The pressure actuator
And a roller screw actuator for converting a rotational torque of the drive motor into a linear motion through the screw shaft. 9. The method of claim 8,
The stationary welder
A connection arm having one end connected to the other end of the connection frame, the connection arm having one end connected to a lower side of the pressure actuator; And
A fixed electrode mounted on the other end of the connecting arm at a position corresponding to the moving electrode;
≪ RTI ID = 0.0 > The method according to claim 1,
The fixed frame
Wherein a transformer is mounted between the mounting portion and the mounting plate, and a lower portion of the transformer is provided with a bus bar and a shunt for passing current through the moving welding machine and the fixed welding machine. The method according to claim 1,
The equalizing unit
And adjusting a position of the moving welding gun to compensate a teaching error of each welding tip when a distance between the welding tips is increased by a dressing operation of the welding tip mounted on the moving welding machine and the fixed welding machine, . The method according to claim 1,
The mounting plate
And an angle sensor is mounted at a rear end thereof.

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