A forging die and die design method for metal forgings

Abstract

The present invention relates to the field of dies, and specifically to a forging die and die design method for metal forgings, wherein the shape of the metal forging is a hollow cone, including a flange and a conical surface located on the flange, and a through hole is arranged on the conical surface; the forging die includes a relatively arranged concave die and a convex die, and a forging protrusion is arranged on the concave die and / or the convex die, and the height of the forging protrusion is 13-17 mm, and the aperture of the through hole is smaller than the diameter of the forging protrusion. The present invention can effectively control the average deformation amount, underpressure value and thickness of the forging surface of the forging to reach the ideal value range, and the forging protrusion squeezes the material during the forming process, so that the flange material of the forging flows in more and the forming is more complete, thereby ensuring that the forging is formed in place while saving materials.

Description

Technical Field

[0001] The present invention relates to the field of dies, in particular to a forging die for metal forgings and a die design method. Background Art

[0002] With the rapid development of the global manufacturing industry, the market demand for forging dies has shown a sustained growth trend. This growth trend is particularly evident in several key areas, especially in the automotive, aerospace, and energy sectors. The increasing demand for high-performance die forgings in these industries has not only promoted the vigorous development of related manufacturing industries, but has also become an important driving force for the continued growth of the forging die industry. In order to meet the stringent requirements of these industries for high precision, high strength, and high reliability of forging dies, die manufacturing companies have increased their investment in technology research and development and innovation, and continuously improved their own technical level and product quality.

[0003] For the forging process of aluminum alloy sealing cover, there are two main types of forging dies in the existing traditional dies. The first type of die is as follows: Figure 6 As shown in a, the upper die is the convex die and the lower die is the concave die. The forming simulation is performed using SIMUFACT FORMING software. Figure 6 As shown in Figure b, during the forging process, the contact area between the blank and the upper die is larger. In the high-temperature die, the blank is easy to adhere to the upper die, making it difficult to demold the workpiece, and it is difficult to ensure the appropriate posture and position of the blank when placed in the die.

[0004] The second mold Figure 7 As shown in a, the upper die is the concave die and the lower die is the convex die. The forming simulation is as follows: Figure 7 As shown in b, during the forging process, the material will flow in two directions, namely, the through hole and the flange, resulting in insufficient material flowing to the forging flange, causing the flange to be not formed in place, and the punch has no positioning structure, resulting in inaccurate positioning of the blank.

[0005] The three forging parameters, namely, the average deformation of the forging, the underpressure value and the thickness of the forging surface, are important standards for measuring the production quality of metal forgings. The average deformation of the forging is the average deformation of each part of the forging after forming. If the average deformation of the forging is too large, the internal grain of the forging will change, reducing the strength of the forging; if the average deformation of the forging is too small, the material utilization rate will be low, resulting in waste of materials. The underpressure value refers to the distance between the upper and lower dies after the forging is formed. When the flange is fully formed, the lower the underpressure value, the higher the material utilization rate. The thickness of the forging surface refers to the thickness of the forging surface after the forging is formed. If the thickness of the forging surface is too large, the material utilization rate will be low. If the thickness of the forging surface is too small, it will be difficult to process and affect the qualified rate of the forging. When existing dies are used to forge metal forgings with flanges, these three forging parameters will affect each other. Adjusting one of these parameters by adjusting the die parameters will cause the other two parameters to deviate from the ideal values. For example, reducing the underpressure value alone will inevitably lead to an increase in the average deformation of the forging and a decrease in the thickness of the forging surface. Therefore, it is extremely difficult for traditional dies to simultaneously control these three forging parameters through die adjustment.

[0006] When designing a mold, technicians will strive to ensure that these three forging parameters reach the ideal value range as a standard for measuring the quality of the mold, that is, the average deformation of the forging is 50%-70%, the underpressure value is about 0.5 times the product thickness, and the forging surface thickness is 2-7 mm larger than the product thickness as a processing allowance (the theoretical value range is the optimal range under the mutual influence of the three forging parameters). Only when the forging parameters are within the above ideal value range can the mold ensure that the forging is formed in place and minimize the waste of raw materials. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a forging die and die design method for metal forgings, which can effectively control the average deformation, underpressure value and forging surface thickness of the forgings to reach an ideal value range. The forging protrusion squeezes the material during the forming process, so that more flange material of the forging flows in and the forming is more complete, thereby ensuring that the forging is formed in place while saving material.

[0008] The specific technical solution of the present invention is as follows: a forging die for a metal forging, wherein the metal forging is in the shape of a hollow cone, including a flange and a conical surface located on the flange, and a through hole is provided on the conical surface; the forging die includes a die and a punch arranged opposite to each other, and the die and / or the punch are provided with a forging protrusion, the height of the forging protrusion is 13-17 mm, and the aperture of the through hole is smaller than the diameter of the forging protrusion.

[0009] Furthermore, the outer edges of the die and punch are planes, and after forging, a space for accommodating the flange is formed within the two planes.

[0010] Furthermore, the outer periphery of the plane of the male mold is provided with a guide outer wall, and the outer periphery of the plane of the female mold is provided with a corresponding guide inner wall.

[0011] Preferably, a forging protrusion is provided on the die.

[0012] Preferably, a positioning protrusion is provided on the male mold, and the positioning protrusion can be accommodated in the through hole.

[0013] Furthermore, the outer periphery of the forging protrusion is provided with an accommodating groove, which is arranged between the forging protrusion and the forming inclined surface of the mold for forming the metal forging, and the accommodating groove includes a first forming surface, a second forming surface and a forming inclined surface connected in sequence, and the first forming surface is connected to the forging protrusion.

[0014] Preferably, the width of the second profile is 18-22 mm, and the angle between the first profile and the second profile is 120°-130°.

[0015] The present invention also provides a die design method for a metal forging die, comprising the following steps:

[0016] S1: Blank selection: Select a blank to perform a hot compression test, obtain performance parameters of the blank, and input the performance parameters of the blank into computer simulation software.

[0017] S2: Preliminary drawing design of the mold: Use computer 3D drawing software to design the punch and die according to the workpiece drawing, and design a forging protrusion in the middle of the punch and / or die.

[0018] S3: Die forming simulation: The die designed in S2 is imported into the computer simulation software, the die forging parameters are set, the performance parameters of the blank and the forging deformation calculation formula are input, and the computer performs die forming simulation to obtain the forging parameters, which are the average deformation of the forging, the underpressure value and the forging surface thickness.

[0019] S4: Die and blank adjustment: Compare the forging parameters obtained in S3 with the ideal values, and adjust the shape of the forging protrusion, the width of the second die surface, and the angle between the first die surface and the second die surface according to the parameter comparison results.

[0020] S5: Repeat S3 and S4 until the forging parameters reach the ideal values ​​and the optimal die parameters are obtained.

[0021] Furthermore, in S3, the calculation formula for the forging deformation is: , is the equivalent plastic strain.

[0022] Furthermore, in S3 , the die forging parameters set are the die and blank temperature, the friction coefficient between the die and the blank, the upper die downward distance, and the maximum stop pressure of the die.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Firstly, the present invention provides a forging protrusion in the die, which squeezes the material during the forming process and prevents the material from flowing toward the inner hole of the forging, so that more material flows into the flange of the forging, and the flange is formed more fully, thereby ensuring that the forging is formed in place while saving material to a great extent; in addition, the height of the forging protrusion is 13-17 mm and the diameter of the forging protrusion is larger than the aperture of the through hole, so that the forging protrusion can be pressed on the blank and effectively squeeze the metal material to flow toward the tapered surface and the flange, thereby ensuring the smooth forming of the forging.

[0025] Secondly, by adjusting the width of the second molding surface and the angle between the first molding surface and the second molding surface, the present invention can more easily and effectively control the average deformation of the forging, the underpressure value and the thickness of the forging surface to be within the ideal value range, thereby reducing the difficulty of mold structure design and the workload of subsequent mold debugging.

[0026] Third, the accommodating groove on the outer periphery of the forging protrusion can accommodate excess material after the forging is formed, further reducing the underpressure value of the forging and the thickness of the forging surface, and avoiding the adverse effects of excess material accumulation on the forging forming surface on the forging. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a product in an embodiment of the present invention;

[0028] Figure 2 A schematic cross-sectional view of a mold structure according to an embodiment of the present invention;

[0029] Figure 3 Schematic diagram of the forging protrusion and the accommodating groove structure in the die according to an embodiment of the present invention;

[0030] Figure 4 This is a computer simulation diagram of a mold forming embodiment of the present invention;

[0031] Figure 5 This is a computer simulation diagram of different forging protrusion heights in an embodiment of the present invention;

[0032] in, Figure 5 a is a computer simulation forming diagram of the embodiment of the present invention when the forging protrusion height is 12, Figure 5 b is the computer simulation forming diagram when the forging protrusion height is 13. Figure 5c is a computer simulation forming diagram of the embodiment of the present invention when the forging protrusion height is 17, Figure 5 d is a computer simulation forming diagram of the embodiment of the present invention when the forging protrusion height is 18;

[0033] Figure 6 This is a schematic diagram of the first mold structure and simulation molding in the prior art;

[0034] in, Figure 6 a is a schematic diagram of the first mold structure in the prior art, Figure 6 b is a schematic diagram of the first computer simulation molding;

[0035] Figure 7 Schematic diagram of the second mold structure and simulation molding in the prior art;

[0036] in, Figure 7 a is a schematic diagram of the second mold structure in the prior art, Figure 7 b is a schematic diagram of the second computer simulation molding;

[0037] In the figure: 1. Die; 101. Guide inner wall; 102. Forming slope; 103. Accommodating groove; 1031. First molding surface; 1032. Second molding surface; 2. Punch; 201. Guide outer wall; 3. Metal forging; 301. Through hole; 302. Conical surface; 303. Flange; 4. Forging protrusion; 5. Positioning protrusion. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0039] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention. Example

[0040] A forging die for metal forgings, see Figure 1 and Figure 2The metal forging 3 is in the shape of a hollow cone and includes a flange 303 and a tapered surface 302 located on the flange 303. The tapered surface 302 is provided with a through-hole 301. The forging die comprises a die 1 and a punch 2 disposed opposite each other. The die 1 is provided with a forging protrusion 4. The height of the forging protrusion 4 is 13-17 mm, and the diameter of the through-hole 301 is smaller than the diameter of the forging protrusion 4. During the forming process, the forging protrusion 4 squeezes the material, preventing it from flowing toward the inner hole of the forging, allowing more material to flow into the flange 303 of the forging, making the flange 303 more fully formed, thereby ensuring that the forging is formed properly while significantly saving material. The height of the forging protrusion 4 is 13-17 mm, and the diameter of the forging protrusion 4 is larger than the diameter of the through-hole 301. This allows the forging protrusion 4 to press against the blank and effectively squeeze the metal material toward the tapered surface 302 and flange 303, thus ensuring smooth forging. In addition, in this embodiment, the die 1 is used as the upper die and the punch 2 is used as the lower die, which makes it easy to remove the forging from the die after forming.

[0041] The outer edges of the die 1 and punch 2 are flat, and after forging, a space is formed between the two planes to accommodate the flange 303. The provision of the forging protrusions 4 enables the metal material to be squeezed by the forging protrusions 4 during the die forging process, flowing more toward the tapered surface 302 and the flange 303 until the entire space accommodating the flange 303 is filled, thereby promoting the proper formation of the flange 303 of the metal forging 3.

[0042] In this embodiment, the outer periphery of the planar surface of the punch 2 is provided with a guide outer wall 201, and the outer periphery of the planar surface of the die 1 is provided with a corresponding guide inner wall 101. The forming force of the forging die is enormous, and the reaction force generated by the forging is also very large. When the die descends, the reaction force acting on the upper die may cause the die 1 to shift during the forming process, causing the forging to deform or even damage the die surface. In this embodiment, the guide inner wall 101 and the guide outer wall 201 of the die 1 cooperate with each other to fix and guide the downward direction of the die, applying the huge reaction force to the die body. Under the constraint of the die body, the die 1 is prevented from shifting, thereby facilitating better forming of the forging.

[0043] In this embodiment, a positioning protrusion 5 is provided on the punch 2, and the positioning protrusion 5 can be accommodated in the through hole 301. When the die is used to produce a metal forging 3, the blank is placed on the punch 2, and the positioning protrusion 5 is accommodated in the through hole 301 to fix the offset of the blank in the XY plane. This allows for rapid positioning of the blank in the die, making feeding easier and faster, and preventing the blank from moving due to the influence of the die force during the die's downward movement, further improving the forming performance of the forging and preventing defects such as deformation and cracking in the forging.

[0044] Furthermore, if Figure 3 As shown, the outer periphery of the forging protrusion 4 is provided with a receiving groove 103, which is disposed between the forging protrusion 4 and the forming inclined surface 102 of the die used to form the metal forging 3. The receiving groove 103 includes a first molding surface 1031, a second molding surface 1032, and the forming inclined surface 102, which are sequentially connected. The first molding surface 1031 is connected to the forging protrusion 4. The receiving groove 103 can accommodate metal material during the die forming process. Under the pressure of the first molding surface 1031 and the second molding surface 1032 and the constraint of the forming inclined surface 102, the metal material flows more toward the flange 303, further promoting the forming of the flange 303. Moreover, at the end of the forming process, when the flange 303 is formed, excess material will accumulate in the receiving groove 103 due to the pressure, further reducing the underpressure value and the thickness of the forging surface, and preventing the accumulation of excess material on the forging forming surface from adversely affecting the forging.

[0045] After die design and forming simulation, in this embodiment, the width of the second die surface 1032 in the forging die is preferably 18-22 mm, and the angle between the first die surface 1031 and the second die surface 1032 is preferably 120°-130°. When the width of the second die surface 1032 and the angle between the first die surface 1031 and the second die surface 1032 are both within this preferred range, the average deformation, understressing value, and forging surface thickness of the forging can be effectively controlled within the ideal ranges sought by technicians, facilitating the forming of the forged flange 303 while also maximizing the blank material utilization.

[0046] The three forging parameters, average deformation, understressing value, and forging surface thickness, are important criteria for measuring the production quality of metal forgings. The average deformation of the forging is the average deformation of each part of the forging after forming. Excessive average deformation of the forging will cause changes in the internal grain of the forging, reducing the strength of the forging; too small an average deformation of the forging will result in low material utilization and waste of materials. The understressing value refers to the distance between the upper and lower dies after the forging is formed. When the flange 303 is fully formed, the lower the understressing value, the higher the material utilization. The forging surface thickness refers to the thickness of the forging surface after the forging is formed. If the forging surface thickness is too large, the material utilization is low, and if the forging surface thickness is too small, it is not conducive to processing and affects the forging qualification rate. These three forging parameters will affect each other. When adjusting one of the parameters by adjusting the mold parameters, the other two parameters will deviate from the ideal value. For example, adjusting the undervoltage value alone to reduce it will inevitably lead to an increase in the average deformation of the forging and a decrease in the thickness of the forging surface. Therefore, it is extremely difficult for traditional molds to control these three forging parameters at the same time through mold adjustment.

[0047] When designing and debugging the mold, technicians use various means to adjust the mold to pursue the ideal value range of the three forging parameters: average deformation of the forging, underpressure value and forging surface thickness. This is used as the standard for measuring the quality of the mold. That is, the average deformation of the forging is 50%-70%, the underpressure value is about 0.5 times the product thickness, and the forging surface thickness is 2-7 mm larger than the product thickness as processing allowance (the theoretical value range is the optimal range under the mutual influence of the three forging parameters). Only when the forging parameters are within the above ideal value range can the mold ensure that the forging is formed in place and minimize the waste of raw materials.

[0048] In this embodiment, the thickness of the forging product is 15 mm, so the ideal value range is that the average deformation of the forging is 50%-70%, the underpressure value is ≤8, and the thickness of the forging surface is 17-22 mm. Only when the forging parameters are within the above ideal value range can the mold of this embodiment ensure that the forging is formed in place and minimize the waste of raw materials.

[0049] In this embodiment, if Figure 3 As shown, the width of the second molding surface 1032 of the mold is set to A value, and the angle between the first molding surface 1031 and the second molding surface 1032 is set to B value. A computer molding simulation test is performed, and the results are as follows:

[0050] The height of the forging protrusion 4 is set to 12, 13, 17, and 18 mm respectively, and the other factors remain the same to perform forging simulation. In this embodiment, the height of the forging protrusion 4 is set in the range of 13-17 mm. Figure 5 The simulation results are shown in the table below. If the height of the forging protrusion 4 is less than 13 mm, the average deformation of the forging will increase and the forging strength will be insufficient. If the height of the forging protrusion 4 is greater than 17 mm, the material will not be squeezed into the flange 303, and the forging cannot be formed.

[0051]

[0052] In this embodiment, the height of the forging protrusion 4 is set to 15 mm, and in the simulation test, the A value is 18-22 mm, and the B value is 120°-130°.

[0053] Set A=18mm, adjust B value, and perform forming simulation. The results are as follows:

[0054]

[0055] Set A=20 mm, adjust B value, and perform forming simulation. The results are as follows:

[0056]

[0057] Set A=22mm, adjust B value, and perform forming simulation. The results are as follows:

[0058]

[0059] It can be seen that when the A value is 18-22 mm and the B value is 120°-130°, the average deformation, underpressure value and forging surface thickness of the forging are all within the ideal value range. Among them, when A is 20 mm and B is 120°, the forging surface thickness is the smallest, which saves the most material and has the best effect.

[0060] The embodiment of the present invention further provides a method for designing a forging die. The die design process requires the use of two computer softwares, SOLIDWORKS (a computer 3D graphics software) and SIMUFACT FORMING (a computer die forming simulation software), and specifically includes the following steps:

[0061] S1: Billet selection: In this embodiment, 2195 aluminum-lithium alloy is selected as the billet. A hot compression test is performed on the 2195 aluminum-lithium alloy to obtain material performance parameters, such as thermal conductivity, specific heat capacity, material density, Young's modulus, Poisson's ratio, and thermal expansion coefficient. The data are input into SIMUFACT FORMING software, and a material database for the 2195 aluminum-lithium alloy is established in SIMUFACT FORMING.

[0062] S2: Preliminary drawing design of mold: Use SOLIDWORKS software to design the mold structure according to the workpiece drawing, design the forging mold structure diagram as described above, and import the mold structure diagram into SIMUFACT FORMING software.

[0063] S3: Die forming simulation: In SIMUFACT FORMING software, set the die temperature to 460 degrees, the blank temperature to 480 degrees, the friction coefficient at the contact between the blank and the die to 0.3, set the upper die pressing distance to 129.2 mm, and the maximum die stop pressure to 12000t. Then enter the blank parameters such as the original thickness of 33, the outer diameter of 750 mm, and the inner diameter of 380 mm, and the forging deformation calculation formula. (EFFPLS is the equivalent plastic strain), SIMUFACT FORMING software is started to simulate the die forming process to obtain forging parameters such as the average deformation of the forging, underpressure value, and forging surface thickness.

[0064] S4: Die and Billet Adjustment: Compare the forging parameters obtained in S3 with the ideal values. In this embodiment, the ideal values ​​are a forging surface thickness of 50-70%, an average forging deformation of 17-22 mm, and an understress value of less than or equal to 8. Based on the parameter comparison results, adjust the shape of the forging protrusion 4, the width of the second die surface 1032, the angle between the first die surface 1031 and the second die surface 1032, and the billet parameters.

[0065] S5: Repeat S3 and S4 until the forging flange 303 fills the flange accommodation space, such as Figure 4 As shown in the figure, the forging parameters reach the ideal value range, and the optimal die parameters and billet parameters are obtained.

[0066] In this embodiment, the fixed blank parameters are blank thickness of 35 mm, outer diameter of 800 mm, and inner diameter of 400 mm.

[0067] In S3 of this embodiment, the values ​​of A and B are adjusted, and the forging parameter results are shown as follows. By individually controlling the variables, the die forming is simulated to obtain the simulation results:

[0068] Set A to 48 mm and adjust the value of B to get the following result:

[0069]

[0070] Set A to 5 mm and adjust the value of B to get the following result:

[0071]

[0072] (3) Set A to 20 mm and adjust the value of B to obtain the following results:

[0073]

[0074] Analysis and simulation results show that increasing the A value prevents the flange from forming properly, increases the underpressure, reduces the average deformation of the forging, and increases the thickness of the forging surface, resulting in material waste. Decreasing the A value facilitates flange forming, but increases the underpressure, excessive deformation, and increases the thickness of the forging surface, also wasting material. While the A value remains unchanged, decreasing the B value prevents the generation of force in the forming direction, resulting in large surface deformation and high underpressure. Increasing the B value causes material to flow toward the center of the two grooves, resulting in minimal deformation of the curved surface.

[0075] After simulation, the flange 303 of the final forging of this embodiment is fully filled, the forging surface thickness is 17.7 mm, the underpressure value is 7.15 mm, and the average deformation of the forging is 17.7 mm, which is within the ideal value range. Therefore, the preferred solution is obtained with mold parameters of A being 20 mm and B being 120 degrees, and blank parameters of 35 mm thickness, 800 mm outer diameter, and 400 mm inner diameter.

[0076] The production process of the metal forging 3 in this embodiment is as follows: a Φ800×34 aluminum alloy plate is blanked, a Φ400 center hole is machined, and the blank weight is 35.249 kg. After the die stroke is set according to the above-mentioned underpressure value, the blank is added and forging begins. After die forging, the forging is machined according to the required size. Finally, the machined forging is subjected to a solution treatment at 510°C for 2 hours and an aging treatment at 160°C for 24 hours to obtain the finished workpiece.

[0077] Comparative Example 1

[0078] like Figure 6 As shown in Figure a, a forging die for a metal forging comprises a metal forging 3, a die 1 and a punch 2. The metal forging 3 is in the shape of a hollow cone, comprising a flange 303 and a conical surface 302 located on the flange 303, and a through hole 301 is provided on the conical surface 302; the die 1 serves as the lower die, and the punch 2 serves as the upper die. When the die is working, the blank is first placed on the die 1, and the punch 2 moves downward. The middle surface of the punch 2 first contacts the blank, and then the conical surface 302 is forged. Import the die structure diagram into the SIMUFACT FORMING software, set the same parameters as above, and obtain the simulation results as shown below. Figure 6 As shown in FIG. 2 , the flange 303 of the metal forging 3 cannot be formed in place, and during the operation of this type of mold, due to the large contact area between the punch 2 and the metal forging 3, the metal forging 3 is easily adhered to the punch 2 after forming and moves upward with the punch 2, making it difficult to remove the material.

[0079] Comparative Example 2

[0080] like Figure 7 As shown in Figure a, a forging die for a metal forging comprises a metal forging 3, a die 1, and a punch 2. The metal forging 3 is in the shape of a hollow cone and comprises a flange 303 and a tapered surface 302 located on the flange 303. The tapered surface 302 is provided with a through hole 301. The die 1 serves as the upper die, and the punch 2 serves as the lower die. The die structure diagram is imported into the SIMUFACTFORMING software, and the same parameters are set as above. The simulation results are shown in FIG. Figure 7 As shown in b, the flange 303 of the metal forging 3 cannot be formed into place.

[0081] When faced with the problem of flange 303 not being properly formed in the comparative example, technicians typically increase the thickness of the blank and add metal material to encourage more metal material to flow into flange 303, thereby ensuring that flange 303 is fully filled and formed. However, this method results in an increased underpressure value of the metal forging 3, increases the thickness of the forging's curved surface, requires a high forming force, and significantly wastes material.

[0082] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0083] The one or more embodiments of this application are intended to encompass all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application should be included in the scope of protection of this application.

Claims

1. A forging die for a metal forging, wherein the metal forging (3) is in the shape of a hollow cone, comprising a flange (303) and a conical surface (302) located on the flange, wherein a through hole (301) is provided on the conical surface; the forging die comprises a concave die (1) and a convex die (2) arranged opposite to each other, wherein: The die (1) and / or the punch (2) are provided with a forging protrusion (4), which squeezes the material during the forming process to prevent the material from flowing toward the inner hole of the forging, so that more material flows into the flange of the forging, and the flange is formed more fully; the height of the forging protrusion (4) is 13-17 mm, and the aperture of the through hole (301) is smaller than the diameter of the forging protrusion (4).

2. The forging die for metal forgings according to claim 1, characterized in that: The outer edges of the concave die (1) and the convex die (2) are planes, and after forging, a space for accommodating the flange (303) is formed within the two planes.

3. The forging die for metal forgings according to claim 2, characterized in that: The outer periphery of the plane of the male mold (2) is provided with a guide outer wall (201), and the outer periphery of the plane of the female mold (1) is provided with a corresponding guide inner wall (101).

4. The forging die for metal forgings according to claim 1, wherein The die (1) is provided with a forging protrusion (4), and the height of the forging protrusion (4) is 15 millimeters.

5. The forging die for metal forgings according to claim 4, characterized in that: The male mold (2) is provided with a positioning protrusion (5), and the positioning protrusion (5) can be accommodated in the through hole (301).

6. The forging die for metal forgings according to any one of claims 1 to 5, characterized in that: The outer periphery of the forging protrusion (4) is provided with a receiving groove (103), which is provided between the forging protrusion (4) and a forming inclined surface (102) of a die for forming a metal forging, the receiving groove (103) comprising a first forming surface (1031), a second forming surface (1032) and a forming inclined surface (102) which are connected in sequence, and the first forming surface (1031) and the forging protrusion (4) are connected.

7. The forging die for metal forgings according to claim 6, characterized in that: The width of the second profile (1032) is 18-22 millimeters, and the angle between the first profile (1031) and the second profile (1032) is 120°-130°.

8. A die design method for a forging die according to any one of claims 1 to 7, characterized in that: The steps include: S1: blank selection: select a blank to perform a hot compression test, obtain performance parameters of the blank, and input the performance parameters of the blank into a computer simulation software; S2: Preliminary drawing design of the mold: according to the workpiece drawing, the punch (2) and the die (1) are designed using computer three-dimensional drawing software, and a forging protrusion (4) is designed in the middle of the punch (2) and / or the die (1); S3: die forming simulation: the die designed in S2 is imported into the computer simulation software, the die forging parameters are set, the performance parameters of the blank and the calculation formula for the forging deformation are input, and the computer performs die forming simulation to obtain the workpiece parameters, which are the average deformation, the underpressure value and the workpiece curved surface thickness; S4: adjusting the die and the blank: comparing the workpiece parameters obtained in S3 with the ideal values, and adjusting the die parameters and the blank parameters according to the parameter comparison result, wherein the die parameters include the shape of the forging protrusion (4), the width of the second profile (1032), and the angle between the first profile (1031) and the second profile (1032); S5: Repeat S3 and S4 until the workpiece parameters reach the ideal values ​​and the optimal mold parameters are obtained.

9. The die design method for a forging die according to claim 8, characterized in that: In S3, the calculation formula for forging deformation is: , is the equivalent plastic strain.

10. The die design method for a forging die according to claim 8, characterized in that: In S3, the die forging parameters set are die and billet temperature, die and billet friction coefficient, upper die downward distance, and die maximum stop pressure.

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