Error compensation tapping method and device based on bottom hole deviation and medium

Abstract

The invention discloses an error compensation tapping method and device based on bottom hole deviation and a medium. The method comprises the steps that the compensation limit value delta lim of a target threaded bottom hole is obtained; establishing a target coordinate system, and acquiring actual coordinates and expected coordinates of the target threaded bottom hole on the target coordinate system; based on the actual coordinates and the expected coordinates, the x-axis direction position deviation delta x and the y-axis direction position deviation delta y of the target threaded bottom hole are obtained; based on the position deviation delta x in the x-axis direction, the position deviation delta y in the y-axis direction and a specified deviation threshold value delta, whether the position of the screw tap needs to be compensated or not is judged; and when the position of the screw tap needs to be compensated, the compensation direction and the compensation amount are obtained based on the compensation limit value delta lim. The technical problem that the threaded hole is unqualified due to the position error of the threaded bottom hole can be effectively solved, and the percent of pass of threaded hole machining can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of threaded hole machining, and in particular to an error compensation tapping method, device and medium based on bottom hole deviation. Background Art

[0002] The steps of machining threaded holes on a plate include two major processes: drilling and tapping. Among them, for drilling, a drill bit with an appropriate diameter is selected to machine the threaded bottom hole according to the required thread specification; for the tapping process, there are various methods. For the machining of threads smaller than M30 (nominal diameter of 30 mm), the most commonly used method is to use a tap to cut threads in the machined threaded bottom hole. Drilling and tapping are necessary steps in the threaded hole machining process, and they jointly determine the final quality and performance of the threaded hole.

[0003] The machining of a large number of small-sized threaded holes on a thin-walled large plate has the following problems: In the drilling process, in order to pursue efficiency, the plates are stacked for drilling. However, due to tool deflection and inconsistent machining quality of the plate surface, irregular deviations occur in the positions of the bottom holes, and some even exceed the specified tolerance. According to the ideal tapping machining principle, theoretically, the central axes of the tap and the threaded bottom hole should be coaxial. Therefore, the position error of the threaded bottom hole machining will be transmitted to the thread machining stage, resulting in corresponding position deviations in the machined threaded holes, which will cause the position qualification rate of the final threaded holes to be unable to be guaranteed. Production statistics show that on average, the proportion of the machining position of the threaded bottom holes on each plate that exceeds the tolerance reaches 20%.

[0004] How to effectively avoid the position accuracy of the finally formed threaded holes while ensuring the tapping efficiency and ensure the qualification rate of the threaded holes is an urgent problem to be solved. Summary of the Invention

[0005] By providing an error compensation tapping method, device and medium based on bottom hole deviation, the embodiments of the present application solve the technical problem that the position error of the threaded bottom hole in the prior art leads to unqualified threaded holes.

[0006] To solve the above technical problem, in a first aspect, the embodiments of the present application provide an error compensation tapping method based on bottom hole deviation, and the method includes:

[0007] Obtain the compensation limit value Δ of the target threaded bottom hole lim ;

[0008] Establish a target coordinate system, and obtain the actual coordinates and expected coordinates of the target threaded bottom hole on the target coordinate system;

[0009] Based on the actual coordinates and the expected coordinates, obtain the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction of the target threaded bottom hole;

[0010] Based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction, and the specified deviation threshold δ, determine whether to compensate the position of the tap;

[0011] When it is necessary to compensate the position of the tap, based on the compensation limit Δ lim Obtain the compensation direction and the compensation amount.

[0012] Furthermore, the obtaining of the compensation limit Δ for the target thread bottom hole lim specifically includes:

[0013] Obtain the first eccentricity limit Δ1, and where, d 底 is the diameter of the thread bottom hole, and d1 is the inner diameter of the tap;

[0014] Obtain the second eccentricity limit Δ2, and Δ2 = h a - 0.7H1, where, h a is the actual tooth height, and H1 is the tooth height of the thread design tooth profile;

[0015] Based on the smaller one of the first eccentricity limit Δ1 and the second eccentricity limit Δ2, perform finite element analysis to obtain the third eccentricity limit Δ3, and the compensation limit Δ lim = Δ3.

[0016] Furthermore, the performing of finite element analysis based on the smaller one of the first eccentricity limit Δ1 and the second eccentricity limit Δ2 to obtain the third eccentricity limit Δ3 specifically includes:

[0017] Obtain the set value of the third eccentricity limit, where the set value of the third eccentricity limit is not greater than the smaller one of the first eccentricity limit Δ1 and the second eccentricity limit Δ2;

[0018] Based on the set value of the third eccentricity limit, obtain the finite element simulation model;

[0019] Based on the finite element simulation model, obtain the third eccentricity limit Δ3.

[0020] Furthermore, the determining whether to compensate the position of the tap based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction, and the specified deviation threshold δ specifically includes:

[0021] When δx ≥ δ, and / or, δy ≥ δ, it is necessary to compensate the position of the tap;

[0022] When δx < δ and δy < δ, there is no need to compensate the position of the tap.

[0023] Further, when it is necessary to compensate the position of the tap, obtaining the compensation direction and the compensation amount specifically includes:

[0024] When δx≥δ and δy<δ, it is necessary to compensate the tap position along the -x axis direction, and the compensation amount is Δ lim ;

[0025] When δx<δ and δy≥δ, it is necessary to compensate the tap position along the -y axis direction, and the compensation amount is Δ lim ;

[0026] When δx≥δ and δy≥δ, it is necessary to compensate the tap position along the -x axis direction, and the compensation amount is Δ x , and at the same time, it is necessary to compensate the tap position along the -y axis direction, and the compensation amount is Δ y , where:

[0027]

[0028] Further, based on the design data of the target thread bottom hole, the expected coordinates of the target thread bottom hole are obtained.

[0029] In a second aspect, an error compensation tapping device based on bottom hole deviation provided by an embodiment of the present application includes:

[0030] A first acquisition module, configured to acquire a compensation limit value Δ of the target thread bottom hole lim ;

[0031] A second acquisition module, configured to establish a target coordinate system and acquire the actual coordinates and expected coordinates of the target thread bottom hole in the target coordinate system;

[0032] A third acquisition module, configured to acquire the x-axis direction position deviation δx and y-axis direction position deviation δy of the target thread bottom hole based on the actual coordinates and the expected coordinates;

[0033] A judgment module, configured to judge whether to compensate the tap position based on the x-axis direction position deviation δx, the y-axis direction position deviation δy and a specified deviation threshold δ;

[0034] A fourth acquisition module, configured to, when it is necessary to compensate the tap position, acquire the compensation direction and the compensation amount based on the compensation limit value Δ lim

[0035] Further, the first acquisition module includes:

[0036] A first acquisition unit, configured to acquire a first eccentricity limit value Δ1, and where d 底 is the diameter of the thread bottom hole, and d1 is the inner diameter of the tap;​

[0037] A second acquisition unit, configured to acquire a second eccentricity limit value Δ2, and Δ2 = h a -0.7H1, where h a is the actual tooth height, and H1 is the tooth height of the thread design tooth profile;

[0038] A third acquisition unit, configured to perform finite element analysis based on the smaller one of the first eccentricity limit value Δ1 and the second eccentricity limit value Δ2, and acquire a third eccentricity limit value Δ3, and the compensation limit value Δ lim = Δ3.

[0039] In a third aspect, an error compensation tapping device based on bottom hole deviation provided by an embodiment of the present application includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the method described in any item of the first aspect is implemented.

[0040] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the method described in any item of the first aspect is implemented.

[0041] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0042] By using the error compensation tapping method based on bottom hole deviation described in the embodiments of the present application for compensation tapping, the technical problem that the thread hole is unqualified due to the position error of the thread bottom hole can be effectively solved, and the qualification rate of the thread hole processing of the plate can be significantly improved.

[0043] In addition, the error compensation tapping method based on bottom hole deviation described in the embodiments of the present application supplements the mechanism research of eccentric tapping, provides a scientific basis for the precise design of the eccentricity value, not only fills the research gap of abnormal tapping, but also solves the problem that the eccentricity value in the industry has long relied on experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0045] Figure 1 is a schematic diagram of the compensation principle of an error compensation tapping method based on bottom hole deviation in an embodiment of the present invention;

[0046] Figure 2 is a schematic flowchart of an error compensation tapping method based on bottom hole deviation in an embodiment of the present invention;

[0047] Figure 3It is a schematic diagram of the working state of a tap cutting threads in the threaded bottom hole of a workpiece Figure 1 ;

[0048] Figure 4 It is a schematic diagram of the working state of a tap cutting threads in the threaded bottom hole of a workpiece Figure 2 ;

[0049] Figure 5 It is a schematic diagram of the working state of a tap cutting threads in the threaded bottom hole of a workpiece Figure 3 ;

[0050] Figure 6 It is a schematic diagram of the working state of eccentric tapping of a tap in the threaded bottom hole of a workpiece;

[0051] Figure 7 It is a schematic diagram of the change of thread part parameters during eccentric tapping;

[0052] Figure 8 It is a schematic diagram of the force on the tap during eccentric tapping Figure 1 ;

[0053] Figure 9 It is a schematic diagram of the force on the tap during eccentric tapping Figure 2 ;

[0054] Figure 10 It is a broken line graph of the simulated torque change in an embodiment of the present application;

[0055] Figure 11 It is a schematic structural diagram of an error compensation tapping device based on bottom hole deviation in an embodiment of the present invention;

[0056] Figure 12 It is a schematic structural diagram of another error compensation tapping device based on bottom hole deviation in an embodiment of the present invention.

[0057] Through the above drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Embodiments

[0058] By providing an error compensation tapping method, device and medium based on bottom hole deviation in the embodiments of the present application, the technical problem that the threaded bottom hole position error in the prior art results in unqualified threaded holes is solved.

[0059] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0060] Embodiment 1

[0061] Figure 1 It is a schematic diagram of the compensation principle of an error compensation tapping method based on the deviation of the bottom hole in an embodiment of the present invention. As Figure 1 shown, taking the actual center position of the threaded bottom hole as the coordinate origin, a compensation coordinate system X1OY1 is established, and the designed position e of the bottom hole of the threaded bottom hole, the actual position f of the bottom hole, and the position g of the tap end face are assembled on the compensation coordinate system X1OY1. There is a position deviation between the actual center position o of the bottom hole and the designed center position o2 of the bottom hole, and this position deviation has exceeded the allowable deviation range t of the bottom hole center (i.e., the red dotted-line square shown in the figure). During tapping, by controlling the eccentricity Δ of the center line of the tap 20 relative to the center line of the threaded bottom hole 30, the actual center position of the tap 20 is at o1, and eccentric tapping is performed, so that the position of the processed threaded hole meets the design requirements.

[0062] Based on the above compensation principle, an embodiment of the present invention discloses an error compensation tapping method based on the deviation of the bottom hole. As Figure 2 shown, the method includes:

[0063] Step S100, obtaining the compensation limit value Δ of the target threaded bottom hole 30 lim ;

[0064] Specifically, the step S100 specifically includes:

[0065] Step S110, obtaining the first eccentricity limit value Δ1 based on the tapping processing conditions;

[0066] Specifically, as Figures 3 - 5 shown, the tap 20 processes a thread in the threaded bottom hole 30 of the workpiece 10. The thread forming process mainly depends on the cooperative action of three key cutting surfaces of the tap 20: the outer side surface 22 of the tap, the upper side surface 24 of the tap, and the lower side surface 23 of the tap. Among them, the outer side surface 22 of the tap undertakes the main material removal task, and the upper side surface 24 of the tap and the lower side surface 23 of the tap are responsible for the formation of the thread root and the thread crest. And the tap end face 21 and the inner side surface 25 of the tap do not participate in the actual cutting during the processing and are non-cutting surfaces. From a mechanical perspective, the existence of the non-cutting surfaces provides necessary support and guidance for the tap 20, but does not participate in any cutting process. Therefore, ensuring that the non-cutting surfaces are in a non-contact state with the machined surface is one of the keys to determining the theoretical eccentricity limit value Δ D of the tap 20 and the threaded bottom hole 30.

[0067] During normal processing, the tap end face 21 is entirely inside the threaded bottom hole 30. If the center line of the tap 20 is eccentric Δ relative to the center line of the threaded bottom hole 30, one side will be closer to the bottom hole side 31 (i.e., the inner wall surface of the threaded bottom hole 30), and the symmetric other side will be farther away from the same-side bottom hole side 31.

[0068] AsFigure 6 As shown in the figure, the center O4 of the end face 21 of the tap is offset by Δ relative to the center O3 of the cross-section of the bottom thread hole 30. Among them, it is offset by ΔS in the horizontal axis direction and by ΔQ in the vertical axis direction. The point A1 on the end face 21 of the tap is closer to the side of the bottom thread hole 30, and the opposite point B1 on the end face 21 of the tap is farther from the bottom hole side 31 on the same side. When Δ is too large, the point A1 on the end face 21 of the tap coincides with the point A on the bottom thread hole 30 (at this time, the point B1 on the end face 21 of the tap is the farthest from the point B on the bottom thread hole 30), which means that the end face 21 of the tap cannot enter the bottom thread hole 30. To ensure that the end face 21 of the tap can enter the bottom thread hole 30, the first theoretical eccentricity limit value Δ of the tap 20 and the bottom thread hole 30 D is the radius difference between the circle of the end face 21 of the tap and the circle of the cross-section of the bottom thread hole, that is:

[0069]

[0070] where d 底 is the diameter of the bottom thread hole 30, and d3 is the diameter of the end face 21 of the tap.

[0071] Secondly, the inner side surface 25 of the tap does not participate in cutting, so it is necessary to ensure that it does not contact the bottom hole side 31. If Δ D is too large, the inner side surface 25 of the tap contacts the bottom hole side 31, causing damage to the tap 20 and unable to ensure subsequent cutting. The same as the analysis principle of the end face 21 of the tap, the second theoretical eccentricity limit value Δ of the tap 20 and the bottom thread hole 30 under this condition N is the radius difference between the radius of the inner side surface 25 of the tap and the radius of the bottom thread hole 30:

[0072]

[0073] where: d1 is the inner diameter of the tap 20, which constitutes the inner side surface 25 of the tap. The eccentricity Δ of the center line of the tap 20 relative to the center line of the bottom thread hole 30 needs to be less than Δ D and Δ N at the same time. Since it is stipulated that d1 is greater than d3 when the tap 20 is designed, so:

[0074]

[0075] Step S120, obtaining the second eccentricity limit value Δ2 based on the thread action condition;

[0076] When the eccentricity Δ of the center line of the tap 20 relative to the center line of the bottom thread hole 30 is 0 (i.e., no eccentricity), the cutting amounts on both sides are uniform and consistent. As Figure 5 shown, the cutting gaps 40 are evenly distributed in the circumferential direction. When there is a certain eccentricity between the center line of the tap 20 and the center line of the bottom thread hole 30, that is, Δ≠0. As Figure 7As shown (the thread on one side has been translated for a clearer and more intuitive understanding), the blue contour m represents the thread position after non-eccentric tapping with the tap 20, and the red contour n represents the thread position when the tap 20 taps with an eccentricity of Δ. From Figure 7 it can be clearly observed that in the eccentric direction, the cutting amount of the tap 20 significantly increases; while in the direction opposite to the eccentricity, the cutting amount decreases. In addition, Figure 7 in [reference number], d0 is the original major diameter of the thread, d0' is the major diameter position of the offset thread, d1 is the original minor diameter of the thread, and d1' is the minor diameter position of the offset thread.

[0077] The difference in the cutting amounts on both sides means that the formed thread is not completely symmetric. From Figure 7 it can be obtained that the tooth height of the formed thread varies in the circumferential direction: in the eccentric direction, the tooth height h' a1 is larger than the tooth height h a of the thread after conventional tapping by Δ; while in the direction opposite to the compensation, the tooth height h' a2 correspondingly decreases by Δ. The change in the tooth height dimension will directly affect the connection strength of the thread, and this effect can be evaluated by the tooth height rate η, with the formula:

[0078] η = (h a / H1) × 100%

[0079] where h a is the actual tooth height, and H1 is the tooth height of the designed thread profile.

[0080] The side with the smallest actual tooth height is the direction opposite to the eccentricity, which will correspondingly decrease by Δ, then the tooth height rate η 反 in the direction opposite to the compensation becomes:

[0081] η 反 = [(h a -Δ) / H1] × 100%

[0082] According to the known relationship curve between the thread connection strength and the tooth height rate, when the tooth height rate reaches 70%, the connection strength can reach more than 98% of the maximum value. Therefore, as long as η 反 is higher than 70%, the connection strength requirement can be met.

[0083] Then the second eccentricity limit value Δ2 can be obtained:

[0084]

[0085] Δ2 = h a - 0.7H1

[0086] where, from Figure 7 it can be obtained that the value of h a is (d0 - d1) / 2, and Among them, H is the height of the original triangle of the thread, all of which are known parameters, and then the second eccentricity limit value Δ2 can be obtained.

[0087] Step S130, obtaining a third eccentricity limit value Δ3 based on the conditions of the state of the tap 20;

[0088] The essence of the tapping process is a process of removing excess material. Due to the mutual contact and friction between the workpiece and the tool face, during the tapping process, the tap 20 will be subjected to complex cutting forces, such as Figure 8 , 9 is the tangential force F t received by the tap 20, the radial force F t and the axial force F a schematic diagram, where the X2-axis direction is the direction of the cutting edge of the tap 20, the Z2-axis direction is the axis direction of the tap 20, and the Y2-axis direction is perpendicular to the X2-axis and Z2-axis directions; and Figure 9 in is the thread lead angle.

[0089] Due to the acting direction of the tangential force F t not being collinear with the axis of the tap 20, the tap 20 will also be subjected to a certain torque. Coupled with the friction received by the tap 20, the calculation formula for the torque T is:

[0090] T = (1 + k)·k c ·A D ·r

[0091] In the formula, k is the proportional coefficient of the frictional resistance received by the tap 20 to the tangential force, k c is the cutting force per unit area, A D is the cutting area, r is the acting radius. From the above formula, it can be seen that when the cutting area A D changes, the torque received by the tap 20 will necessarily change. During centric (i.e., non-eccentric) tapping, the ideal maximum total cutting layer area is as follows:

[0092]

[0093] In the formula, P is the thread pitch, κ r is the taper angle of the tap 20. However, during actual tapping, due to the existence of the cutting gap 40, the actual tooth height h a should be brought in, and due to the geometric relationship between the tooth height and the pitch: The actual total cutting layer area when the center line of the tap 20 is eccentric Δ = 0 relative to the center line of the thread bottom hole 30 can be

[0094] As can be seen from step S120, during eccentric tapping, the tooth height on the eccentric side becomes smaller, while the tooth height on the opposite side becomes larger, with the change value being Δ for both. Then the corresponding tooth height also becomes larger and smaller. Substituting these values gives the cutting layer areas in the two directions as and The total change in the cutting layer area is expressed as the difference between the average value of the two and the actual cutting area, then After simplification, it can be obtained that:

[0095]

[0096] When the tap 20 is eccentric to the threaded bottom hole 30, the cutting layer area will inevitably increase. However, the coefficient k of the frictional resistance and the tangential force also affects the torque of the tap 20. Since the cutting amount on one side increases and the cutting gap for chip evacuation becomes smaller, the frictional resistance is bound to increase, making the coefficient larger. Due to the complexity of the influence of friction, it is relatively difficult to theoretically deduce the specific compensation values for each specification. Therefore, it can be obtained through the finite element analysis method in the prior art, that is, by selecting the smaller one of Δ1 and Δ2 as the range of the setting value of the third eccentricity limit, establishing different eccentric tapping simulation models, and the third eccentricity limit Δ3 of the torque mutation can be obtained from the simulation results. Specifically: comparing Δ1 and Δ2, selecting the smaller one of Δ1 and Δ2 as the range of the setting value of the third eccentricity limit, that is, the setting value of the third eccentricity limit does not exceed the smaller one of Δ1 and Δ2, obtaining the setting value of the third eccentricity limit, and establishing a finite element simulation model based on the setting value of the third eccentricity limit; based on the finite element simulation model, obtaining the third eccentricity limit Δ3.

[0097] It should be noted that the compensation limit Δ lim is the smallest among the first eccentricity limit Δ1, the second eccentricity limit Δ2, and the third eccentricity limit Δ3. Since the third eccentricity limit Δ3 is determined within the smaller one of Δ1 and Δ2, therefore, the third eccentricity limit Δ3 is the smallest, that is, Δ lim = Δ3.

[0098] Step S200: Establish a target coordinate system, and obtain the actual coordinates and expected coordinates of the target threaded bottom hole 30 in the target coordinate system;

[0099] It should be clear that the target thread bottom hole 30 here refers to any one of the thread bottom holes 30 that have been machined on the workpiece to be machined. The target coordinate system is a two-dimensional coordinate system. Establishing this target coordinate system is to synchronously transform the target thread bottom hole 30 and the design data of the target thread bottom hole 30 into the same coordinate system, so as to respectively obtain the actual coordinates of the target thread bottom hole 30 on the coordinate system and the expected coordinates of the target thread bottom hole 30 on the coordinate system (obtained according to the design data, such as design dimensions, positions, shapes, etc.) for easy comparison.

[0100] For example, it can be established with a point on the workpiece 10 to be machined as the origin, and the two directions perpendicular to the origin as the x-axis direction and the y-axis direction to establish the target coordinate system. It can also directly use the drawing coordinate system on the design drawing of the target thread bottom hole 30 as the target coordinate system, and convert the actual data of the target thread bottom hole 30 onto the target coordinate system.

[0101] Step S300, based on the actual coordinates and the expected coordinates, obtain the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction of the target thread bottom hole 30;

[0102] Step S400, based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction and the specified deviation threshold δ, determine whether to compensate the position of the tap 20, specifically including:

[0103] When δx≥δ, and / or, δy≥δ, it is necessary to compensate the position of the tap 20;

[0104] When δx<δ and δy<δ, there is no need to compensate the position of the tap 20, and normal tapping is performed.

[0105] It should be noted that the specified deviation threshold δ corresponding to each thread bottom hole 30 is defined in the design stage and is a known quantity.

[0106] Step S500, when it is necessary to compensate the position of the tap 20, based on the compensation limit Δ lim Obtain the compensation direction and the compensation amount, specifically including:

[0107] When δx≥δ and δy<δ, it is necessary to compensate the position of the tap 20 along the -x axis direction, and the compensation amount is Δ lim ; that is, move the tap 20 along the -x axis direction by a distance of Δ lim , and then perform eccentric tapping;

[0108] When δx<δ and δy≥δ, it is necessary to compensate the position of the tap 20 along the -y axis direction, and the compensation amount is Δ lim; that is, the distance for moving the tap 20 along the -y axis is Δ lim , and then perform eccentric tapping;

[0109] When δx≥δ and δy≥δ, it is necessary to compensate the position of the tap 20 along the -x axis, and the compensation amount is Δ x ; at the same time, it is necessary to compensate the position of the tap 20 along the -y axis, and the compensation amount is Δ y , where:

[0110]

[0111] That is, the distance for moving the tap 20 along the -x axis is Δ x , and the distance for moving the tap 20 along the -y axis is Δ y , and then perform eccentric tapping.

[0112] For example, the plate is a wall panel with dimensions of 2500mm×1000mm×10mm, and there are nearly 200 internal threaded holes of various specifications on it. It is the key to the positioning guide rail and the fixed motor, and plays an important role in ensuring the position accuracy of the work roll. Therefore, there are clear requirements for the processing qualification rate of the threaded holes.

[0113] The characteristics of the plate and the accuracy requirements of the threaded holes are applicable to the error compensation tapping method based on the bottom hole deviation described in the embodiments of the present application. The above error compensation tapping method based on the bottom hole deviation is implemented for the threaded hole with a thread specification of M12×1.75.

[0114] Obtain the first eccentricity limit value Δ1 based on the tapping processing conditions:

[0115]

[0116] For the threaded hole with a thread specification of M12×1.75, the major diameter d0 of the tap is 12mm, the pitch P is 1.75mm, and the diameter d 底 = 10.2mm of the recommended thread bottom hole 30 in the industry is taken, and the inner diameter d1 of the standard tap 20 is 10.104mm. Therefore,

[0117] Obtain the second eccentricity limit value Δ2 based on the thread action conditions:

[0118] Δ2 = h a - 0.7H1

[0119] where h a = (d0 - d1) / 2, d0 = 12mm, d1 = 10.104mm; P = 1.75mm. Substituting the relevant parameters, we can get: Δ2 = h a-0.7H1 ≈ 0.284 mm.

[0120] Obtain the third eccentricity limit value Δ3 based on the condition of the state of the tap 20:

[0121] Δ1 = 0.047 mm, Δ2 = 0.284 mm. It can be obtained that Δ1 < Δ2, so the basis for the range of Δ3 is Δ1, that is, Δ3 ≤ Δ1. Within the range of Δ1, the set values of the third eccentricity limit are respectively 0, 0.01, 0.02, 0.03, 0.04, forming five simulation schemes. Finite element simulation models are respectively established (the finite element simulation software automatically generates according to the set value of the third eccentricity limit). The torque change broken line of the tap 20 during the tapping process can be obtained as Figure 10 shown. According to the condition that the eccentricity torque mutation does not exceed 20% of that without eccentricity, Δ lim = Δ3 = 0.02 mm.

[0122] Specifically, read the results of the eccentricity simulation torque on the finite element simulation software, and then subtract the results without eccentricity respectively. The percentage of the obtained difference relative to the simulation torque without eccentricity is the torque mutation of the tap during eccentric tapping.

[0123] Statistically analyze the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction of each thread bottom hole 30 on the plate. The statistical results of a certain specification of thread bottom hole 30 are as Figure 10 shown. The average position deviation of each thread bottom hole 30 is relatively small, but there are individual thread bottom holes 30 whose position deviations exceed the corresponding specified deviation threshold δ. After statistics, the qualification rate of all thread bottom holes 30 is only 81%.

[0124] To improve the qualification rate of the threaded holes after tapping, the error compensation tapping method based on the bottom hole deviation described in the embodiment of the present application is adopted for error compensation tapping. The thread bottom holes 30 with only the position deviation δx in the x-axis direction or the position deviation δy in the y-axis direction exceeding the corresponding specified deviation threshold δ account for about 80% of all unqualified holes. For such thread bottom holes 30, directly compensate 0.02 mm in the opposite direction of the eccentricity for eccentric compensation tapping. The threaded holes after compensation tapping meet the design requirements. After actual tapping on the entire plate, about 60% of the holes reach the qualified state.

[0125] The thread bottom holes 30 with both the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction exceeding the corresponding specified deviation threshold δ account for about 20% of all the total unqualified holes. Compensate according to step S400. Since the essence of this type of hole is to perform component compensation in both the x and y directions simultaneously, this weakens the overall compensation effect, resulting in only about 30% of the holes becoming qualified.

[0126] It can be seen that the error compensation tapping method based on the bottom hole deviation described in the embodiments of the present application has increased the qualification rate of the threaded holes from 81% to 91%, with an increase of nearly 10% in the qualification rate, and reached 90% of the qualification rate requirement of the plate parts. In addition, although there are still some holes in an unqualified state, through calculation, the reduction of the position deviation has improved the processing consistency of the threaded holes by 14%.

[0127] In summary, by using the error compensation tapping method based on the bottom hole deviation described in the embodiments of the present application for compensation tapping, the problem that the screw holes are unqualified due to the position error of the threaded bottom hole can be effectively solved, thereby significantly improving the qualification rate of the threaded processing of the plate parts.

[0128] In addition, the error compensation tapping method based on the bottom hole deviation described in the embodiments of the present application supplements the mechanism research of eccentric tapping, providing a scientific basis for the precise design of the eccentricity value. It not only fills the research gap of abnormal tapping but also solves the problem that the eccentricity value in the industry has long relied on experience.

[0129] Embodiment 2

[0130] Based on the same inventive concept as the error compensation tapping method based on the bottom hole deviation in the foregoing embodiment, the present invention further provides an error compensation tapping device based on the bottom hole deviation, as Figure 12 shown, the device includes:

[0131] A first acquisition module 201 for acquiring the compensation limit value Δ of the target threaded bottom hole lim ;

[0132] A second acquisition module 202 for establishing a target coordinate system and acquiring the actual coordinates and expected coordinates of the target threaded bottom hole on the target coordinate system;

[0133] A third acquisition module 203 for acquiring the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction of the target threaded bottom hole based on the actual coordinates and the expected coordinates;

[0134] A judgment module 204 for judging whether to compensate the position of the tap based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction and the specified deviation threshold value δ;

[0135] A fourth acquisition module 205 for acquiring the compensation direction and the compensation amount when the position of the tap needs to be compensated.

[0136] Embodiment 3

[0137] Based on the same inventive concept as the error compensation tapping method based on bottom hole deviation in the foregoing embodiments, the present invention further provides an error compensation tapping device based on bottom hole deviation, on which a computer program is stored, and when the program is executed by a processor, the steps of any of the methods of the error compensation tapping method based on bottom hole deviation described above are implemented.

[0138] Among them, in Figure 12 In, the bus architecture (represented by bus 300), bus 300 may include any number of interconnected buses and bridges, and bus 300 links various circuits including one or more processors represented by processor 302 and memory 304 represented by memory together. Bus 300 may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be further described herein. Bus interface 306 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium.

[0139] Processor 302 is responsible for managing bus 300 and general processing, while memory 304 may be used to store data used by processor 302 when performing operations.

[0140] Embodiment 4

[0141] Based on the same inventive concept as the error compensation tapping method based on bottom hole deviation in the foregoing embodiments, the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, any steps in Embodiment 1 are implemented.

[0142] Those skilled in the art should understand that the embodiments of the present application may be provided as a method, a system, or a computer program product. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0143] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded processors, or other programmable data processing devices to generate a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0144] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0145] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0146] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0147] Obviously, those skilled in the art can make various changes and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and variations.

Claims

1. An error compensation tapping method based on the deviation of the bottom hole, characterized in that, The method includes: Obtain the compensation limit Δ of the target thread bottom hole lim ; Establish a target coordinate system, and obtain the actual coordinates and expected coordinates of the target thread bottom hole in the target coordinate system; Based on the actual coordinates and the expected coordinates, obtain the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction of the target thread bottom hole; Based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction and the specified deviation threshold δ, determine whether to compensate the position of the tap; When it is necessary to compensate for the position of the tap, based on the compensation limit Δ lim Obtain the compensation direction and the compensation amount.

2. The error compensation tapping method based on the deviation of the bottom hole according to claim 1, wherein, The obtained compensation limit value Δ of the target thread bottom hole lim , specifically including: Obtain the first eccentricity limit value Δ1, and where d 底 is the diameter of the bottom hole of the thread, and d1 is the inner diameter of the tap; Obtain the second eccentricity limit value Δ2, and Δ2 = h a -0.7H1, where h a is the actual tooth height, and H1 is the tooth height of the thread design tooth profile; Perform finite element analysis based on the smaller one of the first eccentricity limit value Δ1 and the second eccentricity limit value Δ2 to obtain a third eccentricity limit value Δ3, and the compensation limit value Δ lim = Δ3.

3. The error compensation tapping method based on the deviation of the bottom hole according to claim 2, characterized in that, The finite element analysis is performed based on the smaller one of the first eccentricity limit value Δ1 and the second eccentricity limit value Δ2 to obtain the third eccentricity limit value Δ3, specifically including: Obtain a set value of the third eccentricity limit value, where the set value of the third eccentricity limit value is not greater than the smaller one of the first eccentricity limit value Δ1 and the second eccentricity limit value Δ2; Based on the set value of the third eccentricity limit value, obtain a finite element simulation model; Based on the finite element simulation model, obtain the third eccentricity limit value Δ3.

4. The error compensation tapping method based on the deviation of the bottom hole according to claim 2, characterized in that, The determination of whether to compensate the position of the tap based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction and the specified deviation threshold δ specifically includes: When δx≥δ, and / or, δy≥δ, it is necessary to compensate the position of the tap; When δx<δ and δy<δ, there is no need to compensate the position of the tap.

5. The error compensation tapping method based on the bottom hole deviation according to claim 4, characterized in that When it is necessary to compensate the position of the tap, based on the compensation limit Δ lim Obtain the compensation direction and the compensation amount, specifically including: When δx≥δ and δy<δ, the position of the tap needs to be compensated in the -x axis direction, and the compensation amount is Δ lim ; When δx < δ and δy ≥ δ, the position of the tap needs to be compensated in the -y axis direction, and the compensation amount is Δ lim ; When δx ≥ δ and δy ≥ δ, the position of the tap needs to be compensated in the -x axis direction, and the compensation amount is Δ x , and at the same time, the position of the tap needs to be compensated in the -y axis direction, and the compensation amount is Δ y , where: 。 6. The error compensation tapping method based on the deviation of the bottom hole according to claim 1, characterized in that Based on the design data of the target thread bottom hole, obtain the expected coordinates of the target thread bottom hole.

7. An error compensation tapping device based on the deviation of the bottom hole, characterized in that, The device includes: The first acquisition module is configured to acquire the compensation limit value Δ of the target thread bottom hole lim ; A second acquisition module, configured to establish a target coordinate system, and acquire the actual coordinates and expected coordinates of the target thread bottom hole in the target coordinate system; A third acquisition module, configured to obtain the position deviation δx in the x-axis direction and the position deviation δy in the y-axis direction of the target thread bottom hole based on the actual coordinates and the expected coordinates; A judgment module, configured to determine whether to compensate the position of the tap based on the position deviation δx in the x-axis direction, the position deviation δy in the y-axis direction and the specified deviation threshold δ; A fourth acquisition module, configured to, when it is necessary to compensate for the position of the tap, acquire a compensation direction and a compensation amount based on a compensation limit value Δ lim ​ 8. The error compensation tapping device based on the bottom hole deviation according to claim 7, characterized in that The first acquisition module includes: The first acquisition unit is configured to acquire a first eccentricity limit value Δ1, and where d 底 is the diameter of the bottom hole of the thread, and d1 is the inner diameter of the tap; A second acquisition unit, configured to acquire a second eccentricity limit value Δ2, where Δ2 = h a - 0.7H1, where h a is the actual tooth height and H1 is the tooth height of the thread design tooth profile; A third acquisition unit, configured to perform finite element analysis based on the smaller one of the first eccentricity limit value Δ1 and the second eccentricity limit value Δ2, to obtain a third eccentricity limit value Δ3, and the compensation limit value Δ lim = Δ3.

9. An error compensation tapping device based on the deviation of the bottom hole, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, the method described in any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, the method described in any one of claims 1 to 6 is implemented.

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