TWI403380B - Stitch pulse welding apparatus - Google Patents

Abstract

The invention provides a stitch pulse welding device which can beforehand confirm the shape of a welding seam and can form the shape of the welding seam being wanted. The stitch pulse welding device (1) produces an electric arc under a state when a welding torch is stopped according to a preset welding condition, the electric arc is stopped after welding time, the welding torch moves repeatedly in the welding direction and begins to be ignited until moving away from the electric arc with a prescriptive moving distance, then the electric arc is produced again, a welding mark, namely squamous epithelium formed in one production of the electric arc is coincided, and the welding seam is formed on a workpiece. The stitch pulse welding device is provided with a welding condition database part (21) which in advance stores the data of corresponding relation between the welding condition (Tc) and a squamous epithelium diameter value (Sr), a squamous epithelium diameter calculation part (22), which takes the welding condition (Tc) as input and calculates the squamous epithelium diameter value (Sr) by the welding condition database part (21), and a display treatment part (24) which displays the shape information (Yd) of the welding seam on the display part (41) of an operation unit (TP).

Description

Pin pulse welding device

The present invention relates to a stitch pulse welding device which performs welding while minimizing the influence of heat on a base material of a thin plate.

The stitch pulse welding method refers to a welding method that controls the heating and cooling at the time of welding and minimizes the influence on the heat caused by the base material. For example, Japanese Patent Publication No. Hei 6-55268 discloses a welding method for the purpose of automation of thin plate welding. According to the welding method disclosed in this document, the appearance after welding can be improved and the amount of distortion caused by welding can be reduced as compared with the conventional thin plate welding.

The means disclosed in this document is that an arc is generated for a predetermined time in a state in which the welder is stopped to melt the welded base material, and after the set time elapses, the arc is stopped and the welder is moved to the outside of the molten portion. The arc near the edge starts again.

Next, refer to the fifth figure to explain this prior art.

As shown in the fifth figure, the operator M automatically performs arc welding for the finished product W. The manipulator M is provided with a plurality of servo motors (not shown) in which the upper arm 53, the lower arm 54, the arm portion 55, and the three are driven to rotate.

The arc welder T is mounted at the tip end of the upper arm 53 of the operator M. The arc welder T guides the weld line 57 having a diameter of about 1 mm wound by the bobbin 56 to the welding position taught by the finished product W. The welding power source WP supplies a welding power source between the arc welder T and the finished product W. At the time of welding the finished product W, the weld line 57 will be from the tip of the arc welder T Highlight the desired length Ew. Generally, the length Ew is about 15 mm. However, in order to match the groove shape and welding conditions of the welded portion, the operator can also adjust the length Ew to a desired length using a teach pendant TP.

The inside of the guide cable 52 is provided with a coil liner for guiding the weld line 57. The cable 52 is connected to the arc welder T. The cable 52 supplies electric power from the welding power source WP and shielding gas from the gas compression cylinder 58 to the arc welder T.

The teaching suspension system TP as an operating means is a so-called portable operating panel. The teaching suspension system TP is used to set the conditions necessary for the operation of the operator M and the pulse welding of the stitches, specifically, the welding current, the welding voltage, the moving speed, the moving interval, the welding time, the cooling time, and the like. . The operator uses the teaching suspension system TP to create an operation program for setting the above various conditions in accordance with the operation of the operator M.

The machine control device RC performs control of the welding operation of the operator M. The machine control device RC includes a main control unit, an operation control unit, and a servo driver (not shown). The operator outputs an operation control signal to each servo motor of the operator M by the servo driver based on the operation program taught by the teaching suspension system TP, so that the plurality of axes of the operator M are respectively rotated. The servo motor of the operator M is equipped with an encoder (not shown). The machine control unit RC uses the output signal from the encoder to know the current position of the arc welder T. Therefore, the machine control device RC can control the position of the tip end of the arc welder T. The machine control device RC performs stitch pulse welding while repeating the welding, moving, and cooling described below in the welded portion.

Next, refer to the sixth diagram to illustrate the pulse welding of the pins.

The weld line 57 protrudes from the tip end of the arc welder T. The shielding gas G is blown out from the arc welder T at a constant flow rate from the start of welding until the end of welding.

Figure 6 (a) shows the state at the time of arc generation. An arc A is generated between the tip end of the weld line 57 and the finished product W based on the set welding current and the welding voltage. On the finished product W, the weld line 57 is melted to produce the molten pool Y. Starting from the generation of the arc A, the arc A is stopped after the taught welding time has elapsed.

Figure 6 (b) shows the state after the arc is stopped. After the arc is stopped, the state after welding is maintained until the set cooling time elapses. In other words, in a state where the operator M and the arc welder T are stopped in the same manner as in the welding, only the shielding gas G is blown out from the arc welder T. The molten pool Y is substantially solidified by cooling of the shielding gas G.

The sixth figure (c) shows a state in which the arc welder T is moved to the next welding position. After the cooling time has elapsed, the arc welder T is moved in the direction of welding. Thereby, the arc welder T moves to an arc restart point which deviates from the arc start point only by the preset movement interval Mp. The moving speed at this time is set in advance. As shown in the sixth diagram (c), the moving distance of the welding line 57 from the outer circumference of the weld mark Y' from the start of the arc to the solidification of the molten pool Y is the same.

The sixth diagram (d) shows the state when the arc A is regenerated in the arc restart point. At the end of the weld mark Y', the molten pool Y is newly formed and welded. As described above, in the stitch pulse welding device 1, the state in which the arc is generated and welded, and the state of cooling and moving are alternately repeated. As a result, the weld marks are overlapped into a scaly shape, and weld bubbles are formed on the finished product.

Next, refer to the seventh diagram to explain the welding bubbles formed after the welding construction.

As shown in the seventh figure, the weld mark Sc is formed at the initial arc start point P1. Further, the same weld mark Sc is also formed at the arc restart point P2 which is deviated from the movement interval Mp only from the arc start point P1 along the welding progress direction Dr. The weld mark Sc is sequentially formed even below the arc restart point P3. Thus, as a result of the weld marks being formed in a scaly shape, the weld bubbles B are formed.

One of the reasons for forming the scaly soldering foam is to enhance the appearance of the joint portion and to increase the added value of the product. However, with the above-mentioned conventional techniques, it is impossible to predict the shape of the welding bubble after the welding construction. Therefore, it is necessary to confirm the shape of the welding bubble when actually performing welding after teaching, and if the appearance is poor, the so-called trial error of correcting the welding condition is repeated. That is, in order to obtain the desired shape of the welded bubble, great teaching time is required.

An object of the present invention is to provide a stitch pulse welding apparatus capable of confirming the shape of a welding bubble beforehand and obtaining a desired shape of a welding bubble without performing welding in accordance with the operator's teaching.

In order to solve the above problems, according to a first aspect of the present invention, a stitch pulse welding apparatus is provided which is based on a welding condition including a welding current, a welding voltage, and a welding time set by an operation means, in a state in which the welder is stopped. An arc is generated, and after the arc is stopped after the aforementioned welding time elapses, the welding device is repeatedly caused to move from the arc starting point to the arc restart point only from the arc starting point to generate an arc again, and the arc is used again. The weld marks formed by the generation of the arc are superimposed in a scaly shape, thereby forming weld bubbles on the finished product. The needle The foot pulse welding device includes a welding condition database in which the relationship between the welding condition and the diameter of the weld mark is stored in advance, and a diameter calculation unit that calculates the diameter from the welding condition database based on the welding conditions input by the operation means, and includes The shape information of the welding bubble of at least the diameter is displayed on the display processing part of the operation means.

As shown in the first figure, the stitch pulse welding device 1 of the present embodiment is a configuration of a machine control device RC and a teaching suspension system TP as an operation means, which is different from the conventional technique shown in FIG. In the first figure, the operator M, the welding power source WP, the bobbin 56, the gas compression cylinder 58, and the like shown in the fifth diagram are omitted. Hereinafter, the machine control device RC and the teaching suspension system TP which constitute the main part of the present invention will be described.

The machine control device RC performs control of the welding operation for the operator M. The machine control device RC includes a main control unit 3, an operation control unit 11, a drive command unit 12, a hard disk 4, a RAM 5 as a temporary calculation area, a CPU 6 as a central calculation processing device, and a welding control unit for controlling welding of the main division. 13. A servo drive (not shown) connected to each other via a busbar (not shown). The motion control unit 11 executes the trajectory calculation or the like of the operator M, and outputs the calculation result as a drive signal to the drive command unit 12. The drive command unit 12 outputs a servo control signal for controlling the rotation of each servo motor of the operator M. Hard disk 4 memory program and various parameters.

The teaching suspension system TP as an operation means includes a display unit 41 that displays various kinds of information, and a setting unit 42 that sets various conditions such as a movement target position and an operation parameter of the operator M. Various conditions and the like set by the setting unit 42 are input to the machine control device RC.

The main control unit 3 is provided with the memory processing input from the setting unit 42. The teaching processing unit 20 of the welding conditions. As a necessary condition at the time of the stitch pulse welding, the welding current, the welding voltage, the moving speed, the moving interval, and the cooling time are input from the setting unit 42. The teaching processing unit 20 memorizes the input welding conditions Tc (welding current, welding voltage, and welding time), moving speed Sp, moving interval Mp, and cooling time Ct in the hard disk 4 .

The main control unit 3 further includes a diameter calculation unit 22 that calculates the diameter of the weld mark, a movement interval calculation unit 25, a bubble shape generation unit 23, a total number calculation unit 26 that calculates the total number of weld marks, and a display processing unit 24. The welding condition database 21 is memorized in the hard disk 4. Using the welding condition database 21, the welding conditions (welding current, welding voltage, and welding time) are related to the diameter of the weld mark formed under the welding conditions. The welding condition database 21 is prepared in advance by an experiment or the like in advance.

As shown in the second figure, the welding condition database 21 is a product accumulated by the method of recording the diameter of the welding mark while changing the welding current and the welding voltage in an actual welding environment, and adding it to the finished product to be used. The thickness, the material and diameter of the weld line, etc. More specifically, for example, in a welding environment in which the thickness of the finished product is 1 mm, the welding line is iron, and the diameter thereof is 0.6 mm, the welding time is fixed at 0.2 seconds, so that the welding current and the welding voltage are changed while recording. The diameter of the weld mark formed by the pulse welding of the needle is used once. Next, the welding time was fixed at 0.3 seconds, and the diameter of the weld mark was recorded again while changing the welding current and the welding voltage. The data accumulated by repeating this series of operations is preliminarily stored in the hard disk 4 as the welding condition database 21. Of course, in the case where the thickness of the finished product is 1 mm, the welding line is iron, and the diameter is 0.8 mm, it is necessary to prepare a memory condition database corresponding to the welding environment in advance and memorize it.

Next, the operation of the stitch pulse welding device 1 will be described.

As a requirement for the stitch pulse welding, the welding current, the welding voltage, the moving speed, the moving interval, the welding time, and the cooling time are input from the setting unit 42 of the teaching suspension system TP. Then, based on these conditions, the diameter Sr of the weld mark, the predicted bubble shape Bd, and the total number Bn of weld marks can be calculated.

First, a method of calculating the diameter Sr of the weld mark will be described.

The diameter calculation unit 22 calculates the diameter Sr of the weld mark from the welding condition database 21 based on the welding current, the welding voltage, and the welding time of the input welding condition Tc. The welding condition database 21 shown in the second figure is a database obtained in a state in which the representative welding current value and the welding voltage value are selected. These values are developed by an approximate curve inside the main control unit 3. Therefore, for example, even if the intermediate value of the welding time of 0.3 seconds, the welding current value 35A, the welding voltage value of 15 V, or the like is input as the welding condition Tc, the diameter Sr of the weld mark can be calculated based on the approximate curve. The calculated diameter Sr of the weld mark is memorized on the hard disk 4.

Next, a method of calculating the bubble shape will be described.

The bubble shape generating unit 23 generates a predicted bubble shape when viewed from the welder side on the two-dimensional plane based on the diameter Sr of the weld mark and the movement interval Mp.

As shown in the third figure, first, an imaginary two-dimensional plane Hr is generated. Next, on the two-dimensional plane Hr, the arc start point P1 as the starting position is defined at the appropriate coordinate position. A suitable direction is selected for this starting point, and the direction is determined as the welding progress direction Dr. Next, the welding line is divided at equal intervals every one interval from the starting point. When the circle Cr of the diameter Sr is generated on all of the division points P1 to Pn, the predicted bubble shape Bd is generated. The number of division points is the number of degrees of the predicted bubble shape Bd that can be imagined by the operator, and can be set, for example, four to five, or ten or more. Prediction of bubble shape Bd The two-dimensional plane data is memorized on the hard disk 4.

In the above-described example, the movement interval Mp is input from the setting unit 42, but the overlap ratio Lr of the weld mark may be input instead of the movement interval Mp. In other words, the movement interval Mp may be calculated based on the overlap ratio Lr of the weld mark and the diameter Sr of the weld mark.

Referring to the fourth figure, a method of calculating the movement interval in the case where the overlap ratio of the weld mark is input will be described.

As shown in the fourth figure, the overlap ratio Lr of the weld mark is a ratio at which the weld mark and the next weld mark overlap each other. The movement interval calculation unit 25 can calculate the movement interval Mp by the following equation.

Movement interval Mp = diameter of weld mark Sr- (diameter of weld mark Srx overlap rate of weld mark Lr)

The calculated movement interval Mp is memorized on the hard disk 4. Furthermore, the total number of weld marks can also be calculated.

A method for calculating the total number of weld marks will be described.

First, the total number calculation unit 26 calculates the welding length. The welding start position and the welding end position are taught in advance. Therefore, the welding length between the start position and the end position of the welding can be easily calculated. At the same time, the total number Bn of weld marks can be calculated by the following formula.

Total number of weld marks Bn = weld length / movement interval +1

In the case where the above-mentioned "+1" is left because of the calculation, it means that the welding can be performed at the welding end point even if the movement interval is not reached at the welding end position. The total number Bn of weld marks is memorized on the hard disk 4.

Next, the display processing unit 24 will be described.

When the instruction is input from the setting unit 42, the display processing unit 24 records the diameter Sr of the weld mark stored in the shape information and the hard spot 4, the total number Bn of weld marks, the overlap ratio Lr of the weld mark, the movement interval Mp, and Pre The bubble shape Bd is displayed on the display unit 41. As the shape information, it is preferable to display all of the above materials, and any one or a plurality of them may be displayed. Further, it is desirable that the instruction from the setting unit 42 can be input at the time of setting the welding condition for the stitch pulse.

As described above, since the shape of the welding bubble can be predicted before the welding construction, a trial operation for forming a desired welding bubble is not required. That is, it is possible to reduce the man-hours required for the teaching of welding.

Further, since the shape of the predicted welding bubble can be visually confirmed and added to the above effect, the shape of the welding bubble can be easily recognized.

Further, by teaching the overlap ratio of the weld mark to replace the movement interval, it is possible to imagine the appearance of the ideal weld bubble and to add it to the above effect, thereby reducing the number of man-hours required for the teaching of welding.

Further, since the total number of weld marks forming the welding bubbles can be calculated and added to the above effects, the appearance of the welding bubbles after the welding can be easily imagined.

In addition, since any one or a plurality of or all of the diameter, the total number, the overlap ratio, the movement interval, and the predicted bubble shape can be displayed as the shape information of the welding bubble, it can be more easily imagined by adding the above effect. The appearance of the welding bubble after welding.

1‧‧‧needle pulse welding device

3‧‧‧Main Control Department

4‧‧‧ Hard disk

5‧‧‧RAM

6‧‧‧CPU

11‧‧‧Action Control Department

12‧‧‧Drive Command Department

13‧‧‧Welding Control Department

20‧‧‧Teaching and Processing Department

21‧‧‧ welding condition database

22‧‧‧Diameter calculation department

23‧‧‧bubble shape generation department

24‧‧‧Display Processing Department

25‧‧‧Moving interval calculation unit

26‧‧‧Total calculation department

41‧‧‧Display Department

42‧‧‧Setting Department

52‧‧‧Guide cable

53‧‧‧ upper arm

54‧‧‧ Lower arm

55‧‧‧ wrist

56‧‧‧ spool

57‧‧‧welding line

58‧‧‧ gas compression cylinder

A‧‧‧Arc

B‧‧‧ welding bubble

Bd‧‧‧ predicted bubble shape

Bn‧‧‧ total number of weld marks

Cr‧‧‧ Round

Ct‧‧‧Cooling time

Dr‧‧‧ welding direction

Ew‧‧‧ length

G‧‧‧protective gas

Hr‧‧‧2D plane

Lr‧‧‧ overlap rate of weld marks

M‧‧‧ operator

Mp‧‧‧Moving interval

P1‧‧‧ arc starting point

P2‧‧‧ Arc start point

P3‧‧‧ Arc start point

P1~Pn‧‧‧ split point

RC‧‧‧ machine control unit

Sc‧‧‧welding marks

Sp‧‧‧ moving speed

Sr‧‧‧ diameter of weld marks

T‧‧‧Arc Welding Machine

Tc‧‧‧ welding conditions

TP‧‧‧ Teaching Suspension System

W‧‧‧ finished product

WP‧‧‧ welding power supply

Y‧‧·melting pool

Y’‧‧‧welding marks

1 is a block diagram of a stitch pulse welding apparatus according to an embodiment of the present invention; a second diagram is a diagram showing a database of welding conditions; and FIG. 3 is a pattern diagram for explaining a state in which a predicted bubble shape is generated; The figure is a schematic diagram for explaining the overlap ratio of the weld mark; the fifth figure is a schematic view showing a conventional stitch pulse welding device; and the sixth figure is a pattern diagram for explaining the pulse welding of the stitch; The seventh figure is a schematic view for explaining the welding bubbles formed after the welding construction.

1‧‧‧needle pulse welding device

3‧‧‧Main Control Department

4‧‧‧ Hard disk

5‧‧‧RAM

6‧‧‧CPU

11‧‧‧Action Control Department

12‧‧‧Drive Command Department

13‧‧‧Welding Control Department

20‧‧‧Teaching and Processing Department

21‧‧‧ welding condition database

22‧‧‧Diameter calculation department

23‧‧‧bubble shape generation department

24‧‧‧Display Processing Department

25‧‧‧Moving interval calculation unit

26‧‧‧Total calculation department

41‧‧‧Display Department

42‧‧‧Setting Department

Bd‧‧‧ predicted bubble shape

Ct‧‧‧Cooling time

M‧‧‧ operator

Mp‧‧‧Moving interval

RC‧‧‧ machine control unit

Sp‧‧‧ moving speed

Sr‧‧‧ diameter of weld marks

Tc‧‧‧ welding conditions

TP‧‧‧ Teaching Suspension System

WP‧‧‧ welding power supply

Claims (5)

A stitch pulse welding device is based on a welding condition including a welding current, a welding voltage, and a welding time set by an operation means, generates an arc in a state in which the welder is stopped, and after the arc is stopped after the welding time elapses, The overlaying causes the welder to move to the arc restart point only from the arc start point by a predetermined movement interval from the arc start point to generate an arc again, by superimposing the weld marks formed by the generation of the arc to a scaly shape. a welding bubble is formed on the finished product, wherein the stitch pulse welding device includes a welding condition database, and a correspondence relationship between the welding condition and the diameter of the welding mark is memorized in advance; and the diameter calculating unit is input based on the operation means The welding condition is used to calculate the diameter from the welding condition database; and the display processing unit displays the shape information of the welding bubble including at least the diameter in the operation means. The stitch pulse welding device according to claim 1, wherein the stitch pulse welding device further includes: a shape generating unit that generates a predicted bubble shape when the welding bubble is seen from the welder side based on the diameter and the movement interval And the display processing unit displays the shape information including the predicted bubble shape on the operation means. The stitch pulse welding device according to claim 1 or 2, wherein the stitch pulse welding device further includes: a setting unit that sets an overlap ratio of the weld mark instead of the movement interval; and a movement interval calculation unit that sets the aforementioned In the case of the overlap ratio, the movement interval is automatically calculated based on the overlap ratio and the diameter. The stitch pulse welding device according to claim 1 or 2, wherein the stitch pulse welding device further includes: a total number calculating unit that calculates a total number of the weld marks of the welding bubbles based on the diameter and the movement interval; The display processing unit displays the aforementioned shape information including the total number of the above-described operation means. The stitch pulse welding device according to claim 1 or 2, wherein the display processing unit determines any one or all of the diameter, the total number, the overlap ratio, the movement interval, and the predicted bubble shape as described above The shape information is displayed in the aforementioned operation means.