JPH09108838A - Welding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality and the working efficiency by setting the throat depth of each welded layer, the number of weld beads and the target position of the weld bead, and the welding speed based on the thickness and width of a work, an opening width of a forward part and an opening width of an end part of a groove. SOLUTION: A welding equipment is controlled by a controller 22 of a welding robot 21 to drive a welding torch J and a welding condition setting device 23, and an input key board 24, a sensor 25 to measure the data, and a CRT 26 for checking the data are provided. The number of passes of each layer, the welding current, the welding speed, the torch angle, the target positions of the root pass layer and the flush weld layer are stored in the data base in the welding condition setting device 23. The conditions can be easily set even set even by a worker without excellent skill, and the quality of the weld zone and the working efficiency can be improved by setting the throat depth of each welding layer, the number of the weld beads and the target position, etc., based on the thickness and width of a work, the opening width of a forward part and an end part of a groove.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding device for performing multi-layer welding in a horizontal posture for robot welding or automatic welding.

[0002]

2. Description of the Related Art Generally, in so-called sideways welding, in which a rectangular groove formed on a workpiece is welded in a horizontal posture, when the weld metal melts and solidifies, the surface tension of the weld metal itself overcomes gravity. Welding is performed by maintaining the shape so that the deposited metal does not drop. Therefore, the amount of the deposited metal cannot be unnecessarily increased.

By the way, in the multi-layer welding method in the horizontal position of robot welding or automatic welding, in order to maintain a constant shape when the deposited metal is melted and solidified, the welding speed, the welding arc target position, etc. are welded. It is very important to set the conditions, and conventionally, these welding conditions are set by an operator having a high welding skill based on an empirical rule according to the groove shape and the groove size.

[0004]

In spite of the advent of welding robots in response to the shortage of welding workers, in the above-described conventional welding method, the welding conditions must be set by workers having high welding skills. Therefore, the serious problem of the lack of manpower for welding workers cannot be solved.

Further, since the welding conditions are set according to the empirical rule, there is a problem that the quality of the welding is greatly influenced by the skill of the operator and the quality of the welding is deteriorated.
Therefore, an object of the present invention is to provide a sideways welding apparatus in which even a person who does not have a high welding skill can easily set the welding conditions and can stabilize the quality of the welded portion.

[0006]

In order to achieve the above-mentioned object, according to a first aspect of the present invention, a horizontal-direction welding apparatus according to a first aspect of the present invention is used for welding in a horizontal position on a groove formed in an object to be welded. In the welding device for forming a plurality of welding layers with a substantially uniform width in the lateral direction and forming a plurality of welding beads of different numbers in the longitudinal direction on each welding layer, the welding object is By inputting the plate thickness and plate width, the front opening width and the back opening width of the groove,
It is characterized by comprising a welding condition setting device for setting the welding conditions such as at least the throat thickness of each weld layer, the number of weld beads, the target position of the weld bead, and the welding speed.

Here, the welding condition setting device is composed of a microcomputer, and the set welding conditions are input to the controller of the welding robot. With the above configuration, based on the plate thickness and plate width of the input workpiece, the front opening width and the back opening width of the groove, the throat thickness of each welding layer, the number of welding beads, the target position of the welding bead and The welding speed is set.

The other welding conditions, that is, the welding current, the welding voltage, and the torch angle are preset. Further, the laterally downward welding apparatus according to claim 2 is the above-mentioned claim 1.
A laterally-oriented welding device according to claim 1, wherein the welding condition setting device detects the difference between the opening widths at both ends of the front part of the groove by inputting the opening widths at both ends of the front part of the groove. It is characterized by adding a function of setting a welding speed for compensating for the difference in cross-sectional area of the weld bead due to the difference in width.

With the above structure, when there is a difference in the opening width between the objects to be welded, it is necessary to change the cross-sectional area of the welding bead (pass) at both ends. Set faster on the side with a larger cross-sectional area and slower.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a target welding portion in the welding apparatus of the present invention, and FIG. 2 shows a perspective view of the welding portion. In the welding apparatus of the present invention, a backing metal U is applied to the back side of the rectangular groove k formed on the object to be welded D, and the welding torch J is used in a sideways posture to form a multilayer in order from the back side of the groove k. Welding is performed.

The welded portion illustrated in FIG. 1 has a plurality of weld layers (8 layers in the figure) in the lateral direction (the direction of the plate thickness T of the workpiece D).
A1 to A8 are formed, and the welding layers A1 to A8 are
The first layer A1 formed on the innermost side of the groove k and the finishing layer A8 on the surface side, and the six intermediate layers A2 to A7 formed between the first layer A1 and the finishing layer A8 are formed. Is a plurality (two in the figure) of welding beads 1 and 2, intermediate layers A2 to A
7 includes a plurality of (3 to 8 in the figure) welding beads 1 to 7.
8. A plurality of (11 in the figure) welding beads 1 to 11 are formed on the finishing layer A8.

As shown in FIG. 3, the controller of the welding apparatus of the present invention comprises a controller 22 of a welding robot 21 for driving the welding torch J and a welding condition setting apparatus 23 for inputting welding conditions to the controller 22. The welding condition setting device 23 is provided with a keyboard 24 for inputting data (to be described later) of the object to be welded D, or a sensor 25 for measuring and inputting data of the object to be welded D, and a CRT 26 for confirming data. Has been. Controller 22 and welding condition setting device 23
Is formed by a microcomputer.

A procedure for automatically setting welding conditions by the welding condition setting device 23, which is a main part of the present invention, will be described with reference to the flowchart of FIG. The welding condition setting device 23 includes, in advance, the number of passes for the cross-sectional area of each layer, the welding current, the welding speed, the torch angle for each welding pass (welding bead),
It is assumed that the target positions of the first layer A1 and the finishing layer A8 are stored in a database.

Regarding the welding current, it is desirable to use as high a current as possible in consideration of penetration and work efficiency. However, in the lateral-direction welding, the welding bead is drooping because the welding direction and the gravity direction are different. There is a need to.

Regarding the welding speed, if it is too fast,
The amount of heat input per unit area decreases, leading to insufficient melting. On the other hand, if it is too slow, the molten metal precedes the arc, so that the arc does not reach the base metal, resulting in insufficient melting or dripping of the molten metal.

Based on the above, the experiment was repeated.
Then, the proper range of current and speed was determined. This
Therefore, the amount of welding in one pass is naturally decided.
You. "Initial input value setting" Keyboard 24 or sensor 25
Data of welded object D, namely plate thickness T, plate width L, groove
Front part (both ends of welding line m) Opening width H₁, H_Two, Behind the groove
Part opening width G ₁, G_TwoIs set (angle Θ is 35 °
Yes, start setting welding conditions. Average gap V
Is the center of the object to be welded D. "Calculation of A1 conditions for the first layer" Behind the groove of the average gap V
Part opening width G {= (G₁+ G_Two) / 2} first layer A1 construction
Number of passes is standard width G_HBased on.

[0017] 2 path when the G ≧ G _H, when the G <G _H 1
Use as a pass. Next, the welding speed at which the penetration depth is 2 mm or more is set from the above database. Since the welding speed of the first layer A1 is very important, it is necessary to select the optimum speed.

Next, the target position is set. The target position for forming the first bead 1 is the origin of the groove corner, and the target position in the vertical direction of the welding arc for forming the second bead 2 is the above-mentioned welding condition from the database. Select a value according to.

Next, the throat thickness of the first layer A1 is calculated. If the number of passes is determined, the cross-sectional area S (assumed to be the area of a trapezoid) when the construction is performed at the optimum speed can be calculated, so the throat thickness T ₁ is determined. That is, the throat thickness T ₁ corresponds to the height of the trapezoid and can be calculated. [Calculation of Intermediate Layer Throat Thickness] Next, when the welding layers A2 to A8 are formed, the throat thickness of each layer is calculated from the plate thickness T of the workpiece D to the first layer A1.
The value obtained by subtracting the throat thickness T ₁ is a predetermined constant p with a range.
(It is the throat thickness of the weld bead and is, for example, 4.5 to 8 mm) and is obtained as a natural number. That is, in the case of FIG. 1, for example, p = 6.5 is divided to make the number of layers F = 7, and the throat thicknesses of the intermediate first layer A2 to the intermediate sixth layer A7 and the finishing layer A8, which form the intermediate layer, are equal to each other. To be set. "Calculation of cross-sectional area of each layer" The cross-sectional area of each layer is calculated from the determined throat thickness of the intermediate layer. "Calculation of the number of passes of each layer" The number of passes of each layer is determined from the database based on the calculated cross-sectional area of each intermediate layer. At this time, each bead is distributed in an ideal area ratio. "Expansion of welding conditions to cope with taper gap"
Welding conditions are obtained from the database based on the number of passes and the number of layers of each of the intermediate layers A2 to A7, and this is set as the welding condition of the average gap portion V.

If there is a difference in the groove front opening widths H ₁ and H ₂ at both ends of the welding line m due to the mounting error of the object to be welded D, that is, if there is a taper gap, a pass is made within one groove. Since the number of layers and the number of layers cannot be changed, it is necessary to change the cross-sectional area of one weld bead (pass). Therefore, as shown in FIG. 5, the change in the cross-sectional area between the average gap portion V and the gap portions at both ends is obtained, and the welding speed at the gap portions at both ends relative to the welding speed at the average gap portion V is obtained. For example, when welding the weld bead of "1", the welding speed is increased at the position where the opening width is the minimum and the welding speed is decreased at the position where the opening width is the maximum so that the cross-sectional area of the weld bead of "1" is changed in order. Therefore, the difference between the opening widths at both ends can be corrected. “Calculation of Target Positions of Middle Layers A2 to A7” Each Middle Layer A2
The longitudinal aiming position of the welding arc for forming the welding beads 1 to 8 at A7 is determined as follows. However, the target position in the height direction of the first bead 1 is an optimum position obtained by experiment, for example, a position 1.5 mm from the bottom surface. In FIG. 1, the target position of the welding arc in the vertical direction is indicated by a small circle.

The lateral aiming positions of the first to third beads 1 to 3 in the intermediate first layer A2 constituting the intermediate layer are the throat thickness position b1 of the first bead 1 of the first layer A1 and the intermediate first layer A2.
The position of 1.5 mm from the bottom in the center of the throat thickness position b2 of No. 2, the lateral aiming position of the first bead 1 to the fourth bead 4 in the intermediate second layer A3 is the throat thickness position b of the intermediate first layer A2.
2 and the position of 1.5 mm from the bottom surface at the center of the throat thickness position b3 of the middle second layer A3, the lateral target positions of the first bead 1 to the fifth bead 5 on the middle third layer A4 are the middle second layer A3.
The center of the throat thickness position b3 and the throat thickness position b4 of the intermediate third layer A4 is a position 1.5 mm from the bottom surface, and the lateral target positions of the first to sixth beads 6 to 6 in the intermediate fourth layer A5 are intermediate. At the center of the throat thickness position b4 of the third layer A4 and the throat thickness position b5 of the middle fourth layer A5, a position 1.5 mm from the bottom surface, in the lateral direction of the first to seventh beads 7 to 7 in the middle fifth layer A6. The target position is at the center of the throat thickness position b5 of the intermediate fourth layer A5 and the throat thickness position b6 of the intermediate fifth layer A6, and 1.5 m from the bottom surface.
The position of m, the lateral aiming position of the first to eighth beads 8 in the middle sixth layer is the bottom at the center of the throat thickness position b6 of the middle fifth layer A6 and the throat thickness position b7 of the middle sixth layer A7. This is a position of 1.5 mm.

The intermediate first layer A2 to the intermediate sixth layer A7
The target positions in the vertical direction of the welding arc of the second bead 2 to the eighth bead 8 are determined by the following formula (empirical formula).

[0023]

(Equation 1)

However, α (target proportional coefficient), β (target constant)
Is a value determined by welding conditions. Where groove k
The back opening width (G) of 7 to 13 mm (10 mm in the figure), groove k
When the upper surface inclination angle (θ) is 35 ± 5 ° (35 ° in the figure) and the plate thickness (T) of the workpiece D is 16 to 80 mm (50 mm in the figure), the values of α and β are α = 7.2 ± 2 and β = 2 ± 2 mm are adopted. The diameter of the wire used in the welding equipment is 1.4 mm
And

Based on the above equation, the longitudinal aiming position of the welding arc of the second bead 2 to the eighth bead 8 in each of the intermediate first layer A2 to the intermediate sixth layer A7 is determined. "Calculation of conditions for finishing layer A8"
(The number of passes of the intermediate sixth layer A7 + 3 = 11), and from this number of passes, the lateral aiming position is the throat thickness position b7 of the intermediate sixth layer A7, and the longitudinal aiming position of the welding arc is the first layer. A
Similar to 1, it is determined based on the numerical value of the database.

In this way, the welding condition setting device 23 sets all welding conditions. Therefore, even for workers who do not have high welding skills as in the past,
Welding conditions can be set, and therefore, the shortage of welding workers can be resolved, the quality of the welded portion can be stabilized, welding work can be performed systematically, and work efficiency can be improved.

[0027]

As described above, according to the first aspect of the present invention, each welding is performed based on the inputted plate thickness and plate width of the object to be welded and the front opening width and the back opening width of the groove. By setting the throat thickness of the layer, the number of weld beads, the target position of the weld bead, and the welding speed, it is possible to set welding conditions even for workers who do not have high welding skills as in the past. It is possible to eliminate the shortage of welding workers, stabilize the quality of the welded part, and carry out the welding work systematically.
Work efficiency can be improved.

According to the second aspect of the invention, when there is a difference in the opening widths at both ends between the objects to be welded, the welding speed is set to be faster on the side having a smaller cross-sectional area and slower on the side having a larger cross-sectional area. This makes it possible to change the cross-sectional area of the weld bead (pass) at both ends when welding the same pass, and correct the difference in the opening width at both ends.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a welded portion constructed by a welding device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a welded portion constructed in the welding apparatus.

FIG. 3 is a control configuration diagram of the welding apparatus.

FIG. 4 is a flowchart illustrating an operation of a welding condition setting device of the welding device.

FIG. 5 is an explanatory diagram illustrating a setting method of a welding condition setting device of the welding device.

[Explanation of symbols]

 1-11 Weld bead A1-A8 Welding layer A1 First layer A2-A7 Intermediate layer A8 Finishing layer D Welding object G Groove depth opening width H Groove front opening width J Welding torch k Groove L Welding Plate width of object m Welding line T Plate thickness of object to be welded U Backing metal θ Angle of inclination of groove 21 Welding robot 22 Controller 23 Welding condition setting device 24 Keyboard 25 Sensor 26 CRT

Claims (2)

[Claims] 1. When welding a rectangular groove formed on an object to be welded in a horizontal posture, a plurality of welding layers having a substantially uniform width in the horizontal direction are formed, and each welding layer has a longitudinal direction. Is a welding device for forming a plurality of welding beads of different numbers, the plate thickness and plate width of the object to be welded, the front opening width of the groove and the back opening width, at least each of the welding layer A welding apparatus having a welding condition setting device for setting welding conditions such as a throat thickness, the number of welding beads, a target position of the welding bead, and a welding speed. 2. The welding device according to claim 1, wherein the welding condition setting device inputs the opening widths at both ends of the front part of the groove to determine the difference between the opening widths at both ends of the front part of the groove. When detected, a feature is added to set a welding speed for compensating for the difference in the cross-sectional area of the weld bead due to the difference in the opening width.