CN-121988984-A - Manufacturing method of large-size heterogeneous material mixed frame

CN121988984ACN 121988984 ACN121988984 ACN 121988984ACN-121988984-A

Abstract

The invention discloses a manufacturing method of a large-size heterogeneous material mixed frame, which comprises the steps of embedding and forming a front section beam and a mounting seat by adopting high-strength steel or hot forming steel and an electric arc additive combined insert, machining the rear end of the front section beam to form an outer plug-in end, forming the front end of the middle rear section beam by adopting aluminum alloy and electric arc additive, machining the front end of the middle rear section beam to form an inner plug-in end, mutually plug-in connection by adapting the shape of the outer wall of the inner plug-in end and the shape of the inner wall of the outer plug-in end, forming an adhesive layer by adopting self-piercing riveting connection in the circumferential direction of the plug-in connection, coating epoxy glue between the joint surfaces of the plug-in connection, forming a longitudinal beam of the frame, bonding the mounting seat to the top surface and the outer side surface of the longitudinal beam through the inner side surface of an L-shaped structure, and adopting high-strength bolt connection between the mounting seat and the bonding surface of the longitudinal beam.

Inventors

YANG YANG
DING RUIQIAN
Xu Ruxue
LIANG LIWEN
ZHANG HAO
LI LINJING
LI YIHUI
SUN LEI
LIN ZHANYUAN
XIAO ZIYUAN
ZHANG JIAN
HUANG QIZHONG

Assignees

中国科学院宁波材料技术与工程研究所
宁波中科祥龙轻量化科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (10)

1. A manufacturing method of a large-size heterogeneous material mixed frame is characterized by comprising the following steps: According to the division, the longitudinal beam (1) of the frame comprises a front section beam (12) divided into a core bearing area and a middle rear section beam (11) divided into a secondary bearing area, and mounting seats (3) arranged on two sides of the front part and two sides of the rear part of the longitudinal beam (1) are divided into the core bearing area; The front section beam (12) and the mounting seat (3) are formed by adopting high-strength steel or hot forming steel and embedded by an electric arc material-increasing combined insert, and an outer plug-in end (121) is formed by machining the rear end of the front section beam (12) facing the middle rear section beam (11), and an inner plug-in end (111) is formed by machining the front end of the middle rear section beam (11) facing the front section beam (12) by adopting aluminum alloy and electric arc material-increasing forming; The shape of the outer wall of the inner inserting end (111) is matched with the shape of the inner wall of the outer inserting end (121) to be mutually connected in an inserting mode, the circumference of the inserting connection position is connected by self-piercing riveting, and epoxy glue is coated between the opposite surfaces of the inserting connection position to form a glue layer (6); the mounting seat (3) is attached to the top surface and the outer side surface of the longitudinal beam (1) through the inner side surface of the L-shaped structure, and the mounting seat (3) is connected with the attaching surface of the longitudinal beam (1) through high-strength bolts.
2. The method of manufacturing a large-size heterogeneous material hybrid vehicle frame as set forth in claim 1, wherein the insert is made of maraging steel and is formed by selective laser melting, and the insert is formed and then subjected to aging treatment to increase the hardness to a level of HRC45 or more.
3. The method for manufacturing the large-size heterogeneous material mixed frame according to claim 1, wherein in the forming process of the front section beam (12), an arc material-increasing partition is adopted to form a base body, a sawtooth meshing structure is arranged at the interface of adjacent partitions to ensure splicing strength, then oxide skin and stress layers on the surface of a reserved embedded area on the base body are removed to form a clean and rough metallurgical bonding surface, an insert is embedded into the reserved embedded area, and the arc material-increasing partition is adopted to continue forming, so that the front section beam (12) with an integrated structure is formed.
4. The method for manufacturing the large-size heterogeneous material mixed frame is characterized in that after the front section beam (12) and the middle and rear section beam (11) are connected in a plugging mode, rivets with diameters of 4-5mm are adopted for self-piercing riveting, the riveting force is 8-12kN, the glue coating thickness of the epoxy glue is 0.2-0.3mm, and the curing condition is that the glue layer (6) is formed after the glue coating is continuously carried out for 30min at 80 ℃.
5. The manufacturing method of the large-size heterogeneous material mixed frame is characterized in that the core bearing area is a stress concentration area with a stress value of more than or equal to 400MPa and comprises a front section beam (12) and an installation seat (3), the secondary bearing area is a force transmission path area with a stress value of 150-400MPa and comprises a middle rear section beam (11) and a cross beam (4), the auxiliary bearing area is a low-load area with a stress value of 50-150MPa and comprises a bracket (5) and a cover plate, and the non-bearing area is a non-load area with a stress value of less than 50MPa and comprises a wiring groove (2) and a support (7) of a sensor.
6. The method for manufacturing the large-size heterogeneous material mixed frame is characterized in that the cross beam (4) is formed by arc material increase and is glued between the two side stringers (1) by modified polyurethane glue.
7. The method for manufacturing the large-size heterogeneous material mixed frame according to claim 5, wherein the bracket (5) is of a lattice structure formed by adopting aluminum alloy and adopting selective laser melting molding, and the bracket (5) is adhered to the outer side of the mounting seat (3) by adopting modified polyurethane adhesive.
8. The method for manufacturing a large-size heterogeneous material mixed frame according to claim 7, wherein the support (7) is a plastic fastener formed by injection molding, and the support (7) is detachably mounted on the support (5).
9. The method for manufacturing the large-size heterogeneous material mixed frame, as set forth in claim 5, characterized in that the wiring groove (2) is a plastic part formed by injection molding, metal nuts are embedded in the plastic part during molding, and bolts penetrate through the mounting seat (3) and are locked with the metal nuts of the wiring groove (2).
10. The method for manufacturing the large-size heterogeneous material mixed frame is characterized in that the core bearing area is made of high-strength steel or hot forming steel, the tensile strength is more than or equal to 500MPa, the secondary bearing area is made of medium-strength aluminum alloy, the tensile strength is between 340 and 500MPa, the auxiliary bearing area is made of common cast aluminum alloy or cast magnesium alloy, the tensile strength is between 100 and 340MPa, and the non-bearing area is made of industrial plastic or glass fiber reinforced composite material, and the tensile strength is less than or equal to 100MPa.

Description

Manufacturing method of large-size heterogeneous material mixed frame Technical Field The invention relates to the technical field of vehicle frame manufacturing, in particular to a manufacturing method of a large-size heterogeneous material mixed vehicle frame. Background Along with the rapid development of new energy automobiles and high-end rail transit industry, the requirements for the weight reduction, high strength and large-size manufacturing of frames are increasingly urgent. The frame in the prior art is mainly made of all-steel materials, and is formed by combining stamping and welding processes, so that the problems of heavy weight and poor fuel economy exist, and if the frame is made of all-aluminum materials, the frame can realize light weight, but has high manufacturing cost and insufficient rigidity, cannot meet the bearing requirement, and the large-size aluminum component is difficult to form. In the existing emerging steel-aluminum hybrid vehicle frame, single welding (such as MIG welding) or single riveting is adopted at the joint of steel and aluminum, brittle intermetallic compounds are easy to form at the interface of different materials of steel and aluminum in the welding, the compatibility is poor, the connection strength is low, the riveting mode avoids the generation of brittle phases, but the stress at the connection part is concentrated, and the cracking phenomenon is easy to occur in the practical stressed use. Disclosure of Invention In order to solve the problems, the application provides the manufacturing method of the large-size heterogeneous material mixed frame with reasonable structure, thereby realizing the reliable manufacturing of the steel-aluminum mixed frame, realizing the light weight, high strength and low cost of the frame, and being particularly suitable for large-size frames which are required to be light in weight and high in strength, such as automobiles, rail transit, special equipment and the like. The technical scheme adopted by the invention is as follows: A manufacturing method of a large-size heterogeneous material mixed frame comprises the following steps: According to the division, the longitudinal beam of the frame comprises a front section beam divided into a core bearing area and a middle rear section beam divided into a secondary bearing area, and mounting seats arranged on two sides of the front part and the rear part of the longitudinal beam are divided into the core bearing area; the front section beam and the mounting seat are made of high-strength steel or thermal forming steel and are buried and formed by an electric arc additive combined insert, and the rear end of the front section beam facing the middle rear section beam is machined to form an outer plug end; The shape of the outer wall of the inner plug-in end is matched with the shape of the inner wall of the outer plug-in end to be mutually plug-in connected, the circumference of the plug-in connection part is connected by self-piercing riveting, and epoxy glue is coated between the opposite surfaces of the plug-in connection part to form a glue layer; the mounting seat is attached to the top surface and the outer side surface of the longitudinal beam through the inner side surface of the L-shaped structure, and the mounting seat is connected with the attachment surface of the longitudinal beam through high-strength bolts. As a further improvement of the above technical scheme: the insert is formed by selective laser melting and maraging steel, and aging treatment is carried out after the insert is formed so as to improve the hardness to be more than HRC 45. In the forming process of the front section beam, firstly, arc material-increasing partition forming is adopted to form a matrix, a sawtooth meshing structure is arranged at the interface of adjacent partitions to ensure splicing strength, then oxide skin and stress layer on the surface of a reserved embedded area on the matrix are removed to form a clean and rough metallurgical bonding surface, an insert is embedded into the reserved embedded area, and arc material-increasing continuous forming is adopted to form the front section beam with an integrated structure. After the rear section beam in the front section Liang Yu is connected in a plugging manner, the self-piercing riveting adopts rivets with the diameter of 4-5mm, the riveting force is 8-12kN, the glue coating thickness of the epoxy glue is 0.2-0.3mm, and the curing condition is that the glue layer is formed after the glue coating lasts for 30min at 80 ℃. The core bearing area is a stress concentration area with a stress value of more than or equal to 400MPa and comprises a front section beam and a mounting seat, the secondary bearing area is a force transmission path area with a stress value of 150-400MPa and comprises a middle rear section beam and a cross beam, the auxiliary bearing area is a low-load area with a stress value of 50-150MPa and comprises a bracket and