KR20190139387A - Spot welding device and control method of the same - Google Patents

Abstract

Disclosed is a spot welding device. The spot welding device according to an exemplary embodiment of the disclosed present invention relates to in melting a welding part of a welding object which is overlapped with each other by heat by an electric resistance and a set pressing force and the welding object is bonded, comprising: (i) a gun body; (ii) a fixed electrode installed to be fixed to the gun body and supporting a welding part; (iii) a movable electrode installed to reciprocate on the gun body corresponding to the fixed electrode and pressurizing the welding part; and (iv) a magnetic field applying unit installed in at least one of the fixed electrode and the movable electrode, and applying a magnetic field to a molten welding part by passing current of the fixed electrode and the movable electrode.

Description

Spot welding device and control method {SPOT WELDING DEVICE AND CONTROL METHOD OF THE SAME}

An embodiment of the present invention relates to a spot welding apparatus, and more particularly, to a spot welding apparatus for spot welding a welding part of a welding object by pressurization and energization of a welding electrode, and a control method thereof.

In general, a method of welding two or more overlapping metal objects to be welded can be roughly divided into a fusion welding method and a solid phase welding method.

Among these, the melt welding method may be a spot welding method. In particular, in an assembly line of a car body factory, several part parts such as panels are joined by the spot welding method. The spot welding method is a method of welding a welded object by melting welded portions of the welded objects superposed on each other by heat due to electrical resistance and a set pressing force.

For such spot welding, a spot welding device is applied, and the spot welding device basically includes a fixed electrode and a movable electrode installed on the gun body of the welding gun.

The spot welding apparatus presses the welding object supported on the fixed electrode by operating the movable electrode through the actuator, and applies a welding current to the fixed electrode and the movable electrode to spot weld the welding object as an electrical resistance.

The spot welding apparatus in the prior art adjusts welding conditions (current, time, and pressing force) according to welding object conditions such as material type, thickness, and number of layers of the panel with the same equipment, and welds the welding object.

However, in the related art, since only the welding conditions as described above are limitedly regulated according to the conditions of the welding object, research and development of a spot welding apparatus that forms an optimal welding nugget and improves the welding quality for each characteristic of the welded part is possible. It is done.

The matters described in this Background section are intended to enhance the understanding of the background of the invention, and may include matters not previously known to those of ordinary skill in the art.

Embodiments of the present invention are directed to a spot welding apparatus and a control method thereof, which actively respond to various welding conditions of a welding target and improve the welding quality of the welding target.

Spot welding apparatus according to an embodiment of the present invention, the welding parts of the overlapping welding objects by melting with the heat of the electrical resistance and the set pressing force to join the welding object, iii) a gun body, ii) fixed to the gun body A fixed electrode supporting the welded portion, iii) a movable electrode reciprocated in the gun body in correspondence with the fixed electrode, and a movable electrode pressurizing the welded portion; It may be installed on at least one, and may include a magnetic field applying unit for applying a magnetic field to the molten welding portion by the energization of the fixed electrode and the movable electrode.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the fixed electrode may include a fixed electrode tip and a fixed shank for supporting the fixed electrode tip.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the movable electrode may include a movable electrode tip and a movable shank supporting the movable electrode tip.

In the spot welding apparatus according to an embodiment of the present invention, the magnetic field applying unit may include a magnetic field generator as a permanent magnet installed on at least one of the fixed shank and the movable shank.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the magnetic field generator may be installed to be movable along the shank axis direction by an actuator.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the magnetic field generator may be rotatably installed along the shank outer circumferential direction by an actuator.

In addition, the spot welding apparatus according to the embodiment of the present invention is to weld the welded parts of the overlapping welding objects to each other by heat due to electrical resistance and the set pressing force, and to join the welding objects, i) a gun body, and ii) an electrode tip. And a shank for supporting the electrode tip, the fixed electrode being fixed to the gun body, iii) an electrode tip, and a shank for supporting the electrode tip, corresponding to the fixed electrode on the gun body. A movable electrode installed to be reciprocally movable, iii) a housing fixedly installed to the shank of at least one of the fixed electrode and the movable electrode, and iii) selectively movable and rotatable to the shank within the housing. A magnetic field generator as a permanent magnet for applying a magnetic field to a welded portion melted by energization of the fixed electrode and the movable electrode; An actuator installed in the shank corresponding to the field generator and generating an actuation force for selectively moving and rotating the magnetic field generator; and iii) a controller for controlling the actuator according to a set welding condition of the welding object. can do.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the magnetic field generator may be varied in the operating distance with the electrode tip by the actuator.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the magnetic field generator may have a variable rotation speed by the actuator.

In the spot welding apparatus according to an embodiment of the present invention, the actuator may include an electromagnet in which a coil is applied to a stationary body fixed to the shank, and the magnetic field generator corresponding to the electromagnet. The shank may be installed to be selectively moved and rotated, and may include a rotating body coupled to the magnetic field generator as a collection of permanent magnets.

In addition, in the spot welding apparatus according to an embodiment of the present invention, a magnetic field shielding member may be installed between the magnetic field generator and the rotating body.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the magnetic field generator and the actuator may be installed in a bushing member fixed to the shank inside the housing.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the fixing body may be fixed to the bushing member through a fixing member.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the magnetic field generator and the rotating body may be installed to be rotatable and rotatable to the bushing member through a rolling support member in a coupled state. .

In addition, in the spot welding apparatus according to an embodiment of the present invention, the controller may adjust the strength of the electromagnet through a variable resistance, and the variable position of the rotating body and the magnetic field generator coupled to each other.

In the spot welding apparatus according to an embodiment of the present invention, the controller changes the polarity of the electromagnet through a three-phase power source of a set frequency applied to the electromagnet and rotates the rotor together with the magnetic field generator. You can.

In addition, in the spot welding apparatus according to an embodiment of the present invention, the controller may adjust the frequency of the three-phase power source through a variable frequency, and can variably control the rotational speed of the rotating body.

In addition, the spot welding apparatus according to an embodiment of the present invention may include a steel material and an aluminum material.

In addition, in the method of controlling a spot welding apparatus according to an exemplary embodiment of the present invention, the welding parts of the welding objects overlapped with each other are melted by heat due to electrical resistance and a set pressing force, and the welding objects are bonded to each other, but the magnetic field generated by the magnetic field generator is connected. By using a spot welding device to be applied to the welding portion, according to the welding conditions of the welding object, by moving the magnetic field generator to a predetermined position through an actuator, adjust the distance between the magnetic field generator and the electrode tip, The magnetic field generator can be rotated through an actuator.

In addition, the method for controlling the spot welding apparatus according to an embodiment of the present invention, by adjusting the strength of the electromagnet through a variable resistor, it is possible to vary the position of the rotating body and the magnetic field generator coupled to each other.

In addition, the method for controlling the spot welding apparatus according to an embodiment of the present invention, by changing the polarity of the electromagnet through a three-phase power source of a set frequency applied to the electromagnet to rotate the rotor with the magnetic field generator Can be.

In addition, the method for controlling the spot welding apparatus according to an embodiment of the present invention, by adjusting the frequency of the three-phase power source through a variable frequency, it is possible to vary the rotational speed of the rotating body.

According to an embodiment of the present invention, by applying magnetic field and rotational inertia to the molten welded portion by pressurizing and energizing the fixed electrode tip and the movable electrode tip and extending the nugget of the welded portion, an optimum welding knuckle according to the welding conditions of the welded object It can form and improve the welding quality of the welding object.

In addition, the effects that can be obtained or predicted by the embodiments of the present invention will be disclosed directly or implicitly in the detailed description of the embodiments of the present invention. That is, various effects predicted according to an embodiment of the present invention will be disclosed in the detailed description to be described later.

Since these drawings are for reference in describing exemplary embodiments of the present invention, the technical spirit of the present invention should not be construed as being limited to the accompanying drawings.
1 is a view schematically showing a spot welding apparatus according to an embodiment of the present invention.
Figure 2 is a schematic cross-sectional view showing a magnetic field applying unit applied to the spot welding apparatus according to an embodiment of the present invention.
3 is an exploded perspective view of a part of a magnetic field applying unit applied to the spot welding apparatus according to the embodiment of the present invention.
4 is a view for explaining a control method of the spot welding apparatus according to an embodiment of the present invention.
5A and 5B are views illustrating a modified example of the actuator applied to the spot welding apparatus according to the embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

Since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to those illustrated in the drawings, and the thicknesses are enlarged to clearly express various parts and regions.

In the following detailed description, the names of the configurations are divided into first, second, and the like in order to distinguish them in the same relationship, and the description is not necessarily limited to the order in the following description.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

In addition, terms, such as "... part", "" means ", etc. described in the specification mean a unit of a comprehensive configuration that performs at least one function or operation.

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

Referring to FIG. 1, the spot welding apparatus 100 according to an exemplary embodiment of the present invention may be applied to a process of assembling a vehicle body by spot welding the welding object 1 of metal plates superimposed on the vehicle body in a vehicle body assembly process.

However, the scope of protection of the present invention is not to be understood as being limited to welding the vehicle body panel in the process of assembling the vehicle body, and the technical idea of the present invention may be applied to welding objects of various kinds and uses.

The spot welding apparatus 100 according to the embodiment of the present invention may resistance-weld the welding object 1 while melting the welding part by the set pressing force in both directions with respect to the welding part of the welding object 1 and the resistance heat according to the energization. have.

Hereinafter, the components described below will be described based on the spot welding apparatus 100 standing up and down, and the upper portion is defined as the upper portion, the upper portion, the upper portion and the upper portion, and the portion facing downward is described. It can be defined as a lower part, a lower part, a lower part and a lower surface.

However, the definition of the direction as described above is a relative meaning, since the direction may vary according to the reference position of the spot welding apparatus 100 and the welding direction of the welding target 1, and the like. It is not necessarily limited to.

The spot welding apparatus 100 according to the exemplary embodiment of the present invention basically includes a gun body 10, a fixed electrode 30, and a movable electrode 50.

The gun body 10 is for installing various components to be described below, for example, may be mounted to the multi-joint arm of the robot (not shown) through a fixing bracket. Further, the gun body 10 may be provided with a transformer for supplying a welding current to the welding electrode (hereinafter, the electrode tip).

The gun body 10 includes various accessory elements such as housings, plates, blocks, rails, collars, etc. for installing the respective components which will be described further below.

These various accessory elements are to install each of the components to be described in the following to the gun body 10, except in the embodiment of the present invention, the various accessory elements described above to the gun body 10 Collectively.

The fixed electrode 30 supports the welded portion under the welding object 1 and receives a welding current, and the fixed electrode tip 31 and the fixed shank 33 supporting the fixed electrode tip 31. It has a, is installed to be fixed to the gun body (10). The fixed shank 33 is fixed to the gun body 10, and the fixed electrode tip 31 is fixed to the end of the fixed shank 33.

In addition, the movable electrode 50 presses the welding part on the upper side of the welding object 1 in correspondence with the fixed electrode 30, and receives a welding current, thereby allowing the gun body 10 to reciprocate in the vertical direction. Is installed. This movable electrode 50 includes a movable electrode tip 51 and a movable shank 53 supporting the movable electrode tip 51. The movable shank 53 is installed in the gun body 10 so as to be reciprocated in the vertical direction, and the movable electrode tip 51 is fixed to the end of the movable shank 53.

Here, the movable electrode 50 may be installed to move back and forth in the vertical direction by a pressure cylinder (not shown) provided as a driving source provided in the gun body 10. The pressure cylinder may be installed to be fixed in the vertical direction to the gun body (10).

On the other hand, the welding object 1 applied to the embodiment of the present invention may include a metal plate, a plate of steel material which is a ferromagnetic material and a plate of aluminum material that can not impart magnetism in the solid phase.

The spot welding apparatus 100 according to an embodiment of the present invention actively responds to various welding conditions such as the metal plate type, the metal plate thickness, the number of metal plates, and the shape / size of the welded part of the welding object 1, and the welding object 1 ) Is made of a structure to improve the welding quality.

To this end, the spot welding apparatus 100 according to the embodiment of the present invention includes a magnetic field applying unit 60 for applying a magnetic field to the welded part by pressing and energizing the fixed electrode 30 and the movable electrode 50. Doing.

In the embodiment of the present invention, the magnetic field applying unit 60 is configured in at least one of the fixed electrode 30 and the movable electrode 50, it is configured in at least one of the fixed shank 33 and the movable shank 53. Can be.

For example, the magnetic field applying unit 60 may be configured only on the fixed shank 33 of the fixed electrode 30, may be configured only on the movable shank 53 of the movable electrode 50, and the fixed shank 33 And the movable shank 53 may be respectively configured. However, in the embodiment of the present invention, as shown in the drawings and the following, an example in which the magnetic field applying unit 60 is configured in the fixed shank 33 and the movable shank 53 will be described.

The magnetic field applying unit 60 as described above is installed in the fixed shank 33 and the movable shank as the same configuration, respectively, hereinafter, the magnetic field applying unit 60 constituted in one of the shanks 33 or 53. Only the configuration of) will be described in detail.

Furthermore, in the drawings and hereinafter, reference numerals for any one of the shanks 33 or 53 are given as "S" for convenience, and the electrode tips 31 or 51 corresponding to any one of the shanks 33 or 53. Reference numerals are given as "T" for convenience.

2 is a cross-sectional view schematically showing a magnetic field applying unit applied to a spot welding device according to an embodiment of the present invention, Figure 3 is a part of a magnetic field applying unit applied to a spot welding device according to an embodiment of the present invention It is the exploded perspective view of a structure.

1 to 3, the magnetic field applying unit 60 according to an embodiment of the present invention includes a housing 61, a magnetic field generator 63, and an actuator 71. Same as

Prior to explaining the configurations as described above, the bushing member 65 is fixedly fitted to the shank (S) mentioned above. The bushing member 65 is for mounting various components to be described below, and is provided in a cylindrical shape.

In the embodiment of the present invention, the housing 61 is formed in the top and the bottom of the hole through which the bushing member 65 of the shank S penetrates and is fixed to the bushing member 65. That is, the housing 61 forms a space set therein and is fixedly installed to the bushing member 65 penetrating through the holes of the upper and lower ends. The housing 61 may be formed of a material that does not affect the magnetic field, for example, a synthetic resin material.

In the embodiment of the present invention, the magnetic field generator 63 applies a magnetic field to the welded portion melted by pressurization and energization of the fixed electrode 30 and the movable electrode 50, and to the bushing member 65. Is installed. The magnetic field generator 63 may include a permanent magnet in the embodiment of the present invention.

The magnetic field generator 63 is provided to be selectively moved and rotated relative to the bushing member 65 by the actuator 71 which will be described later. Here, the magnetic field generator 63 may be installed to be movable only along the axial direction (up and down direction in the drawing) of the bushing member 65 by the actuator 71. In addition, the magnetic field generator 63 may be installed to be rotatable only along the outer circumferential direction of the bushing member 65 by the actuator 71. Furthermore, the magnetic field generator 63 may be installed to the bushing member 65 by the actuator 71 so as to be movable and rotatable.

In the embodiment of the present invention, the actuator 71 generates an actuation force for selectively moving and rotating the magnetic field generator 63 with respect to the bushing member 65, the shank corresponding to the magnetic field generator 63 It is provided in the bushing member 65 of (S).

The actuator 71 includes an electromagnet 73 and a rotating body 81. The electromagnet 73 is applied to a power source to generate a magnetic force, it is installed to be fixed to the bushing member 65 of the shank (S).

The electromagnet 73 includes a fixture 75 fixed to the bushing member 65 and a coil 77 wound around the fixture 75 and receiving power. The fixture 75 is provided with a ferromagnetic material, for example, may be provided with a steel plate body laminated electrical steel sheet.

In this case, the strength of the electromagnet 73 may be determined according to the amount of power (current) applied. In addition, the fixing member 75 may be fixed to the bushing member 65 through a ring fixing member 79.

The coil 77 may include a coil from which a single phase is drawn, or may include a coil from which three phases U, V, and W are drawn, and may receive a single phase power or a three phase power.

The rotating body 81 is installed to move and rotate selectively to the bushing member 65 of the shank S together with the magnetic field generator 63 corresponding to the electromagnet 73, and the magnetic field generator 63 and Combined. The rotor 81 is provided as a collection of permanent magnets having different polarities.

As described above, the rotor 81 and the magnetic field generator 63 are provided with a magnetic field shielding member 83 for shielding a magnetic field generated from each of them, and the magnetic field shielding member 83 is a magnetic field shielding film. It may include. In addition, the rotor 81 and the magnetic field generator 63 are coupled to each other through bonding means such as a bonding material with the magnetic field shielding member 83 therebetween.

Furthermore, the magnetic field generator 63 and the rotor 81 are coupled to each other (bonded) by the bonding means, and selectively with respect to the bushing member 65 of the shank S. It is moved along the axial direction and can be rotated in the outer circumferential direction of the shank (S).

Accordingly, the magnetic field generating body 63 and the rotating body 81 are installed to the bushing member 65 through a support member 87 to be selectively moved and rotated. The support member 87 includes balls that roll with respect to the outer circumferential surface of the bushing member 65, and a support body that fixes the magnetic field generator 63 and the rotor 81 while supporting the balls.

Accordingly, the magnetic field generating body 63 and the rotating body 81 are fixed to the supporting body while being in contact with the outer circumferential surface of the bushing member 65 along the axial direction of the shank S together with the supporting body. It can be moved and rotated in the circumferential direction of the shank (S).

Meanwhile, in the embodiment of the present invention, the magnetic field generator 63 is reciprocated in the axial direction of the shank S by the actuator 71 as described above, and thus the magnetic field generator 63 and the electrode tip. The working distance from (T) can be adjusted.

In the embodiment of the present invention, the magnetic field generator 63 is rotated in the outer circumferential direction of the shank S by the actuator 71 as described above, and thus the rotational speed of the magnetic field generator 63 is variable. I can regulate it.

Thus, the embodiment of the present invention includes a controller 90 for controlling the actuator 71 according to the welding conditions of the welding object 1 as mentioned above.

The controller 90 may adjust the strength of the electromagnet 73 through the variable resistor 91 and variably control the positions of the rotating body 81 and the magnetic field generator 63 coupled to each other. In addition, the controller 90 may rotate the rotor 81 together with the magnetic field generator 63 while changing the polarity of the electromagnet 73 through a three-phase power source of a set frequency applied to the electromagnet 73. . Furthermore, the controller 90 may adjust the frequency of the three-phase power source through the variable frequency 93 and variably control the rotational speed of the rotor 81 coupled to the magnetic field generator 63.

Hereinafter, the operation and control method of the spot welding apparatus 100 according to an embodiment of the present invention configured as described above will be described in detail with reference to the drawings and the accompanying drawings.

4 is a view for explaining a control method of the spot welding apparatus according to an embodiment of the present invention.

Referring to the above-described drawings and FIG. 4, first, in the embodiment of the present invention, the fixed body 30 is fixed while the gun body 10 is moved to the welding object 1 side through a robot (not shown). The welding portion of the welding object 1 is supported through the electrode tip 31. In this state, in the exemplary embodiment of the present invention, the movable electrode 50 is moved to the welding part side of the welding target 1 by the forward operation of the driving source (S11).

In this process, in the embodiment of the present invention, the electromagnet according to the preset welding conditions of the welding object 1 (for example, the type of metal plate of the welding object 1, the thickness of the metal plate, the number of layers of the metal plate, and the shape / size of the welding part) The intensity of 73 is adjusted through the variable resistor 91, and the positions of the rotating body 81 and the magnetic field generator 63 coupled to each other are adjusted (S12).

In the above process, when the current of the power applied to the coil 77 of the electromagnet 73 is adjusted through the variable resistor 91, the strength of the electromagnet 73 is adjusted and the rotating body 81 and the magnetic field are coupled to each other. The sieve 63 is moved along the axial direction of the shank S, and the working distance between the magnetic field generator 63 and the electrode tip T can be variably adjusted.

On the other hand, when the movable electrode 50 is moved to the welding part side of the welding object 1 in the state which supported the welding part of the lower surface of the welding object 1 via the fixed electrode tip 31 of the fixed electrode 30 as mentioned above. The movable electrode tip 51 of the movable electrode 50 pressurizes the welded portion of the welding object 1.

Then, when a welding current is applied to the fixed electrode tip 31 and the movable electrode tip 51, the welding object 1 may be resistance welded while melting the weld by the set pressing force and resistance heat according to the energization ( S13).

In the process of welding the welded portion of the welding target 1 as described above, in the embodiment of the present invention, the magnetic field generator 63 in the welded portion melted by pressing and energizing the fixed electrode tip 31 and the movable electrode tip 51. Apply a magnetic field generated in the (S14).

Therefore, in the embodiment of the present invention, by applying the magnetic field generated by the magnetic field generator 63 to the molten welding portion, the direction of Lorentz force acting on the welding portion is controlled, and the set welding of the welding object 1 is performed. Depending on the conditions, an optimal welding nugget can be secured.

In this process, in the embodiment of the present invention, the polarization of the electromagnet 73 is changed through a three-phase power source of a set frequency applied to the electromagnet 73 and the rotor 81 is rotated together with the magnetic field generator 63. (S15).

Furthermore, in the embodiment of the present invention, the frequency of the three-phase power source is adjusted through the variable frequency 93 according to the preset welding condition of the welding target 1, and the rotating body coupled to the magnetic field generator 63 ( The rotation speed of the 81 may be adjusted (S16).

Then, in the embodiment of the present invention, by rotating the magnetic field generator 63 together with the Lorentz force in the circumferential direction generated by the magnetic field of the magnetic field generator 63, rotational inertia can be imparted to the molten weld.

Thus, in the embodiment of the present invention by applying the magnetic field and rotational inertia to the molten welding portion by the pressurization and energization of the fixed electrode tip 31 and the movable electrode tip 51, by expanding the nugget of the weld, the welding object (1) According to the welding conditions of the welding portion to form an optimum welding knuckle and can improve the welding quality of the welding target (1).

Furthermore, in the embodiment of the present invention, not only the welding object 1 of the steel material, which is inherently a ferromagnetic material, but also the welding object 1 of the aluminum material, which cannot impart magnetism in the solid phase, may be spot welded.

The reason for spot welding the welding target object 1 of aluminum material as described above is that the aluminum material has a property of being magnetized by an external magnetic field in a molten state.

5A and 5B are views illustrating a modified example of the actuator applied to the spot welding apparatus according to the embodiment of the present invention.

Referring to FIG. 5A, one modified example of the actuator 171 applied to the spot welding apparatus according to the embodiment of the present invention rotates the magnetic field generator 63 through the electromagnet 73 and the rotor 81. In addition, it may include a pneumatic unit 201 for reciprocating the rotating body 81 and the magnetic field generator 63 in the axial direction of the shank (S) through the pneumatic.

In this modified example, the pneumatic unit provided in the pneumatic unit 201 does not reciprocate the rotator 81 and the magnetic field generator 63 in the axial direction of the shank S while adjusting the strength of the electromagnet 73. Through the rotating body 81 and the magnetic field generator 63 can be reciprocated in the axial direction of the shank (S).

Since the pneumatic unit 201 is made as a pneumatic device of the known art that provides the back and forth operating force to the moving body through the supply and discharge of the pneumatic, more detailed description will be omitted herein.

Referring to FIG. 5B, another modified example of the actuator 171 applied to the spot welding apparatus according to the embodiment of the present invention rotates the magnetic field generator 63 through the electromagnet 73 and the rotor 81. In addition, it may include a mobile unit 202 for converting the rotational motion of the servo motor to linear motion and for reciprocating the rotating body 81 and the magnetic field generator 63 in the axial direction of the shank (S).

The mobile unit 202 converts the rotational motion of the servo motor into a linear motion, and is made as a linear moving device of the known art for providing forward and backward actuation force to the moving body, and thus, further detailed description thereof will be omitted.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

1: welding target 10: gun body
30: fixed electrode 31: fixed electrode tip
33: fixed shank 50: movable electrode
51: movable electrode tip 53: movable shank
60: magnetic field applying unit 61: housing
63: magnetic field generator 65: bushing member
71, 171: actuator 73: electromagnet
75: stationary 77: coil
79: fixing member 81: rotating body
83: magnetic field shield member 87: support member
90: controller 91: variable resistor
93: variable frequency S: shank
T: electrode tip 100: spot welding device
201: Pneumatic unit 202: Mobile unit

Claims (20)

A spot welding apparatus for joining the welding targets by melting welding parts of the welding targets overlapped with each other by heat due to electrical resistance and a set pressing force,
Gun body;
A fixed electrode installed to be fixed to the gun body and supporting the welding part;
A movable electrode installed on the gun body so as to reciprocate in correspondence with the fixed electrode, and pressurizing the welding part; And
A magnetic field applying unit installed on at least one of the fixed electrode and the movable electrode, the magnetic field applying unit applying a magnetic field to the welded part by energization of the fixed electrode and the movable electrode;
Spot welding apparatus comprising a. According to claim 1,
The fixed electrode includes a fixed electrode tip and a fixed shank for supporting the fixed electrode tip,
The movable electrode includes a movable electrode tip and a movable shank for supporting the movable electrode tip,
And the magnetic field applying unit includes a magnetic field generator as a permanent magnet installed on at least one of the fixed shank and the movable shank. The method of claim 2,
And the magnetic field generator is installed to be movable along the shank axis direction by an actuator. The method according to claim 2 or 3,
The magnetic field generator is a spot welding device, characterized in that rotatably installed along the shank outer circumferential direction by an actuator. A spot welding apparatus for joining the welding object by melting the welded parts of the welding object overlapped with each other by heat due to electrical resistance and the set pressing force,
Gun body;
A fixed electrode having an electrode tip and a shank for supporting the electrode tip, the fixed electrode being fixed to the gun body;
A movable electrode having an electrode tip and a shank for supporting the electrode tip, the movable electrode being reciprocally installed in the gun body in correspondence with the fixed electrode;
A housing fixed to the shank of at least one of the fixed electrode and the movable electrode;
A magnetic field generator as a permanent magnet provided in the housing so as to be selectively moved and rotatable, and applying a magnetic field to a welded portion melted by energization of the fixed electrode and the movable electrode;
An actuator installed on the shank corresponding to the magnetic field generator and generating an actuation force for selectively moving and rotating the magnetic field generator; And
A controller for controlling the actuator according to a set welding condition of the welding object;
Spot welding apparatus comprising a. The method of claim 5,
The magnetic field generator,
Spot welding device, characterized in that the operating distance with the electrode tip is variable by the actuator. The method according to claim 5 or 6,
The magnetic field generator,
Spot welding device, characterized in that the rotational speed is variable by the actuator. The method of claim 5,
The actuator is,
An electromagnet wound with a coil applied with power to a fixture fixedly mounted to the shank;
Rotating body that is installed to move and rotate selectively to the shank with the magnetic field generating body corresponding to the electromagnet, and is coupled to the magnetic field generating body as a collection of permanent magnets
Spot welding apparatus comprising a. The method of claim 8,
Spot welding apparatus, characterized in that the magnetic field shielding member is installed between the magnetic field generator and the rotating body. The method of claim 8,
The magnetic field generator and the actuator,
Spot welding apparatus, characterized in that installed in the bushing member fixed to the shank inside the housing. The method of claim 10,
Spot fixing device, characterized in that the fixing body is fixed to the bushing member through a fixing member. The method of claim 10,
The magnetic field generator and the rotating body are coupled to each other, the spot welding device, characterized in that installed in the bushing member to be movable and rotatable through a rolling member supporting the movement. The method of claim 8,
The controller,
Spot intensity control device characterized in that for controlling the intensity of the electromagnet through a variable resistance, and the variable position of the rotating body and the magnetic field generator coupled to each other. The method according to claim 8 or 13,
The controller,
Spot welding device, characterized in that for rotating the rotating body with the magnetic field generator while changing the polarity of the electromagnet through a three-phase power source of the set frequency applied to the electromagnet. The method of claim 14,
The controller adjusts the frequency of the three-phase power source through a variable frequency, spot welding apparatus, characterized in that for controlling the rotational speed of the rotating body. The method according to claim 1 or 5,
The spot welding device is a spot welding device, characterized in that for spot welding the welding object comprising a steel material and aluminum material. A method of controlling a spot welding apparatus in which welding parts of welding objects overlapped with each other are melted by heat due to electrical resistance and a set pressing force, and the welding objects are bonded to each other, and a magnetic field generated from a magnetic field generator is applied to the welding part.
According to the welding conditions of the welding object, the magnetic field generator is moved to a predetermined position through an actuator, the distance between the magnetic field generator and the electrode tip is adjusted, and the magnetic field generator is rotated through the actuator. The control method of the spot welding apparatus. The method of claim 17,
And controlling the intensity of the electromagnet through a variable resistor, and varying positions of the rotating body and the magnetic field generator coupled to each other. The method of claim 18,
And rotating the rotor together with the magnetic field generator while changing the polarity of the electromagnet through a three-phase power source of a predetermined frequency applied to the electromagnet. The method of claim 19,
And controlling the frequency of the three-phase power source through a variable frequency and varying the rotational speed of the rotor.

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