Tightening mechanism and automatic tightening equipment

Abstract

The invention discloses a tightening mechanism and automatic tightening equipment, and relates to the technical field of automation. The tightening mechanism comprises a base assembly, an electric screwdriver and a flexible assembly. The flexible assembly comprises a fixed part, an elastic part, a movable part and a guide sleeve, the fixed part is connected with the electric screwdriver, the movable part is connected with the screwdriver head, and the two ends of the elastic part are connected with the fixed part and the movable part respectively; the guide sleeve is arranged on the elastic piece in a sleeving mode and connected with the fixed piece, the guide sleeve is provided with a guide groove extending in the axial direction of the guide sleeve, and the flexible assembly comprises a guide piece which is arranged on the movable piece in a protruding mode and is in sliding fit with the guide groove; the movable part and the fixed part are driven by the electric screwdriver to rotate synchronously, and the elastic part can be compressed or stretched so that the movable part can move towards or away from the fixed part. According to the tightening mechanism, the problem of overpressure or underpressure caused by mismatching of the Z-axis descending speed and the screw screwing-in speed can be relieved, the risks of screw loose and appearance damage are reduced, and the locking and attaching yield is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automation, in particular to a tightening mechanism and an automatic tightening device. BACKGROUND

[0002] In the fields of automotive manufacturing, consumer electronics, aerospace, etc., high-precision tightening of bolt connection is a core link to guarantee the reliability and safety of key components. To improve the tightening efficiency and replace repetitive manual operation, servo automatic tightening systems gradually become mainstream solutions, which usually complete screw locking by driving electric wrenches and tightening chucks with three-axis, four-axis or six-axis manipulators.

[0003] In the locking process of the existing servo automatic tightening system, the Z-axis direction needs to drive the manipulator to descend synchronously with the screw tightening to continuously compensate for the Z-direction displacement generated by the screw rotation. During the descending process, the electric wrench and the tightening chuck are pressed downward as a whole, and once the Z-axis descending speed and the screw rotation speed do not match, the weight of the electric wrench and the tightening chuck and the downward driving force will directly act on the screw, causing the screw to slip and the appearance to be damaged, which seriously affects the product quality. SUMMARY

[0004] The present application aims to at least solve one of the problems in the prior art. To this end, the present application proposes a tightening mechanism which can alleviate the overpressure or underpressure problem caused by the mismatch between the Z-axis descending speed and the screw rotation speed, reduce the risk of screw slipping and appearance damage, and improve the locking yield.

[0005] The present application also proposes an automatic tightening device with the above-mentioned tightening mechanism.

[0006] The tightening mechanism according to the first aspect of the present application comprises: a base assembly; an electric wrench connected with the base assembly; a flexible assembly comprising a fixed part, an elastic part, a movable part and a guide sleeve, the fixed part is connected with the electric wrench, the movable part is used to be connected with a chuck, one end of the elastic part is connected with the fixed part, and the other end is connected with the movable part; the guide sleeve is sleeved on the elastic part, and the guide sleeve is fixedly connected with the fixed part, the guide sleeve is provided with a guide groove extending in the axial direction thereof, and the flexible assembly comprises a guide part protruding from the outer circumferential surface of the movable part and slidingly matched with the guide groove; wherein the movable part and the fixed part are driven to rotate synchronously by the electric wrench, and the elastic part can be compressed or stretched to move the movable part towards or away from the fixed part.

[0007] According to the tightening mechanism of the embodiment of the present application, at least the following beneficial effects are achieved: The tightening mechanism of the present application realizes stable transmission of rotary power through the transmission chain between the electric wrench, the fixed part, the movable part, the wrench head and the screw. In addition, the tightening mechanism is actively pressed to a certain extent before the screw is locked, so that the wrench head and the screw are in advance in contact and maintain a certain pre-pressure, which ensures that the screw is stably positioned in the initial stage of rotation, avoids slippage or locking failure caused by shaking or deflection. At this time, the elastic part is in a compressed state and can reserve a buffer space for subsequent Z-axis compensation. When the screw contacts the workpiece and starts to rotate, if the pressing speed of the electric wrench is inconsistent with the rotation speed of the screw, the elastic part can dynamically adjust the axial position of the wrench head by further compressing or releasing the pre-pressing amount, so as to ensure that the axial force applied to the screw is always stable and controllable. The problem of overpressure or underpressure caused by the mismatch between the Z-axis descending speed and the screw rotation speed is effectively alleviated, the damage to the screw or the workpiece caused by the overpressure or underpressure of the mechanical hand due to the displacement error is avoided, and the locking process is stable and controllable.

[0008] According to some embodiments of the present application, the movable part defines a first channel for inserting the wrench head, and the movable part further defines a first mounting hole penetrating the pipe wall of the movable part and communicating with the first channel. The tightening mechanism further comprises a fastening assembly, the fastening assembly comprises a limiting part penetrating the first mounting hole, and the limiting part can protrude or retract compared with the inner wall of the first channel, so as to limit or release the axial movement of the wrench head.

[0009] According to some embodiments of the present application, the fastening assembly further comprises two fasteners and at least one threaded part, the two fasteners are arranged in a spaced manner and jointly define a second mounting hole for the movable part to pass through; and the threaded part penetrates one of the fasteners and is connected with the other fastener. The fastener is connected with the limiting part and moves synchronously with the limiting part driven by the threaded part.

[0010] According to some embodiments of the present application, the base assembly comprises a first mounting seat and a second mounting seat connected with the electric wrench, and the second mounting seat can move compared with the first mounting seat; the tightening mechanism further comprises a supporting assembly, the supporting assembly comprises a fixed sleeve and a first bearing, the fixed sleeve is used for fixed connection with the wrench head, and the first bearing is sleeved on the fixed sleeve, so that the fixed sleeve and the second mounting seat are rotationally connected.

[0011] According to some embodiments of the present application, the support assembly further comprises a support sleeve having a second passage for the bit to pass through, and at least one second bearing is arranged at each end of the second passage respectively, and the bit and the support sleeve are rotatably connected through the second bearing.

[0012] According to some embodiments of the present application, the support sleeve further has a third mounting hole penetrating through the wall of the support sleeve and communicating with the second passage, and the second mounting seat comprises a first supporting part rotatably connected with the fixed sleeve, and a second supporting part rotatably connected with the support sleeve, the second supporting part is provided with a fourth mounting hole extending along the radial direction of the support sleeve, and the fixed sleeve is provided with a fifth mounting hole extending along the radial direction of the support sleeve. According to some embodiments of the present application, the support assembly further comprises a connecting piece, and the support assembly has a first state and a second state, in the first state, the support sleeve is located at a first position where the third mounting hole and the fourth mounting hole are in communication, and the connecting piece is arranged in the third mounting hole and the fourth mounting hole to fixedly connect the support sleeve and the second supporting part; in the second state, the support sleeve is located at a second position where the third mounting hole and the fifth mounting hole are in communication, and the connecting piece is arranged in the third mounting hole and the fifth mounting hole to synchronously rotate the support sleeve and the fixed sleeve.

[0013] According to some embodiments of the present application, the support sleeve is axially movable to switch between the first position and the second position, in the second position, the top end of the support sleeve is inserted into the fixed sleeve, and in the first position, the top end of the support sleeve is out of the fixed sleeve.

[0014] According to some embodiments of the present application, the support assembly further comprises a clamping spring sleeved on the support sleeve, and the outer peripheral wall of the support sleeve is provided with a first clamping groove and a second clamping groove arranged axially at intervals, the clamping spring is clamped in the first clamping groove when the support sleeve is in the first position, and the clamping spring is clamped in the second clamping groove when the support sleeve is in the second position. According to some embodiments of the present application, the distance from the first clamping groove to the top end of the support sleeve is less than the distance from the second clamping groove to the top end of the support sleeve.

[0015] According to the second aspect of the present application, the automatic tightening device comprises: a multi-axis robot; an image recognition module; a control module; a tightening mechanism as described in any one of the above embodiments, the tightening mechanism being connected with the multi-axis robot; The control module can acquire image information collected by the image recognition module, and control the multi-axis manipulator to move according to the image information.

[0016] According to some embodiments of the present application, the automatic tightening device comprises a variable-distance platform and two tightening mechanisms connected to the variable-distance platform, the variable-distance platform is provided with a sliding rail, and at least one of the tightening mechanisms is connected to the variable-distance platform through the sliding rail; the distance between the two tightening mechanisms is adjustable under the control of the control module.

[0017] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be understood through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present application will be further described below in conjunction with the drawings and embodiments, wherein: Figure 1 It is a structural schematic view of the automatic tightening device of the embodiment of the present application; Figure 2 It is a schematic view of the tightening mechanism of the embodiment of the present application arranged on the variable-distance platform; Figure 3 It is a side view of Figure 2 ; Figure 4 It is a structural schematic view of the flexible assembly and the fastening assembly of the embodiment of the present application; Figure 5 It is a sectional view of Figure 4 ; Figure 6 It is a schematic view of the support assembly of the embodiment of the present application in the first state; Figure 7 It is a sectional view of Figure 6 ; Figure 8 It is a schematic view of the support assembly of the embodiment of the present application in the second state; Figure 9 It is a sectional view of Figure 8 ; Figure 10 It is a matching schematic view of the support sleeve, the fixed sleeve and the bit of the embodiment of the present application.

[0019] Reference signs: Tightening mechanism 10; Multi-axis manipulator 20; Variable-distance platform 30; Sliding rail 31; Bit 40; Base assembly 100; Base 110; First mounting seat 120; Second mounting seat 130; First supporting part 131; Second supporting part 132; Fourth mounting hole 133; High-elasticity spring 140; Electric bit 200; Flexible assembly 300; fixing member 310; elastic member 320; movable member 330; first channel 331; first mounting hole 332; guide sleeve 340; guide groove 341; guide member 350; Fastening assembly 400; limiting member 410; fastening member 420; second mounting hole 421; Support assembly 500; fixed sleeve 510; fifth mounting hole 511; first bearing 520; support sleeve 530; second channel 531; third mounting hole 532; first clamping groove 533; second clamping groove 534; second bearing 540; clamping spring 550; third bearing 560; connecting member 570; DETAILED DESCRIPTION The embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations 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 only, for the purpose of explaining the present application, and should not be understood as a limitation of the present application.

[0020] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as a limitation of the present application.

[0021] In the description of the present application, if the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, etc. is understood as not including the number, above, below, etc. is understood as including the number. If it is described as first, second, it is only for the purpose of distinguishing technical features, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0022] In the description of the present application, unless otherwise explicitly limited, the words such as setting, mounting, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0023] In the description of the application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples.

[0024] In the field of automated manufacturing such as automobile manufacturing, consumer electronics, aerospace, etc., high-precision tightening of bolt connection is a key link to ensure the reliability and safety of key components. To improve the tightening efficiency and replace repetitive manual operation, servo automatic tightening systems gradually become the mainstream solution, which usually complete screw locking by driving electric wrench and tightening chuck with three-axis, four-axis or six-axis manipulator.

[0025] In the existing servo automatic tightening system, the Z-axis direction needs to drive the manipulator to descend synchronously with the screw tightening to continuously compensate for the Z-direction displacement generated by the screw rotation. During the descending process, the electric wrench and the tightening chuck are pressed downward as a whole. Once the Z-axis descending speed and the screw rotation speed do not match, the weight of the electric wrench and the tightening chuck and the downward driving force will directly act on the screw, causing the screw to slip, appearance damage and other problems, which seriously affect the product quality.

[0026] To solve the above problems, as shown in Figures 1 to 10 , the application provides a tightening mechanism 10, as shown in Figures 1 to 3 , which includes a base assembly 100, an electric wrench 200 and a flexible assembly 300. The base assembly 100 is used to connect with a multi-axis manipulator 20. The electric wrench 200 is installed on the base assembly 100 and outputs rotary power. The flexible assembly 300 is arranged at the output end of the electric wrench 200 and connected with a chuck 40, which is used to provide elastic compensation displacement in the axial direction of the chuck 40.

[0027] Specifically, as shown in Figure 4 and Figure 5As shown, the flexible assembly 300 includes a fixed part 310, an elastic part 320 and a movable part 330, the fixed part 310 is fixedly connected to the output end of the electric wrench 200, the movable part 330 is used for fixedly connecting with the chuck 40, one end of the elastic part 320 is connected to the fixed part 310, and the other end is connected to the movable part 330. It can be understood that, since the movable part 330 and the fixed part 310 are flexibly connected through the elastic part 320, when the movable part 330 is pressed or pulled, the movable part 330 can be elastically displaced in the axial direction compared with the fixed part 310, thereby making the chuck 40 have a buffer stroke in the Z direction. When the multi-axis robot 20 drives the whole tightening mechanism 10 to press downward, the flexible assembly 300 dynamically compensates the displacement deviation in the Z-axis direction through the compression or stretching of the elastic part 320, effectively alleviates the overpressure or underpressure problem caused by the mismatch between the Z-axis descending speed and the screw rotating speed, reduces the risk of screw slipping and appearance damage, and improves the locking rate.

[0028] In addition, in order to transmit the rotating power and ensure that the movable part 330 remains stable during axial movement, the flexible assembly 300 further includes a guide sleeve 340, the guide sleeve 340 is sleeved outside the elastic part 320, the top end of the guide sleeve 340 is fixedly connected to the fixed part 310, and the bottom end can be slidably connected to the movable part 330, limiting the relative rotation between the movable part 330 and the fixed part 310, and guiding the movable part 330 to move linearly in the axial direction. Specifically, as shown in Figure 3 and Figure 4 The guide sleeve 340 is provided with a guide groove 341 extending in the axial direction thereof, which can be arranged on the inner side wall of the guide sleeve 340 or can be formed as a through hole structure penetrating through the pipe wall of the guide sleeve 340. The flexible assembly 300 further includes a guide part 350, the guide part 350 is fixedly connected to the movable part 330 and protrudes from the outer peripheral surface of the movable part 330, the guide part 350 is inserted into the guide groove 341, and during the compression or stretching of the elastic part 320, the guide part 350 slides along the guide groove 341, thereby restricting the movable part 330 to move linearly in the axial direction only, avoiding circumferential rotation or radial deviation, and ensuring that the rotating power is stably transmitted to the chuck 40.

[0029] As shown in the embodiment, Figure 5 the guide part 350 is a pin shaft penetrating through the movable part 330, the opposite sides of the guide sleeve 340 are respectively provided with through holes extending in the axial direction as the guide grooves 341, and the two ends of the pin shaft protrude from the movable part 330 and are respectively inserted into the guide grooves 341 on the two sides, achieving sliding fit. In other embodiments, the guide part 350 can also be a guide block protruding from the outer periphery of the movable part 330, and the guide block can be integrally formed or fixedly connected with the movable part 330, and the guide groove 341 is correspondingly designed as a sliding groove structure matched with the guide block. The top end of the guide sleeve 340 is fixedly connected to the fixed part 310 through another pin shaft, ensuring that there is no relative movement between the guide sleeve 340 and the fixed part 310.

[0030] Based on the above, during the screw locking process, the movable part 330 and the fixed part 310 can be driven to rotate synchronously by the electric driver 200, so as to drive the chuck 40 connected with the movable part 330 to rotate synchronously, the chuck 40 is connected with the screw, and the stable transmission of the rotating power is realized through the transmission chain among the electric driver 200, the fixed part 310, the movable part 330, the chuck 40 and the screw. In addition, the tightening mechanism 10 actively presses downward to a certain extent before locking the screw, so that the chuck 40 is in advance contacted with the screw and a certain pre-pressure is maintained, so that the screw is stably positioned in the initial stage of screwing, and the problems of slipping or locking failure caused by shaking or deflection are avoided. At this time, the elastic part 320 is in a compressed state, and a buffer space is reserved for subsequent Z-axis compensation. When the screw contacts the workpiece and starts to screw, if the downward speed of the electric driver 200 is inconsistent with the screwing progress of the screw, the elastic part 320 can dynamically adjust the axial position of the chuck 40 by further compressing or releasing the pre-pressing amount, so as to ensure that the axial force applied to the screw is always stable and controllable, effectively alleviate the problems of overpressure or underpressure caused by the mismatch between the Z-axis downward speed and the screwing speed of the screw, avoid the damage to the screw or the workpiece caused by the overpressure or underpressure of the mechanical hand due to the displacement error, and ensure the smooth and controllable locking process.

[0031] In order to realize the connection and fixation of the movable part 330 and the chuck 40, the movable part 330 is defined with a first channel 331 for inserting the chuck 40, and the first channel 331 penetrates the movable part 330 along the axial direction. It should be noted that the end of the chuck 40 is generally a polygonal structure, such as a common hexagonal or quadrangular shape, and the first channel 331 is provided as a polygonal structure matched with the end of the chuck 40, so as to ensure that the chuck 40 cannot rotate relatively after being inserted, and the reliable transmission of the torque is realized.

[0032] The movable part 330 is also defined with a first mounting hole 332 extending along the radial direction, and the first mounting hole 332 penetrates the pipe wall of the movable part 330 and is in communication with the first channel 331. The tightening mechanism 10 comprises a fastening assembly 400, and the fastening assembly 400 comprises a limiting part 410, which is arranged in the first mounting hole 332 and can protrude or retract relative to the inner wall of the first channel 331, so as to limit or release the axial displacement of the chuck 40. It can be understood that when the chuck 40 is inserted into the first channel 331, one end of the limiting part 410 protrudes into the first channel 331 and abuts against the outer circumferential surface of the chuck 40, so as to limit the axial movement of the chuck 40. By retracting the limiting part 410, the limiting part 410 can be separated from the chuck 40, so that the chuck 40 can move axially.

[0033] Therefore, by adjusting the telescopic state of the limiting member 410, the quick installation or disassembly of the chuck 40 can be realized. It can be understood that the limiting member 410 can be a screw, or an elastic pin or a steel ball structure, which cooperates with the limiting groove arranged on the outer periphery of the chuck 40 to realize positioning. When the limiting member 410 is a screw, the telescopic depth thereof is adjusted by rotation, so that the chuck 40 is compressed or released.

[0034] Further, the fastening assembly 400 of the present application further comprises two fasteners 420 and at least one threaded member (not shown in the figure), the two fasteners 420 are arranged at intervals and are respectively located on the two radial sides of the movable member 330, and each fastener 420 is provided with a semicircular groove, and the two fasteners 420 are oppositely arranged at one end provided with the groove, so as to jointly define a second mounting hole 421 for the movable member 330 to pass through. The threaded member is threaded in the through hole of one of the fasteners 420 and is threadedly connected to the other fastener 420, and by tightening or loosening the threaded member, the two fasteners 420 can be driven to move close to or away from each other, so as to adjust the radial size of the second mounting hole 421 and realize clamping or releasing of the movable member 330.

[0035] It should be noted that the fastener 420 is connected with the limiting member 410, so that the limiting member 410 can move synchronously with the fastener 420 under the driving of the threaded member. Therefore, when the two fasteners 420 move close to each other under the action of the threaded member, the fastener 420 drives the limiting member 410 to move synchronously to the first channel 331, so that the limiting member 410 extends into the first channel 331 and compresses the outer peripheral surface of the chuck 40, thereby realizing the limitation of the axial movement of the chuck 40; when the two fasteners 420 move away from each other under the action of the threaded member, the fastener 420 drives the limiting member 410 to separate from the outer peripheral surface of the chuck 40, so as to release the axial limitation of the chuck 40, thereby facilitating quick disassembly or adjustment.

[0036] It should be noted that the limiting member 410 can be a threaded connecting member such as a bolt, which can be screwed into the movable member 330 in addition to being telescopic through the linkage of the fastener 420 and the threaded member. Therefore, the fastening assembly 400 of the present application can realize the locking of the chuck 40 and the movable member 330 through the double fastening action of the limiting member 410 and the fastener 420, so as to reduce the risk of loosening of the chuck 40 in the process of use due to vibration or external force, and improve the stability and reliability of the connection.

[0037] It can be understood that the number of limiting members 410 can be one, which is connected with one of the fasteners 420; or the number of limiting members 410 can be two, which are respectively connected with the two fasteners 420 one by one. When the limiting member 410 is two, it is symmetrically arranged on the two radial sides of the movable member 330, which can improve the clamping stability.

[0038] In some embodiments, asFigure 3 As shown, the base assembly 100 comprises a base 110, a first mounting seat 120 and a second mounting seat 130, the first mounting seat 120 and the second mounting seat 130 are arranged on the base 110, and the first mounting seat 120 and the second mounting seat 130 are arranged along the axial direction of the movable part 330, the first mounting seat 120 is used for mounting the electric wrench 200, and the second mounting seat 130 is used for connecting with the wrench head 40 to support the wrench head 40, so as to avoid shaking or deviation of the wrench head 40 in the working process due to stress. The second mounting seat 130 can move relative to the first mounting seat 120 to adapt to the telescopic adjustment of the flexible assembly 300.

[0039] In addition, as shown in Figure 3 The high-elasticity spring 140 is arranged between the first mounting seat 120 and the second mounting seat 130, so as to prevent damage to the mechanism due to servo overpressure. The high-elasticity spring 140 does not affect the downward movement of the second mounting seat 130 relative to the first mounting seat 120, and when the servo is overpressure, the second mounting seat 130 moves upward until it abuts against the high-elasticity spring 140, so as to achieve buffering.

[0040] In order to realize the rotary support of the wrench head 40, as shown in Figures 6 to 9 The tightening mechanism 10 further comprises a support assembly 500 arranged on the second mounting seat 130. The support assembly 500 comprises a fixed sleeve 510 and a first bearing 520, the fixed sleeve 510 is used for fixedly connecting with the wrench head 40. For example, the fixed sleeve 510 comprises an expansion sleeve and a locking nut, the expansion sleeve is sleeved on the outer periphery of the wrench head 40, and the locking nut is axially compressed to realize interference fit, so as to firmly connect the fixed sleeve 510 with the wrench head 40. The first bearing 520 is sleeved on the outer periphery of the fixed sleeve 510, the inner ring of the first bearing 520 is interference fit with the fixed sleeve 510, and the outer ring is fixedly connected with the second mounting seat 130, so as to rotatably connect the fixed sleeve 510 with the second mounting seat 130, thereby providing stable support and reducing radial runout when the wrench head 40 rotates, so as to improve the overall structural rigidity.

[0041] In some application scenarios, when the batch head 40 is long, in order to avoid insufficient rigidity of the distal end of the batch head 40 due to excessive overhanging, the support assembly 500 further comprises a support sleeve 530, which defines a second channel 531 extending axially along the support sleeve 530, and a majority of the batch head 40 is arranged in the second channel 531, and the top end of the batch head 40 extends out of the fixed sleeve 510 and is used to be connected with the movable part 330. The support sleeve 530 is provided with a second bearing 540 for rotationally connecting with the batch head 40. It can be understood that at least one second bearing 540 is arranged at each end of the second channel 531 to achieve multi-point support of the batch head 40 and effectively suppress vibration and deflection during high-speed rotation. The outer ring of the second bearing 540 is connected with the support sleeve 530, and the inner ring is connected with the batch head 40 to achieve rotational support of the batch head 40.

[0042] Further, due to the dimensional tolerance in the manufacturing process of the batch head 40, a small gap may exist between the batch head 40 and the inner ring of each bearing, affecting the rotational coaxiality. Therefore, the support assembly 500 is designed to have a first state and a second state. In the first state, the support sleeve 530 does not rotate with the batch head 40; in the second state, the support sleeve 530 rotates synchronously with the batch head 40. When the machining size error of the batch head is small (such as the diameter tolerance and the cylindricity tolerance are within the allowable range), the gap between the outer circle of the batch head and the inner hole of the support sleeve 530 is uniform, and the coaxiality of the two is naturally good. At this time, the batch head is allowed to rotate alone, and the sleeve does not rotate, avoiding the additional friction and vibration caused by the rotation of the support sleeve 530. When the size error of the batch head is large, the gap between the outer circle of the batch head and the inner hole of the sleeve is not uniform (such as the local diameter of the batch head is larger / smaller), which directly leads to the poor coaxiality of the two. At this time, by adjusting the support assembly 500 to the second state, the support sleeve 530 rotates synchronously with the batch head 40, and the non-uniform gap between the batch head 40 and the sleeve is compensated by the rotation of the support sleeve 530. The eccentricity error of the batch head is offset by the rigidity of the sleeve, and the two rotate on the same axis, eliminating the radial swing of the batch head.

[0043] Specifically, the support sleeve 530 further has a third mounting hole 532 penetrating the wall of the support sleeve 530 and communicating with the second channel 531, and the second mounting seat 130 comprises a first supporting part 131 rotationally connected with the fixed sleeve 510, and a second supporting part 132 rotationally connected with the support sleeve 530, as shown in Figure 6 and Figure 7 The second supporting part 132 is provided with two third bearings 560 for rotationally connecting with the support sleeve 530. In addition, the second supporting part 132 is further provided with a fourth mounting hole 133 extending in the radial direction of the support sleeve 530, and the fixed sleeve 510 is provided with a fifth mounting hole 511 extending in the radial direction of the support sleeve 530.

[0044] The support assembly 500 further comprises a connecting piece 570, as shown in Figure 6 and Figure 7 When the support assembly 500 is in the first state, the support sleeve 530 is located at a first position where the third mounting hole 532 and the fourth mounting hole 133 are in alignment and communication, and the connecting piece 570 is arranged through the third mounting hole 532 and the fourth mounting hole 133, so as to limit the rotation of the support sleeve 530 relative to the second supporting part 132, and keep the support sleeve 530 stationary; as shown in Figure 8 and Figure 9 When the support assembly 500 is switched to the second state, the support sleeve 530 moves to a second position where the third mounting hole 532 and the fifth mounting hole 511 are in alignment and communication, and the connecting piece 570 is arranged through the third mounting hole 532 and the fifth mounting hole 511, so as to realize the synchronous rotation of the support sleeve 530 and the fixed sleeve 510. Through the switching of the rotation state of the support sleeve 530, the stability of the chuck 40 in rotation and the coaxiality requirement under different machining precisions are taken into account, the adaptability and reliability of the tightening mechanism 10 are improved, the tightening mechanism 10 can be compatible with the high-precision and conventional-precision chucks 40, the excessive dependence on the manufacturing tolerance is reduced, and the tool cost is saved.

[0045] It should be explained that the third mounting hole 532 is provided with two, which are inserted into different third mounting holes 532 in different states. In other embodiments, the third mounting hole 532 can be provided with only one, and the third mounting hole 532 is aligned with the fourth mounting hole 133 or the fifth mounting hole 511 by switching the position of the support sleeve 530.

[0046] Further, the support sleeve 530 switches between the first position and the second position by moving along the axial direction thereof. It should be explained that, as shown in Figure 9 in the second position, the top end of the support sleeve 530 is inserted into the inner hole of the fixed sleeve 510, and the outer diameter of the top end of the support sleeve 530 is slightly larger than the rest of the region, so that the outer cylindrical surface of the top end of the support sleeve 530 abuts against the inner hole of the fixed sleeve 510, to realize the stable cooperation of the two, and avoid vibration during rotation. In the first position, the top end of the support sleeve 530 exits the fixed sleeve 510 and is located in the second supporting part 132, so as to avoid abrasion of the outer peripheral surface of the top end of the support sleeve 530 when the fixed sleeve 510 rotates.

[0047] In addition, in order to realize the positioning of the support sleeve 530 during the position switching, so as to accurately align the third mounting hole 532 and the fourth mounting hole 133 or the fifth mounting hole 511, as shown in Figure 10As shown, the outer peripheral wall of the support sleeve 530 is provided with a first clamping groove 533 and a second clamping groove 534 axially spaced therealong, and the support assembly 500 further comprises a clamping spring 550 sleeved on the support sleeve 530, which can be embedded in the first clamping groove 533 or the second clamping groove 534 to realize positioning of the support sleeve 530 at the first position and the second position. When the clamping spring 550 is embedded in the first clamping groove 533, the support sleeve 530 is limited to the first position, and the third mounting hole 532 is aligned with the fourth mounting hole 133; when the clamping spring 550 is embedded in the second clamping groove 534, the support sleeve 530 is limited to the second position, and the third mounting hole 532 is aligned with the fifth mounting hole 511. Through cooperation of the clamping spring 550 and different clamping grooves, reliable locking of the axial position of the support sleeve 530 is realized, accurate penetration of the connecting piece 570 is ensured, and the convenience and structural stability of state switching are improved. It can be understood that the distance from the first clamping groove 533 to the top end of the support sleeve 530 is less than the distance from the second clamping groove 534 to the top end of the support sleeve 530.

[0048] The second aspect embodiment of the present application provides an automatic tightening device, which comprises a multi-axis manipulator 20, an image recognition module, a control module, and the tightening mechanism 10 mentioned in any one of the above embodiments. The multi-axis manipulator 20 is used to drive the tightening mechanism 10 to move to a target work station. The image recognition module is used to collect workpiece surface features and locate screw hole positions, so that the control module can obtain image information of the image recognition module and control the multi-axis manipulator 20 to move to guide the multi-axis manipulator 20 to accurately align. It should be noted that the multi-axis manipulator 20 can be a three-axis, six-axis or more-axis manipulator, and the degree of freedom configuration can be flexibly set according to the actual assembly space and motion trajectory requirements.

[0049] Further, as shown in Figure 1 and Figure 2 The automatic tightening device comprises two tightening mechanisms 10 and a variable-distance platform 30, and the variable-distance platform 30 is provided with a sliding rail 31, and at least one of the tightening mechanisms 10 is slidingly connected to the variable-distance platform 30 through the sliding rail 31. Under the control of the control module, the distance between the two tightening mechanisms 10 is adjustable. For example, after obtaining the screw hole spacing information fed back by the image recognition module, the control module drives one of the tightening mechanisms 10 on the variable-distance platform 30 to move along the sliding rail 31 to adjust the relative distance between the two tightening mechanisms 10, so that it accurately matches the screw hole distribution of the current workpiece.

[0050] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge range of ordinary skill in the art without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A tightening mechanism, characterized in that, include: Base assembly; An electric screwdriver, wherein the electric screwdriver is connected to the base assembly; A flexible component includes a fixing member, an elastic member, a movable member, and a guide sleeve. The fixing member is connected to the electric screwdriver, the movable member is used to connect to the screwdriver bit, one end of the elastic member is connected to the fixing member, and the other end is connected to the movable member. The guide sleeve is sleeved on the elastic member and is fixedly connected to the fixing member. The guide sleeve is provided with a guide groove extending along its axial direction. The flexible component includes a guide member that protrudes from the outer peripheral surface of the movable member and slides in cooperation with the guide groove. The movable part and the fixed part are driven to rotate synchronously by the electric screwdriver, and the elastic part can be compressed or stretched to move the movable part toward or away from the fixed part.

2. The tightening mechanism according to claim 1, characterized in that, The movable member defines a first channel for inserting the bit, and the movable member also defines a first mounting hole that penetrates the tube wall of the movable member and communicates with the first channel; The tightening mechanism further includes a fastening component, which includes a limiting member passing through the first mounting hole. The limiting member can extend or retract relative to the inner wall of the first channel to restrict the axial movement of the bit or release the restriction on the bit.

3. The tightening mechanism according to claim 2, characterized in that, The fastening assembly further includes two fasteners and at least one threaded member, the two fasteners being spaced apart and together defining a second mounting hole through which the movable member passes; the threaded member passes through one of the fasteners and is connected to the other fastener. The fastener is connected to the limiting member and is driven by the threaded member, and the limiting member and the fastener move synchronously.

4. The tightening mechanism according to claim 1, characterized in that, The base assembly includes a first mounting base and a second mounting base connected to the electric screwdriver, the second mounting base being movable relative to the first mounting base; the tightening mechanism further includes a support assembly, the support assembly including a fixed sleeve and a first bearing, the fixed sleeve being fixedly connected to the screwdriver bit, and the first bearing being sleeved on the fixed sleeve to allow the fixed sleeve and the second mounting base to be rotatably connected.

5. The tightening mechanism according to claim 4, characterized in that, The support assembly further includes a support sleeve having a second channel through which the bit passes, and at least one second bearing is provided at each end of the second channel, wherein the bit and the support sleeve are rotatably connected via the second bearings.

6. The tightening mechanism according to claim 5, characterized in that, The support sleeve also has a third mounting hole that penetrates the wall of the support sleeve and communicates with the second channel. The second mounting base includes a first support portion rotatably connected to the fixed sleeve and a second support portion rotatably connected to the support sleeve. The second support portion is provided with a fourth mounting hole extending radially along the support sleeve. The fixed sleeve is provided with a fifth mounting hole extending radially along the support sleeve. The support assembly further includes a connector. The support assembly has a first state and a second state. In the first state, the support sleeve is located at a first position where the third mounting hole and the fourth mounting hole are connected, and the connector passes through the third mounting hole and the fourth mounting hole to fix the support sleeve and the second support portion. In the second state, the support sleeve is located at a second position where the third mounting hole and the fifth mounting hole are connected, and the connector passes through the third mounting hole and the fifth mounting hole to make the support sleeve and the fixed sleeve rotate synchronously.

7. The tightening mechanism according to claim 6, characterized in that, The support sleeve is movable along its axial direction to switch between the first position and the second position. In the second position, the top end of the support sleeve is inserted into the fixed sleeve, and in the first position, the top end of the support sleeve is removed from the fixed sleeve.

8. The tightening mechanism according to claim 7, characterized in that, The support assembly further includes a retaining spring sleeved on the support sleeve. The outer peripheral wall of the support sleeve is provided with a first retaining groove and a second retaining groove spaced apart along its axial direction. When the support sleeve is in the first position, the retaining spring is engaged in the first retaining groove. When the support sleeve is in the second position, the retaining spring is engaged in the second retaining groove. Wherein, the distance from the first slot to the top of the support sleeve is less than the distance from the second slot to the top of the support sleeve.

9. An automatic tightening device, characterized in that, include: Multi-axis robotic arm; Image recognition module; Control module; The tightening mechanism as described in any one of claims 1 to 8, wherein the tightening mechanism is connected to the multi-axis manipulator; The control module is capable of acquiring image information collected by the image recognition module and controlling the movement of the multi-axis robot arm based on the image information.

10. The automatic tightening device according to claim 9, characterized in that, The automatic tightening device includes a variable pitch platform and two tightening mechanisms connected to the variable pitch platform. The variable pitch platform is provided with a slide rail, and at least one of the tightening mechanisms is slidably connected to the variable pitch platform through the slide rail. The distance between the two tightening mechanisms is adjustable under the control of the control module.

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