A compact precision automatic butt joint and thread assembly system for a rotary body

Abstract

This invention discloses a compact, precision-automatic docking and thread assembly system for rotating bodies. The system adopts a partitioned, integrated, compact layout, including a main body loading area, a module loading area, a combined body unloading area, loading / unloading robot stations, module assembly stations, and assembly robot stations. The loading / unloading robots rely on a fully covered ground rail, V-shaped slot electric grippers, and dual-light source vision to achieve precise material transfer. The assembly robot integrates a surface array camera, a laser camera, a screwdriver, and an automatic grease application unit to complete positioning, axis fitting, grease application, and assisted tightening. The module assembly station is equipped with a self-centering chuck controlled by a pressure regulating valve and non-metallic grippers to achieve non-destructive clamping, and a tightening mechanism integrating four servo linkage axes (horizontal, lifting, rotating, and extending) and a spring telescopic compensation mechanism for flexible soft-contact docking. This invention effectively avoids damage from misaligned threads and rigid collisions, realizing fully automated, high-precision, and flexible hybrid production lines for rotating body thread assembly.

Description

Technical Field

[0001] This invention belongs to the field of automatic precision assembly technology, and in particular to a compact automatic precision docking and thread assembly system for rotating bodies. Background Technology

[0002] In various fields such as aerospace, military, and drilling, compact cylindrical rotating bodies are frequently encountered. These products, limited by factors such as transport power and underground space, have minimum volume requirements. Internally, they integrate numerous power, measurement, and communication modules, which are densely packed and diverse. Taking a drilling and oil production injection tool as an example, it includes a main control module, a motor drive control module, a flow detection module, a temperature detection module, an auxiliary operating condition detection module, and a power supply and communication main control module. For protection, these modules are all fitted with protective sleeves, have a long shaft shape, and are connected to the tool body via threads.

[0003] Due to the compact space, the traditional assembly method involves manually clamping the tool body with calipers and then manually tightening each module one by one using wrenches and other tools. However, because the modules are so close together, manual operation is often difficult even with tools. Since some modules lack guide threads, it is easy for manual operators to twist the threads incorrectly in the first few turns, causing assembly failures or rendering the module sheath unusable. Inconsistent manual operating force, skill levels, and operating conditions can also lead to damage to the sheath and cable ends, uneven torque, and other issues. With a wide variety of modules and a large number of them, misassembly and cross-contamination are common. Since compact cylindrical rotating bodies are mostly used in extreme environments, the above manual assembly methods inevitably affect the stability of the product.

[0004] In summary, manual operation of compact rotating screw assembly results in high labor intensity, low production efficiency, a large amount of inefficient repetitive work, and high turnover of skilled assembly workers, which affects the efficiency and quality stability of assembly orders for enterprises. Summary of the Invention

[0005] The purpose of this invention is to address the difficulties and shortcomings of manual assembly in the existing thread assembly process of compact cylindrical rotary products, and to provide a compact rotary thread assembly system that achieves automated and precise docking, flexible tightening, and standardized assembly of the rotary body and multiple functional modules. This system replaces the traditional manual assembly mode, effectively avoiding problems such as misalignment of screws, workpiece damage, uneven torque, and incorrect assembly caused by manual assembly. It improves assembly accuracy, assembly efficiency, and product assembly consistency, reduces manual labor intensity, ensures product reliability under extreme working conditions, and meets the needs of batch, high-precision, and flexible production assembly.

[0006] The technical solution to achieve the purpose of this invention is: a compact rotary precision automatic docking and thread assembly system, the system including a main body loading area, a module loading area, a combined body unloading area, loading and unloading robot stations, module assembly stations and assembly robot stations;

[0007] The main body loading area and the module loading area are respectively used to support and center the rotating body to be installed and the module to be installed;

[0008] The assembly unloading area is used to receive and carry the assembled assembly product;

[0009] The material handling robot station has a material handling trajectory that fully covers the main body loading area, module loading area, assembly unloading area and module assembly station, and is used for automatic handling and transfer of materials throughout the production line.

[0010] The module assembly station, as the core assembly execution unit of the system, is used to realize the automated precision docking, flexible screwing and locking assembly between the rotating body to be assembled and the module to be assembled.

[0011] The assembly robot station covers the module assembly station and is used to provide visual-assisted positioning, axis fitting, lubrication, or assisted tightening operations for the assembly process.

[0012] Furthermore, the module assembly station includes:

[0013] Base;

[0014] The main body positioning and rotating mechanism and the tightening clamp are respectively fixedly installed on the upper end face of the base;

[0015] The module docking mechanism is used to provide multi-axis active and passive degrees of freedom for the docking and tightening process of the modules to be installed, ensuring reliable and smooth docking, and at least providing module pre-tightening and rotary body press-fitting functions;

[0016] The four-axis linkage module tightening mechanism is used to rotate and tighten the module to be installed after the module to be installed is properly connected, thereby completing the assembly of the module to be installed and the rotating body to be installed.

[0017] The main body positioning and rotation mechanism and the module docking mechanism are slidably connected to the base through guide mechanisms to achieve precise adjustment and alignment of spatial displacement.

[0018] Furthermore, the body positioning and rotating mechanism includes:

[0019] A rotating frame fixed to the base;

[0020] A rotating mechanism and a self-centering chuck are integrated and mounted on the rotating frame.

[0021] The rotating mechanism engages with the self-centering chuck through a motor, reducer, and gear transmission mechanism to drive the self-centering chuck to rotate precisely around its axis for posture adjustment.

[0022] The self-centering chuck has several sets of jaws arranged along the circumference. The self-centering chuck automatically clamps or releases the object through air circuit control, thereby causing the jaws to adaptively clamp or release the rotating body to be installed.

[0023] Furthermore, a pressure regulating valve is installed on the self-centering chuck to adjust the clamping force according to the material and wall thickness characteristics of the rotating body to be installed, so as to achieve flexible and non-destructive clamping.

[0024] The area where the chuck contacts the rotating body to be loaded is made of non-metallic material;

[0025] The rotating frame and the self-centering chuck have a hollow axis structure along the axial direction of the rotating body to be loaded, which is used to optimize the system's center of gravity and adapt to the clamping of long-axis rotating bodies.

[0026] Furthermore, the four-axis linkage module tightening mechanism includes a frame mounted on the base guide structure, and a horizontal axis, a lifting axis, a rotating axis, an extending axis, a telescopic compensation mechanism, and a tightening chuck mounted on the frame;

[0027] The horizontal shaft drives the frame to move horizontally in a straight line along the base guide structure via a motor and a gear and rack transmission mechanism.

[0028] The lifting shaft drives the rotating shaft, the extension shaft, the telescopic compensation mechanism and the tightening chuck to vertically lift and adjust their positions via a motor and a lead screw transmission structure.

[0029] The rotating shaft drives the extending shaft, telescopic compensation mechanism and tightening chuck to rotate synchronously through a motor and gear transmission mechanism, providing rotational power for thread tightening;

[0030] The extension shaft is driven by a motor in conjunction with a linear module to drive the tightening chuck to perform axial extension and retraction feed motion;

[0031] The telescopic compensation mechanism is used to compensate for changes in the stroke of the extended shaft in order to absorb the impact force of hard contact and achieve flexible soft contact docking to prevent collision.

[0032] Furthermore, sensors are distributed on each linkage axis of the four-axis linkage module tightening mechanism to limit the travel of each axis and achieve full servo closed-loop control.

[0033] Furthermore, the tightening head library includes a frame and support mechanism mounted on a base, as well as a servo drive unit, a circular indexing plate structure, a multi-specification tightening head group, and an error-proof positioning component mounted on the frame and support mechanism; the multi-specification tightening head group includes tightening heads of various specifications stored according to workstation numbers;

[0034] The servo drive unit includes a servo motor, a reducer, and a transmission mechanism, which drives the circular indexing plate structure to perform high-precision rotary indexing and positioning based on closed-loop position feedback control.

[0035] The circular indexing plate structure has multiple workstations for storing tightening chucks of different specifications evenly distributed along its circumference;

[0036] The error-proof positioning component includes a station positioning pin and a chuck detection sensor, used to confirm the indexing status and the tightened chuck status.

[0037] Furthermore, the loading and unloading robot station includes a first robot ground rail that covers the entire production line across the region, a first robot body installed on the robot ground rail, and a first mounting frame connected to the first robot body through a first quick-change tooling.

[0038] The first mounting frame is integrated with multiple sets of electric grippers consisting of multiple sets of electric gripping cylinders, as well as a first vision unit and a second vision unit;

[0039] The electric clamping cylinder is equipped with a chuck, and the chuck has positioning V-shaped slots of different sizes in the gripping feed direction to accommodate workpieces of different diameters.

[0040] The first vision unit includes a 2D camera with a coaxial light source, and the second vision unit includes a 2D camera with a central aperture light source. The two work together to achieve dual-vision collaborative barcode scanning and precise material positioning.

[0041] Furthermore, the assembly robot station includes a second robot ground rail covering each assembly work station, a second robot body installed on the second robot ground rail, and a second mounting frame connected to the second robot body via a second quick-change tooling.

[0042] The second mounting bracket integrates an area scan camera, a laser camera, a nail gun, and an automatic grease applicator.

[0043] The laser camera is used to scan the surface of the workpiece to be assembled and fit the assembly reference axis; the area array camera is used to accurately identify the screw holes and mating angle of the workpiece to be assembled; the screw gun is used to assist in the tightening operation; and the automatic grease applicator is used to apply a quantitative amount of grease to the thread assembly position.

[0044] Furthermore, the main body loading area, module loading area and assembly unloading area all use a pallet body with AGV / forklift handling holes as the bearing base;

[0045] The pallet bodies corresponding to the main body loading area, module loading area and assembly unloading area are respectively provided with main body positioning fixtures, module positioning fixtures and assembly positioning fixtures.

[0046] Each positioning fixture adopts a V-shaped positioning structure to achieve automatic axis centering and positioning of rotating workpieces;

[0047] Furthermore, the positioning fixture and the pallet body adopt a separate and detachable connection structure, which can be used to quickly and flexibly adapt to different models and specifications of products by replacing the positioning fixture.

[0048] Compared with the prior art, the significant advantages of this invention are:

[0049] (1) Completely replaces manual assembly, greatly improves production efficiency, and is suitable for stable batch production.

[0050] This invention employs a material handling robot, an assembly robot, and a multi-station integrated assembly structure to achieve fully automated loading, visual positioning, grease application, docking, pre-tightening, precision tightening, and unloading of the rotating body and various functional modules. This completely replaces the inefficient traditional methods of manual clamping, alignment, and tightening. This invention effectively solves problems such as limited manual operation in confined spaces, high labor intensity, significant fatigue from repetitive tasks, and low productivity, significantly improving assembly cycle time and overall production capacity. It can meet the needs of large-scale, continuous production in the military, aerospace, and oil and gas drilling industries.

[0051] (2) Multi-axis linkage flexible compensation assembly to prevent thread misalignment, chipping, and rigid collision damage.

[0052] This invention incorporates a four-axis linkage module tightening mechanism and a telescopic spring compensation mechanism, enabling dynamic compensation of assembly stroke errors across multiple dimensions. Combined with multi-sensor servo closed-loop control, it achieves flexible feeding and tightening of threaded connections. This design effectively solves problems in traditional manual assembly, such as poor initial thread guidance, easy thread misalignment, damage to the sheath caused by forced tightening, thread breakage, and module scrapping. It avoids rigid collisions at the structural level, significantly reducing workpiece scrap rate and assembly failure rate.

[0053] (3) Non-destructive and precise clamping, high assembly consistency, and significantly improved product reliability.

[0054] This invention employs a three-jaw self-centering chuck with pressure adjustment function, combined with a non-metallic protective jaw structure. It can adaptively adjust the clamping force according to the workpiece wall thickness and material, achieving a uniform, flexible, and damage-free clamping effect. Simultaneously, by combining a V-shaped automatic centering tray, 3D vision positioning, and laser axis fitting technology, the clamping accuracy, tightening torque, and assembly depth of each batch of products are highly consistent. This design completely solves the quality defects caused by uneven force, differences in skill level, and fluctuations in condition during manual operation, such as sheath scratches, cable damage, inconsistent torque, and uneven assembly tightness, ensuring the long-term operational stability of rotating products under extreme working conditions.

[0055] (4) It has the ability to flexibly change to multiple specifications, and has strong versatility and expandability.

[0056] This invention features a servo-driven indexing tightening chuck library, enabling automatic and precise changeover of tightening chucks of various specifications. The loading and unloading chucks employ a multi-size V-groove compatible structure, and the loading and unloading pallets utilize separate, replaceable positioning fixtures. The robot's end effector is equipped with a pneumatic quick-change fixture. The entire machine is adaptable to the assembly of compact rotating products with different outer diameters and module types, solving the problems of traditional fixture limitations, cumbersome changeovers, and poor equipment versatility, thus enabling flexible mixed-line production of multiple product categories.

[0057] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of a compact rotating body precision automatic docking and thread assembly system in one embodiment.

[0059] Figure 2 This is a detailed schematic diagram of the loading and unloading area of ​​the main body module and the assembly in one embodiment.

[0060] Figure 3 This is a detailed schematic diagram of the loading and unloading robot station in one embodiment.

[0061] Figure 4 This is an overall schematic diagram of the module assembly station in one embodiment.

[0062] Figure 5 This is a detailed schematic diagram of the body positioning and rotating mechanism in one embodiment.

[0063] Figure 6 This is a detailed schematic diagram of the tightening mechanism of the four-axis linkage module in one embodiment.

[0064] Figure 7 This is an overall schematic diagram of the module assembly station in one embodiment.

[0065] Figure 8 This is a detailed schematic diagram of the assembly robot station in one embodiment.

[0066] Figure 9 This is a schematic diagram of the tightening mechanism of the four-axis linkage module in one embodiment.

[0067] Figure label:

[0068] 1-Main body loading area, 11-First pallet body, 12-Main body positioning fixture;

[0069] 2-Module loading area, 21-Second pallet body, 22-Module positioning fixture;

[0070] 3-Assembly unloading area; 32-Assembly positioning fixture;

[0071] 4- Loading and unloading robot station, 41- First robot ground rail, 42- First robot body, 43- First quick change tooling, 44- Electric clamping cylinder, 45- Chuck, 46- First vision unit, 47- Second vision unit, 48- First mounting frame;

[0072] 5-Module assembly station, 51-Body positioning rotation mechanism, 52-Module docking mechanism, 53-Four-axis linkage module tightening mechanism, 54-Tightening chuck magazine, 55-Base, 511-Rotating frame, 512-Rotating mechanism, 513-Self-centering chuck, 514-Chuck jaw, 515-Rotating body to be assembled, 516-Module to be assembled, 521-Chuck detection sensor, 531-Frame, 532-Horizontal axis, 533-Lifting axis, 534-Rotating axis, 535-Extending axis, 536-Telescopic compensation mechanism, 537-Tightening chuck, 538-Sensor, 541-Servo drive unit, 542-Frame and support mechanism, 543-Circular indexing plate structure, 544-Tightening chuck assembly;

[0073] 6-Assembly robot station, 61-Second robot ground rail, 62-Second robot body, 63-Second mounting bracket, 64-Second quick-change tooling, 65-Area scan camera, 66-Laser camera, 67-Nail gun, 68-Automatic grease application unit. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0075] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0076] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0077] In one embodiment, combined Figure 1 and Figure 5 A compact rotary precision automatic docking and thread assembly system is provided. The system includes a main body loading area 1, a module loading area 2, a combined body unloading area 3, a loading and unloading robot station 4, a module assembly station 5, and an assembly robot station 6.

[0078] The main body loading area 1 and the module loading area 2 are respectively used to support and center the rotating body 515 to be installed and the module 516 to be installed.

[0079] The assembly unloading area 3 is used to receive and carry the assembled assembly product;

[0080] The loading and unloading robot station 4 has a material handling trajectory that fully covers the main body loading area 1, module loading area 2, assembly unloading area 3 and module assembly station 5, and is used for automatic handling and transfer of materials throughout the production line.

[0081] The module assembly station 5, as the core assembly execution unit of the system, is used to realize the automated precision docking, flexible screwing and locking assembly between the rotating body 515 to be assembled and the module 516 to be assembled.

[0082] The assembly robot station 6 covers the module assembly station 5 and is used to provide visual assistance for positioning, axis fitting, lubrication, or tightening during the assembly process.

[0083] Furthermore, in one embodiment, combined with Figure 4 The module assembly station 5 includes:

[0084] Base 55;

[0085] The main body positioning and rotating mechanism 51 and the tightening clamp 54 are respectively fixedly installed on the upper end face of the base 55;

[0086] The module docking mechanism 52 is used to provide multi-axis active and passive degrees of freedom for the docking and tightening process of the module 516 to be installed, to ensure reliable and smooth docking, and to provide at least module pre-tightening and rotary body pressing functions.

[0087] The four-axis linkage module tightening mechanism 53 is used to rotate and tighten the module 516 after it is properly connected, thereby completing the assembly of the module 516 and the rotating body 515.

[0088] The main body positioning and rotating mechanism 51 and the module docking mechanism 52 are slidably connected to the base 55 through a guide mechanism to achieve precise adjustment and alignment of spatial displacement.

[0089] Preferably, the guiding mechanism uses, but is not limited to, linear guides.

[0090] Preferably, in some embodiments, combined with Figure 5 The main body positioning and rotation mechanism 51 mainly performs the functions of connecting the main body for positioning and clamping, and rotating and adjusting the posture around the axis, facilitating tightening and docking, including:

[0091] A rotating frame 511 fixed to the base 55;

[0092] A rotating mechanism 512 and a self-centering chuck 513 are integrated and mounted on the rotating frame 511.

[0093] The rotating mechanism 512 engages with the self-centering chuck 513 through a motor, reducer and gear transmission mechanism to drive the self-centering chuck 513 to rotate precisely around its axis for posture adjustment.

[0094] The self-centering chuck 513 has several sets of jaws 514 arranged along the circumference. The self-centering chuck 513 automatically clamps or releases the body 515 to be installed by means of air control.

[0095] Preferably, in some embodiments, the rotating body 515 to be installed has an internal thread, and the module to be installed 516 has an external thread, and the two are connected by a relative rotational thread.

[0096] Preferably, in some embodiments, the bottom of the rotating frame 511 is connected to the base 55 by fasteners such as screws.

[0097] Here, the chuck adopts a three-jaw chuck design with a self-centering function, which can realize the rapid and accurate centering of the workpiece, and the stroke meets the clamping range of a certain diameter of the rotating body 515 to be loaded.

[0098] More preferably, in some embodiments, the self-centering chuck 513 is equipped with a pressure regulating valve to adjust the clamping force according to the material and wall thickness characteristics of the rotating body 515 to be mounted, so as to achieve flexible and non-destructive clamping and ensure the reliability of clamping and the integrity of the workpiece structure.

[0099] The area where the jaw 514 contacts the rotating body 515 to be loaded is made of non-metallic material. This material can fit tightly with the product surface to ensure uniform transmission and stable clamping force, and also has wear-resistant and tear-resistant load-bearing performance, which can meet the load-bearing requirements of long-term high-frequency clamping operations.

[0100] The rotating frame 511 and the self-centering chuck 513 have a hollow axis structure along the axial direction of the rotating body 515 to be installed, which is used to optimize the system center of gravity and adapt to the clamping of long-axis rotating bodies (accurately adjust the clamping point based on the product's external dimensions and structural characteristics, so that the system center of gravity is biased towards the chuck direction, improving the structural stability after clamping, and also facilitating the clamping of longer rotating bodies 515 to be installed).

[0101] Furthermore, in one embodiment, combined with Figure 6 The four-axis linkage module tightening mechanism 53 includes a frame 531 mounted on the base guide structure, and a horizontal shaft 532, a lifting shaft 533, a rotating shaft 534, an extension shaft 535, a telescopic compensation mechanism 536 and a tightening chuck 537 mounted on the frame 531.

[0102] The horizontal shaft 532 drives the frame 531 to move horizontally and linearly along the base guide structure through a motor and a gear and rack transmission mechanism.

[0103] The lifting shaft 533 drives the rotating shaft 534, the extension shaft 535, the telescopic compensation mechanism 536 and the tightening chuck 537 to vertically lift and adjust their positions via a motor and lead screw transmission structure.

[0104] The rotating shaft 534 drives the extending shaft 535, the telescopic compensation mechanism 536, and the tightening chuck 537 to rotate synchronously through a motor and gear transmission mechanism, providing rotational power for thread tightening.

[0105] The extension shaft 535 is driven by a motor in conjunction with a linear module to drive the tightening chuck 537 to perform axial extension and retraction feed movements;

[0106] The telescopic compensation mechanism 536 is used to compensate for the stroke change of the extension shaft 535, so as to absorb the impact force of hard contact, prevent hard collision, and realize flexible soft contact docking anti-collision.

[0107] Preferably, in some embodiments, the telescopic compensation mechanism 536 includes a guide structure and a spring assembly. The spring assembly is compressed when the multi-axis linkage stroke changes or when there is a deviation in the module docking, so as to absorb the hard contact impact force and realize flexible soft contact docking anti-collision.

[0108] Preferably, in some embodiments, sensors 538 are distributed on each linkage axis of the four-axis linkage module tightening mechanism 53 to limit the travel of each axis and realize full servo closed-loop control.

[0109] Furthermore, in one embodiment, combined with Figure 7 The tightening head storage 54 includes a frame and support mechanism 542 mounted on a base 55, and a servo drive unit 541, a circular indexing plate structure 543, a multi-specification tightening head assembly 544, and an error-proof positioning component mounted on the frame and support mechanism 542; the multi-specification tightening head assembly 544 includes tightening heads of various specifications (such as hexagonal prism sleeves and screwdriver bits adapted to different types of circuit modules) stored according to workstation numbers.

[0110] The servo drive unit 541 includes a servo motor, a reducer and a transmission mechanism, and drives the circular indexing disk structure 543 to perform high-precision rotary indexing positioning by relying on closed-loop position feedback control.

[0111] The circular indexing structure 543 has multiple workstations for storing tightening chucks of different specifications evenly distributed along its circumference.

[0112] The error-proof positioning component includes a station positioning pin and a chuck detection sensor, which are used to confirm the indexing status and the tightened chuck status to prevent tool changing errors.

[0113] Preferably, in some embodiments, a dedicated clamp holder or positioning seat is installed at each workstation for storing clamps of different specifications.

[0114] Preferably, in some embodiments, the chuck head and chuck head seat adopt a positioning structure (using, but not limited to, a matching structure of conical positioning and anti-rotation key) to ensure coaxiality and torque transmission reliability during replacement.

[0115] Preferably, in some embodiments, the frame and support mechanism 542 includes a vertical frame, a base and a reinforcing rib structure, which provides stable support for the turntable and drive unit, while ensuring the spatial positioning accuracy of the tool changing station.

[0116] Preferably, in some embodiments, the circular indexing disk structure 543 is supported by a central bearing seat to achieve low-friction, high-precision rotation.

[0117] Furthermore, in one embodiment, combined with Figure 3 The loading and unloading robot station 4 includes a first robot ground rail 41 that covers the entire production line across the region, a first robot body 42 installed on the robot ground rail 41, and a first mounting frame 48 connected to the first robot body 42 through a first quick-change tooling 43.

[0118] The first mounting bracket 48 integrates multiple sets of electric grippers (with fast response speed and wide compatibility size range) composed of multiple sets of electric gripping cylinders 44, as well as a first vision unit 46 and a second vision unit 47.

[0119] The electric clamping cylinder 44 is equipped with a chuck 45. The chuck 45 has positioning V-shaped slots of different sizes in the gripping feed direction to accommodate workpieces of different diameters.

[0120] The first vision unit 46 includes a 2D camera with a coaxial light source, and the second vision unit 47 includes a 2D camera with a central aperture surface light source. The two work together to achieve dual-vision collaborative barcode scanning and precise material positioning.

[0121] Furthermore, in one embodiment, combined with Figure 8 The assembly robot station 6 includes a second robot ground rail 61 covering each assembly operation station, a second robot body 62 installed on the second robot ground rail 61, and a second mounting bracket 63 connected to the second robot body 62 via a second quick-change tooling 64.

[0122] The second mounting bracket 63 integrates and mounts an area array camera 65, a laser camera 66, a nail gun 67, and an automatic grease applicator 68.

[0123] The laser camera 66 is used to scan the surface of the workpiece to be assembled and fit the assembly reference axis; the area array camera 65 is used to accurately identify the screw holes and mating angle of the workpiece to be assembled; the screw gun 67 is used to assist in the tightening operation; and the automatic grease applicator 68 is used to apply a quantitative amount of grease to the thread assembly position.

[0124] Preferably, in some embodiments, the laser camera 66 is a line laser scanner (camera) that scans the fitting axis of the docking rotating body; the screw-on gun 67 is an electric servo screw-on gun; and the automatic grease application unit 68, consisting of a 1-liter pressure plate pump, a filter pressure reducing valve, a pressure reducing valve, a glue delivery tube, a back suction valve, and a brush needle, is used for grease application. The second quick-change tooling 64 is a pneumatic quick-change tooling, improving the expandability of the robot's end effector.

[0125] Furthermore, in one embodiment, the main body loading area 1, the module loading area 2, and the assembly unloading area 3 all use pallet bodies (first pallet body 11 and second pallet body 21) with AGV / forklift handling ports as the bearing base.

[0126] The pallet bodies corresponding to the main body loading area 1, module loading area 2 and assembly unloading area 3 are respectively provided with main body positioning fixture 12, module positioning fixture 22 and assembly positioning fixture 32.

[0127] Each positioning fixture adopts a V-shaped positioning structure to achieve automatic axis centering and positioning of rotating workpieces;

[0128] Furthermore, the positioning fixture and the pallet body adopt a separate and detachable connection structure, which can be used to quickly and flexibly adapt to different models and specifications of products by replacing the positioning fixture.

[0129] The working principle of the system of the present invention is explained below:

[0130] 1. Overview of Four-Axis Tightening:

[0131] The four-axis linkage module tightening mechanism 53 is responsible for carrying the module to be installed 516 and performing horizontal movement, lifting, rotation, and extension compensation in space. Finally, it completes the multi-axis linkage tightening action with the internal thread structure of the rotating body 515 to be installed. The two work together to realize the entire process of docking, centering, screwing and locking of the body and module.

[0132] 2. Four-axis tightening and docking

[0133] The assembly robot station 6 uses an area scan camera 65 to take pictures of the hexagonal prism position of the module 516 to be assembled to confirm the angle, and then takes pictures of the position of the tightening chuck 537 of the four-axis linkage module tightening mechanism 53. According to the position of the relevant mechanism, the module 516 to be assembled is pre-installed on the tightening chuck 537 and fixed by the clamping mechanism of the chuck.

[0134] The horizontal axis 532 drives the entire tightening mechanism to move horizontally, aligning the tightening chuck with the axis of the main body positioning station.

[0135] The lifting shaft 533 adjusts the vertical position of the mechanism according to the preset initial height, so that the tightening head and the main body axis are in the same plane.

[0136] The rotating shaft 534 drives the extending shaft 535, the telescopic compensation mechanism 536, and the tightening clamp 537 to initially align the hexagonal threaded structure of the module to be installed 516 with the corresponding interface of the main body.

[0137] Principle: By linking horizontal, lifting and rotating axes, the initial spatial posture between the tightening clamp and the main body is established, preparing for subsequent precise compensation and docking.

[0138] 3. Key Compensation: Lifting and Extension Travel Compensation under Angle Linkage

[0139] like Figure 9 As shown, when the module rotates upward by an angle α with the rotation axis 534, in order to keep the tightening chuck aligned with the center of the body, displacement in two directions must be compensated simultaneously:

[0140] Lifting shaft compensation (vertical direction)

[0141] Principle: Taking the distance R from the center of the module to the center of the rotary motor as the hypotenuse, after rotating by an angle α, the vertical displacement is R·tan(α);

[0142] Action: The lifting shaft 533 rises at this distance to ensure that the tightening chuck is always at the height of the main body axis.

[0143] Extended shaft compensation (horizontal direction)

[0144] Principle: After rotating by an angle α, the straight-line distance from the center of the module to the center of the rotary motor becomes R / cos(α), therefore an additional R(1 / cos(α)-1) needs to be extended.

[0145] Action: The extension shaft 535 drives the tightening chuck to extend forward, counteracting the horizontal offset caused by rotation, so that the circuit module can always contact the threaded end face of the body.

[0146] Principle: By using a trigonometric function model, synchronous linkage compensation between the lifting shaft and the extension shaft is achieved, ensuring that the tightening chuck and the center of the body remain aligned at any rotation angle, thus establishing a precise coaxial relationship for subsequent tightening.

[0147] 4. Flexible docking and collision avoidance compensation

[0148] Main body: Four-axis linkage module tightening mechanism 53

[0149] The extension shaft drives the tightening chuck to continue extending slowly, so that the threaded / hexagonal prism structure of the module comes into contact with the interface of the body.

[0150] At this point, the guide structure and spring of the telescopic compensation mechanism 536 begin to function:

[0151] If there is a slight positional error or travel deviation, the spring will be compressed to absorb the impact force of the hard contact, preventing the circuit module or the main body from being damaged.

[0152] At the same time, it ensures stable contact pressure, providing reliable axial preload for subsequent tightening.

[0153] Principle: By using spring-type flexible compensation, the stroke error during multi-axis linkage is resolved, soft contact docking is achieved, and hard collisions are prevented from damaging the workpiece.

[0154] 5. Multi-axis linkage rotary tightening (core action)

[0155] Main body: Body positioning and rotating mechanism 51 + four-axis linkage module tightening mechanism 53

[0156] The rotating shaft 534 of the tightening mechanism is started, which drives the tightening clamp and the circuit module (module 516 to be installed) to rotate in the forward direction along the axis.

[0157] The rotating mechanism 512 of the body positioning and rotating mechanism starts synchronously, driving the chuck and connecting body to rotate in opposite directions along the axis (or rotate at the same speed in opposite directions / differential speeds according to process requirements).

[0158] The extension shaft 535 advances forward at a set feed rate according to the thread lead and tightening speed, maintaining stable axial pressure.

[0159] Throughout the process, sensor 538 monitors the position, torque, and speed of each axis in real time to achieve closed-loop control.

[0160] When the torque reaches the set value, it is determined that the screw is tightened in place;

[0161] If the position is out of tolerance or the torque is abnormal, the machine should be stopped immediately and an alarm should be triggered to prevent damage to the threads or the workpiece.

[0162] Principle: Through the dual-axis linkage of "reverse rotation of the main body + forward rotation of the module", resistance-free tightening is achieved. At the same time, the feed compensation thread lead through the extended shaft ensures dual control of tightening torque and stroke.

[0163] 6. Tightening completed and resetting

[0164] Once the set torque and number of turns are reached, tighten the chuck to release the circuit module, and the extended shaft will retract.

[0165] The rotary axis, lifting axis, and horizontal axis move in opposite directions according to the compensation formula, returning to the initial reference position to prepare for the next workpiece.

[0166] The chuck of the body positioning and rotating mechanism is released, and the assembled workpiece is removed.

[0167] The system's working process is explained in detail below:

[0168] 1. The target model body and the module to be installed are manually placed on the positioning fixtures of the first pallet body 11 and the second pallet body 21. AGV or manual forklift guides them into the body loading area 1 and the module loading area 2. The pallets, the rotating body 515 to be installed, and the module 516 to be installed are marked with QR codes and other labels. The end face of the rotating body 515 to be installed has multiple internal threaded holes for installing and tightening multiple different modules 516. The external thread at the end of the module 516 to be installed has a hexagonal prism structure between it and the module body.

[0169] 2. At the loading / unloading robot station 4, a 2D camera scans the QR codes on the robot body, modules, and pallets. The control system performs product matching to prevent incorrect assembly and controls the four-axis linkage module tightening mechanism 53 to move to the tightening head library 54 to match the corresponding tightening heads. The loading / unloading robot uses an electric clamping cylinder 44 and a clamp 45 to clamp the robot body and modules, and moves using the first robot ground rail 41 to place them into the corresponding module assembly station 5, where they are respectively placed into the robot body positioning rotation mechanism 51 and the module docking mechanism 52.

[0170] 3. Assembly robot station 6 uses a 3D line laser camera to scan the axial surface of the rotating body 515 to be assembled, fits the axis of the rotating body 515 to be assembled, and the position of the end face of the rotating body 515 to be assembled. By comparing with the preset benchmark, it is determined whether there is any offset in the clamping. If there is an offset, the body positioning and rotation mechanism 51 needs to re-clamp the rotating body 515 to be assembled; determine the offset distance of the end face in the X-axis (as compensation for the tooling distance of the subsequent 2D camera photo).

[0171] 4. The loading / unloading robot at station 4 moves its 2D industrial camera to the imaging position (using X-axis compensation to ensure a fixed tooling distance) to photograph and identify the end face of the rotating body 515 to be assembled, determine the angle of the end face, and rotate the end face to the reference position by rotating the chuck; (Up to this point, secondary positioning is performed by rotating each module's mounting hole until it is tightened. The overall shooting has parallax to determine the angle. Then, the camera is moved to the mounting hole position of the circuit module for secondary shooting to determine the position of multiple tightened screw holes and record them for later use.)

[0172] 5. At the assembly robot station 6, the area scan camera 65 takes a picture of the first mounting hole of the rotating body 515 to be installed on the main body positioning and rotating mechanism 51 to confirm the position and posture of the current mounting hole. The robot moves to the module 516 to be installed on the module docking mechanism 52 via the second robot ground rail 61 and takes a picture using the area scan camera 65. Then, the automatic grease application unit 6 at the end applies grease to the module.

[0173] 6. Based on the position and orientation of the mounting holes of the rotating body 515 to be assembled, obtained by the vision system in steps 3 and 4, the module docking mechanism 52 adjusts the position and orientation of the module to be assembled through the six-degree-of-freedom platform, moving it to be just close to the mounting holes of the rotating body 515 to be assembled. The assembly robot station 6 uses the area scan camera 65 to take pictures of the installation position to confirm whether the position of the module to be assembled 516 is correct. If it is correct, the module docking mechanism 52 is used to pre-tighten the module to be assembled 516.

[0174] 7. The assembly robot station 6 uses an area scan camera 65 to take pictures of the hexagonal prism position of the module to be assembled 516 to confirm the angle, and then takes pictures of the position of the tightening chuck 537 of the four-axis linkage module tightening mechanism 53 to guide the four-axis linkage module tightening mechanism 53 to tighten the module to be assembled 516 relative to the rotating body 515 to be assembled.

[0175] 8. The loading and unloading robot station 4 removes the assembled module 516 and the rotating body 515, which have been tightened, from the body positioning and rotating mechanism 51 and places them into the assembly unloading area 3.

[0176] It should be noted that for components without special structural limitations, any component that can achieve the corresponding function in the existing technology is acceptable.

[0177] It should also be noted that the above-mentioned settings, installations, connections, and fixations can be made using, but are not limited to, bolts, threads, etc. Any existing fixed or movable connection scheme can be adapted, as long as the corresponding function can be achieved.

[0178] This system features a compact overall structure and high integration. Through machine vision positioning, multi-axis servo linkage compensation, flexible clamping, and automatic tool changing technology, it achieves automated and precise threaded docking and tightening assembly of the rotating body and the external threaded circuit module. This effectively improves assembly accuracy and work efficiency, avoids workpiece assembly damage, and has the capability to produce multiple product models. Its flexibility, automation, and stability are significantly enhanced, making it suitable for large-scale automated assembly operations of various rotating precision threaded components.

[0179] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention without departing from its spirit and scope should be included within the protection scope of the present invention.

Claims

1. A compact precision automatic butt joint and threaded assembly system of a rotary body, characterized in that, The system includes a main body loading area (1), a module loading area (2), a combined body unloading area (3), a loading and unloading robot station (4), a module assembly station (5), and an assembly robot station (6). The main body loading area (1) and the module loading area (2) are respectively used to carry and center the rotating body (515) to be installed and the module (516) to be installed. The assembly unloading area (3) is used to receive and carry the assembled assembly product; The loading and unloading robot station (4) has a material handling trajectory that fully covers the main body loading area (1), module loading area (2), assembly unloading area (3) and module assembly station (5), and is used for automatic handling and transfer of materials throughout the production line. The module assembly station (5) serves as the core assembly execution unit of the system, and is used to realize the automated precision docking, flexible screwing and locking assembly between the rotating body (515) to be assembled and the module to be assembled (516). The assembly robot station (6) covers the module assembly station (5) and is used to provide visual assistance for positioning, axis fitting, lubrication or tightening for the assembly process.

2. The compact rotating body precision automatic docking and thread assembly system according to claim 1, characterized in that, The module assembly station (5) includes: Base (55); The main body positioning and rotating mechanism (51) and the tightening clamp (54) are respectively fixedly installed on the upper surface of the base (55); The module docking mechanism (52) is used to provide multi-axis active and passive degrees of freedom for the docking and tightening process of the module to be installed (516), to ensure reliable and smooth docking, and to provide at least module pre-tightening and rotary body pressing functions. The four-axis linkage module tightening mechanism (53) is used to tighten the module to be installed (516) by rotating it after the module to be installed (516) is properly connected, thereby completing the assembly of the module to be installed (516) and the rotating body (515) to be installed. The main body positioning and rotating mechanism (51) and the module docking mechanism (52) are slidably connected to the base (55) through the guide mechanism to achieve precise adjustment and alignment of spatial displacement.

3. The compact rotary precision automatic docking and thread assembly system according to claim 2, characterized in that, The body positioning and rotating mechanism (51) includes: A rotating frame (511) fixed to the base (55); A rotating mechanism (512) and a self-centering chuck (513) are integrated and installed on the rotating frame (511). The rotating mechanism (512) engages with the self-centering chuck (513) through a motor, reducer and gear transmission mechanism to drive the self-centering chuck (513) to rotate precisely around its axis for posture adjustment; The self-centering chuck (513) has several sets of jaws (514) arranged along the circumferential direction. The self-centering chuck (513) automatically clamps or releases the body through the air circuit control, thereby driving the jaws (514) to adaptively clamp or release the rotating body body (515) to be installed.

4. The compact rotary precision automatic docking and thread assembly system according to claim 3, characterized in that, The self-centering chuck (513) is equipped with a pressure regulating valve to adjust the clamping force according to the material and wall thickness characteristics of the rotating body (515) to be installed, so as to achieve flexible and non-destructive clamping. The area in contact between the claw (514) and the rotating body (515) to be installed is made of non-metallic material; The rotating frame (511) and the self-centering chuck (513) have a hollow axis structure along the axial direction of the rotating body (515) to be loaded, in order to optimize the system center of gravity and adapt to the clamping of long-axis rotating bodies.

5. The compact rotary precision automatic docking and thread assembly system according to claim 2, characterized in that, The four-axis linkage module tightening mechanism (53) includes a frame (531) mounted on the base guide structure, and a horizontal shaft (532), a lifting shaft (533), a rotating shaft (534), an extension shaft (535), a telescopic compensation mechanism (536), and a tightening chuck (537) mounted on the frame (531). The horizontal shaft (532) drives the frame (531) to move horizontally in a straight line along the base guide structure through a motor and a gear and rack transmission mechanism; The lifting shaft (533) drives the rotating shaft (534), the extension shaft (535), the telescopic compensation mechanism (536), and the tightening chuck (537) to vertically lift and adjust their positions as a whole through a motor and lead screw transmission structure. The rotating shaft (534) drives the extending shaft (535), the telescopic compensation mechanism (536), and the tightening chuck (537) to rotate synchronously through a motor and gear transmission mechanism, providing rotational power for thread tightening; The extension shaft (535) is driven by a motor in conjunction with a linear module to drive the tightening chuck (537) to perform axial extension and retraction feed movements; The telescopic compensation mechanism (536) is used to compensate for the stroke change of the extension shaft (535) to absorb the impact force of hard contact and realize the collision prevention of flexible soft contact docking.

6. The compact rotary precision automatic docking and thread assembly system according to claim 5, characterized in that, Sensors (538) are distributed on each linkage axis of the four-axis linkage module tightening mechanism (53) to limit the travel of each axis and realize full servo closed-loop control.

7. The compact rotary precision automatic docking and thread assembly system according to claim 2, characterized in that, The tightening head storage (54) includes a frame and support mechanism (542) mounted on a base (55), a servo drive unit (541), a circular indexing plate structure (543), a multi-specification tightening head group (544), and an error-proof positioning component mounted on the frame and support mechanism (542); the multi-specification tightening head group (544) includes tightening heads of various specifications stored according to workstation numbers; The servo drive unit (541) includes a servo motor, a reducer and a transmission mechanism, and drives the circular indexing disk structure (543) to perform high-precision rotary indexing positioning by relying on closed-loop position feedback control. The circular indexing structure (543) has multiple workstations for storing tightening chucks of different specifications evenly distributed along its circumference. The error-proof positioning component includes a station positioning pin and a chuck detection sensor, used to confirm the indexing status and the tightened chuck status.

8. The compact rotating body precision automatic docking and thread assembly system according to claim 1, characterized in that, The loading and unloading robot station (4) includes a first robot ground rail (41) that covers the entire production line across the region, a first robot body (42) installed on the robot ground rail (41), and a first mounting frame (48) connected to the first robot body (42) through a first quick-change tooling (43). The first mounting bracket (48) is integrated with multiple sets of electric grippers consisting of multiple sets of electric gripping cylinders (44), as well as a first vision unit (46) and a second vision unit (47). The electric clamping cylinder (44) is equipped with a chuck (45), and the chuck (45) has positioning V-shaped slots of different sizes in the gripping feed direction to be compatible with gripping workpieces of different diameters. The first vision unit (46) includes a 2D camera with a coaxial light source, and the second vision unit (47) includes a 2D camera with a central aperture surface light source. The two work together to achieve dual-vision collaborative scanning and precise material positioning.

9. The compact rotating body precision automatic docking and thread assembly system according to claim 1, characterized in that, The assembly robot station (6) includes a second robot ground rail (61) covering each assembly operation station, a second robot body (62) installed on the second robot ground rail (61), and a second mounting bracket (63) connected to the second robot body (62) via a second quick-change tooling (64). The second mounting bracket (63) integrates an area array camera (65), a laser camera (66), a nail gun (67), and an automatic grease applicator (68). The laser camera (66) is used to scan the surface of the workpiece to be assembled and fit the assembly reference axis; the area array camera (65) is used to accurately identify the screw holes and docking angle of the workpiece to be assembled; the screw gun (67) is used to achieve auxiliary tightening operation; and the automatic grease applicator (68) is used to apply a quantitative amount of grease to the thread assembly position.

10. The compact rotating body precision automatic docking and thread assembly system according to claim 1, characterized in that, The main body loading area (1), module loading area (2) and assembly unloading area (3) all use a pallet body with AGV / forklift handling holes as the bearing base; The pallet bodies corresponding to the main body loading area (1), module loading area (2) and assembly unloading area (3) are respectively provided with main body positioning fixture (12), module positioning fixture (22) and assembly positioning fixture (32). Each positioning fixture adopts a V-shaped positioning structure to achieve automatic axis centering and positioning of rotating workpieces; Furthermore, the positioning fixture and the pallet body adopt a separate and detachable connection structure, which can be used to quickly and flexibly adapt to different models and specifications of products by replacing the positioning fixture.

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