SU1749270A2 - Apparatus for quenching balls - Google Patents

Abstract

SUMMARY OF THE INVENTION: The device comprises a loading chute 2, a pipe 3C with internal screw coils 5.6 and a quench medium supply manifold 7. Pipe 3 has helical turns of different heights along the length of the quenching tube. The inner diameter of the screw turns 5 at the distance of one step in the loading part of the pipe is made 0.75-0.85 of its diameter, and the rest part - 0.40-0.60 of the pipe diameter. 2 Il.

Description

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The invention relates to metallurgy, in particular to devices for hardening balls, and is an improvement of the device according to ed. No. 688525.

The known device for hardening balls contains a quenching drum (tube) with helical turns. Screw coils have the same height along the entire length of the quenching drum.

A disadvantage of the known construction 10 is the insufficiently high quality of hardening balls and a decrease in yield due to an increase in the internal stresses of the balls during cooling and loading, leading to a decrease in impact resistance and service life of the grinding balls.

The aim of the invention is to improve the quality of quenching and increase the yield by reducing the internal stresses of the balls during cooling and charging.

This goal is achieved by the fact that in the device the inner diameter of the first screw turn at the loading section is made 0.75-0.85 of the pipe diameter, and 25 other turns of the drum are made with an internal diameter equal to 0.4-0.6 of this diameter.

In the loading section of the pipe, when the internal diameter of the screw turns is greater than 30 0.85 of its diameter, due to the low height of the screw turns, the reliability of movement of products along the axis of the pipe is not ensured. When the inner diameter of the helical turns is less than 0.75 of the pipe diameter, due to a large drop height and mechanical shocks, a part of the large-diameter balls rolled from the head and bottom parts of high-carbon ingots (0.65-1.00 e), for example - 40 owl, steel.

In the rest of the active zone of the rotating tube, when the inner diameter of the helical turns is greater than 0.6 of the diameter of the tube, a sufficient depth of quench bathing immersion in the quenching medium and uniform hardening of the balls is not provided, overflow occurs through the top of the helical loops and a significant consumption of quenching medium. When the inner diameter of the screw 50 turns is less than 0.4 of the pipe diameter, the depth and volume of the quenching bath are excessively large, which leads to an insufficient increase in the temperature of the quenching medium (water), the unacceptably high cooling rate of 55 martsitic transformations of steel

significant thermal stress, reducing the impact resistance and service life of grinding balls.

1 shows a device for hardening balls, a general view; figure 2 is the same, side view.

A device for quenching grinding balls rolled on a mill (not shown) contains a conveyor 1, a loading chute 2, a rotating drum (tube) 3 and a discharge chute 4.

The rotating pipe 3 in the head part, at a distance of one pitch of the helix, has turns 5 of low height, and the rest of the rotating pipe 3 has turns of high speed. Along the axis of the rotating pipe, a quenching medium supply manifold 7 is installed. The pipe 3 is mounted on rollers 8 provided with a rotational drive 9.

The device works as follows

The grinding balls rolled in the mill by the conveyor 1 and loading tray 2 are fed into the rotating tube 3. When the tube 3 rotates, the balls roll on the inner side of its wall while cooling with quenching medium / from the collector 7. The balls first move at a distance of one pitch of the screw coils 5 of low height, and then along the rest of the rotating pipe 3 by screw coils 6 of a high height roll into the discharge chute 4. Rotation of the pipe 3 is performed on the rollers 3 by means of an actuator 9.

The experiments on the hardening of grinding balls with diameters 60.80, 100 and 125 mm show that the proposed device improves the quality of hardening balls and increases the yield of suitable ones while reducing the consumption of quenching medium and increasing the impact resistance, hardness and service life of grinding balls.

Claims (1)

Invention Formula Ball hardening device according to ed. St. No. 688525, characterized in that, in order to improve the quality of quenching and increase the yield by decreasing the internal stresses of the balls during cooling and loading, the internal diameter of the first helical coil at the loading section is equal to 0.75-0.85 of the pipe diameter, and the rest turns of the drum are made with an internal diameter equal to 0.4-0.6 of this diameter. Fie.2