阅读说明：本技术 薄壁网格筋锥形环件的挤压成形方法 (Extrusion forming method of thin-wall grid rib conical ring piece ) 是由 韩星会 田端阳 华林 于 2019-09-24 设计创作，主要内容包括：本发明涉及一种薄壁网格筋锥形环件的挤压成形方法,包括以下步骤：S1、组装薄壁网格筋锥形环件的挤压成形装置；S2、将环形毛坯套在芯轴上；S3、第二液压缸驱动环形压板竖直向下运动；S4、第一液压缸驱动冲头竖直向下运动,并推动环形毛坯向下进给；在冲头、芯轴以及扇形约束模的作用下,金属逐渐填充扇形约束模内锥面上的型腔；S5、冲头停止进给并退回到其初始位置；S6、位于芯轴底部的顶出机构开始工作,卸下套筒；S7、位于芯轴底部的顶出机构向下运动,取下薄壁网格筋锥形环件。本发明可以实现薄壁网格筋锥形环件顺利脱模,实现了薄壁网格筋锥形环件高性能、高效率、低成本成形制造。(The invention relates to an extrusion forming method of a thin-wall grid rib conical ring piece, which comprises the following steps: s1, assembling an extrusion forming device of the thin-wall grid rib conical ring piece; s2, sleeving the annular blank on the mandrel; s3, driving the annular pressure plate to vertically move downwards by the second hydraulic cylinder; s4, driving the punch to vertically move downwards by the first hydraulic cylinder, and pushing the annular blank to feed downwards; under the action of the punch, the mandrel and the fan-shaped restraining die, metal gradually fills a cavity on the conical surface in the fan-shaped restraining die; s5, stopping feeding the punch and retreating to the initial position of the punch; s6, starting the ejection mechanism at the bottom of the mandrel to work, and detaching the sleeve; and S7, moving the ejection mechanism at the bottom of the mandrel downwards, and taking down the thin-wall grid rib conical ring. The invention can realize smooth demoulding of the thin-wall grid rib conical ring piece and realize the forming and manufacturing of the thin-wall grid rib conical ring piece with high performance, high efficiency and low cost.)

1. The extrusion forming method of the thin-wall grid rib conical ring piece is characterized by comprising the following steps of:

s1, assembling an extrusion forming device of the thin-wall grid rib conical ring piece, wherein the extrusion forming device comprises a workbench, an annular base, a mandrel and n fan-shaped restraining dies, the annular base is coaxially arranged on the annular workbench, the mandrel is matched and connected with the inner conical surface of the annular base, the n fan-shaped restraining dies are vertically arranged on the annular base, the n fan-shaped restraining dies are uniformly distributed along the circumferential direction of the annular base to jointly form a closed annular restraining die, the fan-shaped restraining dies are connected with the annular base in a sliding mode, a sleeve is matched and connected with the outer circumferential surface formed by the n fan-shaped restraining dies, and the sleeve is fixed on the annular workbench; an annular pressing plate is arranged at the upper end of the fan-shaped restraining die, a punch is arranged inside the annular pressing plate, a first hydraulic cylinder is arranged between the top of the punch and the annular pressing plate, and the top of the annular pressing plate is also connected with a second hydraulic cylinder;

s2, sleeving the annular blank on the mandrel;

s3, driving the annular pressure plate to vertically move downwards by the second hydraulic cylinder until the lower end face of the annular pressure plate is contacted with the upper end faces of the n fan-shaped restraint molds and applying a blank holder force; the hydraulic cylinder positioned at the bottom of the mandrel starts to work, so that pretightening force is generated between the mandrel and the base;

s4, driving the punch to vertically move downwards by the first hydraulic cylinder, and pushing the annular blank to feed downwards; under the action of the punch, the mandrel and the fan-shaped restraining die, metal gradually fills a cavity on the conical surface in the fan-shaped restraining die;

s5, when the cavity on the conical surface of the fan-shaped constraint die is completely filled with metal, stopping feeding the punch and returning to the initial position; subsequently, the annular pressure plate is also retracted to its initial position;

s6, the ejection mechanism positioned at the bottom of the mandrel starts to work to drive the mandrel, the extrusion forming piece, the annular base and the n fan-shaped restraint molds to move upwards together until the base is completely separated from the sleeve; subsequently, sequentially taking off the n fan-shaped restraint molds from the annular base, and then unloading the sleeve;

s7, driving the mandrel, the extrusion part and the annular base to move downwards together by the ejection mechanism positioned at the bottom of the mandrel, and when the annular base contacts the annular workbench again, continuously driving the mandrel to move downwards for a certain distance by the ejection mechanism to separate the extrusion-formed thin-wall grid rib conical ring from the mandrel; and finally, taking down the thin-wall grid rib conical ring piece from the base.

2. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the ejection mechanism comprises an ejector block and a third hydraulic cylinder, the ejector block is installed in a clamping groove at the bottom of the mandrel, and the third hydraulic cylinder is connected with the ejector block.

3. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the inner surface of the annular base is a conical surface, the minimum diameter of the conical surface is equal to the maximum diameter of the target thin-wall grid rib conical ring piece skin, the cone angle is not less than 15 degrees, the outer diameter of the annular base is larger than the inner diameter of the annular workbench, the n square sliding grooves are uniformly distributed at the upper end of the annular base along the circumferential direction, and the draft angle of the bottom surface of the sliding groove is equal to the transverse rib inclination of the target thin-wall grid rib conical ring piece.

4. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the mandrel is a variable-section special-shaped revolving body, the upper end of the mandrel is a cylinder, and the lower end of the mandrel is a frustum; the diameter of the cylinder at the upper end of the mandrel is equal to the minimum inner diameter of the target thin-wall grid rib conical ring piece skin, and the height of the cylinder at the upper end of the mandrel is greater than the axial height of the annular blank; the maximum diameter of the frustum at the lower end of the mandrel is equal to the maximum diameter of the inner conical surface of the annular base, the axial height of the frustum is equal to the sum of the axial heights of the target thin-wall grid rib conical ring and the annular base, and the taper of the frustum is equal to the taper of the inner surface of the annular base.

5. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the inner diameter of the annular workbench is larger than the maximum diameter of the frustum at the lower end of the mandrel, and the outer diameter of the annular workbench is at least 200mm larger than the inner diameter of the annular workbench.

6. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the central angle of the fan-shaped restraining die is 360 °/n, n is the number of longitudinal ribs of the target thin-wall grid rib conical ring piece, the upper side of the inner surface of the fan-shaped restraining die is a cylindrical surface, the diameter of the cylindrical surface is equal to the outer diameter of the annular blank, and the axial height of the cylindrical surface is equal to the axial height of a cylinder at the upper end of the mandrel; the lower side of the inner surface of the fan-shaped restraint module is a conical surface, the conical surface is matched with the outer conical surface of the skin of the target grid rib conical ring piece, criss-cross cavities are arranged on the conical surface, and the cavities are matched with grid ribs of the target grid rib conical ring piece.

7. The method for extrusion molding of a thin-walled mesh rib-cone ring according to claim 1, wherein the thickness of the annular blank is equal to the skin thickness of the target mesh rib-cone ring, the inner diameter of the annular blank is equal to the minimum diameter of the inner conical surface of the target mesh rib-cone ring, and the axial height of the annular blank is determined according to the principle of plastic equal volume.

8. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the sleeve is a flange ring piece, and the inner diameter of the sleeve is equal to the outer diameter of the fan-shaped restraining die.

9. The extrusion forming method of the thin-wall grid rib conical ring piece according to claim 1, wherein the annular pressing plate is a cup-shaped body, the inner diameter of the annular pressing plate is 2-3 mm larger than the diameter of the inner side cylindrical surface of the fan-shaped constraint die, and the outer diameter of the annular pressing plate is equal to the outer diameter of the fan-shaped constraint die plate.

10. The method for extrusion forming of thin-wall mesh rib conical ring according to claim 1, wherein the punch is a cup-shaped body, the inner diameter of the punch is equal to the diameter of the cylinder at the upper end of the mandrel, and the outer diameter of the punch is equal to the outer diameter of the annular blank.

Technical Field

The invention relates to precise plastic forming of a thin-wall grid rib conical ring component, in particular to an extrusion forming method of a thin-wall grid rib conical ring component.

Background

The thin-wall grid rib conical ring piece is very commonly applied in the fields of aviation and aerospace, and is characterized in that the skin is thin, and ribs are arranged on the conical surface in a longitudinally and transversely staggered manner, so that the equipment is light in weight, high in rigidity and high in strength. At present, the thin-wall grid rib conical ring is mainly manufactured by adopting electrochemical machining and mechanical milling machining technologies. Electrochemical machining and mechanical milling machining technologies can manufacture integral components with complex shapes, but the machining efficiency is low, the material utilization rate is low, continuous metal flow lines cannot be formed, and the mechanical properties of the components are seriously weakened. The plastic forming technology has the characteristics of high material utilization rate, high processing efficiency, low cost and excellent performance, and is an important development trend of high-performance manufacturing of international high-end equipment. However, there is a bottleneck problem with the swaging technique in that the member cannot be removed from the die.

Disclosure of Invention

The invention aims to solve the technical problem of providing an extrusion forming method of a thin-wall grid rib conical ring piece, which can realize smooth demoulding of the thin-wall grid rib conical ring piece and realize high-performance, high-efficiency and low-cost forming and manufacturing of the thin-wall grid rib conical ring piece.

The technical scheme adopted by the invention for solving the technical problems is as follows: an extrusion forming method for constructing a thin-wall grid rib conical ring piece, wherein the thin-wall grid rib conical ring piece comprises a conical skin, and grid ribs are arranged on the outer surface of the skin, and the method comprises the following steps:

s1, assembling an extrusion forming device of the thin-wall grid rib conical ring piece, wherein the extrusion forming device comprises a workbench, an annular base, a mandrel and n fan-shaped restraining dies, the annular base is coaxially arranged on the annular workbench, the mandrel is matched and connected with the inner conical surface of the annular base, the n fan-shaped restraining dies are vertically arranged on the annular base, the n fan-shaped restraining dies are uniformly distributed along the circumferential direction of the annular base to jointly form a closed annular restraining die, the fan-shaped restraining dies are connected with the annular base in a sliding mode, a sleeve is matched and connected with the outer circumferential surface formed by the n fan-shaped restraining dies, and the sleeve is fixed on the annular workbench; an annular pressing plate is arranged at the upper end of the fan-shaped restraining die, a punch is arranged inside the annular pressing plate, a first hydraulic cylinder is arranged between the top of the punch and the annular pressing plate, and the top of the annular pressing plate is also connected with a second hydraulic cylinder;

s2, sleeving the annular blank on the mandrel;

s3, driving the annular pressure plate to vertically move downwards by the second hydraulic cylinder until the lower end face of the annular pressure plate is contacted with the upper end faces of the n fan-shaped restraint molds and applying a blank holder force; the hydraulic cylinder positioned at the bottom of the mandrel starts to work, so that pretightening force is generated between the mandrel and the base;

s4, driving the punch to vertically move downwards by the first hydraulic cylinder, and pushing the annular blank to feed downwards; under the action of the punch, the mandrel and the fan-shaped restraining die, metal gradually fills a cavity on the conical surface in the fan-shaped restraining die;

s5, when the cavity on the conical surface of the fan-shaped constraint die is completely filled with metal, stopping feeding the punch and returning to the initial position; subsequently, the annular pressure plate is also retracted to its initial position;

s6, the ejection mechanism positioned at the bottom of the mandrel starts to work to drive the mandrel, the extrusion forming piece, the annular base and the n fan-shaped restraint molds to move upwards together until the base is completely separated from the sleeve; subsequently, sequentially taking off the n fan-shaped restraint molds from the annular base, and then unloading the sleeve;

s7, driving the mandrel, the extrusion part and the annular base to move downwards together by the ejection mechanism positioned at the bottom of the mandrel, and when the annular base contacts the annular workbench again, continuously driving the mandrel to move downwards for a certain distance by the ejection mechanism to separate the extrusion-formed thin-wall grid rib conical ring from the mandrel; and finally, taking down the thin-wall grid rib conical ring piece from the base.

In the above scheme, the ejection mechanism comprises an ejector block and a third hydraulic cylinder, the ejector block is installed in the clamping groove at the bottom of the mandrel, and the third hydraulic cylinder is connected with the ejector block.

In the scheme, the inner surface of the annular base is a conical surface, the minimum diameter of the conical surface is equal to the maximum diameter of the target thin-wall grid rib conical ring piece skin, the cone angle is not less than 15 degrees, the outer diameter of the annular base is larger than the inner diameter of the annular workbench, the n square sliding grooves are uniformly distributed at the upper end of the annular base along the circumferential direction, and the drawing gradient of the bottom surface of each sliding groove is equal to the transverse rib gradient of the target thin-wall grid rib conical ring piece.

In the scheme, the mandrel is a special-shaped revolving body with a variable cross section, the upper end of the mandrel is a cylinder, and the lower end of the mandrel is a frustum; the diameter of the cylinder at the upper end of the mandrel is equal to the minimum inner diameter of the target thin-wall grid rib conical ring piece skin, and the height of the cylinder at the upper end of the mandrel is greater than the axial height of the annular blank; the maximum diameter of the frustum at the lower end of the mandrel is equal to the maximum diameter of the inner conical surface of the annular base, the axial height of the frustum is equal to the sum of the axial heights of the target thin-wall grid rib conical ring and the annular base, and the taper of the frustum is equal to the taper of the inner surface of the annular base.

In the scheme, the inner diameter of the annular workbench is larger than the maximum diameter of the frustum at the lower end of the mandrel, and the outer diameter of the annular workbench is at least larger than the inner diameter of the annular workbench by 200 mm.

In the scheme, the central angle of the fan-shaped restraining die is 360 degrees/n, n is the number of longitudinal ribs of the target thin-wall grid rib conical ring piece, the upper side of the inner surface of the fan-shaped restraining die is a cylindrical surface, the diameter of the cylindrical surface is equal to the outer diameter of the annular blank, and the axial height of the cylindrical surface is equal to the axial height of a cylinder at the upper end of the mandrel; the lower side of the inner surface of the fan-shaped restraint module is a conical surface, the conical surface is matched with the outer conical surface of the skin of the target grid rib conical ring piece, criss-cross cavities are arranged on the conical surface, and the cavities are matched with grid ribs of the target grid rib conical ring piece.

In the scheme, the thickness of the annular blank is equal to the skin thickness of the target grid ribbed-conical ring, the inner diameter of the annular blank is equal to the minimum diameter of the inner conical surface of the target grid ribbed-conical ring, and the axial height of the annular blank is determined according to the equal volume principle of plasticity.

In the above scheme, the sleeve is a flange ring, and the inner diameter of the sleeve is equal to the outer diameter of the fan-shaped restraining die.

In the scheme, the annular pressing plate is a cup-shaped body, the inner diameter of the annular pressing plate is larger than the diameter of the inner side cylindrical surface of the fan-shaped constraint die by 2-3 mm, and the outer diameter of the annular pressing plate is equal to that of the fan-shaped constraint die plate.

In the scheme, the punch is a cup-shaped body, the inner diameter of the punch is equal to the diameter of the cylinder at the upper end of the mandrel, and the outer diameter of the punch is equal to the outer diameter of the annular blank.

The extrusion forming method of the thin-wall grid rib conical ring piece has the following beneficial effects:

1. the invention forms a closed annular restraining die together by arranging the split type fan-shaped restraining die, the die cavity on the conical surface in the restraining die is used for forming the grid ribs, the extrusion forming effect is good, and the forming and manufacturing of the thin-wall grid rib conical ring piece with high performance, high efficiency and low cost can be realized.

2. The extrusion forming method of the thin-wall grid rib conical ring piece adopts a split type fan-shaped constraint mould design, and is matched with the ejection mechanism, the mandrel, the annular base and other parts, so that the thin-wall grid rib conical ring piece can be smoothly demoulded, and the interference between a component and a mould is avoided.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic structural diagram of a target thin-wall mesh rib conical ring;

FIG. 2 is a schematic structural view of an annular blank;

FIG. 3 is a schematic structural view of the mandrel;

FIG. 4 is a schematic view of another angle of the mandrel;

FIG. 5 is a schematic structural view of the ring base;

FIG. 6 is a cross-sectional view A-A of FIG. 5;

FIG. 7 is a schematic structural diagram of a fan-shaped confinement mold;

FIG. 8 is a schematic view of the assembly between the constraining die, mandrel, base, table and ring blank;

FIG. 9 is a schematic longitudinal sectional view of the entire extrusion apparatus at the initial stage of extrusion;

fig. 10 is a schematic longitudinal sectional view of the entire extrusion apparatus at the end of extrusion.

Detailed Description

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in fig. 1-10, the extrusion forming method of the thin-wall mesh rib tapered ring piece of the invention comprises the following steps:

s1, in a preferred embodiment of the present invention, as shown in fig. 1, the material of the thin-walled mesh rib-tapered ring 14 is a high-strength aluminum alloy, the skin thickness of which is equal to the minimum extrusion thickness of the material, the inner surface taper angle α is 15 °, and the skin is provided with 5 transverse ribs and 16 longitudinal ribs. The annular blank 9 shown in figure 2 is obtained by upsetting, casting or turning, the wall thickness of the annular blank 9 is equal to the skin thickness of the target thin-wall grid rib-cone ring member 14, the inner diameter of the annular blank 9 is equal to the minimum diameter of the inner conical surface of the target thin-wall grid rib-cone ring member 14, and the axial height of the annular blank 9 is determined according to the equal volume principle.

S2, as shown in FIGS. 5-6, the inner surface of the annular base 6 is a conical surface, the minimum diameter of the conical surface is equal to the maximum diameter of the skin of the target thin-wall grid rib conical ring 14, the cone angle is 15 degrees, the outer diameter of the annular base 6 is larger than the inner diameter of the annular workbench 3 by 100mm, n square sliding grooves are uniformly distributed at the upper end of the annular base 6 along the circumferential direction, and the draft slope of the bottom surface of each sliding groove is equal to the gradient of the transverse ribs of the target thin-wall grid rib conical ring 14.

S3, as shown in FIG. 3, the mandrel 7 is a deformed revolving body with a variable cross section, the upper end of the mandrel 7 is a cylinder, and the lower end is a frustum. The diameter of the cylinder at the upper end of the mandrel 7 is equal to the minimum diameter of the target thin-wall grid rib conical ring 14 skin, and the height of the cylinder at the upper end of the mandrel 7 is 20mm greater than the axial height of the annular blank 9. The maximum diameter of the frustum at the lower end of the mandrel 7 is equal to the maximum diameter of the inner conical surface of the annular base 6, the axial height of the frustum is equal to the sum of the axial heights of the target thin-wall grid rib conical ring 14 and the annular base 6, and the taper of the frustum is 15 degrees. The bottom center of the frustum is provided with a direction clamping groove for connecting the square top block 2. The side length of the square top block 2 is equal to that of the clamping groove of the mandrel 7.

S4, as shown in FIG. 8, the inner diameter of the annular workbench 3 is larger than the maximum diameter of the lower end frustum of the mandrel 7, the outer diameter of the annular workbench 3 is larger than the inner diameter thereof by 200mm, 4 threaded holes uniformly distributed along the circumferential direction are arranged on the outer side of the annular workbench 3, and the distance from the threaded holes to the outer circumferential surface of the annular workbench 3 is 20 mm.

S5, as shown in fig. 7, the central angle of the fan-shaped restraining die 8 is 22.5 °, the upper side of the inner surface of the fan-shaped restraining die 8 is a cylindrical surface, the diameter of the cylindrical surface is equal to the outer diameter of the annular blank 9, and the axial height of the cylindrical surface is equal to the axial height of the cylinder at the upper end of the mandrel 7. The lower side of the inner surface of the fan-shaped restraint die 8 is a conical surface, the conical surface is matched with the outer conical surface of the skin of the target grid rib conical ring piece 14, criss-cross cavities are arranged on the conical surface, the cavities are matched with grid ribs of the target grid rib conical ring piece 14, the number of the transverse cavities is 5, and the number of the longitudinal cavities is 1. In addition, the outer side of the lower end face of the fan-shaped restraint die 8 is provided with a special-shaped boss which is completely matched with the clamping groove on the annular base 6. The middle part of the upper end surface of the fan-shaped restraint module 8 is provided with a lug hole for installing and unloading the fan-shaped restraint module 8. The other surface roughness of the fan-shaped confining mold 8 except the inner surface was 0.3 μm.

S6, as shown in fig. 9, the sleeve 4 is a flange ring, the inner diameter of the sleeve 4 is equal to the outer diameter of the fan-shaped restraining die 8, and the flange face is provided with 4 through holes, which are arranged in the same way as the threaded holes on the annular workbench 3. The axial height of the sleeve 4 cannot be smaller than the axial height of the mandrel 7. The roughness of the inner surface of the sleeve 4 was 0.3 μm.

S7, as shown in FIG. 9, the annular pressing plate 11 is a cup-shaped body, the inner diameter of the annular pressing plate 11 is larger than the inner diameter of the fan-shaped restraining die 8 by 2mm, the outer diameter of the annular pressing plate 11 is smaller than the outer diameter of the fan-shaped restraining die 8 by 2mm, and the two sides of the bottom surface of the annular pressing plate 11 are respectively connected with the first hydraulic cylinder 12 and the second hydraulic cylinder 13.

And S8, as shown in FIG. 9, the punch 10 is a cup-shaped body, the inner diameter of the punch 10 is equal to the diameter of the cylinder at the upper end of the mandrel 7, the outer diameter of the punch 10 is equal to the outer diameter of the annular blank 9, the bottom of the punch is connected with a first hydraulic cylinder 12, the first hydraulic cylinder 12 is connected with the bottom of the annular pressing plate 11, and the roughness of the inner and outer circumferential surfaces of the punch 10 is 0.3 μm.

S9, the annular base 6 is coaxially mounted on the annular workbench 3, the mandrel 7 is connected with the inner conical surface of the annular base 6 in a matched mode, and the square ejector block 2 is sleeved in the square clamping groove in the bottom of the mandrel 7 and connected with the third hydraulic cylinder 1.

S10, vertically installing the 16 fan-shaped restraint modules 8 on the annular base 6, wherein the 16 fan-shaped restraint modules 8 are uniformly distributed along the circumferential direction of the annular base 6 to jointly form a closed annular restraint module, and the fan-shaped restraint modules 8 are connected with the annular base 6 in a sliding manner.

S11, the sleeve 4 is matched and connected with the outer circumference composed of 16 fan-shaped restraint dies, the sleeve 4 is fixed on the annular workbench 3 by 4 screws 5, and then the annular blank 9 is sleeved on the mandrel 7.

S12, the second hydraulic cylinder 13 drives the annular pressure plate 11 to move vertically downwards until the lower end face of the annular pressure plate 11 contacts with the upper end faces of the 16 fan-shaped restraint dies 8 and applies a large enough blank holding force to prevent the fan-shaped restraint dies 8 from moving axially in the deformation process of the annular blank 9. At this time, the third hydraulic cylinder 1 located at the bottom of the mandrel 7 starts to work, so that a large enough pre-tightening force is generated between the mandrel 7 and the annular base 6, and the mandrel 7 cannot move up and down when the annular blank 9 deforms.

And S13, the punch 10 is driven by hydraulic pressure to move vertically downwards, and the annular blank 9 is pushed to continuously feed downwards. Under the action of the punch 10, the mandrel 7 and the fan-shaped restraining die 8, the metal gradually fills the cavity on the inner conical surface of the fan-shaped restraining die 8.

S14, when the feeding amount of the punch 10 reaches the preset value and the cavity on the inner conical surface of the fan-shaped restraining die 8 is completely filled with metal, the punch 10 stops feeding and retracts to the initial position. Subsequently, the annular pressure plate 11 is also retreated to its original position.

S15, the third hydraulic cylinder 1 starts to work, and drives the square top block 2, the mandrel, the extrusion piece 14, the annular base 6 and the 16 fan-shaped restraining dies 8 to move upward together until the annular base 6 is completely separated from the sleeve 4. Subsequently, the 16 fan-shaped restraining dies 8 are sequentially removed from the ring base 6, the 4 screws 5 connected to the ring table 3 are removed, and the sleeve 4 is withdrawn from the ring table 3.

And S16, the third hydraulic cylinder 1 enters a working state again to drive the square ejector block 2, the mandrel 7, the extrusion part 14 and the annular base 6 to move downwards together, and when the annular base 6 contacts the annular workbench 3 again, the third hydraulic cylinder 1 continues to drive the square ejector block 2 and the mandrel 7 to move downwards for a certain distance, so that the extrusion-formed thin-wall grid rib conical ring 14 is separated from the mandrel 7. Finally, the thin-walled mesh rib conical ring 14 is removed from the annular base 6.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.