Nut sleeve riveting apparatus and method

Abstract

This application provides a nut sleeve riveting device, which achieves precise positioning of the riveting point height by setting the height position of the riveting head at the center of the process groove; by adjusting the horizontal angle of the nut and nut sleeve through a positioning structure and a rotary drive structure, it ensures that the center point of each process groove is aligned with the riveting head as the riveting center point; and by driving the riveting gun through a pressure device to rivet the nut sleeve and nut. The entire process requires no manual intervention, effectively improving the positioning accuracy and the efficiency of the riveting process.

Description

Technical Field

[0001] This invention relates to the field of nut sleeve riveting technology, specifically to a nut sleeve riveting device and riveting method. Background Technology

[0002] In some equipment, it is necessary to rivet the nut onto the nut in the ball screw assembly. For example... Figure 1 As shown, nut N1 and lead screw N2 are installed together by threaded engagement. A riveting connecting block N3 is provided on one end face of nut N1. Adjacent connecting blocks N4 are not connected. Connecting blocks N4 have an arc-shaped structure, and all connecting blocks N4 are located on the concentric circumference of nut N1. Nut sleeve N3 has a multi-petaled plum blossom-shaped cross-section; the protruding parts of the sleeve form the plum blossom petal shape. Figure 1 In this embodiment, it has a 4-petal plum blossom-shaped structure. The size of the recessed portion on the tube wall of the nut sleeve N3 is adapted to the spacing between adjacent connecting blocks N4 on the end face of the nut N1.

[0003] In the riveting process, the nut sleeve N3 is installed on the end face of the nut N1. The protruding petal-shaped structure of the nut sleeve N3 is fitted onto the outside of the connecting block N4, and the recessed part is engaged between adjacent connecting blocks N4. A process groove N5 is provided on the outside of the connecting block N4. When riveting the nut N1 and the nut sleeve N3, the protruding petal-shaped structure of the nut sleeve N3 is fitted onto the connecting block N4, and the nut sleeve N3 is riveted into the process groove N5 using a riveting device, ensuring that the nut sleeve N3 and the nut N1 are fixed together and cannot be separated. To ensure even riveting, the specific riveting point is set at the center of the process groove N5. Existing technologies mostly use manual riveting methods, but because both the connecting block N4 and the nut sleeve N3 are arc-shaped structures, the probability of error in determining the riveting center point is relatively high, and the positioning method is cumbersome, resulting in low overall efficiency. Summary of the Invention

[0004] To address the problems of low efficiency and proneness to positioning errors in manual riveting of nuts and nut sleeves, this invention provides a nut sleeve riveting device that can accurately position the riveting point, effectively improving overall efficiency. Simultaneously, this application also discloses a nut sleeve riveting positioning method.

[0005] The technical solution of the present invention is as follows: a nut sleeve riveting device, characterized in that it includes: a controller, a product support base mounted on a workbench, a positioning structure, a rotary drive structure, and a riveting structure;

[0006] The controller is electrically connected to all sensors and drive devices;

[0007] The nuts and nut sleeves to be riveted are movably placed in the product support base by gravity;

[0008] The riveting structure includes: a riveting gun and a pressure device; the riveting gun is horizontally arranged on one side of the product support base, and the height of the riveting head of the riveting gun is set at the center position of the riveting groove of the connecting block on the nut.

[0009] The positioning structure includes: a preliminary positioning structure, wherein the preliminary positioning structure includes: a position sensor, wherein the position sensor is disposed on the side of the product support base and the measuring position is disposed on the side wall of the nut sleeve;

[0010] The product support base rotates based on the rotary drive structure, causing the nut and nut sleeve to adjust their angles.

[0011] Its further features are:

[0012] The positioning structure further includes a calibration structure, which includes a contour calibration head and a lifting drive structure.

[0013] The contour calibration head is positioned above the product support base and moves up and down based on the lifting drive structure.

[0014] The conformal calibration head includes: a calibration block body and a conical head. The calibration block body is provided with a protruding conformal shape, the position, size and shape of which are adapted to the petal-shaped protrusions in the inner cavity of the nut sleeve.

[0015] The conical head is located below the calibration block body; the conical head is a tapered conical structure that is wider at the top and narrower at the bottom, and a tapered inclined surface is provided on the side wall of the conical head at the position corresponding to each protruding contour. The bottom side length of each inclined surface is less than the width of the protruding contour, and the top side length is equal to the width of the protruding contour.

[0016] The mounting angle of the contour calibration head meets the following conditions:

[0017] A protruding profile on the profile calibration head is set as a rivet point profile; the projection of the center point of the rivet point profile in the horizontal width direction is located on the extension line of the rivet head of the riveting gun.

[0018] The detection angle of the position sensor is perpendicular to the riveting gun;

[0019] The product support base includes: a support base body and a rotating shaft;

[0020] The support body has a Y-shaped cavity structure, and recessed nut support seats are respectively provided on the inner cavity sidewalls of the two vertical parts; the two nut support seats are symmetrically arranged, and their shape and size are adapted to the nuts; the rotating shaft is located below the support body;

[0021] The riveting structure further includes: a pressure support block; the pressure support block is disposed on the other side of the nut sleeve at a position corresponding to the riveting gun;

[0022] The pressure support block includes: a concave support arc surface, the shape and size of which are adapted to the size and shape of the nut sleeve;

[0023] It also includes a feeding structure, which includes a feeding horizontal cylinder, a sliding cross plate, a nut seat sliding groove, and a feeding slide rail;

[0024] The feeding slide rail is located below the workbench, and the sliding cross plate is slidably mounted on the feeding slide rail; the feeding horizontal cylinder is mounted on the workbench, and the horizontally arranged output shaft is connected to the sliding cross plate.

[0025] The nut seat sliding groove is formed on the worktable; the product support seat passes through the nut seat sliding groove from top to bottom, and the bottom rotating shaft is rotatably mounted on the sliding horizontal plate; the rotation drive structure is located below the sliding horizontal plate, and the rotating shaft is rotated under the drive of the rotation drive structure.

[0026] A method for riveting a nut sleeve, characterized by comprising the following steps:

[0027] S1: The position sensor in the structure is initially located based on the distance sensor;

[0028] S2: Inspect the nut sleeve and find the included angle between adjacent rivet points, denoted as: rivet point angle;

[0029] The included angle of the riveting point = 360 / N; where N is the total number of riveting points on the nut sleeve;

[0030] S3: Inspect the nut sleeve. Based on the height and dimensions of the petal-shaped protrusions on the nut sleeve and the specific shape of the packaging protrusions, determine the corresponding accuracy threshold DH for the nut sleeve.

[0031] Find the point on the outer wall of the nut sleeve where the first change occurs between the recessed and raised parts, and record it as the initial detection point; record the height difference before and after the initial detection point as the accurate threshold DH.

[0032] Each of the petal-shaped protrusions has an initial detection point on each side, denoted as point p and point p' respectively;

[0033] S4: Inspect the nut sleeve and determine the initial alignment angle corresponding to the nut sleeve based on the specific width of the petal-shaped protrusions on the nut sleeve;

[0034] A coordinate system is constructed with the center of the nut as the origin in the horizontal direction; in the rotation direction of the nut sleeve, the angle between the radius of the initial detection point and the radius of the next riveting point is the angle between the distance sensor detection point and the next riveting point, which is denoted as: the initial alignment angle;

[0035] Let α be the initial alignment angle corresponding to point p, and β be the initial alignment angle corresponding to point p'.

[0036] S5: Install the nut sleeve to be riveted on top of the nut. The protruding petal-shaped structure of the nut sleeve is fitted onto the connecting block. The nut sleeve, nut, and lead screw are installed together and placed vertically on the product support base. The product is then transported to the angle calibration position to complete the loading process.

[0037] The product support base is driven to rotate by a rotary drive structure, which in turn causes the nut and nut sleeve to rotate. The position sensor detects the distance value fed back by the outer wall of the nut sleeve in real time and transmits the distance value to the controller.

[0038] S6: The controller calculates the difference d between the (i+1)th distance value and the ith distance value in real time;

[0039] And compare d with the preset accuracy threshold DH in real time;

[0040] Once d equals DH, the point corresponding to the (i+1)th distance value is recorded as: the point where the angle is located.

[0041] S7: The controller refers to the current rotation direction of the nut sleeve, and determines whether the current initial detection point is point p or point p' based on whether the detection value of the position sensor increases or decreases, and then determines the corresponding preliminary alignment angle.

[0042] Then read the included angle A between the riveting gun and the distance sensor; based on the initial detection point and the preliminary accurate angle and angle A, calculate the adjustment rotation angle B;

[0043] After the rotational drive structure is controlled to rotate the support body by adjusting the rotation angle B, the rotation stops and the nut sleeve reaches the initial positioning point.

[0044] Its further features are:

[0045] It also includes the following steps:

[0046] S8: Activate the lifting drive structure to drive the contour calibration head downwards and insert it into the inner cavity of the nut sleeve from the top until the contour calibration head is fully inserted into the inner cavity of the nut sleeve; complete the position calibration of the nut sleeve and nut.

[0047] S9: The reverse start lifting drive structure drives the contour calibration head to move upward, causing the contour calibration head to disengage from the nut sleeve;

[0048] S10: Start the pressure application device to drive the riveting gun to move horizontally and complete the riveting of the nut and nut sleeve at one point;

[0049] S11: According to the included angle of the riveting point, the nut and nut sleeve are rotated by the rotation drive structure to rotate to the next riveting point, and the riveting process of other riveting points is completed one by one.

[0050] In step S4, the initial aligning angle satisfies the condition: α + β = the included angle of the riveting point;

[0051] In step S8: the controller's control method for the pressure application device includes: pressure mode and distance mode;

[0052] The pressure mode is as follows: a preset riveting pressure threshold is set, and when the pressure received by the nut sleeve meets the pressure threshold, the pressure is stopped and the riveting is completed.

[0053] The distance mode is as follows: a preset riveting joint stroke threshold is set. When the distance by which the riveting joint pushes the nut into the process groove reaches the riveting joint stroke threshold, the pressure is stopped and the riveting is completed.

[0054] This application provides a nut sleeve riveting device, which achieves precise positioning of the riveting point height by setting the height of the riveting head at the center of the process groove; the horizontal angle of the nut and nut sleeve is adjusted by a positioning structure in conjunction with a rotary drive structure to ensure that the center point of each process groove is aligned with the riveting head; the riveting gun is driven by a pressure device to rivet the nut and nut sleeve; the entire process requires no manual intervention, effectively improving the positioning accuracy and the efficiency of the riveting process. The positioning structure in this application includes a preliminary positioning structure and a calibration structure. Based on the preliminary positioning structure, the current angle of the nut sleeve is measured by the petal-shaped protrusions and indentations on the nut sleeve, and then the angle of the nut and nut sleeve is adjusted by the rotary drive structure to achieve preliminary positioning; after preliminary positioning, the nut and nut sleeve have completed large-angle adjustment. To achieve precise adjustment of the horizontal angle of the nut sleeve, this application also includes a calibration structure. A certain protruding profile on the contour calibration head is set as the riveting point profile. The projection of the center point of the riveting point profile in the horizontal width direction is set on the extension line of the riveting head of the riveting gun. When the contour calibration head descends and inserts into the nut sleeve, because the bottom side length of each inclined surface of the conical head is less than the width of the protruding profile, even if the nut sleeve is slightly offset from the preset riveting position, the conical head with the upper wide and lower narrow contraction structure can still be inserted into the inner cavity of the nut sleeve. As the contour calibration head penetrates deeper into the inner cavity of the nut sleeve, the groove on the outer wall of the contour calibration head becomes a guide structure, gradually guiding the nut sleeve and the nut to apply a torsional force, causing the nut to rotate slightly in the product support seat, gradually twisting to the same angle as the contour calibration head, thus achieving precise positioning of the nut sleeve and the nut. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the nut and nut sleeve to be riveted.

[0056] Figure 2 This is a three-dimensional structural diagram of the nut sleeve riveting device of this application;

[0057] Figure 3 This is a cross-sectional structural schematic diagram of the nut sleeve riveting device of this application;

[0058] Figure 4 This is a structural schematic diagram of the support base;

[0059] Figure 5 This is a schematic diagram of the contour calibration head.

[0060] Figure 6 A comparison diagram of the contour calibration head and the nut sleeve;

[0061] Figure 7 This is a schematic diagram of the structure after the square head is fully inserted into the nut sleeve;

[0062] Figure 8 This is a diagram illustrating the initial angle determination. Detailed Implementation

[0063] like Figures 2-4 As shown, this application includes a nut sleeve riveting device, comprising: a controller (not marked in the figure), and a riveting structure 2, a product support base 3, a positioning structure, a rotary drive structure 7, and a feeding structure 8 mounted on a workbench 1. The controller is electrically connected to all sensors and drive devices, and the specific connection method is based on existing technology.

[0064] The nut N1 and nut sleeve N3 to be riveted are movably placed in the product support 3 by gravity. For example... Figure 3 and Figure 4 As shown, the product support base 3 includes: a support body 31 and a rotating shaft 32; the support body 31 has a Y-shaped cavity structure, with recessed nut support seats 311 respectively provided on the inner cavity sidewalls of the two vertical parts; the two nut support seats 311 are symmetrically arranged and support the nuts simultaneously, and the shape and size of the nut support seats 311 are adapted to the nuts; the rotating shaft 32 is located below the support body 31. To ensure smooth feeding during material loading, an inlet 312 that is wider at the top and narrower at the bottom is provided above the nut support seat.

[0065] In practice, the nut N1, screw N2, and nut sleeve N3 are transported to the product support base via a handling structure (not marked in the figure). The nut sleeve to be riveted is installed above the nut, and the protruding petal-shaped structure of the nut sleeve is fitted onto the nut connecting block to ensure that the nut and nut sleeve can rotate synchronously. The handling structure installs the nut sleeve, nut, and screw together and places them vertically on the product support base 3. Of course, the product handling work can also be completed manually.

[0066] The feeding structure 8 includes a feeding horizontal cylinder 81, a sliding horizontal plate 82, a nut seat sliding groove 83, and a feeding slide rail 84; the feeding slide rail 84 is located below the worktable 1, and the sliding horizontal plate 82 is slidably mounted on the feeding slide rail 84; the feeding horizontal cylinder 81 is mounted on the worktable 1, and the output shaft is horizontally connected to the sliding horizontal plate 82.

[0067] A nut seat sliding groove 83 is formed on the worktable 1; the product support base 3 passes through the nut seat sliding groove 83 from top to bottom, and the bottom rotating shaft 32 is rotatably mounted on the sliding cross plate 82 via a bearing structure 33. Specifically, the rotation drive structure 7 is based on a rotary motor, which is located below the sliding cross plate 82. A synchronous pulley 34 is provided on the outer periphery of the bottom of the rotating shaft 32, and a synchronous pulley is also provided at the output end of the rotary motor. The rotary motor is connected to the synchronous pulley 34 on the outer periphery of the rotating shaft 32 via a synchronous belt 72 to drive the rotating shaft 32 to rotate. When rotation is required, the rotary motor is started, and the output shaft drives the rotating shaft 32 to rotate via the synchronous pulley and the synchronous belt, thereby driving the nut and nut sleeve in the support base 31 to adjust their angle.

[0068] The riveting structure 2 includes a riveting gun 21, a pressure support block 23, and a pressure device 22. The riveting gun 21 is horizontally disposed on one side of the product support base 3, and the height of the riveting head of the riveting gun 21 is set at the center position of the riveting groove of the connecting block on the nut. In this embodiment, the pressure device 22 is implemented based on a servo electric cylinder.

[0069] The nut and nut sleeve are placed in the support body 31 and are fixed at a certain height. Therefore, this application ensures that the height of the rivet point is positioned in one go by setting the height of the rivet head of the rivet gun 21 at the center of the rivet groove of the connecting block on the nut.

[0070] A pressure support block 23 is positioned on the opposite side of the nut sleeve, corresponding to the riveting gun 21. The pressure support block 23 includes a concave support arc surface, the shape and size of which are adapted to the size and shape of the nut sleeve. By setting the pressure support block 23 at the opposite position to the riveting gun 21, this application ensures support for the nut sleeve and nut during the riveting process, thus enabling the riveting operation to be completed smoothly.

[0071] The initial position of the horizontal cylinder 81 for loading is set in the sliding groove 83 of the nut seat, away from the pressure support block 23. After the nut and nut sleeve are placed on the product support, the horizontal cylinder 81 for loading starts, and slides the sliding plate 82 horizontally along the loading slide rail 84. The product support 3 slides along the sliding groove 83 of the nut seat toward the pressure support block 23 until it reaches the angle calibration position, at which point the horizontal cylinder 81 for loading stops. The angle calibration position is located at the detection position of the position sensor of the preliminary positioning structure 5, and is also located directly below the contour calibration head 41, preparing for subsequent angle adjustment. Moreover, its proximity to the pressure support block 23 ensures that the nut sleeve can be supported by the pressure support block 23 during the riveting process.

[0072] Because the angle of the nut and nut sleeve during the feeding process is uncontrollable, this application sets a preliminary positioning structure 5 and a calibration structure 4 in the positioning structure, which are divided into two parts to achieve positioning of the horizontal angle of the rivet point, so as to ensure that accurate positioning can be achieved.

[0073] The preliminary positioning structure 5 includes a position sensor, which is located on the side of the product support 3, and the measuring position is located on the side wall of the nut sleeve. Because the petal-shaped protrusions on the outer wall of the nut sleeve are evenly distributed around the circumference, the preliminary positioning is mainly based on finding the edge position of a specific protrusion by detecting the height changes of these protrusions on the outer wall of the nut sleeve, thus preliminarily determining the current horizontal angle of the nut sleeve. In this embodiment, the angle is accurately determined by detecting the instantaneous change in the position of the petal-shaped protrusions and depressions on the outer wall of the nut sleeve using a distance sensor.

[0074] The calibration structure 4 includes a contour calibration head 41 and a lifting drive structure 42; in this embodiment, the lifting drive structure 42 is implemented based on a cylinder.

[0075] The contour calibration head 41 is positioned directly above the product support base 3 and moves up and down based on the lifting drive structure 42.

[0076] like Figure 5 and Figure 6 As shown, the contour calibration head 41 includes: a calibration block body 411 and a conical head. The calibration block body 411 is provided with a protruding contour 413. The position, size and shape of the protruding contour 413 are adapted to the petal-shaped protrusion in the inner cavity of the nut sleeve. The center point of the contour calibration head 41 coincides with the center of the nut to be riveted at the angle calibration position, ensuring that the contour calibration head 41 can be smoothly inserted into the inner cavity of the nut sleeve at the angle calibration position.

[0077] A conical head is positioned below the calibration block body 411. The conical head has a tapered structure that is wider at the top and narrower at the bottom. A tapering ramp 412 is provided on the sidewall of the conical head at a position corresponding to each raised contour 413. The bottom edge 4121 of each tapering ramp 412 is shorter than the width of the raised contour 413, and the top edge of the tapering ramp 412 is equal to the width of the raised contour 413. This ensures that even if the nut sleeve angle at the angle calibration position is slightly off, the narrower bottom edge of the tapering ramp 412 can smoothly guide the recessed portion on the sidewall of the nut sleeve into the space between the two raised contours 413. In this embodiment, the width of the raised contour 413, i.e., the top edge length of the tapering ramp 412, is 19.1 mm, and the bottom edge length of the tapering ramp 412 is 15.1 mm.

[0078] As the contour calibration head 41 continues to penetrate deeper into the inner cavity of the nut sleeve, the recessed portion of the side wall of the nut sleeve cavity is gradually guided between the two protruding contours 413 of the calibration block body 411, causing the nut to rotate within the support base 31, thus guiding the torsional angle of the nut sleeve until the contour calibration head 41 is fully inserted into the inner cavity of the nut sleeve. Figure 7 As shown.

[0079] The mounting angle of the contour calibration head 41 meets the following conditions:

[0080] A protruding profile 413 on the profile calibration head 41 is set as the riveting point profile; the projection of the center point of the riveting point profile in the horizontal width direction is located on the extension line of the riveting head of the riveting gun 21.

[0081] Ensure that when the contour calibration head 41 is fully inserted into the inner cavity of the nut sleeve, a certain petal-shaped protrusion on the nut sleeve is fitted onto the contour of the rivet point and is also aligned with the riveting gun 21, thereby ensuring that the center point of its corresponding process groove is aligned with the rivet joint.

[0082] The nut riveting method implemented based on the above-mentioned nut riveting equipment specifically includes the following steps.

[0083] S1: The position sensor in structure 5 is used to achieve preliminary positioning based on the distance sensor.

[0084] S2: Inspect the nut sleeve, find the included angle between adjacent rivet points, and record it as: rivet point included angle. Pre-store the rivet point included angle in the system.

[0085] If the rivet points are evenly distributed on the outer circumference of the nut sleeve, then the rivet point angle is: 360 / N; where N is the total number of rivet points on the nut sleeve.

[0086] The riveting equipment and riveting method in this application are applicable to riveting of nut sleeves with various numbers of petal-shaped protrusions. This embodiment is based on... Figure 1 The nut sleeve with four rivet points is shown for illustration.

[0087] like Figure 8 As shown, the four riveting points RP1~RP4 are evenly distributed on the circumference. The included angle between adjacent riveting points is 360 / 4 = 90°. If there are only two points, the included angle is 180°; if there are six points, the included angle is 60°.

[0088] S3: Detect the nut sleeve. Based on the height of the petal-shaped protrusions on the nut sleeve and the specific shape of the packaging protrusions, the accuracy threshold DH corresponding to the nut sleeve can be determined. Find the point on the outer wall of the nut sleeve where the concave part and the protruding part first change, and record it as: the initial detection point. Record the height difference before and after the initial detection point as: the accuracy threshold DH. Pre-store the DH value in the system.

[0089] Figure 8 In this context, the DH value is the height difference between point p or point p' and its adjacent concave portion.

[0090] S4: Inspect the nut sleeve. Based on the specific width of the petal-shaped protrusions on the nut sleeve, the initial alignment angle corresponding to the nut sleeve can be determined and pre-stored in the system.

[0091] The angle between the radius of the initial detection point and the radius of the next riveting point is the angle between the distance sensor detection point and the next riveting point, which is denoted as the initial alignment angle.

[0092] like Figure 8 As shown, a coordinate system is constructed in the horizontal direction with the center o of the nut as the origin; the initial detection point is located on one side of a petal-shaped protrusion. Each petal-shaped protrusion has an initial detection point on each side, denoted as point p and point p', respectively. Figure 8 Points p and p' are both initial detection points. The initial alignment angle corresponding to point p is α, and the initial alignment angle corresponding to point p' is β.

[0093] Figure 8 In the example, the nut sleeve rotates clockwise. If the initial detection point is p, then point p passes through the position sensor, and the distance sensor detects that the distance value suddenly changes from the distance value at the recess to the distance value at point p. At this time, the corresponding initial alignment angle is α. That is, the nut sleeve rotates another angle α, and the sensor detects the next rivet point.

[0094] If the initial monitoring point detected by the sensor is p', and the initial alignment angle corresponding to the clockwise rotation of the nut sleeve is β, then the sensor will detect the next riveting point when the nut sleeve rotates by another β angle.

[0095] The specific relationship between α and β satisfies the condition: α + β = the included angle of the riveting points. In this embodiment, when there are 4 riveting points on the nut sleeve, located at the four vertices of a square, the initial angle meets the condition: α + β = 90°. Furthermore, based on the relationship between points p and p', the specific value of α is half the included angle between the radii of points p and p'.

[0096] S5: Install the nut sleeve to be riveted on top of the nut. The protruding petal-shaped structure of the nut sleeve is fitted onto the connecting block. After the nut sleeve, nut and lead screw are installed together and placed vertically on the product support base 3, start the horizontal cylinder 81 for feeding. The feeding structure pulls the nut sleeve to the preset angle calibration position to complete the feeding process.

[0097] The rotating drive structure 7 drives the product support steel structure to rotate, causing the nut and nut sleeve to rotate. The position sensor detects the distance value fed back by the outer wall of the nut sleeve in real time and transmits the distance value to the controller.

[0098] S6: The controller calculates the difference d between the (i+1)th distance value and the i-th distance value in real time; i≥1; and compares d with the preset accuracy threshold DH in real time; once d equals DH, the point corresponding to the (i+1)th distance value is recorded as: the accuracy angle point.

[0099] In practice, the threshold DH is set as an absolute value, and the absolute value of d is used for comparison. Meanwhile, the value of d may have slight differences due to inaccurate machining of the nut sleeve, etc. Depending on the specific detection accuracy, a tolerance range can be set; as long as the difference between d and DH is within the tolerance range, they are considered equal.

[0100] S7: The rotation direction of the nut sleeve is preset and is a known condition. The controller can directly read the current rotation direction.

[0101] The controller, referring to the current rotation direction of the nut sleeve, determines whether the current initial detection point is point p or point p' based on whether the position sensor detection value increases or decreases, and determines the corresponding preliminary alignment angle.

[0102] The initial angle is determined as the angle between the distance sensor and the next riveting point; the angles between all riveting points are known, and the angle A between the riveting gun 21 and the distance sensor is also known. Therefore:

[0103] Based on the aforementioned accurate location, and based on the initial accurate angle and included angle A, the adjustment rotation angle B can be calculated according to plane geometry; the adjustment rotation angle B is the angle between the riveting gun 21 and the next riveting point;

[0104] The rotation drive structure is controlled to rotate the support body. After adjusting the rotation angle B, the rotation stops; the nut sleeve reaches the initial positioning point.

[0105] In this embodiment, in order to reduce computational complexity, the included angle A between the riveting gun 21 and the distance sensor is set to 90°, which is exactly the included angle between two riveting points; that is, when the distance sensor detects the next riveting point, the riveting gun 21 is also aligned with the adjacent riveting point.

[0106] Therefore, in Figure 8 In this embodiment, the controller reads that the current rotation direction is clockwise. Assuming that the current initial detection point is point p, the initial aiming angle of the distance sensor is α. Then, the rotation angle B is adjusted to be equal to α.

[0107] Then: Based on accurately locating the riveting point, the rotary drive structure 7 drives the support body 31 to rotate to initially locate the angle α, and then stops rotating; the nut sleeve reaches the initial positioning point. At this point, the nut and nut sleeve have completed a large angle adjustment, almost reaching the preset riveting angle. In order to further accurately calibrate the angle of the riveting point, continue to execute step S8.

[0108] S8: Activate the lifting drive structure 42, causing the contour calibration head 41 to move downwards and insert into the inner cavity of the nut sleeve from the top until the contour calibration head 41 is fully inserted into the inner cavity of the nut sleeve. Twist the nut sleeve and nut completely to the same angle as the contour calibration head 41 to complete the position calibration of the nut sleeve and nut. Figure 7 As shown; at this time, the horizontal center point of a process groove N5 on the nut is exactly aligned with the rivet head of the riveting gun 21.

[0109] S9: The reverse start lifting drive structure 42 drives the contour calibration head 41 to move upward, causing the contour calibration head to disengage from the nut sleeve.

[0110] S10: Start the pressure device 22, drive the riveting gun 21 to move horizontally, and complete the riveting of the nut and nut sleeve at one point.

[0111] S11: According to the pre-calculated riveting point angle, the nut and nut sleeve are rotated by the rotation drive structure 7 to the next riveting point, and the riveting process of other riveting points is completed one by one.

[0112] In this application, the control method of the controller on the pressure application device 22 includes: pressure mode and distance mode.

[0113] The pressure mode is as follows: a preset riveting pressure threshold is set. When the pressure received by the nut sleeve meets the pressure threshold, the pressure application stops, and the riveting is completed. This equipment also includes a pressure sensor to monitor the pressure applied by the pressure application device 22. The specific installation method is based on existing technology. For example, if the preset riveting pressure threshold is 500N, the pressure received by the nut sleeve at the riveting location is monitored. Once the pressure of 500N is met, the servo electric gun stops pushing the riveting gun.

[0114] The distance mode is as follows: a preset riveting joint stroke threshold is set. When the distance the riveting joint pushes the nut sleeve into the process groove reaches the preset riveting joint stroke threshold, the pressure is stopped, and the riveting is completed. For example, if the riveting gun is driven by a servo electric cylinder, and the preset riveting joint stroke threshold is 1mm, the calculation starts from the moment the riveting joint contacts the side wall of the nut sleeve. After the riveting joint is pushed 1mm, the servo electric cylinder stops pushing.

[0115] The specific control mode to be selected depends on the actual conditions of the products to be assembled. If the materials of the nuts and nut sleeves to be riveted are relatively soft, or have inconsistent hardness, distance mode control can be selected. If the hardness is relatively consistent, pressure mode control can be selected. If the products to be riveted have high machining precision and basically consistent outer diameters, distance mode control can be selected. By setting the control mode, this application ensures its adaptability to various different situations.

[0116] In this application, the data communication and control process between the controller and all sensors and drive devices is implemented based on the existing PLC control system, ensuring that the entire riveting process can be completed automatically and efficiently.

Claims

1. A nut sleeve riveting device, characterized in that, It includes: The controller, as well as the product support base, positioning structure, rotary drive structure, and riveting structure based on the workbench mounting; The controller is electrically connected to all sensors and drive devices; The nuts and nut sleeves to be riveted are movably placed in the product support base by gravity; The riveting structure includes: a riveting gun and a pressure device; the riveting gun is horizontally arranged on one side of the product support base, and the height of the riveting head of the riveting gun is set at the center position of the riveting groove of the connecting block on the nut. The positioning structure includes: a preliminary positioning structure, wherein the preliminary positioning structure includes: a position sensor, wherein the position sensor is disposed on the side of the product support base and the measuring position is disposed on the side wall of the nut sleeve; The product support base rotates based on the rotary drive structure, causing the nut and nut sleeve to adjust their angles. The positioning structure further includes a calibration structure, which includes a contour calibration head and a lifting drive structure. The contour calibration head is positioned above the product support base and moves up and down based on the lifting drive structure. The conformal calibration head includes: a calibration block body and a conical head. The calibration block body is provided with a protruding conformal shape, the position, size and shape of which are adapted to the petal-shaped protrusions in the inner cavity of the nut sleeve. The conical head is located below the calibration block body; the conical head is a tapered conical structure that is wider at the top and narrower at the bottom, and a tapered inclined surface is provided on the side wall of the conical head at the position corresponding to each protruding contour. The bottom side length of each inclined surface is less than the width of the protruding contour, and the top side length is equal to the width of the protruding contour. The mounting angle of the contour calibration head meets the following conditions: A protruding profile on the profile calibration head is set as a rivet point profile; the projection of the center point of the rivet point profile in the horizontal width direction is located on the extension line of the rivet head of the riveting gun. The product support base includes: a support base body and a rotating shaft; The support body has a Y-shaped cavity structure, and recessed nut support seats are respectively provided on the inner cavity sidewalls of the two vertical parts; the two nut support seats are symmetrically arranged, and their shape and size are adapted to the nuts; the rotating shaft is located below the support body; It also includes a feeding structure, which includes a horizontal cylinder for feeding, a sliding cross plate, a nut seat sliding groove, and a feeding slide rail; The feeding slide rail is located below the workbench, and the sliding cross plate is slidably mounted on the feeding slide rail; the feeding horizontal cylinder is mounted on the workbench, and the horizontally arranged output shaft is connected to the sliding cross plate. The nut seat sliding groove is formed on the worktable; the product support seat passes through the nut seat sliding groove from top to bottom, and the bottom rotating shaft is rotatably mounted on the sliding horizontal plate; the rotation drive structure is located below the sliding horizontal plate, and the rotating shaft is rotated under the drive of the rotation drive structure.

2. The nut sleeve riveting device according to claim 1, characterized in that: The detection angle of the position sensor is perpendicular to the riveting gun.

3. The nut sleeve riveting device according to claim 1, characterized in that: The riveting structure further includes: a pressure support block; the pressure support block is disposed on the other side of the nut sleeve at a position corresponding to the riveting gun; The pressure support block includes a concave support arc surface, the shape and size of which are adapted to the size and shape of the nut sleeve.

4. A nut sleeve riveting method based on the nut sleeve riveting equipment according to any one of claims 1 to 3, characterized in that, It includes the following steps: S1: The position sensor in the structure is initially located based on the distance sensor; S2: Inspect the nut sleeve and find the included angle between adjacent rivet points, denoted as: rivet point angle; The included angle of the riveting point = 360 / N; where N is the total number of riveting points on the nut sleeve; S3: Inspect the nut sleeve. Based on the height and dimensions of the petal-shaped protrusions on the nut sleeve and the specific shape of the packaging protrusions, determine the corresponding accuracy threshold DH for the nut sleeve. Find the point on the outer wall of the nut sleeve where the first change occurs between the recessed and raised parts, and record it as the initial detection point; record the height difference before and after the initial detection point as the accurate threshold DH. Each of the petal-shaped protrusions has an initial detection point on each side, denoted as point p and point p' respectively; S4: Inspect the nut sleeve and determine the initial alignment angle corresponding to the nut sleeve based on the specific width of the petal-shaped protrusions on the nut sleeve; A coordinate system is constructed with the center of the nut as the origin in the horizontal direction; in the rotation direction of the nut sleeve, the angle between the radius of the initial detection point and the radius of the next riveting point is the angle between the distance sensor detection point and the next riveting point, which is denoted as: the initial alignment angle; Let α be the initial alignment angle corresponding to point p, and β be the initial alignment angle corresponding to point p'. S5: Install the nut sleeve to be riveted on top of the nut. The protruding petal-shaped structure of the nut sleeve is fitted onto the connecting block. The nut sleeve, nut, and lead screw are installed together and placed vertically on the product support base. The product is then transported to the angle calibration position to complete the loading process. The product support base is driven to rotate by a rotary drive structure, which in turn causes the nut and nut sleeve to rotate. The position sensor detects the distance value fed back by the outer wall of the nut sleeve in real time and transmits the distance value to the controller. S6: The controller calculates the difference d between the (i+1)th distance value and the ith distance value in real time; And compare d with the preset accuracy threshold DH in real time; Once d equals DH, the point corresponding to the (i+1)th distance value is recorded as: the point where the angle is located. S7: The controller refers to the current rotation direction of the nut sleeve, and determines whether the current initial detection point is point p or point p' based on whether the detection value of the position sensor increases or decreases, and then determines the corresponding preliminary alignment angle. Then read the included angle A between the riveting gun and the distance sensor; based on the initial detection point and the preliminary accurate angle and angle A, calculate the adjustment rotation angle B; After the rotational drive structure is controlled to rotate the support body by adjusting the rotation angle B, the rotation stops and the nut sleeve reaches the initial positioning point.

5. The nut sleeve riveting method according to claim 4, characterized in that: It also includes the following steps: S8: Activate the lifting drive structure to drive the contour calibration head downwards and insert it into the inner cavity of the nut sleeve from the top until the contour calibration head is fully inserted into the inner cavity of the nut sleeve; complete the position calibration of the nut sleeve and nut. S9: The reverse start lifting drive structure drives the contour calibration head to move upward, causing the contour calibration head to disengage from the nut sleeve; S10: Start the pressure application device to drive the riveting gun to move horizontally and complete the riveting of the nut and nut sleeve at one point. S11: According to the included angle of the riveting point, the nut and nut sleeve are rotated by the rotation drive structure to rotate to the next riveting point, and the riveting process of other riveting points is completed one by one.

6. The nut sleeve riveting method according to claim 4, characterized in that: In step S4, the initial aligning angle satisfies the condition: α + β = the included angle of the riveting point.

7. The nut sleeve riveting method according to claim 5, characterized in that: In step S8: the controller's control method for the pressure application device includes: pressure mode and distance mode; The pressure mode is as follows: a preset riveting pressure threshold is set, and when the pressure received by the nut sleeve meets the pressure threshold, the pressure is stopped and the riveting is completed. The distance mode is as follows: a preset riveting joint stroke threshold is set. When the distance by which the riveting joint pushes the nut sleeve into the process groove reaches the riveting joint stroke threshold, the pressure is stopped and the riveting is completed.

Images