Predictive control method and system for friction stir welding deformation

Abstract

The invention provides a prediction control method and system for friction stir welding deformation, and relates to the technical field of friction stir welding. The method comprises the steps that the diameter of a stirring needle and the diameter of a shaft shoulder are input into a thermal deformation function, and a shrinkage difference value of a welding stirring head is obtained; according to the shrinkage difference value, the thickness of each to-be-welded part and the length of each to-be-welded part, the welding warping amount of each to-be-welded part is determined; according to the welding warping amount of each to-be-welded part and the size chains of the multiple to-be-welded parts, the welding deformation amount of each welding seam of the target part relative to the clamp datum plane is predicted; according to the welding deformation amount of each welding seam of the target part, the height of the base plate and the clamp of the part to be welded are adjusted, the welding deformation amount to be generated is preposed, and when welding is completed, the welding deformation amount generated by cooling is counteracted with the opposite preposed deformation amount, so that the final part achieves higher flatness, and the production efficiency and the welding quality are improved.

Description

Technical Field

[0001] The invention relates to the technical field of friction stir welding, and in particular to a prediction control method and system for friction stir welding deformation. Background Art

[0002] Friction stir welding technology has been widely used in aerospace, rail vehicle and automobile manufacturing. For example, it is used to weld aircraft skins and ribs, wing frames, ground decks, as well as key structural parts such as launch vehicle fairings and automobile chassis.

[0003] During the friction stir welding process, the stirring head rotates at high speed while continuously forging the weld surface of the parent material through the shoulder, and the friction heat between the stirring needle and the parent material is used to connect the parent material into a whole. However, the continuous heat generated during the welding process will cause plastic deformation of the aluminum profile in the forging area, which will cause continuous warping at the weld. Especially when welding a large base plate with multiple welds on one side, it is difficult to ensure the flatness of the base plate as the number of welds increases. Summary of the invention

[0004] The problem to be solved by the present invention is that warping may occur at the weld during the friction stir welding process, making it difficult to ensure the flatness of the welded bottom plate.

[0005] To solve the above problems, in a first aspect, the present invention provides a prediction and control method for deformation of friction stir welding, which is applied to a target part, wherein the target part is composed of a plurality of parts to be welded in sequence, and there is a weld between each two adjacent parts to be welded, and the method comprises:

[0006] Obtaining the diameter of the stirring needle and the diameter of the shaft shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each weld seam and the length of the parts to be welded in the direction perpendicular to the weld seam;

[0007] Inputting the diameter of the stirring needle and the diameter of the shaft shoulder into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head;

[0008] Determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded;

[0009] According to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, predicting the welding deformation of each weld seam of the target part relative to the reference plane of the fixture, wherein the fixture is used to clamp the parts to be welded;

[0010] The height of the backing plate and the clamp of the part to be welded are adjusted according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

[0011] Optionally, the thermal deformation function is:

[0012] M=(D1-D2)*K*T,

[0013] Wherein, M represents the shrinkage difference value of the welding stirring head, D1 represents the diameter of the shoulder, D2 represents the diameter of the stirring needle, K represents the temperature expansion coefficient, and T represents the welding temperature.

[0014] Optionally, determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded comprises:

[0015] For one of the parts to be welded, the shrinkage difference value, the thickness of the part to be welded and the length of the part to be welded in a direction perpendicular to the weld are input into a warping deformation function to obtain the welding warping amount of the part to be welded.

[0016] Optionally, the warping function is:

[0017]

[0018] Among them, C represents the welding warpage of the part to be welded, L represents the length of the part to be welded in the direction perpendicular to the weld, h represents the thickness of the part to be welded, and M represents the shrinkage difference value of the welding stirring head.

[0019] The step of predicting the welding deformation of each weld of the target part relative to the fixture reference surface according to the welding warpage of each part to be welded and the dimension chain of the plurality of parts to be welded comprises:

[0020] The welding warpage amount of each of the parts to be welded and the length of each of the parts to be welded are input into the weld deformation height function to determine the welding deformation amount of each of the welds of the target part relative to the fixture reference surface.

[0021] Optionally, when the number of the parts to be welded constituting the target part is an even number, and the target part is symmetrically placed on the reference plane of the fixture, the weld deformation height function is:

[0022]

[0023] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, j represents the serial number of the j-th part to be welded starting from the reference plane of the fixture, H i represents the welding deformation of the ith weld relative to the fixture reference surface, L j represents the length of the jth part to be welded, θ p represents the angle between the pth part to be welded and the horizontal plane, θ n represents the angle between the nth part to be welded and the horizontal plane, sinθ p =C p / L p , C p represents the welding warpage of the pth part to be welded, L p represents the length of the pth part to be welded, sinθ n =C n / L n , C n represents the welding warpage of the nth part to be welded, L n Represents the length of the nth part to be welded.

[0024] Optionally, when the number of the parts to be welded constituting the target part is an odd number, the parts to be welded in the target part and penetrated by the center line of the target part are parallel to the reference plane of the fixture, and the target part is symmetrically placed on the reference plane of the fixture, the weld deformation height function is:

[0025]

[0026] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, j represents the serial number of the j-th part to be welded starting from the reference plane of the fixture, H i represents the welding deformation of the ith weld relative to the fixture reference surface, L j represents the length of the jth part to be welded, θ p represents the angle between the pth part to be welded and the horizontal plane, θ n represents the angle between the nth part to be welded and the horizontal plane, sinθ p =C p / L p , C p represents the welding warpage of the pth part to be welded, L p Represents the length of the pth part to be welded.

[0027] Optionally, when the number of the parts to be welded constituting the target part is an even number, the target parts are symmetrically placed on the reference plane of the fixture, and the lengths and thicknesses of the multiple parts to be welded are equal, the weld deformation height function is:

[0028]

[0029] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, and H i represents the welding deformation of the i-th weld relative to the fixture reference plane, C represents the welding warpage of any one of the parts to be welded, and q represents a decreasing value and is an integer.

[0030] Optionally, when the number of the parts to be welded constituting the target part is an odd number, the target parts are symmetrically placed on the reference plane of the fixture, and the lengths and thicknesses of the multiple parts to be welded are equal, the weld deformation height function is:

[0031]

[0032] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, and H i represents the welding deformation of the i-th weld relative to the fixture reference plane, C represents the welding warpage of any one of the parts to be welded, and q represents a decreasing value and is an integer.

[0033] In a second aspect, the present invention provides a prediction control system for friction stir welding deformation, which is applied to a target part, wherein the target part is formed by sequentially welding a plurality of parts to be welded, and there is a weld seam between each two adjacent parts to be welded, and the system comprises:

[0034] A data acquisition module, used to acquire the diameter of the stirring needle and the diameter of the shaft shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each of the welds and the length of the parts to be welded perpendicular to the weld direction;

[0035] A shrinkage difference analysis module, used for inputting the diameter of the stirring needle and the diameter of the shaft shoulder into a thermal deformation function to obtain a shrinkage difference value of the welding stirring head;

[0036] A part warpage analysis module, used to determine the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded and the length of each of the parts to be welded;

[0037] A weld deformation prediction module, used to predict the welding deformation of each weld of the target part relative to a fixture reference surface according to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, wherein the fixture is used to clamp the parts to be welded;

[0038] The adjustment control module is used to adjust the height of the backing plate and the clamp of the part to be welded according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

[0039] The beneficial effects of the prediction and control method of friction stir welding deformation of the present invention are as follows: obtaining the diameter of the stirring needle and the diameter of the shoulder in the welding stirring head, as well as the thickness of the parts to be welded at the weld and the length of the parts to be welded in the direction perpendicular to the weld; inputting the diameter of the stirring needle and the diameter of the shoulder into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head, first obtaining the shrinkage difference value at the welding point from the dimensions of the stirring needle and the shoulder, so as to facilitate the subsequent calculation of the welding warpage of each part to be welded; determining the welding warpage of the parts to be welded according to the shrinkage difference value, the thickness of the parts to be welded and the length of the parts to be welded, thereby predicting the deformation degree of each part to be welded, which is convenient for early prevention of welding deformation and also convenient for subsequent analysis of the deformation amount of multiple parts to be welded in continuous welding, and predicting the deformation degree of each part to be welded according to the welding warpage amount and The dimension chain of multiple parts to be welded is used to predict the welding deformation of each weld relative to the fixture reference plane. Then, according to the welding deformation at each weld, the height of the pad and the fixture of the parts to be welded are adjusted. The pad is located directly below the weld of the parts to be welded, and the welding deformation that is about to be generated is pre-set. Before welding, the welding deformation is taken into account in the placement and clamping of the parts to be welded. By adjusting the height of the pad and the clamping of the fixture, the final part shape formed after placement has the opposite pre-set deformation at each weld. Therefore, when the welding is completed, the final part is removed for natural cooling. The welding deformation generated by cooling offsets the opposite pre-set deformation, so that the final part achieves a higher flatness. The large plate after cooling does not require shaping or only requires smaller shaping, which improves production efficiency, reduces production defect rate, and improves welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a friction stir welding process provided by an embodiment of the present invention;

[0041] Figure 2 A schematic flow chart of a method for predicting and controlling deformation of friction stir welding provided by an embodiment of the present invention;

[0042] Figure 3 The weld bead deformation process provided by the embodiment of the present invention is attempted;

[0043] Figure 4 A schematic diagram of weld deformation size analysis provided by an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of welding deformation of multiple plates provided in an embodiment of the present invention;

[0045] Figure 6 A schematic diagram of welding, clamping and placing multiple bottom plates provided in an embodiment of the present invention;

[0046] Figure 7 A schematic diagram of welding deformation analysis of an even number of base plates provided in an embodiment of the present invention;

[0047] Figure 8 A schematic diagram of welding deformation analysis of odd-numbered base plates provided in an embodiment of the present invention;

[0048] Fig. 9 A schematic structural diagram of a predictive control system for friction stir welding deformation provided in an embodiment of the present invention.

[0049] Description of reference numerals:

[0050] 1. Welding seam; 2. Parts to be welded; 3. Shaft shoulder; 4. Stirring needle; 5. Pad; 21; First plate; 22. Second plate. DETAILED DESCRIPTION

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0052] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0053] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0054] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0055] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0056] In related technologies, such as Figure 1 As shown, the welding edges of the two parts to be welded 2 are aligned and pressed tightly together and placed on the pad 5. The shoulder 3 presses the two parts to be welded 2. The shoulder 3 and the stirring needle 4 rotate synchronously. The shaft 3 and the stirring needle 4 can be controlled to approach the parts to be welded 2 while rotating, or the shaft 3 and the stirring needle 4 only rotate to control the parts to be welded 2 and the pad 5 to approach the stirring needle 4. The stirring needle 4 rotates at the joint of the two parts to be welded 2. The stirring needle 4 breaks, melts and mixes the metal materials of the two parts to be welded 2. After this part of the metal material cools and solidifies, a weld 1 is formed. At this time, the joint edges of the two parts to be welded 2 are fused with each other and welded into one.

[0057] In view of the problems existing in the above-mentioned related technologies, the present embodiment provides a predictive control method, device, electronic device and storage medium for stir friction welding deformation.

[0058] like Figure 2 As shown, a prediction and control method for friction stir welding deformation provided by an embodiment of the present invention is applied to a target part, wherein the target part is formed by sequentially welding a plurality of parts to be welded, and there is a weld between each two adjacent parts to be welded, and the method comprises:

[0059] S1: Obtain the diameter of the stirring needle and the diameter of the shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each weld seam and the length of the parts to be welded in the direction perpendicular to the weld seam.

[0060] Specifically, the diameters of the stirring needle and the shoulder, as well as the thickness and length of the parts to be welded are measured in advance and input into the system in advance, so that the system can obtain the required dimensional parameters. Alternatively, the dimensional parameters in the manual of the friction stir welding equipment are obtained by automatic picking and the dimensional parameters of the parts to be welded are obtained by automatic measuring equipment.

[0061] S2: Input the diameter of the stirring needle and the diameter of the shaft shoulder into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head.

[0062] Specifically, aluminum alloy plates are used as parts to be welded, and a temperature transfer gradient model and an aluminum alloy expansion model are established to analyze the deformation law of aluminum alloy plates. Figure 3 As shown, before welding, the first plate 21 and the second plate 22 are bonded together. At this time, the parts to be welded are at room temperature, and the two plates are not deformed. Stir friction welding is performed on the bonded edges. The stirring needle and the shoulder rotate at high speed during the welding process, and the weld metal is continuously forged and stirred to form a weld bead. During the welding process, a large amount of heat is generated. The shoulder influence zone, the weld core zone, the thermomechanical influence zone, the heat influence zone and the parent material zone together form a dynamic welding temperature gradient field. During the welding heating process, due to the expansion of the metal due to heat, the metal at the weld exerts pressure on the parent materials on both sides; and the weld area that has been welded and is in the cooling process will produce tensile stress on the parent materials on both sides due to cooling contraction. When the two plates and the weld are completely cooled to room temperature, the first plate 21 and the second plate 22 are warped. After testing and analysis, it was found that the larger the shoulder of the stirring needle, the greater the heat generated by friction welding, and the welding heat is proportional to the shoulder size. The thermal deformation function is obtained as follows:

[0063] M=(D1-D2)*K*T,

[0064] Wherein, M represents the shrinkage difference value of the welding stirring head, D1 represents the diameter of the shoulder, D2 represents the diameter of the stirring needle, K represents the temperature expansion coefficient, and T represents the welding temperature.

[0065] For example, if the welding temperature T is about 400°, the temperature expansion coefficient K is 25.6μm / (m·K), the shoulder diameter D1 is 14mm, and the stirring needle diameter D2 is 3mm, then the shrinkage difference is:

[0066] M=(14-3)*400*25.6 / 1000000=0.112mm.

[0067] S3: determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded.

[0068] Specifically, Figure 3 and Figure 4 As shown in the figure, the final cooled plate warps on both sides, and the amount of warping is related to the length and thickness of the plate. For the same stirring needle and shoulder, the thicker the plate, the smaller the warping; and for the same plate, the smaller the shoulder of the stirring head, the smaller the warping. The amount of warping is proportional to the width of the product. The larger the width, the greater the deformation. Since the shrinkage part of stir friction welding is on the surface of the profile, it can be considered that the deformation is a triangular shrinkage at the weld, for example Figure 4 In the figure, the difference between the lower side of the weld and the upper side of the weld is a triangular area.

[0069] Exemplarily, for one of the parts to be welded, the shrinkage difference value, the thickness of the part to be welded and the length of the part to be welded in a direction perpendicular to the weld seam may be input into a warping deformation function to obtain the welding warpage of the part to be welded.

[0070] Wherein, the warping deformation function is:

[0071]

[0072] Among them, C represents the welding warpage of the part to be welded, L represents the length of the part to be welded in the direction perpendicular to the weld, h represents the thickness of the part to be welded, and M represents the shrinkage difference value of the welding stirring head.

[0073] For example, the length L of the plate is 200 mm, the thickness h of the plate is 20 mm, and the size parameters of the stirring head in the above example are used to calculate the shrinkage difference value M to be 0.112 mm. The welding warpage of the plate is C = 200*0.112 / 2 / 20 = 0.56 mm.

[0074] S4: predicting the welding deformation of each weld of the target part relative to a reference plane of a fixture according to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, wherein the fixture is used to clamp the parts to be welded.

[0075] Specifically, Figure 5 As shown in the figure, take welding a base plate as an example, the base plate is welded and assembled by multiple plates. When multiple plates need to be welded and assembled into a base plate of larger size, multiple plates need to be welded together one by one, and deformation will occur at each weld. The deformation at these welds will gradually accumulate, making the final target base plate present a convex deformation, and the deformation at the weld in the middle of the final target plate is the largest. According to the welding warpage at each weld and the size relationship between multiple plates, the deformation of each weld can be obtained.

[0076] S5: adjusting the height of a backing plate and a fixture of the part to be welded according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

[0077] Specifically, due to the continuous welding of multiple plates, the following problems may occur: Figure 5 The conventional method is to pressurize and reshape the large plate after welding to restore the flatness of the large plate. However, the weld of the large plate after reshaping may be torn, or there may be defects inside the weld, which will cause internal defects that are not visible to the naked eye and pose safety problems for future use. After knowing the possible deformation height at each weld, the placement and clamping of the parts to be welded can be pre-controlled in advance, for example, Figure 6 As shown, a pad 5 is placed under each weld, and the height of the pad 5 at each weld is adjusted to make the height of the pad 5 equal to the welding deformation that may occur in the weld, and then each part 2 to be welded is clamped and fixed. After welding is completed, the welded parts are removed and allowed to cool naturally to room temperature without clamping. At this time, due to the welding deformation, according to Figure 6 The welding is arranged in the form of welding, and the cooling of the welded large plate occurs as follows Figure 5 In the reverse deformation shown, the large plate has a higher flatness after deformation, and the large plate does not need to be reshaped or only needs a small reshaped after cooling. In addition, multiple liftable pads can be set on the reference surface of the fixture. When the size of the part to be welded changes or the size of the welding head changes, the height of the pad can be automatically adjusted according to the predicted results to adapt to the various deformation amounts. After the pad height adjustment is completed, the fixture is controlled to automatically clamp the part.

[0078] In this embodiment, the diameter of the stirring needle and the diameter of the shoulder in the welding stirring head, as well as the thickness of the part to be welded at the weld and the length of the part to be welded in the direction perpendicular to the weld are obtained; the diameter of the stirring needle and the diameter of the shoulder are input into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head, and the shrinkage difference value at the welding point is first obtained from the sizes of the stirring needle and the shoulder, so as to facilitate the subsequent calculation of the welding warpage of each part to be welded; the welding warpage of the part to be welded is determined according to the shrinkage difference value, the thickness of the part to be welded and the length of the part to be welded, so as to predict the deformation degree of each part to be welded, which is convenient for early prevention of welding deformation and the subsequent analysis of the deformation amount of continuous welding of multiple parts to be welded, according to the welding warpage amount of each part to be welded and the sizes of multiple parts to be welded. Chain, predict the welding deformation of each weld relative to the fixture reference plane, and then adjust the height of the pad and the fixture of the part to be welded according to the welding deformation at each weld. The pad is located directly below the weld of the part to be welded, and the welding deformation that is about to be generated is pre-set. Before welding, the welding deformation is taken into account in the placement and clamping of the parts to be welded. By adjusting the height of the pad and the clamping of the fixture, the final part shape formed after placement has the opposite pre-set deformation at each weld. Therefore, when the welding is completed, the final part is removed for natural cooling. The welding deformation generated by cooling offsets the opposite pre-set deformation, so that the final part achieves a higher flatness. The large plate after cooling does not need to be reshaped or only needs a smaller reshaping, which improves production efficiency, reduces production defect rate, and improves welding quality.

[0079] Optionally, predicting the welding deformation of each weld of the target part relative to the fixture reference plane according to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded includes:

[0080] The welding warpage amount of each of the parts to be welded and the length of each of the parts to be welded are input into the weld deformation height function to determine the welding deformation amount of each of the welds of the target part relative to the fixture reference surface.

[0081] Specifically, Figure 5 As shown in the figure, take welding a base plate as an example. The base plate is welded and assembled from multiple plates. During welding, the deformation of the base plate at each weld is in the same direction, so the deformation at the weld will gradually accumulate during each welding process, and the deformation will be transferred with the dimension chain. Without pretreatment, the base plate will be bulging after welding. Large base plates are mostly symmetrical structures. According to the results of dimension transfer, the deformation height at each weld can be calculated.

[0082] Optionally, when the number of the parts to be welded constituting the target part is an even number, and the target part is symmetrically placed on the reference plane of the fixture, the weld deformation height function is:

[0083]

[0084] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, j represents the serial number of the j-th part to be welded starting from the reference plane of the fixture, H i represents the welding deformation of the ith weld relative to the fixture reference surface, L j represents the length of the jth part to be welded, θ p represents the angle between the pth part to be welded and the horizontal plane, θ n represents the angle between the nth part to be welded and the horizontal plane, sinθ p =C p / L p , C p represents the welding warpage of the pth part to be welded, L p represents the length of the pth part to be welded, sinθ n =C n / L n , C n represents the welding warpage of the nth part to be welded, L n Represents the length of the nth part to be welded.

[0085] For example, Figure 7 As shown in the figure, six plates are spliced ​​into a base plate. Since the base plate is a symmetrical structure, only half of the structure is analyzed. Starting from the center line of the base plate, the welding deformation of the welds on the center line and on one side of the center line is analyzed. Assuming that the six plates have different lengths and different angles of warping deformation, the lengths of the three plates on one side of the center line are L1, L2 and L3, respectively, and the warping deformation angles are θ1, θ2 and θ3, respectively. Then the welding deformation at each weld is:

[0086] H1=L1*sinα 1＝ L1*sin(θ3+2θ2+2θ1),

[0087] H2=L1*sinα1+L2*sinα2=L1*sin(θ3+2θ2+2θ1)+L2*sin(θ3+2θ2),

[0088] H3=L1*sinα1+L2*sinα2+L3*sinα3=L1*sin(θ3+2θ2+2θ1)+L2*sin(θ3+2θ2)+L3*sinθ3,

[0089] The calculation result is consistent with the weld deformation height function, where sinθ1=C1 / L1, sinθ2=C2 / L2, sinθ3=C3 / L3. The deformation height of each weld is obtained by trigonometric calculation and the welding warpage of each plate.

[0090] In this embodiment, when the number of the parts to be welded constituting the target part is an even number, the target parts are symmetrically placed on the reference plane of the fixture, and the lengths and thicknesses of the multiple parts to be welded are equal, the weld deformation height function is:

[0091]

[0092] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, and H i represents the welding deformation of the i-th weld relative to the fixture reference plane, C represents the welding warpage of any one of the parts to be welded, and q represents a decreasing value and is an integer.

[0093] For example, Figure 7 As shown in the figure, six plates are spliced ​​into a base plate. Assuming that the lengths and thicknesses of the six plates are equal, the angle and amount of warping deformation are equal, then the welding deformation at each weld is:

[0094] H1=L1*sin(θ3+2θ2+2θ1)=L*sin5θ,

[0095] H2=L1*sin(θ3+2θ2+2θ1)+L2*sin(θ3+2θ2)=L*(sin5θ+sin3θ),

[0096] H3=L1*sin(θ3+2θ2+2θ1)+L2*sin(θ3+2θ2)+L3*sinθ 3＝ L*(sin5θ+sin3θ+sinθ),

[0097] Because the deformation angle is small, the value of the trigonometric function is approximated, that is, sin5θ≈5sinθ, sin3θ≈3sinθ, sinθ=C / L, then H1=5C, H2=8C, H3=9C, which is consistent with the calculation result of the weld deformation height function. By taking approximate values, the welding deformation at each weld can be quickly calculated, thereby improving the prediction speed.

[0098] Optionally, when the number of the parts to be welded constituting the target part is an odd number, the parts to be welded in the target part and penetrated by the center line of the target part are parallel to the reference plane of the fixture, and the target part is symmetrically placed on the reference plane of the fixture, the weld deformation height function is:

[0099]

[0100] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, j represents the serial number of the j-th part to be welded starting from the reference plane of the fixture, H i represents the welding deformation of the ith weld relative to the fixture reference surface, L j represents the length of the jth part to be welded, θ p represents the angle between the pth part to be welded and the horizontal plane, θ n represents the angle between the nth part to be welded and the horizontal plane, sinθ p =C p / L p , C p represents the welding warpage of the pth part to be welded, L p Represents the length of the pth part to be welded.

[0101] For example, Figure 8 As shown in the figure, 5 plates are spliced ​​into a base plate, and counting starts from the fixture reference surface. Since only two welds on one side of the center line need to be calculated, the lengths of the two plates on one side of the center line involved are L1 and L2, and the warping deformation angles are θ1 and θ2. The welding deformation at each weld is:

[0102] H1=L1*sinα 1＝ L1*sin(2θ2+2θ1),

[0103] H2=L1*sinα1+L2*sinα2=L1*sin(2θ2+2θ1)+L2*sin2θ1,

[0104] This is consistent with the calculation result of the weld deformation height function, where sinθ1=C1 / L1, sinθ2=C2 / L2. The deformation height of each weld is obtained by trigonometric calculation and the welding warpage of each plate.

[0105] In this embodiment, when the number of the parts to be welded constituting the target part is an odd number, the target parts are symmetrically placed on the reference plane of the fixture, and the lengths and thicknesses of the multiple parts to be welded are equal, the weld deformation height function is:

[0106]

[0107] Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, and H i represents the welding deformation of the i-th weld relative to the fixture reference plane, C represents the welding warpage of any one of the parts to be welded, and q represents a decreasing value and is an integer.

[0108] For example, Figure 8 As shown in the figure, five plates are spliced ​​into a base plate. Assuming that the lengths and thicknesses of the five plates are equal, the angle and amount of warping deformation are equal, then the welding deformation at each weld is:

[0109] H1=L1*sin(2θ2+2θ1)=L*sin4θ,

[0110] H2=L1*sin(2θ2+2θ1)+L2*sin2θ1=L*(sin4θ+sin2θ),

[0111] Because the deformation angle is small, the value of the trigonometric function is approximated, that is, sin4θ≈4sinθ, sin2θ≈2sinθ, sinθ=C / L, then H1=4C, H2=6C, which is consistent with the calculation result of the weld deformation height function. By taking approximate values, the welding deformation at each weld can be quickly calculated, thereby improving the prediction speed.

[0112] like Fig. 9 As shown, a prediction control system for stir friction welding deformation provided by an embodiment of the present invention is applied to a target part, wherein the target part is formed by sequentially welding a plurality of parts to be welded, and there is a weld between each two adjacent parts to be welded. The system comprises:

[0113] The data acquisition module 100 is used to acquire the diameter of the stirring needle and the diameter of the shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each weld seam and the length of the parts to be welded in the direction perpendicular to the weld seam;

[0114] The shrinkage difference analysis module 200 is used to input the diameter of the stirring needle and the diameter of the shaft shoulder into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head;

[0115] A part warpage analysis module 300, for determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded and the length of each of the parts to be welded;

[0116] The weld deformation prediction module 400 is used to predict the welding deformation of each weld of the target part relative to the reference plane of the fixture according to the welding warpage of each of the parts to be welded and the dimension chain of the parts to be welded, wherein the fixture is used to clamp the parts to be welded;

[0117] The adjustment control module 500 is used to adjust the height of the backing plate and the clamp of the part to be welded according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

[0118] The predictive control system for friction stir welding deformation described in the present invention has similar technical effects to the predictive control method for friction stir welding deformation described above, and will not be described in detail herein.

[0119] An electronic device provided by an embodiment of the present invention includes a memory and a processor; the memory is used to store a computer program; the processor is used to implement the above-mentioned predictive control method for stir friction welding deformation when executing the computer program.

[0120] In other words, an electronic device includes a memory and a processor coupled to the memory; the memory is configured to store a computer program; and the processor is configured to perform the following operations when executing the computer program:

[0121] Obtaining the diameter of the stirring needle and the diameter of the shaft shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each of the welds and the length of the parts to be welded in a direction perpendicular to the weld;

[0122] Inputting the diameter of the stirring needle and the diameter of the shaft shoulder into a thermal deformation function to obtain a shrinkage difference value of the welding stirring head;

[0123] Determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded;

[0124] According to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, predicting the welding deformation of each weld seam of the target part relative to the reference plane of the fixture, wherein the fixture is used to clamp the parts to be welded;

[0125] The height of the backing plate and the clamp of the part to be welded are adjusted according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

[0126] The electronic device described in the present invention has similar technical effects to the above-mentioned predictive control method for stir friction welding deformation, which will not be described in detail here.

[0127] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned predictive control method for friction stir welding deformation is implemented.

[0128] In other words, a non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor performs the following operations:

[0129] Obtaining the diameter of the stirring needle and the diameter of the shaft shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each weld seam and the length of the parts to be welded in the direction perpendicular to the weld seam;

[0130] Inputting the diameter of the stirring needle and the diameter of the shaft shoulder into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head;

[0131] Determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded;

[0132] According to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, predicting the welding deformation of each weld seam of the target part relative to the reference plane of the fixture, wherein the fixture is used to clamp the parts to be welded;

[0133] The height of the backing plate and the clamp of the part to be welded are adjusted according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

[0134] The computer-readable storage medium of the present invention has similar technical effects to the above-mentioned predictive control method for stir friction welding deformation, which will not be described in detail here.

[0135] An electronic device that can be used as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. Electronic devices are intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples, and are not intended to limit the implementation of the present invention described and / or required herein.

[0136] The electronic device includes a computing unit, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for the operation of the device can also be stored. The computing unit, ROM and RAM are connected to each other through a bus. An input / output (I / O) interface is also connected to the bus.

[0137] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc. In the present application, the unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present invention. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0138] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A prediction and control method for deformation of friction stir welding, characterized in that: Applied to a target part, the target part is formed by sequentially welding a plurality of parts to be welded, and there is a weld seam between each two adjacent parts to be welded, the method comprises: Obtaining the diameter of the stirring needle and the diameter of the shaft shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each weld seam and the length of the parts to be welded in the direction perpendicular to the weld seam; Inputting the diameter of the stirring needle and the diameter of the shaft shoulder into the thermal deformation function to obtain the shrinkage difference value of the welding stirring head; Determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded; According to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, predicting the welding deformation of each weld seam of the target part relative to the reference plane of the fixture, wherein the fixture is used to clamp the parts to be welded; The height of the backing plate and the clamp of the part to be welded are adjusted according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

2. The prediction and control method for friction stir welding deformation according to claim 1, characterized in that: The thermal deformation function is: M=(D1-D2)*K*T, Wherein, M represents the shrinkage difference value of the welding stirring head, D1 represents the diameter of the shoulder, D2 represents the diameter of the stirring needle, K represents the temperature expansion coefficient, and T represents the welding temperature.

3. The prediction and control method for friction stir welding deformation according to claim 1, characterized in that: Determining the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded, and the length of each of the parts to be welded includes: For one of the parts to be welded, the shrinkage difference value, the thickness of the part to be welded and the length of the part to be welded in a direction perpendicular to the weld are input into a warping deformation function to obtain the welding warping amount of the part to be welded.

4. The prediction and control method for friction stir welding deformation according to claim 3, characterized in that: The warping function is: Among them, C represents the welding warpage of the part to be welded, L represents the length of the part to be welded in the direction perpendicular to the weld, h represents the thickness of the part to be welded, and M represents the shrinkage difference value of the welding stirring head.

5. The prediction and control method for friction stir welding deformation according to claim 1, characterized in that: The step of predicting the welding deformation of each weld of the target part relative to the fixture reference surface according to the welding warpage of each part to be welded and the dimension chain of the plurality of parts to be welded comprises: The welding warpage amount of each of the parts to be welded and the length of each of the parts to be welded are input into the weld deformation height function to determine the welding deformation amount of each of the welds of the target part relative to the fixture reference surface.

6. The prediction and control method for friction stir welding deformation according to claim 5, characterized in that: When the number of the parts to be welded constituting the target part is an even number, and the target part is symmetrically placed on the reference surface of the fixture, the weld deformation height function is: Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, j represents the serial number of the j-th part to be welded starting from the reference plane of the fixture, H i represents the welding deformation of the ith weld relative to the fixture reference surface, L j represents the length of the jth part to be welded, θ p represents the angle between the pth part to be welded and the horizontal plane, θ n represents the angle between the nth part to be welded and the horizontal plane, sinθ p =C p / L p , C p represents the welding warpage of the pth part to be welded, L p represents the length of the pth part to be welded, sinθ n =C n / L n , C n represents the welding warpage of the nth part to be welded, L n Represents the length of the nth part to be welded.

7. The prediction and control method for friction stir welding deformation according to claim 5, characterized in that: When the number of the parts to be welded constituting the target part is an odd number, the parts to be welded in the target part that are penetrated by the center line of the target part are parallel to the reference plane of the fixture, and the target part is symmetrically placed on the reference plane of the fixture, the weld deformation height function is: Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, j represents the serial number of the j-th part to be welded starting from the reference plane of the fixture, H i represents the welding deformation of the ith weld relative to the fixture reference surface, L j represents the length of the jth part to be welded, θ p represents the angle between the pth part to be welded and the horizontal plane, θ n represents the angle between the nth part to be welded and the horizontal plane, sinθ p =C p / L p , C p represents the welding warpage of the pth part to be welded, L p Represents the length of the pth part to be welded.

8. The prediction and control method for friction stir welding deformation according to claim 5, characterized in that: When the number of the parts to be welded constituting the target part is an even number, the target parts are symmetrically placed on the reference plane of the fixture, and the lengths and thicknesses of the multiple parts to be welded are equal, the weld deformation height function is: Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, and H i represents the welding deformation of the i-th weld relative to the fixture reference plane, C represents the welding warpage of any one of the parts to be welded, and q represents a decreasing value and is an integer.

9. The method for predicting and controlling deformation of friction stir welding according to claim 5, characterized in that: When the number of the parts to be welded constituting the target part is an odd number, the target parts are symmetrically placed on the reference plane of the fixture, and the lengths and thicknesses of the multiple parts to be welded are equal, the weld deformation height function is: Wherein, i represents the serial number of the i-th weld starting from the reference plane of the fixture, n represents the total number of welds between the center line of the target part and the reference plane of the fixture, and H i represents the welding deformation of the i-th weld relative to the fixture reference plane, C represents the welding warpage of any one of the parts to be welded, and q represents a decreasing value and is an integer.

10. A predictive control system for friction stir welding deformation, characterized in that: Applied to a target part, the target part is formed by sequentially welding a plurality of parts to be welded, and there is a weld seam between each two adjacent parts to be welded, the system comprises: A data acquisition module, used to acquire the diameter of the stirring needle and the diameter of the shaft shoulder in the welding stirring head, as well as the thickness of the parts to be welded at each of the welds and the length of the parts to be welded perpendicular to the weld direction; A shrinkage difference analysis module, used for inputting the diameter of the stirring needle and the diameter of the shaft shoulder into a thermal deformation function to obtain a shrinkage difference value of the welding stirring head; A part warpage analysis module, used to determine the welding warpage of each of the parts to be welded according to the shrinkage difference value, the thickness of each of the parts to be welded and the length of each of the parts to be welded; A weld deformation prediction module, used to predict the welding deformation of each weld of the target part relative to a fixture reference surface according to the welding warpage of each of the parts to be welded and the dimension chains of the multiple parts to be welded, wherein the fixture is used to clamp the parts to be welded; The adjustment control module is used to adjust the height of the backing plate and the clamp of the part to be welded according to the welding deformation at each weld of the target part, wherein the backing plate is located directly below the weld of the part to be welded.

Images