A core roll for rolling special-shaped ring parts, a rolling device and a manufacturing method for an annular end cover

Abstract

The present invention discloses a core roll for rolling special-shaped ring parts, a rolling device, and a manufacturing method for an annular end cover. The special-shaped sleeve ring is provided with an annular end cover and a rolling part for rolling the special-shaped ring part with a main roll. The outer peripheral wall of the rolling part is of an arc surface structure. The annular end cover is located at the front end of the arc surface structure along the climbing direction of the special-shaped ring part. One side of the annular end cover close to the arc surface structure abuts against the end of the special-shaped ring part. Specifically, the special-shaped ring part to be manufactured is asymmetric in the height direction, and its inner wall surface is of an arc-shaped structure. Then, the outer peripheral wall of the rolling part is also of a correspondingly adapted arc surface structure. During the rolling process, the special-shaped ring part can climb axially along the arc surface structure, that is, the special-shaped ring part is prone to move towards the side with a larger curvature. By adding the annular end cover, the axial climbing force generated during the rolling of the special-shaped ring part is balanced, thereby suppressing the axial climbing of the special-shaped ring part, solving the problems of incomplete filling of the cavity and end face folding during the rolling process of this type of special-shaped ring part, and improving the material utilization rate.

Description

Technical Field

[0001] The present invention relates to the technical field of special-shaped ring rolling, in particular to a core roll for special-shaped ring rolling, a rolling device and a manufacturing method for an annular end cover. Background Art

[0002] Ring rolling technology is an advanced manufacturing technology for producing seamless rings. Due to its many excellent process characteristics, it has been increasingly widely used in industrial fields such as machinery, automobiles, trains, ships, aerospace, etc. Traditional ring rolling processes are applicable to rings with rectangular or nearly rectangular cross-sections. The special-shaped ring rolling process has the characteristics of high material utilization rate, low production cost, high production efficiency and good ring quality, which has attracted great attention and rapid development. However, when rolling special-shaped rings, the metal flow is more complex, and defects such as incomplete filling of the cross-sectional profile, local folding, axial climbing, and poor roundness are likely to occur. Especially for special-shaped rings that are asymmetric in the height direction, axial climbing is very likely to occur during rolling, which in turn causes the defect that the die cavity cannot be filled. To eliminate such defects, usually two solutions are adopted: one is to symmetrically process the ring during the design of the forging drawing and roll two rings at the same time. This method is a commonly used measure in forging production to improve the filling property of forgings. However, the ring after symmetrical processing often has a significantly increased height in the height direction and is very likely to exceed the rolling capacity range of the rolling mill, and is not applicable to rings with a large height; the other is to increase the machining allowance at the end of the ring where climbing is likely to occur during the design of the forging drawing, make it as symmetrical as possible with the other end and then roll it, but the material utilization rate of this method is often not high, resulting in a greatly increased production cost.

[0003] At present, the core roll is mainly designed according to the cavity, without considering the axial climbing during the rolling process of the special-shaped ring and its influence on the filling of the ring cross-section. In Document 1 (Feng Kai. Simulation Analysis of the Radial-Axial Rolling Forming of Large L-Shaped Rings [J]. Modern Manufacturing Technology and Equipment, 2014(04): 21-23.), the longitudinal metal flow law during the rolling of special-shaped cross-sections was analyzed, but no solution to the complexity of its forming height was proposed. In Document 2 (Peng Qianzhi, Li Jianjun, Yu Sanshan, Piao Xuehua, Zhang Qiang, Long Rujun, Pan Yong, Zhou Guilin, Liu Keming, Li Xiaolong. Influence of the Blank Cross-Section Shape on the Rolling of L-Shaped Special-Shaped Rings [J]. Heat Treatment Technology and Equipment, 2014(04): 30-33.), the defects of burrs and fish tails were analyzed and studied by designing three kinds of rolling blanks, but no solution was proposed to improve the metal flow in terms of axial asymmetry. Patent Document CN103143658B discloses a rolling forming method for a bearing steel ring with a complex special-shaped cross-section. The rolling forming method of the ring is to roll a bearing steel bar cut according to specifications into a rectangular pre-rolled blank after heating, upsetting, punching and ring rolling; heat the rectangular pre-rolled blank and roll it into a special-shaped pre-rolled blank with a structure shape opposite to that of the final-rolled special-shaped cross-section ring in a pre-rolled special-shaped hole by a pre-rolled inner module and a pre-rolled outer module; heat the special-shaped pre-rolled blank and roll it into a special-shaped cross-section ring in a final-rolled special-shaped hole by a final-rolled inner module and a final-rolled outer module. However, mainly a sealed cavity structure is formed between the core roll and the main roll, and there is no motivation and it cannot reasonably control the movement of the blank in the axial direction. Summary of the Invention

[0004] The object of the present invention is to provide a core roll for rolling special-shaped rings, a rolling device and a manufacturing method for a ring end cover, so as to solve the problems existing in the above-mentioned prior art. For a special-shaped ring that is asymmetric in the height direction, by adding a ring end cover to balance the axial climbing force generated during the rolling of the special-shaped ring, the axial climbing of the special-shaped ring is inhibited, the problems of incomplete filling of the cavity and end face folding during the rolling process of this type of special-shaped ring are solved, and the material utilization rate is improved.

[0005] To achieve the above object, the present invention provides the following solution: The present invention provides a core roll for rolling special-shaped rings, including a core shaft and a special-shaped sleeve ring sleeved on the core shaft and rotating synchronously with it. The special-shaped sleeve ring is provided with a ring end cover and a rolling part for rolling a special-shaped ring with a main roll. The outer peripheral wall of the rolling part is of an arc surface structure. The special-shaped ring can axially climb along the arc surface structure. The ring end cover is coaxially arranged with the arc surface structure and is located at the front end of the arc surface structure along the climbing direction of the special-shaped ring. One side of the ring end cover close to the arc surface structure abuts against the end of the special-shaped ring.

[0006] Preferably, when the main roll rolls the special-shaped ring, the end face of the main roll and the side of the annular end cover close to the arc surface structure are arranged at an axial interval.

[0007] Preferably, the part of the annular end cover close to the arc surface structure is a conical structure, the conical structure gradually narrows axially and towards the arc surface structure, and the initial width of the special-shaped ring is greater than the extension length of the annular end cover along the outer peripheral side.

[0008] Preferably, the rolling part includes a first forming part integrally formed with the end cover and a second forming part coaxially arranged on the side of the first forming part away from the end cover, and the first forming part and the second forming part are detachably connected.

[0009] Preferably, the contact surfaces of the first forming part and the second forming part are in a stepped structure that fits together.

[0010] Preferably, a connecting bolt is detachably inserted axially between the first forming part and the second forming part.

[0011] Preferably, an annular flange protruding towards the outer peripheral side is provided on the mandrel, and the side of the second forming part away from the first forming part is clamped on the annular flange.

[0012] Preferably, a matching connecting key and keyway are provided between both the first forming part and the second forming part and the core roll.

[0013] There is also provided a rolling device, including a main roll, a core roll for rolling the special-shaped ring with a radial linear feed, a special-shaped sleeve ring sleeved on the core roll for cooperating with the main roll to roll the special-shaped ring, an annular end cover located above the special-shaped ring on the special-shaped sleeve ring, and a rolling platform for carrying the special-shaped ring provided on the lower side of the special-shaped sleeve ring.

[0014] There is also provided a method for manufacturing an annular end cover on a core roll, including the following steps:

[0015] Determine the extension length L in the radial direction of the dimension design of the annular end cover, the inclination angle θ of the end face of the annular end cover close to the conical structure, and the thickness H1 of the annular end cover according to the wall thickness of the special-shaped ring and the moment balance principle during the rolling process; θ = 3 - 5°, the end cover thickness H1 = 20 - 30 mm; the blank of the special-shaped ring is a rectangular ring blank, the height of the rectangular ring blank is h, the outer diameter is R, the inner diameter is r, and the thickness of the rectangular ring blank is R - r;

[0016] The radial rolling force during the rolling of the special-shaped ring is:

[0017]

[0018] Where: P—radial rolling force;

[0019] p—radial rolling pressure per unit area;

[0020] k—shear yield strength of the rectangular ring blank under rolling conditions;

[0021] h—height of the rectangular ring blank;

[0022] S—contact arc length between the core roll and the rectangular ring blank;

[0023] The axial climbing force F generated by the rectangular ring blank 轴 , then:

[0024] F 轴 = Ptanα;

[0025] And there is a 6 - 10 mm gap between the end face of the annular end cap and the end face of the main roll, then:

[0026] L max = 2R3 - (6 - 10) + (r4 - r3), where:

[0027] L max —the maximum value of the length of the annular end cap;

[0028] r2—inner diameter of the upper end face of the rectangular ring blank;

[0029] r1—outer diameter of the upper end face of the rectangular ring blank;

[0030] R3—width of the second forming part;

[0031] The direction of the moment borne by the annular end cap is counterclockwise, then: F 轴 = F3; F3 is the force exerted by the main roll on the top of the rectangular ring blank;

[0032] The wall thickness reduction of the rectangular ring blank during rolling is 20%; after rolling the rectangular ring blank, A1 = r1 + 0.2(R - r) can be obtained;

[0033] The centroid of the rectangular ring blank

[0034] The force exerted on the rectangular ring blank by the core roll is F2; under the combined action of the forces F2 and F3, the bending moment that causes the rectangular ring blank to rotate clockwise is:

[0035]

[0036] It can be obtained:

[0037]

[0038] Then there is:

[0039]

[0040] During the rolling process, |x c2 -x c1 | gradually decreases, the bending moment generated by the rectangular ring blank gradually decreases, and the axial climb generated by the rectangular ring blank during rolling is the largest;

[0041] The minimum value of the length of the annular end cover is:

[0042] L min = 2S2;

[0043] L min — The minimum value of the length of the end cover above the core roll.

[0044] The present invention has achieved the following technical effects compared with the prior art:

[0045] First, it includes a mandrel and a special-shaped sleeve ring sleeved on the mandrel and rotating synchronously with it. The special-shaped sleeve ring is provided with an annular end cover and a rolling part for rolling a special-shaped ring part with a main roll. The outer peripheral wall of the rolling part is an arc surface structure. The special-shaped ring part can axially climb along the arc surface structure. The annular end cover is coaxially arranged with the arc surface structure and is located at the front end of the arc surface structure along the climbing direction of the special-shaped ring part. One side of the annular end cover close to the arc surface structure abuts against the end of the special-shaped ring part. Specifically, the special-shaped ring part to be manufactured is asymmetric in the height direction, and its inner wall surface is an arc structure. Then the outer peripheral wall of the rolling part is also an arc surface structure adapted thereto. During the rolling process, the special-shaped ring part can axially climb along the arc surface structure, that is, the special-shaped ring part is easy to move towards the side with a larger curvature. By adding an annular end cover, the axial climbing force generated during the rolling of the special-shaped ring part is balanced, thereby suppressing the axial climbing of the special-shaped ring part, solving the problems of incomplete filling of the cavity and end face folding during the rolling process of this type of special-shaped ring part, and improving the material utilization rate.

[0046] Second, the part of the annular end cover close to the arc surface structure is a conical structure, and the conical structure gradually shrinks axially and towards the arc surface structure. That is to say, by setting the conical structure, one side of the annular end cover close to the arc surface structure is a whole inclined surface. During the process of the edge of the main roll pressing the special-shaped ring part, it gradually approaches the annular end cover along the inclined surface of the annular end cover, avoiding interference between the annular end cover and the main roll during rolling. Moreover, the initial width of the special-shaped ring part is greater than the extension length of the annular end cover along the outer peripheral side. And because the outer peripheral side of the conical structure on the annular end cover is inclined upwards, that is, at the beginning stage of rolling, the annular end cover does not completely envelope the blank of the special-shaped ring part (generally a rectangular ring blank). That is to say, a semi-closed rolling cavity is formed between the main roll and the rolling part, which can reasonably control the axial flow of the blank, further avoiding the problem that the end face is easy to fold due to excessive closing degree.

[0047] Third, the rolling part includes a first forming part integrally formed with the end cover and a second forming part coaxially arranged on the side of the first forming part away from the end cover. The first forming part and the second forming part are detachably connected to realize the split structure of the rolling part. Furthermore, according to different rolling requirements, the first forming part and the second forming part with different structures can be conveniently replaced, that is, it is beneficial to replace the mold cavity, and thus the disadvantages of waste of mold materials, long processing and replacement cycles caused by integral replacement can be avoided.

[0048] Fourth, matching connecting keys and key grooves are provided between both the first forming part and the second forming part and the core roll to prevent the first forming part and the second forming part from jumping up and down during the rolling process. Description of the Drawings

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0050] Figure 1 It is a forging drawing;

[0051] Figure 2 It is the split structure design of the core roll;

[0052] Figure 3 It is the dimension design of each part of the core roll;

[0053] Figure 4 It is a forging ring blank;

[0054] Figure 5 It is a schematic diagram of the initial rolling stage;

[0055] Figure 6 It is a schematic diagram of the end rolling stage;

[0056] Figure 7 It is a schematic diagram of the force and moment of the ring blank;

[0057] Figure 8 It is a schematic diagram of the length design of the annular end cover;

[0058] Figure 9 It is a schematic diagram of the overall structure of the present invention;

[0059] Among them, 1 - special-shaped sleeve ring, 2 - second forming part, 3 - first forming part, 4 - core shaft, 5 - connecting key, 6 - connecting bolt, 7 - rectangular ring blank, 8 - main roll, 9 - rolling platform, 10 - special-shaped ring part, 11 - tapered roll. Detailed Embodiments

[0060] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0061] The object of the present invention is to provide a core roll for rolling special-shaped ring parts, a rolling device and a manufacturing method for annular end covers, so as to solve the problems existing in the above-mentioned prior art. For special-shaped ring parts that are asymmetric in the height direction, an annular end cover is added to balance the axial climbing force generated during the rolling of the special-shaped ring parts, thereby suppressing the axial climbing of the special-shaped ring parts, solving the problems of incomplete filling of the cavity and end face folding during the rolling process of such special-shaped ring parts, and improving the material utilization rate.

[0062] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0063] Please refer to Figures 1 to 9 , the present invention provides a core roll for rolling a special-shaped ring part 10, which includes a core shaft 4 and a special-shaped sleeve ring 1 sleeved on the core shaft 4 and rotating synchronously therewith. The special-shaped sleeve ring 1 is provided with an annular end cover and a rolling part for rolling the special-shaped ring part 10 with a main roll 8. The outer peripheral wall of the rolling part is in an arc surface structure. The special-shaped ring part 10 can axially climb along the arc surface structure. The annular end cover is coaxially arranged with the arc surface structure and is located at the front end of the arc surface structure along the climbing direction of the special-shaped ring part 10. One side of the annular end cover close to the arc surface structure abuts against the end of the special-shaped ring part 10. Specifically, the special-shaped ring part 10 to be manufactured is asymmetric in the height direction, and its inner wall surface is in an arc structure. Then, the outer peripheral wall of the rolling part is also in a matching arc surface structure. During the rolling process, the special-shaped ring part 10 can axially climb along the arc surface structure, that is, the special-shaped ring part 10 is prone to move towards the side with a larger curvature. The existing core rolls for rolling special-shaped ring parts 10 are designed according to the rolling deformation conditions of the ring parts and the structural requirements of the ring rolling mill, and do not mention how to balance the upward axial force for axially asymmetric special-shaped ring parts 10. In actual production, if axial climbing occurs at the end of the special-shaped ring part 10, it will cause a defect that the cavity of the other end of the special-shaped ring part 10 is not filled. In the present invention, an annular end cover is added to balance the axial climbing force generated during the rolling of the special-shaped ring part 10, thereby suppressing the axial climbing of the special-shaped ring part 10, solving the problems of incomplete filling of the cavity and end face folding during the rolling process of such special-shaped ring parts 10, and improving the material utilization rate.

[0064] Furthermore, the annular end cap is required to suppress the axial force. At the same time, to avoid interference between the annular end cap and the main roller 8 during rolling, when the main roller 8 rolls the special-shaped ring 10, the end face of the main roller 8 is spaced from the side of the annular end cap close to the arc surface structure. Preferably, a distance of 6-10 mm is left between the annular end cap and the main roller 8 to fully avoid interference between the annular end cap and the main roller 8.

[0065] As a preferred embodiment of the present invention, the part of the annular end cap close to the arc surface structure is a conical structure, and the conical structure gradually shrinks axially and towards the arc surface structure. That is to say, by setting the conical structure, the side of the annular end cap close to the arc surface structure is a whole inclined plane. During the process of the edge of the main roller 8 pressing the special-shaped ring, it gradually approaches the annular end cap along the inclined plane of the annular end cap, avoiding interference between the annular end cap and the main roller 8 during rolling. Moreover, the initial width of the special-shaped ring 10 is greater than the extension length of the annular end cap along the outer peripheral side. And since the outer peripheral side of the conical structure on the annular end cap is inclined upwards, at the beginning stage of rolling, the annular end cap does not completely envelope the blank of the special-shaped ring 10 (generally a rectangular ring blank 7). That is to say, a semi-closed rolling cavity is formed between the main roller 8 and the rolling part, which can reasonably control the axial flow of the blank and further avoid the problem that the end face is prone to folding due to excessive closing degree.

[0066] Furthermore, the rolling part includes a first forming part 3 integrally formed with the end cap and a second forming part 2 coaxially arranged on the side of the first forming part 3 away from the end cap. Preferably, both the first forming part 3 and the second forming part 2 are metal sleeve ring structures and are sleeved on the mandrel 4. The first forming part 3 and the second forming part 2 are detachably connected to realize the split structure of the rolling part. Then, according to different rolling requirements, the first forming part 3 and the second forming part 2 with different structures can be conveniently replaced. That is to say, it is beneficial to the replacement of the die cavity, and further avoids the disadvantages of waste of die materials, long processing and replacement cycles caused by the replacement of the whole.

[0067] To ensure the radial stability of the first forming part 3 and the second forming part 2, the contact surfaces of the first forming part 3 and the second forming part 2 are in an interlocking stepped structure. The stepped structure realizes the radial clamping effect between the first forming part 3 and the second forming part 2, avoiding the easy radial separation of the first forming part 3 and the second forming part 2.

[0068] Preferably, to ensure the detachable connection between the first forming part 3 and the second forming part 2, a connecting bolt 6 is detachably penetrated axially between the first forming part 3 and the second forming part 2, realizing the rapid connection of the first forming part 3 and the second forming part 2 with a simple structure.

[0069] Furthermore, an annular flange protruding towards the outer peripheral side is provided on the mandrel 4, and the side of the second forming part 2 away from the first forming part 3 is clamped on the annular flange, ensuring the stability of the entire special-shaped collar 1 on the mandrel 4. Alternatively, preferably, the mandrel 4 can also be divided into two parts. The upper part is thinner for sleeving the special-shaped collar 1, and the lower part is thicker for clamping the special-shaped collar 1 to ensure the stability of the special-shaped collar 1.

[0070] As a preferred embodiment of the present invention, a matching connection key 5 and keyway are provided between both the first forming part 3 and the second forming part 2 and the core roll to prevent the first forming part 3 and the second forming part 2 from jumping up and down during the rolling process.

[0071] A rolling device is also provided, including a main roll 8 and a core roll for rolling special-shaped workpieces with a radial linear feed. A special-shaped collar 1 is sleeved on the core roll and is used in cooperation with the main roll 8 to roll a special-shaped ring 10. An annular end cap is provided on the special-shaped collar 1 above the special-shaped ring 10. A rolling platform 9 for carrying the special-shaped ring 10 is provided below the special-shaped collar 1. During use, the core roll feeds linearly in the radial direction and gradually approaches the main roll 8, so that the special-shaped collar 1 cooperates with the main roll 8 to roll a blank of the special-shaped ring. The rolling platform 9 is carried below the special-shaped ring 10, and the special-shaped ring 10 gradually climbs upward along the axial direction during the rolling process. Furthermore, the blank is abutted through the annular end cap to achieve balancing the upward axial force for the axially asymmetric special-shaped ring 10. Preferably, two taper rolls 11 are provided on the side of the blank away from the special-shaped ring 10. The two taper rolls 11 are symmetrically arranged up and down on both sides of the blank, and the two taper rolls 11 perform a rotational end face rolling motion and an axial feed motion.

[0072] The size of the annular end cap needs to be reasonably designed. On the one hand, it is necessary to ensure that the axial force generated during the ring rolling can be completely balanced. On the other hand, it is also necessary to avoid flow defects such as fishtails and folds on the end face of the ring. Furthermore, a method for manufacturing the annular end cap on the core roll is also provided, including the following steps:

[0073] Determine the radially extending length L of the size design of the annular end cap, the inclination angle θ of the end face of the annular end cap close to the conical structure, and the thickness H1 of the annular end cap according to the wall thickness of the special-shaped ring 10 and the moment balance principle during the rolling process; θ = 3 - 5°, the end cap thickness H1 = 20 - 30 mm; the blank of the special-shaped ring 10 is a rectangular ring blank 7, the height of the rectangular ring blank 7 is h, the outer diameter is R, the inner diameter is r, and the thickness of the rectangular ring blank 7 is R - r; preferably, the material of the special-shaped ring 10 is 2219 aluminum alloy.

[0074] The radial rolling force during the rolling of the special-shaped ring 10 is:

[0075]

[0076] In the formula: P - radial rolling force;

[0077] p—Radial rolling pressure per unit area;

[0078] k—Shear yield strength of the rectangular ring blank 7 under rolling conditions;

[0079] h—Height of the rectangular ring blank 7;

[0080] S—Contact arc length between the core roll and the rectangular ring blank 7;

[0081] At the beginning of rolling, the upper end of the outer ring surface of the rectangular ring blank 7 contacts the main roll 8, and the lower end of the inner ring surface of the rectangular ring blank 7 contacts the core roll, as Figure 5 shown; forcing the cross-section of the rectangular ring blank 7 to generate a clockwise bending moment, causing the rectangular ring blank 7 to undergo axial climbing, and then the end cap inhibits the axial climbing of the ring part. The axial climbing force F 轴 , then there is:

[0082] F 轴 = Ptanα;

[0083] As Figure 6 shown is the schematic diagram of the rolled blank. Through comprehensive analysis of the rolling process of this ring part, it can be found that when the moment of the annular end cap on the special-shaped ring part 10 is greater than the moment of the cavity cross-section on the special-shaped ring part 10, the overall cross-section of the special-shaped ring part 10 is subjected to a counterclockwise axial moment, thereby inhibiting the axial climbing of the special-shaped ring part 10.

[0084] From Figure 7 it can be seen that the annular end cap needs to inhibit the axial force. At the same time, to avoid interference between the annular end cap and the main roll 8 during rolling, a distance of 6 - 10 mm is left between the end cap and the main roll 81. Then there is:

[0085] L max = 2R3 - (6 - 10) + (r4 - r3), where:

[0086] L max —Maximum value of the length of the annular end cap;

[0087] r2—Inner diameter of the upper end face of the rectangular ring blank 7;

[0088] r1—Outer diameter of the upper end face of the rectangular ring blank 7;

[0089] R3—Width of the second forming part 2;

[0090] Since during the rolling process, the annular end cap on the core roll not only needs to inhibit the maximum axial force but also needs to bear the maximum moment, and the direction of the moment borne by the annular end cap is counterclockwise, then: F 轴 = F3; F3 is the acting force of the main roll 8 on the top end of the rectangular ring blank 7;

[0091] As Figure 7As shown, the rectangular blank ring is regarded as being composed of a homogeneous material of the same kind, so the centroid and the center of gravity are the same point. During the ring rolling process involved in this patent, the wall thickness reduction is 20%. After the rectangular ring blank 7 is rolled, A1 = r1 + 0.2(R - r) can be obtained;

[0092] The centroid of the rectangular ring blank 7

[0093] The force exerted on the rectangular ring blank 7 by the core roll is F2; under the combined action of the forces F2 and F3, the bending moment that causes the rectangular ring blank 7 to rotate clockwise is:

[0094]

[0095] It can be obtained that:

[0096]

[0097] Then there is:

[0098]

[0099] During the rolling process, |x c2 - x c1 | gradually decreases, and the bending moment generated by the rectangular ring blank 7 gradually decreases. When rolling, the axial climb generated by the rectangular ring blank 7 is the largest;

[0100] The minimum value of the length of the annular end cover is:

[0101] L min = 2S2;

[0102] L min — The minimum value of the length of the end cover above the core roll.

[0103] Furthermore, the shapes and dimensions of the other parts of the core roll are designed through the following steps:

[0104] First, determine the structure of the core roll according to the forging drawing of the ring forging;

[0105] Second, determine the external dimensions of each part of the core roll, namely the core shaft 4, the first forming part 3, and the second forming part 2;

[0106] Third, determine the external shapes and positioning dimensions of the fasteners and key grooves;

[0107] Determine the structure of the core roll according to the forging drawing of the ring forging: As Figure 1 shown is the forging drawing of the special-shaped ring 10, with the outer diameters r1, r4 of the upper and lower end faces, the inner diameters r2, r3 of the upper and lower end faces, the forging height h, the inner fillet radius r n , the outer fillet radius r w , and the inclination angles of the outer diameter and the inner diameter are θ1 and θ2 respectively. As Figure 2As shown in the figure, the core roll designed by the present invention includes a first forming part 3, a second forming part 2, a mandrel 4, a keyway, and a connecting bolt 6. The connecting bolt 6 is used to connect the first forming part 3 and the second forming part 2, and the connecting key 5 and the keyway are used to fix the special-shaped collar 1 and the mandrel 4 to prevent the special-shaped collar 1 from bouncing up and down during the rolling process.

[0108] Determine the outer dimensions of the mandrel 4, the first forming part 3, and the second forming part 2: First, as Figure 3 shown, the dimensions D a , D b , H a , H b of the mandrel 4 are determined according to the installation requirements of the rolling mill and the rolling plane. Second, the profile shape of the second forming part 2 is determined according to the forging drawing, specifically including: the height H4 of the second forming part 2, the fillet radius R n , the collar width R3 and the inclination angle θ3 are equal to the forging dimensions h4, r n , r3, θ2 on the forging drawing, that is, H4 = h4, R n = r n , R3 = r3, θ3 = θ2. Third, the outer dimension R2 of the first forming part 3 is determined as R2 = r2 according to the inner diameter r2 of the upper end face of the forging, and the collar height H c is determined according to the forging height h and the end cover height H1: H c = h + H1. According to experience, H3 = (0.4 - 0.6)H c , L n = 2 / 3(R3 - D a / 2), H2 = (0.08 - 0.15)H3.

[0109] Determine the outer shape and positioning dimensions of the connecting bolt 6 and the keyway: The connecting bolt 6 and the keyway used in the present invention are both standard parts. The connecting bolt 6 is a hexagonal head bolt of M24×8, and the keyway is a common flat key.

[0110] All adaptive changes made according to actual needs are within the protection scope of the present invention.

[0111] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0112] In the present invention, specific examples are used to illustrate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A manufacturing method for an annular end cover on a core roll, characterized in that, Applied to a rolling device, the rolling device includes a main roll and a core roll for rolling a special-shaped ring along a radial linear feed; The core roll for rolling the special-shaped ring includes a core shaft and a special-shaped collar sleeved on the core shaft and rotating synchronously therewith. The special-shaped collar is provided with an annular end cover and a rolling part for cooperating with the main roll to roll the special-shaped ring. The outer peripheral wall of the rolling part is of an arc surface structure. The special-shaped ring can axially climb along the arc surface structure. The annular end cover is coaxially arranged with the arc surface structure and is located at the front end of the arc surface structure along the climbing direction of the special-shaped ring. One side of the annular end cover close to the arc surface structure abuts against the end of the special-shaped ring; The special-shaped collar is used to cooperate with the main roll to roll the special-shaped ring; the annular end cover is located above the special-shaped ring, and a rolling platform for carrying the special-shaped ring is arranged on the lower side of the special-shaped collar; The rolling part includes a first forming part integrally formed with the annular end cover and a second forming part coaxially arranged on the side of the first forming part away from the annular end cover. The first forming part and the second forming part are detachably connected; The manufacturing method of the annular end cover on the core roll is as follows: Determine the radial extension length L of the size design of the annular end cover, the inclination angle θ of the end face of the annular end cover close to the conical structure, and the thickness H1 of the annular end cover according to the wall thickness of the special-shaped ring and the moment balance principle during the rolling process; θ = 3 - 5°, the end cover thickness H1 = 20 - 30 mm; the blank of the special-shaped ring is a rectangular ring blank, the height of the rectangular ring blank is h, the outer diameter is R, the inner diameter is r, and the thickness of the rectangular ring blank is R - r; The radial rolling force during the rolling of the special-shaped ring is: In the formula: P - radial rolling force; p - unit area radial rolling pressure; k - shear yield strength of the rectangular ring blank under rolling conditions; h - height of the rectangular ring blank; S - contact arc length between the core roll and the rectangular ring blank; The axial climbing force F generated by the rectangular ring blank 轴 , then there is: F 轴 = P tan α; Where: α - lift angle; And there is a 6 - 10 mm interval between the end face of the annular end cover and the end face of the main roll, then: L max = 2R3 - (6 to 10) + (r4 - r3), where: L max — The maximum value of the length of the annular end cap; r4 - outer diameter of the lower end face of the special-shaped ring; r3 - inner diameter of the lower end face of the special-shaped ring; r2 - inner diameter of the upper end face of the special-shaped ring; r1 - outer diameter of the upper end face of the special-shaped ring; R3 - width of the second forming part; If the torque direction borne by the annular end cover is counterclockwise, then: F 轴 = F3; F3 is the acting force of the main roller on the top end of the rectangular ring blank; The wall thickness reduction of the rectangular ring blank during the rolling process is 20%; after rolling the rectangular ring blank, A1 = r1 + 0.2(R - r) can be obtained; The centroid of the rectangular ring blank The force exerted on the rectangular ring blank by the core roll is F2; under the combined action of the force F2 and F3, the bending moment that causes the rectangular ring blank to rotate clockwise is: It can be obtained: Then: During the rolling process, |x c2 -x c1 gradually decreases, and the bending moment generated by the rectangular ring blank gradually decreases; The minimum value of the length of the annular end cover is: L min = 2S2; L min — The minimum value of the length of the end cover above the core roll; h4 = H4; H4 is the height of the second forming part.

2. The method for manufacturing the annular end cap on the core roll according to claim 1, characterized in that, When the main roll rolls the special-shaped ring, the end face of the main roll and the side of the annular end cover close to the arc surface structure are axially spaced.

3. The manufacturing method of the annular end cap on the core roll according to claim 2, characterized in that, The part of the annular end cover close to the arc surface structure is a conical structure, and the conical structure gradually shrinks axially and towards the arc surface structure, and the initial width of the special-shaped ring is greater than the extension length of the annular end cover along the outer peripheral side.

4. The method for manufacturing the annular end cover on the core roll according to claim 3, characterized in that, The contact surface between the first forming part and the second forming part is a stepped structure that fits into each other.

5. The manufacturing method of the annular end cap on the core roll according to claim 4, characterized in that, A connecting bolt is detachably inserted axially between the first forming part and the second forming part.

6. The method for manufacturing the annular end cap on the core roll according to claim 5, wherein An annular flange protruding toward the outer peripheral side is provided on the mandrel, and the side of the second forming part away from the first forming part is clamped on the annular flange.

7. The manufacturing method of the annular end cap on the core roll according to claim 6, characterized in that, A matching connecting key and keyway are provided between both the first forming part and the second forming part and the core roll.

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