RU2516324C2 - Device for electromagnetic deceleration of heat-hardened ferromagnetic reinforcing bar upstream of refrigerator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Proposed device comprises lift valves secured to swing levers arranged between the rollers of refrigerator intake table, stationary straightening flutes arranged parallel with said valves and to-pole slotted brake electromagnets. Stable braking forces result from rigid fastening of said brake electromagnets at swing levers, not the valves, upstream of refrigerator. Note here that one pole follows the valve crosswise profile while another one follows the profile of straightening flute sidewall. Surfaces of kinetic friction of said poles have crosswise ribs made at spacing multiple of that of recesses made between reinforcing bar stiffness ribs.

EFFECT: stable electromechanical properties.

2 cl, 3 dwg

Description

The invention relates to the field of rolling production of ferrous metallurgy. It can be most effectively used on small-grade mills specialized in the production of thermally hardened (ferromagnetic) reinforcing bars in bars.

The aim of the invention is to increase the efficiency of the braking process.

An analogue of the proposed technical solution is a device for braking rolled products, containing lifting valves installed between the rollers of the receiving roller table of the refrigerator, stationary straightening grooves located parallel to the valves and slotted brake electromagnets integrated under the first stream of the straightening groove [1, 2].

The main disadvantage of the analogue is that while ensuring a high intensity of forced braking, the process is carried out at the final stage of the rolling movement, i.e. at low speeds V _t , which reduces its effectiveness (for small-graded mills, the speed of the rods entering the leveling trough does not exceed 5–7 m / s, with the speed of entry into the refrigerator 15–17 m / s).

The prototype is a device for braking the rolling stock, containing lifting valves located between the rollers of the receiving roller table of the refrigerator, installed parallel to the valves, stationary straightening grooves, two-way slotted brake electromagnets, one pole, a core and an excitation coil which is fixed in the stationary straightening groove, and the second with a gap to the core is integrated in the lifting valves [3].

The disadvantage of the prototype is: the presence of a gap between the mutually moving pole built into the lift valves and the stationary core of the bipolar slotted brake electromagnet, which interrupts and significantly reduces the magnetic flux affecting the rental, therefore, reduces the electromechanical characteristics (force braking) of the brake electromagnet.

The proposed device for electromagnetic braking of heat-strengthened ferromagnetic long products in front of the refrigerator is presented on:

- figure 1. Arrangement of device equipment on the mill;

- figure 2. Section AA in figure 1;

- figure 3. Section BB in Fig.3.

The device includes: lifting valves 1, installed between the rollers 2 of the receiving roller table of the refrigerator, on levers 3 swinging from the drive, stationary leveling grooves 4, parallel to the valves, bipolar slotted brake electromagnets 5, rigidly fixed to the levers swinging from the drive 3. Pole 6 of a two-pole brake electromagnet 5, repeats the transverse profile of the lifting valve 1, and the pole 7, the transverse profile of the side wall of the leveling channel 4.

In addition, the surface of attraction of the poles 6 and 7 of the brake electromagnet 5 is equipped, for braking the reinforcing bar, with transverse protrusions 8, located with a step L _{in a} multiple step of the depressions between the stiffeners of the reinforcing bar.

The device operates as follows.

The hot rolls of reinforcing steel at the exit from the finishing stand 9 are thermally hardened and acquire ferromagnetic properties in the installation 10, after which on flying shears 11 they are cut into rods 12 corresponding to the length of the refrigerator 13. The cooled ferromagnetic bars of rolled 12 are transported alternately by rollers of the receiving roller table 2 to the refrigerator 13 . When the front end of the bar 12 reaches a predetermined position, a signal is issued to raise the valves 1. At the same time as a signal to lift the valves, a signal is sent to turn on the O brake electromagnets 5. Lifting valves 1 and brake electromagnets slot 5 from the drive for the rocker arm 3 synchronously move upward and lift the moving rolled rod from the rollers 2 receiving roller table. At the same time, the ferromagnetic rods of rolling 12 are attracted to the poles 6 and 7 of the brake electromagnets 5, which provides intensive remote controlled forced braking (reducing the path and time of braking).

Due to the fact that the reinforcing profile has annular stiffeners on the surface, and the friction surfaces of the poles 6 and 7 are provided with transverse protrusions 8, when the rolled products are drawn to the poles, along with the contact sliding friction forces in the magnetic field, when the normal electromagnetic attraction force P is intensified _e and the sliding friction coefficient of the magnetized surfaces μ _e , when the stiffeners of the moving reinforcing bar meet with the protrusions 8, additional mechanical tangential braking forces Q _t arise. Therefore, the total braking force Q _∑ is equal to:

Q _∑ = P _e µ _e + Q _t

Information sources

1. RF patent No. 1444010, CL B21B 43/00, 1987

2. Declaration patent of Ukraine No. 50534A, CL B21B 43/00, 2002

3. USSR author's certificate No. 1710159, class B21B 43/00, 1992

Claims (2)

1. A device for electromagnetic braking of heat-strengthened ferromagnetic reinforcing bars in front of a refrigerator, comprising lifting valves mounted on levers swaying from the drive located between the rollers of the receiving roller table of the refrigerator, stationary leveling grooves mounted parallel to the valves, and bipolar slotted brake electromagnets, characterized in that bipolar slotted brake electromagnets are rigidly fixed to levers swinging from the drive in front of the refrigerator, while The pole repeats the transverse profile of the valve, and the other the transverse profile of the side wall of the leveling channel. 2. The device according to claim 1, characterized in that the sliding friction surfaces of the poles of the brake electromagnets are provided with transverse protrusions arranged in increments that are a multiple of the pitch of the depressions between the stiffeners of the reinforcing bar.

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