SU815053A1 - Device for tempering metallic balls - Google Patents

Description

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The invention relates to heat treating products and can be used for quenching metal balls.

A device for hardening metal balls is known, which comprises a spiral guide located around a vertical screw with a drive. The balls in it are fed to the spiral guide and under the action of their own weight or due to the rotation of the spiral move down, cooled in the quenching fluid supplied by the pump from below towards the movement f |.

; The disadvantage of this device is to JJ StertcH that it does not break the steam jacket off the surface of the hardened balls, which impede heat dissipation, and does not allow obtaining the maximum hardness corresponding to the chemical composition of this steel.

It is also known a device for centrifugal hardening of balls, containing a quenching bath, a pump, a hydrocyclone, a tangentially located nozzle, supply of a quenching medium and a conveyor for dispensing balls from the bath 2

The disadvantage of this device is that it does not allow the possible residence time to be adjusted over a fairly wide range.

ball in a hydrocyclone, because with an increase in tangential pump water supply, this is sharply reduced, and with decreasing intensity - balls along the inner surface

no hydrocyclone transported. In addition, it becomes more difficult to use the device in the event that a significant change in the hardening process parameters is required, in view of the variety of steel grades entering the ball rolling.

The closest to the present invention is a device for heat treatment of metal balls, containing a bath with a feeding chute and a transport mechanism located inside it, made in the form of a cone, on the vertical axis of which a carrier shaft with a drive is mounted,

jfj blades and conveyor.

The disadvantages of this device are the instability of the hardening process, which is expressed in the transition of the balls during the movement from the lower disk.

to the inner surface of the transfer-conveying cone, and then to the distribution cross, which does not allow to achieve the maximum intensity of the cooling of the balls. The presence of various defects on the surface of the balls drastically changes the trajectory, their movement along the lower disks and the inner surfaces of the cones, which affects the hardness spread from the kshara ball. In addition, this device has a relatively complex structure.

The purpose of the invention is to stabilize the cooling of the balls and simplify the design.

The goal is achieved by the fact that the device is provided with a perforated spiral guide fixed at an angle to the inner surface of the cone, the angle of installation of the perforated spiral guide to the inner surface of the cone being 70-90 °.

The angle between the inner surface of the cone and the spiral guide, less than 70 °, causes the balls with the guide to slide and hit them on the rotating blades, causing the latter to break, and the angle larger than 90 makes it difficult to transport the balls along the guide. The annular gap between the blades and the inner surface of the cone should be 1.5-2.0 times the diameter of the balls to be machined. A gap of less than 1.5 times the diameter of the balls being machined results in blows of the latter on the rotating blades, which leads to their breakage, and a gap of more than two diameters leads to low-intensity mixing of the coolant in the zone of motion of the hardened balls.

Fig. 1 schematically shows a vertical section along the axis of the device j in Fig. 2, a plan view of the device.

The device contains a bearing bracket 1, on which the engine 2 is mounted, connected to the gearbox 3 and the pulley 4. Bearing holder 5 is fixed to the bearing bracket 1, in which the supporting shaft with blades 7 mounted with an annular gap in relation to the spiral direction is mounted 8, rigidly mounted on the inner surface of the cone 9. The cone 9 is placed in the quenching bath 10 and fixed to its walls by the edges of the frame 11. Tangentially with respect to the upper cone funnel of the cone 9, a feed chute 12 is installed. Between the bottom hardening bath 10 and the outlet of the cone 9 installed the conveyor 13 issuing balls in the cumulative capacity 14.

The proposed mustache; the trio works as follows.

The metal balls from the ball mill, having passed the separator (not shown in Fig.) Fall into the feed chute 12, are tangentially inserted into the cavity of the funnel of the cone 9 on the spiral guides 8. At the same time, the actuator 2 is connected, connected via gear 3 and pulley 4 with the supporting shaft 6. The shaft b fixed in the holder 5 begins to rotate, creating blades 7 of the centrifugal flow of quenching medium that picks up the balls and moves them along the groove formed by the spiral-shaped guide 8 and the inner surface of the cone 9. During the movement, the balls are subjected to continuous uniform and intensive cooling. After exiting the cone 9, the balls fall on the conveyor 13 and are transmitted by means of it to the storage tank 14. The cooling time of the building of the balls is controlled by the speed of rotation of the shaft b with the blade 7.

Claims (3)

1. A device for hardening metal balls, containing a quenching bath with a feed chute and located inside it a transporting mechanism, made in the form of a cone, along the vertical axis of which a supporting drive shaft, blades and conveyor, characterized by TeUf, are installed. the structure, it is provided with a reinforced at an angle to the inner surface of the body of the perforated spiral guide. 2. A device according to claim 1, characterized in that the installation angle of the perforated spiral guide to the inner surface of the cone is 70-90. Sources of information taken into account in the examination 1. US Patent No. 3618922, cl. 266 / 6R, 1971. 2. Patent Czechoslovakia No. 149033, cl. 18 s, 1/64, 1971. 3. USSR author's certificate number 564342, cl. C 21 D 3/36, 1977.