CN113878200A

CN113878200A - Intelligent robot surfacing method

Info

Publication number: CN113878200A
Application number: CN202111260929.4A
Authority: CN
Inventors: 钟立明; 张书生; 李宏利; 陆璐; 秦立家; 朱维金
Original assignee: Tianjin Xinsong Robot Automation Co ltd
Current assignee: Tianjin Xinsong Robot Automation Co ltd
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-01-04
Anticipated expiration: 2041-10-28
Also published as: CN113878200B

Abstract

The invention relates to an intelligent robot surfacing method, which comprises the following steps: acquiring surfacing parameters; controlling the distance between adjacent surfacing areas according to surfacing parameters; and obtaining a welding gun strip conveying track according to the distance, and realizing surfacing by a welding gun according to the welding gun strip conveying track to achieve the purpose of swinging arc strip conveying surfacing one layer with consistent height. The invention has high welding quality and stability. The welding specification can be automatically controlled and adjusted to keep stability. The flux has good protection effect and can prevent the invasion of air to the metal of the molten pool. And the current is large, so that the molten pool metal and slag react fully, and the components are uniform. The surfacing welding has high surface quality, stable performance and beautiful appearance, and effectively reduces welding quality defects such as air holes, slag inclusion, cracks and the like.

Description

Intelligent robot surfacing method

Technical Field

The invention belongs to the technical field of welding, and particularly relates to an intelligent robot surfacing method.

Background

Surfacing refers to a process of applying a material with certain properties on the surface of a weldment by welding. The purpose is not to connect the weldment, but to obtain a deposited metal layer with special properties such as wear resistance, heat resistance and corrosion resistance on the surface of the weldment, or to recover or increase the size of the weldment. The weld overlay method finds wide application in manufacturing and repair. The automatic surfacing welding is applied to automatic surfacing welding with higher requirements in industries such as petrochemical industry, power station steam turbine manufacturing, boiler pressure vessels and the like. Can carry out automatic surfacing welding on various workpieces such as inner holes, outer circles, end faces and the like, and completely achieves the purpose of one machine with multiple functions. Welding is a material connection technology, separated materials are connected together by generating atomic or intermolecular force through a certain physical and chemical process, and with the continuous development of the welding technology, the application of the welding technology in production is gradually widened, and the welding technology has become an important processing means so far. With the large-scale and high-parameter of modern industry, the robot welding technology is fully embodied. The robot welding technique can improve welding quality since it is compared with conventional arc welding.

The manual surfacing can be realized by human vision, so that each layer is uniformly filled by surfacing as much as possible, and the hand feeling control of a senior technician is realized at each swing arc corner.

The labor cost is higher and higher at present, especially for advanced technicians. If a new welder is used for surfacing a layer of hollow, the welding quality is difficult to guarantee. Can cause welding quality defects such as air holes, slag inclusion, cracks and the like.

Therefore, automatic overlaying welding by a robot is needed, the swing arc of each layer of overlaying welding is uniform, and especially the trajectory control of the swing arc turning position is needed.

Disclosure of Invention

The invention aims to solve the technical problem of how to make the swing arc of each layer of overlaying welding uniform for the automatic welding of a robot, and particularly the technical problem of the trajectory control of the swing arc turning position.

The technical scheme adopted by the invention for realizing the purpose is as follows: an intelligent robot surfacing method comprises the following steps:

for the surfacing welding with the strip conveying mode of swing arc multi-zone splicing, surfacing welding parameters are obtained;

controlling the distance between adjacent surfacing areas according to surfacing parameters;

and obtaining a welding gun strip conveying track according to the distance, and realizing surfacing by a welding gun according to the welding gun strip conveying track.

Controlling the distance between two adjacent overlaying areas with parallel swing directions according to overlaying parameters, and obtaining the distance by the following formula:

m×c×s＝n×2πR×s

wherein c is the distance between adjacent surfacing areas, m is the swinging frequency of the welding wire, s is the sectional area of the welding wire, R is the radius of the welding wire, and n is 1/2 of the number of semicircles formed at the turning position of the welding wire in the overlapping area of the two adjacent surfacing areas with the same swinging direction.

The overlapping area of two adjacent surfacing areas with parallel swing directions is an area formed by two surfacing area welding wires, two semicircles formed at the turning part are mutually abutted, and the welding wires are in a nonlinear state.

The distance between the adjacent surfacing areas is the distance between two area inflection points of the overlapping area of the adjacent surfacing areas parallel to the two swinging directions in the swinging direction.

Controlling the distance between two adjacent overlaying areas with vertical swinging directions according to overlaying parameters, and obtaining the distance by the following formula:

d×s×e/2/R＝p×2πR×s

wherein e is the distance between adjacent overlaying areas, d is the amplitude of oscillation of the overlaying areas sequenced in the two adjacent overlaying areas, s is the sectional area of the welding wire, R is the radius of the welding wire, and p is 1/2 of the number of semicircles formed at the turning positions of the welding wire in the overlapping area of the two adjacent overlaying areas with the vertical oscillation directions.

The overlapping area of the two adjacent overlaying areas with the vertical swing directions is an area formed by a semicircle formed at a welding wire turning position of one overlaying area and a straight-line welding wire of the other overlaying area.

The distance between the adjacent surfacing areas is the projection of the distance between the inflection point of one surfacing area and the linear welding wire swinging side edge of the other surfacing area on the horizontal plane for the overlapping areas of the two adjacent surfacing areas with the vertical swinging directions.

The inflection point is a switching point of a straight line segment and a turning semicircle between the two swing amplitudes.

An intelligent robot surfacing device comprises a memory and a processor; the memory for storing a computer program; the processor is used for realizing the intelligent robot overlaying method when the computer program is executed.

A computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements an intelligent robotic weld overlay method.

The invention has the following beneficial effects and advantages:

compared with the prior art, the invention has the beneficial effects that:

(1) the production efficiency is high and is improved by 5-10 times compared with manual electric arc welding.

(2) The welding quality is high and stable. The welding specification can be automatically controlled and adjusted to keep stability. The flux has good protection effect and can prevent the invasion of air to the metal of the molten pool. And the current is large, so that the molten pool metal and slag react fully, and the components are uniform. The submerged arc welding has high weld metal quality, stable performance and beautiful appearance.

(3) Improve the labor condition and reduce the labor intensity.

(4) The invention effectively reduces the welding quality defects of air holes, slag inclusion, cracks and the like.

Drawings

FIG. 1 is a schematic view of a working scenario of the present invention;

FIG. 2 is a schematic diagram of theoretical weld build-up fill;

FIG. 3 is a schematic diagram of the filling trajectory;

FIG. 4 is a schematic view of a superimposed area of orthogonal swing arc build-up welding;

FIG. 5 is a schematic view of a superimposed area of offset parallel swing arc build-up welding;

FIG. 6 is a schematic view of a superimposed area of opposed parallel swing arc weld overlays;

FIG. 7 is a schematic view of a weld overlay multi-layer position.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

An intelligent robot surfacing station comprises a welding robot 1, a welding gun 2, a workpiece 3, surfacing 4, a surfacing track 5, an arc starting point 6, a first swing arc track 7, a semi-circle reversing track 8, a second swing arc track 9, a trans-regional track 10, a large-radius trans-regional quarter-circle swing arc track 11, a small-radius trans-regional quarter-circle swing arc track 12, a straight line and semi-circle volume overlapping region 13, a straight line and semi-circle volume filling region 14, a staggered semi-circle volume overlapping region 15, a staggered semi-circle volume filling region 16, a centering semi-circle volume overlapping region 17, a centering semi-circle volume filling region 18, a first swing arc track body 19, a second swing arc track body 20 and a third swing arc track body 21.

As shown in fig. 1. One end of the welding robot 1 is fixed on the ground, and the other end of the welding robot 1 is provided with a welding gun 2. The welding robot 1 can provide welding motion with six spatial degrees of freedom of the welding gun 2. Surfacing refers to a process of applying a material with certain properties on the surface of a weldment by welding. The purpose is not to connect the weldment, but to obtain a deposited metal layer with special properties such as wear resistance, heat resistance and corrosion resistance on the surface of the weldment, or to recover or increase the size of the weldment. The weld overlay method finds wide application in manufacturing and repair.

The welding robot 1 deposits 4 a welding torch 2 on a workpiece 3. The welding track of the overlay welding 4 is an overlay welding track 5. Consider a wire diameter as shown in FIG. 2.

An intelligent robot surfacing station comprises the following steps;

first, striking an arc

As shown in fig. 3. The arcing point 6 performs an arcing degree operation. The tail end of the welding wire of the welding gun 2 is aligned with the workpiece 3, then the tail end of the welding wire of the welding gun 2 is scratched on the surface of the workpiece 3, when the electric arc is introduced and then the distance between the tail end of the welding rod and the welded surface is maintained at a distance of 2-4 mm at the moment when the metal does not start to be greatly melted, and the electric arc can be stably burnt. If the tail end of the welding wire of the welding gun 2 is stuck with the surface of the workpiece 3, the welding gun 2 can be separated from the workpiece 3 only by shaking the welding gun 2 for a few times left and right, and if the welding gun 2 can not be separated from the workpiece 3 at this time, the welding gun 2 is immediately loosened to disconnect a welding loop, and the welding wire of the welding gun 2 is detached after being slightly cooled.

Second, swing arc first section

As shown in fig. 3. Swing arc is defined as a "bar-moving method in which a welding wire is welded while moving alternately at a right angle to a welding direction". The moving width of "moving alternately" is generally called swing arc width. As shown in FIG. 3, the length of the first swing arc track 7 or the second swing arc track 9 is the swing arc width, and when the welding rod (welding wire) moves from left to right and returns to the left, the strip moving method is carried out by moving the welding rod to the right and returning to the left under the condition that the left molten pool is not solidified. When the molten pool is not solidified and the swing arc width is to be enlarged, the current must be increased to enlarge the molten pool. When the molten pool is enlarged, the heat input amount is increased by increasing the current, and this reduces the effect of protecting the molten pool, and as a result, gas such as hydrogen in the air flows into the weld metal, and as a result, the impact value is reduced, and if the swing arc is wide without increasing the current, the molten pool on both sides is solidified and re-welded. In this case, both sides of the molten pool cannot be sufficiently melted, resulting in defects such as slag inclusion or non-fusion. Therefore, the proper welding current range is selected according to the swing arc width. The swing arc width is not particularly limited except for special cases, but it is advantageous to obtain good weld metal mechanical properties by not making a large swing arc width in order to prevent deterioration of weld metal mechanical properties or occurrence of internal defects. The first section of welding seam surface is completed from an arc starting point 6, a first swing arc track 7, a semicircular reversing track 8, a second swing arc track 9 to a trans-regional track 10.

Thirdly, overlaying welding with upper parallel section swing arc

The cross-region track 10 is about one time longer than the first swing arc track 7 than the swing arc width, and a second section of welding seam surface is started. The second section of weld face is adjacent to one side of the first section of weld face. Swinging to a large radius and crossing a quarter circle swinging arc track 11. And finishing the second section of welding seam surface.

As shown in fig. 6. And controlling the welding edge of the upper parallel section by means of swing arc surfacing.

The second section of welding seam surface is collinear with the swing track middle section on one side of the first section of welding seam surface, and the central points of the semicircular reversing tracks 8 are aligned left and right. And controlling the distance between the lower inflection point of the swing arc middle section of the second section of the welding line surface and the upper inflection point of the swing arc middle section of the first section of the welding line surface. Let the volume of the centering semicircular volume overlap region 17 equal the volume of the two centering semicircular volume filling regions 18. The volume of the central semicircle volume overlapping region 17 is equal-height common-volume regions of two space semi-rings, and the calculation method is volume integration. The volume of the centering semicircle volume filling area 18 is a common volume area of the space semi-ring and the equal-height cylinder, and the calculation method is volume integral. The purpose is that the second section of welding seam surface and the first section of welding seam surface are equal in height after cooling surfacing.

Fourthly, left swing arc overlaying

And the large-radius span quarter circle swing arc track 11 takes the last track of the second section of welding seam surface as a trimming edge, the radius of 3 times of a welding wire as a turning radius and the shape of the large-radius span quarter circle, and starts to swing the third section of welding seam surface. The third section of welding line surface is respectively adjacent to the second section of welding line surface and one side of the first section of welding line surface. Swinging to a small radius and crossing a quarter circle swinging arc track 12. And finishing the third section of welding seam surface.

As shown in fig. 4. And controlling the swing arc welding edge of the third section of welding line surface.

And the third section of welding seam surface is orthogonal to the swing track of one side of the first section of welding seam surface, and the distance between the right turning point of the third section of welding seam surface and the swing arc line segment of the first section of welding seam surface is controlled.

The volume of the linear and semicircular volume overlap region 13 is equal to the volume of the two linear and semicircular volume fill regions 14. The linear and semicircular volume overlapping area 13 is a common volume area of the space semi-ring and the equal-height cylinder, and the calculation method is volume integration. The volume of the semicircular volume filling area 14 is a common volume area of the space semi-ring outer part and the equal-height cylinder, and the calculation method is volume integration. The purpose is that the second section welding seam surface and the third section welding seam surface are equal in height after cooling surfacing.

Fifthly, arc overlaying of lower hem

And a small-radius trans-regional quarter-circle swing arc track 12, taking the last track of the welding seam surface of the third section as a trimming edge, taking the radius of 2 times of a welding wire as a turning radius, taking the shape of the welding seam surface of the fourth section as a quarter circle, and starting swinging the welding seam surface of the fourth section. The fourth section of welding seam surface is respectively adjacent to the third section of welding seam surface and one side of the first section of welding seam surface. Swing for a certain length. And finishing the fourth section of welding seam surface.

As shown in fig. 5. And controlling the swing arc welding edge of the fourth section of welding line surface.

The fourth section of welding seam surface is parallel to the swing track on one side of the first section of welding seam surface, the middle section of the swing track is collinear, and the central points of the semicircular reversing tracks 8 are staggered at equal intervals from left to right. And controlling the height distance between the lower inflection point of the swing arc middle section of the first section of welding line surface and the upper inflection point of the swing arc middle section of the fourth section of welding line surface.

The staggered semicircular volume overlap region 15 has a volume equal to the volume of the two staggered semicircular volume fill regions 16. The volume of the staggered semicircular volume filling area 16 is a common volume area of the space semi-ring and the equal-height cylinder, and the calculation method is volume integration. The staggered semicircle volume overlapping area 15 is a common volume area of the space half ring and the space half ring outer body, and the calculation method is volume integration. The purpose is that the welding seam surface of the fourth section and the welding seam surface of the third section have the same height after cooling surfacing.

Sixthly, overlaying a layer

On the basis of the logic of the five steps, the length of the welding seam of each welding area is gradually longer, and a required layer is filled clockwise.

Seventh, overlaying the upper layer

As shown in fig. 7. And the swing arc track of the upper layer fully utilizes the lower layer to form a ship-shaped welding seam. The first swing arc track body 19 and the second swing arc track body 20 on the next layer are two cylindrical bodies which can become two semi-cylinders due to the molten bath effect, and the third swing arc track body 21 on the swing arc track on the last layer fully utilizes the ship-shaped space of the semi-cylinders of the first swing arc track body 19 and the second swing arc track body 20.

As shown in Table 1, the control flow of the present invention is as follows:

TABLE 1

Control formula of one-directional and same-directional area overlapping area

The target is as follows: the height of the area overlaying welding of the size a and the size b is the same as that of the area overlaying welding of the size b and the size c so as to achieve the above aim; controlling the distance of c, if c approaches zero, the swing radius between the first overlaying area and the second overlaying area can be piled up to bulge; conversely, if c approaches a certain value higher, then the radius of oscillation between the first weld pool and the second weld pool will result in a depression. The objective of the patent is to obtain a reasonable geometric numerical value of the distance between certain areas, provide the geometric numerical value for a robot control system, achieve the aim of surfacing a layer of smooth and flat, and achieve the process purpose of reducing welding quality defects such as air holes, slag inclusion, cracks and the like.

The dimension a and the dimension b are in a surfacing plane, and the determined area is a first surfacing area;

dimension c and dimension b the first weld build-up zone fills the second weld build-up zone overlap region;

the physical characteristics of the first surfacing area are that the strip conveying mode is a straight line segment, and the filling volume is as follows;

volume identity side; m, a, the number of oscillations is 6, and the welding wire section s has an oscillation amplitude;

the filling volume of the overlapping area of the first overlaying area and the second overlaying area is as follows;

the other side of the volume constant equation; n 2 pi R s is the length of the welding wire cross-sectional area s which is completed into a whole circle number 3 welding gun TCP points and passes through 1 circle;

if the first overlaying area and the first overlaying area are filled with the overlapping area of the second overlaying area, the overlaying heights are equal;

the distance between the first overlay welding area and the overlap area of the first overlay welding area and the second overlay welding area can be set, if the distance is also calculated in a straight line mode, wherein the distance is equal to the distance between the overlap area of the welding wire section s and the number of times of swinging.

Therefore, there is the following relation

R is the volume radius of the welding wire and the turning radius of the trace point of the welding wire

n＝3，m＝6

m*c*s＝n*2*π*R*s

The physical meaning of m is the swinging times of the welding wire within the range of the size b;

the physical meaning of n is the number of semi-circles in the area of dimension b and dimension c that make up a complete circle;

volume identity side; m c s means the height of the weld deposit produced in the area of the size b and the size c if the strip conveying mode of the area of the size a and the size b is adopted;

the other side of the volume constant equation; n x 2 x pi R s means the height of the weld build-up that can be produced by the corner fill in the area of dimension b and dimension c;

c is the control target, the control distance between the surfacing area with the size a and the size b and the equidirectional swinging area;

s is the wire feeding volume of the welding wire in unit time;

and pi is the circumferential ratio.

Control formula of second, orthogonal region overlapping region

The third overlaying area and the fourth overlaying area are filled by the dimension d and the dimension e;

if a linear bar conveying mode is adopted, the volume of the surfacing contains a formula; d, e/2/R is the fourth zone amplitude d, the width of the cross-sectional area of the welding wire d, and the width occupied by 1 welding wire 2R;

p 2 x pi R s p is integrated into a whole number of turns 2.75 x welding gun TCP points travel a length of 1 turn 2 x pi R welding wire cross-sectional area s;

the height of the bead welding with the size a and the size b is the same as the height of the bead welding with the size d and the size e;

therefore, the following relationship is provided

d*s*e/2/R＝p*2*π*R*s

p＝2.75

The physical meaning of p is the number of semi-circles in the area of dimension d and dimension e that make up a full circle;

d, e/2/R is in the area with the size d and the size e, if the area with the size a and the size b is used for strip conveying, the height of the overlaying welding can be generated;

p x 2 x pi R s in the region of dimension d and dimension e, turns fill the height of the weld build-up that can be produced.

Claims

1. An intelligent robot surfacing method is characterized by comprising the following steps:

2. An intelligent robot surfacing method according to claim 1, wherein the distance between two adjacent surfacing areas with parallel swing directions is controlled according to surfacing parameters, and is obtained by the following formula:

m×c×s＝n×2πR×s

3. The intelligent robot surfacing welding method according to claim 2, wherein the overlapping area of the two adjacent surfacing areas with parallel swing directions is an area formed by welding wires in two surfacing areas, semicircles formed at the turning positions are mutually abutted, and the welding wires are in a nonlinear state.

4. An intelligent robot overlaying method according to claim 2, wherein the distance between adjacent overlaying areas is the distance between two area inflection points in the swinging direction of a superposed area of the two adjacent overlaying areas parallel in the swinging direction.

5. An intelligent robot surfacing method according to claim 1, wherein the distance between two adjacent surfacing areas with perpendicular swinging directions is controlled according to surfacing parameters, and is obtained by the following formula:

d×s×e/2/R＝p×2πR×s

6. The intelligent robot surfacing method according to claim 5, wherein the overlapping area of two adjacent surfacing areas with perpendicular swing directions is an area formed by a semicircle formed at a welding wire turning position of one surfacing area and a straight welding wire of the other surfacing area.

7. An intelligent robot overlaying method according to claim 5, wherein the distance between adjacent overlaying areas is a projection of the distance between an inflection point of one overlaying area and a linear welding wire swinging side edge of the other overlaying area on a horizontal plane for a superposition area of the two adjacent overlaying areas with vertical swinging directions.

8. An intelligent robot overlaying method according to claim 4 or 7, wherein the inflection point is a transfer point of a straight line segment and a turning semicircle between two swing amplitudes.

9. An intelligent robot surfacing device is characterized by comprising a memory and a processor; the memory for storing a computer program; the processor, when executing the computer program, for implementing an intelligent robotic weld overlay method according to any one of claims 1-8.

10. A computer-readable storage medium, having stored thereon a computer program which, when executed by a processor, implements an intelligent robotic weld overlay method according to any one of claims 1-8.