Welding spot quality visual inspection system based on machine vision

Abstract

The utility model discloses a welding spot quality visual inspection system based on machine vision, which relates to the technical field of inspection equipment and comprises a support portion, a camera portion, a motor stator positioning portion and a motor stator portion. According to the utility model, motor stator welding spots in a visual field are captured and 3D images are generated through assistance of the 3D camera and a plurality of light sources, and the 3D images are detected in the industrial personal computer and whether the 3D images are qualified or not is judged; the detection efficiency is high and accurate; the quality characteristic data related to the welding spot can be measured, such as the height of the welding spot, the area of a molten ball of the welding spot, the length and width of an external rectangle of the outer contour of the welding spot, the interlayer spacing, the slot spacing and the like; according to the utility model, different welding spot positions and various welding spot numbers of different product models can be compatible; and the detection precision and the detection efficiency can be ensured at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of detection equipment, in particular to a visual detection system for solder joint quality based on machine vision. Background Technique

[0002] For the flat wire motor applied to new energy vehicles, the current welding processes for flat copper wires are mainly laser welding and argon arc welding; laser welding requires a vision system to achieve precise guidance of the welding position, so that the laser beam is aligned with the impact solder joint. And argon arc welding relies on the vision system to take pictures for positioning and then guides the welding torch for welding. Both of these methods form solder joints by melting copper at high temperature, so as to achieve the electrical connection of windings.

[0003] Regarding the welding quality of the two welding methods, on the one hand, there will be points that cannot be recognized when the pre-welding vision guidance system conducts positioning and guidance, resulting in some solder joints being missed; on the other hand, the guidance deviation generated when the vision guidance system conducts positioning and guidance welding, and the inappropriate welding parameters. In addition, there are multiple factors such as the wear of the welding core of the welding torch in argon arc welding and the untimely replacement of the galvanometer lens in laser welding, which will cause the welding quality to be unqualified. At present, the unqualified solder joints after the welding process of flat copper wires are mainly divided into missed welding, explosion welding, false welding, exposed shoulders, welding deviation, and over-sized solder joints.

[0004] Therefore, in order to efficiently identify the unqualified solder joints and missed solder joints in welding quality, a visual detection method can be adopted to accurately and efficiently distinguish the unqualified solder joints after welding, reduce the outflow of unqualified stators, and avoid unnecessary losses.

[0005] At present, there is a solution that uses 2D vision hardware, robots, multi-directional lighting and cooperates with deep learning vision algorithms. The disadvantages of this method are as follows: Each solder joint needs to be photographed from at least 3 angles, and there are many photographing points, resulting in the robot's moving speed not meeting the beat requirements. At the same time, the pictures of each angle need to be separately deep-learned, and the algorithm is very complex, resulting in a high cost for the entire workstation and high requirements for debugging personnel. Content of the Utility Model

[0006] The purpose of the utility model is to provide a visual detection system for solder joint quality based on machine vision, so as to solve the problems that after the stator of the flat wire motor is welded, it is affected by various factors such as the deviation of the pre-welding positioning guidance, the setting of welding parameters, and the wear of the welding core of the welding torch in argon arc welding, and the missed welding, explosion welding, false welding, exposed shoulders, welding deviation, over-sized solder joints, etc. may occur at the solder joints of the stator copper wires after welding, directly resulting in the unqualified problem at the stator solder joints.

[0007] To achieve the above object, the present utility model provides the following technical solution: A visual inspection system for solder joint quality based on machine vision, including a bracket part, on the top surface of which there is a camera part near the rear side and a motor stator positioning part near the front side, and a motor stator part is arranged on the motor stator positioning part; the bracket part includes a bracket frame arranged in a rectangle and a bracket flat plate arranged on the top surface thereof; the camera part includes a fixed support rod vertically arranged on the top surface of the bracket flat plate and a 3D structured light camera arranged on the upper part of the front side surface thereof; the 3D structured light camera includes a 3D camera at the center, and four light source modules are annularly and evenly arranged outside the 3D camera; the motor stator positioning part includes two stator positioning slides horizontally arranged on the top surface of the bracket flat plate, a horizontal stator positioning bottom plate is jointly arranged on the two stator positioning slides through sliders, a motor stator rotating disk is arranged on the top surface of the stator positioning bottom plate through a rotating mechanism, and a motor stator part is arranged on the top surface of the motor stator rotating disk; the motor stator part is directly below the shooting field of view of the 3D structured light camera; the motor stator part includes a vertical stator core, on the inner wall of the stator core, a plurality of axially penetrating and concave insertion slots are annularly and evenly arranged, and multiple layers of stator copper wires are inserted radially along the stator core in the insertion slots, and the plane at the top end of the stator copper wire is the copper wire welding end, that is, the copper wire end surface to be detected.

[0008] Preferably, an adjusting foot is arranged at each of the four bottom feet of the bracket frame.

[0009] Preferably, two vertical camera slides are arranged on the upper part of the front side surface of the fixed support rod, a camera moving plate that can move up and down is jointly arranged on the two camera slides through sliders, a camera mounting frame perpendicular to it is arranged on the front side surface of the camera moving plate, and a 3D structured light camera is arranged on the bottom surface of the camera mounting frame.

[0010] Preferably, an adjusting screw rod parallel to the two camera slides is arranged on the front side surface of the fixed support rod between the two camera slides through two bearing seats, a threaded slider with a threaded match is arranged between the two bearing seats on the adjusting screw rod, the threaded slider is fixedly connected to the rear side surface of the camera moving plate, and an adjusting hand wheel is arranged at the top end of the adjusting screw rod.

[0011] Preferably, the four light source modules are respectively arranged at different lighting angles.

[0012] Preferably, the bottom surface of the motor stator rotating disk is connected to a rotating motor through a speed reducer; three movable stator clamping claws are arranged on the top surface of the motor stator rotating disk, and the three stator clamping claws can move synchronously towards or away from the axis along with the rotation of the motor stator rotating disk.

[0013] Preferably, the 3D structured light camera is electrically connected to the industrial control computer, and the industrial control computer is electrically connected to a PLC and a display respectively.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] 1. The present utility model captures the motor stator solder joints in the field of view with the assistance of a 3D camera and multiple light sources and generates a 3D image, and the 3D image is detected and judged whether it is qualified in the industrial control computer; the detection efficiency is high and accurate;

[0016] 2. The present utility model can also measure the quality characteristic data related to the solder joints, such as the solder joint height, the solder joint molten ball area, the length and width of the circumscribed rectangle of the outer contour of the solder joint, the layer spacing, the slot spacing, etc.;

[0017] 3. The present utility model can be compatible with different solder joint positions and various solder joint numbers of different product models; it can also ensure the detection accuracy and detection efficiency at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the present utility model;

[0019] Figure 2 It is a schematic structural diagram of the present utility model;

[0020] Figure 3 It is a schematic diagram of the motor stator part;

[0021] Figure 4 It is a schematic diagram of the 3D structured light camera;

[0022] Figure 5 It is a schematic diagram of the working process of the present utility model;

[0023] In the figure: support part - 1, support frame - 11, support flat plate - 12, adjusting foot - 13, camera part - 2, fixed support rod - 21, camera slideway - 22, camera moving plate - 23, camera mounting bracket - 24, 3D structured light camera - 25, 3D camera - 251, light source module - 252, adjusting lead screw - 26, adjusting handwheel - 27, motor stator positioning part - 3, stator positioning slideway - 31, stator positioning bottom plate - 32, rotating mechanism - 33, motor stator rotating disk - 34, stator jaw - 35, motor stator part - 4, stator core - 41, slot - 42, stator copper wire - 43, copper wire welding end - 44. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to enable those skilled in the art to better understand the technical solutions of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments.

[0025] Please refer toFigures 1-5 , Figure 1 is a schematic diagram of the present utility model; Figure 2 is a structural schematic diagram of the present utility model; Figure 3 is a schematic diagram of the motor stator part; Figure 4 is a schematic diagram of a 3D structured light camera; Figure 5 is a schematic diagram of the working process of the present utility model.

[0026] The present utility model provides a visual inspection system for solder joint quality based on machine vision, including a bracket part 1. On the top surface of the bracket part 1, a camera part 2 near the rear side and a motor stator positioning part 3 near the front side are provided, and a motor stator part 4 is positioned and arranged through the motor stator positioning part 3.

[0027] The bracket part 1 includes a bracket frame 11 arranged in a rectangle, and a bracket flat plate 12 is provided on the top surface of the bracket frame 11. On the top surface of the bracket flat plate 12, a camera part 2 near the rear side and a motor stator positioning part 3 near the front side are provided; at the four bottom feet of the bracket frame 11, an adjusting foot 13 is provided at each to adjust the bracket flat plate 12 to be in a horizontal state.

[0028] The camera part 2 includes a fixed support rod 21 vertically arranged on the top surface of the bracket flat plate 12. On the upper part of the front side of the fixed support rod 21, two vertical camera slideways 22 are provided, and a camera moving plate 23 that can move up and down is jointly arranged on the two camera slideways 22 through sliders. On the front side of the camera moving plate 23, a camera mounting frame 24 perpendicular to it is provided, and a 3D structured light camera 25 is provided on the bottom surface of the camera mounting frame 24; the 3D structured light camera 25 collects pictures of the welded end 35 of the stator copper wire after welding through 3D structured light shooting to deeply restore the model of the solder joint;

[0029] On the front side of the fixed support rod 21, between the two camera slideways 22, an adjusting screw rod 26 parallel to the two camera slideways 22 is arranged through two bearing seats. A threaded slider with a matching thread is arranged between the two bearing seats of the adjusting screw rod 26, and the threaded slider is fixedly connected to the rear side of the camera moving plate 23, and an adjusting handwheel 27 is arranged at the top end of the adjusting screw rod 26.

[0030] The 3D structured light camera 25 includes a 3D camera 251 at the center, and four light source modules 252 are evenly distributed in a ring outside the 3D camera 251, and the four light source modules 252 are respectively set at different lighting angles; the solder joints of the motor stator part 4 are ellipsoidal, and there are significant differences in the shapes of qualified and unqualified solder joints, with irregular contour shapes. It is difficult for general 2D and 3D cameras to completely capture various states of the solder joint surface. The 3D structured light camera 25 can project structured light onto the solder joint surface of the motor stator part 4, and then the 3D camera takes a structured light image of the measured surface and calculates the depth data of the object, so as to perform three-dimensional reconstruction of the contour of the solder joint surface. The outer contour of the solder joint is restored to a high degree through the 3D map.

[0031] The motor stator positioning part 3 includes two stator positioning chutes 31 horizontally arranged on the top surface of the support flat plate 12. A horizontal stator positioning bottom plate 32 is jointly arranged on the two stator positioning chutes 31 through sliders. A motor stator rotating disk 34 is arranged on the top surface of the stator positioning bottom plate 32 through a rotating mechanism 33, and a motor stator part 4 is arranged on the top surface of the motor stator rotating disk 34; the bottom surface of the rotating mechanism 33 is connected to a rotating motor through a speed reducer, so that the motor stator part 4 can be driven to rotate at a constant speed by the rotating motor.

[0032] The motor stator part 4 is directly below the shooting field of view of the 3D structured light camera 25; three movable stator claws 35 are arranged on the top surface of the motor stator rotating disk 34, and the three stator claws 35 can move synchronously towards or away from the axis of rotation as the motor stator rotating disk 34 rotates, so that the motor stator part 4 can be positioned and fixed.

[0033] The motor stator part 4 includes a vertical stator core 41. A plurality of axially penetrating and concave insertion slots 42 are evenly distributed in a ring on the inner wall of the stator core 41, and multiple layers of stator copper wires 43 are inserted radially along the stator core in the insertion slots 42. The plane at the top end of the stator copper wire 43 is the copper wire welding end 44, that is, the copper wire end face to be detected.

[0034] The 3D structured light camera 25 is electrically connected to the industrial control computer, and the industrial control computer is respectively electrically connected to a PLC and a display; the motor stator rotating disk 34 drives the motor stator part 4 to rotate. Each time the solder joint of the copper wire welding end 44 rotates to the photographing position, the camera takes a picture of the solder joint. The display can display the detection effect and detection result of the obtained stator picture in real time. The PLC receives the output result from the industrial control computer and transmits communication instructions with the industrial control computer.

[0035] In use, first place the motor stator part 4 on the motor stator rotating disk 34, and clamp and fix the motor stator part 4 with three stator jaws 35; then, according to the height of the copper wire welding end 44 of the stator copper wire 43, adjust the height of the 3D structured light camera 2 by adjusting the adjusting handwheel 27 to ensure that the welding point height is within the shooting field of view of the camera light source module.

[0036] The field of view of the 3D structured light camera 2 is not sufficient to capture all the welding points. Therefore, after collecting a set of welding point images, an electrical communication transmission signal is used to rotate the rotating motor under the stator base 35 by a certain angle until it stops at the next photographing position and waits for shooting. After several rotations, all the welding point images of the motor stator part 4 are collected. The collected images are transmitted to the industrial control computer, and the welding points are detected and judged in the industrial control computer, and the judgment result is output to the PLC. The pictures and data are saved in the storage path.

[0037] The utility model captures the motor stator welding points in the field of view with the assistance of a 3D camera and multiple light sources and generates a 3D image. The 3D image is detected and judged in the industrial control computer to determine whether it is qualified; the detection efficiency is high and accurate; and it can also measure the quality characteristic data related to the welding points, such as the welding point height, the welding point molten ball area, the length and width of the circumscribed rectangle of the outer contour of the welding point, the layer spacing and the slot spacing, etc.; the utility model can be compatible with different welding point positions and various numbers of welding points of different product models; and it can also ensure the detection accuracy and detection efficiency at the same time.

[0038] Although the embodiments of the present utility model have been shown and described, obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, for those of ordinary skill in the art, it can be understood that without departing from the principle and spirit of the present utility model, all other embodiments obtained by making various changes, modifications, substitutions and variations to these embodiments without creative labor belong to the scope of protection of the present utility model.

Claims

1. A visual inspection system for solder joint quality based on machine vision, characterized in that: It includes a bracket part (1), on the top surface of which there is a camera part (2) near the rear side and a motor stator positioning part (3) near the front side, and a motor stator part (4) is arranged on the motor stator positioning part (3); the bracket part (1) includes a bracket frame (11) arranged in a rectangle and a bracket flat plate (12) arranged on its top surface; the camera part (2) includes a fixed support rod (21) vertically arranged on the top surface of the bracket flat plate (12) and a 3D structured light camera (25) arranged on the upper part of its front side; the 3D structured light camera (25) includes a 3D camera (251) at the center, and four light source modules (252) are annularly and evenly arranged outside the 3D camera (251); the motor stator positioning part (3) includes two stator positioning slideways (31) horizontally arranged on the top surface of the bracket flat plate (12), a horizontal stator positioning bottom plate (32) is jointly arranged on the two stator positioning slideways (31) through sliders, a motor stator rotating disc (34) is arranged on the top surface of the stator positioning bottom plate (32) through a rotating mechanism (33), and a motor stator part (4) is arranged on the top surface of the motor stator rotating disc (34); the motor stator part (4) is located directly below the shooting field of view of the 3D structured light camera (25); the motor stator part (4) includes a vertical stator core (41), a plurality of concave and axially penetrating slot ducts (42) are annularly and evenly arranged on the inner wall of the stator core (41), and multiple layers of stator copper wires (43) are inserted along the radial direction of the stator core in the slot ducts (42), and the plane at the top end of the stator copper wire (43) is the copper wire welding end (44), that is, the copper wire end face to be detected.

2. The visual inspection system for solder joint quality based on machine vision according to claim 1, characterized in that: An adjusting foot (13) is arranged at each of the four bottom feet of the bracket frame (11).

3. The visual inspection system for solder joint quality based on machine vision according to claim 2, wherein: Two vertical camera slideways (22) are arranged on the upper part of the front side of the fixed support rod (21), a camera moving plate (23) that can move up and down is jointly arranged on the two camera slideways (22) through sliders, a camera mounting bracket (24) perpendicular to it is arranged on the front side of the camera moving plate (23), and a 3D structured light camera (25) is arranged on the bottom surface of the camera mounting bracket (24).

4. The visual inspection system for solder joint quality based on machine vision according to claim 3, wherein: An adjusting screw rod (26) parallel to the two camera slideways (22) is arranged on the front side of the fixed support rod (21) between the two camera slideways (22) through two bearing seats, a threaded slider with a matching thread is arranged between the two bearing seats of the adjusting screw rod (26), the threaded slider is fixedly connected to the rear side of the camera moving plate (23), and an adjusting handwheel (27) is arranged at the top end of the adjusting screw rod (26).

5. The visual inspection system for solder joint quality based on machine vision according to claim 4, wherein: The four light source modules (252) are respectively set at different lighting angles.

6. The visual inspection system for solder joint quality based on machine vision according to claim 5, wherein: The bottom surface of the rotation mechanism (33) is connected to a rotation motor through a speed reducer; on the top surface of the motor stator rotating disk (34), three movable stator jaws (35) are provided, and the three stator jaws (35) can move synchronously towards or away from the axis along with the rotation of the motor stator rotating disk (34).

7. The visual inspection system for solder joint quality based on machine vision according to claim 6, characterized in that: The 3D structured light camera (25) is electrically connected to the industrial control computer, and the industrial control computer is electrically connected to a PLC and a display respectively.

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