Bolt fastening method, clamp fastening device, and computer program product

Abstract

The embodiment of the application is suitable for the field of bolt fastening, and provides a bolt fastening method, a hoop fastening device and a computer program product. The method comprises the following steps: controlling multiple motors to respectively fasten corresponding bolts until the tightening torque of each bolt reaches a preset standard torque; detecting the parallelism of the mounting surface of the hoop; if the parallelism is greater than or equal to a preset parallelism, obtaining the interval distance between each bolt and a preset reference surface; determining a first bolt corresponding to the maximum value of the interval distance, a first motor corresponding to the first bolt, a second bolt located at the opposite side of the first bolt, and a second motor corresponding to the second bolt; determining a deflection angle according to the deviation between the interval distance corresponding to the first bolt and the interval distance corresponding to the second bolt; and controlling the first motor to loosen the first bolt by the deflection angle, and controlling the second motor to tighten the second bolt by the deflection angle. By using the above method, the reliability of the bolt connection of the hoop can be ensured, and the installation quality can be improved.

Description

Technical Field

[0001] This application belongs to the field of bolt fastening technology, and in particular relates to a bolt fastening method, clamp fastening equipment and computer program product. Background Technology

[0002] In power systems, large-scale mechanical equipment (e.g., nuclear power plant equipment), and other fields, clamps are a common connecting component widely used to achieve reliable connections between conductors, pipes, and rods (e.g., conductive rods). In these applications, the connection quality between the clamp and the connecting component is crucial, and bolt tightening is a key step in ensuring a reliable clamp connection. Poor bolt tightening can lead to problems such as non-parallel clamp mounting surfaces, increased contact resistance, and localized overheating, and in severe cases, may even cause equipment failure, power outages, and other major accidents.

[0003] In the existing technology, the tightening of clamp bolts is usually done manually. When doing so, the operator relies on experience and manual tools to tighten the bolts. This method is not only inefficient, but also makes it difficult to ensure that the tightening torque of each bolt is uniform. This can easily result in some bolts being too tight and others being too loose, affecting the reliability of the connection and the installation quality of the clamp. Summary of the Invention

[0004] This application provides a bolt fastening method, clamp fastening equipment, and computer program product, which can address the problems of low reliability and installation quality of bolt connections in clamps.

[0005] In a first aspect, embodiments of this application provide a bolt tightening method applied to a clamp tightening device. The clamp tightening device includes multiple motors, each of which outputs power to tighten a corresponding bolt in the clamp. The method includes:

[0006] Control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque;

[0007] Check the parallelism of the mounting surfaces of the clamp;

[0008] If the parallelism is greater than or equal to the preset parallelism, then obtain the interval distance between each bolt and the preset reference surface;

[0009] The first bolt corresponding to the maximum value of the interval distance is determined, the first motor corresponding to the first bolt is determined, the second bolt is located on the opposite side of the first bolt, and the second motor corresponding to the second bolt is determined;

[0010] The deflection angle is determined based on the deviation between the spacing distance corresponding to the first bolt and the spacing distance corresponding to the second bolt.

[0011] The first motor is controlled to loosen the first bolt by a deflection angle, and the second motor is controlled to tighten the second bolt by a deflection angle.

[0012] In one embodiment, controlling multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches a preset standard torque includes:

[0013] Multiple motors are controlled to simultaneously tighten the corresponding bolts at preset speeds until the tightening torque of each bolt reaches the preset initial tightening torque; the initial tightening torque is less than the preset standard torque.

[0014] Multiple motors are controlled to increase the tightening torque of each bolt at the same rate of torque increase, starting from the initial tightening torque, until the tightening torque reaches the preset standard torque.

[0015] In one embodiment, controlling multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches a preset standard torque further includes:

[0016] During the process of controlling multiple motors to tighten their corresponding bolts, the current output of each motor is collected.

[0017] Based on multiple currents, the third and fourth motors, which have deviations in the tightening torque output by the multiple motors, are identified; the first current corresponding to the third motor is greater than the second current corresponding to the fourth motor.

[0018] Reduce the first current output of the third motor, and increase the second current output of the fourth motor;

[0019] Multiple motors are controlled to tighten corresponding bolts based on the adjusted current until the tightening torque of each bolt reaches the preset standard torque.

[0020] In one embodiment, based on multiple currents, identifying a third motor and a fourth motor where the tightening torque output by the multiple motors deviates includes:

[0021] Calculate the current difference between any two currents in a given set of multiple currents;

[0022] Calculate the ratio between the maximum current difference among multiple current differences and the average of the multiple current differences;

[0023] If the ratio is greater than the preset ratio, then the two motors corresponding to the maximum current difference are determined to be the third motor and the fourth motor, respectively.

[0024] In one embodiment, after collecting the current output by each of the multiple motors during the process of controlling multiple motors to tighten their corresponding bolts, the method further includes:

[0025] If the current does not meet the preset current constraint condition, then control multiple motors to execute the target fault response action corresponding to the current constraint condition.

[0026] If multiple currents satisfy the current constraint conditions, then based on the multiple currents, the third and fourth motors, which have deviations in the tightening torque output by the multiple motors, are identified.

[0027] In one embodiment, after controlling multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches a preset standard torque, the process includes:

[0028] Within a preset time period, the tightening torque of each bolt is maintained at the preset standard torque.

[0029] In one embodiment, after controlling the first motor to loosen the first bolt by a deflection angle and controlling the second motor to tighten the second bolt by a deflection angle, the method further includes:

[0030] Repeat the target step and all subsequent steps until the parallelism is less than the preset parallelism; the target step is to control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque.

[0031] In one embodiment, after repeatedly executing the target step and each subsequent step until the parallelism is less than a preset parallelism, the method further includes:

[0032] Detect the contact resistance between the clamp and the connector;

[0033] If the contact resistance is greater than the preset resistance, an ultrasonic vibration signal is sent to the contact surface between the clamp and the connector.

[0034] After stopping the transmission of ultrasonic vibration signals, repeat the target step and all subsequent steps until the contact resistance is less than or equal to the preset resistance.

[0035] Secondly, embodiments of this application provide a bolt fastening device applied to a clamp fastening equipment. The clamp fastening equipment includes multiple motors, each of which outputs power to fasten a corresponding bolt in the clamp. The device includes:

[0036] The first control module is used to control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque.

[0037] The detection module is used to detect the parallelism of the mounting surface of the clamp;

[0038] The acquisition module is used to acquire the interval distance between multiple bolts and the preset reference surface if the parallelism is greater than or equal to the preset parallelism.

[0039] The first determining module is used to determine the first bolt corresponding to the maximum value of the interval distance, the first motor corresponding to the first bolt, the second bolt on the opposite side of the first bolt, and the second motor corresponding to the second bolt.

[0040] The second determining module is used to determine the deflection angle based on the deviation between the interval distance corresponding to the first bolt and the interval distance corresponding to the second bolt.

[0041] The second control module is used to control the first motor to loosen the first bolt by a deflection angle, and to control the second motor to tighten the second bolt by a deflection angle.

[0042] Thirdly, embodiments of this application provide a clamp fastening device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. It also includes multiple motors. When the processor executes the computer program, it implements the method described in the first aspect above to control the multiple motors to output power for fastening the corresponding bolts in the clamp.

[0043] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect above.

[0044] Fifthly, embodiments of this application provide a computer program product that, when running on a clamp fastening device, causes the clamp fastening device to perform the method described in the first aspect.

[0045] The beneficial effects of this application embodiment compared to the prior art are as follows: The clamp fastening device can first control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque. This ensures the consistency of the tightening torque of each bolt, avoiding the uneven torque problems that may occur during manual or simple automated tightening. This lays the foundation for subsequent parallelism detection and adjustment, and helps improve the overall connection reliability of the clamp. Afterwards, the parallelism of the clamp mounting surface can be detected. When the parallelism is greater than or equal to the preset parallelism, the interval distance between multiple bolts and the preset reference surface is measured to determine the first bolt corresponding to the maximum interval distance, the first motor corresponding to the first bolt, the second bolt on the opposite side of the first bolt, and the second motor corresponding to the second bolt. Parallelism is typically used to measure the installation quality of the clamp. If the parallelism does not meet the standard, it may affect the contact effect between the clamp and the connecting parts, increase contact resistance, and lead to unstable equipment operation. Based on this, when parallelism is found to be substandard, the key bolts causing the parallelism deviation can be accurately identified by measuring the distance between the bolts and the preset reference surface. These are the first bolt with the largest distance and the second bolt on the opposite side, making subsequent adjustments more targeted and improving efficiency and accuracy. Furthermore, adjusting on the opposite side minimizes the impact on the torque balance of other bolts during adjustment, ensuring overall torque stability. Finally, the deflection angle is calculated based on the deviation in the distance between the first and second bolts. The first motor is controlled to loosen the first bolt by the deflection angle, and the second motor is controlled to tighten the second bolt by the deflection angle. This allows for precise quantification of the adjustment amount (deflection angle) based on the actual deviation, making the adjustment operation more accurate. Moreover, by loosening the overtightened first bolt and tightening the overly loosened second bolt, the stress state of the clamp can be changed, effectively correcting the parallelism deviation of the mounting surface, improving adjustment accuracy, and ultimately enhancing the installation quality of the clamp. Based on this, by adopting the above-mentioned coordinated adjustment method, the parallelism problem can be solved quickly and accurately while ensuring that the torque of other bolts remains basically unchanged, thereby improving the efficiency and reliability of the adjustment and avoiding unnecessary trouble and risks caused by retightening all bolts or random adjustments. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart illustrating the implementation of a bolt fastening method according to an embodiment of this application;

[0048] Figure 2 This is a schematic diagram illustrating an implementation method of tightening a bolt to a preset standard torque in a bolt tightening method according to an embodiment of this application;

[0049] Figure 3 This is a flowchart illustrating the implementation of a bolt fastening method according to another embodiment of this application;

[0050] Figure 4 This is a flowchart illustrating the implementation of a bolt fastening method according to another embodiment of this application;

[0051] Figure 5 This is a schematic diagram of the structure of a bolt fastening device provided in one embodiment of this application;

[0052] Figure 6 This is a schematic diagram of the structure of a clamp fastening device provided in one embodiment of this application. Detailed Implementation

[0053] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0054] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0055] It should be noted that the information collection process (such as patient information collection process, physiological information collection process, etc.) / feature extraction process involved in this application is carried out with the user's knowledge and permission. That is, the information collection process / feature extraction process complies with the requirements of laws and regulations and does not constitute an act that harms the public interest.

[0056] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0057] In power systems, large-scale mechanical equipment (e.g., nuclear power plant equipment), and other fields, clamps are a common connecting component widely used to achieve reliable connections between conductors, pipes, and rods (e.g., conductive rods). In these applications, the connection quality between the clamp and the connecting component is crucial, and bolt tightening is a key step in ensuring a reliable clamp connection. Poor bolt tightening can lead to problems such as non-parallel clamp mounting surfaces, increased contact resistance, and localized overheating, and in severe cases, may even cause equipment failure, power outages, and other major accidents.

[0058] For example, a nuclear power plant is divided into multiple functional areas (such as inside the containment, outside the containment, auxiliary buildings, etc.), each with different requirements for safety and sealing. Electrical penetrations (e.g., medium-voltage electrical penetrations) need to bring electricity from one area to another to power equipment (such as pumps, fans, control systems, etc.) without compromising the area isolation. Voltage penetrations include a housing and a conductive rod. The housing is embedded in the partition structure between different functional areas (e.g., concrete walls or metal partitions). The conductive rod is used to electrically connect the two functional areas. After the conductive rod enters the housing from one functional area, it is electrically connected to electrical components (e.g., cables, conductive plates, electrical connecting rods, etc.) in other areas through clamps.

[0059] In the existing technology, the tightening of clamp bolts is usually done manually. When doing so, the operator relies on experience and manual tools to tighten the bolts. This method is not only inefficient, but also makes it difficult to ensure that the tightening torque of each bolt is uniform. This can easily result in some bolts being too tight and others being too loose, which affects the reliability of the connection.

[0060] Therefore, in order to ensure the reliability of the bolt connections of the clamp and improve the installation quality of the clamp, this application provides a bolt tightening method that can be applied to clamp tightening equipment. The clamp tightening equipment may include multiple motors, each of which outputs power to tighten the corresponding bolts in the clamp.

[0061] As an example, the clamp fastening device can be a specialized fastening fixture designed according to the clamp's external dimensions for precisely positioning the four fastening bolts of the clamp. The fastening fixture can employ a split upper and lower pressure cap structure. Upper pressure cap: Installed on one side of the hexagonal head of the clamp bolt, it integrates multiple sleeves (e.g., four), each sleeve mounted on a connecting rod directly connected to a knob. The connecting rod is equipped with a ratchet mechanism (allowing counter-clockwise rotation in the fastening direction). The knob is used for manual pre-engaging of the bolt head, and the ratchet mechanism acts as a reaction arm during servo drive. Lower pressure cap: Installed on the side of the clamp bolt nut, it integrates multiple sleeves (e.g., four), each sleeve connected to an independently rotating connecting rod (e.g., four independent shafts). A connecting seat is designed on the back of the lower pressure cap for connecting the power unit (servo motor assembly). Power and control system: The power unit consists of multiple independently operating motors, each driving one of the multiple independent shafts of the lower pressure cap. The motors are centrally controlled by a programmable logic controller (PLC) for precise torque setting and output.

[0062] Among them, a clamp is a ring-shaped clamp used to fix or connect cylindrical objects (such as pipes, utility poles, shaft parts, etc.). It is usually composed of two semi-circular or arc-shaped metal parts, which are fastened by bolts. The clamping force is used to clamp the fixed object or connect it with other components (such as fixing pipes to supports, connecting equipment to foundations, etc.).

[0063] Please see Figure 1 , Figure 1 The following is a flowchart illustrating the implementation of a bolt fastening method according to an embodiment of this application. The method includes the following steps:

[0064] S101. Control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque.

[0065] In one embodiment, the aforementioned multiple motors refer to multiple servo motors equipped in the clamp fastening device. Each motor corresponds to a different bolt on the clamp, and each motor is responsible for providing power to tighten the corresponding bolt. By driving multiple motors separately, independent control and synchronous operation of multiple bolts can be achieved.

[0066] The number of motors mentioned above can be 2, 3, 4, etc., and there is no limit to this.

[0067] The aforementioned tightening of the bolts refers to the process of using a motor to output power, causing the bolts to rotate and thus tightly connecting the clamp to the connector. The purpose of the tightening operation is to enable the clamp to withstand a certain load and maintain a stable connection.

[0068] It should be noted that each motor is responsible for driving a specific bolt, which is the bolt corresponding to that motor. That is, in the clamp fastening equipment, there is a one-to-one correspondence between the motor and the bolt. In other words, during the fastening process, each motor drives only one specific bolt for tightening or adjustment.

[0069] The tightening torque mentioned above refers to the torque output by the motor during the bolt tightening process. This tightening torque is an important indicator for measuring the tightness of the bolt. Appropriate tightening torque ensures the connection strength and stability of the clamp, while preventing damage to the bolt or clamp due to excessive torque, or a weak connection due to insufficient torque.

[0070] The aforementioned preset standard torque is a torque value pre-set before bolt tightening. This value can be determined based on factors such as the clamp's design requirements, material properties, and operating environment, and is a key parameter for ensuring the clamp connection quality. When the bolt tightening torque reaches the preset standard torque, the bolt tightness can be considered to meet the requirements. As an example, the aforementioned target torque can be 10 Nm.

[0071] In one embodiment, since each bolt corresponds to a motor, the torque output of the motor can be adjusted by controlling the motor's current and speed to ensure that the tightening torque of each bolt reaches a preset standard torque. For example, the motor can detect its own output tightening torque and, if the tightening torque is less than the preset standard torque, increase the output current to increase the tightening torque to the preset standard torque.

[0072] A torque sensor can be connected in series in the transmission chain between the motor and the bolt to detect the output tightening torque. Alternatively, the tightening torque can be calculated indirectly through the current. For example, it can be calculated using T = Kt * Iq, where Kt is the motor's torque constant, Iq is the motor's q-axis current, and T is the equivalent torque.

[0073] It should be noted that in vector control of motors, to achieve precise control of motor torque and flux, the stator current is typically decomposed into two components: the d-axis current and the q-axis current. The d-axis current generates the motor's magnetic field, controlling the magnitude of the magnetic flux. The q-axis current is directly related to the motor's torque; generally, the magnitude of the q-axis current directly determines the magnitude of the motor's output torque.

[0074] It is important to clarify that the q-axis is not the physical output axis of the motor (such as the rotor axis), but rather a virtual coordinate axis constructed through a mathematical model for precise control of the motor's torque and magnetic field. This method of constructing a virtual coordinate axis effectively simplifies the complex three-phase current control logic and provides a theoretical basis for motor torque regulation.

[0075] During bolt tightening, the torque output by the motor is ultimately converted into the tightening torque of the bolt. Therefore, by collecting the q-axis current, the magnitude of the motor's output torque can be indirectly and accurately reflected, thus providing a basis for subsequent current-based torque control and dynamic adjustment.

[0076] It should be noted that although T is not the actual torque acting on the bolt directly measured by a torque sensor, but rather an equivalent torque derived from the characteristics of the motor and the relationship between current and torque, this equivalent torque can be considered as a tightening torque that indirectly reflects the magnitude of the motor's output torque, thus reflecting the final torque exerted by the motor on the bolt.

[0077] In another embodiment, the clamp fastening device can first control multiple motors to simultaneously tighten corresponding bolts at preset speeds until the tightening torque of each bolt reaches a preset initial tightening torque. The initial tightening torque is less than a preset standard torque. Then, the multiple motors are controlled to increase the tightening torque of each bolt from the initial tightening torque at the same torque increase rate until the tightening torque reaches the preset standard torque.

[0078] In one embodiment, the preset rotational speed refers to the motor rotation speed pre-set in the initial stage of controlling multiple motors to synchronously tighten the corresponding bolts. The preset rotational speed can be determined based on factors such as the material of the clamp, the specifications of the bolts, and the requirements of the tightening process. It is understood that selecting a suitable preset rotational speed can ensure the tightening effect while avoiding damage to the bolts or clamps due to excessive impact from too high a rotational speed, or affecting tightening efficiency due to too low a rotational speed. For example, the preset rotational speed can be 10 rpm.

[0079] The aforementioned synchronous tightening refers to the operation where multiple motors, following the same control command, simultaneously drive the corresponding bolts to rotate and tighten at a preset speed. The purpose of synchronous tightening is to ensure that multiple bolts are tightened at the same speed and rhythm in the initial stage, so as to ensure that the force on each bolt is as uniform as possible, laying the foundation for the subsequent torque increase process.

[0080] The initial tightening torque mentioned above is a preset intermediate torque value during the bolt tightening process. The initial tightening torque must be less than the final preset standard torque, serving as a transition torque value from the start of tightening to reaching the preset standard torque. The purpose of setting the initial tightening torque is to: in the initial tightening stage of the bolt, create a certain preload between the clamp and the bolt, ensuring that the clamp mounting surfaces initially fit together, and establishing an initial balanced plane for subsequent tightening.

[0081] The aforementioned uniform torque growth rate refers to the fact that, during the process of increasing the tightening torque from the initial torque to the preset standard torque, the speed at which multiple motors drive the corresponding bolts to increase the tightening torque is the same. The torque growth rate can be expressed as the increase in torque per unit time (e.g., Nm / s). It should be noted that maintaining a uniform torque growth rate ensures that the stress on each bolt remains relatively uniform during the torque increase process, avoiding problems such as excessively fast or slow torque growth on some bolts leading to deviations in the parallelism of the clamp mounting surface. For example, the aforementioned torque growth rate could be 2 Nm / s.

[0082] Based on the above explanation, it can be understood that when the torque does not reach the preset standard torque, the motor can be controlled to adjust the tightening torque by changing the magnitude of the applied current until the preset standard torque is reached. For example, the clamp fastening device can control multiple motors to output current corresponding to preset speeds, so that the multiple motors simultaneously tighten the corresponding bolts at preset speeds until the tightening torque of each bolt reaches the preset initial tightening torque. Furthermore, the clamp fastening device can control multiple motors to increase the current at the same rate, so that the multiple motors increase the torque at the same rate, increasing the tightening torque of each bolt from the initial tightening torque until the tightening torque reaches the preset standard torque.

[0083] In another embodiment, the motor speed may also be related to factors such as the magnetic flux of the motor excitation winding and the pulse frequency of the motor driver. Therefore, the motor speed can also be controlled by adjusting other factors of the motor. Furthermore, the output torque of the motor is also related to factors such as the motor power and the efficiency of the transmission mechanism. Therefore, the rate of increase of the output torque of the motor can also be controlled by adjusting other factors of the motor. In this embodiment, the method of controlling multiple motors to operate at a preset speed or controlling multiple motors to operate at the same torque increase rate is not limited.

[0084] In this embodiment, multiple motors are controlled to simultaneously tighten corresponding bolts at preset speeds until the tightening torque of each bolt reaches the preset initial tightening torque. This ensures that all bolts approach the clamp's contact surface at a consistent pace during the initial tightening, allowing each bolt to reach a uniform initial stress state (i.e., initial tightening torque). This eliminates initial gaps and installation deviations between the bolts and the clamp, establishing an initial balanced reference plane for subsequent tightening. Then, based on the initial tightening torque, multiple motors are controlled to synchronously increase the torque at the same rate, achieving a gradual and balanced increase in bolt stress. Because the torque change rhythm of each motor is consistent, it ensures that the stress increment of all bolts is the same at every moment from the initial state to the final standard torque, avoiding localized stress concentration caused by a sudden increase in torque on a single bolt. Furthermore, it ensures that the clamp's mounting surface remains uniformly stressed during the bolt tightening process, effectively reducing the risk of parallelism deviations caused by individual bolts being too tight or too loose.

[0085] S102. Inspect the parallelism of the mounting surface of the clamp.

[0086] In one embodiment, the aforementioned mounting surface refers to the inner surface of the clamp that contacts the object being fixed, or the mating surface when the two halves of the clamp are joined together (such as the connecting flange surface of a flange-type clamp). The flatness and fitting accuracy of the mounting surface directly affect the clamping effect. It is understood that if the mounting surface is uneven or poorly fitted, it may lead to uneven stress, loosening of the fixation, or even deformation of the fixed object.

[0087] The parallelism mentioned above is a type of geometric tolerance, referring to the state where two planes (or lines, surfaces) maintain an equal distance. For the mounting surfaces of clamps, parallelism usually refers to: the parallelism between the inner mounting surfaces (the surfaces in contact with the object being fixed) of the two half-rings of the clamp; or the parallelism between the flange mating surfaces of the two half-rings when the clamps are spliced. The smaller the parallelism error, the more uniform the mating of the mounting surfaces and the more stable the transmission of clamping force.

[0088] In one embodiment, the clamp fastening device can use a steel ruler (or knife-edge ruler) with high straightness to be placed against different positions on the mounting surface (for example, 3-4 measuring points are evenly selected along the circumference) to observe the gap between the steel ruler and the mounting surface and obtain the above-mentioned parallelism.

[0089] In another embodiment, the clamp fastening device may also be equipped with multiple laser rangefinders, which emit laser beams to perform high-speed scanning of the clamp mounting surface and collect three-dimensional coordinate data (point cloud) of the surface. For example, the point cloud density is >20 points / cm². 2This means collecting at least 20 points per square centimeter to ensure that surface details are fully captured (such as minute bumps and deformations). Then, based on the point cloud data, an algorithm is used to fit an ideal plane (i.e., a preset reference plane) to the mounting surface, and the vertical distance between all scanned point clouds and the ideal plane is calculated. At this point, the clamping device can determine the vertical distance corresponding to each scanned point as the aforementioned parallelism, or it can determine the maximum value among the vertical distances as the aforementioned parallelism; there is no limitation on this.

[0090] It should be noted that using a non-contact laser rangefinder to check parallelism avoids contact with the mounting surface of the clamp, preventing damage to precision surfaces. Furthermore, the laser rangefinder offers high accuracy, thus allowing for precise quantification of the bolt tightening effect.

[0091] In another embodiment, after obtaining the parallelism corresponding to each point cloud, a deformation field of the mounting surface can also be generated to visually display the deformation distribution of the mounting surface, providing a basis for subsequent operations such as angle adjustment.

[0092] S103. If the parallelism is greater than or equal to the preset parallelism, then obtain the interval distance between the multiple bolts and the preset reference surface.

[0093] In one embodiment, the aforementioned preset parallelism refers to a pre-set maximum allowable parallelism value, such as 2.5 mm. If the actual measured parallelism is greater than or equal to the preset parallelism, it can be considered that the fitting accuracy of the clamp mounting surface does not meet the requirements and adjustment is necessary.

[0094] The aforementioned preset reference plane can be considered as a reference plane with known accuracy, used to measure the relative position of the bolt and the mounting surface. For example, the preset reference plane may include the design reference plane of the clamp, the mounting platform plane obtained through fitting, etc.

[0095] The aforementioned interval distance can be considered as the vertical distance between the bolt head (or nut) and the preset reference surface. This distance reflects the bolt's elevation on the mounting surface. It is understandable that if the interval distance of a bolt is too large, it can be assumed that the installation position is too high (or the clamp is deformed at that position), or the bolt is too tight. That is, the mounting surface at the bolt's location is deformed and needs adjustment.

[0096] In one embodiment, the aforementioned interval distance can be measured using the laser rangefinder device described in the example above, or by capturing images of the bolts and the reference surface using an industrial camera, and then calculating the interval distance using an image processing algorithm (i.e., a visual inspection algorithm). In this embodiment, the method for obtaining the interval distances between multiple bolts and the preset reference surface is not limited.

[0097] It should be noted that if the parallelism is less than the preset parallelism, the bolt tightening effect can be considered to meet the installation requirements. Therefore, the clamp installation can be terminated.

[0098] S104. Determine the first bolt corresponding to the maximum value of the interval distance, the first motor corresponding to the first bolt, the second bolt on the opposite side of the first bolt, and the second motor corresponding to the second bolt.

[0099] In one embodiment, the bolt corresponding to the maximum interval distance is the first bolt. Typically, the location of the first bolt is one of the main factors causing the parallelism of the clamp mounting surface to exceed the tolerance. It is understandable that because the distance between the first bolt and the preset reference surface is too large, the force or position of the clamp at that location may be abnormal.

[0100] In this clamping and fastening device, each bolt is driven to rotate by a corresponding motor, thereby achieving the tightening or loosening operation. Therefore, after the first bolt is identified, the motor connected to the first bolt and responsible for providing power for tightening or adjustment is the first motor.

[0101] In one embodiment, the bolts in the clamp structure are typically symmetrically distributed. After determining the position of the first bolt on the clamp, the second bolt located on the opposite side of the first bolt can be determined. It should be noted that selecting the opposite bolt for coordinated adjustment allows for a more effective change in the stress state and position of the clamp during subsequent adjustments, thereby correcting parallelism deviations of the mounting surfaces. Symmetrical adjustment can, to some extent, reduce the impact on the torque balance of other bolts, ensuring overall torque stability.

[0102] The method for determining the second motor is the same as that for determining the first motor, and will not be described in detail here.

[0103] S105. Determine the deflection angle based on the deviation between the interval distance corresponding to the first bolt and the interval distance corresponding to the second bolt.

[0104] In one embodiment, the clamp fastening device may have a pre-set mapping relationship between deviation and angle to determine the deviation angle corresponding to the deviation based on the mapping relationship. In another embodiment, the deflection angle may be determined by multiplying a preset coefficient by the deviation. For example, the preset coefficient may be 0.5. In this embodiment, the method of determining the deflection angle is not limited.

[0105] It should be noted that the deviation in the aforementioned spacing usually directly reflects the degree of tilt of the clamp. If the spacing between the first bolt on one side is too large and the spacing between the second bolt on the opposite side is too small, the clamp will tilt, resulting in parallelism exceeding the tolerance. In this case, the deflection angle can quantify the degree of tilt and be used to guide the subsequent adjustment of the first and second bolts, thereby reducing the deviation in the spacing between the bolts on both sides and correcting the parallelism.

[0106] S106. Control the first motor to loosen the first bolt by a deflection angle, and control the second motor to tighten the second bolt by a deflection angle.

[0107] In one embodiment, the bolt deflection angle is the final mechanical action to be achieved, but the motor rotation angle needs to take into account the influence of the reduction mechanism (such as a reducer or gearbox). Therefore, the clamp fastening device can determine the target rotation angle corresponding to the aforementioned deflection angle based on a pre-set mapping relationship between the rotation angle and the bolt deflection angle. Then, the first motor is controlled to loosen (reverse rotate) the first bolt by the aforementioned target rotation angle. And, the second motor is controlled to continue tightening the second bolt by the aforementioned target rotation angle.

[0108] In this embodiment, the clamp fastening device can first control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque. This ensures the consistency of the tightening torque of each bolt, avoiding the uneven torque problems that may occur during manual tightening or simple automated tightening. This lays the foundation for subsequent parallelism detection and adjustment, and helps to improve the overall connection reliability of the clamp. Afterwards, the parallelism of the clamp mounting surface can be detected. When the parallelism is greater than or equal to the preset parallelism, the distance between each bolt and the preset reference surface is measured to determine the first bolt corresponding to the maximum distance, the first motor corresponding to the first bolt, the second bolt on the opposite side of the first bolt, and the second motor corresponding to the second bolt. Parallelism is typically used to measure the installation quality of the clamp. If the parallelism does not meet the standard, it may affect the contact effect between the clamp and the connecting parts, increase contact resistance, and lead to unstable equipment operation. Based on this, when parallelism is determined to be substandard, the key bolts causing the parallelism deviation can be accurately identified by measuring the distance between the bolts and the preset reference surface. These are the first bolt with the largest distance and the second bolt on the opposite side, making subsequent adjustments more targeted and improving efficiency and accuracy. Furthermore, adjusting on the opposite side minimizes the impact on the torque balance of other bolts during adjustment, ensuring overall torque stability. Finally, the deflection angle is calculated based on the deviation in the distance between the first and second bolts. The first motor is controlled to loosen the first bolt by the deflection angle, and the second motor is controlled to tighten the second bolt by the deflection angle. This allows for precise quantification of the adjustment amount (deflection angle) based on the actual deviation, making the adjustment operation more accurate. Moreover, by loosening the overtightened first bolt and tightening the overly loosened second bolt, the stress state of the clamp can be changed, effectively correcting the parallelism deviation of the mounting surface and improving the accuracy and effect of the adjustment. Therefore, using this coordinated adjustment method, parallelism problems can be quickly and accurately resolved while ensuring that the torque of other bolts remains essentially unchanged, improving the efficiency and reliability of the adjustment and avoiding unnecessary trouble and risks associated with retightening all bolts or random adjustments.

[0109] In another embodiment, during the process of executing S101 to control multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches the preset standard torque, even if the same control parameters (such as speed and torque growth rate) are preset, the tightening torque output by each motor will still deviate in actual operation due to the following factors:

[0110] Individual motor differences: Different motors may have slight variations in torque constant, internal resistance, and response speed, resulting in inconsistent output torque under the same current. Mechanical transmission errors: Differences in the friction coefficient and transmission efficiency of the transmission chains (reducers, couplings, sleeves) of each bolt lead to varying efficiency in transmitting motor output torque to the bolts. Load fluctuations: Differences in the thread precision, lubrication condition, and surface roughness of bolts and nuts result in varying tightening resistance, requiring the motor to output different torques to maintain synchronous speed.

[0111] Based on the above factors, the output current of some motors will be too high (corresponding to higher torque), while the output current of other motors will be too low (corresponding to lower torque), ultimately leading to an imbalance in the tightening torque of each bolt.

[0112] It should be noted that if the tightening torque of each bolt is unbalanced during the tightening process, the bolt with excessively high tightening torque may experience excessive stress before reaching the initial tightening torque or the preset standard torque, resulting in an actual tightening torque exceeding the preset standard torque. Conversely, the bolt with insufficient tightening torque may fail to reach the initial tightening torque or the preset standard torque within the specified time, ultimately leading to inconsistent torque across the bolts. Furthermore, if the tightening speed of each bolt differs due to the imbalance in tightening torque, the preload distribution of the bolts may be uneven, resulting in uneven stress on the clamp and affecting the reliability and stability of the clamp fastening. In other words, it may result in a greater degree of parallelism of the mounting surface after step S101.

[0113] Therefore, in order to improve the tightening effect during the clamp tightening process, the clamp tightening equipment can also be configured according to, for example... Figure 2 The steps S201-S204 shown are for tightening the bolts, detailed below:

[0114] S201. During the process of controlling multiple motors to tighten their corresponding bolts, the current output by each motor is collected.

[0115] In one embodiment, the current described above can be considered as the q-axis current in the example of S101 described above.

[0116] Among these, the clamping and fastening equipment can detect the aforementioned current using current sensing elements related to the motor. For example, a current sensor, such as a Hall effect current sensor, can be installed in the stator winding of the motor to detect the magnitude of the current in the stator winding in real time.

[0117] S202. Based on multiple currents, identify the third and fourth motors whose tightening torques output by multiple motors have deviations.

[0118] In one embodiment, the third motor and the fourth motor are two motors that are determined to have a deviation in tightening torque among a plurality of motors, wherein the current (first current) corresponding to the third motor is greater than the current (second current) corresponding to the fourth motor.

[0119] In one embodiment, based on the above explanation of tightening torque and current, the clamp fastening device can identify the motors corresponding to two currents as having a tightening torque deviation when the current difference between the two currents is greater than a preset difference. Furthermore, when there are multiple current differences greater than the preset difference, the two motors corresponding to the largest current difference among the multiple current differences can be identified as the third and fourth motors with tightening torque deviations. The deviation value can be set according to actual needs and is not limited thereto.

[0120] In another embodiment, the clamping device can first calculate the actual torque output of each motor based on multiple currents. Then, the third and fourth motors are determined based on the multiple actual torques. The method of determining the third and fourth motors based on multiple actual torques can be referred to the example described above, and will not be described in detail here.

[0121] As an example, the clamp fastening device can first calculate the current difference between any two currents among multiple currents. Then, it calculates the ratio between the maximum current difference and the average of the multiple current differences. If this ratio is greater than a preset ratio, the two motors corresponding to the maximum current difference are identified as the third and fourth motors, respectively. Otherwise, if the ratio is less than or equal to the preset ratio, the maximum current difference can be considered small, and the difference in tightening torque output by the two corresponding motors is small; therefore, no additional current adjustment is needed.

[0122] The preset ratio can be set according to actual needs and is not limited thereto. For example, the preset ratio can be 0.5%.

[0123] It should be noted that when calculating the maximum current difference and the average current difference, the absolute value of each current difference is usually taken to eliminate the influence of direction and only focus on the magnitude of the current difference.

[0124] For example, the clamping device can subtract the current value of each motor from the current values ​​of all other motors to obtain the current difference between each pair. For instance, taking motors 1, 2, 3, and 4 as examples, their current values ​​are I1, I2, I3, and I4 respectively. Then, I1-I2, I1-I3, I1-I4, I2-I3, I2-I4, and I3-I4 are calculated to obtain six current differences. Each of these current differences can be described in absolute value. Then, if the current difference corresponding to I1-I4 is the largest (i.e., the maximum current difference), the ratio of the maximum current difference corresponding to I1-I4 to the average value of all current values ​​can be calculated. When the ratio is greater than a preset ratio (1) and I4 is greater than I1, the motor that outputs current I4 can be considered the third motor mentioned above, and the motor that outputs current I1 can be considered the fourth motor.

[0125] In another embodiment, when determining the maximum current difference, the difference between the maximum and minimum currents can be directly defined as the maximum current difference. However, since it is necessary to calculate the average of multiple current differences, the maximum current difference can also be determined after calculating the current differences between each pair of currents.

[0126] In this embodiment, by calculating the current difference between any two currents, the clamping device can comprehensively capture the differences in output torque of each motor, avoiding the omission of local deviations. Then, the maximum current difference (reflecting the most significant torque deviation) can be extracted from all current differences, and the average value of all current differences (reflecting the overall deviation level) can be calculated. The ratio of the maximum current difference to the average value quantifies the relative relationship between local extreme deviations and the overall average deviation. Finally, when the ratio is greater than a preset ratio, it can be considered that there is an extreme deviation far exceeding the overall average level. At this point, the two motors corresponding to the maximum current difference are identified as the third and fourth motors requiring adjustment. This not only improves the flexibility and accuracy of the judgment, avoiding misjudgments or omissions caused by fixed thresholds, but also avoids indiscriminate adjustment of all motors, enabling targeted adjustments and ensuring adjustment efficiency and effectiveness.

[0127] S203, reduce the first current output of the third motor, and increase the second current output of the fourth motor.

[0128] S204. Control multiple motors to tighten corresponding bolts based on the adjusted current until the tightening torque of each bolt reaches the preset standard torque.

[0129] In one embodiment, the reduction of the first current can be achieved by using the difference between the first current and a first preset current as the reduced first current; or by using the product of the first current and a first preset percentage (less than 1) as the reduced first current. For example, the product of the first current and 90% can be used as the reduced first current.

[0130] The second current can be increased by summing the second current with a second preset current, or by multiplying the second current by a second preset percentage (greater than 1). For example, the product of the second current and 105% can be used as the increased second current.

[0131] In this embodiment, the method of reducing the first current and increasing the second current is not limited.

[0132] The method of controlling multiple motors to tighten the corresponding bolts based on the adjusted current can be as follows: controlling the third motor to tighten the bolt based on the reduced first current, controlling the fourth motor to tighten the bolt based on the increased second current, and controlling the remaining motors to maintain their own output current unchanged to tighten the bolts.

[0133] It should be noted that when the tightening torque of each bolt does not reach the preset standard torque, the clamp fastening device can execute the above steps S201-S204 once at preset intervals to maintain a balanced tightening torque for each bolt. For example, the above process can be executed every 0.5 seconds.

[0134] In this embodiment, during the process of controlling multiple motors to tighten their corresponding bolts, the current value output by each motor is collected in real time. This provides data support for subsequent determination of whether there is a deviation in the torque output of each motor. Then, based on the collected current values, the difference between each pair of currents is calculated to identify the third and fourth motors with deviations in tightening torque. The current corresponding to the third motor (first current) is greater than the current corresponding to the fourth motor (second current), accurately identifying the motors with output torque deviations. This provides a clear target for subsequent adjustment operations, avoiding blindly adjusting all motors and improving the targeting and efficiency of the adjustment. Finally, for the identified third and fourth motors, measures can be taken to reduce the first current output of the third motor and increase the second current output of the fourth motor. Multiple motors are then controlled to tighten their corresponding bolts based on the adjusted currents until the tightening torque of each bolt reaches the preset standard torque. Therefore, by reducing the current of the third motor to decrease its output torque, excessive tightening torque of the bolts corresponding to that motor can be avoided. Simultaneously, increasing the current of the fourth motor to increase its output torque increases the tightening torque of the bolts corresponding to that motor. Furthermore, through the above adjustments, the tightening torque of each bolt during the tightening process can gradually become more balanced. That is, it ensures that the force on each bolt is balanced in real time, avoiding clamp misalignment caused by uneven force.

[0135] In another embodiment, due to factors such as individual differences in motors, mechanical transmission errors, and load fluctuations (thread jamming during bolt tightening), the motor output current may become abnormal. If abnormal current is not addressed promptly, it may lead to problems such as motor overload, insufficient output torque, or instability, thereby affecting the bolt tightening effect.

[0136] Therefore, to ensure the bolt tightening effect, after performing step S201 above, if the current does not meet the preset current constraint condition, the clamp tightening device can control multiple motors to perform the target fault response action corresponding to the current constraint condition. Otherwise, when it is determined that multiple currents meet the current constraint condition, the third and fourth motors, which are identified as having deviations in tightening torque output by the multiple motors based on the multiple currents, are then executed in step S202 above.

[0137] There can be one or more current constraints, without limitation. Fault response actions can correspond to current constraints; for example, one fault response action can correspond to one or more current constraints. In this case, the target fault response action is the fault response action corresponding to the current constraint that the current currently satisfies.

[0138] As an example, current constraints may include a current change rate greater than a preset change rate (e.g., a current change rate greater than 2 A / s), a current greater than a first preset multiple of the rated current and less than or equal to a second preset multiple of the rated current, and a current greater than a second preset multiple of the rated current. For example, the first preset multiple could be 1.1, and the second preset multiple could be 1.3.

[0139] Furthermore, corresponding to the aforementioned current constraint conditions, when the current change rate is greater than the preset change rate, the fault response action (corresponding to progressive bolt jamming) can be: within 100ms, reduce the current corresponding to the current change rate greater than the preset change rate (e.g., reduce the current by 50%), and issue an audible and visual alarm; when the current is greater than the rated current of the first preset multiple, but less than or equal to the rated current of the second preset multiple, the fault response action (corresponding to sudden bolt jamming) can be: within 50ms, control the motor corresponding to the current to loosen the bolt by a preset angle (e.g., control the motor to reverse the bolt by 0.5 turns), and issue an audible and visual alarm; and when the current is greater than the rated current of the second preset multiple, the fault response action (corresponding to bolt mechanical jamming) can be: within 20ms, control the main power supply to shut off, stop tightening the bolt, and issue an audible and visual alarm.

[0140] In the examples above, different current constraints correspond to different levels of fault types, and therefore, the corresponding fault response actions also differ. Based on this, by setting different current constraints and corresponding fault response actions for different fault types (progressive jamming, sudden jamming, mechanical lockup), a graded processing approach can be adopted to take appropriate measures according to the severity of the fault, avoiding overreaction or underreaction, and effectively ensuring the safety of the clamped equipment and operators.

[0141] In another embodiment, there can be multiple current constraints, and the fault response action can be only one. For example, the fault response action could be to control the main power supply to shut down within 20ms, stop tightening the bolts, and issue an audible and visual alarm to ensure safety during the tightening process to the greatest extent possible.

[0142] In this embodiment, the current of each motor is monitored in real time. When the current of any one or more motors fails to meet the preset current constraint condition, multiple motors are immediately controlled to execute the corresponding target fault response action. This allows for immediate action to be taken when abnormal motor current occurs, preventing further damage to the motors and the entire bolt tightening process. Furthermore, if multiple currents meet the current constraint condition, the motors are considered to be operating normally. Therefore, step S202 and subsequent steps can be performed to tighten the bolts.

[0143] In another embodiment, the process of detecting whether the current meets the preset current constraint condition can also be performed in step S106. That is, the process of detecting whether the current meets the preset current constraint condition can be applied to the entire process when the motor needs to output torque, so as to ensure the safety of motor operation.

[0144] In one embodiment, based on the above embodiment, after executing the step S101 of controlling multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches the preset standard torque, steps S102-S105 are used to detect parallelism, and when the parallelism is greater than or equal to the preset parallelism, the deflection angle is determined. In these multiple steps, the motors do not need to output tightening torque.

[0145] Based on this, after S101, the clamp fastening device can maintain the tightening torque of each bolt at the preset standard torque for a preset time period. That is, the motor does not need to run within the preset time period, and the clamp fastening device can perform steps S102-S105.

[0146] The preset duration can be set according to actual needs and is not limited thereto. For example, the preset duration can be 2 seconds.

[0147] It should be noted that maintaining the tightening torque of each bolt at the preset standard torque within the preset time period can effectively counteract the initial creep effect between the bolt and the clamp. After the bolt is tightened, due to the plasticity of the material itself and the micro-deformation of the clamp, slight creep may occur under stress. That is, the bolt will slowly loosen due to continuous stress, and the contact area of ​​the clamp may also undergo slight deformation due to stress release, resulting in a slight decrease in the actual torque over time. By maintaining the preset standard torque within the preset time period, the initial creep can be controlled, avoiding unexpected torque decay due to unreleased creep during subsequent use, thus ensuring torque stability during long-term use. Furthermore, within the preset time period, if the parallelism is detected to be greater than or equal to the preset parallelism, subsequent adjustments can be performed to further improve the clamp tightening effect.

[0148] Based on the explanations of the above embodiments, it can be assumed that after executing S101-S106 once, the parallelism may still not meet the requirements. Therefore, to ensure that the parallelism of the clamp after installation meets the requirements, the clamp fastening device can repeatedly execute the target step and all subsequent steps until the parallelism is less than the preset parallelism. The target step involves controlling multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque. That is, execution starts again from step S101.

[0149] In another embodiment, as explained in S101, the tightening process includes: controlling multiple motors to synchronously tighten corresponding bolts at preset speeds until the tightening torque of each bolt reaches a preset initial tightening torque; and controlling multiple motors to increase the tightening torque of each bolt from the initial tightening torque at the same torque increase rate until the tightening torque reaches a preset standard torque. In this embodiment, since the tightening torque of each bolt after performing steps S101-S106 once is usually close to the preset standard torque, during repeated execution, the process can start from the step in S101: controlling multiple motors to increase the tightening torque of each bolt from the initial tightening torque at the same torque increase rate until the tightening torque reaches the preset standard torque; this is not limited.

[0150] It should be noted that even if the tightening torque of each bolt is close to the preset standard torque during the repeated execution of the above steps, repeating the tightening process can further adjust bolts with uneven stress. This, in turn, allows for more even stress distribution on each bolt, reducing the parallelism of the clamp mounting surface.

[0151] It's important to note that the parallelism of the mounting surfaces is typically a geometric accuracy indicator, reflecting the degree of fit between the clamp mounting surface and the connector surface (e.g., the uniformity of planar gaps). Its core purpose is to ensure the stability of the mechanical structure and prevent localized stress concentration, component deformation, or mechanical wear caused by mounting surface tilt. However, a parallelism less than the preset parallelism only indicates that the clamp mounting surface and the connector surface are aligned; it cannot guarantee a microscopically tight contact between the contact surfaces. That is, even if macroscopically parallel, the contact surfaces may still have insufficient actual contact area due to the presence of oil, oxide layers, tiny protrusions, or depressions. This, in turn, affects the electrical conductivity after the clamp and connector come into contact.

[0152] Therefore, in order to further improve the conductivity of the clamp and connector, the clamp fastening device can also be configured according to, for example... Figure 3 The steps S301-S303 shown for tightening the bolts are described in detail below:

[0153] S301. Detect the contact resistance between the clamp and the connector.

[0154] In one embodiment, the aforementioned connector includes, but is not limited to, components such as conductors, pipes, and rods (e.g., conductive rods), and is not limited thereto. For ease of explanation, the aforementioned connector may be a conductive rod.

[0155] The contact resistance mentioned above refers to the resistance generated when current passes through the contact surface of two conductors (such as a clamp and a connector), and it is a core indicator for measuring the quality of electrical connection between conductors.

[0156] It's important to note that from a microscopic perspective, even if two conductor surfaces are macroscopically in contact, actual contact only occurs at a few raised "contact points" (due to surface roughness, oxide layers, contaminants, etc.). When current flows through these limited contact points, additional resistance is generated due to the reduced conductive area and concentrated current path—this is contact resistance. Its magnitude is closely related to the pressure, cleanliness, material properties, and surface treatment processes of the contact surfaces. Generally, the greater the contact surface pressure, the higher the cleanliness, and the better the metal's conductivity, the lower the contact resistance. The presence of oxide films, oil stains, rust, etc., will significantly increase the contact resistance.

[0157] In one embodiment, the contact resistance described above can be detected by measuring the voltage drop when current flows through the contact surface using a dedicated instrument or method, and then calculating the resistance value using Ohm's law. Common detection methods may include: DC voltage drop method, four-wire method for measuring voltage drop, and micro-ohmmeter method, which will not be described in detail here.

[0158] S302. If the contact resistance is greater than the preset resistance, an ultrasonic vibration signal is sent to the contact surface between the clamp and the connector.

[0159] In one embodiment, the preset resistance is a contact resistance threshold preset according to the device's conductivity requirements, safety standards, or design requirements. When the actual contact resistance exceeds this value, measures need to be taken to optimize the connection quality. For example, the preset resistance can be 5Ω.

[0160] The aforementioned ultrasonic vibration signal is a mechanical vibration signal with a frequency higher than 20kHz (inaudible to the human ear). It is converted into high-frequency mechanical vibration by an ultrasonic generator and applied to the contact surface to remove impurities and improve the fit. Based on this, the clamp fastening device can be connected to an ultrasonic activation system to generate and send ultrasonic vibration signals.

[0161] The ultrasonic activation system may include an ultrasonic generator, a transducer (vibrator), and an amplitude transformer. The ultrasonic generator converts electrical energy into a high-frequency (e.g., 20 kHz) electrical signal (ultrasonic vibration signal) to drive the transducer to vibrate. The transducer utilizes the piezoelectric effect to convert the electrical signal into mechanical vibration (e.g., amplitude 3 μm), and is the core component for energy conversion. The amplitude transformer amplifies the vibration amplitude and transmits it to the clamp surface, allowing the vibration energy to act on the contact surface.

[0162] Among them, the amplitude of ultrasonic vibration directly affects the shear stress (the lateral force generated by the vibration) of the contact surface. By controlling the amplitude to 3μm, the shear stress between the micro protrusions on the contact surface can exceed the yield strength of copper (33MPa), thereby breaking the oxide layer and promoting close contact between metals.

[0163] Furthermore, during the transmission of ultrasonic vibration signals, servo fine-tuning can be used to compensate for pressure fluctuations (e.g., ±0.1 Nm). It should be noted that the clamping force between the clamp and the connector is controlled by the servo system. When pressure fluctuations exceed ±0.1 Nm, the motor can adjust the clamping force in real time to ensure stable contact surface pressure and prevent fluctuations in contact resistance due to pressure changes.

[0164] In another embodiment, when the contact resistance is less than or equal to the preset resistance, the electrical connection quality of the contact surface between the clamp and the connector can be considered to meet the requirements, and no further processing is needed. Therefore, the clamp tightening process can be terminated.

[0165] S303. After stopping the transmission of ultrasonic vibration signals, repeat the target step and all subsequent steps until the contact resistance is less than or equal to the preset resistance.

[0166] In one embodiment, the conditions for stopping the transmission of ultrasonic vibration signals may be: the duration of transmitting ultrasonic vibration signals reaches a preset duration (e.g., 20s), or the temperature of the contact surface is greater than or equal to a preset temperature (e.g., 80°C).

[0167] It should be noted that the duration of the ultrasonic vibration signal is 20 seconds, which balances the need to remove impurities with the need to avoid overheating (excessive vibration may cause the contact surface temperature to exceed the limit). Furthermore, due to the contact resistance at the contact surface between the clamp and the connector, Joule heating is generated when current flows. If the contact surface temperature rises, it may accelerate the formation of the oxide layer (high temperature promotes metal oxidation), further increasing the contact resistance; also, uneven thermal expansion of the material leads to changes in the pressure distribution at the contact surface, affecting the connection stability.

[0168] It should be added that during the transmission of ultrasonic vibration signals, high-frequency vibration may have a certain impact on the tightening torque of the bolt. On the one hand, vibration may cause changes in the friction between the bolt and the connected parts, resulting in a loss of tightening torque; on the other hand, vibration may cause changes in the preload distribution of the bolt, affecting the tightening quality.

[0169] Therefore, after stopping the transmission of ultrasonic vibration signals, in order to ensure the tightening effect of the clamp, it is necessary to start the process again from step S101 until the contact resistance is less than the preset resistance. At this point, after the entire clamp tightening process is completed, not only will the parallelism of the clamp mounting surface be less than the preset parallelism, but the contact resistance between the clamp and the connector will also be less than or equal to the preset resistance.

[0170] In this embodiment, contact resistance is a key indicator for measuring the quality of the electrical connection between the clamp and the connector. By detecting the contact resistance, problems in the electrical connection can be identified in a timely manner, providing a basis for subsequent processing. Then, the detected contact resistance is compared with a preset resistance to determine whether the current contact resistance meets the requirements. That is, when the contact resistance is greater than the preset resistance, it indicates that the electrical connection quality does not meet the requirements. At this time, the clamp fastening device can send an ultrasonic vibration signal to the contact surface between the clamp and the connector to effectively remove oxide layers, oil, dust, and other impurities from the contact surface, improve the microstructure of the contact surface, and promote tight contact between the metals. Finally, after stopping the ultrasonic vibration signal, the steps of controlling multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque are repeated, as well as subsequent steps, until the contact resistance is less than or equal to the preset resistance. The tightening torque of the bolts can then be readjusted to compensate for the torque loss caused by the ultrasonic vibration signal, ensuring that the tightening torque, parallelism, and contact resistance of the bolts still meet the preset standards, guaranteeing the reliability and stability of the bolt connection. That is, ensure that the mechanical and electrical connections between the clamp and the connector meet the requirements to improve the clamp's fastening effect.

[0171] To more clearly illustrate the solutions in this application, specific embodiments are used below to explain the solutions. See details below. Figure 4 , Figure 4 This is a schematic diagram illustrating the implementation of a bolt fastening method provided in another embodiment of this application.

[0172] The clamp fastening device may include a display touch screen, allowing users to set one or more parameters such as initial tightening torque, preset standard torque, preset parallelism, torque increment, preset ratio, current constraint, preset duration, and preset resistance. In practical applications, the clamp fastening device can control multiple motors to synchronously tighten corresponding bolts at preset speeds until the tightening torque of each bolt reaches the preset initial tightening torque. Furthermore, it can control multiple motors to increase the tightening torque of each bolt from the initial tightening torque at the same torque increment rate until the tightening torque reaches the preset standard torque.

[0173] During the tightening of the bolts, the clamp-tightening device can also collect the current output from multiple motors and, based on these currents, identify the third and fourth motors whose tightening torques deviate from the specified values. Then, the first current output from the third motor is reduced, and the second current output from the fourth motor is increased, to control the multiple motors to tighten the corresponding bolts based on the adjusted currents, until the tightening torque of each bolt reaches the preset standard torque.

[0174] Subsequently, within a preset time period, the clamp tightening device can maintain the tightening torque of each bolt at a preset standard torque. Furthermore, within the preset time period, it can also detect the parallelism of the clamp's mounting surface, and when the parallelism is greater than or equal to a preset parallelism, obtain the interval distance between each bolt and a preset reference surface. It also determines the first bolt corresponding to the maximum interval distance, the first motor corresponding to the first bolt, the second bolt on the opposite side of the first bolt, and the second motor corresponding to the second bolt.

[0175] Then, the clamp fastening device can determine the deflection angle based on the deviation between the interval distance corresponding to the first bolt and the interval distance corresponding to the second bolt, so as to control the first motor to loosen the first bolt by the deflection angle and control the second motor to tighten the second bolt by the deflection angle. Furthermore, the steps of controlling multiple motors to tighten their corresponding bolts are repeated until the tightening torque of each bolt reaches the preset standard torque, and subsequent steps are performed until the parallelism is less than the preset parallelism.

[0176] Finally, when the parallelism is less than the preset parallelism, the clamp fastening device can detect the contact resistance between the clamp and the connector. Furthermore, when the contact resistance is greater than the preset resistance, an ultrasonic vibration signal is sent to the contact surface between the clamp and the connector. After stopping the ultrasonic vibration signal, the process of controlling multiple motors to tighten the corresponding bolts is repeated until the tightening torque of each bolt reaches the preset standard torque, and subsequent steps are performed until the contact resistance is less than or equal to the preset resistance.

[0177] It should be noted that during each step of the bolt tightening process described above, it is necessary to check whether the current fails to meet the preset current constraint conditions. Furthermore, if the current fails to meet the constraint conditions, multiple motors are controlled to execute the target fault response actions corresponding to the current constraint conditions to ensure safety during the tightening process. Conversely, if multiple currents meet the current constraint conditions, subsequent steps are continued based on these multiple currents. For example, the step of determining the third and fourth motors, based on multiple currents, where deviations in the tightening torque outputs of the multiple motors are identified.

[0178] In this embodiment, during the process of controlling multiple motors to tighten corresponding bolts, reducing the current of the third motor to decrease its output torque can prevent excessive tightening torque of the bolt corresponding to that motor. Simultaneously, increasing the current of the fourth motor to increase its output torque can increase the tightening torque of the bolt corresponding to that motor. Furthermore, through these adjustments, the tightening torque of each bolt gradually becomes more balanced during the tightening process. That is, it ensures that the force on each bolt is balanced in real time, avoiding clamp misalignment due to uneven force, which would cause the parallelism to be less than the preset parallelism. Moreover, after the parallelism becomes less than the preset parallelism, by sending an ultrasonic vibration signal when the contact resistance is greater than the preset resistance, and repeatedly executing the target step of controlling multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches the preset standard torque, and subsequent steps, until the contact resistance is less than or equal to the preset resistance, the tightening torque of the bolts can be readjusted to compensate for the torque loss caused by the ultrasonic vibration signal. This ensures that the tightening torque, parallelism, and contact resistance of the bolts still meet the preset standards, guaranteeing the reliability and stability of the bolt connection. That is, ensure that the mechanical and electrical connections between the clamp and the connector meet the requirements to improve the clamp's fastening effect.

[0179] Please see Figure 5 , Figure 5 This is a schematic diagram of a bolt fastening device according to an embodiment of this application. The bolt fastening device in this embodiment includes modules for performing... Figures 1 to 4 The steps in the corresponding embodiments. Please refer to the details. Figures 1 to 4 as well as Figures 1 to 4 The relevant descriptions in the corresponding embodiments are shown below. For ease of explanation, only the parts relevant to this embodiment are shown. The bolt fastening device can be applied to a clamp fastening device, which includes multiple motors, each motor outputting power to fasten the corresponding bolt in the clamp. See also... Figure 5 The bolt fastening device 500 may include: a first control module 510, a detection module 520, an acquisition module 530, a first determination module 540, a second determination module 550, and a second control module 560, wherein:

[0180] The first control module 510 is used to control multiple motors to tighten corresponding bolts until the tightening torque of each bolt reaches the preset standard torque.

[0181] The detection module 520 is used to detect the parallelism of the mounting surface of the clamp.

[0182] The acquisition module 530 is used to acquire the interval distance between multiple bolts and the preset reference surface if the parallelism is greater than or equal to the preset parallelism.

[0183] The first determining module 540 is used to determine the first bolt corresponding to the maximum value of the interval distance, the first motor corresponding to the first bolt, the second bolt on the opposite side of the first bolt, and the second motor corresponding to the second bolt.

[0184] The second determining module 550 is used to determine the deflection angle based on the deviation between the interval distance corresponding to the first bolt and the interval distance corresponding to the second bolt.

[0185] The second control module 560 is used to control the first motor to loosen the first bolt by a deflection angle, and to control the second motor to tighten the second bolt by a deflection angle.

[0186] In one embodiment, the first control module 510 is further configured to:

[0187] Multiple motors are controlled to simultaneously tighten the corresponding bolts at preset speeds until the tightening torque of each bolt reaches the preset initial tightening torque; the initial tightening torque is less than the preset standard torque.

[0188] Multiple motors are controlled to increase the tightening torque of each bolt at the same rate of torque increase, starting from the initial tightening torque, until the tightening torque reaches the preset standard torque.

[0189] In one embodiment, the first control module 510 is further configured to:

[0190] During the process of controlling multiple motors to tighten their corresponding bolts, the current output of each motor is collected.

[0191] Based on multiple currents, the third and fourth motors, which have deviations in the tightening torque output by the multiple motors, are identified; the first current corresponding to the third motor is greater than the second current corresponding to the fourth motor.

[0192] Reduce the first current output of the third motor, and increase the second current output of the fourth motor;

[0193] Multiple motors are controlled to tighten corresponding bolts based on the adjusted current until the tightening torque of each bolt reaches the preset standard torque.

[0194] In one embodiment, the first control module 510 is further configured to:

[0195] Calculate the current difference between any two currents in a given set of multiple currents;

[0196] Calculate the ratio between the maximum current difference among multiple current differences and the average of the multiple current differences;

[0197] If the ratio is greater than the preset ratio, then the two motors corresponding to the maximum current difference are determined to be the third motor and the fourth motor, respectively.

[0198] In one embodiment, the bolt fastening device 500 further includes:

[0199] The third control module is used to control multiple motors to execute the target fault response action corresponding to the current constraint condition if the current does not meet the preset current constraint condition.

[0200] The third determination module is used to determine the third and fourth motors whose tightening torques output by the multiple motors deviate, based on the multiple currents, if multiple currents all meet the current constraint conditions.

[0201] In one embodiment, the bolt fastening device 500 further includes:

[0202] The maintenance module is used to maintain the tightening torque of each bolt at the preset standard torque for a preset time period.

[0203] In one embodiment, the bolt fastening device 500 further includes:

[0204] The first execution module is used to repeatedly execute the target step and all subsequent steps until the parallelism is less than the preset parallelism. The target step is to control multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque.

[0205] In one embodiment, the bolt fastening device 500 further includes:

[0206] The detection module is used to detect the contact resistance between the clamp and the connector.

[0207] The ultrasonic module is used to send ultrasonic vibration signals to the contact surface between the clamp and the connector if the contact resistance is greater than the preset resistance.

[0208] The second execution module is used to repeatedly execute the target step and all subsequent steps after stopping the transmission of ultrasonic vibration signals until the contact resistance is less than or equal to the preset resistance.

[0209] When it is understood that, Figure 5 In the schematic diagram of the bolt fastening device shown, each module is used to perform... Figures 1 to 4 The steps in the corresponding embodiments, and for Figures 1 to 4 The steps in the corresponding embodiments have been explained in detail in the above embodiments. Please refer to them for details. Figures 1 to 4 as well as Figures 1 to 4 The relevant descriptions in the corresponding embodiments will not be repeated here.

[0210] Figure 6 This is a structural schematic diagram of a clamp fastening device provided in one embodiment of this application. Figure 6As shown, the clamp fastening device 600 of this embodiment includes a processor 610, a memory 620, and a computer program 630 stored in the memory 620 and executable by the processor 610, such as a program for a bolt fastening method. The clamp fastening device includes multiple motors 640. When the processor 610 executes the computer program 630, it implements the steps in the various embodiments of the bolt fastening methods described above, thereby controlling the multiple motors 640 to output power for fastening the corresponding bolts in the clamp. For example... Figure 1 S101 to S104 are shown. Alternatively, the processor 610 implements the above when executing the computer program 630. Figure 5 The functions of each module in the corresponding embodiments, for example, Figure 5 For details on the functions of each module shown, please refer to [link / reference]. Figure 5 The relevant descriptions in the corresponding embodiments.

[0211] For example, the computer program 630 can be divided into one or more modules, one or more of which are stored in the memory 620 and executed by the processor 610 to implement the bolt tightening method provided in the embodiments of this application. One or more modules can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 630 in the clamp fastening device 600. For example, the computer program 630 can implement the bolt tightening method provided in the embodiments of this application.

[0212] The clamp fastening device 600 may include, but is not limited to, a processor 610 and a memory 620. Those skilled in the art will understand that... Figure 6 This is merely an example of the clamp fastening device 600 and does not constitute a limitation on the clamp fastening device 600. It may include more or fewer components than shown, or combine certain components, or different components. For example, the clamp fastening device may also include input / output devices, network access devices, buses, etc.

[0213] The processor 610 may be a central processing unit, or it may be other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0214] The memory 620 can be an internal storage unit of the clamp fastening device 600, such as a hard drive or memory of the clamp fastening device 600. The memory 620 can also be an external storage device of the clamp fastening device 600, such as a plug-in hard drive, smart memory card, flash memory card, etc., equipped on the clamp fastening device 600. Furthermore, the memory 620 can include both internal storage units and external storage devices of the clamp fastening device 600.

[0215] This application provides a computer-readable storage medium, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the bolt tightening method as described in the above embodiments.

[0216] This application provides a computer program product that, when run on a clamp fastening device, causes the clamp fastening device to perform the bolt fastening methods described in the above embodiments.

[0217] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A bolt fastening method, characterized in that, The method is applied to a clamp fastening device, which includes multiple motors, each of which outputs power to fasten a corresponding bolt in the clamp; the method includes: Control the multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque; Check the parallelism of the mounting surface of the clamp; If the parallelism is greater than or equal to the preset parallelism, then the interval distance between the multiple bolts and the preset reference surface is obtained; The first bolt corresponding to the maximum value of the interval distance is determined, the first motor corresponding to the first bolt is determined, the second bolt is located on the opposite side of the first bolt, and the second motor corresponding to the second bolt is determined; The deflection angle is determined based on the deviation between the interval distance corresponding to the first bolt and the interval distance corresponding to the second bolt; The first motor is controlled to loosen the first bolt by the deflection angle, and the second motor is controlled to tighten the second bolt by the deflection angle. The method of controlling the plurality of motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque also includes: During the process of controlling the multiple motors to tighten the corresponding bolts, the current output by the multiple motors is collected respectively; Based on the multiple currents, a third motor and a fourth motor are identified as having deviations in the tightening torque output by the multiple motors; the first current corresponding to the third motor is greater than the second current corresponding to the fourth motor; Decrease the first current output by the third motor, and increase the second current output by the fourth motor; The multiple motors are controlled to tighten the corresponding bolts based on the adjusted current until the tightening torque of each bolt reaches the preset standard torque. The method of determining, based on multiple currents, that the third and fourth motors, respectively, have deviations in the tightening torque output by the multiple motors, includes: Calculate the current difference between any two of the multiple currents; Calculate the ratio between the maximum current difference among the plurality of current differences and the average value of the plurality of current differences; If the ratio is greater than the preset ratio, then the two motors corresponding to the maximum current difference are determined to be the third motor and the fourth motor, respectively.

2. The method according to claim 1, characterized in that, The control of the plurality of motors to tighten the corresponding bolts until the tightening torque of each bolt reaches a preset standard torque includes: The multiple motors are controlled to simultaneously tighten the corresponding bolts at preset speeds until the tightening torque of each bolt reaches the preset initial tightening torque; the initial tightening torque is less than the preset standard torque. The multiple motors are controlled to increase the tightening torque of each bolt by the same torque increase rate, starting from the initial tightening torque, until the tightening torque reaches the preset standard torque.

3. The method according to claim 1, characterized in that, After collecting the current output by each of the multiple motors during the process of controlling the multiple motors to tighten the corresponding bolts, the method further includes: If the current does not meet the preset current constraint condition, then control the multiple motors to execute the target fault response action corresponding to the current constraint condition; If all of the currents satisfy the current constraint condition, then based on the multiple currents, the third motor and the fourth motor, which have deviations in the tightening torque output by the multiple motors, are determined.

4. The method according to claim 1, characterized in that, After controlling the plurality of motors to tighten the corresponding bolts until the tightening torque of each bolt reaches a preset standard torque, the process includes: Within a preset time period, the tightening torque of each bolt is maintained at the preset standard torque.

5. The method according to any one of claims 1-4, characterized in that, After controlling the first motor to loosen the first bolt by the deflection angle and controlling the second motor to tighten the second bolt by the deflection angle, the method further includes: Repeat the target step and all subsequent steps until the parallelism is less than the preset parallelism; the target step is to control the multiple motors to tighten the corresponding bolts until the tightening torque of each bolt reaches the preset standard torque.

6. The method according to claim 5, characterized in that, After repeatedly executing the target step and each subsequent step until the parallelism is less than the preset parallelism, the method further includes: Detect the contact resistance between the clamp and the connector; If the contact resistance is greater than the preset resistance, an ultrasonic vibration signal is sent to the contact surface between the clamp and the connector; After stopping the transmission of the ultrasonic vibration signal, the target step and all subsequent steps are repeated until the contact resistance is less than or equal to the preset resistance.

7. A clamp fastening device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, It also includes multiple motors, wherein when the processor executes the computer program, it implements the method as described in any one of claims 1 to 6, to control the multiple motors to output power for the corresponding bolts in the clamping hoop.

8. A computer program product, characterized in that, When the computer program product is run on the clamp fastening device, the clamp fastening device performs the method as described in any one of claims 1 to 6.

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