Forming process of automobile lift door gas spring reinforcing outer plate

Abstract

The application discloses a forming process of a car lift door air spring reinforcing outer plate. Before a forming process, a process is optimized, and then five forming processes are carried out. One side of the body is firstly formed through a first side forming process, and the other side of the body is formed through a second side forming process. Local feeding is carried out during the first side forming process and the second side forming process, and the feeding part is trimmed during a first punching and trimming process and a second punching and trimming process. The first side forming die and the second side forming die are combined into a same set of drawing forming die assembly, and the first punching and trimming die and the second punching and trimming die are combined into a same set of punching and trimming forming die assembly. In this way, the two sides of the product body are separately and sequentially formed through unilateral forming, so that the insufficient strength of the die caused by the narrow width of the middle body is avoided, and the strength of the die is improved and the service life of the die is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of forming process, in particular to a forming process of a gas spring reinforced outer plate of an automobile lift door. BACKGROUND

[0002] At present, the domestic automobile market demand is very large, and the domestic automobile field is developing rapidly. Small trucks, sport utility vehicles, hatchbacks and other vehicles have openings at the rear of the vehicle body, so these vehicles are provided with lift doors that selectively open and close the openings at the rear of the vehicle. The automobile lift door mainly isolates the vehicle and the external environment in the closed state, providing a safe and comfortable environment for the owner. In the prior art, the lift door assembly includes a lift door outer plate assembly and a lift door inner plate assembly, the lift door outer plate assembly is composed of a lift door outer plate and a tail lamp bracket by welding or riveting, and the lift door inner plate assembly is composed of a hinge reinforcement plate assembly, a gas spring bracket assembly, a lock reinforcement plate assembly and a lift door inner plate by welding or riveting. The opening and closing of the automobile lift door is realized through the gas spring bracket assembly, and the gas spring bracket assembly is also connected to the lift door hinge. Whether the lift door is closed manually or under power, the lift door can be supported by a strut when it is opened. In addition, the reinforced outer plate in the gas spring bracket assembly of the lift door is used to support the reinforcement between the back door and the gas spring, and various parts of the reinforced outer plate will be subjected to various loads during operation, and such loads cause deflection at multiple points relative to the outer plate.

[0003] As shown in the accompanying drawings, Figure 1 The automobile lift door gas spring reinforced outer plate body 1-1 itself is a long strip-shaped plate part, which has various shaped holes 1-2 and concave-convex grooves 1-3, and various bends 1-4. The two sides of the body 1-1 are respectively provided with asymmetrically designed first and second side walls, the first side wall is provided with a side wing I 1-5, and the second side wall is provided with a side wing II 1-6. The side wing I 1-5 is a square plate part, and a notch is provided at the free end edge thereof. The side wing II 1-6 is a thin strip-shaped rod part, and a hole-equipped boss 1-7 is further provided at the transition with the second side wall. In the prior art, in order to achieve the purpose of lightening the automobile, the automobile lift door gas spring reinforced outer plate is made of aluminum material with a thickness of 2.5 mm, which has the advantages of high strength and light weight. The aluminum material is formed into the required product by one-time stretching forming process.

[0004] However, the product formed by one-time stretching forming has the following disadvantages:

[0005] Firstly, since the width of the body part of the product is relatively narrow, only 30 mm, the strength of the die at this part is insufficient to withstand the reaction force generated during pressing, so the die is easily damaged, thereby shortening its service life;

[0006] Secondly, due to the complex shape of the product and the asymmetric design of the two sides of the body, the product after one-time stretch forming has the phenomenon of local cracking at the edge and the phenomenon of torsional springback at the bent corner, so that the size and precision requirements of the formed product cannot be guaranteed. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a forming process for an automobile lift door gas spring reinforcing outer plate, which can prolong the service life of the mold, avoid the phenomena of local cracking and local torsional springback of the formed product, guarantee the size and precision requirements of the formed product, and further improve the product qualification rate.

[0008] To solve the above technical problems, the forming process for an automobile lift door gas spring reinforcing outer plate provided by the present application first optimizes the automobile lift door gas spring reinforcing outer plate before the forming process, then performs five forming processes in turn, which are blanking process, first side forming process, second side forming process, one-time punching and trimming process, and two-time punching and trimming process. The above five processes are formed by blanking forming mold, first side forming mold, second side forming mold, one-time punching and trimming mold, and two-time punching and trimming mold in turn, and get blanking semi-finished product, first side forming semi-finished product, second side forming semi-finished product, one-time punching and trimming semi-finished product, and finished product in turn. One side of the body of the automobile lift door gas spring reinforcing outer plate along the length direction is first formed by the first side forming process, and then the other side of the body is formed by the second side forming process. And, local feeding is performed during the first side forming process and the second side forming process, and the feeding part is trimmed during the one-time punching and trimming process and the two-time punching and trimming process. The first side forming mold and the second side forming mold are combined into the same pair of stretch forming mold assembly, and the one-time punching and trimming mold and the two-time punching and trimming mold are combined into the same pair of punching and trimming forming mold assembly.

[0009] The step of first optimizing the automobile lift door gas spring reinforcing outer plate before the forming process is as follows:

[0010] 1) Use a high-precision three-dimensional laser scanner to scan the product;

[0011] 2) Based on the product's digital model, fit the scanning results to the product's digital model;

[0012] 3) Make a one-to-one displacement comparison line on the product and the scanning surface respectively;

[0013] 4) Use the displacement comparison line obtained in step 3) to complete the compensation of the mold surface, so as to obtain a new compensation surface.

[0014] In step 2), according to the geometric dimension tolerance drawing of the product, 3 face references and 2 hole references are fitted.

[0015] In steps 3) and 4), the selection principle of the displacement contrast line is to avoid the round corners of the product and pay attention to the projection direction of the line, and the reference line on the product and the line on the scanning surface are one-to-one corresponding and equal in length.

[0016] All the forming dies in the five forming processes are one die two outputs, and are respectively located on the front and rear sides of the die.

[0017] In the stretching forming die assembly, the upper die assembly of the first side forming die and the upper die assembly of the second side forming die are connected to the upper die fixing plate of the forming die assembly, the lower die assembly of the first side forming die and the lower die assembly of the second side forming die are connected to the lower die fixing plate of the forming die assembly, and the front and rear two forming cavities of the primary forming die and the front and rear two forming cavities of the secondary forming die are arranged side by side.

[0018] In the first side forming process, the first side forming die forms the first side of the product, including the first side wall and the wing I, and also forms the middle long strip-shaped body of the product and the concave-convex groove and the bending on the body; in the second side forming process, the second side forming die forms the second side of the product, including the second side wall and the wing II and the boss at the connection between the wing II and the second side wall.

[0019] In the punching and trimming forming die assembly, the upper die assembly of the primary punching and trimming die and the upper die assembly of the secondary punching and trimming die are connected to the upper die fixing plate of the punching and trimming forming die assembly, the lower die assembly of the primary punching and trimming die and the lower die assembly of the secondary punching and trimming die are connected to the lower die fixing plate of the punching and trimming forming die assembly, and the front and rear two forming cavities of the primary punching and trimming die and the front and rear two forming cavities of the secondary punching and trimming die are arranged side by side.

[0020] The outer side of each forming die block forming the forming cavity in each pair of forming die is provided with a limiting device; the limiting device comprises a limiting piece, the lower end of the limiting piece is detachably connected to the lower die assembly, and the upper end of the limiting piece is clamped in the limiting groove of the forming die block.

[0021] The limiting piece comprises an L-shaped horizontal block and a vertical block connected as a whole, the horizontal block is provided with a positioning hole for positioning with the mounting groove on the lower die assembly and a long waist hole for detachable connection with the lower die assembly, and the upper end of the vertical block is accommodated in the limiting groove of the forming die block; the side surface of the vertical block facing the forming cavity comprises a lower plane, an upper inclined surface and an upper arc surface connected in sequence from bottom to top.

[0022] Compared with the prior art, the present application has the following advantages after adopting the above forming process:

[0023] Since the aluminum plate is sequentially formed through the blanking forming process, the first side forming process, the second side forming process, the first punching and trimming forming process and the second punching and trimming forming process, especially, the unilateral forming is sequentially performed on both sides of the product body, the strength deficiency caused by the narrow width of the mold at the middle body is avoided, thereby improving the mold strength and prolonging the service life of the mold. In addition, the first side forming mold and the second side forming mold are combined into the same pair of stretch forming mold assembly, and the first punching and trimming forming mold and the second punching and trimming forming mold are combined into the same pair of punching and trimming forming mold assembly, on the one hand, the number of molds is reduced, the production cost is greatly reduced, on the other hand, the assembly can be concentrated after the assembly, the assembly can be produced in a flow line, the production efficiency can be greatly improved, on the other hand, the same pair of mold assembly ensures that the semi-finished product after the previous process can be sent to the next process as soon as possible, and the forming positioning precision is further ensured, and the quality of the formed product is further ensured. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structure schematic diagram of the automobile lift door gas spring reinforcing outer plate involved in the present application.

[0025] Figure 2 It is a process flow schematic diagram of the forming process of the automobile lift door gas spring reinforcing outer plate of the present application.

[0026] Figure 3 It is a structure schematic diagram of the stretch forming mold assembly in the present application.

[0027] Figure 4 It is a structure schematic diagram of the punch trimming forming mold assembly in the present application. Figure 3

[0028] Figure 5 It is a structure schematic diagram of the punch trimming forming mold assembly in the present application.

[0029] Figure 6 It is a structure schematic diagram of the limiting piece in the present application.

[0030] 1, automobile lift door gas spring reinforcing outer plate; 1-1, body; 1-2, first side wall; 1-3, second side wall; 1-4, wing I; 1-5, wing II; 1-6, hole; 1-7, concave-convex groove; 1-8, bend; 1-9, notch; 1-10, boss; 2, blanking semi-finished product; 3, first side forming semi-finished product; 4, second side forming semi-finished product; 5, first punching and trimming semi-finished product; 6, finished product; 7, stretch forming mold assembly; 8, punch trimming forming mold assembly; 9, limiting piece; 9-1, horizontal block; 9-2, vertical block; 9-3, long waist hole; 9-4, positioning hole; 9-5, lower plane; 9-6, upper inclined surface; 9-7, upper arc surface. DETAILED DESCRIPTION​

[0031] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0032] In combination Figures 1-6 As shown in the schematic diagram of the forming process of the automobile lift door gas spring reinforcing outer plate of the application, before the forming process, the automobile lift door gas spring reinforcing outer plate 1 is first subjected to process optimization, and then five forming processes are carried out, which are in turn blanking process, first side forming process, second side forming process, first punching and trimming process and second punching and trimming process. The above-mentioned five processes are in turn formed by blanking forming die, first side forming die, second side forming die, first punching and trimming die and second punching and trimming die, and in turn obtain blanking semi-finished product 2, first side forming semi-finished product 3, second side forming semi-finished product 4, first punching and trimming semi-finished product 5 and finished product 6. One side of the body of the automobile lift door gas spring reinforcing outer plate in the length direction is first formed by the first side forming process, and then the other side of the body is formed by the second side forming process. Moreover, local feeding is carried out during the first side forming process and the second side forming process, and the feeding part is trimmed during the first punching and trimming process and the second punching and trimming process. The first side forming die and the second side forming die are combined into the same pair of stretch forming die assembly 7, and the first punching and trimming die and the second punching and trimming die are combined into the same pair of punching and trimming forming die assembly 8.

[0033] The step of first subjecting the automobile lift door gas spring reinforcing outer plate 1 to process optimization before the forming process is as follows:

[0034] 1) Use a high-precision three-dimensional laser scanner to scan the product;

[0035] 2) Take the product's numerical model as the benchmark, and fit the scanning results to the product numerical model;

[0036] 3) Make a one-to-one displacement comparison line on the product and the scanning surface respectively;

[0037] 4) Use the displacement comparison line obtained in step 3) to complete the compensation of the die surface, thereby obtaining a new compensation surface.

[0038] In step 2), according to the geometric dimension tolerance drawing of the product, 3 face benchmarks and 2 hole benchmarks are used for fitting.

[0039] In steps 3) and 4), the selection principle of the displacement comparison line is to avoid the round corners of the product, and pay attention to the projection direction of the line. The benchmark line on the product and the line on the scanning surface are one-to-one corresponding and equal in length.

[0040] All the molding dies in the five molding processes are dual-outlet dies, located on the front and back sides of the die respectively.

[0041] In the stretch forming die assembly 7, the upper die assembly of the first side forming die and the upper die assembly of the second side forming die are both connected to the upper die fixing plate of the forming die assembly 7, and the lower die assembly of the first side forming die and the lower die assembly of the second side forming die are both connected to the lower die fixing plate of the forming die assembly 7. Furthermore, the front and rear forming cavities of the primary forming die and the front and rear forming cavities of the secondary forming die are arranged side by side.

[0042] In the first side forming process, the first side of the product is formed by the first side forming mold, including the first sidewall 1-2 and the side wing I 1-4, and the middle long strip body 1-1 of the product, as well as the groove 1-7 and the bend 1-8 on the body 1-1 are also formed; in the second side forming process, the second side of the product is formed by the second side forming mold, including the second sidewall 1-3 and the side wing II 1-5, as well as the boss 1-10 at the connection between the side wing II 1-5 and the second sidewall 1-3.

[0043] In the punching and trimming forming mold assembly 8, the upper mold assembly of the primary punching and trimming mold and the upper mold assembly of the secondary punching and trimming mold are both connected to the upper mold fixing plate of the punching and trimming forming mold assembly 8, and the lower mold assembly of the primary punching and trimming mold and the lower mold assembly of the secondary punching and trimming mold are both connected to the lower mold fixing plate of the punching and trimming forming mold assembly 8. Furthermore, the front and rear forming cavities of the primary punching and trimming mold and the front and rear forming cavities of the secondary punching and trimming mold are arranged side by side.

[0044] Each molding simulation block forming the molding cavity in each molding die is provided with a limiting device on its outer side; the limiting device includes a limiting member 9, the lower end of which is detachably connected to the lower die assembly, and the upper end of which is engaged in the limiting groove of the molding simulation block.

[0045] The limiting member 9 includes an L-shaped horizontal block 9-1 and a vertical block 9-2 connected as one piece. The horizontal block 9-1 is provided with a positioning hole 9-4 for positioning with the mounting groove on the lower mold assembly and an elongated hole 9-3 for detachable connection with the lower mold assembly. The upper end of the vertical block 9-2 is accommodated in the limiting groove of the molding simulation block. The side of the vertical block 9-2 facing the molding cavity includes a lower plane 9-5, an upper inclined plane 9-6 and an upper arc surface 9-7 connected in sequence from bottom to top.

[0046] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. For those skilled in the art, all other corresponding modifications made using the technical solutions and concepts of the present invention should fall within the protection scope of the claims of the present invention.

Claims

1. A molding process for a reinforcing outer plate of a car liftgate gas spring, characterized in that: Before the molding process, the following steps are taken to optimize the process of the outer reinforcing plate (1) of the car liftgate gas spring: 1) Use a high-precision 3D laser scanner to scan the product; 2) Using the product's digital model as a reference, and according to the product's geometric dimension tolerance drawings, fit the scan results onto the product's digital model using 3 surface references and 2 hole references. 3) Draw corresponding displacement comparison lines on the product and the scanning surface respectively; the principle for selecting displacement comparison lines is to avoid the rounded corners of the product and pay attention to the projection direction of the lines. The baseline on the product and the line on the scanning surface should correspond one-to-one and have the same length. 4) Use the displacement comparison line obtained in step 3) to complete the compensation of the mold surface, and then wait for the new compensation surface. After the above process optimization is completed, five forming processes are then carried out, namely blanking process, first side forming process, second side forming process, first punching and trimming process, and second punching and trimming process. The above five forming processes are formed by blanking forming mold, first side forming mold, second side forming mold, first punching and trimming mold, and second punching and trimming mold respectively, to obtain blanking semi-finished product (2), first side forming semi-finished product (3), second side forming semi-finished product (4), first punching and trimming semi-finished product (5), and finished product (6); car lifting One side of the body of the door gas spring reinforced outer plate along the length direction is first formed by the first side forming process, and then the other side of the body is formed by the second side forming process; and, local material is added during the first side forming process and the second side forming process, and the material is trimmed during the first punching and trimming process and the second punching and trimming process; the first side forming mold and the second side forming mold are combined into the same stretching forming mold assembly (7), and the first punching and trimming mold and the second punching and trimming mold are combined into the same punching and trimming forming mold assembly (8); All the molding dies in the five molding processes are two-stage dies, located on the front and back sides of the die respectively; In the stretch forming die assembly (7), the upper die assembly of the first side forming die and the upper die assembly of the second side forming die are both connected to the upper die fixing plate of the forming die assembly (7), the lower die assembly of the first side forming die and the lower die assembly of the second side forming die are both connected to the lower die fixing plate of the forming die assembly (7), and the front and rear forming cavities of the primary forming die and the front and rear forming cavities of the secondary forming die are arranged side by side; In the first side forming process, the first side of the product is formed by the first side forming mold, including the first sidewall (1-2) and the side wing I (1-4), and the middle long strip body (1-1) of the product and the groove (1-7) and bend (1-8) on the middle long strip body (1-1) are also formed; in the second side forming process, the second side of the product is formed by the second side forming mold, including the second sidewall (1-3) and the side wing II (1-5) and the boss (1-10) at the connection between the side wing II (1-5) and the second sidewall (1-3); In the punching and trimming forming mold assembly (8), the upper mold assembly of the primary punching and trimming mold and the upper mold assembly of the secondary punching and trimming mold are both connected to the upper mold fixing plate of the punching and trimming forming mold assembly (8), the lower mold assembly of the primary punching and trimming mold and the lower mold assembly of the secondary punching and trimming mold are both connected to the lower mold fixing plate of the punching and trimming forming mold assembly (8), and the front and rear forming cavities of the primary punching and trimming mold and the front and rear forming cavities of the secondary punching and trimming mold are arranged side by side.

2. The molding process of the automotive liftgate gas spring reinforcing outer plate according to claim 1, characterized in that: Each molding simulation block forming the molding cavity in each molding die is provided with a limiting device on its outer side; the limiting device includes a limiting member (9), the lower end of which is detachably connected to the lower mold assembly, and the upper end of which is locked in the limiting groove of the molding simulation block.

3. The molding process of the automotive liftgate gas spring reinforcing outer plate according to claim 2, characterized in that: The limiting member (9) includes an L-shaped horizontal block (9-1) and a vertical block (9-2) that are connected as one piece. The horizontal block (9-1) is provided with a positioning hole (9-4) for positioning with the mounting groove on the lower mold assembly and an elongated hole (9-3) for detachable connection with the lower mold assembly. The upper end of the vertical block (9-2) is accommodated in the limiting groove of the molding simulation block. The side of the vertical block (9-2) facing the molding cavity includes a lower plane (9-5), an upper inclined plane (9-6), and an upper arc surface (9-7) connected in sequence from bottom to top.

Images