Metal piece connecting tool, connecting workpiece and connecting method

Abstract

The invention relates to the technical field of machining, and discloses a metal piece connecting tool, a connecting workpiece and a connecting method which are used for connecting a first metal piece and a second metal piece which are heterogeneous. Comprising a rivet which is used for being riveted with a first metal piece and welded with a second metal piece; the rivet comprises a first connecting part, a second connecting part and at least one first locking part, and the first locking part is located on the side wall of the second connecting part; in the riveting process, the second connecting part extends into and penetrates through the first metal piece to form a riveting hole and a metal piece blanking, and a locking matching part which is matched and interlocked with the first locking part is formed on the hole wall of the riveting hole; and the riveting assembly comprises an upper riveting die and a lower riveting die, the rivet is adsorbed to the bottom of the upper riveting die, and the lower riveting die is provided with a through blanking hole which is arranged in a profiling mode with the second connecting part and used for allowing the metal piece to pass through in a blanking mode. Effective connection between the first metal piece and the second metal piece which are heterogeneous is achieved through the rivet, the connection strength is high, and the connection reliability is good.

Description

Technical Field

[0001] This application relates to the field of machining technology, and in particular to a metal part connecting fixture, a workpiece connecting, and a connecting method. Background Technology

[0002] The application prospects of magnesium alloys in the automotive field are benefiting from a convergence of technological breakthroughs and market demand. With the rapid increase in the penetration rate of new energy vehicles, magnesium alloys, with their inherent advantage of having a density only 2 / 3 that of aluminum and 1 / 4 that of steel, have become a strategic material for achieving lightweighting goals. Current technological developments have broken through the limitations of traditional corrosion resistance. Through surface treatment technologies such as micro-arc oxidation and rare earth alloying, magnesium alloy components are expanding from enclosed areas such as dashboard brackets to open areas such as electric drive housings and integrated die-cast rear bodies. Practice has shown that magnesium alloy rear bodies can achieve weight reductions of over 20%, while significantly reducing the cost per unit, thus combining economic and environmental benefits.

[0003] However, magnesium alloys have a melting point of about 650°C. The low melting point makes them sensitive to the heat effect of welding. Magnesium alloys also have poor plasticity and low ductility. Traditional welding methods cannot meet the requirements for effective connection, which prevents magnesium alloys from being widely used in automotive structural components. Summary of the Invention

[0004] This application provides a metal part connecting fixture, a connecting workpiece, and a connecting method, which realizes an effective connection between dissimilar first and second metal parts, with high connection strength and good connection reliability.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a metal part connecting fixture for connecting dissimilar first and second metal parts; the metal part connecting fixture includes: A rivet is used to rivet with the first metal part and weld with the second metal part; the rivet includes a first connecting part, a second connecting part and at least one first locking part, the first locking part being located on the side wall of the second connecting part; during the riveting process between the rivet and the first metal part, the second connecting part extends into and penetrates the first metal part to form a riveting hole and a metal part blanking, and a locking engagement part matching the first locking part is formed on the hole wall of the riveting hole, the first locking part and the locking engagement part forming an interlock; The riveting assembly includes an upper riveting die and a lower riveting die. The rivet is adsorbed onto the bottom of the upper riveting die, and the lower riveting die is used to place the first metal part. The lower riveting die has a through-hole for material dropping, which is shaped to fit the second connecting part and is used for material dropping through the metal part.

[0006] In one embodiment, the first metal member includes a first surface and a second surface facing away from each other; the second connecting portion is embedded in the first metal member from the first surface and can protrude from the second surface, and the end of the second connecting portion protruding from the second surface is used for welding to the second metal member located on one side of the second surface.

[0007] In one embodiment, the height of the second connecting portion is determined based on the thickness of the first metal part, and the difference between the height of the second connecting portion and the thickness of the first metal part is 0.1 mm to 0.3 mm.

[0008] In one embodiment, the sidewall of the second connecting portion is provided with a plurality of first locking portions, which are arranged at intervals along the circumferential direction of the rivet.

[0009] In one embodiment, the first locking portion protrudes from the sidewall surface of the second connecting portion, such that the locking mating portion is recessed into the wall of the riveting hole; or, The first locking portion is recessed into the side wall surface of the second connecting portion, so that the locking engagement portion protrudes from the wall of the riveting hole.

[0010] In one embodiment, the connecting fixture further includes a positioning element and a moving element, the positioning element being used to position the first metal part, and the moving element being used to move the first metal part between the positioning element and the riveting assembly.

[0011] In one embodiment, the first metal component comprises a magnesium alloy, and the second metal component comprises steel.

[0012] Secondly, embodiments of this application provide a connecting workpiece, which is manufactured based on the metal part connecting fixture as described in any of the above claims. The connecting workpiece includes a first metal part, a rivet, and a second metal part. The rivet is riveted to the first metal part and welded to the second metal part.

[0013] Thirdly, embodiments of this application provide a connection method based on the metal part connection fixture described in any of the preceding claims, the connection method comprising: Place the first metal part in the lower riveting die and attach the rivet to the bottom of the upper riveting die; The upper riveting die is pressed down so that the rivet is riveted to the first metal part; during the riveting process between the rivet and the first metal part, the second connecting part of the rivet extends into and penetrates the first metal part to form a riveting hole and a metal part blanking, and a locking engagement part matching the first locking part is formed on the hole wall of the riveting hole. The first locking part and the locking engagement part interlock, and the metal part blanking is discharged from the blanking hole of the lower riveting die; The rivet is welded to the second metal part to obtain a connected workpiece between the second metal part and the first metal part.

[0014] In one embodiment, the first metal member includes a first surface and a second surface facing away from each other; pressing down the upper riveting die to rivet the rivet to the first metal member includes: Press down the upper riveting die so that the second connecting portion of the rivet is embedded from the first surface and riveted to the first metal part, the end of the second connecting portion protruding from the second surface; The step of welding the rivet to the second metal part to obtain the connected workpiece between the second metal part and the first metal part includes: The second metal part is placed on one side of the second surface, and the end of the second connecting part protruding from the second surface is welded to the second metal part to obtain the connected workpiece. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a partial cross-sectional schematic diagram of the metal connection fixture in this application; Figure 2 This application provides a structural schematic diagram of a lower riveting die; Figure 3 for Figure 2 Cross-sectional view of the lower and middle riveting dies; Figure 4 for Figure 2 A schematic diagram of the cross-section of the contour section of the lower riveting die; Figure 5 This is a single-point top force test result at the riveting joint in a specific embodiment; Figure 6 This is the result of a single-point jacking force test at the riveting joint in another specific embodiment; Figure 7 This is a schematic diagram of the first surface of the first metal part after it has been riveted to the rivet in a specific embodiment of this application; Figure 8 This is a schematic diagram of the weld nugget surface of the first metal part after it has been welded by rivets in a specific embodiment of this application; Figure 9 This is an isometric view of the first metal part, the fixing part, and the moving part of this application; Figure 10 This is a schematic diagram of the welding process between the second metal part and the riveted first metal part in this application; Figure 11 A physical diagram showing the interlocking formed by the first locking part and the locking mating part of this application; Figure 12 This is a physical schematic diagram of the connected workpiece of this application.

[0017] [Explanation of Labels in the Attached Image] 1-First metal part, 11-Locking mating part, 12-First surface, 13-Second surface, 2-Second metal part, 3-Rivet, 31-First connecting part, 32-Second connecting part, 33-First locking part, 4-Riveting assembly, 41-Upper riveting die, 42-Lower riveting die, 43-Drop hole, 430-Contouring section, 431-Drop section, 432-Contouring part, 5-Positioning part, 51-Positioning block, 6-Moving part, 7-Welded workpiece. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0020] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0024] Existing magnesium alloys cannot be effectively joined by welding, which limits their widespread application in automotive structural components. To address this issue, this application provides a metal part joining fixture, a joining workpiece, and a joining method. The metal part joining fixture is used to form the joining workpiece using the joining method. Specifically, it is used to join dissimilar first metal part 1 and second metal part 2 to achieve an effective connection between the first metal part 1 and the second metal part 2, thereby improving the connection strength, connection stability, and connection reliability.

[0025] Specifically, such as Figure 1As shown, the metal part connecting fixture includes a rivet 3, which is used to rivet with a first metal part 1 and weld with a second metal part 2. The rivet 3 includes a first connecting portion 31, a second connecting portion 32, and at least one first locking portion 33. One end of the first connecting portion 31 is connected to one end of the second connecting portion 32, and the first locking portion 33 is located on the side wall of the second connecting portion 32. During the riveting process between the rivet 3 and the first metal part 1, the first connecting portion 31 remains outside one side surface of the first metal part 1, and the second connecting portion 32 extends into and penetrates the first metal part 1, forming a riveting hole and a metal part blanking, and is located at the riveting hole. A locking engagement portion 11 is formed on the hole wall to match the first locking portion 33. The first locking portion 33 and the locking engagement portion 11 interlock to prevent the rivet 3 and the first metal part 1 from rotating relative to each other during and after riveting, thereby improving the fixing reliability of the riveting between the rivet 3 and the first metal part 1. Thus, the riveting strength and reliability are high when the rivet 3 is riveted to the first metal part 1. Furthermore, the rivet 3 is also welded to the second metal part 2, which also has high welding strength and good welding reliability, thereby greatly improving the connection strength and connection reliability of the indirect connection between the first metal part 1 and the second metal part 2.

[0026] Specifically, such as Figure 1 As shown, the metal part connecting fixture also includes a riveting assembly 4, which includes an upper riveting die 41 and a lower riveting die 42. The rivet 3 is attached to the bottom of the upper riveting die 41, and the lower riveting die 42 is used to hold the first metal part 1. Furthermore, it should be noted that, as... Figure 1 and Figure 2 As shown, the lower riveting die 42 has a through blanking hole 43, which is shaped to conform to the second connecting part 32 and is used for blanking metal parts. This helps to improve the stability and reliability of riveting, improve the shape accuracy of the rivet 3 and the first metal part 1 after riveting, and avoid the undesirable external force on the side wall of the blanking hole 43 in the lower riveting die 42 that causes undesirable deformation of the riveting hole shape of the rivet 3 and the first metal part 1, thus greatly improving the riveting accuracy and reliability.

[0027] In some preferred embodiments, such as Figure 3As shown, the section of the blanking hole 43 near the upper riveting die 41 is a contour section 430. This contour section 430 is contoured to the second connecting part 32 to avoid unnecessary extrusion force on the rivet 3 by the sidewall of the blanking hole 43, which would cause the rivet 3 to undergo undesirable deformation. This is beneficial to improving the effectiveness and stability of riveting. The section of the blanking hole 43 away from the upper riveting die 41 is the blanking section 431. At this time, the blanking section 431 can be contoured to the second connecting part 32 or not. The inner diameter of the blanking section 431 is larger than the inner diameter of the contour section 430, which improves the convenience of the metal part passing through and prevents the adverse effects that the metal part may get stuck and accumulate during industrial continuous production on the riveting process. This can further improve the riveting reliability of the first metal part 1 and the rivet 3.

[0028] Specifically, in one embodiment, the first metal part 1 includes a magnesium alloy and the second metal part 2 includes steel. The rivet 3 is riveted to the magnesium alloy and then welded to the steel using the tooling connecting the metal parts. This eliminates the need to heat the magnesium alloy, which helps reduce energy consumption. Furthermore, it avoids the problem of magnesium alloy having a low melting point and being difficult to connect effectively after welding. This effectively improves the connection effectiveness, connection strength, and connection reliability between the magnesium alloy and the steel, making it easier for magnesium alloy to be widely used in automotive structural parts, thereby improving the lightweighting of automobiles and reducing costs.

[0029] Specifically, in one embodiment, the sidewall of the second connecting portion 32 is provided with a plurality of first locking portions 33, each first locking portion 33 extending axially along the rivet 3, and the plurality of first locking portions 33 are arranged at intervals along the circumference of the rivet 3, which can form a plurality of interlocking limiting points, further improving the limiting effectiveness and limiting reliability of preventing relative rotation between the rivet 3 and the first metal part 1. Furthermore, after subsequent welding with the second metal part 2, it can also reduce the risk of self-rotation between the rivet 3 and the first metal part 1 caused by the failure of the interlocking structure due to welding heat; for example, such as Figure 4 As shown, in one specific embodiment, three first locking portions 33 are evenly distributed on the side wall of the second connecting portion 32 at intervals along the circumference. Correspondingly, three circumferentially spaced contour portions 432 are provided on the inner wall of the blanking hole 43 that is contoured to the second connecting portion 32. During the riveting process, a riveting hole can be formed on the first metal part 1, and a mating portion is formed on the wall of the riveting hole that matches each of the first locking portions 33.

[0030] Furthermore, when reworking the connecting workpieces of the first metal part 1 and the second metal part 2 connected by the rivet 3, at least one first locking part 33 can also serve as a reference. The same process can be used to rework the workpieces at the same position, avoiding the interlock formed by the first locking part 33 and the locking mating part 11. Riveting can be performed at the original position, which effectively reduces the difficulty of maintenance, improves the efficiency of maintenance, and helps to reduce maintenance costs.

[0031] Specifically, in one embodiment, the first locking part 33 protrudes from the side wall surface of the second connecting part 32, so that the locking mating part 11 is recessed into the wall of the riveting hole; or, in another embodiment, the first locking part 33 is recessed into the side wall surface of the second connecting part 32, so that the locking mating part 11 protrudes from the wall of the riveting hole; thus, the interlocking strength and interlocking stability between the first locking part 33 and the locking mating part 11 are high, and at the same time, the shape of the first locking part 33 is flexibly set.

[0032] The rivet 3 and the first metal part 1 are pressed together by the riveting assembly 4, forming an S-shaped interlock between the rivet 3 and the first metal part 1. This effectively enhances both the riveting strength and reliability. The single-point ejection force of the interlocking structure at each of the first locking parts 33 is 1550N to 1800N. Understandably, this single-point ejection force can be any value within the range of 1550N to 1800N. For example, this single-point ejection force can be 1600N, 1625N, 1650N, 1700N, 1750N, 1800N, etc. Within this range of single-point ejection force, the interlocking formed by each of the first locking parts 33 and the locking mating part 11 has extremely high mechanical strength and structural reliability. For example, in some specific embodiments, the single-point ejection force after riveting is tested, such as... Figure 5 and Figure 6 As shown, the single-point jacking force is relatively high, indicating that after riveting, the connection strength between rivet 3 and the first metal part 1 is high, and the connection reliability is high.

[0033] Specifically, in one implementation, such as Figure 7 and Figure 8As shown, the first metal part 1 includes a first surface 12 and a second surface 13 facing away from each other; the second connecting part 32 is embedded into the first metal part 1 from the first surface 12 and can protrude from the second surface 13. The end of the second connecting part 32 protruding from the second surface 13 is used for welding with the second metal part 2 located on one side of the second surface 13; that is, during the riveting process, the rivet 3 is embedded from one side surface of the first metal part 1, while in the subsequent welding process, the second metal part 2 is located on the other side surface of the first metal part 1; in a specific embodiment, assuming that the first surface 12 of the first metal part 1 is the front and the second surface 13 is the back, then during riveting, the front of the first metal part 1 faces upward, and the upper riveting die 41 drives the rivet 3 to press down, so that The second connecting part 32 of the rivet 3 is embedded into the first metal part 1 from top to bottom. Then, during welding, the second metal part 2 is welded to the first metal part 1 from the back side, so that the welded connected workpiece including the first metal part 1 and the second metal part 2 is flush on both sides. The way in which the second metal part 2 is connected to the end of the rivet 3 away from the first connecting part 31 can further improve the strength and reliability of the indirect connection between the first metal part 1 and the second metal part 2. Compared with the way the second metal part 2 is welded to the first connecting part 31, it effectively reduces the risk that the rivet 3 will come out of the riveting hole and the second metal part 2 will also detach from the first metal part 1, greatly improving the overall connection reliability.

[0034] Specifically, such as Figure 8As shown, in one embodiment, the height of the second connecting portion 32 is determined based on the thickness of the first metal part 1, and the difference between the height of the second connecting portion 32 and the thickness of the first metal part 1 is 0.1mm to 0.3mm. It can be understood that the difference between the height of the second connecting portion 32 and the thickness of the first metal part 1 can be any value within the range of 0.1mm to 0.3mm. For example, the difference between the height of the second connecting portion 32 and the thickness of the first metal part 1 can be 0.1mm, 0.12mm, 0.15mm, 0.2mm, 0.23mm, 0.25mm, 0.3mm, etc. Within this thickness difference range, the second connecting portion 32 can effectively protrude from the second surface 13 after riveting, thereby ensuring contact with the second metal part 2 and facilitating connection with the part located on the second surface. Welding is performed on the second metal part 2 on one side of 13 to prevent incomplete welding. At the same time, the rivet 3 protrudes slightly from the second surface 13. While ensuring effective welding, the protruding part of the rivet 3 is embedded between the first metal part 1 and the second metal part 2, avoiding excessive space occupation and excessive protrusion of the first metal part 1. It also does not affect the flatness of the surface of the second metal part 2, thereby improving the flatness of the exposed surfaces of the first metal part 1 and the second metal part 2 after welding. It avoids the appearance of undesirable protrusion structures at the rivet 3, which would become interference objects. This improves the appearance quality of the connected workpiece after connection, that is, the connected workpiece is flush on both sides after connection, and will not affect the overlap with other parts after welding. When applied to automotive structural parts, it can also reduce gaps and improve vehicle sealing.

[0035] Specifically, in one embodiment, the rivet 3 is a resistance element rivet, which facilitates subsequent welding with the second metal part 2. For example, it is easy to achieve the connection between the rivet 3 and the second metal part through resistance spot welding, resulting in high welding efficiency and high weld connection strength.

[0036] Specifically, such as Figure 9 As shown, in one embodiment, the connecting fixture further includes a positioning member 5 and a moving member 6. The moving member 6 is used to move the first metal part 1 between the positioning member 5 and the riveting assembly 4. The positioning member 5 is used to position and place the first metal part 1, specifically to position and place the first metal part 1 before riveting. The positioning member 5 is provided with a plurality of positioning blocks 51 to limit the relative position of the first metal part 1. The positioning accuracy is high, which makes it easy for the moving member 6 to accurately clamp the first metal part 1 to the riveting assembly 4, thereby improving the positioning accuracy and positioning reliability of the first metal part 1 in the riveting assembly 4, which is beneficial to improving the accuracy and reliability of riveting and welding.

[0037] Furthermore, in some implementations, such as Figure 10 As shown, the connecting fixture may also include a welding workpiece 7, such as a resistance spot welding gun, to weld the riveted rivet 3 to the second metal part 2, resulting in high welding strength and good welding reliability.

[0038] This application provides a workpiece connection method based on the metal part connection fixture described above, such as... Figure 11 and Figure 12 As shown, the connecting workpiece includes a rivet 3, and a first metal part 1 and a second metal part 2 of different materials. The rivet 3 is riveted to the first metal part 1 and welded to the second metal part 2, realizing an effective connection between the first metal part 1 and the second metal part 2. This avoids the problem that the first metal part 1 has a low melting point and is difficult to maintain good connection strength after welding, greatly improving the connection strength and reliability between the first metal part 1 and the second metal part 2. When the first metal part 1 includes a magnesium alloy, it can effectively improve the universality of magnesium alloy in automotive structural parts, thereby helping to improve the lightweighting of automotive structural parts and save the cost of automotive structural parts.

[0039] Furthermore, embodiments of this application also provide an automobile, including the connecting parts described above, which helps to improve the lightweighting of the automobile and save costs.

[0040] This application provides a connection method based on the metal part connection fixture described above. The connection method includes: S101, Place the first metal part in the lower riveting die and attach the rivet to the bottom of the upper riveting die; S103, the upper riveting die is pressed down so that the rivet is riveted to the first metal part; during the riveting process between the rivet and the first metal part, the second connecting part of the rivet extends into and penetrates the first metal part to form a riveting hole and a metal part blanking, and a locking engagement part matching the first locking part is formed on the hole wall of the riveting hole. The first locking part and the locking engagement part interlock, and the metal part blanking is discharged from the blanking hole of the lower riveting die; S105, the rivet is welded to the second metal part to obtain a connecting workpiece between the second metal part and the first metal part.

[0041] In step S101, the first metal part can be gripped by the moving part and positioned and fixed by the positioning part. Then, the first metal part is gripped and moved to the riveting assembly and placed on the lower riveting die, so that the area on the first metal part that needs to be connected with the second metal part moves to the center of the upper riveting die (that is, the position corresponding to the blanking hole). At this time, the lower riveting die is close to the bottom of the first metal part.

[0042] Next, in step S103, the rivet nose of the upper riveting die pre-presses the upper surface of the first metal part, the upper riveting die pushes the rivet into the rivet nose, and applies pressure so that the second connecting part of the rivet is embedded and penetrates the first metal part, and the resulting metal part is discharged through the blanking hole. The rivet forms an interlocking first locking part and locking engagement part with the first metal part through the pressing of the upper and lower riveting dies.

[0043] Specifically, in one embodiment, the first metal part includes a first surface and a second surface facing away from each other; pressing down the upper riveting die to rivet the rivet to the first metal part, i.e., step S103 includes: The upper riveting die is pressed down so that the second connecting portion of the rivet is embedded from the first surface and riveted to the first metal part, with the end of the second connecting portion protruding from the second surface.

[0044] Accordingly, the step of welding the rivet to the second metal part to obtain the connected workpiece of the second metal part and the first metal part, i.e., step S105, includes: The second metal part is placed on one side of the second surface, and the end of the second connecting part protruding from the second surface is welded to the second metal part to obtain the connected workpiece.

[0045] In step S103, the rivet is inserted from the first surface of the first metal part and protrudes from the second surface.

[0046] Next, in step S105, in the first metal part after riveting, the first connecting part of the rivet located on one side of the first surface is used as the welding contact surface. The end of the rivet away from the first connecting part and protruding from the second surface is used as the welding nugget surface for welding with the second metal part. The welding nugget surface is overlapped with the second metal part, and the first metal part and the second metal part are clamped. The electrode of the welding workpiece 7 (i.e., the resistance welding gun) is aligned with the welding contact surface of the rivet. Pressure is applied by clamping the two electrodes. Welding is performed by the resistance heat generated by the current flowing through the contact surface of the electrode joint and the adjacent area. In this way, the indirect connection between the first metal part and the second metal part is realized through the rivet, which greatly improves the connection strength and connection reliability of the two.

[0047] For example, in one specific embodiment, a connection strength test was performed, wherein the first metal part is an AM50A magnesium alloy, and the second metal part is an HC340 / 590 high-strength steel; the pre-welding current during welding was 4.5KA, the welding current was 8.0KA, the downward pressure was 2kN, the pre-welding time was 350ms, the welding time was 500ms, and the holding time was 10ms; the weld nugget diameter was 6mm to 7mm. In the connected workpiece of magnesium alloy and steel after welding, the cross tensile strength was measured to be approximately 6100N, and the shear force was measured to be 4500N, which meets the requirements for effective connection of magnesium alloy as an automotive structural part with steel.

[0048] As can be seen, the metal connection fixture, workpiece connection and connection method provided in the embodiments of this application solve the problems of difficult efficient welding of magnesium alloy and steel connection by traditional methods, easy oxidation, poor porosity and mechanical properties. In particular, it solves the problem of low performance of welded joints caused by easy oxidation of magnesium alloy at high temperature, realizes efficient low temperature connection of magnesium alloy and steel, avoids oxidation, and also improves the shear strength of welded joint, i.e. rivet. It is suitable for complex structures and large-area parts, and the process is green and environmentally friendly.

[0049] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

[0050] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A metal part connecting fixture, characterized in that, For connecting a first metal part (1) and a second metal part (2) of different materials; the metal part connecting fixture includes: A rivet (3) is used to rivet with the first metal part (1) and weld with the second metal part (2); the rivet (3) includes a first connecting part (31), a second connecting part (32) and at least one first locking part (33), the first locking part (33) being located on the side wall of the second connecting part (32); during the riveting process between the rivet (3) and the first metal part (1), the second connecting part (32) extends into and penetrates the first metal part (1) to form a riveting hole and a metal part blanking, and a locking engagement part (11) matching the first locking part (33) is formed on the hole wall of the riveting hole, the first locking part (33) and the locking engagement part (11) interlock; The riveting assembly (4) includes an upper riveting die (41) and a lower riveting die (42). The rivet (3) is attached to the bottom of the upper riveting die (41), and the lower riveting die (42) is used to place the first metal part (1). The lower riveting die (42) has a through-hole (43), which is set in the same shape as the second connecting part (32) for the metal part to pass through.

2. The metal part connecting fixture according to claim 1, characterized in that, The first metal part (1) includes a first surface (12) and a second surface (13) facing away from each other; the second connecting part (32) is embedded in the first metal part (1) from the first surface (12) and can protrude from the second surface (13), and the end of the second connecting part (32) protruding from the second surface (13) is used to weld to the second metal part (2) located on one side of the second surface (13).

3. The metal part connecting fixture according to claim 1, characterized in that, The height of the second connecting part (32) is determined based on the thickness of the first metal part (1), and the difference between the height of the second connecting part (32) and the thickness of the first metal part (1) is 0.1 mm to 0.3 mm.

4. The metal part connecting fixture according to claim 1, characterized in that, The sidewall of the second connecting part (32) is provided with a plurality of first locking parts (33), and the plurality of first locking parts (33) are arranged at intervals along the circumferential direction of the rivet (3).

5. The metal part connecting fixture according to any one of claims 1-4, characterized in that, The first locking part (33) protrudes from the side wall surface of the second connecting part (32), so that the locking mating part (11) is recessed into the wall of the riveting hole; or, The first locking part (33) is recessed into the side wall surface of the second connecting part (32) so that the locking mating part (11) protrudes from the wall of the riveting hole.

6. The metal part connecting fixture according to any one of claims 1-4, characterized in that, The connecting fixture also includes a positioning component (5) and a moving component (6). The positioning component (5) is used to position and place the first metal part (1), and the moving component (6) is used to move the first metal part (1) between the positioning component (5) and the riveting assembly (4).

7. The metal part connecting fixture according to any one of claims 1-4, characterized in that, The first metal part (1) comprises a magnesium alloy, and the second metal part (2) comprises steel.

8. A method for connecting workpieces, characterized in that, The metal part connecting fixture as described in any one of claims 1-7 is used to manufacture the connecting workpiece, which includes a first metal part (1), a rivet (3) and a second metal part (2), wherein the rivet (3) is riveted to the first metal part (1) and welded to the second metal part (2).

9. A connection method, characterized in that, The connection is performed using the metal part connecting fixture as described in any one of claims 1-7, and the connection method includes: Place the first metal part in the lower riveting die and attach the rivet to the bottom of the upper riveting die; The upper riveting die is pressed down so that the rivet is riveted to the first metal part; during the riveting process between the rivet and the first metal part, the second connecting part of the rivet extends into and penetrates the first metal part to form a riveting hole and a metal part blanking, and a locking engagement part matching the first locking part is formed on the hole wall of the riveting hole. The first locking part and the locking engagement part interlock, and the metal part blanking is discharged from the blanking hole of the lower riveting die; The rivet is welded to the second metal part to obtain a connected workpiece between the second metal part and the first metal part.

10. The connection method according to claim 9, characterized in that, The first metal part includes a first surface and a second surface facing away from each other; pressing down the upper riveting die to rivet the rivet to the first metal part includes: Press down the upper riveting die so that the second connecting portion of the rivet is embedded from the first surface and riveted to the first metal part, the end of the second connecting portion protruding from the second surface; The step of welding the rivet to the second metal part to obtain the connected workpiece between the second metal part and the first metal part includes: The second metal part is placed on one side of the second surface, and the end of the second connecting part protruding from the second surface is welded to the second metal part to obtain the connected workpiece.

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