KR20170073892A - Spot welding device for weldability test of sheet steel - Google Patents

Abstract

The point welding apparatus for evaluating the spot weldability of the steel plate specimen includes a spot welder having an upper welding electrode and a lower welding electrode and performing spot welding on the specimen located between the upper welding electrode and the lower welding electrode, A specimen conveyor for moving the specimen in the x- and y-axis directions, and the position of the spot to be spot welded on the specimen can be adjusted to a desired position.

Description

Technical Field [0001] The present invention relates to a spot welding apparatus for evaluating spot weldability of a steel plate specimen,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding apparatus, and more particularly to a spot welding apparatus for performing spot welding on a steel plate specimen and for evaluating the spot weldability.

In a variety of mechanical devices having joints connecting a large number of steel plates such as an automobile, the joining means of the joining portion, the joining portion evaluation method, and the physical properties of the joining portion greatly affect the quality of the apparatus.

In the production of finished vehicles, the most commonly used methods for joining metal sheets are mechanical joining using fasteners and spot welding using two or more steel sheets.

The point welding method is the most fundamental and important bonding method for steel makers producing automotive steel plates and automobiles. In this regard, the point welding of the steel plate, that is, the shear strength of the spot weld, the nugget of the welding spot, Size, tensile strength, and electrode life.

The evaluation criteria for spot weldability are standardized by the KS standard, and roughly divided into an allowable range evaluation for determining the allowable current range of the welding, and an electrode life evaluation (two evaluations are referred to as " evaluation " .

The allowable range evaluation can be made by tensile shear test according to KSB0851 specification or by + self tensile test according to KSB0852 specification. The electrode life evaluation can be made according to the KSB ISP 18278-2 standard.

In order to proceed with the evaluation, pre-conditioning is performed so that the welding electrode reaches the stabilization condition before the test.

Preconditioning is performed by performing point welding of a 300-point spot by using a predetermined pressing force on a predetermined thickness and material steel plate specimen, and then performing the evaluation using the electrode.

Conventionally, the specimens were manually spot welded one by one to proceed with the evaluation items such as preconditioning.

Therefore, in particular, a lot of time and cost have been consumed in the pre-conditioning, the working efficiency is lowered and the fatigue of the worker is accumulated. In addition, the specimen could not be stably fixed, which could lead to inaccurate test results. In addition, there is a problem that the safety of the worker is threatened because the worker is continuously positioned near the welding part.

Korean Patent Laid-Open No. 10-2009-0067434

The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to improve the efficiency of the pre-conditioning and evaluation process in the spot weldability evaluation, to save cost and time, to secure the safety of workers, And to provide a spot welding apparatus capable of improving the strength of the spot welding apparatus.

In order to achieve the above object, according to one aspect of the present invention, there is provided a spot welding apparatus for evaluating spot weldability of a steel plate specimen, the spot welding apparatus including an upper welding electrode and a lower welding electrode, A spot welder for performing spot welding on the specimen, and a specimen conveyer for moving the specimen in the x- and y-axis directions while holding the specimen in a fixed position, and a spot welding device capable of adjusting the position of the spot to be spot- / RTI >

According to one embodiment, while the specimen conveyer moves the specimen, the spot welder performs continuous spot welding, and the number of the total spot spots of the spot welding to be continuously performed can be set.

According to one embodiment, the specimen is moved such that a plurality of spot points of spot welding are formed in rows and columns.

According to an embodiment, it is possible to set the number of RBs or the number of RBs constituting the row.

According to one embodiment, the distance between the points of the spot welding can be set.

According to one embodiment, the specimen conveyor includes a fixing member in the form of a forceps for holding and fixing one end of the specimen.

According to one embodiment, the fixing member fixes the specimen so that the other end of the specimen facing one end of the specimen fixed to the fixing member is arranged to face the spot welder.

1 is a perspective view of a spot welding apparatus according to an embodiment of the present invention.
Fig. 2 shows the positions of the upper and lower electrodes with respect to the specimen in the spot welding apparatus of Fig. 1. Fig.
Figure 3 shows a specimen conveyor of the spot welding apparatus of Figure 1;
Fig. 4 is a side view of the support of the spot welding apparatus of Fig. 1;
Fig. 5 shows a specimen in which spot welding is performed by the spot welding apparatus of Fig. 1. Fig.
Figure 6 shows a display of the control input of the sample feeder.
Figures 7 and 8 illustrate auxiliary supports for dot welding performance on cross-shaped specimens.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may be added unless "only" is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

It is to be understood that elements or layers are referred to as being "on " other elements or layers, including both intervening layers or other elements directly on or in between. Like reference numerals refer to like elements throughout the specification.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

The sizes and thicknesses of the individual components shown in the figures are shown for convenience of explanation and the present invention is not necessarily limited to the size and thickness of the components shown.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other partially or entirely and technically various interlocking and driving is possible as will be appreciated by those skilled in the art, It may be possible to cooperate with each other in association.

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

1, the spot welding apparatus 1 includes a specimen conveyor 10 that fixes and supports a specimen 2 and a spot welder 20 that performs spot welding with respect to the specimen 2 .

The spot welder 20 includes a box-shaped main body 21 and electrode arms 23 and 24 arranged vertically and extending forward of the main body 21.

The upper electrode arm 23 is provided with an electrode moving body 230 which can be raised or lowered along the longitudinal direction of the arm by using a pneumatic cylinder or the like and the upper electrode arm 23 is provided with an upper welding An electrode rod 210 is provided. An upper electrode 211 is replaceably attached to a lower side end portion of the upper welding electrode rod 210.

The upper welding electrode rod 210 can move up and down as the electrode moving body 230 moves up and down.

Although not shown in detail in FIG. 1, a lower welding electrode rod 220 is coupled to the lower electrode arm 24 so as to extend in the up-and-down direction so as to form the same axis as the upper welding electrode rod 210, And a lower electrode 221 is replaceably attached to the side end portion (see Fig. 2).

Fig. 2 shows the positions of the upper and lower electrodes with respect to the specimen 2 which is a spot welding target.

As shown in FIG. 2, the specimen 2 to be welded is disposed between the upper welding electrode rod 210 and the lower welding electrode rod 220 arranged side by side.

In this specification, the specimen 2 refers to two steel plates 3 and 4 superimposed one above the other.

According to the present embodiment, the position of the lower welding electrode rod 220 is fixed, and the specimen 2 is brought into contact with the lower electrode 221.

When the upper welding electrode rod 210 descends at the raised position and comes into contact with the upper steel plate 3 of the test piece 2, electric current flows to the upper electrode, the test piece and the lower electrode, and the specimen 2 is melted and spot welded .

During continuous spot welding, the upper welding electrode rod 210 is controlled to move up and down repeatedly.

1, the main body 21 of the spot welder 20 is capable of controlling the pressing force of the spot welding, the welding speed, the flow rate of the cooling water flowing to the upper and lower electrodes, and observing the welding specification of the spot welding machine such as the cooling water temperature A control / monitoring device 22 may be attached.

The welding principle and operation of the spot welder for performing spot welding by bringing the two electrodes into contact with the steel sheet are well known and will not be described in detail here.

3 shows the specimen conveyor 10 of the spot welding apparatus 1 according to the present embodiment.

As shown in FIG. 3, the specimen conveyor 10 includes a box-shaped main body 110 and a plurality of tabs. A movable support 120 installed at an upper end of the main body 110 and capable of moving the specimen while fixedly supporting the specimen and a control unit 120 installed at the upper end of the main body 110 to input a control command of the specimen conveyor 10 And a control input 150,

The body 110 is formed in a box shape and a wheel 111 is provided at the lower end to move the position of the sample conveyor 10.

The main body 110 includes a control box 112 having a controller for processing the power supply of the test piece feeder 10 and the input of the control input unit 150 to operate the test piece feeder 10.

The movable supporting part 120 includes a supporting part 130 for fixing and supporting the test piece 2 and a moving part 140 for moving the supporting part 130 in the x and y axis directions to move the test piece 2.

In this specification, the x-axis and the y-axis are defined as axes parallel to the plane of the drawing and perpendicular to each other.

The moving unit 140 includes a y-axis rail member 141 fixed to the upper end of the main body 110 and extending in the y-axis direction, an x-axis rail member 140 extending in the x- Member 144 as shown in FIG.

The y-axis rail member 141 includes a y-axis rail 142 extending in the y-axis direction and a knocking 147 formed at the lower end of the x-axis rail member 144 is engaged with the y- Is slidably inserted along the rail (142). A first pneumatic cylinder (not shown in detail) capable of moving the cylinder in the y-axis direction is connected to the latch 147.

According to this configuration, the latch 147 is guided by the y-axis rail 142 to move linearly in the y direction by the action of the cylinder of the first pneumatic cylinder. Accordingly, the entire x-axis rail member 144 can move in the y-axis direction.

The x-axis rail member 144 includes an x-axis rail 145 extending in the x-axis direction and an engaging member 132 (not shown) formed at the lower end of the support plate 131 of the support portion 130. [ Is slidably inserted along the x-axis rail 145. A second pneumatic cylinder (not shown in detail) capable of moving the cylinder in the x-axis direction is connected to the latch 132.

According to this configuration, the action of the cylinder of the second pneumatic cylinder causes the latch 132 to be guided by the x-axis rail 145 to move linearly in the x direction. Accordingly, the entire support portion 130 moves in the y-axis direction.

In short, the x-axis rail member 144 moves in the y-axis direction by the action of the first pneumatic cylinder, and the support portion 130 can move in the y-axis direction, and the support portion 130 can be moved by the action of the second pneumatic cylinder. Can be moved in the x-axis direction. The movement of the support 130 is accompanied by the movement of the specimen 2 fixed thereto.

Therefore, according to the present embodiment, the first pneumatic cylinder and the second pneumatic cylinder are independently controlled, and the specimen can be freely moved in the x-axis and y-axis directions.

4 shows the support 130 in side view.

As shown in FIG. 4, the support 130 includes a fixing member 133 formed on the support plate 131.

The fixing member 135 holds and fixes the specimen 2 from above and below in the form of a forceps and supports the upper forceps 135 for pressing the upper surface of the specimen 2 and the lower forceps 136 for supporting the lower surface of the specimen 2 .

When the fixing knob 134 is turned, the upper forceps 135 move up and down. The upper specimen 2 is placed between the upper forceps 135 and the lower forceps 136 and then the upper forceps 135 is lowered to press the upper and lower portions of the specimen 2 firmly.

As shown in Fig. 4, the fixing member 135 has a structure for holding and fixing one end of the specimen 2.

The other end of the specimen 2, which is not fixed to the fixing member 135, is disposed to face the upper and lower electrodes of the spot welder.

According to the present embodiment, it is possible to freely select and fix the specimen 2 having various areas by making the fixing member 135 only hold and fix only one end of the specimen 2. That is, the area of the test piece 2 provided on the spot welding apparatus can be freely selected without being limited by the standard.

In addition, since the free end of the untreated specimen 2 is directed toward the welding electrode, there is an advantage that the moving range of the moving unit 140 can be maximized.

It is also possible to separate or install the test piece 2 very quickly and simply by configuring the fixing member 135 in the form of a forceps receiving the test piece 2 from above and below, ) Can be installed.

Fig. 5 shows a specimen 2 in which spot welding is performed by the spot welding apparatus 1 according to the present embodiment.

The spot welding apparatus 1 according to the present embodiment can automatically perform continuous spot welding with respect to the specimen 2.

The continuous spot welding operation is performed by vertically moving the upper electrode 211 of the spot welder 20 at predetermined time intervals and simultaneously moving the specimen along the predetermined path to change the spot welding spot .

Fig. 5 shows a specimen 2 in which spot welding is performed by the spot welding apparatus 1 according to the present embodiment.

As shown in Fig. 5, the spot welding apparatus 1 according to the present embodiment allows spot welding points formed continuously to be formed in rows and columns.

According to this embodiment, in automatic continuous welding mode, the first spot weld made by spaced apart by a first spot (S ₁₎ is completed, a predetermined in the test piece along the x axis (FIG left direction in Fig. 5) the distance (P _x) And the next welding is performed at the position.

According to this embodiment, it is possible to arbitrarily set the number of spot spots S which are continuously performed from start to stop at one time. Also, the number n of rows to be routed and the number m of rows can be arbitrarily set.

Continuous welding is performed while moving the specimen in the x-axis direction. When the last spot (S _n ) of one row is made by the number of the set number of rows, the specimen 2 is moved in the y- Ensure welding is achieved.

At this time, according to the setting, the welding of two rows may be performed in the direction opposite to the one row starting from the last spot (S _n ) of one row and the spot position (S ₃ ) immediately adjacent to the specimen by moving the specimen only in the y- In the x-axis and y-axis directions so as to start in the same direction as one row, starting from the first spot (S ₁ ) of the first row and the _second spot position (S ₂ ) immediately adjacent thereto.

At this time, a distance between the distance (pitch) (P _x ) between the row points in the row direction and a distance (P _y ) between the column direction row points can also be arbitrarily set.

This process is repeated, and when the continuous spot welding is performed for a predetermined number of RBs, the welding process is terminated.

The condition determination of the continuous point welding is performed according to the input of the user through the control input unit 150.

6 shows the display 151 (see Fig. 1) of the control input 150 of the sample transport machine 10 according to the present embodiment. The display 151 according to the present embodiment configures a user interface with a touch screen.

As shown in FIG. 6, the display 151 may select a manual or automatic mode of welding.

In addition, the number of RBs can be arbitrarily set through the RB number designation window 152. [ For example, the number displayed on the window 152 may be increased or decreased by using the arrow key 156, or a number may be directly input using a number pad provided separately.

Similarly, in the display 151, matrix designation windows 153 and 154 for designating the number of rows and columns of consecutive rubbers are displayed, and a distance designation window 155 for designating the distance between the rubbers is displayed.

In addition to the above items, the display 151 may also include an emergency stop key for emergency stop of welding and a status display window 159 for indicating the status of welding.

It will be appreciated that the configuration of the display 151 shown in FIG. 6 is exemplary and that various types of UI configurations are possible.

On the other hand, the display 151 is provided with a spot position adjustment key 157 for manually adjusting a spot position to be spot welded to a desired position.

The spot welding apparatus 1 according to the present embodiment can be set by finely adjusting the spot position to be spot welded to the desired position in the specimen 2 by operating the corresponding spot spot position adjustment key 157. [

When the other spot position adjustment key 157 is operated, the specimen moves in the corresponding direction. When the upper and lower electrodes are positioned at the position of the desired specimen by moving the specimen, the position is inputted to the initial position where the continuous spot welding is started by pressing the setting key, and welding is started from the position.

Such an adjustment operation of the target position can be usefully used, for example, in the evaluation of electrode life.

According to the standard, 200 (or 100 or 50) RBs are applied to one specimen (100 RBs for 400-600 welds and 50 RBs for less than 400 welds) for one specimen, And the electrode life is evaluated through evaluation of the separate specimen by performing spot welding.

Referring again to FIG. 5, for example, if the specimen 2 has an area capable of accommodating about 300 RBs, if the initial RB is formed at a designated position when a new continuous spot welding process is performed, The test piece (2) consisting of 100 RBs can not be used again.

According to the present embodiment, as shown in FIG. 5, when a new continuous spot welding process is started, the initial spot position S ₁ 'can be designated by moving the test piece to the existing spot position. Therefore, the continuous spot welding process is started from the initial spot position S ₁ 'to the portion of the specimen 2 to be welded.

Accordingly, it is possible to prevent the specimen 2 having the remaining space from being discarded unnecessarily.

As described above, in the spot welding apparatus 1 according to the present embodiment, the area of the specimen 2 to be installed is not standardized, and the specimen 2 having various areas can be fixed and installed as required.

When these characteristics and the characteristics capable of arbitrarily designating the initial spot position S ₁ 'are combined when a new continuous spot welding process is started, the residual space not welded is found in the large area specimen 2, Or a pre-conditioning operation can be carried out, so that the saving of evaluation specimens can be maximized.

The saving aspect of the evaluation specimen can be further maximized depending on the number of RBs, the distance between RBs, and the number of rows and columns.

On the other hand, for example, spot welding for a separate specimen in the electrode life evaluation is performed for a cruciform specimen 2 'in which two steel plates 3' and 4 'are arranged in a cross as shown in Fig. To this end, an auxiliary support 160 having a cross groove 162 on which the cruciform specimen 2 'is placed is used.

Figs. 7 and 8 illustrate auxiliary supports for point welding of the cross-shaped specimen 2 '.

An opening 162 is formed at the center of the auxiliary supporting unit 160 so that the lower electrode 221 is exposed to contact the lower surface of the cruciform specimen 2 '. It will be appreciated that an auxiliary support airfoil may be used that has a straight groove instead of a cross depending on the standard.

A sleeve 163 to which the lower welding electrode rod 220 is inserted and a fastening member 164 to strongly support the auxiliary supporting device 160 on the lower welding electrode rod 220 are provided on the lower surface of the auxiliary supporting device 160.

The auxiliary support 160 may be secured in a manner that it simply fits over the lower welding electrode rod 220, as best seen in FIG.

The auxiliary supporting device 160 is installed near the electrode by a person. The sample conveying device 10 according to the present embodiment is easily separated from the point welder 20 by rolling the wheel 111 So that it is possible to easily secure a working space for the installation of the auxiliary support device 160 and the welding performance.

According to the spot welding apparatus 1 according to the present embodiment, the continuous welding process is automated to improve the efficiency of the weldability evaluation process and to secure safety by improving worker fatigue accumulation and working environment. In addition, the reliability of the evaluation result can be improved through automation.

In addition, compatibility with various specimens having different sizes is very excellent, and the number of turns of the spot welding, the spacing and the like can be freely adjusted, so that it is possible to flexibly cope with the standard change in the evaluation of the spot weldability.

In addition, a remarkable saving of the evaluation material can be achieved through the arbitrary setting of the RB position, thereby reducing the cost.

Claims (7)

A point welding apparatus for evaluating the spot weldability of a steel plate specimen,
A spot welder having an upper welding electrode and a lower welding electrode to perform spot welding on the specimen located between the upper welding electrode and the lower welding electrode;
And a specimen conveyor for moving the specimen in the x-axis and y-axis directions by fixing and supporting the specimen,
Wherein the spot welding position to be spot welded in the specimen can be adjusted to a desired position. The method according to claim 1,
Wherein the specimen conveyor moves the specimen while the spot welder performs continuous spot welding,
And the number of total rub points of the point welding to be continuously performed can be set. The method according to claim 1,
And moving the specimen so that a plurality of spot points of spot welding are formed in rows and columns. The method of claim 3,
And the number of the other points constituting the row or the number of the other points constituting the column can be set. 3. The method of claim 2,
And the distance between the point of the spot welding can be set. The method according to claim 1,
The specimen conveyor comprises:
And a fixing member in the form of a forceps for holding and fixing one end of the specimen. The method according to claim 6,
And the other end of the specimen facing the one end of the specimen fixed to the fixing member is disposed so as to face the spot welder.

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