Automobile front end frame positioning connection structure and positioning assembly method
By using a self-positioning structure and welding fixtures between the front bumper beam and the front frame and front longitudinal beam assembly, the problems of complexity and low precision in front frame assembly were solved, achieving an efficient and precise assembly process and improving overall vehicle quality and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN VOCATIONAL COLLEGE OF SOFTWARE & ENG (WUHAN OPEN UNIV)
- Filing Date
- 2026-03-19
- Publication Date
- 2026-07-10
AI Technical Summary
In the existing technology, the assembly process of the front-end frame is complex and the assembly accuracy is not high, which leads to unstable vehicle quality and increases operating time and manufacturing difficulty.
The system employs a first self-positioning structure between the front bumper beam and the front frame, and a second self-positioning structure between the front longitudinal beam assembly. Combined with welding fixtures and welding clamps, it performs XYZ-axis positioning and achieves precise positioning through multiple bolts, thereby shortening the dimensional chain and improving assembly accuracy.
It improves the assembly precision of the front frame relative to the vehicle body, simplifies the assembly process, reduces investment in tooling and equipment and the difficulty of on-site management, improves production quality and efficiency, and ensures the precision of functional components such as headlights and front bumper.
Smart Images
Figure CN122354652A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of automotive structural assembly technology, specifically relating to a positioning and connection structure and positioning and assembly method for an automotive front-end frame. Background Technology
[0002] As the automotive industry places increasingly stringent demands on lightweight vehicle technology, more and more automakers are adopting plastic front-end frame structures. These frames integrate exterior components such as headlights and front bumpers, as well as functional components like radiators, front grilles, and hood locks, all onto a single plastic front-end frame. Figure 1 As shown, the dimensional accuracy of the front-end frame on the vehicle body is extremely important. It determines whether the front-end surface tolerance (DTS) is up to standard and whether the functions of precision-required parts can be achieved, thus having a significant impact on the overall vehicle quality. The precise positioning of the front-end frame on the vehicle body is a crucial condition for determining the accuracy level of the front end.
[0003] Chinese patent (CN112623043B) provides a front-end frame and its positioning method, relating to the field of automotive manufacturing technology. This method can improve the safety of the entire vehicle and ensure the accuracy of the relative positions of components such as headlights, front bumper, grille, and hood lock mounted on the front-end frame. However, this patent uses tooling to position the front-end frame, which adds dimensional chain links. The Z-axis positioning of the tooling at the front of the vehicle is ensured by a robotic arm, which is not directly related to the vehicle body and increases the possibility of error.
[0004] Chinese patent (CN115593524A) provides a front-end frame and vehicle body connection structure, including a front-end frame and a vehicle body. The front-end frame has an upper Y-axis sliding limit mechanism and a lower Y-axis sliding limit mechanism respectively provided on the upper and lower parts of both sides in the same direction. The vehicle body includes two front-end plates and two engine compartment side beams, with the front-end plates detachably connected to the engine compartment side beams. The two front-end plates are slidably disposed between the upper and lower Y-axis sliding limit mechanisms on both sides of the front-end frame. Both ends of the two front-end plates have transverse oblong holes. In this patent, the front-end frame can only be adjusted in the Y-axis direction relative to the vehicle body via the Y-axis sliding limit mechanism, but not in the Z-axis direction. Furthermore, it lacks a mechanism to adjust the sliding position of the corresponding slider; the front-end plates can only be fixed with bolts after adjustment, preventing dimensional adjustments during the manufacturing process and reducing the efficiency of quickly addressing defects.
[0005] Currently, the front frame is assembled by first using sub-assembly fixtures to attach the front bumper beam to the front frame, and then using a large mechanical gripper to manually position the front frame and front bumper beam together on the front longitudinal beam of the vehicle body using positioning references on the vehicle body. This process is complex and requires high precision from the final assembly fixtures. Moreover, the Z-axis positioning of the front frame assembly's assembly gripper cannot be located on the vehicle body, relying entirely on its own Z-axis mechanical limit, resulting in a long assembly dimension chain, unstable assembly quality, increased operating time, increased difficulty in subsequent production and manufacturing equipment management, and impact on production efficiency. Summary of the Invention
[0006] In view of the shortcomings of the existing technology, the present invention proposes a positioning and connection structure and positioning and assembly method for a front-end frame of an automobile, aiming to improve the assembly accuracy of the front-end frame relative to the vehicle body, so as to solve the problems mentioned in the background art.
[0007] This invention is achieved through the following technical solution: A positioning and connection structure for a car front frame includes a front frame, a front anti-collision beam, and a front longitudinal beam; A first self-positioning structure is formed between the front bumper beam and the front frame. The front bumper beam is assembled on the front frame through the first self-positioning structure and a plurality of first bolts to form a front frame assembly. The front longitudinal beam has two beams, which are symmetrically arranged along the vehicle body axis. Each front longitudinal beam has a front longitudinal beam cover plate welded to its front end for mounting the front frame assembly. The two front longitudinal beam cover plates are a left front longitudinal beam cover plate and a right front longitudinal beam cover plate. Each front longitudinal beam cover plate has a front end plate on its front side. The two front end plates are a left front end plate and a right front end plate. The front end plate and the front longitudinal beam cover plate are positioned in the XYZ direction by a welding fixture and then spot welded together by welding clamps. The front longitudinal beam, the front longitudinal beam cover plate, and the front end plate constitute the front longitudinal beam assembly. A second self-positioning structure is formed between the front frame assembly and the front longitudinal beam assembly. The front frame assembly is assembled onto the front longitudinal beam assembly via the second self-positioning structure and a plurality of second bolts. Based on the fact that the front longitudinal beam cover plate will undergo torsional deformation during the welding process at the front end of the front longitudinal beam, unlike the prior art, this application welds a front end plate after precise positioning in the XYZ direction on the front longitudinal beam cover plate as a positioning part with higher precision for mounting the front end frame assembly. The front end plate is welded and set under the vehicle body reference to serve as the assembly reference for the front bumper beam and the front end frame. The dimensional chain is shorter, which can improve the assembly accuracy of the front bumper beam and the front end frame.
[0008] Furthermore, the first self-positioning structure includes positioning posts symmetrically arranged at the left and right ends of the front frame and slots symmetrically arranged at the left and right ends of the front anti-collision beam. The slot at the left end of the front anti-collision beam is fitted onto the positioning post at the left end of the front frame, and the slot at the right end of the front anti-collision beam is fitted onto the positioning post at the right end of the front frame. The front anti-collision beam forms XZ-direction positioning by cooperating with the positioning posts at the left and right ends of the front frame through the slots at the upper left and upper right ends.
[0009] Furthermore, the upper left and lower left ends of the front bumper beam are respectively fastened to the left end of the front frame by two first bolts, and the upper right and lower right ends of the front bumper beam are respectively fastened to the right end of the front frame by two first bolts, forming a symmetrical installation structure. The lower left and lower right ends of the front bumper beam are each positioned on the front frame by passing through a first elongated hole in the front bumper beam with one first bolt. The front bumper beam and the front frame are fastened together by a total of four first bolts at the top, bottom, left, and right positions, positioning the front bumper beam in the Y direction on the front frame to form the front frame assembly.
[0010] Furthermore, each of the front end plates has a 12mm second circular hole at its upper part for inserting an 11.8mm cylindrical pin from the upper part of the welding fixture, and a 16mm (length) * 12mm (width) second oblong hole at its lower part for inserting an 11.8mm cylindrical pin from the lower part of the welding fixture, with the long side of the second oblong hole extending vertically; each of the front longitudinal beam cover plates has a 16mm third circular hole at its upper part for inserting an 11.8mm cylindrical pin from the upper part of the welding fixture, and a 16mm third circular hole at its lower part for inserting an 11.8mm cylindrical pin from the lower part of the welding fixture; when the front end plates are positioned and welded onto the front longitudinal beam cover plates, the upper and lower parts of the welding fixture are provided with 11.8mm cylindrical pins for... For welding positioning, the 11.8mm cylindrical pin at the top of the welding fixture is passed sequentially through the 12mm second circular hole at the top of the front end plate and the 16mm third circular hole at the top of the front longitudinal beam cover plate. Similarly, the 11.8mm cylindrical pin at the bottom of the welding fixture is passed sequentially through the 16mm (length) * 12mm (width) second elongated circular hole at the bottom of the front end plate and the 16mm third circular hole at the bottom of the front longitudinal beam cover plate. This achieves YZ-direction positioning before welding. The X-plane of the welding fixture is pressed against the front end plate and the front longitudinal beam cover plate to form X-direction positioning. After XYZ-direction positioning, the front end plate is welded to the front longitudinal beam cover plate by spot welding with welding clamps. Before welding, the welding positioning reference of the front end plate can be changed by adjusting the positioning reference on the welding fixture, thereby changing the assembly dimensions of the front end frame.
[0011] Furthermore, the second self-positioning structure includes an 8mm positioning pin on the rear sidewall of the left end of the front bumper beam, an 8mm positioning pin on the rear sidewall of the right end of the front bumper beam, an 8.2mm fifth circular hole on the upper part of the left front end plate through which the positioning pin passes, a 12mm (length) * 8.2mm (width) third elongated circular hole on the upper part of the right front end plate through which the positioning pin passes, and a 16mm fourth circular hole on the upper part of the front longitudinal beam cover plate through which the positioning pin passes. The front frame assembly is assembled through the second self-positioning structure. When the front longitudinal beam assembly is in place, the front anti-collision beam of the front end frame assembly is positioned relative to the front end plate. The positioning pin at the left end of the front anti-collision beam passes through the third elongated hole on the left front end plate and the fourth round hole on the left front longitudinal beam cover plate in sequence. The positioning pin at the right end of the front anti-collision beam passes through the third elongated hole on the right front end plate and the fourth round hole on the right front longitudinal beam cover plate in sequence. The positioning pin on the left side is used for YZ-axis positioning, and the positioning pin on the right side is used for Z-axis positioning. The positioning assembly methods on the left and right sides are symmetrical.
[0012] Furthermore, the left end of the front bumper beam is fastened to the left front end plate by four second bolts, and the second bolts pass through the left front end plate and are threadedly connected to the left front longitudinal beam cover plate. The right end of the front bumper beam is fastened to the right front end plate by four second bolts, and the second bolts pass through the right front end plate and are threadedly connected to the right front longitudinal beam cover plate. This is a symmetrical installation structure. The front bumper beam and the front longitudinal beam assembly are fastened together by four second bolts at each end for X-axis positioning.
[0013] A method for positioning and assembling a car front-end frame includes the following steps: S1. The left and right ends of the front anti-collision beam are positioned and assembled with the front frame in the XZ direction through the first self-positioning structure. Then, the left and right ends of the front anti-collision beam are respectively tightened on the front frame by two first bolts to achieve Y-direction positioning and form the front frame assembly. S2. Weld front longitudinal beam cover plates to the front ends of the two front longitudinal beams respectively, and weld front end plates to the two front longitudinal beam cover plates respectively. During welding, the front end plate and the front longitudinal beam cover plate are first positioned in the XYZ direction by welding fixture, and then the front end plate is welded to the front longitudinal beam cover plate by spot welding with welding clamp to form the front longitudinal beam assembly. The assembly size of the front frame can be changed by directly adjusting the positioning reference on the welding fixture according to the positioning reference requirements of the final assembly exterior parts (such as front bumper, headlight, front through light, etc.) on the front frame assembly. S3. The left and right ends of the front anti-collision beam of the front frame assembly are positioned and assembled with the left and right ends of the front longitudinal beam assembly through a second self-positioning structure in the YZ direction. Then, the left and right ends of the front anti-collision beam are respectively tightened on the front longitudinal beam assembly by four second bolts to achieve X-direction positioning.
[0014] Furthermore, in step S1, the slot at the left end of the front bumper beam is fitted onto the positioning post at the left end of the front frame, and the slot at the right end of the front bumper beam is fitted onto the positioning post at the right end of the front frame, thereby forming XZ-direction positioning. The two first bolts pass through the first elongated holes at the lower left and lower right ends of the front bumper beam, respectively, to form X-direction positioning on the front frame. The front bumper beam and the front frame are tightened together at the top, bottom, left, and right positions by a total of four first bolts, thereby positioning the front bumper beam in the Y direction on the front frame to form the front frame assembly.
[0015] Furthermore, in step S2, the 11.8mm cylindrical pin at the top of the welding fixture is passed sequentially through the 12mm second circular hole at the top of the front end plate and the 16mm third circular hole at the top of the front longitudinal beam cover plate. Similarly, the 11.8mm cylindrical pin at the bottom of the welding fixture is passed sequentially through the 16mm (length) * 12mm (width) second elongated circular hole at the bottom of the front end plate and the 16mm third circular hole at the bottom of the front longitudinal beam cover plate. This achieves YZ-direction positioning before welding, and the X-plane of the welding fixture is pressed against the front end plate and the front longitudinal beam cover plate to form X-direction positioning.
[0016] Furthermore, in step S3, the positioning pin at the left end of the front bumper beam passes sequentially through the third elongated hole on the left front end plate and the fourth round hole on the left front longitudinal beam cover plate, and the positioning pin at the right end of the front bumper beam passes sequentially through the third elongated hole on the right front end plate and the fourth round hole on the right front longitudinal beam cover plate. The positioning pin on the left side is used for YZ-direction positioning, and the positioning pin on the right side is used for Z-direction positioning. The front bumper beam and the front longitudinal beam assembly are tightened by four second bolts at each end for X-direction positioning.
[0017] As can be seen from the above technical solution, the automotive front-end frame positioning and connection structure and positioning assembly method provided by the present invention have the following advantages: (1) High positioning accuracy: Since the YZ dimensions of the left and right front longitudinal beams are difficult to guarantee, a front plate for positioning the front frame assembly in the XYZ direction is welded on the front longitudinal beam cover plate using welding fixtures and welding clamps. This serves as a transition structure and assembly reference for the positioning connection between the front frame and the vehicle body. This structure has a shorter dimension chain, which solves the problem of cumulative dimensional fluctuation caused by multiple welding dimension chain links of the front longitudinal beam. The welding fixture can be adjusted according to the final assembly dimension status to adjust the dimensional accuracy of the front plate, thereby directly changing the dimensional status of the front frame assembly and quickly solving the dimensional defects of the front face of the final assembly.
[0018] (2) By using the self-positioning structure of the front frame assembly on the front plate added to the vehicle body, the tooling for assembling the front frame assembly onto the vehicle body is reduced, saving the investment cost of tooling equipment, reducing the difficulty of on-site equipment management, and improving the efficiency of equipment use and current production quality management.
[0019] (3) By setting a positioning reference for the front frame during the body forming process, the front frame can be self-positioned and assembled on the body relative to the body reference. This ensures the assembly accuracy and stability of the front frame relative to the body, and ensures that the assembly accuracy of the headlights, front bumper, hood lock, front grille, and hood lock is without deviation. This ensures the gap difference of the front face of the whole vehicle and the accuracy of the functional components, thereby improving the functional dimensions of the whole vehicle and the appearance perception quality of the front face. The structure is compact, the operation is simple, and it has great promotional value. Attached Figure Description
[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.
[0021] Figure 1 A schematic diagram of the assembly structure at the front frame of a car.
[0022] Figure 2 This is a schematic diagram of the assembly structure of the front frame and the front bumper beam.
[0023] Figure 3 This is a structural diagram of the front-end frame assembly during assembly.
[0024] Figure 4 This is a schematic diagram of the left end of the front frame when it is assembled with the front bumper beam.
[0025] Figure 5 for Figure 4 A schematic diagram of the structure during assembly.
[0026] Figure 6 for Figure 5 A magnified schematic diagram of the local structure at point A in the middle.
[0027] Figure 7 This is a schematic diagram of the positioning and assembly structure of the front end plate on the front longitudinal beam cover plate using welding fixtures.
[0028] Figure 8 This is a schematic diagram of the positioning and assembly structure of the left front end plate and the left front longitudinal beam cover plate.
[0029] Figure 9 This is a schematic diagram of the positioning and assembly structure of the right front end plate and the right front longitudinal beam cover plate.
[0030] Figure 10 This is the rear view of the front-end framework assembly.
[0031] Figure 11 for Figure 10 Rear view of the right end of the front bumper beam at point B.
[0032] Figure 12 for Figure 10 Rear view of the left end of the front bumper beam at point C.
[0033] Figure 13 This is a front view of the front longitudinal beam assembly.
[0034] Figure 14 This is a structural schematic diagram of the right front longitudinal beam cover plate.
[0035] Figure 15 This is a structural schematic diagram of the left front longitudinal beam cover plate.
[0036] The components in the diagram are named as follows: 1. Front frame; 1.1. Positioning post; 1.2. First nut; 2. Front bumper beam; 2.1. First round hole; 2.2. Slot; 2.3. First oblong hole; 2.4. Positioning pin; 2.5. Sixth round hole; 3. Front longitudinal beam; 4. First bolt; 5. Front longitudinal beam cover plate; 5.1. Left front longitudinal beam cover plate; 5.2. Right front longitudinal beam cover plate; 5.3. Third round hole; 5.4. Fourth round hole; 5.5. Threaded hole; 6. Front plate; 6.1. Left front plate; 6.2. Right front plate; 6.3. Second round hole; 6.4. Second oblong hole; 6.5. Fifth round hole; 6.6. Third oblong hole; 6.7. Seventh round hole; 7. Welding fixture; 7.1. Cylindrical pin; 8. Second bolt. Detailed Implementation
[0037] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.
[0038] Example 1 A positioning and connection structure for a car front-end frame, such as Figures 1 to 15 As shown, it mainly includes a front frame 1, a front anti-collision beam 2, a front longitudinal beam 3, a front longitudinal beam cover plate 5, and a front plate 6.
[0039] like Figures 2 to 6 As shown, a first self-positioning structure is formed between the front bumper beam 2 and the front end frame 1. The front bumper beam 2 is assembled on the front end frame 1 through the first self-positioning structure and multiple first bolts 4 to form a front end frame assembly. like Figures 4 to 6 As shown, the first self-positioning structure includes positioning posts 1.1 symmetrically arranged at the left and right ends of the front frame 1 and slots 2.2 symmetrically arranged at the left and right ends of the front anti-collision beam 2. The slot 2.2 at the left end of the front anti-collision beam 2 is fitted onto the positioning post 1.1 at the left end of the front frame 1, and the slot 2.2 at the right end of the front anti-collision beam 2 is fitted onto the positioning post 1.1 at the right end of the front frame 1. The front anti-collision beam 2 forms XZ-direction positioning by cooperating with the positioning posts 1.1 at the left and right ends of the front frame 1 through the slots 2.2 at the upper left and upper right ends. Specifically, both the front frame 1 and the front anti-collision beam 2 are left-right symmetrical structures, and this left-right orientation is the same as the left-right orientation of the vehicle body. like Figure 4 and Figure 5 As shown, the upper left and lower left ends of the front bumper beam 2 are respectively fastened to the left end of the front frame 1 by two first bolts 4, and the upper right and lower right ends of the front bumper beam 2 are respectively fastened to the right end of the front frame 1 by two first bolts 4. It is a symmetrical installation structure. The lower left and lower right ends of the front bumper beam 2 are each fastened to the front frame 1 by one first bolt 4 through the first elongated hole 2.3 opened on the front bumper beam 2 to form an X-direction positioning on the front frame 1. The front bumper beam 2 and the front frame 1 are fastened together by a total of four first bolts 4 at the upper, lower, left and right positions, and the Y-direction positioning of the front bumper beam 2 on the front frame 1 forms the front frame assembly. Specifically, the first bolt 4 is an M12 bolt. The upper left and upper right ends of the front bumper beam 2 are each provided with a 12mm first circular hole 2.1 through which the first bolt 4 can pass. The upper left and lower right ends of the front bumper beam 2 are each provided with a 16mm (length) * 12mm (width) first elongated circular hole 2.3 through which the first bolt 4 can pass. The long side of the first elongated circular hole 2.3 extends vertically. The front end frame 1 is fixedly provided with a first nut 1.2 that matches each of the four first bolts 4. The first nut 1.2 is an M12 nut. M12 bolt refers to the diameter of the threaded part being 12mm, and the 12mm first circular hole 2.1 refers to the hole diameter being 12mm.
[0040] like Figure 7 As shown, there are two front longitudinal beams 3, which are symmetrically arranged along the vehicle body axis. Each front longitudinal beam 3 has a front longitudinal beam cover plate 5 welded to its front end for mounting the front frame assembly. The two front longitudinal beam cover plates 5 are the left front longitudinal beam cover plate 5.1 and the right front longitudinal beam cover plate 5.2. Each front longitudinal beam cover plate 5 has a front end plate 6 on its front side. The two front end plates 6 are the left front end plate 6.1 and the right front end plate 6. The front end plate 6 and the front longitudinal beam cover plate 5 are positioned in the XYZ direction by a welding fixture 7 and then spot welded together by welding clamps. The front longitudinal beam 3, the front longitudinal beam cover plate 5 and the front end plate 6 constitute the front longitudinal beam assembly. like Figures 8 to 9 As shown, each of the front end plates 6 has a 12mm second circular hole 6.3 on its upper part for inserting an 11.8mm cylindrical pin 7.1 from the upper part of the welding fixture 7, and a 16mm (length) * 12mm (width) second oblong hole 6.4 on its lower part for inserting an 11.8mm cylindrical pin 7.1 from the lower part of the welding fixture 7. The long side of the second oblong hole 6.4 extends vertically; each of the front longitudinal beam cover plates 5 has a 12mm second oblong hole 6.3 on its upper part for inserting an 11.8mm cylindrical pin 7.1 from the lower part of the welding fixture 7. Each front longitudinal beam cover plate 5 has a 16mm third circular hole 5.3 for inserting an 11.8mm cylindrical pin 7.1 at the top of the welding fixture 7, and a 16mm third circular hole 5.3 for inserting a 11.8mm cylindrical pin 7.1 at the bottom of the welding fixture 7. When the front end plate 6 is positioned and welded onto the front longitudinal beam cover plate 5, the welding fixture 7 has 11.8mm cylindrical pins 7.1 at both the top and bottom (this is prior art). (Technical and / or conventional settings) are used for welding positioning. The 11.8mm cylindrical pin 7.1 on the upper part of the welding fixture 7 is sequentially passed through the 12mm second circular hole 6.3 on the upper part of the front end plate 6 and the 16mm third circular hole 5.3 on the upper part of the front longitudinal beam cover plate 5. Similarly, the 11.8mm cylindrical pin 7.1 on the lower part of the welding fixture 7 is sequentially passed through the 16mm (length) * 12mm (width) second elongated circular hole 6.4 on the lower part of the front end plate 6 and the front longitudinal beam cover plate 5. The lower 16mm third circular hole 5.3 is used to achieve YZ-direction positioning before welding. The X-plane of the welding fixture 7 is pressed onto the front end plate 6 and the front longitudinal beam cover plate 5 to form X-direction positioning. After XYZ-direction positioning, the front end plate 6 is welded onto the front longitudinal beam cover plate 5 by spot welding with welding clamps. Before welding, the welding positioning reference of the front end plate 6 can be changed by adjusting the positioning reference on the welding fixture 7, thereby changing the assembly size of the front end frame 1.
[0041] like Figures 10 to 15As shown, a second self-positioning structure is formed between the front frame assembly and the front longitudinal beam assembly, and the front frame assembly is assembled onto the front longitudinal beam assembly through the second self-positioning structure and a plurality of second bolts 8; like Figures 10 to 15 As shown, the second self-positioning structure includes an 8mm positioning pin 2.4 on the left rear sidewall of the front bumper beam 2, an 8mm positioning pin 2.4 on the right rear sidewall of the front bumper beam 2, an 8.2mm fifth circular hole 6.5 on the upper part of the left front end plate 6.1 through which the positioning pin 2.4 passes, a 12mm (length) * 8.2mm (width) third elongated circular hole 6.6 on the upper part of the right front end plate 6.2 through which the positioning pin 2.4 passes, and a 16mm fourth circular hole 5.4 on the upper part of the front longitudinal beam cover plate 5 through which the positioning pin 2.4 passes. The front end frame assembly is assembled on the front end through the second self-positioning structure. When the longitudinal beam assembly is mounted, it is positioned by the front anti-collision beam 2 of the front frame assembly and the front plate 6. The positioning pin 2.4 at the left end of the front anti-collision beam 2 passes through the third elongated hole 6.6 on the left front plate 6.1 and the fourth round hole 5.4 on the left front longitudinal beam cover plate 5.1 in sequence. The positioning pin 2.4 at the right end of the front anti-collision beam 2 passes through the third elongated hole 6.6 on the right front plate 6.2 and the fourth round hole 5.4 on the right front longitudinal beam cover plate 5.2 in sequence. The positioning pin 2.4 on the left side is used for YZ-direction positioning, and the positioning pin 2.4 on the right side is used for Z-direction positioning. The positioning assembly methods on the left and right sides are symmetrical. like Figures 10 to 15 As shown, the left end of the front bumper beam 2 is fastened to the left front end plate 6.1 by four second bolts 8, and the second bolts 8 pass through the left front end plate 6.1 and are threadedly connected to the left front longitudinal beam cover plate 5.1. The right end of the front bumper beam 2 is fastened to the right front end plate 6.2 by four second bolts 8, and the second bolts 8 pass through the right front end plate 6.2 and are threadedly connected to the right front longitudinal beam cover plate 5.2. It is a symmetrical installation structure. The front bumper beam 2 and the front longitudinal beam assembly are fastened together by four second bolts 8 at each end for X-axis positioning. Specifically, the second bolt 8 is an M8 bolt, and the left and right ends of the front anti-collision beam 2 are provided with four ⌀8mm sixth circular holes 2.5 through which the second bolt 8 can pass. Each of the four corners of the front end plate 6 is provided with ⌀8mm seventh circular holes 6.7 through which the second bolt 8 can pass. Each of the four corners of the front longitudinal beam cover plate 5 is provided with M8 threaded holes 5.5 for threaded connection with the second bolt 8.
[0042] Example 2 A method for positioning and assembling a car front-end frame includes the following steps: S1. The left and right ends of the front anti-collision beam 2 are positioned and assembled with the front frame 1 in the XZ direction through the first self-positioning structure. Then, the left and right ends of the front anti-collision beam 2 are respectively tightened on the front frame 1 by two first bolts 4 to achieve Y-direction positioning and form the front frame assembly. In step S1, the slot 2.2 at the left end of the front bumper beam 2 is fitted onto the positioning post 1.1 at the left end of the front frame 1, and the slot 2.2 at the right end of the front bumper beam 2 is fitted onto the positioning post 1.1 at the right end of the front frame 1, thereby forming XZ-direction positioning. The two first bolts 4 pass through the first elongated holes 2.3 at the lower left and lower right ends of the front bumper beam 2, respectively, forming X-direction positioning on the front frame 1. The front bumper beam 2 and the front frame 1 are tightened together at the top, bottom, left, and right positions by a total of four first bolts 4, thereby positioning the front bumper beam 2 in the Y direction on the front frame 1 to form the front frame assembly. S2. Front longitudinal beam cover plates 5 are welded to the front ends of the two front longitudinal beams 3 respectively, and front end plates 6 are welded to the two front longitudinal beam cover plates 5 respectively. During welding, the front end plate 6 and the front longitudinal beam cover plate 5 are first positioned in the XYZ direction by welding fixture 7, and then the front end plate 6 is welded to the front longitudinal beam cover plate 5 by spot welding with welding clamp to form a front longitudinal beam assembly. The assembly size of the front frame 1 can be changed by directly adjusting the positioning reference on the welding fixture 7 according to the positioning reference requirements of the final assembly exterior parts (such as front bumper, headlight, front through light, etc.) on the front frame assembly. In step S2, the 11.8mm cylindrical pin 7.1 on the upper part of the welding fixture 7 is passed through the 12mm second circular hole 6.3 on the upper part of the front end plate 6 and the 16mm third circular hole 5.3 on the upper part of the front longitudinal beam cover plate 5. The 11.8mm cylindrical pin 7.1 on the lower part of the welding fixture 7 is passed through the 16mm (length) * 12mm (width) second elongated circular hole 6.4 on the lower part of the front end plate 6 and the 16mm third circular hole 5.3 on the lower part of the front longitudinal beam cover plate 5 to achieve YZ-direction positioning before welding. The X-plane of the welding fixture 7 is pressed onto the front end plate 6 and the front longitudinal beam cover plate 5 to form X-direction positioning. S3. The left and right ends of the front anti-collision beam 2 of the front frame assembly are positioned and assembled with the left and right ends of the front longitudinal beam assembly through the second self-positioning structure in the YZ direction. Then, the left and right ends of the front anti-collision beam 2 are respectively tightened on the front longitudinal beam assembly by four second bolts 8 to achieve X-direction positioning. In step S3, the positioning pin 2.4 at the left end of the front bumper beam 2 passes through the third elongated hole 6.6 on the left front end plate 6.1 and the fourth round hole 5.4 on the left front longitudinal beam cover plate 5.1 in sequence. The positioning pin 2.4 at the right end of the front bumper beam 2 passes through the third elongated hole 6.6 on the right front end plate 6.2 and the fourth round hole 5.4 on the right front longitudinal beam cover plate 5.2 in sequence. The positioning pin 2.4 on the left side is used for YZ-direction positioning, and the positioning pin 2.4 on the right side is used for Z-direction positioning. The front bumper beam 2 and the front longitudinal beam assembly are tightened by four second bolts 8 at each end for X-direction positioning.
Claims
1. A positioning and connection structure for a car front frame, comprising a front frame (1), a front anti-collision beam (2), and a front longitudinal beam (3), characterized in that: A first self-positioning structure is formed between the front anti-collision beam (2) and the front end frame (1). The front anti-collision beam (2) is assembled on the front end frame (1) through the first self-positioning structure and multiple first bolts (4) to form a front end frame assembly. The front longitudinal beam (3) has two beams, and each front longitudinal beam (3) has a front longitudinal beam cover plate (5) welded to its front end. The two front longitudinal beam cover plates (5) are the left front longitudinal beam cover plate (5.1) and the right front longitudinal beam cover plate (5.2). Each front longitudinal beam cover plate (5) has a front end plate (6) on its front side. The two front end plates (6) are the left front end plate (6.1) and the right front end plate (6.2). The front end plate (6) and the front longitudinal beam cover plate (5) are positioned in the XYZ direction by a welding fixture (7) and then spot welded together by welding clamps. The front longitudinal beam (3), the front longitudinal beam cover plate (5) and the front end plate (6) constitute the front longitudinal beam assembly. A second self-positioning structure is formed between the front frame assembly and the front longitudinal beam assembly. The front frame assembly is assembled onto the front longitudinal beam assembly via the second self-positioning structure and a plurality of second bolts (8).
2. The automotive front-end frame positioning and connection structure according to claim 1, characterized in that: The first self-positioning structure includes positioning posts (1.1) symmetrically arranged at the left and right ends of the front frame (1) and slots (2.2) symmetrically arranged at the left and right ends of the front anti-collision beam (2). The slot (2.2) at the left end of the front anti-collision beam (2) is fitted onto the positioning post (1.1) at the left end of the front frame (1), and the slot (2.2) at the right end of the front anti-collision beam (2) is fitted onto the positioning post (1.1) at the right end of the front frame (1).
3. The automotive front-end frame positioning and connection structure according to claim 2, characterized in that: The upper left end and lower left end of the front anti-collision beam (2) are respectively fastened to the left end of the front end frame (1) by two first bolts (4), and the upper right end and lower right end of the front anti-collision beam (2) are respectively fastened to the right end of the front end frame (1) by two first bolts (4).
4. The automotive front-end frame positioning and connection structure according to any one of claims 1 to 3, characterized in that: Each of the front end plates (6) has a 12mm second circular hole (6.3) on its upper part for inserting an 11.8mm cylindrical pin (7.1) on the upper part of the welding fixture (7), and a 16mm (length) * 12mm (width) second elongated circular hole (6.4) on its lower part for inserting an 11.8mm cylindrical pin (7.1) on the lower part of the welding fixture (7); each of the front longitudinal beam cover plates (5) has a 16mm third circular hole (5.3) on its upper part for inserting an 11.8mm cylindrical pin (7.1) on the upper part of the welding fixture (7), and a 16mm third circular hole (5.3) on its lower part for inserting an 11.8mm cylindrical pin (7.1) on the lower part of the welding fixture (7).
5. The automotive front-end frame positioning and connection structure according to claim 1, characterized in that: The second self-positioning structure includes an 8mm positioning pin (2.4) provided on the rear side wall of the left end of the front anti-collision beam (2), an 8mm positioning pin (2.4) provided on the rear side wall of the right end of the front anti-collision beam (2), an 8.2mm fifth circular hole (6.5) opened on the upper part of the left front end plate (6.1) for the positioning pin (2.4) to pass through, a 12mm (length) * 8.2mm (width) third elongated circular hole (6.6) opened on the upper part of the right front end plate (6.2) for the positioning pin (2.4) to pass through, and a 16mm fourth circular hole (5.4) opened on the upper part of the front longitudinal beam cover plate (5) for the positioning pin (2.4) to pass through.
6. The automotive front-end frame positioning and connection structure according to claim 5, characterized in that: The left end of the front anti-collision beam (2) is fastened to the left front end plate (6.1) by four second bolts (8), and the second bolts (8) pass through the left front end plate (6.1) and are threadedly connected to the left front longitudinal beam cover plate (5.1). The right end of the front anti-collision beam (2) is fastened to the right front end plate (6.2) by four second bolts (8), and the second bolts (8) pass through the right front end plate (6.2) and are threadedly connected to the right front longitudinal beam cover plate (5.2).
7. A method for assembling a vehicle front-end frame, used for assembling the vehicle front-end frame positioning and connection structure according to any one of claims 1 to 6, characterized in that: Includes the following steps: S1. The left and right ends of the front anti-collision beam (2) are positioned and assembled with the front frame (1) in the XZ direction through the first self-positioning structure. Then, the left and right ends of the front anti-collision beam (2) are respectively tightened on the front frame (1) by two first bolts (4) to achieve Y-direction positioning and form the front frame assembly. S2. Weld front longitudinal beam cover plates (5) to the front ends of the two front longitudinal beams (3) respectively, and weld front end plates (6) to the two front longitudinal beam cover plates (5) respectively. During welding, the front end plate (6) and the front longitudinal beam cover plate (5) are first positioned in the XYZ direction by welding fixture (7), and then the front end plate (6) is welded to the front longitudinal beam cover plate (5) by spot welding with welding clamp to form the front longitudinal beam assembly. S3. The left and right ends of the front anti-collision beam (2) of the front frame assembly are positioned and assembled in the YZ direction with the left and right ends of the front longitudinal beam assembly through the second self-positioning structure. Then, the left and right ends of the front anti-collision beam (2) are respectively tightened on the front longitudinal beam assembly by four second bolts (8) to achieve X-direction positioning.
8. The automotive front-end frame positioning and assembly method according to claim 7, characterized in that: In step S1, the slot (2.2) at the left end of the front bumper beam (2) is fitted onto the positioning post (1.1) at the left end of the front frame (1), and the slot (2.2) at the right end of the front bumper beam (2) is fitted onto the positioning post (1.1) at the right end of the front frame (1), thereby forming XZ-direction positioning. The two first bolts (4) pass through the first elongated holes (2.3) at the lower left and lower right ends of the front bumper beam (2) respectively to form X-direction positioning on the front frame (1). The front bumper beam (2) and the front frame (1) are tightened together at the upper, lower, left and right positions by a total of four first bolts (4), and the Y-direction positioning of the front bumper beam (2) on the front frame (1) is formed to form the front frame assembly.
9. The automotive front-end frame positioning and assembly method according to claim 7, characterized in that: In step S2, the 11.8mm cylindrical pin (7.1) on the upper part of the welding fixture (7) is passed through the 12mm second round hole (6.3) on the upper part of the front end plate (6) and the 16mm third round hole (5.3) on the upper part of the front longitudinal beam cover plate (5). The 11.8mm cylindrical pin (7.1) on the lower part of the welding fixture (7) is passed through the 16mm (length) * 12mm (width) second elongated round hole (6.4) on the lower part of the front end plate (6) and the 16mm third round hole (5.3) on the lower part of the front longitudinal beam cover plate (5) to achieve YZ-direction positioning before welding. The X-plane of the welding fixture (7) is pressed onto the front end plate (6) and the front longitudinal beam cover plate (5) to form X-direction positioning.
10. The automotive front-end frame positioning and assembly method according to claim 7, characterized in that: In step S3, the positioning pin (2.4) at the left end of the front anti-collision beam (2) passes through the third elongated hole (6.6) on the left front end plate (6.1) and the fourth round hole (5.4) on the left front longitudinal beam cover plate (5.1) in sequence. The positioning pin (2.4) at the right end of the front anti-collision beam (2) passes through the third elongated hole (6.6) on the right front end plate (6.2) and the fourth round hole (5.4) on the right front longitudinal beam cover plate (5.2) in sequence. The positioning pin (2.4) on the left side is used for YZ-direction positioning, and the positioning pin (2.4) on the right side is used for Z-direction positioning. The front anti-collision beam (2) and the front longitudinal beam assembly are tightened by four second bolts (8) at each end for X-direction positioning.