Equipment and method for continuously extruding cylindrical shell with bottom by adopting segmented core mold

Abstract

The invention discloses equipment and a method for continuously extruding a cylindrical shell with a bottom by adopting a segmented core mold. According to the process, the cylindrical shell with the bottom is extruded and formed through the segmented core mold, raw materials enter an extrusion cylinder in the form of molten metal liquid to be extruded and formed, the varieties of the raw materials are less limited, the quality requirement is low, and raw material blanks do not need to be subjected to complex pretreatment. The process is few in production steps and simple in process, and does not need to bear extreme stress common to a deep drawing process, so that complex and expensive tools and molds are not needed. And meanwhile, the production of the cylindrical shells with the bottoms and different specifications can be realized only by replacing the extrusion barrels and the core molds with different specifications. In the process, as the deformability of the molten metal liquid and the high-temperature metal is better, and the deformation condition in the machining process is simple and stable, the analysis and optimization of machining parameters and a machining mold are easier, and compared with a deep drawing process, the process can achieve a lower rejection rate.

Description

Technical Field

[0001] The present invention belongs to the technical field of machining, and relates to an equipment and a method for continuously extruding a bottomed cylindrical shell by using a segmented core mold. Background Art

[0002] Batteries play an important role in modern society and are the core power sources for mobile devices, electric transportation, renewable energy storage, emergency power supplies, and consumer electronics. In the current battery technology field, cylindrical batteries have been widely concerned and applied due to their unique advantages such as high energy density, excellent heat dissipation performance, and strong structural stability, and have long occupied more than 20% of the global power battery market share. Compared with traditional square batteries, the energy density of cylindrical batteries can be increased by 10% to 20%, and the heat conductivity can be increased by 10% to 15%.

[0003] The cell housing is the core part of the battery. The cell housing of a cylindrical battery is a bottomed cylindrical shell, and the currently commonly used mass production method is the deep drawing process. When manufacturing by the deep drawing process, a circular blank metal sheet flows into the die cavity under the action of the pressure applied by the punch and the blank holder, forming a predetermined shape. According to the relationship between the diameter and depth of the cylindrical shell, usually several sets of dies with different shapes and sizes are used to repeat the above process several times, and then through trimming, grinding, polishing and other treatments, a bottomed cylindrical shell that meets the requirements is finally produced. [Zhao Shengdun. (2008). A hydraulic deep drawing forming device. CN101244440A. Swapna D, Rao C S, Radhika S. A review on deep drawing process [J]. International Journal of Emerging Research in Management and Technology, 2018, 6(6): 146 - 149.] Currently, the deep drawing forming technology has been widely used in the mass production of the cell housing of 2170 - sized (diameter 21 mm, height 70 mm) cylindrical batteries. [China Automotive Technology and Research Center Co., Ltd. China New Energy Vehicle Power Battery Industry Development Report (2023) [M]. Beijing: Social Sciences Academic Press. 2023.]

[0004] In recent years, large cylindrical batteries represented by 4680 - sized (diameter 46 mm, height 80 mm) cylindrical batteries have shown higher safety and more excellent performance. At the same time, large cylindrical batteries have higher production efficiency expectations and are very suitable for the integrated design of the whole vehicle. Large cylindrical batteries are gradually becoming the mainstream direction of the market.

[0005] However, compared with the traditional small cylindrical battery of 2170 specification, the 4680 battery has a higher capacity and output power, so the requirements for safety are more stringent. The cell housing, as an important structural component of the cylindrical battery, is the basis for determining the battery performance and safety and needs to meet higher quality requirements. Although the deep drawing process has been widely used in the production of the cell housing of traditional 2170-specification cylindrical batteries in the past, the deep drawing process has exposed some insurmountable problems such as demanding requirements for raw materials, high costs, high rejection rates, and low efficiency. Most of these problems will become more prominent in the production of the cell housing of large cylindrical batteries represented by the 4680 specification. First, the large cylindrical battery has a higher capacity and output power, and while the requirements for safety are more stringent, the structural strength decreases due to the increase in size. However, the deep drawing process can only process metals with good deformability such as stainless steel and cannot be used for lightweight and high-strength materials such as aluminum alloy and titanium alloy, which will result in poor quality of the large cylindrical cell housing produced by the deep drawing process. Second, the dies and tooling for the deep drawing process are expensive. When producing larger-sized large cylindrical cell housings, larger-sized dies and tooling are required, further increasing the production cost. Third, the ratio of the outer dimension to the thickness of the large cylindrical cell housing is larger, and it is easier to generate defects such as cracks, fractures, and wrinkles during the deep drawing process, resulting in a high rejection rate. Finally, whether producing the cell housing of traditional specifications or the new large cylindrical cell housing, the deep drawing process requires multiple processes (such as lubricating the blank, multiple deep drawing, etc.) and a long processing time, resulting in low production efficiency. [Ikumapayi O M, Afolalu S A, Kayode J F, et al. A concise overview of deep drawing in the metal forming operation [J]. Materials Today: Proceedings, 2022, 62: 3233-3238.]

[0006] In summary, the existing deep drawing process has problems such as poor production quality, high production cost, high rejection rate, and low production efficiency in the production of large cylindrical cell housings, and cannot meet the high-quality, high-efficiency, and low-cost production requirements of the bottomed cylindrical housings of large cylindrical cells. Therefore, there is an urgent need to develop a high-efficiency, high-quality, and low-cost production process for bottomed cylindrical housings suitable for large cylindrical battery cell housings. Summary of the Invention

[0007] The object of the present invention is to solve the problems of poor production quality, high production cost, high rejection rate, and low production efficiency in the production of bottomed cylindrical housings for large cylindrical cell housings by the deep drawing process, and to propose a method for continuously extruding bottomed cylindrical housings using a segmented core mold.

[0008] The technical solution of the present invention:

[0009] An equipment for continuously extruding a cylindrical shell with a bottom by using a segmented mandrel, comprising an extrusion cylinder 2, a mandrel 5, a first mandrel 6, a head 8 and a push rod 9; wherein,

[0010] The extrusion cylinder 2 is a hollow stepped cylindrical structure, and the inner diameter of its left end is smaller than that of its right end; the inner diameter of the left end of the extrusion cylinder 2 is the same as the diameter of the mandrel 5 and the left end diameter of the first mandrel 6, forming a tight fit; the inner diameter of the right end of the extrusion cylinder 2 is the same as the right end diameter of the first mandrel 6 and the outer diameter of the formed cylindrical shell with a bottom, forming a tight fit; a circumferential gate 3 for pouring metal is arranged on the barrel wall of the extrusion cylinder 2; a first mandrel automatic positioning device 4 that cooperates with the right end of the first mandrel 6 is arranged on the inner side of the barrel wall of the extrusion cylinder 2, and its extending and contracting actions can be manually controlled;

[0011] The mandrel 5 is a cylinder, and its diameter is the same as the inner diameter of the formed cylindrical shell with a bottom and the inner diameter of the left end of the extrusion cylinder 2;

[0012] The first mandrel 6 is a stepped cylinder, the diameter of its right end is larger than that of its left end, the diameter of its right end is the same as the inner diameter of the right end of the extrusion cylinder 2, forming a tight fit, and a groove-shaped structure is arranged at the right end of the first mandrel 6, which cooperates with the first mandrel automatic positioning device 4 arranged on the inner wall of the extrusion cylinder 2; the left end diameter of the first mandrel 6 is the same as the inner diameter of the formed cylindrical shell with a bottom;

[0013] The head 8 is a circular ring structure, and its right end face cooperates with the left end face of the extrusion cylinder 2. A head driving device 12 is connected to the left side of the head 8, and the head driving device 12 is fixed on the head driving device fixing mechanism 14. Through the cooperation of the above structures, the left and right translation movements of the head 8 are realized, and thus the opening and closing of the left opening of the extrusion cylinder 2 are realized;

[0014] The push rod 9 is a cylinder and can extend or retract from the push rod driving device 13. The push rod driving device 13 is fixed on the left side of the head 8. Through the cooperation of the above structures, the left and right translation movements of the push rod 9 relative to the head 8 are realized, and thus the movement of the push rod 9 extending and retracting from the circular hole in the center of the head 8 is realized.

[0015] The mutual cooperation of the movements of the head 8 and the push rod 9 realizes the following various movements:

[0016] (1) The right end face of the head 8 abuts against the left end face of the extrusion cylinder 2, and the right end face of the push rod 9 is flush with the right end face of the head 8, realizing the sealing of the forming metal liquid 10 in the extrusion cylinder 2;

[0017] (2) The right end face of the head 8 moves leftward away from the left end face of the extrusion cylinder 2, and the right end face of the push rod 9 is flush with the left end face of the head 8, which is used for the next mandrel 5 to be inserted into the cavity of the extrusion cylinder 2 from the left opening of the extrusion cylinder 2;

[0018] (3) The right end face of the head 8 approaches the left end face of the extrusion cylinder 2 to the right. The right end face of the push rod 9 remains flush with the right end face of the head 8, and the mandrel 5 is inserted from the left opening of the extrusion cylinder 2 into the predetermined position 11 of the next mandrel in the cavity of the extrusion cylinder 2.

[0019] (4) The right end face of the head 8 abuts against the left end face of the extrusion cylinder 2. The push rod 9 extends to the right relative to the right end face of the head 8, and the mandrel 5 and the formed metal are pushed forward to the predetermined position.

[0020] A method for continuously extruding a cylindrical shell with a bottom using a segmented mandrel is as follows:

[0021] Step 1: At the right extrusion outlet of the extrusion cylinder 2, the first mandrel 6 is loaded. After it is in place, several first mandrel automatic positioning devices 4 driven by electromagnetic or pneumatic means provided inside the extrusion cylinder 2 cooperate with the groove-shaped structure at the right end of the first mandrel 6 to fix the position of the first mandrel 6; the right side of the first mandrel 6 is closely fitted with the inside of the extrusion cylinder 2 and cooperates with the first mandrel automatic positioning device 4 to achieve axial positioning, forming a sealed cavity that can withstand a certain fluid pressure.

[0022] Step 2: The head 8 and the push rod 9 move to the left under the action of the head driving device 12 and the push rod driving device 13, opening the left opening of the extrusion cylinder 2, and sending the mandrel 5 to the left extrusion inlet of the extrusion cylinder 2. Then, the head 8 and the push rod 9 move to the right simultaneously to tightly press against the extrusion cylinder 2, pressing the mandrel 5 into the predetermined position in the extrusion cylinder 2; then, the head driving device 12 and the push rod driving device 13 continuously apply forces to the head 8 and the push rod 9 to ensure that the head 8 tightly presses against the extrusion cylinder 2 to achieve the sealing effect; at this time, the position of the first mandrel 6 is fixed, and the movement tendency of the mandrel 5 to move to the left when subjected to fluid pressure is jointly restricted by the head 8 and the push rod 9. The first mandrel 6, the mandrel 5, and the extrusion cylinder 2 jointly form a stable forming cavity.

[0023] Step 3: Using a circumferential gate 3 on the extrusion cylinder 2, the air existing in the forming cavity is pumped out by a vacuum pump; then, molten metal liquid is injected at a certain pressure from several circumferential gates evenly distributed on the extrusion cylinder 2 until the forming cavity formed by the mandrel 5 and the extrusion cylinder 2 is filled, and the pressure is maintained to make the molten metal liquid fully and evenly fill the forming cavity; then it is cooled until the molten metal liquid solidifies to ensure that the metal forms a relatively stable shape.

[0024] Step 4: The automatic positioning device 4 of the first core mold retracts, releasing the axial positioning of the first core mold 6. The push rod 9 moves forward to the designated position, driving the core mold 5 and the formed metal to move forward to the designated position. Then, the push rod 9 retracts to the initial position. After that, under the action of the head drive device 12 and the push rod drive device 13, the head 8 and the push rod 9 move to the left, opening the left opening of the extrusion cylinder 2, and sending the core mold 5 to the left extrusion inlet of the extrusion cylinder 2. Then, the head 8 and the push rod 9 move to the right simultaneously to tightly press against the extrusion cylinder 2, pressing the core mold 5 into the predetermined position in the extrusion cylinder 2. After that, the head drive device 12 and the push rod drive device 13 continuously apply forces to the head 8 and the push rod 9 to ensure that the head 8 tightly presses against the extrusion cylinder 2 to achieve the sealing effect. At this time, the movement tendency of the combination of the core mold 5 on the right side and the formed metal to the right under the action of the fluid pressure is restricted by the frictional force between it and the inner wall of the extrusion cylinder 2, and the movement tendency of the core mold 5 on the left side to move to the left under the action of the fluid pressure is restricted by the head 8 and the push rod 9 together. Thus, the combination of the left core mold 5, the right core mold 5 and the formed metal together forms a stable forming cavity. Then, repeat Step 3 and Step 4 to obtain multiple bottomed cylindrical shells.

[0025] Step 5: According to the production requirements, after continuously extruding several bottomed cylindrical shells, take out the multiple bottomed cylinders, cut them into segments, and perform local grinding. Then, take out the core mold to obtain the finished product of the bottomed cylindrical shell.

[0026] Advantages of the present invention:

[0027] (1) This process uses segmented core molds to extrude and form bottomed cylindrical shells. The raw materials enter the extrusion cylinder in the form of molten metal liquid for extrusion and forming. There are few restrictions on the types of raw materials, the quality requirements are low, and the raw material blanks do not need to go through complex pretreatment. While improving efficiency and reducing costs, it can manufacture bottomed cylindrical shells of more materials.

[0028] (2) This process has fewer production steps, is simple, and does not need to bear extreme stresses such as in the drawing process. Therefore, it does not require complex and expensive tooling and molds. At the same time, only by replacing the extrusion cylinder and core mold of different specifications can the production of bottomed cylindrical shells of different specifications be realized. Through the above two points, the production cost can be effectively controlled, the production efficiency can be improved, and high production flexibility can be achieved.

[0029] (3) In this process, since the deformation ability of molten metal liquid and high-temperature metal is better, and the deformation situation during the processing is simple and stable, it is easier to analyze and optimize the processing parameters and processing molds. Compared with the drawing process, this process can achieve a lower scrap rate. Description of the Drawings

[0030] Figure 1Schematic diagram of the finished product dimensions of the cylindrical battery cell housing. Among them, (a) is the sectional view A of the finished product model of the cylindrical battery cell housing, and (b) is the front view of the finished product model of the cylindrical battery cell housing;

[0031] Figure 2 Schematic diagram of the structure and dimensions of the extrusion cylinder. Among them, (a) is the front view of the extrusion cylinder model, (b) is the sectional view A of the extrusion cylinder model, and (c) is the three-dimensional auxiliary view of the extrusion cylinder model;

[0032] Figure 3 Schematic diagram of the structure and dimensions of the core mold. Among them, (a) is the front view of the core mold model, (b) is the side view of the core mold model, and (c) is the three-dimensional auxiliary view of the core mold model;

[0033] Figure 4 Schematic diagram of the structure and dimensions of the first core mold. Among them, (a) is the front view of the first core mold model, (b) is the side view of the first core mold model, and (c) is the three-dimensional auxiliary view of the first core mold model;

[0034] Figure 5 Schematic diagram of the structure of the end head and the push rod device;

[0035] Figure 6 Schematic diagram of Step 1 in the technical solution of the present invention;

[0036] Figure 7 Schematic diagram of Step 2 in the technical solution of the present invention;

[0037] Figure 8 Schematic diagram of Step 3 in the technical solution of the present invention;

[0038] Figure 9 Schematic diagram of Step 4 in the technical solution of the present invention;

[0039] Figure 10 Schematic diagram of continuously processing to obtain multiple bottomed cylindrical shells;

[0040] Figure 11 Three-dimensional schematic diagram of the processing process;

[0041] Figure 12 Schematic diagram of Step 5 and post-processing in the technical solution of the present invention.

[0042] In the figure: 1 Finished product of the cylindrical battery cell housing; 2 Extrusion cylinder; 3 Circumferential gate; 4 Automatic positioning device for the first core mold; 5 Core mold; 6 First core mold; 7 Positioning groove for the first core mold; 8 End head; 9 Push rod; 10 Forming molten metal; 11 Predetermined position of the next core mold; 12 End head driving device; 13 Push rod driving device; 14 Fixed structure of the end head driving device; 15 Fixing device for the push rod driving device. Detailed implementation manners

[0043] The specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings and technical solutions.

[0044] Example 1:

[0045] Combined with Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 It is described that the method for continuously extruding a cylindrical shell with a bottom by using a segmented core mold in the present invention is carried out according to the following steps:

[0046] This embodiment takes the production of a cylindrical shell with a bottom made of aluminum alloy material with a specification of 4680 as an example. As Figure 1 shown, the specific dimensions of the finished product 1 of the cylindrical battery cell shell of this specification are d = 46 mm, h = 80 mm, and t = 0.6 mm.

[0047] Step 1: From the extrusion outlet on the right side of the extrusion cylinder 2, through manual or machine operation, the first core mold 6 is loaded using a special tooling. After it is in place, a number of first core mold automatic positioning devices 4 driven by electromagnetic or pneumatic means in the extrusion cylinder 2 cooperate with the first core mold positioning groove 6 to fix the position of the first core mold 6, and finally achieve the effect as Figure 6 shown.

[0048] Step 2: The head 8 and the push rod 9 move to the left under the action of a driving device such as a cylinder or an electric push rod, opening the extrusion inlet on the left side of the extrusion cylinder 2. The automatic mechanism for transporting the core mold 5 sends the core mold 5 to the extrusion inlet of the extrusion cylinder 2. Then, the head 8 and the push rod 9 move to the right until they tightly press against the left side of the extrusion cylinder 2, pressing the core mold 5 into the predetermined position in the extrusion cylinder 2. After that, the driving device also continuously applies a force to the head 8 and the push rod 9 to ensure that the head 8 tightly presses against the extrusion cylinder 2 to achieve a sealing effect, and finally achieve the effect as Figure 7 shown.

[0049] Step 3: Use a certain circumferential gate 3 on the extrusion cylinder 2 to evacuate the air existing in the cavity using a vacuum pump. Then, inject molten aluminum alloy at 700 °C into the cavity formed by the core mold 5 and the extrusion cylinder 2 from a number of circumferential gates 3 evenly distributed on the extrusion cylinder 2 at a pressure of 5 MPa until the cavity is filled, as Figure 8As shown. Maintain a pressure of 5 MPa for 1.5 s. Then cool until the molten metal solidifies to ensure that the metal forms a relatively stable shape. Among them, the wall thickness t of the cylindrical shell with a bottom is 0.6 mm, the thickness of the cavity gap and the core mold spacing T = t + machining allowance = 0.65 mm, the outer diameter d of the cylindrical shell with a bottom is 46 mm, the diameter D of the core mold 5 = d - 2T = 44.7 mm, the height h of the cylindrical shell with a bottom is 80 mm, and the height H of the core mold 5 = h - T = 79.35 mm.

[0050] Step 4: The first core mold automatic positioning device 4 retracts, releasing the axial positioning of the first core mold 6. The push rod 9 moves forward to the specified position, driving the core mold 5 and the formed metal to move forward to the specified position, as Figure 9 shown. Then the push rod 9 retracts to the initial position. Then, the head 8 and the push rod 9 move to the left under the action of the driving device, opening the left opening of the extrusion cylinder 2, sending the core mold 5 to the left extrusion inlet of the extrusion cylinder 2. Then the head 8 and the push rod 9 move to the right simultaneously to tightly press against the extrusion cylinder 2, pressing the core mold 5 into the predetermined position in the extrusion cylinder 2. Then the driving device also continuously applies a force to the head 8 and the push rod 9 to ensure that the head 8 tightly presses against the extrusion cylinder 2 to achieve a sealing effect. At this time, the movement tendency of the combination of the core mold 5 on the right side and the formed metal to the right under the action of fluid pressure is restricted by the friction force between it and the inner wall of the extrusion cylinder 2, and the movement tendency of the core mold 5 on the left side to move to the left under the action of fluid pressure is restricted by the head 8 and the push rod 9 together. Thus, the combination of the left core mold, the right core mold and the formed metal jointly forms a stable forming cavity. Then repeat Step 3 and Step 4 to obtain multiple cylindrical shells with bottoms. The continuous production status is as Figure 10 and Figure 11 shown.

[0051] Step 5: As Figure 12 shown, according to the production requirements, after continuously extruding several cylindrical shells with bottoms, take out multiple cylindrical bodies with bottoms, cut and segment them, and perform local grinding. Then take out the core mold 5 (which can be reused) to obtain the finished product of the cylindrical shell with a bottom.

[0052] A typical special equipment for a method of continuously extruding a cylindrical shell with a bottom using a segmented core mold, specifically including an extrusion cylinder 2, a core mold 5, a first core mold 6, a head 8 and a push rod 9 device.

[0053] (1) Extrusion cylinder 2: As Figure 2As shown in the figure, the main body of the extrusion cylinder 2 is a hollow cylindrical structure. At the smaller inner diameter section at the left end, the inner diameter corresponds to the diameter of the core mold and the smaller diameter part at the left end of the first core mold 6, forming a tight fit. At the larger inner diameter section at the right end, the inner diameter corresponds to the larger diameter part at the right end of the first core mold 6 and the outer diameter of the formed cylindrical shell with a bottom, forming a tight fit. In addition, a circumferential gate 3 for pouring metal is provided on the wall of the extrusion cylinder 2; a first core mold automatic positioning device 4 that can cooperate with the right end of the first core mold 6 is provided on the inner side of the wall of the extrusion cylinder 2, and its extension and contraction actions can be manually controlled.

[0054] (2) Core mold 5: As Figure 3 shown, the main body of the core mold is a cylinder, and the diameter dimension corresponds to the inner diameter dimension of the formed cylindrical shell with a bottom and the inner diameter dimension of the smaller inner diameter section at the left end of the extrusion cylinder 2.

[0055] (3) First core mold 6: As Figure 4 shown, the main outer contour of the first core mold 6 is a stepped cylinder, with a larger diameter at the right end, and the dimension corresponds to the inner diameter dimension of the larger inner diameter section at the right end of the extrusion cylinder 2, forming a tight fit. And a groove-shaped structure is provided at the right end, which can cooperate with the first core mold automatic positioning device 4 provided on the inner wall of the extrusion cylinder 2. The diameter at the left end is smaller and corresponds to the inner diameter of the formed cylindrical shell with a bottom.

[0056] (4) Head 8 and push rod 9 device: As Figure 5 shown, the main structure of the head 8 and push rod 9 device consists of a left fixed end and a right movable head 8. The push rod 9 and its driving device are fixed on the head 8, and the head 8 is connected to the left fixed end via the driving device and can drive the push rod 9 to perform left and right translation movements together. When the push rod 9 has no action, the front end face is flush with the front end face of the head 8, forming the same plane. When the push rod 9 acts, it can extend to the right from the central hole of the head 8.

[0057] The beneficial effects of this specific embodiment are as follows: The segmented core die extrusion forming method is used to produce the cylindrical shell with a bottom. The raw material enters the extrusion cylinder 2 in the form of molten metal liquid for extrusion forming. Various materials of raw materials can be used, and the raw material blanks do not need to undergo complex pre-treatment, which can effectively improve production efficiency, reduce production costs, and expand the selection range of materials for the cylindrical shell with a bottom. At the same time, the production steps in this method are few, the process is simple, the tooling and die structures are simple, and they do not need to withstand extreme processing conditions, thus effectively reducing the investment cost of production equipment. In addition, when using this method to produce the cylindrical shell with a bottom, only by replacing the extrusion cylinder 2 and the core die 5 with different specifications can the production of cylindrical shells with different specifications be realized, and relatively high production flexibility can be achieved. In this embodiment, since the molten metal liquid and the hot metal have better deformation ability, and the deformation situation during the processing is simple and stable, it is easier to analyze and optimize the processing parameters and processing dies, and a lower rejection rate can be achieved. Through the innovative segmented core die continuous extrusion method, this method effectively solves the problems of poor production quality, high production cost, high rejection rate, and low production efficiency in the production of cylindrical battery cell shells, especially large cylindrical battery cell shells by the traditional drawing process, and can effectively meet the high-quality, high-efficiency, and low-cost production requirements of the cylindrical shell with a bottom for future large cylindrical battery cells.

[0058] Example 2: In combination with Figure 2 , Figure 8 it is described that a temperature control pipeline structure is installed inside or on the surface of the pipe wall of the extrusion cylinder 2 to control the temperature of the extrusion cylinder 2 during the processes of molten metal liquid injection, pressure holding, cooling, etc. in Step 3. Other steps are the same as those in the first specific embodiment.

[0059] The beneficial effects of this specific embodiment are as follows: By designing the pipeline structure of the extrusion cylinder 2, the extrusion cylinder 2 can be controlled to be at the optimal temperature during each process, achieving a better metal crystal structure and surface quality, improving the product quality, and effectively accelerating the production rhythm and improving the overall efficiency of the process flow.

[0060] Example 3: In combination with Figure 1 , Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 it is described that for the case where the wall thickness t of the cylindrical shell with a bottom is too small, the thickness T of the cavity gap can be made greater than the wall thickness t of the cylindrical shell with a bottom. After manufacturing the blank of the cylindrical shell with a bottom that is thicker than the finished product wall thickness through Step 3, Step 4, and Step 5, other processes are then used to thin the blank, and finally the finished product of the cylindrical shell with a bottom with the required wall thickness is obtained. Other steps are the same as those in the first specific embodiment.

[0061] The beneficial effects of this specific implementation are as follows: For a cylindrical shell with a bottom and an overly thin wall thickness, by first extruding to manufacture a thicker blank and then thinning it to make the final product, the problem of low yield rate that is prone to occur when extruding and manufacturing an overly thin cylindrical shell with a bottom can be effectively avoided, the product quality is effectively guaranteed, and the size range of the cylindrical shell with a bottom that can be manufactured by this process method is expanded.

Claims

1. An equipment for continuously extruding a cylindrical shell with a bottom using a segmented core mold, characterized in that: The equipment comprises an extrusion cylinder (2), a core mold (5), a first core mold (6), a sealing head (8) and a push rod (8); wherein: The extrusion barrel (2) is a hollow stepped cylindrical structure, and the inner diameter of the left end is smaller than that of the right end; the inner diameter of the left end of the extrusion barrel (2) is the same as the diameter of the core mold (5) and the left end diameter of the first core mold (6), forming a tight fit; the inner diameter of the right end of the extrusion barrel (2) is the same as the right end diameter of the first core mold (6) and the outer diameter of the formed bottom cylinder, forming a tight fit; a ring gate (3) for pouring metal is arranged on the barrel wall of the extrusion barrel (2); an automatic positioning device (4) for the first core mold that cooperates with the right end of the first core mold (6) is arranged on the inner side of the barrel wall of the extrusion barrel (2), and its extension and contraction movements can be manually controlled; The core mold (5) is a cylinder, and its diameter is the same as the inner diameter of the formed bottomed cylindrical shell and the inner diameter of the left end of the extrusion cylinder (2); The first core mold (6) is a stepped cylinder, the diameter of the right end of which is larger than the diameter of the left end, and the diameter of the right end is the same as the inner diameter of the right end of the extrusion cylinder (2), forming a tight fit, and a groove structure is arranged at the right end of the first core mold (6), which cooperates with the first core mold automatic positioning device (4) arranged on the inner wall of the extrusion cylinder (2); the diameter of the left end of the first core mold (6) is the same as the inner diameter of the formed bottom cylindrical shell; The sealing head (8) is a circular ring structure, and its right end face cooperates with the left end face of the extrusion cylinder (2). The left side of the sealing head (8) is connected to a sealing head driving device (12), and the sealing head driving device (12) is fixed on a sealing head driving device fixing mechanism (14). Through the cooperation of the above structures, the left and right translation movement of the sealing head (8) is realized, thereby realizing the opening and closing of the left opening of the extrusion cylinder (2); The push rod (8) is a cylinder and can be extended or retracted from the push rod driving device (13). The push rod driving device (13) is fixed on the left side of the head (8). Through the cooperation of the above structure, the push rod (8) can achieve left and right translation movement relative to the head (8), thereby achieving the movement of the push rod (8) extending and retracting from the circular hole in the center of the head (8).

2. The equipment for continuously extruding a cylindrical shell with a bottom using a segmented core mold according to claim 1 is characterized in that: The movements of the head (8) and the push rod (8) cooperate with each other to achieve the following multiple movements: (1) The right end surface of the sealing head (8) is in close contact with the left end surface of the extrusion cylinder (2), and the right end surface of the push rod (8) is flush with the right end surface of the sealing head (8), so as to achieve sealing of the forming metal liquid (10) in the extrusion cylinder (2); (2) the right end surface of the end cap (8) is away from the left end surface of the extrusion cylinder (2) to the left, and the right end surface of the push rod (8) is flush with the left end surface of the end cap (8), so that the next core mold (5) can be inserted into the cavity of the extrusion cylinder (2) from the left opening of the extrusion cylinder (2); (3) The right end surface of the end cap (8) approaches the left end surface of the extrusion cylinder (2) to the right, the right end surface of the push rod (8) is kept flush with the right end surface of the end cap (8), and the core mold (5) is inserted from the left opening of the extrusion cylinder (2) into the predetermined position (11) of the next core mold in the cavity of the extrusion cylinder (2); (4) The right end face of the branch head 8 is close to the left end face of the extrusion cylinder (2), and the push rod (8) extends to the right relative to the right end face of the end cap (8), pushing the core mold (5) and the formed metal forward to a predetermined position.

3. A method for continuously extruding a cylindrical shell with a bottom using a segmented core mold, characterized in that: Here are the steps: Step 1: insert the first core mold (6) from the extrusion outlet on the right side of the extrusion cylinder (2); after it is in place, use a plurality of electromagnetically driven or pneumatically driven first core mold automatic positioning devices (4) arranged inside the extrusion cylinder (2) to cooperate with the groove structure on the right end of the first core mold (6) to fix the position of the first core mold (6); the right side of the first core mold (6) is tightly matched with the inside of the extrusion cylinder (2), and cooperates with the first core mold automatic positioning device (4) to achieve axial positioning, thereby forming a closed cavity that can withstand a certain fluid pressure; Step 2: The end cap (8) and the push rod (8) move to the left under the action of the end cap driving device (12) and the push rod driving device (13), open the opening on the left side of the extrusion cylinder (2), and send the core mold (5) to the extrusion inlet on the left side of the extrusion cylinder (2). Then, the end cap (8) and the push rod (8) move to the right at the same time to press against the extrusion cylinder (2), and press the core mold (5) into a predetermined position in the extrusion cylinder (2); then, the end cap driving device (12) and the push rod driving device (13) continuously apply force to the end cap (8) and the push rod (8) to ensure that the end cap (8) presses against the extrusion cylinder (2) to achieve a sealing effect; at this time, the position of the first core mold (6) is fixed, and the movement tendency of the core mold (5) to move to the left when subjected to fluid pressure is jointly restricted by the end cap (8) and the push rod (8), and the first core mold (6), the core mold (5) and the extrusion cylinder (2) jointly form a stable forming cavity; Step 3: Utilize an annular gate (3) on the extrusion barrel (2) and use a vacuum pump to extract the air in the forming cavity; then, inject molten metal at a certain pressure from a plurality of annular gates evenly distributed on the extrusion barrel (2) until the forming cavity formed by the core mold (5) and the extrusion barrel (2) is filled, and the pressure is maintained so that the molten metal fills the forming cavity fully and evenly; then, cool the molten metal until it solidifies to ensure that the metal forms a relatively stable shape; Step 4: The automatic positioning device (4) of the first core mold retracts to release the axial positioning of the first core mold (6), and the push rod (8) is pushed forward to the specified position, driving the core mold (5) and the formed metal to move forward to the specified position, and then the push rod (8) retracts to the initial position; then, the head (8) and the push rod (8) move to the left under the action of the head drive device (12) and the push rod drive device (13), opening the left side opening of the extrusion cylinder (2), and sending the core mold (5) to the extrusion inlet on the left side of the extrusion cylinder (2), and then the head (8) and the push rod (8) move to the right at the same time to press the extrusion cylinder (2), and press the core mold (5) into the predetermined position in the extrusion cylinder (2); then the head drive device The device (12) and the push rod driving device (13) continuously apply force to the head (8) and the push rod (8) to ensure that the head (8) is pressed tightly against the extrusion cylinder (2) to achieve a sealing effect; at this time, the rightward movement tendency of the combination of the right core mold (5) and the formed metal when subjected to fluid pressure is limited by the friction between it and the inner wall of the extrusion cylinder (2), and the leftward movement tendency of the left core mold (5) when subjected to fluid pressure is jointly limited by the head (8) and the push rod (8); thus, the combination of the left core mold (5), the right core mold (5) and the formed metal together forms a stable forming cavity; then, steps three and four are repeated to obtain a multi-section cylindrical shell with a bottom; Step 5: According to production requirements, after continuously extruding several sections of cylindrical shells with bottoms, take out the multiple sections of cylindrical shells with bottoms, cut them into sections, and perform local grinding; then take out the core mold to obtain the finished product of the cylindrical shell with bottoms.

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