Forging tool of skirt edge cylinder for pressure container and integral forming method of skirt edge cylinder

Abstract

The invention provides a forging tool of a skirt edge cylinder for a pressure container and an integral forming method of the skirt edge cylinder. The forging tool comprises a bottom gasket, an inner die, a lower outer die and an upper outer die. By means of the forging tool and the integral forming method, integral forming of the skirt edge cylinder can be achieved, the size precision of the skirt edge position of the cylinder is high, the machining amount is small, the material utilization rate is increased, the skirt edge position is integrally formed, the metal streamline is matched with the appearance structure, the fatigue life of the structure can be effectively prolonged, and the anti-pressure capacity of the structure can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of pressure vessel cylinder forming, and in particular to a forging tool for a skirt cylinder for a pressure vessel and an integral forming method thereof. Background Art

[0002] Pressure vessels are usually welded structures composed of plates and shells. They play an important role in many fields of industry, civil, military and scientific research. In the structure of pressure vessels, a cylinder connected to the outer shell of the pressure vessel is required to achieve certain functions (see Figure 1 ), as a passage for personnel, equipment and materials to enter and exit the container. Generally, the axis of this cylinder is perpendicular to the axis of the pressure vessel. It can be located directly above the pressure vessel or on its side, and its forms are various.

[0003] In the manufacturing process of vessels with higher pressure levels, the cylinder is connected to the pressure vessel body by welding. In order to avoid the superposition of welding stress and structural stress, the cylinder is designed as a cylinder with a skirt (see Figure 2 ), stagger the structural stress concentration position and the welding stress concentration position (see Figure 3 ).

[0004] This kind of cylinder with skirt cannot be manufactured by steel plate coil welding, and is currently usually obtained by forging or casting. The forging method is: forging the envelope of the skirt (see Figure 4 ), and then obtain the precise skirt size by machining. This method has a low material utilization rate, especially when the distance between the highest point and the lowest point of the envelope is large, the processing volume is large, the construction period is long, and in the process of envelope processing, the forged metal streamline at the skirt is destroyed, which reduces the pressure resistance of the skirt position to a certain extent; and the skirt cylinder manufactured by casting has a low internal quality grade and cannot meet the quality requirements of high-grade pressure vessels.

[0005] It can be seen that providing a forging tool for a skirt cylinder to improve the forging dimensional accuracy of the skirt position, improve material utilization, ensure that the metal streamline matches the external structure, and effectively improve the fatigue life and pressure resistance of the skirt cylinder structure is of great significance for the production of pressure vessels. Summary of the invention

[0006] In view of this, the present invention provides a forging tool for a skirt cylinder for a pressure vessel and an integral forming method thereof, the forging tool comprising a bottom gasket, an inner die, a lower outer die and an upper outer die; using the forging tool and the integral forming method, the integral forming of the skirt cylinder can be achieved, the forging dimensional accuracy of the skirt position of the cylinder is high, the processing amount is small, the material utilization rate is improved, and the skirt position is integratedly formed, the metal streamlines match the external structure, and the fatigue life and compressive resistance of the skirt cylinder structure can be effectively improved.

[0007] The technical solution of the present invention is as follows: A forging tool for a skirt cylinder for a pressure vessel, comprising a bottom gasket, an inner die, a lower outer die and an upper outer die; The bottom gasket comprises a circular ring base and three limiting guide blocks evenly distributed on the outer side of the base; The inner mold includes a cylinder A with upper and lower openings, a support member is provided inside the cylinder A, the top surface of the support member and the top of the cylinder A are located on the same horizontal plane, the support member can support the cylinder A and can also be used for lifting; the outer surface of the lower end of the cylinder A matches the inner surface of the bottom gasket base; The lower outer mold includes a cylinder B with upper and lower openings, the upper end surface of the cylinder B is a curved surface, matching the lower surface of the skirt of the cylinder, and the intersection of the upper end surface and the inner surface is rounded; the lower end surface of the cylinder B is a plane; The upper outer mold comprises a cylinder C with upper and lower openings, and the cylinder C comprises a coaxially arranged ring A and a ring B, the upper end face of the ring B contacts the lower end face of the ring A, the inner diameter of the ring A is smaller than the inner diameter of the ring B, and a step is formed between the two, and the outer diameters of the rings A and B are the same; the upper end face of the ring A is a plane; the lower end face of the ring B is a curved surface, the lower end face of the ring B matches the upper surface of the skirt of the cylinder, and the intersection of the lower end face and the inner surface is chamfered; the inner surface of the ring A matches the outer surface of the upper end of the inner mold cylinder A.

[0008] Preferably, a positioning block A is provided on the top surface of the bottom gasket base.

[0009] Preferably, the support member is a Y-shaped structure, which can avoid deformation of the cylinder A as much as possible and make the interior of the cylinder A streamlined.

[0010] Preferably, in order to facilitate demoulding of the inner mold, the cylinder A is tapered from top to bottom.

[0011] Preferably, three lifting ears A of the same height are evenly distributed on the outer surface of the cylinder B for lifting.

[0012] Preferably, a positioning groove is provided on the lower end face of the cylinder B, the vertex position of the positioning groove is at the same circumferential angle as the lowest point of the upper end face curve, and the positioning groove matches the positioning block A on the base, and the radial widths of the two are the same; it is used to position the bottom gasket and the lower outer mold.

[0013] Preferably, in order to facilitate demoulding of the lower outer mold, the barrel B is tapered from top to bottom.

[0014] Preferably, three lifting ears B of the same height are evenly distributed on the outer surface of the cylinder C for lifting.

[0015] Preferably, a positioning block B is provided on the outer surface of the cylinder C, the top of the positioning block B is flush with the upper end surface of the ring A, and the extension line of the bottom end of the positioning block B coincides with the lowest point of the curved surface of the ring B; this arrangement enables the vertex of the positioning block B and the fixed point of the positioning block A to be located at the same circumferential angle, which facilitates angle positioning when the tooling is used.

[0016] Preferably, the cylinder C is tapered from bottom to top to facilitate demoulding.

[0017] The overall forming method of forging the skirt cylinder using the forging tool is as follows: (1) Blank preparation: a. Use a forging press to forge the steel ingot into a cylindrical blank by free forging, and then use a CNC vertical lathe for rough machining to obtain a cylindrical barrel with a full surface machined state; The inner diameter of the cylinder is 20~50mm larger than the outer diameter of the cylinder A; the inner diameter of the cylinder B is 20~50mm larger than the outer diameter of the cylinder; the inner diameter of the ring B of the cylinder C is 20~50mm larger than the outer diameter of the cylinder; this setting is convenient for the hoisting and installation of the forging tooling and the cylinder; the height of the cylinder is determined according to the principle that the volume of the skirt cylinder after forming remains unchanged; b. Place the cylindrical tube in a heating furnace for heating. The axis must be vertical for easy lifting. Heat it to the forging temperature and keep it warm for a period of time to ensure that the temperature of each part is consistent. Then set it aside. (2) Forging tooling preparation: c. Place the bottom washer on the forging rotating platform so that it can rotate at any angle in the circumferential direction; d. Place the lower end of the cylinder A in the base of the bottom washer by lifting the support of the inner mold, so that the lower end surface of the cylinder A and the lower end surface of the base are on the same plane; apply lithium-based grease on the outer surface of the inner mold and the upper end surface of the base to facilitate demoulding and reduce forging surface friction; e. Apply lithium-based grease on the inner surface of the cylinder B to facilitate demoulding and reduce forging surface friction; place the lower outer mold on the upper end surface of the bottom gasket through the three lifting ears A of the cylinder B; the limiting guide block of the bottom gasket plays a guiding role to facilitate the placement of the lower outer mold. During this process, the positioning groove of the cylinder B cooperates with the positioning block A on the base; f. Apply lithium-based grease on the inner surface of the cylinder C to facilitate demoulding and reduce forging surface friction; preheat the assembled bottom gasket, inner die, lower outer die and upper outer die with gas at the same time to a temperature of 200~300℃ and set aside; (3) Overall molding: g. After the forging tool is preheated, the heated cylindrical blank is placed in the cavity between the inner die and the lower outer die through a two-point clamp; h. Place it on the upper end of the cylindrical barrel blank through the three ears B of the upper outer die. At this time, the inner surface of the ring A matches the outer surface of the upper end of the cylinder A, and the lower end surface of the ring A contacts the upper end surface of the cylindrical barrel blank, that is, the top end of the cylindrical barrel blank is stuck on the step formed by the ring A and the ring B, and the extension line of the bottom end of the positioning block B of the upper outer die and the vertex of the positioning block A of the bottom gasket are at the same circumferential angle; the forging tooling and cylindrical barrel blank are assembled; i. Move the assembled forging tooling and cylindrical blank to the bottom of the forging press by moving the forging rotating platform; j. The upper outer die is continuously pressed down by the pressure of the forging press. Under the action of the forging tooling, the cylindrical barrel blank is extruded and deformed, and the height gradually becomes lower. It bulges outward at the gap between the lower end surface of the upper outer die and the upper end surface of the lower outer die, and the skirt structure is gradually formed, and finally a forged blank of a skirt cylinder is formed; k. After the overall forming of the skirt cylindrical forging blank is completed, the forging rotating platform is moved to a position where the crane can lift it, and the upper outer die and inner die are lifted off in turn, and then the forging blank is lifted out to obtain the skirt cylindrical forging blank; l. Through the subsequent performance heat treatment and machining processes, a skirt cylinder with material properties and dimensions of each part that meet the requirements is obtained.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. The forging tool provided by the present invention comprises a bottom gasket, an inner die, a lower outer die and an upper outer die. Through the above arrangement, the forging tool can realize the extrusion of the cylindrical blank, and realize the overall forming of the skirt by lowering the height of the cylindrical blank, which can effectively improve the forging dimensional accuracy of the skirt position, improve the material utilization rate, ensure that the metal streamline matches the external structure, thereby improving the fatigue life and compressive resistance of the skirt cylinder.

[0019] 2. The forging tool provided by the present invention enables the four components of the forging tool to be accurately positioned through the setting of the positioning block A, the positioning block B and the positioning groove, thereby ensuring that the forging tool can ensure the consistency of product quality during repeated forging and the high forging dimensional accuracy of the skirt position of multiple batches of skirt cylinders.

[0020] 3. The forging tool provided by the present invention has the advantages of reasonable design, strong practicality and easy use; using the forging tool to prepare the skirt cylinder has the advantages of small processing volume and high material utilization rate; and using the forging tool, the skirt is integrally formed, which can ensure that the metal streamline matches the external structure and improve product performance.

[0021] 4. The integral forming method provided by the present invention realizes the forging of skirt cylinders with high efficiency, high precision and low material consumption through the rational use of forging tools; the forming method has the advantages of good repeatability and high practicality, and is suitable for being widely used in the manufacture of skirt cylinders. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a schematic diagram of the structure of a pressure vessel in the prior art.

[0024] Figure 2 It is a schematic diagram of a cylinder structure with a skirt in the prior art.

[0025] Figure 3 It is a schematic diagram of welding a cylinder with a skirt in the prior art.

[0026] Figure 4 It is a schematic diagram of the structure of a forged cylinder with a skirt in the prior art.

[0027] Figure 5 This is a schematic diagram of the structure of the forging tooling.

[0028] Figure 6 Schematic diagram of the structure of the bottom gasket.

[0029] Figure 7 This is a schematic diagram of the structure of the inner mold.

[0030] Figure 8 It is a schematic diagram of the structure of the lower outer mold.

[0031] Fig. 9 Schematic diagram of the structure of the upper outer mold.

[0032] Fig.10 This is a cross-sectional view of the upper outer mold.

[0033] Fig.11 Schematic diagram of the cylindrical blank structure.

[0034] Fig.12 This is the assembly diagram of the bottom gasket and inner mold.

[0035] Fig.13 The bottom gasket, inner mold assembly drawing and lower outer mold assembly drawing are shown.

[0036] Fig.14 This is the installation diagram of the cylindrical blank.

[0037] Fig.15 For overall molding Figure 1 .

[0038] Fig.16 For overall molding Figure 2 .

[0039] Fig.17 For overall molding Figure 3 .

[0040] Fig.18 It is a schematic diagram of the structure of the skirt cylinder.

[0041] Fig.19 It is a schematic diagram of the metal streamlines of the integrally formed skirt cylinder.

[0042] In the figure, 1-bottom gasket, 101-base, 102-limiting guide block, 2-inner mold, 201-cylinder A, 202-support, 3-lower outer mold, 301-cylinder B, 4-upper outer mold, 401-cylinder C, 4011-ring A, 4012-ring B, 5-positioning block A, 6-lifting ear A, 7-positioning groove, 8-lifting ear B, 9-positioning block B, 10-cylindrical blank, 11-skirt, 12-cylinder, 13-pressure vessel shell, 14-butt weld, 15-envelope. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] Example 1 Combination Figure 5-Figure 10, the present invention provides a forging tool for a skirt cylinder for a pressure vessel, comprising a bottom gasket 1, an inner die 2, a lower outer die 3 and an upper outer die 4; The bottom gasket 1 includes a circular base 101 and three limiting guide blocks 102 evenly distributed on the outer surface of the base 101; a positioning block A5 is provided on the top surface of the base 101 of the bottom gasket 1; The inner mold 2 includes a cylinder A201 with upper and lower openings. A support member 202 is provided inside the cylinder A201. The top surface of the support member 202 and the top of the cylinder A201 are located on the same horizontal plane. The support member 202 can support the cylinder A201 and can also be used for lifting. The support member 202 is a Y-shaped structure, which can avoid deformation of the cylinder A201 as much as possible and make the interior of the cylinder A201 streamlined; The outer surface of the lower end of the cylinder A201 matches the inner surface of the base 101; In order to facilitate demoulding of the inner mold 2, the cylinder A201 is gradually reduced from top to bottom; The lower outer mold 3 includes a cylinder B301 with upper and lower openings. The upper end surface of the cylinder B301 is a curved surface, which matches the lower surface of the skirt 11 of the cylinder 12. The intersection of the upper end surface and the inner surface is rounded; the lower end surface of the cylinder B301 is a flat surface. Three lifting lugs A6 of the same height are evenly distributed on the outer surface of the cylinder B301 for lifting; A positioning groove 7 is provided on the lower end surface of the cylinder B301, the vertex position of the positioning groove 7 and the lowest point of the upper end surface are located at the same circumferential angle, and the positioning groove 7 matches the positioning block A5 on the base 101, and the radial widths of the two are the same; it is used to position the bottom gasket 1 and the lower outer mold 3; In order to facilitate demoulding of the lower outer mold 3, the cylinder B301 is gradually reduced from top to bottom; The upper outer mold 4 includes a cylinder C401 with upper and lower openings, and the cylinder C401 includes a coaxially arranged ring A4011 and a ring B4012, the upper end face of the ring B4012 is in contact with the lower end face of the ring A4011, the inner diameter of the ring A4011 is smaller than the inner diameter of the ring B4012, and a step is formed between the two; the outer diameter of the ring A4011 is the same as the outer diameter of the ring B4012; the upper end face of the ring A4011 is a plane; the lower end face of the ring B4012 is a curved surface, the lower end face of the ring B4012 matches the upper surface of the skirt 11 of the cylinder 12, and the intersection of the lower end face and the inner surface is chamfered; the inner surface of the ring A4011 matches the outer surface of the upper end of the cylinder A201 of the inner mold 2; Three lifting lugs B8 of the same height are evenly distributed on the outer surface of the cylinder C401 for lifting; A positioning block B9 is provided on the outer surface of the cylinder C401, the top of the positioning block B9 is flush with the upper end surface of the ring A4011, and the extension line of the bottom of the positioning block B9 coincides with the lowest point of the curved surface of the ring B4012; this arrangement enables the vertex of the positioning block B9 and the fixed point of the positioning block A5 to be located at the same circumferential angle, which is convenient for angle positioning when the tooling is used; The cylinder C401 is tapered from bottom to top to facilitate demoulding.

[0045] Example 2 Based on Example 1, Figure 11-Figure 19 This embodiment provides a method for integrally forming the forged skirt 11 and the cylinder 12 using the forging tool, and the process is as follows: (1) Blank preparation: a. Using a forging press, the steel ingot is forged into a cylindrical blank by free forging, and then rough-processed using a CNC vertical lathe to obtain a cylindrical blank 10 in a fully machined state; The inner diameter of the cylindrical barrel blank 10 is 30 mm larger than the outer diameter of the barrel A201; the inner diameter of the barrel B301 is 30 mm larger than the outer diameter of the cylindrical barrel blank 10; the inner diameter of the ring B4012 of the barrel C401 is 30 mm larger than the outer diameter of the cylindrical barrel blank 10; this arrangement facilitates the lifting and installation of the forging tooling and the cylindrical barrel blank 10; the height of the cylindrical barrel blank 10 is determined according to the principle that the volume of the skirt 11 and the barrel 12 after forming remains unchanged; b. Place the cylindrical blank 10 in a heating furnace for heating, with the axis vertical for easy lifting, heat to forging temperature and keep warm for a period of time to ensure that the temperature of each part is consistent, and then set aside; (2) Forging tooling preparation: c. Place the bottom washer 1 on the forging rotating platform so that it can rotate at any angle in the circumferential direction; d. By lifting the support 202 of the inner mold 2, place the lower end of the cylinder A201 in the base 101 of the bottom gasket 1, so that the lower end surface of the cylinder A201 and the lower end surface of the base 101 are on the same plane; apply lithium-based grease on the outer surface of the inner mold 2 and the upper end surface of the base 101 to facilitate demoulding and reduce forging surface friction; e. Lithium-based grease is applied to the inner surface of the cylinder B301 to facilitate demoulding and reduce the friction of the forging surface; the lower outer mold 3 is placed on the upper end surface of the bottom gasket 1 through the three lifting ears A6 of the cylinder B301; the limiting guide block 102 of the bottom gasket 1 plays a guiding role to facilitate the placement of the lower outer mold 3. During this process, the positioning groove 7 of the cylinder B301 cooperates with the positioning block A5 on the base 101; f. Apply lithium-based grease on the inner surface of the cylinder C401 to facilitate demoulding and reduce forging surface friction; preheat the assembled bottom gasket 1, inner die 2, lower outer die 3 and upper outer die 4 with gas at the same time to a temperature of 250°C and set aside; (3) Overall molding: g. After the forging tooling is preheated, the heated cylindrical blank 10 is placed in the cavity between the inner die 2 and the lower outer die 3 through a two-point clamp; h. Place the upper outer die 4 on the upper end of the cylindrical blank 10 through the three ears B8 of the upper outer die 4. At this time, the inner surface of the ring A4011 matches the outer surface of the upper end of the cylinder A201, and the lower end surface of the ring A4011 contacts the upper end surface of the cylindrical blank 10, that is, the top end of the cylindrical blank 10 is stuck on the step formed by the ring A4011 and the ring B4012, and the extension line of the bottom end of the positioning block B9 of the upper outer die 4 is at the same circumferential angle as the vertex of the positioning block A5 of the bottom gasket 1; the forging tooling and the cylindrical blank 10 are assembled; i. By moving the forging rotating platform, the assembled forging tooling and the cylindrical barrel blank 10 are moved directly below the forging press; j. The upper outer die 4 is continuously pressed downward by the pressure of the forging press. Under the action of the forging tooling, the cylindrical tube blank 10 is extruded and deformed, and the height gradually becomes lower. It protrudes outward at the gap between the lower end surface of the upper outer die 4 and the upper end surface of the lower outer die 3, and the skirt 11 structure is gradually formed, and finally a forged blank with a skirt 11 and a cylinder 12 is formed; k. After the overall forming of the forging blank of the skirt 11 cylinder is completed, the forging rotating platform is moved to a position where the crane can lift it, and the upper outer die 4 and the inner die 2 are lifted off in turn, and then the forging blank is lifted out to obtain the forging blank of the skirt 11 cylinder 12; l. Through the subsequent performance heat treatment and machining process, the skirt 11 and cylinder 12 with material properties and dimensions of each part that meet the requirements are obtained.

[0046] Example 3 Introduction to existing technology: Figure 1 A schematic diagram of the structure of a pressure vessel in the prior art is given, in which a cylinder 12 is arranged on a pressure vessel shell 13; Figure 2 It is a schematic diagram of the structure of a cylinder 12 with a skirt 11 in the prior art, and the skirt 11 is fixed on the cylinder 12; Figure 3 It is a schematic diagram of welding a cylinder 12 with a skirt 11 in the prior art. During welding, the skirt 11 is welded to the shell of the pressure vessel to form a butt weld 14; Figure 4It is a schematic structural diagram of a forged cylinder 12 with a skirt 11 in the prior art. The skirt 11 is formed on the outside of the cylinder 12 by machining the envelope 15 .

[0047] Although the present invention has been described in detail by reference to the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A forging tool for a skirt cylinder for a pressure vessel, characterized in that: including a bottom gasket, an inner mold, a lower outer mold, and an upper outer mold; The bottom gasket comprises a circular ring base and three limiting guide blocks evenly distributed on the outer side of the base; The inner mold comprises a cylinder A with upper and lower openings, a support member is provided inside the cylinder A, and the top surface of the support member and the top of the cylinder A are located on the same horizontal plane; the outer surface of the lower end of the cylinder A matches the inner surface of the bottom gasket base; The lower outer mold includes a cylinder B with upper and lower openings, the upper end surface of the cylinder B is a curved surface, matching the lower surface of the skirt of the cylinder, and the intersection of the upper end surface and the inner surface is rounded; the lower end surface of the cylinder B is a plane; The upper outer mold comprises a cylinder C with upper and lower openings, and the cylinder C comprises a coaxially arranged ring A and a ring B, the upper end face of the ring B contacts the lower end face of the ring A, the inner diameter of the ring A is smaller than the inner diameter of the ring B, and a step is formed between the two, and the outer diameters of the rings A and B are the same; the upper end face of the ring A is a plane; the lower end face of the ring B is a curved surface, the lower end face of the ring B matches the upper surface of the skirt of the cylinder, and the intersection of the lower end face and the inner surface is chamfered; the inner surface of the ring A matches the outer surface of the upper end of the inner mold cylinder A.

2. The forging tool for the skirt cylinder for a pressure vessel according to claim 1, characterized in that: A positioning block A is provided on the top surface of the bottom washer base.

3. The forging tool for the skirt cylinder for a pressure vessel according to claim 1, characterized in that: The supporting member is a Y-shaped structure.

4. The forging tool for the skirt cylinder for a pressure vessel according to claim 3, characterized in that: The cylinder A is tapered from top to bottom.

5. The forging tool for the skirt cylinder for a pressure vessel according to claim 1, characterized in that: Three lifting ears A of the same height are evenly distributed on the outer surface of the cylinder B.

6. The forging tool for the skirt cylinder for a pressure vessel according to claim 5, characterized in that: A positioning groove is provided on the lower end surface of the cylinder B, the vertex of the positioning groove is at the same circumferential angle as the lowest point of the upper end surface, and the positioning groove matches the positioning block A on the base, and the radial widths of the two are the same.

7. The forging tool for the skirt cylinder for a pressure vessel according to claim 6, characterized in that: The cylinder B is tapered from top to bottom.

8. The forging tool for the skirt cylinder for a pressure vessel according to claim 1, characterized in that: Three lifting ears B of the same height are evenly distributed on the outer surface of the cylinder C; the cylinder C is tapered from bottom to top to facilitate demoulding.

9. The forging tool for the skirt cylinder for a pressure vessel according to claim 8, characterized in that: A positioning block B is provided on the outer surface of the cylinder C. The top end of the positioning block B is flush with the upper end surface of the ring A, and the extension line of the bottom end of the positioning block B coincides with the lowest point of the curved surface of the ring B.

10. An integral forming method for forging a skirt cylinder using the forging tool as claimed in any one of claims 1 to 9, characterized in that: The process is as follows: (1) Blank preparation: a. Use a forging press to forge the steel ingot into a cylindrical blank by free forging, and then use a CNC vertical lathe for rough machining to obtain a cylindrical barrel with a full surface machined state; b. Place the cylindrical tube in a heating furnace for heating, with the axis vertical, and heat to forging temperature and keep warm for later use; (2) Forging tooling preparation: c. Place the bottom washer on the forging rotating platform so that it can rotate at any angle in the circumferential direction; d. Place the lower end of the cylinder A in the base of the bottom gasket by lifting the support of the inner mold, so that the lower end surface of the cylinder A and the lower end surface of the base are on the same plane; apply lithium-based grease on the outer surface of the inner mold and the upper end surface of the base; e. Apply lithium-based grease to the inner surface of the cylinder B; place the lower outer mold on the upper end surface of the bottom gasket through the three ears A of the cylinder B; during this process, the positioning groove of the cylinder B matches the positioning block A on the base; f. Apply lithium-based grease on the inner surface of the cylinder C; preheat the assembled bottom gasket, inner mold, lower outer mold and upper outer mold with gas at the same time to a temperature of 200~300℃ and set aside; (3) Overall molding: g. After the forging tool is preheated, the heated cylindrical blank is placed in the cavity between the inner die and the lower outer die through a two-point clamp; h. Place it on the upper end of the cylindrical barrel blank through the three ears B of the upper outer die. At this time, the inner surface of the ring A matches the outer surface of the upper end of the cylinder A, and the lower end surface of the ring A contacts the upper end surface of the cylindrical barrel blank, that is, the top end of the cylindrical barrel blank is stuck on the step formed by the ring A and the ring B, and the extension line of the bottom end of the positioning block B of the upper outer die and the vertex of the positioning block A of the bottom gasket are at the same circumferential angle; the forging tooling and cylindrical barrel blank are assembled; i. Move the assembled forging tooling and cylindrical blank to the bottom of the forging press by moving the forging rotating platform; j. The upper outer die is continuously pressed down by the pressure of the forging press. Under the action of the forging tooling, the cylindrical blank is squeezed and deformed, and the height gradually decreases. It bulges outward at the gap between the lower end surface of the upper outer die and the upper end surface of the lower outer die, and the skirt structure is gradually formed, and finally a forged blank of a skirt cylinder is formed; k. After the overall forming of the skirt cylindrical forging blank is completed, the forging rotating platform is moved to a position where the crane can lift it, and the upper outer die and inner die are lifted off in turn, and then the forging blank is lifted out to obtain the skirt cylindrical forging blank; l. Through the subsequent performance heat treatment and machining processes, a skirt cylinder with material properties and dimensions of each part that meet the requirements is obtained.

Images