Noise-driven self-adaptive tightening assembly device and method

Abstract

The invention discloses a noise-driven self-adaptive tightening assembly device which is provided with a servo motor, a power shaft of the servo motor is connected with an output shaft through a planetary gear reducer, a torque sensor is arranged between the output shaft and the planetary gear reducer, and a temperature sensor is installed near the output shaft. The torque sensor and the temperature sensor are connected and output induction signals to a controller of the device. The tightening machine is suitable for the industries of automobile manufacturing and the like, and is particularly suitable for application scenes with strict requirements on tightening quality. The method has the advantages that compared with the prior art, the tightening strategy can control the tightening process more accurately, the production efficiency is improved, the product quality is ensured, and the method can adapt to variable production environments.

Description

Technical Field

[0001] The invention relates to the technical field of automobile assembly. Background Art

[0002] In the process of automobile assembly, bolt tightening is a key step, and the tightening quality directly affects the safety performance and service life of the automobile. In order to improve the level of production automation, automatic tightening equipment came into being. Traditional tightening equipment usually adopts fixed torque control. In the tightening operation, for example, the public document with the publication number CN102513976A, the publication date is June 27, 2012, and the patent name is "A torque self-balancing hydraulic bolt tightening device and tightening method". The disclosed bolt tightening device includes a hydraulic ratchet drive mechanism connected to the hydraulic drive mechanism, composed of an inner sleeve and a housing that are integrated with a fine-toothed ratchet, an outer sleeve that is integrated with the housing of the hydraulic ratchet drive mechanism, and a torque transmission sleeve for fixing the bolt head of a multi-angle head bolt; the inner sleeve is sleeved in the lower part of the outer sleeve, and the torque transmission sleeve is sleeved in the upper part of the outer sleeve.

[0003] Due to various uncontrollable noise factors, such as differences in material properties caused by changes in ambient temperature, the tightening quality may be unstable, and the final product quality is difficult to achieve the ideal state.

[0004] With the rapid development of sensor technology, measuring equipment and signal processing technology, some uncontrollable noise factors (such as ambient temperature) that affect the target torque during the tightening process can be quantified through precise measuring tools, achieving real-time monitoring of the process and ensuring the stability and consistency of product quality. The designed adaptive tightening machine can improve the overall performance of the car, improve assembly efficiency and efficient production.

[0005] Common bolt tightening methods:

[0006] 1. Torque method: In the tightening operation, tightening stops when the target torque is reached.

[0007] A) Low cost, easy operation and wide application;

[0008] B) Preload accuracy is low;

[0009] 2. Torque-angle method: In the tightening operation, after reaching the target torque, turn the screw

[0010] The pattern reaches the target angle.

[0011] A) The tightening quality is stable, and the friction coefficient of the threaded parts has little effect on the tightening quality;

[0012] B) Tightening tools are expensive and inconvenient to operate;

[0013] 3. Yield Point Method: Tightening is achieved by tightening the bolt or nut to the yield point.

[0014] A) High pre-tightening force accuracy;

[0015] B) Low work efficiency, high cost, and relatively cumbersome to use. Summary of the Invention

[0016] The technical problem to be solved by the present invention is to implement a noise-driven adaptive tightening assembly strategy. By integrating a temperature sensor, the tightening torque is adjusted online according to the real-time observed value of the ambient temperature to adapt to the tightening operation under different environmental conditions and ensure the best tightening effect under different environmental conditions.

[0017] To achieve the above object, the technical solution adopted by the present invention is: a noise-driven adaptive tightening assembly device, which is provided with a servo motor. The power shaft of the servo motor is connected to the output shaft through a planetary gear reducer. A torque sensor is provided between the output shaft and the planetary gear reducer. A temperature sensor is installed near the output shaft. The torque sensor and the temperature sensor are connected and output induction signals to the controller of the device.

[0018] The housing is a cylindrical housing that encloses the servo motor, the planetary gear reducer, and the torque sensor. The output shaft extends out of the housing. The temperature sensor is fixed on the housing at one end of the output shaft.

[0019] The controller is fixed inside the housing. The controller is connected and outputs a status signal to the result display LED lamp on the housing for display. A start switch for controlling the servo motor is provided on the housing.

[0020] The servo motor provides power. The reducer is connected to the servo motor to reduce the speed and increase the torque. The torque sensor monitors the torque and angle data during the tightening process. The temperature sensor is installed near the output shaft to observe the ambient temperature during the tightening process. The output shaft is connected to the sensor. The controller monitors and adjusts the tightening process in real time, including a storage unit and a processing unit. The storage unit stores the tightening torque parameters at different temperatures. The processing unit calculates and updates the tightening torque online according to the data observed by the temperature sensor in real time and the stored parameters.

[0021] An assembly method based on the above-mentioned noise-driven adaptive tightening assembly device includes the following steps:

[0022] Step 1: Start the tightening machine. The operator turns on the power of the tightening machine through the start switch.

[0023] Step 2: The temperature sensor built into the tightening machine starts to observe the temperature of the tightening area in real time and transmits the data to the control unit.

[0024] Step 3: The control unit determines whether to update the tightening torque based on the observed ambient temperature.

[0025] Step 4: The operator selects an appropriate tightening program or mode and sets it through the tool buttons or the touch screen interface.

[0026] Step 5: The servo motor of the tightening machine operates according to the instructions of the controller, driving the output shaft to perform the tightening operation.

[0027] Step 6: The torque sensor monitors the torque in real time during the tightening process to ensure that the tightening operation meets the predetermined torque requirements.

[0028] Step 7: During the tightening process, the control unit continuously monitors the data of the temperature sensor and the torque sensor.

[0029] Step 8: After the tightening is completed, the control unit automatically records the tightening data.

[0030] Step 9: The operator confirms the completion of the tightening operation through the user interface of the tightening machine.

[0031] In Step 3, if an update is needed, the preset algorithm model is used to adjust the tightening torque online to compensate for the influence of temperature changes on material properties and tightening effects.

[0032] The steps for determining whether to update the tightening torque target value in Step 3 are as follows:

[0033] Step 1: Calculate the mass loss based on the tightening torque applied by the tightening shaft at the previous moment.

[0034] Step 2: Set the upper limit U of the mass loss. If the mass loss is less than U, the tightening torque is not updated.

[0035] If the loss is greater than U, the tightening torque of the servo tightening shaft is updated online according to the preset algorithm based on the ambient temperature observed in real time.

[0036] The controller includes a data analysis module that analyzes the tightening data to identify potential tightening problems or optimize the tightening strategy; and a user feedback module that allows the operator to provide feedback during the tightening process to further optimize the tightening strategy.

[0037] The tightening machine includes a battery management system and a safety locking mechanism. The battery management system monitors and manages the charging and discharging status of the battery to ensure that the tightening machine operates in the best state. When the tightening machine is not operated correctly or a failure occurs, the safety locking mechanism automatically locks to prevent accidental injuries.

[0038] The advantages of the present invention are that the tightening machine is applicable to industries such as automobile manufacturing, especially in application scenarios with strict requirements for tightening quality. The advantages of the present invention are as follows: Compared with the prior art, the tightening strategy of the present invention can more precisely control the tightening process, improve production efficiency, ensure product quality, and can adapt to variable production environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The following briefly describes the content expressed in each drawing in the specification of the present invention and the marks in the drawings:

[0040] Figure 1 It is a mounting position diagram of the temperature sensor in the servo tightening shaft;

[0041] Figure 2 It is a tightening operation flow chart;

[0042] Figure 3 It is a flow chart of the adaptive adjustment algorithm;

[0043] Figure 4 It is a flow chart of the update criterion for on-line control variables;

[0044] The marks in the above figures are all: 1. Servo motor; 2. Planetary gear reducer; 3. Torque sensor; 4. Temperature sensor; 5. Output shaft; 6. Start switch; 7. Result display LED lamp. DETAILED DESCRIPTION OF THE INVENTION

[0046] The following further describes in detail the specific implementation manners of the present invention, such as the shapes, structures of the various components involved, the mutual positions and connection relationships between the various parts, the functions and working principles of each part, the manufacturing process, and the operation and use methods, etc., with reference to the drawings, so as to help those skilled in the art have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0047] The present invention is a noise-driven adaptive tightening assembly strategy for improving the accuracy and reliability in the tightening assembly process. This tightening strategy adjusts the tightening parameters online through the real-time observed values of observable noise factors to adapt to different working environments and ensure the tightening quality.

[0048] The main technical features include:

[0049] Integrated sensor system: The tightening machine is equipped with a torque sensor 3 and a temperature sensor 4 to monitor the key parameters in the tightening process in real time.

[0050] Noise-driven model: A tightening process model based on noise drive is constructed, and this model can predict and compensate for the fluctuations caused by noise.

[0051] Adaptive control algorithm: Through the adaptive control algorithm, the tightening torque is adjusted online according to the real-time data of the ambient temperature to achieve a better tightening effect.

[0052] User interface: Provide a user interface that allows the operator to monitor the tightening process and perform manual intervention if necessary.

[0053] Data recording and analysis: The tightening machine can record all data during the tightening process, which is convenient for quality traceability and continuous improvement.

[0054] As Figure 1 shown, the installation position of the temperature sensor 4 is as Figure 1 shown. The temperature sensor 4 is installed near the output shaft 6. When the operator performs the tightening operation, the temperature sensor 4 observes the current temperature in real time. The control system judges whether to update the target torque according to the real-time observed value of the temperature, and sends the optimal target torque to the output shaft 6. All electronic components are connected to the control system.

[0055] The noise-driven adaptive tightening assembly device includes a servo tightening shaft, a controller, and a host computer system. The servo tightening shaft performs the tightening operation. The controller controls the operation of the tightening machine and sets tightening parameters such as torque, angle, etc. The host computer system monitors and manages the tightening process.

[0056] The servo tightening shaft includes a servo motor, a reducer, a torque sensor 3, a temperature sensor 4, and an output shaft 6. The servo motor provides power and rotates according to the instructions of the controller. The reducer is connected to the servo motor to reduce the speed and increase the torque. The torque sensor 3 and the temperature sensor 4 are installed near the output shaft 6 to detect torque and angle data during the tightening process and observe the temperature during the tightening process. The output shaft 6 is connected to the sensor to transmit data to the controller.

[0057] The controller is connected to the temperature sensor 4 and the torque sensor 3, sets the tightening parameters, controls the operation of the tightening machine, and monitors and adjusts the tightening process in real time. The controller includes a storage unit and a processing unit. The storage unit stores the tightening torque parameters at different temperatures. The processing unit calculates and updates the tightening torque online according to the data observed by the temperature sensor 4 in real time and the stored parameters.

[0058] A temperature sensor 4 is provided in the servo tightening shaft. The overall process is as follows (as Figure 2 shown).

[0059] Step 1: Vehicle positioning and information acquisition When the vehicle arrives at the preset tightening process position, the staff uses a barcode scanner to scan the VIN code of the vehicle. The scanned VIN code information is transmitted to the control system. This system communicates with the database to retrieve the specific tightening torque and angle information associated with this VIN code.

[0060] Step 2: Preparation of the Tightening Program The control system for preparation retrieves the tightening parameters and displays them on the operation interface. Meanwhile, the system automatically selects a suitable tightening head for the automatic tightening machine and sets the required torque and angle parameters.

[0061] Step 3: Start-up and Operation of the Tightening Machine The operator ensures that the tightening machine is correctly connected to the vehicle and starts the equipment. The servo motor of the tightening machine begins to work, reducing the rotational speed and increasing the torque through the reducer, and the output shaft 6 transmits power to the tightening head.

[0062] Step 4: Monitoring the Tightening Process During the tightening process, the torque sensor 3 monitors the tightening parameters in real time to ensure that the tightening operation meets the predetermined torque and angle requirements. The temperature sensor 4 monitors the temperature change during the tightening process, and based on the real-time observed value of the temperature, it confirms whether to update the tightening torque online.

[0063] Step 5: Completion of the Tightening Operation Once the tightening operation reaches the preset torque and angle, the tightening machine automatically stops the operation and sends a completion signal. The control system records the results of the tightening operation, including information such as torque, angle, and temperature, for subsequent quality traceability and analysis.

[0064] Step 6: Data Archiving and Quality Control After the tightening is completed, the control system archives all relevant data, including the tightening results and operation parameters, for subsequent quality management and process improvement.

[0065] A noise-driven adaptive tightening assembly strategy, as Figure 3 shown, includes the following calculation processes:

[0066] Step 1: System Modeling Establish a corresponding regression model, where y is the output during the tightening process (such as torque, angle, etc.), x is the control variable (influence factors that cannot be adjusted online), u is the control input (influence factors that can be adjusted online, such as tightening torque), and z represents the noise factors in the process.

[0067] Step 2: Construction of the Quality Loss Function:

[0068] 1) Define the quality loss function J, where E(y) and Var(y) are the expected value and variance of y, T is the target value, and z is the real-time observed value of the noise (such as ambient temperature);

[0069] 2) Calculate the expected value of the response y;

[0070] 3) Calculate the variance of the response y;

[0071] Step 3: Construction of the Optimization Model Construct an optimization problem to find the optimal control inputs u and x to minimize the quality loss J.

[0072] Step 4: Solve for the first derivative of the online control variable u with respect to the quality loss function J. Set the first derivative equal to 0 to solve for the online control variable u, obtaining the control strategy u = g(x, z).

[0073] Step 5: Construct a time series model for the noise factor z:

[0074] 1) Based on the online observed values of the noise factor, establish a time series model:

[0075] 2) Predict the future observed values of the noise factor:

[0076] Step 6: Optimal setting of the offline control variable. Based on the online control, use the Monte Carlo method to determine the optimal setting of the offline control variable.

[0077] Step 7: Optimal setting of the online control variable. Based on the real-time observed environmental temperature (noise variable), obtain the optimal setting of the online control variable u.

[0078] Step 8: Implement the tightening strategy. Start the tightening operation according to the optimal setting of the offline control variable x, and online adjust the target value of the tightening torque based on the real-time observed temperature data.

[0079] Step 9: Feedback loop. Feed the tightening result back into the system for updating and optimizing the strategy, forming a closed-loop control.

[0080] A noise-driven tightening assembly strategy, and the update criterion for the tightening torque is as Figure 4 shown. Calculate the quality loss based on the tightening torque applied by the tightening shaft at the previous moment; set an upper limit U for the quality loss. If the quality loss is less than U, do not update the tightening torque; if the loss is greater than U, then based on the real-time observed environmental temperature and according to a preset algorithm, online update the tightening torque of the servo tightening shaft.

[0081] The advantages of the present invention are as follows:

[0082] 1. Strong environmental adaptability: By real-time monitoring the environmental temperature and online adjusting the tightening torque according to the temperature change, it can adapt to different working environments and ensure the best tightening effect under various temperature conditions.

[0083] 2. Improve the tightening quality: The adaptive adjustment of the tightening torque reduces the impact of material property differences caused by temperature changes on the tightening quality.

[0084] 3. Easy to operate: The device is equipped with a user interface, and the operator can easily monitor and adjust the tightening parameters.

[0085]

[0086] ​4. Data recording and traceability: Recording key data such as temperature, torque, and angle during the tightening process helps with quality control and problem diagnosis.

[0087] The present invention has been described exemplarily above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An assembly device for noise-driven adaptive tightening, which is provided with a servo motor. The power shaft of the servo motor is connected to the output shaft through a planetary gear reducer. A torque sensor is provided between the output shaft and the planetary gear reducer. It is characterized in that: A temperature sensor is installed near the output shaft. The torque sensor and the temperature sensor are connected and output induction signals to the controller of the device.

2. The noise-driven adaptive tightening and assembling device according to claim 1, characterized in that: The housing is a cylindrical housing that encloses the servo motor, planetary gear reducer, and torque sensor. The output shaft extends out of the housing, and the temperature sensor is fixed on the housing at one end of the output shaft.

3. The noise-driven adaptive tightening and assembling device according to claim 2, characterized in that: The controller is fixed inside the housing. The controller is connected and outputs status signals to the result display LED lights on the housing for display. A start switch for controlling the servo motor is provided on the housing.

4. The noise-driven adaptive tightening assembly device according to claim 3, characterized in that: The servo motor provides power. The reducer is connected to the servo motor to reduce the speed and increase the torque. The torque sensor monitors the torque and angle data during the tightening process. The temperature sensor is installed near the output shaft to observe the ambient temperature during the tightening process. The output shaft is connected to the sensor. The controller monitors and adjusts the tightening process in real time, including a storage unit and a processing unit. The storage unit stores the tightening torque parameters at different temperatures. The processing unit calculates and updates the tightening torque online according to the data observed by the temperature sensor in real time and the stored parameters.

5. An assembly method of a noise-driven adaptive tightening assembly device according to any one of claims 1-4, characterized in that, It includes the following steps: Step 1: Start the tightening machine. The operator turns on the power of the tightening machine through the start switch. Step 2: The temperature sensor built into the tightening machine starts to observe the temperature of the tightening area in real time and transmits the data to the control unit. Step 3: The control unit determines whether to update the tightening torque according to the observed ambient temperature. Step 4: The operator selects an appropriate tightening program or mode and sets it through the tool button or touch screen interface. Step 5: The servo motor of the tightening machine works according to the instructions of the controller, driving the output shaft to perform the tightening operation. Step 6: The torque sensor monitors the torque during the tightening process in real time to ensure that the tightening operation meets the predetermined torque requirements. Step 7: During the tightening process, the control unit continuously monitors the data of the temperature sensor and the torque sensor. Step 8: After the tightening is completed, the control unit automatically records the tightening data. Step 9: The operator confirms the completion of the tightening operation through the user interface of the tightening machine.

6. The noise-driven adaptive tightening assembly method according to claim 5, characterized in that: In Step 3, if an update is needed, the tightening torque is adjusted online using a preset algorithm model to compensate for the influence of temperature changes on material properties and tightening effects.

7. The noise-driven adaptive tightening assembly device according to claim 5, characterized in that, The steps for determining whether to update the tightening torque target value in Step 3 are as follows: Step 1: Calculate the mass loss according to the tightening torque applied by the tightening shaft at the previous moment. Step 2: Set the upper limit U of the mass loss. If the mass loss is less than U, the tightening torque is not updated. If the loss is greater than U, the tightening torque of the servo tightening shaft is updated online according to the ambient temperature observed in real time and the preset algorithm.

8. The noise-driven adaptive tightening assembly device according to claim 5, 6 or 7, characterized in that: The controller includes a data analysis module that analyzes the tightening data to identify potential tightening problems or optimize the tightening strategy. A user feedback module that allows the operator to provide feedback during the tightening process to further optimize the tightening strategy.

9. The noise-driven adaptive tightening assembly device according to claim 8, characterized in that: The tightening machine includes a battery management system and a safety locking mechanism. The battery management system monitors and manages the charging and discharging status of the battery to ensure that the tightening machine works in the best state. When the tightening machine is not operated correctly or fails, the safety locking mechanism automatically locks to prevent accidental injury.

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