RU2231405C1 - Guiding device for step feed of billets - Google Patents

Abstract

FIELD: rolled stock production, namely mechanisms for lengthwise motion of rolled pieces at guiding them to rolls of rolling stand.

SUBSTANCE: guiding device includes crossbeam, carriage, both mounted with possibility of motion on guides by means of drive unit, elastic member (spring) arranged between crossbeam and carriage. Ratchet is mounted on said crossbeam; pawl is mounted on carriage. Pitch of ratchet is equal to feed value.

EFFECT: enhanced efficiency, improved quality of rolled products due to high operational reliability of guiding device.

1 dwg

Description

The invention relates to rolling production, and in particular to mechanisms used for the longitudinal movement of the rental when it is tasked in rolls of the rolling stand.

Known mechanisms [1, p. 192], serving for the longitudinal movement of the workpiece along the axis of rolling using a screw-nut gear. When rolling a billet, the transmission of the screw - nut and the billet itself have significant axial forces leading to rapid wear of the screw and nut, and when rolling thin-walled pipes, corrugations appear on them (pipes).

Another disadvantage of this mechanism is the complexity of its design due to the need to use cam-lever-slider mechanisms that provide intermittent feed of the workpiece only during the formation of the gap between the working surface of the rolls and the workpiece.

The closest in technical essence and the achieved effect is the master device of the step rolling mill [2], containing a crosshead and a carriage mounted with the ability to move along the guides from the drive, an elastic element (in a particular case, a spring) located between the crosshead and the carriage.

The use of an elastic element allows continuous operation of the drive of the master device, which at the moment of compression by the rolls of the workpiece moves only the crosshead by the amount of feed. Traverse, acting on the spring, compresses it. The spring force is transmitted to the carriage and the workpiece without moving them along the rolling axis. When a gap appears between the rolls and the workpiece, the carriage and the workpiece are moved along the guide by the spring by the feed amount.

All this greatly simplifies the drive mechanism of the master device and increases the reliability of its operation.

However, the use of such a design of the master device requires a sufficiently fine adjustment of the pre-compression force of the spring, which exceeds the friction force between the guide and the workpiece, as well as the guide and the carriage.

If the friction force between the carriage and its guide is practically constant, then the friction force between the workpiece and the guide depends on the geometry of the workpiece, its roughness, etc. Therefore, depending on the parameters of the workpiece, the force of resistance to movement of the workpiece also changes.

This requires prior to rolling each billet to adjust the pre-compression force of the elastic element.

If there is insufficient pre-compression force of the spring, the workpiece and carriage will not receive the required movement by the amount of feed during the formation of the gap between the rolls and the workpiece. In the case of creating a significant pre-compression force, the workpiece due to inertial forces will receive a movement significantly higher than the feed.

In the first case, the design performance of the step rolling process will not be ensured due to low feed. In the second case, if the project feed is exceeded, the step rolling process will be carried out under increased deformation and power conditions, which may lead to a decrease in the quality of rolled products in geometric dimensions or to breakdown of technological equipment.

Thus, the master device according to the prototype has low reliability, leading to a decrease in the productivity of the step rolling process and the quality of the geometric dimensions of the cross section of the rolled product.

The task of the invention is to remedy these shortcomings of the master device, namely, increasing the reliability of its operation, increasing the productivity of the step rolling process, improving the quality of the rental.

The task is achieved in that the master device for the step-by-step feeding of workpieces, including a traverse and a carriage, mounted for movement along the guides from the drive, an elastic element located between the traverse and the carriage, is equipped with a ratchet mechanism, the ratchet and dog of which are separately mounted on the traverse and the carriage and the tooth pitch of the ratchet is equal to the feed.

The installation of ratchet and dogs on these structural elements of the master device allows automatic adjustment of the preload force of the elastic element (spring) required for supplying each workpiece and restrict the movement of the carriage in each step rolling cycle. Performing a pitch of ratchet teeth equal to feed allows the carriage with the workpiece to move in each rolling cycle by an amount not exceeding the feed amount.

This is provided as follows.

During the operation of the master device, the traverse from the continuously operating drive in each step rolling cycle moves by a predetermined feed amount. At the same time, the elastic element is compressed due to the action of the beam on it when the carriage is stationary with the workpiece held by the rolls of the rolling stand.

During the formation of the gap between the rolls and the workpiece, the latter, together with the carriage, can move towards the rolling stand. However, if the compression force of the spring does not exceed the force required to move the carriage with the workpiece, the latter will not receive movement by the amount of feed. In each subsequent step rolling cycle, the compression amount of the elastic element increases by the amount of feed, and when the elastic element reaches a force that exceeds the resistance to movement of the carriage and the workpiece, the latter will move towards the rolls.

The magnitude of this movement will not exceed the ratchet pitch and the feed rate, as this movement limits the dog. In the next cycles of step rolling, the workpiece will be cycled by the feed amount, as a compression force sufficient to move the carriage and the workpiece is set in the spring.

The invention is illustrated in the drawing, which shows a diagram of a master device.

The master device comprises a traverse 1 and a carriage 2 mounted on guide columns 3, mounted on the foundation 4, with the possibility of movement along them. A nut 5 is fixed in the traverse 1, connected by a screw 6 and connected to the drive 7. A pusher is fixed at the bottom of the carriage 2. A spring 9 is installed between the traverse 1 and the carriage 2 on the columns 3. The ratchet 10 is pivotally mounted on the traverse 1, and on the carriage 2 dog 11. With another design (not shown), the ratchet 10 can be mounted on the carriage 2, and the dog 11 on the traverse 1.

The operation of the master device is as follows.

The drive 7 of rotation of the screw 6 is turned on, which, interacting with the nut 5, moves the beam 1 along the guide columns 3. In this case, the drive is set to an operating mode that moves the beam 1 with nut 5 during the rolling cycle by the feed rate m. The traverse 1 through the spring 9 acts on the carriage 2 with the pusher 8 and moves it along the guide columns 3 in the direction of the arrow. When approaching the pusher 8 to the workpiece (shown by thin lines), the friction force F _Tr between the workpiece and the wiring holding the workpiece acts on it. In the event that the friction force F _Tr exceeds the compression force of the spring 9 P _CR , then the carriage 2 with the pusher 8 and the dog 11 will remain stationary, and the crosshead 1 together with the ratchet 10 will move along the columns 3 towards the rolling stand, compressing the spring 9 In this case, the force of the spring 9 increases, and the ratchet 10 moves relative to the dog 11. When the force in the spring 9 P _ol exceeds the friction force F _Tr , the carriage 2 with the pusher 8 and with the workpiece will move in the direction of the rolling stand. Moreover, this movement cannot exceed the feed rate m, because this movement is limited by the ratchet pitch 10.

Therefore, if P _CR > F _Tr , then in each step rolling cycle during the formation of the gap between the rolls and the workpiece, the latter, together with the carriage 2 and the pusher 8, receives a displacement equal to the feed m.

Thus, when rolling workpieces with different parameters that determine different forces of resistance to its movement to the rolling stand of step rolling, the driver is automatically adjusted to the required spring compression force, fixed by a ratchet mechanism, after which the driver is stable in the feed mode, in which the feed rate cannot exceed m.

Even in the event of an emergency, when the force F _Tr significantly exceeds P _ol , the spring will compress and switch to another mode of operation, and then there will be a sharp decrease in force F _Tr , the workpiece will move to the rolling mill due to the ratchet device and will not exceed the feed rate m.

Thus, the use of a master device of this design provides automatic adjustment to the normal mode of operation and provides a constant design mode of supply of the workpiece by the value of m. This achieves the design performance of the step rolling process and the specified quality of the geometric dimensions of the rolled product.

The proposed design of the master device was tested on an industrial mill of step rolling with swinging rolls, installed in 2002 at OOO UZPS (Berezovsky, Sverdlovsk Region). Due to the use of such a design of the master device, trouble-free operation of the mill and the absence of marriage of finished products by the geometric dimensions of the cross section are ensured.

Sources of information

1. Verderevsky V.A., Gleiberg A.Z., Nikitin A.S. Pipe rolling mills. - M.: Metallurgy, 1983, p. 192.

2. Koval G.I., Dremin V.G., Bezhanyan A.R. New rolling technologies and mills for the production of engineering blanks // Metallurg, 1998, No. 7, p. 36-37.

Claims (1)

The master device for the step-by-step feeding of workpieces, including a traverse and a carriage, mounted for movement along the guides from the drive, an elastic element located between the traverse and the carriage, characterized in that it is equipped with a ratchet mechanism, the ratchet and dog of which are separately mounted on the traverse and the carriage, moreover, the distance between the teeth of the ratchet is equal to the pitch of the feed.