Heating type upsetting-backward extrusion progressive die for thixoforming of copper alloy thin-wall shaft sleeve

Abstract

The invention discloses a heating type upsetting-backward extrusion progressive die for thixoforming of a copper alloy thin-wall shaft sleeve, and relates to the technical field of semi-solid backward extrusion. An upsetting male die (1) is matched with an upsetting female die (5-1), a step male die (7) is matched with a backward extrusion female die (5-2), the lower end of the upsetting male die (1) and the lower end of the backward extrusion female die (5-2) are fixed to a female die fixing plate (10), and a first ejector rod (6-1) and a second ejector rod (6-2) are correspondingly arranged on the lower portion of the upsetting male die (1) and the lower portion of the backward extrusion female die (5-2). The upsetting male die (1) and the stepped male die (7) are fixedly connected with a hydraulic machine through a male die base plate (2). The thin-wall shaft sleeve part is manufactured through thixoforming, the die is simple, the production efficiency is high, the material utilization rate is high, and automatic production is easy to achieve.

Description

Technical field:

[0001] The invention relates to the technical field of semi-solid reverse extrusion, in particular to a heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled shaft sleeve. Background technology:

[0002] Copper alloys are widely used in electronic connectors, heat dissipation devices, precision bushings and other fields due to their excellent electrical conductivity, thermal conductivity, corrosion resistance and mechanical properties. However, traditional hot forging or cold forging processes face significant challenges in processing complex thin-walled copper alloy parts: high-temperature reverse extrusion easily causes oxidation and grain coarsening, resulting in reduced surface quality; cold forging requires multiple annealing due to the high hardness and low plasticity of copper alloys, with a long process cycle and high cost. In addition, thin-walled parts are prone to defects such as insufficient filling and cracks in traditional forming, and the yield is difficult to improve. Thixoforming technology can not only achieve high-precision forming of complex components, but also significantly reduce casting defects such as shrinkage cavities and segregation. During the forming process, this technology can achieve high density, stable filling, rapid forming, excellent formability of the parts, and the final product is close to the shape. In this context, semi-solid thixoforming technology has become an important breakthrough direction for precision processing of copper alloys.

[0003] However, the thixoforming of copper alloys has extremely high requirements for process continuity and temperature control: the semi-solid slurry needs to be filled and solidified in a very short time to avoid component segregation or uneven structure. Traditional single-station molds are difficult to meet the needs of efficient coordination of multiple processes, and the introduction of progressive die technology effectively solves this contradiction. The progressive die adopts a step-by-step continuous production mode. Through the time-sequential connection layout of multiple stations, the pre-upsetting, thixotropic temperature control, and precision extrusion of copper alloys are integrated into one, realizing efficient connection and coordination between processes in the "heating-forming-cooling" process. For example, the first station performs local upsetting on the copper billet to optimize the material distribution, and the second station completes thixotropic reverse extrusion under precise temperature control. This step-by-step forming strategy not only reduces the load of a single station and extends the life of the mold, but also maintains the fluidity and stability of the semi-solid slurry through the temperature compensation system between stations, avoiding filling defects caused by temperature drop. Summary of the invention:

[0004] The purpose of the present invention is to provide a heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled sleeve. The invention can realize one-piece forming of a copper alloy blank after thixoforming, and has high production efficiency, high material utilization rate, easy automation, and good quality of the formed parts.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] The invention provides a heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled shaft sleeve, which is divided into an upsetting cavity, a reverse extrusion cavity and an ejection mechanism; the die comprises an upsetting punch (1), a punch pad (2), a positioning pin (3), a copper alloy blank (4), an upsetting die (5-1), a reverse extrusion die (5-2), an ejector rod (6-1), an ejector rod (6-2), a stepped punch (7), a die heating hole (8), a semi-solid blank (9-1), a thin-walled shaft set (9-2) and a die fixing plate (10);

[0007] The upsetting cavity is composed of an upsetting punch (1) and an upsetting die (5-1), the upsetting cavity is in the shape of a cylindrical cavity and is used for upsetting and heating the blank; the reverse extrusion cavity is composed of a stepped punch (7) and a reverse extrusion die (5-2), the reverse extrusion cavity is in the shape of a cylinder and is used for forming a thin-walled shaft set; the ejection mechanism is composed of an ejector rod (6-1) and an ejector rod (6-2);

[0008] The upsetting die (5-1) and the reverse extrusion die (5-2) are cylindrical cavity structures with an opening facing upward. The upsetting die (5-1) and the reverse extrusion die (5-2) are respectively provided with circumferentially surrounding heating holes. A heating coil is placed in the heating hole. The heating coil is connected to a PID temperature control device and is used to control the heating temperature of the die. The upsetting punch (1) and the stepped punch (7) are axially upright cylindrical structures. The lower part of the upsetting punch (1) is matched and located in the cavity of the upsetting die (5-1) and can move freely up and down. The lower part of the stepped punch (7) is matched and located coaxially in the cavity of the reverse extrusion die (5-2) and can move freely up and down. There is a gap between the outer surface of the stepped punch (7) and the inner surface of the reverse extrusion die (5-2). The gap is used to form a copper alloy thin-walled shaft sleeve.

[0009] The upper part of the upsetting punch (1) and the upper part of the step punch (7) are connected to the punch fixing plate through a horizontal and transverse punch pad (2) to form an integrated structure. The punch fixing plate is fixed to the workbench of the hydraulic press by bolts. The hydraulic press drives the punch fixing plate, the punch pad (2), the upsetting punch (1) and the step punch (7) to move vertically up and down together. The die fixing plate (10) is located at the bottom. Two circular grooves are processed on the upper surface of the die fixing plate (10) for placing the upsetting die (5-1) and the reverse extrusion die (5-2). At the same time, the upsetting die (5-1) and the reverse extrusion die (5-2) are fixed in the groove of the die fixing plate (10), and the die and the die fixing plate are fixed by a pressure plate bolt, so as to ensure the fixation of the die during the upsetting and reverse extrusion process and prevent the die from moving and rotating; the upper surfaces of the upsetting die (5-1) and the reverse extrusion die (5-2) correspond to the steps of the upsetting punch (1) and the stepped punch (7), and the upper port edges of the upsetting die (5-1) and the reverse extrusion die (5-2) are respectively provided with positioning pins (3) for matching and positioning the corresponding punch and die;

[0010] The bottom end of the upsetting die (5-1) is provided with a first downward through hole, the first downward through hole penetrates the die fixing plate (10) downward, and the first through hole is equipped with a first push rod (6-1); the bottom end of the reverse extrusion die (5-2) is provided with a second downward through hole, the second downward through hole penetrates the die fixing plate (10) downward, and the second through hole is equipped with a second push rod (6-2).

[0011] The upsetting punch (1) and the step punch (7) are of a stepped diameter-reducing structure, with the upper portion having a relatively large diameter and the lower portion corresponding to the upsetting die (5-1) and the reverse extrusion die (5-2) having a relatively small diameter.

[0012] The upsetting punch (1) and the step punch (7) are both passed through a transverse punch pad (2): the upper die pad (2) is provided with two through holes, the through holes have equal diameters, and the through hole diameters are respectively equal to the maximum outer diameters of the upper parts of the upsetting punch (1) and the step punch (7);

[0013] The lower diameter of the upsetting punch is equal to the inner diameter of the upsetting die, the inner diameter of the reverse extrusion die is equal to the outer diameter of the thin-walled sleeve, the lower outer diameter of the stepped punch (7) is equal to the inner diameter of the thin-walled sleeve; the inner diameter of the groove of the die fixing plate (10) is equal to the outer diameter of the die.

[0014] The use process of the mold of the present invention is as follows:

[0015] (A): Before deformation, the hydraulic press is driven to drive the upsetting punch (5) and the step punch (7) to move upward, so that the copper alloy blank can be placed in the cavity of the upsetting die (5-1); a release agent is sprayed on the surfaces of the upsetting punch (1), the upsetting die (5-1), the reverse extrusion die (5-2), and the step punch (7);

[0016] (B): placing the copper alloy billet into the cavity of the upsetting die (5-1), controlling the hydraulic press to move vertically downward, causing the upsetting punch (1) and the stepped punch (7) to move vertically downward, so that the upsetting punch applies pressure to the copper alloy billet, thereby completing the upsetting of the billet; then setting the temperature through the PID temperature control device so that the internal temperature range of the upsetting die (5-1) and the reverse extrusion die (5-2) cavities is 800°C to 980°C, and the upset copper alloy billet is kept warm in the upsetting cavity until it reaches a semi-solid temperature and is kept warm for a certain period of time to obtain a copper alloy semi-solid billet, and then controlling the hydraulic press to move upward so that the upsetting punch (1) and the stepped punch (7) move to the top of the hydraulic press, and then the copper alloy semi-solid billet is pushed out of the upsetting die (5-1) through the first push rod (6-1);

[0017] (C) the ejected copper alloy semi-solid billet is quickly placed into the reverse extrusion die (5-2), and the hydraulic press is controlled to drive the upsetting punch (1) and the stepped punch (7) to move downward simultaneously, so that the copper alloy semi-solid billet is filled in the reverse extrusion cavity and the pressure is maintained for a period of time, and then the hydraulic press is controlled to drive the upsetting punch (1) and the stepped punch (7) to move upward to the top of the hydraulic press; and the second ejector rod (6-2) is controlled to eject the copper alloy thin-walled shaft set;

[0018] The above steps (B) and (C) are performed simultaneously. When the steps are performed simultaneously, step (B) performs upsetting of the second batch of copper alloy blanks, and the blanks of the first batch of copper alloy upsetting are filled in step (C) simultaneously with step (B). After step (B) is completed, step (C) is also completed, the first batch of copper alloy thin-walled sleeves filled in step (C) are taken out, and the second batch of upsetting copper alloy blanks are immediately placed in, and the cycle is repeated.

[0019] The inner diameter of the thin-walled shaft sleeve is determined by the lower diameter of the stepped punch (7), and the side thickness of the shaft sleeve is determined by the lower diameter of the stepped punch (7) and the inner diameter of the reverse extrusion die (5-2).

[0020] The upper ends of the push rods (6-1) and the push rods (6-2) pass through the through holes of the concave die and the concave die pad, the upper ends of the push rods are aligned with the lower surface of the concave die cavity, and the lower half of the push rods is connected to the hydraulic press cylinder. After the deformation and die opening are completed, the push rods eject the workpiece.

[0021] The wall thickness of the copper alloy thin-walled sleeve can be 2-5mm.

[0022] Compared with the existing inventions, the present invention has the following advantages:

[0023] 1. The core advantage of the present invention is that it integrates upsetting pre-deformation, semi-solid temperature control and reverse extrusion precision forming into a progressive die system. Compared with rheoforming, the temperature of preparing semi-solid slurry by rheoforming is higher and the semi-solid slurry needs to be transferred. This invention has low cost and can improve the quality of formed parts. The upsetting blank is directly heated in the die, which is simpler than traditional thixoforming and reduces the heating cost.

[0024] 2. The copper alloy billet is subjected to three-dimensional compressive stress in the pre-deformation cavity, so that the billet is uniformly deformed and more dense during the upsetting process, so that the deformation energy stored in each position of the billet is equal, which will be activated and released by thermal energy in the subsequent remelting process as the driving force for recovery, recrystallization, particle segmentation and spheroidization.

[0025] 3. Compared with traditional casting, the shaft set prepared by the present invention has dense structure, no defects such as shrinkage and shrinkage holes, and better mechanical properties.

[0026] 4. The mold of the present invention has a simple structure, is easy to operate, can be mechanized and automated, can achieve mass production, greatly improves production efficiency, and has a high material utilization rate. Description of the drawings:

[0027] Figure 1 This is a front structural cross-sectional view of a heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled shaft sleeve proposed by the present invention;

[0028] Figure 2 A schematic diagram of the upsetting and back-extrusion process of a heated upsetting-back-extrusion progressive die for thixoforming of a copper alloy thin-walled shaft sleeve proposed by the present invention;

[0029] Figure 3 A schematic diagram of the ejection process of a heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled shaft sleeve proposed by the present invention;

[0030] In the figure: 1 upsetting punch, 2 punch pad, 3 locating pin, 4 copper alloy billet, 5-1 upsetting die, 5-2 reverse extrusion die, 6-1 first push rod, 6-2 second push rod, 7 stepped punch, 8 die heating hole, 9-1 semi-solid billet, 9-2 thin-walled shaft kit, 10 die fixing plate. Specific implementation method:

[0031] The embodiments of the present invention are further described below by way of examples in conjunction with the accompanying drawings.

[0032] The semi-solid thixoforming die for a copper alloy thin-walled shaft set comprises an upsetting punch (1), a punch pad (2), a positioning pin (3), a copper alloy blank (4), an upsetting die (5-1), a reverse extrusion die (5-2), a first ejector pin (6-1), a second ejector pin (6-2), a stepped punch (7), a die heating hole (8), a semi-solid blank (9-1), a thin-walled shaft set (9-2), and a die fixing plate (10); the die fixing plate is fixed to a working table of a hydraulic press by bolts, the upsetting die (5-1) and the reverse extrusion die (5-2) are fixed to the die fixing plate, and the die and the die fixing plate are further fixed by pressure plate bolts. Annular holes are provided around the upsetting die (5-1) and the reverse extrusion die (5-2) for placing heating coils, and for controlling the temperature of the blank in the upsetting cavity and the temperature in the reverse extrusion cavity; the upsetting punch (1) and the upsetting die (5-1) are closed to form an upsetting cavity, and the stepped punch (7) and the reverse extrusion die (5-2) form a reverse extrusion cavity; the upsetting punch (1) and the stepped punch (7) are both connected via a punch pad (2), and the punch pad (2) and the punch fixing plate are fixed to a workbench on a hydraulic press via bolts, and the hydraulic press controls the punch fixing plate, thereby controlling the vertical movement of the upsetting punch (1) and the stepped punch (7).

[0033] Embodiment 1:

[0034] The copper alloy material for thixoforming is CuSn10 tin bronze. A CuSn10 copper alloy blank is placed in an upsetting die (5), and a hydraulic press is driven to drive an upsetting punch (1) and a stepped punch (7) to move vertically downward at the same time, so that the blank is upset in the upsetting cavity. After upsetting, the deformation amount of the blank is 15%. After upsetting, the heating coils outside the upsetting die and the reverse extrusion die are set to a forming temperature of 875°C. At this time, the temperature is in a semi-solid temperature range. After the upsetting blank is heated to 875°C and kept warm for 25 minutes, the hydraulic press is controlled to drive the upsetting die. The punch and the stepped punch move upward, and the upward distance ensures that the semi-solid copper alloy billet after insulation can be taken out from the pre-deformation cavity. Then the heated CuSn10 semi-solid billet is quickly placed in the reverse extrusion cavity, and then the hydraulic press is controlled to drive the upsetting punch and the stepped punch to vertically extrude the semi-solid billet at a speed of 5 mm / s. The forming specific pressure is 200 MPa. After the reverse extrusion is completed, the pressure is maintained for 30 seconds to obtain the CuSn10 copper alloy thin-walled bushing. The tensile strength of the CuSn10 copper alloy is increased from 348.9 MPa in the cast state to 492.7 MPa.

[0035] After the thixoforming is completed, the hydraulic press is driven upward, driving the upsetting punch and the stepped punch to move upward together, and the lower hydraulic ejector cylinder moves vertically upward to push out the ejector rod to eject the copper alloy thixoforming shaft kit. Finally, a CuSn10 copper alloy thin-walled shaft kit with an outer diameter of 60mm, an inner diameter of 52mm, and a side wall thickness of 4mm is obtained.

[0036] Embodiment 2:

[0037] The mold structure of this embodiment is similar to that of embodiment 1, except that the copper alloy materials used are different, the size of the formed parts is different, and the forming process parameters are different. The copper alloy material used is QSn6.5, and the copper alloy blank is placed in the upsetting die for upsetting, and the upsetting deformation is 20%. After upsetting, the temperature of the die heating coil is set to 960°C, and the copper alloy after upsetting is kept at this temperature for 20 minutes. At this time, the solid phase rate of the copper alloy semi-solid blank is 80%. The prepared copper alloy semi-solid blank is placed in the reverse extrusion die for thixotropic reverse extrusion, and the forming pressure is set to 260MPa, and finally the thixotropic forming of the copper alloy shaft set is realized, and the pressure is maintained for 30s. After the thixotropic forming is completed, the hydraulic press is controlled to drive the punch upward, and then the hydraulic press top cylinder is controlled to push the ejector rod to eject the formed part. Finally, the thixotropic forming copper alloy shaft set is obtained, and the shaft set has an outer diameter of 60mm, an inner diameter of 54mm, and a wall thickness of 3mm. The tensile strength of CuSn10 copper alloy is increased from 329.8MPa in the cast state to 392.2MPa.

[0038] The thixoforming copper alloy shaft set prepared by the invention has a smooth surface without cracks and a size corresponding to the designed size.

[0039] Although the preferred embodiments of the present invention have been described in detail herein, they are not limited to the above embodiments. Any improvements, additions, equivalent substitutions, etc. made within the spirit and principles of the present invention shall be deemed to be within the scope of protection of the present invention as defined by the claims.

Claims

1. A heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled sleeve, characterized in that: It is divided into an upsetting cavity, a reverse extrusion cavity and an ejection mechanism; the mold comprises an upsetting punch (1), a punch pad (2), a positioning pin (3), a copper alloy blank (4), an upsetting die (5-1), a reverse extrusion die (5-2), an ejector rod (6-1), an ejector rod (6-2), a stepped punch (7), a die heating hole (8) and a die fixing plate (10); The upsetting cavity is composed of an upsetting punch (1) and an upsetting die (5-1), and the upsetting cavity is in the shape of a cylindrical cavity, which is used for upsetting and heating the blank; the reverse extrusion cavity is composed of a stepped punch (7) and a reverse extrusion die (5-2), and the reverse extrusion cavity is in the shape of a cylinder, which is used for forming a thin-walled shaft sleeve; The ejection mechanism is composed of an ejector rod (6-1) and an ejector rod (6-2); The upsetting die (5-1) and the reverse extrusion die (5-2) are cylindrical cavity structures with an opening facing upward. The upsetting die (5-1) and the reverse extrusion die (5-2) are respectively provided with circumferentially surrounding heating holes. A heating coil is placed in the heating hole. The heating coil is connected to a PID temperature control device and is used to control the heating temperature of the die. The upsetting punch (1) and the stepped punch (7) are axially upright cylindrical structures. The lower part of the upsetting punch (1) is matched and located in the cavity of the upsetting die (5-1) and can move freely up and down. The lower part of the stepped punch (7) is matched and located coaxially in the cavity of the reverse extrusion die (5-2) and can move freely up and down. There is a gap between the outer surface of the stepped punch (7) and the inner surface of the reverse extrusion die (5-2). The gap is used to form a copper alloy thin-walled shaft sleeve. The upper part of the upsetting punch (1) and the upper part of the step punch (7) are connected to the punch fixing plate through a horizontal and transverse punch pad (2) to form an integrated structure. The punch fixing plate is fixed to the workbench of the hydraulic press by bolts. The hydraulic press drives the punch fixing plate, the punch pad (2), the upsetting punch (1) and the step punch (7) to move vertically up and down together. The die fixing plate (10) is located at the bottom. Two circular grooves are processed on the upper surface of the die fixing plate (10) for placing the upsetting die (5-1) and the reverse extrusion die (5-2). At the same time, the upsetting die (5-1) and the reverse extrusion die (5-2) are fixed in the groove of the die fixing plate (10), and the die and the die fixing plate are fixed by a pressure plate bolt, so as to ensure the fixation of the die during the upsetting and reverse extrusion process and prevent the die from moving and rotating; the upper surfaces of the upsetting die (5-1) and the reverse extrusion die (5-2) correspond to the steps of the upsetting punch (1) and the stepped punch (7), and the upper port edges of the upsetting die (5-1) and the reverse extrusion die (5-2) are respectively provided with positioning pins (3) for matching and positioning the corresponding punch and die; The bottom end of the upsetting die (5-1) is provided with a first downward through hole, the first downward through hole penetrates the die fixing plate (10) downward, and the first through hole is equipped with a first push rod (6-1); the bottom end of the reverse extrusion die (5-2) is provided with a second downward through hole, the second downward through hole penetrates the die fixing plate (10) downward, and the second through hole is equipped with a second push rod (6-2).

2. A heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled sleeve according to claim 1, characterized in that: The upsetting punch (1) and the stepped punch (7) are of stepped diameter-reducing structure, with the upper portion having a relatively large diameter and the lower portion corresponding to the upsetting die (5-1) and the reverse extrusion die (5-2) having a relatively small diameter.

3. A heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled sleeve according to claim 1, characterized in that: The upsetting punch (1) and the stepped punch (7) are both passed through a transverse punch pad (2): the upper die pad (2) is provided with two through holes with equal diameters, which are respectively equal to the maximum outer diameters of the upper parts of the upsetting punch (1) and the stepped punch (7).

4. A heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled sleeve according to claim 1, characterized in that: The lower diameter of the upsetting punch is equal to the inner diameter of the upsetting die, the inner diameter of the reverse extrusion die is equal to the outer diameter of the thin-walled sleeve, the lower outer diameter of the stepped punch (7) is equal to the inner diameter of the thin-walled sleeve; the inner diameter of the groove of the die fixing plate (10) is equal to the outer diameter of the die.

5. A method for using a heated upsetting-reverse extrusion progressive die for thixoforming of a copper alloy thin-walled sleeve according to any one of claims 1 to 4, characterized in that: Usage process: (A): Before deformation, the hydraulic press is driven to drive the upsetting punch (5) and the step punch (7) to move upward, so that the copper alloy blank can be placed in the cavity of the upsetting die (5-1); a release agent is sprayed on the surfaces of the upsetting punch (1), the upsetting die (5-1), the reverse extrusion die (5-2), and the step punch (7); (B): placing the copper alloy billet into the cavity of the upsetting die (5-1), controlling the hydraulic press to move vertically downward, causing the upsetting punch (1) and the stepped punch (7) to move vertically downward, so that the upsetting punch applies pressure to the copper alloy billet, thereby completing the upsetting of the billet; then setting the temperature through the PID temperature control device so that the internal temperature range of the upsetting die (5-1) and the reverse extrusion die (5-2) cavities is 800°C to 980°C, and the upset copper alloy billet is kept warm in the upsetting cavity until it reaches a semi-solid temperature and is kept warm for a certain period of time to obtain a copper alloy semi-solid billet, and then controlling the hydraulic press to move upward so that the upsetting punch (1) and the stepped punch (7) move to the top of the hydraulic press, and then the copper alloy semi-solid billet is pushed out of the upsetting die (5-1) through the first push rod (6-1); (C) The ejected copper alloy semi-solid billet is quickly placed into the reverse extrusion die (5-2), and the hydraulic press is controlled to drive the upsetting punch (1) and the stepped punch (7) to move downward simultaneously, so that the copper alloy semi-solid billet is filled in the reverse extrusion cavity and the pressure is maintained for a period of time, and then the hydraulic press is controlled to drive the upsetting punch (1) and the stepped punch (7) to move upward to the top of the hydraulic press; and the second ejector rod (6-2) is controlled to eject the copper alloy thin-walled shaft set.

6. The method according to claim 5, characterized in that The above steps (B) and (C) are performed simultaneously. When the steps are performed simultaneously, step (B) performs upsetting of the second batch of copper alloy blanks, and the blanks of the first batch of copper alloy upsetting are filled in step (C) simultaneously with step (B). After step (B) is completed, step (C) is also completed, the first batch of copper alloy thin-walled sleeves filled in step (C) are taken out, and the second batch of upsetting copper alloy blanks are immediately placed in, and the cycle is repeated. The inner diameter of the thin-walled shaft sleeve is determined by the lower diameter of the stepped punch (7), and the side thickness of the shaft sleeve is determined by the lower diameter of the stepped punch (7) and the inner diameter of the reverse extrusion die (5-2).

7. The method according to claim 5, characterized in that The upper ends of the ejector rod (6-1) and the ejector rod (6-2) pass through the through holes of the concave die and the concave die pad, the upper ends of the ejector rods are aligned with the lower surface of the concave die cavity, and the lower half of the ejector rods is connected to the ejector cylinder of the hydraulic press. After the deformation and die opening are completed, the ejector rods eject the workpiece; The wall thickness of the copper alloy thin-walled sleeve can be 2-5mm.

Images