Shell tube expansion joint method and tube expansion device

Abstract

The invention provides a shell tube expanded connection method and a tube expanding device. The shell tube expanded connection method comprises the steps that an actual coordinate system of a to-be-inserted face of a to-be-expanded connection shell tube and an actual X coordinate axis in the actual coordinate system are preliminarily obtained; correcting the rotation angle of the actual X coordinate axis and the rotation angle of the actual Y coordinate axis in the actual coordinate system; finely adjusting the position of the actual X coordinate axis and the position of the actual Y coordinate axis in the actual coordinate system; and the pipe expander is controlled to expand the to-be-expanded shell pipe, so that the problem that in the prior art, a robot expanded connection system for pipe expansion cannot achieve accurate positioning is solved.

Description

Technical Field

[0001] This invention relates to the field of air conditioner manufacturing, and more specifically, to a shell and tube expansion method and expansion device. Background Technology

[0002] In existing technologies for central air conditioning manufacturing, the fixed connection between the shell and the tube is mainly achieved through expansion joint technology. Under traditional manual operation, this technology is quite difficult and time-consuming due to the large size of the shell and tube, and the limited precision of manual operation leads to unstable expansion joint effect, high material scrap rate, and increased production cost.

[0003] With the widespread application of industrial robots in the manufacturing field, robotic expansion systems are gradually being introduced into the production of central air conditioning systems to improve production efficiency and expansion accuracy. However, existing robotic expansion technologies still have some key problems that have not been effectively solved. First, accurately determining the position of the expander on the robot fixture inside the shell tube is a challenge, and the lack of an effective feedback mechanism to ensure that the expander is precisely aligned with the shell tube directly affects the accuracy and success rate of expansion. Second, even if expansion is automated through robots, the displacement parameter range of the expander cannot be fed back in real time during the expansion process, which challenges the stability of the equipment. Summary of the Invention

[0004] The main objective of this invention is to provide a shell tube expansion method and tube expansion device to solve the problem that existing robotic expansion systems for tube expansion cannot accurately position the tubes.

[0005] To achieve the above objectives, according to one aspect of the present invention, a shell tube expansion method is provided, comprising: initially obtaining the actual coordinate system of the insertion surface of the shell tube to be expanded and the actual X-axis in the actual coordinate system; correcting the rotation angle of the actual X-axis and the rotation angle of the actual Y-axis in the actual coordinate system; fine-tuning the position of the actual X-axis and the position of the actual Y-axis in the actual coordinate system; and controlling the tube expander to expand the shell tube to be expanded.

[0006] Furthermore, the step of correcting the rotation angles of the actual X-axis and the actual Y-axis in the actual coordinate system includes: obtaining the coordinates of the centers of the three first preset holes to be processed, which form a right triangle, on the insertion surface of the tube to be expanded in the actual coordinate system, using the coordinates of the centers of the three first preset holes to be processed as three reference points; controlling the tube expander to move sequentially to three distance measurement positions where the line connecting the center of the tube expander and the three reference points is perpendicular to the preset insertion surface, so as to obtain the distance between each reference point and the center of the tube expander. The first actual distance L1, the second actual distance L2, and the third actual distance L3 are calculated; the actual distance difference between any two of the first actual distance L1, the second actual distance L2, and the third actual distance L3 is calculated to obtain the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3; the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3 are compared with the preset distance difference ΔL0 to determine whether the insertion surface of the tube to be expanded is parallel to the preset insertion surface.

[0007] Further, the steps for initially obtaining the actual coordinate system and the actual X-axis of the insertion surface of the tube to be expanded include: obtaining the insertion surface of the tube after successful expansion processing; establishing a preset coordinate system based on the insertion surface of the tube after successful expansion processing, and establishing a preset X-axis in the preset coordinate system; obtaining the actual position of the edge of the insertion surface of the tube to be expanded in the X direction; updating the preset X-axis and the preset coordinate system based on the actual position of the edge of the insertion surface of the tube to be expanded in the direction parallel to the X-axis to form the actual X-axis and the actual coordinate system; controlling the distance detection component of the tube expander to move from the periphery of the preset X-axis along the positive direction of the preset X-axis until the edge of the insertion surface of the tube to be expanded in the X direction is detected, and defining the edge of the insertion surface of the tube to be expanded in the X direction as the X origin of the actual X-axis.

[0008] Furthermore, the three reference points are designated as a first reference point, a second reference point, and a third reference point. The first reference point is located on one side of a first edge of the tube to be expanded. The second reference point is on a straight line with the first reference point and is located on the other side of the tube to be expanded, near the first reference point. The third reference point is located directly above the second reference point, forming a right triangle with the line connecting the first and second reference points. The actual distance between the first reference point and the center of the tube expander is the first actual distance L1; the actual distance between the second reference point and the center of the tube expander is the second actual distance L2; and the actual distance between the third reference point and the center of the tube expander is the third actual distance L3. The difference between the first and third actual distances is ΔL1 = L1 - L2, ΔL2 = L1 - L3, and ΔL3 = L2 - L3.

[0009] Furthermore, the step of initially obtaining the actual coordinate system of the insertion surface of the tube to be expanded and the actual X-axis in the actual coordinate system also includes: a preset distance difference ΔL0 = 1.5 mm; wherein, if at least one of the first actual distance difference ΔL1, the second actual distance difference ΔL2 and the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, it is determined that the insertion surface of the tube to be expanded is not parallel to the preset insertion surface, and the rotation angle of the actual coordinate system is corrected; if all of the first actual distance difference ΔL1, the second actual distance difference ΔL2 and the third actual distance difference ΔL3 are less than or equal to the preset distance difference ΔL0, it is confirmed that the insertion surface of the tube to be expanded is parallel to the preset insertion surface, and the next process is continued.

[0010] Furthermore, the coordinates of the center of the first preset hole to be processed corresponding to the second reference point are (X2, Y1); the coordinates of the center of the first preset hole to be processed corresponding to the third reference point are (X2, Y2); if the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, then the rotation angle correction value of the actual X coordinate axis of the actual coordinate system is calculated using the following formula: X θ =arctan[(L3-L2) / (Y2-Y1)].

[0011] Further, the coordinates of the center of the first preset hole to be processed corresponding to the first reference point are (X1, Y1); the coordinates of the center of the first preset hole to be processed corresponding to the second reference point are (X2, Y1); if the first actual distance difference ΔL1 is greater than the preset distance difference ΔL0, then the rotation angle correction value of the actual Y coordinate axis of the actual coordinate system is calculated using the following formula: Y θ =arctan[L2-L1) / (X2-X1)].

[0012] Furthermore, the step of fine-tuning the positions of the actual X-axis and the actual Y-axis in the actual coordinate system includes: acquiring an image of the two second preset holes to be processed on the insertion surface of the tube to be expanded to obtain the coordinates of the center of the two second preset holes to be processed; comparing the coordinates of the center of the two second preset holes to be processed with the preset hole center coordinates to further adjust the positions of the actual X-axis and the actual Y-axis in the actual coordinate system.

[0013] Further, the steps for controlling the tube expander to expand the tube to be expanded include: obtaining the length of the expander as H1; setting the distance between the expander and the insertion surface of the tube to be expanded as H2, and calculating the sum of the length of the expander (H1) and the distance between the expander and the insertion surface of the tube to be expanded (H2) as ΔH; obtaining the first Z-coordinate Z1 of the expander in the Z direction perpendicular to the actual coordinate system when the distance between the expander and the insertion surface of the tube to be expanded is H2; controlling the expander to enter the tube to be expanded, and when the cylinder used to drive the expansioner senses that the pressure from the tube to be expanded is greater than the preset pressure, obtaining the second Z-coordinate Z2 of the expander in the Z direction at this time; calculating the difference ΔZ between the first Z-coordinate Z1 and the second Z-coordinate Z2; determining the relationship between ΔH and ΔZ; if ΔZ ≥ ΔH, then determining that the expander has completely entered the tube to be expanded.

[0014] According to another aspect of the present invention, a shell tube expansion device is provided, including a shell tube expansion method, wherein the shell tube expansion method is the shell tube expansion method described above. The shell tube expansion device includes: a robot gripper for driving a tube expander to move; a cylinder, wherein the power output end of the robot gripper is connected to the cylinder, and the piston rod of the cylinder is connected to the tube expander to drive the tube expander to move; wherein a distance sensor is connected to the robot gripper for determining the position of the shell tube to be expanded.

[0015] By applying the technical solution of this invention, this application initially obtains the actual coordinate system of the shell tube to be expanded, including the actual X-axis, enabling the robot to accurately identify the position of the shell tube relative to its own coordinate system, providing basic positioning information for subsequent expansion operations. By correcting the rotation angles of the actual X-axis and actual Y-axis in the actual coordinate system, it ensures that the robot tool can maintain the correct angular alignment with the shell tube opening during the expansion process, avoiding expansion failure or product quality degradation due to angular deviation. In addition, this application also includes fine-tuning the positions of the actual X-axis and actual Y-axis to accurately correct the relative position between the robot fixture and the shell tube, further improving the accuracy and stability of the expansion tool positioning and reducing expansion errors caused by position deviation. Based on the above coordinate system acquisition, rotation angle correction, and position fine-tuning, the tube expander can be intelligently controlled to expand the shell tube, achieving high precision and high efficiency in the automated expansion process, reducing manual intervention, and solving the problem of inaccurate positioning in existing robot expansion systems for tube expansion. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0017] Figure 1A schematic flowchart of a portion of an embodiment of the shell-and-tube expansion method according to the present invention is shown;

[0018] Figure 2 A schematic flowchart of another part of an embodiment of the shell-and-tube expansion method according to the present invention is shown;

[0019] Figure 3 A schematic diagram of the overall structure of an embodiment of the tube expansion device according to the present invention is shown;

[0020] Figure 4 A schematic diagram of the structure of a robot gripper according to an embodiment of the tube expansion device of the present invention is shown;

[0021] Figure 5 A front view of a shell tube to be expanded according to an embodiment of the tube expansion device according to the present invention is shown.

[0022] The above figures include the following reference numerals:

[0023] 10. Tube to be expanded; 20. Insertion surface; 30. Tube expander;

[0024] 40. First preset hole to be machined; 60. Second preset hole to be machined;

[0025] 70. Robot gripper; 80. Cylinder. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] like Figures 1 to 5 As shown, the shell tube expansion method of this application includes: initially obtaining the actual coordinate system of the insertion surface 20 of the shell tube 10 to be expanded and the actual X-axis in the actual coordinate system; correcting the rotation angle of the actual X-axis and the rotation angle of the actual Y-axis in the actual coordinate system; fine-tuning the position of the actual X-axis and the position of the actual Y-axis in the actual coordinate system; and controlling the tube expander 30 to expand the shell tube 10 to be expanded.

[0028] In this way, by initially obtaining the actual coordinate system of the shell tube to be expanded, including the actual X-axis, this application enables the robot to accurately identify the position of the shell tube relative to its own coordinate system, providing basic positioning information for subsequent expansion operations. By correcting the rotation angles of the actual X-axis and actual Y-axis in the actual coordinate system, it ensures that the robot tool can maintain the correct angular alignment with the shell tube opening during the expansion process, avoiding expansion failure or product quality degradation due to angular deviation. In addition, this application also includes fine-tuning the positions of the actual X-axis and actual Y-axis to accurately correct the relative position between the robot fixture and the shell tube, further improving the accuracy and stability of the expansion tool positioning and reducing expansion errors caused by position deviation. Based on the above coordinate system acquisition, rotation angle correction, and position fine-tuning, the tube expander can be intelligently controlled to expand the shell tube, achieving high precision and high efficiency in the automated expansion process, reducing manual intervention, and solving the problem of inaccurate positioning in existing robot expansion systems for tube expansion.

[0029] Specifically, the steps for correcting the rotation angles of the actual X-axis and the actual Y-axis in the actual coordinate system include: obtaining the coordinates of the centers of the three first preset holes 40 for forming a right triangle on the insertion surface 20 of the tube to be expanded 10 in the actual coordinate system, using the coordinates of the centers of the three first preset holes 40 as three reference points; controlling the expander 30 to move sequentially to three distance measurement positions where the line connecting the center of the expander 30 and the three reference points is perpendicular to the preset insertion surface, so as to obtain the distance between each reference point and the expander 30. The first actual distance L1, the second actual distance L2, and the third actual distance L3 between the centers are calculated; the actual distance difference between any two of the first actual distance L1, the second actual distance L2, and the third actual distance L3 is calculated to obtain the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3; the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3 are compared with the preset distance difference ΔL0 to determine whether the insertion surface 20 of the expansion shell tube 10 is parallel to the preset insertion surface.

[0030] By obtaining the coordinates of the centers of three preset holes on the insertion surface of the tube to be expanded as reference points, the distance between these hole centers and the center of the expander can be accurately measured, thereby calculating the actual parallelism deviation between the insertion surface of the tube and the preset insertion surface. This application uses the distance measurement results to calculate the actual distance difference and compares it with the preset distance difference to automatically determine whether the insertion surface of the tube is parallel to the preset insertion surface. If they are not parallel, the system can perform necessary rotation angle correction to ensure that the expander performs the expansion operation at the correct angle.

[0031] Specifically, the steps for initially obtaining the actual coordinate system and the actual X-axis of the insertion surface 20 of the tube to be expanded and connected include: obtaining the insertion surface of the tube after the tube has been successfully expanded; establishing a preset coordinate system based on the insertion surface of the tube after the tube has been successfully expanded and establishing a preset X-axis in the preset coordinate system; obtaining the actual position of the edge of the insertion surface 20 of the tube to be expanded and connected in the X direction; updating the preset X-axis and the preset coordinate system based on the actual position of the edge of the insertion surface 20 of the tube to be expanded and connected in the direction parallel to the X-axis, so as to form the actual X-axis and the actual coordinate system.

[0032] By first acquiring the qualified expansion tube surface to be inserted, a preset coordinate system and its preset X-axis are established. Combined with the specific position information of the tube to be expanded, the actual coordinate system of the tube can be established more accurately. This process ensures effective alignment between the robot coordinate system and the actual tube coordinate system, improving positioning accuracy. Even if the tube's position on the production line changes slightly, the preset coordinate system can be updated in real time by detecting the actual edge position of the tube's insertion surface in the X direction, converting it into the actual coordinate system corresponding to the current tube position. This dynamic adjustment mechanism improves the flexibility of the robotic expansion system, can tolerate small deviations during production to a certain extent, and reduces the need for manual adjustments.

[0033] This application utilizes edge detection to update the preset X-axis, simplifying the preparation stage before expansion jointing and improving production efficiency compared to traditional manual calibration methods. This method rapidly establishes the coordinate framework required for expansion jointing through automated edge recognition, reducing the time spent on initial positioning.

[0034] Specifically, the step of updating the preset X-coordinate axis and preset coordinate system according to the actual position of the edge of the insertion surface 20 of the tube to be expanded 10 in the direction parallel to the X-coordinate axis to form the actual X-coordinate axis and actual coordinate system includes: controlling the distance detection component of the tube expander 30 to move from the periphery of the preset X-coordinate axis along the positive direction of the preset X-coordinate axis until the edge of the insertion surface 20 of the tube to be expanded 10 in the X direction is detected, and the edge of the insertion surface 20 of the tube to be expanded 10 in the X direction is defined as the X origin of the actual X-coordinate axis.

[0035] Using the edge of the shell tube as the X origin ensures that the tube expander operates along the correct X-axis direction during expansion, avoiding inaccurate expansion position due to coordinate system deviation, thereby improving expansion accuracy and reducing material waste caused by expansion failure. Traditional coordinate system calibration usually requires complex measuring tools and tedious manual adjustments. This application can complete the positioning of the X origin with only the distance detection component, simplifying the calibration process and reducing equipment investment and maintenance costs.

[0036] like Figure 5 As shown, the three reference points are the first reference point, the second reference point, and the third reference point. The first reference point is located on one side of a first edge of the tube to be expanded 10. The second reference point is on a straight line with the first reference point and is located on the other side of the first reference point near the other first edge of the tube to be expanded 10. The third reference point is located directly above the second reference point, so that the line connecting the first reference point and the second reference point together forms a right triangle.

[0037] The right-angled triangle reference point layout provides a clear positioning benchmark. Even if the shell tube has slight positional or angular deviations on the production line, the coordinate system can be quickly corrected by detecting these three points, ensuring the stability of the expansion joint operation. Furthermore, constructing the coordinate system by detecting three reference points simplifies the process compared to complex manual correction or multiple-point detection. Only these three specifically arranged points need to be detected to complete the establishment and correction of the coordinate system, improving production efficiency.

[0038] Furthermore, the right-angled triangle reference point layout ensures that the X and Y coordinate axes are aligned with the edge of the tube, which helps the tube expander to expand in the correct direction, avoiding expansion failures caused by inaccurate coordinate axis orientation and improving operational reliability. Regardless of the size of the tube, this method is applicable as long as three reference points satisfying the right-angled triangle layout can be found, enhancing the versatility and adaptability of the expansion method in this application.

[0039] Specifically, the actual distance between the first reference point and the center of the tube expander 30 is the first actual distance L1; the actual distance between the second reference point and the center of the tube expander 30 is the second actual distance L2; and the actual distance between the third reference point and the center of the tube expander 30 is the third actual distance L3. Among these, the difference between the first actual distance ΔL1 = L1 - L2, the difference between the second actual distance ΔL2 = L1 - L3, and the difference between the third actual distance ΔL3 = L2 - L3.

[0040] This application calculates the differences ΔL1, ΔL2, and ΔL3 between the first actual distance L1, the second actual distance L2, and the third actual distance L3, thereby accurately determining the position of the tube expander relative to the shell tube. This calculation method, based on triangular geometry, provides fine-grained position control of the tube expander on the shell tube expansion surface; the measurement of the actual distance differences can be used for real-time error detection and compensation. If the value of ΔL1, ΔL2, or ΔL3 exceeds the predetermined tolerance range, the control system can immediately adjust the position of the tube expander to ensure that the expansion operation is performed in the correct position, avoiding expansion failure due to positional misalignment.

[0041] This application effectively improves the accuracy of tube expansion by accurately measuring the distance between the tube expander and different reference points and calculating the relative position difference. Before expansion, by comparing the difference between the expected position and the actual position, it ensures that the tube expander is accurately aligned with the expansion position of the shell tube, reducing quality problems caused by inaccurate positioning.

[0042] Specifically, the step of initially obtaining the actual coordinate system of the insertion surface 20 of the tube to be expanded 10 and the actual X-axis in the actual coordinate system further includes: a preset distance difference ΔL0 = 1.5 mm; wherein, if at least one of the first actual distance difference ΔL1, the second actual distance difference ΔL2 and the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, it is determined that the insertion surface 20 of the tube to be expanded 10 is not parallel to the preset insertion surface, and the rotation angle of the actual coordinate system is corrected; if the first actual distance difference ΔL1, the second actual distance difference ΔL2 and the third actual distance difference ΔL3 are all less than or equal to the preset distance difference ΔL0, it is confirmed that the insertion surface 20 of the tube to be expanded 10 is parallel to the preset insertion surface, and the next process is continued.

[0043] Even when the shell and tube are not perfectly parallel or slightly tilted, the system can adaptively adjust to the correct working position by correcting the rotation angle, which enhances the adaptability of the expansion joint system and ensures accurate expansion joint operations under various conditions.

[0044] The parallelism between the shell and tube to be inserted and the preset insertion surface is crucial to the quality of the expansion joint. By implementing this technology, expansion defects caused by positional deviations can be reduced, the scrap rate in production can be lowered, raw materials can be saved, and production costs can be reduced. Moreover, once the shell and tube to be inserted and the preset insertion surface are confirmed to be parallel, the system can smoothly execute the next process, avoiding unnecessary stops and corrections, and ensuring the continuity and efficiency of the production process.

[0045] This application uses a preset distance difference ΔL0 as a threshold to determine parallelism, which simplifies the quality control process and makes checking the parallelism of the shell tube to be inserted before expansion joint an automated and standardized process, reducing the complexity and uncertainty of manual inspection and improving the level of production automation.

[0046] Specifically, the coordinates of the center of the first preset hole 40 to be processed corresponding to the second reference point are (X2, Y1); the coordinates of the center of the first preset hole 40 to be processed corresponding to the third reference point are (X2, Y2); if the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, then the rotation angle correction value of the actual X coordinate axis of the actual coordinate system is calculated using the following formula: X θ =arctan[(L3-L2) / (Y2-Y1)].

[0047] When the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, it indicates that there is a rotational angle deviation between the expander and the X-axis of the tube to be inserted. This is achieved by calculating X... θ =arctan[(L3-L2) / (Y3-Y2)], which can accurately determine the required rotation angle, ensuring that the tube expander can be accurately aligned with the preset hole to be processed, thus improving the accuracy and consistency of the expansion joint. This method can automatically adapt to small angular deviations in the placement of the shell tube, and through real-time correction, ensure that the expansion joint operation is always performed at the correct angle. This enhances the adaptability of the expansion joint system to changes in the position of the shell tube.

[0048] The automated angle correction process of this application reduces reliance on operator skills and experience, lowers the difficulty of operation, reduces errors that may be caused by human operation, and improves the automation level of expansion joint operations.

[0049] Specifically, the coordinates of the center of the first preset hole 40 to be processed corresponding to the first reference point are (X1, Y1); the coordinates of the center of the first preset hole 40 to be processed corresponding to the second reference point are (X2, Y1); if the first actual distance difference ΔL1 is greater than the preset distance difference ΔL0, then the rotation angle correction value of the actual Y coordinate axis of the actual coordinate system is calculated using the following formula: Y θ =arctan[L2-L1) / (X2-X1)].

[0050] When the third actual distance difference ΔL1 exceeds the preset distance difference ΔL0, it indicates that there may be a rotational deviation between the expander and the insertion surface of the shell tube in the Y-axis direction. This can be addressed by using the formula Y... θ =arctan[(L2-L1) / (X2-X1)] calculates the specific rotation angle correction value. The system can automatically adjust the position of the tube expander to ensure its correct alignment with the hole to be processed, thus improving the accuracy of the expansion joint operation. This method allows the system to automatically detect and correct the rotation deviation of the Y-axis without manual intervention, enhancing the flexibility and automation of the expansion joint system and enabling it to better adapt to small changes in the position and angle of the tube.

[0051] This application avoids expansion joint failure caused by Y-axis deviation by timely rotation angle correction, thereby reducing the number of defective products in production and reducing production losses and costs.

[0052] like Figure 5As shown, the steps for fine-tuning the positions of the actual X-axis and the actual Y-axis in the actual coordinate system include: acquiring an image of the area outside the two second preset holes 60 to be processed on the insertion surface 20 of the tube to be expanded 10 to obtain the coordinates of the center of the two second preset holes 60; comparing the coordinates of the center of the two second preset holes 60 with the preset hole center coordinates to further adjust the positions of the actual X-axis and the actual Y-axis in the actual coordinate system.

[0053] By acquiring images outside the two second preset holes to be processed, a more comprehensive understanding of the actual position information of the shell tube to be inserted surface can be obtained. This provides additional reference points for the calibration of the actual coordinate system. Compared with using only preset reference points, this method can more accurately adjust the position of the X and Y axes and improve the calibration accuracy of the coordinate system.

[0054] Specifically, the steps of controlling the tube expander 30 to expand the tube 10 to be expanded include: obtaining the length of the tube expander 30 as H1; setting the distance between the tube expander 30 and the insertion surface 20 of the tube 10 to be expanded as H2; calculating the sum ΔH of the length of the tube expander 30 as H1 and the distance between the tube expander 30 and the insertion surface 20 of the tube 10 to be expanded as H2; and obtaining the distance between the tube expander 30 and the insertion surface 20 of the tube 10 to be expanded as H2, with the tube expander 30 perpendicular to the actual... The first Z-coordinate Z1 in the Z direction of the international coordinate system is obtained; the tube expander 30 is controlled to enter the tube to be expanded 10. When the cylinder used to drive the tube expander 30 senses that the pressure from the tube to be expanded 10 is greater than the preset pressure, the second Z-coordinate Z2 in the Z direction of the tube expander 30 at this time is obtained; the difference ΔZ between the first Z-coordinate Z1 and the second Z-coordinate Z2 is calculated; the relationship between ΔH and ΔZ is determined; if ΔZ≥ΔH, it is determined that the tube expander 30 has completely entered the tube to be expanded 10.

[0055] This application calculates the sum of the tube expander length H1 and the preset distance H2 between the tube expander and the insertion surface of the shell tube, ΔH, and compares it with the actual insertion depth, represented by ΔZ. This ensures that the tube expander is fully inserted into the shell tube, avoiding the problem of weak expansion joint caused by insufficient insertion depth and improving the reliability of the expansion joint.

[0056] By acquiring the first coordinate Z1 and the second coordinate Z2 of the tube expander in the Z direction, and then calculating the difference ΔZ between the two, this process provides real-time monitoring and precise control of the expansion depth, making the expansion process more controllable and reducing operational uncertainty. This application avoids damage to the tube caused by insufficient or excessive insertion depth by precisely controlling the insertion depth of the tube expander.

[0057] like Figures 3 to 5As shown, the shell tube expansion device of this application includes a shell tube expansion method, which is the shell tube expansion method described above. The shell tube expansion device includes: a robot gripper 70, which is used to drive the tube expander 30 to move; a cylinder 80, the power output end of the robot gripper 70 is connected to the cylinder 80, and the piston rod of the cylinder 80 is connected to the tube expander 30 to drive the tube expander 30 to move; wherein, a distance sensor is connected to the robot gripper 70 to determine the position of the shell tube 10 to be expanded.

[0058] The tube expansion device of this application automates the tube expansion process by using a robotic gripper to drive the expansion device. The robotic gripper can precisely control the position and movement path of the expansion device according to a pre-set program, greatly improving the efficiency and accuracy of the expansion operation. By driving the expansion device with a cylinder, and combining a preset pressure threshold and the change in the Z-coordinate, the device can accurately determine and control the insertion depth of the expansion device. This ensures that the expansion device fully enters the shell tube, avoiding problems of insufficient or excessive depth, and improving the quality and reliability of the expansion.

[0059] The inclusion of a distance sensor in this application enables the device to detect and determine the position of the shell tube to be expanded in real time, which is crucial for achieving accurate coordinate correction and fine-tuning. The sensor's data feedback ensures the accuracy of the shell tube's position before the expansion operation, reducing the scrap rate in production.

[0060] By combining functions such as coordinate correction, depth control, and position detection in the shell-and-tube expansion method, the expansion device can effectively cope with minor deviations in the position and angle of the shell and tube, enhancing its adaptability. Regardless of the initial position of the shell and tube, the device can make corresponding adjustments to ensure the success rate of the expansion joint.

[0061] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0062] The shell tube expansion method of this application includes: initially obtaining the actual coordinate system of the insertion surface 20 of the shell tube 10 to be expanded and the actual X-axis in the actual coordinate system; correcting the rotation angle of the actual X-axis and the rotation angle of the actual Y-axis in the actual coordinate system; fine-tuning the position of the actual X-axis and the position of the actual Y-axis in the actual coordinate system; and controlling the tube expander 30 to expand the shell tube 10 to be expanded.

[0063] As can be seen, this application initially obtains the actual coordinate system of the shell tube to be expanded, including the actual X-axis, enabling the robot to accurately identify the position of the shell tube relative to its own coordinate system, providing basic positioning information for subsequent expansion operations. By correcting the rotation angles of the actual X-axis and actual Y-axis in the actual coordinate system, it ensures that the robot tool can maintain the correct angular alignment with the shell tube opening during the expansion process, avoiding expansion failure or product quality degradation due to angular deviation. In addition, this application also includes fine-tuning the positions of the actual X-axis and actual Y-axis to accurately correct the relative position between the robot fixture and the shell tube, further improving the accuracy and stability of the expansion tool positioning and reducing expansion errors caused by position deviation. Based on the above coordinate system acquisition, rotation angle correction, and position fine-tuning, the tube expander can be intelligently controlled to expand the shell tube, achieving high precision and high efficiency in the automated expansion process, reducing manual intervention, and solving the problem of inaccurate positioning in existing robot expansion systems for tube expansion.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for expanding and connecting a shell-and-tube assembly, characterized in that, include: The actual coordinate system of the insertion surface (20) of the tube to be expanded (10) and the actual X coordinate axis in the actual coordinate system are initially obtained; The rotation angles of the actual X-axis and the actual Y-axis in the actual coordinate system are corrected. Fine-tune the positions of the actual X-axis and the actual Y-axis in the actual coordinate system; The tube expander (30) is used to expand the tube (10) to be expanded.

2. The shell-and-tube expansion method according to claim 1, characterized in that, The steps for correcting the rotation angles of the actual X-axis and the actual Y-axis in the actual coordinate system include: Obtain the coordinates of the center of the three first preset holes (40) on the insertion surface (20) of the expansion shell tube (10) in the actual coordinate system, and use the coordinates of the center of the three first preset holes (40) as three reference points. The expander (30) is controlled to move sequentially to three distance measurement positions where the line connecting the center of the expander (30) and the three reference points is perpendicular to the preset insertion surface, so as to obtain the first actual distance L1, the second actual distance L2 and the third actual distance L3 between each reference point and the center of the expander (30); Calculate the actual distance difference between any two of the first actual distance L1, the second actual distance L2, and the third actual distance L3 to obtain the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3; The first actual distance difference ΔL1, the second actual distance difference ΔL2 and the third actual distance difference ΔL3 are compared with the preset distance difference ΔL0 to determine whether the insertion surface (20) of the expansion shell tube (10) is parallel to the preset insertion surface.

3. The shell-and-tube expansion method according to claim 1, characterized in that, The steps of initially obtaining the actual coordinate system of the insertion surface (20) of the expansion shell tube (10) and the actual X-axis in the actual coordinate system include: Obtain the insertion surface of the shell tube that has passed the expansion processing; A preset coordinate system is established based on the insertion surface of the shell tube that has passed the expansion process, and a preset X-axis is established in the preset coordinate system. Obtain the actual position of the edge of the insertion surface (20) of the expansion shell tube (10) in the X direction; The preset X-axis and the preset coordinate system are updated according to the actual position of the edge of the insertion surface (20) of the expansion shell tube (10) in the direction parallel to the X-axis to form the actual X-axis and the actual coordinate system. The distance detection component of the tube expander (30) is controlled to move from the periphery of the preset X coordinate axis along the positive direction of the preset X coordinate axis until the edge of the insertion surface (20) of the tube to be expanded (10) in the X direction is detected, and the edge of the insertion surface (20) of the tube to be expanded (10) in the X direction is defined as the X origin of the actual X coordinate axis.

4. The shell-and-tube expansion method according to claim 2, characterized in that, The three reference points are a first reference point, a second reference point, and a third reference point. The first reference point is located on one side of a first edge of the tube to be expanded (10). The second reference point is on a straight line with the first reference point and is located on the other side of the first reference point near the other first edge of the tube to be expanded (10). The third reference point is located directly above the second reference point, so that the line connecting the first reference point and the second reference point together forms the right triangle. The actual distance between the first reference point and the center of the tube expander (30) is the first actual distance L1; The actual distance between the second reference point and the center of the tube expander (30) is the second actual distance L2; The actual distance between the third reference point and the center of the tube expander (30) is the third actual distance L3; Wherein, the first actual distance difference ΔL1 = L1 - L2, the second actual distance difference ΔL2 = L1 - L3, and the third actual distance difference ΔL3 = L2 - L3.

5. The shell-and-tube expansion method according to claim 4, characterized in that, The step of initially obtaining the actual coordinate system of the insertion surface (20) of the expansion shell tube (10) and the actual X-axis in the actual coordinate system further includes: The preset distance difference ΔL0 = 1.5 mm; where, If at least one of the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, then it is determined that the insertion surface (20) of the expansion shell tube (10) is not parallel to the preset insertion surface, and the rotation angle of the actual coordinate system is corrected. If the first actual distance difference ΔL1, the second actual distance difference ΔL2, and the third actual distance difference ΔL3 are all less than or equal to the preset distance difference ΔL0, then it is confirmed that the insertion surface (20) of the expansion shell tube (10) is parallel to the preset insertion surface, and the next process is continued.

6. The shell-and-tube expansion method according to claim 4, characterized in that, The coordinates of the center of the first preset hole to be processed (40) corresponding to the second reference point are (X2, Y1). The coordinates of the center of the first preset hole to be processed (40) corresponding to the third reference point are (X2, Y2). If the third actual distance difference ΔL3 is greater than the preset distance difference ΔL0, then the rotation angle correction value of the actual X coordinate axis of the actual coordinate system is calculated using the following formula: Xθ=arctan[(L3-L2) / (Y2-Y1)].

7. The shell-and-tube expansion method according to claim 4, characterized in that, The coordinates of the center of the first preset hole to be processed (40) corresponding to the first reference point are (X1, Y1). The coordinates of the center of the first preset hole to be processed (40) corresponding to the second reference point are (X2, Y1). If the first actual distance difference ΔL1 is greater than the preset distance difference ΔL0, then the rotation angle correction value of the actual Y-axis of the actual coordinate system is calculated using the following formula: Yθ = arctan[L2-L1) / (X2-X1)].

8. The shell-and-tube expansion method according to claim 1, characterized in that, The step of fine-tuning the positions of the actual X-axis and the actual Y-axis in the actual coordinate system includes: Obtain an image of the area outside the two second preset holes (60) on the insertion surface (20) of the expansion shell tube (10) to obtain the coordinates of the center of the two second preset holes (60); The coordinates of the center of the two second preset holes (60) to be processed are compared with the preset hole center coordinates in order to further adjust the positions of the actual X coordinate axis and the actual Y coordinate axis of the actual coordinate system.

9. The shell-and-tube expansion method according to claim 1, characterized in that, The step of controlling the tube expander (30) to expand the shell tube (10) includes: The length of the tube expander (30) is H1; The distance between the tube expander (30) and the insertion surface (20) of the tube to be expanded (10) is set to H2; The sum of the length of the tube expander (30) as H1 and the distance between the tube expander (30) and the insertion surface (20) of the tube to be expanded (10) as H2 is calculated as ΔH. When the distance between the tube expander (30) and the insertion surface (20) of the tube to be expanded (10) is H2, the first Z coordinate Z1 of the tube expander (30) in the Z direction perpendicular to the actual coordinate system is obtained; Control the tube expander (30) to enter the tube to be expanded (10). When the cylinder used to drive the tube expander (30) to move senses that the pressure from the tube to be expanded (10) is greater than the preset pressure, obtain the second Z coordinate Z2 of the tube expander (30) in the Z direction at this time. Calculate the difference ΔZ between the first Z-coordinate Z1 and the second Z-coordinate Z2; Determine the relationship between the magnitudes of ΔH and ΔZ; If ΔZ≥ΔH, then it is determined that the tube expander (30) is fully inserted into the shell tube (10) to be expanded.

10. A tube expansion device, characterized in that, The method includes a shell-and-tube expansion joint method, wherein the shell-and-tube expansion joint method is any one of claims 1 to 9, and the expansion device comprises: A robotic gripper (70) is used to drive the tube expander (30) to move; The cylinder (80) is connected to the power output end of the robot gripper (70), and the piston rod of the cylinder (80) is connected to the expander (30) to drive the expander (30) to move. A distance sensor, connected to the robot gripper (70), is used to determine the position of the expansion shell tube (10).

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