CN102357531B - Composite roll forming process of thick-wall deep-groove ring member - Google Patents

Abstract

The invention relates to a composite roll forming process of a thick-wall deep-groove ring member. The process is characterized by comprising the following steps of: (1) blank design of the ring member: based on the principle of constant volume, determining the size of ring member blank according to the size of the ring member and the rolling ratio; (2) groove design: designing the sizes of the working surfaces of a main roller and a core roller according to the rolling deformation conditions of the ring member and the equipment structural requirements; and determining the size and position of the working surface of an auxiliary roller according to the sizes of the ring member blank, ring member and the main roller; (3) design of forming parameters: successively designing the rotation speed of the main roller as well as the feed speed and rolling time of the main roller according to the rolling deformation conditions of the ring member and the size of the main roller; and (4) roll forming. Through the invention, reasonable design of the composite roll forming process of the thick-wall deep-groove ring member can be realized, normal stable roll forming of the thick-wall deep-groovering member is guaranteed, the rejection rate and defective rate of the rolling are reduced, and the energy-saving material-saving high-quality and efficient roll forming of the mechanical parts suchas duplicate gears, bilateral flanges, bilateral supporting wheel bodies, high-pressure ball valves and the like is realized.

Description

Composite rolling forming process for thick-wall deep-groove ring piece

Technical Field

The invention relates to a composite rolling forming process of a thick-wall deep-groove ring piece.

Background

The geometric characteristics of the ring shown in fig. 1 are thick wall (the wall thickness is usually larger than the radius of an inner hole), small aperture and deep groove (the groove depth usually occupies more than one fourth of the wall thickness) on the surface, and the ring is called a thick-wall deep groove ring (the ring is simply called as a ring in the invention). The mechanical parts such as duplicate gears, bilateral flanges, bilateral thrust wheel bodies, high-pressure ball valve bodies and the like which are commonly used in engineering belong to the ring parts. The deep grooves on the surface of the ring piece are difficult to directly form by die forging, and the deep grooves are usually formed simply by die forging and then machined to the size of a finished product. The machining process has high energy consumption and low material utilization rate, and the subsequent cutting machining not only consumes working hours, but also cuts off the metal fiber streamline of the ring, so that the production efficiency is low and the product performance is poor.

The ring compound rolling is a new plastic processing method for forming a thick-wall deep-groove ring by continuous rotary plastic deformation, and the principle of the method is shown in figure 2. In fig. 2, the main roll 1 performs active rotation and downward linear feeding simultaneously, the core roll 2, the right auxiliary roll 4 and the left auxiliary roll 5 are idle rolls, and perform passive rotation under the driving of a ring, and the whole deformation process can be divided into two stages: (a) and (b) in the ring rolling stage, the main roller 1, the core roller 2, the right auxiliary roller 4 and the ring blank 3 form a common ring rolling deformation mode, the ring blank generates continuous local plastic deformation in a hole pattern formed by the main roller 1 and the core roller 2 to reduce the wall thickness and enlarge the diameter, and the right auxiliary roller 4 ensures the stability of the ring deformation process. (b) The three-roller cross rolling stage: when the outer diameter of the ring blank is enlarged to be in contact with the left auxiliary roller 5, the main roller 1, the right auxiliary roller 4, the left auxiliary roller 5 and the ring blank 3 form a three-roller cross rolling deformation mode, the three-point rotary rolling of the main roller 1, the right auxiliary roller 4 and the left auxiliary roller 5 on the ring blank limits the diameter enlargement of the ring blank, metal on the surface of the ring blank is forced to fill a roller cavity, the ring blank generates continuous local plastic deformation in a hole pattern formed by the main roller 1, the right auxiliary roller 4 and the left auxiliary roller 5 to form a groove, when the roller cavity is filled with the ring blank metal, the groove is completely formed, and the whole deformation process is finished. The composite rolling of the ring piece is realized by combining the rolling deformation of the common ring piece and the three-roller cross rolling deformation, so that the ring piece can obtain an accurate outer diameter size and a surface deep groove at the same time, the limitation that the common ring piece rolling method is only suitable for forming the thin-wall large-hole ring piece with a simple section shape is broken through, and the composite rolling method has the technical and economic advantages of low energy consumption, high material utilization rate, high production efficiency, good product quality and the like. However, the ring compound rolling forming is a complex deformation process, the process parameters are many, the parameters have different and mutual influences on the rolling deformation, various rolling defects are easily generated in the rolling process, and waste products and defective products are formed. Therefore, reasonable process parameter design is important for normal and stable rolling forming of the thick-wall deep-groove ring piece.

Disclosure of Invention

The invention aims to provide a composite rolling forming process for thick-wall deep-groove ring pieces, which can ensure stable rolling process and normal ring piece forming and can effectively reduce the waste and defective rate of the rolling formed ring pieces.

In order to achieve the purpose, the technical scheme of the invention is as follows: the composite rolling forming process of the thick-wall deep-groove ring piece is characterized by comprising the following steps of:

(1) blank preparation: uniformly heating the bar section from room temperature to thermal deformation temperature, then upsetting, punching and connecting skin on the hot bar section, and performing stress relief annealing to prepare a ring blank for rolling;

the ring blank is designed into a rectangular section, and the ring blank size design process is as follows:

a) calculating the volume V of the ring

$V=\frac{\mathrm{\π}}{4}[(D_1^2-d^2)h_1+(D_g^2-d^2)h_g+(D_2^2-d^2)h_2]$

D₁、D_g、D₂D is the diameter of the upper step, the diameter of the groove, the diameter of the lower step and the inner diameter of the ring respectively, h₁、h_g、h₂Respectively the height of the upper step, the height of the groove and the height of the lower step of the ring piece;

b) determination of the Rolling ratio k

The rolling ratio k is the ratio of the inner diameter of the ring to the inner diameter of the ring blank, i.e. k is d/d₀Wherein d is₀The inner diameter of the ring blank; the rolling ratio reflects the deformation degree of the ring blank, and the larger the rolling ratio is, the larger the deformation amount of the ring blank is; because the thick-wall deep-groove ring piece has large wall thickness and small inner diameter, if k is larger, the wall thickness of the ring piece blank is larger, the inner diameter of the ring piece blank is smaller, the section of the ring piece blank is not easy to be penetrated by plasticity to generate uniform deformation in rolling, and the diameter of a core roller penetrating into the ring piece blankSmaller, lower strength; therefore, in order to enable the ring blank to generate uniform plastic deformation and ensure the strength of the core roller and prevent the core roller from rolling fracture, k is preferably 1.2-1.5;

c) determining the ring blank height h₀

Adopting closed hole type rolling to take out the blank height h of the ring₀Is equal to the height h of the ring, h ═ h₁+h_g+h₂；

d) Determining the inner diameter d of the ring blank₀And the outer diameter D of the ring blank₀

Based on the principle of unchanged volume of plastic deformation, according to the rolling ratio k and the height h of the ring blank₀Determining the inner diameter d of the ring blank₀And an outer diameter D₀Is composed of

d₀＝d/k，

$D_0=\sqrt{\frac{(D_1^2-d^2)h_1+(D_g^2-d^2)h_g+(D_2^2-d^2)h_2}{h_1+h_g+h_2}+\frac{d^2}{k^2}};$

(2) Design of rolling pass

The thick-wall deep groove ring piece composite rolling pass comprises a ring piece rolling stage and a three-roller cross rolling stage, wherein the ring piece rolling stage is a pass formed by a main roller and a core roller, and the three-roller cross rolling stage is a pass formed by the main roller and two auxiliary rollers; in order to prevent the ring blank from generating end surface depression due to axial metal flow in the rolling process, the rolling pass in the two stages is designed into a closed pass; the working surface cavities of the main roller and the two auxiliary rollers correspond to the cross section of the ring piece in shape, and the working surface of the core roller is a cylindrical surface; the roll size is designed as follows:

a) main roll and core roll face size

The size of the main roller and the core roller is designed to meet the following conditions

First, in order to enable the ring blank to bite into the hole pattern formed by the main roll and the core roll and to be penetrated by plasticity to generate continuous rolling deformation during rolling, the minimum working face radius R of the main roll and the core roll_m2And R_iThe following formula should be satisfied,

$\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_m}+\frac{1}{R_i}\&le;\frac{17.5\mathrm{\&beta;}}{{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000099595970000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_0}$

in the formula, R_m2Is the radius of the lower cavity surface of the main roll (i.e. the radius of the minimum working surface of the main roll), R_iThe radius of the working surface of the core roll; beta-arctan mu is a friction angle, mu is a friction coefficient, and mu is 0.3-0.35H for the steel ring piece₀＝(D₀-d₀)/2，H₀The wall thickness of the ring blank;

secondly, in order to ensure the strength of the core roller and enable the core roller to smoothly penetrate into the ring blank, the diameter of the working surface of the core roller is generally designed to be

R_i＝d₀/2-3～5mm；

Thirdly, according to the structural requirements of the ring rolling mill, the closed center distance between the main roller and the core roller is within the range of the limit closed center distance of the ring rolling mill; minimum cavity width (B) when main roll and core roll are closed_m2And B_i) The maximum wall thickness of the ring should not be exceeded, usually by definition

$R_{m2}+R_i+B_{m2}+B_i=\frac{L_{\max }+{\mathrm{<figure-callout\; id="2"\; label="L\; min"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">L</figure-callout>}}_{\min }}{2},$ B_m2+B_i＝H₂-1～2mm；

In the formula, L_maxAnd L_minMaximum and minimum closing center distances allowed by the ring rolling mill; b is_m2Is the width of the lower cavity of the main roller, B_iThe width of the core roller cavity; h₂＝(D₂-d)/2 is the maximum wall thickness of the ring;

determining R according to the conditions of the first, the second and the third_m2、R_i、R_m2、B_iThen, the radius R of the upper cavity surface of the main roller can be further determined according to the geometrical relationship_m1Radius R of the convex surface_mgAnd upper cavity width B_m1As follows

R_m1＝R_m2+(D₂-D₁)/2，R_mg＝R_m2+(D₂-D_g)/2，B_m1＝B_m2-(D₂-D₁)/2

In order to ensure the dimensional accuracy of the section of the formed ring piece, the height h of the upper step of the ring piece is determined₁Height h of the groove_gAnd lower step height h₂Can determine the height h of the upper cavity of the main roller_m1Height h of boss_mgHeight h of lower cavity_m2And core roller cavity height h_iIs composed of

h_m1＝h₁+0.3～0.5mm，h_mg＝h_g，h_m2＝h₂+0.3～0.5mm，h_i＝h_m1+h_mg+h_m2；

In order to ensure the corresponding pass, the height of the upper side wall and the height of the lower side wall h of the main roller_mu、h_mdThe height h of the upper side wall and the lower side wall of the core roller_iu、h_idAre respectively the same as the above-mentioned components,the size of the device can be determined according to the specific installation size of the device;

b) minor roll face size and position

The two auxiliary rollers are designed to be the same; the radius of the working surface of the auxiliary roller is usually determined according to the space size of equipment so as to ensure that the auxiliary roller is convenient to mount and does not interfere with other parts of the equipment, and the radius of the boss surface of the auxiliary roller is usually designed as

R_pg≈1/3～1/5R_mg

R_pgAfter the determination, the radius R of the lower cavity surface of the secondary roller can be determined according to the geometric relationship_p2＝R_pg-(D₂-D_g) /2, radius R of upper cavity surface of auxiliary roller_p1＝R_pg-(D₁-D_g)/2；

To ensure the hole pattern correspondence, the determination of the hole pattern

Width of upper cavity B of auxiliary roller_p1＝B_m1Width of lower cavity of auxiliary roller B_p2＝B_m2Height h of upper side wall of auxiliary roll_pu＝h_muHeight h of lower side wall of auxiliary roll_pd＝h_mdHeight h of upper cavity of auxiliary roller_p1＝h_m1Height h of the boss of the auxiliary roller_pg＝h_mgHeight h of lower cavity of auxiliary roller_p2＝h_m2；

After the sizes of the ring blank, the working surfaces of the main roller and the auxiliary roller are determined, the circle center positions of the left auxiliary roller and the right auxiliary roller can be determined through geometric relation drawing, and the circle center position O of the main roller at the end of rolling can be determined according to the geometric relation drawing of the outer diameter surface of the ring blank, the groove surface of the ring (namely the groove surface of a finished product) and the convex table surface of the main roller_m1And the circle center position O of the thick-wall deep groove ring piece_r1，O_mRepresenting the initial circle center position of the main roller; the boss surface of the right auxiliary roller 4 is always contacted with the ring in the whole rolling process, is contacted with the outer diameter surface of the ring blank when the rolling is started, and is contacted with the groove surface of the ring when the rolling is finished, and then the circle center position O of the ring blank is used_rAs the circle center, the ring part hairThe sum R of the outer radius of the blank and the radius of the convex table surface of the right auxiliary roller₀+R_pgMaking a circle for the radius; with O_r1Is the sum R of the circle center, the radius of the groove surface of the ring piece and the radius of the boss surface of the auxiliary roller_g+R_pgMaking a circle with a radius, wherein the intersection point of the two circles is the center O of the right auxiliary roll_pr(ii) a When the rolling of the boss surface of the left auxiliary roller 5 is finished, the boss surface of the left auxiliary roller is contacted with the groove surface of the ring piece, and the position of the circle center of the left auxiliary roller is determined by firstly determining the angle theta between the connecting line of the circle center of the left auxiliary roller and the circle center of the ring piece and the vertical line; considering the self gravity of the vertical rolling ring piece, in order to play a good role in supporting the ring piece and forming, the angle theta can be designed to be 45-60 degrees; after the theta angle is determined, drawing according to the geometric relationship to determine the circle center position O of the left auxiliary roller_pl。

(3) Design of forming parameters

The forming parameters comprise the rotating speed of a main roller, the feeding speed of the main roller and the rolling time, and are designed as follows:

a) main roll speed n_m

In order to ensure the stable rolling of the ring piece, the linear velocity V of a main roller_mUsually 1.1-1.3 m/s; according to the radius D of the working surface of the main roller_mgThe rotation speed of the main roller can be calculated to be n_m＝V_m/2πR_mg；

b) Main roll feed speed v

In order to ensure that the ring blank can bite into the pass formed by the main roll and the core roll and be plastically pierced to produce continuous rolling deformation, the feed speed of the main roll is usually designed according to the following formula

$v=0.1~0.2\frac{{\mathrm{\&beta;}}^2{n}_{\mathrm{<figure-callout\; id="2"\; label="m\; R\; mg"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">m</figure-callout>}}{R}_{\mathrm{mg}}^{}{}_2^{}}{30R_0{(1+\frac{R_{\mathrm{mg}}}{R_i})}^2}(1+\frac{R_{\mathrm{mg}}}{R_i}+\frac{R_{\mathrm{mg}}}{R_0}-\frac{R_{\mathrm{mg}}}{r_0})$

Wherein r is₀＝d₀/2、R₀＝D₀The/2 is the inner radius and the outer radius of the ring part blank respectively;

c) time of rolling

The rolling process adopts uniform feeding, the rolling time T can be determined as T ═ delta h/v, wherein delta h is the total rolling feeding amount, and the rolling time T can be determined as

$\mathrm{\&Delta;h}=H_0-\frac{D_g-\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">d</figure-callout>}}{2};$

(4) Rolling and forming the ring piece: and (3) blanking and blanking according to the ring blank design, processing a main roller, a core roller, a left auxiliary roller and a right auxiliary roller according to the rolling hole pattern design, installing the main roller, the core roller, the left auxiliary roller and the right auxiliary roller in rolling equipment, putting the processed ring blank into the rolling equipment, and rolling into a ring according to the rolling parameters.

The composite rolling forming of the ring piece is a novel rotary plastic processing method of the thick-wall deep-groove ring piece, and has the advantages of energy conservation, material conservation, high efficiency, high quality and the like. The energy-saving, material-saving, high-quality and high-efficiency forming manufacturing of mechanical parts such as a duplicate gear, a bilateral flange, a bilateral thrust wheel body, a high-pressure ball valve body and the like can be realized.

The invention has the beneficial effects that: by adopting the composite rolling process for the thick-wall deep-groove ring piece, the reasonable design of the composite rolling process parameters of the thick-wall deep-groove ring piece can be realized, the stable running of the rolling process and the normal forming of the ring piece are ensured, and the waste and defective rate of the ring piece formed by rolling is effectively reduced.

Drawings

FIG. 1 is a schematic cross-sectional view of a thick-walled deep groove ring;

FIG. 2 is a schematic diagram of the composite rolling forming of a thick-wall deep-groove ring piece;

1-main roll, 2-core roll, 3-ring blank, 4-right auxiliary roll (first auxiliary roll), 5-left auxiliary roll (second auxiliary roll) and 6-forming ring;

FIG. 3 is a schematic cross-sectional view of a ring blank for the clad rolling of a thick-wall deep-groove ring;

FIG. 4(a) is a schematic view of the structure of the main roll;

FIG. 4(b) is a schematic view of the structure of the core roller;

fig. 4(c) is a schematic structural view of the auxiliary rolls (right auxiliary roll, left auxiliary roll);

fig. 5 is a schematic diagram of the position determination of the right and left auxiliary rolls 4 and 5.

Detailed Description

A composite rolling forming process for thick-wall deep-groove ring pieces comprises the following steps:

(1) blank preparation: uniformly heating the bar section from room temperature to thermal deformation temperature, then upsetting, punching and connecting skin on the hot bar section, and performing stress relief annealing to prepare a ring blank for rolling;

the ring blank is designed into a rectangular section, and the ring blank size design process is as follows:

a) calculating the volume V of the ring

$V=\frac{\mathrm{\&pi;}}{4}[(D_1^2-d^2)h_1+(D_g^2-d^2)h_g+({\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">D</figure-callout>}}_2^2-d^2)h_2]$

D₁、D_g、D₂D is the diameter of the upper step, the diameter of the groove, the diameter of the lower step and the inner diameter of the ring respectively, h₁、h_g、h₂Respectively the height of the upper step, the height of the groove and the height of the lower step of the ring piece;

b) determination of the Rolling ratio k

The rolling ratio k is the ratio of the inner diameter of the ring to the inner diameter of the ring blank, i.e. k is d/d₀Wherein d is₀The inner diameter of the ring blank; the rolling ratio reflects the deformation degree of the ring blank, and the larger the rolling ratio is, the larger the deformation amount of the ring blank is; because the thick-wall deep-groove ring piece is large in wall thickness and small in inner diameter, if k is larger, the wall thickness of the ring piece blank is larger, the inner diameter of the ring piece blank is smaller, the section of the ring piece blank is not easy to be penetrated by plasticity in rolling to generate uniform deformation, and the diameter of a core roller penetrating into the ring piece blank is smaller, and the strength is lower; therefore, in order to enable the ring blank to generate uniform plastic deformation and ensure the strength of the core roller and prevent the core roller from rolling fracture, k is preferably 1.2-1.5;

c) determining the ring blank height h₀

Adopting closed hole type rolling to take out the blank height h of the ring₀Is equal to the height h of the ring, h ═ h₁+h_g+h₂；

d) Determining the inner diameter d of the ring blank₀And the outer diameter D of the ring blank₀

Based on the principle of unchanged volume of plastic deformation, according to the rolling ratio k and the height h of the ring blank₀Determining the inner diameter d of the ring blank₀And an outer diameter D₀Is composed of

d₀＝d/k，

${\mathrm{<figure-callout\; id="0"\; label="D"\; filenames="HDA0000099595970000031.png"\; state="\{\{state\}\}">D</figure-callout>}}_0=\sqrt{\frac{(D_1^2-d^2)h_1+(D_g^2-d^2)h_g+({\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">D</figure-callout>}}_2^2-d^2)h_2}{h_1+h_g+{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">h</figure-callout>}}_2}+\frac{d^2}{{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">k</figure-callout>}}^2}};$

(2) Design of rolling pass

The thick-wall deep groove ring piece composite rolling pass comprises a ring piece rolling stage and a three-roller cross rolling stage, wherein the ring piece rolling stage is a pass formed by a main roller and a core roller, and the three-roller cross rolling stage is a pass formed by the main roller and two auxiliary rollers; in order to prevent the ring blank from generating end surface depression due to axial metal flow in the rolling process, the rolling pass in the two stages is designed into a closed pass; the working surface cavities of the main roller and the two auxiliary rollers correspond to the cross section of the ring piece in shape, and the working surface of the core roller is a cylindrical surface; the roll size is designed as follows:

a) main roll and core roll face size

The size of the main roller and the core roller is designed to meet the following conditions

First, in order to enable the ring blank to bite into the hole pattern formed by the main roll and the core roll and to be penetrated by plasticity to generate continuous rolling deformation during rolling, the minimum working face radius R of the main roll and the core roll_m2And R_iThe following formula should be satisfied,

$\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_m}+\frac{1}{R_i}\&le;\frac{17.5\mathrm{\&beta;}}{{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000099595970000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_0}$

in the formula, R_m2Is the radius of the lower cavity surface of the main roll (i.e. the radius of the minimum working surface of the main roll), R_iThe radius of the working surface of the core roll; beta-arctan mu is a friction angle, mu is a friction coefficient, and mu is 0.3-0.35H for the steel ring piece₀＝(D₀-d₀)/2，H₀The wall thickness of the ring blank;

secondly, in order to ensure the strength of the core roller and smoothly penetrate into the ring blank, the core roller worksThe face diameter is generally designated R_i＝d₀/2-3～5mm；

Thirdly, according to the structural requirements of the ring rolling mill, the closed center distance between the main roller and the core roller is within the range of the limit closed center distance of the ring rolling mill; minimum cavity width (B) when main roll and core roll are closed_m2And B_i) The maximum wall thickness of the ring should not be exceeded, usually by definition

${\mathrm{<figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_m+R_i+{\mathrm{<figure-callout\; id="2"\; label="B\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">B</figure-callout>}}_m+B_i=\frac{L_{\max }+{\mathrm{<figure-callout\; id="2"\; label="L\; min"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">L</figure-callout>}}_{\min }}{2},$ B_m2+B_i＝H₂-1～2mm；

In the formula, L_maxAnd L_minMaximum and minimum closing center distances allowed by the ring rolling mill; b is_m2Is the width of the lower cavity of the main roller, B_iThe width of the core roller cavity; h₂＝(D₂-d)/2 is the maximum wall thickness of the ring;

determining R according to the conditions of the first, the second and the third_m2、R_i、B_m2、B_iThen, the radius R of the upper cavity surface of the main roller can be further determined according to the geometrical relationship_m1Radius R of the convex surface_mgAnd upper cavity width B_m1As follows

R_m1＝R_m2+(D₂-D₁)/2，R_mg＝R_m2+(D₂-D_g)/2，B_m1＝B_m2-(D₂-D₁)/2

In order to ensure the dimensional accuracy of the section of the formed ring piece, the height h of the upper step of the ring piece is determined₁Height h of the groove_gAnd lower step height h₂Can determine the height h of the upper cavity of the main roller_m1Height h of boss_mgHeight h of lower cavity_m2And core roller cavity height h_iIs composed of

h_m1＝h₁+0.3～0.5mm，h_mg＝h_g，h_m2＝h₂+0.3～0.5mm，h_i＝h_m1+h_mg+h_m2；

In order to ensure the corresponding pass, the height of the upper side wall and the height of the lower side wall h of the main roller_mu、h_mdThe height h of the upper side wall and the lower side wall of the core roller_iu、h_idThe sizes of the components are respectively the same and can be determined according to the specific installation size of the equipment;

b) minor roll face size and position

The two auxiliary rollers are designed to be the same; the radius of the working surface of the auxiliary roller is usually determined according to the space size of equipment so as to ensure that the auxiliary roller is convenient to mount and does not interfere with other parts of the equipment, and the radius of the boss surface of the auxiliary roller is usually designed as

R_pg≈1/3～1/5R_mg

R_pgAfter the determination, the radius R of the lower cavity surface of the secondary roller can be determined according to the geometric relationship_p2＝R_pg-(D₂-D_g) /2, radius R of upper cavity surface of auxiliary roller_p1＝R_pg-(D₁-D_g)/2；

To ensure the hole pattern correspondence, the determination of the hole pattern

Width of upper cavity B of auxiliary roller_p1＝B_m1Width of lower cavity of auxiliary roller B_p2＝B_m2Height h of upper side wall of auxiliary roll_pu＝h_muHeight h of lower side wall of auxiliary roll_pd＝h_mdHeight h of upper cavity of auxiliary roller_p1＝h_m1Height h of the boss of the auxiliary roller_pg＝h_mgHeight h of lower cavity of auxiliary roller_p2＝h_m2；

After the sizes of the ring blank, the working surfaces of the main roller and the auxiliary roller are determined, the circle center positions of the left auxiliary roller and the right auxiliary roller can be determined through geometric relation drawing, and the circle center position O of the main roller at the end of rolling can be determined according to the geometric relation drawing of the outer diameter surface of the ring blank, the groove surface of the ring (namely the groove surface of a finished product) and the convex table surface of the main roller_m1And the circle center position O of the thick-wall deep groove ring piece_r1，O_mRepresenting the initial circle center position of the main roller; the boss surface of the right auxiliary roller 4 is always contacted with the ring in the whole rolling process, is contacted with the outer diameter surface of the ring blank when the rolling is started, and is contacted with the groove surface of the ring when the rolling is finished, and then the circle center position O of the ring blank is used_rIs the sum R of the circle center, the outer radius of the ring blank and the radius of the right auxiliary roller boss surface₀+R_pgMaking a circle for the radius; with O_r1Is the sum R of the circle center, the radius of the groove surface of the ring piece and the radius of the boss surface of the auxiliary roller_g+R_pgMaking a circle with a radius, wherein the intersection point of the two circles is the center O of the right auxiliary roll_pr(ii) a When the rolling of the boss surface of the left auxiliary roller 5 is finished, the boss surface of the left auxiliary roller is contacted with the groove surface of the ring piece, and the position of the circle center of the left auxiliary roller is determined by firstly determining the angle theta between the connecting line of the circle center of the left auxiliary roller and the circle center of the ring piece and the vertical line; considering the self gravity of the vertical rolling ring piece, in order to play a good role in supporting the ring piece and forming, the angle theta can be designed to be 45-60 degrees; after the theta angle is determined, drawing according to the geometric relationship to determine the circle center position O of the left auxiliary roller_pl。

(3) Design of forming parameters

The forming parameters comprise the rotating speed of a main roller, the feeding speed of the main roller and the rolling time, and are designed as follows:

a) main roll speed n_m

In order to ensure the stable rolling of the ring piece, the linear velocity V of a main roller_mUsually 1.1-1.3 m/s; according to the radius D of the working surface of the main roller_mgCan countCalculating the main roll rotation speed as n_m＝V_m/2πR_mg；

b) Main roll feed speed v

In order to ensure that the ring blank can bite into the pass formed by the main roll and the core roll and be plastically pierced to produce continuous rolling deformation, the feed speed of the main roll is usually designed according to the following formula

$v=0.1~0.2\frac{{\mathrm{\&beta;}}^2{n}_m{\mathrm{<figure-callout\; id="2"\; label="R\; mg"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_{\mathrm{mg}}^{}}{30R_0{(1+\frac{R_{\mathrm{mg}}}{R_i})}^2}(1+\frac{R_{\mathrm{mg}}}{R_i}+\frac{R_{\mathrm{mg}}}{R_0}-\frac{R_{\mathrm{mg}}}{r_0})$

Wherein r is₀＝d₀/2、R₀＝D₀The/2 is the inner radius and the outer radius of the ring part blank respectively;

c) time of rolling

The rolling process adopts uniform feeding, the rolling time T can be determined as T ═ delta h/v, wherein delta h is the total rolling feeding amount, and the rolling time T can be determined as

$\mathrm{\&Delta;h}=H_0-\frac{D_g-\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">d</figure-callout>}}{2};$

(4) Rolling and forming the ring piece: and (3) blanking and blanking according to the ring blank design, processing a main roller, a core roller, a left auxiliary roller and a right auxiliary roller according to the rolling hole pattern design, installing the main roller, the core roller, the left auxiliary roller and the right auxiliary roller in rolling equipment, putting the processed ring blank into the rolling equipment, and rolling into a ring according to the rolling parameters.

Specific example 1:

taking the dual gear shown in FIG. 1 as an embodiment, the diameter D of the step on the ring member to be roll-formed is required₁Diameter D of the groove_gLower step diameter D₂And the inner diameter d is 248mm, 258mm, 218mm and 112mm respectively, and the height h of the upper step of the ring piece₁Height h of the groove_gAnd lower step height h₂Respectively 11mm, 28mm and 11mm, and the design method of the composite rolling forming process comprises the following steps:

(1) blank making

The ring blank is shaped asAccording to the ring blank size design method, the rolling ratio k is 1.3, and the outer diameter D of the ring blank for rolling is designed according to the rectangular section ring shown in figure 3₀Inner diameter d₀And height h₀222.86mm, 86.15mm and 50mm respectively. Uniformly heating a bar section (specifically GCr15 steel) from room temperature to a high-plasticity low-resistance thermal deformation temperature (1100-1200 ℃) according to the size of the ring blank, upsetting, punching and connecting a skin of the hot bar section, and performing stress relief annealing to prepare the ring blank for rolling;

(2) design of rolling pass

a) Main roll and core roll face size

Designing the structure of the main roll according to the design principle and design method of the size of the main roll and the core roll as shown in FIG. 4(a), the radius R of the lower cavity surface of the main roll_m2Upper cavity surface radius R_m1And the radius R of the boss surface_mg152.5mm, 157.5mm and 172.5mm respectively, and the widths B of the upper and lower cavities of the main roller_m1And B_m221mm and 26mm respectively, and the height h of the upper cavity of the main roller_m1Height h of boss_mgAnd lower cavity height h_m211.5mm, 28mm and 11.5mm respectively; the core roll was designed to have a working surface radius R as shown in FIG. 4(b)_iIs 40mm and the width B of the cavity_iIs 26mm and the height h of the cavity_iIs 51 mm.

b) Minor roll face size and position

Designing the structure of the auxiliary roll according to the size design method of the working surface of the auxiliary roll is shown in figure 4(c), and the diameter R of the convex table surface of the auxiliary roll_pgUpper cavity surface radius R_p1Radius R of lower cavity surface_p2Respectively 55mm, 40mm and 35mm, and the widths B of the upper and lower cavities_p1And B_p221mm and 26mm respectively, and the height h of the upper cavity_p1Height h of boss_pgAnd lower cavity height h_p211.5mm, 28mm and 11.5mm respectively. According to the determined sizes, the included angle theta of the left auxiliary roller is designed to be 60 degrees, and the circle center positions of the left and right auxiliary rollers can be determined by drawing according to the geometrical relationship shown in the figure 5.

(3) Design of forming parameters

a) Main roll speed n_m

Linear velocity V of the main roller_mTaking 1.3m/s, and determining the rotating speed n of the main roller according to a main roller rotating speed design formula_mIs 72 r/min.

b) Main roll feed speed v

And determining the feeding speed of the main roller to be 1mm/s according to a main roller rotating speed design formula.

c) Rolling time T

The total rolling feed delta h is 15.35mm, and the rolling time T is determined to be 15.35s according to a rolling time design formula.

(4) Rolling and forming the ring piece: blanking and making blanks according to the ring blank design, designing and processing a roller according to the rolling hole pattern, installing the roller in rolling equipment, putting the processed ring blank into the rolling equipment, and rolling the ring blank into the duplex gear shown in the figure 1 according to the rolling parameters.

The yield of 100 duplicate gears produced by the method can be improved to 99% from 95%. The rolling process can be stably carried out and the ring can be normally formed.

The rolling forming process of the mechanical parts such as the double-sided flange, the double-sided thrust wheel body or the high-pressure ball valve body is the same as the above example, and the effects are also the same, and the embodiments are not listed here.

The upper and lower limit values of each process parameter and the interval value thereof can realize the invention, and the embodiments are not listed.

Claims (1)

1. The composite rolling forming process of the thick-wall deep-groove ring piece is characterized by comprising the following steps of:

(1) blank preparation: uniformly heating the bar section from room temperature to thermal deformation temperature, then upsetting, punching and connecting skin on the hot bar section, and performing stress relief annealing to prepare a ring blank for rolling;

the ring blank is designed into a rectangular section, and the ring blank size design process is as follows:

a) calculating ring volume

Respectively the diameter of the upper step, the diameter of the groove, the diameter of the lower step and the inner diameter of the ring piece,

respectively the height of the upper step, the height of the groove and the height of the lower step of the ring piece;

b) determination of the Rolling ratio

Rolling ratioThe ratio of the inner diameter of the ring to the inner diameter of the ring blank, i.e.

WhereinThe inner diameter of the ring blank;

taking 1.2-1.5;

c) determining ring blank height

By means of closuresPass rolling, ring-taking blank height

Height to ring

The phase of the two phases is equal to each other,

；

d) determining the inner diameter of a ring blank

And the outer diameter of the ring blank

Based on the principle of unchanged volume of plastic deformation according to the rolling ratio

And ring blank height

Determining the inner diameter of the ring blankAnd outer diameter

Is composed of

，

；

(2) Design of rolling pass

The thick-wall deep groove ring piece composite rolling pass comprises a ring piece rolling stage and a three-roller cross rolling stage, wherein the ring piece rolling stage is a pass formed by a main roller and a core roller, and the three-roller cross rolling stage is a pass formed by the main roller and two auxiliary rollers; rolling pass in the ring rolling stage and the three-roller cross rolling stage are designed into closed pass; the working surface cavities of the main roller and the two auxiliary rollers correspond to the cross section of the ring piece in shape, and the working surface of the core roller is a cylindrical surface; the main roll and core roll dimensions are designed as follows:

a) main roll and core roll face size

The size of the main roller and the core roller is designed to meet the following conditions

Radius of working surface of main roll and core roll

And

the following formula should be satisfied,

in the formula,

is the radius of the lower cavity surface of the main roller,the radius of the working surface of the core roll;

in order to be the angle of friction,

for the coefficient of friction, for a steel ring,

usually, the concentration is 0.3 to 0.35,

，H ₀the wall thickness of the ring blank;

② the radius of the working surface of the core roller is designed as

-3～5mm；

Thirdly, according to the structural requirements of the ring rolling mill, the closed center distance between the main roller and the core roller is within the range of the limit closed center distance of the ring rolling mill; the minimum width of the cavity when the main roll and the core roll are closed should not exceed the maximum wall thickness of the ring, and is usually determined as

，

-1～2mm；

In the formula,and

maximum and minimum closing center distances allowed by the ring rolling mill;

is the width of a lower cavity of the main roller,the width of the core roller cavity;

maximum wall thickness of the ring;

determining according to the conditions

、、

、

Then, further determining the radius of the upper cavity surface of the main roller according to the geometric relationship

Radius of boss surface

And upper cavity width

As follows

，

，

According to the height of the upper step of the ring

Height of the groove

And lower step heightDegree of rotation

Determining the height of the upper cavity of the main roll

Height of boss

Height of lower cavityAnd core roller cavity height

Is composed of

+0.3～0.5mm，

，+0.3～0.5mm，

；

The height of the upper side wall and the height of the lower side wall of the main roller

The height of the upper side wall and the height of the lower side wall of the core roller

Respectively identical;

b) minor roll face size and position

The two auxiliary rollers are designed to be the same; the radius of the working surface of the auxiliary roller is determined according to the space size of the equipment so as to ensure that the auxiliary roller is convenient to install and does not interfere with other parts of the equipment, and the radius of the boss surface of the auxiliary roller is designed to be

1/3～1/5

After the determination, determining the radius of the lower cavity surface of the secondary roller according to the geometric relationship

Radius of upper cavity surface of auxiliary roll；

Width of upper cavity of auxiliary roller

Width of lower cavity of auxiliary rollHeight of side wall on auxiliary rollHeight of lower side wall of auxiliary roll

Height of upper cavity of auxiliary roller

Height of the boss of the auxiliary rollerHeight of lower cavity of auxiliary roller

；

After the sizes of the ring blank, the working surfaces of the main roller and the auxiliary roller are determined, the circle center positions of the left auxiliary roller and the right auxiliary roller are determined through geometric relation drawing, and the circle center position of the main roller at the end of rolling is determined according to the geometric relation drawing of the outer diameter surface of the ring blank, the groove surface of the ring and the convex table surface of the main roller

And the circle center position of the thick-wall deep-groove ring piece

，

Representing the initial circle center position of the main roller; the boss surface of the right auxiliary roller is always contacted with the ring in the whole rolling process, is contacted with the outer diameter surface of the ring blank when the rolling is started, and is contacted with the groove surface of the ring when the rolling is finished, and the circle center position of the ring blank is used

Is the sum of the circle center, the outer radius of the ring blank and the radius of the right auxiliary roller boss surface

Making a circle for the radius; to be provided with

Is the sum of the circle center, the radius of the groove surface of the ring piece and the radius of the boss surface of the auxiliary roller

Making a circle with a radius, wherein the intersection point of the two circles is the center of the right auxiliary roll

(ii) a When the rolling of the boss surface of the left auxiliary roller 5 is finished, the boss surface is contacted with the groove surface of the ring piece, and the circle center position of the left auxiliary roller is determined by firstly determining the circle center of the left auxiliary roller and the included angle between the connecting line of the circle centers of the ring piece and the vertical line

；

The angle is 45 degrees to 60 degrees;

after the angle is determined, drawing according to the geometric relationship to determine the position of the circle center of the left auxiliary roller

；

(3) Design of forming parameters

The forming parameters comprise the rotating speed of a main roller, the feeding speed of the main roller and the rolling time, and are designed as follows:

a) main roll speed

Linear speed of main roll

Taking 1.1-1.3 m/s; according to the radius of the convex table surface of the main roller

Calculating the rotation speed of the main roll to；

b) Main roll feed speed

The main roller feed speed is designed according to the following formula

0.1～0.2

Wherein,、

respectively the inner radius and the outer radius of the ring blank;

c) time of rolling

The rolling process adopts uniform feeding and rolling time

Is determined as

Wherein

For rolling the total feed is determined according to the geometrical relationship

；

(4) Rolling and forming the ring piece: and (3) processing a main roller, a core roller, a left auxiliary roller and a right auxiliary roller according to the rolling hole pattern design, installing the main roller, the core roller, the left auxiliary roller and the right auxiliary roller in rolling equipment, putting the processed ring blank into the rolling equipment, and rolling the ring blank into a ring according to the rolling parameters.

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