Method for spin riveting a seat framework

Abstract

The present invention relates to a spin riveting processing method for a seat frame. The method includes: positioning and placing a spin riveting part in a positioning hole, the spin riveting part sequentially passing through a first frame and a second frame, controlling the spin riveting mechanism to move downward at a preset first speed, and controlling the spin riveting head to spin and press the end of the spin riveting part along a preset eccentricity until the end of the spin riveting part expands to form a frustum-shaped limiting end. Moving it to the detection platform of the detection device, the detection platform positions and limits the seat frame, and controlling the detection mechanism of the detection device to quantitatively detect the morphological parameters of the limiting end. The morphological parameters include the diameter, thickness and flanging angle of the limiting end. When the morphological parameters are all within the preset qualified range, it is determined that the spin riveting connection of the seat frame is qualified. The hierarchical spin pressing control of the spin riveting mechanism accurately controls the deformation range and morphology of the spin riveting part, so that the end of the spin riveting part forms a frustum-shaped limiting end and has a clearance fit with the second frame, effectively controlling the deformation range of the spin riveting part.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and in particular to a riveting method for seat frames. Background Technology

[0002] The car seat has a base assembly and a backrest assembly that are rotatably connected. The base assembly has a built-in base frame, which includes a first frame made of sheet metal stamping. The backrest assembly has a built-in backrest frame, which includes a second frame made of sheet metal stamping. The first frame and the second frame are riveted together using press-fit components to connect them. The first frame is rotatable relative to the second frame.

[0003] However, the first and second frames are connected by press-fit parts. Since it is difficult to effectively limit the deformation range and position of the press-fit parts during the press-fitting process, especially when the deformation position of the press-fit parts occurs at the through holes of the first and second frames, it is easy to cause the first and second frames to jam, resulting in the first frame being unable to rotate relative to the second frame, low production qualification rate, and uncontrollable deformation area. Therefore, improvements are needed. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this invention provides a riveting method for seat frames, which solves the technical problems of low yield rate and uncontrollable deformation area when using press riveting process to process seat frames.

[0005] According to a first aspect of the present invention, a riveting method for a seat frame is provided. The riveting method is applied to a processing equipment having a riveting device and a detection device. The riveting device includes a positioning seat and a riveting mechanism located above the positioning seat. The positioning seat is provided with a positioning hole, an intersecting first groove and a second groove, and the positioning hole is located at the intersection of the first groove and the second groove. The riveting process includes: S101, the riveting part is positioned in the positioning hole, the positioning hole limits the radial direction of the riveting part so that the axis of the riveting part is collinear with the axis of the positioning hole; S102, the first frame is placed in the first slot, the second frame is placed in the second slot and mounted on top of the first frame, the riveting component passes through the through hole of the first frame and the through hole of the second frame in sequence, and the end of the riveting component extends beyond the upper surface of the second frame by a preset height. S103, control the riveting mechanism to descend at a preset first speed. After the riveting head contacts the end of the riveting part, control the riveting head to press the end of the riveting part along a preset eccentricity until the end of the riveting part unfolds to form a frustum-shaped limiting end. The limiting end is clearance-fitted with the upper surface of the second frame. The riveting part connects the first frame and the second frame to form a movable seat frame. S104, the seat frame is moved from the positioning seat of the riveting device to the detection platform of the detection device, and the detection platform positions and limits the seat frame. S105, the detection mechanism of the control detection device performs quantitative detection on the shape parameters of the limiting end. The shape parameters include the diameter, thickness and flange angle of the limiting end. When the shape parameters are all within the preset qualified range, the seat frame riveting connection is deemed qualified.

[0006] In one embodiment, the first groove and the second groove intersect at an angle, the depth of the first groove matches the thickness of the first skeleton, the depth of the second groove matches the thickness of the second skeleton, the bottom of the second groove is higher than the bottom of the first groove, the surfaces of the first skeleton and the second skeleton are in contact, and the positioning hole is recessed from the bottom of the first groove.

[0007] In one embodiment, an elastic positioning sleeve is embedded in the positioning hole to buffer the radial vibration generated by the riveting part during the riveting process. The elastic positioning sleeve has at least one positioning surface that is adapted to the shape of the riveting part. The positioning surface defines the angle of the riveting part. The top end of the elastic positioning sleeve is flush with the bottom of the first groove.

[0008] In one embodiment, the riveting mechanism includes a displacement sensor and a pressure sensor. In step S103, The riveting mechanism approaches the riveting part at a first speed value, and based on the real-time displacement signal output by the displacement sensor, controls the riveting head of the riveting mechanism to decelerate to a second speed value when it is a first distance away from the riveting part. The riveting mechanism is controlled to approach the riveting part at a second speed value, and based on the real-time displacement signal output by the displacement sensor, it decelerates to a third speed value when the riveting head abuts the riveting part. The riveting mechanism is controlled to spin the riveted part at a third speed, and the speed of the riveting mechanism is dynamically adjusted according to the real-time changes in spinning force detected by the pressure sensor. Based on the displacement sensor outputting an electrical signal indicating that it has reached the preset endpoint position, the riveting mechanism is controlled to move away from the riveted part at a first speed.

[0009] In one embodiment, the centerline of the riveting head has a preset eccentricity relative to the centerline of the riveted part, the preset eccentricity being 0.5mm-2mm; The initial spinning speed of the riveting head on the riveted part is controlled based on the preset eccentricity. The initial spinning speed is between 1000 r / min and 3000 r / min. The spinning speed is adjusted in real time according to the spinning force detected by the pressure sensor. The spinning speed of the riveting head is automatically reduced by 10%-20% when the spinning force reaches a preset threshold. The spinning duration of the riveting head is controlled to be 3s-8s.

[0010] In one embodiment, the detection mechanism consists of an industrial camera and an image processing module. The industrial camera is used to capture clear images of the limiting end, and the image processing module is used to analyze and process the captured images, extract the morphological parameters of the limiting end, and compare the extracted morphological parameters with a preset qualified range.

[0011] In one embodiment, the image processing module employs a multi-feature fusion recognition algorithm, including: The images of the limiting end captured by the industrial camera are preprocessed, and Gaussian filtering algorithm is used for noise reduction to remove noise interference in the image. Then, histogram equalization is used to enhance grayscale and improve image contrast and clarity. An edge detection algorithm is used to locate the contour of the limiting end, and the diameter, thickness, flange angle and surface defect features of the limiting end are extracted simultaneously. Each extracted morphological parameter is compared with a preset acceptable range. When any morphological parameter exceeds the preset acceptable range or a surface defect is detected, the image processing module immediately sends an abnormal signal to the detection device.

[0012] In one embodiment, the detection mechanism further includes a supplementary lighting component, wherein the shooting angle of the industrial camera is 0°-45° from the center line of the limiting end, and the supplementary lighting angle of the supplementary lighting component corresponds to the shooting angle of the industrial camera.

[0013] In one embodiment, the detection mechanism includes a first lifting component, a second lifting component, a sleeve component mounted on the first lifting component, and a height contact rod mounted on the second lifting component. The sleeve component includes a detection hole adapted to the outer diameter of the limiting end. The height contact rod slides coaxially on the sleeve component to detect the height of the limiting end.

[0014] In one embodiment, a cooling channel is provided inside the positioning seat, and the cooling channel is arranged around the positioning hole. During the riveting process of the riveting mechanism, a cooling medium is controlled to be introduced into the cooling channel through a refrigerant device, and the positioning seat and the riveting part are cooled in real time through the cooling medium.

[0015] The technical solution provided by the embodiments of the present invention can include the following beneficial effects: the first groove, the second groove, and the positioning hole of the positioning seat correspond to the comprehensive and precise positioning of the first skeleton, the second skeleton, and the riveting part. Combined with the graded spinning control of the riveting mechanism, the deformation range and shape of the riveting part are precisely controlled, so that the end of the riveting part forms a frustum-shaped limiting end and is in clearance fit with the second skeleton, effectively controlling the deformation range of the riveting part, avoiding deformation of the riveting part in the area within the through hole, solving the problem of jamming between the first skeleton and the second skeleton, and allowing the first skeleton to move smoothly relative to the second skeleton. The detection mechanism performs quantitative detection on the morphological parameters of the limiting end, promptly screening out defective products and significantly improving the product qualification rate. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] Figure 1 This is a flowchart illustrating a method according to one embodiment.

[0018] Figure 2 This is a schematic diagram of the riveting device according to one embodiment.

[0019] Figure 3 This is an enlarged cross-sectional view of the seat frame at the riveted joint, according to one embodiment.

[0020] Figure 4 This is a schematic diagram illustrating a riveting mechanism riveting a riveted part according to an embodiment.

[0021] Figure 5 This is a schematic diagram illustrating a riveting mechanism riveting a riveted part according to an embodiment.

[0022] In the figure, the following components are included: riveting mechanism 10; riveting head 11; positioning seat 20; first groove 21; second groove 22; auxiliary seat 23; positioning column 24; support seat 25; positioning pin 26; seat frame 30; first frame 31; second frame 32; riveting component 33; limiting end 331; detection mechanism 40; sleeve assembly 41; first lifting assembly 42; second lifting assembly 43; and height contact rod 44. Detailed Implementation

[0023] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images, and should not be construed as limiting the invention. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. Example

[0024] like Figures 1 to 4As shown, the present invention provides a riveting process for a seat frame. The seat frame 30 includes a riveting component 33, a first frame 31, and a second frame 32. The riveting component 33 passes through the through hole of the first frame 31 and the through hole of the second frame 32. The riveting component 33 is processed and connected by a riveting device.

[0025] The riveting method is applied to a processing equipment for seat frames, which has a riveting device and a testing device. The riveting device includes a positioning seat 20 and a riveting mechanism 10 located above the positioning seat 20. The positioning seat 20 is a rigid platform-type structural component, and a positioning hole, an intersecting first groove 21 and a second groove 22 are provided on the positioning seat 20. The positioning hole is located at the intersection of the first groove 21 and the second groove 22.

[0026] The depth of the first groove 21 matches the thickness of the first frame 31. Optionally, the first frame 31 is curved into an arc shape, and the first groove 21 is an arc-shaped groove structure. The depth of the second groove 22 matches the thickness of the second frame 32. The bottom of the second groove 22 is higher than the bottom of the first groove 21, and the positioning hole is recessed from the bottom of the first groove 21.

[0027] The riveting process includes the following steps: S101, the riveting part 33 is first positioned in the positioning hole. The positioning hole limits the radial direction of the riveting part 33 so that the axis of the riveting part 33 is collinear with the axis of the positioning hole. Preferably, an elastic positioning sleeve is embedded in the positioning hole to buffer the radial vibration generated by the riveting part 33 during the riveting process, preventing the riveting part 33 from shifting or the positioning seat 20 from wearing due to vibration. The elastic positioning sleeve has a slight elastic deformation effect. Correspondingly, the riveting part 33 and the elastic positioning sleeve can be tightly fitted together, thereby avoiding the problem of setting an assembly gap between the riveting part 33 and the positioning hole. The elastic positioning sleeve has at least one positioning surface that matches the shape of the riveting part 33. The positioning surface limits the angle of the riveting part 33 to improve the positioning accuracy of the riveting part 33. The top of the elastic positioning sleeve is flush with the bottom of the first groove 21, so as not to affect the stable placement of the first frame 31. Optionally, the elastic positioning sleeve is made of silicone or polyurethane material, which has good elasticity and cushioning properties.

[0028] S102, then the first frame 31 is placed in the first groove 21 and fitted onto the riveting piece 33, and then the second frame 32 is placed in the second groove 22 and mounted on top of the first frame 31, so that the riveting piece 33, the first frame 31 and the second frame 32 are connected in sequence. The positioning hole is recessed from the bottom of the first groove 21 to facilitate the riveting piece 33 to pass through the first frame 31 and the second frame 32 for spinning operation. The first groove 21 and the second groove 22 intersect at an angle to adapt to the assembly angle requirements of the rotating part of the seat frame 30, and the depth of the first groove 21 matches the thickness of the first frame 31.

[0029] Preferably, an auxiliary seat 23 and a positioning post 24 fixed to the auxiliary seat 23 are installed on the positioning seat 20, and the other end of the second frame 32 is mounted on the positioning seat 20. The assembly hole of the second frame 32 is positioned and defined by the positioning post 24, thereby forming a three-point positioning with the riveting part 33 to improve the processing accuracy.

[0030] The end of the riveting part 33 extends beyond the upper surface of the second skeleton 32 by a preset height. This preset height is set according to the forming requirements of the limiting end 331 after riveting, providing sufficient deformation allowance for subsequent spin forming. Furthermore, the deformation of the riveting part 33 is concentrated in the part of the riveting part 33 that extends beyond the second skeleton 32, avoiding deformation of the part of the riveting part 33 located in the through hole.

[0031] S103, the riveting mechanism 10 is controlled to descend at a preset first speed. The first speed is relatively fast to achieve rapid movement. After the riveting head 11 contacts the end of the riveting part 33, the riveting head 11 is controlled to spin the end of the riveting part 33 along a preset eccentricity until the end of the riveting part 33 unfolds to form a frustum-shaped limiting end 331. The limiting end 331 is clearance-fitted with the upper surface of the second frame 32. The riveting part 33 connects the first frame 31 and the second frame 32 to form a movable seat frame 30.

[0032] The riveting head 11 spins the riveting part 33 with preset pressure and rotation speed, which can precisely limit the deformation range of the riveting part 33 to the end part beyond the second frame 32. This allows for precise control of the deformation range and shape of the riveting part 33, avoiding the drawback of the deformation of the riveting part 33 extending into the through hole and causing the seat frame 30 to jam. The limiting end 331 and the second frame 32 have a clearance fit, which allows the first frame 31 and the second frame 32 to rotate smoothly without axial wobble.

[0033] S104, the seat frame 30 is moved from the positioning seat 20 of the riveting device to the inspection platform of the inspection device, where the inspection platform positions and limits the seat frame 30. The inspection device and the riveting device are arranged side by side at intervals. After the riveting device completes the riveting process, the seat frame 30 can be moved to the inspection device in a timely manner, thereby achieving continuity of processing and inspection. This allows for real-time detection of the processing quality of the riveting device and timely correction when the riveting device experiences wear or excessive deviation, avoiding processing defects caused by wear and tear of the riveting head 11.

[0034] S105, the detection mechanism 40 of the control detection device quantitatively detects the morphological parameters of the limiting end 331. The morphological parameters include the diameter, thickness, and flange angle of the limiting end 331. When all morphological parameters are within the preset qualified range, the seat frame 30 is deemed to be qualified for riveting connection. If any parameter exceeds the qualified range, it is deemed unqualified, which facilitates timely screening of defective products, improves the overall product quality, and reduces batch problems caused by unqualified products.

[0035] Furthermore, the riveting mechanism 10 includes a displacement sensor and a pressure sensor. In step S103, the riveting mechanism 10 adopts graded speed control, specifically including the following steps: S201. The riveting mechanism 10 approaches the riveting part 33 at a first speed value, and based on the real-time displacement signal output by the displacement sensor, controls the riveting head 11 of the riveting mechanism 10 to decelerate to a second speed value when it is a first distance away from the riveting part 33, so as to avoid a rigid collision between the riveting head 11 and the riveting part 33 and protect the riveting part 33 and the riveting head 11. The riveting mechanism 10 moves quickly at the first speed value, which can improve the production cycle and shorten the movement time.

[0036] S202, the riveting mechanism 10 approaches the riveting part 33 at a second speed value, based on the real-time displacement signal output by the displacement sensor. The displacement sensor outputs the displacement signal of the riveting head 11 in real time, thereby enabling the control system to determine the position of the riveting head 11 and achieve linkage control in conjunction with the movement of the riveting mechanism 10. When the riveting head 11 abuts against the riveting part 33, it decelerates to a third speed value to ensure smooth contact between the riveting head 11 and the riveting part 33, preparing for subsequent riveting.

[0037] S203. The riveting mechanism 10 is controlled to spin the riveting part 33 at a third speed, and the speed of the riveting mechanism 10 is dynamically adjusted according to the real-time changes in the spinning force detected by the pressure sensor, so as to ensure that the force is uniform during the spinning process and avoid excessive local force that could cause damage or abnormal deformation of the riveting part 33.

[0038] In this step, the centerline of the riveting head 11 has a preset eccentricity relative to the centerline of the riveting part 33. This preset eccentricity is 0.5mm-2mm, and it is flexibly adjusted based on the material of the riveting part 33 and the size of the limiting end 331. This eccentricity range allows the end of the riveting part 33 to unfold evenly to form a frustum-shaped limiting end 331, while avoiding excessive eccentricity that could cause the riveting part 33 to break.

[0039] For example, the riveting mechanism 10 includes a displacement sensor, a pressure sensor, and a riveting head 11, with a preset eccentricity of 2 mm between the centerline of the riveting head 11 and the centerline of the riveting part 33.

[0040] The control system controls the initial spinning speed of the riveting head 11 on the riveted part 33 based on a preset eccentricity. The initial spinning speed is between 1000 r / min and 3000 r / min. The spinning speed is adjusted in real time according to the spinning pressure detected by the pressure sensor. Specifically, the spinning speed of the riveting head 11 automatically decreases by 10%-20% when the spinning pressure reaches a preset threshold to prevent excessive deformation of the riveted part 33 due to excessive spinning pressure. The spinning duration of the riveting head 11 is controlled to be 3s-8s to ensure that the end of the riveted part 33 is fully unfolded and formed. During the riveting process, displacement and pressure sensors are used to achieve real-time monitoring and dynamic speed adjustment, while avoiding excessive processing time that would affect production efficiency.

[0041] S204. Based on the position signal output by the displacement sensor when it moves to the preset end position, the riveting mechanism 10 is controlled to move away from the riveting part 33 at a first speed to improve processing efficiency.

[0042] In one embodiment, a cooling channel is provided inside the positioning seat 20, surrounding the positioning hole. During the riveting process of the riveting mechanism, a cooling medium is introduced into the cooling channel through a controlled refrigerant device. The cooling medium cools the positioning seat 20 and the riveting part 33 in real time, preventing the heat generated during the riveting process from causing changes in the material properties of the riveting part 33, preventing defects such as cracks and deformation in the riveting part 33, and extending the service life of the positioning seat 20. The cooling medium can be cooling water or coolant. Optionally, the cooling channel has a U-shaped structure, and the positioning hole is located within the area surrounding the cooling channel.

[0043] In one embodiment, the riveting device operates as follows: cooling water is introduced into the cooling channel to cool the positioning seat 20 in real time. The riveting mechanism 10 is controlled to descend at a first speed of 100 mm / min. The displacement sensor detects the displacement of the riveting head 11 in real time. When the riveting head 11 is 5 mm away from the end of the riveted part 33, it decelerates to a second speed of 50 mm / min and continues to descend. When the riveting head 11 abuts the end of the riveted part 33, the displacement sensor sends a signal to control the riveting head 11 to decelerate to a third speed of 20 mm / min, and spins the end of the riveted part 33 with an initial spinning speed of 2000 r / min along a preset eccentricity of 2 mm. The pressure sensor detects the spinning pressure in real time. When the spinning pressure reaches a preset threshold of 5000 N, the spinning speed is automatically reduced by 15% to 1700 r / min. After continuous spinning for 5 seconds, the displacement sensor detects that the riveting head 11 has moved to the preset endpoint position and sends a position signal to control the riveting mechanism 10 to move away from the riveting part 33 at a first speed of 100 mm / min. At this time, the end of the riveting part 33 unfolds to form a frustum-shaped limiting end 331. The limiting end 331 is in clearance fit with the upper surface of the second frame 32. The riveting part 33 is firmly connected to the first frame 31 and the second frame 32, and both can rotate smoothly.

[0044] After the seat frame 30 is riveted, it is moved to the testing platform of the testing device by manual or robotic arm. The testing mechanism 40 then tests the center position, riveting height, and riveting shape of the riveted part 33.

[0045] like Figure 5 As shown, in one embodiment, the detection device includes a detection platform and a detection mechanism 40. The detection platform includes a support base 25, a positioning pin 26, and a flexible clamping assembly. The positioning pin 26 is installed on the support base 25, and the seat frame 30 is mounted on the support base 25. The positioning pin 26 engages with the mounting holes of the seat frame 30 to position the seat frame 30. The flexible clamping assembly uses a rotating cylinder and a pressure rod mounted on the cylinder shaft. The pressure rod is equipped with a rubber head. The rubber head presses against the end of the seat frame 30 away from the riveting member 33 to position the seat frame 30 in the detection position.

[0046] The testing unit 40 includes an industrial camera and an image processing module. The industrial camera is used to capture clear images of the limiting end 331, and the image processing module is used to analyze and process the captured images, extract the morphological parameters of the limiting end 331, and compare the extracted morphological parameters with the preset qualified range to achieve quantitative detection of morphological parameters. Compared with manual inspection, this improves the accuracy and efficiency of the inspection.

[0047] The image processing module employs a multi-feature fusion recognition algorithm, specifically including the following steps: S301. Image Preprocessing: The image of the limit end 331 captured by the industrial camera is preprocessed. Gaussian filtering algorithm is used for noise reduction to remove noise interference in the image. Histogram equalization is then used to enhance grayscale, improve image contrast and clarity, and provide data and parameter basis for subsequent feature extraction.

[0048] S302, Feature Extraction: The edge detection algorithm is used to locate the contour of the limiting end 331, and the diameter, thickness, flange angle and surface defect features of the limiting end 331 are extracted simultaneously to comprehensively detect the forming quality of the limiting end 331.

[0049] S303. Comparison and Judgment: Each extracted morphological parameter is compared with the preset acceptable range one by one. When any morphological parameter exceeds the preset acceptable range or a surface defect is detected, the image processing module immediately sends an abnormal signal to the detection device, so that the staff can handle the defective products in a timely manner.

[0050] To further improve the accuracy of image acquisition, the detection mechanism 40 also includes a supplementary lighting component. The shooting angle of the industrial camera is at an angle of 0°-45° to the center line of the limiting end 331. The supplementary lighting angle of the supplementary lighting component corresponds to the shooting angle of the industrial camera, ensuring that the industrial camera can capture a clear and complete image of the limiting end 331, avoiding detection deviations caused by insufficient light. Preferably, two industrial cameras are provided, including a longitudinal camera and a transverse camera, to acquire images of the limiting end 331 from different angles respectively.

[0051] The specific workflow is as follows: The supplementary lighting component is activated and aligned with the shooting angle of the industrial camera. The industrial camera captures a clear image of the limiting end 331 and transmits it to the image processing module. The image processing module preprocesses the image, first using a Gaussian filtering algorithm to remove noise interference, and then using histogram equalization to improve image contrast and clarity. An edge detection algorithm is used to locate the contour of the limiting end 331, and the diameter, thickness, flange angle, and surface defect features of the limiting end 331 are extracted simultaneously. The extracted morphological parameters are compared with preset acceptable ranges. For example, the preset standard values ​​for the limiting end 331 are a diameter of 15mm-25mm and a thickness of 1mm-3mm. Each morphological parameter is compared with the preset standard values ​​one by one. If all parameters are within the acceptable range and no surface defects are detected, the riveting connection of the seat frame 30 is deemed acceptable, and the product is sent to the next process. If any parameter exceeds the acceptable range or a surface defect is detected, the image processing module immediately sends an abnormal signal to the detection device, and the operator sorts and reworks the defective products. Example

[0052] like Figures 1 to 5 As shown, in this embodiment, the structure of the riveting device is the same as in Embodiment 1, and will not be described again here. The detection device includes a detection platform and a detection mechanism 40, wherein the detection platform has the same structure as the positioning seat 20 in Embodiment 1. The detection mechanism 40 includes a first lifting assembly 42, a second lifting assembly 43, a sleeve assembly 41 installed on the first lifting assembly 42, and a height contact rod 44 installed on the second lifting assembly 43. The sleeve assembly 41 includes a detection hole that is adapted to the outer diameter of the limiting end 331. The second lifting assembly 43 is installed on the first lifting assembly 42, and the height contact rod 44 slides coaxially on the sleeve assembly 41 for detecting the height of the limiting end 331.

[0053] The detection mechanism 40 employs a mechanical contact method to detect the morphological parameters of the limiting end 331. The specific detection process is as follows: The first lifting assembly 42 is controlled to drive the sleeve assembly 41 downwards, causing the detection hole to be fitted onto the outside of the limiting end 331, thus achieving rapid detection of the outer diameter of the limiting end 331. Then, the second lifting assembly 43 is controlled to drive the height contact rod 44 downwards, and the height dimension of the limiting end 331 is obtained based on the downward displacement of the height contact rod 44, completing the height detection. This mechanical contact detection method can be implemented independently or combined with image detection to form a comprehensive detection system.

[0054] In a preferred embodiment, if the detection hole of the sleeve assembly 41 can be smoothly fitted onto the outside of the limiting end 331, the outer diameter of the limiting end 331 is determined to be qualified and the shape is regular. If the detection hole of the sleeve assembly 41 cannot be fitted or gets stuck after fitting, the outer diameter of the limiting end 331 is determined to be unqualified.

[0055] Furthermore, an annular pressure sensor is embedded in the inner wall of the detection hole of the sleeve assembly 41, and the annular pressure sensor is electrically connected to the control module of the detection device. When the detection hole is fitted to the outside of the limiting end 331, the annular pressure sensor can detect the contact pressure between the limiting end 331 and the inner wall of the detection hole in real time. If the pressure is uniform and within the preset pressure range, it is determined that the outer diameter of the limiting end 331 is qualified and the shape is regular. Preferably, the inner wall of the detection hole is provided with a wear-resistant coating to reduce wear caused by long-term fitting and extend the service life of the sleeve assembly 41.

[0056] A flexible contact head is added to the end of the height contact rod 44, and a miniature pressure sensor is built into the flexible contact head. When the contact head contacts the upper surface of the limiting end 331 and reaches the preset contact pressure, the displacement sensor records the downward displacement data. Combined with the preset initial position parameters of the height contact rod 44, the height value of the corresponding limiting end 331 is obtained. The height value is compared with the preset standard value. When the height value is within the qualified range, the height is judged to be qualified.

[0057] Preferably, a guide sleeve is added to the height contact rod 44, and the guide sleeve is fixedly connected to the sleeve assembly 41 to ensure that the height contact rod 44 always slides coaxially with the detection hole, thereby further improving the accuracy of height detection.

[0058] It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed in this invention.

Claims

1. A method for riveting a seat frame, wherein the riveting method is applied to processing equipment having a riveting device and a detection device, characterized in that, The riveting device includes a positioning seat and a riveting mechanism located above the positioning seat. The positioning seat is provided with a positioning hole, an intersecting first groove and a second groove, and the positioning hole is located at the intersection of the first groove and the second groove. The riveting process includes: S101, the riveting part is positioned in the positioning hole, the positioning hole limits the radial direction of the riveting part so that the axis of the riveting part is collinear with the axis of the positioning hole; S102, the first frame is placed in the first slot, the second frame is placed in the second slot and mounted on top of the first frame, the riveting component passes through the through hole of the first frame and the through hole of the second frame in sequence, and the end of the riveting component extends beyond the upper surface of the second frame by a preset height. S103, control the riveting mechanism to descend at a preset first speed. After the riveting head contacts the end of the riveting part, control the riveting head to press the end of the riveting part along a preset eccentricity until the end of the riveting part unfolds to form a frustum-shaped limiting end. The limiting end is clearance-fitted with the upper surface of the second frame. The riveting part connects the first frame and the second frame to form a movable seat frame. S104, the seat frame is moved from the positioning seat of the riveting device to the detection platform of the detection device, and the detection platform positions and limits the seat frame. S105, the detection mechanism of the control detection device performs quantitative detection on the shape parameters of the limiting end. The shape parameters include the diameter, thickness and flange angle of the limiting end. When the shape parameters are all within the preset qualified range, the seat frame riveting connection is deemed qualified.

2. The riveting method according to claim 1, characterized in that, The first groove and the second groove intersect at an angle. The depth of the first groove matches the thickness of the first skeleton, and the depth of the second groove matches the thickness of the second skeleton. The bottom of the second groove is higher than the bottom of the first groove. The surfaces of the first skeleton and the second skeleton are in contact. The positioning hole is recessed from the bottom of the first groove.

3. The riveting method according to claim 2, characterized in that, An elastic positioning sleeve is embedded in the positioning hole to buffer the radial vibration generated by the riveting part during the riveting process. The elastic positioning sleeve has at least one positioning surface that is adapted to the shape of the riveting part. The positioning surface defines the angle of the riveting part. The top of the elastic positioning sleeve is flush with the bottom of the first groove.

4. The riveting method according to claim 1, characterized in that, The riveting mechanism includes a displacement sensor and a pressure sensor. In step S103... The riveting mechanism approaches the riveting part at a first speed value, and based on the real-time displacement signal output by the displacement sensor, controls the riveting head of the riveting mechanism to decelerate to a second speed value when it is a first distance away from the riveting part. The riveting mechanism is controlled to approach the riveting part at a second speed value, and based on the real-time displacement signal output by the displacement sensor, it decelerates to a third speed value when the riveting head abuts the riveting part. The riveting mechanism is controlled to spin the riveted part at a third speed, and the speed of the riveting mechanism is dynamically adjusted according to the real-time changes in spinning force detected by the pressure sensor. Based on the displacement sensor outputting an electrical signal indicating that it has reached the preset endpoint position, the riveting mechanism is controlled to move away from the riveted part at a first speed.

5. The riveting method according to claim 4, characterized in that, The centerline of the riveting head has a preset eccentricity relative to the centerline of the riveted part, and the preset eccentricity is 0.5mm-2mm; The initial spinning speed of the riveting head on the riveted part is controlled based on the preset eccentricity. The initial spinning speed is between 1000 r / min and 3000 r / min. The spinning speed is adjusted in real time according to the spinning force detected by the pressure sensor. The spinning speed of the riveting head is automatically reduced by 10%-20% when the spinning force reaches a preset threshold. The spinning duration of the riveting head is controlled to be 3s-8s.

6. The riveting method according to claim 1, characterized in that, The detection mechanism consists of an industrial camera and an image processing module. The industrial camera is used to capture clear images of the limiting end, and the image processing module is used to analyze and process the captured images, extract the morphological parameters of the limiting end, and compare the extracted morphological parameters with a preset qualified range.

7. The riveting method according to claim 6, characterized in that, The image processing module employs a multi-feature fusion recognition algorithm, including: The images of the limiting end captured by the industrial camera are preprocessed, and Gaussian filtering algorithm is used for noise reduction to remove noise interference in the image. Then, histogram equalization is used to enhance grayscale and improve image contrast and clarity. An edge detection algorithm is used to locate the contour of the limiting end, and the diameter, thickness, flange angle and surface defect features of the limiting end are extracted simultaneously. Each extracted morphological parameter is compared with a preset acceptable range. When any morphological parameter exceeds the preset acceptable range or a surface defect is detected, the image processing module immediately sends an abnormal signal to the detection device.

8. The riveting method according to claim 6, characterized in that, The detection mechanism also includes a supplementary lighting component. The shooting angle of the industrial camera is 0°-45° from the center line of the limiting end, and the supplementary lighting angle of the supplementary lighting component corresponds to the shooting angle of the industrial camera.

9. The riveting method according to claim 1, characterized in that, The detection mechanism includes a first lifting component, a second lifting component, a sleeve component installed on the first lifting component, and a height contact rod installed on the second lifting component. The sleeve component includes a detection hole adapted to the outer diameter of the limiting end. The height contact rod slides coaxially on the sleeve component to detect the height of the limiting end.

10. The riveting method according to claim 1, characterized in that, The positioning seat has a cooling channel inside, which surrounds the positioning hole. During the riveting process of the riveting mechanism, the cooling medium is controlled to be introduced into the cooling channel to cool the positioning seat and the riveting part in real time.

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