A subframe bolt tightening control method and system

Abstract

The disclosure provides a subframe bolt tightening control method and system, the method: obtaining vehicle model information through the identification code pre-prepared on the vehicle body; according to the vehicle model information, the electric tightening machine obtains the subframe tightening program matched with the vehicle model; the tightening program is divided into three stages according to the specified torque, and different tightening speeds are configured for each stage; the electric tightening machine executes three-stage tightening according to different speeds, monitors the starting and ending bolt rotation angle values of the three stages and the bolt rotation angle value sequence of the third stage until the tightening reaches the specified torque; according to the final tightening torque value and the bolt rotation angle value, it is judged whether the tightening result is qualified; if qualified, the tightening data of this tightening process is generated to generate a tightening curve for analysis. By setting the three-stage tightening strategy, the effectiveness and controllability of the process monitoring are improved; in the stage where the bolt is prone to deformation or fracture, angle monitoring is concentrated, the diversity of tightening process monitoring data is improved, and resource consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of intelligent assembly and adjustment technology, and in particular to a method and system for controlling the tightening of subframe bolts. Background Technology

[0002] Currently, car manufacturers are producing more and more models, and car assembly lines have shifted from dedicated production lines to flexible production lines, meaning that one production line can produce multiple models. This has led to a significant increase in the probability of incorrect assembly.

[0003] As a key component of the vehicle, the subframe's assembly process is highly valued and strictly controlled. Traditionally, the subframe and body are connected with bolts, tightened using an electric tightening machine to a calculated torque. The process involves several steps: first, a human identifies the vehicle model and selects the appropriate subframe tightening torque; then, the electric tightening machine is operated to tighten the subframe to the set torque in one pass, and the final torque value is used to determine if it passes inspection. However, this tightening method has a problem:

[0004] (1) Recognizing vehicle models based on human eyes and engineering experience to determine the corresponding tightening torque is prone to misjudgment;

[0005] (2) One-time tightening lacks process monitoring and feedback. If the tightening result is unqualified, it is difficult to locate which stage of the tightening process has a problem or deviation through one-time operation, and it is impossible to provide effective correction guidance.

[0006] (3) The existing angle-torque tightening curves are drawn based on the final angle monitoring value or the full-process angle monitoring value. Tightening curves drawn based only on the final angle monitoring value cannot show the detailed information in the tightening process, while tightening curves drawn based on the full-process angle monitoring value require too much resource consumption. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a subframe bolt tightening control method and system. By setting a three-stage tightening strategy, different tightening speeds are configured for different stages to improve the effectiveness and controllability of process monitoring. Simultaneously, the bolt rotation angle is monitored at the beginning and end of each stage, and angle monitoring is concentrated in the third stage, i.e., the stage where the bolt is prone to deformation or breakage. This increases the diversity of tightening process monitoring data and reduces resource consumption.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for controlling the tightening of subframe bolts, comprising:

[0010] Vehicle information can be obtained through pre-printed identification codes on the vehicle body;

[0011] Based on the vehicle model information, the electric tightening machine obtains a subframe tightening program that matches the vehicle model; the tightening program is divided into three stages according to the specified torque, and each stage is configured with a different tightening speed;

[0012] The electric tightening machine performs three-stage tightening at different speeds, monitoring the bolt rotation angle values ​​at the beginning and end of each of the three stages, as well as the bolt rotation angle value sequence in the third stage, until the specified torque is achieved.

[0013] Based on the final tightening torque value and bolt rotation angle value, determine whether the tightening result is qualified; if qualified, generate a tightening curve from the tightening data of this tightening process for analysis.

[0014] Preferably, obtaining vehicle model information through a pre-printed identification code on the vehicle body specifically involves:

[0015] Using a scanning device, the identification code on the vehicle body is scanned to identify the vehicle model; based on the vehicle model, the corresponding subframe tightening procedure is retrieved from the vehicle model association information database.

[0016] Preferably, the vehicle model association information database includes each vehicle model identification code, vehicle model, and corresponding subframe tightening procedure;

[0017] The identification codes for each vehicle model are established based on data from the production management system.

[0018] Preferably, the tightening procedure includes a tightening sequence, a specified torque, a three-stage torque range, and a tightening speed corresponding to each stage.

[0019] Preferably, the step of determining whether the tightening result is qualified based on the final tightening torque value and the bolt rotation angle value is as follows: if both the final tightening torque value and the bolt rotation angle value do not exceed the preset range, then the tightening result is determined to be qualified.

[0020] Preferably, if qualified, the tightening data of this tightening process is used to generate a tightening curve for analysis. The tightening data includes the starting and ending torque values ​​and bolt rotation angle values ​​of three stages, as well as the bolt rotation angle value sequence of the third stage.

[0021] A coordinate system is established based on the torque value and the bolt rotation angle value to generate a curve.

[0022] Preferably, the method further includes: when the tightening result is determined to be unqualified, adjusting the electric tightening machine to rotate in the opposite direction, removing the faulty bolt, replacing it with a new bolt, and re-performing the tightening according to the tightening procedure.

[0023] Secondly, the present invention provides a subframe bolt tightening control system, comprising:

[0024] The scanning device is used to scan the identification code on the vehicle body to identify the vehicle model; according to the vehicle model, the corresponding subframe tightening program is retrieved from the vehicle model association information database and transmitted to the electric tightening machine;

[0025] An electric tightening machine is used to receive and execute a tightening procedure; the tightening procedure is divided into three stages according to a specified torque, and each stage is configured with a different tightening speed.

[0026] The tightening angle acquisition device is used to collect the bolt rotation angle values ​​at the beginning and end of the three stages and the bolt rotation angle value sequence of the third stage when the electric tightening machine is performing a three-stage tightening process at different speeds.

[0027] The terminal equipment is used to determine whether the tightening result is qualified after the tightening procedure is completed, based on the final tightening torque value and bolt rotation angle value; if qualified, the tightening data of this tightening process is used to generate a tightening curve for analysis.

[0028] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the subframe bolt tightening control method described in the first aspect.

[0029] Fourthly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps in the subframe bolt tightening control method described in the first aspect.

[0030] Compared with the prior art, the beneficial effects of this disclosure are as follows:

[0031] 1. When tightening torque, this invention not only determines whether the tightening is qualified by the final tightening torque value, but also adds monitoring and judgment of whether the torque is normal or abnormal by tightening angle. The tightening angle monitor obtains bolt angle information at the beginning and end of three stages, and monitors the bolt rotation angle from the moment of torque change, i.e., the third stage, to obtain the bolt rotation angle value sequence; thus ensuring the accuracy of dual-dimensional judgment, while avoiding angle monitoring throughout the tightening process, reducing resource consumption.

[0032] 2. This invention adds an identification code recognition device to the final assembly, using a barcode scanner to scan the vehicle model's identification code to identify the specific vehicle model, and then identifies the tightening torque of the subframe used for that vehicle model and transmits it to the electric tightening machine. This allows the electric tightening machine to accurately select the tightening program corresponding to the vehicle model, reducing the human judgment step, improving the accuracy of tightening program recognition, and avoiding errors in human identification and operation.

[0033] 3. This invention generates a tightening curve by reading the torque and angle information output by the electric tightening machine and simultaneously records it in a designated storage medium. By analyzing a large number of tightening curves, the monitoring range of tightening speed and bolt tightening angle at each stage of the electric tightening machine can be optimized, thereby improving tightening speed and bolt utilization. The recorded content enables work feedback and provides guidance for refined production and processing.

[0034] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0035] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute a limitation thereof.

[0036] Figure 1 This is a main flowchart of a subframe bolt tightening control method provided in this disclosure;

[0037] Figure 2 A detailed flowchart of a subframe bolt tightening control method provided in this disclosure;

[0038] Figure 3 This is a schematic diagram of the subframe bolt mounting points provided in this disclosure;

[0039] Figure 4 This is a schematic diagram of the theoretical tightening curve of the electric tightening machine provided in this disclosure. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment discloses a method for controlling the tightening of subframe bolts, including the following steps:

[0043] S1: Obtain vehicle model information through the identification code pre-printed on the vehicle body;

[0044] S2: Based on the vehicle model information, the electric tightening machine obtains a subframe tightening program that matches the vehicle model; the tightening program is divided into three stages according to the specified torque, and each stage is configured with a different tightening speed;

[0045] S3: The electric tightening machine performs three-stage tightening at different speeds, monitoring the bolt rotation angle values ​​at the beginning and end of the three stages, as well as the bolt rotation angle value sequence in the third stage, until the specified torque is achieved;

[0046] S4: Determine whether the tightening result is qualified based on the final tightening torque value and bolt rotation angle value; if qualified, generate a tightening curve from the tightening data of this tightening process for analysis.

[0047] In this specific embodiment, accurate vehicle model information and corresponding tightening procedures are obtained through the identification code recognition function. A three-stage tightening strategy is proposed, with different tightening speeds configured for each stage, improving the effectiveness of process monitoring. Simultaneously, monitoring at a specific torque trigger angle increases the diversity of tightening process monitoring while reducing resource consumption. Figure 2 The following is a detailed process provided in this specific embodiment:

[0048] First, a scanning device is used to scan the identification code pre-printed on the vehicle body to identify the vehicle model. Based on the obtained vehicle model information, the corresponding subframe tightening procedure is retrieved from the vehicle model association information database.

[0049] As one or more embodiments, the vehicle model association information database is a relational database. The vehicle model association information database includes each vehicle model identification code, vehicle model, and the corresponding subframe tightening procedure.

[0050] As one or more embodiments, the tightening procedure is obtained by statistically analyzing historical tightening data. Specifically, based on historical experience, when the threaded pair is fully engaged, the current torque value is collected as the starting torque value of the second stage; when the workpiece is pre-fitted, it indicates that the torque is about to change abruptly, and after the workpiece is pre-fitted, the torque value is collected as the starting torque value of the third stage.

[0051] As one or more embodiments, each vehicle model identification code is established based on data from the production management system. Establishing vehicle model identification codes based on production management system data means that the generation and allocation of these codes are based on various data within the production management system. This data may include production plans, material usage, production process records, quality inspection reports, etc. In this way, it can be ensured that the vehicle model identification code closely corresponds to the actual production information of the vehicle, enabling accurate traceability and management of vehicle information.

[0052] It should be understood that this embodiment does not specifically limit the type of identification code, which can be a QR code, barcode, RFID, etc., and those skilled in the art can choose according to actual needs.

[0053] A barcode scanning device is added next to the electric tightening machine to identify the vehicle model by scanning the barcode. This identification then determines the appropriate subframe tightening torque for that model and transmits this information to the electric tightening machine, allowing it to accurately select the corresponding tightening procedure. The tightening procedure includes the tightening sequence, specified torque, and corresponding tightening speed. Different vehicle models have different tightening procedures; that is, depending on the vehicle model, the tightening sequence of the subframe and the torque and speed values ​​involved in the three-stage tightening method will vary.

[0054] In this embodiment, preferably, when the electric tightening machine is tightening, the specified torque of 220 nm is applied according to the tightening procedure. Figure 3 Tighten according to the indicated tightening positions and tightening sequence (L1-R1-R2-L2).

[0055] Each tightening should be done using a three-stage tightening method, such as... Figure 4 As shown in the diagram. In this embodiment, the torque range of the first stage is 0 nm to 65 nm, using a speed of 30 rpm; the torque range of the second stage is 65 nm to 150 nm, using a speed of 20 rpm; and the torque range of the third stage is 150 nm to 220 nm, using a speed of 8 rpm. Different speeds are set for different tightening stages, and the tightening speed decreases as the number of stages increases, meaning the tightening speed becomes increasingly slower, thus improving the controllability of the tightening process.

[0056] In the later stages of tightening, the bolts experience increasing stress, making them more prone to deformation or breakage. Therefore, the tightening speed gradually decreases based on different stages to protect the material from unnecessary damage. Simultaneously, lower speeds make it easier to control the torque tightening precision. This overcomes the difficulty of accurately locating problems or deviations with traditional one-time tightening, providing a foundation for effective process monitoring and feedback.

[0057] While tightening, the tightening angle is monitored to track the bolt rotation angle values ​​at the beginning and end of the three stages. When the torque reaches 150nm, the bolt rotation angle value sequence is recorded starting from the third stage.

[0058] It should be understood that the sequence is a set of bolt rotation angle values ​​based on torque variation.

[0059] During the bolt tightening process, deformation or breakage is likely to occur in the third stage. Therefore, the angle monitoring in this embodiment is mainly for the third stage. It can not only monitor torque and rotation angle at the same time, providing comprehensive monitoring of the tightening process, but also avoids angle monitoring throughout the tightening process, thus reducing resource consumption.

[0060] In this embodiment, the preset range for judging whether the monitoring angle is qualified is 5° to 300°. The final tightening torque value and the angle monitoring value are used to determine whether the tightening result is qualified. The torque judgment standard is set to 220nm ± 3%nm, and the angle judgment standard is 5° to 300°. If both conditions are met, it is qualified. If any condition is not met, it is unqualified. When unqualified, the rotation direction of the electric tightening machine needs to be adjusted, the faulty bolt needs to be completely disassembled, and then a new bolt needs to be replaced and tightened again.

[0061] To ensure the quality and efficiency of tightening, the terminal equipment connected to the electric tightening machine will immediately read the tightening data and generate a tightening curve after each tightening operation, provided that the tightening result is satisfactory. This data includes the three-stage start and end torque values, angle monitoring values, and time-series angle monitoring values ​​after the tightening angle monitor is activated. These data are recorded in detail and stored in a designated storage device.

[0062] A coordinate system is established based on torque and angle monitoring values ​​to generate curves. In-depth analysis of a large number of tightening curves is an important means to improve bolt tightening technology. By analyzing these curves, we can understand various changes during the bolt tightening process, including changes in tightening torque, tightening speed, and the distribution of bolt tightening angles. This information helps to identify potential problems during tightening, such as overtightening, undertightening, or uneven tightening.

[0063] Based on these analysis results, the tightening speed of the electric tightening machine can be adjusted. By optimizing the tightening speed, production efficiency can be improved while ensuring tightening quality. For example, if the tightening speed is found to be too slow at a certain stage, the speed at that stage can be appropriately increased, thereby shortening the overall tightening process time.

[0064] Furthermore, narrowing the monitoring range of bolt tightening angles is also an effective way to improve bolt utilization and tightening reliability. By precisely controlling the bolt tightening angle, it can be ensured that the bolt is tightened within the appropriate range, avoiding bolt damage due to overtightening or insecure connections due to undertightening. This not only improves bolt utilization and reduces waste but also enhances tightening reliability, ensuring the safety and stability of the connection.

[0065] It is evident that by reading and analyzing tightening data, adjusting the tightening speed of the electric tightening machine, and optimizing the monitoring range of the bolt tightening angle, the goals of improving productivity and controlling bolt utilization and tightening reliability can be achieved. This not only improves production efficiency but also ensures product quality and safety.

[0066] This specific embodiment introduces an identification code recognition function to obtain accurate vehicle model information and corresponding tightening procedures, ensuring a high degree of matching between the tightening procedures and the vehicle model, and avoiding the impact of misidentification of the tightening procedures on production progress. A three-stage tightening strategy is proposed, with different tightening speeds configured for each stage, improving the effectiveness and controllability of process monitoring. Simultaneously, supervisory monitoring is triggered at the start and end of each of the three stages, and at moments of sudden torque changes, increasing the diversity of tightening process monitoring and reducing resource consumption. The tightening curve generated based on this tightening data will also provide technicians with accurate and targeted data support for correcting the tightening process.

[0067] Example 2

[0068] This embodiment provides a subframe bolt tightening control system, including:

[0069] The scanning device is used to scan the identification code on the vehicle body to identify the vehicle model; according to the vehicle model, the corresponding subframe tightening program is retrieved from the vehicle model association information database and transmitted to the electric tightening machine;

[0070] An electric tightening machine is used to receive and execute a tightening procedure; the tightening procedure is divided into three stages according to a specified torque, and each stage is configured with a different tightening speed.

[0071] The tightening angle acquisition device is used to collect the bolt rotation angle values ​​at the beginning and end of the three stages and the bolt rotation angle value sequence of the third stage when the electric tightening machine is performing a three-stage tightening process at different speeds.

[0072] The terminal equipment is used to determine whether the tightening result is qualified after the tightening procedure is completed, based on the final tightening torque value and bolt rotation angle value; if qualified, the tightening data of this tightening process is used to generate a tightening curve for analysis.

[0073] Preferably, it also includes a torque monitoring device for real-time monitoring of torque values, determining the stage of tightening, and obtaining the final torque value.

[0074] Example 3

[0075] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the subframe bolt tightening control method described in Embodiment 1 above.

[0076] This specific embodiment is based on the subframe bolt tightening control method described in Embodiment 1. By introducing an identification code recognition function to obtain accurate vehicle model information and corresponding tightening procedures, it ensures a high degree of matching between the tightening procedure and the vehicle model, and avoids the impact of misidentification of the tightening procedure on the production schedule. A three-stage tightening strategy is proposed, with different tightening speeds configured for different stages, improving the effectiveness and controllability of process monitoring. At the same time, monitoring is triggered at the beginning and end of the three stages and at torque abrupt changes, increasing the diversity of tightening process monitoring and reducing resource consumption. The tightening curve generated based on this tightening data will also provide technicians with accurate and targeted tightening process correction data support.

[0077] Example 4

[0078] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the subframe bolt tightening control method described in Embodiment 1 above.

[0079] This specific embodiment is based on the subframe bolt tightening control method described in Embodiment 1. By introducing an identification code recognition function to obtain accurate vehicle model information and corresponding tightening procedures, it ensures a high degree of matching between the tightening procedure and the vehicle model, and avoids the impact of misidentification of the tightening procedure on the production schedule. A three-stage tightening strategy is proposed, with different tightening speeds configured for different stages, improving the effectiveness and controllability of process monitoring. At the same time, monitoring is triggered at the beginning and end of the three stages and at torque abrupt changes, increasing the diversity of tightening process monitoring and reducing resource consumption. The tightening curve generated based on this tightening data will also provide technicians with accurate and targeted tightening process correction data support.

[0080] The steps or modules involved in Embodiments 2 to 4 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the tightening of subframe bolts, characterized in that, include: Vehicle information can be obtained through pre-printed identification codes on the vehicle body; Based on the vehicle model information, the electric tightening machine obtains the subframe tightening procedure that matches the vehicle model; The tightening process is divided into three stages based on the specified torque, with each stage configured with a different tightening speed; The tightening procedure includes the tightening sequence, specified torque, three-stage torque range, and tightening speed corresponding to each stage; The electric tightening machine performs three-stage tightening at different speeds, monitors the bolt rotation angle values ​​at the beginning and end of the three stages, and records the bolt rotation angle value sequence starting from the third stage until the specified torque is reached; Based on the final tightening torque value and bolt rotation angle value, determine whether the tightening result is qualified; if qualified, generate a tightening curve from the tightening data of this tightening process for analysis. The tightening data includes the starting and ending torque values ​​and bolt rotation angle values ​​for three stages, as well as a sequence of bolt rotation angle values ​​for the third stage; A coordinate system is established based on the torque value and the bolt rotation angle value to generate a curve.

2. The subframe bolt tightening control method as described in claim 1, characterized in that, The method of obtaining vehicle model information through a pre-printed identification code on the vehicle body is as follows: Using a scanning device, the identification code on the vehicle body is scanned to identify the vehicle model; based on the vehicle model, the corresponding subframe tightening procedure is retrieved from the vehicle model association information database.

3. The subframe bolt tightening control method as described in claim 2, characterized in that, The vehicle model association information database contains each vehicle model identification code, vehicle model, and corresponding subframe tightening procedure; The identification codes for each vehicle model are established based on data from the production management system.

4. The subframe bolt tightening control method as described in claim 1, characterized in that, The determination of whether the tightening result is qualified based on the final tightening torque value and the bolt rotation angle value is as follows: if the final tightening torque value and the bolt rotation angle value do not exceed the preset range, the tightening result is determined to be qualified.

5. The subframe bolt tightening control method as described in claim 1, characterized in that, Also includes: If the tightening result is deemed unqualified, adjust the electric tightening machine to rotate in the opposite direction, remove the faulty bolt, replace it with a new bolt, and repeat the tightening process according to the tightening procedure.

6. A subframe bolt tightening control system, characterized in that, include: The scanning device is used to scan the identification codes on the vehicle body to identify the vehicle model; According to the vehicle model, the corresponding subframe tightening program is retrieved from the vehicle model association information database and transmitted to the electric tightening machine; An electric tightening machine is used to receive and execute a tightening procedure; the tightening procedure is divided into three stages according to a specified torque, and each stage is configured with a different tightening speed. The tightening procedure includes the tightening sequence, specified torque, three-stage torque range, and tightening speed corresponding to each stage; The tightening angle acquisition device is used to collect the bolt rotation angle values ​​at the beginning and end of the three stages when the electric tightening machine is performing a three-stage tightening process at different speeds, and to record the bolt rotation angle value sequence starting from the third stage. The terminal equipment is used to determine whether the tightening result is qualified after the tightening procedure is completed, based on the final tightening torque value and bolt rotation angle value; if qualified, the tightening data of this tightening process is used to generate a tightening curve for analysis. The tightening data includes the starting and ending torque values ​​and bolt rotation angle values ​​for three stages, as well as a sequence of bolt rotation angle values ​​for the third stage; A coordinate system is established based on the torque value and the bolt rotation angle value to generate a curve.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps in the subframe bolt tightening control method as described in any one of claims 1-5.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the subframe bolt tightening control method as described in any one of claims 1-5.

Images