CN111633115A - A die structure for sheet springback experiment that can realize multiple stamping process switching - Google Patents

Abstract

The invention relates to a die structure capable of realizing a plate springback experiment for switching between various stamping processes. The die structure is arranged up and down by an upper die and a lower die; the upper die comprises an upper die seat, an upper die pressing plate and a concave die insert; The two concave die inserts are symmetrically fixed on the left and right sides of the center of the lower end of the upper die base, and the upper die pressing material plate can extend between the two concave die inserts when going down; the lower die includes a blank holder, a punch bottom plate, and a punch insert. Block, lower die insert, punch; two lower die inserts are symmetrically fixed on the upper end of the blank holder on the left and right sides of the punch; the punch is fixed on the punch bottom plate, and the punch and the punch insert are fixedly connected; the punch The inserts are coaxially arranged with the upper molding material plate, and the blank holder can be lifted by the machine; the mold structure is drawn and formed through the relative movement of the upper molding material plate and the punching die inserts, the concave die inserts and the lower die inserts Or flanging and stamping sheet. The present invention realizes the punching springback experiment of different thickness plates by three processes of drawing, forming and flanging through a set of die structures.

Description

A die structure for sheet springback experiment that can realize multiple stamping process switching

technical field

The invention relates to a die structure for a plate springback experiment, in particular to a die structure for a plate springback experiment capable of switching between various stamping processes.

Background technique

In actual engineering, the sheet usually needs to pass one or more stamping processes such as drawing, forming, flanging, shaping, etc. to obtain complete parts, but in today's actual stamping production process, most sheet stamping parts have certain springback problems. Among them, the springback problem of high-strength steel plates is more serious. Due to the characteristics of Bauschinger, high strength, high flow stress and low hardening index, such plates tend to produce large springback when cold stamping.

At present, the springback problem in actual production is solved by analyzing the springback law by conducting a punching springback experiment on the sheet. For example, the international standard conference NUMISHEET2011 carried out the drawing and stamping springback experiment of hat-shaped parts, but the designed die structure is only aimed at the springback experiment of one thickness of plate under a single process, and cannot fully grasp the various types of metal plates. Basic characteristics of springback under various stamping processes. By performing various stamping and forming experiments on standard plates, measuring the springback size of the plate is an important means to solve the springback, so as to ensure that the steel factory has a comprehensive understanding of the springback of the metal plate after stamping and forming, and produces high-quality, high-quality products. The performance of the sheet, further ensure that the car OEMs design and produce parts that meet the actual engineering requirements.

In order to accurately obtain the springback size of various types of plates and fully understand the basic characteristics of the springback of plate stamping, it is necessary to carry out punching springback experiments on the plates through various commonly used stamping processes in practical engineering. If a set of corresponding molds is designed for each stamping process, the mold design and manufacturing costs will be increased, resulting in waste of resources, and at the same time, the total mold processing and manufacturing cycle will be prolonged; secondly, during the experiment, multiple sets of molds will be replaced to increase sheet stamping. The springback experiment is difficult, resulting in a long experimental period and low efficiency; finally, the application of multiple sets of molds is likely to cause accuracy problems in the experimental results, resulting in certain errors.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems in the prior art, the present invention provides a die structure that can realize the plate springback experiment of various stamping process switching, which can realize the drawing and forming commonly used in practical engineering through a set of die structures. The three processes of flanging and punching springback experiments on plates of different thicknesses can accurately obtain the springback size of various types of plates, which is enough to fully understand the basic characteristics of the springback of plate punching.

The concrete technical scheme of the present invention is as follows:

A die structure capable of realizing a variety of stamping process switching for sheet rebound experiments, characterized in that the die structure consists of an upper die and a lower die arranged up and down;

The upper mold includes an upper mold base, an upper molding material plate, and a concave mold insert; the two concave mold inserts are symmetrically fixed on the left and right sides of the center of the lower end of the upper mold base, and the upper mold material plate is arranged at the In the center of the upper die base, the upper molding material plate can extend between the two concave die inserts when it descends;

The lower die includes a blank holder, a punch bottom plate, a punch insert, a lower die insert, and a punch; the two lower die inserts are symmetrically fixed on the blank holder on the left and right sides of the punch. The upper end is opposite to the position of the die insert; the punch is fixed on the punch bottom plate under the blank holder, and the punch passes through the central hole of the blank holder and the convex The die inserts are fixedly connected; the punch inserts are coaxially arranged with the upper die pressing material plate, and the edge holder can be lifted up by the machine and move upward relative to the punch bottom plate;

There is a maximum plate thickness gap between the female die insert and the side wall of the male die insert to process and accommodate the plate, and the die structure passes through the upper molding blank and the male die insert. , The relative movement of the insert of the female die and the insert of the lower die draws, forms or flanges and punches the plate.

Further, the concave die insert and the male die insert are respectively composed of a base insert and a supplementary insert, and the base insert of the concave die insert is formed for the maximum flanging required by the experiment. The design angle of the complementary inserts of the female die inserts is the difference between the maximum flanging forming angle and the target flanging forming angle; the base inserts of the male die inserts are experimental The shape of the insert with the required minimum flanging forming angle, the design angle of the supplementary insert of the punch insert is the target flanging forming angle; Design angle, and the base inserts respectively form the female die inserts and the male die inserts with different flanging forming angles.

Further, a plurality of front and rear symmetrical grooves are arranged on the side surface of the base insert, and a gap exceeding the width of the plate is left between the front and rear grooves, and the supplementary insert is opposite to the base insert. One side is provided with a plurality of protrusions corresponding to the grooves, and the female die inserts and the male mold inserts are respectively inserted into the grooves through the convex blocks to form an interference fit.

Further, the upper die also includes a cylinder device, and the four cylinder devices are respectively connected to the front and rear sides of the left and right die inserts, and are used to apply uniform lateral pressure to the die inserts, Adjust the forming gap between the female die insert and the male die insert.

Further, the upper mold further includes a pressing material core and a pressure source device, the pressure source device is fixed on the upper mold base, the pressing material core is fixed on the upper molding material plate, and the pressure source device is The device applies a force to the upper molding blank through the blank core.

Further, the two pressure source devices are respectively arranged on the front and rear sides above the binder core.

Further, a guide plate is fixed on the upper mold base for guiding the up and down movement of the upper mold and the lower mold.

Further, positioners are respectively fixed on the left and right sides of the blank holder, which are used to limit the front and rear and left and right directions of the plate.

Further, a plurality of stroke limit blocks are arranged around the blank holder for controlling the stamping stroke.

Further, one side of the die insert is mounted on the upper die seat through a back support.

Beneficial effects of the present invention:

The die structure of the invention has universality, and is suitable for various stamping processes such as drawing, forming, and flanging of sheets of different materials and different thicknesses. The integration of the forming mode reflects the springback of the sheet metal under different blank holding forces, different gaps, different flanging forming angles and other process modes, which is convenient for the in-depth study of the sheet metal springback mechanism. The structure is simple, the operability is strong, and the improved The experimental efficiency avoids the waste of resources caused by the need to make a variety of stamping process molds, reduces the manufacturing cost, and shortens the mold production cycle. In addition, the mold structure has neutrality and high precision, and multiple experiments share a set of molds The structure improves the accuracy of the rebound experiment, and can meet the research on the rebound performance of the metal sheet in the steel factory.

The invention provides lateral force through the cylinder device to adjust the gap between the convex and concave dies, realizes the switching of various stamping processes for plates with different material thicknesses, makes full use of resources, has strong operability and high experimental efficiency. By supplementing the superimposed assembly of the inserts and the base inserts, the present invention adapts to the springback test requirements of different flanging forming angles, further saves the manufacturing cost of the mold, and realizes the modularization of the female die inserts and the male die inserts. The interference and tight fit of the grooves and the bumps can quickly replace the supplementary inserts, quickly switch the flanging forming angle, easy to operate, and greatly improve the experimental efficiency.

Description of drawings

Fig. 1 is the axial schematic diagram of the die structure of the plate springback experiment that can realize various stamping process switching according to the present invention;

Fig. 2 is the front sectional view of the die structure of the plate springback experiment that can realize various stamping process switching according to the present invention;

3 is a schematic diagram of the installation of the cylinder device in the present invention;

Fig. 4 is the front sectional view of the upper mold in the present invention;

Fig. 5 is the bottom view of the upper mold in the present invention;

Fig. 6 is the structure diagram of lower mold in the present invention;

Fig. 7 is the front sectional view of the lower mold in the present invention;

FIG. 8 is a schematic structural diagram of a die insert in the present invention;

FIG. 9 is a schematic structural diagram of a punch insert in the present invention;

10 is a cross-sectional view of the mold structure in the initial state of 0° flanging of the present invention;

11 is a cross-sectional view of the mold structure in the closed state of the 0° flanging of the present invention;

12 is a cross-sectional view of the mold structure in the initial state of 3° flanging of the present invention;

Figure 13 is a schematic diagram of the mold structure under the 3° flanging closed state of the present invention;

14 is a cross-sectional view of the mold structure in the initial state of 6° flanging of the present invention;

15 is a schematic diagram of the mold structure under the 6° flanging closed state of the present invention;

16 is a cross-sectional view of the mold structure in the initial state of drawing in the present invention;

FIG. 17 is a schematic diagram of the mold structure in the drawn closed state of the present invention;

18 is a cross-sectional view of the mold structure in the initial state of forming according to the present invention;

Fig. 19 is a schematic diagram of the structure of the mold in the closed state of forming according to the present invention.

Among them: 1 – upper die seat, 2 – blank holder, 3 – punch bottom plate, 4 – connecting plate, 5 – guide plate, 6 – connecting plate, 7 – pressing material core, 8 – upper moulding material plate, 9 – concave Die insert, 9.1-left die base insert, 9.2-right die base insert, 9.3-left die supplementary insert, 9.3.1-left die 3° supplementary insert, 9.3.2-left concave Die 0° Supplementary Insert, 9.4 - Right Female Die Supplementary Insert, 9.4.1 - Right Female Die 0° Supplementary Insert, 9.4.2 - Right Female Die 3° Supplementary Insert, 10 - Punch Die Insert, 10.1 - Punch base insert, 10.2- Left punch supplementary insert; 10.2.1- Left punch 3° supplementary insert, 10.2.2- Left punch 6° supplementary insert, 10.3- Right punch supplementary insert , 10.3.1-Right punch 6° supplementary insert, 10.3.2-Right punch 3° supplementary insert, 11-Lower die insert, 12-Punch, 13-Cylinder device, 14-Pressure source device, 15 - Pressure source device mounting plate, 16 - Back bracket, 17 - Positioner, 18 - Travel limit block, 19 - Groove, 20 - Bump, 21 - Plate.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present application, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

Orientation terms such as upper, lower, left, right, front and rear in this application document are established based on the positional relationship shown in the accompanying drawings. If the drawings are different, the corresponding positional relationship may also change accordingly, so this should not be construed as a limitation on the protection scope.

In the present invention, the terms "installed", "connected", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection Connection can be mechanical connection, electrical connection or mutual communication, direct connection or indirect connection through an intermediate medium, internal communication between two components, or two components interaction relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

This embodiment describes a die structure that can realize a springback experiment of sheet metal that can switch between various stamping processes. Complete the drawing, forming, flanging and other punching springback experiments of standard size plates of different thicknesses and materials to meet the requirements of punching springback experiments on the plates.

In production, after one or more stamping processes such as drawing, forming, flanging, shaping, etc., the sheet will have a certain springback, especially the springback of beam parts is relatively large, in order to fully reflect the side wall and method of beam parts. The springback size of the blue area determines the use of the die structure to punch the plate into a cap shape. Through the investigation of various models on the market, to understand and count the height range of the side wall of the commonly used beams, refer to the relevant dimensions of the international standard conference NUMISHEET, and select a suitable side wall height that can fully reflect the rebound, so as to determine this set of The final stamping stroke of the die, select the appropriate plate size.

The mold structure consists of an upper mold and a lower mold set up and down. As shown in Figure 1, the upper mold includes an upper mold seat 1, and the lower mold includes a blank holder 2 and a punch bottom plate 3. When the mold structure is idle, the upper mold seat 1 and the press The edge ring 2 is integrally placed through the connecting plate 6 , the edge holder 2 and the punch bottom plate 3 through the connecting plate 4 . When the mold structure is working, the connecting plate 4 and the connecting plate 6 are disassembled, and the upper die base 1 and the blank holder 2 are guided by the guide plate 5 on the upper die base 1 to perform relative movement to complete the sheet stamping.

As shown in FIG. 2 , the upper mold further includes a pressing material core 7 , an upper molding material plate 8 , and a concave mold insert 9 . Two concave die inserts 9 are symmetrically fixed on the left and right sides of the center of the lower end of the upper die base 1, the pressing material core 7 and the upper molding material plate 8 are arranged up and down in the center of the upper die base 1 in turn, and the pressing material core 7 and the upper molding material plate are arranged up and down. 8 can extend into the gap between the left and right concave die inserts 9 when going down. The lower mold also includes a punch insert 10 , a lower die insert 11 , and a punch 12 . The two lower die inserts 11 are symmetrically fixed on the upper end of the blank holder 2 on the left and right sides of the punch 12, and are arranged opposite to the female die inserts 9. The punch 12 is fixed on the punch bottom plate 3, and the punch 12 passes through the pressure die. The center hole of the edge ring 2 is fixedly connected with the punch insert 10, the punch insert 10 is coaxially arranged with the upper die pressing material plate 8, and the edge holder 2 can be lifted up by the ejector rod of the machine, and is upward relative to the punch bottom plate 3 move. The mold structure realizes the drawing, forming and flanging of the plate through the relative movement of the upper molding blank 8 and the convex mold insert 10, and the female die insert 9 and the lower mold insert 11.

Between the side wall of the female die insert 9 and the male die insert 10, the plate is processed and accommodated with the maximum plate thickness gap. In this embodiment, in order to meet the requirements of different thicknesses and different forming gaps of the plate, the outer left and right die inserts 9 The front and rear sides are respectively connected with air cylinder devices 13, and the air cylinder devices 13 are installed upside down on the bottom of the upper die base 1, as shown in FIG. 3 . By controlling the cylinder force in the cylinder device 13 by a preset program, a uniform lateral pressure can be applied to the die inserts 9 when the die structure is in operation, so as to adjust the force between the die inserts 9 and the punch inserts 10 . The forming gap can meet the requirements of punching experiments with various convex and concave die gaps for plates of different thicknesses.

In addition, as shown in Figures 4 and 5 for the upper die of this embodiment, four guide plates 5 are symmetrically fixed on the front and rear ends of the upper die base 1 by bolts, respectively, and the guide plates 5 can guide the up and down movement of the upper and lower dies. . The pressing material core 7 and the upper molding material plate 8 are fixedly connected by bolts, and pressure source devices 14 are respectively provided on the front and rear sides above the pressing material core 7, and the pressure source device 14 is fixed to the upper mold seat through the pressure source device mounting plate 15 1, when the flanging process is performed, the pressure source device 14 exerts a force on the upper mold pressing material plate 8 through the pressing material core 7, so as to play the role of first pressing the material. The two pressure source devices 14 in this embodiment can make the plate force evenly and ensure that the plate is symmetrical before and after it is formed. Two concave die inserts 9 are respectively installed and fixed on the upper die base 1 by bolts on the left and right sides of the upper die pressing material plate 8, so that the flange edge of the hat-shaped part is pressed, and the side of the concave die insert 9 passes through the back. The support piece 16 is installed on the upper die base 1 , and the back support piece 16 is used to limit and locate the die insert 9 , which can ensure the smooth installation of the die insert 9 and realize the connection between the die insert 9 and the upper die base 1 . Tight fit and secure. The die insert 9 realizes the adjustment of the gap between the convex and concave die through the cylinder device 13 .

The lower mold of this embodiment is shown in FIG. 6 and FIG. 7 , the punch insert 10 can be fixed on the punch 12 by bolts, and the punch 12 has an L-shaped structure, which ensures that the punch insert 10 can be accurately limited , and at the same time, the punch insert 10 will not be deviated due to the action of force during operation. The punch base 3 is fixed under the punch 12 by screwing, and supports the punch 12. The punch base 3 can make the whole set of moulds more stably placed on the machine table, and the punch 12 is always stationary during operation. The lower die insert 11 is fixed on the edge holder 2, and together with the concave die insert 9 of the upper die, the flange edge of the plate is pressed. Positioners 17 are respectively fixed on the left and right sides of the blank holder 2, which are used to limit the front and rear and left and right directions of the plate, which is beneficial to the fixation of the plate. A plurality of travel limit blocks 18 are arranged around the blank holder 2. As shown in FIG. 5, there are eight in this embodiment, which are used to control the stamping stroke. For plates with different material thicknesses, the corresponding travel limit blocks 18 need to be replaced. (that is, the thickness of the plate decreases or increases, and the travel limit block 18 reduces or increases the absolute value of the difference between the thickness of the original plate material and the existing plate material thickness on the original basis), which can ensure that the gap between the inserts when the mold is closed meets the Plate thickness. In this embodiment, the punch insert 10 is higher than the lower die insert 11, and the height difference is the height of the sheet after stamping and forming.

The flanging forming angle range of the auto parts is understood and determined through the preliminary investigation, so as to design the flanging tool of the mold structure. Flanging at different angles greatly reduces the cost of designing and processing multiple sets of molds, avoids waste of resources, and reduces the total cycle of mold processing and manufacturing.

The female die inserts 9 and the male die inserts 10 in this embodiment are both composed of base inserts and supplementary inserts. The base inserts of the female die inserts 9 are designed to be the maximum flanging forming angle required by the experiment (this embodiment 6°), and the base insert of the punch insert 10 is designed to be the insert shape with the minimum flanging forming angle (0° in this embodiment) required for the experiment, on the side surface of the base insert A plurality of front and rear symmetrical grooves 19 are provided to ensure the fastening with the supplementary inserts, and a gap exceeding the width of the plate is left between the front and rear grooves 19 to ensure the normal punching of the plate. The design angle of the supplementary insert of the female die insert 9 is the difference between the maximum flanging forming angle and the target flanging forming angle, and the design angle of the supplementary insert of the male die insert 10 is the target flanging forming angle. A plurality of bumps 20 corresponding to the grooves 19 are provided on the opposite side of the supplementary insert and the base insert. The female die insert 9 and the male die insert 10 form an interference tight fit by inserting the convex block 20 into the groove 19. The supplementary insert can be prepared with multiple supplementary inserts with different angles, and different plates can be realized by replacing the supplementary inserts. The flange of the target flange forming angle. The grooves 19 and the bumps 20 are manufactured with positive and negative tolerances, respectively, to prevent the two inserts from sliding apart through friction, so as to realize the tight connection between the base insert and the supplementary insert, and ensure the overall performance and experimental accuracy of the insert.

This embodiment takes 0°, 3°, and 6° flanging as examples for detailed description.

As shown in Fig. 8, the left and right concave die inserts 9 include a left concave die base insert 9.1, a right concave die base insert 9.2, a left concave die supplementary insert 9.3, a right concave die supplementary insert 9.4, and a left concave die insert 9.4. The base insert 9.1 and the right female die base insert 9.2 are insert shapes with 6° inner sides respectively, and eight grooves that can be inserted into the convex blocks 20 are respectively arranged on the inner side (ie, the side with the flanging forming angle). 19. Angled left female die supplementary inserts 9.3 and right female die supplementary inserts 9.4 are respectively combined with left female die base inserts 9.1 and right female die base inserts 9.2 by means of bumps 20 to form corresponding flanging forming Angled die insert 9. The left die supplementary insert 9.3 includes the left die 3° supplementary insert 9.3.1, the left die 0° supplementary insert 9.3.2, and the right die supplementary insert 9.4 includes the right die 0° supplementary insert 9.4. 1. The 3° supplementary insert for the right die is 9.4.2.

When reducing the angle to achieve punching with different flanging forming angles, the inner side of the left die base insert 9.1 and the right die base insert 9.2 are respectively inserted into the left die supplementary insert 9.3 and the right die supplementary insert through the groove 19 9.4. The design angle of the die supplementary insert is the difference between the maximum flanging forming angle and the target flanging forming angle. For example, the left die base insert 9.1 and the right die base insert 9.2 are respectively combined with the left die 3° supplementary insert 9.3.1 and the right die 3° supplementary insert 9.4.2 to form 3° left and right concave inserts. Die inserts, among which, the design angle of the left die 3° supplementary insert 9.3.1 and the right die 3° supplementary insert 9.4.2 is the difference between the experimental maximum flanging forming angle and 3°, which is used for A 3° flanging forming angle is formed. The left die base insert 9.1 and the right die base insert 9.2 are respectively combined with the left die 0° supplementary insert 9.3.2 and the right die 0° supplementary insert 9.4.1 to form a 0° left and right die Inserts, among which, the insert design angle of the left die 0° supplementary insert 9.3.2 and the right die 0° supplementary insert 9.4.1 is the difference between the experimental maximum flanging forming angle and 0°, which is used to form 0°Flanging forming angle.

As shown in FIG. 9 , the punch insert 10 includes a punch base insert 10.1, a left punch supplementary insert 10.2, and a right punch supplementary insert 10.3. The two sides of the punch base insert 10.1 are vertical edges (ie 0°), and eight grooves 19 that can be embedded in the convex block 20 are provided on the opposite side surfaces of the punch base insert 10.1, and the grooves 19 on the front and rear sides are symmetrical about the punch base insert 10.1. There are four grooves 19 on the front and rear sides to ensure that the subsequent assembly is tightened and the force is uniform. The left side punch supplementary insert 10.2 and the right punch supplementary insert 10.3 opposite to the punch base insert 10.1 are vertical sides, and the other side forms a certain angle with the vertical side, and the design angle is the corresponding turning point. Edge forming angle. The left punch supplementary insert 10.2 includes the left punch 3° supplementary insert 10.2.1, the left punch 6° supplementary insert 10.2.2, and the right punch supplementary insert 10.3 includes the right punch 6° supplementary insert 10.3. 1. The right punch 3° supplementary insert 10.3.2. Consistent with the manufacturing and assembling principle of the die insert 9, when increasing the angle to achieve punching with different flanging forming angles, the corresponding angle is directly inserted into the groove 19 on the left and right sides of the punch base insert 10.1 by means of interference and tight fitting. The left punch supplementary insert 10.2 and the right punch supplementary insert 10.3 are combined into a punch insert 10 corresponding to the flange forming angle. For example, the punch base insert 10.1 is combined with the left punch 3° supplementary insert 10.2.1 and the right punch 3° supplementary insert 10.3.2 to form a punch insert with a flanging forming angle of 3°, the punch base insert The block 10.1 is combined with the left punch 6° supplementary insert 10.2.2 and the right punch 6° supplementary insert 10.3.1 to form a punch insert with a flanging forming angle of 6°.

During the flanging experiment, as shown in Figure 10, in the initial state of 0° flanging, in the die insert 9, the left die base insert 9.1 and the right die base insert 9.2 are respectively embedded in the left die 0° supplementary insert 9.3.2 and the right female die 0° supplementary insert 9.4.1, the punch insert 10 is the punch base insert 10.1. The pressure source device 14 provides a pressing force for the upper die pressing plate 8 through the pressing core 7, the upper die holder 1 goes down, the upper die pressing plate 8 first presses the plate 21 on the punch insert 10, and then the upper die holder 1 Continue to descend, at this time, the female die insert 9 presses the plate 21 on the male die insert 10 and the lower die insert 11 to perform flanging until the flanging is closed as shown in FIG. 11 .

When flanging experiments at different angles are carried out, the left concave die supplementary inserts 9.3 and the right concave inserts with corresponding target angles are respectively embedded in the left concave die base insert 9.1, right concave die base insert 9.2 and punch base insert 10.1. Die supplementary inserts 9.4, left punch supplementary inserts 10.2, right punch supplementary inserts 10.3, are combined into a new angle of concave die inserts and punch die inserts, and then perform the above 0° flanging experiment. To achieve flanging at different angles, as shown in Figure 12, Figure 13, Figure 14, Figure 15, the initial state and closed state of the mold for 3° and 6° flanging are respectively.

During the drawing experiment, as shown in Figure 16, at the initial state of the mold, the blank holder 2 is pushed up by the ejector pin of the machine. When the mold is working, the upper mold base 1 drives the upper molding material plate 8 and the die inserts. 9. Go down, press the plate 21 on the lower die insert 11, the blank holder 2 provides a blank holder force to the lower die insert 11, and exerts a downward pressure on the plate 21, and then the upper die holder 1 follows the blank holder 2. At the same time, the drawing of the plate 21 is realized by going down through the punch insert 10, and the closed state of the die structure during drawing is shown in FIG. 17 .

When performing the forming stamping experiment, as shown in FIG. 18 , in the initial state of the die, unlike the drawing stamping, the blank holder 2 is not lifted up. When the mold is working, the upper mold base 1 drives the upper molding material plate 8 and the concave mold insert 9 to go down, and presses the plate 21 directly on the convex mold insert 10 and the lower mold insert 11 of the lower mold to complete the forming experiment of the plate 21. , as shown in Figure 19.

11 , 13 , 15 , 17 , and 19 , it can be seen that when the plate 21 is subjected to flanging, drawing and forming experiments, the mold structure in the closed state is consistent. In this embodiment, a set of mold structures is used to complete the drawing, forming, and flanging experiments of the plate 21 , which ensures the accuracy of the entire experimental results and avoids experimental errors caused by different mold processing precisions.

Although the principle of the present invention has been described in detail above in conjunction with the preferred embodiments of the present invention, those skilled in the art should understand that the above-mentioned embodiments are only illustrative of the exemplary implementation of the present invention, rather than limiting the scope of the present invention. The details in the embodiments do not constitute a limitation to the scope of the present invention. Without departing from the spirit and scope of the present invention, any obvious changes such as equivalent transformations and simple replacements based on the technical solutions of the present invention fall within the scope of the present invention. within the scope of protection.

Claims (10)

1. A die structure capable of realizing a plate springback experiment for switching various stamping processes is characterized in that the die structure is composed of an upper die and a lower die which are arranged up and down;

the upper die comprises an upper die base (1), an upper die pressure plate (8) and a die insert (9); the two die inserts (9) are symmetrically fixed on the left side and the right side of the center of the lower end of the upper die base (1), the upper die pressing plate (8) is arranged in the center of the upper die base (1), and the upper die pressing plate (8) can extend into the space between the two die inserts (9) when moving downwards;

the lower die comprises a blank holder (2), a punch bottom plate (3), a punch insert (10), a lower die insert (11) and a punch (12); the two lower die insert blocks (11) are symmetrically fixed at the upper end of the blank holder (2) at the left side and the right side of the male die (12) and are opposite to the female die insert block (9); the male die (12) is fixed on the male die base plate (3) below the blank holder (2), and the male die (12) penetrates through a central hole of the blank holder (2) and is fixedly connected with the male die insert (10); the male die insert (10) and the upper die pressure plate (8) are coaxially arranged, and the blank holder (2) can be jacked up by a machine table and moves upwards relative to the male die bottom plate (3);

the die structure draws, forms or flanging the plate through the relative movement of the upper die pressure plate (8) and the punch insert (10) and the die insert (9) and the lower die insert (11).

2. The die structure capable of realizing the plate rebound experiment switched by various stamping processes according to claim 1, wherein the die insert (9) and the punch insert 10 are respectively formed by stacking and assembling a base insert and a complementary insert, the base insert of the die insert (9) is in an insert shape with a maximum flanging forming angle required by an experiment, and the complementary insert of the die insert (9) is designed at an angle which is the difference between the maximum flanging forming angle and a target flanging forming angle; the base insert of the male die insert (10) is in an insert shape with a minimum flanging forming angle required by an experiment, and the design angle of the supplementary insert of the male die insert (10) is a target flanging forming angle; the supplementary inserts are multiple and respectively have different design angles, and the supplementary inserts and the matrix insert respectively form the female die insert (9) and the male die insert (10) with different flanging forming angles.

3. The die structure capable of realizing the plate rebound test switched by various stamping processes according to claim 2, wherein a plurality of front and back symmetrical grooves (19) are formed in the side surface of the base insert, a gap exceeding the width of the plate is reserved between the front and back grooves (19), a plurality of protrusions (20) corresponding to the grooves (19) are formed in the opposite side of the supplementary insert and the base insert, and the die insert (9) and the punch insert (10) are respectively embedded into the grooves (19) through the protrusions (20) to form interference tight fit.

4. The die structure capable of realizing the plate rebound experiment switched by various stamping processes as claimed in claim 1, wherein the upper die further comprises cylinder devices (13), and the four cylinder devices (13) are respectively connected to the front and rear sides of the outer portions of the left and right die inserts (9) and used for applying uniform lateral pressure to the die inserts (9) and adjusting the forming gap between the die inserts (9) and the punch insert (10).

5. The die structure capable of realizing the plate rebound experiment switched by multiple stamping processes as claimed in claim 1, wherein the upper die further comprises a pressure core (7) and a pressure source device (14), the pressure source device (14) is fixed on the upper die holder (1), the pressure core (7) is fixed on the upper die pressing plate (8), and the pressure source device (14) applies force to the upper die pressing plate (8) through the pressure core (7).

6. The die structure capable of realizing the plate rebound experiment switched by various stamping processes as claimed in claim 5, wherein two pressure source devices (14) are respectively arranged at the front side and the rear side above the material pressing core (7).

7. The die structure capable of realizing the plate rebound experiment switched by various stamping processes as claimed in claim 1, wherein a guide plate (5) is fixed on the upper die base (1) and used for guiding the up-and-down movement of the upper die and the lower die.

8. The die structure capable of realizing the plate rebound experiment with switching of various stamping processes as claimed in claim 1, wherein locators (17) are respectively fixed on the left side and the right side of the blank holder (2) and used for limiting the plate in the front-back direction and the left-right direction.

9. The die structure capable of realizing the plate rebound experiment switched by various stamping processes as claimed in claim 1, wherein a plurality of stroke limiting blocks (18) are arranged on the blank holder (2) at the periphery for controlling the stamping stroke.

10. The die structure capable of realizing the plate rebound experiment switched by various stamping processes as claimed in claim 1, wherein one side of the die insert (9) is mounted on the upper die base (1) through a backing piece (16).

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