Torque coefficient determination method, apparatus and device

Abstract

The application provides a torque coefficient determination method, device and equipment, the method obtains the first pose change and torque of a target point on a target surface; a first fitting relationship is obtained by fitting the relationship between the obtained torque and the first pose change; the second pose change and pre-tightening force of the target point under the scene of applying a constant-increment pre-tightening force field at different loading steps of an assembly model of a to-be-tested part and a connecting part are obtained from simulation software; the pre-tightening force and the second pose change are fitted to obtain a second fitting relationship; based on the first fitting relationship and the second fitting relationship, the values of the torque and the pre-tightening force corresponding to each target point under the same pose change are found out, so as to determine the torque coefficient of the to-be-tested part based on the values. It can be seen that the technical solution provided in the embodiment can more accurately control the accuracy of the pre-tightening force, thereby improving the measurement accuracy of the precision instrument.

Description

Technical Field

[0001] This application relates to precision measurement technology, and in particular to a method, apparatus and equipment for determining torque coefficient. Background Technology

[0002] With the increasing demands for precision and stability in aviation, aerospace, military, and medical fields, higher requirements are being placed on the connection quality of mechanical products, making the task of improving the precision and stability of precision instruments increasingly urgent. Among these, threaded connections have become the most widely used connection method due to their ability to achieve high connecting forces, ease of assembly and disassembly, ease of mass production through standardization of the test parts, low connection costs, inexpensive test parts, and interchangeability. The quality of threaded connections directly affects the assembly quality and reliability of the entire product. From an economic perspective, while the value of threaded fasteners themselves is low, the products they connect are typically expensive. When a threaded connection fails due to quality issues, damage is not limited to the threaded fastener itself, but extends to the entire product.

[0003] Currently, the torque method is used in existing technologies to control the preload of screw connections. This method is simple to operate, flexible in application, and low in process cost, making it the most widely used screw tightening method. During the tightening process, this method indirectly controls the preload by controlling the torque, i.e., T = KdF, where T is the torque; K is the torque coefficient; d is the nominal diameter of the screw; and F is the preload of the screw. However, when using precision instruments or other high-precision equipment, and precise control of the preload is required, the empirical value of K is clearly insufficient to meet the actual engineering needs due to various uncertainties such as materials, temperature, and lubrication conditions. Therefore, poor measurement accuracy of precision instruments is caused by inadequate control of the preload. Summary of the Invention

[0004] This application provides a method, apparatus, and equipment for determining torque coefficient, in order to improve the measurement accuracy of precision instruments.

[0005] In a first aspect, embodiments of this application provide a method for determining a torque coefficient, applied to an electronic device, the method comprising:

[0006] During the assembly process of the connector used for assembling with the test part (PT), the first pose change and torque of a target point on the target surface are obtained each time a preset value of torque is added to the PT; wherein, the target surface is the surface that is in contact with the PT but is not completely covered by the PT; the target point is all the target surface points around the center of the PT; the target surface point is the point on the target surface that is close to the center of the PT and is not completely covered by the PT.

[0007] The relationship between the torque and the first pose change is fitted to obtain a first fitting equation;

[0008] The second pose change and preload of the target point are obtained from the assembly model of the test part and the connector under different loading steps and constant incremental preload scenarios.

[0009] The preload force and the second pose change are fitted to obtain a second fitting relationship;

[0010] Based on the first fitting relationship and the second fitting relationship, the values ​​of torque and preload corresponding to each target point under the same pose change are found, so as to determine the torque coefficient of the test piece based on the values.

[0011] Secondly, embodiments of this application provide a torque coefficient determining device, applied to an electronic device, the device comprising:

[0012] The pose torque acquisition unit is used to acquire the first pose change and torque of a target point on a target surface during the assembly process of a connector used for assembling with the test part, each time a preset value of torque is added to the test part; wherein, the target surface is the surface that is in contact with the test part but is not completely covered by the test part; the target point is all target surface points on the target surface that are closest to the center of the test part around the perimeter; the target surface point is a point on the target surface that is close to the center of the test part and is not completely covered by the test part.

[0013] The first relationship obtaining unit is used to fit the relationship between the torque and the first pose change to obtain the first fitting relationship;

[0014] The pose preload acquisition unit is used to acquire the second pose change and preload of the target point from the simulation software under different loading steps when a fixed incremental preload is applied to the assembly model of the test part and the connector.

[0015] The second relationship obtaining unit is used to fit the preload and second pose changes to obtain the second fitting relationship;

[0016] The torque coefficient determination unit is used to find the values ​​of torque and preload corresponding to each target point under the same pose change based on the first fitting relationship and the second fitting relationship, so as to determine the torque coefficient of the test piece based on the values.

[0017] As can be seen from the above technical solution, in this application, the first pose change and torque of the target point on the target surface are obtained; the relationship between the obtained torque and the first pose change is fitted to obtain a first fitting relationship; the second pose change and preload of the target point are obtained from the simulation software under different loading steps and constant incremental preload scenarios for the assembly model of the test part and the connector; the preload and the second pose change are fitted to obtain a second fitting relationship; based on the first fitting relationship and the second fitting relationship, the values ​​of torque and preload corresponding to each target point under the same pose change are found, and the torque coefficient of the test part is determined based on the values. It is evident that the torque coefficient determined by the technical solution provided in this embodiment no longer relies on empirical values, but is determined based on the actual assembly. Therefore, when facing precision instruments or other high-precision instruments that require indirect control of preload through torque control, the accuracy of the preload can be controlled more precisely, thereby improving the measurement accuracy of precision instruments. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0019] Figure 1 A flowchart illustrating a method for determining the torque coefficient provided in this application;

[0020] Figure 2(a) is a schematic diagram of the fitting curve of the relationship between torque and first position change provided in this application;

[0021] Figure 2(b) is a schematic diagram of the fitting curve of preload and second pose change provided in this application;

[0022] Figure 3 A schematic diagram of a precision measuring instrument provided in this application measuring the assembly of a workpiece and a connector;

[0023] Figure 4 A layout diagram of point cloud data for a target surface provided in this application;

[0024] Figure 5(a) is a schematic diagram of a first connecting mold provided in this application;

[0025] Figure 5(b) is a schematic diagram of a second connector mold provided in this application.

[0026] Figure 6 A schematic diagram of a torque coefficient determination device provided in this application;

[0027] Figure 7 This is a schematic diagram of the structure of an electronic device provided in this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] See Figure 1 , Figure 1 A flowchart of a torque coefficient determination method provided in this application embodiment, the method being applied to an electronic device, the method comprising the following steps:

[0030] Step 101: Obtain the first pose change and torque of the target point on the target surface when a preset value of torque is added to the test piece during the assembly process of the connector used for assembling with the test piece.

[0031] Wherein, the target surface is the surface that is in contact with the test piece but is not completely covered by the test piece; the target point is all the target surface points on the target surface that are closest to the center of the test piece; the target surface point is the point on the target surface that is close to the center of the test piece and is not completely covered by the test piece.

[0032] In this embodiment, the first pose change is named only to distinguish it from the pose changes mentioned later, and is not used to limit a specific pose change.

[0033] In this embodiment, the test piece and the connector are in an assembly relationship, such as the assembly relationship between a connector with a threaded hole and a screw, or the assembly relationship between a double-headed bolt and a connector.

[0034] The preset value is the torque force applied once during the assembly process of the connector and the test piece. For example, during the assembly process of a connector with a threaded hole and a screw, each time a force of a N·m is added to the connector, the pose change of the target point on the target surface in the connector is measured, and the torque is the cumulative force value of each torque force at different times.

[0035] As an example, when assembling the test piece and the connector, a torque wrench is used to gradually increase the torque force. At the same time, for each increase of a certain amount of torque force, a precision measuring instrument is used to detect the change in the pose of the target surface point.

[0036] Step 102: Fit the relationship between the torque and the first pose change to obtain the first fitting relationship.

[0037] As an example, after step 102, the method further includes:

[0038] Select a first target point from the first fitting relationship so that the stress state of the component to be tested at the first target point is a first preset value of the maximum yield strength that the component to be tested can withstand.

[0039] Select a second target point from the first fitting relationship so that the stress state of the component to be measured at the second target point is a second preset value of the yield strength of the component to be measured.

[0040] Calculate the difference between the horizontal and vertical coordinates of the first target point and the second target point, and use the difference between the horizontal and vertical coordinates to eliminate the influence of the assembly surface error.

[0041] In this embodiment, the first fitting relationship is shown in Figure 2(a). In Figure 2(a), ΔL represents the absolute value of the Z-axis coordinate of a target point relative to the initial Z-coordinate value, T represents the torque value of the test piece, and the coordinate point (T1, ΔL1) represents the absolute value of the Z-axis coordinate of the first target point relative to the initial Z-coordinate value when the torque value of the test piece is T1. The stress strength of the test piece in the T1 state is the first preset value of the yield strength of the test piece. As is common knowledge in the art, this first preset value can be taken as 70% to 80% to eliminate the influence of assembly surface error. The coordinate point (T2, ΔL2) represents the absolute value of the Z-axis coordinate of the second target point relative to the initial Z-coordinate value when the torque value of the test piece is T2. The stress strength of the test piece in the T2 state is the second preset value of the yield strength of the test piece. Through a large number of experiments, it has been verified that when the stress state of the test piece reaches 30% of the yield strength of the test piece and thereafter, the deformation of the assembly surface remains unchanged. Based on this, the second preset value is 30% to 40%.

[0042] Step 103: Obtain from the simulation software the second pose change and preload of the target point under different loading steps when a fixed increment bN preload is applied to the assembly model of the test part and the connector.

[0043] In this embodiment, the simulation software can be either ANSYS or ADAMS; this embodiment is not limited to either.

[0044] As an example, the assembly model of the component under test and the connector can be completed in advance in drawing software. Then, the assembly model is saved in a format that the simulation software can recognize. After that, the assembly model is imported into the simulation software for further analysis. This example utilizes the powerful drawing functions of the drawing software combined with the analytical capabilities of the simulation software. This not only compensates for the drawing function of the simulation software but also leverages its simulation analysis capabilities, making the analysis more accurate.

[0045] As another example, the assembly model of the test piece and the connector is drawn in simulation software.

[0046] Step 104: Fit the preload and the second pose change to obtain a second fitting relationship.

[0047] Here, the term "second pose change" is used for ease of description and is not intended to limit a specific pose change.

[0048] The second fitting relationship is shown in Figure 2(b). In Figure 2(b), ΔL represents the absolute value of the Z-axis coordinate of the third target point relative to the initial Z-axis coordinate, F represents the preload value of the test piece, and the coordinate point (F1, ΔL1) represents the absolute value of the Z-axis coordinate of the third target point relative to the initial Z-axis coordinate when the preload value of the test piece is F1; the coordinate point (F2, ΔL2) represents the absolute value of the Z-axis coordinate of the fourth target point relative to the initial Z-axis coordinate when the preload value of the test piece is F2.

[0049] Step 105: Based on the first fitting relationship and the second fitting relationship, find the values ​​of torque and preload corresponding to each target point under the same pose change, and determine the torque coefficient of the test piece based on the values.

[0050] Based on the first and second fitting relationships, the values ​​of torque and preload corresponding to each target point under the same pose change are found, i.e., T = T1 - T2 ~ ΔL1 - ΔL2 ~ F = F1 - F2. As an example, the torque coefficient K of the test piece is determined using this value according to the formula T = KdF.

[0051] As an example, the specific implementation of determining the torque coefficient of the test piece based on the numerical value in step 105 includes the following steps: taking the average value of the numerical value and using the average value as the torque coefficient of the test piece.

[0052] In this embodiment, after determining the torque T, preload F and the nominal diameter of the test piece, the K value corresponding to each point is calculated using the formula T = KdF, such as K1, K2, ..., Km, where m is the number of target surface points, and the average value of K1, K2, ..., Km is calculated.

[0053] As another embodiment, the specific implementation of determining the torque coefficient of the test piece based on the numerical value in step 105 includes the following steps: denoising the numerical value, taking the average value of the processed numerical value, and using the average value as the torque coefficient of the test piece.

[0054] In this embodiment, after determining the torque T, warning force F, and nominal diameter of the test piece, the K value corresponding to each point is calculated using the formula T = KdF, such as K1, K2, ..., Km, where m is the number of target surface points. The discrete values ​​corresponding to K1, K2, ..., Km are calculated, and K values ​​with discrete values ​​greater than the threshold are removed. For example, if the value to be removed is Km, then the mean of K1, K2, ..., Km-1 is calculated.

[0055] This concludes the process. Figure 1 The description shown.

[0056] Therefore, the technical solution provided in this embodiment involves obtaining the first pose change and torque of a target point on the target surface; fitting the obtained torque with the first pose change to obtain a first fitting relationship; obtaining the second pose change and preload of the target point from simulation software under different loading steps and incremental preload scenarios for the assembly model of the test part and connector; fitting the preload and second pose change to obtain a second fitting relationship; and finding the values ​​of torque and preload corresponding to each target point under the same pose change, based on the values, to determine the torque coefficient of the test part. It is evident that the torque coefficient determined by the technical solution provided in this embodiment no longer relies on empirical values, but is determined based on the actual assembly. This allows for more accurate control of the preload by controlling torque in precision instruments or other high-precision instruments, thereby improving the measurement accuracy of precision instruments.

[0057] After completing the above Figure 1 Following the flowchart, as an example, before step 101, the method includes steps A to B:

[0058] Step A: Obtain point cloud data of the assembly surfaces between the connectors used for assembly with the test piece and point cloud data of the set target surface; the target surface points are the points on the target surface that are close to the center of the test piece and are not completely covered by the test piece.

[0059] Before installing the device under test and the connectors, such as Figure 3 As shown, the part under test 2 is assembled through the first connector 4 and the second connector 6, and is mounted on the worktable 8 of the precision measuring instrument 1 by a fixing fixture 7. The precision measuring instrument measures the point cloud data of the assembly surface 5 between the first connector 4 and the second connector 6 assembled with the part under test 2, and the point cloud data on the target surface 3 of the first connector 4. The point cloud data format can be (X1,Y1,Z1), (X2,Y2,Z2), ..., (Xm,Ym,Zm), where m is the sorting of the data in the point cloud data. It should be noted that the first connector is only named for ease of distinction from the connectors mentioned later, and is not used to limit a specific connector. Here, the second connector is also only named for ease of description, and is not used to limit a specific connector.

[0060] Step B: Based on the acquired point cloud data, draw the assembly model of the test part and the connector in the preset drawing software, and then input the assembly model into the simulation software.

[0061] The drawing software mentioned above can be CAD, PROE or UG. This embodiment does not limit this. Taking CAD as an example, the point cloud data measured in step A is reconstructed in the CAD software. The specific implementation method is as follows: First, the point cloud data is fitted using the NURBS surface modeling method. Then, the fitted surface is attached to the ideal model. Finally, the connection between the two test pieces is realized in the CAD software under stress-free conditions using the test piece.

[0062] As one embodiment, the target points are points on the target surface that are circumferentially distributed from the center of the workpiece under test and are arranged in a radially identical array, with at least three radial points. In some embodiments, the workpiece under test is a screw, and the target points are all points on the target surface closest to the center of the screw cap. See details. Figure 4 As shown, Figure 4 All points around the center of the screw cap, i.e. Figure 4 At the location indicated by the middle arrow.

[0063] In practical applications, using actual connectors to measure the torque coefficient of the test piece may be difficult due to the high cost of the connectors and their unsuitability for dedicated measurement. Therefore, as an embodiment, the connector uses a connector mold, which includes a first connector mold and a second connector mold. The surfaces of the first and second connector molds are designed according to the surface of the connector in actual working conditions, and the materials of the first and second connector molds are the same as those of the connector in the actual assembly.

[0064] The first connecting mold satisfies the first relationship shown in Figure 5(a): Where D1 is the diameter of the first connecting mold, n is the number of parts to be tested in the actual assembly formed by the part to be tested and the connecting parts, S is the effective contact area of ​​the connecting parts corresponding to the first connecting mold and the connecting parts corresponding to the second connecting mold in the actual assembly; H1 in Figure 5(a) is the force-bearing height of the connecting parts corresponding to the first connecting mold in the actual assembly.

[0065] The second connector mold satisfies the second relationship shown in Figure 5(b): H2 = L + d, and D2 is greater than D1, where H2 is the height of the second connector mold, L is the depth of the threaded hole in the second connector mold, d is the nominal diameter of the part to be tested, and D2 is the diameter of the second connector mold.

[0066] The first connector mold is the mold that simulates the first connector as shown in Figure 2, and the second connector mold is the mold that simulates the second connector as shown in Figure 2, so that the corresponding molds can be used to simulate the assembly of the actual connector and the part to be tested.

[0067] Figure 6 This is a structural diagram of an apparatus for a torque coefficient determination method 300 provided in this embodiment. Applied to electronic devices, the apparatus includes:

[0068] The pose torque acquisition unit 301 is used to acquire the first pose change and torque of a target point on the target surface during the assembly process of the connector used for assembling with the test part, each time a preset value of torque force is added to the test part; wherein, the target surface is the surface that is in contact with the test part but is not completely covered by the test part; the target point is all the target surface points around the center of the test part on the target surface; the target surface point is the point on the target surface that is close to the center of the test part and is not completely covered by the test part;

[0069] The first relationship obtaining unit 302 is used to fit the relationship between the torque and the first pose change to obtain the first fitting relationship;

[0070] The pose preload acquisition unit 303 is used to acquire from the simulation software the second pose change and preload of the target point under different loading steps when a fixed incremental preload is applied to the assembly model of the assembly of the test part and the connector.

[0071] The second relationship obtaining unit 304 is used to fit the preload and the second pose change to obtain the second fitting relationship;

[0072] The torque coefficient determination unit 305 is used to find the values ​​of torque and preload corresponding to each target point under the same pose change based on the first fitting relationship and the second fitting relationship, so as to determine the torque coefficient of the test piece based on the values.

[0073] As one embodiment, the device further includes:

[0074] The point cloud data acquisition unit is used to acquire point cloud data of the assembly surface between each connector used for assembly with the part under test and point cloud data on a set target surface; the target surface point is the point on the target surface that is close to the center of the part under test and is not completely covered by the part under test.

[0075] The assembly model drawing unit is used to draw the assembly model of the test part and the connector in a preset drawing software based on the acquired point cloud data, so as to input the assembly model into the simulation software.

[0076] As an example, the target surface points are the points on the target surface that are distributed circumferentially from the center of the test piece and have the same radial array, with at least 3 radial points.

[0077] As one embodiment, the connector is made of a connector mold, which includes a first connector mold and a second connector mold; the surfaces of the first connector mold and the second connector mold are designed according to the surface of the connector in actual working conditions, and the materials of the first connector mold and the second connector mold are the same as the materials of the connector in the actual assembly.

[0078] The first connector mold satisfies the first relation: Where D1 is the diameter of the first connecting mold, n is the number of parts to be tested in the actual assembly formed by the part to be tested and the connecting parts, S is the effective contact area of ​​the connecting parts corresponding to the first connecting mold and the connecting parts corresponding to the second connecting mold in the actual assembly, and the height of the first connecting mold is the force-bearing height of the connecting parts corresponding to the first connecting mold in the actual assembly.

[0079] The second connector mold satisfies the second relationship: H2 = L + d, and D2 is greater than D1, where H2 is the height of the second connector mold, L is the depth of the threaded hole in the second connector mold, d is the nominal diameter of the part to be tested, and D2 is the diameter of the second connector mold.

[0080] As an example, the test piece is a screw, and the target points are all points on the target surface that are closest to the center of the screw cap.

[0081] As one embodiment, the device further includes: an error elimination unit, used for:

[0082] Select a first target point from the first fitting relationship so that the stress state of the component to be tested at the first target point is a first preset value of the maximum yield strength that the component to be tested can withstand.

[0083] Select a second target point from the first fitting relationship so that the stress state of the component to be measured at the second target point is a second preset value of the yield strength of the component to be measured.

[0084] Calculate the difference between the horizontal and vertical coordinates of the first target point and the second target point, and use the difference between the horizontal and vertical coordinates to eliminate the influence of the assembly surface error.

[0085] Therefore, the technical solution provided in this application involves obtaining the first pose change and torque of a target point on the target surface; fitting the obtained torque with the first pose change to obtain a first fitting relationship; obtaining the second pose change and preload of the target point from simulation software under different loading steps and incremental preload scenarios for the assembly model of the test part and connector; fitting the preload and second pose change to obtain a second fitting relationship; and finding the torque and preload values ​​corresponding to each target point under the same pose change, based on the first and second fitting relationships, to determine the torque coefficient of the test part. It is evident that the torque coefficient determined by the technical solution provided in this embodiment no longer relies on empirical values, but is determined based on the actual assembly. This allows for more accurate control of the preload by controlling torque in precision instruments or other high-precision instruments, thereby improving the measurement accuracy of precision instruments.

[0086] The specific implementation process of the functions and roles of each unit in the above device can be found in the implementation process of the corresponding steps in the above method, and will not be repeated here.

[0087] The electronic device provided in this application, from a hardware perspective, can be found in the hardware architecture diagram. Figure 7 As shown, it includes a machine-readable storage medium and a processor, wherein: the machine-readable storage medium stores machine-executable instructions that can be executed by the processor; the processor is used to execute the machine-executable instructions to implement the torque coefficient determination operation disclosed in the above example.

[0088] The machine-readable storage medium provided in this application embodiment stores machine-executable instructions. When the machine-executable instructions are invoked and executed by a processor, the machine-executable instructions cause the processor to perform the torque coefficient determination operation disclosed in the above example.

[0089] Here, a machine-readable storage medium can be any electronic, magnetic, optical, or other physical storage device that can contain or store information, such as executable instructions, data, etc. For example, a machine-readable storage medium can be: RAM (Random Access Memory), volatile memory, non-volatile memory, flash memory, storage drives (such as hard disk drives), solid-state drives, any type of storage disk (such as optical discs, DVDs, etc.), or similar storage media, or combinations thereof.

[0090] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0091] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0092] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, embodiments of this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0093] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0094] Furthermore, these computer program instructions can also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in the process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0095] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0096] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the torque coefficient, characterized in that, Applied to electronic devices, the method includes: During the assembly process of the connector used for assembling with the test part (PT), the first pose change and torque of a target point on a target surface are obtained each time a preset value of torque is added to the PT; wherein, the target surface is the surface that is in contact with the PT but is not completely covered by the PT; the target point is all target surface points around the center of the PT closest to the center of the PT on the target surface; the target surface point is a point on the target surface that is close to the center of the PT and is not completely covered by the PT. The relationship between the torque and the first pose change is fitted to obtain a first fitting equation; The second pose change and preload of the target point are obtained from the assembly model of the test part and the connector under different loading steps and constant incremental preload scenarios. The preload force and the second pose change are fitted to obtain a second fitting relationship; Based on the first fitting relationship and the second fitting relationship, the values ​​of torque and preload corresponding to each target point under the same pose change are found, so as to determine the torque coefficient of the test piece based on the values.

2. The method according to claim 1, characterized in that, Before obtaining the first pose change and torque of the target point on the target surface when a preset value of torque is added to the test piece during the assembly process of the connector used for assembling with the test piece, the method further includes: Acquire point cloud data of the assembly surfaces between the connectors used for assembling with the part under test and point cloud data of the set target surface; the target surface points are the points on the target surface that are close to the center of the part under test and are not completely covered by the part under test. Based on the acquired point cloud data, an assembly model of the test part and the connector is drawn in a preset drawing software, and then the assembly model is input into the simulation software.

3. The method according to claim 1, characterized in that, The target surface points are the points on the target surface that are distributed circumferentially from the center of the test piece and have the same radial array, with at least 3 radial points.

4. The method according to claim 3, characterized in that, The part to be tested is a screw, and the target points are all points on the target surface that are closest to the center of the screw cap.

5. The method according to claim 1, characterized in that, The connector is made using a connector mold, which includes a first connector mold and a second connector mold. The surfaces of the first connector mold and the second connector mold are designed according to the surface of the connector in actual working conditions. The materials of the first connector mold and the second connector mold are the same as the materials of the connector in the actual assembly. The first connecting mold satisfies the first relationship: D1= Where D1 is the diameter of the first connecting mold, n is the number of parts to be tested in the actual assembly formed by the part to be tested and the connecting parts, S is the effective contact area of ​​the connecting parts corresponding to the first connecting mold and the connecting parts corresponding to the second connecting mold in the actual assembly; the height of the first connecting mold is the force-bearing height of the connecting parts corresponding to the first connecting mold in the actual assembly. The second connector mold satisfies the second relationship: H2=L+d, and D2 is greater than D1, where H2 is the height of the second connector mold, L is the depth of the threaded hole in the second connector mold, d is the nominal diameter of the part to be tested, and D2 is the diameter of the second connector mold.

6. The method according to any one of claims 1 to 5, characterized in that, Determining the torque coefficient of the test piece based on the numerical value includes: The average of the values ​​is taken and used as the torque coefficient of the test piece; or The numerical values ​​are denoised, and the average value of the processed values ​​is taken as the torque coefficient of the test piece.

7. The method according to claim 1, characterized in that, After fitting the relationship between the torque and the first pose change to obtain a first fitting expression, the method further includes: Select a first target point from the first fitting relationship so that the stress state of the component to be tested at the first target point is a first preset value of the maximum yield strength that the component to be tested can withstand. Select a second target point from the first fitting relationship so that the stress state of the component to be measured at the second target point is a second preset value of the yield strength of the component to be measured. Calculate the differences in horizontal and vertical coordinates between the first target point and the second target point, and use these differences to eliminate the influence of errors on the assembly surface.

8. A torque coefficient determining device, characterized in that, Applied to electronic devices, the device includes: The pose torque acquisition unit is used to acquire the first pose change and torque of a target point on a target surface during the assembly process of a connector used for assembling with the test part, each time a preset value of torque force is added to the test part; wherein, the target surface is the surface that is in contact with the test part but is not completely covered by the test part; the target point is all target surface points on the target surface that are closest to the center of the test part around the perimeter; the target surface point is a point on the target surface that is close to the center of the test part and is not completely covered by the test part. The first relationship obtaining unit is used to fit the relationship between the torque and the first pose change to obtain the first fitting relationship; The pose preload acquisition unit is used to acquire the second pose change and preload of the target point from the simulation software under different loading steps when a fixed incremental preload is applied to the assembly model of the test part and the connector. The second relationship obtaining unit is used to fit the preload and second pose changes to obtain the second fitting relationship; The torque coefficient determination unit is used to find the values ​​of torque and preload corresponding to each target point under the same pose change based on the first fitting relationship and the second fitting relationship, so as to determine the torque coefficient of the test piece based on the values.

9. The apparatus according to claim 8, characterized in that, The connector is made using a connector mold, which includes a first connector mold and a second connector mold. The surfaces of the first connector mold and the second connector mold are designed according to the surface of the connector in actual working conditions. The materials of the first connector mold and the second connector mold are the same as the materials of the connector in the actual assembly. The first connecting mold satisfies the first relationship: D1= Where D1 is the diameter of the first connecting mold, n is the number of parts to be tested in the actual assembly formed by the part to be tested and the connecting parts, S is the effective contact area of ​​the connecting parts corresponding to the first connecting mold and the connecting parts corresponding to the second connecting mold in the actual assembly; the height of the first connecting mold is the force-bearing height of the connecting parts corresponding to the first connecting mold in the actual assembly. The second connector mold satisfies the second relationship: H2=L+d, and D2 is greater than D1, where H2 is the height of the second connector mold, L is the depth of the threaded hole in the second connector mold, d is the nominal diameter of the part to be tested, and D2 is the diameter of the second connector mold.

10. An electronic device, characterized in that, The method includes a processor and a machine-readable storage medium storing machine-executable instructions that can be executed by the processor; the processor is configured to execute the machine-executable instructions to implement the steps of the method as claimed in any one of claims 1 to 7.

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