Multi-position adaptive bolt tightening device

Abstract

The multi-posture adaptive bolt fastening device of the present invention belongs to the field of bolt fastening tools, and its purpose is to improve its adaptability. It includes a displacement base, a right arm and a left arm; the displacement base includes a frame and a bidirectional screw; the two ends of the bidirectional screw are movably installed in the inner cavity of the frame, the left end and the right section of the bidirectional screw are both threadedly connected with a moving nut, and the top of the moving nut is connected with a steering gear; the steering gear at the left end of the bidirectional screw is connected to the left arm to drive the left arm to rotate; the steering gear at the right end of the bidirectional screw is connected to the right arm to drive the right arm to rotate. Through the setting of the bidirectional screw and the steering gear, the right arm and the left arm can be driven to change their postures, and it has good adaptability to the situation of multi-space and multi-posture distribution of bolts in contact maintenance operations. The steering gear drives the right arm and the left arm to rotate, which is conducive to movement in a narrow range and is suitable for operation scenes with limited working space.

Description

Technical Field

[0001] The invention belongs to the field of bolt fastening tools, in particular to a multi-posture adaptive bolt fastening device. Background Art

[0002] As a key equipment of the railway traction power supply system, the performance of the contact network directly determines the current-collecting quality of the pantograph of the electric locomotive, and affects the running speed and safety of the train. The maintenance work of the contact network mainly includes the adjustment of the height of the conductor, the adjustment of the pull-out value, the tightening of the wrist arm bolts, etc. The bolt tightening and loosening operations account for a large proportion of the operation process. At present, the maintenance and repair of the contact network of the electrified railway relies on manual work. Manual maintenance has problems such as low maintenance efficiency, high labor intensity, poor operating environment, and unsafe high-altitude operations. Therefore, according to the existing operation process and process requirements, it is very urgent to carry out targeted design and product development work through automation and intelligent technical means. The present invention designs and develops a multi-posture adaptive bolt tightening device for the contact network, which automatically tightens and loosens bolts of multiple spatial postures and multiple sizes encountered in the maintenance operation of the contact network, so as to reduce the workload of personnel, reduce the labor intensity of the operation, and improve the accuracy and quality of the maintenance operation. It is of great significance to the development of intelligent equipment in the maintenance field of the rail transit industry.

[0003] The Chinese invention patent application with application number CN202211590227 discloses a transmission line drain plate bolt fastening device, which relates to the field of power grid bolt fastening technology, including a support seat, a first transmission mechanism is provided on the support seat, a main shaft is provided for rotation, and a floating seat is provided for sliding, a second transmission mechanism is provided on the floating seat, the first transmission mechanism and the second transmission mechanism are arranged in parallel and the two are connected by the main shaft transmission, and the floating seat is connected to the convex block adjustment mechanism provided at one end of the support seat; the first transmission mechanism and the second transmission mechanism are respectively provided with corresponding first sleeves and second sleeves, and the first sleeve and the second sleeve are connected by the first transmission mechanism, the main shaft, and the second transmission mechanism, and the first transmission mechanism or the second transmission mechanism or the main shaft is detachably connected to the ratchet wrench. The device has a light structure and is labor-saving to operate, and the clamping process is more convenient and efficient, which solves the problem that the heavy weight of the fastening device in the prior art leads to labor-intensive operation and inconvenient clamping. However, it only has one tightening posture, the end sleeve is a rigid output, has no compensation function, no visual perception system, lacks torque detection function, and the process of the sleeve approaching and sleeved on the bolt relies on manual operation, with a low degree of automation, and can only achieve a labor-saving effect.

[0004] The Chinese invention patent with publication number CN114473469A (such as Figure 2) discloses a bolt fastening device, robot and method for drain plate of overhead transmission line, wherein the device mentioned comprises a displacement part, a flexible sleeve part and a nut fastening part; the flexible sleeve part is on the bolt side of the drain plate, the nut fastening part is on the nut side of the drain plate, and the flexible sleeve part and the nut fastening part are mounted opposite to each other on both sides of the displacement part; the displacement part is used to drive the flexible sleeve part and the nut fastening part to move toward the middle at the same time, respectively approaching the head and nut of the drain plate bolt to be fastened, so as to achieve the purpose of fastening the drain plate bolt. However, when it is screwed, only one side has power, and the other side needs to rely on the robot arm to adjust the position to cover the nut, and only one side has flexible compensation, which makes it inconvenient to align the bolts, and there is also no visual system and torque detection function.

[0005] Generally speaking, existing bolt tightening devices only have one tightening posture, that is, the scenario of tightening bolts on both sides. The requirements of tightening bolts on one side or both sides during contact network maintenance operations cannot be met at the same time. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of low applicability of existing bolt fastening devices due to single fastening posture, and to provide a multi-posture adaptable bolt fastening device to improve its adaptability.

[0007] The technical solution adopted by the present invention is: a multi-posture adaptive bolt fastening device, including a displacement base, a right arm wrist and a left arm wrist; the displacement base includes a frame and a bidirectional screw rod; the frame is a shell structure with an opening on the top, and the left and right ends of the bidirectional screw rod are movably installed in the inner cavity of the frame, the left end of the bidirectional screw rod is threadedly connected with a movable nut, and the top end of the movable nut is connected with a steering gear; the right end of the bidirectional screw rod is threadedly connected with a movable nut, and the top end of the movable nut is connected with a steering gear; an arm wrist driving motor for driving the bidirectional screw rod to move forward and reverse is arranged at the bottom of the frame; the steering gear at the left end of the bidirectional screw rod is transmission-connected with the left arm wrist to drive the left arm wrist to rotate; the steering gear at the right end of the bidirectional screw rod is transmission-connected with the right arm wrist to drive the right arm wrist to rotate.

[0008] Furthermore, a connecting plate is installed on the top of the movable nut; the connecting plate includes a bottom plate and side plates located on both sides of the bottom plate, and is surrounded by the bottom plate and the side plates to form a slot; the servo is clamped in the slot of the connecting plate.

[0009] Furthermore, the right arm and the left arm adopt the same structure, including a reducer, a stroke shaft, a sleeve, a wrench drive motor and a bracket for supporting the reducer and the stroke shaft; the sleeve includes a sleeve portion for fitting a nut and a connecting portion for installation along its axial direction; the input shaft of the reducer is connected to the wrench drive motor, the output shaft of the reducer is connected to the input end of the stroke shaft through a universal coupling, and the output end of the stroke shaft is connected to the connecting portion of the sleeve; a compression spring arranged axially along the stroke shaft is provided between the stroke shaft and the sleeve; a radial error compensation structure for driving the stroke shaft to float radially is provided at one end of the stroke shaft adjacent to the sleeve.

[0010] Furthermore, the bracket includes a wrist shell and an arm shell, the wrist shell is horizontally arranged, the arm shell extends obliquely upward and is connected to the wrist shell at the top, and the hollow inner cavity of the wrist shell is connected to the hollow inner cavity of the arm shell; the stroke shaft is arranged in the wrist shell, and the reducer is arranged in the arm shell.

[0011] Furthermore, the stroke shaft includes, along its axial direction, a segment 1 adjacent to the universal coupling and a segment 2 adjacent to the sleeve; the segment 1 is a solid shaft; the segment 2 is coaxial with the segment and has a diameter larger than that of the segment 1; the segment 2 is a hollow shaft, including an annular side wall and a bottom wall connected to the segment 2; a long strip-shaped slide groove extending axially along the segment 2 and penetrating the open end of the segment 2 is provided on the inner surface of the hollow area of ​​the segment 2, an annular limit ring is provided in the hollow area of ​​the segment 2, a slider is provided on the outer peripheral surface of the limit ring, the slider is movably connected in the slide groove along the axial direction of the segment 2, and a limit structure for limiting the limit ring from detaching from the segment 2 is provided at the open end of the segment 2; the compression spring is provided in the hollow area of ​​the segment 2, one end of which abuts against the bottom wall of the segment 2, and the other end abuts against the limit ring.

[0012] Furthermore, the limiting structure is a limiting screw that extends through the side wall of segment two to the hollow area of ​​segment two, and the limiting screw is limited against the outer end surface of the slider; the slider is a sliding key, and the sliding groove is a long key groove. A short key groove that is compatible with the sliding key is provided on the outer peripheral surface of the limiting ring, and the slider is installed between the short key groove and the long key groove.

[0013] Furthermore, the output end of the stroke shaft is connected to the connecting portion of the sleeve via a connecting shaft; one end of the connecting shaft is fixedly connected to the limit ring, and the other end is detachably connected to the connecting portion of the sleeve.

[0014] Furthermore, the radial error compensation structure includes a copper sleeve and several tension springs evenly distributed on the copper sleeve along the circumferential direction of the copper sleeve; the copper sleeve is sleeved on the outer surface of segment two of the stroke shaft, one end of the tension spring is connected to the outer surface of the copper sleeve, and the other end is connected to the inner surface of the wrist shell.

[0015] Furthermore, a monocular camera facing the side where the sleeve is located is installed on the top of the wrist shell.

[0016] Furthermore, a torque sensor is provided, which is located in the arm housing and has a top end connected to the input end of the reducer.

[0017] The beneficial effects of the present invention are as follows: the multi-posture adaptive bolt tightening device disclosed in the present invention can drive the right arm wrist and the left arm wrist to change their postures through the setting of the bidirectional screw and the steering gear, and has good adaptability to the situation of multi-space and multi-posture distribution of bolts in contact maintenance operations, and can not only meet the use of contact network maintenance operation scenarios, but also complete bolt tightening operations in various other complex situations. The right arm wrist and the left arm wrist are driven by the steering gear to perform rotational motion, and the right arm wrist and the left arm wrist simulate the movement of the arm wrist joint, which is conducive to their movement within a narrow range, and is suitable for operation scenarios with limited working space. The sleeve can be detachably installed, and can adapt to bolts of multiple specifications by replacing the sleeve.

[0018] Through the setting of monocular camera and torque sensor, sensor technology and visual perception system are integrated to achieve the goal of intelligent identification of positioning bolts. At the same time, it can automatically loosen or tighten bolts, improve work efficiency, reduce labor intensity and improve work accuracy.

[0019] The flexible adaptive floating design of the sleeve at the end can compensate for the bolt and alignment errors. When aligning close to the bolt head or nut, the existence of this technology will reduce the alignment time and reduce the alignment accuracy requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 It is a cross-sectional view of the displacement base;

[0022] Figure 3 It is a cross-sectional view of the right arm / left arm structure;

[0023] Figure 4 It is a schematic diagram of the sleeve end;

[0024] Figure 5 It is the stroke axis section view;

[0025] Figure 6 is a schematic diagram of the connection plate;

[0026] Figure 7 A schematic diagram of the contralateral twisting performed by the present invention;

[0027] Figure 8 This is a schematic diagram of single-side single twisting using the present invention;

[0028] Fig. 9 A schematic diagram of reverse contralateral twisting using the present invention;

[0029] Fig.10 The figure is a schematic diagram of single-side double twisting using the present invention.

[0030] In the figure, displacement base 1, right arm wrist 2, left arm wrist 3, frame 4, servo 5, connecting plate 8, bottom plate 8A, side plate 8B, bidirectional screw 9, movable nut 10, external meshing gear 11, arm wrist drive motor 12, arm housing 13, sleeve 14, connecting shaft 15, compression spring 16, stroke shaft 17, segment one 17A, segment two 17B, slide groove 17B1, limit screw 17B2, limit block 17C, monocular camera 18, universal coupling 19, wrist housing 20, reducer 21, torque sensor 22, copper sleeve 23, tension spring 24. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0032] In the present invention, the terms "top", "top end", "bottom", "bottom end", "left" and "right" indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] Multi-position adaptable bolt fastening device, such as Figure 1 As shown, it includes a displacement base 1, a right arm wrist 2 and a left arm wrist 3.

[0034] like Figure 2 As shown, the displacement base 1 includes a frame 4 and a bidirectional screw 9. The frame 4 is a shell structure with an opening at the top, and the left and right ends of the bidirectional screw 9 are movably installed in the inner cavity of the frame 4. The left end of the bidirectional screw 9 is threadedly connected with a moving nut 10, and the top of the moving nut 10 is connected with a steering gear 5; the right end of the bidirectional screw 9 is threadedly connected with a moving nut 10, and the top of the moving nut 10 is connected with a steering gear 5; an arm drive motor 12 for driving the bidirectional screw 9 to move forward and backward is arranged at the bottom of the frame 4; the steering gear 5 at the left end of the bidirectional screw 9 is connected to the left arm 3 for driving the left arm 3 to rotate; the steering gear 5 at the right end of the bidirectional screw 9 is connected to the right arm 2 for driving the right arm 2 to rotate.

[0035] The multi-posture adaptive bolt fastening device disclosed in the present invention has a right arm wrist 2 and a left arm wrist 3 which act as wrenches for tightening bolts. The actuator can be the jaws of the wrench, which directly clamp the head of the bolt or the nut; or it can be a sleeve, which is directly sleeved on the head of the bolt or on the nut, and then the actuator is rotated to tighten the bolt.

[0036] The bottom of the frame 4 is provided with a mounting flange, which can be installed at the end of the mechanical arm for use. The arm drive motor 12 at the bottom of the frame 4 can be a stepper motor, and the arm drive motor 12 transmits power to the bidirectional screw 9 through a pair of external meshing gears 11. The left and right ends of the bidirectional screw 9 are respectively threaded with a moving nut 10. It should be noted that a servo 5 is installed on the moving nut 10, and the servo 5 is connected to the right arm 2 and the left arm 3. Through the limiting effect of the frame 4, etc., the moving nut 10 in the present invention will not rotate with the rotation of the bidirectional screw 9, but will perform linear motion on the bidirectional screw 9 with the rotation of the bidirectional screw 9. Moreover, with the rotation of the bidirectional screw 9, the moving nuts 10 at both ends move in the opposite direction, that is, when the bidirectional screw 9 rotates forward, the moving nuts 10 at both ends are close to each other; when the bidirectional screw 9 rotates reversely, the moving nuts 10 at both ends are away from each other, so as to achieve the effect of adjusting the distance between the right arm 2 and the left arm 3. Moreover, the steering engine 5 can respectively drive the right arm wrist 2 and the left arm wrist 3 to rotate, so as to adjust the right arm wrist 2 and the left arm wrist 3 to various postures, such as Figure 7 Twist the opposite side as shown, Figure 8 The single-side single twist shown, Fig. 9 The reverse double-sided screwing shown and Fig.10 The single-sided double twist shown can adapt to different working scenarios.

[0037] The bottom end of the servo 5 can be directly connected to the moving nut 10. However, if a conventional nut is directly purchased as the moving nut 10, it is not convenient to connect with the servo 5. If the moving nut 10 is made by yourself, it is inconvenient to make and the cost is high. In order to avoid the above problems, in the present invention, preferably, a connecting plate 8 is installed on the top of the moving nut 10; Figure 6 As shown, the connecting plate 8 includes a bottom plate 8A and side plates 8B located on both sides of the bottom plate 8A, and the bottom plate 8A and the side plates 8B are surrounded to form a slot; the servo 5 is clamped in the slot of the connecting plate 8. In this structure, conventional nuts can be directly purchased as movable nuts 10, and the connecting plate 8 can be fixed by welding or other methods, and the manufacturing of the connecting plate 8 is simple. Moreover, the servo 5 is clamped in the slot, which is conducive to ensuring the stability of the installation of the servo 5.

[0038] Preferably, Figure 3As shown, the right arm wrist 2 and the left arm wrist 3 adopt the same structure, including a reducer 21, a stroke shaft 17, a sleeve 14, a wrench drive motor and a bracket for supporting the reducer 21, the stroke shaft 17 and the drive motor; Figure 5 As shown, the sleeve 14 includes a sleeve portion for fitting a nut and a connecting portion for installation along its axial direction; the input shaft of the reducer 21 is connected to the wrench driving motor, the output shaft of the reducer 21 is connected to the input end of the stroke shaft 17 through a universal coupling 19, and the output end of the stroke shaft 17 is connected to the connecting portion of the sleeve 14; a compression spring 16 arranged along the axial direction of the stroke shaft 17 is provided between the stroke shaft 17 and the sleeve 14; a radial error compensation structure for driving the stroke shaft 17 to float along its radial direction is provided at one end of the stroke shaft 17 adjacent to the sleeve 14.

[0039] Among them, the sleeve 14 is in direct contact with the bolt to be tightened, and a hexagonal head socket is provided at the center of its sleeve part. When in use, the head of the bolt to be tightened or the nut is inserted into the hexagonal head socket of the sleeve part, and the bolt is tightened by applying force to the sleeve 14 to rotate the sleeve 14 around its axis.

[0040] The force driving the sleeve 14 to rotate comes from the wrench drive motor, specifically: the wrench drive motor rotates, and after being decelerated by the reducer 21, the output power is transmitted to the stroke shaft 17 through the universal coupling 19. The compression spring 16 arranged between the stroke shaft 17 and the sleeve 14 can make the end sleeve 14 produce a certain stroke in the axial direction, so that the sleeve 14 has the ability to float in the axial direction of the stroke shaft 17. The radial error compensation structure can drive the stroke shaft 17 to swing in the radial direction, thereby realizing the radial floating of the sleeve 17. Through the dual effects of the compression spring 16 and the radial error compensation structure, the end sleeve 17 has a flexible floating effect, and the alignment error can be adaptively compensated when the sleeve 17 and the bolt are aligned, thereby shortening the alignment time and reducing the alignment accuracy requirements.

[0041] Preferably, the bracket includes a wrist shell 20 and an arm shell 13, the wrist shell 20 is horizontally arranged, the arm shell 13 extends obliquely upward, and the top is connected to the wrist shell 20, and the hollow inner cavity of the wrist shell 20 is connected to the hollow inner cavity of the arm shell 13;

[0042] The stroke shaft 17 is disposed in the wrist housing 20 , and the speed reducer 21 is disposed in the arm housing 13 .

[0043] The stroke shaft 17 can be a conventional solid shaft, and the compression spring 16 is directly connected to the end of the stroke shaft 17. In the present invention, preferably, the stroke shaft 17 includes a segment 17A adjacent to the universal coupling 19 and a segment 2 17B adjacent to the sleeve 14 along its axial direction;

[0044] The segment 17A is a solid shaft;

[0045] The second segment 17B is coaxial with the first segment 17A, and its diameter is larger than that of the first segment 17A; the second segment 17B is a hollow shaft, including a circular side wall and a bottom wall connected to the second segment 17B;

[0046] A long strip-shaped slide groove 17B1 extending axially along the segment 17B and penetrating the open end of the segment 17B is provided on the inner surface of the hollow area of ​​the segment 17B. An annular limiting ring 17C is provided in the hollow area of ​​the segment 17B. A slider is provided on the outer circumferential surface of the limiting ring 17C. The slider is movably connected to the slide groove 17B1 along the axial direction of the segment 17B. A limiting structure that limits the limiting ring 17C from being separated from the segment 17B is provided at the open end of the segment 17B.

[0047] The compression spring 16 is disposed in the hollow area of ​​the second segment 17B, with one end abutting against the bottom wall of the second segment 17B and the other end abutting against the limiting ring 17C.

[0048] The limiting structure is a limiting screw 17B2 that passes through the side wall of segment 2 17B and extends to the hollow area of ​​segment 2 17B. The limiting screw 17B2 is pressed against the outer end surface of the slider for limiting.

[0049] In this structure, the slider can slide in the slide groove 17B1. When the sleeve 14 moves to the right due to external force, the limit ring 17C will compress the compression spring 16. When the sleeve 14 is not subjected to external force, the compression spring 16 extends. However, due to the setting of the limit screw 17B2, the limit ring 17C is restricted from moving to the left by the limit screw 17B2, thereby realizing the left and right movement of the sleeve 14.

[0050] The slider and the stop ring 17C can be directly processed and set as one piece. In the present invention, the slider is a sliding key, the slide groove 17B1 is a long key groove, and a short key groove adapted to the sliding key is provided on the outer peripheral surface of the stop ring 17C, and the slider is installed between the short key groove and the long key groove. The key groove cooperates with the key, and is easy to process and replace.

[0051] The arrangement of the second segment 17B of the travel shaft 17 of the structure has the following advantages:

[0052] First, a hollow area is provided to install the compression spring 16, which limits the compression spring 16 in the radial direction to prevent the compression spring 16 from being separated from the stroke shaft 17, and the limiting effect of the annular side wall facilitates the axial expansion and contraction of the compression spring 16 to a certain extent.

[0053] Second, the compression spring 16 is installed in the stroke shaft 17 to save space.

[0054] If the connecting portion of the sleeve 14 is directly connected to the compression spring 16, it is inconvenient to disassemble, which makes it inconvenient to replace the sleeve 14. In order to avoid this problem, preferably, the output end of the stroke shaft 17 is connected to the connecting portion of the sleeve 14 through a connecting shaft 15; one end of the connecting shaft 15 is fixedly connected to the limit ring 17C in an interference fit or other direction, and the other end is detachably connected to the connecting portion of the sleeve 14. In this structure, the sleeve 14 and the connecting shaft 15 are detachably connected, and the sleeve 14 can be replaced according to the size of the nut to be screwed.

[0055] like Figure 4 As shown, the radial error compensation structure includes a copper sleeve 23 and a plurality of tension springs 24 evenly distributed on the copper sleeve 23 along the circumferential direction of the copper sleeve 23; the copper sleeve 23 is sleeved on the outer surface of segment 2 17B of the stroke shaft 17, and one end of the tension spring 24 is connected to the outer surface of the copper sleeve 23, and the other end is connected to the inner surface of the wrist shell 20.

[0056] There can be three, four or five tension springs 24, etc. The connection points of these tension springs 24 on the copper sleeve 23 are located on the same circumference, and the spacing between adjacent tension springs 24 is equal. There are four tension springs 24 disclosed in this embodiment. Through the expansion and contraction of the tension springs 24, the copper sleeve 23 can drive the stroke shaft 17 to move in the four directions where the tension springs 24 are located. Therefore, the end sleeve 14 installed on the stroke shaft 17 has four degrees of freedom of movement, and a flexible floating effect is achieved in these four directions.

[0057] In order to facilitate the acquisition of close-up images and use machine vision algorithms to align the bolts, preferably, a monocular camera 18 is installed at the top of the wrist shell 20 facing the side where the sleeve 14 is located.

[0058] In order to obtain the bolt tightening torque in real time, preferably, a torque sensor 22 is provided, which is located in the arm housing 13, and the top end of which is connected to the input end of the reducer 21. The torque sensor 22 can detect the output torque of the wrench drive motor in real time, thereby obtaining the bolt tightening torque in real time, and can feedback the tightening torque in real time during the bolt tightening operation, monitor the screwing state, and tighten the bolt to the required torque with high precision.

[0059] The multi-posture adaptive bolt tightening device disclosed in the present invention integrates sensor technology and a visual perception system through the provision of a monocular camera 18 and a torque sensor 22, thereby achieving the goal of intelligently identifying positioning bolts. At the same time, it can automatically loosen or tighten bolts, thereby improving operating efficiency, reducing labor intensity and improving operating accuracy.

[0060] Through the setting of the bidirectional screw 9 and the steering gear 5, the right arm wrist 2 and the left arm wrist 3 can be driven to change their postures, which has good adaptability to the situation of multi-space and multi-posture distribution of bolts in contact maintenance operations. It can not only meet the use of contact network maintenance operation scenarios, but also complete bolt tightening operations in various other complex situations. The right arm wrist 2 and the left arm wrist 3 are driven by the steering gear 5 to perform rotational motion, and the right arm wrist 2 and the left arm wrist 3 simulate the movement of the arm wrist joint, which is conducive to their movement in a narrow range, and is suitable for operation scenarios with limited working space. The sleeve 14 can be detachably installed, and can be adapted to bolts of various specifications by replacing the sleeve 14.

[0061] The flexible adaptive floating design of the sleeve 14 at the end can compensate for the alignment error between the bolt and 14. When 14 is close to the bolt head or nut for alignment, the existence of this technology will reduce the alignment time and reduce the alignment accuracy requirements.

Claims

1. Multi-position adaptive bolt fastening device, characterized by: It comprises a displacement base (1), a right arm wrist (2) and a left arm wrist (3); The displacement base (1) comprises a frame (4) and a bidirectional screw rod (9); The frame (4) is a shell structure with an opening at the top; the left and right ends of the bidirectional screw rod (9) are movably mounted in the inner cavity of the frame (4); the left end of the bidirectional screw rod (9) is threadedly connected to a movable nut (10), and the top end of the movable nut (10) is connected to a steering gear (5); the right end of the bidirectional screw rod (9) is threadedly connected to a movable nut (10), and the top end of the movable nut (10) is connected to a steering gear (5); an arm drive motor (12) for driving the bidirectional screw rod (9) to move forward and backward is arranged at the bottom of the frame (4); The steering gear (5) at the left end of the bidirectional screw rod (9) is connected to the left arm wrist (3) for driving the left arm wrist (3) to rotate; The steering gear (5) at the right end of the bidirectional screw rod (9) is connected to the right arm (2) for driving the right arm (2) to rotate; The right arm (2) and the left arm (3) have the same structure, including a reducer (21), a travel shaft (17), a sleeve (14), a wrench drive motor and a bracket for supporting the reducer (21) and the travel shaft (17); The sleeve (14) comprises, along its axial direction, a sleeve portion for fitting a nut and a connecting portion for installation; The input shaft of the reducer (21) is connected to the wrench driving motor, the output shaft of the reducer (21) is connected to the input end of the stroke shaft (17) through a universal coupling (19), and the output end of the stroke shaft (17) is connected to the connecting portion of the sleeve (14); A compression spring (16) is provided between the stroke shaft (17) and the sleeve (14) and is arranged axially along the stroke shaft (17); A radial error compensation structure for driving the stroke shaft (17) to float in its radial direction is provided at one end of the stroke shaft (17) adjacent to the sleeve (14); the radial error compensation structure comprises a copper sleeve (23) and a plurality of tension springs (24) evenly distributed on the copper sleeve (23) along the circumferential direction of the copper sleeve (23); the copper sleeve (23) is sleeved on the outer surface of the second segment (17B) of the stroke shaft (17); one end of the tension spring (24) is connected to the outer surface of the copper sleeve (23), and the other end is connected to the inner surface of the wrist housing (20); The bracket comprises a wrist shell (20) and an arm shell (13), wherein the wrist shell (20) is arranged horizontally, and the arm shell (13) extends obliquely upward and is connected to the wrist shell (20) at the top, and the hollow inner cavity of the wrist shell (20) is communicated with the hollow inner cavity of the arm shell (13); The stroke shaft (17) is arranged in the wrist housing (20), and the speed reducer (21) is arranged in the arm housing (13); The travel shaft (17) includes, along its axial direction, a segment 1 (17A) adjacent to the universal joint (19) and a segment 2 (17B) adjacent to the sleeve (14); The segment 1 (17A) is a solid shaft; The segment 2 (17B) is coaxial with the segment 1 (17A), and its diameter is larger than that of the segment 1 (17A); the segment 2 (17B) is a hollow shaft, including a circular side wall and a bottom wall connected to the segment 2 (17B); A long strip-shaped slide groove (17B1) is arranged on the inner surface of the hollow area of ​​segment two (17B) and extends along the axial direction of segment two (17B) and passes through the open end of segment two (17B); an annular limiting ring (17C) is arranged in the hollow area of ​​segment two (17B); a slider is arranged on the outer peripheral surface of the limiting ring (17C); the slider is movably connected to the slide groove (17B1) along the axial direction of segment two (17B); and a limiting structure for limiting the limiting ring (17C) from separating from segment two (17B) is arranged at the open end of segment two (17B); The compression spring (16) is arranged in the hollow area of ​​the second segment (17B), with one end abutting against the bottom wall of the second segment (17B) and the other end abutting against the limiting ring (17C).

2. The multi-posture adaptive bolt fastening device according to claim 1, characterized in that: A connecting plate (8) is installed at the top end of the movable nut (10); the connecting plate (8) comprises a bottom plate (8A) and side plates (8B) located on both sides of the bottom plate (8A), and is surrounded by the bottom plate (8A) and the side plates (8B) to form a slot; the steering gear (5) is snap-connected in the slot of the connecting plate (8).

3. The multi-position adaptive bolt fastening device according to claim 2, characterized in that: The limiting structure is a limiting screw (17B2) that passes through the side wall of segment 2 (17B) and extends to the hollow area of ​​segment 2 (17B), and the limiting screw (17B2) abuts against the outer end surface of the slider to limit the position; The slider is a sliding key, the sliding groove (17B1) is a long key groove, a short key groove adapted to the sliding key is arranged on the outer peripheral surface of the limiting ring (17C), and the slider is installed between the short key groove and the long key groove.

4. The multi-position adaptive bolt fastening device according to claim 3, characterized in that: The output end of the travel shaft (17) is connected to the connecting portion of the sleeve (14) via a connecting shaft (15); One end of the connecting shaft (15) is fixedly connected to the limiting ring (17C), and the other end is detachably connected to the connecting portion of the sleeve (14).

5. The multi-position adaptive bolt fastening device according to claim 4, characterized in that: A monocular camera (18) is installed at the top end of the wrist housing (20) and faces the side where the sleeve (14) is located.

6. The multi-position adaptive bolt fastening device according to claim 5, characterized in that: A torque sensor (22) is provided, and the torque sensor (22) is located in the arm housing (13), and the top end of the torque sensor (22) is connected to the input end of the reducer (21).

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