WO2009131293A1

WO2009131293A1 - Welding apparatus provided with carrier being able moving independently

Info

Publication number: WO2009131293A1
Application number: PCT/KR2008/007583
Authority: WO
Inventors: Byung Ha Huh
Original assignee: Wooshin System Co., Ltd
Priority date: 2008-03-26
Filing date: 2008-12-22
Publication date: 2009-10-29
Also published as: CN101543932A; KR100865795B1; CN101543932B

Abstract

The present invention relates to a welding apparatus, and in particular, to a welding apparatus provided with independently movable carrier, in which a gate used in a body welding process and the carrier for carrying the gate are separated from each other, and a detachable common gate transferring device capable of moving independently in which various types of gates can be moved in a simply reciprocating manner is provided to remarkably reduce a movement region of the carrier. According to the welding apparatus of the present invention, a series of gate replacement processes such as a gate recovery, replacement, preparation, and placement can be further quickly and efficiently performed with respect to the body arriving at a welding position. In addition, the processes can be simplified, and the operation efficiency can be improved, and also, a regions and equipment required for replacing the gate, a processing time, and total equipment costs can be remarkably reduced.

Description

[DESCRIPTION] [Invention Title]

WELDING APPARATUS PROVIDED WITH CARRIER BEING ABLE MOVING INDEPENDENTLY [Technical Field]

The present invention relates to a welding apparatus for a body welding process of a vehicle assembly line, and in particular, to a welding apparatus, which is provided with a plurality of welding robots to which welding guns are attached and is configured to operate the welding robots to perform a spot welding process on a vehicle body in a state where position gates are coupled and fixed to corresponding fixed positions of the welding operation. [Background Art]

In a general automobile, a body is a part that forms the exterior of the automobile except the engine and power transmission parts. The body is formed by integrally assembling various panels and members and provides spaces for passengers, the engine, and freights.

In an automobile mass production process, parts of a body frame such as a floor frame, lateral frames, a roof, and a cowl frame are separately manufactured, and then, the parts are assembled to complete the body frame expect opening and closing parts such as a door, a trunk lid, and a hood.

In a vehicle assembly line, a temporarily assembled body is welded in a welding process to complete an assembly of the body frame. The panels constituting the body are moved to a welding apparatus in a state where the panels are loosely previously assembled, and the panels are spot-welded by a plurality of welding robots to assemble the panels in one body.

Typically, the welding apparatus includes the plurality of welding robots to which welding guns are attached. In the welding apparatus, a gate for welding the body is coupled and fixed to a fixed portion in an operation process, and then, the welding robots operate to perform a spot-welding operation on the body moved by a conveyor.

An automobile manufacturing company not produces only a single car model, but produces various car models according to the customers and their taste. Thus, it is need to prepare equipment for producing the various car models. As a result, for this, much financial burden is imposed.

Thus, it is economically advantageous to provide equipment commonly adapted for producing car models as much as possible.

This is no exception to the welding process in the vehicle assembly line using a multi-model mixed production system. Various gates are prepared according to car models to be produced in the welding process, and then, when a body is reached, a gate is replaced with a gate adapted for the car model of the body to perform a welding process.

A ROBOGATE system that is well known as an apparatus for spot-welding a body or parts of the body includes two or more gates which can be quickly replaced in a welding process and are associated with each other to operate at various bodies.

Since the ROBOGATE system is operable with respect to various bodies, the same line may be used for bodies of different models, and the ROBOGATE system may be relatively easily and quickly manipulated. Thus, when a new body model is produced, manufacturing costs may be remarkably reduced. In addition, all of the models having the same form may have uniform quality.

In a well-known technique using the ROBOGATE system, a body reaches the welding process after the body is loosely assembled (tabbed). That is, the body reaches the welding process after one or more toy-tabbing process in which various parts such as panels defining the body are temporarily assembled by bending connection taps. The temporary connection state denotes a loose connection state in which positions of the parts can be spaced a little from each other.

As a result, each of the gates provided in the welding apparatus includes a robot provided with welding units, i.e., locking units connecting various portions of the body to each other such that the body is locked at a proper assembly position before the welding robot performs the spot welding.

However, since gates of system must be used according to a target car model, the gates need to be replaced according the car model arriving at a welding position. That is, according to car models, the gates adapted for an existing car model are disposed, and at the same time, the gates that are not used are moved to a standby position. Thus, because of the processes in which the gates to be used are inputted into the welding position and the gates that are not used are moved to the standby position, the processes and devices are complicated. Also, it is disadvantageous in space and economical efficiency.

Specifically, in a related art welding process, since gates and carriers for carrying the gates are integrally coupled, regions for standby of the gates are used over a plurality of processes, e.g., five processes. Therefore, there is a limitation that many devices movable in left, right, front and rear directions are used to increase the space and costs.

[Disclosure]

[Technical Problem]

Accordingly, the present disclosure provides a welding apparatus provided with independently movable carriers, in which a gate and the carrier for carrying the gate are separated from each other, a detachable common gate transferring device capable of moving independently is provided to further quickly and efficiently perform a series of gate replacement processes such as a gate recovery, replacement, preparation, and placement with respect to a body arriving at a welding position, processes are simplified, operation efficiency is improved, and a region and equipment required for replacing the gate, a processing time, and total equipment costs are remarkably reduced.

[Technical Solution]

According to an aspect of the present invention, there is provided a welding apparatus provided with an independently movable carrier, the welding apparatus including: a welding processing part; a replacement processing part; a gate transferring device including the carrier movable in a state where a gate is detached or attached and a carrier moving unit for moving the carrier between the welding processing part and the replacement processing part, wherein the welding processing part couples the gate transferred from the replacement processing part to a body transferred to a welding position to perform a welding operation and transfers the used gate to the gate transferring device, and the welding processing part includes a handling robot picking up the gate attached to the carrier, separating the gate from the carrier, moving the gate into the body to couple and fix the gate to the body and moves the gate from the body to the carrier to seat the gate after a body welding operation is finished, and wherein the replacement processing part replaces the used gate transferred from the welding processing part with a new gate to provide the new gate to the gate transferring device.

[Description of Drawings]

Fig. 1 is a perspective view of a welding apparatus according to the present invention.

Fig. 2 is a perspective view illustrating a gate transferring device of a welding apparatus according to the present invention.

Figs. 3 to 11 are perspective views illustrating an operation state of respective components of a welding apparatus according to the present invention.

- Description of the principal element number on drawing -

10 : body 20 : gate

110 : replacement processing part 111,112 : handling robot

120 : welding processing part 121,122 : handling robot

123,124 : welding robot 130 : replacement processing part

131,132 : handling robot 140 : gate transferring device

141,142 : slide rail 143 : carrier

145 : electric motor [Mode for Invention]

In the following description, the technical terms are used only for explaining a specific exemplary embodiment while not limiting the present invention. The terms of a singular form may include plural forms unless otherwise specified. The meaning of "include", "comprise", "including", or "comprising" specifies a property, a fixed number, a step, a operation, an element, a component or combinations thereof, but does not exclude other properties, fixed numbers, steps, operations, elements, components or combinations thereof.

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

The present invention relates to a welding apparatus provided with a plurality of welding robots to which welding guns are attached and operating the welding robots in a state where gates for welding a body are coupled and fixed to corresponding fixed positions of an operation process to perform a spot welding operation on the body.

The welding apparatus according to the present invention includes a carrier (a part movable along a rail of a transferring device that will be described later) and a gate (a hand jig attached to the carrier to move to a welding processing part) that are separated from each other. Also, the welding apparatus includes a detachable common gate transferring device capable of moving independently in which various types of gates can be moved in a simply reciprocating manner to remarkably reduce a movement region of the carrier.

In the welding apparatus according to the present invention, the carrier may be independently movable in a state where the gate is separated. Thus, since a post-operative gate may be previously prepared, a total operation time does not increase.

As a result, in the welding apparatus of the present invention, a series of gate replacement processes such as a gate recovery, replacement, preparation, and placement may be further quickly and efficiently performed with respect to the body arriving at a welding position after a tabbing process. In addition, the processes can be simplified, and operation efficiency can be improved, and also, a region and equipment required for replacing the gate, a processing time, and total equipment costs may be remarkably reduced.

Fig. 1 is a perspective view of a welding apparatus according to the present invention, and Fig. 2 is a perspective view illustrating a gate transferring device of a welding apparatus according to the present invention.

A welding apparatus of the present invention includes a welding processing part 120, replacement processing parts 110 and 130, and a gate transferring device 140. The welding processing part 120 couples gates 20 transferred from the replacement processing parts 110 and 130 to a body 10 transferred to a welding position by a conveyor system to perform a body welding operation. Also, the welding processing part 120 transfers the used gates 20 to the gate transferring device 140. The replacement processing parts 110 and 130 mount the used gates 20 transferred from the welding processing part 120 and replace the used gates 20 with new gates to provide the new gates to the gate transferring device 140. The gate transferring device 140 includes carriers 143 movable in a state where the gates 20 are detached or attached and a carrier moving unit for moving the carriers 143 between the welding processing part 120 and the replacement processing parts 110 and 130.

Basically, in the welding apparatus of the present invention, the gates 20 for welding the body 10 are separable from the carriers 143 of the gate transferring device 140, and the gates 20 are detachable from the carriers 143 of the gate transferring device 140. Also, the carriers 143 may be independently reciprocated forward and backward between the welding processing part 120 and the replacement processing parts 110 and 130 by the carrier moving unit of the gate transferring device 140 in a state where the gates 20 are separated.

The welding processing part 120 includes handling robots 111, 112, 131, and 132 and welding robots 123 and 124. The handling robots 111, 112, 131, and 132 pick up the gates 20 transferred from the replacement processing parts 110 and 130 by the carriers 143 of the gate transferring device 140 to separate the gates 20 from the carriers 143, and then, the handling robots

111, 112, 131, and 132 place the separated gates 20 on corresponding operation portions to couple, fix, and support the gates 20 to the operation portions. The welding robots 123 and 124 perform a spot welding operation on the body in a state where the gates 20 are coupled to fixed portions of an operation process with respect to the body 10 by the handling robots 111,

112, 131, and 132.

In the welding processing part 120, the two handling robots 121 and 122 for placing the gates 20 are respectively provided at both sides of a body transferring line such that the two gates 20 to be used for both side surfaces of the body 10 are placed at the same time. That is, the handling o

robots 121 and 122 of the welding processing part 120 fundamentally include a pair of handing robots 121 and 122 disposed at the both sides of the welding position of the body 10.

The handling robots 121 and 122 of the welding processing part 120 reversely move the gates 20 from the fixed portions of the operation process after the welding process is finished to seat the gates 20 on the carriers 143 of the gate transferring device 140. Thus, the gates 20 in which a welding operation is finished may be movable to the replacement processing parts 110 and 130 by the carriers 143.

The welding robots 123 and 124 of the welding processing part 120 are adequately disposed in plurality to perform a predetermined welding operation with respect to the both side surfaces of the body 10.

The replacement processing parts 110 and 130 include mounts 113, 114, 133, and 134 on which a plurality of gates 20 are mounted and the handling robots 111, 112, 131, and 132. The handling robots 111, 112, 131, and 132 pick up the gates 20 transferred from the welding processing part 120 by the carriers 143 of the gate transferring device 140 to separate the gates 20 from the carriers 143, and then, the handling robots 111, 112, 131, and 132 move the gates 20 to the mounts 113, 114, 133, and 134 and mount the gates 20 on the mounts 113, 114, 133, and 134. Thereafter, the handling robots 111, 112, 131, and 132 pick up other gates 20 to seat the picked-up gates on the carriers 143.

In the replacement processing parts 110 and 130, the mounts 113, 114, 133, and 134 on which the gates 20 are mounted and the handling robots 111, 112, 131, and 132 for replacing the gates 20 are respectively provided at the both sides of the body transferring line such that the two gates 20 to be used for the both side surfaces of the body 10 are replaced at the same time. The handling robots 111, 112, 131, and 132 are disposed one by one at the both sides of the body transferring line.

In the gate replacement process, the handling robots 111, 112, 131, and 132 of the replacement processing parts 110 and 130 pick up the used gates 20 to separate the gates 20 from the carriers 143 and move and mount the gates 20 onto the mounts 113, 114, 133, and 134. Also, the handling robots 111, 112, 131, and 132 select and pick up other gates 20 corresponding to a car model from the mounts 113, 114, 133, and 134 to transfer the picked-up gates 20 to the welding processing part 120 and seat the gates 20.

In the above-described welding apparatus of the present invention, each of the handling robots 111, 112, 121, 122, 131, and 132 may be coupled to a coupling part 21 disposed on each of the gates 20 to pick up or support the gates 20.

In a preferred embodiment, according to the welding apparatus of the present invention, the robots of the welding processing part 120 and the replacement processing parts 110 and 130 are disposed along a direction in which a target body 10 is moved, i.e., the body transferring line, and the replacement processing parts 110 and 130 may be provided in plurality as necessary.

For example, the replacement processing parts 110 and 130 are disposed before and after the welding processing part 120 along a body movement direction, respectively. Also, the first replacement processing part 110, the welding processing part 120, and the second replacement processing part 130 are sequentially disposed along the body transferring line. At this time, the gate transferring device 140 may linearly reciprocatively transfer the carriers 143 between the first replacement processing part 110, the welding processing part 120, and the second replacement processing part 130.

Thus, the gates 20 replaced in the first replacement processing part 110 may be transferred to the welding processing part 120 by the carriers 143 of the gate transferring device 140 and be used in the welding processing part 120. Thereafter, the used gates 20 may be transferred to the second replacement processing part 130 and mounted. The gates 20 replaced in the second replacement processing part 130 may be reversely transferred by the carriers 143 of the gate transferring device 140 and be used in the welding processing part 120. Thereafter, the used gates 20 may be transferred to the first replacement processing part 110 and mounted.

Of course, the gates 20 may be replaced in only one replacement processing part. For example, the gates 20 replaced in the first replacement processing part 110 may be transferred and used to/in the welding processing part 120, and thereafter, the gates 20 may be transferred and mounted again onto the first replacement processing part 110. Also, the gates 20 replaced in the second replacement processing part 130 may be transferred and used to/in the welding processing part 120, and thereafter, the gates 20 may be transferred and mounted again onto the second replacement processing part 130.

The gate transferring device 140 includes the carriers 143 to which the gates 20 picked up by the handling robots 111, 112, 131, 132, 121, and 122 are attached and detached and the carrier moving unit for moving the carriers 143 between the welding processing part 120 and the replacement processing parts 110 and 130. The carrier moving unit may include an electrical drive unit capable of linearly reciprocatively moving the carriers 143 between the processes.

In a preferred embodiment, the linear drive unit may be longitudinally disposed between the processes. The linear drive unit may include slide rails 141 and 142 to which the carriers 143 are slidably coupled and an electric motor 145, which is coupled to the carriers 143, for driving the carriers 143 to provide a driving force to the carriers 143 such that the carriers 143 are reciprocated along the slide rails 141 and 142.

The slide rails 141 and 142 are longitudinally disposed along the body transferring line to connect the processing parts to each other at both sides thereof. The carriers 143 coupled to the slide rails 141 and 142 are slidably moved along the slide rails 141 and 142 in a selected direction due to the driving force of the electric motor 145.

The carriers 143 may be provided with two carriers in case where the welding apparatus includes three processing parts, i.e., the first replacement processing part 110, the welding processing part 120, and the second replacement processing part 130. At this time, the two carriers 143 may be movable in the same direction or in a direction opposite to each other at the same time or in order. The number of carriers 143 and an interaction therebetween may be variously changed and controlled.

In the welding apparatus of the present invention, the robots (the handling robot and the welding robot) of the respective processing parts and the carrier moving unit (the electric motor, etc.) may be controlled by a controller (not shown). The controller controls a control target element such that the robots and the carrier moving unit are organically operated to adequately perform the gate replacement, movement, placement and fixture on a corresponding process and, and separation.

In a basic operation state, the controller grasps a target car model to determine a replacement processing part, to which the gates 20 corresponding to an existing car model are mounted, of the first replacement processing part 110 and the second replacement processing part 130, and then, operates the handling robots 111, 112, 131, and 132 of the corresponding replacement processing part to select the gates 20 corresponding to the car model from the mounts 113, 114, 133, and 124 and mount the selected gates 20 on the carriers 143.

The electric motor 145 operates to move the carriers 143 to the welding processing part 120, and then, the handling robots 121 and 122 of the welding processing part 120 pick up the gates 20 from the carriers 143 to place the picked-up gates 20 onto the welding process. At this time, the welding robots 123 and 124 operate in a state where the gates 20 are coupled to the fixed portions of the operation process to perform the body welding process. During the welding process, the handling robots 121 and 122 fix and support the gates 20 in a state where the handling robots 121 and 122 are coupled to the gates 20.

When the welding process is finished, the gates 20 used in the welding process are mounted again on the carriers 143 using the handling robots 121 and 122 of the welding processing part 120 to replace the gates 20. The gates 20 mounted on the carriers 143 are moved again to the replacement processing parts 110 and 130 to mount the gates 20 on the mounts 113, 114, 133, and 134.

Preferably, high weight load robots may be used as the handling robots used in the welding apparatus. As robot technologies are developed, a weight of an object operable by being attached to each of the robots increases by movement ranges of the gates 20 for the welding. Thus, the gates 20 fixed to the existing carriers may be changed in a manner in which the gates 20 are detached using the high weight load robots to remarkably reduce the required regions and devices.

Referring to FIG. 1, the welding processing part 120 is disposed at a central portion between the first replacement processing part 110 and the second replacement processing part 130. Also, the gate replacement and mounting regions are disposed in both side directions of the body transferring line at each of the replacement processing parts 110 and 130 to perform the gate replacement and mounting processes at total four regions.

The high weight load handling robots 111, 112, 131, 132, 121 and 122 are disposed one by one at the both sides of the body transferring line. Thus, total six handling robots are disposed over the three processing parts, i.e., the first replacement processing part 110, the welding processing part 120, and the second replacement processing part 130.

The two handling robots 121 and 122 of the welding processing part 120 move the gates 20 to the body 10 to couple/fix the gates 20 to the operation positions of the welding process. The four handling robots 111, 112, 131, and 132 of the two front and rear replacement processing parts 110 and 130 are robots for replacing the gates 20.

The slide rails 141 and 142 of the gate transferring device 140 are disposed one by one at the both sides of the body transferring line, and thus, total two slide rails are provided and provided over the three processes.

The two carriers 143 are slidably coupled to each of the slide rails 141 and 142 in front and rear directions. Each of the carriers 143 may be moved in a state where the gates 20 are attached (a state in which the gates are transferred), and also, each of the carriers 143 may be moved in a state where each of the carriers 143 is separated from the gates 20 to provide a state in which the carriers are empty (a state in which only the carriers are moved in position) .

When the carriers 143 are moved along the slide rails 141 and 142 in the state where the carriers are empty, the gates 20 may become a state in which the gates 20 are picked up by the handling robots 111, 112, 131, 132, 121, and 122 of the replacement processing parts 110 and 130 and the welding processing part 120 or a state in the gates are coupled to the fixed portions of the operation process at the welding processing part 120 (a state in which the body is welded by the welding robots).

In the welding apparatus of the present invention, the two left and right handling robots 121 and 122 detach the gates 20 from the carriers 143, and then, attach the gates 20 to the fixed portions of the operation process to use the gates 20 in the welding process. At this time, the carriers 143 are empty, and thus, the carriers 143 may be independently movable.

During the welding process, since the carriers 142 are movable in the state where the carriers 142 are empty, if necessary, the gates 20 for a next process may be previously attached to increase production.

Hereinafter, the welding processes will be described in order with reference to Figs. 3 to 10.

The tabbed body 10 is transferred to the welding processing part 120 by a conveyor, and the handling robots 121 and 122 of the welding processing part 120 pick up and separate the gates 20 from the carriers 143 transferred along the slide rails 141 and 142 from the second replacement processing part 130 (See Fig. 3). Thereafter, the gates 20 are moved to the body 10 to attach the gates 20 to the fixed portions of the operation process.

Thereafter, units included in each of the gates 20 fix the body 10, and then, several welding robots 123 and 124 weld the loosely assembled body 10. During this process, in the first replacement processing part 110, the handling robots 111 and 112 pick up and separate the gates 20 previously used in the welding processing part 120 from the carriers 143 to move the gates 20 to the mounts 113 and 114 and mount the gates 20 on the mounts 113 and 114 (See Fig. 4).

The two empty carriers 143 are moved along the slide rails 141 and 142 in the direction opposite to each other, i.e., the carrier 143 of the welding processing part 120 is moved to the second replacement processing part 130, and the carrier 143 of the first replacement processing part 110 is moved to the welding processing part 120 (See Fig. 5).

In the second replacement processing part 130, the handling robots 131 and 132 select new gates 20 corresponding to a next car model to pick up the selected gates 20 from the mounts 133 and 134 (See Fig. 6), and then, the gates 20 are attached to the carrier 143 transferred from the welding processing part 120 to provide a state in which the carriers 143 are movable for placing the new gates 20 (the gate replacement of the second replacement processing part).

When the welding process is finished in the welding processing part 120, the units included in each of the gates 20 place the body 10 to provide a detachable state, and then, the handling robots 121 and 122 separate the gates 20 from the fixed portions to seat the separated gates 20 on the carriers 143, thereby providing a state in which the carriers 143 are movable for replacing the gateδs 20.

The welded body 10 is moved to a next process, and the following body is moved to the welding processing part 120.

At this time, the carrier 143 of the welding processing part 120 and the carrier 143 of the second replacement processing part 130 are respectively moved to the first replacement processing part 110 and the welding processing part 120 along the slide rails 141 and 142 in a state where the gates 20 are attached thereto (See Fig. 7).

The handling robots 111 and 112 of the first replacement processing part 110 pick up and separate the previously used gates 20 from the carrier 143 transferred from the welding processing part 120, and then, the handling robots 111 and 112 move the gates 20 to the mounts 113 and 114 to mount the gates 20 thereon.

During this process, in the welding processing part 120, the handling robots 121 and 122 pick up and separate the gates 20 from the carrier 143 transferred from the second replacement processing part 130 to move the gates 20 to the body 10 and attach the gates 20 to the fixed portions.

Thereafter, the units included in each of the gates 20 fix the body 10, and then, several welding robots 123 and 124 weld the loosely assembled body 10 (See Fig. 8).

The handling robots 111 and 112 of the first replacement processing part 110 mount the previously used gates 20 and select new gates 20 corresponding to a next car model according to car model information to pick up the new gates 20 from the mounts 113 and 114 and attach the new gates 20 to the carriers 143, thereby providing a state in which the carriers 143 are movable for placing the new gates 20 (the gate replacement of the first replacement processing part) (See Figs. 9 and 10).

When the welding process is finished in the welding processing part 120, the units included in each of the gates 20 place the body 10 to provide a detachable state, and then, the handling robots 121 and 122 separate the gates 20 from the fixed portions to seat the separated gates on the carriers 143, thereby providing a state in which the carriers 143 are movable for replacing the gates 20.

At this time, the carrier 143 of the first replacement processing part 110 and the carrier 143 of the welding processing part 120 are respectively moved to the welding processing part 120 and the second replacement processing part 130 along the slide rails 141 and 142 in a state where the gates 20 are attached thereto. The welding process of the body 10 is performed using the new gates 20 in the welding processing part 120, and the new gates are replaced in the second replacement processing part 130 (See Fig. 11).

Although the gate replacement process is performed in all of the first replacement processing part 110 and the second replacement processing part 130 in this embodiment, the present invention is not limited thereto. For example, the gate replacement process may be performed in one replacement processing part of the two replacement processing parts 110 and 130. Also, the gate replacement process may be alternately performed in the two replacement processing parts 110 and 130, and if necessary, the gate replacement process may be sequentially performed in any one of the two replacement processing parts 110 and 130.

As described above, the car model information and the position, on which the required gates are mounted, of the next target object can be exactly grasped to adequately operate each of the drive units, whereby accurately utilizing the gates adapted for the existing body.

A specific preferred embodiment of the present invention has been shown and described.

However, this invention is not limited to the aforementioned embodiment, and it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. [Industrial Applicability]

According to the welding apparatus of the present invention, the series of the gate replacement processes such as the gate recovery, replacement, preparation, and placement can be further quickly and efficiently performed with respect to the body arriving at the welding position. In addition, the processes can be simplified, and the operation efficiency can be improved, and also, the region and equipment required for replacing the gate, a processing time, and total equipment costs can be remarkably reduced.

Claims

[CLAIMS] [Claim 1]

A welding apparatus provided with an independently movable carrier, the welding apparatus comprising: a welding processing part; a replacement processing part; a gate transferring device comprising the carrier movable in a state where a gate is detached or attached and a carrier moving unit for moving the carrier between the welding processing part and the replacement processing part, wherein the welding processing part couples the gate transferred from the replacement processing part to a body transferred to a welding position to perform a welding operation and transfers the used gate to the gate transferring device, and the welding processing part comprises a handling robot picking up the gate attached to the carrier, separating the gate from the carrier, moving the gate into the body to couple and fix the gate to the body and moves the gate from the body to the carrier to seat the gate after a body welding operation is finished, and wherein the replacement processing part replaces the used gate transferred from the welding processing part with a new gate to provide the new gate to the gate transferring device.

[Claim 2]

The welding apparatus of claim 1, wherein the welding processing part and the replacement processing part are disposed along a body transferring line.

[Claim 3]

The welding apparatus of claim 1 or 2, wherein the welding processing part further comprise a welding robot for welding the body to which the gate is coupled, and the handling robot and the welding robot are disposed at both sides of a welding position of the body, respectively. o

[Claim 4]

The welding apparatus of claim 1 or 2, wherein the replacement processing part comprises: a mount on which the gates are mounted; and the handling robot picking up and separating the gate from the carrier to move and mount the gate onto the mount, the handling robot picking up the gate mounted on the mount to move and place the gate onto the carrier, and wherein the mount and the handling robot are disposed at both sides of the body transferring line, respectively. [Claim 5]

The welding apparatus of claim 1 or 2, wherein the replacement processing part is disposed along the body transferring line in a front-to- rear direction of the welding processing part and disposed in order of a first replacement processing part, the welding processing part, and a second replacement processing part. [Claim 6]

The welding apparatus of claim 1, wherein the carrier moving unit compr ises : slide rails to which one or more carriers are slidably coupled in singularity or plurality, the slide rails being longitudinally disposed between the replacement processing part and the welding processing part; and an electric motor for driving, which is coupled to the carrier to provide a driving force to the carrier such that the carrier is reciprocated along the slide rails. [Claim 7]

The welding apparatus of claim 6, wherein the slide rails are respectively disposed at both sides of a body transferring line in a state where the carrier is coupled to the slide rails.