A method and apparatus for laser marking a straight-through connector

Abstract

This invention discloses a method and equipment for laser marking of straight connectors. A feeding device feeds straight connectors one by one, placing them in the placement slots of a clamp on a conveyor belt. A camera captures a photograph of a group of straight connectors on the clamp, and a computer analyzes and calculates the angle that each straight connector needs to be adjusted. An adjustment component rotates and adjusts each straight connector on the clamp to ensure that there are no reinforcing ribs of the straight connectors within the marking area. A laser marking device then marks each straight connector. This invention features a design with four spaced reinforcing ribs to ensure that the laser QR code is precisely marked in the arc-shaped area between adjacent reinforcing ribs, completely avoiding the protrusions of the reinforcing ribs and preventing QR code deformation and distortion.

Description

Technical Field

[0001] This invention relates to the field of pipe fitting production equipment technology, and more specifically, to a laser marking method and equipment for straight-through fittings. Background Technology

[0002] In current production, to improve product anti-counterfeiting, the anti-counterfeiting code has been changed from the original paper label to a laser QR code. Due to the special surface of the through connector product, which is cylindrical, it will roll during the transfer process on the conveyor belt or other carriers and cannot remain stationary. Secondly, four reinforcing ribs are evenly distributed on the product surface at 90° intervals. The laser QR code must be printed within the range between the reinforcing ribs. The QR code cannot touch the reinforcing ribs. If the QR code is printed on the reinforcing ribs, it will be deformed and cannot be scanned normally. Therefore, a technical solution is needed to solve the above problems. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art, and to automatically identify the area where the QR code is printed and adjust the pipe joint so that the QR code can be printed in the specified area, thus providing a laser marking method and equipment for a through connector.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention discloses a laser marking method for a through connector, comprising the following steps:

[0006] S1. The straight connectors are fed one by one by the feeding device and placed in the placement slot of the clamp on the conveyor belt.

[0007] S2. Take photos of a set of straight connectors on the fixture using a camera, and use a computer to analyze and calculate the angle that each straight connector needs to be adjusted.

[0008] S3. Adjust each straight connector on the fixture by rotating the adjustment component to ensure that there are no reinforcing ribs with straight connectors in the coding area;

[0009] S4. Use a laser marking device to mark each straight connector.

[0010] Furthermore, step S2 includes:

[0011] 2.1. Take a full-area photo: Take a photo of the clamp area located below the lens using the camera to obtain a full-area photo;

[0012] 2.2. Segmenting the image into blocks: Convert the entire image to black and white and divide it into multiple blocks equally along its length;

[0013] 2.3 Analyze the content of the blocks: Divide the bright and dark areas, divide the bright area into multiple partitions, and analyze the length of each partition in the length direction of the whole area of ​​the photo;

[0014] 2.4 Calculate the rotation angle: Calculate the angle that the straight connector needs to rotate by calculating the difference between the standard partition length and the photo partition length;

[0015] 2.5 Output rotation angle: Output the required rotation angle of the corresponding straight connector to the motor in the corresponding position of the adjustment component.

[0016] Furthermore, in step S2, the bright area is divided by the dividing line area generated by the reinforcing rib of the straight connector. The bright area division is marked as C1, C2, and C3 from left to right. The length of C1 in the photo partition is L1, and the lengths of C1 and C3 in the standard partition are L0. The difference between the length of the standard partition and the length of the photo partition is L2 = L1 - L0.

[0017] Furthermore, in step S2, the intersection point between the left edge line of the bright area and the length line of the entire area photo is set as P0, and the coordinate of P0 on the length line of the entire area photo is X0. Under standard partitioning: the intersection point between the leftmost dividing line area and the length line of the entire area photo is P1, and the coordinate of P1 on the length line of the entire area photo is X1, X1-X0=L0; under photo partitioning: the intersection point between the leftmost dividing line area and the length line of the entire area photo is P2, and the coordinate of P2 on the length line of the entire area photo is X2, X2-X0=L1.

[0018] Furthermore, in step S2, the projection of P1 onto the circumference of the straight connector is P1', the projection of P2 onto the circumference of the straight connector is P2', the center of the straight connector is O, and the angle between O-P1' and 0-P2' is θ.

[0019] Furthermore, in step S2, when θ is a positive value, the straight connector rotates counterclockwise, and when θ is a negative value, the straight connector rotates clockwise.

[0020] Furthermore, in step S2, the radian measure of θ is calculated using the following equation:

[0021]

[0022] Where k is the error compensation coefficient, and D is the outer diameter of the straight connector, the calculation equation converted to angle system is:

[0023]

[0024] Furthermore, in step S3, after the straight connector is rotated and adjusted, it is checked a second time by the vision system. If the angle deviation is >1°, then θ is corrected and fine-tuned a second time until the deviation is ≤1°.

[0025] This invention also provides a laser marking device for a straight connector, used for the aforementioned laser marking method for straight connectors. The device includes a feeding device, a conveyor belt, a first camera, a clamping assembly, an adjusting assembly, a second camera, and a laser marking device. The feeding device, first camera, clamping assembly, adjusting assembly, second camera, and laser marking device are arranged along the length of the conveyor belt. Multiple clamps are installed on the conveyor belt, and the straight connector is placed in one of the clamps. The clamping assembly and the adjusting assembly are capable of clamping the straight connector. The second camera is located above the clamping assembly on the conveyor belt. The adjusting assembly is capable of rotating the straight connector. The laser marking device marks the straight connector.

[0026] Furthermore, the clamping assembly includes a plurality of first clamps that can move closer to or further away from the adjusting assembly, and the adjusting assembly includes a plurality of second clamps that can move closer to or further away from the clamping assembly, each second clamp being rotated by a motor.

[0027] The beneficial effects of this invention are:

[0028] 1. This invention precisely solves the problem of QR code deformation and ensures anti-counterfeiting function. For the design of the four-spaced reinforcing ribs of the straight connector, through quantitative algorithm and closed-loop adjustment, it ensures that the laser QR code is strictly hit in the arc area between adjacent reinforcing ribs, completely avoiding the protrusion of the reinforcing ribs, eliminating QR code deformation and distortion, and effectively fulfilling the anti-counterfeiting and traceability requirements of laser QR codes.

[0029] 2. The device of the present invention prevents the straight connector from rolling freely by placing a triangular groove in the clamp, thus solving the problem of rolling of cylindrical products, achieving stable positioning, strong adaptability, and compatibility with multiple product specifications. Attached Figure Description

[0030] Figure 1 This is a flowchart of step S2 in this embodiment.

[0031] Figure 2 This is a schematic diagram of a whole-area photograph in this embodiment.

[0032] Figure 3 This is a schematic diagram of a block in this embodiment.

[0033] Figure 4 This is a schematic diagram of step S2.4 in this embodiment.

[0034] Figure 5 This is a schematic diagram of a through-connector laser marking device in this embodiment.

[0035] Reference numerals: 101, Dark area; 102, Bright area; 103, Separator line area; 201, Straight connector; 202, Reinforcing rib; 1, Conveyor belt; 11, Fixture; 111, Placement slot; 2, Clamping assembly; 21, First cylinder; 22, First chuck; 23, First mounting plate; 3, Adjustment assembly; 31, Second cylinder; 32, Second chuck; 33, Second mounting plate; 34, Motor. Detailed Implementation

[0036] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] like Figures 1-5 As shown, this embodiment discloses a laser marking method for straight connectors, implemented using a laser marking device for straight connectors. The laser marking device includes a feeding device, a conveyor belt 1, a first camera, a clamping assembly 2, an adjusting assembly 3, a second camera, and a laser marking device. These components are arranged along the length of the conveyor belt 1. The feeding device is located at the front end of the conveyor belt 1 and can be connected to the production line of straight connectors 201. The feeding device includes a vibratory feeder for organizing and conveying the straight connectors 201 and a pusher for pushing the straight connectors 201 one by one. The device includes a conveyor belt 1 with multiple clamps 11 arranged along the length of the conveyor belt 1. Each clamp 11 includes multiple placement slots 111, which are arranged along the length of the clamp 11. The placement slots 111 are triangular and their length is parallel to the axis of the straight connector 201. The straight connector 201 is placed in the placement slot 111, which structurally restricts the free rolling of the cylindrical straight connector 201. When a clamp 11 is filled with 6 straight connectors 201, it is conveyed by the conveyor belt 1 to the area below the first camera. The first camera takes a picture of the clamp 11 below to obtain a full-area photo.

[0038] Clamping assembly 2 and adjusting assembly 3 are located on both sides of conveyor belt 1. Clamping assembly 2 and adjusting assembly 3 can clamp the straight connector 201. Clamping assembly 2 includes a first cylinder 21, a first mounting plate 23, and multiple first clamps 22. The first clamps 22 can move closer to or further away from adjusting assembly 3. The multiple first clamps 22 are mounted on the first mounting plate 23 and are rotatably mounted on the first mounting plate 23. The first mounting plate 23 is driven by the first cylinder 21. One end of each first clamp 22 facing the straight connector 201 has a conical surface, which allows a portion of the first clamp 22 to extend into the straight connector 201. Adjusting assembly 3 includes a second cylinder 31, a second mounting plate 33, multiple second clamps 32, and multiple motors 34. The second clamps 32 can move closer to or further away from clamping assembly 2. The multiple second clamps 32 are mounted on the second mounting plate 33. 2. Rotatably mounted on the second mounting plate 33, which is driven by the second cylinder 31. The second clamp 32 has a conical surface at one end facing the straight connector 201. The conical surface allows part of the second clamp 32 to extend into the straight connector 201. Each second clamp 32 is controlled to rotate by a motor 34. The first clamp 22 and the second clamp 32 can clamp the straight connector 201 from both ends. The design of the two clamp conical surfaces allows the straight connector 201 to rotate coaxially with the first clamp 22 and the second clamp 32 for rotational adjustment of the straight connector 201. The motor 34 can receive the rotation angle signal from the computer to adjust the corresponding straight connector 201 individually, so that the part of the straight connector 201 without the reinforcing rib 202 faces upward. After the angle is adjusted, the first clamp 22 and the second clamp 32 release the straight connector 201.

[0039] The second camera is located above the clamping component 2 on the conveyor belt 1. It is used to perform a secondary verification of the straight connector 201 after rotation adjustment. After confirming that all the straight connectors 201 are in the correct position, the conveyor belt 1 transmits the clamp 11 to the bottom of the laser marking device, and the laser marking device marks the straight connector 201.

[0040] The laser marking method for straight connectors includes the following steps:

[0041] S1. The straight connectors 201 are arranged and fed by the feeding device with a vibrating plate. The straight connectors 201 are pushed one by one into the placement groove 111 of the clamp 11 of the conveyor belt 1. The placement groove 111 is a triangular groove, which restricts the free rolling of the cylindrical straight connectors 201 from the structure. The clamp 11 is adapted to the clamping component 2 and the adjusting component 3 to realize the stable clamping and rotation of the straight connectors 201.

[0042] S2. Take photos of a set of straight connectors 201 on the fixture 11 using the first camera, and calculate the angle that each straight connector 201 needs to be adjusted using computer analysis, specifically including:

[0043] 2.1 Take a full-area photo: Take a photo of the area of ​​clamp 11 located below the lens using the camera to obtain a full-area photo. The photo covers clamp 11 to ensure that the 6 straight connectors 201 are fully imaged.

[0044] 2.2 Dividing the area into blocks: such as Figure 2 As shown, the entire image is first filtered by Gaussian to remove noise, and then the Otsu method is used to automatically determine the grayscale threshold. The image is then black and white to highlight the contrast of the clamp 11, the straight connector 201, and the reinforcing rib 202. The entire image is then divided into multiple blocks along the length direction, and the blocks are labeled as B1, B2, B3, B4, B5, and B6, so that each block contains only one straight connector 201. Each block is analyzed separately.

[0045] 2.3 Analysis of Block Content: Divide the bright area 102 and the dark area 101. Divide the bright area 102 into multiple partitions and analyze the length of each partition in the length direction of the whole area of ​​the photo. Divide the bright area 102 into the dividing line area 103 generated by the reinforcing rib 202 of the straight connector 201. The division of the bright area 102 from left to right is marked as C1 (left partition), C2 (middle partition, i.e., target inkjet area), and C3 (right partition).

[0046] In the standard partition, the length of C1 and C3 is L0, and the length of C1 in the photo partition is L1. The intersection point between the left edge of the bright area 102 and the length line of the entire photo is set as P0, and the coordinate of P0 on the length line of the entire photo is X0. Under the standard partition: the intersection point between the leftmost dividing line area 103 and the length line of the entire photo is P1, and the coordinate of P1 on the length line of the entire photo is X1, X1-X0=L0. Under the photo partition: the intersection point between the leftmost dividing line area 103 and the length line of the entire photo is P2, and the coordinate of P2 on the length line of the entire photo is X2, X2-X0=L1. The difference between the standard partition length and the photo partition length is L2=L1-L0.

[0047] 2.4 Calculate the rotation angle: Calculate the required rotation angle for the straight connector 201 by calculating the difference between the standard partition length and the photo partition length.

[0048] The straight connector 201 is cylindrical in shape, and the outer circumference of the straight connector 201 is circular. The straight line of the bright area 102 along the length of the photograph is the same as the horizontal diameter of the straight connector 201. The projection of P1 on the circumference of the straight connector 201 is P1', and the projection of P2 on the circumference of the straight connector 201 is P2'. The center of the straight connector 201 is O, and the angle between O-P1' and 0-P2' is θ.

[0049] The radian measure of θ is calculated using the following equation:

[0050]

[0051] Where k is the error compensation coefficient, and D is the outer diameter of the straight connector, the calculation equation converted to angle system is:

[0052]

[0053] The error compensation coefficient k is obtained through calibration using a known angle, and the calibration equation is:

[0054]

[0055] Where θ0 is the preset rotation angle (e.g., 5°), and L20 is the measured length difference corresponding to θ0. Multiple calibrations (≥5 times) are performed and the average value is taken to ensure that the error is ≤0.1°, thereby improving the accuracy of angle calculation.

[0056] When θ is positive, the straight connector 201 rotates counterclockwise; when θ is negative, the straight connector 201 rotates clockwise. That is, when θ > 0, the straight connector 201 rotates counterclockwise, causing the reinforcing rib 202 to shift to the right, restoring the standard bright area length and ensuring that C2 is a coding area without the reinforcing rib 202. When θ < 0, the straight connector 201 rotates clockwise by an angle |θ|, causing the reinforcing rib 202 to shift to the left, restoring the standard bright area length. When θ = 0, no rotation is required.

[0057] 2.5 Output rotation angle: Convert the calculated rotation angle θ (including direction) into a servo motor control signal, output it to the corresponding motor 34, and feed back the signal to the control system to complete the angle command issuance, and output the required rotation angle of the corresponding straight connector 201 to the motor 34 at the corresponding position in the adjustment component 3;

[0058] S3. Adjust each straight connector 201 on the fixture 11 by adjusting component 3 to ensure that there is no reinforcing rib 202 of straight connector 201 in the coding area. After the straight connector 201 is rotated and adjusted, it is checked twice by the vision system. If the angle deviation is >1°, then θ is corrected and fine-tuned again until the deviation is ≤1°.

[0059] Specifically, when the fixture 11 is transferred to the adjustment station, the first chuck 22 of the clamping component 2 and the second chuck 32 of the adjustment component 3 work together. The first chuck 22 approaches and clamps the straight connector 201 from one side, and the second chuck 32 clamps the straight connector 201 from the other side. After receiving the control signal, the corresponding servo motor 34 drives the second chuck 32 to rotate the straight connector 201 by an angle θ (clockwise / counterclockwise is determined according to the sign of θ). After the rotation is completed, the second camera takes an image of the area of ​​the fixture 11 again and repeats steps S2.3-S2.4 to verify whether there is no reinforcing rib 202 in the inkjet area. If the angle deviation is >1°, θ is corrected based on the new measured value and a second fine adjustment is performed until the deviation is ≤1°, and the verification is completed.

[0060] S4. After the angle adjustment is qualified, the clamping component 2 and the adjusting component 3 release the straight connector 201. The conveyor belt 1 sends the fixture 11 to the laser marking station. The laser marking device marks each straight connector 201. After the marking is completed, the clarity, integrity and whether the reinforcing rib 202 is touched can be detected by the newly added visual inspection module. Qualified products flow into the next process.

[0061] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method of laser marking a straight through connection, characterized in that, Includes the following steps: S1. The straight connectors are fed one by one by the feeding device and placed in the placement slot of the clamp on the conveyor belt. S2. Take photos of a set of straight connectors on the fixture using a camera, and use a computer to analyze and calculate the angle that each straight connector needs to be adjusted. S3. Adjust each straight connector on the fixture by rotating the adjustment component to ensure that there are no reinforcing ribs with straight connectors in the coding area; S4. Use a laser marking device to mark each straight connector; Step S2 includes: 2.

1. Take a full-area photo: Take a photo of the clamp area located below the lens using the camera to obtain a full-area photo; 2.

2. Segmenting the image into blocks: Convert the entire image to black and white and divide it into multiple blocks equally along its length; 2.3 Analyze the content of the blocks: Divide the bright and dark areas, divide the bright area into multiple partitions, and analyze the length of each partition in the length direction of the whole area of ​​the photo; 2.4 Calculate the rotation angle: Calculate the angle that the straight connector (201) needs to rotate by calculating the difference between the standard partition length and the photo partition length; 2.5 Output rotation angle: Output the required rotation angle of the corresponding straight connector to the motor at the corresponding position in the adjustment component; In step S2, the bright area is divided by the dividing line area generated by the reinforcing rib of the straight connector. The bright area division is marked as C1, C2, and C3 from left to right. The length of C1 in the photo partition is L1, and the lengths of C1 and C3 in the standard partition are L0. The difference between the length of the standard partition and the length of the photo partition is L2 = L1 - L0. In step S2, the intersection point between the left edge of the bright area and the length line of the entire area photo is set as P0, and the coordinate of P0 on the length line of the entire area photo is X0. Under standard partitioning: the intersection point between the leftmost dividing line area and the length line of the entire area photo is P1, and the coordinate of P1 on the length line of the entire area photo is X1, X1-X0=L0; under photo partitioning: the intersection point between the leftmost dividing line area and the length line of the entire area photo is P2, and the coordinate of P2 on the length line of the entire area photo is X2, X2-X0=L1. In step S2, the projection of P1 onto the circumference of the straight connector is P1', the projection of P2 onto the circumference of the straight connector is P2', the center of the straight connector is O, and the angle between O-P1' and 0-P2' is θ, where θ is the rotation angle.

2. The method of claim 1, wherein, In step S2, when θ is positive, the straight connector rotates counterclockwise; when θ is negative, the straight connector rotates clockwise.

3. The method of claim 1, wherein the laser marking is performed on the straight through connector. In step S2, the radian measure of θ is calculated using the following equation: Where k is the error compensation coefficient and D is the outer diameter of the straight connector, the calculation equation converted to angle system is: 。 4. The laser marking method for a straight connector according to claim 1, characterized in that, In step S3, after the straight connector (201) is rotated and adjusted, it is checked a second time by the vision system. If the angle deviation is >1°, then θ is corrected and fine-tuned a second time until the deviation is ≤1°.

5. A through connection laser marking apparatus for carrying out the through connection laser marking method according to any one of claims 1 to 4, characterized by The device includes a feeding device, a conveyor belt (1), a first camera, a clamping assembly (2), an adjustment assembly (3), a second camera, and a laser marking device. The feeding device, the first camera, the clamping assembly (2), the adjustment assembly (3), the second camera, and the laser marking device are arranged along the length of the conveyor belt (1). The conveyor belt (1) is equipped with multiple clamps (11). A straight connector (201) is placed in the clamps (11). The clamping assembly (2) and the adjustment assembly (3) can clamp the straight connector (201). The second camera is located above the clamping assembly (2) on the conveyor belt (1). The adjustment assembly can rotate the straight connector (201). The laser marking device marks the straight connector (201).

6. The through connection laser marking apparatus of claim 5, wherein, The clamping assembly (2) includes a plurality of first clamps (22), which can move closer to or further away from the adjusting assembly (3). The adjusting assembly (3) includes a plurality of second clamps (32), which can move closer to or further away from the clamping assembly (2). Each second clamp (32) is controlled to rotate by a motor (34).

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