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

Abstract

The present invention relates to a thick-walled deep-groove ring compound rolling forming process, which is characterized in that it includes the following contents: (1) Ring blank design: based on the principle of constant volume, determine the ring size and rolling ratio according to the ring size and rolling ratio. (2) pass design: firstly design the working surface size of the main roll and core roll according to the ring rolling deformation conditions and equipment structure requirements, and then determine the working surface size of the auxiliary roll according to the size of the ring blank, ring and main roll. Surface size and position; (3) Forming parameter design: According to the ring rolling deformation conditions and main roll size, the main roll speed, main roll feed speed and rolling time are sequentially designed; (4) Roll forming. Through the present invention, it is possible to realize the rational design of the compound rolling forming process of the thick-walled deep-groove ring, ensure the normal and stable rolling-forming of the thick-walled deep-groove ring, reduce the rolling waste and defective product rate, and realize the duplex gear and double-sided method High-quality and efficient forming and manufacturing of energy-saving and material-saving mechanical parts such as flanges, double-sided roller bodies, and high-pressure ball valve bodies.

Description

A Composite Rolling Forming Process for Thick-walled and Deep-grooved Rings

technical field

The invention relates to a compound rolling forming process of a thick-walled deep-groove ring.

Background technique

The geometric characteristics of the ring shown in Figure 1 are thick wall (the wall thickness is usually greater than the radius of the inner hole), small hole diameter, and deep grooves on the surface (the groove depth usually accounts for more than a quarter of the wall thickness), which is called a thick-walled deep groove ring. Parts (referred to as rings in the present invention). Duplex gears, double-sided flanges, double-sided roller bodies, high-pressure ball valve bodies and other mechanical parts commonly used in engineering are all such rings. The deep grooves on the surface of such rings are difficult to form directly by die forging. Usually, die forging is used for simple forming first, and then cut to the finished product size. This processing technology has high energy consumption and low material utilization rate. The subsequent cutting process not only consumes man-hours but also cuts off the metal fiber streamline of the ring, resulting in low production efficiency and poor product performance.

Ring compound rolling is a new plastic processing method for forming thick-walled deep groove rings through continuous rotary plastic deformation. Its principle is shown in Figure 2. In Fig. 2, the main roll 1 performs active rotary motion and downward linear feed motion at the same time, the core roll 2, the right auxiliary roll 4, and the left auxiliary roll 5 are idling rolls, which are driven by the ring to perform passive rotational motion. The entire deformation process It can be divided into two stages: (a) ~ (b) is the ring rolling stage, the main roll 1, the core roll 2, the right auxiliary roll 4 and the ring blank 3 constitute a common ring rolling deformation mode, and the ring blank Continuous local plastic deformation occurs in the pass formed by the main roll 1 and the core roll 2 to reduce the wall thickness and expand the diameter. The right auxiliary roll 4 ensures the stability of the deformation process of the ring. (b)-(c) is the stage of three-roll cross rolling: when the outer diameter of the ring blank is expanded to contact with the left auxiliary roll 5, the main roll 1, the right auxiliary roll 4, the left auxiliary roll 5 and the ring blank 3 form three Roller cross-rolling deformation mode, the three-point rotating rolling of the main roll 1, the right auxiliary roll 4, and the left auxiliary roll 5 on the ring blank limits its diameter expansion, forcing the metal on the surface of the ring blank to fill the roll cavity. Continuous local plastic deformation occurs in the pass formed by main roll 1, right auxiliary roll 4, and left auxiliary roll 5 to form grooves. When the blank metal of the ring fills the cavity of the roll, the grooves are completely formed and the entire deformation process ends. Through the combination of ordinary ring rolling deformation and three-roll cross rolling deformation, ring composite rolling can obtain precise outer diameter size and surface deep groove at the same time, breaking through the ordinary ring rolling method which is only suitable for simple cross-sectional shapes. It has many technical and economic advantages such as low energy consumption, high material utilization rate, high production efficiency, and good product quality. However, compound rolling forming of rings is a complex deformation process with many process parameters, each parameter has different and mutual influence on rolling deformation, and various rolling defects are prone to occur during rolling, resulting in waste and defective products. Therefore, reasonable process parameter design is very important for the normal and stable rolling forming of thick-walled deep-groove rings.

Contents of the invention

The purpose of the present invention is to provide a composite rolling forming process for thick-walled and deep-groove rings, which can ensure the stable rolling process and normal ring forming, and can effectively reduce the waste and defective rate of rolled rings.

In order to achieve the above object, the technical solution of the present invention is: a thick-walled deep groove ring compound rolling forming process, which is characterized in that it includes the following steps:

(1) Billet making: uniformly heat the bar section from room temperature to the thermal deformation temperature, then upsetting, punching, punching and skinning the hot bar section, and annealing for stress relief to make a ring blank for rolling ;

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

a) Calculate the ring volume V

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ]</span>$

D ₁ , D _g , D ₂ , d are the upper step diameter, groove diameter, lower step diameter and inner diameter of the ring respectively, h ₁ , h _g , h ₂ are the ring upper step height, groove height and lower step height high;

b) Determine 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, that is, k=d/d ₀ , where d ₀ is the inner diameter of the ring blank; the rolling ratio reflects the degree of deformation of the ring blank, and the greater the rolling ratio, The greater the deformation of the ring blank; because the thick-walled deep-groove ring has a large wall thickness and a small inner diameter, if k is larger, the ring blank has a larger wall thickness and a smaller inner diameter, and the cross-section of the ring blank is not easy to be plastically worn during rolling. and the smaller the diameter of the core roll penetrating into the ring blank, the lower the strength; therefore, in order to make the ring blank produce uniform plastic deformation while ensuring the strength of the core roll and preventing its rolling fracture, k is taken as 1.2～1.5 is more suitable;

c) Determine the ring blank height h ₀

Closed pass rolling is adopted, and the height h ₀ of the ring blank is equal to the height h of the ring, h=h ₁ +h _g +h ₂ ;

d) Determine the inner diameter d ₀ of the ring blank and the outer diameter D ₀ of the ring blank

Based on the principle of constant volume of plastic deformation, according to the rolling ratio k and the height h ₀ of the ring blank, the inner diameter d ₀ and outer diameter D ₀ of the ring blank can be determined as

d ₀ =d/k,

${\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\sqrt{\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="h"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="k"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">k</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; ;</span>$

(2) Rolling pass design

The thick-walled deep groove ring compound rolling pass includes rolling ring rolling stage and three-roll cross rolling stage. The ring rolling stage is composed of main roll and core roll. The three-roll cross rolling stage consists The pass formed by the main roll and two auxiliary rolls; in order to prevent the end surface of the ring blank from being sunken due to the axial metal flow during the rolling process, the two-stage rolling pass is designed as a closed pass; the main roll and the two The cavity of the working surface of the auxiliary roll corresponds to the cross-sectional shape of the ring, and the working surface of the core roll is a cylindrical surface; the size of the roll is designed as follows:

a) Dimensions of working surface of main roll and mandrel roll

The size design of the main roll and core roll should meet the following conditions

①In order to enable the ring blank to bite into the pass formed by the main roll and core roll during rolling and be plastically penetrated to produce continuous rolling deformation, the minimum working surface radius R _m2 and R of the main roll and core roll _i should satisfy the following formula,

$\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout></span><figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; \&le;</span>\frac{\mathrm{<span\; class="notranslate">\; 17.5</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="h"\; filenames="HDA0000099595970000031.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}$

In the formula, R _m2 is the radius of the lower cavity surface of the main roll (i.e. the minimum working surface radius of the main roll), R _i is the working surface radius of the core roll; β=arctan μ is the friction angle, μ is the friction coefficient, and for steel rings, μ Usually take 0.3～0.35, H ₀ =(D ₀ -d ₀ )/2, H ₀ is the wall thickness of the ring blank;

②In order to ensure the strength of the core roll and to smoothly penetrate the ring blank, the diameter of the core roll working surface is generally designed as

R _i ＝d ₀ /2-3～5mm;

③According to the structural requirements of the ring rolling machine, the closed center distance between the main roll and the core roll should be within the range of the limit closed center distance of the ring rolling machine; the minimum cavity width (B _m2 and B _i ) when the main roll and the core roll are closed should exceed the maximum wall thickness of the ring, usually specified as

$R_{m2}+R_i+B_{m2}+B_i=\frac{L_{\max }+{\mathrm{<figure-callout\; id="2"\; label="L\; min"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">L</figure-callout>}}_{\min }}{2},$ B _m2 +B _i =H ₂ -1~2mm;

In the formula, L _max and L _min are the maximum and minimum closed center distances allowed by the ring rolling machine; B _m2 is the cavity width under the main roll, and B _i is the cavity width of the core roll; H ₂ =(D ₂ -d)/ 2 is the maximum wall thickness of the ring;

After determining R _m2 , R _i , R _m2 , _{and Bi} according to the conditions ①, ②, and ③, the radius R _m1 of the upper cavity surface of the main roll, the radius R _mg of the boss surface and the width B _m1 of the upper cavity of the main roll can be further determined according to the geometric relationship as follows

R _m1 =R _m2 +(D ₂ -D ₁ )/2, R _mg =R _m2 +(D ₂ -D _g )/2, B _m1 =B _m2 -(D ₂ -D ₁ )/2

In order to ensure the dimensional accuracy of the forming ring section, the height h _{m1 of the upper cavity of the main roll, the height of the boss h mg and the height of the lower cavity can be determined according to the height of the upper step h 1 ,} the height of the groove h _g and the height of the lower step h ₂ of the _ring h _m2 and core roll cavity height h _i are

h _m1 ＝h ₁ +0.3～0.5mm, h _mg ＝h _g , h _m2 ＝h ₂ +0.3～0.5mm, h _i ＝h _m1 +h _mg +h _m2 ;

In order to ensure the corresponding pass type, the height of the upper side wall, the height of the lower side wall h _mu , h _md of the main roll is the same as the height of the upper side wall, the height of the lower side wall h _iu , h _id of the core roll respectively, and the size can be determined according to the specific installation size of the equipment Sure;

b) Dimensions and positions of the auxiliary roll working face

The two auxiliary rolls are designed to be the same; the radius of the working surface of the auxiliary roll is usually determined according to the size of the equipment space to ensure that the auxiliary roll is easy to install and does not interfere with other parts of the equipment. Usually, the radius of the convex table surface of the auxiliary roll is designed as

R _pg ≈1/3～1/5R _mg

After R _pg is determined, according to the geometric relationship, it can be determined that the radius of the lower cavity surface of the auxiliary roll R _p2 = R _pg -(D ₂ -D _g )/2, and the radius of the upper cavity surface of the auxiliary roll R _p1 = R _pg -(D ₁ - D _g )/2;

In order to ensure that the hole type corresponds, it can be determined

The width of the upper cavity of the auxiliary roll B _p1 = B _m1 , the width of the lower cavity of the auxiliary roll B _p2 = B _m2 , the height of the upper side wall of the auxiliary roll h _pu = h _mu , the height of the lower side wall of the auxiliary roll h _pd = h _md , the auxiliary roll The height of the upper cavity h _p1 = h _m1 , the height of the boss of the auxiliary roll h _pg = h _mg , the height of the lower cavity of the auxiliary roll h _p2 = h _m2 ;

After the dimensions of the ring blank, the main roll and the working surface of the auxiliary roll are determined, the center positions of the left auxiliary roll and the right auxiliary roll can be determined by drawing the geometric relationship. The groove surface of the finished product) and the geometric relationship of the main roll boss surface can be determined by drawing the center position O _m1 of the main roll and the center position O _r1 of the thick-walled deep groove ring at the end of rolling, and O _m represents the initial center position of the main roll; The convex table surface of roll 4 is always in contact with the ring during the whole rolling process. It contacts with the outer diameter surface of the ring blank at the beginning of rolling, and contacts with the groove surface of the ring at the end of rolling. _r is the center of the circle, the sum of the outer radius of the ring blank and the radius of the convex surface of the right auxiliary roll R ₀ + R _pg is the radius to make a circle; take O _r1 as the center of the circle, the sum of the radius of the groove surface of the ring and the radius of the convex surface of the auxiliary roll R _g +R _pg is a circle with a radius, and the intersection point of the two circles is the center O _pr of the right auxiliary roll; when the rolling of the 5 convex table surfaces of the left auxiliary roll is in contact with the groove surface of the ring, the position of the center of the left auxiliary roll needs to be determined first The angle θ between the center of the circle and the center of the ring and the vertical line; considering the gravity of the vertical rolling ring itself, in order to better support the ring and form it, the angle θ can be designed as 45°~60°; After the θ angle is determined, the position O _pl of the center of the left auxiliary roll can be determined by drawing a graph according to the geometric relationship.

(3) Forming parameter design

The forming parameters include main roll speed, main roll feed speed, and rolling time, which are designed as follows:

a) Main roll speed n _m

In order to ensure stable rolling of the ring, the main roll line speed V _m is usually set at 1.1~1.3m/s; according to the main roll face radius D _mg , the main roll speed can be calculated 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 core roll and be plastically penetrated to produce continuous rolling deformation, the feed speed of the main roll is usually designed according to the following formula

$\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 0.2</span>}\frac{{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m\; R\; mg"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">m</figure-callout></span><figure-callout\; id="2"\; label="m\; R\; mg"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">\; </figure-callout>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{}^{}{\mathrm{<span\; class="notranslate">\; mg</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{}}{\mathrm{<span\; class="notranslate">\; 30</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>$

Among them, r ₀ =d ₀ /2, R ₀ =D ₀ /2 are the inner radius and outer radius of the ring blank respectively;

c) Rolling time

The rolling process adopts uniform feed, and the rolling time T can be determined as T=Δh/v, where Δh is the total rolling feed, which can be determined according to the geometric relationship as

$\mathrm{<span\; class="notranslate">\; \&Delta;h</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="d"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">d</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ;</span>$

(4) Ring rolling forming: According to the design of the above-mentioned ring blank, blanking is made, and the main roll, core roll, left auxiliary roll and right auxiliary roll are processed according to the above-mentioned rolling pass design, and the main roll, core roll, The left auxiliary roll and the right auxiliary roll are installed in the rolling equipment, and the processed ring blanks are put into the rolling equipment, and rolled into rings according to the above rolling parameters.

Ring compound rolling forming is a new method of rotary plastic processing of thick-walled and deep-grooved rings, which has the advantages of energy saving, material saving, high efficiency and high quality. It can realize high-quality and high-efficiency forming and manufacturing of energy-saving and material-saving mechanical parts such as duplex gears, double-sided flanges, double-sided roller bodies, and high-pressure ball valve bodies.

The beneficial effects of the present invention are: adopting the thick-walled deep-groove ring compound rolling process of the present invention can realize the reasonable design of thick-walled deep-groove ring compound rolling process parameters, ensure the stable rolling process and the normal forming of the ring, effectively The waste and defective rate of rolled ring parts are reduced.

Description of drawings

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

Fig. 2 is a schematic diagram of compound rolling forming of thick-walled deep-groove ring;

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

Fig. 3 is a schematic cross-sectional view of a ring blank for composite rolling of a thick-walled deep groove ring;

Fig. 4 (a) is the structural representation of main roll;

Fig. 4 (b) is the structural representation of core roller;

Fig. 4 (c) is the structural representation of auxiliary roll (right auxiliary roll, left auxiliary roll);

Fig. 5 is a schematic diagram of determining the positions of the right auxiliary roll 4 and the left auxiliary roll 5.

Detailed ways

A composite rolling forming process for a thick-walled deep-groove ring, which comprises the following steps:

(1) Billet making: uniformly heat the bar section from room temperature to the thermal deformation temperature, then upsetting, punching, punching and skinning the hot bar section, and annealing for stress relief to make a ring blank for rolling ;

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

a) Calculate the ring volume V

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ]</span>$

D ₁ , D _g , D ₂ , d are the upper step diameter, groove diameter, lower step diameter and inner diameter of the ring respectively, h ₁ , h _g , h ₂ are the ring upper step height, groove height and lower step height high;

b) Determine 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, that is, k=d/d ₀ , where d ₀ is the inner diameter of the ring blank; the rolling ratio reflects the degree of deformation of the ring blank, and the greater the rolling ratio, The greater the deformation of the ring blank; because the thick-walled deep-groove ring has a large wall thickness and a small inner diameter, if k is larger, the ring blank has a larger wall thickness and a smaller inner diameter, and the cross-section of the ring blank is not easy to be plastically worn during rolling. and the smaller the diameter of the core roll penetrating into the ring blank, the lower the strength; therefore, in order to make the ring blank produce uniform plastic deformation while ensuring the strength of the core roll and preventing its rolling fracture, k is taken as 1.2～1.5 is more suitable;

c) Determine the ring blank height h ₀

Closed pass rolling is adopted, and the height h ₀ of the ring blank is equal to the height h of the ring, h=h ₁ +h _g +h ₂ ;

d) Determine the inner diameter d ₀ of the ring blank and the outer diameter D ₀ of the ring blank

Based on the principle of constant volume of plastic deformation, according to the rolling ratio k and the height h ₀ of the ring blank, the inner diameter d ₀ and outer diameter D ₀ of the ring blank can be determined as

d ₀ =d/k,

${\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\sqrt{\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="h"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="k"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">k</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; ;</span>$

(2) Rolling pass design

The thick-walled deep groove ring compound rolling pass includes rolling ring rolling stage and three-roll cross rolling stage. The ring rolling stage is composed of main roll and core roll. The three-roll cross rolling stage consists The pass formed by the main roll and two auxiliary rolls; in order to prevent the end surface of the ring blank from being sunken due to the axial metal flow during the rolling process, the two-stage rolling pass is designed as a closed pass; the main roll and the two The cavity of the working surface of the auxiliary roll corresponds to the cross-sectional shape of the ring, and the working surface of the core roll is a cylindrical surface; the size of the roll is designed as follows:

a) Dimensions of working surface of main roll and mandrel roll

The size design of the main roll and core roll should meet the following conditions

①In order to enable the ring blank to bite into the pass formed by the main roll and core roll during rolling and be plastically penetrated to produce continuous rolling deformation, the minimum working surface radius R _m2 and R of the main roll and core roll _i should satisfy the following formula,

$\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout></span><figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; \&le;</span>\frac{\mathrm{<span\; class="notranslate">\; 17.5</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="h"\; filenames="HDA0000099595970000031.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}$

In the formula, R _m2 is the radius of the lower cavity surface of the main roll (i.e. the minimum working surface radius of the main roll), R _i is the working surface radius of the core roll; β=arctan μ is the friction angle, μ is the friction coefficient, and for steel rings, μ Usually take 0.3～0.35, H ₀ =(D ₀ -d ₀ )/2, H ₀ is the wall thickness of the ring blank;

②In order to ensure the strength of the core roll and can smoothly penetrate into the ring blank, the diameter of the working surface of the core roll is generally designed as R _i =d ₀ /2-3~5mm;

③According to the structural requirements of the ring rolling machine, the closed center distance between the main roll and the core roll should be within the range of the limit closed center distance of the ring rolling machine; the minimum cavity width (B _m2 and B _i ) when the main roll and the core roll are closed should exceed the maximum wall thickness of the ring, usually specified as

${\mathrm{<figure-callout\; id="2"\; label="R\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_m+R_i+{\mathrm{<figure-callout\; id="2"\; label="B\; m"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">B</figure-callout>}}_m+B_i=\frac{L_{\max }+{\mathrm{<figure-callout\; id="2"\; label="L\; min"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">L</figure-callout>}}_{\min }}{2},$ B _m2 +B _i =H ₂ -1~2mm;

In the formula, L _max and L _min are the maximum and minimum closed center distances allowed by the ring rolling machine; B _m2 is the cavity width under the main roll, and B _i is the cavity width of the core roll; H ₂ =(D ₂ -d)/ 2 is the maximum wall thickness of the ring;

After determining R _m2 , R _i , B _m2 , _{and Bi} according to the conditions ①, ②, and ③, the radius R _m1 of the upper cavity surface of the main roll, the radius R _mg of the boss surface and the width B _m1 of the upper cavity of the main roll can be further determined according to the geometric relationship as follows

R _m1 =R _m2 +(D ₂ -D ₁ )/2, R _mg =R _m2 +(D ₂ -D _g )/2, B _m1 =B _m2 -(D ₂ -D ₁ )/2

In order to ensure the dimensional accuracy of the forming ring section, the height h _{m1 of the upper cavity of the main roll, the height of the boss h mg and the height of the lower cavity can be determined according to the height of the upper step h 1 ,} the height of the groove h _g and the height of the lower step h ₂ of the _ring h _m2 and core roll cavity height h _i are

h _m1 ＝h ₁ +0.3～0.5mm, h _mg ＝h _g , h _m2 ＝h ₂ +0.3～0.5mm, h _i ＝h _m1 +h _mg +h _m2 ;

In order to ensure the corresponding pass type, the height of the upper side wall, the height of the lower side wall h _mu , h _md of the main roll is the same as the height of the upper side wall, the height of the lower side wall h _iu , h _id of the core roll respectively, and the size can be determined according to the specific installation size of the equipment Sure;

b) Dimensions and positions of the auxiliary roll working face

The two auxiliary rolls are designed to be the same; the radius of the working surface of the auxiliary roll is usually determined according to the size of the equipment space to ensure that the auxiliary roll is easy to install and does not interfere with other parts of the equipment. Usually, the radius of the convex table surface of the auxiliary roll is designed as

R _pg ≈1/3～1/5R _mg

After R _pg is determined, according to the geometric relationship, it can be determined that the radius of the lower cavity surface of the auxiliary roll R _p2 = R _pg -(D ₂ -D _g )/2, and the radius of the upper cavity surface of the auxiliary roll R _p1 = R _pg -(D ₁ - D _g )/2;

In order to ensure that the hole type corresponds, it can be determined

The width of the upper cavity of the auxiliary roll B _p1 = B _m1 , the width of the lower cavity of the auxiliary roll B _p2 = B _m2 , the height of the upper side wall of the auxiliary roll h _pu = h _mu , the height of the lower side wall of the auxiliary roll h _pd = h _md , the auxiliary roll The height of the upper cavity h _p1 = h _m1 , the height of the boss of the auxiliary roll h _pg = h _mg , the height of the lower cavity of the auxiliary roll h _p2 = h _m2 ;

After the dimensions of the ring blank, the main roll and the working surface of the auxiliary roll are determined, the center positions of the left auxiliary roll and the right auxiliary roll can be determined by drawing the geometric relationship. The groove surface of the finished product) and the geometric relationship of the main roll boss surface can be determined by drawing the center position O _m1 of the main roll and the center position O _r1 of the thick-walled deep groove ring at the end of rolling, and O _m represents the initial center position of the main roll; The convex table surface of roll 4 is always in contact with the ring during the whole rolling process. It contacts with the outer diameter surface of the ring blank at the beginning of rolling, and contacts with the groove surface of the ring at the end of rolling. _r is the center of the circle, the sum of the outer radius of the ring blank and the radius of the convex surface of the right auxiliary roll R ₀ + R _pg is the radius to make a circle; take O _r1 as the center of the circle, the sum of the radius of the groove surface of the ring and the radius of the convex surface of the auxiliary roll R _g +R _pg is a circle with a radius, and the intersection point of the two circles is the center O _pr of the right auxiliary roll; when the rolling of the 5 convex table surfaces of the left auxiliary roll is in contact with the groove surface of the ring, the position of the center of the left auxiliary roll needs to be determined first The angle θ between the center of the circle and the center of the ring and the vertical line; considering the gravity of the vertical rolling ring itself, in order to better support the ring and form it, the angle θ can be designed as 45°~60°; After the θ angle is determined, the position O _pl of the center of the left auxiliary roll can be determined by drawing a graph according to the geometric relationship.

(3) Forming parameter design

The forming parameters include main roll speed, main roll feed speed, and rolling time, which are designed as follows:

a) Main roll speed n _m

In order to ensure stable rolling of the ring, the main roll line speed V _m is usually set at 1.1~1.3m/s; according to the main roll face radius D _mg , the main roll speed can be calculated 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 core roll and be plastically penetrated to produce continuous rolling deformation, the feed speed of the main roll is usually designed according to the following formula

$\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 0.2</span>}\frac{{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m\; R\; mg"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">m</figure-callout></span><figure-callout\; id="2"\; label="m\; R\; mg"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">\; </figure-callout>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{}^{}{\mathrm{<span\; class="notranslate">\; mg</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{}}{\mathrm{<span\; class="notranslate">\; 30</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; mg</span>}}}{{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>$

Among them, r ₀ =d ₀ /2, R ₀ =D ₀ /2 are the inner radius and outer radius of the ring blank respectively;

c) Rolling time

The rolling process adopts uniform feed, and the rolling time T can be determined as T=Δh/v, where Δh is the total rolling feed, which can be determined according to the geometric relationship as

$\mathrm{<span\; class="notranslate">\; \&Delta;h</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="d"\; filenames="HDA0000099595970000012.png"\; state="\{\{state\}\}">d</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ;</span>$

(4) Ring rolling forming: According to the design of the above-mentioned ring blank, blanking is made, and the main roll, core roll, left auxiliary roll and right auxiliary roll are processed according to the above-mentioned rolling pass design, and the main roll, core roll, The left auxiliary roll and the right auxiliary roll are installed in the rolling equipment, and the processed ring blanks are put into the rolling equipment, and rolled into rings according to the above rolling parameters.

Specific embodiment 1:

Taking the duplex gear shown in Figure 1 as a specific example, it is required that the upper step diameter D ₁ , the groove diameter D _g , the lower step diameter D ₂ and the inner diameter d of the rolled ring are 248mm, 258mm, 218mm and 112mm respectively. The upper step height h ₁ , the groove height h _g and the lower step height h ₂ of the ring are 11mm, 28mm and 11mm respectively, and the design method of the compound rolling forming process includes the following steps:

(1) Billet making

The shape of the ring blank is a rectangular cross-section ring as shown in Figure 3. According to the design method of the ring blank size, the rolling ratio k is taken as 1.3, and the outer diameter D ₀ , inner diameter d ₀ and height h ₀ of the designed rolling ring blank are respectively 222.86mm, 86.15mm and 50mm. According to the size of the designed ring blank, the bar section (the specific material is GCr15 steel) is evenly heated from room temperature to the heat distortion temperature (1100-1200°C) with high plasticity and low resistance, and then the hot bar section is upset , punching, punching, and stress relief annealing to make ring blanks for rolling;

(2) Rolling pass design

a) Dimensions of working surface of main roll and mandrel roll

According to the principle and method of dimension design of _the main roll and _mandrel roll, _the structure of the designed main roll is shown in Fig. 4(a). are 152.5mm, 157.5mm and 172.5mm, the upper and lower cavity widths B _m1 and B _m2 of the main roll are 21mm and 26mm respectively, the height of the upper cavity of the main roll h _m1 , the height of the boss h _mg and the height of the lower cavity h _m2 They are 11.5mm, 28mm and 11.5mm, respectively; the designed core roll structure is shown in Figure 4(b), the working surface radius R _i of the core roll is 40 mm, the cavity width B _i is 26 mm, and the cavity height h _i is 51 mm.

b) Dimensions and positions of the auxiliary roll working face

According to the size design method of the working face of the auxiliary roll, the structure of the designed auxiliary roll is shown in Figure 4(c). The diameter R _pg of the convex table of the auxiliary roll, the radius R _p1 of the upper cavity surface, and the radius R _p2 of the lower cavity surface are 55mm and 40mm respectively , 35mm, upper and lower cavity widths B _p1 and B _p2 are 21mm and 26mm respectively, upper cavity height h _p1 , boss height h _pg and lower cavity height h _p2 are 11.5mm, 28mm and 11.5mm respectively. According to the above dimensions determined, the angle θ of the left auxiliary roll is designed to be 60°, and the center positions of the left and right auxiliary rolls can be determined by drawing the geometric relationship shown in Figure 5.

(3) Forming parameter design

a) Main roll speed n _m

The line speed V _m of the main roll is 1.3m/s, and the speed n _m of the main roll is determined to be 72r/min according to the design formula of the main roll speed.

b) Main roll feed speed v

According to the main roll speed design formula, the feed speed of the main roll is determined to be 1mm/s.

c) Rolling time T

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

(4) Ring rolling forming: According to the design of the above-mentioned ring blank, the blank is made, and the roll is processed according to the above-mentioned rolling pass design, and the roll is installed in the rolling equipment, and the processed ring blank is put into the rolling mill. In the manufacturing equipment, according to the above rolling parameters, the duplex gear shown in Figure 1 is rolled.

According to the above method to produce 100 double gears, the pass rate can be increased from 95% to 99%. The rolling process can be carried out stably and the ring can be formed normally.

The rolling forming process of mechanical parts such as double-sided flanges, double-sided roller bodies or high-pressure ball valve bodies is the same as the above-mentioned examples, and the effects are also the same, so the examples are not listed one by one here.

The values of the upper and lower limits of each process parameter in the present invention, as well as the interval values thereof, can realize the present invention, and the examples are not listed here.

Claims (1)

1. A thick-walled deep groove ring compound rolling forming process is characterized in that it comprises the steps: (1) Billet making: evenly heat the bar section from room temperature to the thermal deformation temperature, then upsetting, punching, punching and skinning the hot bar section, and annealing for stress relief to make a ring blank for rolling ; The shape of the ring blank is designed as a rectangular section, and the design process of the ring blank size is as follows: a) Calculate ring volume

are the upper step diameter, the groove diameter, the lower step diameter and the inner diameter of the ring, respectively,

are the height of the upper step, the height of the groove and the height of the lower step of the ring, respectively; b) Determine the rolling ratio

Rolling ratio is the ratio of the inner diameter of the ring to the inner diameter of the ring blank, that is

,in is the inner diameter of the ring blank;

Take 1.2~1.5; c) Determine the height of the ring blank

Closed pass rolling is adopted, and the height of the ring blank is taken

with ring height

equal,

; d) Determine the inner diameter of the ring blank

and ring blank outer diameter Based on the principle of constant plastic deformation volume, according to the rolling ratio

and ring blank height

, to determine the inner diameter of the ring blank and outer diameter

for

,

; (2) Rolling pass design The thick-walled deep groove ring compound rolling pass includes rolling ring rolling stage and three-roll cross rolling stage. The ring rolling stage is composed of main roll and core roll. The three-roll cross rolling stage consists The pass formed by the main roll and two auxiliary rolls; the rolling pass of the ring rolling stage and the three-roll cross rolling stage are all designed as closed passes; the working surface cavity of the main roll and the two auxiliary rolls Corresponding to the cross-sectional shape of the workpiece, the working surface of the core roll is a cylindrical surface; the dimensions of the main roll and the core roll are designed as follows: a) Dimensions of working surface of main roll and mandrel roll The size design of the main roll and core roll should meet the following conditions ① Working face radius of main roll and core roll

and

should satisfy the following formula,

In the formula,

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

is the friction angle,

is the friction coefficient, for the steel ring,

Usually take 0.3 ~ 0.35,

, H ₀ is the wall thickness of the ring blank; ②The radius of the working surface of the core roller is designed as -3～5mm; ③According to the structural requirements of the ring rolling machine, the closed center distance between the main roll and the core roll should be within the limit closed center distance of the ring rolling machine; the minimum cavity width when the main roll and the core roll are closed should not exceed the maximum wall of the ring thick, usually ,

-1～2mm; In the formula, and

The maximum and minimum closed center distances allowed by the ring rolling machine;

The cavity width under the main roll, is the core roll cavity width;

is the maximum wall thickness of the ring; Determined according to ①, ②, ③ conditions

, ,

,

Finally, according to the geometric relationship, the radius of the upper cavity surface of the main roll is further determined

, Convex surface radius

and upper cavity width

as follows

,

,

According to the height of the step on the ring

, groove height

and step height

Determine the cavity height on the main roll

, Boss height

, lower cavity height and core roll cavity height

for

+0.3～0.5mm,

, +0.3～0.5mm,

; Main roll upper side wall height, lower side wall height

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

respectively the same; b) Dimensions and positions of the working surface of the auxiliary roll The two auxiliary rolls are designed to be the same; the radius of the working surface of the auxiliary roll is determined according to the size of the equipment space to ensure that the auxiliary roll is easy to install and does not interfere with other parts of the equipment. The radius of the convex table surface of the auxiliary roll is designed as 1/3～1/5

After determination, determine the radius of the lower cavity surface of the auxiliary roll according to the geometric relationship

, the radius of the upper cavity surface of the auxiliary roll ; Cavity width on auxiliary roll

, the cavity width under the auxiliary roll , the height of the upper side wall of the auxiliary roll , the height of the lower side wall of the auxiliary roll

, cavity height on auxiliary roll

, height of auxiliary roll boss , cavity height under the auxiliary roll

; After the dimensions of the ring blank, the main roll and the working surface of the auxiliary roll are determined, the position of the center of the left auxiliary roll and the right auxiliary roll is determined by drawing the geometric relationship. Determining the position of the center of the main roll at the end of rolling by drawing the geometric relationship of the boss surface

and the center position of the ring with thick wall and deep groove

,

Indicates the initial center position of the main roll; the convex surface of the right auxiliary roll has been in contact with the ring throughout the rolling process, contacted with the outer diameter surface of the ring blank at the beginning of rolling, and contacted with the groove surface of the ring at the end of rolling, Then take the position of the center of the ring blank

It is the sum of the center of the circle, the outer radius of the ring blank and the radius of the boss surface of the right auxiliary roll

make a circle with a radius of

is the sum of the center of the circle, the radius of the groove surface of the ring and the radius of the convex table surface of the auxiliary roll

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

;The convex table surface of the left auxiliary roll 5 is in contact with the ring groove surface at the end of rolling. To determine the center position of the left auxiliary roll, the angle between the center of the left auxiliary roll and the center of the ring and the vertical line must be determined first.

;

The angle is 45°～60°;

After the angle is determined, draw a graph according to the geometric relationship to determine the center position of the left auxiliary roll

; (3) Forming parameter design The forming parameters include main roll speed, main roll feed speed, and rolling time, which are designed as follows: a) Main roll speed Line speed of main roll

Take 1.1～1.3m/s; according to the radius of the boss surface of the main roll

, calculate the main roll speed as ; b) Main roll feed speed

The feed speed of the main roll is designed according to the following formula

0.1～0.2

in, ,

Respectively, the inner radius and outer radius of the ring blank; c) Rolling time The rolling process is fed at a constant speed, and the rolling time is

identified as

,in

is the total rolling feed rate, which is determined according to the geometric relationship as ; (4) Ring rolling forming: process the main roll, core roll, left auxiliary roll and right auxiliary roll according to the above rolling pass design, and install the main roll, core roll, left auxiliary roll and right auxiliary roll on the rolling In the equipment, put the processed ring blanks into the rolling equipment, and roll them into rings according to the above rolling parameters.

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