Intelligent tightening system and control method

Abstract

The application provides an intelligent tightening system and a control method, the intelligent tightening system comprising: a housing; a driving assembly arranged at one axial end of the housing; an output head in transmission connection with an output end of the driving assembly, the output head being provided with a first position and a second position spaced in the axial direction; two angle detection assemblies arranged at the first position and the second position respectively, each angle detection assembly comprising a rotation sensing element fixed to the output head and a fixed sensing element fixed to the housing, the rotation sensing element and the fixed sensing element being arranged in a spaced manner; a master control in electrical connection with the two angle detection assemblies, the master control being internally provided with a torque calculation circuit to calculate the torque borne by the output head according to the difference between the first rotation angle and the second rotation angle. According to the intelligent tightening system of the application, the non-contact angle detection assemblies are arranged at the first position and the second position respectively, the detection result is stable, and the stability and repeatability of the measurement result are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of intelligent tightening system technology, specifically to an intelligent tightening system and control method. Background Technology

[0002] With the development of automated assembly technology, intelligent tightening systems are widely used in fixed assembly scenarios such as robotic arms and bench fixtures. Intelligent tightening systems typically drive the output head to rotate through a drive component to tighten fasteners, and use a torque detection device to obtain the torque borne by the output head, thereby controlling the tightening process.

[0003] However, existing intelligent tightening systems typically attach strain gauges to the shaft of the output head and determine the torque based on the shaft deformation detected by the strain gauges. This detection method is easily affected by the adhesion of the strain gauges and temperature changes, making it difficult to consistently and reliably detect the torque borne by the output head during continuous rotation. Summary of the Invention

[0004] In view of this, the present invention aims to provide an intelligent tightening system and control method to solve the problems of existing intelligent tightening systems that are easily affected by the adhesion state and temperature changes, and are difficult to detect torque stably for a long time, due to the use of strain gauges to detect torque.

[0005] In a first aspect, this application proposes an intelligent tightening system, comprising: a housing; A drive assembly is disposed at one axial end of the housing; An output head is connected to the output end of the drive assembly, and the output head is provided with a first position and a second position spaced apart in the axial direction. Two angle detection components are respectively disposed at the first position and the second position. The two angle detection components are used to detect a first rotation angle of the output head at the first position and a second rotation angle at the second position. Each angle detection component includes a rotation sensor fixed to the output head and a fixed sensor fixed inside the housing, the rotation sensor and the fixed sensor being spaced apart. The main control is electrically connected to the two angle detection components. The main control has a built-in torque calculation circuit to calculate the torque borne by the output head based on the difference between the first rotation angle and the second rotation angle.

[0006] Optionally, the output head has a reduced diameter section between the first position and the second position, the diameter of which is smaller than the diameter of the output head at the first position and the second position.

[0007] Optionally, it also includes two support bearings, the inner rings of which are respectively fitted and fixed to the output head and located on both sides of the reduced diameter section, and the outer rings of which are fixed to the inner wall of the housing.

[0008] Optionally, the inner wall of the housing and / or the output head are provided with a positioning part, and at least a portion of the angle detection component abuts against the positioning part to define the installation position of the angle detection component in the axial direction.

[0009] Optionally, the angle detection component further includes a mounting housing, which is fixed to the inner wall of the outer shell. The fixed sensor and the rotation sensor are both disposed inside the mounting housing. The mounting housing has a shaft hole through which the output head passes, and the output head passes through the shaft hole and is fixedly connected to the rotation sensor.

[0010] Optionally, the positioning part is provided on both the inner wall of the housing and the output head. The rotation sensor abuts against the positioning part on the output head to position the rotation sensor at the first position or the second position. The fixed sensor abuts against the positioning part on the inner wall of the housing to limit the axial position of the fixed sensor relative to the rotation sensor within the housing.

[0011] Optionally, at least one of the rotation sensing elements is a ring-shaped magnetic element, which is fixedly mounted on the outside of the output head. The ring-shaped magnetic element includes different magnetic poles arranged alternately along the circumference. The fixed sensing element corresponding to the ring-shaped magnetic element is a magnetic sensor, which is fixed to the inner wall of the housing and is positioned opposite to and spaced apart from the ring-shaped magnetic element.

[0012] Optionally, the magnetic sensor includes one of a Hall sensor and a magnetoresistive sensor.

[0013] Optionally, at least one of the rotation sensors is integrally formed with the output head. The rotation sensor has a plurality of spaced grooves distributed along its circumference. The fixed sensor corresponding to the rotation sensor has a sensing surface, which faces the grooves and is opposite to and spaced from them.

[0014] Optionally, the fixed sensing element includes one of an inductive sensor and a magnetoresistive sensor.

[0015] Optionally, at least one of the rotation sensing elements is annular, and the rotation sensing element is provided with multiple light-transmitting areas and light-blocking areas. The multiple light-transmitting areas and light-blocking areas are alternately arranged along the circumferential direction of the rotation sensing element. The fixed sensing element corresponding to the rotation sensing element includes a light-emitting group and a sensing and receiving group, and the light-emitting group and the sensing and receiving group are respectively arranged on both sides of the axial direction of the annular rotation sensing element.

[0016] Optionally, the light-transmitting area is a slit that passes through the rotation sensing element along the axial direction, and the light-shielding area is the solid portion between adjacent slits.

[0017] Secondly, this application proposes a control method for the aforementioned intelligent tightening system, the control method comprising: Obtain the first rotation angle and the second rotation angle; Calculate the angle difference between the first rotation angle and the second rotation angle; The torque borne by the output head of the intelligent tightening system is calculated based on the angle difference. When the torque meets the preset torque condition, the output head is controlled to stop rotating.

[0018] The technical solutions provided in this application have the following advantages compared with the prior art: The intelligent tightening system provided in this application has a drive component installed at one axial end of the housing. The output end of the drive component is connected to the output head, enabling the drive component to drive the output head to rotate for tightening the fastener. Two angle detection components are respectively installed at a first position and a second position. One angle detection component detects a first rotation angle of the output head at the first position, and the other angle detection component detects a second rotation angle of the output head at the second position. Each angle detection component includes a rotation sensor fixed to the output head and a fixed sensor fixed inside the housing. The rotation sensor and the fixed sensor are spaced apart to form a non-contact angle detection pair. When the output head is subjected to torque during tightening, torsional deformation occurs between the first and second positions due to the torque, resulting in a difference in the rotation angle between the two positions. The magnitude of this difference is positively correlated with the torque borne by the output head. The main control unit is electrically connected to the two angle detection components. By receiving the rotation angle signals detected by the two angle detection components, the main control unit calculates the angle difference between the first and second rotation angles and calculates the torque borne by the output head based on this angle difference, thus achieving non-contact torque detection.

[0019] Because the angle detection component adopts a non-contact structure, the rotation sensing element and the fixed sensing element have no mechanical contact and are spaced apart, avoiding the effects of traditional strain gauges such as differences in adhesion, temperature changes, and mechanical wear caused by long-term rotation. This allows for long-term, stable detection of the torque borne by the output head during continuous rotation, improving the reliability and service life of torque detection. Simultaneously, this application sets angle detection components at the first and second positions respectively to detect the first and second rotation angles and calculate their difference. This difference is the relative torsional angle of the output head between the first and second positions. Since this torsional angle is proportional to the torque borne by the output head, and the differential operation eliminates the common-mode component of the overall rotation of the output head, retaining only the torsional component caused by the torque, the main control system can accurately calculate the torque borne by the output head based on this angle difference, thereby achieving real-time, high-precision closed-loop control of the tightening process.

[0020] Compared with single-point angle measurement, the method of detecting at the first and second positions is not affected by fluctuations in the absolute rotational speed of the output head, changes in the rotational speed of the drive component, or external vibration interference. The torque measurement result depends only on the relative torsional deformation between the two positions, thus significantly improving the stability and repeatability of the measurement results. Attached Figure Description

[0021] Figure 1 The image shown is a front view of an intelligent tightening system according to some embodiments of this application.

[0022] Figure 2 As shown Figure 1 Sectional view at point AA.

[0023] Figure 3 The image shown is a front view of an intelligent tightening system according to some embodiments of this application, where the output head is shown.

[0024] Figure 4 The image shown is a perspective view of an intelligent tightening system according to some embodiments of this application.

[0025] Figure label: Intelligent tightening system 100, housing 10, drive assembly 20, motor 21, reducer 22. Output head 30, reduced diameter section 31, positioning part 32, first shaft section 33, second shaft section 34, third shaft section 35, fourth shaft section 36, fifth shaft section 37. Angle detection component 40, support bearing 50, Coupling 60, inner snap ring 61, end cover 62, bushing 63, first position 64, second position 65. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0028] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0029] With the development of automated assembly technology, intelligent tightening systems are widely used in fixed assembly scenarios such as robotic arms and bench fixtures. An intelligent tightening system typically includes a drive assembly and an output head that is driven by the output end of the drive assembly. The drive assembly drives the output head to rotate, enabling it to tighten fasteners such as bolts and screws. During the tightening process, it is usually necessary to detect the torque applied to the output head to determine whether the fastener has reached the predetermined tightening state, and to control the drive assembly accordingly.

[0030] In related technologies, strain gauges can be attached to the surface of the output head's shaft. When the output head undergoes torsional deformation due to the reaction force of the fasteners, the strain gauges deform along with the output head, generating corresponding detection signals. By processing these detection signals, the torque borne by the output head can be obtained.

[0031] However, strain gauge readings are susceptible to variations in adhesion location, adhesion quality, and adhesion condition, and differences in assembly consistency may exist between different strain gauges or different intelligent tightening systems. Furthermore, during continuous operation of the intelligent tightening system, the temperature of the drive components and output head may change, causing the strain gauge output signal to drift and thus affecting the torque detection results. With continuous rotation of the output head and repeated tightening operations, these effects may reduce the long-term stability of torque detection.

[0032] Based on this, this application provides an intelligent tightening system. The intelligent tightening system includes a housing, a drive assembly, an output head, two angle detection components 40, and a main control unit. The drive assembly is disposed at one axial end of the housing, and the output head is connected to the output end of the drive assembly so that the drive assembly can drive the output head to rotate relative to the housing. The output head is provided with a first position 64 and a second position 65 spaced apart along the axial direction. The two angle detection components 40 are respectively disposed at the first position 64 and the second position 65 to detect the rotation angle of the output head at the first position 64 and the second position 65, respectively.

[0033] A drive assembly is provided at one axial end of the housing. The output end of the drive assembly is connected to the output head, enabling the drive assembly to drive the output head to rotate for tightening the fastener. Two angle detection assemblies 40 are respectively located at a first position and a second position, used to detect a first rotation angle of the output head at the first position and a second rotation angle at the second position. Each angle detection assembly 40 includes a rotation sensor and a fixed sensor. The rotation sensor is fixed to the output head and can rotate with the output head, while the fixed sensor is fixed inside the housing and remains fixed relative to the housing. The rotation sensor and the fixed sensor are spaced apart, allowing the fixed sensor to detect the rotation position of the rotation sensor without mechanical contact, thereby obtaining the rotation angle of the output head at the corresponding position.

[0034] When the drive assembly drives the output head to rotate under no-load or when the torque on the output head is small, the first position 64 and the second position 65 rotate with the output head as a whole, maintaining a corresponding initial angular relationship between their rotation angles. When the output head engages with the fastener and bears tightening resistance, the output head undergoes torsional deformation under the combined action of the driving torque output by the drive assembly and the reaction torque generated by the fastener. Since the first position 64 and the second position 65 are spaced apart along the axial direction of the output head, a difference corresponding to the torsional deformation is generated between the rotation angles of the output head at the first position 64 and the second position 65.

[0035] The main control is electrically connected to two angle detection components 40. The main control receives the rotation angle signals detected by the two angle detection components 40, calculates the angle difference between the first rotation angle and the second rotation angle, and calculates the torque borne by the output head based on the angle difference, thereby realizing non-contact torque detection.

[0036] The main control is electrically connected to two angle detection components 40. The main control has a built-in torque calculation circuit to calculate the torque borne by the output head 30 based on the difference between the first rotation angle and the second rotation angle.

[0037] The torque calculation circuit is electrically connected to two angle detection components 40 and is used to receive angle signals output by the angle detection components 40. The torque calculation circuit can perform differential calculations on the received angle signals and output the torque value borne by the output head 30 based on the differential calculation result. The torque calculation circuit may include one or more combinations of operational amplifiers, analog-to-digital converters, microprocessors, or digital signal processors. The torque calculation circuit can be integrated into the control chip or signal processing circuit of the main control unit, or it can be a separate signal processing module. By integrating the torque calculation circuit inside the main control unit, no external additional calculation unit is required, which is beneficial to improving the real-time performance and integration of signal processing.

[0038] Because the angle detection component 40 adopts a non-contact structure, the rotating sensing element and the fixed sensing element have no mechanical contact and there is a gap between them. This avoids the effects of traditional strain gauges caused by differences in bonding state, temperature changes, and mechanical wear caused by long-term rotation. It can detect the torque borne by the output head for a long time and stably during the continuous rotation of the output head, thus improving the reliability and service life of torque detection.

[0039] Meanwhile, this application sets angle detection components 40 at the first and second positions respectively to detect the first rotation angle and the second rotation angle and calculate their difference. This difference is the relative torsional angle of the output head between the first and second positions. Since this torsional angle is proportional to the torque borne by the output head, and the differential operation eliminates the common-mode component of the overall rotation of the output head, retaining only the torsional component caused by the torque, the main control can accurately calculate the torque borne by the output head based on this angle difference, thereby realizing real-time, high-precision closed-loop control of the tightening process.

[0040] Based on the completion of dynamic torque acquisition under all working conditions, the angle detection component 40 near the front end of the output head can also simultaneously realize real-time monitoring and data feedback of the final tightening angle, providing complete data support for the closed-loop control of torque-angle dual parameters in the tightening process. For example, during the tightening process, the main control unit continuously acquires the real-time torque value and real-time angle value of the output head, and compares them with the preset torque target value and angle target value, respectively. When either the torque or angle parameter reaches the preset target, the main control unit controls the drive component to stop or adjust the output, so that the fastener simultaneously meets the dual precision requirements of torque and angle. The main control unit can output a control signal to the drive component according to the precise torque value, so that the output torque of the output head is accurately maintained within the target range, avoiding insufficient tightening or overload damage to the fastener due to torque deviation, and ensuring the consistency and reliability of assembly quality.

[0041] Compared with single-point angle measurement, the method of detecting at the first position 64 and the second position 65 is not affected by fluctuations in the absolute speed of the output head, changes in the speed of the drive component, or external vibration interference. The torque measurement result depends only on the relative torsional deformation between the two positions, thereby significantly improving the stability and repeatability of the measurement results.

[0042] Please see Figure 1 , Figure 2 and Figure 3 The intelligent tightening system provided in this application can be applied to robotic arms, bench fixtures, or other fixed assembly equipment to perform tightening operations on bolts, screws, nuts, or other fasteners. The intelligent tightening system can be used in fixed assembly scenarios requiring multiple tightening operations consecutively, or it can be used for handheld operation by an operator. The intelligent tightening system includes a housing 10, a drive assembly 20, an output head 30, two angle detection assemblies 40, and a main control unit (not shown in the figure). For ease of explanation, the direction of the rotation axis of the output head 30 is defined as the axial direction, the side of the output head 30 used to mate with the fastener is defined as the front end, and the side where the drive assembly 20 is located is defined as the rear end. The front and rear ends are only used to illustrate the relative positions between the structures and do not constitute a limitation on the actual installation posture of the intelligent tightening system.

[0043] The housing 10 extends axially and internally forms an installation space for accommodating at least a portion of the output head 30, two angle detection components 40, and related support structures. The housing 10 serves as a mounting base for internal components of the intelligent tightening system, allowing the output head 30 to rotate relative to the housing 10 and keeping components of the angle detection components 40 that do not rotate with the output head 30 fixed relative to the housing 10. The housing 10 can be mounted on the actuator end of a robotic arm, a bench fixture, or other assembly equipment to enable the intelligent tightening system to perform tightening operations in a relatively fixed position. The housing 10 may have multiple sections with different inner diameters along its axial direction. For example, the housing 10 may have sections with larger inner diameters and sections with smaller inner diameters, the wall thickness of the smaller inner diameter section being greater than the wall thickness of the larger inner diameter section. Different inner diameter sections can respectively form spaces and positioning surfaces for mounting the angle detection components 40, support bearings 50, bushings 63, or end caps 62. The specific inner diameter and wall thickness of the housing 10 can be set according to the radial dimension of the output head 30, the installation space of the angle detection components 40, and the load-bearing requirements of the intelligent tightening system.

[0044] like Figure 1 and Figure 4 As shown, the drive assembly 20 is disposed at one axial end of the housing 10. Figure 1 and Figure 2 In the illustrated embodiment, the drive assembly 20 is disposed at the rear end of the housing 10. The drive assembly 20 is used to provide power to drive the output head 30 to rotate. The drive assembly 20 may include a motor 21 and a reducer 22 that is driveably connected to the motor 21. The motor 21 is used to output rotational power, and the reducer 22 is used to convert the speed and torque output by the motor 21, and transmit the rotational power to the output head 30 through the output end of the reducer 22.

[0045] The output head 30 is connected to the output end of the drive assembly 20 via a transmission connection. Figure 2 In the illustrated embodiment, the rear end of the output head 30 is connected to the output end of the reducer 22 via a coupling 60, so that the power output by the motor 21 is transmitted sequentially to the output head 30 via the reducer 22 and the coupling 60. The coupling 60 is used to connect the output head 30 and the output end of the reducer 22, and to transmit the torque output by the reducer 22 to the output head 30. The front end of the output head 30 extends out of the housing 10 to facilitate engagement with the fastener to be tightened. The front end of the output head 30 may have a mating structure adapted to fit bolt heads, screw heads, nuts, or other fasteners. When the drive assembly 20 drives the output head 30 to rotate, the output head 30 drives the fastener to rotate, so as to screw the fastener into the object to be assembled, or to bring the fastener to a predetermined tightening state relative to the object to be assembled.

[0046] Please refer to the following: Figure 2 and Figure 3The output head 30 can be formed into multiple shaft segments of different diameters along the axial direction. Figure 3 In the illustrated embodiment, the output head 30 may sequentially include a first shaft segment 33, a second shaft segment 34, a third shaft segment 35, a reduced diameter segment 31, a fourth shaft segment 36, and a fifth shaft segment 37 from the front end to the rear end, and may continue to extend behind the fifth shaft segment 37 to form a connecting shaft segment that mates with the coupling 60. In some embodiments, the diameter of the second shaft segment 34 is larger than the diameter of the first shaft segment 33, and a limiting end face is formed between the first shaft segment 33 and the second shaft segment 34. The first shaft segment 33 extends beyond the front end of the housing 10, and the limiting end face may form an axial limiting relationship with the corresponding structure of the housing 10. The diameter of the third shaft segment 35 may be larger than the diameter of the second shaft segment 34, and a positioning part 32 is formed between the second shaft segment 34 and the third shaft segment 35. The fourth shaft segment 36 is located behind the reduced diameter segment 31, and the diameters of the third shaft segment 35 and the fourth shaft segment 36 may be approximately equal, and are respectively used to install the support bearing 50. The diameter of the fifth shaft segment 37 can be smaller than that of the fourth shaft segment 36, and it is used to form the connection and limiting structure at the rear of the output head 30. The specific diameter relationship of the above shaft segments can be determined according to the load-bearing requirements, support requirements and installation requirements of the output head 30.

[0047] The output head 30 is provided with a first position 64 and a second position 65 spaced apart along the axial direction. The first position 64 and the second position 65 are two angle detection positions on the output head 30. Figure 3 In the illustrated embodiment, one detection position is relatively close to the front end of the output head 30, and the other detection position is relatively close to the drive component 20. The naming of the first position 64 and the second position 65 is used to distinguish the two detection positions, and there is no limitation on their fixed correspondence with the front end and the back end.

[0048] An axial gap exists between the first position 64 and the second position 65, allowing the portion of the output head 30 located between these positions to transmit torque. When the output head 30 is not subjected to tightening resistance, the first position 64 and the second position 65 rotate as a whole with the output head 30, maintaining a corresponding initial angular relationship. When the front end of the output head 30 engages with the fastener and experiences the reaction torque generated by the fastener, the drive assembly 20 still inputs a driving torque from the rear end of the output head 30, causing torsional deformation in the portion of the output head 30 located between the first position 64 and the second position 65. Consequently, a difference corresponding to this torsional deformation is generated between the rotation angles of the output head 30 at the first position 64 and the second position 65.

[0049] Two angle detection components 40 are respectively disposed at a first position 64 and a second position 65. One angle detection component 40 detects a first rotation angle of the output head 30 at the first position 64, and the other angle detection component 40 detects the rotation angle of the output head 30 at the second position 65. Each angle detection component 40 includes a rotation sensor and a fixed sensor. The rotation sensor rotates with the output head 30 and provides the fixed sensor with an angular feature characterizing the rotation position of the output head 30. The rotation sensor is fixed to the output head 30 so that no relative rotation occurs between the rotation sensor and the output head 30 that would affect the angle detection. The rotation sensor can be an independent component mounted and fixed outside the output head 30, or it can be formed by a local structure of the output head 30 itself. When the drive component 20 drives the output head 30 to rotate, the rotation sensors located at the first position 64 and the second position 65 rotate synchronously with the corresponding positions of the output head 30. The fixed sensor senses the rotation position of the corresponding rotation sensor and generates a detection signal related to the rotation angle of the output head 30. The fixed sensor is fixed inside the housing 10, so that the fixed sensor remains fixed relative to the housing 10 and does not rotate with the output head 30.

[0050] Two fixed sensors correspond to rotating sensors located at the first position 64 and the second position 65, respectively, forming two independent angle detection positions. The rotating sensors and their corresponding fixed sensors are spaced apart. This spacing means that the rotating sensors do not need to have continuous mechanical contact with the fixed sensors during rotation with the output head 30; the fixed sensors can sense the rotational position of the rotating sensors through changes in magnetic fields, light signals, inductance, or other non-contact detection methods. Figure 2 In the illustrated embodiment, the rotation sensor and the fixed sensor may also be spaced apart axially, forming an axial detection gap between them. In other embodiments, depending on the detection principle employed by the angle detection assembly 40, the rotation sensor and the fixed sensor may also be spaced apart radially, or have both axial and radial spacing.

[0051] The two angle detection components 40 can employ the same angle detection principle so that the two detection signals have the same or similar signal form and processing method. In some embodiments, the two angle detection components 40 can also employ different angle detection principles, as long as the two angle detection components 40 can respectively obtain the rotation angle of the output head 30 at the first position 64 and the second position 65, and enable the main control to compare the first rotation angle and the second rotation angle.

[0052] The main control unit is electrically connected to two angle detection components 40. The main control unit has a built-in torque calculation circuit, which is electrically connected to the two angle detection components 40 to acquire the detection signals output by each component 40, process the signals, and obtain the torque borne by the output head 30 based on the processing result. The main control unit may include a processor, a control chip, a signal processing circuit, or a combination thereof. The torque calculation circuit may be integrated into the processor, control chip, or signal processing circuit. In some embodiments, the angle detection component 40 may output an angle signal representing the absolute angular position of the rotation sensor.

[0053] In other embodiments, the angle detection component 40 can output a signal related to the number or sequence of times the rotation sensor passes through a predetermined sensing position, and the main control determines the rotation angle of the output head 30 relative to an angle reference based on this signal. The main control can determine a first rotation angle of the output head 30 at the first position 64 based on the detection signal output by the angle detection component 40 at the first position 64, and a second rotation angle of the output head 30 at the second position 65 based on the detection signal output by the angle detection component 40 at the second position 65. The first rotation angle and the second rotation angle can be angles determined relative to the same angle reference, or they can be angles that can be compared after reference conversion. For ease of explanation, the first rotation angle at the first position 64 can be denoted as θ1, and the second rotation angle at the second position 65 can be denoted as θ2. The angle difference between the two positions can then be expressed as the difference between θ1 and θ2. The main control can determine the magnitude of the torque based on the magnitude of the angle difference. When it is necessary to identify the direction of torque, the main control can also determine the torsion direction of the output head 30 based on the sign of the angle difference.

[0054] In some implementations, a pre-established correspondence between the angle difference between the output head 30 at the first position 64 and the second position 65 and the torque borne by the output head 30 can be established. This correspondence can be determined based on the structural parameters and material properties of the portion of the output head 30 between the two positions, or it can be obtained through calibration by applying a known torque to the output head 30. After obtaining the angle difference between the two positions, the main control calculates the torque borne by the output head 30 based on the aforementioned correspondence.

[0055] In some implementations, the initial angle difference between the first position 64 and the second position 65 can be obtained when the output head 30 is not under torque or is under a reference torque. During the tightening process, the main control uses the change in the real-time angle difference relative to the initial angle difference as the effective torsion angle of the output head 30, and calculates the torque borne by the output head 30 based on the effective torsion angle. In this way, the influence of the initial installation angle difference of the two rotation sensors on the torque calculation result can be reduced.

[0056] In operation, the drive assembly 20 drives the output head 30 to rotate, and the front end of the output head 30 drives the fastener to rotate. When the fastener has not yet generated significant tightening resistance, the output head 30 rotates approximately synchronously at the first position 64 and the second position 65, and the difference between the rotation angles detected by the two angle detection assemblies 40 is small. As the fastener is gradually tightened and generates a larger reaction torque on the output head 30, the output head 30 undergoes torsional deformation between the first position 64 and the second position 65, and the difference between the rotation angles at the two positions changes accordingly. The main control unit calculates the torque borne by the output head 30 based on the difference, thereby obtaining the tightening state of the fastener.

[0057] In some implementations, the angle detection component 40 near the front end of the output head 30 can also be used to detect the rotation angle of the output end of the output head 30. The main control can determine the final tightening angle of the output head 30 based on the detection result of the angle detection component 40 relative to a preset angle reference. In this way, the angle detection component 40 near the front end of the output head 30 can both cooperate with another angle detection component 40 to obtain the angle difference and be used to obtain the tightening angle of the output end of the output head 30.

[0058] Please refer to the following: Figure 2 and Figure 3 In some embodiments, the output head 30 has a reduced diameter section 31 between the first position 64 and the second position 65. The diameter of the reduced diameter section 31 is smaller than the diameter of the output head 30 at the first position 64 and the second position 65. That is, the diameter of the reduced diameter section 31 is smaller than the diameter of the output head 30 at the first position 64 and smaller than the diameter of the output head 30 at the second position 65.

[0059] The first position 64 and the second position 65 are located on opposite sides of the axial direction of the reduced diameter section 31, respectively, so that the torque transmitted by the output head 30 can be transmitted from one side of the reduced diameter section 31 to the other side of the reduced diameter section 31. Figure 3 In the embodiment shown, the reduced diameter section 31 extends axially, and its front end and rear end are connected to the third shaft section 35 and the fourth shaft section 36, respectively, thereby forming a region where torsional deformation is relatively concentrated between the two angle detection positions of the output head 30.

[0060] When the drive assembly 20 drives the output head 30 to rotate and the front end of the output head 30 is subjected to the reaction torque generated by the fastener, the torque is transmitted along the axial direction of the output head 30. Since the diameter of the reduced-diameter section 31 is smaller than the diameter of the output head 30 at the first position 64 and the second position 65, the torsional stiffness of the reduced-diameter section 31 is lower than that of the adjacent shaft section with a larger diameter. Under the same torque, the reduced-diameter section 31 can produce relatively large torsional deformation, resulting in a significant difference between the rotation angle at the first position 64 and the rotation angle at the second position 65. The reduced-diameter section 31 constitutes the torque-sensitive area of ​​the output head 30, concentrating the torque borne by the output head 30 into a detectable relative torsional angle. By setting a smaller-diameter reduced-diameter section 31 between the first position 64 and the second position 65 of the output head 30, the torsional stiffness of the reduced-diameter section 31 is significantly lower than that of the non-reduced-diameter sections at both ends.

[0061] Under the same torque, the torsional deformation of the reduced diameter section 31 is much greater than that of the shaft sections on both sides, thereby amplifying the angle difference between the first position 64 and the second position 65, and effectively improving the sensitivity of torque detection.

[0062] The diameter and axial length of the reduced diameter section 31 can be optimized according to the torque range of the output head 30, the material shear modulus, and the desired angle difference detection resolution. Under the premise of meeting the strength and fatigue life requirements of the output head 30, appropriately reducing the diameter of the reduced diameter section 31 or increasing its length can further increase the torsion angle under unit torque, making it easier for the two angle detection components 40 to distinguish small torque changes. Conversely, if it is necessary to withstand a larger torque, the diameter of the reduced diameter section 31 can be appropriately increased or its length shortened to ensure that the output head 30 has sufficient load-bearing capacity.

[0063] In some embodiments, the reduced-diameter section 31 may occupy only a portion of the axial length between the first position 64 and the second position 65. The larger-diameter third shaft section 35 and fourth shaft section 36 are retained on both sides of the reduced-diameter section 31 to accommodate the support bearing 50 and maintain the support rigidity of the output head 30. The diameter and axial length of the reduced-diameter section 31 can be set according to the torque range of the output head 30, material properties, and desired angle difference detection sensitivity to achieve a balance between the load-bearing capacity of the output head 30 and the torsion angle detection sensitivity. Through this optimized design, the intelligent tightening system can achieve high-precision torque measurement for tightening operations of different torque levels.

[0064] Please see Figure 2 In some embodiments, the intelligent tightening system also includes two support bearings 50. The inner rings of the two support bearings 50 are respectively fitted and fixed on the output head 30 and are located on both sides of the reduced diameter section 31, and the outer rings of the two support bearings 50 are fixed relative to the inner wall of the housing 10.

[0065] Specifically, one support bearing 50 is fitted onto the third shaft section 35 in front of the reduced diameter section 31, and another support bearing 50 is fitted onto the fourth shaft section 36 in front of the reduced diameter section 31. The reduced diameter section 31 is located between the two support bearings 50.

[0066] The inner ring of the support bearing 50 can rotate synchronously with the output head 30, while the outer ring of the support bearing 50 remains fixed relative to the housing 10, thus forming a rotational support relationship between the output head 30 and the housing 10. When the output head 30 performs a tightening operation, in addition to bearing the torque transmitted along its axial direction, the output head 30 may also be subjected to radial forces caused by assembly deviations, fastener reaction forces, or equipment vibrations.

[0067] Two support bearings 50 restrict the radial movement of the output head 30 relative to the housing 10 from both axial sides of the reduced diameter section 31, reducing the bending and sway of the output head 30 near the reduced diameter section 31, so that the reduced diameter section 31 mainly produces torsional deformation around the axis of the output head 30 when the output head 30 is subjected to torque. The two support bearings 50 also help maintain the detection interval between the rotational sensing element and the fixed sensing element, thereby improving the repeatability of angle detection and the stability of torque calculation.

[0068] In some embodiments, a bushing 63 is disposed between the two support bearings 50. The bushing 63 extends axially between the two support bearings 50, and its two axial ends are respectively opposite to the outer rings of the two support bearings 50 to define the axial position of the outer rings of the two support bearings 50 facing each other. The outer periphery of the bushing 63 can mate or fit against the inner wall of the housing 10 in the corresponding section, so that the bushing 63 remains stable relative to the housing 10. In some embodiments, the bushing 63 is sleeved on the radially outer side of the reduced diameter section 31 and is radially spaced from the reduced diameter section 31. Thus, the bushing 63 can define the axial distance between the two support bearings 50 without directly contacting or tightly enclosing the reduced diameter section 31, avoiding the bushing 63 restricting the reduced diameter section 31 from torsional deformation under torque.

[0069] In some embodiments, the inner wall of the housing 10 may form a limiting boss located on the front side of the support bearing 50 near the front end of the output head 30. This limiting boss restricts the forward movement of the outer ring of the corresponding support bearing 50. The outer ring of the support bearing 50 near the front end of the output head 30 may be confined between the limiting boss and the bushing 63. In some embodiments, a limiting groove is provided on the rear side of the support bearing 50 near the drive assembly 20, and the limiting groove is formed on the inner wall of the housing 10. The inner retaining spring 61 engages with the limiting groove and axially limits the outer ring of the support bearing 50. The outer ring of the support bearing 50 near the drive assembly 20 may be confined between the bushing 63 and the inner retaining spring 61. Thus, the limiting boss, bushing 63, and inner retaining spring 61 on the housing 10 together define the axial position of the two support bearings 50 relative to the housing 10.

[0070] In some embodiments, shoulders or bosses are formed between shaft segments of different diameters on the output head 30 to define the axial position of the inner ring of the support bearing 50 relative to the output head 30. After the inner and outer rings of the support bearing 50 are axially positioned, they can maintain a relatively stable installation state during the rotation of the output head 30. The specific correspondence between each shoulder, boss, and support bearing 50 can be set according to the shaft segment structure and assembly direction of the output head 30.

[0071] Please refer to the following: Figure 2 and Figure 3 In some embodiments, a positioning portion 32 is provided on the inner wall of the housing 10 and / or the output head 30, and at least a portion of the angle detection component 40 abuts against the positioning portion 32 to define the axial mounting position of the angle detection component 40. The positioning portion 32 is used to restrict the axial movement of the angle detection component 40 or a corresponding component in the angle detection component 40 along the axial direction of the output head 30 by axial contact.

[0072] The positioning part 32 may be provided only on the output head 30. A radially extending shoulder surface may be formed between two adjacent shaft segments of different diameters on the output head 30, and this shoulder surface constitutes the positioning part 32. For example... Figure 3 As shown, a positioning part 32 is formed on the output head 30, and the positioning part 32 abuts against the angle detection component 40 to limit the axial mounting position of the angle detection component 40 on the output head 30. Figure 3 In the illustrated embodiment, the angle detection component 40 is an encoder component, including a mounting housing that is fitted over the output head 30. A positioning part 32 abuts against the end face of the mounting housing, thereby positioning the entire angle detection component 40 at a first position 64 or a second position 65. When installing the angle detection component 40, the mounting housing can be moved axially along the output head 30 until it abuts against the positioning part 32. The positioning part 32 prevents the mounting housing from moving further in the corresponding direction, providing an axial positioning reference for the angle detection component 40.

[0073] The positioning part 32 can also directly abut against the rotation sensor to define the axial mounting position of the rotation sensor on the output head 30. The output head 30 can be formed with positioning parts 32 corresponding to two rotation sensors respectively, and the two rotation sensors abut against the corresponding positioning parts 32 respectively, so that the two rotation sensors are respectively held in the first position 64 and the second position 65.

[0074] The positioning part 32 can also be disposed on the inner wall of the housing 10. The inner wall of the housing 10 can form a stepped surface by changing its inner diameter. This stepped surface can directly abut against other parts of the fixed sensing element, mounting housing, or angle detection assembly 40 that are fixed relative to the housing 10. An end cap 62 can also be disposed inside the housing 10. The end cap 62 is fixed to the housing 10 and is located on the side of the corresponding angle detection assembly 40 opposite to the positioning part 32 on the output head 30. The end cap 62 forms a positioning structure for defining the axial installation position of the angle detection assembly 40. It cooperates with the positioning part 32 on the output head 30 to clamp and fix the angle detection assembly 40 between the two.

[0075] For example, shims may also be provided on the axial sides of the two angle detection components 40 that are opposite to each other. The shims are located between the end cap 62 and the corresponding angle detection component 40 to accommodate the axial assembly tolerances between the end cap 62, the angle detection component 40, and the housing 10. The specific thickness of the shims can be set according to assembly requirements.

[0076] Please see Figure 2 In some embodiments, the angle detection assembly 40 further includes a mounting housing fixed to the inner wall of the outer casing 10, and both the fixed sensor and the rotation sensor are disposed within the mounting housing. The mounting housing has a shaft hole through which the output head 30 passes, and the output head 30 passes through the shaft hole and is fixedly connected to the rotation sensor.

[0077] The mounting housing supports and holds the fixed sensor relative to the outer casing 10. The mounting housing surrounds at least a portion of the outer periphery of the output head 30 and forms a space within it to accommodate the rotation sensor and the fixed sensor. After the mounting housing is fixed to the outer casing 10, the mounting housing and the fixed sensor disposed within it do not rotate with the output head 30, while the rotation sensor rotates synchronously with the output head 30. A shaft hole on the mounting housing extends through the mounting housing along the axial direction of the output head 30. The output head 30 passes through the shaft hole and is able to rotate about its own axis relative to the mounting housing. The rotation sensor rotates with the output head 30 within the internal space of the mounting housing, while the fixed sensor remains fixed relative to the outer casing 10. The sensing area of ​​the fixed sensor faces the rotation sensor to detect changes in the detection signal generated when the rotation sensor rotates with the output head 30.

[0078] During assembly, the angle detection assembly 40 is a pre-installed encoder module, including a mounting housing, a fixed sensor, and a rotation sensor. Both the fixed and rotation sensors are pre-installed within the internal space of the mounting housing. The angle detection assembly 40 is inserted axially along the output head 30, allowing the output head 30 to pass through the shaft hole of the mounting housing. The output head 30 is then fixedly connected to the rotation sensor, which rotates synchronously with the output head 30 and is positioned opposite and spaced apart from the fixed sensor. Subsequently, the mounting housing is fixed to the inner wall of the outer casing 10, with the mounting housing abutting against the positioning part 32 on the inner wall of the outer casing 10 to define the axial installation position of the mounting housing.

[0079] During assembly, first, an angle detection component 40 is inserted into one end of the housing 10. The positioning part 32 on the inner wall of the housing 10 is used to axially position the mounting housing of the angle detection component 40, and the mounting housing is fixed to the inner wall of the housing 10. Next, a support bearing 50 is installed into the housing 10, with its outer ring mating with the inner wall of the housing 10, and the support bearing 50 is axially limited by the limiting boss on the inner wall of the housing 10. Subsequently, a bushing 63 is installed into the housing 10, with the bushing 63 abutting against the outer ring of the installed support bearing 50. Then, another support bearing 50 is installed into the housing 10, with its outer ring abutting against the bushing 63, and the support bearing 50 is axially limited by the inner retaining spring 61.

[0080] Then, the output head 30 is inserted into one end of the housing 10, passing sequentially through the inner rings of the two installed support bearings 50 and the bushing 63, and the corresponding shaft section on the output head 30 mates with the inner ring of the support bearing 50. After the output head 30 is inserted, it simultaneously passes through the shaft hole of the first angle detection component 40 and is fixedly connected to the rotation sensor inside the angle detection component 40. Then, another angle detection component 40 is inserted from the insertion end of the output head 30 or the other end of the housing 10, so that the output head 30 passes through the shaft hole of the angle detection component 40, and the rotation sensor inside the angle detection component 40 is fixedly connected to the output head 30. The mounting housing of the angle detection component 40 abuts against and is fixed to the positioning part 32 on the inner wall of the housing 10. Finally, the end cap 62 is installed on the corresponding end of the housing 10 to axially limit the two angle detection components 40, and the rear part of the output head 30 is connected to the coupling 60.

[0081] Please see Figure 2In some embodiments, at least one rotation sensing element is a ring-shaped magnetic element, which is fitted and fixed to the outside of the output head 30. The ring-shaped magnetic element includes different magnetic poles arranged alternately along the circumference. The fixed sensing element corresponding to the ring-shaped magnetic element is a magnetic sensor, which is fixed to the inner wall of the housing 10 and is positioned opposite and spaced apart from the ring-shaped magnetic element. The ring-shaped magnetic element is used to rotate synchronously with the output head 30 and characterizes the rotation position of the output head 30 by the magnetic field characteristics distributed along its circumference. The ring-shaped magnetic element has a central space through which the output head 30 passes and is fitted onto the outer periphery of the output head 30 corresponding to the first position 64 or the second position 65.

[0082] After the annular magnetic component is fixed to the output head 30, there is no relative rotation between them that would affect the rotation angle detection. Different magnetic poles are arranged alternately along the circumference of the annular magnetic component. For example, the annular magnetic component can be provided with a first magnetic pole and a second magnetic pole with opposite magnetic properties along the circumference, and the first magnetic pole and the second magnetic pole can be the N pole and the S pole, respectively.

[0083] As the annular magnetic component rotates with the output head 30, different magnetic poles pass sequentially through the sensing positions corresponding to the magnetic sensor, causing the direction or intensity of the magnetic field sensed by the magnetic sensor to change with the rotation of the annular magnetic component.

[0084] A magnetic sensor is used to convert changes in the magnetic field generated by a ring-shaped magnetic element into an electrical signal. The magnetic sensor is fixed to the inner wall of the housing 10 and remains fixed relative to the housing 10. The sensing area of ​​the magnetic sensor faces the magnetic pole distribution area of ​​the ring-shaped magnetic element, and a detection gap is maintained between the magnetic sensor and the ring-shaped magnetic element so that the ring-shaped magnetic element does not need to make mechanical contact with the magnetic sensor during rotation with the output head 30.

[0085] The output head 30 drives the ring-shaped magnetic component to rotate synchronously. Different magnetic poles pass through the magnetic sensor in sequence, and the magnetic sensor outputs a detection signal that changes with the magnetic field. The main control unit can determine the rotation angle of the output head 30 at the first position 64 or the second position 65 based on the sequence of changes, the number of changes, or the corresponding magnetic field state of the detection signal.

[0086] In some implementations, the magnetic sensor employs a Hall sensor. As different magnetic poles on the ring-shaped magnetic component pass sequentially through the sensing area of ​​the Hall sensor, the magnetic field acting on the Hall sensor changes. The Hall sensor converts the magnetic field change into an electrical signal based on the Hall effect, and the main control unit determines the rotation angle of the output head 30 at the corresponding position based on this electrical signal.

[0087] In other embodiments, a magnetoresistive sensor is used as the magnetic sensor. The resistive characteristics of the magnetoresistive sensor change with the magnetic field acting upon it. As the toroidal magnetic element rotates with the output head 30, different magnetic poles sequentially pass through the sensing area of ​​the magnetoresistive sensor, causing the magnetoresistive sensor to output a detection signal related to the rotational position of the toroidal magnetic element. Hall effect sensors and magnetoresistive sensors are optional and can be used in parallel. Both angle detection components 40 can be Hall sensors or magnetoresistive sensors; alternatively, one angle detection component 40 can be a Hall sensor and the other can be a magnetoresistive sensor, as long as the main control can determine the rotation angle at the first position 64 and the second position 65 based on the detection signals output by the two components.

[0088] In some embodiments, one of the two angle detection components 40 employs a ring-shaped magnetic element and a magnetic sensor, while the other angle detection component 40 employs other non-contact angle detection structures. In other embodiments, both angle detection components 40 employ a ring-shaped magnetic element and a magnetic sensor.

[0089] Please continue reading. Figure 2 In some embodiments, at least one rotation sensor is integrally formed with the output head 30. Specifically, the output head 30 has a ring tooth portion integrally formed with the output head 30, and the ring tooth portion has a plurality of spaced grooves distributed circumferentially. The fixed sensor corresponding to the rotation sensor has a sensing surface facing the grooves and is spaced apart from the grooves.

[0090] The ring tooth portion is integrally formed with the output head 30, meaning that the ring tooth portion is formed as a local structure on the body of the output head 30, without the need for a separate rotating component installed outside the output head 30. This integral forming method reduces the assembly steps of the independent rotation sensing element, eliminates detection errors caused by loose fit or relative rotation between the independent component and the output head, and helps improve the long-term stability and reliability of angle detection. Specifically, a ring tooth portion can be provided on the outer periphery of the output head 30 corresponding to the first position 64 or the second position 65. Multiple grooves are formed on the outer peripheral surface of the ring tooth portion, and the ring tooth portion with multiple grooves constitutes the rotation sensing element.

[0091] Multiple grooves are spaced apart circumferentially along the ring tooth portion. A solid portion of the ring tooth portion is retained between adjacent grooves, creating an alternating pattern of grooved and non-grooved areas along the circumferential direction. When the output head 30 rotates around its own axis, the multiple grooves and non-grooved areas sequentially pass the positions corresponding to the sensing surface of the fixed sensor, enabling the fixed sensor to identify the rotational position of the output head 30 based on the difference in detection signals caused by the grooved and non-grooved areas.

[0092] In some embodiments, multiple grooves are evenly spaced along the circumference of the ring tooth portion, so that adjacent grooves have the same or substantially the same circumferential spacing. Each time the fixed sensor detects a groove passing through the sensing surface, it determines the angle through which the output head 30 has rotated, corresponding to the spacing between adjacent grooves.

[0093] In other embodiments, multiple grooves are distributed at a predetermined non-uniform spacing, so that different grooves or combinations of different grooves form coding features that can characterize the different angular positions of the output head 30. The sensing surface of the fixed sensor faces the outer peripheral area of ​​the groove formed by the ring tooth portion, and a detection gap is maintained between the fixed sensor and the outer peripheral area. The fixed sensor can detect signal changes generated when the groove and adjacent solid parts alternately pass through the sensing surface without directly contacting the ring tooth portion or the groove wall.

[0094] Because the ring gear section and the output head 30 are integrally formed, there is no need to install an additional independent rotor. This avoids the loosening, wobble, or relative slippage between the independent rotor and the output head that may occur during long-term rotation. This ensures that the ring gear section and the output head 30 always maintain a synchronous rotation relationship, which is beneficial for maintaining the accuracy of angle detection. At the same time, the integrally formed ring gear section structure reduces the number of parts and assembly steps, lowers manufacturing costs and assembly tolerance accumulation, and makes the angle detection positions of the output head 30 on both sides of the reduced diameter section 31 have higher coaxiality and consistency, further improving the stability and repeatability of torque detection.

[0095] In some embodiments, the fixed sensing element includes an inductive sensor. The sensing surface of the inductive sensor faces the outer peripheral area of ​​the output head 30, which has multiple grooves. As the grooves and the solid portions between adjacent grooves sequentially pass over the sensing surface, the distance or metal distribution between the groove area and the solid portion relative to the sensing surface differs, causing the detection signal output by the inductive sensor to change. The main control determines the rotation angle of the output head 30 at the corresponding position based on the number of changes, the order of changes, or the timing of changes in the output signal of the inductive sensor.

[0096] In other embodiments, the fixed sensing element includes a magnetoresistive sensor. The sensing surface of the magnetoresistive sensor faces the recessed area on the output head 30. As the recess and adjacent solid portions sequentially pass over the sensing surface, the magnetic field state sensed by the magnetoresistive sensor changes, causing the magnetoresistive sensor to output a detection signal related to the rotational position of the output head 30. The corresponding magnetic field conditions can be configured according to the structure of the angle detection component 40. The magnetoresistive sensor has high sensitivity to changes in the magnetic field and can distinguish small angle changes, which helps to improve the detection resolution of the rotational angle of the output head 30, thereby improving the accuracy of torque calculation.

[0097] One of the two angle detection components 40 may be a rotation sensor integrally formed with the output head 30, while the other angle detection component 40 may employ a different non-contact angle detection structure.

[0098] In some embodiments, both rotation sensors are integrally formed with the output head 30, and multiple circumferentially spaced grooves are formed at the first position 64 and the second position 65 of the output head 30, respectively. The main control unit obtains the rotation angle at the first position 64 and the second position 65 based on the detection signals output by the two fixed sensors. The integral structure of both rotation sensors with the output head 30 eliminates the need for separate rotors at both ends of the output head 30, further reducing the number of parts and assembly errors, and helping to maintain consistency between the two detection positions, thereby improving the accuracy of angle difference detection.

[0099] Please continue reading. Figure 2 In some embodiments, at least one rotation sensor is annular. The rotation sensor has multiple light-transmitting areas and multiple light-blocking areas, which are alternately arranged along the circumference of the rotation sensor. A fixed sensor corresponding to the rotation sensor includes a light-emitting group and a sensing and receiving group, which are respectively disposed on opposite axial sides of the annular rotation sensor.

[0100] A ring-shaped rotation sensor is arranged around the output head 30 and rotates synchronously with the output head 30. The ring-shaped rotation sensor has a central space through which the output head 30 passes and is fixed to the outer periphery of the output head 30 at the corresponding first position 64 or second position 65. When the drive assembly 20 drives the output head 30 to rotate, the ring-shaped rotation sensor rotates with the output head 30 around the axis of the output head 30, so that the light-transmitting area and the light-blocking area disposed thereon pass sequentially between the light-emitting group and the sensing and receiving group.

[0101] The light-transmitting area allows at least a portion of the detection light emitted by the light-emitting group to pass through the rotating sensor and reach the sensing and receiving group, while the light-shielding area blocks or reduces the detection light emitted by the light-emitting group from reaching the sensing and receiving group. The light-transmitting and light-shielding areas are alternately arranged along the circumference of the rotating sensor, so that the rotating sensor forms alternating light-transmitting and light-shielding features along the circumference.

[0102] The light-emitting group emits detection light to the sensing and receiving group, which receives the detection light passing through the rotating sensing element and converts the on / off state or intensity change of the received detection light into an electrical signal. The light-emitting group and the sensing and receiving group are fixed relative to the housing 10 and do not rotate with the output head 30 and the rotating sensing element.

[0103] The light-emitting group and the sensing and receiving group are respectively arranged on both sides of the axial direction of the annular rotating sensor, so that the light-emitting group, the annular rotating sensor, and the sensing and receiving group correspond sequentially along the axial direction of the output head 30. The detection light emitted by the light-emitting group propagates axially towards the sensing and receiving group, and the annular rotating sensor is located in the propagation path of the detection light. The annular rotating sensor is spaced apart from both the light-emitting group and the sensing and receiving group, so that the rotating sensor does not make mechanical contact with the light-emitting group or the sensing and receiving group when it rotates.

[0104] When a light-transmitting area rotates between the light-emitting group and the sensing and receiving group, at least part of the detection light emitted by the light-emitting group passes through the light-transmitting area and is received by the sensing and receiving group. When a light-blocking area rotates between the light-emitting group and the sensing and receiving group, the detection light is blocked or weakened. As the output head 30 continues to rotate, the sensing and receiving group outputs a detection signal that changes as the light-transmitting and light-blocking areas alternately pass through. The main control unit can determine the rotation angle of the output head 30 at the corresponding position based on the number of changes, the order of changes, the timing of changes, or the optical characteristics formed by different light-transmitting areas of the detection signal.

[0105] In some embodiments, multiple light-transmitting areas are evenly spaced along the circumference of the rotation sensor, and a light-blocking area is formed between two adjacent light-transmitting areas.

[0106] In other embodiments, multiple light-transmitting areas are arranged at a preset non-uniform spacing, so that different light-transmitting areas or combinations of different light-transmitting areas form optical features that can distinguish different rotation positions.

[0107] In some embodiments, the light-transmitting area is a slit that passes through the rotation sensor along the axial direction, and the light-shielding area is the solid portion between adjacent slits.

[0108] Multiple slits are spaced apart along the circumference of the annular rotational sensor, with solid material of the rotational sensor remaining between adjacent slits, thus alternating the slits and solid portion along the circumference of the rotational sensor. The slits penetrate both axial surfaces of the rotational sensor. When a slit rotates between the light-emitting group and the sensing and receiving group, at least a portion of the detection light emitted by the light-emitting group passes through the slit axially and reaches the sensing and receiving group.

[0109] When the solid part between adjacent slits rotates between the light-emitting group and the sensing and receiving group, the solid part blocks or weakens the detection light, causing the sensing and receiving group to output a detection signal that is different from the detection signal when the slit passes through.

[0110] In some embodiments, multiple slits are evenly spaced along the circumference of the rotation sensor, such that adjacent slits correspond to the same or substantially the same circumferential angle. The main control unit can determine the number of slits passing the detection position based on the number of changes in the output signal of the sensing receiver group, and determine the rotation amount of the output head 30 based on the circumferential angles corresponding to adjacent slits.

[0111] In other embodiments, multiple slits are distributed at different preset intervals to characterize different angular positions of the rotation sensor through different combinations of slit intervals.

[0112] The aforementioned magnetic detection method, output head body feature detection method, and optical detection method are selectable angle detection methods. The two angle detection components 40 can use the same detection method or different detection methods. Regardless of the method used, the rotation sensor rotates with the corresponding position of the output head 30, and the fixed sensor remains fixed relative to the outer casing 10. The rotation angle of the corresponding position of the output head 30 is obtained through the detection relationship set at intervals with the rotation sensor.

[0113] As can be seen from the above embodiments, this application sets angle detection components 40 at the first position 64 and the second position 65 of the output head 30 respectively, and sets the rotation sensing element and the fixed sensing element at intervals. The main control calculates the torque borne by the output head 30 based on the difference between the rotation angles at the two positions. This realizes non-contact detection of the torsional deformation of the output head 30 during continuous rotation, reduces the risk of contact wear of the angle detection component 40, and helps to reduce the influence of strain gauge adhesion status and temperature changes on the torque detection results, thereby improving the torque detection stability of the intelligent tightening system.

[0114] The control method according to the embodiments of this application is used in the above-mentioned intelligent tightening system. The control method includes: Step S10: Obtain the first rotation angle and the second rotation angle; Step S20: Calculate the angle difference between the first rotation angle and the second rotation angle; Step S30: Calculate the torque borne by the output head of the intelligent tightening system based on the angle difference; Step S40: When the torque meets the preset torque condition, control the output head to stop rotating.

[0115] In step S10, the main control unit acquires the first rotation angle of the output head 30 at the first position 64 and the second rotation angle at the second position 65 through two angle detection components 40. The two angle detection components 40 are respectively disposed at the first position 64 and the second position 65 of the output head 30. Each angle detection component 40 includes a rotation sensor fixed to the output head 30 and a fixed sensor fixed inside the housing 10. The rotation sensor and the fixed sensor are spaced apart to form a non-contact angle detection pair. When the driving component 20 drives the output head 30 to rotate, the two rotation sensors rotate synchronously with the output head 30, and the two fixed sensors respectively sense the rotation position of the corresponding rotation sensor and generate a detection signal related to the rotation angle of the output head 30.

[0116] The main control is electrically connected to two angle detection components 40, and receives the detection signals output by the two angle detection components 40 in real time, thereby obtaining the first rotation angle of the output head 30 at the first position 64 and the second rotation angle at the second position 65. Because non-contact angle detection is used, there is no need to attach strain gauges to the surface of the output head 30, avoiding detection errors caused by differences in the adhesion state of the strain gauges, temperature changes, or long-term rotation. This allows for stable acquisition of the real-time rotation angles at the two positions during the continuous rotation of the output head 30. For example, when the output head 30 is subjected to torque during tightening, the main control synchronously reads the angle signals output by the two angle detection components 40 at a preset sampling frequency to obtain the first rotation angle θ1 and the second rotation angle θ2.

[0117] In step S20, the main control calculates the angle difference between the first and second rotation angles based on the acquired first and second rotation angles. The main control has a built-in processor or control chip capable of performing differential calculations on the received angle signals. When the output head 30 is subjected to torque, a relative rotation angle is generated between the first position 64 and the second position 65 due to torsional deformation. This relative rotation angle is represented by the difference between the first and second rotation angles. By calculating the angle difference, the main control can eliminate the common-mode component of the overall rotation of the output head 30 (e.g., the overall rotation caused by fluctuations in the rotational speed of the drive component 20 or external vibrations), retaining only the relative torsional deformation component caused by torque. This differential calculation method improves the anti-interference capability of torque detection, making the measurement result depend only on the relative deformation between the two positions, and independent of the absolute rotational speed of the output head 30. For example, the main control subtracts the second rotation angle θ2 from the first rotation angle θ1 to obtain the angle difference Δθ = θ1 - θ2, which is the relative torsional angle of the output head 30 between the first position 64 and the second position 65.

[0118] In step S30, the main control unit calculates the torque borne by the output head 30 based on the angle difference obtained in step S20. According to the torsion formula in mechanics of materials, the relative torsion angle between the first position 64 and the second position 65 of the output head 30 is directly proportional to the torque borne. The main control unit pre-stores the correspondence between the angle difference and the torque. This correspondence can be determined based on the structural parameters (such as diameter, length, and moment of inertia of the section) and material properties (such as shear modulus) of the output head 30 between the two positions, or it can be obtained by calibration by applying a known torque to the output head 30. After obtaining the angle difference Δθ, the main control unit calculates the current torque value borne by the output head 30 based on the pre-stored correspondence. Because the design of the reduced diameter section 31 further amplifies the angle difference, it improves the sensitivity of torque detection, enabling the main control unit to distinguish minute torque changes.

[0119] For example, the main control multiplies the angle difference Δθ by a preset scaling factor K to obtain the torque value T=K×Δθ, where K is predetermined based on the structural parameters and material properties of the output head 30.

[0120] In step S40, the main control unit compares the torque value calculated in step S30 with a preset torque condition. The preset torque condition can be a torque threshold, a torque range, or a torque-time curve, and is preset according to the accuracy requirements of the tightening process. When the calculated torque value reaches or meets the preset torque condition, the main control unit outputs a control signal to the drive assembly 20, controlling the drive assembly 20 to stop outputting power, thereby stopping the output head 30 from rotating.

[0121] During the tightening process, the angle detection component 40 near the front end of the output head 30 can simultaneously monitor the tightening angle value of the output head 30 in real time. The main control receives real-time angle signals output by both angle detection components 40, obtains the real-time torque value through differential calculation, and simultaneously obtains the real-time tightening angle value of the output head 30 from the angle detection component 40 near the front end of the output head 30. The main control can have preset torque target value and angle target value, as well as allowable deviation range. During the tightening operation, the main control can continuously compare the real-time torque with the torque target value, and the real-time angle with the angle target value. The judgment logic can adopt one of the following methods: The first judgment method is a two-parameter condition judgment. The first preset target value is the torque target value, and the second preset target value is the angle target value. When the real-time torque reaches the first target value and the real-time angle simultaneously falls within the range of the second target value, the tightening is judged to be complete.

[0122] When the real-time torque reaches the first target value before the real-time angle reaches the second target value range, the main control determines the stopping time based on preset priority logic. For example, the drive component 20 can be kept rotating temporarily until the real-time angle enters the second target value range before stopping.

[0123] When the real-time angle reaches the second target value before the real-time torque reaches the first target value, the main control determines the stopping time based on preset priority logic. For example, it can continue tightening until the real-time torque reaches the range of the first target value before stopping.

[0124] The second judgment method is torque-angle comprehensive curve monitoring. The main control can draw the torque-angle relationship curve in real time and compare it with the preset standard curve. Once the curve deviates beyond the allowable range, the output of the drive component 20 can be automatically adjusted or an alarm signal can be issued.

[0125] When the preset two-parameter conditions are met, the main control sends a stop signal to the drive component 20, and the output head 30 stops rotating.

[0126] An example of a dual-parameter condition is when the torque reaches the target value and the angle is within a reasonable range. This torque-angle dual-parameter closed-loop control method helps compensate for deviations in single torque control caused by factors such as fluctuations in the thread friction coefficient, differences in the hardness of the mating surfaces, or deformation of the gasket. For example, when simply achieving the torque target, the angle may deviate from the set value, resulting in insufficient or overloaded fastener preload. By simultaneously monitoring torque and angle, more comprehensive and precise control of the tightening process can be achieved, thereby helping to ensure the consistency of preload for each fastener in mass production. Furthermore, this dual-parameter data can also be used for quality traceability and process optimization, providing data support for intelligent assembly.

[0127] Since the main control can calculate the real-time torque based on the angle difference and respond in a timely manner through the above-mentioned dual-parameter closed-loop control, it helps to reduce the risk of insufficient tightening or overload damage to fasteners caused by torque detection delay or inaccuracy, and further improves the consistency of tightening quality.

[0128] For example, the preset torque condition is a torque threshold. When the torque value calculated by the main control is greater than or equal to the torque threshold and the real-time angle is within the preset angle range, the main control sends a stop signal to the motor 21 of the drive component 20. The motor 21 stops rotating, and the output head 30 stops rotating accordingly, thus completing the tightening operation.

[0129] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms such as “a,” “an,” etc., used herein may also refer to the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated, unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0130] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0131] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An intelligent tightening system, characterized in that, include: shell; A drive assembly is disposed at one axial end of the housing; An output head is connected to the output end of the drive assembly, and the output head is provided with a first position and a second position spaced apart in the axial direction. Two angle detection components are respectively disposed at the first position and the second position. The two angle detection components are used to detect the first rotation angle of the output head at the first position and the second rotation angle at the second position. Each angle detection component includes a rotation sensor fixed to the output head and a fixed sensor fixed inside the housing. The rotation sensor and the fixed sensor are arranged at intervals. as well as The main control is electrically connected to the two angle detection components. The main control has a built-in torque calculation circuit to calculate the torque borne by the output head based on the difference between the first rotation angle and the second rotation angle.

2. The intelligent tightening system according to claim 1, characterized in that, The output head has a reduced diameter section between the first position and the second position, the diameter of which is smaller than the diameter of the output head at the first position and the second position.

3. The intelligent tightening system according to claim 2, characterized in that, It also includes two support bearings, the inner rings of which are respectively fitted and fixed to the output head and located on both sides of the reduced diameter section, and the outer rings of which are fixed to the inner wall of the housing.

4. The intelligent tightening system according to any one of claims 1-3, characterized in that, The inner wall of the housing and / or the output head are provided with a positioning part, and at least a portion of the angle detection component abuts against the positioning part to define the installation position of the angle detection component in the axial direction.

5. The intelligent tightening system according to claim 4, characterized in that, The angle detection component also includes a mounting housing, which is fixed to the inner wall of the outer shell. The fixed sensor and the rotation sensor are both disposed inside the mounting housing. The mounting housing has a shaft hole for the output head to pass through, and the output head passes through the shaft hole and is fixedly connected to the rotation sensor.

6. The intelligent tightening system according to claim 4, characterized in that, The positioning part is provided on both the inner wall of the housing and the output head. The rotation sensor abuts against the positioning part on the output head to position the rotation sensor at the first position or the second position. The fixed sensor abuts against the positioning part on the inner wall of the housing to limit the axial position of the fixed sensor relative to the rotation sensor within the housing.

7. The intelligent tightening system according to any one of claims 1-3, characterized in that, At least one of the rotation sensing elements is a ring-shaped magnetic element, which is fixedly mounted on the outside of the output head. The ring-shaped magnetic element includes different magnetic poles arranged alternately along the circumference. The fixed sensing element corresponding to the ring-shaped magnetic element is a magnetic sensor, which is fixed to the inner wall of the housing and is opposite to and spaced apart from the ring-shaped magnetic element.

8. The intelligent tightening system according to claim 7, characterized in that, The magnetic sensor includes one of a Hall sensor and a magnetoresistive sensor.

9. The intelligent tightening system according to any one of claims 1-3, characterized in that, At least one of the rotation sensors is integrally formed with the output head. The rotation sensor has a plurality of spaced grooves along its circumferential direction. The fixed sensor corresponding to the rotation sensor has a sensing surface, which faces the grooves and is opposite to and spaced from them.

10. The intelligent tightening system according to claim 9, characterized in that, The fixed sensing element includes one of an inductive sensor and a magnetoresistive sensor.

11. The intelligent tightening system according to any one of claims 1-3, characterized in that, At least one of the rotation sensors is annular in shape, and the rotation sensor is provided with a plurality of light-transmitting areas and light-blocking areas. The plurality of light-transmitting areas and light-blocking areas are alternately arranged along the circumferential direction of the rotation sensor. The fixed sensor corresponding to the rotation sensor includes a light-emitting group and a sensing and receiving group, and the light-emitting group and the sensing and receiving group are respectively arranged on both sides of the axial direction of the annular rotation sensor.

12. The intelligent tightening system according to claim 11, characterized in that, The light-transmitting area is a slit that passes through the rotation sensing element along the axial direction, and the light-shielding area is the solid portion between adjacent slits.

13. A control method, characterized in that, For the intelligent tightening system as described in any one of claims 1-12, the control method includes: Obtain the first rotation angle and the second rotation angle; Calculate the angle difference between the first rotation angle and the second rotation angle; The torque borne by the output head of the intelligent tightening system is calculated based on the angle difference. When the torque meets the preset torque condition, the output head is controlled to stop rotating.

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