Nut screwing control system and control method thereof

Abstract

The invention discloses a nut screwing control system and method, and the system comprises a screwing mechanism which comprises a servo motor and a nut screwing tool, and the nut screwing tool is connected with an output shaft of the servo motor; and the control device is in communication connection with the servo motor, and the control device is configured to control the servo motor to operate to enable the nut tightening tool to tighten the nut. The nut tightening tool is driven by the servo motor to achieve automatic tightening, torque and angle data are obtained, and the two parameters and the preset range are subjected to dual comparison judgment, so that the tightening quality is accurately evaluated, and the judgment result is output. The automatic judgment mechanism based on multi-parameter monitoring not only improves the automation level of the screwing process, but also ensures the reliability of screwing quality judgment, effectively solves the problem of inaccurate quality judgment in the nut screwing process of the existing equipment, and can reduce the frequency of manual reinspection.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical manufacturing, and in particular to a nut tightening control system and a control method thereof. Background Art

[0002] In the production of air conditioners, tightening the plastic nut onto the copper pipe with the pipe joint is an important process. This process requires aligning the plastic nut with the center of the pipe joint, making the two coaxial, and tightening within a specific torque range. The traditional production method has a low degree of automation and requires a lot of manual operation and monitoring. Long-term repetitive operations are prone to mistakes and affect product quality.

[0003] Although the industry has also developed some automated equipment for the tightening operation and monitoring of nuts, the existing equipment still has shortcomings in practical applications: these devices cannot effectively identify abnormal conditions during the installation process, and thus cannot effectively determine whether the tightening is qualified, and the final product still needs to be manually re-inspected. Summary of the invention

[0004] The main purpose of the present invention is to provide a nut tightening control system and a control method thereof to solve the above technical problems.

[0005] In a first aspect, the present invention provides a nut tightening control system, comprising:

[0006] A tightening mechanism, the tightening mechanism comprising a servo motor and a nut tightening tool, the nut tightening tool being connected to an output shaft of the servo motor;

[0007] A control device, the control device is communicatively connected with the servo motor, and the control device is configured as follows:

[0008] Controlling the servo motor to operate so that the nut tightening tool tightens the nut;

[0009] Obtaining torque data and angle data output by the servo motor;

[0010] Determining whether the torque data is within a preset torque range and whether the angle data is within a preset angle range;

[0011] When the torque data is within the preset torque range and the angle data is within the preset angle range, a determination result of qualified tightening is output; otherwise, a determination result of unqualified tightening is output.

[0012] Among them, the control of the servo motor to operate so that the nut tightening tool tightens the nut is configured as: controlling the servo motor to operate in reverse so that the nut tightening tool reverses a preset number of turns, and then controlling the servo motor to operate in forward direction so that the nut tightening tool tightens the nut.

[0013] Wherein, the control device comprises: a main controller and a human-computer interaction unit in communication connection;

[0014] The human-computer interaction unit is configured as follows:

[0015] receiving settings of the preset torque range and the preset angle range, and transmitting the settings to the main controller;

[0016] The main controller is configured as follows:

[0017] Controlling the servo motor to operate according to the received preset torque range and the preset angle range;

[0018] Acquire the torque data and the angle data of the servo motor, and transmit the torque data and the angle data to the human-computer interaction unit;

[0019] Determine whether the torque data is within the preset torque range and whether the angle data is within the preset angle range;

[0020] When the torque data is within the preset torque range and the angle data is within the preset angle range, outputting a tightening qualified judgment result to the human-computer interaction unit, otherwise outputting a tightening unqualified judgment result;

[0021] The human-computer interaction unit is also configured as:

[0022] The torque data, the angle data, and the qualified tightening determination result and / or the unqualified tightening determination result are displayed.

[0023] Wherein, the nut tightening tool comprises a tightening shaft, one end of which is connected to the output shaft of the servo motor, and the other end is provided with a nut tightening head, and a spring is sleeved between the tightening shaft and the nut tightening head.

[0024] Wherein, the servo motor includes: ASD-A2 series driver and ECMA series motor.

[0025] Wherein, it also includes a lifting mechanism, and the tightening mechanism is respectively arranged on two opposite sides of the lifting mechanism, and the servo motors of the tightening mechanism are respectively connected to the control device for communication.

[0026] Wherein, the lifting mechanism comprises:

[0027] A ball screw assembly, the ball screw assembly comprising a stepper motor and a screw drivingly connected to the stepper motor;

[0028] Two sets of linear guide rail assemblies, the two sets of linear guide rail assemblies are respectively arranged on opposite sides of the lead screw;

[0029] A mounting plate, wherein the mounting plate is fixedly connected to the nut seat of the screw rod, and both ends of the mounting plate are respectively fixedly connected to the sliders of the corresponding linear guide rail assembly;

[0030] Wherein, the tightening mechanism is fixedly connected to the mounting plate.

[0031] In a second aspect, the present invention further provides a control method for the nut tightening control system according to the first aspect, comprising:

[0032] Control the servo motor to run so that the nut tightening tool tightens the nut;

[0033] Obtaining torque data and angle data output by the servo motor;

[0034] Determining whether the torque data is within a preset torque range and whether the angle data is within a preset angle range;

[0035] When the torque data is within the preset torque range and the angle data is within the preset angle range, a determination result of qualified tightening is output; otherwise, a determination result of unqualified tightening is output.

[0036] Wherein, controlling the servo motor to operate so that the nut tightening tool tightens the nut comprises:

[0037] The servo motor is controlled to run in reverse direction so that the nut tightening tool is reversed by a preset number of turns, and then the servo motor is controlled to run in forward direction so that the nut tightening tool tightens the nut.

[0038] Among them, it also includes:

[0039] Based on the tightening qualified determination result and / or the tightening unqualified determination result, sending a control signal to the robot system includes:

[0040] When the determination result is that the tightening is qualified, a first control signal is sent, and the robot system transfers the product to a qualified product storage area according to the first control signal;

[0041] When the determination result is that the tightening is unqualified, a second control signal is sent and the reason for the unqualified is displayed, and the robot system transfers the product to the unqualified product storage area according to the second control signal.

[0042] Beneficial technical effects of the present invention: The present invention realizes automatic tightening by driving the nut tightening tool with a servo motor, and obtains torque and angle data. By performing a double comparison and judgment between these two parameters and the preset range, the tightening quality is accurately evaluated and the judgment result is output. This automatic judgment mechanism based on multi-parameter monitoring not only improves the automation level of the tightening process, but also ensures the reliability of the tightening quality judgment, effectively solves the problem of inaccurate quality judgment of existing equipment during the nut tightening process, and can reduce the number of manual re-inspections. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0044] Figure 1 A front view schematic diagram of a nut tightening control system provided by an embodiment of the present invention;

[0045] Figure 2 A three-dimensional schematic diagram of a nut tightening control system provided by an embodiment of the present invention;

[0046] Figure 3 A schematic diagram of a control device of a nut tightening control system provided in an embodiment of the present invention;

[0047] Figure 4 A flow chart of a control method for a nut tightening control system provided in an embodiment of the present invention.

[0048] Description of reference numerals:

[0049] In the figure: 10-servo motor, 20-nut tightening tool, 21-tightening shaft, 22-nut tightening head, 23-spring, 30-control device, 31-main controller, 32-human-machine interaction unit, 100-lifting mechanism, 101-stepping motor, 102-screw, 103-nut seat, 104-bearing seat, 105-guide rail body, 106-slider, 107-mounting plate, 110-tightening mechanism. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be understood that when used in this specification and the appended claims, the terms including and comprising indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0052] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of one, an and the are intended to include plural forms.

[0053] It should be further understood that the terms and / or used in the present description and appended claims refer to and include any and all possible combinations of one or more of the associated listed items.

[0054] Please also refer to Figure 1-Figure 3 ,in Figure 1 A front view schematic diagram of a nut tightening control system provided by an embodiment of the present invention; Figure 2 A three-dimensional schematic diagram of a nut tightening control system provided by an embodiment of the present invention; Figure 3 Schematic diagram of a control device of a nut tightening control system provided by an embodiment of the present invention. A nut tightening control system provided by an embodiment of the present invention comprises: a tightening mechanism 110, the tightening mechanism 110 comprises a servo motor 10 and a nut tightening tool 20, the nut tightening tool 20 is connected to the output shaft of the servo motor 10; a control device 30, the control device 30 is connected to the servo motor 10 for communication, and the control device 30 is configured to: control the servo motor 10 to operate so that the nut tightening tool 20 tightens the nut; obtain the torque data and angle data output by the servo motor 10; determine whether the torque data is within the preset torque range and whether the angle data is within the preset angle range; when the torque data is within the preset torque range and the angle data is within the preset angle range, output a qualified tightening judgment result, otherwise output a unqualified tightening judgment result.

[0055] In this embodiment, the control system mainly includes a tightening mechanism 110 and a control device 30. The tightening mechanism 110 includes a servo motor 10 and a nut tightening tool 20, and the nut tightening tool 20 is fixedly connected to the output shaft of the servo motor 10 through a coupling. The servo motor 10 includes a matching motor and a (servo) driver. The control device 30 is connected to the servo driver through a communication bus.

[0056] Specifically, the control device 30 is connected to the servo driver via the EtherCAT protocol to control the servo motor 10. The control device 30 sets the servo motor 10 to operate in a torque mode so that the nut tightening tool 20 tightens the nut it clamps onto the pipe joint aligned with the nut. In this torque mode, the purpose of outputting the target torque can be achieved by controlling the current of the servo motor 10. At the same time, the control device 30 can collect the torque data and angle data output by the servo motor 10 in real time.

[0057] The control device 30 compares the collected torque data with a preset torque range, and compares the angle data with a preset angle range. The preset torque range includes an upper torque limit and a lower torque limit, and the preset angle range includes an upper angle limit and a lower angle limit. Based on the comparison results, the control device 30 can determine whether the nut tightening process is qualified.

[0058] When the torque data and angle data are both within their respective preset ranges, the tightening is judged to be qualified; if any parameter exceeds the preset range, it is judged to be unqualified. This comprehensive judgment method based on multiple parameters improves the accuracy of abnormal state recognition, effectively solves the problem of high misjudgment rate in the existing technology, and reduces the workload of subsequent manual inspections.

[0059] In this embodiment, the control device 30 can simultaneously collect and monitor two parameters in real time: torque data and angle data. The torque data reflects whether the force of tightening the nut is appropriate. If it is too large, the plastic nut will be damaged, and if it is too small, the tightness cannot be guaranteed; the angle data reflects the actual rotation of the nut, which can effectively identify abnormal conditions such as nut misalignment and thread cross-threading.

[0060] The control device 30 performs a double comparison on the collected data: the torque data is compared with the preset torque range (including upper and lower limits) to ensure that the tightening force meets the requirements; the angle data is compared with the preset angle range (including upper and lower limits) to verify whether the nut rotates according to the expected trajectory.

[0061] Through this dual parameter monitoring and comparison mechanism, the nut tightening control system provided by this embodiment can: timely detect abnormal conditions such as nut deviation and thread misthreading. For example, when the nut is deviated, even if the torque reaches the set value, it will be judged as unqualified due to abnormal angle data; it can also accurately identify specific problems in the tightening process. According to the specific deviation of torque and angle data, it can be judged whether the torque is too large / too small, or there is a problem of poor alignment.

[0062] In this embodiment, a torque sensor and an angle encoder (not shown in the drawings) are integrated inside the servo driver, which can collect the torque and rotation angle data of the output shaft of the servo motor 10 in real time, so as to transmit the collected data to the control device 30.

[0063] In this embodiment, EtherCAT (Ethernet for Control Automation Technology) is a high-performance, real-time industrial Ethernet communication protocol.

[0064] In one embodiment, the servo motor 10 is controlled to run so that the nut tightening tool 20 tightens the nut, and the configuration is: the servo motor 10 is controlled to run in reverse so that the nut tightening tool 20 reverses a preset number of turns, and then the servo motor 10 is controlled to run forward so that the nut tightening tool 20 tightens the nut.

[0065] In this embodiment, in order to ensure that the nut can be accurately aligned with the thread of the pipe joint and tightened smoothly, the control device 30 will first control the nut tightening tool 20 to reverse a predetermined number of turns before controlling the nut tightening tool 20 to perform the forward tightening action. Due to the existence of assembly errors, the nut and the pipe joint may be slightly eccentric in the initial state. By pre-reversing the action, this eccentricity can be eliminated, so that the nut and the pipe joint can be better aligned. This pre-reversal operation can improve the success rate of tightening and reduce tightening failures caused by misaligned threads.

[0066] In a specific embodiment, the control device 30 controls the servo motor 10 to reversely rotate a specified number of turns, such as two turns, through a servo driver. During the reversal process, the control device 30 monitors the number of reverse turns in real time. When the predetermined number of turns is reached, the control device 30 immediately controls the servo motor 10 to reverse and start to perform the forward tightening action.

[0067] In one embodiment, the control device 30 includes: a main controller 31 and a human-machine interaction unit 32 which are communicatively connected.

[0068] The human-machine interaction unit 32 is configured to receive settings of a preset torque range and a preset angle range, and transmit the settings to the main controller 31 .

[0069] The main controller 31 is configured to: control the operation of the servo motor 10 according to the received preset torque range and preset angle range; obtain the torque data and angle data of the servo motor 10, and transmit the torque data and angle data to the human-machine interaction unit 32; determine whether the torque data is within the preset torque range and whether the angle data is within the preset angle range; when the torque data is within the preset torque range and the angle data is within the preset angle range, output a judgment result of qualified tightening to the human-machine interaction unit 32, otherwise output a judgment result of unqualified tightening.

[0070] The human-machine interaction unit 32 is further configured to display torque data, angle data, and a qualified tightening determination result and / or a unqualified tightening determination result.

[0071] In this embodiment, the main controller 31 and the human-machine interaction unit 32 are connected to each other by means of the Ether IP protocol, wherein the main controller 31 is a PLC controller, and the human-machine interaction unit 32 is implemented by a touch screen.

[0072] The human-computer interaction unit 32 is provided with a parameter configuration interface, through which the operator can input a preset torque range and a preset angle range. Specifically, the operator can set the torque upper limit value, the torque lower limit value, the angle upper limit value and the angle lower limit value respectively. These parameters are transmitted to the main controller 31 via the Ether IP protocol for subsequent tightening process control and judgment.

[0073] During the tightening process, the servo driver transmits real-time torque data and angle data to the main controller 31 via the EtherCAT protocol, and the main controller 31 transmits these data to the human-machine interaction unit 32 for display via the Ether IP protocol. The operator can intuitively see the real-time data of the current tightening process, including real-time torque data and angle data. After the tightening is completed or during the tightening process, the judgment result (qualified / unqualified) and the specific reason description (such as excessive torque, angle exceeding the limit, etc.) will be displayed on the human-machine interaction unit 32, which is convenient for the operator to monitor and manage the tightening process in real time.

[0074] In this embodiment, the Ether IP protocol is used to establish a communication connection between the main controller 31 (PLC controller) and the human-machine interaction unit 32 (touch screen). Through this protocol, non-IP protocol data (such as data between the PLC controller and the touch screen) can be encapsulated in an IP data packet and thus transmitted in an IP network.

[0075] In a specific embodiment, the human-computer interaction unit 32 displays torque data, angle data, and the judgment result of qualified tightening and / or the judgment result of unqualified tightening, specifically displaying: the torque value measured during the tightening process, the set torque upper limit value and lower limit value, the cumulative rotation angle measured during the tightening process, the set angle upper limit value and lower limit value, OK-tightening is completed normally: the torque and angle are both within the set range, E01-torque is too large: the actual torque exceeds the upper limit value, E02-torque is insufficient: the actual torque is lower than the lower limit value, E03-angle is too large: the rotation angle exceeds the upper limit value, there may be a slipping buckle, E04-angle is insufficient: the rotation angle does not reach the lower limit value, there may be incomplete tightening.

[0076] In one embodiment, the nut tightening tool 20 includes a tightening shaft 21 , one end of the tightening shaft 21 is connected to the output shaft of the servo motor 10 , and the other end is provided with a nut tightening head 22 , and a spring 23 is sleeved between the tightening shaft 21 and the nut tightening head 22 .

[0077] In this embodiment, one end of the tightening shaft 21 is fixedly connected to the output shaft of the servo motor 10 through a coupling, and the other end is equipped with a tightening head 22 for clamping the nut. A spring 23 is sleeved between the tightening shaft 21 and the nut tightening head 22 to help achieve better alignment between the nut and the pipe joint.

[0078] Specifically, the elastic deformation characteristics of the spring 23 are utilized to make the nut tightening head 22 have a certain adaptive activity ability, so that it is easier to align the nut with the pipe joint. More specifically, when there is a slight position deviation between the nut and the pipe joint, the elastic deformation of the spring 23 can play a compensatory role, avoiding forced matching caused by rigid connection, and effectively reducing the risk of nut deviation and thread cross-threading. In particular, when performing the pre-reversal action, the presence of the spring 23 makes the alignment process of the nut and the pipe joint more reliable.

[0079] In one embodiment, the servo motor 10 includes: an ASD-A2 series driver and an ECMA series motor.

[0080] In this embodiment, the servo motor 10 specifically uses ASD-A2-0421-E servo driver and ECMA-CA0604SS servo motor produced by Delta Electronics. The servo motor and servo driver have a wide range of applications in the market, and the accessories are in sufficient supply, which is convenient for maintenance and replacement.

[0081] In other embodiments, the driver and motor of the servo motor 10 may be selected from other types of servo drivers in the ASDA-A2 series and other types of servo motors in the ECMA series of Delta Corporation.

[0082] In one embodiment, a lifting mechanism 100 is further included. Tightening mechanisms 110 are respectively disposed on opposite sides of the lifting mechanism 100 . The servo motors 10 of the tightening mechanisms 110 are respectively connected to the control device 30 for communication.

[0083] In this embodiment, tightening mechanisms 110 are respectively arranged on opposite sides of the lifting mechanism 100, so that double-station synchronous operation can be realized. The servo drivers of the two tightening mechanisms 110 are both connected to the same control device 30 for unified control.

[0084] Specifically, independent tightening mechanisms 110 are arranged in the left and right spaces of the lifting mechanism 100, respectively, and the lifting mechanism 100 is responsible for the vertical lifting movement of the tightening mechanism 110. In actual operation, the lifting mechanism 100 first moves to the loading position, and cooperates with the cylinder assembly (including upper and lower material taking cylinders, material taking claw cylinders, material discharge forward cylinders and pipe joint fixing cylinders, etc., not shown in the drawings) to complete the loading of nuts and the fixing of pipe joints.

[0085] After the nuts at both sides are loaded and the pipe joints are fixed, the lifting mechanism 100 drives the tightening mechanism 110 to move to the working position. After the nuts are aligned with the corresponding pipe joints, the tightening mechanisms 110 on both sides start tightening at the same time. Each tightening mechanism 110 works independently and feeds back the torque data and angle data generated by the tightening process to the control device 30 in real time. The control device 30 determines whether the tightening process of the two tightening mechanisms 110 is qualified or not.

[0086] In one embodiment, the lifting mechanism 100 includes: a ball screw assembly, the ball screw assembly includes a stepper motor 101 and a screw 102 transmission-connected to the stepper motor 101; two sets of linear guide rail assemblies, the two sets of linear guide rail assemblies are respectively arranged on opposite sides of the screw 102; a mounting plate 107, the mounting plate 107 is fixedly connected to the nut seat 103 of the screw 102, and the two ends of the mounting plate 107 are respectively fixedly connected to the slider 106 of the corresponding linear guide rail assembly; wherein, the tightening mechanism 110 is fixedly connected to the mounting plate 107.

[0087] In this embodiment, the stepper motor 101 is connected to the screw rod 102 through a coupling, and bearing seats 104 are respectively provided at opposite ends of the screw rod 102. The linear guide rail assemblies on the left and right sides of the screw rod 102 include a guide rail body 105 and a matching slider 106, and the two sets of linear guide rail assemblies are arranged in parallel. The mounting plate 107 is fixedly connected to the nut seat 103 on the screw rod 102, and the two ends of the mounting plate 107 are respectively fixedly connected to the slider 106 of the corresponding linear guide rail assembly.

[0088] The stepper motor 101 drives the screw rod 102 to rotate; the screw rod 102 and the nut seat 103 cooperate to convert the rotational motion into the linear motion of the mounting plate 107, and the linear guide assembly provides guidance and support for the mounting plate 107, thereby realizing the rise and fall of the tightening mechanism 110 on both sides.

[0089] Figure 4 The following is a flow chart of a control method of a nut tightening control system provided by an embodiment of the present invention. Figure 4 As shown, corresponding to the above nut tightening control system, an embodiment of the present invention further provides a control method based on the nut tightening control system, including the following steps S100 to S400.

[0090] S100, controlling the servo motor 10 to operate so that the nut tightening tool 20 tightens the nut.

[0091] In this embodiment, the control device 30 sends an operation instruction to the servo driver through the EtherCAT protocol, sets the servo motor 10 to operate in torque mode, and screws the nut by driving the nut tightening tool 20 so that the nut is tightened on the pipe joint aligned with it.

[0092] S200 , obtaining torque data and angle data output by the servo motor 10 .

[0093] In this embodiment, during the tightening process, the control device 30 collects the torque data and angle data output by the servo motor 10 in real time through the servo driver. The collected data is transmitted to the PLC controller via the EtherCAT protocol, and then transmitted to the human-computer interaction unit 32 (touch screen) via the Ether IP protocol for display, so that the operator can monitor the tightening process in real time.

[0094] S300, determining whether the torque data is within a preset torque range and whether the angle data is within a preset angle range.

[0095] In this embodiment, the control device 30 compares the real-time collected torque data with the preset torque range, and compares the angle data with the preset angle range. The upper and lower limits of the preset range can be set and adjusted through the interface of the human-computer interaction unit 32.

[0096] S400: When the torque data is within the preset torque range and the angle data is within the preset angle range, output a determination result of qualified tightening; otherwise, output a determination result of unqualified tightening.

[0097] In this embodiment, the result obtained by comparison is used to determine whether the tightening process is qualified, and the determination result is displayed on the human-computer interaction unit 32 .

[0098] Different from the prior art that only relies on a single state signal to judge the tightening result, the control method provided in this embodiment monitors two parameters, torque and angle, at the same time. The control device 30 collects the torque data and angle data output by the servo motor 10 in real time. Through the data analysis of these two dimensions, it can more comprehensively reflect the state of the nut tightening process. For example: when the torque meets the standard but the angle is abnormal, it may indicate that the nut is deviated or has floating threads; when the angle meets the standard but the torque is abnormal, it may indicate that there is a problem with the thread fit; only when the torque and angle data meet the preset range requirements at the same time, it is determined that the finished product of the tightened pipe joint and nut is a qualified product.

[0099] The control method provided in this embodiment collects the operation data of the servo motor 10 through the EtherCAT protocol, and displays the data in real time on the human-machine interaction unit 32 through the Ether IP protocol. This real-time monitoring mechanism allows the operator to intuitively observe the torque change and angle change during the tightening process; when an abnormality occurs, the human-machine interaction unit 32 will immediately display the specific abnormal cause (such as torque overlimit or angle overlimit), which is convenient for the operator to find problems in time and optimize the process.

[0100] In this embodiment, the preset ranges of torque and angle are allowed to be flexibly set through the interface provided by the human-computer interaction unit 32: the appropriate torque range can be adjusted according to nuts and pipe joints of different specifications; a reasonable angle range can be set to ensure that the nut is installed in place.

[0101] In a specific embodiment, in S400, when the torque data is within the preset torque range and the angle data is within the preset angle range, the determination result of qualified tightening is output, otherwise the determination result of unqualified tightening is output. The torque data and angle data here may refer to the final data collected by the control device 30 after the tightening process is completed. The specific implementation process is as follows:

[0102] When the tightening process reaches a preset time, the control device 30 stops the operation of the servo motor 10, and records the maximum torque value and the cumulative rotation angle value output by the servo motor 10. The control device 30 compares the maximum torque value with the preset torque range, and compares the cumulative rotation angle value with the preset angle range.

[0103] Only when the maximum torque value falls within the preset torque range (i.e., greater than or equal to the lower limit value of the torque and less than or equal to the upper limit value of the torque), and the cumulative rotation angle value falls within the preset angle range (i.e., greater than or equal to the lower limit value of the angle and less than or equal to the upper limit value of the angle), the control device 30 will output a tightening qualified judgment result. If any item in the final data exceeds its corresponding preset range, the control device 30 will output a tightening unqualified judgment result.

[0104] In one embodiment, S100, controlling the servo motor 10 to operate so that the nut tightening tool 20 tightens the nut includes:

[0105] S101, controlling the servo motor 10 to run in reverse so that the nut tightening tool 20 is reversed by a preset number of turns.

[0106] In this embodiment, the control method adds a pre-reversal step before performing the nut tightening action. In specific implementation, the control device 30 first controls the servo motor 10 to reversely run a predetermined number of turns, such as two turns, so that the nut tightening tool 20 performs a reverse action.

[0107] The purpose of this pre-reversal design is to ensure that the nut can better align with the thread of the pipe fitting. Because in actual production, due to processing errors and assembly tolerances, there may be a slight position deviation between the nut and the pipe fitting. The pre-reversal action can help correct the position of the nut and improve the success rate of the subsequent forward tightening action.

[0108] S102, controlling the servo motor 10 to run in the forward direction so that the nut tightening tool 20 tightens the nut.

[0109] In this embodiment, after the pre-reversal is completed, the control device 30 immediately switches the running direction of the servo motor 10 and starts to perform the forward tightening action. The entire process is automatically completed by the control device 30 without manual intervention. By combining the two steps of pre-reversal and forward tightening, the reliability and qualified rate of the tightening process are improved.

[0110] In one embodiment, the control method further includes S500, sending a control signal to the robot system based on the tightening qualified determination result and / or the tightening unqualified determination result, and this step specifically includes:

[0111] When the judgment result is that the tightening is qualified, the first control signal is sent, and the robot system transfers the product to the qualified product storage area according to the first control signal; when the judgment result is that the tightening is unqualified, the second control signal is sent and the reason for the unqualified is displayed, and the robot system transfers the product to the unqualified product storage area according to the second control signal.

[0112] In this embodiment, for qualified products, the control device 30 sends a qualified signal to the back-end robot system through the communication interface; for unqualified products, the control device 30 sends an unqualified signal and displays the specific reasons for the unqualified (such as torque exceeding the limit, angle exceeding the limit, etc.) on the human-computer interaction unit 32.

[0113] After the robot system receives the signal sent by the control device 30, it performs different sorting actions according to different signals: for qualified signals, the robot will transfer the pipe fittings that have completed nut tightening to a qualified product conveyor belt or storage area; for unqualified signals, the robot will transfer the corresponding unqualified products to a conveyor belt or storage area dedicated to unqualified products for subsequent rework or inspection.

[0114] In this embodiment, S500 is a process executed after the tightening action is completed and the determination result is obtained.

[0115] In a specific embodiment, while the robot takes away the product, the lifting mechanism 100 performs an automatic reset action: preparing to perform the next round of nut picking and loading actions.

[0116] The control method based on the nut tightening control system provided by the embodiment of the present invention not only achieves accurate tightening of the nuts, but also ensures automatic classification of products and continuous operation of the device, fully demonstrating the advantages of the device in improving production efficiency and reducing manual intervention.

[0117] Based on the above embodiments, the nut tightening control system and control method provided by the embodiments of the present invention drive the nut tightening tooling through a servo motor and realize precise tightening based on torque mode control, and simultaneously collect the two key parameters of torque and angle in real time to establish a double comparison and judgment mechanism. By comparing the two parameters with the preset range, all-round monitoring of the tightening process is achieved, which not only solves the misjudgment problem caused by the traditional single state signal, but also can timely identify abnormal states such as nut deviation and thread misthreading.

[0118] The system also uses EtherCAT and Ether IP communication protocols to achieve real-time data transmission and display, allowing operators to intuitively grasp the tightening status and adjust parameters, effectively improving the operability of the system. In addition, by adding a spring structure and pre-reversal design, the alignment accuracy between the nut and the pipe joint is improved, further ensuring the tightening quality.

[0119] The overall solution provided in this embodiment not only significantly improves the automation level and judgment accuracy in the nut tightening process, but also reduces maintenance costs and maintenance time through standardized component selection, thereby achieving improved system stability and production efficiency.

[0120] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A nut tightening control system, characterized in that: include: A tightening mechanism, the tightening mechanism comprising a servo motor and a nut tightening tool, the nut tightening tool being connected to an output shaft of the servo motor; A control device, the control device is communicatively connected with the servo motor, and the control device is configured as follows: Controlling the servo motor to operate so that the nut tightening tool tightens the nut; Obtaining torque data and angle data output by the servo motor; Determining whether the torque data is within a preset torque range and whether the angle data is within a preset angle range; When the torque data is within the preset torque range and the angle data is within the preset angle range, a determination result of qualified tightening is output; otherwise, a determination result of unqualified tightening is output.

2. The nut tightening control system according to claim 1, characterized in that: The control of the servo motor to operate so that the nut tightening tool tightens the nut is configured as follows: controlling the servo motor to operate in reverse so that the nut tightening tool reverses a preset number of turns, and then controlling the servo motor to operate in forward direction so that the nut tightening tool tightens the nut.

3. The nut tightening control system according to claim 1, characterized in that: The control device comprises: a main controller and a human-machine interaction unit in communication connection; The human-computer interaction unit is configured as follows: receiving settings of the preset torque range and the preset angle range, and transmitting the settings to the main controller; The main controller is configured as follows: Controlling the servo motor to operate according to the received preset torque range and the preset angle range; Acquire the torque data and the angle data of the servo motor, and transmit the torque data and the angle data to the human-computer interaction unit; Determine whether the torque data is within the preset torque range and whether the angle data is within the preset angle range; When the torque data is within the preset torque range and the angle data is within the preset angle range, outputting a tightening qualified judgment result to the human-computer interaction unit, otherwise outputting a tightening unqualified judgment result; The human-computer interaction unit is also configured as: The torque data, the angle data, and the qualified tightening determination result and / or the unqualified tightening determination result are displayed.

4. The nut tightening control system according to claim 1, characterized in that: The nut tightening tool comprises a tightening shaft, one end of which is connected to the output shaft of the servo motor, and the other end of which is provided with a nut tightening head, and a spring is sleeved between the tightening shaft and the nut tightening head.

5. The nut tightening control system according to claim 1, characterized in that: The servo motor includes: an ASD-A2 series driver and an ECMA series motor.

6. The nut tightening control system according to any one of claims 1 to 5, characterized in that: It also includes a lifting mechanism, and the tightening mechanisms are respectively arranged on opposite sides of the lifting mechanism, and the servo motors of the tightening mechanisms are respectively connected to the control device for communication.

7. The nut tightening control system according to claim 6, characterized in that: The lifting mechanism comprises: A ball screw assembly, the ball screw assembly comprising a stepper motor and a screw drivingly connected to the stepper motor; Two sets of linear guide rail assemblies, the two sets of linear guide rail assemblies are respectively arranged on opposite sides of the lead screw; A mounting plate, wherein the mounting plate is fixedly connected to the nut seat of the screw rod, and both ends of the mounting plate are respectively fixedly connected to the sliders of the corresponding linear guide rail assembly; Wherein, the tightening mechanism is fixedly connected to the mounting plate.

8. A control method for a nut tightening control system according to any one of claims 1 to 7, characterized in that: include: Control the servo motor to run so that the nut tightening tool tightens the nut; Obtaining torque data and angle data output by the servo motor; Determining whether the torque data is within a preset torque range and whether the angle data is within a preset angle range; When the torque data is within the preset torque range and the angle data is within the preset angle range, a determination result of qualified tightening is output; otherwise, a determination result of unqualified tightening is output.

9. The control method according to claim 8, characterized in that: The controlling the servo motor to operate so that the nut tightening tool tightens the nut comprises: The servo motor is controlled to run in reverse direction so that the nut tightening tool is reversed by a preset number of turns, and then the servo motor is controlled to run in forward direction so that the nut tightening tool tightens the nut.

10. The control method according to claim 8, characterized in that: Also includes: Based on the qualified tightening determination result and / or the unqualified tightening determination result, sending a control signal to the robot system includes: When the determination result is that the tightening is qualified, a first control signal is sent, and the robot system transfers the product to a qualified product storage area according to the first control signal; When the determination result is that the tightening is unqualified, a second control signal is sent and the reason for the unqualified is displayed, and the robot system transfers the product to the unqualified product storage area according to the second control signal.

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