Automatic assembly line for ball screw pair

Abstract

The utility model discloses a kind of ball screw pair automatic assembly line, it is related to the technical field of automatic assembly.The assembly line includes first to fourth robot, and main rod feeding mechanism, main rod posture adjusting mechanism, line rod feeding mechanism, line rod posture adjusting mechanism, retainer feeding mechanism, main rod assembly mechanism, line rod assembly mechanism, nut feeding mechanism and nut assembly mechanism.Through the cooperative work of each robot, angle adjustment of main rod and line rod, flaring of retainer, assembly of main rod and retainer, one-by-one press fitting of line rod and final screwing of nut are automatically completed.The utility model realizes the automation of ball screw pair assembly whole process, effectively solves the problems of high labor intensity, low production efficiency and assembly precision not easy to guarantee existing in traditional manual assembly, significantly improves product pass rate and consistency.

Description

Technical Field

[0001] This utility model relates to the field of automated assembly technology, and more specifically, to an automated assembly line for ball screw pairs. Background Technology

[0002] Ball screw assemblies, as high-precision and high-efficiency transmission components, are widely used in high-end CNC equipment, industrial robot joints, precision medical devices, and other fields. Their structure mainly includes core components such as the main rod, nut, sliding rod, and cage. Among these, the cage, as one of the key components of the ball screw assembly, is mainly used to position and guide the balls, ensuring the smoothness and accuracy of the transmission process. Appendix Figure 1 The diagram shows a cage structure used in this ball screw assembly.

[0003] As shown in the attached diagram, the cage has an overall annular structure with a central hole (labeled 901) for mounting the main rod. The cage is not completely closed; there is a gap (labeled 904) on its annular band. This structure allows the cage to have a certain degree of elastic opening capacity. During assembly, external force can be applied to both sides to widen the gap, thereby increasing the diameter of the central hole and facilitating the insertion of the main rod. After the external force is removed, the cage springs back and contracts, securely covering the outer wall of the main rod. In addition, the outer peripheral wall of the cage is alternately equipped with rod catches. The slot (labeled 902 in the figure) and the assembly process slot (labeled 903 in the figure) are used for precise insertion of the rod. The assembly process slot has a dual function: first, when assembling the main rod, an outward pulling force is applied to a pair of assembly process slots located on both sides of the gap, causing the cage to expand and the center hole to enlarge, so that the main rod can be inserted; second, when assembling the rod, a locking block can be inserted into each assembly process slot. The locking blocks around the circumference apply a pre-tightening force towards the center hole of the cage, thereby achieving circumferential fixation of the entire cage and preventing it from moving or deforming.

[0004] In traditional assembly processes, the assembly of ball screw assemblies relies heavily on manual operation. Workers must first rotate the main rod around its axis to a specific first angle to ensure its external thread correctly meshes with the internal thread of the subsequently installed sliding rods before inserting the main rod into the center hole of the cage. Next, each sliding rod must be rotated around its own axis to a preset second angle so that its external thread not only mates with the main rod thread but also aligns with the external threads of all sliding rods during the final assembly stage. This ensures that the nut can smoothly engage with all sliding rods simultaneously. This process demands a high level of operator skill and suffers from high labor intensity, low production efficiency, and poor assembly consistency. Especially in the dual-angle alignment stage between the main rod and sliding rods, complete reliance on manual observation and operation makes it difficult to guarantee accuracy, easily leading to a decrease in product qualification rate and an increase in rework rate. Utility Model Content

[0005] The purpose of this invention is to overcome the defects in the prior art and provide an automatic ball screw assembly line that can automatically complete the angle adjustment of the main rod and the travel rod to achieve automatic assembly of multiple parts.

[0006] To address the aforementioned problems, this utility model provides an automated assembly line for ball screw pairs, comprising a first robot, a second robot, a third robot, and a fourth robot. Its distinguishing feature is that it further includes: a main rod feeding mechanism, a main rod attitude adjustment mechanism, a traveling rod feeding mechanism, a traveling rod attitude adjustment mechanism, a cage feeding mechanism, a main rod assembly mechanism, a traveling rod assembly mechanism, a nut feeding mechanism, and a nut assembly mechanism. The traveling rod feeding mechanism and the traveling rod attitude adjustment mechanism are arranged within the working area of ​​the first robot. The first robot is used to transfer the traveling rod from the traveling rod feeding mechanism to the traveling rod attitude adjustment mechanism, and the traveling rod attitude adjustment mechanism is used to drive the traveling rod to rotate around its axis. The second angle is set; the cage loading mechanism and the main rod assembly mechanism are arranged within the working range of the third robot. The third robot is used to transfer the cage from the cage loading mechanism to the main rod assembly mechanism, and drive the cage to rotate around its axis to a position with the gap facing upwards before positioning it at the assembly station of the main rod assembly mechanism. The main rod assembly mechanism is used to apply outward pulling force to the assembly process slots on both sides of the cage gap to widen the cage gap. The main rod loading mechanism, the main rod attitude adjustment mechanism, the main rod assembly mechanism, and the traveling rod assembly mechanism are arranged within the working area of ​​the second robot. The second robot is used to transfer the main rod from the main rod loading mechanism to the main rod attitude adjustment mechanism. The adjustment mechanism includes a main rod attitude adjustment mechanism for driving the main rod to rotate around its axis to a set first angle; the second robot is also used to transfer the main rod at the first angle from the main rod attitude adjustment mechanism to the main rod assembly mechanism, assemble it with the cage with the enlarged gap to form a first assembly, and transfer the first assembly to the link assembly mechanism; the link assembly mechanism includes an assembly positioning mechanism and an assembly execution mechanism; the assembly positioning mechanism is located within the working range of the second robot, and is used to receive and fix the first assembly, and drive the assembly to rotate intermittently around the main rod axis so that the link slots on the cage of the assembly are sequentially aligned with the execution end of the assembly execution mechanism; The assembly execution mechanism is moved between the assembly positioning mechanism and the traverse attitude adjustment mechanism. It is used to transfer multiple traverses that are already at the second angle from the traverse attitude adjustment mechanism to the assembly positioning mechanism, and assemble them one by one into the corresponding traverse slots on the retainer of the first assembly to form the second assembly. The nut feeding mechanism, the nut assembly mechanism, and the assembly positioning mechanism are arranged within the working range of the fourth robot. The fourth robot is used to transfer the second assembly at the assembly positioning mechanism and the nuts at the nut feeding mechanism to the nut assembly mechanism. The nut assembly mechanism is used to screw the nuts into the outer threads of the traverses of the second assembly to assemble the final product.

[0007] Compared with the prior art, the advantages of this utility model are as follows: This utility model automatically and precisely rotates the main rod and the traveling rod to preset first and second angles respectively through the main rod attitude adjustment mechanism and the traveling rod attitude adjustment mechanism, ensuring the correct meshing of the main rod external thread and the traveling rod internal thread, as well as the final alignment of all traveling rod external threads, fundamentally eliminating the errors and uncertainties caused by manual adjustment; this utility model, through the collaborative operation of multiple robots, realizes the automatic transfer and assembly of multiple components such as the main rod, traveling rod, cage, and nut, significantly reducing manual intervention and lowering labor intensity and production costs; furthermore, the main rod assembly mechanism of this utility model, through the gap in the cage… The assembly process slots on both sides apply symmetrical outward pulling force, reliably widening the cage gap, facilitating the insertion of the main rod, and improving the reliability of the assembly operation. The traverse rod assembly mechanism, driven by the intermittent rotation of the assembly positioning mechanism, aligns each slot sequentially with the assembly station. Combined with the assembly execution mechanism, the traverse rod with the adjusted angle is precisely pressed in, ensuring the consistency and accuracy of the traverse rod assembly. The nut assembly mechanism automatically completes the final tightening, further improving the overall automation level. In summary, this utility model effectively solves the prominent problems of low production efficiency, poor assembly consistency, and reliance on worker experience for product accuracy in traditional manual assembly, significantly improving the product qualification rate and reducing the rework rate.

[0008] Specifically, the main rod attitude adjustment mechanism includes a first clamping and rotating mechanism and a first vision detection mechanism. The first clamping and rotating mechanism is located in the working area of ​​the second robot and includes a base, a first servo motor, and a first pneumatic gripper. The first servo motor is fixedly mounted on the base, and its output shaft is vertically upward. The first pneumatic gripper is fixedly mounted on the output shaft of the first servo motor, and its gripping end is upward, and it is used to grip the main rod. The first vision detection mechanism includes a photographing unit. The photographing unit includes a first side frame and a camera. The first side frame is located on one side of the base, and the camera is mounted on the first side frame with its lens facing the first pneumatic gripper, and it is used to photograph and detect the main rod. This structure uses a first servo motor to drive the first pneumatic gripper and main rod to rotate precisely, and combines the camera of the first vision inspection mechanism to take pictures, identify and provide feedback. It can automatically and with high precision rotate the main rod around its axis to a preset first angle. This ensures the consistency of the phase of the external thread of the main rod, which prepares for the correct engagement with the traveling rod. It completely replaces manual visual adjustment, greatly improves the accuracy and efficiency of angle alignment, and reduces quality fluctuations caused by human factors.

[0009] As an improvement, the first vision inspection mechanism also includes a supplementary lighting unit. This unit comprises a second side frame, a light source, a reflector, and a pusher cylinder. The second side frame is located on the other side of the base, the reflector is fixedly mounted on the second side frame, and the light source is mounted on the first side frame via the pusher cylinder and can move back and forth along the optical axis of the camera lens. This supplementary lighting unit, by adjusting the distance between the light source and the camera lens optical axis via the pusher cylinder, combined with the reflector, provides sufficient, uniform, and adjustable lighting conditions for the camera's shooting area. This effectively eliminates ambient light interference and reflections and shadows on the workpiece surface, significantly improving the quality, contrast, and clarity of the images acquired by the first vision inspection mechanism. This greatly enhances the reliability and accuracy of the main shaft angle recognition and positioning, providing a solid foundation for the accuracy of the entire main shaft attitude adjustment process.

[0010] Specifically, the lever attitude adjustment mechanism includes a first turntable, a first cam divider, a second vision detection mechanism, and a second clamping and rotating mechanism. The top surface of the first turntable has multiple lever adjustment stations spaced circumferentially. Each lever adjustment station is equipped with a bracket, a second pneumatic gripper, and a gripper clamping mechanism. The bracket is fixedly mounted on the top of the first turntable. The second pneumatic gripper is rotatably mounted on the bracket, with its gripping end facing upwards and used to clamp the lever. The gripper clamping mechanisms are located on both sides of the second pneumatic gripper and are movably mounted on the bracket, used to clamp the second pneumatic gripper to restrict its rotation. The second vision detection mechanism is located on one side of the first turntable and corresponds to one of the lever adjustments. The system includes a workstation for photographing and inspecting the mast at that workstation; a first cam divider is supported at the bottom of the first turntable and drives the first turntable to rotate intermittently so that each mast adjustment workstation rotates sequentially to the second vision inspection mechanism; a first lifting mechanism is located below the mast adjustment workstation corresponding to the second vision inspection mechanism, and a second clamping and rotating mechanism is mounted on the first lifting mechanism. The first lifting mechanism drives the second clamping and rotating mechanism to move up and down within the mast adjustment workstation, and the second clamping and rotating mechanism clamps the lower part of the second pneumatic gripper to drive it to rotate; each mast adjustment workstation on the first turntable has a lifting channel through which the clamping end of the second clamping and rotating mechanism passes. This design uses a first cam divider to drive the first turntable to rotate intermittently, enabling the cyclical flow of multiple rod adjustment stations and providing a foundation for parallel operations. When a station rotates to the detection position, the second vision detection mechanism takes a picture of the rod for identification. Subsequently, the second clamping and rotating mechanism rises under the drive of the first lifting mechanism, clamping and driving the second pneumatic gripper and the rod to rotate to a preset second angle. Immediately afterwards, the gripper clamping mechanism acts to clamp the second pneumatic gripper from both sides, effectively preventing it from rotating back, thereby reliably locking the adjusted rod angle. The entire process achieves full automation of rod angle adjustment and multi-station parallel operation, significantly improving the production efficiency of the rod preparation stage and ensuring the high consistency and stability of all rod angles, laying a solid foundation for subsequent batch automated assembly.

[0011] Specifically, the main rod assembly mechanism includes a cage positioning seat and a pair of cage opening mechanisms symmetrically arranged on both sides of the cage positioning seat; the cage positioning seat is located within the working range of the second robot, and its top is recessed downward with at least two arc-shaped positioning grooves that are spaced apart along a first direction and extend along a second direction, the first direction and the second direction being perpendicular to each other; the shape of the arc-shaped positioning grooves is adapted to the outer wall of the cage, and the bottom of the arc-shaped positioning grooves is provided with an anti-rotation limiting block for engaging an assembly process groove of the cage; the cage opening mechanisms are arranged along the second direction and are used to apply an outward pulling force to the cage placed in the arc-shaped positioning grooves to widen its gap. This mechanism, by setting multiple arc-shaped positioning grooves and anti-rotation limiting blocks, can achieve parallel positioning and fixation of multiple cages, preventing them from rotating during assembly. The cage opening mechanism on both sides can reliably widen the gap of the cage by applying precise and symmetrical outward pulling force to the assembly process grooves on both sides of the cage, creating the necessary conditions for the smooth installation of the subsequent main rod. Its structural design ensures the stability and centering of the flaring process, avoiding damage or skewing of the cage.

[0012] Specifically, each cage opening mechanism includes a first base, a first linear module, a plate, multiple swing blocks, and multiple telescopic cylinders. The first linear module is fixedly mounted on the top of the first base. The plate is fixedly mounted on the movable block of the first linear module and is driven by the first linear module to move back and forth in the second direction. The number of swing blocks is twice the number of arc-shaped positioning slots. One end of each swing block is rotatably mounted on the top of the plate through a first rotating joint. The other end of each swing block extends toward the corresponding arc-shaped positioning slot and bends downward to form a pulling part. The pulling part is provided with a snap-fit ​​part for engaging with the cage assembly process slot. The number of telescopic cylinders is the same as the number of swing blocks. The cylinder body of each telescopic cylinder is hinged to the top of the plate through a hinge seat at the end away from the arc-shaped positioning slot, and its piston rod is rotatably connected to the other end of the corresponding swing block through a second rotating joint. After applying this structure, the first linear module drives the flat plate and all its components to move closer to or further away from the cage positioning seat. When the cage needs to be pried open, the piston rod of the telescopic cylinder extends and pushes the other end of the swing block through the second rotary joint, causing the swing block to rotate around the first rotary joint, thereby causing the end of the snap-fit ​​part to snap into and pull outward the assembly process groove of the cage. The symmetrical design of multiple swing blocks and telescopic cylinders can simultaneously apply uniform tension to both sides of multiple cages, ensuring balanced flaring force and avoiding excessive local stress that could damage the cage.

[0013] Specifically, the assembly positioning mechanism includes a second turntable, a second cam divider, an intermediate fixing mechanism, and multiple peripheral fixing mechanisms. The second turntable is located on one side of the assembly execution mechanism. The second cam divider is supported at the bottom of the second turntable and is used to drive the second turntable to rotate intermittently. The intermediate fixing mechanism is a third pneumatic gripper fixedly mounted on the top surface of the second turntable with its gripping end facing upwards. The third pneumatic gripper is used to grip the main rod of the first assembly. Multiple peripheral fixing mechanisms are circumferentially distributed on the top of the second turntable and are set corresponding to the assembly process slots of the first assembly's retainer. Each peripheral fixing mechanism includes a first lifting cylinder, a first horizontal pushing cylinder, a mounting base, and a clamping block. The piston rod of the first lifting cylinder is fixedly mounted on the second turntable with its piston facing upwards and is located on the periphery of the third pneumatic gripper. The first horizontal pushing cylinder is fixed to the piston rod of the first lifting cylinder through the mounting base and extends horizontally toward the third pneumatic gripper. The clamping block is fixed to the piston rod of the first horizontal pushing cylinder, and its extended end is provided with a snap-in part, which is used to snap into the assembly process slots of the first assembly's retainer. This mechanism drives a second turntable to perform precise intermittent rotation via a second cam divider, allowing multiple rod slots on the first assembly to stop sequentially and accurately at preset assembly positions. This achieves multi-station cyclic flow and precise positioning. The intermediate fixing mechanism uses a third pneumatic gripper to firmly clamp the main rod from below the first assembly, providing a stable center reference. Simultaneously, the peripheral fixing mechanism, through the coordinated action of a first lifting cylinder and a first pushing cylinder, drives the locking part on the clamping block to precisely embed and clamp the assembly process slots on both sides of the retainer, thereby applying constraint forces from both the axial and circumferential directions of the main rod, forming a three-dimensional clamping system. This design achieves complete fastening of the first assembly (main rod and retainer), effectively eliminating axial movement, circumferential rotation, or elastic deformation that may occur during subsequent rod pressing, providing crucial stability for the precise and smooth pressing of the rod. This design directly guarantees the assembly accuracy of the final product. Furthermore, the key design element is the use of a liftable peripheral fixing mechanism. When a glider needs to be assembled in a specific glider slot of the first assembly, the control system controls the first lifting cylinder to lower the clamping blocks inserted into the assembly process slots on both sides of the target slot, actively withdrawing them from the assembly area. This intelligently avoids spatial interference between the peripheral fixing mechanism and the assembly execution mechanism (such as the glider pressing head), ensuring a smooth assembly process and enabling sequential and collaborative operation of different execution mechanisms at the same workstation. In summary, this assembly positioning mechanism not only solves the problem of stable fixing of complex assemblies through multi-degree-of-freedom clamping but also solves the spatial interference problem during multi-mechanism collaborative operation through a liftable avoidance design. It combines high precision, high stability, and high flexibility, making it one of the core devices ensuring the efficient and reliable operation of the entire production line.

[0014] Specifically, the assembly actuator includes a crossbeam, a fourth pneumatic gripper and a translation drive mechanism mounted on the crossbeam, and a material handling mechanism located at the rear end of the crossbeam. The crossbeam is laterally arranged between the first and second turntables. The translation drive mechanism includes a second linear module, a sliding seat, a first slider rail assembly, and a second push cylinder. The second linear module is laterally distributed on the crossbeam. The sliding seat is slidably mounted on the crossbeam via the first slider rail assembly and is fixedly connected to the movable block of the second linear module. The second push cylinder is mounted on the sliding seat. The assembly includes a fourth pneumatic gripper, which is mounted on the piston rod of the second push cylinder via a first fixed base, with its gripping end facing the center of the second turntable. The fourth pneumatic gripper is used to grip the traverse rod already at the second angle and insert it into the traverse rod slot of the retainer of the first assembly. The second push cylinder drives the fourth pneumatic gripper to move towards or away from the center of the second turntable. The material handling mechanism is positioned near the first turntable and is used to transfer the traverse rod already at the second angle on the first turntable to the gripping end of the fourth pneumatic gripper. With this structure, the assembly execution mechanism drives the sliding seat via the second linear module, causing the fourth pneumatic gripper on it to perform a large-stroke, high-precision reciprocating lateral movement between the first turntable (traverse rod attitude adjustment station) and the second turntable (assembly positioning station), efficiently completing the traverse rod transfer task between the two stations. When the fourth pneumatic gripper carrying rod moves to the front of the first assembly on the second turntable, the second flat-push cylinder precisely drives the fourth pneumatic gripper to move forward or backward radially (i.e., towards or away from the center of the second turntable), ultimately pressing the rod precisely into the currently aligned rod slot on the retainer of the first assembly. This division of labor design, where "long-distance lateral movement is handled by the module and precise positioning and pressing is performed by the cylinder," takes into account both the execution range and assembly accuracy, reliably realizing the automatic material picking, transfer, and assembly operations of the rod.

[0015] Specifically, the material handling mechanism includes a first upright frame and a second lifting cylinder, a third horizontal pushing cylinder, and a fifth pneumatic gripper mounted on the first upright frame. The first upright frame is located at one end of the horizontal frame near the first turntable. The second lifting cylinder is located on the upper part of the first upright frame with its piston rod vertically downward. The third horizontal pushing cylinder is fixed to the lower end of the piston rod of the second lifting cylinder via a second fixed seat. The fifth pneumatic gripper is fixed to the piston rod of the third horizontal pushing cylinder via a third fixed seat. The second lifting cylinder is used to drive the fifth pneumatic gripper to move up and down above the first turntable. The third horizontal pushing cylinder is used to drive the fifth pneumatic gripper to move towards the direction of the fourth pneumatic gripper. The gripping end of the fifth pneumatic gripper faces the gripping end of the fourth pneumatic gripper and is used to grip the rod that is already at the second angle from the first turntable and transfer it to the gripping end of the fourth pneumatic gripper. This mechanism drives the fifth pneumatic gripper through the second lifting cylinder and the third horizontal pushing cylinder, realizing the compound movement of the fifth pneumatic gripper in the vertical and horizontal directions. It accurately completes the entire set of actions of grabbing the traverse rod from the first turntable, lifting it, translating it, and reliably placing the traverse rod into the fourth pneumatic gripper. As a key link connecting the traverse rod attitude adjustment mechanism and the assembly execution mechanism, it realizes the stable and reliable automatic handover and precise positioning of the traverse rod between the two major modules, ensuring the continuity and stability of the assembly process.

[0016] Specifically, the nut assembly mechanism includes a second base, a second upright, a nut fixing mechanism, a rotating assembly mechanism, and a lifting drive mechanism. The second base is located within the working area of ​​the fourth robot. The second upright and the nut fixing mechanism are arranged side-by-side on the second base. The rotating assembly mechanism and the lifting drive mechanism are located on the second upright. The lifting drive mechanism is used to drive the rotating assembly mechanism to move up and down above the nut fixing mechanism. The nut fixing mechanism includes a fixing frame, a finger cylinder, and a pair of nut grippers fixedly mounted on the gripping end of the finger cylinder for holding the nut. The fixing frame is fixedly mounted on the second base, and the finger cylinder is fixedly mounted on the fixing frame and is used to drive the pair of nut grippers to open and close horizontally. The rotating assembly mechanism includes a rotary motor and a sixth pneumatic gripper. The driving mechanism includes a first movable seat, a second movable seat, a second slider rail assembly, a third slider rail assembly, a third lifting cylinder, and a fourth lifting cylinder. The first movable seat is slidably mounted on the second upright via the second slider rail assembly. The third lifting cylinder is fixedly mounted on the upper part of the second upright and is used to drive the first movable seat to move up and down. The second movable seat is slidably mounted on the first movable seat via the third slider rail assembly. The fourth lifting cylinder is fixedly mounted on the first movable seat and is used to drive the second movable seat to move up and down. A rotary motor is fixedly mounted on the second movable seat. The output end of the rotary motor faces downward and is fixedly connected to the sixth pneumatic gripper. The clamping end of the sixth pneumatic gripper is vertically downward and faces the clamping area of ​​the nut gripper, and is used to clamp the main rod of the second assembly. After applying this structure, the fourth robot transfers the second assembly to the nut assembly mechanism, and the sixth pneumatic gripper then firmly clamps the upper end of the main rod of the second assembly, providing a stable center of rotation. At the same time, the fourth robot transfers the nut to the nut fixing mechanism, where a pair of nut grippers driven by finger cylinders precisely grip and fix the nut. Subsequently, the third lifting cylinder drives the entire rotating assembly mechanism to descend smoothly, so that the threads at the lower ends of all the rods of the second assembly held by the sixth pneumatic gripper are simultaneously and accurately aligned with the threaded holes of the nut. Next, the rotary motor starts, driving the sixth pneumatic gripper and the second assembly to rotate as a whole. At the same time, the fourth lifting cylinder provides precise feed motion, driving the sixth pneumatic gripper and the second assembly to move downwards, thereby synchronously and smoothly screwing multiple rods into the nuts, completing the final assembly. The core advantage of this mechanism lies in its unique "clamping the main rod and rotating the assembly" assembly strategy. By driving the entire assembled rod assembly to rotate and feed, rather than rotating the nuts individually in the traditional way, it ensures that the threads of all rods and the threads of the nuts can maintain precise phase synchronization, achieving true synchronous meshing. This method effectively avoids problems such as meshing jamming, thread damage, or decreased assembly accuracy caused by misalignment of individual rod threads, significantly improving the assembly quality, consistency, and reliability of the final product. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the cage structure in the prior art; Figure 2 This is a schematic diagram of the overall structure of this utility model; Figure 3 This is a schematic diagram of the main rod attitude adjustment mechanism in this utility model; Figure 4 This is a schematic diagram of the structure of the lever attitude adjustment mechanism of this utility model; Figure 5 This is a schematic diagram of the main rod assembly mechanism in this utility model; Figure 6 This is a perspective view of the main rod assembly mechanism in this utility model; Figure 7 This is the first perspective view of the rod assembly mechanism of this utility model; Figure 8 This is the second perspective view of the rod assembly mechanism of this utility model; Figure 9 This is the first perspective view of the nut assembly mechanism in this utility model; Figure 10 This is the second perspective view of the nut assembly mechanism in this utility model.

[0018] Explanation of reference numerals in the attached figures: 101. First robot; 102. Second robot; 103. Third robot; 104. Fourth robot; 1. Main rod feeding mechanism; 2. Main rod posture adjustment mechanism; 21. First clamping and rotating mechanism; 211. Base; 212. First servo motor; 213. First pneumatic gripper; 22. First vision inspection mechanism; 221. First side frame; 222. Camera; 223. Second side frame; 224. Light source; 225. Reflector; 226. Push cylinder; 3. Traveling rod feeding mechanism; 4. Traveling rod posture adjustment mechanism; 41. First turntable; 410. Lifting channel; 411. Support; 412. Second pneumatic gripper 413. Claw; 42. Gripper clamping mechanism; 43. First cam divider; 44. Second vision inspection mechanism; 45. Second clamping rotation mechanism; 5. First lifting mechanism; 6. Cage feeding mechanism; 6. Main rod assembly mechanism; 61. Cage positioning seat; 611. Arc-shaped positioning groove; 612. Anti-rotation limit block; 62. Cage opening mechanism; 620. First base; 621. First linear module; 622. Flat plate; 623. Swing block; 6231. Pulling part; 6232. Snap-fit ​​part; 624. Telescopic cylinder; 7. Traveling rod assembly mechanism; 71. Assembly positioning mechanism; 711. Second turntable; 712. Second convex... Wheel divider; 713, third pneumatic gripper; 714, peripheral fixing mechanism; 7141, first lifting cylinder; 7142, first horizontal pushing cylinder; 7143, mounting base; 7144, clamping block; 71440, locking part; 72, assembly execution mechanism; 7201, first fixed base; 7202, second fixed base; 7203, third fixed base; 721, cross frame; 722, fourth pneumatic gripper; 723, material handling mechanism; 7231, first upright frame; 7232, second lifting cylinder; 7233, third horizontal pushing cylinder; 7234, fifth pneumatic gripper; 724, translation drive mechanism; 7241, second linear mold Group; 7242, sliding seat; 7243, first slider rail assembly; 7244, second flat push cylinder; 8, nut feeding mechanism; 9, nut assembly mechanism; 91, second base; 92, second upright; 93, nut fixing mechanism; 931, fixing frame; 932, finger cylinder; 933, nut gripper; 94, rotary assembly mechanism; 941, rotary motor; 942, sixth pneumatic gripper; 95, lifting drive mechanism; 951, first movable seat; 952, second movable seat; 953, second slider rail assembly; 954, third slider rail assembly; 955, third lifting cylinder; 956, fourth lifting cylinder. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0020] like Figure 2As shown, an automatic assembly line for ball screw pairs includes a first robot 101, a second robot 102, a third robot 103, and a fourth robot 104. It is characterized by further comprising: a main rod feeding mechanism 1, a main rod posture adjustment mechanism 2, a traveling rod feeding mechanism 3, a traveling rod posture adjustment mechanism 4, a cage feeding mechanism 5, a main rod assembly mechanism 6, a traveling rod assembly mechanism 7, a nut feeding mechanism 8, and a nut assembly mechanism 9. The traveling rod feeding mechanism 3 and the traveling rod posture adjustment mechanism 4 are arranged within the working area of ​​the first robot 101. The first robot 101 is used to transfer the traveling rod from the traveling rod feeding mechanism 3 to the traveling rod posture adjustment mechanism 4. The traveling rod posture adjustment mechanism 4 is used to drive the traveling rod to rotate around its axis to a set position. The second angle is determined; the cage loading mechanism 5 and the main rod assembly mechanism 6 are arranged within the working range of the third robot 103. The third robot 103 is used to transfer the cage from the cage loading mechanism 5 to the main rod assembly mechanism 6, and drive the cage to rotate around its axis to a position with the gap facing upwards before positioning it at the assembly station of the main rod assembly mechanism 6. The main rod assembly mechanism 6 is used to apply outward pulling force to the assembly process grooves on both sides of the cage gap to widen the cage gap; the main rod loading mechanism 1, the main rod posture adjustment mechanism 2, the main rod assembly mechanism 6, and the traveling rod assembly mechanism 7 are arranged within the working area of ​​the second robot 102. The second robot 102 is used to transfer the main rod from the main rod loading mechanism 1 to the main rod posture adjustment mechanism 6. The adjustment mechanism 2, the main rod attitude adjustment mechanism 2, is used to drive the main rod to rotate around its axis to a set first angle; the second robot 102 is also used to transfer the main rod at the first angle from the main rod attitude adjustment mechanism 2 to the main rod assembly mechanism 6, assemble it with the cage with the enlarged gap to form a first assembly, and transfer the first assembly to the link assembly mechanism 7; the link assembly mechanism 7 includes an assembly positioning mechanism 71 and an assembly execution mechanism 72; the assembly positioning mechanism 71 is located within the working range of the second robot 102, and is used to receive and fix the first assembly, and drive the assembly to rotate intermittently around the main rod axis, so that the link slots on the cage of the assembly are sequentially aligned with the execution end of the assembly execution mechanism 72; The actuator 72 is movably positioned between the assembly positioning mechanism 71 and the traverse posture adjustment mechanism 4. It is used to transfer multiple traverses that are already at the second angle from the traverse posture adjustment mechanism 4 to the assembly positioning mechanism 71, and assemble them one by one into the corresponding traverse slots on the retainer of the first assembly to form the second assembly. The nut feeding mechanism 8, the nut assembly mechanism 9, and the assembly positioning mechanism 71 are arranged within the working range of the fourth robot 104. The fourth robot 104 is used to transfer the second assembly at the assembly positioning mechanism 71 and the nuts at the nut feeding mechanism 8 to the nut assembly mechanism 9. The nut assembly mechanism 9 is used to screw the nuts into the outer threads of the traverses of the second assembly to assemble the final product.

[0021] In this embodiment, the main rod loading mechanism 1, the traveling rod loading mechanism 3, and the nut loading mechanism 8 are all loading mechanisms in the prior art consisting of an AGV trolley, a pallet, and a placement rack. The AGV trolley transports the pallet containing the main rod to the placement rack within the working range of the second robot 102, where it is picked up by the second robot 102. The execution end of the second robot 102 is equipped with a gripper for clamping the main rod. The AGV trolley also transports the pallet containing the traveling rod to the placement rack within the working range of the first robot 101, where it is picked up by the first robot 101. The first robot 101 has a gripper at its execution end for gripping the rod; the AGV trolley transfers the tray containing nuts to a placement rack within the working range of the fourth robot 104 for the fourth robot 104 to pick up; the fourth robot 104 has a gripper at its execution end for gripping the nuts; the retainer feeding mechanism 5 is a vibratory feeder feeding mechanism in the prior art, the vibratory feeder stores the retainer, and its transmission track extends into the working area of ​​the third robot 103, allowing the third robot 103 to pick up the nuts from the end of the transmission track.

[0022] This embodiment uses the main rod attitude adjustment mechanism 2 and the traveling rod attitude adjustment mechanism 4 to automatically and precisely rotate the main rod and traveling rod to preset first and second angles, respectively, ensuring the correct meshing of the main rod external thread and the traveling rod internal thread, as well as the final alignment of all traveling rod external threads, fundamentally eliminating the errors and uncertainties caused by manual adjustment. This embodiment also achieves automatic transfer and assembly of multiple components such as the main rod, traveling rod, cage, and nut through the collaborative operation of multiple robots, significantly reducing manual intervention and lowering labor intensity and production costs. Furthermore, the main rod assembly mechanism 6 in this embodiment applies symmetrical pressure to the assembly process grooves on both sides of the cage gap. The outward pulling force reliably widens the cage gap, facilitating the insertion of the main rod and improving the reliability of the assembly operation. The rod assembly mechanism 7, driven by the intermittent rotation of the assembly positioning mechanism 71, aligns each slot sequentially with the assembly station. Combined with the assembly execution mechanism 72, the rod with the adjusted angle is precisely pressed in, ensuring the consistency and accuracy of the rod assembly. The nut assembly mechanism 9 automatically completes the final tightening, further enhancing the overall automation level. In summary, this embodiment effectively solves the prominent problems of low production efficiency, poor assembly consistency, and reliance on worker experience for product accuracy in traditional manual assembly, significantly improving the product qualification rate and reducing the rework rate.

[0023] like Figure 2 and Figure 3As shown, the main rod attitude adjustment mechanism 2 includes a first clamping and rotating mechanism 21 and a first vision detection mechanism 22. The first clamping and rotating mechanism 21 is located in the working area of ​​the second robot 102 and includes a base 211, a first servo motor 212, and a first pneumatic gripper 213. The first servo motor 212 is fixedly mounted on the base 211, and its output shaft is vertically upward. The first pneumatic gripper 213 is fixedly mounted on the output shaft of the first servo motor 212, and its gripping end is upward, and it is used to grip the main rod. The first vision detection mechanism 22 includes a photographing unit. The photographing unit includes a first side frame 221 and a camera 222. The first side frame 221 is located on one side of the base 211, and the camera 222 is mounted on the first side frame 221, with its lens facing the first pneumatic gripper 213, and it is used to photograph and detect the main rod. This structure drives the first pneumatic gripper 213 and the main rod to rotate precisely via the first servo motor 212, and combines the camera 222 of the first vision inspection mechanism 22 to take pictures, identify and provide feedback. It can automatically and with high precision rotate the main rod around its axis to a preset first angle, which ensures the consistency of the phase of the external thread of the main rod, and prepares for the correct engagement with the traveling rod. It completely replaces manual visual adjustment, greatly improves the accuracy and efficiency of angle alignment, and reduces quality fluctuations caused by human factors.

[0024] As shown in Figure 3, the first vision inspection mechanism 22 also includes a supplementary lighting unit. This unit comprises a second side frame 223, a light source 224, a reflector 225, and a pusher cylinder 226. The second side frame 223 is located on the other side of the base 211. The reflector 225 is fixedly mounted on the second side frame 223. The light source 224 is mounted on the first side frame 221 via the pusher cylinder 226 and can move back and forth along the optical axis of the camera 222's lens. This supplementary lighting unit adjusts the distance between the light source 224 and the optical axis of the camera 222's lens via the pusher cylinder 226. Combined with the reflector 225, it provides sufficient, uniform, and adjustable lighting conditions for the camera 222's shooting area. This effectively eliminates ambient light interference and reflections and shadows on the workpiece surface, significantly improving the quality, contrast, and clarity of the images acquired by the first vision inspection mechanism 22. This greatly enhances the reliability and accuracy of the main rod angle recognition and positioning, providing a solid foundation for the accuracy of the entire main rod attitude adjustment process.

[0025] like Figures 2 to 4As shown, the rod attitude adjustment mechanism 4 includes a first turntable 41, a first cam divider 42, a second vision inspection mechanism 43, and a second clamping and rotating mechanism 44. Multiple rod adjustment stations are circumferentially distributed on the top surface of the first turntable 41. Each rod adjustment station is equipped with a bracket 411, a second pneumatic gripper 412, and a gripper clamping mechanism 413. The bracket 411 is fixedly mounted on the top of the first turntable 41. The second pneumatic gripper 412 is rotatably mounted on the bracket 411, with its gripping end facing upwards and used to clamp the rod. The gripper clamping mechanism 413 is located on both sides of the second pneumatic gripper 412 and is movably mounted on the bracket 411, used to clamp the second pneumatic gripper 412 to restrict its rotation. The second vision inspection mechanism 43 is located on one side of the first turntable 41 and corresponds to one of the rod adjustment stations, used to photograph and inspect the rod at that station. The first cam divider 42 is supported at the bottom of the first turntable 41 and is used to drive the first turntable 41 to rotate intermittently so that each rod adjustment station rotates sequentially to the second vision inspection mechanism 43. A first lifting mechanism 45 is provided below the rod adjustment station and at the position corresponding to the second vision inspection mechanism 43. The first lifting mechanism 45 is an existing structure, including a column and a drive cylinder with the piston rod fixed upward on the column. The second clamping rotation mechanism 44 is provided on the first lifting mechanism 45. The second clamping rotation mechanism 44 and the first clamping rotation mechanism 21 have the same structure. The first lifting mechanism 45 is used to drive the second clamping rotation mechanism 44 to move up and down within the rod adjustment station. The second clamping rotation mechanism 44 is used to clamp the lower part of the second pneumatic gripper 412 to drive it to rotate. The first turntable 41 is provided with a lifting channel 410 in each rod adjustment station for the clamping end of the second clamping rotation mechanism 44 to pass through. This design uses a first cam divider 42 to drive the first turntable 41 to rotate intermittently, enabling the cyclical flow of multiple rod adjustment stations and providing a foundation for parallel operations. When a station rotates to the detection position, the second vision detection mechanism 43 takes a picture of the rod for identification. Subsequently, the second clamping and rotating mechanism 44 rises under the drive of the first lifting mechanism 45, clamping and driving the second pneumatic gripper 412 and the rod to rotate to a preset second angle. Immediately afterwards, the gripper holding mechanism 413 actuates, clamping the second pneumatic gripper 412 from both sides, effectively preventing it from rotating back, thereby reliably locking the adjusted rod angle. The entire process realizes the complete automation of rod angle adjustment and multi-station parallel operation, greatly improving the production efficiency of the rod preparation stage and ensuring the high consistency and stability of all rod angles, laying a solid foundation for subsequent batch automated assembly.

[0026] like Figure 2 , Figure 5 and Figure 6As shown, the main rod assembly mechanism 6 includes a retainer positioning seat 61 and a pair of retainer prying mechanisms 62 symmetrically arranged on both sides of the retainer positioning seat 61. The retainer positioning seat 61 is located within the working range of the second robot 102. Its top is recessed downward and has at least two arc-shaped positioning grooves 611 that are spaced apart along a first direction and extend along a second direction. The first direction and the second direction are perpendicular to each other. The shape of the arc-shaped positioning grooves 611 is adapted to the outer wall of the retainer. The bottom of the arc-shaped positioning grooves 611 is provided with an anti-rotation limiting block 612 for engaging an assembly process groove of the retainer. The retainer prying mechanism 62 is arranged along the second direction and is used to apply an outward pulling force to the retainer placed in the arc-shaped positioning grooves 611 to widen its gap. This mechanism, by setting multiple arc-shaped positioning grooves 611 and anti-rotation limiting blocks 612, can achieve parallel positioning and fixation of multiple cages, preventing them from rotating during assembly. The cage opening mechanism 62 on both sides can reliably widen the gap of the cage by applying precise and symmetrical outward pulling force to the assembly process grooves on both sides of the cage, creating the necessary conditions for the smooth installation of the main rod. Its structural design ensures the stability and centering of the flaring process, avoiding damage or skewing of the cage.

[0027] like Figure 6 As shown, each retainer opening mechanism 62 includes a first base 620, a first linear module 621, a plate 622, multiple swing blocks 623, and multiple telescopic cylinders 624; the first linear module 621 is fixedly mounted on the top of the first base 620; the plate 622 is fixedly mounted on the movable block of the first linear module 621 and is driven by the first linear module 621 to move back and forth in the second direction; the number of swing blocks 623 is twice the number of arc-shaped positioning slots 611, and one end of each swing block 623 is rotatably mounted through a first rotating joint. At the top of the plate 622, the other end of each swing block 623 extends toward the corresponding arc-shaped positioning groove 611 and the end is bent downward to form a pull part 6231. The pull part 6231 is provided with a snap-fit ​​part 6232 for snapping into the cage assembly process groove. The number of telescopic cylinders 624 is the same as the number of swing blocks 623. The cylinder body of each telescopic cylinder 624 is hinged to the top of the plate 622 at the end away from the arc-shaped positioning groove 611 through a hinge seat. Its piston rod is rotatably connected to the other end of the corresponding swing block 623 through a second rotating joint. After applying this structure, the first linear module 621 drives the flat plate 622 and all its components to move closer to or further away from the cage positioning seat 61. When the cage needs to be pried open, the piston rod of the telescopic cylinder 624 extends and pushes the other end of the swing block 623 through the second rotary joint, causing the swing block 623 to rotate around the first rotary joint, thereby causing the end locking part 6232 to engage with and pull outward the assembly process groove of the cage. The symmetrical design of multiple swing blocks 623 and telescopic cylinders 624 can simultaneously apply uniform tension to both sides of multiple cages, ensuring balanced flaring force and avoiding excessive local stress that could damage the cage.

[0028] like Figure 2 and Figure 7As shown, the assembly positioning mechanism 71 includes a second turntable 711, a second cam divider 712, an intermediate fixing mechanism, and multiple peripheral fixing mechanisms 714. The second turntable 711 is located on one side of the assembly execution mechanism 72. The second cam divider 712 is supported at the bottom of the second turntable 711 and is used to drive the second turntable 711 to rotate intermittently. The intermediate fixing mechanism is a third pneumatic gripper 713 fixedly mounted with its gripping end facing upward at the center of the top surface of the second turntable 711. The third pneumatic gripper 713 is used to grip the main rod of the first assembly. Multiple peripheral fixing mechanisms 714 are circumferentially distributed on the top of the second turntable 711 and correspond to the assembly process of the cage of the first assembly. The slot is configured such that each peripheral fixing mechanism 714 includes a first lifting cylinder 7141, a first horizontal pushing cylinder 7142, a mounting base 7143, and a clamping block 7144. The piston rod of the first lifting cylinder 7141 is fixedly mounted on the second turntable 711 with its piston rod facing upward and is located on the periphery of the third pneumatic gripper 713. The first horizontal pushing cylinder 7142 is fixed to the piston rod of the first lifting cylinder 7141 through the mounting base 7143 and extends horizontally toward the third pneumatic gripper 713. The clamping block 7144 is fixed to the piston rod of the first horizontal pushing cylinder 7142, and its extended end is provided with a snap-in part 71440. The snap-in part 71440 is used to correspondingly snap into the assembly process slot of the retainer of the first assembly.This mechanism drives the second turntable 711 to perform precise intermittent rotation through the second cam divider 712, enabling multiple rod slots on the first assembly to stop sequentially and accurately at preset assembly positions. This achieves multi-position cyclic flow and precise positioning. The intermediate fixing mechanism uses a third pneumatic gripper 713 to firmly clamp the main rod from below the first assembly, providing a stable center reference. Simultaneously, the peripheral fixing mechanism 714, through the coordinated action of the first lifting cylinder 7141 and the first pushing cylinder 7142, drives the locking part 71440 on the clamping block 7144 to precisely embed and clamp the assembly process slots on both sides of the retainer, thereby applying constraint forces from both the axial and circumferential directions of the main rod, forming a three-dimensional clamping system. This design achieves complete fastening of the first assembly (main rod and retainer), effectively eliminating possible axial movement, circumferential rotation, or elastic deformation of the assembly during subsequent rod pressing, providing crucial support for the accurate and smooth pressing of the rod. The necessary stability directly guarantees the assembly accuracy of the final product. Furthermore, designing the peripheral fixing mechanism 714 as a liftable type is a key design feature. When a rod needs to be assembled in a specific rod slot of the first assembly, the control system controls the first lifting cylinder 7141 to move, causing the clamping blocks 7144, which are inserted into the assembly process slots on both sides of the target slot, to descend as a whole and actively exit the assembly area. This design intelligently avoids spatial interference between the peripheral fixing mechanism 714 and the assembly execution mechanism 72 (such as the rod pressing head), ensuring a smooth and unobstructed assembly process and enabling sequential and collaborative operation of different execution mechanisms at the same workstation. In summary, this assembly positioning mechanism 71 not only solves the problem of stable fixing of complex assemblies through multi-degree-of-freedom clamping but also solves the spatial interference problem during multi-mechanism collaborative operation through a liftable avoidance design. It combines high precision, high stability, and high flexibility, making it one of the core devices ensuring the efficient and reliable operation of the entire production line.

[0029] like Figure 2 , Figure 7 and Figure 8As shown, the assembly actuator 72 includes a crossbeam 721, a fourth pneumatic gripper 722 and a translation drive mechanism 724 mounted on the crossbeam 721, and a material handling mechanism 723 mounted at the rear end of the crossbeam 721. The crossbeam 721 is laterally arranged between the first turntable 41 and the second turntable 711. The translation drive mechanism 724 includes a second linear module 7241, a sliding seat 7242, a first slider rail assembly 7243, and a second push cylinder 7244. The second linear module 7241 is laterally distributed on the crossbeam 721. The sliding seat 7242 is slidably mounted on the crossbeam 721 via the first slider rail assembly 7243 and is fixedly connected to the movable block of the second linear module 7241. The moving base 7242 is provided with a second flat-push cylinder 7244 and a fourth pneumatic gripper 722. The fourth pneumatic gripper 722 is mounted on the piston rod of the second flat-push cylinder 7244 through a first fixed base 7201, and its gripping end is set towards the middle of the second turntable 711. The fourth pneumatic gripper 722 is used to grip the rod that is already at the second angle and put it into the rod slot of the retainer of the first assembly. The second flat-push cylinder 7244 is used to drive the fourth pneumatic gripper 722 to move in a direction close to or away from the middle of the second turntable 711. The material picking mechanism 723 is set close to the first turntable 41 and is used to transfer the rod that is already at the second angle on the first turntable 41 to the gripping end of the fourth pneumatic gripper 722. After applying this structure, the assembly actuator 72 drives the sliding seat 7242 through the second linear module 7241, which in turn drives the fourth pneumatic gripper 722 on it to achieve a large-stroke, high-precision reciprocating lateral movement between the first turntable 41 (the rod attitude adjustment station) and the second turntable 711 (the assembly positioning station), efficiently completing the transfer task of the rod between the two stations. When the fourth pneumatic gripper 722 moves the rod to the front of the first assembly on the second turntable 711, the second flat-push cylinder 7244 precisely drives the fourth pneumatic gripper 722 to move forward or backward radially (i.e., towards or away from the center of the second turntable 711), ultimately pressing the rod precisely into the currently aligned rod slot on the retainer of the first assembly. This division of labor design, where "long-distance lateral movement is handled by the module and precise positioning and pressing are performed by the cylinder," takes into account both the execution range and assembly accuracy, reliably realizing the automatic material picking, transfer, and assembly operations of the rod.

[0030] like Figure 2 , Figure 7 and Figure 8As shown, the material handling mechanism 723 includes a first upright frame 7231 and a second lifting cylinder 7232, a third horizontal pushing cylinder 7233, and a fifth pneumatic gripper 7234 mounted on the first upright frame 7231. The first upright frame 7231 is located at one end of the horizontal frame 721 near the first turntable 41. The second lifting cylinder 7232 is located on the upper part of the first upright frame 7231 with its piston rod vertically downward. The third horizontal pushing cylinder 7233 is fixed to the lower end of the piston rod of the second lifting cylinder 7232 by a second fixed seat 7202. The fifth pneumatic gripper 7234... The piston rod of the third flat-push cylinder 7233 is fixed to the third fixed seat 7203. The second lifting cylinder 7232 is used to drive the fifth pneumatic gripper 7234 to move up and down above the first turntable 41. The third flat-push cylinder 7233 is used to drive the fifth pneumatic gripper 7234 to move towards the fourth pneumatic gripper 722. The gripping end of the fifth pneumatic gripper 7234 is set towards the gripping end of the fourth pneumatic gripper 722 and is used to grip the rod that is already at the second angle from the first turntable 41 and transfer it to the gripping end of the fourth pneumatic gripper 722. This mechanism drives the fifth pneumatic gripper 7234 through the second lifting cylinder 7232 and the third horizontal pushing cylinder 7233, realizing the compound movement of the fifth pneumatic gripper 7234 in the vertical and horizontal directions. It accurately completes the entire set of actions of grabbing the rod from the first turntable 41, lifting, translating and reliably placing the rod into the fourth pneumatic gripper 722. As a key link connecting the rod attitude adjustment mechanism 4 and the assembly execution mechanism 72, it realizes the stable and reliable automatic handover and precise positioning of the rod between the two modules, ensuring the continuity and stability of the assembly process.

[0031] like Figure 2 , Figure 9 and Figure 10As shown, the nut assembly mechanism 9 includes a second base 91, a second upright 92, a nut fixing mechanism 93, a rotary assembly mechanism 94, and a lifting drive mechanism 95. The second base 91 is located within the working area of ​​the fourth robot 104. The second upright 92 and the nut fixing mechanism 93 are arranged side by side on the second base 91. The rotary assembly mechanism 94 and the lifting drive mechanism 95 are arranged on the second upright 92. The lifting drive mechanism 95 is used to drive the rotary assembly mechanism 94 to move up and down above the nut fixing mechanism 93. The nut fixing mechanism 93 includes a fixing frame 931, a finger cylinder 932, and a pair of nut grippers 933 fixedly mounted on the gripping end of the finger cylinder 932 for gripping the nut. The fixing frame 931 is fixedly mounted on the second base 91, and the finger cylinder 932 is fixedly mounted on the fixing frame 931 and is used to drive the pair of nut grippers 933 to open and close horizontally. The rotary assembly mechanism 94 includes a rotary motor 941 and a sixth pneumatic gripper 942. The lifting drive mechanism 95 is used to drive the rotary assembly mechanism 94 to move up and down above the nut fixing mechanism 93. Mechanism 95 includes a first movable seat 951, a second movable seat 952, a second slider rail assembly 953, a third slider rail assembly 954, a third lifting cylinder 955, and a fourth lifting cylinder 956. The first movable seat 951 is slidably mounted on the second upright 92 via the second slider rail assembly 953. The third lifting cylinder 955 is fixedly mounted on the upper part of the second upright 92 and is used to drive the first movable seat 951 to move up and down. The second movable seat 952 is slidably mounted on the first movable seat 951 via the third slider rail assembly 954. The fourth lifting cylinder 956 is fixedly mounted on the first movable seat 951 and is used to drive the second movable seat 952 to move up and down. A rotary motor 941 is fixedly mounted on the second movable seat 952. The output end of the rotary motor 941 is fixedly connected to the sixth pneumatic gripper 942 with its downward facing end. The clamping end of the sixth pneumatic gripper 942 is vertically downward and faces the clamping area of ​​the nut gripper 933, and is used to clamp the main rod of the second assembly. After applying this structure, the fourth robot 104 transfers the second assembly to the nut assembly mechanism 9, and the sixth pneumatic gripper 942 then firmly clamps the upper end of the main rod of the second assembly, providing a stable center of rotation. At the same time, the fourth robot 104 transfers the nut to the nut fixing mechanism 93, and a pair of nut grippers 933 driven by the finger cylinder 932 precisely clamp and fix the nut. Subsequently, the third lifting cylinder 955 drives the entire rotating assembly mechanism 94 to descend smoothly, so that the threads at the lower ends of all the rods of the second assembly held by the sixth pneumatic gripper 942 are simultaneously and accurately aligned with the threaded holes of the nut.Next, the rotary motor 941 starts, driving the sixth pneumatic gripper 942 and the second assembly to rotate as a whole. At the same time, the fourth lifting cylinder 956 provides precise feed motion, driving the sixth pneumatic gripper 942 and the second assembly to move down as a whole, thereby synchronously and smoothly screwing multiple rods into the nut, completing the final assembly. The core advantage of this mechanism lies in its unique "clamping the main rod and rotating the assembly" assembly strategy. By driving the entire assembled rod assembly to rotate and feed, rather than rotating the nut individually in the traditional way, it ensures that the threads of all rods and the threads of the nut can maintain precise phase synchronization, achieving true synchronous meshing. This method effectively avoids problems such as meshing jamming, thread damage, or decreased assembly accuracy caused by misalignment of individual rod threads, significantly improving the assembly quality, consistency, and reliability of the final product.

[0032] Although the disclosure is as stated above, the scope of protection of this disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this utility model.

Claims

1. An automated assembly line for ball screw pairs, comprising a first robot (101), a second robot (102), a third robot (103), and a fourth robot (104), characterized in that, Also includes: Main rod feeding mechanism (1), main rod posture adjustment mechanism (2), traveling rod feeding mechanism (3), traveling rod posture adjustment mechanism (4), cage feeding mechanism (5), main rod assembly mechanism (6), traveling rod assembly mechanism (7), nut feeding mechanism (8) and nut assembly mechanism (9); The rod loading mechanism (3) and the rod posture adjustment mechanism (4) are arranged in the working area of ​​the first robot (101). The first robot (101) is used to transfer the rod from the rod loading mechanism (3) to the rod posture adjustment mechanism (4). The rod posture adjustment mechanism (4) is used to drive the rod to rotate around its axis to a set second angle. The cage loading mechanism (5) and the main rod assembly mechanism (6) are arranged within the working range of the third robot (103). The third robot (103) is used to transfer the cage from the cage loading mechanism (5) to the main rod assembly mechanism (6), and drive the cage to rotate around its axis to a position with the gap facing upwards before positioning it at the assembly station of the main rod assembly mechanism (6). The main rod assembly mechanism (6) is used to apply outward pulling force to the assembly process grooves on both sides of the gap of the cage to widen the gap of the cage. The main rod feeding mechanism (1), the main rod posture adjustment mechanism (2), the main rod assembly mechanism (6), and the rod assembly mechanism (7) are arranged in the working area of ​​the second robot (102). The second robot (102) is used to transfer the main rod from the main rod feeding mechanism (1) to the main rod posture adjustment mechanism (2). The main rod posture adjustment mechanism (2) is used to drive the main rod to rotate around its axis to a set first angle. The second robot (102) is also used to transfer the main rod at the first angle from the main rod attitude adjustment mechanism (2) to the main rod assembly mechanism (6), assemble it with the cage with the enlarged gap to form a first assembly, and transfer the first assembly to the rod assembly mechanism (7). The rod assembly mechanism (7) includes an assembly positioning mechanism (71) and an assembly execution mechanism (72). The assembly positioning mechanism (71) is located within the working range of the second robot (102) and is used to receive and fix the first assembly and drive the assembly to rotate intermittently around the main rod axis so that the rod slots on the assembly holder are sequentially aligned with the execution end of the assembly execution mechanism (72). The assembly execution mechanism (72) is movably disposed between the assembly positioning mechanism (71) and the rod posture adjustment mechanism (4) and is used to transfer multiple rods that are already at the second angle from the rod posture adjustment mechanism (4) to the assembly positioning mechanism (71) and assemble them one by one into the corresponding rod slots on the holder of the first assembly to form the second assembly. The nut feeding mechanism (8), the nut assembly mechanism (9), and the assembly positioning mechanism (71) are arranged within the working range of the fourth robot (104). The fourth robot (104) is used to transfer the second assembly at the assembly positioning mechanism (71) and the nut at the nut feeding mechanism (8) to the nut assembly mechanism (9). The nut assembly mechanism (9) is used to screw the nut into the outer thread of the rod of the second assembly to assemble the final product.

2. The automatic assembly line for ball screw pairs according to claim 1, characterized in that: The main rod posture adjustment mechanism (2) includes a first clamping rotation mechanism (21) and a first vision detection mechanism (22); the first clamping rotation mechanism (21) is located in the working area of ​​the second robot (102) and includes a base (211), a first servo motor (212) and a first pneumatic gripper (213); the first servo motor (212) is fixedly installed on the base (211) and its output shaft is vertically upward; the first pneumatic gripper (213) is fixedly installed on the output shaft of the first servo motor (212) and its gripping end is upward, and is used to grip the main rod; the first vision detection mechanism (22) includes a photographing unit; the photographing unit includes a first side frame (221) and a camera (222), the first side frame (221) is located on one side of the base (211), the camera (222) is installed on the first side frame (221) and its lens faces the first pneumatic gripper (213), and is used to photograph and detect the main rod.

3. The automatic assembly line for ball screw pairs according to claim 2, characterized in that: The first visual inspection mechanism (22) further includes a supplementary lighting unit; the supplementary lighting unit includes a second side frame (223), a light source (224), a reflector (225) and a push cylinder (226). The second side frame (223) is located on the other side of the base (211). The reflector (225) is fixedly installed on the second side frame (223). The light source (224) is installed on the first side frame (221) through the push cylinder (226) and can move back and forth along the optical axis of the lens of the camera (222).

4. The automatic assembly line for ball screw pairs according to claim 1, characterized in that: The lever posture adjustment mechanism (4) includes a first turntable (41), a first cam divider (42), a second vision detection mechanism (43), and a second clamping and rotating mechanism (44). The top surface of the first turntable (41) has multiple lever adjustment stations spaced circumferentially. Each lever adjustment station is equipped with a bracket (411), a second pneumatic gripper (412), and a gripper clamping mechanism (413). The bracket (411) is fixedly mounted on the top of the first turntable (41). The second pneumatic gripper (412) is rotatably mounted on the bracket (411), with its gripping end facing upwards and used to grip the rod; the gripper clamping mechanism (413) is arranged on both sides of the second pneumatic gripper (412) and is movably mounted on the bracket (411), used to clamp the second pneumatic gripper (412) to restrict its rotation; the second visual inspection mechanism (43) is located on one side of the first turntable (41) and corresponds to One of the aforementioned rod adjustment stations is set up and used to photograph and detect the rod at the station; the first cam divider (42) is supported at the bottom of the first turntable (41) and is used to drive the first turntable (41) to rotate intermittently so that each of the rod adjustment stations rotates sequentially to the second vision detection mechanism (43); a first lifting mechanism (45) is provided below the rod adjustment station at a position corresponding to the second vision detection mechanism (43), and a second clamping rotation mechanism (44) is set on the first lifting mechanism (45). The first lifting mechanism (45) is used to drive the second clamping rotation mechanism (44) to move up and down within the rod adjustment station, and the second clamping rotation mechanism (44) is used to clamp the lower part of the second pneumatic gripper (412) to drive it to rotate; a lifting channel (410) is provided on the first turntable (41) in each rod adjustment station for the clamping end of the second clamping rotation mechanism (44) to pass through.

5. The automatic assembly line for ball screw pairs according to claim 1, characterized in that: The main rod assembly mechanism (6) includes a cage positioning seat (61) and a pair of cage opening mechanisms (62) symmetrically arranged on both sides of the cage positioning seat (61). The cage positioning seat (61) is located within the working range of the second robot (102). Its top is recessed and has at least two arc-shaped positioning grooves (611) that are spaced apart along a first direction and extend along a second direction. The first direction and the second direction are perpendicular to each other. The shape of the arc-shaped positioning groove (611) is adapted to the outer wall of the cage. The bottom of the arc-shaped positioning groove (611) is provided with an anti-rotation limiting block (612) for engaging an assembly process groove of the cage. The cage opening mechanism (62) is arranged along the second direction and is used to apply an outward pulling force to the cage placed in the arc-shaped positioning groove (611) to widen its gap.

6. The automatic assembly line for ball screw pairs according to claim 5, characterized in that: Each of the retainer opening mechanisms (62) includes a first base (620), a first linear module (621), a plate (622), multiple swing blocks (623), and multiple telescopic cylinders (624); the first linear module (621) is fixedly mounted on the top of the first base (620); the plate (622) is fixedly mounted on the movable block of the first linear module (621) and is driven by the first linear module (621) to move back and forth along the second direction; the number of swing blocks (623) is twice the number of arc-shaped positioning grooves (611), and one end of each swing block (623) is rotatably mounted through a first rotating joint. At the top of the plate (622), the other end of each swing block (623) extends toward the corresponding arc-shaped positioning groove (611) and the end is bent downward to form a pull part (6231). The pull part (6231) is provided with a snap-fit ​​part (6232) for snapping into the cage assembly process groove. The number of telescopic cylinders (624) is the same as the number of swing blocks (623). The cylinder body of each telescopic cylinder (624) is hinged to the top of the plate (622) at the end away from the arc-shaped positioning groove (611) through a hinge seat. Its piston rod is rotatably connected to the other end of the corresponding swing block (623) through a second rotating joint.

7. The automatic assembly line for ball screw pairs according to claim 4, characterized in that: The assembly positioning mechanism (71) includes a second turntable (711), a second cam divider (712), an intermediate fixing mechanism, and multiple peripheral fixing mechanisms (714). The second turntable (711) is located on one side of the assembly execution mechanism (72). The second cam divider (712) is supported on the bottom of the second turntable (711) and is used to drive the second turntable (711) to rotate intermittently. The intermediate fixing mechanism is a third pneumatic gripper (713) with its gripping end facing upward and fixedly disposed in the middle of the top surface of the second turntable (711). The third pneumatic gripper (713) is used to grip the main rod of the first assembly. Multiple peripheral fixing mechanisms (714) are circumferentially distributed on the top of the second turntable (711) and are provided with corresponding assembly process grooves for the retainer of the first assembly. Each of the peripheral fixing mechanisms (714) includes a first lifting cylinder (7141), a first flat-push cylinder (7142), a mounting base (7143), and a clamping block (7144). The piston rod of the first lifting cylinder (7141) is fixedly mounted on the second turntable (711) with its piston rod facing upward and located on the periphery of the third pneumatic gripper (713). The first flat-push cylinder (7142) is fixed to the piston rod of the first lifting cylinder (7141) through the mounting base (7143) and extends horizontally toward the third pneumatic gripper (713). The clamping block (7144) is fixed to the piston rod of the first flat-push cylinder (7142), and its extended end is provided with a snap-in part (71440). The snap-in part (71440) is used to be snapped into the assembly process groove of the retainer of the first assembly.

8. The automatic assembly line for ball screw pairs according to claim 7, characterized in that: The assembly execution mechanism (72) includes a crossbeam (721), a fourth pneumatic gripper (722) and a translation drive mechanism (724) disposed on the crossbeam (721), and a material handling mechanism (723) disposed at the rear end of the crossbeam (721); the crossbeam (721) is arranged laterally between the first turntable (41) and the second turntable (711), and the translation drive mechanism (724) includes a second linear module (7241), a sliding seat (7242), a first slider rail assembly (7243), and a second horizontal push cylinder (7244). The second linear module (7241) is laterally distributed on the crossbeam (721), and the sliding seat (7242) is slidably disposed on the crossbeam (721) through the first slider rail assembly (7243) and fixedly connected to the movable block of the second linear module (7241). The sliding seat (7242) is provided with the second flat-push cylinder (7244) and the fourth pneumatic gripper (722). The fourth pneumatic gripper (722) is mounted on the piston rod of the second flat-push cylinder (7244) through the first fixed seat (7201), and its gripping end is set towards the middle of the second turntable (711). The fourth pneumatic gripper (722) is used to grip the rod that is already at the second angle and put it into the rod slot of the retainer of the first assembly. The second flat-push cylinder (7244) is used to drive the fourth pneumatic gripper (722) to move in a direction close to or away from the middle of the second turntable (711). The material picking mechanism (723) is set close to the first turntable (41) and is used to transfer the rod that is already at the second angle on the first turntable (41) to the gripping end of the fourth pneumatic gripper (722).

9. The automatic assembly line for ball screw pairs according to claim 8, characterized in that: The material handling mechanism (723) includes a first upright (7231) and a second lifting cylinder (7232), a third horizontal pushing cylinder (7233), and a fifth pneumatic gripper (7234) mounted on the first upright (7231). The first upright (7231) is located at one end of the crossbeam (721) near the first turntable (41). The second lifting cylinder (7232) is located on the upper part of the first upright (7231) with its piston rod vertically downward. The third horizontal pushing cylinder (7233) is fixed to the lower end of the piston rod of the second lifting cylinder (7232) by a second fixed seat (7202). The fifth pneumatic gripper (7234) The piston rod of the third flat-push cylinder (7233) is fixed by the third fixed seat (7203). The second lifting cylinder (7232) is used to drive the fifth pneumatic gripper (7234) to move up and down above the first turntable (41). The third flat-push cylinder (7233) is used to drive the fifth pneumatic gripper (7234) to move towards the fourth pneumatic gripper (722). The gripping end of the fifth pneumatic gripper (7234) is set towards the gripping end of the fourth pneumatic gripper (722) and is used to grip the rod that is already at the second angle from the first turntable (41) and transfer it to the gripping end of the fourth pneumatic gripper (722).

10. The automatic assembly line for ball screw pairs according to claim 8, characterized in that: The nut assembly mechanism (9) includes a second base (91), a second upright (92), a nut fixing mechanism (93), a rotating assembly mechanism (94), and a lifting drive mechanism (95). The second base (91) is located in the working area of ​​the fourth robot (104). The second upright (92) and the nut fixing mechanism (93) are arranged side by side on the second base (91). The rotating assembly mechanism (94) and the lifting drive mechanism (95) are arranged on the second upright (92). The lifting drive mechanism (95) is used to drive the rotating assembly mechanism (94) to move up and down above the nut fixing mechanism (93). The nut fixing mechanism (93) includes a fixing frame (931), a finger cylinder (932), and a pair of nut grippers (933) fixedly disposed on the gripping end of the finger cylinder (932) for gripping the nut. The fixing frame (931) is fixedly disposed on the second base (91), and the finger cylinder (932) is fixedly disposed on the fixing frame (931) and is used to drive the pair of nut grippers (933) to open and close horizontally. The rotary assembly mechanism (94) includes a rotary motor (941) and a sixth pneumatic gripper (942). The lifting drive mechanism (95) includes a first movable seat (951), a second movable seat (952), a second slider slide rail assembly (953), a third slider slide rail assembly (954), a third lifting cylinder (955), and a fourth lifting cylinder (956). The first movable seat (951) is connected to the second slider slide rail assembly (952). 953) Slidingly mounted on the second upright (92), the third lifting cylinder (955) is fixedly mounted on the upper part of the second upright (92) and is used to drive the first movable seat (951) to move up and down, the second movable seat (952) is slidably mounted on the first movable seat (951) through the third slider rail assembly (954), the fourth lifting cylinder (956) is fixedly mounted on the first movable seat (951) and is used to drive the second movable seat (952) to move up and down, the rotary motor (941) is fixedly mounted on the second movable seat (952), the output end of the rotary motor (941) is fixedly connected to the sixth pneumatic gripper (942) with the output end facing down, the gripping end of the sixth pneumatic gripper (942) is vertically downward and faces the gripping area of ​​the nut gripper (933), and is used to clamp the main rod of the second assembly.

Images