CN102266885A - Variable radius bending method of straight welded pipe cage forming - Google Patents

Abstract

The invention relates to a variable radius bending method of a straight welded pipe cage forming, belonging to the technical field of straight welded pipe manufacture. In the invention, longitudinal deformation form and strip steel lateral bending mode in the strip steel formation by downhill forming, and then obtaining three bends of strip steel horizontal, horizontal and vertical positions of strip steel edge, finally producing a welded pipe according to the strip steel space formation. According to the invention, a problem that the technology of the straight welded pipe cage forming mainly depends on empty bending forming in the prior art is solved and the method in the invention has the advantage of a good coincidence between section contour of the strip steel formation calculated by the variable radius bending method and the result measured by the method after production.

Description

The ERW row roller forming becomes the radius bend method

Technical field

What the present invention relates to is the method in a kind of ERW manufacturing technology field, specifically is that a kind of ERW row roller forming based on the distortion blind area becomes the radius bend method.

Background technology

ERW production generally is to adopt roll forming technology.Roll forming technology is the multi-pass forming rolls by arranged in order, metal strap is bent to gradually a kind of Technology of Plastic Processing of particular cross section from straightened condition.The structure of early stage conventional roll o ing unit is plain-barreled roll and edger roll arranged crosswise, be mainly used in the production small-diameter welded pipes, afterwards through updating, early stage shaping unit develops gradually becomes form flat, that edger roll adds the edger roll group, can produce caliber and also develop into middle diameter by minor diameter, after this in order to overcome in the conventional roll o ing edge deformation and resilience is excessive and the shortcoming of the shared property of shaping edger roll difference, and then develop and row roller forming technology.

Row roller forming is meant that the band steel is rolled into the roll forming technology of socket by some groups of passive pony roll Curved Continuous of two rows, promptly in the continuous row roller forming process of skelp, utilize the three-point bending principle, at the adjustable passive little roller frame in essence shaping one or more groups position of (closed type) preceding employing, the some active horizontal frames and the passive standing roller frame that replace common roll-type to be shaped, the band steel can be deformed into socket by designed pass schedule.The resilience of band steel is little, the edge shaping quality is good and the strong characteristics of the shared property of roll because row roller forming technology has, the roll-type shaping in a row of the not only intermediate diameters welded tube unit of the operation all row's of employing roll-type shapings mostly newly in the world, and the also all numerous and confused transformation of in the past traditional roll-type shaping unit at present.Row roller forming technology is considered to the trend of present welded tube production technology development.Typical straight welded pipe roller forming machine group model as shown in Figure 1, along band steel shaping direction, it is five parts that its formation is divided into, and is respectively to pinch passage, crimp passage, preform section, line shaped segment and smart shaped segment.The band steel enters shaped segment through pinch roll apparatus, under the effect of crimp roller, the band steel is carried out prebuckling, band steel after the crimp is further crooked in the preform section, four internal shaping top rolls of preform section make the middle part bending of band steel, the outer shaping row roller group of two groups of non-drivings makes strip edge portion continue crooked and prevents resilience, a pair of dumming depress roller (BD) makes the band steel further crooked, and for the band steel provides power, the band steel is constantly advanced forward.The line shaped segment is divided into into three son row roller sections, each son section comprises the outer shaping row roller group of two groups of non-drivings of symmetric arrangement, is arranged in the internal shaping roller of non-driving between the outer row's of shaping roller section, and the lower support roller of non-driving, during band steel process line shaped segment, bend to cylindric gradually.Smart shaped segment comprises three four-roll rack (F _P1～F _P3), the smart shaping deflector roll of centre and limit portion, the band steel becomes circle basically through cross section profile behind the smart shaped segment.

The welded tube roll forming belongs to the multi-pass continuous bend and is shaped, and the deflection distribution method of each passage has determined the space morpheme in the shaping of band steel, and is most important for forming quality.The shaping amount distribution of band steel is the direct factor that influences the strip plastic deformation pattern, obtains reasonable section flower type form in the forming technology process, is the prerequisite foundation and the elementary object of the roll forming parameter and the roller position parameter designing of all forming rolls in the row roller forming unit.Appropriate design shaping amount can effectively reduce the size of edge percentage elongation, plastic deformation and the residual stress of band steel in the forming process, thereby suppresses the generation of forming defectses such as limit wave, bulge, reduces the percent defective of product, improves band steel forming quality.As shown in Figure 2, traditional roll-type forming technology is mainly based on the press shaping die of plain-barreled roll, and row roller forming technology mainly is based on the empty o ing based on the three-point bending principle.The roll forming restraining force of press-bending distortion is strong in traditional roll forming, and real curved section is abundant, but roll pass does not have compatibility substantially.The three-point bending pattern of row roller forming more meets the characteristics of ERW distortion, can reduce edge deformation effectively, increases the shared property of roll, has satisfied the low roller consumption requirement that welded tube is produced simultaneously.Because there is essential distinction in two kinds of technologies on the shaping principle, conventional roll o ing technology deflection distribution method between the passage that generally adopts, as center curvature forming process, circumference crooked forming method, curved edge forming process, two radius bend forming processes etc. [Sun Jia. welded tube is the design of footpath passes mostly. welded tube, 2009,32 (3): 42-44; High Qing Dynasty army, Liu Fengling. medium-small diameter ERW Three Points Bending Rollers Type technology and application. welded tube, 2006,29 (3): 53-56.], the characteristics of band steel transverse curvature distortion in the row roller forming process can't be correctly reflected, straight welded pipe roller forming technology can not be applicable to effectively.Two semidiameters are bigger in two radius bend manufacturing process, stress at intersection band steel is discontinuous, and too small limit portion radius makes again and deflection unreasonable distribution in the forming process produced unnecessary stress and distortion, cause the uneven wear of band steel, produced more energy consumption.

Summary of the invention

The present invention is directed to the prior art above shortcomings, provide a kind of ERW row roller forming to become the radius bend method, solved in the prior art straight welded pipe roller forming technology based on empty o ing, row's roller is in incomplete contact condition because the band steel and the outside are shaped, cause the defective that always exists certain zone directly to contact on the band steel and form the distortion blind area, as shown in Figure 3 with forming rolls.

The present invention is achieved by the following technical solutions, linear deformation form during the present invention is shaped by the band steel that adopts the down-hill method shaping and band steel transverse curvature pattern, and according to band steel space morpheme in the forming process obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position, finally carry out the manufacturing of welded tube with this.

Described linear deformation form is meant: get quadric form along the shaping direction bottom line of going down the hill, i.e. y=lx ²+ mx+n goes down the hill to measure 0.4～1.2D, and D is the production tube diameter.

Described band steel transverse curvature pattern is meant: will be divided into the center curvature section with the transverse curvature of steel

Non-abundant bending section promptly is out of shape the blind area section

And curved edge section

Three parts, wherein:

A) center curvature section

Length determine by distortion blind area starting point, in the row roller forming process, the center curvature section Deformation rule and circumference bending method similar, as shown in Figure 4, its radius of curvature ρ _iBy infinity convergence final finished pipe radius progressively, the angle of bend θ of this section ₁Determine by the edge floor projection;

B) non-abundant bending section promptly is out of shape the blind area section Length determine jointly that by distortion blind area starting point and terminal point the scope of distortion blind area relative position is 0.47～0.73,

The angle of bend θ of section ₂It is constant,

The radius of curvature of section is 5～10 times of final finished pipe radius;

C) curved edge section

Length determine by the terminal point of distortion blind area, The angle of bend θ of section ₃Be definite value and satisfied:

The radius of curvature of section is 1～1.5 times of final finished pipe radius.

In the described forming process band steel space morpheme obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position, may further comprise the steps:

1) strip edge acies point lateral attitude in the shaping: the A point coordinates is (X on the bottom line of band steel center _a, Y _a), according to geometrical relationship obtain the edge end points the cross section coordinate (Xd Yd) can be expressed as:

$X_d=X_a+{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\sin {\mathrm{\&theta;}}_1+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})---\left(1\right)$

$Y_d=Y_a+R_1-R_1\cos {\mathrm{\&theta;}}_1+2R_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\sin ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\sin ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})---\left(2\right)$

Wherein: θ ₂For non-abundant bending section promptly is out of shape the blind area section

Angle of bend and be constant, θ ₃Be the curved edge section

Angle of bend and be constant, R ₁, θ ₁Be amount to be determined, distortion blind area radius of curvature R ₂=(5～10) R,

Curved edge angle θ ₃=25～45.,

A is the initial relative position of distortion blind area, and b is the end relative position of distortion blind area, and l is a strip width, and R is the welded tube radius;

2) adopt the monobasic cubic curve to realize longitudinal projection's morpheme of strip edge edge in the forming process:

$X_i=A{\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+B{\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+C\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)+D---\left(3\right)$

Wherein: A, B, C and D are undetermined coefficient, Z _iBe the i passage at the lengthwise position coordinate figure, Z _Fp1The coordinate figure of the 1st passage lengthwise position that is shaped for first is smart;

3) floor projection based on the strip edge edge all satisfies continuity boundary conditions at crimp passage inlet and the smart first passage porch that is shaped, and can obtain undetermined coefficient thus, thereby the floor projection expression formula of determining the vertical morpheme of strip edge edge is:

$X_i=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}---\left(4\right)$

Wherein: l is a strip width, W _F1For the be shaped width of the 1st passage place guide ring of essence, promptly with the opening degree of steel in this position;

4) reach formula (4) by the horizontal projection table of simultaneous strip edge acies point expression formula (1) and edge, determine the center curvature section

Angle of bend θ ₁:

$\left\{\begin{array}{c}{X}_d={\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\sin {\mathrm{\&theta;}}_1+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})\\ X_i=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}\end{array}\right.---\left(5\right)$

Wherein:, have X for same shaping pipe _i=X _d, therefore can set up about band steel central segment angle of bend θ by (5) formula ₁With vertical shaping position Z _iNonlinear equation, its expression formula is:

${\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\sin \left({\mathrm{\&theta;}}_1\right)+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}---\left(6\right)$

Find the solution this nonlinear equation and can obtain under the correspondingly configured position angle of bend θ of band steel center curvature section ₁, and then can get

Obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position has been all definite, the band steel morpheme of utilizing this method to determine can fully reflect the strip plastic deformation feature in the row roller forming, realizes the reasonable distribution of each passage shaping amount.

The present invention is by calculating the horizontal relative curvature of band steel under differing formed position, determine the scope of distortion blind area in the row roller forming process, overcome the problem of the deflection unreasonable distribution that existing various traditional shaping methods for designing exist in the welded tube row roller forming, reduced to be out of shape the influence of blind area.

The present invention can be used for the design of straight welded pipe roller shaping unit band steel forming parameter, consider that the change radius bend method of distortion blind area has overcome the limitation of process parameters design in the existing various welded tube row roller forming technologies, reflect the characteristics of band steel transversely deforming in the row roller forming process truly, can be applicable to straight welded pipe roller forming technology well.The bending method that is proposed can reduce edge percentage elongation, plastic deformation and the residual stress of band steel in the forming process, suppress the generation of forming defectses such as limit wave, bulge, thereby reduce the percent defective of product, improve band steel forming quality, can be used as the roll forming parameter of forming rolls in the production unit and the foundation of roller position parameter designing.

Description of drawings

Fig. 1 straight welded pipe roller shaping unit schematic diagram;

Among the figure: 1. for pinch passage, 2. for the crimp passage, 3. for the line shaped segment, 4. for the preform section, 5. for smart shaped segment.

Fig. 2 is empty curved and push crooked schematic diagram.

Fig. 3 is out of shape the blind area schematic diagram.

Fig. 4 circumference bending method calculates schematic diagram.

Fig. 5 band steel becomes radius bend shaping amount distribution method schematic diagram.

Fig. 6 preform and line are shaped and arrange the roller section diverse location relative curvature of band steel cross section down.

Strip edge edge shaping schematic diagram in Fig. 7 shaping amount method for designing.

Fig. 8 adopts the difference that the becomes radius bend shaping amount distribution method shaping morpheme figure of band steel in the φ 325mm welded tube row roller forming unit of going down the hill under the amount.

Fig. 9 adopts the difference that the becomes radius bend shaping amount distribution method shaping morpheme figure of band steel in the φ 406mm welded tube row roller forming unit of going down the hill under the amount.

Figure 10 experiment measuring position view

Adopt in Figure 11 production and become the resulting band steel of radius bend method cross section profile and the section morphology comparison diagram that calculates.

The specific embodiment

Below embodiments of the invention are elaborated, present embodiment is being to implement under the prerequisite with the technical solution of the present invention, provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

Embodiment 1

1. adopt the change radius bend method of ERW row roller forming of the present invention, respectively for the shaping amount design of φ 325mm welded tube row roller forming technology under the amount (0.1D, 0.4D, 0.7D, 1.0D) of going down the hill of four kinds of differences with steel.Other initial input parameter of shaping amount design is respectively:

Final forming tube radius R=325/2mm;

The starting point a=0.5 of distortion blind area;

The terminal point b=0.72 of distortion blind area;

Curved edge angle θ ₃=38;

The radius of curvature R of distortion blind area ₂=R/0.1=1625mm;

The smart first passage F that is shaped _P1Lengthwise position coordinate figure Z _Fp1=16100mm;

The smart first passage F that is shaped _P1The width W of place's guide ring _F1=64.38mm.

As Fig. 5-shown in Figure 7, present embodiment may further comprise the steps:

Linear deformation form during the first step, the band steel that adopts down-hill method to be shaped are shaped, wherein: get quadric form along the shaping direction bottom line of going down the hill, i.e. y=lx ²+ mx+n, the amount of going down the hill is got 0.1D, 0.4D, 0.7D, 1.0D, D=325mm respectively.

Second the step, regulation band steel transverse curvature pattern is set, concrete steps comprise: will be divided into the center curvature section with the transverse curvature of steel

Non-abundant bending section promptly is out of shape the blind area section

And curved edge section

Three parts, wherein:

A) center curvature section

Length determine by distortion blind area starting point, the starting point a=0.5 of distortion blind area, in the row roller forming process, the center curvature section

Radius of curvature by infinity convergence final finished pipe radius progressively, the angle of bend θ of this section ₁Determine by the edge floor projection;

B) non-abundant bending section promptly is out of shape the blind area section

Length determine the starting point relative position a=0.5 of distortion blind area jointly by distortion blind area starting point and terminal point; The terminal point relative position b=0.72 of distortion blind area,

The radius of curvature of section is 10 times of final finished pipe radius, R ₂=10R=10 * 162.5=1625mm,

The angle of bend θ of section ₂It is constant,

${\mathrm{\&theta;}}_2=\frac{(b-a)1}{2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}=\frac{(0.72-0.5)\&times;2\&times;162.5\&times;180}{2\&times;1625}=3.96;$

C) curved edge section

Length determine by the terminal point of distortion blind area,

The angle of bend θ of section ₃Remain constant, θ ₃=38, the principle of value is to guarantee

The radius of curvature of section is 1～1.5 times of final finished pipe radius.

The 3rd step, according to band steel space morpheme in the forming process obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position, and with this manufacturing of carrying out welded tube, concrete steps comprise:

3.1) be shaped in strip edge acies point lateral attitude: the A point coordinates is (X on the bottom line of steel center when being with _a, Y _a), according to geometrical relationship obtain the edge end points the cross section coordinate (Xd Yd) can be expressed as:

$X_d=X_a+{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\sin {\mathrm{\&theta;}}_1+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})---\left(1\right)$

$Y_d=Y_a+R_1-{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\cos {\mathrm{\&theta;}}_1+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\sin ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\sin ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})---\left(2\right)$

Wherein: θ ₂For non-abundant bending section promptly is out of shape the blind area section

Angle of bend and be constant, θ ₃Be the curved edge section

Angle of bend and be constant, R ₁, θ ₁Be amount to be determined, distortion blind area radius of curvature R ₂=1625mm, θ ₂=3.96, curved edge angle θ ₃=38 °,

3.2) adopt the monobasic cubic curve to realize longitudinal projection's morpheme of strip edge edge in the forming process:

$X_i=A{\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+B{\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+C\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)+D---\left(3\right)$

Wherein: A, B, C and D are undetermined coefficient, Z _iBe the i passage at the lengthwise position coordinate figure, Z _Fp1The coordinate figure of the 1st passage lengthwise position that is shaped for first is smart, Z _Fp1=16100mm.

3.3) all satisfy continuity boundary conditions based on the floor projection of strip edge edge at crimp passage inlet and the smart first passage porch that is shaped, can obtain undetermined coefficient thus, thereby the floor projection expression formula of determining the vertical morpheme of strip edge edge is:

$X_i=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}---\left(4\right)$

Wherein: l is a strip width, l=π * D=π * 325=1020.5mm, W _F1Be the be shaped width of the 1st passage place guide ring of essence, W _F1=64.38mm;

3.4) reach formula (4) by the horizontal projection table of simultaneous strip edge acies point expression formula (1) and edge, determine the center curvature section

Angle of bend θ ₁:

$\left\{\begin{array}{c}{X}_d={\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\sin {\mathrm{\&theta;}}_1+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})\\ X_i=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}\end{array}\right.---\left(5\right)$

Wherein:, have X for same shaping pipe _i=X _d, therefore can set up about band steel central segment angle of bend θ by (5) formula ₁With vertical shaping position Z _iNonlinear equation, its expression formula is:

${\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1\sin \left({\mathrm{\&theta;}}_1\right)+2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000076226720000041.png"\; state="\{\{state\}\}">R</figure-callout>}}_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}---\left(6\right)$

Find the solution this nonlinear equation and can obtain under the correspondingly configured position angle of bend θ of band steel center curvature section ₁, and then can get Obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position has been all definite, the band steel morpheme of utilizing this method to determine can fully reflect the strip plastic deformation feature in the row roller forming, realizes the reasonable distribution of each passage shaping amount.

It is listed into shaping amount parameter such as the table 1 of 0.7D finally to obtain amount according to above-mentioned change radius bend method, and the designed difference that goes out is gone down the hill shaping morpheme figure under the amount respectively as (a) and (b) among Fig. 8, (c) and (d).

Table 1

Embodiment 2

Adopt the change radius bend method of ERW row roller forming of the present invention, respectively for the shaping amount design of φ 406mm welded tube row roller forming technology under the amount (0.1D, 0.4D, 0.7D, 1.0D) of going down the hill of four kinds of differences with steel.Other initial input parameter of shaping amount design is respectively:

Final forming tube radius R=406/2mm;

The starting point a=0.53 of distortion blind area;

The terminal point b=0.75 of distortion blind area;

Curved edge angle θ ₃=38;

The radius of curvature R of distortion blind area ₂=R/0.1=2030mm;

The smart first passage F that is shaped _P1Lengthwise position coordinate figure Z _Fp1=16100mm.

It is listed into shaping amount parameter such as the table 2 of 0.7D finally to obtain amount according to above-mentioned change radius bend method, and the designed difference that goes out is gone down the hill shaping morpheme figure under the amount respectively as (a) and (b) among Fig. 9, (c) and (d).

Table 2

In order further to verify the accuracy of this method, on φ 325mm * 10.3mm welded tube row roller forming unit, carried out experiments such as opening degree and cross section profile measurement, and experimental data and result of calculation have been contrasted.

The selection of experiment measuring position as shown in figure 10, be respectively crimp passage outlet (ED), preform section outlet (Prf),, line be shaped second section outlet (Lf2) and the line of first section outlet (Lf1), line that be shaped be shaped the 3rd section and export (Lf3).

Experiment 1---the measurement and the contrast of opening degree, as shown in table 3.

Table 3

The circumferential lengths contrast of experiment 2---Zona transformans steel, as shown in table 4.

Table 4

Become the resulting band steel of radius bend method cross section profile and the section morphology figure that calculates in conjunction with adopting in the aforementioned production, adopt the experiment and the result of calculation that become the radius bend method to compare, opening degree, the maximum relative error that plate is wide and cross section profile is tested are respectively 4.5%, 0.5% and 6.8%; As shown in figure 11, the section morphology that adopts change radius bend method resulting band steel cross section profile in the actual production and calculate more as can be seen, by becoming band steel shaping cross section profile that the radius bend method calculates and to adopt this method to produce the measured anastomose property as a result in back better, proved that the ERW row roller forming becomes the validity and the practicality of radius bend method.

Claims (4)

1. an ERW row roller forming becomes the radius bend method, it is characterized in that, by linear deformation form in the band steel shaping of adopting the down-hill method shaping and band steel transverse curvature pattern, and according to band steel space morpheme in the forming process obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position, finally carry out the manufacturing of welded tube with this.

2. ERW row roller forming according to claim 1 becomes the radius bend method, it is characterized in that described linear deformation form is meant: get quadric form along the shaping direction bottom line of going down the hill, i.e. y=lx ²+ mx+n goes down the hill to measure 0.4～1.2D, and D is the production tube diameter.

3. ERW row roller forming according to claim 1 becomes the radius bend method, it is characterized in that described band steel transverse curvature pattern is meant: will be divided into the center curvature section with the transverse curvature of steel

Non-abundant bending section promptly is out of shape the blind area section

And curved edge section

Three parts, wherein:

A) center curvature section

Length determine by distortion blind area starting point, in the row roller forming process, the center curvature section

Radius of curvature by infinity convergence final finished pipe radius progressively, the angle of bend θ of this section ₁Determine by the edge floor projection;

B) non-abundant bending section promptly is out of shape the blind area section Length determine jointly that by distortion blind area starting point and terminal point the scope of distortion blind area relative position is 0.47～0.73, The angle of bend θ of section ₂It is constant,

The radius of curvature of section is 5～10 times of final finished pipe radius;

C) curved edge section

Length determine by the terminal point of distortion blind area,

The angle of bend θ of section ₃Be definite value and satisfied:

The radius of curvature of section is 1～1.5 times of final finished pipe radius.

4. ERW row roller forming according to claim 1 becomes the radius bend method, it is characterized in that, in the described forming process band steel space morpheme obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position, may further comprise the steps:

1) strip edge acies point lateral attitude in the shaping: the A point coordinates is (X on the bottom line of band steel center _a, Y _a), according to geometrical relationship obtain the edge end points the cross section coordinate (Xd Yd) can be expressed as:

$X_d=X_a+R_1\sin {\mathrm{\&theta;}}_1+2R_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})---\left(1\right)$

$Y_d=Y_a+R_1-R_1\cos {\mathrm{\&theta;}}_1+2R_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\sin ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\sin ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})---\left(2\right)$

Wherein: θ ₂For non-abundant bending section promptly is out of shape the blind area section Angle of bend and be constant, θ ₃Be the curved edge section Angle of bend and be constant, R ₁, θ ₁Be amount to be determined, distortion blind area radius of curvature R ₂=(5～10) R,

Curved edge angle θ ₃=25～45.,

A is the initial relative position of distortion blind area, and b is the end relative position of distortion blind area, and l is a strip width, and R is the welded tube radius;

2) adopt the monobasic cubic curve to realize longitudinal projection's morpheme of strip edge edge in the forming process:

$X_i=A{\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+B{\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+C\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)+D---\left(3\right)$

Wherein: A, B, C and D are undetermined coefficient, Z _iBe the i passage at the lengthwise position coordinate figure, Z _Fp1The coordinate figure of the 1st passage lengthwise position that is shaped for first is smart;

3) floor projection based on the strip edge edge all satisfies continuity boundary conditions at crimp passage inlet and the smart first passage porch that is shaped, and can obtain undetermined coefficient thus, thereby the floor projection expression formula of determining the vertical morpheme of strip edge edge is:

$X_i=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}---\left(4\right)$

Wherein: l is a strip width, W _F1For the be shaped width of the 1st passage place guide ring of essence, promptly with the opening degree of steel in this position;

4) reach formula (4) by the horizontal projection table of simultaneous strip edge acies point expression formula (1) and edge, determine the center curvature section Angle of bend θ ₁:

$\left\{\begin{array}{c}{X}_d=R_1\sin {\mathrm{\&theta;}}_1+2R_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})\\ X_i=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}\end{array}\right.---\left(5\right)$

Wherein:, have X for same shaping pipe _i=X _d, therefore can set up about band steel central segment angle of bend θ by (5) formula ₁With vertical shaping position Z _iNonlinear equation, its expression formula is:

$R_1\sin \left({\mathrm{\&theta;}}_1\right)+2R_2\sin \left(\frac{{\mathrm{\&theta;}}_2}{2}\right)\cos ({\mathrm{\&theta;}}_1+\frac{{\mathrm{\&theta;}}_2}{2})+2R_3\sin \left(\frac{{\mathrm{\&theta;}}_3}{2}\right)\cos ({\mathrm{\&theta;}}_1+{\mathrm{\&theta;}}_2+\frac{{\mathrm{\&theta;}}_3}{2})=(l-2W_{f1}){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^3+(3W_{f1}-\frac{3}{2}l){\left(\frac{Z_i}{Z_{\mathrm{fp}1}}\right)}^2+\frac{l}{2}---\left(6\right)$

Find the solution this nonlinear equation and can obtain under the correspondingly configured position angle of bend θ of band steel center curvature section ₁, and then can get

Obtain being with horizontal three bending sections of steel and strip edge edge laterally, lengthwise position has been all definite, the band steel morpheme of utilizing this method to determine can fully reflect the strip plastic deformation feature in the row roller forming, realizes the reasonable distribution of each passage shaping amount.

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