CN114858104A

CN114858104A - Pre-welding ultrasonic detection method and device for laser welding robot

Info

Publication number: CN114858104A
Application number: CN202210489354.1A
Authority: CN
Inventors: 朱晓磊
Original assignee: Danyang Chaorui Industrial Intelligent Technology Co ltd
Current assignee: Danyang Chaorui Industrial Intelligent Technology Co ltd
Priority date: 2022-05-07
Filing date: 2022-05-07
Publication date: 2022-08-05

Abstract

The invention belongs to the technical field of ultrasonic detection, in particular to an ultrasonic detection device and a detection method for a welding robot, which comprise a fixed frame component; a C-shaped working section; a slider; a limiting block; a spring; the spring is contacted with the ultrasonic probe, so that the probe has certain elastic compensation when being tightly attached to the panel. The invention fixes the assembly on the tool of the welding head, the laser on the welding head shines on the photoresistor through the small light-transmitting hole on the light-blocking cover by moving the sliding block, then the locking limiting block is moved to enable the probe to press the panel, the first and last positions of the core in the panel can be judged, the manual point-aligning and scribing can be replaced, whether a gap exists can also be judged, and the core can also be judged whether to bend or not by moving once according to the first and last positions in the operation program after the first and last points are finished. Can replace complex manual operation, greatly improve the efficiency and the accuracy of welding.

Description

Pre-welding ultrasonic detection method and device for laser welding robot

Technical Field

The invention belongs to the technical field of ultrasonic detection, and particularly relates to an ultrasonic detection method and device used before welding of a laser welding robot.

Background

At present, all the welding sandwich structures are manually scribed and compressed, and then a laser welding robot is used for welding operation, and the method has the following problems:

1. the marking operation is carried out by manual operation, and manual judgment is easy to make mistakes, so that the panel and the core of the sandwich structure are easy to be welded in a missing manner; 2. whether a gap exists between the panel and the core cannot be detected, so that the panel and the core are subjected to cold joint; these problems do not guarantee the strength requirements of the sandwich structure. The ultrasonic flaw detection technology can carry out all-dimensional flaw detection on surface cracks, embedded part cracks, internal defects and the like, and for the design, the ultrasonic flaw detection technology can judge the relation between the core and the panel through the waveform returned by ultrasonic waves and accurately judge the position of the core and the gap between the core and the panel through the distance between the waves. For the traditional ultrasonic probe, manual operation is needed for flaw detection, for welding a panel and a core, the probe needs to be moved back and forth during detection, so that the operation is troublesome, errors often occur in the actual operation process, the welding position is possibly influenced, and the quality of a sandwich structure is influenced.

Disclosure of Invention

The invention aims to provide a pre-welding ultrasonic detection device for a laser welding robot, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention adopts the following technical scheme:

a pre-welding ultrasonic detection device for a laser welding robot comprises a fixing frame assembly, wherein the fixing frame assembly comprises an upper fixing frame fixing end and an upper fixing frame extending end, the upper fixing frame fixing end and a welding head tool are fixed together through bolts, a stepped hole for placing a hexagon bolt is formed in the upper fixing frame extending end, symmetrical U-shaped through grooves are formed in two sides of a lower support, and the upper fixing frame extending end and the lower support are also fixed together through bolts;

the lower end of the lower support is provided with a C-shaped working end, a sliding block is arranged on the C-shaped working end, the tail end of the C-shaped working end is provided with symmetrical circular through holes, bolts are inserted into the circular through holes and tightly clamp the sliding block when being screwed, the sliding block does not move any more, symmetrical protruding ends are arranged on the upper surface of the sliding block, the sliding block moves back and forth in the C-shaped working end under the limitation of the symmetrical protruding ends, a limiting block is arranged on the C-shaped working end, and the limiting block is locked through hexagon socket head bolts on the limiting block;

a circular hole is formed in the center of the sliding block, the ultrasonic probe is concentric with the circular hole formed in the center of the sliding block, and the ultrasonic probe moves up and down along with the circular hole. A spring is arranged between the ultrasonic probe and the sliding block, the upper end and the lower end of the spring are respectively abutted against the ultrasonic probe and the sliding block and are compressed along with the up-and-down movement of the ultrasonic probe, the ultrasonic probe is connected with a photoresistor, a light blocking cover is covered on the photoresistor and fixed with the sliding block, and a light transmitting small hole is formed in the center of the top end of the light blocking cover.

The upper fixing frame extending end and the lower fixing frame are fixed on the two sides of the lower fixing frame through changing the positions of the symmetrical U-shaped through grooves formed in the two sides of the lower fixing frame through bolts, so that the fixing mechanism is adaptive to welding head tooling mechanisms with different heights.

The upper end face of the sliding block is provided with symmetrical protruding ends for limiting the sliding block to be connected in a sliding mode along the outer surface of the C-shaped working end.

A method for ultrasonic detection before welding of laser welding robot includes setting panel and core to be welded on bottom fixture, fixing fixed end of upper fixing frame on welding head fixture by bolt, regulating position of U-shaped through slot and bolt to make lower fixing frame be at proper position, moving slide block to make laser emitted by welding gun to penetrate through center of top of light-blocking cover to irradiate on photosensitive resistor, measuring resistance value of photosensitive resistor to know that ultrasonic probe is symmetrical to welding gun center, fastening bolt on circular through hole at end of C-shaped working end, fastening limiting block by hexagon socket head cap bolt, reducing defocusing amount of welding gun, fastening panel by ultrasonic probe, the spring is also compressed to provide flexible compensation for the ultrasonic probe, then the position of the probe is moved by an operation program, the position of the core under the panel can be simply judged through the waveform to finish the operation of point-to-point scribing, meanwhile, the probe can also judge whether the core is bent or not according to the movement of the head and the tail points, the deviation information of the position and the condition of the core is judged through the waveform generated by the wave receiver, and then the slide block is moved away to be adjusted through the operation robot arm so as to be accurately welded.

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

1. before welding of a first workpiece, symmetrical U-shaped through grooves are formed in the fixing frame assembly and on two sides of the lower support, and the fixing frame can move and is locked by locking nuts to be adaptive to different welding tools.

2. After the resistance value of the photoresistor changes, the laser welding head and the ultrasonic probe are centrosymmetric, and then the symmetrical round inner part of the tail end of the C-shaped working end is penetrated and screwed by bolts. The position of the robot is adjusted to reach the position away from the focus, so that the ultrasonic probe is tightly attached to the panel when compressing the spring. Programmatically moving the probe can replace cumbersome manual movement.

3. Due to the existence of the spring, when the probe contacts the panel, the probe can be tightly attached along with the movement of the panel, and certain flexible compensation is realized.

4. The positions of the core and the panel can be simply checked through the detection result of the ultrasonic probe, the positions of the head and the tail can be detected, then the operation of pointing and scribing can be easily finished, and errors possibly caused by manual pointing and scribing are solved.

5. Whether a gap exists between the core and the panel can be observed through the detection result of the ultrasonic probe.

6. The probe is moved according to the position of the head and the tail ends and the result of the probe by the ultrasonic probe can judge the condition of the core and judge whether the core is bent or not.

7. And judging deviation information of the position and the condition of the core through a waveform generated by the wave receiver, and then adjusting the position of the robot arm through an operation program so as to adjust the welding head to weld accurately. And the deviation of the position of the workpiece in the welding work is corrected, and the error possibly generated by manual point-to-point scribing is reduced.

8. Then after welding, the position of the sliding block does not need to be repeatedly calibrated due to the existence of the limiting block, so that the welding accuracy and the working efficiency are improved, and the working period is shortened.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

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

FIG. 2 is a schematic view of the structure of the present invention during welding;

FIG. 3 is an overall view of the clamping detection structure of the present invention;

FIG. 4 is a schematic view of the structure of the upper and lower extension frames of the present invention;

FIG. 5 is a schematic structural view of the limiting block during operation;

FIG. 6 is an enlarged view of the structure of the ultrasonic probe;

fig. 7 is a schematic view of a laser centering structure of the present invention.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention. The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Referring to fig. 1 to 7, a pre-welding ultrasonic detection apparatus for a laser welding robot is characterized in that: including mount subassembly 2, it includes that the upper mounting frame stiff end 3 extends end 4 with the upper mounting frame, the upper mounting frame stiff end 3 passes through the bolt fastening with soldered connection frock 1 and is in the same place, and the upper mounting frame extends end 4 and opens the shoulder hole 5 of placing the hex bolts. Two sides of the lower bracket 6 are provided with symmetrical U-shaped through grooves 10, and the extension end 4 of the upper fixing frame and the lower bracket 6 are fixed together through bolts.

The lower end of the lower support 6 is provided with a C-shaped working end 11, a sliding block 8 is arranged on the C-shaped working end 11, symmetrical circular through holes 12 are formed in the tail ends of the C-shaped working end 11, and the sliding block 8 can be clamped and prevented from moving when bolts are screwed down and inserted into the circular through holes 12. The upper surface of the sliding block is provided with symmetrical protruding ends 13, the sliding block 8 moves back and forth in the C-shaped working end 11 under the limitation of the symmetrical protruding ends 13, the C-shaped working end 11 is provided with a limiting block 7, and the limiting block is locked by an inner hexagon bolt 14 on the limiting block.

A circular hole 22 is formed in the center of the sliding block 8, the ultrasonic probe 9 is concentric with the circular hole 22 formed in the center of the sliding block 8, and the ultrasonic probe 9 can move up and down along with the circular hole 22. A spring 21 is arranged between the ultrasonic probe 9 and the slide block 8, the upper end and the lower end of the spring are respectively abutted against the ultrasonic probe 9 and the slide block 8, and the spring can move up and down along with the ultrasonic probe 9. The ultrasonic probe 9 is connected with a photoresistor 15, and a light blocking cover 16 is covered on the photoresistor 15. The light blocking cover 16 is fixed with the slide block 8, and a light transmitting small hole 17 is formed in the center of the top end of the light blocking cover 16.

When a laser point emitted by the welding gun 18 irradiates the sensitive resistor 15 through the small light-transmitting hole 17 in the center of the top end of the light-blocking cover 16, the change of the resistance value of the sensitive resistor is detected, and the position of the center of the ultrasonic probe 9 clinging to the panel is the subsequent welding position of the welding gun 18, the sliding block 8 can be inserted into the round through hole 12 formed in the tail end of the C-shaped working end 11 in a penetrating mode to be locked after the position is determined, and then the position can be detected. And a limiting block 7 is arranged at the lower part of the C-shaped working end 11, so that the limiting block 7 is locked after the position of the sliding block 8 is determined, the sliding block 8 is moved away during welding, the point alignment is not needed again after the welding is finished, the sliding block 8 is moved to a position tightly attached to the limiting block 7, the position of the circle center of the ultrasonic probe 9 is the position to be welded, and the time is greatly saved.

The working principle is as follows: firstly, a panel 19 and a core 20 which need to be welded are placed on a tool at the bottom, the fixed end 3 of the upper fixing frame is fixed on the welding head tool 1 through a bolt, and the positions of the U-shaped through groove 10 and the bolt are adjusted, so that the lower support 6 is in a proper position. Then, the position of the sliding block 8 is moved to enable the laser emitted by the welding gun 18 to penetrate through the center of the top end of the light blocking cover 16 to be provided with a light transmitting small hole 17 to irradiate on the photosensitive resistor 15, after the resistance value change of the photosensitive resistor 15 is measured, the ultrasonic probe 9 and the welding gun 18 are known to be centrosymmetric, and the position of the center of the ultrasonic probe 9, which is close to the panel, is the position for welding the subsequent welding gun 18. Then, the bolt on the circular through hole 12 formed at the tail end of the C-shaped working end 11 is screwed, and the limiting block 12 is fixed by screwing the hexagon socket head cap screw 14. Then, the welding gun 18 is lowered to keep the defocusing amount, the ultrasonic probe 9 is tightly attached to the panel 19, the spring 21 is compressed to provide certain flexibility compensation for the ultrasonic probe 9, then the position of the probe 9 is moved by an operation program, the position of the core 20 under the panel 19 can be simply judged through the waveform, the point-to-point scribing operation can be easily completed, and meanwhile, whether the core 20 is bent or not can be judged by moving the probe according to the first point and the last point. The deviation information of the position and the state of the core 20 is judged through the waveform generated by the wave receiver, and then the slide block is moved away and is adjusted by the operation and control robot arm, so that the welding is accurate.

The deviation of correcting the work piece position among the welding process, reduced the error that artifical counter point marking off probably caused, improved the degree of accuracy and the work efficiency of welding seam, and the existence of stopper need move the slider to paste the stopper when detecting again after the welding and just hungry can not need centering once more, has shortened duty cycle.

Claims

1. The ultrasonic detection device before welding for the laser welding robot is characterized by comprising a fixing frame assembly (2), wherein the fixing frame assembly (2) comprises an upper fixing frame fixing end (3) and an upper fixing frame extending end (4), the upper fixing frame fixing end (3) and a welding head tool (1) are fixed together through bolts, a stepped hole (5) for placing a hexagon bolt is formed in the upper fixing frame extending end (4), symmetrical U-shaped through grooves (10) are formed in two sides of a lower support (6), and the upper fixing frame extending end (4) and the lower support (6) are also fixed together through bolts;

the lower end of the lower support (6) is provided with a C-shaped working end (11), a sliding block (8) is arranged on the C-shaped working end (11), the tail end of the C-shaped working end (11) is provided with symmetrical circular through holes (12), the sliding block (8) is clamped and does not move when a bolt is screwed down in the circular through holes (12) in a penetrating manner, symmetrical protruding ends (13) are arranged on the upper surface of the sliding block, the sliding block (8) moves back and forth in the C-shaped working end (11) under the limitation of the symmetrical protruding ends (13), a limiting block (7) is arranged on the C-shaped working end (11), and the limiting block (7) is locked through an inner hexagon bolt (14) on the limiting block;

a round hole (22) is formed in the center of the sliding block (8), the ultrasonic probe (9) and the round hole (22) formed in the center of the sliding block (8) are concentric, the ultrasonic probe (9) moves up and down along with the round hole (22), a spring (21) is arranged between the ultrasonic probe (9) and the sliding block (8), the upper end and the lower end of the spring are respectively connected with the ultrasonic probe (9) and the sliding block (8) in a butting mode and are compressed along with the ultrasonic probe (9) when moving up and down, a photosensitive resistor (15) is connected onto the ultrasonic probe (9), a light blocking cover (16) is covered on the photosensitive resistor (15), the light blocking cover (16) is fixed with the sliding block (8), and a light transmitting small hole (17) is formed in the center of the top end of the light blocking cover (16).

2. The apparatus of claim 1, wherein: the upper fixing frame extension end (4) and the lower fixing frame (6) are fixed at the positions of the two sides of the lower fixing frame (6) which are provided with the symmetrical U-shaped through grooves (10) through changing bolts, so that the fixing mechanism is adaptive to welding head tool (1) mechanisms with different heights.

3. The apparatus of claim 1, wherein: the upper end face of the sliding block (8) is provided with symmetrical protruding ends (13) for limiting the sliding block (8) to be connected with the outer surface of the C-shaped working end (11) in a sliding mode.

4. A pre-welding ultrasonic detection method for a laser welding robot is characterized in that a panel (19) and a core (20) which need to be welded are placed on a tool at the bottom, a fixed end (3) of an upper fixing frame is fixed on a welding head tool (1) through a bolt, the positions of a U-shaped through groove (10) and the bolt are adjusted to enable a lower support (6) to be in a proper position, then laser emitted by a welding gun (18) penetrates through the center of the top end of a light blocking cover (16) to irradiate on a photosensitive resistor (15) through the position of a movable sliding block (8), after the resistance value of the photosensitive resistor (15) is measured, the center symmetry of the ultrasonic probe (9) and the welding gun (18) can be known, the position where the center of the ultrasonic probe (9) is attached to the panel is the welding position of a subsequent welding gun (18), and then the bolt on a round through hole (12) formed in the tail end of a C-shaped working end (11) is tightened, and tightening the hexagon socket head cap screw (14) to fix the limiting block (12), then lowering the welding gun (18) to keep the defocusing amount, at the moment, the ultrasonic probe (9) is tightly attached to the panel (19), the spring (21) is also compressed to provide flexible compensation for the ultrasonic probe (9), then an operation program moves the position of the probe (9), the position of the core (20) under the panel (19) can be simply judged through the waveform to finish the operation of point-to-point scribing, meanwhile, the probe can be moved according to the head and tail points to judge whether the core (20) is bent, deviation information of the position and the condition of the core (20) is judged through the waveform generated by a wave receiver, and then the slide block is moved away to be accurately welded through the position adjustment of an operation and control robot arm.