Split type extrusion die and forming method

Abstract

The invention provides a split extrusion die and a forming method, and relates to the technical field of dies, the die comprises a punch rod, a stripper plate, a split punch, a punch sleeve, a positioning block and a female die, the stripper plate is movably connected to the top of the female die, a forming cavity is formed in the middle of the female die, the punch rod is movably connected in the forming cavity, and the lower end of the punch rod is sleeved with the split punch; the punch sleeve is sleeved at the lower end of the split punch, and the positioning block is sleeved outside the punch sleeve. A sliding groove is formed in the stripper plate, a positioning pin is movably connected into the sliding groove, and the bottom of the positioning pin is movably connected with the female die. The problems that in the prior art, due to the fact that an integral punch is adopted, the integral punch can only be used for manufacturing specific machine tools and specific products, and manufacturing of products with the large length-diameter ratio cannot be achieved are solved.

Description

Technical Field

[0001] This application relates to the technical field of molds, and particularly relates to a split extrusion mold and a forming method. Background Art

[0002] The backward extrusion technology is one of the main methods for the forming and processing of parts made of non-ferrous metals, steel and other materials. Its core feature is that the metal flow direction is opposite to the movement direction of the extrusion shaft (or extrusion rod), so it is also called reverse extrusion. This technology applies pressure to the metal blank to make it form a product with a specific shape through the mold, and is widely used in the production of components such as thin-walled cylindrical parts, oil cylinders, and missile shells. The Chinese patents with the publication numbers of CN204093854U, CN218020389U, and CN203917449U that have been publicly announced adopt an integral punch. The opening of the extrusion press needs to reach more than twice the size of the product to ensure the extrusion of the product. However, under the condition that the opening size of the machine tool is limited, it is difficult to realize the extrusion of products with a large length-diameter ratio. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a split extrusion mold, aiming to solve the problem in the prior art that due to the integral punch, it can only be used for the manufacture of specific machine tools and specific products, and it is impossible to manufacture products with a large length-diameter ratio.

[0004] To achieve the above purpose, the embodiments of the present invention adopt the following technical solutions:

[0005] A split extrusion mold includes: a punch rod, a stripper plate, a split punch, a punch sleeve, a positioning block, and a die. The stripper plate is movably connected to the top of the die. The middle part of the die has a forming cavity. The punch rod is movably connected in the forming cavity. The lower end of the punch rod is sleeved with the split punch. The punch sleeve is sleeved on the lower end of the split punch. The positioning block is sleeved outside the punch sleeve.

[0006] Further, a sliding groove is opened on the stripper plate, and a positioning pin is movably connected in the sliding groove. The bottom of the positioning pin is movably connected to the die.

[0007] Further, the outer circle of the top of the split punch has a tenon connected to the punch rod, and the inner circle of the top of the split punch has a stripping convex tenon.

[0008] Further, the positioning block is pressed from a lubricating material, and the inner hole diameter of the positioning block is the same as the outer circle of the punch sleeve.

[0009] On the other hand, this application provides a forming method for a split extrusion mold. Using the above split extrusion mold, it includes the following steps:

[0010] Step 1: Bond the split punch and the punch sleeve to form a total punch;

[0011] Step 2: Open the stripper plate to make it in an open state;

[0012] Step 3: Heat the blank to a specified temperature and place it into the forming cavity;

[0013] Step 4: Place the positioning block into the forming cavity and make it located above the blank;

[0014] Step 5: Place the total punch into the positioning block;

[0015] Step 6: The punch rod slides downward and presses into the split punch;

[0016] Step 7: The punch rod and the punch squeeze the blank downward, the positioning block breaks to form lubrication and the blank forms a finished product;

[0017] Step 8: Push the stripper plate to make it in a closed state;

[0018] Step 9: The punch rod and the punch sleeve slide upward, the binder volatilizes under high temperature, and the punch sleeve separates from the split punch;

[0019] Step 10: After the temperature of the finished product drops to the specified temperature, the punch rod slides upward and separates from the split punch under the action of the stripper plate;

[0020] Step 11: Take out the finished product, the punch sleeve, and the split punch from the forming cavity to complete the extrusion.

[0021] Further, the length of the blank is:

[0022]

[0023] wherein, L0 is the depth of the forming cavity, D is the outer diameter of the finished product to be processed, d is the inner diameter of the finished product to be processed, h is the bottom thickness of the finished product to be processed, and H0 is the maximum opening size of the machine tool.

[0024] Further, the length of the total punch is: L3 = H0 - L0 - h, and the thickness is: G = 2L0 + h - H0.

[0025] Based on the above technical features, the beneficial effects of the present application are as follows: For the process of backward extrusion of tubular parts in the prior art, the present application provides a split extrusion die and a forming method, which break through the length of the backward extrusion parts in a limited space. Through the split extrusion die, under the condition of limited opening of the press, the production extrusion of larger-sized products is realized, and the problem in the prior art that due to the integral punch, it can only be used for the manufacture of specific machine tools and specific products and cannot realize the manufacture of products with a large length-diameter ratio is solved. Brief Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 Structural schematic diagram of the present application;

[0028] Figure 2 Structural schematic diagram of the split punch in the present application;

[0029] Figure 3 Structural schematic diagram of the positioning block in the present application;

[0030] Figure 4 Structural schematic diagram of the total punch in Embodiment 2;

[0031] Figure 5 Schematic diagram of Embodiment 2;

[0032] Figure 6 Schematic diagram of Step 4 in Embodiment 2;

[0033] Figure 7 Schematic diagram of Step 6 in Embodiment 2;

[0034] Figure 8 Schematic diagram of Step 7 in Embodiment 2;

[0035] Figure 9 Schematic diagram of Step 8 in Embodiment 2;

[0036] Figure 10 Schematic diagram of Step 10 in Embodiment 2.

[0037] In the figure: 1 - punch rod; 2 - stripper plate; 3 - split punch; 4 - punch sleeve; 5 - positioning block; 6 - blank; 7 - die; 8 - finished product; 9 - tenon; 10 - stripper projection. Detailed Description of the Embodiments

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0039] Embodiment 1

[0040] Please refer to Figures 1 - 10 , the embodiment of the present application provides a split extrusion die, which relates to the technical field of dies. The device includes: a punch rod 1, a stripper plate 2, a split punch 3, a punch sleeve 4, a positioning block 5, and a die 7. The stripper plate 2 is movably connected to the top of the die 7. The middle of the die 7 has a forming cavity, and the punch rod 1 is movably connected in the forming cavity. The lower end of the punch rod 1 is sleeved with the split punch 3. The punch sleeve 4 is sleeved on the lower end of the split punch 3. The positioning block 5 is sleeved outside the punch sleeve 4.

[0041] It is worth noting that the prior art uses an integral punch. The opening of the extruder needs to reach more than twice the size of the product to ensure the extrusion of the product. However, under the condition that the opening size of the machine tool is limited, it is difficult to extrude products with a large length-to-diameter ratio. In this embodiment, the punch rod 1 and the split punch 3 are movably connected to form a total punch. During the demolding process, the split punch 3 is separated from the punch sleeve 4, and then the punch rod 1 and the punch are pulled out together. This embodiment breaks through the length of the inverse extrusion part in the limited space in the prior art. Through the split extrusion die, the production and extrusion of larger-sized products are realized under the condition of limited opening of the press. On the other hand, in the conventional hot extrusion process of the prior art, friction between the punch and the product during the demolding process is likely to cause drawing marks on the inner surface. In the split die provided in this embodiment, the punch rod does not contact the product during the demolding process, which can effectively improve the quality of the inner surface of the product, solve the problem that the integral punch in the prior art can only be used for the manufacture of specific machine tools and specific products and cannot realize the manufacture of products with a large length-to-diameter ratio, and also solve the problem of poor product quality in the prior art.

[0042] Furthermore, in this embodiment, a stripper plate 2, a punch sleeve 4, a positioning block 5, and a female die 7 are also provided. The punch sleeve 4 is preferably thin-walled and can undergo elastoplastic deformation during the cooling process, effectively preventing the cracking problem caused by inconsistent deformation of different materials during cooling. The positioning block 5 will break during the extrusion process, forming lubrication between the punch rod 1 and the product, thereby improving the quality of the mouth part of the tubular part. The stripper plate 2 is provided. During the demolding process, the punch rod 1 and the split punch 3 are separated by the stripper plate 2. The positioning of the mold is achieved through the provided female die 7, and the formed cavity opened thereon can provide space for placing the blank 6. Preferably, the punch rod 1 and the split punch 3 are connected by bonding. Optionally, the punch rod 1 and the split punch 3 can be connected using glue. Optionally, the positioning block 5 is pressed from graphite material.

[0043] Furthermore, a sliding groove is opened on the stripper plate 2, and a positioning pin is movably connected in the sliding groove. The bottom of the positioning pin is movably connected to the female die 7. It should be noted that there are two stripper plates 2, which are symmetrically arranged at the opening position on the top of the female die 7. Through the provided sliding groove and positioning pin, the adjustment of the distance between the two stripper plates 2 can be achieved.

[0044] Furthermore, the outer circle of the top of the split punch 3 has a tenon 9 connected to the punch rod 1, and the inner circle of the top of the split punch 3 has a stripping tenon 10. Through the provided tenon 9 and stripping tenon 10, the tenon 9 connection between the punch rod 1 and the split punch 3 can be achieved, facilitating the combination and separation between the punch rod 1 and the split punch 3.

[0045] Furthermore, the positioning block 5 is pressed from lubricating material, and the inner hole diameter of the positioning block 5 is the same as the outer circle of the punch sleeve 4. In the prior art, in the extrusion of large-sized tubular parts, due to the insufficient fluidity of the lubricating material, cracks and wrinkles are likely to appear at the mouth part of the tubular part. In this application, lubrication can be formed between the punch rod 1 and the product through the breaking of the lubricating material positioning block 5, thereby improving the quality of the mouth part of the tubular part.

[0046] Embodiment 2

[0047] Please refer to Figures 1 - 10 simultaneously. This embodiment provides a forming method for a split extrusion die, using the above-mentioned split extrusion die, including the following steps:

[0048] Step 1, bond the split punch 3 and the punch sleeve 4 to form a total punch;

[0049] Step 2, open the stripper plate 2 to make it in an open state;

[0050] Step 3, heat the blank 6 to a specified temperature and place it in the formed cavity;

[0051] Step 4: Place the positioning block 5 into the forming cavity and position it above the blank 6.

[0052] Step 5: Place the main punch into the positioning block 5.

[0053] Step 6: The punch rod 1 slides downward and presses into the split punch 3.

[0054] Step 7: The punch rod 1 and the punch squeeze the blank 6 downward, the positioning block 5 breaks to form lubrication, and the blank 6 forms the finished product 8.

[0055] Step 8: Push the stripper plate 2 to make it in the closed state.

[0056] Step 9: The punch rod 1 and the punch sleeve 4 slide upward. Under the action of high temperature, the binder volatilizes, and the punch sleeve 4 separates from the split punch 3.

[0057] Step 10: After the temperature of the finished product 8 drops to the specified temperature, the punch rod 1 slides upward and separates from the split punch 3 under the action of the stripper plate 2.

[0058] Step 11: Take out the finished product 8, the punch sleeve 4, and the split punch 3 from the forming cavity to complete the extrusion.

[0059] Furthermore, the length of the blank 6 is: In the formula, L0 is the depth of the forming cavity, D is the outer diameter of the finished product 8 to be processed, d is the inner diameter of the finished product 8 to be processed, h is the bottom thickness of the finished product 8 to be processed, and H0 is the maximum opening size of the machine tool.

[0060] Furthermore, the length of the main punch is: L3 = H0 - L0 - h, and the thickness is: G = 2L0 + h - H0.

[0061] It should be noted that the length of the blank 6 is determined according to the shape of the finished product 8. The length and thickness of the main punch are determined according to the opening size of the machine tool and the length of the blank 6. Taking the extrusion of a certain cylindrical part as an example, the opening size of the press is 2400 mm, the diameter of the product is 200 mm, the inner diameter is 160 mm, the bottom thickness is 100 mm, and the inner hole depth is 1300 mm. If the method of the existing technology is used, the maximum length of the product does not exceed 1150 mm; while for the product processed by the provided split die in this embodiment, the inner hole depth of the maximum pressurized product can reach 1690 mm, the length of the blank 6 is 568 mm, the length of the punch rod 1 is 1000 mm, and the thickness of the split punch 3 is 400 mm.

[0062] It should be noted that the split punch can overcome the performance bottleneck of the integral punch through modular design, multi-material cooperation, and integrated heat dissipation, enabling its comprehensive advantages to increase the production efficiency by 3-5 times and reduce the die cost by more than 50%. It is particularly suitable for high-value-added and diverse production scenarios. Specifically, the split punch can decompose the load transfer path into multiple functional modules, effectively increasing its lifespan to 3-6 times that of the integral punch; the material utilization rate of the split punch can reach over 80%, which is much higher than that of the integral punch.

[0063] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of the present disclosure. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be equivalently replaced without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A split extrusion die, characterized in that: include: A punch rod (1), a stripping plate (2), a split punch (3), a punch sleeve (4), a positioning block (5), and a die (7); the stripping plate (2) is movably connected to the top of the die (7); the middle of the die (7) has a forming cavity; the punch rod (1) is movably connected to the forming cavity; the split punch (3) is sleeved on the lower end of the punch rod (1); the punch sleeve (4) is sleeved on the lower end of the split punch (3); and the positioning block (5) is sleeved outside the punch sleeve (4).

2. The mold according to claim 1, characterized in that: The stripping plate (2) is provided with a sliding groove, a positioning pin is movably connected in the sliding groove, and the bottom of the positioning pin is movably connected to the concave mold (7).

3. The mold according to claim 1, characterized in that: The outer circle at the top of the split punch (3) has a tenon (9) connected to the punch rod (1), and the inner circle at the top of the split punch (3) has a stripping cam (10).

4. The mold according to claim 1, characterized in that: The positioning block (5) is formed by pressing a lubricating material, and the inner diameter of the positioning block (5) is the same as the outer diameter of the punch sleeve (4).

5. A split extrusion die molding method, characterized in that: Using a split extrusion die as described in any one of claims 1 to 4 comprises the following steps: Step 1, bonding the split punch (3) and the punch sleeve (4) to form a complete punch; Step 2, opening the stripping plate (2) to put it in an open state; Step 3, heating the blank (6) to a specified temperature and placing it into the molding cavity; Step 4, placing the positioning block (5) into the molding cavity and positioning it above the blank (6); Step 5, placing the main punch into the positioning block (5); Step 6, the punch rod (1) slides downward and is pressed into the split punch (3); Step 7, the punch rod (1) and the punch head press the blank (6) downward, the positioning block (5) is broken to form lubrication and the blank (6) is formed into a finished product (8); Step 8, pushing the stripping plate (2) to be in a closed state; Step 9, the punch rod (1) and the punch sleeve (4) slide upward, the binder volatilizes under the action of high temperature, and the punch sleeve (4) is separated from the split punch (3); Step 10, after the temperature of the finished product (8) drops to a specified temperature, the punch rod (1) slides upward and is separated from the split punch (3) under the action of the stripping plate (2); Step 11, taking out the finished product (8), the punch sleeve (4), and the split punch (3) from the forming cavity to complete the extrusion.

6. The molding method according to claim 5, characterized in that: The length of the blank (6) is: Wherein, L0 is the depth of the molding cavity, D is the outer diameter of the finished product (8) to be processed, d is the inner diameter of the finished product (8) to be processed, h is the bottom thickness of the finished product (8) to be processed, and H0 is the maximum opening size of the machine tool.

7. The molding method according to claim 6, characterized in that: The length of the total punch is: L3 = H0-L0-h, and the thickness is: G = 2L0+h-H0.

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