Servo tightening module

Abstract

The present application relates to a servo tightening module, comprising a suction pipe head assembly; a suction seat, which is sleeved on the suction pipe head assembly, the suction seat is connected with the suction pipe sleeved on the suction pipe head assembly; a tightening tool assembly, which is fixed on the other end of the suction pipe head assembly for driving the suction pipe head assembly to rotate and can detect torque; an axial feeding unit; an elastic connecting piece, which is fixed between the suction seat and the tightening tool assembly for driving the suction seat to move synchronously and feeding back elastic force; a gun head. The present application has compact and reasonable structure, convenient operation, through setting the suction pipe, the suction seat, the guide rail brake and the spring connecting piece, in the mode of servo motor control, the screw can be conveniently sent into the deep hole, at the same time, the guide rail brake provides efficient braking effect, and then in the process of screw tightening, the down pressure can be accurately obtained, so that the tightening process can be adaptively carried out through the closed loop servo control system, which has strong practicability.

Description

Technical Field

[0001] This invention relates to the field of tightening module technology, and in particular to servo tightening modules. Background Technology

[0002] The standard tightening process involves the following steps: First, the screw enters the through hole, and the screw thread contacts the product thread. Second, the screwdriver bit engages with the screw thread, a process known as bit engagement. Third, the screwdriver bit is quickly rotated to screw the thread into the product. Fourth, the lower surface of the screw contacts the product surface. Fifth, the screw is further tightened to achieve the required torque. Finally, the screwdriver bit is removed, completing the tightening process.

[0003] During this series of processes, the following problems may occur: thread damage may occur during screw insertion and rapid screwing; after the screw reaches the mating surface, during the torque setting process, the bit and the screw pattern may jump, resulting in damage to the screw pattern and making it impossible to remove; after tightening, the bit and screw may become stuck together, making it impossible to remove the bit.

[0004] The above problems are mostly caused by a mismatch between the screw's drive stroke and rotation torque. Therefore, the screw needs to be fitted with different torques at each stage to achieve a better tightening effect.

[0005] However, the common tightening modules are mainly driven by pneumatic cylinders or electric cylinders.

[0006] A cylinder is a pneumatic actuator that converts the pressure energy of compressed gas into mechanical energy. As is well known, compared to electric actuators, cylinders can work reliably under harsh conditions, are simple to operate, and are essentially maintenance-free. Cylinders excel at reciprocating linear motion, making them particularly suitable for the most common conveying requirements in industrial automation—the linear transport of workpieces. From a user convenience perspective, most people prefer cylinders because they allow for quick and easy adjustment of speed and output pressure, making them the easiest to maintain for inexperienced field maintenance personnel. However, using cylinders as a power source is not without its drawbacks; they lack precise control, cannot be used at multiple points, and lack positive feedback.

[0007] Electric cylinders are very flexible and can be used as long as there is electricity, without the need for an air source. Air sources are often the main reason why electric cylinders are not effective. Electric cylinders can operate at multiple points and are easy to use in different working conditions without changing the mechanical structure. By utilizing the torque characteristics of the motor, different downward pressures can be provided for segmented tightening. The encoder can be used to monitor the screw driving depth.

[0008] Currently, traditional methods, such as the tightening device for automatically executing a tightening process disclosed in Chinese Patent CN 115229480 A, use an electric cylinder to automatically control the tightening process. However, in this patent, the transmission tool 16 directly contacts the screw for tightening, and the pressure control of the motor on the transmission tool 16 is also direct, without other excessive interference. Therefore, this patent uses…

[0009] a) Feed the helical drive tool to the screw head;

[0010] b) Check for proper meshing by evaluating instantaneous data on position and feed force;

[0011] c) Improved control of the rotary drive and / or the feed unit in the event of incorrect engagement;

[0012] d) Further feed and monitor the position and feed force to determine if proper engagement has been achieved;

[0013] This method enables the automatic execution of the tightening process.

[0014] However, there is a major flaw in this patent;

[0015] That is, since the transmission tool 16 directly contacts the screw, it can only be used when the fixing element 26 can contact the screw hole. If the screw hole is too deep or there is interference from the gun head, making it impossible for the fixing element 26 to deliver the screw into the screw hole, this method cannot be used.

[0016] Currently, the common approach to this situation is to use a nail suction tube and a screwdriver bit (transmission tool 16) simultaneously. The nail suction tube and the screwdriver bit fix the screw at the same time, and the nail suction tube can extend out of the gun head (fixing element 26) to feed the screw into the excessively deep screw hole, and then the screw is pushed out by the screwdriver bit for tightening.

[0017] However, if a nail suction tube is used, the bit and the nail suction tube move synchronously, and both the bit and the nail suction tube are fed by the same feed unit. At this time, the bit will generate the first type of feed force. At the same time, there is also independent movement (the bit pushes out the screw to tighten). When the bit and the nail suction tube move independently, the nail suction tube needs to be braked. Therefore, the feed force of the bit will generate the second type of feed force.

[0018] This makes it difficult to control the feed force of the bit, making it difficult to automatically tighten according to the comparison document. Because the second type of feed force is generated at the same time as the tightening process, multiple forces affect each other, making it difficult to judge the feed force and thus making it difficult to achieve automatic tightening.

[0019] Furthermore, when the bit and the nail suction tube move independently, the nail suction tube needs to be braked. Since the guide rail surface is plated with hard chrome and has no flat surface, it is impossible to achieve rapid braking without damaging the linear guide rail, and the braking effect is not good. Therefore, the second type of feed force is mixed with other forces, making it even more difficult to judge the feed force of the screw.

[0020] Therefore, we propose a servo tightening module. Summary of the Invention

[0021] In response to the shortcomings of the existing production technology, the applicant provides a servo tightening module, which can accurately measure the downward pressure of the screw while the suction tube feeds the screw into the deep hole, facilitating automatic tightening and demonstrating strong practicality.

[0022] The technical solution adopted in this invention is as follows: including:

[0023] A screw-picking tube bit assembly, the end of which is connected to a bit for mating screws;

[0024] A nail suction holder is fitted onto the nail suction tube bit assembly, and the nail suction holder is connected to a nail suction tube that is fitted onto the nail suction tube bit assembly.

[0025] Tighten the tool assembly, which is fixed to the other end of the nail suction tube bit assembly to drive the nail suction tube bit assembly to rotate and to detect torque;

[0026] An axial feed unit, connected to a tightening tool assembly, is used to generate axial feed motion within a stroke range. The axial feed unit includes a motor assembly and is capable of detecting the pressure and speed of the axial motion.

[0027] The elastic connector is fixed between the nail-holding base and the tightening tool assembly to drive the nail-holding base to move synchronously and to provide feedback elastic force;

[0028] The guide rail brake is fixed on the nail-catching seat and controls the movement of the nail-catching seat.

[0029] The nozzle has a pre-drilled channel for the nail suction tube bit assembly to pass through, and a spare screw is also pre-drilled in the channel.

[0030] Its further features are:

[0031] It also includes a housing, with the gun head fixed on the housing. A guide rail is connected to the housing, and the guide rail is arranged parallel to the nail suction tube bit assembly. The nail suction seat, guide rail brake, and tightening tool assembly are all slidably connected to the guide rail.

[0032] The screw-collecting seat is connected to a gun barrel that mates with the screw-collecting tube, used to control the engagement and disengagement of the screw-collecting tube bit assembly with the screw.

[0033] The drive end of the motor assembly is connected to the lead screw assembly, and the tightening tool assembly is threaded onto the lead screw assembly through its mounting seat. The nail holder has a through hole for the lead screw assembly to pass through.

[0034] The gun head includes a gun barrel, a nail feeding mechanism for feeding nails into the channel is connected to the gun barrel, and a nail clamping structure for fixing screws is connected to the end of the gun barrel. The nail clamping structure is controlled to open and close by a clamping control structure to control the clamping and release of the nail. A proximity sensor corresponding to the clamping control structure is connected to the outer shell.

[0035] The elastic connector includes a mandrel that extends through the nail-holding seat, and a spring is fitted onto a section of the mandrel located between the nail-holding seat and the tightening tool assembly.

[0036] The guide rail brake includes a sleeve assembly, which includes two relatively fixed sleeves and a slide rail disposed between the two sleeves to facilitate the movement of the guide rail.

[0037] The sleeve is connected to a piston that moves in a vertical direction, and the lower end of the piston is connected to a connecting rod. The lower end of the connecting rod abuts against the sliding block and drives the sliding block to move horizontally to one side of the slide.

[0038] The sleeve has an air inlet for ventilation, and the ventilation through the air inlet causes the piston to move up and down. At the same time, the air pressure causes the sliding block to move towards the slide rail and contact the guide rail for braking.

[0039] The upper end of the sleeve is threaded with a connecting sleeve, and a compression spring is provided inside the connecting sleeve. The compression spring extends into the sleeve and contacts the piston, providing downward preload to the piston.

[0040] The connecting rod extends to a section of the side wall between the mounting block and the sliding block, and a rectangular hole is provided. Two rolling shafts, which roll on the mounting block and the sliding block respectively, are connected in the rectangular hole. The sliding block has a "T" shaped structure, with its wider end sliding on the inner wall of the sleeve. The end of the sliding block near the connecting rod is inclined, and its narrower end passes through a through hole in the side wall of the sleeve and moves in the direction of the slide. At the same time, an elastic washer for pre-tightening and resetting is connected between the sleeve and the sliding block.

[0041] When the screwdriver bit tightens the screw, it generates downward pressure, and the downward pressure value F = Fs - Ft ± G, where Fs = the output force of the motor assembly; Ft = the elastic force of the elastic connector; and G = the weight of other parts.

[0042] Where Fs = 2πηT / L; η: transmission efficiency of the lead screw assembly; T: torque; L: lead of the lead screw assembly;

[0043] Ft = kx; k: elastic coefficient of the elastic connector; X: displacement of the motor assembly relative to the nail holder.

[0044] The beneficial effects of this invention are as follows:

[0045] This invention features a compact and reasonable structure, and is easy to operate. By incorporating a nail-suction tube, a nail-suction seat, a guide rail brake, and a spring connector, and controlled by a servo motor, it can easily feed screws into deep holes. Simultaneously, the guide rail brake provides an efficient braking effect, and thus, during the screw tightening process, it can accurately obtain downward pressure. Therefore, the tightening process can be adaptively performed through a closed-loop servo control system, making it highly practical.

[0046] In addition, the present invention also has the following advantages:

[0047] (1). The guide rail brake provides a stopping function in different processes. With this function, we can extend the bit out of the barrel and the barrel out of the head for tightening. Moreover, the guide rail brake provides a large braking force with a small volume, which is convenient for subsequent tightening. At the same time, since the nail suction seat and the tightening tool assembly are connected by an elastic connector, the braking force generated when the nail suction seat is braked is transformed into the elastic force of the elastic connector. Since the elastic force is known, the specific value of the downward pressure can be obtained.

[0048] (2) The braking effect is achieved by directly moving the sliding block in the direction of the guide rail through the air supply. On the other hand, the piston moves upward through the air supply, and the sliding block is squeezed by the rolling shaft, which further improves the connection between the sliding block and the guide rail. The braking efficiency is improved through the dual measures, which has strong practicality.

[0049] (3) Through the application of various project sites, by collecting parameters such as different tightening screws, tightened materials, and tightening processes of customers, we can obtain a detailed database. After analyzing these data, we can generalize and provide a comprehensive tightening solution. This also includes the matching of tightening parameters, such as which screw requires which tightening logic, and which product requires what pressure and speed to tighten. In this way, we can achieve more refined and intelligent tightening. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of the present invention.

[0051] Figure 2 This is a cross-sectional view of the present invention.

[0052] Figure 3 for Figure 2 A magnified view of part A in the middle.

[0053] Figure 4for Figure 2 A magnified view of part B in the middle.

[0054] Figure 5 This is a schematic diagram of the structure of the present invention.

[0055] Figure 6 This is a cross-sectional view of the present invention.

[0056] Figure 7 for Figure 6 An enlarged schematic diagram of part C.

[0057] Figure 8 This is a diagram showing the parameters of the present invention under the tightened state.

[0058] Figure 9 This is a line graph showing the changes in pressure, speed, and position over time under the condition of screw tightening, according to the present invention.

[0059] Figure 10 This is a line graph showing the torque change over time under the screw tightening condition according to the present invention.

[0060] Figure 11 This is a line graph showing the changes in pressure, speed, position, and torque over time under the condition of screw tightening, according to the present invention.

[0061] Figure 12 This is a flowchart of the control system in this invention.

[0062] in:

[0063] 100. Guide rail brake; 200. Nail suction holder; 300. Housing; 400. Nail suction tube bit assembly; 500. Gun head; 600. Nail feeding mechanism; 700. Lead screw assembly; 800. Motor assembly; 900. Tightening tool assembly; 1000. Mandrel; 1100. Spring; 1200. Guide rail;

[0064] 101. Sleeve; 102. Connecting block; 103. Mounting block; 1031. Sealing ring; 104. Connecting sleeve; 105. Air inlet; 106. Sliding block; 1061. Elastic washer; 107. Piston; 108. Compression spring; 109. Connecting rod; 110. Rolling shaft.

[0065] 301. Proximity sensor;

[0066] 401. Screwdriver bit; 402. Air tube assembly; 403. Suction tube;

[0067] 501. Barrel; 502. Clamping control structure;

[0068] 601. Screw. Detailed Implementation

[0069] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0070] Example 1

[0071] like Figures 1-12 As shown, this embodiment discloses a servo tightening module, the specific structure of which includes a nail suction seat 200, a housing 300, a nail suction tube bit assembly 400, a gun head 500, a nail feeding mechanism 600, a lead screw assembly 700, a motor assembly 800, a tightening tool assembly 900, a guide rail brake 100, a spindle 1000, and a spring 1100. It is used to feed the screw 601 into the through hole through the suction tube 403, and to automatically drive and tighten the screw 601 to achieve a segmented tightening effect.

[0072] like Figures 1-2 ,as well as Figure 4 As shown, the nail suction tube bit assembly 400 is the driving body of this embodiment. The movement and rotation of the nail suction tube bit assembly 400 can control the tightening effect, and the bit 401 of the nail suction tube bit assembly 400 is connected to the end of the bit 401 of the mating screw 601.

[0073] The nail suction holder 200 has a through hole to facilitate the movement of the nail suction tube bit assembly 400, providing support for the movement of the nail suction tube bit assembly 400. The nail suction holder 200 is connected to a nail suction tube 403 that is sleeved on the nail suction tube bit assembly 400, and the nail suction holder 200 is connected to a gun barrel 501 that docks with the nail suction tube 403, which is used to control the docking and disengagement of the nail suction tube bit assembly 400 with the screw 601. In this embodiment, the docking is performed by compressed air. Other similar docking methods are also within the protection scope of this application.

[0074] In this embodiment, as Figure 2 As shown, the tightening tool assembly 900 is fixed to the other end of the nail suction tube bit assembly 400 to drive the nail suction tube bit assembly 400 to rotate and to detect torque. The tightening tool assembly 900 includes a rotating unit (not shown in the figure) and a mounting base. The rotating unit is a rotary motor or a rotary cylinder, which can controllably adjust the torque and record the torque.

[0075] In this embodiment, as Figure 2As shown, the axial feed unit is connected to the tightening tool assembly 900 to generate axial feed motion within the stroke range. The axial feed unit includes a motor assembly 800 and can detect the pressure and speed of the axial motion. Specifically, the drive end of the motor assembly 800 is connected to a lead screw assembly 700. The tightening tool assembly 900 is threaded onto the lead screw assembly 700 through its mounting seat. The motor assembly 800 drives the lead screw assembly 700 to rotate, thereby driving the mounting seat to move. The nail suction seat 200 has a through hole for the lead screw assembly 700 to pass through, so that the lead screw assembly 700 cannot directly drive the nail suction seat 200 to move.

[0076] like Figure 3 As shown, in this embodiment, the elastic connector is fixed between the nail suction holder 200 and the tightening tool assembly 900 to drive the nail suction holder 200 to move synchronously and to provide feedback of elastic force. At the same time, according to the elastic formula F=kx, the elastic force can be quantified.

[0077] Preferably, the elastic connector includes a spindle 1000 that passes through the nail-collecting seat 200. A spring 1100 is sleeved on a section of the side wall of the spindle 1000 located between the nail-collecting seat 200 and the tightening tool assembly 900. The elastic connector can drive the nail-collecting seat 200 and the tightening tool assembly 900 to move synchronously. At the same time, after the nail-collecting seat 200 comes to a stop, the elastic connector can achieve a pre-tightening effect and increase the tightening pressure.

[0078] In this embodiment, as Figure 4 As shown, the gun head 500 has a channel for the bit 401 to pass through, and a spare screw is reserved in the channel. The gun head 500 includes a gun barrel 501, and a nail feeding mechanism 600 for feeding nails into the channel is connected to the gun barrel 501. A nail clamping structure for fixing the screw 601 is connected to the end of the gun barrel 501. The nail clamping structure is controlled to open and close by a clamping control structure 502 to control the clamping and release of the nail. A proximity sensor 301 corresponding to the clamping control structure 502 is connected to the outer shell 300 to control the activation of the clamping control structure 502.

[0079] It also includes a housing 300, with the gun head 500 fixed on the housing 300. At the same time, a guide rail 1200 is connected to the housing 300. The guide rail 1200 is arranged parallel to the nail suction tube bit assembly 400. The nail suction seat 200, the guide rail brake 100, and the tightening tool assembly 900 are all slidably connected to the guide rail 1200.

[0080] like Figures 5-7 As shown, in this embodiment, the guide rail brake 100 is fixed on the nail suction seat 200 and can controllably restrict the movement of the nail suction seat 200;

[0081] This embodiment discloses a guide rail brake for rapid braking on a guide rail 1200. Generally, the guide rail brake 100 is connected to the equipment that needs to be braked for rapid braking of the equipment. Its main structure is a sleeve assembly.

[0082] like Figure 5 and Figure 6 As shown, in this embodiment, the sleeve assembly includes two opposing sleeves 101 and a connecting block 102 connected between the two sleeves 101. The two sleeves 101 and the connecting block 102 are integrally formed, which can improve the overall stability. At the same time, a slide is reserved at the lower end of the connecting block 102 and between the two sleeves 101 to facilitate the movement of the guide rail 1200. That is, the sleeve assembly spans the guide rail 1200 and can slide on the guide rail 1200.

[0083] like Figure 6 As shown, a piston 107 that moves vertically is connected inside the sleeve 101, and a connecting rod 109 is connected to the lower end of the piston 107. The piston 107 and the connecting rod 109 are also integrally formed. The lower end of the connecting rod 109 abuts against a sliding block 106. The sliding block 106 is slidably connected to the side of the sleeve 101 near the slide rail, and the end of the sliding block 106 near the connecting rod 109 is inclined. With this inclined surface, when the connecting rod 109 moves up and down and cooperates with the inclined surface, it will drive the sliding block 106 to move horizontally. In this embodiment, the width of the inclined surface decreases from top to bottom. That is, when the connecting rod 109 moves upward, it will drive the sliding block 106 to move towards the slide rail, so that the sliding block 106 contacts the guide rail 1200 to increase the friction and achieve the pre-tightening effect.

[0084] In this embodiment, as Figures 5-7 As shown, the sleeve 101 has an air inlet 105 for ventilation, which is generally supplied with compressed air to increase the instantaneous air pressure. The ventilation through the air inlet 105 drives the piston 107 to move up and down, and simultaneously, the air pressure drives the sliding block 106 to move towards the slide rail. A piston ring is also fitted onto the piston 107 to improve sealing performance, thereby improving the efficiency of the pneumatic transmission. Specifically, in this embodiment, as... Figures 5-7 As shown, the air inlet 105 is located on the side wall of the sleeve 101 below the piston 107 and close to the connecting rod 109. Only at this location can the piston 107 be moved upwards at the same time, and pressure be directly applied to the sliding block 106. This dual approach drives the sliding block 106 to move closer to the guide rail, thereby improving the braking effect.

[0085] In this embodiment, as Figure 5 and Figure 6As shown, a connecting sleeve 104 is threaded into the upper end of the sleeve 101, and a compression spring 108 is provided inside the connecting sleeve 104. The compression spring 108 extends into the sleeve 101 and contacts the piston 107, providing downward preload to the piston 107. By providing the connecting sleeve 104, it is convenient to install the equipment inside the sleeve 101. On the other hand, by rotating the connecting sleeve 104, the elasticity of the compression spring 108 can be adjusted, which is convenient to adjust according to the actual situation.

[0086] In this embodiment, as Figure 7 As shown, the sliding block 106 has a "T" shaped structure. Its wider end slides on the inner wall of the sleeve 101, and its narrower end passes through the through hole opened on the side wall of the sleeve 101 and moves in the direction of the slide. This structure can improve the sealing performance inside the sleeve 101. The connecting block 102 is provided with a sliding groove for the sliding block 106 to slide.

[0087] like Figure 7 As shown, an elastic washer 1061 for pre-tightening and resetting is connected between the sleeve 101 and the sliding block 106. On the one hand, it can provide elastic force for the sliding block 106 to move into the sleeve 101, allowing the sliding block 106 to move away from the guide rail 1200 when braking is not required. On the other hand, when the sliding block 106 is close to the guide rail 1200, the elastic washer 1061 can be used for pre-tightening to improve the connection effect.

[0088] In this embodiment, as Figure 7 As shown, the sleeve 101 has an installation hole on the side wall opposite to the sliding block 106, and an installation block 103 is fixedly inserted into the installation hole. A sealing ring 1031 is connected between the installation block 103 and the sleeve 101 for the installation and maintenance of the sleeve 101.

[0089] In this embodiment, as Figure 6 and Figure 7 As shown, a rectangular hole is provided on a section of the side wall of the connecting rod 109 extending between the mounting block 103 and the sliding block 106. Two rolling shafts 110 are connected in the rectangular hole, which roll on the mounting block 103 and the sliding block 106 respectively. By setting the rolling shafts 110, the connection effect between the rolling shafts 110 and the sliding block 106 can be improved, thereby improving the pre-tightening effect of the sliding block 106 and the guide rail 1200. Moreover, the rolling method reduces wear on the one hand, and evenly drives the sliding block 106 to contact the guide rail 1200 on the other hand, thus improving the pre-tightening effect.

[0090] In summary, this invention, through its simple structural combination and convenient operation, achieves a braking effect by directly moving the sliding block 106 towards the guide rail 1200 via air ventilation. On the other hand, by moving the piston 107 upward through air ventilation, and then pressing the sliding block 106 with the rolling shaft 110, the connection between the sliding block 106 and the guide rail 1200 is further improved. By implementing braking through these dual measures, the braking efficiency is improved, making it highly practical.

[0091] The guide rail brake 100 provides a stopping function in different processes. Using this function, we can extend the bit 401 out of the barrel 501 and the barrel 501 out of the head 500 for tightening. Moreover, the guide rail brake 100 provides a large braking force with a small size, which facilitates subsequent tightening. At the same time, since the nail suction holder 200 and the tightening tool assembly 900 are connected by an elastic connector, the braking force generated when the nail suction holder 200 is braked is converted into the elastic force of the elastic connector. Since the elastic force is known, the specific value of the downward pressure can be obtained.

[0092] Example 2

[0093] like Figures 8-12 As shown, this embodiment discloses a control system for a servo tightening module, including a controller. The controller can collect signals transmitted by the motor assembly 800, the tightening tool assembly 900, and the proximity sensor 301, as well as the output force of the motor assembly 800, and determine the moving distance, moving speed, and torque of the nail suction tube bit assembly 400.

[0094] Includes the following steps:

[0095] Release the brake by guide rail brake 100 and start motor assembly 800. Motor assembly 800 drives tightening tool assembly 900 to move through lead screw assembly 700. At the same time, tightening tool assembly 900 drives nail suction seat 200 to move synchronously through elastic connector. Nail suction tube bit assembly 400 also moves synchronously.

[0096] At the same time, the nail feeding mechanism 600 feeds the nail into the gun barrel 501. As the nail suction tube 403 approaches the screw 601, under the action of the air tube assembly 402, the nail suction tube 403 connects with the screw 601 and extends out of the gun head 500 to move towards the through hole. When the nail suction tube 403 delivers the screw 601 to the through hole position, the guide rail brake 100 starts to brake, thereby stopping the nail suction seat 200.

[0097] At this time, the bit 401 drives the screw 601 to extend out of the screw suction tube 403;

[0098] At the same time, the tightening tool assembly 900 starts and drives the screw 601 to rotate through the bit 401, which in turn drives the screw 601 to move in conjunction with the motor assembly 800 to tighten it.

[0099] In this case, since the nail-holding base 200 and the tightening tool assembly 900 are connected by an elastic connector, the braking force generated when the nail-holding base 200 brakes is converted into the elastic force of the elastic connector. Therefore, the downward pressure generated by the screw 601 at this time is F = Fs - Ft ± G, where Fs = the output force of the motor assembly 800; Ft = the elastic force of the elastic connector; and G = the weight of other parts.

[0100] And because,

[0101] Where Fs = 2πηT / L; these values ​​are all known, and the specific value of Fs can be obtained;

[0102] In this embodiment, η: transmission efficiency of the lead screw assembly 700, approximately 0.9 to 0.95; T: torque; L: lead of the lead screw assembly 700;

[0103] Meanwhile, Ft = kx; k: elastic coefficient of the elastic connector; X: displacement of the motor assembly 800 relative to the pin holder 200. These are also known values, so the value of Ft is also known.

[0104] Therefore, if the value of F is kept constant at 0, the value of Fs can be increased synchronously according to the value of Ft to keep the value of F constant. The value of Ft is a linear function of x, so the increase of Fs can also be adjusted by the motor assembly 800 to keep the value of F constant. Subsequently, the automatic tightening process can be realized by using a closed-loop servo system. For the specific process, please refer to the comparative document mentioned in the background technology.

[0105] In this embodiment, as Figures 9-11 As shown, since the position of screw 601 and the position of the through hole in the part are constant, they can be measured in advance. At the same time, the length of screw 601 and the depth of the through hole can also be measured in advance.

[0106] When screw 601 approaches the through hole of the part, the moving speed of screw 601 is reduced by motor assembly 800 so that the speed of screw 601 is close to 0 when it contacts the through hole, so as to avoid damage to the part.

[0107] In this embodiment, the tightening logic is significantly improved. The servo module can provide different levels of pressure according to the condition of the part's hole, and pressure is a very important characteristic in the tightening process. Traditional pneumatic tightening modules cannot decelerate before the bit contacts the screw, making it difficult to reduce the impact of impact on the product. When the product is subjected to impact, problems such as thread damage and product displacement may occur. The servo module uses electronic control to achieve deceleration when entering the hole while tightening with near-zero impact. When a larger pressure is required to tighten the screw to the mating surface, the servo module can steplessly adjust the pressure according to the specific situation. After tightening, the encoder record can accurately determine whether the screw is fully screwed into the threaded hole. In contrast, the pneumatic module requires an additional displacement sensor for detection.

[0108] The tightening process, from screw 601 contacting the through hole to tightening, is mainly divided into three stages: screw 601 contacting the through hole, screw 601 adhering to the product surface, and fastening.

[0109] In actual use, there are three scenarios depending on the customer's product:

[0110] Scenario 1: The customer's screw and the product's thread are very weak, requiring very little force to contact the thread. When the screw is almost fully tightened, a large downward pressure is needed to complete the tightening. The servo can adjust the downward pressure according to the different height states of the screw, basically meeting the requirements that at the beginning of tightening, the torque is very small, the feed speed is very fast, and the downward pressure is very small; at the end of tightening, the torque is very large, the feed speed is very slow, and the downward pressure is very large.

[0111] Scenario 2: If the customer doesn't know the required torque and downforce, the pressure and torque values ​​during testing can be obtained using the principle of servo closed-loop control. This allows for the derivation of process parameters, which are then stored in a database for analysis and adjustment. This enables automatic execution of the tightening process when using the same or similar processes, based on the parameters retrieved from the database. Figure 12 As shown.

[0112] Scenario 3: If the customer does not know the required torque and downforce, we can provide a database of similar working conditions for the customer to use.

[0113] Using automatic nail feeding and tightening can improve the control of the product manufacturing process, ensure that qualified products are provided to customers or the market, and avoid production or use accidents caused by tightening risks.

[0114] It enables continuous production, with more stable automatic tightening quality and efficiency; it allows for control over tightening quantity and sequence; it enables traceability of tightening results – which can be uploaded to the system; it reduces employee operations and enhances safety.

[0115] like Figure 12As shown, our future vision for servo modules is to make them intelligent. Through on-site applications in various projects, and by collecting parameters such as different tightening screws, materials being tightened, and tightening processes from customers, we can obtain a detailed database. After analyzing this data, we can generalize and provide a comprehensive tightening solution. This also includes matching tightening parameters, such as which screw requires which tightening logic, and what pressure and speed are needed for tightening different products. In this way, we can achieve more refined and intelligent tightening.

[0116] In addition to the above embodiments, the present invention may have other implementations. Any technical solutions formed by equivalent substitution or equivalent transformation applied to different tightening devices and different screw pairs shall fall within the scope of protection claimed by the present invention.

[0117] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A servo tightening module, characterized in that, include: A screw-in tube bit assembly (400) with a bit (401) connected to a mating screw (601) at its end. The drive end of the motor assembly (800) is connected to the lead screw assembly (700), and the tightening tool assembly (900) is threaded onto the lead screw assembly (700) through its mounting seat. The nail holder (200) has a through hole for the lead screw assembly (700) to pass through. A nail suction holder (200) is sleeved on a nail suction tube bit assembly (400), and the nail suction holder (200) is connected to a nail suction tube (403) sleeved on the nail suction tube bit assembly (400). The tightening tool assembly (900) is fixed to the other end of the nail suction tube bit assembly (400) to drive the nail suction tube bit assembly (400) to rotate and to detect torque; An axial feed unit, connected to a tightening tool assembly (900), is used to generate axial feed motion within a stroke range. The axial feed unit includes a motor assembly (800) and is capable of detecting the pressure and speed of the axial motion. An elastic connector is fixed between the nail suction cup (200) and the tightening tool assembly (900) to drive the nail suction cup (200) to move synchronously and to provide feedback elastic force; A guide rail brake (100) is fixed to the pin holder (200) and controllably restricts the movement of the pin holder (200); The gun head (500) has a channel inside for the nail suction tube bit assembly (400) to pass through, and a spare screw is reserved in the channel; When the bit (401) drives the screw (601) to tighten, it will generate downward pressure, and the downward pressure value F = Fs - Ft ± G, where Fs = the output force of the motor assembly (800); Ft = the elastic force of the elastic connector; G = the weight of other parts, and provides different pressures according to the hole of the part; Where Fs = 2πηT / L; η: transmission efficiency of the lead screw assembly (700); T: torque; L: lead of the lead screw assembly (700); Ft=kx; k: elastic coefficient of the elastic connector; X: displacement of the motor assembly (800) relative to the nail holder (200); Meanwhile, when the torque and downforce are unknown, the pressure and torque values ​​during the test are obtained through the principle of servo closed-loop control, and then the process parameters are derived. These process parameters are then formed into a database, and the tightening process is automatically executed by retrieving the process parameters from the database.

2. The servo tightening module as described in claim 1, characterized in that: It also includes a housing (300), a gun head (500) fixed on the housing (300), and a guide rail (1200) connected to the housing (300). The guide rail (1200) is arranged parallel to the nail suction tube bit assembly (400), and the nail suction seat (200), the guide rail brake (100) and the tightening tool assembly (900) are all slidably connected to the guide rail (1200).

3. The servo tightening module as described in claim 1, characterized in that: The nail suction holder (200) is connected to a gun barrel (501) that engages with the nail suction tube (403), which is used to control the engagement and disengagement of the nail suction tube bit assembly (400) with the screw (601).

4. The servo tightening module as described in claim 1, characterized in that: The gun head (500) includes a gun barrel (501), a nail feeding mechanism (600) for feeding nails into the channel is connected to the gun barrel (501), and a nail clamping structure for fixing screws (601) is connected to the end of the gun barrel (501). The nail clamping structure is controlled to open and close by a clamping control structure (502) to control the clamping and release of the nail. A proximity sensor (301) corresponding to the clamping control structure (502) is connected to the outer shell (300).

5. The servo tightening module as described in claim 2, characterized in that: The elastic connector includes a spindle (1000) extending through the nail holder (200), and a spring (1100) is fitted onto a section of the spindle (1000) on a side wall between the nail holder (200) and the tightening tool assembly (900).

6. The servo tightening module as described in claim 1, characterized in that: The guide rail brake (100) includes a sleeve assembly, which includes two relatively fixed sleeves (101) and a slide rail disposed between the two sleeves (101) to facilitate the movement of the guide rail (1200). The sleeve (101) is connected to a piston (107) that moves in a vertical direction, and the lower end of the piston (107) is connected to a connecting rod (109). The lower end of the connecting rod (109) abuts against the sliding block (106) and drives the sliding block (106) to move horizontally to one side of the slide. The sleeve (101) is provided with an air inlet (105) for ventilation. The ventilation of the air inlet (105) drives the piston (107) to move up and down. At the same time, the air pressure drives the sliding block (106) to move towards the slide and contact the guide rail (1200) for braking.

7. The servo tightening module as described in claim 6, characterized in that: The upper end of the sleeve (101) is threaded with a connecting sleeve (104), and a compression spring (108) is provided inside the connecting sleeve (104). The compression spring (108) extends into the sleeve (101) and contacts the piston (107), and provides downward pre-pressure to the piston (107).

8. The servo tightening module as described in claim 6, characterized in that: The connecting rod (109) extends to a section of the side wall between the mounting block (103) and the sliding block (106) and has a rectangular hole. Two rolling shafts (110) are connected in the rectangular hole and roll on the mounting block (103) and the sliding block (106) respectively. The sliding block (106) has a "T" shaped structure. Its wider end slides on the inner wall of the sleeve (101). The end of the sliding block (106) near the connecting rod (109) is inclined. Its narrower end passes through the through hole on the side wall of the sleeve (101) and moves in the direction of the slide. At the same time, an elastic washer (1061) for pre-tightening and resetting is connected between the sleeve (101) and the sliding block (106).

Images