A stamping process method for a back door inner panel of a hatchback

Abstract

The application relates to a stamping process method for a back door inner plate of a hatchback, which comprises the following steps: firstly, placing a back door inner plate blank into a drawing die, stamping the back door inner plate blank by the drawing die, and drawing the back door inner plate blank into a back door inner plate drawing piece with the back door guard plate mounting surface facing upwards; then, placing the back door inner plate drawing piece into a rough trimming die, and trimming the outer peripheral line and the window frame line of the back door inner plate drawing piece to partially cut off a process supplement surface to form a rough trimming back door inner plate workpiece; finally, placing the rough trimming back door inner plate workpiece into a fine trimming die, and trimming the residual process supplement surface of the back door inner plate workpiece by the fine trimming die. According to the application, the back door guard plate mounting surface faces upwards to draw the back door inner plate blank, so that the process supplement surface is closer to the product, the drawing depth of the back door inner plate is reduced, and the problems of drawing cracking caused by the excessively deep drawing depth of the back door inner plate and the difficult guarantee of size precision and surface quality caused by subsequent shaping are prevented.

Description

Technical Field

[0001] This application relates to the field of vehicle tailgate inner panel manufacturing technology, and particularly to a stamping process method for the tailgate inner panel of a hatchback automobile. Background Technology

[0002] The tailgate, also known as the tailgate or rear door, is located at the rear of the car and serves to protect and cover passengers or stored items. It is suspended from the rear crossbeam of the roof by two chains. Traditional tailgates create a large exhaust vortex at the rear of the car, which is detrimental to air resistance and reduces the vehicle's power and fuel economy. In contrast, hatchback tailgates have smaller exhaust vortices and wake areas, resulting in less aerodynamic drag. Therefore, the vast majority of new energy electric vehicles on the market now adopt a hatchback design.

[0003] See Figure 1 As shown, the hatchback tailgate inner panel has a significant structural undulation and deep drawing depth, typically requiring four or five stamping processes. It is one of the key structural components that tests the stamping process level. Below is a hatchback door of one of our company's models. This part has a particularly complex shape, with large curvature and dramatic internal structural changes. The shapes in the hinge, electric support rod, and automatic door lock mounting areas are complex, which severely tests the stamping process level.

[0004] In related technologies, the stamping process for the inner panel parts of a hatchback tailgate consists of four steps, which are briefly described below:

[0005] First step: Drawing process, see below. Figure 2 As shown, the work involves drawing the parts with the protective plate mounting surface facing down to form most of the part shapes.

[0006] Second step: Trimming and punching, see below. Figure 3 As shown, the work involves trimming the upper and lower sections of the part with beveled edges, trimming the window area and the vertical edges on both sides, punching the mounting holes of the middle guard plate, and trimming the beveled edges of the surrounding weight-reducing holes.

[0007] The third step, shaping and punching, see below. Figure 4 As shown, the work involves punching holes for hinge mounting holes, shaping the flange edge of the part downwards around its perimeter, shaping the inner flange edge of the window upwards, and shaping the mounting hole area of ​​the electric strut bracket upwards.

[0008] Fourth step, trimming and punching, see below. Figure 5 As shown, the work involves completing the remaining trimming and punching.

[0009] However, the above-mentioned stamping process for the hatchback tailgate inner panel has the following drawbacks:

[0010] First, excessive drawing depth in the process, especially in the area where the electric strut is installed, is particularly prone to forming cracks. To solve this problem, the general approach is to reduce the drawing depth in this area to prevent cracking, and then complete the shaping process in subsequent steps. However, excessive shaping can lead to unstable dimensional accuracy and defects such as surface scratches.

[0011] Secondly, the punching direction is from the inside of the product to the outside. This will cause all the burrs formed by the punching to face outwards. The problem is that when installing the rear door inner panel, the burrs will press against the panel mounting surface, which can easily cause the rear door inner panel to become loose or not installed properly. Over time, the rear door inner panel will fall off.

[0012] Third, the forming range is too large. In order to make the first-stage drawing depth as shallow as possible, a large number of surface structures need to be formed in subsequent processes, making it difficult to guarantee dimensional accuracy and surface quality. Among them, the interior of the window and the mounting surface of the ejector pin are formed in the upper form, making the mold structure particularly complex and difficult to maintain in daily life. Summary of the Invention

[0013] This application provides a stamping process for the tailgate inner panel of a hatchback vehicle to solve the problem of excessive drawing depth in related technologies, especially in the area of ​​the electric strut, which is particularly prone to forming cracks.

[0014] This application provides a method for stamping the tailgate inner panel of a hatchback vehicle, the method comprising:

[0015] In the rear door inner panel drawing process, the rear door inner panel blank is placed into the drawing die, the drawing die presses the rear door inner panel blank, and the rear door inner panel blank is drawn into a rear door inner panel drawing part with the rear door guard panel mounting surface facing up in one go.

[0016] In the rough trimming process of the back door inner panel, the drawn part of the back door inner panel is placed into the rough trimming mold. The rough trimming mold performs partial trimming on the outer perimeter line and window frame edge line of the drawn part of the back door inner panel. The partial removal process supplements the surface to form the back door inner panel workpiece after rough trimming.

[0017] In the process of fine trimming the back door inner panel, the back door inner panel workpiece after rough trimming is placed into the fine trimming mold. The fine trimming mold performs fine trimming on the remaining process supplementary surfaces of the back door inner panel workpiece to form the trimmed back door inner panel workpiece.

[0018] In some embodiments, the rough trimming process of the back door inner panel specifically includes the following steps:

[0019] In the first rough trimming process of the back door inner panel, the back door inner panel drawing part is placed into the first rough trimming die. The first trimming die performs local straight trimming on the outer perimeter line and window frame edge line of the back door inner panel drawing part, so as to partially remove the process supplement surface to form a back door inner panel workpiece with remaining process supplement surface.

[0020] In the second rough trimming process of the back door inner panel, the back door inner panel workpiece from the previous process is placed into the second trimming mold. The second trimming mold performs straight trimming on the remaining process supplementary surfaces around the back door inner panel drawing part and the window frame edge line to form the back door inner panel workpiece after rough trimming.

[0021] In some embodiments, the first rough trimming process of the back door inner panel further includes using a first rough trimming mold to perform rough trimming on the center position of the tail area of ​​the back door inner panel drawing part. The width of the rough trimming of the tail area of ​​the back door inner panel drawing part is 250-300mm, and the distance between the edge line of the rough trimming of the tail area of ​​the back door inner panel drawing part and the product edge line is 5-8mm.

[0022] In some embodiments, the first rough trimming process of the back door inner panel further includes using a first rough trimming mold to rough trim the process supplementary surfaces of the front and rear parts of the electric strut mounting areas on both sides of the back door inner panel drawing part, so as to retain the process supplementary surfaces of the electric strut mounting areas on both sides of the back door inner panel drawing part.

[0023] In some embodiments, the second rough trimming process of the rear door inner panel further includes using a second rough trimming die to punch a straight hole in the rear door panel mounting surface of the rear door inner panel drawing part, wherein the direction of the straight hole punching is from top to bottom.

[0024] In some embodiments, the second rough trimming process of the rear door inner panel further includes punching holes in the rear door panel mounting surface of the rear door inner panel drawing part using a second rough trimming die, so as to form a plurality of weight reduction holes in the rear door panel mounting surface of the rear door inner panel drawing part.

[0025] In some embodiments, the second rough trimming process of the back door inner panel further includes using a second rough trimming mold to rough trim the electric strut mounting areas on both sides of the back door inner panel drawing, so as to remove part of the process supplement surface of the electric strut mounting areas on both sides of the back door inner panel drawing.

[0026] In some embodiments, the finishing edge mold for finishing the remaining process supplementary surface of the back door inner panel workpiece specifically includes:

[0027] The fine trimming mold trims the edges along the product edge lines of the electric strut installation areas on both sides of the back door inner panel workpiece using trimming wedges, and trims the edges along the product edge lines of the tail area of ​​the back door inner panel workpiece using hook trimming wedges.

[0028] In some embodiments, the hook trimming wedge is further provided with a scrap cutter to cut off the process supplement surface of the tail area of ​​the back door inner panel workpiece.

[0029] In some embodiments, the edge trimming process of the rear door inner panel further includes punching holes in the mounting surface of the rear door panel to form door lock mounting holes.

[0030] The beneficial effects of the technical solution provided in this application include:

[0031] This application provides a stamping process for the tailgate inner panel of a hatchback automobile. The process involves first placing the tailgate inner panel blank into a drawing die, which then stamps the blank to form a tailgate inner panel drawing with the rear tailgate trim panel mounting surface facing upwards. Next, the drawn tailgate inner panel is placed into a rough trimming die, which partially trims the outer perimeter and window frame edges of the drawing, removing some of the process-added surfaces to form a roughly trimmed tailgate inner panel workpiece. Finally, the roughly trimmed tailgate inner panel workpiece is placed into a fine trimming die, which finely trims the remaining process-added surfaces to form a trimmed tailgate inner panel workpiece.

[0032] Therefore, the tailgate inner panel stamping process of this application employs a tailgate inner panel drawing process, a tailgate inner panel rough trimming process, and a tailgate inner panel fine trimming process to process and manufacture the tailgate inner panel. In the tailgate inner panel drawing process, the drawing die stamps the tailgate inner panel blank, drawing the blank in one go into a tailgate inner panel drawing with the rear tailgate trim panel mounting surface facing upwards. Drawing the tailgate inner panel blank with the rear tailgate trim panel mounting surface facing upwards brings the process supplement surface closer to the product, thereby reducing the tailgate inner panel drawing depth and preventing drawing cracks caused by excessive drawing depth or problems with dimensional accuracy and surface quality that are difficult to guarantee in subsequent shaping. The use of the tailgate inner panel rough trimming and fine trimming processes for trimming the tailgate inner panel eliminates the shaping process, ensuring the dimensional accuracy and surface quality requirements of the tailgate inner panel workpiece. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the structure of the rear door inner panel workpiece;

[0035] Figure 2 This is a structural schematic diagram of the first drawing process in the background art;

[0036] Figure 3 This is a structural schematic diagram of the second-order trimming and punching process in the background art;

[0037] Figure 4 This is a structural schematic diagram of the third-order shaping and punching process in the background art;

[0038] Figure 5 This is a structural schematic diagram of the fourth-order trimming and punching process in the background art;

[0039] Figure 6 This is a structural schematic diagram of the back door inner panel drawing process according to an embodiment of this application;

[0040] Figure 7 This is a structural schematic diagram of the first rough trimming process of the back door inner panel in an embodiment of this application;

[0041] Figure 8 This is a schematic diagram of the structure for rough trimming the center position of the tail area of ​​the back door inner panel drawing part according to an embodiment of this application;

[0042] Figure 9 This is a structural schematic diagram of the second rough trimming process of the back door inner panel in an embodiment of this application;

[0043] Figure 10 This is a schematic diagram of the structure for rough trimming the electric strut mounting areas on both sides of the back door inner panel drawing part according to an embodiment of this application;

[0044] Figure 11 This is a structural schematic diagram of the edge trimming process of the back door inner panel in an embodiment of this application. Detailed Implementation

[0045] 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.

[0046] This application provides a stamping process for the tailgate inner panel of a hatchback vehicle, which can solve the problem of excessive drawing depth in related technologies, especially in the area of ​​the electric strut, where forming cracks are particularly prone to occur.

[0047] See Figures 6 to 11 As shown in the figure, this application provides a stamping process method for the tailgate inner panel of a hatchback automobile, the method comprising:

[0048] Step 1: Back door inner panel drawing process. Place the back door inner panel blank into the drawing die. The drawing die presses the back door inner panel blank and draws the back door inner panel blank into a back door inner panel drawing part with the rear door guard panel mounting surface facing up in one go.

[0049] Step 2: Rough trimming process of the back door inner panel. The back door inner panel drawing is placed into the rough trimming mold. The rough trimming mold performs partial trimming on the outer perimeter line and window frame edge line of the back door inner panel drawing. The partial removal process supplements the surface to form the rough trimmed back door inner panel workpiece.

[0050] Step 3: Fine trimming of the rear door inner panel. The rough trimmed rear door inner panel workpiece is placed into the fine trimming mold. The fine trimming mold performs fine trimming on the remaining finishing surfaces of the rear door inner panel workpiece to form... Figure 1 The trimmed back door inner panel workpiece is shown.

[0051] The tailgate inner panel stamping process of the hatchback automobile of this application embodiment adopts a tailgate inner panel drawing process, a tailgate inner panel rough trimming process, and a tailgate inner panel fine trimming process to process and manufacture the tailgate inner panel. In the tailgate inner panel drawing process, the drawing die stamps the tailgate inner panel blank, and draws the tailgate inner panel blank into a tailgate inner panel drawing part with the rear tailgate panel mounting surface facing upward in one go.

[0052] The rear door panel is drawn with the mounting surface facing upwards, so that the process supplement surface on the pressure ring is closer to the product. This reduces the drawing depth of the rear door panel and prevents problems such as drawing cracks caused by excessive drawing depth or difficulty in ensuring dimensional accuracy and surface quality in subsequent shaping.

[0053] The rear door inner panel is trimmed using both rough and fine trimming processes, eliminating the need for a shaping process and ensuring the dimensional accuracy and surface quality of the workpiece. Simultaneously, the rough trimming die locally trims the outer perimeter and window frame edges of the drawn rear door inner panel, reducing the use of scrap cutters and minimizing the negative impact of scrap material on product quality.

[0054] In some alternative embodiments, see Figures 7 to 10 As shown in the figure, this application provides a stamping process method for the tailgate inner panel of a hatchback automobile. The rough trimming process of the tailgate inner panel of this method specifically includes the following steps:

[0055] In the first rough trimming process of the back door inner panel, the drawn back door inner panel is placed into the first rough trimming die. The first trimming die performs local straight trimming on the outer perimeter line and window frame edge line of the drawn back door inner panel, so as to partially remove the process supplement surface to form a back door inner panel workpiece with remaining process supplement surface.

[0056] In the second rough trimming process of the back door inner panel, the back door inner panel workpiece from the previous process is placed into the second trimming mold. The second trimming mold performs straight trimming on the remaining process supplementary surfaces around the back door inner panel drawing part and the window frame edge line to form the back door inner panel workpiece after rough trimming.

[0057] In this embodiment, the rough trimming process for the back door inner panel is configured as a two-step process: a first rough trimming process for the back door inner panel and a second rough trimming process for the back door inner panel. The first rough trimming process for the back door inner panel is used to partially remove the outer perimeter line of the back door inner panel drawing and the window frame edge line as process supplementary surfaces.

[0058] The first rough trimming process of the back door inner panel is used to straighten the remaining process supplementary surfaces around the drawn parts of the back door inner panel and the window frame edge. The first and second rough trimming processes of the back door inner panel work together to remove the process supplementary surfaces, avoiding the problem of waste chips generated by using a scrap knife to remove the process supplementary surfaces.

[0059] In some alternative embodiments, see Figure 7 and Figure 8 As shown in the embodiment of this application, a stamping process method for the tail door inner panel of a hatchback automobile is provided. The first rough trimming process of the tail door inner panel further includes using a first rough trimming die to rough trim the center position of the tail area of ​​the tail door inner panel drawing. The width 'a' of the rough trimming of the tail area of ​​the tail door inner panel drawing is 250-300mm, and the distance 'b' between the edge line of the rough trimming of the tail area of ​​the tail door inner panel drawing and the edge line of the product is 5-8mm.

[0060] In some alternative embodiments, see Figure 7 and Figure 9 As shown, this application embodiment provides a stamping process method for the tailgate inner panel of a hatchback automobile. The first rough trimming process of the tailgate inner panel further includes using a first rough trimming die to rough trim the process supplementary surfaces of the front and rear parts of the electric strut mounting areas on both sides of the tailgate inner panel drawing, so as to retain the process supplementary surfaces of the electric strut mounting areas on both sides of the tailgate inner panel drawing.

[0061] The second rough trimming process of the back door inner panel also includes using a second rough trimming mold to rough trim the electric strut installation area on both sides of the back door inner panel drawing part, so as to remove part of the process supplement surface of the electric strut installation area on both sides of the back door inner panel drawing part.

[0062] In some alternative embodiments, see Figure 9 and Figure 10 As shown in the figure, this application embodiment provides a stamping process method for the tailgate inner panel of a hatchback automobile. The second rough trimming process of the tailgate inner panel of this method further includes using a second rough trimming die to punch a straight hole in the rear tailgate panel mounting surface of the tailgate inner panel drawing part. The direction of the straight hole punching is from top to bottom.

[0063] The second rough trimming die punches holes from top to bottom to form mounting holes for the rear door inner panel. When installing the rear door inner panel, the burrs in the holes face the inside of the rear door inner panel and will not press against the panel mounting surface, thus preventing the rear door inner panel from becoming loose or not installed properly, which could lead to the rear door inner panel falling off over time.

[0064] The second rough trimming process of the rear door panel also includes punching holes on the rear door panel mounting surface of the rear door panel drawing part using a second rough trimming die, so as to form multiple weight-reducing holes on the rear door panel mounting surface of the rear door panel drawing part, thereby reducing the weight of the rear door panel and realizing the lightweight design of the rear door panel.

[0065] In some alternative embodiments, see Figure 9 and Figure 10 As shown in the figure, this application provides a stamping process method for the tailgate inner panel of a hatchback automobile. The method's finishing die specifically includes finishing the remaining process surfaces of the tailgate inner panel workpiece by:

[0066] The fine trimming mold trims the edges along the product edge lines of the electric strut installation areas on both sides of the back door inner panel workpiece using trimming wedges, and trims the edges along the product edge lines of the tail area of ​​the back door inner panel workpiece using hook trimming wedges.

[0067] The hook trimming wedge is also equipped with a scrap cutter to cut off the process supplement surface of the tail area of ​​the rear door inner panel workpiece. The scrap cutter cuts off the process supplement surface of the tail area of ​​the rear door inner panel workpiece to facilitate the removal of scrap material. The finishing edge process of the rear door inner panel also includes punching holes in the mounting surface of the rear door panel to form door lock mounting holes.

[0068] Working principle

[0069] This application provides a stamping process for the tailgate inner panel of a hatchback automobile. The tailgate inner panel stamping process of this application first places the tailgate inner panel blank into a drawing die, and the drawing die stamps the tailgate inner panel blank, drawing the tailgate inner panel blank into a tailgate inner panel drawing part with the rear tailgate guard panel mounting surface facing up in one go.

[0070] Then, the back door inner panel drawing part is placed into the rough trimming die. The rough trimming die performs partial trimming on the outer perimeter line and window frame edge line of the back door inner panel drawing part, and the partial removal process supplements the surface to form the back door inner panel workpiece after rough trimming.

[0071] Finally, the rough trimmed back door inner panel workpiece is placed into the fine trimming mold. The fine trimming mold performs fine trimming on the remaining process supplementary surfaces of the back door inner panel workpiece to form the trimmed back door inner panel workpiece.

[0072] Therefore, the tailgate inner panel stamping process of this application employs a tailgate inner panel drawing process, a tailgate inner panel rough trimming process, and a tailgate inner panel fine trimming process to process and manufacture the tailgate inner panel. In the tailgate inner panel drawing process, the drawing die stamps the tailgate inner panel blank, drawing the tailgate inner panel blank into a tailgate inner panel drawing part with the rear tailgate trim panel mounting surface facing upward in one go.

[0073] The rear door panel is drawn with the mounting surface facing upwards, bringing the process supplement surface closer to the product. This reduces the drawing depth of the rear door panel and prevents problems such as drawing cracks caused by excessive drawing depth or difficulties in ensuring dimensional accuracy and surface quality during subsequent shaping.

[0074] The back door inner panel is trimmed using a rough trimming process and a fine trimming process, which eliminates the need for a shaping process and ensures the dimensional accuracy and surface quality requirements of the back door inner panel workpiece.

[0075] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0076] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0077] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A stamping process for the tailgate inner panel of a hatchback automobile, characterized in that, The method includes: In the rear door inner panel drawing process, the rear door inner panel blank is placed into the drawing die, the drawing die presses the rear door inner panel blank, and the rear door inner panel blank is drawn into a rear door inner panel drawing part with the rear door guard panel mounting surface facing up in one go. In the rough trimming process of the back door inner panel, the drawn part of the back door inner panel is placed into the rough trimming mold. The rough trimming mold performs partial trimming on the outer perimeter line and window frame edge line of the drawn part of the back door inner panel. The partial removal process supplements the surface to form the back door inner panel workpiece after rough trimming. In the process of fine trimming the back door inner panel, the back door inner panel workpiece after rough trimming is placed into the fine trimming mold. The fine trimming mold performs fine trimming on the remaining process supplementary surfaces of the back door inner panel workpiece to form the trimmed back door inner panel workpiece. The rough trimming process for the back door inner panel specifically includes the following steps: In the first rough trimming process of the back door inner panel, the back door inner panel drawing part is placed into the first rough trimming die. The first trimming die performs local straight trimming on the outer perimeter line and window frame edge line of the back door inner panel drawing part, so as to partially remove the process supplement surface to form a back door inner panel workpiece with remaining process supplement surface. In the second rough trimming process of the back door inner panel, the back door inner panel workpiece from the previous process is placed into the second trimming mold. The second trimming mold performs straight trimming on the remaining process supplementary surfaces around the back door inner panel drawing part and the window frame edge line to form the back door inner panel workpiece after rough trimming.

2. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 1, characterized in that: The first rough trimming process of the back door inner panel also includes using a first rough trimming mold to rough trim the center position of the tail area of ​​the back door inner panel drawing part. The width of the rough trimming of the tail area of ​​the back door inner panel drawing part is 250-300mm, and the distance between the edge line of the rough trimming of the tail area of ​​the back door inner panel drawing part and the edge line of the product is 5-8mm.

3. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 1, characterized in that: The first rough trimming process of the back door inner panel also includes using the first rough trimming mold to rough trim the process supplementary surfaces of the front and rear parts of the electric strut installation area on both sides of the back door inner panel drawing part, so as to retain the process supplementary surfaces of the electric strut installation area on both sides of the back door inner panel drawing part.

4. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 1, characterized in that: The second rough trimming process of the back door inner panel also includes using a second rough trimming mold to punch straight holes in the back door panel mounting surface of the back door inner panel drawing part, wherein the direction of the straight punching holes is from top to bottom.

5. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 1, characterized in that: The second rough trimming process of the rear door inner panel also includes punching holes on the rear door panel mounting surface of the rear door inner panel drawing part using a second rough trimming mold, so as to form multiple weight reduction holes on the rear door panel mounting surface of the rear door inner panel drawing part.

6. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 1, characterized in that: The second rough trimming process of the back door inner panel also includes using a second rough trimming mold to rough trim the electric strut installation areas on both sides of the back door inner panel drawing part, so as to remove part of the process supplement surface of the electric strut installation areas on both sides of the back door inner panel drawing part.

7. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 1, characterized in that, The finishing edge mold is used to finish the remaining process supplementary surfaces of the back door inner panel workpiece, specifically including: The fine trimming mold trims the edges along the product edge lines of the electric strut installation areas on both sides of the back door inner panel workpiece using trimming wedges, and trims the edges along the product edge lines of the tail area of ​​the back door inner panel workpiece using hook trimming wedges.

8. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 7, characterized in that: The hook trimming wedge is also equipped with a scrap cutter to cut off the process supplement surface of the tail area of ​​the back door inner panel workpiece.

9. The stamping process for the tailgate inner panel of a hatchback automobile as described in claim 7, characterized in that: The finishing process of the rear door inner panel also includes punching holes in the mounting surface of the rear door panel to form door lock mounting holes.

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