CN104588549B - Multi-ring roll-forming method for thin ring parts - Google Patents

Abstract

The invention discloses a multi-ring roll-forming method for thin ring parts to solve the problems of the prior art that during thin ring part processing, production efficiency is low and the performance of annular parts is poor. The method comprises the steps of 1, blank manufacturing, wherein a first annular part blank is manufactured; 2, rolling groove designing; 3, forming parameter designing; 4, roll forming, wherein the first annular part blank is arranged on a core roller (2) in a sleeving mode, the core roller (2) moves upwards to roll the first annular part blank, the next step is executed after a second annular part blank is formed by rolling the first annular part blank, the core roller (2) moves downwards till the second annular ring part blank is clamped by the core roller (2) and a second driving roller (6), deep groove rolling is conducted and finished after the depth of a deep groove reaches a predetermined value so that a third annular part blank can be formed, the third annular part blank is taken down, inner ring burrs on the third annular part blank are removed through a lathe, the three thin ring part blanks are separated, and the flat end faces of the thin ring part blanks are finally machined to obtain qualified thin annular parts.

Description

Multi-ring Roll Forming Method for Thin Ring Parts

technical field

The present invention relates to a rolling forming method of ring parts, more precisely, the present invention relates to a multi-ring rolling forming method of thin ring parts.

Background technique

Refer to Figure 2. The geometrical feature of the ring shown in the figure is that the height h is very small, the diameter is large, and the height-to-diameter ratio is generally less than 1:25. This type of ring is called a thin ring, which is often used in automotive rear axle reinforcement rings . The reinforcing ring is an important part of the rear axle of the car. Its function is not only to undertake the total reducer assembly and the axle housing, but also to strengthen the middle part of the axle housing. Therefore, the working environment of the ring determines that it must have high strength. Nowadays, the processing methods of such thin rings mainly include plasma cutting, casting, welding, etc., but the above processing methods all have many defects. For example, plasma cutting, the quality of the reinforced ring processed by it is stable and the welding performance is good, but due to the slow speed of plasma cutting, the production efficiency is greatly reduced, which also affects the economic benefits of the enterprise; although casting and welding can also process qualified However, due to a series of defects such as bubbles and cracks inside the metal during the casting and welding process, the mechanical properties of the ring cannot be guaranteed, resulting in a short service life of the ring, which greatly affects the quality of the ring. As we all know, ring rolling is the most effective method for producing and processing rings, which not only can ensure the quality of rings, but also has high production efficiency. However, if such thin rings are directly rolled by rings, defects such as distortion are prone to occur during the rolling process, so it is often not possible to directly use ring rolling for production and processing.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the problems of low production efficiency and poor ring performance in the existing thin ring processing process, and provide a thin ring multi-ring rolling forming method.

In order to solve the above-mentioned technical problems, the present invention is realized by adopting the following technical scheme: the steps of the thin ring multi-ring rolling forming method are as follows:

1) Blank making:

The blank making is to prepare the No. 1 ring blank;

2) Rolling pass design:

Described rolling pass design is the design of driving roll and core roll, and its steps are as follows:

(1) Determine the diameter of the working surface of the driving roller and the core roller:

In order to ensure that the No. 1 ring blank can be continuously bitten during the rolling process and ensure that the ring can be forged through, the diameter of the driving roll and the core roll should meet the following conditions:

Drive roll and core roll limit radii R ₁ and R ₂ :

In the formula: R _1min , R _2min , R, r are the minimum radius of the working surface of the driving roller and the core roller and the inner and outer radius of the No. 1 ring blank, the unit is mm; β = arctan μ is the friction angle, μ is the friction coefficient, For 45 steel, it is taken as 0.5;

(2) The maximum radius of the driving roller is limited by the center distance between the driving roller and the core roller allowed by the ring rolling machine; the maximum radius of the core roller cannot exceed the radius of the inner hole of the No. 1 ring blank;

(3) Core roll cavity size design:

The core roller is designed as a closed pass, the minimum value of the cavity width B ₀ cannot be greater than the wall thickness of the No. 1 ring blank; the cavity height h _c = h ₁ +0.3 ~ 0.5mm, the value of the cavity inclination α of the core roll α=1°～3°; and perform chamfering R _C on the upper and lower steps between the cylindrical surface of the cavity and the core roller 2, the value is R _C =3mm, and the height of the upper and lower steps of the cavity is h _t =h;

(4) Size design of the second drive roller

The function of the second driving roller is to cut the No. 2 ring blank into three connected thin ring blanks, the specific dimensions are as follows:

The working radius R ₃ of the second driving roller is equal to the radius R ₁ of the driving roller: namely R ₃ =R ₁ ;

The height of the second drive roller h _s1 = h _s2 + 2h + 2h ₃ + f, f is the height value of the upper and lower cylindrical surfaces outside the two bosses of the second drive roller above a single thin ring, which is taken as

The height between two bosses with the same structure h _s2 =h+λh, where λ is 0.01; the sections of the two bosses are designed to be isosceles trapezoidal, and the rounded corner R _S is designed on the outside of the boss, and its value is R _S =R -0.1～0.3mm, where R is the fillet radius at the groove of the No. 3 ring blank, and its specific dimensions are as follows:

Boss inside height outside height Outer fillet radius R _S =0.5mm;

Boss for grooving section width: Where a is the thickness of the continuous skin at the end of rolling of the No. 3 ring blank.

3) Forming parameter design:

The forming parameter design is to select the forming parameters of the driving roller speed and the core roller feed speed, and the steps are as follows:

(1) The rotational speed of the driving roller is represented by n ₁ : Among them: v is the feed speed, the unit is mm/s; △h is the feed rate per revolution, the unit is mm;

(2) During the rolling process, the core roll plays a role in both rolling stages. The core roll can move up and down through the hydraulic cylinder, and the feed speed of the core roll is proportional to the feed per revolution. The forging through of the ring ensures that the ring can be bitten in normally, so its limit value is as follows:

In the formula: R ₁ and R ₂ are the radii of the driving roller and the core roller respectively, R and r are the outer and inner radii of the No. 1 ring blank respectively, and the unit is mm; β=arctan μ is the friction angle, and μ is the friction coefficient ;

(3) In the process of rolling deep grooves, in order to ensure that the second driving roller can smoothly cut into the No. 2 ring blank, the core roll adopts a small feed rate at the initial stage to prevent metal deformation when the core roll cuts into the No. 2 ring blank Seriously, a large feed rate is used when the rolling is stable; in the full circle stage, the feed speed is reduced to ensure the quality of the full circle.

4) Roll forming:

(1) Put the No. 1 ring blank on the core roll, and the core roll moves up to roll the No. 1 ring blank. When the No. 1 ring blank is rolled into the No. 2 ring blank, enter the next step;

(2) Move the core roller down to the second drive roller to clamp the No. 2 ring blank, and roll the deep groove. When the deep groove reaches the predetermined size, the deep groove rolling stage ends and the No. 3 ring blank is formed. ;

(3) Remove the No. 3 ring blank and use a lathe to remove the inner ring skin on the No. 3 ring blank, separate the three thin ring blanks, and finally process a qualified thin ring on the flat end face of the thin ring blank.

The billet making described in the technical scheme comprises the following steps:

1) Determine the volume V of the No. 3 ring blank:

Among them: D is the outer diameter of the No. 3 ring blank, in millimeters; d is the inner diameter of the No. 3 ring blank after removing the skin, in millimeters; h ₁ is the overall height of the No. 3 ring blank at the end of rolling, in millimeters mm; h ₂ is the height of the inner groove of the deep groove, in millimeters; h ₃ is the height of the outer groove of the deep groove, in millimeters; a is the thickness of the continuous skin, in millimeters;

2) Determine the rolling ratio K:

The rolling ratio of rings with rectangular cross-section is taken as K=1.5~3;

3) Determine the height of the No. 1 ring blank:

With closed-pass rolling, the overall height of the No. 1 ring blank is h ₁ =3h+2h ₃ , where h is the height of the final single thin ring;

4) Determine the inner diameter d ₀ and outer diameter D ₀ of the No. 1 ring blank:

Based on the principle of constant plastic deformation volume, as well as the ring rolling ratio and the height of the No. 3 ring blank, the inner diameter d ₀ and outer diameter D ₀ of the No. 1 ring blank are determined as

5) According to the above design, the material is cut first, the bar is heated to 1200°C in the electric furnace, and then the bar is upset, punched, peeled off on the press, and annealed to eliminate internal stress, and finally rolled into diameter To the No. 1 ring blank of the torus shape with a rectangular cross section.

Compared with prior art, the beneficial effects of the present invention are:

1. The multi-ring rolling forming method of thin rings according to the present invention aims at defects such as low production efficiency and poor performance of rings in the current thin ring processing process. The concept of "ring" is to roll out three thin ring blanks at one time, which is equivalent to manufacturing blanks with a height three times greater than the original thin ring for rolling, thus returning to the rolling forming method of general rectangular rings.

2. Referring to Figure 9, when implementing thin ring multi-ring rolling forming method, only the original vertical ring rolling machine is simply modified, and on the basis of the original ring rolling machine, a machine with The roll of the "cutter" and the core roll of the ring rolling machine are set as the feed roll, which is beneficial for the core roll to play a role in both rolling stages; the modified ring rolling machine can make the two stages in the same It can be carried out on a ring rolling machine without removing the rings, which saves time, increases work efficiency and reduces equipment investment.

3. The thin ring multi-ring rolling forming method of the present invention effectively improves a series of defects such as low production efficiency and poor ring performance in the past manufacturing processes of thin ring cutting, casting, welding, etc., and can Qualified products are processed in a short period of time, which improves production efficiency, saves processing costs, and greatly increases economic benefits.

Description of drawings

Below in conjunction with accompanying drawing, the present invention will be further described:

Fig. 1 is the block flow diagram of thin ring multi-ring rolling forming method of the present invention;

Fig. 2 is a full sectional view on the front view of the thin ring in the embodiment of the thin ring multi-ring rolling forming method of the present invention;

Fig. 3 is a schematic diagram of the rolling principle of the thin ring multi-ring rolling forming method according to the present invention;

Fig. 4 is a full sectional view on the front view of the No. 1 ring blank, that is, the initial ring blank, used in the thin ring multi-ring rolling forming method of the present invention;

Fig. 5 is a full cross-sectional view on the front view of the No. 3 ring blank, that is, the final formed part in the second rolling stage, processed by the thin ring multi-ring rolling forming method according to the present invention;

Fig. 6 is a partial enlarged view of the deep groove structure between two thin ring blanks at A in Fig. 5;

Fig. 7 is a full sectional view on the front view of the drive roller in the refitted ring rolling machine used to implement the multi-ring rolling forming method for thin rings according to the present invention;

Fig. 8 is a full cross-sectional view on the front view of the core roller in the modified ring rolling machine used to implement the multi-ring rolling forming method for thin rings according to the present invention;

Fig. 9 is a full cross-sectional view on the front view of the second drive roller in the refitted ring rolling machine used to implement the thin ring multi-ring rolling forming method according to the present invention;

Fig. 10 is a partially enlarged view of the second drive roller boss at B in Fig. 9;

In the figure: 1. Driving roller, 2. Core roller, 3. Guide roller, 4. Ring, 5. Signal roller, 6. Second driving roller.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing:

Referring to Fig. 1, first determine the shape and volume of the No. 1 ring blank when adopting the multi-ring rolling forming method of the thin ring of the present invention to roll; then design a reasonable rolling pass according to the requirements of the thin ring; Then determine the forming parameters; finally roll forming. When rolling, the ring 4 is first placed on the core roll 2, and then the core roll 2 is moved up. When the No. 1 ring blank is in contact with the driving roll 1, the first rolling stage starts, that is, the No. 2 ring with a rectangular cross section Rolling of blanks; after rolling to a certain size, the No. 2 ring blank is formed, and the core roller 2 moves down to make the No. 2 ring blank contact with the second driving roller 6, and the deep groove rolling process starts In the rolling stage, until the No. 3 ring blank is rolled, and then use a lathe to remove the continuous skin between the three thin ring blanks on the No. 3 ring blank, so that the three thin ring blanks are separated. The flat end face of the ring blank is finally processed into a qualified thin ring.

The steps of the multi-ring roll forming method of thin rings according to the present invention are as follows:

1. Blank making: (preparation of No. 1 ring blank)

The steps for preparing the No. 1 ring blank are as follows:

1) Determine the volume V of the No. 3 ring blank:

Among them: D is the outer diameter of the No. 3 ring blank, in millimeters; d is the inner diameter of the No. 3 ring blank after removing the skin, in millimeters; h ₁ is the overall height of the No. 3 ring blank at the end of rolling, in millimeters h ₂ is the height of the inner groove of the deep groove, in millimeters; h ₃ is the height of the outer groove of the deep groove, in millimeters; a is the thickness of the continuous skin, in millimeters.

2) Determine the rolling ratio K:

The rolling ratio of rings with rectangular cross-section is generally taken as K=1.5~3. When the outer diameter of the ring is larger, the K value is a little larger, and when it is smaller, take a smaller value. Considering that the outer diameter of the thin ring is larger, so The rolling ratio takes a larger value of 2.5.

3) Determine the height of the No. 1 ring blank:

With closed pass rolling, the overall height of the No. 1 ring blank is h ₁ =3h+2h ₃ , where h is the height of the final single thin ring.

4) Determine the inner diameter d ₀ and outer diameter D ₀ of the No. 1 ring blank:

Based on the principle of constant volume of plastic deformation, and the rolling ratio of the ring and the height of the ring, the inner diameter d ₀ and outer diameter D ₀ of the No. 1 ring blank are determined as

5) Referring to Figure 4, according to the above design, first blank the material, heat the bar to 1200°C in an electric furnace, then upsetting, punching, peeling and annealing the bar on a press to eliminate internal stress. Rolling into the No. 1 ring blank; that is, the No. 1 ring blank is designed to be a torus-shaped blank with a rectangular cross-section in the radial direction.

2. Rolling pass design:

The forming process of the No. 3 ring blank is divided into the rolling stage of the No. 2 ring blank and the deep groove rolling stage. The No. 2 ring blank rolling stage is mainly formed by driving roll 1 and core roll 2, and the process is the same as the rectangular ring rolling forming process; while deep groove rolling is jointly rolled by the second drive roll 6 and core roll 2 The forming process is similar to a "cutting" process. Because it is rolled and formed, the No. 3 ring blank maintains the continuity of the metal well, and the performance of the product remains good. The shape of the drive roller 1 is designed to be cylindrical; in order to limit the axial flow of metal during the grooving stage, the core roller 2 is designed as a closed pass, thus ensuring the quality of the end face of the No. 3 ring blank during the grooving stage. The shape of the working surface of the second driving roller 6 corresponds to the shape of the ring blank when it is finally rolled and formed. The design dimensions of the driving roller 1 and the core roller 2 are as follows:

1) Determine the diameter of the driving roller 1 and core roller 2 working surfaces:

In order to ensure that the No. 1 ring blank can be continuously bitten during the rolling process and ensure that the ring can be forged through, the diameters of the driving roll 1 and the core roll 2 should meet the following conditions:

Drive roll 1 and core roll 2 limiting radii (R ₁ and R ₂ ):

In the formula: R _1min , R _2min , R, r are the minimum radius of the working surface of driving roller 1 and core roller 2 and the inner and outer radius of No. 1 ring blank respectively, the unit is mm; β = arctan μ is the friction angle, μ is the friction The coefficient is generally taken as 0.5 for 45 steel.

2) Of course, there are also restrictions on the maximum radius of the driving roller 1 and the core roller 2. The maximum radius of the driving roller 1 is limited by the center distance between the driving roller 1 and the core roller 2 allowed by the ring rolling machine; and the maximum radius of the core roller 2 The radius of the inner hole of the No. 1 ring blank cannot be exceeded, otherwise the No. 1 ring blank cannot be inserted into the core roller 2.

3) Core roll 2 cavity size design:

In order to ensure the quality of the end face of the No. 2 ring blank in the second body rolling stage, that is, the deep groove rolling stage, and prevent "fish tail" and warping, the core roll 2 is designed as a closed pass, and its cavity width is B The minimum value of ₀ cannot be greater than the wall thickness of the No. 1 ring blank; the height of the cavity h _c = h ₁ +0.3 ~ 0.5mm, which will help the No. 1 ring blank to be placed in the cavity well and set the core roller Cavity inclination α, its value is α=1°～3°; and chamfering R _C is performed at the upper and lower steps between the cylindrical surface of the cavity and the core roller 2, and its value is R _C =3mm to prevent metal distortion; As for the height of the upper and lower steps of the cavity, since it has no effect on the ring rolling, it is only to well limit the axial flow of metal during the ring rolling process, so there is no rigid requirement on the height, and h _t = h.

4) 6 size design of the second driving roller

The function of the second driving roller 6 is mainly to divide the No. 2 ring blank into three connected thin ring blanks when the No. 1 ring blank is rolled to a predetermined size, which is similar to a "cutting" process, and its specific The shape corresponds to the final cut-to-shape thin ring, and the specific dimensions are as follows:

The working radius R ₃ of the second driving roller 6 is equal to the radius R _{1 of the driving roller 1} : namely R ₃ =R ₁ ;

The height h _s1 of the second driving roller 6 =h _s2 +2h+2h ₃ +f, the two bosses with the same structure on the second driving roller 6 are mainly used for "cutting" the No. 2 ring blank in the second stage, and f is To ensure the stable rolling of the ring, the height of the upper and lower cylindrical surfaces on the outer sides of the two bosses of the second drive roller 6 above a single thin ring is generally taken as And the height h _s2 between the two bosses = h+λh, λ is generally taken as 0.01; in order to reduce the rolling resistance in the rolling process, the sections of the two bosses are designed to be isosceles trapezoidal, and a circle is designed on the outside of the bosses Angle R _S , its value is R _S ＝R-0.1～0.3mm, where R is the fillet radius at the groove of the No. 3 ring blank, which is conducive to the smooth cutting of the boss into the No. 2 ring blank and greatly reduces the Stress concentration is avoided, so that the process can proceed smoothly. Its specific dimensions are as follows:

Boss inside height outside height Outer fillet radius R _S =0.5mm;

Boss for grooving section width: Where a is the thickness of the continuous skin at the end of rolling of the No. 3 ring blank.

3. Forming parameter design:

The forming parameters mainly include the rotational speed of the drive roller 1 and the feed speed of the core roller 2, and the design is as follows:

1) The rotational speed of the driving roller 1 is represented by n ₁ : Among them: v is the feed speed, the unit is mm/s; △h is the feed rate per revolution, the unit is mm.

2) Since the core roll 2 plays a role in both rolling stages during the rolling process, the core roll 2 is set as a feed roll, and can move up and down through the hydraulic cylinder to ensure that the rolling process and the driving Either the roller 1 or the second drive roller 6 can be in contact. The feed speed of the core roller 2 is proportional to the feed per revolution, which should not only ensure that the ring is forged through, but also ensure that the ring can be bitten in normally, so its limit value is as follows:

In the formula: R ₁ and R ₂ are the radii of the drive roller 1 and the core roller 2 respectively, R and r are the outer and inner radii of the No. 1 ring blank respectively, and the unit is mm; β=arctan μ is the friction angle, and μ is coefficient of friction.

3) In the process of rolling deep grooves, in order to ensure that the second drive roller 6 can smoothly cut into the No. 2 ring blank, the core roll 2 adopts a small feed rate at the initial stage to prevent the core roll 2 from cutting into the No. 2 ring blank When the metal deformation is serious, a larger feed rate is used when the rolling is stable, which saves time and improves productivity. In the full circle stage, the feed speed is reduced to ensure the quality of the full circle.

4. Roll forming:

1) Put the No. 1 ring blank on the core roll 2, and the core roll 2 moves up to roll the No. 1 ring blank. The process is equivalent to the rolling process of the rectangular cross-section ring. When the No. 1 ring blank is rolled Enter the next step when the predetermined size is formed into the No. 2 ring blank;

2) The core roller 2 moves down to clamp the No. 2 ring blank with the second driving roller 6, and rolls deep grooves. In this process, it is assumed that the inner diameter of the No. 2 ring blank remains unchanged. According to the metal fluidity and volume, The principle of changing the main flow direction of the metal in the deep groove increases the outer diameter. When the deep groove reaches the predetermined size, the rolling stage of the deep groove ends, that is, the No. 3 ring blank is formed.

3) Remove the No. 3 ring blank and use a lathe to remove the inner ring skin on the No. 3 ring blank, separate the three thin ring blanks, and finally process the flat end face of the thin ring blank to obtain a qualified thin ring.

Example:

Referring to Figure 2, the figure shows the thin ring to be processed. The thin ring is a rear axle reinforcement ring _{of an} automobile. The circle diameter d _inside is 424mm, d _inside =424mm, and the height h is 20mm, namely h=20mm.

The steps of the multi-ring rolling forming method for thin rings are as follows:

1. Billet making:

Referring to Figure 2, three thin rings are finally determined to be rolled at one time through finite element simulation. The blank volume required by the rolling process is 3801893.16mm ³ , and assuming that the inner diameter of the No. 2 ring blank remains unchanged during the second rolling process, it can be concluded that the final rectangular No. The diameter is D ₂ =499mm, the inner diameter is d ₂ =422mm; according to the design of the ring blank, the rolling ratio is determined to be 2.5, and the outer diameter D ₀ =315.3mm and the inner diameter of the No. 1 ring blank are finally determined to be d ₀ =168.8mm , and the height is h ₁ =68mm.

2. Rolling pass design

1) According to the design requirements of the limit size of driving roll 1 and core roll 2, in the compound rolling process, the working diameter of driving roll 1 is designed to be 400mm and the height is 70mm;

2) The working diameter of the core roll 2 is designed to be 150mm. In order to prevent the axial flow of metal during the rolling process, the core roll is designed as a closed pass, and the cavity height h _c is designed to be 68+0.3~0.5mm, and the cavity The inclination angle α of the lower side of the boss is 1°, which helps the ring to be placed into the cavity smoothly, and the width B ₀ of the boss is designed to be 40mm, the height h _t of the boss is taken as 20mm, and the inner chamfer R of the cavity is _C is 1°～3°;

3) Since there is no specific reference basis for the size design of the deep groove ring rolling roll, temporarily refer to the roll size design requirements in the rectangular ring rolling process, and design the diameter of the second driving roll to be the same as that of the first stage driving roll. 400mm, the height h _s1 is designed to be 68mm, the boss width B ₁ is 41mm, and the inner height h _s3 of the boss is 4mm, the outer height h _s2 is 2mm, and the chamfer R _s at the outer side is 0.5mm, the inner side of the two bosses The height between h and _s2 is 20.2mm;

3. Forming parameter design:

In the first rolling stage of the ring, in order to ensure that the ring can be forged through and can be bitten continuously, the speed of the driving roll is set to 10rad/s, and the feed speed of the core roll is set to 1.5mm/s; in the second rolling stage, the second The speed of the driving roll is also set at 10rad/s, and in order to prevent serious distortion of the metal due to excessive feeding at the beginning of the deep groove rolling of the ring, a small feeding amount of 1mm/s is used at the beginning; the rolling is relatively stable The feed rate is increased to 2mm/s, and the feed rate is adjusted to 0.8mm/s until the end of rolling in order to ensure the stability of ring rolling and maintain a good round effect when the rolling is about to end.

4. Roll forming: first put the No. 1 ring blank on the core roller 2, and then move the core roller 2 up through the hydraulic system. When the No. 1 ring blank contacts the driving roller 1, stop moving, and then drive the roller 1 rotation, the speed is 10rad/s, the core roll 2 is fed upwards with a small feed rate of 1.5mm/s, and the first rolling stage of the ring is started, and the diameter of the No. 1 ring blank begins to increase. When the outer diameter of the ring reaches When the predetermined size is 499mm, it is formed into the No. 2 ring blank, and the No. 2 ring blank is in contact with the signal roller 5, so that the equipment sends out a termination signal, and the core roller 2 moves down and contacts with the lower part of the No. 2 ring blank. At this time, the No. The second driving roller 6 moves up until it contacts the No. 2 ring blank, and the second rolling stage, that is, the deep groove rolling stage, is started. At this time, the second driving roller 6 rotates at 10rad/s, and the core roller /s feed, when the rolling is relatively stable, the feed is increased to 2mm/s, and when the rolling is about to end, in order to ensure the stability of ring rolling and keep the full circle effect, adjust the feed to 0.8 mm/s until the No. 3 ring blank is formed, and the entire ring rolling process ends. Then the No. 3 ring blank is removed, and then the inner circle is turned, the skin between the three thin ring blanks is removed by turning, and the end face is flattened, and finally a thin ring that meets the standard is processed.

Claims (2)

1. a kind of multi-ring roll-forming method of slim ring is it is characterised in that the described multi-ring roll-forming method of slim ring Step as follows：

1) base：

Described base prepares No. 1 ring blank；

2) rolling groove design：

Described rolling groove design is driven roller (1) and the design of core roller (2), and its step is as follows：

(1) driven roller (1) and the diameter of core roller (2) work surface are determined：

In order that No. 1 ring blank can either continuously nip in the operation of rolling and ensure that ring can be forged, driven roller (1) and Core roller (2) diameter should meet following condition：

Driven roller (1) and core roller (2) limit radius R₁And R₂：

In formula：R_1min、R_2min, R, r be respectively the least radius of driven roller (1) and core roller (2) work surface and No. 1 ring blank Interior outer radius, unit is mm；β=arctan μ is angle of friction, and μ is coefficient of friction, is taken as 0.5 for 45 steel；

(2) driven roller (1) maximum radius is allowed by ring rolls driven roller (1) and core roller (2) centre-to-centre spacing size limitation；Core The maximum radius of roller (2) not can exceed that No. 1 ring blank internal bore radius；

(3) core roll shape chamber size design：

Core roller (2) is designed as enclosed pass, die cavity width B₀Minima can not be more than the wall thickness of No. 1 ring blank；Die cavity height h_c =h₁+ 0.3～0.5mm, core roll shape cavity dumping degree α value is α=1 °～3 °；And in the die cavity face of cylinder and core roller 2 up/down steps Place carries out chamfering R_C, value is taken as R_C=3mm, die cavity up/down steps height value is h_t=h；

(4) second driven roller (6) size design

The effect of the second driven roller (6) is that No. 2 ring blanks are cut into three connected slim ring blanks, and concrete size is such as Under：

Radius of clean-up R of the second driven roller (6)₃Radius R equal to driven roller (1)₁：I.e. R₃=R₁；

The height h of the second driven roller (6)_s1=h_s2+2h+2h₃+ f, f are the upper and lower two cylindrical surfaces of the second driven roller (6) two outside the boss Place exceeds the height value of single slim ring, takes

Height h between two structure identical boss_s2=h+ λ h, λ take 0.01；Two boss sections are all designed as isosceles trapezoid, and Design fillet R in outside the boss_S, its value is R_S=R-0.1～0.3mm, wherein R are the fillet half of 3 ring part blank groove Footpath, its concrete size is as follows：

Boss inside heightOutside heightFlare radius R_S=0.5mm；

Boss is used for slot portion width：Wherein a is Web thickness at the end of 3 ring part blank rolling；

3) forming parameter design：

Forming parameter design selects the forming parameter of driven roller (1) rotating speed and core roller (2) feed speed, and its step is as follows：

(1) driven roller (1) rotary speed n₁Represent：Wherein：V is feed speed, and unit is mm/s；△ h is Feed of every rotation, unit is mm；

(2) all play a role in two rolling sequences in operation of rolling SMIS roller (2), core roller (2) pass through hydraulic cylinder can more than Lower movement, core roller (2) feed speed is directly proportional to feed of every rotation, and it had not only met and ensure that ring forging thoroughly again guarantee ring energy Enough normally nip, so its ultimate value is as follows：

$v\≥v_{\min }=6.55\×{10}^{-3}{n}_1\frac{R_1^2}{R}{(\frac{R}{R_1}-\frac{r}{R_1})}^2(1+\frac{R_1}{R_2}+\frac{R_1}{R}-\frac{R_1}{r})$

$v\≤v_{max}=\frac{2{\mathrm{\β}}^2{n}_1{R}_1^2}{{(1+\frac{R_1}{R_2})}^2}(1+\frac{R_1}{R_2}+\frac{R_1}{R}-\frac{R_1}{r})$

In formula：R₁、R₂It is respectively the radius of driven roller (1) and core roller (2), R, r are respectively the outer, inside radius of No. 1 ring blank, Unit is mm；β=arctan μ is angle of friction, and μ is coefficient of friction；

(3) during rolling deep trouth, in order to ensure that the second driven roller (6) can smoothly cut No. 2 ring blanks, in initial rank Section core roller (2) adopts the little amount of feeding, prevents core roller (2) flow of metal when cutting No. 2 ring blanks serious, flat carrying out rolling Large inflow is adopted when steady；It is to reduce feed speed it is ensured that full circle quality in the full circle stage；

4) roll forming：

(1) No. 1 ring blank is enclosed within core roller (2), core roller (2) is upper to move No. 1 ring blank of rolling, when by No. 1 ring blank Roll forming is to enter next step during No. 2 ring blanks；

(2) core roller (2) is displaced downwardly to and with the second driven roller (6), No. 2 ring blanks is clamped, roll deep trouth, when deep trouth reaches During preliminary dimension, deep trouth rolling sequence terminates to be configured to 3 ring part blank；

(3) taking off 3 ring part blank adopts lathe car to remove the inner ring gross weight on 3 ring part blank, and three slim ring blanks divide From qualified slim ring is finally processed to slim ring blank flat end face.

2. according to the multi-ring roll-forming method of slim ring described in claim 1 it is characterised in that described base include as Lower step：

1) determine 3 ring part blank volume V：

$V=\frac{\mathrm{\π}}{4}\[D^2-{(d-2a)}^2\]h_1-\frac{\mathrm{\π}}{4}(D^2-d^2)(h_2+h_3)$

Wherein：D is 3 ring part blank external diameter, and unit is millimeter；D is the internal diameter after 3 ring part blank removes gross weight, and unit is Millimeter；h₁For 3 ring part blank whole height at the end of rolling, unit is millimeter；h₂For groove height inside deep trouth, unit is milli Rice；h₃For groove height outside deep trouth, unit is millimeter；A is Web thickness, and unit is millimeter；

2) determine that K is compared in rolling：

The ring rolling ratio of square-section is taken as K=1.5～3；

3) determine No. 1 ring blank height：

Using enclosed groove rolling, No. 1 ring blank whole height is h₁=3h+2h₃, wherein h is final single slim ring Highly；

4) determine No. 1 ring blank internal diameter d₀And outer diameter D₀:

Based on plastic deformation constancy of volume principle, and ring rolling highly determines in No. 1 ring blank than with 3 ring part blank Footpath d₀And outer diameter D₀For

$d_0=\frac{d}{k}$

$D_0=\sqrt{\frac{\[D^2-{(d-2a)}^2\]h_1-(D^2-d^2)(h_2+h_3)}{h_1}+{\left(\frac{d}{k}\right)}^2};$

5) designed according to above, blanking first, bar is heated in electric furnace 1200 DEG C, then that bar is enterprising in forcing press Row jumping-up, punching, remove gross weight, and elimination internal stress of annealing, finally it is rolled into the 1 of the annulus bodily form that radial section is square-section Number ring blank.