JPH0118802B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a three-roll rolling method for section steel.

Three-roll (triaxial) rolling mills for rolling shaped steel are known. As shown in Fig. 1, this rolling mill is equipped with a lower roll 1 and a pair of inclined upper rolls 2 on the same vertical plane. It is possible to roll steel sections of different sizes using the rolls, and especially when rolling angle-shaped steel, it is easy to ensure the fullness of the peak part, and when rolling T-beam steel, it is easy to obtain the stem height. It has the following advantages.

The present invention was invented in order to more effectively obtain the advantages of rolling using a three-roll rolling mill. It is an object of the present invention to provide a three-roll rolling method that can be carried out more appropriately and accurately.

Therefore, in the present invention, the axis of each upper roll is given a skew angle in the rolling direction, and each upper roll is positioned so that the outer end of the roll is inclined toward the downstream side of rolling with respect to the axis of the lower roll. It is characterized by having a horizontal lower roll and two upper rolls whose roll axes are inclined with respect to the horizontal and whose roll surfaces are convex on the same vertical plane. A roll rolling machine rolls a rolled material having a peak or stem on the top surface of the flat part, and the horizontal lower roll hits the bottom surface of the flat part of the rolled material, and each upper roll rolls the rolled material into a flat with the top of the peak or stem as a boundary. When rolling so as to contact each upper surface of the part and each side of the peak part or the stem part, each upper roll is positioned so that the outer end side of the roll is inclined toward the downstream side of rolling with respect to the axial direction of the lower roll. The reason is that it is rolled.

Hereinafter, the present invention will be explained based on the drawings.

2 and 3 show the implementation situation when the present invention is applied to the rolling of T-shaped steel. 1 is a horizontal lower roll, 2 is a pair of upper rolls, and A is the axis of the lower roll 1 ( (roll axis), B is the axis of the upper roll 2.

The upper roll 2 has an axis B inclined with respect to the horizontal, and a roll surface having a convex shape.

According to such a rolling mill, the rolled material 3 having the stem portion S on the upper surface of the flat portion is rolled with the horizontal lower roll 1 hitting the lower surface of the rolled material (flat portion), and each upper roll 2 touching the lower surface of the stem portion S. Rolling is performed so as to contact each upper surface of the flat portion bordering on the top and each side surface of the stem portion S.

In the present invention, rolling is performed by positioning each upper roll so that the outer end of the roll is inclined toward the downstream side of rolling with respect to the lower roll axis direction (direction perpendicular to the rolling direction). The roll axis B is inclined with respect to the lower roll axis A in the rolling direction, and the roll outer end 21 is positioned so as to be inclined toward the rolling downstream side with respect to the lower roll axis A. The rolling material 3 is rolled by the rolls 2, 2.

In such rolling, both upper rolls 2, 2
Due to the inclination toward the rolling downstream side, a velocity component force F on the outer peripheral surface of the roll acts on the inner side of the rolled material 3.
The height of the stem portion S can be easily increased by this velocity component force, and the dimensions of that portion can also be adjusted with high precision due to such a large forming action.

Figure 4 shows the relationship between the inclination angle θ of the upper roll 2 in the rolling direction and the amount of change Δh in the stem height in rolling a T-shaped steel of size TB300×24.
Roll radius 240mm, upper roll with axis angle (inclination of roll axis from horizontal direction) of 20° and roll radius 520mm
Rolling was performed using the lower roll. Note that a negative value of θ indicates a case where the outer end portion 21 of the upper roll is inclined in the opposite direction, that is, toward the upstream side of rolling. According to the figure, by giving the upper roll 2 an inclination angle θ such that its outer end 21 is inclined toward the downstream side of rolling, the forming action on the stem portion is increased and the height of the stem can be easily increased. I see that it is possible. Conversely, the upper roll 2 tilts in the opposite direction (rolling upstream direction) (when θ is a negative value)
It can be seen that the molding effect on the stem portion decreases.

Although the above explanation relates to rolling of T-shaped steel, the present invention can be applied to rolling of various shaped steel such as angle steel. FIG. 5 shows a case in which the method is applied to the rolling of equilateral angle shape steel, in which the speed component force F allows an appropriate filling effect on the peak m to be obtained.

In addition, FIGS. 7 and 8 show a case where the application is applied to rolling of scalene thickness angle shape steel. In this case, the inclination angle θ ₁ of the upper roll 2a on the short side is changed to It is preferable to set the inclination angle θ ₂ of the upper roll 26 to be larger than that during rolling. In rolling with a three-roll rolling mill, the upper rolls 2, 2 are given an axial angle α as shown in FIG. From both sides of material 3 towards the center, as shown below.
The forces f ₁ and f ₂ act.

f ₁ = μ・P ₁ ≒ μ・ρ・l ₁ f ₂ = μ・P ₂ ≒ μ・ρ・l ₂ However, μ: Friction coefficient P ₁ , P ₂ : Pressure force on flat part ρ: Unit of flat part Force acting per area The magnitude of these forces f ₁ and f ₂ is determined by each upper roll 2,
Since it is proportional to the contact length l ₁ and l _{2 of} 2 with the rolled material 3,
When rolling a steel section with a symmetrical cross section, such as a T-section steel or an equilateral angle section, an appropriate centering effect is produced. However, in the case of a scalene shape steel (or a scalene shape steel of equal thickness) as shown in FIG. 6, the centering effect causes the disadvantageous result that the thickness shifts to the shorter side. Therefore, in this embodiment, the upper roll 2 on the short side
The inclination angle θ ₁ of a is the inclination angle θ ₂ of the upper roll 2b on the long side.
Rolling is performed by setting the speed component force F ₁ on the short side to be larger than the speed component force F ₂ on the long side, and thereby (f ₁ + F ₁ ) and (f ₂ +F ₂ ) and eliminates the unbalanced influence of f ₁ and f ₂ .

According to the present invention described above, rolling is performed by positioning each upper roll so that the outer end of the roll is inclined toward the rolling downstream side with respect to the axial direction of the lower roll. There is an excellent effect that rolling can be performed while performing part-extrusion forming more efficiently and with high precision.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a conventional three-roll rolling method. FIGS. 2 and 3 show the implementation situation when the present invention is applied to rolling of T-section steel, with FIG. 2 being a plan view and FIG. 3 being a rear view. FIG. 4 shows the relationship between the inclination angle of the upper roll and the change in the stem height of the T-beam. FIG. 5 is a rear view showing the implementation situation when the present invention is applied to rolling of equilateral angle steel. FIG. 6 is an explanatory diagram showing the rolling situation of scalene angle steel with uneven thickness using a three-roll rolling mill. FIGS. 7 and 8 show a state of implementation in which the present invention is applied to the rolling of angle-shaped steel with scalene sides and uneven thickness, with FIG. 7 being a plan view and FIG. 8 being a rear view. In the drawings, 1 is a horizontal lower roll, 2 is an upper roll, 3 is a rolled material, 21 is an outer end, and A and B are roll axes.

Claims (1)

[Claims] 1. A three-roll rolling mill equipped with a horizontal lower roll and two upper rolls whose roll axes are inclined with respect to the horizontal and whose roll surfaces are convex on the same vertical plane, is used to roll flat parts. A rolled material having a peak or a stem on the upper surface is rolled, and the horizontal lower roll hits the lower surface of the flat part of the rolled material, and each upper roll touches each upper surface of the flat part and the peak, bordering on the top of the peak or stem. Alternatively, when rolling is performed so as to contact each side of the stem portion, each upper roll is positioned so that the outer end side of the roll is inclined toward the downstream side of rolling with respect to the axial direction of the lower roll. Three-roll rolling method for shaped steel. 2 When rolling rolled material for scalene angle steel,
A three-roll rolling method for a section steel according to claim 1, characterized in that the inclination angle of the upper roll in the rolling downstream direction is set such that the rolling material short side upper roll > the rolling material long side upper roll .