CN101862757B - Pinch roll for pipes and bars - Google Patents

Abstract

The invention relates to a pinch roll for pipes and bars. The shape of the circumferential surface of the roll comprises an improved hyperbolic curve as the upper part and an oval curve smooth transition as the lower part, wherein the improved hyperbolic curve of the upper part is as follows: cos<2>alphaX<2>-deltaY<2>=deltad<2>; and the oval curve of the lower part is as follows: cos<2>alphaX<2>+Y<2>=d<2>; wherein d is the diameter of a cylindrical blank, alpha is the included angle between the central axis of the roll and the central axis of the cylindrical blank, delta is a coefficient with a numerical range of 0.5-1, X represents a major axis, and Y represents a minor axis. In the pinch roll, two rollers of the pinch roll device and the cylindrical blank are arranged crosswise, and the self rotation of the rollers drives the cylindrical blank to move forward. By using the technical scheme, the roll curved surfaces of the rollers are brought in good contact with the blank. Thereby, the contact rate is ensured to the greatest extent, and the roll bite is smooth in the rolling process.

Description

Pinch roll for pipes and bars

Technical field

The present invention relates to a kind of pinch roll for pipes and bars.

Background technology

Manage at present; It is more extensive that rolling bar is used, and generally on production line, all adopts a cover pinch roll apparatus to carry the cylinder blank, two rollers of pinch roll apparatus and cylinder blank arranged crosswise; Spinning drive cylinder blank through roller advances, and helps blank and is nipped by milling train.The design of the many in the past employing hyperbolic-types of the roll design of pinch roll, algorithm is simple, but contact rate is quite low; As shown in fig. 1; Curve a is exactly a hyperbolic-type, and curve c is a pipe, the projection ellipse of bar on α angle plane; The contact rate of curve a has only 51%, and departing from diameter has 17% more than.When metal blank is transmitted by such roll shape, will inevitably multi-direction play, will strengthen the difficulty of nipping of milling train, reduce rolling accuracy.

Summary of the invention

The objective of the invention is for overcoming the deficiency of above-mentioned prior art, provide a kind of pinch roll roll shape curved surface to contact well, guarantee contact rate to greatest extent, the pinch roll for pipes and bars smoothly of nipping when rolling with the cylinder blank.

For realizing above-mentioned purpose, the present invention adopts following technical proposals:

It is that modified hyperbola and the latter half are that oval curve rounding off is formed that a kind of pinch roll for pipes and bars, this roller peripheral surface are shaped as the first half, and wherein, the first half for the modified hyperbola is: cos ²α X ²-δ Y ²=δ d ²The oval curve of the latter half is: cos ²α X ²+ Y ²=d ²In the formula, d is the cylinder blank diameter, and α is the angle between roller center axis and the cylinder blank central axis, and δ is a coefficient, and its number range is 0.5-1, and X representes long axis direction, and Y representes short-axis direction.

Among the present invention; Two rollers of pinch roll apparatus and cylinder blank arranged crosswise, the spinning through roller drives the cylinder blank advances, and gets the axis of roller and the joining on the roller and the cylinder blank face of cylinder and makes face; With this face circle of contact post blank face of cylinder; The cylinder blank obtains an oval-shaped tangent plane, and this oval sideline promptly is the optimal engagement curve, is technique scheme as roller curve after then this curve being processed.

The invention has the beneficial effects as follows that the roll shape curved surface contacts with blank well, has guaranteed contact rate to greatest extent, it is smooth and easy to nip when rolling.Curve of the present invention is that the first half is that modified hyperbola and the latter half are that oval curve rounding off is formed, and the modified hyperbola is shown in curve b among Fig. 1, and the contact rate of curve and cylinder blank is 72%, and departing from diameter has only 8%.And according to practical production experience, it is too tight that roller can not contact with blank, will have influence on the pace of blank.The ensemble average contact rate of top and the bottom is 86%, and contact is good, is not sent to milling train and do not influence blank.

Description of drawings

Fig. 1 is each curve relation figure;

Fig. 2 is that roller of the present invention and cylinder bland position concern sketch map;

Fig. 3 is Fig. 2 left view;

Fig. 4 is the angle sketch map between roller center axis of the present invention and the cylinder blank central axis;

Fig. 5 is that the axis of roller of the present invention and the joining on the roller and the cylinder blank face of cylinder are made the oval tangent plane sketch map that the face circle of contact post blank face of cylinder obtains;

Fig. 6 roll profile sketch map of the present invention;

1. cylinder blanks wherein, 2. roller, 3. modified hyperbola, 4 ellipses.

The specific embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is further specified.

Like Fig. 2, shown in 3, two rollers 2 of pinch roll apparatus and cylinder blank 1 arranged crosswise, roller 2 forms an inclined angle alpha (as shown in Figure 4) with cylinder blank 1.Spinning drive cylinder blank 1 through roller 2 advances; Get the axis and the roller 2 of roller 2 and make face with the joining on cylinder blank 1 face of cylinder; With this face circle of contact post blank 1 face of cylinder; Cylinder blank 1 is cut obtains an oval-shaped tangent plane (as shown in Figure 5), and this oval sideline promptly is the optimal engagement curve.

Among Fig. 4,5, d is the cylinder blank diameter, and a is oval tangent plane major axis, and b is oval tangent plane minor axis, and α is the roller inclination angle.

Have according to geometrical relationship

$a=\frac{d}{\cos \mathrm{\&alpha;}}---(1-1)$

b＝d (1-2)

Elliptic curve does

$\frac{X^2}{a^2}+\frac{Y^2}{b^2}=1---(1-3)$

Formula (1-1) and (1-2) substitution formula (1-3) are had

cos ²αX ²+Y ²＝d ² (1-4)

Get into pinch roll smoothly for the ease of the cylinder blank, the first half of roller curve is revised as modified hyperbola 3, promptly as shown in the formula expressed:

cos ²αX ²-δY ²＝δd ² (1-5)

In the formula, δ is a coefficient, and its number range is 0.5-1.

Some fillets processing are done in two curve junctions and other places about the pair of rollers surface, finally obtain roller as shown in Figure 62 shapes, and the circumferential the first half of roller is a modified hyperbola 3, and the latter half is oval 4.Optimized roll shape so to greatest extent, made roll shape more accurate, the roll shape curved surface contacts with blank well, has guaranteed contact rate to greatest extent, and it is smooth and easy to nip when rolling.

Claims (1)

1. pinch roll for pipes and bars is characterized in that: it is that modified hyperbola and the latter half are that oval curve rounding off is formed that this roller peripheral surface is shaped as the first half, and wherein, the first half for the modified hyperbola is: cos ²α X ²-δ Y ²=δ d ²The oval curve of the latter half is: cos ²α X ²+ Y ²=d ²In the formula, d is the cylinder blank diameter, and α is the angle between roller center axis and the cylinder blank central axis, and δ is a coefficient, and its number range is 0.5-1, and X representes long axis direction, and Y representes short-axis direction.

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