KR102532894B1 - Friction stir welding device - Google Patents

Abstract

A friction stir welding device capable of manufacturing a super-large aluminum LNG tank having a storage capacity of at least 8000 m3 (20 m × 20 m × 20 m) is disclosed. The friction stir welding device includes a joint side arm support; a joint-side arm support disposed in parallel with the joint-side arm support; a joining tool provided to be linearly movable in the X-axis direction on the joining-side arm support; a backing plate provided to be linearly movable in the X-axis direction on the arm support on the side to be bonded and facing the bonding tool; and a rotation unit for rotating the backing plate in a direction parallel to the bonding tool.

Description

Friction stir welding device {FRICTION STIR WELDING DEVICE}

The present invention relates to a friction stir welding device, and more particularly, to a friction stir welding device that can be applied to all stages of sintering, neutralization, and control for manufacturing a super-large aluminum LNG tank.

In general, since LNG (Liquefied Natural Gas, Liquid Natural Gas) is stored and transported in a liquid state at -162 ° C, the material and welded parts of the LNG storage tank must be structurally stable at cryogenic temperatures. The material for the LNG tank is made of Ni-based iron alloy (36% Ni steel), stainless steel, or aluminum, and plasma arc welding (GTAW, GMAW) is commercialized. Among them, in the case of an LNG tank made of aluminum, a spherical shape (type C) or a polygonal column shape (type B) in which a thick Al plate is welded by GMAW welding is common.

Conventional arc welding (GMAW, GTAW, etc.) has a problem in that manufacturing cost and duration are long because it is highly difficult to weld due to the characteristics of low-melting aluminum alloys and pores in the welded part are easily generated. On the other hand, friction stir welding (FSW) has recently been attracting attention as a solid-state welding of aluminum, and its commercialization is accelerating as a new technology for weight reduction of vehicles such as railways, aircraft, and automobiles.

Therefore, it is necessary to develop a unique new technology that increases production efficiency and reduces welding defects by manufacturing a polygonal column type (independent LNG tank type-B) with a large storage capacity by friction stir welding (FSW) specialized for aluminum welding.

Republic of Korea Patent Publication No. 10-2016-0056414 (2016.05.20)

In order to solve such conventional problems, the present invention provides a friction stir welding device capable of manufacturing a super-large aluminum LNG tank having a storage capacity of at least 8000 m 3 (20 m × 20 m × 20 m).

Friction stir welding device according to the present invention includes a bonding side arm support; a joint-side arm support disposed in parallel with the joint-side arm support; a joining tool provided to be linearly movable in the X-axis direction on the joining-side arm support; a backing plate provided to be linearly movable in the X-axis direction on the arm support on the side to be bonded and facing the bonding tool; and a rotation unit for rotating the backing plate in a direction parallel to the bonding tool.

The friction stir welding device according to the present invention can reduce welding defects in the manufacture of a large square aluminum LNG tank with a side length of at least 20 m, can be applied from the initial tank assembly stage to the final large tank assembly stage, and arc welding In addition, the production speed is fast and the production efficiency is greatly improved.

1 is a side view showing a friction stir welding device according to an embodiment of the present invention;
2 is a front view showing a friction stir welding device according to an embodiment of the present invention;
3 is a front sectional view showing a work table of a friction stir welding device according to an embodiment of the present invention;
4 is a plan view showing a work table of a friction stir welding device according to an embodiment of the present invention;
5 is a front sectional view showing a friction stir welding device according to an embodiment of the present invention;
6 is a perspective view showing a work table of a friction stir welding device according to an embodiment of the present invention;
7 is a rear perspective view of FIG. 6;
Figure 8 is a front view of Figure 6;
9 is a perspective view showing a backing plate and a rotating part of a friction stir welding device according to an embodiment of the present invention;
10 is a side view showing a backing plate of a friction stir welding device according to an embodiment of the present invention;
11 and 12 are perspective views showing examples of use of the friction stir welding device according to the welding direction according to an embodiment of the present invention;
13 illustrates a process of changing the direction of a backing plate of a friction stir welding device according to an embodiment of the present invention.
14 and 15 are plan views showing examples of use of the friction stir welding device according to the welding direction according to an embodiment of the present invention;
16 is a perspective view showing an example of Y-axis direction welding of a friction stir welding device according to an embodiment of the present invention;
17 is a plan view showing an example of Y-axis direction welding of the friction stir welding device according to the modified example of FIG. 16;
18 and 19 show application examples of the friction stir welding device according to an embodiment of the present invention.

Hereinafter, the technical configuration of the friction stir welding device will be described in detail according to the accompanying drawings.

1 is a side view showing a friction stir welding device according to an embodiment of the present invention, and FIG. 2 is a front view showing a friction stir welding device according to an embodiment of the present invention. In the following description, for convenience, X-axis, Y-axis, and Z-axis directions will be separately described. The X-axis direction is the linear movement direction of the work tool and the backing plate, and the Z-axis direction is the separation direction between the work tool and the backing plate.

As shown in FIGS. 1 and 2 , the friction stir welding apparatus 100 according to an embodiment of the present invention includes a joint side arm support 101, a joint side arm support 102, and a joining tool 120 ), and a backing plate 130 and a rotating part 140.

The joint side arm support 101 and the joint side arm support 102 are formed in the form of a bar having a predetermined length in the X-axis direction. The joint-side arm support 102 is disposed parallel to the joint-side arm support 101 and is provided with respect to the joint-side arm support 101 so that an angle can be adjusted. The joined-side arm support 101 and the joined-side arm support 102 are rotatably connected to ends through a joint 103 .

The joined-side arm support 101 and the joined-side arm support 102 are configured to be able to rotate at one end, and take a shape similar to a compass capable of changing an angle between the two supports.

The bonding tool 120 is provided on the bonding-side arm support 101 to be linearly movable in the X-axis direction. The joining tool 120 is composed of a welding tool having a friction stir welding (FSW) means to perform welding on a material to be joined.

The backing plate 130 faces the bonding tool 120 and is provided to the arm support 102 on the side to be bonded to be linearly movable in the X-axis direction. The backing plate 130 supports a load acting on the back side of the material to be joined when the bonding tool 120 solidly bonds the material to be joined of the butt joint.

Gear guides 170 are formed to extend in the X-axis direction, which is the longitudinal direction, between the arm support 101 on the joined side and the arm support 102 on the joined side. 1 shows that the gear guide 170 is exposed to the outside in a side view, but in this embodiment, the gear guide 170 is substantially provided inside the concave groove and is not exposed to the outside. The gear guide will be described in detail later. The bonding tool 120 and the backing plate 130 face each other in the Z-axis direction and are spaced apart from each other.

The backing plate 130 may be configured to linearly move together in conjunction with the work tool 120 in the X-axis direction. That is, a workbench to be described later that is provided on the joint side arm support 101 and the joined side arm support 102 and travels in a straight line is synchronized with an electric signal, so that each support can be linearly moved along the gear guide 170 .

A plurality of fixing protrusions 110 are protruded from the joint-side arm support 101 and the joint-side arm support 102 in the X-axis, Y-axis, and Z-axis directions. The fixing protrusion 110 protrudes from the surface of each support and protrudes from each surface of each support in the X-axis, Y-axis, and Z-axis directions.

18 and 19 show application examples of the friction stir welding device according to an embodiment of the present invention. Referring to FIGS. 18 and 19 , the fixing protrusion 110 is configured to be inserted into the fixing groove 204 formed on the surface plate 203 . In the case of an application example when the joint line 202 of the material to be joined 201 is formed perpendicularly to the surface plate 203, the fixing protrusion 110 formed on the joint side arm support 101 and the joint side arm support 102 It is inserted into the fixing groove 204 of the surface plate 203, and the friction stir welding device 100 is installed in the surface plate 203 in the longitudinal direction. The longitudinal direction of the friction stir welding device 100 is parallel to the X-axis direction. In this case, it is preferable that a plurality of fixing grooves 204 are formed in a checkerboard pattern on the surface plate 203 .

The rotation unit 140 rotates the backing plate 130 in a direction parallel to the bonding tool 120 . The rotating part 140 is provided on the work table of the arm support 102 on the side to be joined, and the backing plate 130 is coupled to the rotating part 140 . The rotation unit 140 rotates the backing plate 130 by +90° or -90° so that it can correspond appropriately according to the direction of the welding line of the material to be joined 201. That is, the rotating part 140 has one side fixed to the arm support 102 on the side to be joined and the other side fixed to the backing plate 130, so that the backing plate 130 is moved from -90° to -90° to the linear movement direction. Rotate 90°.

In this case, the rotation unit 140 does not necessarily have to be rotated at 90° intervals, and may be configured to freely rotate at an appropriate angle as needed.

3 is a front cross-sectional view showing a work table of a friction stir welding device according to an embodiment of the present invention, FIG. 4 is a plan view showing a work table of a friction stir welding device according to an embodiment of the present invention, and FIG. It is a front sectional view showing a friction stir welding device according to an embodiment of the present invention.

Referring to FIGS. 3 to 5 , a work table 160 for linearly traveling by coupling a joining tool 120 and a backing plate 130 to the joining side arm support 101 and the joining side arm support 102, respectively. are provided

Concave grooves for accommodating the work table 160 are formed in the longitudinal direction on the facing surfaces of the joint side arm support 101 and the joint side arm support 102, respectively, so that the cross section has a “┖┚” shape. Guide grooves 1011 and 1021 are formed on both walls of the concave groove in the Y-axis direction.

In addition, guide rollers 164 inserted into the guide grooves 1011 and 1021 are provided on both sides of the worktable 160 in the Y-axis direction. The guide rollers 164 are rotatably connected to roller shafts 163 extending on both sides of the work table 160 in the Y-axis direction. As the guide rollers 164 are inserted into the guide grooves 1011 and 1021 and rotated idle, the worktable 160 is guided in the X-axis direction during straight travel. Guide rollers 164 may be provided in a plurality of rows along the X-axis direction.

A gear guide 170 is provided on the bottom surface of the concave groove in the Z-axis direction. The gear guide 170 is provided on the joint side arm support 101 and the joint side arm support 102, respectively, and is formed to extend in the longitudinal direction of the joint side arm support 101 and the joint side arm support 102. do. In addition, at least one gear 162 and 162a engaged with the gear guide 170 is provided on the bottom surface of the work table 160 in the Z-axis direction.

The work table 160 includes a driving motor 161 that rotates and drives the gear 162 . The gears 162 and 162a include a drive gear 162 connected to the drive shaft of the drive motor 161 and rotated, and a non-drive gear 162a rotated idle. The work table 160 must linearly move in one direction (X-axis direction) while enduring a high load generated during friction stir welding.

The joint-side arm support 101 and the joint-side arm support 102 are rotatably connected to ends through a joint 103 so that angles can be adjusted to each other. Through this configuration, when the material to be joined is inclined while belonging to a large structure, it is possible to respond by giving an angle between the arm support 101 and the arm support 102 on the joined side.

6 is a perspective view showing a work table of a friction stir welding device according to an embodiment of the present invention, FIG. 7 is a rear perspective view of FIG. 6 , and FIG. 8 is a front view of FIG. 6 .

6 to 8, the work table 160 on the side of the arm support 101 on the bonding side to which the work tool 120 is coupled has a multi-point contact restraint 165 for pressing the material 201 to be joined in the Z-axis direction. ) is provided. At least one of the multi-point contact restraints 165 is provided around the work tool 120 and is composed of a plurality of balls 166 capable of rolling on the surface of the material 201 to be joined.

The multi-point contact restraining part 165 may be composed of a kind of ball caster made of a plurality of cemented carbide or steel balls that have undergone surface hardening and modification treatment such as carburizing. The multi-point contact restraining unit 165 is capable of transporting the material to be joined in any direction, but increases the degree of restraint during welding and improves the quality of joining by preventing vertical displacement of the material to be joined around the work tool.

In FIG. 8 , the solid line of the material to be joined 201 shows an un-joined state, and the dotted line shows a state in which the joining of the lap joint is completed. The multi-point contact restraining portion 165 composed of balls 166 evenly distributes and presses the material to be joined 201 from top to bottom.

9 is a perspective view showing a backing plate and a rotating part of a friction stir welding device according to an embodiment of the present invention, and FIG. 10 is a side view showing a backing plate of a friction stir welding device according to an embodiment of the present invention.

Referring to FIGS. 9 and 10 , the backing plate 130 is composed of a plurality of multi-sections 135 rotated in an endless orbit to withstand high loads. More specifically, the backing plate 130 is composed of a support frame 131 and a crawler module 132 .

The support frame 131 has a “┖┚” shape and is fixed to a second rotation unit 141 to be described later among the rotation units 140. The caterpillar module 132 has a pair of conveying rollers 134 . The conveying rollers 134 are installed at a predetermined distance from each other, and a plurality of multi-segments 135 are rotatably connected to each other to form an endless track wound around the pair of conveying rollers 134 . A plurality of fixing rollers 133 are provided in the support frame 131 to prevent the multi-segments 135 from being separated. The backing plate 130 includes a motor 136 that rotates the feed roller 134 to rotate the caterpillar.

In this case, the fixing roller 133 may interfere with the multi-point contact restraining part 165 in some cases (in the case of the application example shown in FIG. 17). For this reason, when a plurality of multi-point contact restraining units 165 are provided, the fixing roller 133 becomes unnecessary and can be omitted.

11 and 12 are perspective views illustrating usage examples of a friction stir welding device according to a bonding direction according to an embodiment of the present invention, and FIG. 13 is a perspective view of a backing plate of a friction stir welding device according to an embodiment of the present invention. It shows the direction change process.

Referring to FIGS. 11 to 13 , the rotation unit 140 includes a first rotation unit 142 and a second rotation unit 141 . The first rotating part 142 is fixed to the side of the arm support 102 to be joined. The second rotating part 141 is fixed to the side of the backing plate 130 and is rotatable in a direction parallel to the first rotating part 142 . In addition, the second rotation unit 141 can move up and down in the Z-axis direction with respect to the first rotation unit 142 .

11 shows that the rotation direction of the backing plate 130 is the X-axis direction, parallel to the X-axis direction, which is the driving direction of the work tool 120, and FIG. 12 shows the rotation direction of the backing plate 130 as the Y-axis direction. It is a direction orthogonal to the X-axis direction, which is the traveling direction of the tool 120. FIG. 13 illustrates a process in which the backing plate 130 is rotated from the state shown in FIG. 11 to the state shown in FIG. 12 by the rotation unit 140 . Referring to FIG. 13 , in the state of FIG. 11 , the second rotation unit 141 moves upward with respect to the first rotation unit 142 and then rotates 90°, and then the second rotation unit 141 attaches to the first rotation unit 142. move down about

14 and 15 are plan views illustrating usage examples of the friction stir welding device according to the bonding direction according to an embodiment of the present invention, and FIG. 16 is a Y-axis direction of the friction stir welding device according to an embodiment of the present invention. FIG. 17 is a perspective view showing a bonding example, and FIG. 17 is a plan view illustrating a Y-axis direction bonding example of the friction stir welding device according to the modified example of FIG. 16 .

As shown in FIG. 14 , when the joining direction of the materials to be joined 201 is in the X-axis direction, the transfer means becomes the work table 160 of the arm support 101 on the joining side. In addition, when the joining direction of the material to be joined 201 is the Y-axis direction as shown in FIG. 15, the conveying means becomes the endless track multi-section 135 of the backing plate 130.

Referring to FIG. 16 , the joining direction of the material to be joined 201 is in the Y-axis direction, and the length of the material to be joined 201 may be set to be unlimited. In this case, the work table 160 of the joint side arm support 101 and the work table 160 of the joint side arm support 102 are fixed, and bonding can be performed while moving only the material 201 to be joined. Referring to FIG. 17 , the joining direction of the material to be joined 201 is in the Y-axis direction, and the length of the material to be joined 201 may be set to be unlimited. In addition, the maximum width of the finished jointed product of the material to be joined 201 is the same as the distance that the work table 160 can run in a straight line.

In the case of the material to be joined at the lap joint, the part to be friction stir welded on the support side base material uses an extrusion profile so that it is locally 4 times or more thicker than the plate material adjacent to the work tool 120, so that the support side base material is the backing plate. can be substituted for In this case, the backing plate 130 is not used, and the bonding tool 120 and the backing plate 130 do not face each other. Adjustment of the relative position between the bonding tool 120 and the backing plate 130 may be performed by adjusting a rotation angle between the aforementioned arm supports. That is, the backing plate 130 can be adjusted to be used or not used as needed.

In the above, the backing plate 130 is doubled and realized as a two-stage structure configured to proceed in a direction of 90 ° with the direction of the endless track, so that friction stir welding of long plates in one direction is possible. In this case, since the friction stir welding device of the present invention is fixed and the plate material to be joined must be transported, in addition to the two-stage endless track type backing plate, a separate device for loading and transporting the joined member from the outside of the device It is possible to configure a guide roller of.

The friction stir welding device according to an embodiment of the present invention can reduce welding defects in the manufacture of a large square aluminum LNG tank with a side length of at least 20 m, and can be applied from the initial tank assembly stage to the final large tank assembly stage. do. In addition, compared to arc welding, defects are reduced, production speed is fast, and production efficiency is greatly improved.

In summary, the friction stir welding device 100 according to an embodiment of the present invention is a backing plate designed to be robust enough to withstand the load by the multi-point contact restraint 165 for FSW bonding and restraining the displacement of the material to be joined in the vertical direction. It is provided with a support frame 131 of 130, a plurality of multi-pieces 135 capable of linearly moving the material to be joined while enduring the above load, and a rotating part 140 for changing the joining direction.

In addition, the endless orbital multi-segment backing plate 130 withstands the load transferred from the joining tool 120 and the multi-point contact restraint 165 located on the workbench of the arm support on the joining side after joining, and adjusts the welding length of the joint to be joined. It is configured to be able to transfer the material to be joined without being restricted. In order to serve as a backing plate without limiting the length of the welding field, as an endless track composed of a plurality of segments capable of uniaxially transported by a motor drive is provided, each multi-section is small enough to enable orbital movement while enduring the load on the bonding side. The load can be distributed and transmitted by means of rollers.

On the other hand, in the above, the rotation unit 140 is attached to the work table 160, and although not shown, relative rotational movement between the first rotation unit 142 and the second rotation unit 141 is possible by driving an internal motor, An elevation movement between the first rotation unit 142 and the second rotation unit 141 may be implemented by a separate actuator or the like.

The rotating part 140 raises and separates the upper second rotating part 141 by 10 mm or more in the +Z-axis direction in the absence of load during rotation in order to withstand a high load during bonding, rotates it by a desired angle, and then rotates it in the -Z-axis direction. Lower it to its original position. The traveling direction of the caterpillar may be adjusted by the rotation angle of the second rotation unit 141 changed in this step.

In addition, a downward load loading device is provided between the work table 160 of the joint side arm support 101 and the multi-point contact restraining part 165, so that vertical movement and downward load application are possible. When the multi-point contact restraining part 165 restrains the material to be joined 201, pressure is applied so that the material to be joined 201 is firmly fixed to the lower endless track multi-segment backing plate 130.

In this case, the restraining pressure on the material to be joined does not cause severe plastic deformation in the plate material to be joined, there is no vertical displacement of the material to be joined after the restraint, and it must be able to be transported by the lower endless track backing plate. The restraining pressure varies depending on the thickness and material of the plate materials to be joined, and it is preferable to determine the appropriate pressure through 3 to 4 actual pressing experiments in the range of approximately 5% or more and 50% or less of the yield stress.

So far, the friction stir welding device according to the present invention has been described with reference to the embodiment shown in the drawings, but this is only exemplary, and anyone skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of technical protection should be determined by the technical spirit of the appended claims.

100: friction stir welding device
101: joint side arm support 102: joined side arm support
103: joint 110: fixed protrusion
120: work tool 130: backing plate
131: support frame 132: caterpillar module
133: fixing roller 134: transfer roller
135: multisection
140: rotating part 142: first rotating part
141: second rotating part
160: work table 161: drive motor
162: gear 164: guide roller
165: multi-point contact restraint 166: ball
170: gear guide
201: material to be joined 202: joint line
203: surface plate 204: fixed groove

Claims (10)

joint side arm support 101;
a jointed side arm support 102 spaced apart from the jointed side arm support 101 in the Z-axis direction;
a joining tool 120 provided to be linearly movable in the X-axis direction on the joining-side arm support 101;
a backing plate 130 provided to be linearly movable in the X-axis direction on the arm support 102 on the side to be bonded; and
A rotating part 140 for rotating the backing plate 130 in the Z-axis direction as an axis,
The joint side arm support 101 and the joint side arm support 102 are provided with a work table 160 for straight driving by combining the joining tool 120 and the backing plate 130, respectively,
Concave grooves for accommodating the worktable 160 are formed in the longitudinal direction on the facing surfaces of the joint side arm support 101 and the joint side arm support 102, respectively, and guides are formed on both walls of the concave groove in the Y-axis direction. Grooves 1011 and 1021 are formed,
Friction stir welding device characterized in that guide rollers 164 inserted into the guide grooves 1011 and 1021 are provided on both sides of the worktable 160 in the Y-axis direction. According to claim 1,
The rotating part 140 has one side fixed to the joint arm support 102 and the other side fixed to the backing plate 130, so that the backing plate 130 is moved at -90° to 90° with respect to the linear movement direction. A friction stir welding device characterized in that for rotating. delete delete According to claim 1,
A gear guide 170 is provided on the bottom surface of the concave groove in the Z-axis direction,
At least one gear (162, 162a) engaged with the gear guide 170 is provided on the bottom surface of the worktable 160 in the Z-axis direction, and a drive motor 161 for rotationally driving the gear is included. A friction stir welding device. joint side arm support 101;
a jointed side arm support 102 spaced apart from the jointed side arm support 101 in the Z-axis direction;
a joining tool 120 provided to be linearly movable in the X-axis direction on the joining-side arm support 101;
a backing plate 130 provided to be linearly movable in the X-axis direction on the arm support 102 on the side to be bonded; and
A rotating part 140 for rotating the backing plate 130 in the Z-axis direction as an axis,
The joint-side arm support (101) and the joint-side arm support (102) are rotatably connected at their ends through a joint (103) so that angles can be adjusted to each other. According to claim 2,
The rotating part 140,
A first rotation part 142 fixed to the side of the arm support 102 on the side to be joined;
A second rotation unit 141 fixed to the backing plate 130, rotatable in a direction parallel to the first rotation unit 142, and elevating in the Z-axis direction with respect to the first rotation unit 142. A friction stir welding device, characterized in that consisting of. delete delete According to claim 1,
The friction stir welding device, characterized in that the backing plate 130 is composed of a plurality of multi-pieces 135 rotated in the form of an endless orbit.

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