Bolt Preloading Force Application Method, Device, Equipment and Storage Medium

Abstract

The present invention discloses a method, device, equipment and computer-readable storage medium for applying bolt pre-tightening force, which relates to the technical field of bolt-connected mechanical structures. The method includes applying a preset tensile force determined in advance to the bolt by using a stretcher; when the bolt is in a tensile state under the action of the preset tensile force, performing a screwing and tightening operation on the nut corresponding to the bolt; controlling the stretcher to unload the preset tensile force applied to the bolt; wherein, the preset tensile force is the tensile force applied to the bolt during the corresponding pre-tightening process when the residual pre-tightening force after the bolt is pre-tightened reaches the required pre-tightening force as the preset tensile force. In this application, the pre-tightening process of the bolt is simulated in advance, so as to determine the magnitude of the tensile force during the pre-tightening process corresponding to the condition that the residual pre-tightening force of the bolt is greater than the required pre-tightening force, and the bolt is pre-tightened with this, which is beneficial to ensuring the safety and reliability of high-strength bolts connecting various mechanical components and equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical connection structures, and particularly to a method, device, equipment and computer-readable storage medium for applying bolt pre-tightening force. Background Art

[0002] Bolts are commonly used connection and fixing components in various mechanical structures. For example, when applied to key parts of equipment such as large wind turbines, high-strength bolts are mostly required for connection; and in order to ensure the reliability of the bolt connection surface, the bolt can be pre-tightened so that the bolt has a certain pre-tightening force and enhances the connection strength of the bolt. However, when the pre-tightening force applied to the bolt is insufficient, problems such as slippage of the bolt connection surface and opening near the bolt hole may occur. When the bolt is applied to equipment such as wind turbines, it will obviously have a certain impact on the normal operation of the wind turbine, and in severe cases, it may even endanger the operation safety of the wind turbine, thereby causing significant economic losses. Therefore, how to ensure that the pre-tightening force of the bolt meets the requirements of high-strength fixed connection is one of the key issues that need to be focused on in the industry. Summary of the Invention

[0003] The purpose of the present invention is to provide a method, device, equipment and computer-readable storage medium for applying bolt pre-tightening force, which can improve the reliability and effectiveness of the pre-tightening force applied to the bolt to a certain extent, and ensure the fixed connection strength and safety of the bolt.

[0004] To solve the above technical problems, the present invention provides a method for applying bolt pre-tightening force, including:

[0005] Applying a preset tensile force determined in advance to the bolt by a stretcher;

[0006] When the bolt is in a tensile state under the action of the preset tensile force, performing a screwing and tightening operation on the nut corresponding to the bolt;

[0007] Controlling the stretcher to unload the preset tensile force applied to the bolt;

[0008] Among them, the process of determining the preset tensile force in advance includes:

[0009] Simulating the process of applying the bolt pre-tightening force, and determining the corresponding tensile force as the preset tensile force when the residual pre-tightening force of the bolt after pre-tightening reaches the required pre-tightening force.

[0010] In an optional embodiment of the present application, the process of simulating the process of applying the bolt pre-tightening force includes:

[0011] Establish a three-dimensional model of the bolt, the stretcher, and the structural components connected by the bolt, and perform finite element mesh division of hexahedral meshes on the three-dimensional model to obtain a three-dimensional finite element mesh model;

[0012] Simulate the process of applying tensile forces with the same magnitude and opposite directions to the two surfaces where the prosthetic bolt and the prosthetic stretcher in the three-dimensional finite element network model are in contact with each other, so as to complete the simulation of the bolt stretching stage of the bolt;

[0013] Simulate the process of keeping the tensile forces on the surfaces of the prosthetic bolt and the prosthetic stretcher unchanged and applying a torsional moment to the surface of the prosthetic nut in the three-dimensional finite element mesh model, so as to complete the simulation of the nut screwing stage;

[0014] Simulate the process of unloading the tensile forces applied to the prosthetic bolt and the prosthetic stretcher and unloading the torsional moment applied to the surface of the prosthetic nut, so as to complete the simulation of the unloading and preloading stage;

[0015] Determine the residual pre-tightening force of the prosthetic bolt in the unloading and preloading stage through finite element solution.

[0016] In an optional embodiment of the present application, the simulation of the bolt stretching stage includes:

[0017] During the process of applying tensile forces to the prosthetic bolt and the prosthetic stretcher, if the magnitude of the pre-tightening force on the cross-section of the prosthetic bolt output by the simulation reaches the magnitude of the tensile force, the simulation process of the bolt stretching stage is completed;

[0018] The simulation of the nut screwing stage includes:

[0019] Simulate the process of applying a torsional moment to the surface of the prosthetic nut, and output the contact pressure in the normal direction of the surface where the prosthetic nut and the prosthetic structural components are in contact through finite element solution;

[0020] When the magnitude of the contact pressure reaches the preset pressure, the simulation of the nut screwing stage is completed.

[0021] In an optional embodiment of the present application, when the residual pre-tightening force of the prosthetic bolt in the unloading and preloading stage is less than the required pre-tightening force, set a new tensile force, and repeat the operation steps of simulating the process of applying tensile forces with the same magnitude and opposite directions to the two surfaces where the prosthetic bolt and the prosthetic stretcher in the three-dimensional finite element network model are in contact with each other, so as to complete the simulation of the bolt stretching stage of the bolt, until the preset tensile force corresponding to the residual pre-tightening force not less than the required pre-tightening force is determined.

[0022] In an alternative embodiment of the present application, the process of establishing the three-dimensional model of the bolt includes:

[0023] Establish a three-dimensional model of the bolt that includes at least one of the thread profile information, pitch information, and lead angle information of the bolt.

[0024] In an alternative embodiment of the present application, the structural components connected by the bolt include a pitch bearing in a wind turbine, a tooling connected to the pitch bearing, an embedded bushing, a spacer, a gasket, a nut, and a tensioner;

[0025] Establishing the three-dimensional models of the bolt, the tensioner, and the structural components connected by the bolt includes:

[0026] Establish a three-dimensional model of a three-dimensional structure that is connected to each other by the bolt and the nut and includes the pitch bearing, the tooling, the embedded bushing, the spacer, the gasket, the nut, and the tensioner.

[0027] A bolt pre-tightening force applying device includes:

[0028] A pre-tightening simulation module for pre-simulating the process of applying the bolt pre-tightening force and determining, when the residual pre-tightening force after the bolt is driven and pre-tightened reaches the required pre-tightening force, the tensile force applied to the bolt during the corresponding driving and pre-tightening process as the preset tensile force;

[0029] A pre-tightening driving module for applying the preset tensile force determined in advance to the bolt by using a tensioner;

[0030] A nut screwing module for screwing and tightening the nut corresponding to the bolt when the bolt is in a tensile state under the action of the preset tensile force;

[0031] An unloading pre-tightening module for controlling the tensioner to unload the preset tensile force applied to the bolt.

[0032] In an alternative embodiment of the present application, the pre-tightening simulation module specifically includes:

[0033] A modeling unit for establishing the three-dimensional models of the bolt, the tensioner, and the structural components connected by the bolt, and performing finite element mesh division of hexahedron meshes on the three-dimensional models to obtain a three-dimensional finite element mesh model;

[0034] A first simulation unit for simulating the process of applying tensile forces with the same magnitude and opposite directions to two surfaces where the prosthetic bolt and the prosthetic tensioner are in contact with each other in the three-dimensional finite element network model, so as to complete the simulation of the bolt stretching stage of the bolt;

[0035] A second simulation unit, configured to simulate the process of keeping the tensile force on the surfaces of the prosthesis bolt and the prosthesis stretcher unchanged and applying a torsional moment to the surface of the prosthesis nut in the three-dimensional finite element mesh model, so as to complete the simulation of the nut screwing stage;

[0036] A third simulation unit, configured to simulate the process of unloading the tensile force applied to the prosthesis bolt and the prosthesis stretcher and unloading the torsional moment applied to the surface of the prosthesis nut, so as to complete the simulation of the unloading and preloading stage;

[0037] A residual pre-tightening force determination unit, configured to determine the residual pre-tightening force of the prosthesis bolt in the unloading and preloading stage through finite element solution.

[0038] A bolt pre-tightening force application device, comprising:

[0039] A memory, configured to store a computer program;

[0040] A processor, configured to execute the computer program to implement the operation steps of the bolt pre-tightening force application method described in any one of the above.

[0041] A computer-readable storage medium, in which a computer program is stored, and the computer program is executed by a processor to implement the operation steps of the bolt pre-tightening force application method described in any one of the above.

[0042] A bolt pre-tightening force application method, device, equipment and computer-readable storage medium provided by the present invention. The bolt pre-tightening force application method includes applying a preset tensile force to a bolt by using a stretcher; when the bolt is in a tensile state under the action of the preset tensile force, performing a screwing and tightening operation on the nut corresponding to the bolt; controlling the stretcher to unload the preset tensile force applied to the bolt; wherein, the process of determining the preset tensile force includes: simulating the bolt pre-tightening force application process, and when the residual pre-tightening force of the bolt after pre-tightening reaches the required pre-tightening force, using the tensile force applied to the bolt in the corresponding pre-tightening process as the preset tensile force.

[0043] In this application, considering that during the application of bolt pre-tightening force, when maintaining the tensile force applied to the bolt and after the tensile force is unloaded, the pre-tightening force of the bolt has a certain deformation rebound at the moment of tensile force release, resulting in pre-tightening force loss, and further leading to the hidden danger that the magnitude of the final residual pre-tightening force of the bolt cannot reach the required strength of the actual working condition; for this reason, in this application, the process of applying bolt pre-tightening force is simulated in advance, so as to determine the magnitude of the tensile force corresponding to the process of applying pre-tightening force under the condition that the residual pre-tightening force of the bolt is greater than the required pre-tightening force, and apply the pre-tightening force to the bolt according to this tensile force, so as to ensure that the magnitude of the final pre-tightening force of the bolt can meet the strength requirements of component connection, which is beneficial to ensuring the safety and reliability of high-strength bolt connection of various mechanical component devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0045] Figure 1 It is a schematic structural diagram of a method for applying bolt pre-tightening force provided by an embodiment of this application;

[0046] Figure 2 It is a schematic structural diagram of the bolt connection between the pitch bearing and the blade root in a wind turbine provided by an embodiment of this application;

[0047] Figure 3 It is a schematic diagram of the change in the magnitude of the pre-tightening force during the simulation of bolt driving provided by an embodiment of this application;

[0048] Figure 4 It is a structural block diagram of a bolt pre-tightening force applying device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] Applying pre-tightening force to bolts is a common means to enhance the connection strength of bolt-connected mechanical structure components. The process of applying pre-tightening force to bolts is also called the process of applying pre-tightening to bolts. Based on different bolt structures and the structures of the mechanical components connected by bolts, there are various ways to apply pre-tightening to bolts; the method of applying pre-tightening to bolts involved in this application is mainly the stretching method, and its pre-tightening process is generally as follows: After the bolt is screwed into the corresponding bolt hole, the bolt is stretched to make the bolt deformed (the amount of deformation is generally very small and difficult to distinguish by the human eye). While maintaining the state of stretching the bolt, the nut on the bolt is screwed and tightened. After the nut is screwed to the tightest position, the tensile force applied to the bolt is unloaded. Obviously, at this time, the bolt fixed and tightened by the nut always maintains a certain amount of deformation stress, and this deformation stress is the pre-tightening force of the nut.

[0050] Based on the above discussion, it is further considered in this application that after the nut is screwed and tightened and before and after the tensile force applied to the bolt is unloaded, although there is the tightening and fixing effect of the nut, there is still a certain amount of deformation rebound of the bolt, which reduces the deformation stress of the bolt, and thus results in a certain pre-tightening force loss of the bolt.

[0051] However, in the current conventional process of applying pre-tightening to bolts, the problem of bolt pre-tightening force loss is often easily overlooked. More often, the magnitude of the bolt pre-tightening force is determined based on the relationship between the tensile force applied to the bolt and the deformation stress that the bolt can generate, which results in the final pre-tightening force of the bolt being smaller than the expected pre-tightening force, thus increasing the safety hazard of the bolt-connected mechanical components.

[0052] Therefore, this application proposes a method that fully considers the bolt pre-tightening force loss and ensures the accuracy of the magnitude of the pre-tightening force applied to the bolt.

[0053] To enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0054] Refer to Figure 1 , Figure 1 which is a schematic structural diagram of a method for applying bolt pre-tightening force provided by an embodiment of this application. The method may include:

[0055] S11: Simulate the process of applying bolt pre-tightening force in advance, and determine the corresponding tensile force as the preset tensile force when the residual pre-tightening force after applying pre-tightening to the bolt reaches the required pre-tightening force.

[0056] In the process of simulating the application of bolt pre-tightening force, the process of applying different magnitudes of tensile force to the bolt can be simulated, so as to determine the magnitude of the residual pre-tightening force of the corresponding bolt after unloading the tensile force under different magnitudes of tensile force. If the magnitude of the residual pre-tightening force does not reach the required pre-tightening force of the bolt, the tensile force is increased and the process of applying bolt pre-tightening force is simulated again until the residual pre-tightening force of the bolt is greater than or equal to the required pre-tightening force, and then the tensile force corresponding to the residual pre-tightening force is used as the preset tensile force.

[0057] There can be various different ways to simulate the process of applying bolt pre-tightening force. For example, a three-dimensional solid structure model can be established based on the specific structural components of the bolt connection, and then its processes such as applying tensile force and releasing tensile force can be simulated to determine the relationship between the tensile force and the residual pre-tightening force of the bolt, and then the most reasonable tensile force is selected as the preset tensile force.

[0058] Of course, it is also possible to directly not create a three-dimensional model and only perform simulation operations based on the acting forces between each mechanical structural component and the mechanical equations to determine the relationship between the tensile force and the residual pre-tightening force, and determine the most reasonable tensile force as the preset tensile force.

[0059] In addition, it is also possible to actually conduct multiple groups of bolt pre-tightening force application tests, with different magnitudes of tensile force in each group, collect the magnitudes of the residual pre-tightening force under different tensile force conditions, and simulate the corresponding relationship between the tensile force and the residual pre-tightening force. Finally, the most reasonable tensile force is selected based on the corresponding relationship between the two, etc. There is no specific limitation in this embodiment.

[0060] S12: Use a tensioner to apply the preset tensile force determined in advance to the bolt.

[0061] S13: When the bolt is in a tensile state under the action of the preset tensile force, perform a screwing and tightening operation on the nut corresponding to the bolt.

[0062] S14: Control the tensioner to unload the preset tensile force applied to the bolt.

[0063] In this embodiment, after determining the preset tensile force of the bolt, the normal pre-tightening process of the bolt can be carried out. Because the tensile force applied to the bolt in this embodiment is set based on ensuring that the residual pre-tightening force is greater than the required pre-tightening force; and this required pre-tightening force is also the pre-tightening force to ensure that the bolt can be tightly connected with high strength, thus ensuring the high-strength connection performance of the bolt when actually connecting various mechanical structural components.

[0064] To introduce the technical solution of this application more clearly, refer to Figure 2 , Figure 2This is a schematic structural diagram of the bolt connection between the pitch bearing and the blade root in the wind turbine provided by the embodiment of the present application. In Figure 2 In the shown embodiment, the bolt 1 is mainly used to connect the pitch bearing 4 and the tooling 5; on this basis, there are also structures such as a nut 2, an embedded bushing 6, a spacer 7, and a gasket 8. In addition, a stretcher 3 for stretching the bolt 1 is further provided on the bolt 1; it can be understood that because the stretcher 3 has a certain shielding effect on the nut 2 and the gasket 8, therefore, Figure 2 The stretcher 3 shown in is a sectional view. The normal stretcher 3 is generally a hollow cylindrical structure, and the nut 2, gasket 8, etc. are located inside the stretcher. In this regard, it will not be repeated in this embodiment. The middle section of the bolt 1 passes through the bolt hole in the structure where the pitch bearing 4 and the tooling 5 are connected, and one end is inserted into the embedded bushing 6, and the other end is connected to the nut 2. The spacer 7 is arranged at the position between the pitch bearing 4 and the embedded bushing 6, and the gasket 8 is located between the pitch bearing 4 and the nut 2.

[0065] In the actual process of determining the preset tensile force of the bolt 1, the Figure 2 shown mechanical structure can be pre-simulated and modeled. After determining the magnitude of the preset tensile force, the preset tensile force is applied to the bolt 1 axially through the stretcher 3. When the bolt 1 is in a stretched state, the bolt 1 elongates slightly along the axial direction, which may cause a slight gap between the nut 2 and the gasket 8 instead of a tight connection. At this time, the nut 2 can be screwed and tightened in the direction close to the gasket 8. After ensuring that the nut 2 is firmly tightened, the preset tensile force applied to the bolt 1 is unloaded and released. At this time, because the nut 2, the gasket 8, and the pitch bolt are tightly squeezed and fitted, the bolt 1 still maintains its stretched deformation state after the preset tensile force is released. However, obviously, although the nut 2 can maintain the deformation state of the bolt 1 to a certain extent, thereby enabling the bolt 1 to have a pre-tightening force, obviously, the elongation of the bolt 1 still rebounds compared with the state when the preset tensile force is directly applied. That is to say, before and after the preset tensile force of the bolt 1 is released, there is a certain loss of its deformation stress, and thus there is a certain loss of pre-tightening force; and the final pre-tightening force of the bolt 1 is the magnitude of the residual pre-tightening force of the bolt 1 after the preset tensile force is completely released.

[0066] In the current conventional process of applying pre-tightening force to bolts, the problem of pre-tightening force loss caused by bolt rebound after tensile force unloading is often not considered. Instead, based on the corresponding relationship between the magnitude of the tensile force applied to the bolt and the magnitude of the deformation stress that the bolt can generate, the corresponding relationship between the tensile force and the pre-tightening force is determined, and then the magnitude of the tensile force when applying pre-tightening to the bolt is determined; obviously, this pre-tightening method makes the actual pre-tightening force of the bolt significantly smaller than the expected pre-tightening force, resulting in insufficient pre-tightening force of the bolt and thus insufficient connection strength between mechanical structures.

[0067] Therefore, in the present application, the process of applying pre-tightening force to the bolt in advance is simulated to determine a tensile force that can ensure that the residual pre-tightening force after the bolt unloads the tensile force can also reach the required pre-tightening force. Obviously, the tensile force corresponding to the residual pre-tightening force is also the tensile force that can make the connection strength of the bolt reach the required value.

[0068] In summary, in the process of applying pre-tightening force to the bolt in the present application, the problem of a small amount of springback in the deformation of the bolt and thus a certain loss of pre-tightening force after applying tensile force and unloading tensile force to the bolt is fully considered. When simulating the process of applying pre-tightening force to the bolt in advance, the tensile force of the bolt is determined based on the standard that the residual pre-tightening force of the bolt reaches the required pre-tightening force. Thus, it is ensured that after actually applying pre-tightening force to the bolt, the pre-tightening force of the bolt can reach a sufficient magnitude, thereby ensuring the effectiveness of applying pre-tightening force to the bolt and the connection strength of the bolt.

[0069] Based on the above embodiments, in an alternative embodiment of the present application, the process of simulating the process of applying pre-tightening force to the bolt may include:

[0070] S21: Establish a three-dimensional model of the bolt, the tensioner, and the structural components connected by the bolt, and perform finite element mesh division of hexahedron meshes on the three-dimensional model to obtain a three-dimensional finite element mesh model.

[0071] Taking Figure 2 the structure shown as an example, in the process of three-dimensional modeling, a three-dimensional model of each structural component connected to the bolt and each structural component in the three-dimensional solid structure after being connected to the bolt should be established. At the same time, material parameters of each component structure, such as elastic modulus, Poisson's ratio, and density, etc., need to be input according to the size and material of the specific component.

[0072] In addition, in order to simulate the friction force on the bolt surface more accurately in the subsequent simulation process, when establishing the three-dimensional model of the bolt, the thread detail information on the bolt surface can be included at the same time. For example, it can include one or more of the thread profile information, pitch information, and lead angle information on the bolt; the information on the thread profile, pitch, and lead angle of the bolt can jointly describe the thread shape. Among them, the thread profile describes the cross-sectional shape of the thread, such as common triangles, isosceles trapezoids, etc., the pitch describes the distance between two adjacent threads, and the lead angle describes the spiral rising state of the thread and the angle of spiral rising, etc.; through the information on the thread profile, pitch, and lead angle of the bolt, in the simulation process, the bolt is not only a rod-shaped component with a smooth surface, but a rod-shaped component with a thread structure on the surface, which is closer to the real structure of the bolt and is beneficial to ensuring the authenticity of the subsequent simulation of the pre-tightening force and tensile force magnitude of the bolt.

[0073] TakingFigure 2 Taking the illustrated embodiment as an example, a 3D model including mechanical structures such as bolt 1, nut 2, gasket 8, tensioner 3, pitch bearing 4, tooling 5, spacer 7, and embedded bushing 6 can be first established through 3D modeling software; then the established 3D model is imported into finite element processing software, such as hypermesh finite element processing software, for mesh generation, and a 3D finite element mesh model can be obtained.

[0074] To ensure the accuracy of subsequent simulation results, when performing mesh generation, hexahedral meshes can be used to generate meshes for the 3D model.

[0075] S22: Simulate the process of applying tensile forces with the same magnitude and opposite directions to two surfaces where the prosthetic bolt and the prosthetic tensioner in the 3D finite element network model are in contact with each other, so as to complete the simulation of the bolt tensioning stage of the bolt.

[0076] It can be understood that in this embodiment, and in each subsequent embodiment, the prosthetic bolt, the prosthetic tensioner, and other prosthetic structures are the prosthetic structures of the respective structural components in the 3D finite element model.

[0077] Optionally, when simulating the process of applying tensile forces to the prosthetic bolt and the prosthetic tensioner, if the magnitude of the pre-tightening force on the cross-section of the prosthetic bolt reaches substantially the same as the magnitude of the tensile force, it can be considered that the simulation of the bolt tensioning stage is completed.

[0078] In order to determine the cross-section of the prosthetic bolt, the magnitude of the pre-tightening force on the cross-section of the prosthetic bolt under the action of being stretched by the tensile force can be solved by means of finite element solution; among them, the cross-section of the prosthetic bolt can be any cross-section of the part of the bolt being stretched.

[0079] S23: Simulate the process of keeping the tensile forces on the surfaces of the prosthetic bolt and the prosthetic tensioner unchanged and applying a torque to the surface of the prosthetic nut in the 3D finite element mesh model, so as to complete the simulation of the nut screwing stage.

[0080] While simulating the application of a torque to the surface of the prosthetic nut, the contact pressure in the normal direction of the surface where the prosthetic nut and the prosthetic structural component are in contact can be simulated and output; when the magnitude of the contact pressure reaches the preset pressure, the nut screwing stage is completed, and the simulation of the next unloading pre-tightening stage can be carried out.

[0081] The contact pressure of the prosthetic nut can also be determined by means of finite element solution, which will not be elaborated in detail in this embodiment.

[0082] S24: Simulate the process of unloading the tensile force applied to the prosthesis bolt and the prosthesis stretcher, and applying a torsional moment to the surface of the prosthesis nut to complete the simulation of the unloading pre-tightening stage.

[0083] S25: Determine the residual pre-tightening force of the prosthesis bolt in the unloading pre-tightening stage through finite element solution.

[0084] In this embodiment, the process of applying pre-tightening to the bolt is divided into three stages, namely: the bolt stretching stage, the nut screwing stage, and the unloading pre-tightening stage. The acting forces that need to be simulated and applied to the prosthesis bolt are different in different stages.

[0085] Taking Figure 2 the structure shown as an example, three reference points can be selected on the three-dimensional finite element mesh model; among them, reference point one is the surface point on the prosthesis bolt that interacts with the prosthesis stretcher, reference point two is the surface point where the prosthesis stretcher applies a tensile force to the prosthesis bolt; reference point three is the surface point of the prosthesis nut.

[0086] In the simulation of the process of applying pre-tightening to the bolt, assuming a tensile force of 500 KN as an example, in the simulation of the bolt stretching stage, tensile forces with equal magnitudes and opposite directions are applied to reference point one and reference point two simultaneously; obviously, the direction of this tensile force should be parallel to the axis of the bolt. On this basis, the tensile force applied to reference point one is along the direction of stretching the prosthesis bolt.

[0087] In the bolt stretching stage, with the stretching action of the tensile force, the prosthesis bolt undergoes a small amount of deformation until its deformation reaches a stable state. And judging that it reaches a stable state is determined based on the pre-tightening force of the prosthesis bolt. In this process, the magnitude of the pre-tightening force of the prosthesis bolt can be solved by finite element through finite element solution software.

[0088] Optionally, several grid nodes on a cross-section of the stretched part of the bolt can be used as the analysis object. For example, the magnitudes of the pre-tightening forces corresponding to each grid node on the cross-section of the prosthesis bolt in the three-dimensional finite element mesh model during the process of being stretched by the tensile force can be obtained by using the abaqus finite element solution element, and then the pre-tightening forces of each grid node are summed up, which is the magnitude of the current pre-tightening force of the bolt.

[0089] In practical applications, during the simulation processes of the above bolt stretching stage, nut screwing stage, and unloading pre-tightening stage, the magnitude of the pre-tightening force of the bolt during the entire process of applying pre-tightening force can be determined by using the finite element solution method.

[0090] Referring to Figure 3 , Figure 3 is a schematic diagram showing the change in the magnitude of the pre-tightening force during the simulation of the process of applying pre-tightening to the bolt provided in the embodiment of the present application. It should be noted that Figure 3The change in the bolt pre-tightening force shown in [reference] is mainly for Figure 2 the schematic diagram of the change in the bolt pre-tightening force simulated for the structure in Figure 3 Based on [[reference]], it can be seen that during the bolt stretching stage, as the time for applying the tensile force to the bolt extends, the magnitude of this pre-tightening force gradually increases. When the magnitude of this pre-tightening force is basically the same as the magnitude of the tensile force simulated on the surface of the prosthesis bolt, Figure 3 which is 500 KN in [reference], it can be considered that the pre-tightening force of this prosthesis bolt has reached a stable state, and thus the simulation of the nut screwing stage can be entered.

[0091] In the simulation of the nut screwing stage, the tensile forces applied to the reference point 1 corresponding to the prosthesis bolt and the reference point 2 corresponding to the stretcher remain unchanged. At the same time, the simulation of the process of further applying a torque to the surface of the prosthesis nut to drive the bolt to screw and tighten towards the gasket is also carried out.

[0092] In order to determine the degree of screwing and tightening of the prosthesis nut, the magnitude of the contact pressure on the contacting surface between the prosthesis nut and the gasket can be further determined by using the finite element solution method. Obviously, under normal circumstances, the magnitude of the contact pressure of this prosthesis nut should gradually increase as the screwing process progresses. When the magnitude of this contact pressure reaches a certain preset pressure, it can be considered that the prosthesis nut has been completely tightened. At this time, it can be considered that the nut screwing stage is completed, and the unloading pre-tightening stage can be entered.

[0093] Of course, it can be understood that during the nut screwing stage, the magnitude of the pre-tightening force of the prosthesis bolt can also be determined by finite element solution to determine its change in pre-tightening force.

[0094] In the simulation of the unloading pre-tightening stage, the process of completely unloading and removing the acting forces applied to components such as the prosthesis bolt, the prosthesis stretcher, and the prosthesis nut is simulated; at the same time, the pre-tightening force of the prosthesis nut should also be further solved by finite element method; and based on the above discussion, it can be seen that the pre-tightening force of the prosthesis bolt obtained by solving at this time is the residual pre-tightening force of the prosthesis bolt.

[0095] Referring to [[reference]] Figure 3 it can be seen that during the simulation process of the bolt stretching stage, the pre-tightening force of the bolt determined by simulation solution gradually increases as the stretching time extends. When entering the simulation stage of the nut screwing stage, the pre-tightening force of the prosthesis bolt enters a relatively stable state, basically remaining in a state similar to the tensile force. When entering the unloading pre-tightening stage, after unloading the tensile force, the pre-tightening force of the prosthesis bolt has a relatively obvious decrease and fluctuation, and finally tends to be stable, but the pre-tightening force after stabilization is also smaller than the pre-tightening force in the nut screwing stage. Thus, it can be seen that there is an obvious pre-tightening force loss at the moment when the tensile force applied to the prosthesis bolt is unloaded and removed.

[0096] Of course, in the actual application process, it is also possible that the residual pre-tightening force of the bolt simulated and emulated is less than the pre-tightening force required by the actual working condition. At this time, the tensile force in the bolt stretching stage can be reset and set, and the above-mentioned bolt stretching stage, nut screwing stage, and unloading pre-tightening stage are simulated repeatedly. Furthermore, under the condition that the bolt is stretched with the reset tensile force, the residual pre-tightening force of the bolt obtained is determined until the residual pre-tightening force determined by the simulation can reach the required pre-tightening force. Then, the tensile force corresponding to the residual pre-tightening force that can reach the required pre-tightening force can be used as the preset tensile force.

[0097] The bolt pre-tightening force applying device provided by the embodiment of the present invention will be introduced below. The bolt pre-tightening force applying device described below can be correspondingly referred to the bolt pre-tightening force applying method described above.

[0098] Figure 4 is a structural block diagram of the bolt pre-tightening force applying device provided by the embodiment of the present invention. Refer to Figure 4 The bolt pre-tightening force applying device may include:

[0099] A pre-tightening simulation module 100, configured to pre-simulate the process of applying the bolt pre-tightening force, and when it is determined that the residual pre-tightening force of the bolt after pre-tightening reaches the required pre-tightening force, use the tensile force applied to the bolt during the corresponding pre-tightening process as the preset tensile force;

[0100] A pre-tightening application module 200, configured to apply the preset tensile force determined in advance to the bolt by using a stretcher;

[0101] A nut screwing module 300, configured to perform a screwing and tightening operation on the nut corresponding to the bolt when the bolt is in a stretched state under the action of the preset tensile force;

[0102] An unloading pre-tightening module 400, configured to control the stretcher to unload the preset tensile force applied to the bolt.

[0103] In an optional embodiment of the present application, the pre-tightening simulation module 100 specifically includes:

[0104] A modeling unit, configured to establish a three-dimensional model of the bolt, the stretcher, and the structural components connected by the bolt, and perform finite element mesh division of hexahedron meshes on the three-dimensional model to obtain a three-dimensional finite element mesh model;

[0105] A first simulation unit, configured to simulate the process of applying tensile forces with the same magnitude and opposite directions to two surfaces where the prosthetic bolt and the prosthetic stretcher in the three-dimensional finite element network model are in contact with each other, so as to complete the simulation of the bolt stretching stage of the bolt;

[0106] The second simulation unit is used to simulate the process of keeping the tensile force on the surfaces of the prosthesis bolt and the prosthesis stretcher unchanged and applying a torsional moment to the surface of the prosthesis nut in the three-dimensional finite element mesh model, so as to complete the simulation of the nut screwing stage;

[0107] The third simulation unit is used to simulate the process of unloading the tensile force applied to the prosthesis bolt and the prosthesis stretcher and unloading the torsional moment applied to the surface of the prosthesis nut, so as to complete the simulation of the unloading and preloading stage;

[0108] The pre-tightening force determination unit is used to determine the residual pre-tightening force of the prosthesis bolt in the unloading and preloading stage through finite element solution.

[0109] In an alternative embodiment of the present application, the first simulation unit is specifically configured to, during the process of applying a tensile force to the prosthesis bolt and the prosthesis stretcher, if the magnitude of the pre-tightening force on the cross-section of the prosthesis bolt output by the simulation reaches the magnitude of the tensile force, the simulation process of the bolt stretching stage is completed;

[0110] The second simulation unit is specifically configured to simulate the process of applying a torsional moment to the surface of the prosthesis nut, and output the contact pressure in the normal direction of the surface where the prosthesis nut and the prosthesis structural component are in contact through finite element solution; when the magnitude of the contact pressure reaches a preset pressure, the simulation of the nut screwing stage is completed.

[0111] In an alternative embodiment of the present application, the pre-tightening simulation module is specifically configured to, when the residual pre-tightening force of the prosthesis bolt in the unloading and preloading stage is less than the required pre-tightening force, set a new tensile force, and repeat the operation of simulating the process of applying tensile forces with the same magnitude and opposite directions to the two surfaces where the prosthesis bolt and the prosthesis stretcher in the three-dimensional finite element network model are in contact with each other, so as to complete the simulation of the bolt stretching stage of the bolt, until the preset tensile force corresponding to the residual pre-tightening force not less than the required pre-tightening force is determined.

[0112] In an alternative embodiment of the present application, the modeling unit is specifically configured to establish a three-dimensional model of the bolt including at least one of the thread profile information, pitch information, and lead angle information of the bolt.

[0113] In another alternative embodiment of the present application, the structural components connected by the bolt include a pitch bearing in a wind turbine, a tooling connected to the pitch bearing, an embedded bushing, a spacer, a gasket, a nut, and a stretcher;

[0114] The modeling unit is specifically configured to establish a three-dimensional model of a three-dimensional structure that is interconnected by the bolt and the nut and includes the pitch bearing, the tooling, the embedded bushing, the spacer, the gasket, the nut, and the tensioner.

[0115] The bolt pre-tightening force application device of this embodiment is used to implement the aforementioned bolt pre-tightening force application method. Therefore, the specific implementation in the bolt pre-tightening force application device can be seen in the embodiment part of the bolt pre-tightening force application method in the previous text and will not be elaborated here.

[0116] This application also provides a bolt pre-tightening force application device, including:

[0117] A memory for storing a computer program;

[0118] A processor for executing the computer program to implement the operation steps of the bolt pre-tightening force application method as described in any one of the above.

[0119] The steps of the bolt pre-tightening force application method executed by the processor may include:

[0120] Applying a preset tensile force determined in advance to the bolt using a tensioner;

[0121] When the bolt is in a tensile state under the action of the preset tensile force, performing a screwing and tightening operation on the nut corresponding to the bolt;

[0122] Controlling the tensioner to unload the preset tensile force applied to the bolt;

[0123] Among them, the process of determining the preset tensile force in advance includes:

[0124] Simulating the bolt pre-tightening force application process, and determining the tensile force corresponding to when the residual pre-tightening force of the bolt after driving and pre-tightening reaches the required pre-tightening force as the preset tensile force.

[0125] This application also provides a computer-readable storage medium, in which a computer program is stored, and the computer program is executed by a processor to implement the operation steps of the bolt pre-tightening force application method as described in any one of the above.

[0126] The computer-readable storage medium may include a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the technical field.

[0127] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that the elements inherent in a process, method, article or device comprising a series of elements. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element. In addition, the parts of the above technical solutions provided in the embodiments of the present application that are consistent with the corresponding technical solutions in the prior art are not described in detail to avoid excessive elaboration.

[0128] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for applying bolt pre-tightening force, characterized in that, Including: Applying a predetermined preset tensile force to the bolt by a stretcher; When the bolt is in a tensile state under the action of the preset tensile force, performing a screwing and tightening operation on the nut corresponding to the bolt; Controlling the stretcher to unload the preset tensile force applied to the bolt; Wherein, the process of determining the preset tensile force includes: Simulating the process of applying the pre-tightening force to the bolt, and when the residual pre-tightening force after the bolt is driven and pre-tightened reaches the required pre-tightening force, the corresponding tensile force is used as the preset tensile force; The process of simulating the process of applying the pre-tightening force to the bolt includes: Establishing a three-dimensional model of the bolt, the stretcher, and the structural components connected by the bolt, and performing finite element mesh division of hexahedron meshes on the three-dimensional model to obtain a three-dimensional finite element mesh model; Simulating the process of applying tensile forces with the same magnitude and opposite directions to two surfaces where the prosthetic bolt and the prosthetic stretcher in the three-dimensional finite element network model are in contact with each other, so as to complete the simulation of the bolt stretching stage of the bolt; Simulating the process of keeping the tensile forces on the surfaces of the prosthetic bolt and the prosthetic stretcher unchanged and applying a torque to the surface of the prosthetic nut in the three-dimensional finite element mesh model, so as to complete the simulation of the nut screwing stage; Simulating the process of unloading the tensile forces applied to the prosthetic bolt and the prosthetic stretcher, and unloading the torque applied to the surface of the prosthetic nut, so as to complete the simulation of the unloading pre-tightening stage; Determining the residual pre-tightening force of the prosthetic bolt in the unloading pre-tightening stage through finite element solution.

2. The method for applying bolt pre-tightening force according to claim 1, characterized in that, The simulation of the bolt stretching stage includes: During the process of applying tensile forces to the prosthetic bolt and the prosthetic stretcher, if the magnitude of the pre-tightening force on the cross-section of the prosthetic bolt output by the simulation reaches the magnitude of the tensile force, the simulation process of the bolt stretching stage is completed; The simulation of the nut screwing stage includes: Simulating the process of applying a torque to the surface of the prosthetic nut, and outputting the contact pressure in the normal direction of the surface where the prosthetic nut and the prosthetic structural components are in contact through finite element solution; When the magnitude of the contact pressure reaches the preset pressure, the simulation of the nut screwing stage is completed.

3. The method for applying bolt pre-tightening force according to claim 1, characterized in that, When the residual pre-tightening force of the prosthetic bolt in the unloading pre-tightening stage is less than the required pre-tightening force, setting a new tensile force, and repeating the operation steps of simulating the process of applying tensile forces with the same magnitude and opposite directions to two surfaces where the prosthetic bolt and the prosthetic stretcher in the three-dimensional finite element network model are in contact with each other, so as to complete the simulation of the bolt stretching stage of the bolt, until the preset tensile force corresponding to the residual pre-tightening force not less than the required pre-tightening force is determined.

4. The method for applying bolt pre-tightening force according to any one of claims 1 to 3, characterized in that, The process of establishing the three-dimensional model of the bolt includes: Establishing a three-dimensional model of the bolt including at least one of the thread profile information, pitch information, and lead angle information of the bolt.

5. The method for applying bolt pre-tightening force according to claim 4, characterized in that, The structural components connected by the bolt include a pitch bearing in a wind turbine, a tooling connected to the pitch bearing, an embedded bushing, a spacer, a gasket, a nut, and a stretcher; Establish a 3D model of the bolt, the tensioner, and the structural components connected by the bolt, including: Establish a 3D model of a three-dimensional structure including the pitch bearing, the tooling, the embedded bushing, the spacer, the gasket, the nut, and the tensioner, which are interconnected by the bolt and the nut.

6. A device for applying bolt pre-tightening force, characterized in that, Including: A pre-tightening simulation module for pre-simulating the process of applying pre-tightening force to the bolt, and determining the tensile force applied to the bolt during the corresponding pre-tightening process when the residual pre-tightening force of the bolt after pre-tightening reaches the required pre-tightening force as the preset tensile force; A pre-tightening application module for applying the preset tensile force determined in advance to the bolt by using a tensioner; A nut screwing module for screwing and tightening the nut corresponding to the bolt when the bolt is in a tensile state under the action of the preset tensile force; An unloading pre-tightening module for controlling the tensioner to unload the preset tensile force applied to the bolt; The pre-tightening simulation module specifically includes: A modeling unit for establishing a 3D model of the bolt, the tensioner, and the structural components connected by the bolt, and performing finite element mesh division of hexahedron meshes on the 3D model to obtain a 3D finite element mesh model; A first simulation unit for simulating the process of applying tensile forces with the same magnitude and opposite directions to two surfaces where the prosthetic bolt and the prosthetic tensioner in the 3D finite element network model are in contact with each other, so as to complete the simulation of the bolt tensioning stage of the bolt; A second simulation unit for simulating the process of keeping the tensile forces on the surfaces of the prosthetic bolt and the prosthetic tensioner unchanged and applying a torque to the surface of the prosthetic nut in the 3D finite element mesh model, so as to complete the simulation of the nut screwing stage; A third simulation unit for simulating the process of unloading the tensile forces applied to the prosthetic bolt and the prosthetic tensioner and unloading the torque applied to the surface of the prosthetic nut, so as to complete the simulation of the unloading pre-tightening stage; A pre-tightening force determination unit for determining the residual pre-tightening force of the prosthetic bolt in the unloading pre-tightening stage through finite element solution.

7. A bolt pre-tightening force applying device, characterized in that, Including: A memory for storing computer programs; A processor for executing the computer program to implement the operation steps of the bolt pre-tightening force application method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and the computer program is executed by the processor to implement the operation steps of the bolt pre-tightening force application method according to any one of claims 1 to 5.

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