An automatic assembly mechanism of railway track fastener nut

Abstract

The application discloses an automatic assembling mechanism for railway track fastener nuts, and belongs to the technical field of automatic assembling equipment. The mechanism comprises a mechanical arm, a nut assembling mechanism, a power transmission device, a propelling device, a connecting seat and a visual device. The nut assembling mechanism is composed of a compliant device and a magnetic attraction device. The end of the mechanical arm is fixed through the connecting seat. The visual device can identify the position of the fastener in real time and guide the positioning of the mechanical arm. The servo motor can transmit torque through a speed reducer and a telescopic universal connecting assembly, so that the nut can be tightened. The compliant device can absorb the assembling error and adapt to the posture, so that the thread cross-fastening and jamming can be prevented. The magnetic attraction device is used for the adsorption and fixation of the nut. The six-dimensional force sensor can monitor and feedback the torque in real time. The control system can adjust the pre-tightening force. The propelling device can apply axial thrust. The compression spring can provide the pressing force, so that the nut tightening can be reliable. The device can realize the automatic identification, positioning, tightening and pre-tightening control of the nut, and is suitable for various track tie structures and complex track working conditions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of automatic assembly equipment, and relates to an automatic assembly mechanism for railway track fastener nuts, which is suitable for automatic identification, grabbing, positioning and tightening of railway track fastener nuts. BACKGROUND

[0002] A railway fastener system is composed of a clamping part, an elastic pad, a fastener and a gauge baffle, etc., and is used to reliably fix a steel rail to a sleeper, bear and transmit dynamic loads generated by train operation, ensure the stability of track geometric parameters and the safety of train operation, and the assembly quality of the fastener directly affects the stability of the track structure and the safety of operation.

[0003] At present, the assembly of the nut fastener mainly relies on manual operation, which not only consumes a large amount of manpower, but also the assembly quality is affected by the experience of workers, and there are problems of low efficiency, poor precision and high labor intensity. Therefore, an intelligent device capable of realizing automatic identification, grabbing, positioning and assembly of nuts is urgently needed to improve the operation efficiency and quality, reduce the labor intensity, and promote the intelligent and automatic development of railway construction and maintenance.

[0004] The automatic assembly mechanism provided by the present application can replace manual operation, realize automatic grabbing, accurate positioning and flexible tightening of nuts through visual identification and intelligent control system, ensure the consistency of assembly pre-tightening force, improve the assembly efficiency and quality of track fasteners, and is suitable for various working conditions and sleeper structures, further promoting the intelligent development of track fastener assembly operation. SUMMARY

[0005] In view of the problems in the technical background, the present application provides an automatic assembly mechanism for railway track fastener nuts, which can effectively reduce the number of personnel and labor intensity in railway track laying operation, and improve the operation efficiency and quality. The mechanism integrates visual identification, intelligent control, mechanical execution and torque feedback control functions, and can realize automatic identification and grabbing, accurate positioning, flexible tightening and torque adaptive control of track fastener nuts, and is suitable for various sleeper types and complex construction environments, which can significantly improve the operation efficiency while ensuring the assembly quality.

[0006] The application provides an automatic assembly mechanism for railway track fastener nuts, characterized in that it comprises a mechanical arm, a nut assembly mechanism, a base plate, a power transmission device, a propulsion device, a connecting seat and a visual detection and recognition device; the nut assembly mechanism is composed of a compliant device and a magnetic attraction device; the nut assembly mechanism comprises a mounting seat, an electric slip ring, a power transmission shaft, a rolling bearing, a bearing seat, an input end coupling flange, an output end coupling flange, a universal joint coupling, a compression spring, a six-dimensional force sensor, a fixing seat, a magnetic attraction sleeve and an annular magnet; the propulsion device comprises a DC brushless reduction motor, a motor mounting plate, a slide rail mounting seat, a slide rail, a sliding block, a stop block, a bent plate, a propulsion plate, a flange seat, a linear bearing, a sliding bearing and a circular plate; the mechanical arm and the power transmission device are both vertically installed on the base plate; the nut assembly mechanism, the power transmission device and the propulsion device constitute a cross-domain coupled composite assembly system, which forms a composite assembly system with rigid transmission, compliant adjustment, magnetic field centralization and visual guidance cooperation at the structural level, and realizes trajectory self-adaptation, misalignment absorption and disturbance suppression based on the five-modal information fusion of force, position, angle, torque and vision, so as to adapt to the working conditions such as bolt axial error, radial offset, spike inclination and track surface deformation; the nut assembly mechanism is fixed at the end of the mechanical arm through the connecting seat, and is used for providing six-dimensional spatial positioning and anti-vibration capability; the propulsion device is connected and fixed through the lower end of the motor mounting plate and the fixing seat, so that the axial propulsion force and the threaded engagement state are synchronously real-time; the visual detection and recognition device adopts a binocular camera and is installed above the nut assembly mechanism, and is parallel to the end thereof, and is used for acquiring a three-dimensional image of the track fastener area and forming a posture feedforward and mechanical feedback double closed-loop control with the six-dimensional force sensor; the power transmission device provides torque output to the nut under the action of the compliant mechanism to complete the assembly of the nut.

[0007] The working principle of the present application is that the nut assembly mechanism is fixed to the end of the mechanical arm through the connecting seat, and the binocular vision detection device is installed above the nut assembly mechanism and keeps parallel view angle, which is used to collect the stereoscopic image of the fastener area. The vision controller extracts features and recognizes the pose of the image, calculates the deviation between the actual image and the expected image, and outputs the error signal to the motion controller. The mechanical arm adjusts the posture according to the control instruction, so that the nut assembly mechanism accurately aligns with the position of the bolt to be assembled. When the mechanical arm reaches the predetermined position, the servo motor transmits torque through the planetary reducer and the telescopic universal joint assembly to realize the screw nut spin assembly. The telescopic universal joint assembly is used to compensate the axis and position error to ensure stable transmission; the compliant device absorbs the assembly deviation and uneven stress to realize the posture self-adjustment, avoiding the thread misalignment and jamming. The magnetic attraction device adsorbs and fixes the nut, and the six-dimensional force sensor detects the torque in real time and feeds back to the control system to realize the torque self-adaptive adjustment, ensuring the consistency of the nut pre-tightening force. The propulsion device is provided for applying a pushing force in the axial direction to the compression spring during the assembly stage, so that the compression spring produces elastic deformation after being stressed and continuously provides downward pressure, thereby ensuring that the nut has sufficient axial compression force during the tightening process to prevent loosening and improve assembly reliability. After the assembly is completed, the mechanical arm moves to the next fastener position to start the cycle operation.

[0008] As a further technical solution, the mechanical arm is preferably a Zhibo six-degree-of-freedom robot and is driven by a servo motor; the control system includes a main power supply, a computer power supply unit, a computer control module, an input / output board, a user connection port, an axis control board, and a servo drive unit, which is used to realize high-precision positioning control of multiple degrees of freedom, and complete automatic recognition, positioning and assembly guidance of the nut based on binocular vision recognition and control algorithm; the mechanical arm is fixedly installed on the bottom plate through bolts; the cylindrical surface of the connecting seat is provided with a plurality of bolt holes, which are reliably connected with the end of the mechanical arm through bolts, and the left and right sides of the connecting seat are respectively provided with bolt holes, which are connected with the two sides of the mounting seat through bolts to realize stable support; the vision system adopts a binocular camera, which is fixedly installed on the mounting seat and used to collect the stereoscopic image of the track fastener area and output spatial pose information; the power transmission device includes a servo motor, a planetary reducer, a rigid coupling and a telescopic universal joint assembly; the servo motor is fixedly installed on the bottom plate and coaxially connected with the planetary reducer to realize efficient power transmission and speed matching; the telescopic universal joint assembly includes an outer cylinder, a sliding inner shaft and an angular offset compensation unit, which is used to compensate the axial offset and the inclination angle of the spike; the power transmission device judges the meshing depth and adjusts the torque threshold and assembly parameters in real time through the radial force, axial force and torque feedback of the servo motor torque and the six-dimensional force sensor.

[0009] As a further technical solution, the nut assembly mechanism is provided with a compliant device; the compliant device comprises a fixed module and a flexible module; the fixed module comprises a mounting seat, an electric slip ring, a power transmission shaft, a bearing seat and a rolling bearing; the fixed module reduces rotational runout through a bearing support structure, so that the compliant module can still maintain a stable power transmission path under high load conditions; the electric slip ring is fixedly installed on the mounting seat, and the output end thereof is connected with the power transmission shaft, for realizing continuous transmission of electrical signals and electrical energy during rotation; the bearing seat is fixedly connected to the lower end of the mounting seat through bolts, and the rolling bearing is installed in the bearing seat, for supporting the rotation of the power transmission shaft and reducing rotational friction, thereby ensuring the stability and reliability of transmission; the flexible module in the nut assembly mechanism comprises an input end coupling flange, an output end coupling flange, a universal joint coupling, a compression spring and a six-dimensional force sensor; the universal joint coupling is used to compensate for angular deviation and avoid jamming caused by axis misalignment, and provides low-frequency angular compensation capability for the flexible module; the compression spring has a nonlinear segmented stiffness characteristic, presents a low stiffness energy absorption characteristic at the initial stage of engagement, and presents a high stiffness anti-bias load capability at the stable stage of thread engagement; the six-dimensional force sensor is installed between the output end coupling flange and the magnetic attraction device, for detecting torque signals in real time during assembly; the compliant device and the power transmission device jointly act, so that the entire assembly process has comprehensive compliant capabilities of variable stiffness constraint, dynamic contact buffering and nonlinear mechanical disturbance suppression, thereby improving the assembly stability of the system under bolt inclination, track vibration or engagement deviation.

[0010] As a further technical solution, the magnetic attraction device comprises a fixed seat, a magnetic attraction sleeve and an annular magnet; the fixed seat is detachably connected with the six-dimensional force sensor through screws; the magnetic attraction sleeve is arranged at the lower end of the fixed seat, and the annular magnet arranged in the circumferential direction is built-in, for forming a magnetic field gradient and providing passive posture guidance before the nut enters the thread entrance, so that the nut is naturally centered and enters the initial engagement area, thereby improving the initial alignment accuracy and reducing the assembly failure rate.

[0011] As a further technical solution, the propelling device comprises a driving module and a sliding module; the driving module comprises a direct-current brushless speed reducer, a motor mounting plate, a slide rail mounting seat, a slide rail, a sliding block, a stop block and a bent plate; the direct-current brushless speed reducer is fixedly connected with the mounting seat of the nut assembly mechanism through the motor mounting plate, and is used for providing stable linear driving force for the propelling device; the slide rail mounting seat is arranged at the right side of the direct-current brushless speed reducer and is fixedly connected with the same through bolts, so as to form a sliding guide support structure; the slide rail is fixedly connected with the slide rail mounting seat through screws, and the sliding block is matched with the slide rail in a buckle type, so as to realize stable sliding in the direction of the slide rail; the stop block is fixed at both ends of the slide rail respectively, and is used for limiting the movement stroke of the sliding block and preventing the sliding block from falling off; the bent plate is fixedly connected with the sliding block through screws, and the output shaft of the direct-current brushless speed reducer is connected with the bent plate, and is used for driving the bent plate to make reciprocating linear motion in the direction of the slide rail; the sliding module comprises a propelling plate, a flange seat, a linear bearing, a sliding bearing and a circular plate; one end of the propelling plate is abutted with the lower end surface of the bent plate, and the other end is fixedly connected with the flange seat through bolts, and is used for transmitting the linear propelling force of the driving module to the flange seat; the lower end of the flange seat is connected with the mounting holes on the circular plate through four supporting columns in alignment, so as to form stable rigid support; the inner ring of the sliding bearing is connected with the outer circle of the shaft end of the power transmission shaft in an interference fit, and the outer ring is fixed by a jackscrew through the threaded holes on the circular plate, so as to realize coaxial constraint and reliable positioning of the power transmission component and the propelling structure; in the working process of the propelling mechanism, the dynamic relationship among the thread engagement resistance, the six-dimensional force sensor feedback and the output torque of the power transmission device is used to realize torque and propelling coupling control, so as to avoid the problems of jamming, slipping or failure of screwing in due to too fast propelling speed or insufficient torque.

[0012] As a further technical solution, the nut assembly mechanism can be used as a track fastener assembly device alone, or can be integrated into an automatic operation system of a track operation vehicle.

[0013] Additional aspects and advantages of the application will be made apparent by the following description.

[0014] The beneficial effects of the application are:

[0015] 1. The integrated binocular vision detection system, mechanical arm and intelligent control algorithm can automatically identify the position of the fastener and complete accurate positioning and tightening operation of the nut, realize automatic operation of the whole process from identification to assembly, greatly improve the assembly efficiency and precision, and reduce the labor intensity.

[0016] 2. The compensation structure combined with the flexible device through the telescopic universal connecting assembly can effectively absorb the axis deviation, attitude error and uneven force in the assembly process, realizes the adaptive adjustment of the attitude, prevents the wrong screwing or jamming of the screw, and ensures the smooth and reliable assembly process.

[0017] 3. The six-dimensional moment sensor realizes the real-time detection and adaptive adjustment of the torque, ensures the uniform and consistent nut pre-tightening force, the mechanism adopts the modular design, has the compact structure, convenient maintenance, can adapt to various sleeper structures and complex working conditions, and has good universality and stability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a whole schematic view of the automatic assembly mechanism of the railway track fastener nut of the embodiment of the application.

[0019] Figure 2 It is a structural schematic view of the nut assembly mechanism and the power transmission device in the application.

[0020] Figure 3 It is an exploded structural schematic view of the nut assembly mechanism in the application.

[0021] Figure 4 It is a front view schematic view of the nut assembly mechanism and the visual detection and identification device in the application.

[0022] Figure 5 It is a sectional view of the nut assembly mechanism and the visual detection and identification device A-A cross section line in the application.

[0023] Figure 6 It is a structural schematic view of the advancing device in the application.

[0024] Figure 7 It is a front view schematic view of the advancing device in the application.

[0025] Figure 8 It is a sectional view of the advancing device B-B cross section line in the application.

[0026] Figure 9 It is a component structural schematic view of the connecting seat in the application.

[0027] Figure 10 It is a component structural schematic view of the fastener in the application.

[0028] Reference signs: base plate 1, mechanical arm 2, power transmission device 3, connecting seat 4, visual detection and identification device 5, nut assembly mechanism 6, pushing device 7, fastener 8, soft device 61, fixed module 62, flexible module 63, magnetic attraction device 64, drive module 71, sliding module 72, stud 81, nut 82, servo motor 31, planetary reducer 32, rigid coupling 33, telescopic universal joint assembly 34, outer cylinder 341, inner sliding shaft 342, cylindrical surface 41, left side plate 43, right side plate 44, bolt hole 45, binocular camera 51, camera mounting plate 52, mounting seat 621, power transmission shaft 623, rolling bearing 624, bearing seat 625, input end coupling flange 631, output end coupling flange 632, universal joint coupling 633, compression spring 634, six-dimensional force sensor 635, fixing seat 641, magnetic attraction sleeve 642, annular magnet 643, DC brushless reduction motor 711, motor mounting plate 712, sliding rail mounting seat 713, sliding rail 714, sliding block 715, stop block 716, bent plate 717, pushing plate 721, flange seat 722, linear bearing 723, sliding bearing 724, circular plate 725; upper cover plate 6211, bolt hole 6212, lower cover plate 6213, bolt hole 6214, bolt hole 6215, key 6231, outer ring 6221, inner ring 6222, threaded hole 6223, fixing seat flange face 6411, threaded hole 6412, flange face 6413, threaded hole 6414, end face 6421, output shaft 7111, support column 7221, mounting hole 7251, threaded hole 7252. DETAILED DESCRIPTION

[0029] The technical solutions of the patent will be further described in detail below in combination with specific embodiments.

[0030] The embodiments of the patent will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the patent, and cannot be understood as a limitation on the patent.

[0031] In the description of the patent, it should be understood that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "side", "between" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the patent and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the patent.

[0032] In the description of the present patent, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "arrangement" should be understood broadly, for example, it can be fixedly connected, arranged, or detachably connected, arranged, or integrally connected, arranged. For those skilled in the art, the specific meanings of the above terms in the present patent can be understood according to the specific circumstances.

[0033] Please refer to the attached drawings Figures 1-10 The application discloses an automatic assembly mechanism for railway track fastener nuts, which integrates visual identification, intelligent control, mechanical execution and torque feedback control functions, and can realize automatic identification and grabbing, accurate positioning, flexible tightening and torque self-adaptive control of track fastener nuts, and is suitable for various types of sleepers and complex construction environments. The mechanism is characterized in that a mechanical arm 2 and a power transmission device 3 are vertically fixed to a bottom plate 1 through bolts, respectively, a nut assembly mechanism 6, the power transmission device 3 and a propulsion device 7 are constructed as a cross-domain coupling type composite assembly system, the system forms a rigid transmission, soft adjustment, magnetic field centralization, power coupling and visual guidance assembly link at a structural level, and builds a force, position, angle, torque, visual five-modal information fusion mechanism at a control level. The system is used to realize track adjustment, misalignment absorption, assembly stable control and mechanical disturbance suppression under the working conditions that the track fastener 8 has axial errors, radial offsets, angle inclinations, track surface deformations and spike 81 posture offsets. The nut assembly mechanism 6 is fixed at the end of the mechanical arm 2 through a connecting seat 4, and is used to provide six-dimensional spatial positioning accuracy and anti-vibration support ability under high load conditions. The propulsion device 7 is connected and fixed below the motor mounting plate 712 and the mounting seat 621, so that the axial propulsion force and the thread engagement state produce real-time dynamics synchronization. The binocular camera 51 in the visual detection and identification device 5 is installed above the nut assembly mechanism 6 through a camera mounting plate 52 and is arranged in parallel, and is used to acquire three-dimensional images of the track fastener area. The micro-contact force sensed by the binocular vision data and the six-dimensional force sensor 635 constitutes a double closed-loop control system of spatial pose feedforward and mechanical state feedback, and the power transmission device 3 provides torque output to the nut under the action of the soft mechanism to complete the assembly of the nut 82.

[0034] The nut assembly mechanism 6 is fixed to the end of the mechanical arm 2 through the connecting seat 4, the advancing device 7 is fixedly connected to the lower part of the mounting seat 621 through the motor mounting plate 712, the binocular vision detection device 5 is installed above the nut assembly mechanism 6 and keeps a parallel visual angle, and is used for collecting the stereoscopic image of the fastener 8 area. The vision controller performs feature extraction and pose recognition on the image, calculates the deviation between the actual image and the expected image, and outputs an error signal to the motion controller. The mechanical arm 2 adjusts the posture according to the control instruction, so that the nut assembly mechanism 6 is accurately aligned with the position directly above the to-be-assembled spike 81. When the mechanical arm 2 reaches the predetermined position, the servo motor 31 transmits torque through the planetary reducer 32 and the telescopic universal connecting assembly 34, so as to realize the assembly of the nut 82. The telescopic universal connecting assembly 34 compensates the axis and position error, ensures the stable transmission, the compliant device 61 absorbs the assembly deviation and uneven stress, realizes the adaptive adjustment of the posture, avoids the thread cross-fastening and jamming, the advancing device 7 ensures the stable transmission of the advancing force in the assembly process and the reliability of the structural connection, the magnetic attraction device 64 adsorbs and fixes the nut 82, the six-dimensional force sensor 635 detects the assembly torque in real time and feeds back to the control system, realizes the adaptive adjustment of the pre-tightening force, and ensures the consistency of the pre-tightening force of the nut 82. After the assembly is completed, the mechanical arm 2 moves to the next fastener position to continue the work.

[0035] The mechanical arm 2 is preferably a Yubob six-degree-of-freedom robot driven by a servo motor, and its control system includes a main power supply, a computer power supply unit, a computer control module, an input / output board, a user connection port, an axis control board, and a servo drive unit, etc., for realizing high-precision positioning control of multiple degrees of freedom, and based on the visual recognition and control algorithm of the binocular camera 51 to complete the automatic recognition, positioning and assembly guidance of the nut 82. The mechanical arm 2 is fixedly installed on the bottom plate 1 by bolts, and the cylindrical surface 41 of the connecting seat 4 is provided with a plurality of bolt holes 42 for connecting the end of the mechanical arm 2; the left side plate 43 and the right side plate 44 of the connecting seat 4 are respectively provided with bolt holes 45, which are fixed with the left and right side plates of the mounting seat 621 by bolts, to realize reliable structural installation and stable support; the binocular camera 51 in the visual detection and recognition device 5 is fixed above the nut assembly mechanism 6 through a camera mounting plate 52, and the camera mounting plate 52 is fixed at the lower cover plate 6213 of the mounting seat 621 by bolts, and the lower cover plate 6213 is provided with a bolt hole 6215; the binocular camera 51 acquires a three-dimensional image of the track fastener area and outputs spatial pose information for automatic guidance of nut assembly. The power transmission device 3 includes a servo motor 31, a planetary reducer 32, a rigid coupling 33, and a telescopic universal joint assembly 34; the servo motor 31 is fixedly installed on the bottom plate 1 and coaxially connected with the planetary reducer 32 by bolts, to realize efficient power transmission and speed matching; the telescopic universal joint assembly 34 includes an outer cylinder 341, an inner slide shaft 342, and an angular offset compensation unit, the inner slide shaft 342 slides along the axis direction of the outer cylinder for compensating the axial offset of the nut 82 and the spike 81, and the angular offset compensation unit adopts a universal joint structure for absorbing the angular deviation of the spike inclination; the power transmission device 3 monitors the output torque of the servo motor 31 and combines the radial force, axial force and torque information collected by the six-dimensional force sensor 635 to judge the thread engagement depth and contact state, and to adjust the torque threshold and assembly control parameters in real time.

[0036] The nut assembly mechanism 6 is provided with a compliance device 61, which includes a fixed module 62 and a flexible module 63. The fixed module 62 includes a mounting seat 621, an electric slip ring 622, a power transmission shaft 623, a rolling bearing 624, and a bearing seat 625. The fixed module 62 reduces rotational runout through bearing support structure, so that the flexible module 63 can still maintain a stable power transmission path under high load conditions. The outer ring 6221 of the electric slip ring 622 is fixedly connected with the bolt hole 6212 of the upper cover plate 6211 of the mounting seat 621 through bolts, the inner ring 6222 is sleeved on the power transmission shaft 623, and is fixed through a top wire pressing threaded hole 6223, so as to ensure that the electric slip ring 622 provides continuous rotation of the electric signal and continuous transmission of the electric energy for the six-dimensional force sensor 635 when the power transmission shaft 623 rotates. The shaft end of the power transmission shaft 623 is connected with the telescopic universal joint assembly 34 through a key 6231, forming a torque transmission connection structure. The bearing seat 625 is fixed at the lower cover plate 6213 of the mounting seat 621 through bolts, and the bolt hole 6214 is arranged at the lower cover plate 6213. The rolling bearing 624 is installed in the bearing seat 625, used for supporting the rotation of the power transmission shaft 623 and reducing the rotation friction, so as to ensure the stability and reliability of the transmission. The flexible module 63 in the nut assembly mechanism 6 includes an input end coupling flange 631, an output end coupling flange 632, a universal joint coupling 633, a compression spring 634, and a six-dimensional force sensor 635. The universal joint coupling 633 is connected between the input end coupling flange 631 and the output end coupling flange 632, used for compensating the angle deviation within a certain range, ensuring the continuous and smooth power transmission, preventing the jamming or wear caused by the axis misalignment, and providing the low-frequency angle compensation capability for the flexible module 63. The compression spring 634 is arranged between the input end coupling flange 631 and the output end coupling flange 632, having a nonlinear segmented stiffness characteristic. In the initial stage of engagement, the compression spring 634 presents a low stiffness energy absorption characteristic, and in the stable stage of thread engagement, the compression spring 634 presents a high stiffness anti-bias load capability. The six-dimensional force sensor 635 is installed between the output end coupling flange 632 and the magnetic attraction device 64, used for detecting the torque signal in the assembly process in real time, realizing the torque feedback and compliance control. The compliance device 61 and the power transmission device 3 jointly act, so that the entire assembly process has the comprehensive compliance capability of variable stiffness constraint, dynamic contact buffering, and nonlinear mechanical disturbance suppression, thereby improving the assembly stability of the system under the conditions of spike inclination, track vibration, or engagement deviation.

[0037] The magnetic attraction device 64 comprises a fixed seat 641, a magnetic attraction sleeve 642 and a ring magnet 643. A flange surface 6411 of the fixed seat is detachably connected with the six-dimensional force sensor 635 through a threaded hole 6412, and an opposite flange surface 6413 is connected with the magnetic attraction sleeve 642 through a threaded hole 6414. The magnetic attraction sleeve 642 is arranged at the lower end of the fixed seat 641, and the built-in ring magnet 643 forms a magnetic field gradient in a circumferential direction to provide passive guidance before the nut 82 enters the threaded entrance, so that the nut enters the meshing initial area in a natural stable posture, thereby improving the initial alignment accuracy and reducing the assembly failure rate.

[0038] The advancing device 7 comprises a driving module 71 and a sliding module 72. The driving module 71 comprises a direct-current brushless reduction motor 711, a motor mounting plate 712, a sliding rail mounting seat 713, a sliding rail 714, a sliding block 715, a stop block 716 and a bent plate 717. The direct-current brushless reduction motor 711 is fixed to the mounting seat 621 of the nut assembly mechanism 6 through the motor mounting plate 712 by means of bolts, and is used to provide stable linear driving force for the advancing device. The sliding rail mounting seat 713 is mounted on the right side of the direct-current brushless reduction motor 711 and is fixed by means of bolts to form a sliding guide support structure. The sliding rail 714 is fixedly connected with the sliding rail mounting seat 713 by means of screws. The sliding block 715 is connected with the sliding rail 714 in a buckle type to realize smooth sliding in the direction of the sliding rail. The stop block 716 is fixed at both ends of the sliding rail 714, respectively, to limit the movement stroke of the sliding block 715 and prevent it from falling off. The bent plate 717 is fixedly connected with the sliding block 715 by means of screws. The output shaft 7111 of the direct-current brushless reduction motor 711 is connected with the bent plate 717, and is used to drive the bent plate to make reciprocating linear motion in the direction of the sliding rail. The sliding module 72 comprises a pushing plate 721, a flange seat 722, a linear bearing 723, a sliding bearing 724 and a circular plate 725. One end of the pushing plate 721 abuts against the lower end surface of the bent plate 717, and the other end is fixed to the flange seat 722 by means of bolts, and is used to transmit the linear advancing force of the driving module to the flange seat 722. The lower end of the flange seat 722 is connected with the mounting hole 7251 of the circular plate 725 through four support columns 7221 in alignment, to form a stable rigid support. The inner ring of the sliding bearing 724 is in interference fit with the outer circle of the power transmission shaft end, and the outer ring is fixed by means of the threaded hole 7252 on the circular plate 725 with a jackscrew, to realize coaxial constraint and reliable positioning of the power transmission components and the advancing structure, and to ensure the axial advancing accuracy and torque transmission stability during the nut 82 assembly process. During the working process of the advancing device 7, the torque and advancing coupling control are realized according to the dynamic relationship among the threaded meshing resistance, the six-dimensional force sensor 635 feedback and the output torque of the power transmission device 3, that is, the advancing speed is automatically adjusted according to the torque change, so that the threaded meshing has dynamic followability, and the jamming, slipping or rotation failure caused by too fast advancing speed or insufficient torque is avoided.

[0039] The nut assembly mechanism 6 can be used independently as a track fastener assembly device, or can be integrated into an automatic construction system of a track operation vehicle.

[0040] The application provides an automatic assembly mechanism for railway track fastener nuts. The mechanism integrates a binocular vision device at the end of the nut assembly mechanism, and through the cooperation of a mechanical arm and a vision system, the accurate identification and automatic positioning of the position and posture of the fastener nuts are realized without manual intervention. The use of automatic assembly can reduce the intensity of manual operation, reduce potential safety risks, and significantly improve work efficiency. The nut assembly mechanism can stably complete the automatic tightening operation of the fastener nuts, has the advantages of reliable transmission, simple control, convenient maintenance, stable and consistent assembly quality, and the like, thereby realizing the efficient and automatic assembly of the railway track fastener nuts.

[0041] Obviously, those skilled in the art can make various modifications, improvements and replacements to the application without departing from the spirit and essence of the application. As long as these modifications, improvements and replacements fall within the protection scope of the claims of the application and equivalent technical solutions thereof, they shall be included in the protection scope of the application.

Claims

1. An automated assembly mechanism for railway track fastener nuts, characterized by: The device comprises a mechanical arm, a nut assembly mechanism, a bottom plate, a power transmission device, a propulsion device, a connecting seat and a visual detection and recognition device. The nut assembly mechanism is composed of a compliant device and a magnetic attraction device. The nut assembly mechanism comprises a mounting seat, an electric slip ring, a power transmission shaft, a rolling bearing, a bearing seat, an input end coupling flange, an output end coupling flange, a universal joint coupling, a compression spring, a six-dimensional force sensor, a fixing seat, a magnetic attraction sleeve and a ring-shaped magnet. The propulsion device comprises a DC brushless reduction motor, a motor mounting plate, a slide rail mounting seat, a slide rail, a slide block, a stop block, a bent plate, a propulsion plate, a flange seat, a linear bearing, a sliding bearing and a circular plate. The mechanical arm and the power transmission device are both vertically installed on the bottom plate. The nut assembly mechanism, the power transmission device and the propulsion device constitute a cross-domain coupled composite assembly system, which forms a composite assembly system with rigid transmission, compliant adjustment, magnetic field centralization and visual guidance cooperation at the structural level. Based on the five-mode information fusion of force, position, angle, torque and vision, the trajectory is self-adaptive, misalignment is absorbed and disturbance is suppressed to adapt to the working conditions of bolt axial error, radial offset, spike inclination and rail surface deformation. The nut assembly mechanism is fixed at the end of the mechanical arm through the connecting seat to provide six-dimensional spatial positioning and anti-vibration capability. The propulsion device is connected and fixed through the lower end of the motor mounting plate and the connecting seat to synchronize the axial propulsion force and the thread engagement state in real time. The visual detection and recognition device adopts a binocular camera and is installed above the nut assembly mechanism, parallel to the end thereof, to obtain a three-dimensional image of the rail fastener area and form a posture feedforward and mechanical feedback double closed-loop control with the six-dimensional force sensor. The power transmission device provides torque output to the nut under the action of the compliant mechanism to complete the assembly of the nut. The nut assembly mechanism is provided with a compliance device; the compliance device comprises a fixed module and a flexible module; the fixed module comprises a mounting seat, an electric slip ring, a power transmission shaft, a bearing seat and a rolling bearing; the fixed module reduces rotation runout through a bearing support structure, so that the compliance module can still maintain a stable power transmission path under high load conditions; the electric slip ring is fixedly installed on the mounting seat, and an output end thereof is connected with the power transmission shaft, so as to realize continuous transmission of electric signals and electric energy in the rotation process; the bearing seat is fixedly connected to the lower end of the mounting seat through bolts, and the rolling bearing is installed in the bearing seat, so as to support the rotation of the power transmission shaft and reduce the rotation friction, thereby ensuring the stability and reliability of transmission; the flexible module in the nut assembly mechanism comprises an input end coupling flange, an output end coupling flange, a universal joint coupling, a compression spring and a six-dimensional force sensor; the universal joint coupling is used to compensate for angular deviation and avoid jamming caused by axis misalignment, and provides low-frequency angular compensation capability for the flexible module; the compression spring has a nonlinear segmented stiffness characteristic, presents a low stiffness energy absorption characteristic in the initial engagement stage, and presents a high stiffness anti-bias load capacity in the stable thread engagement stage; the six-dimensional force sensor is installed between the output end coupling flange and the magnetic attraction device, and is used to detect the torque signal in real time during the assembly process; the compliance device and the power transmission device jointly act, so that the entire assembly process has comprehensive compliance capabilities of variable stiffness constraint, dynamic contact buffering and nonlinear mechanical disturbance suppression, thereby improving the assembly stability of the system under bolt inclination, track vibration or engagement deviation; The magnetic attraction device comprises a fixed seat, a magnetic attraction sleeve and an annular magnet; the fixed seat is detachably connected with the six-dimensional force sensor through screws; the magnetic attraction sleeve is arranged at the lower end of the fixed seat, and the annular magnet arranged in the circumferential direction is arranged in the magnetic attraction sleeve, so as to form a magnetic field gradient and provide passive posture guidance before the nut enters the thread entrance, so that the nut is naturally centered and enters the initial engagement area, thereby improving the initial alignment accuracy and reducing the assembly failure rate. The propelling device comprises a driving module and a sliding module; the driving module comprises a direct-current brushless reduction motor, a motor mounting plate, a slide rail mounting seat, a slide rail, a sliding block, a stop block and a bent plate; the direct-current brushless reduction motor is fixedly connected with the mounting seat of the nut assembly mechanism through the motor mounting plate, and is used for providing stable linear driving force for the propelling device; the slide rail mounting seat is arranged at the right side of the direct-current brushless reduction motor and is fixedly connected with the same through bolts, so as to form a sliding guide support structure; the slide rail is fixedly connected with the slide rail mounting seat through screws, and the sliding block is matched with the slide rail in a buckle type, so as to realize smooth sliding in the direction of the slide rail; the stop blocks are respectively fixed at both ends of the slide rail, and are used for limiting the movement stroke of the sliding block and preventing the sliding block from falling off; the bent plate is fixedly connected with the sliding block through screws, and the output shaft of the direct-current brushless reduction motor is connected with the bent plate, and is used for driving the bent plate to make reciprocating linear motion in the direction of the slide rail; the sliding module comprises a propelling plate, a flange seat, a linear bearing, a sliding bearing and a circular plate; one end of the propelling plate abuts against the lower end surface of the bent plate, and the other end is fixedly connected with the flange seat through bolts, and is used for transmitting the linear propelling force of the driving module to the flange seat; the lower end of the flange seat is connected with the mounting holes on the circular plate through four supporting columns, so as to form stable rigid support; the inner ring of the sliding bearing is connected with the outer circle of the shaft end of the power transmission shaft in an interference fit, and the outer ring is fixed by a jackscrew through the threaded holes on the circular plate, so as to realize coaxial constraint and reliable positioning of the power transmission component and the propelling device; in the working process of the propelling device, the dynamic relationship among the thread engagement resistance, the feedback of the six-dimensional force sensor and the output torque of the power transmission device is used to realize torque and propelling coupling control, so as to avoid clamping, slipping or rotation failure caused by too fast propelling speed or insufficient torque.

2. An automated assembly mechanism for railway track fastener nuts as claimed in claim 1, wherein: The mechanical arm is a Zhibo six-degree-of-freedom robot and is driven by a servo motor; the control system includes a main power supply, a computer power supply unit, a computer control module, an input / output board, a user connection port, an axis control board and a servo drive unit, for realizing high-precision positioning control of multiple degrees of freedom, and based on binocular vision recognition and control algorithm, automatic recognition, positioning and assembly guidance of the nut are completed; the mechanical arm is fixedly installed on the bottom plate by bolts; the cylindrical surface of the connecting seat is provided with a plurality of bolt holes, which are reliably connected with the tail end of the mechanical arm through bolts, and the left and right sides of the connecting seat are respectively provided with bolt holes, which are connected with the two sides of the mounting seat by bolts to realize stable support; the vision system adopts a binocular camera, which is fixedly installed on the mounting seat and is used for collecting stereoscopic images of the track fastener area and outputting spatial pose information; the power transmission device includes a servo motor, a planetary reducer, a rigid coupling and a telescopic universal joint assembly; the servo motor is fixedly installed on the bottom plate and coaxially connected with the planetary reducer by bolts, to realize efficient power transmission and speed matching; the telescopic universal joint assembly includes an outer cylinder, a sliding inner shaft and an angular offset compensation unit, for compensating axial offset and stud inclination angle; the power transmission device judges the meshing depth by servo motor torque and radial force, axial force and torque feedback of the six-dimensional force sensor, and adjusts the torque threshold and assembly parameters in real time.

3. An automated assembly mechanism for railway track fastener nuts according to any one of claims 1-2, characterized in that: The nut assembly mechanism can be used as a track fastener assembly device alone, or can be integrated into an automatic operation system of a track operation vehicle.

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