CS209442B2 - Induction continuous furnace for heating the metal workpieces - Google Patents

Description

(54) Induction continuous furnace for heating metal workpieces

BACKGROUND OF THE INVENTION The present invention relates to an induction continuous furnace for heating metal workpieces, with a device intermittently conveying workpieces through the furnace chamber, through which at least one slide bar passes, through which the individual workpiece slides as it passes through the furnace chamber. in the direction of transport.

Devices of this kind serve in automatic production lines for heating smaller metal blocks of round or square cross-section, such heating machines being arranged in front of forging or other machines in automatic production lines. A pair of slide rails passes through the induction furnace space, on which the metal blocks slide in stacked columns. At the furnace inlet, the column is always moved by the length of the workpiece into the furnace space by means of a block pusher serving as a conveying device, then supplemented by placing a new workpiece on the slide rails at the furnace inlet and then pushed again by pushing the blocks into the oven. Workpieces coming out of the kiln after cycles are removed and fed for further processing.

Known devices of this kind have the disadvantage that the individual workpieces are pressed against each other by relatively considerable forces and possibly welded to each other during transport through the furnace space under the influence of the transport force acting on them and due to the thermal expansion to which they are subjected during transport. This interrupts the production process and disrupts the work cycle.

A number of solutions have been proposed to overcome these shortcomings. For example, it is known to place inserts between the workpieces to prevent them from welding. These inserts may optionally be formed by spraying liquid substances. It is also known to convey workpieces over uneven slide rails, so that the workpieces are moved relative to each other during transport of the furnaces and their welding is prevented. Finally, it is known to oscillate the workpieces by oscillating the guide rails by means of vibrators, so that the relative movements between the workpieces that occur prevent the welding of the workpieces. However, none of these solutions is reliable.

These drawbacks are eliminated by an induction continuous furnace for heating metal workpieces according to the invention, characterized in that it is provided with a reciprocating axially movable conveyor bar passing through the furnace space between sliding rails arranged above the conveyor bar which is rotatable about its longitudinal axis. adjustable angular range and equipped with feeding devices for transporting workpieces.

In an induction continuous furnace according to the invention, advancing workpieces do not exert a pressing force on each other, although they may pass closely behind each other, so that there is no risk of welding together. In addition, the friction of the workpieces on the slide rails is greatly reduced and the movement of the workpieces is smoother. The furnace does not have the block pressure that is otherwise necessary for transport.

An exemplary embodiment of the invention is illustrated in the drawing, where p. 1 is a partial cross-sectional side view of an induction continuous furnace; FIG. 2 is a cross-section in the vertical plane II-II of FIG. 1; and FIG.

Mounted on the base 1 is a machine base 2 (FIG. 1), on which there is an induction coil body 5 forming the furnace on the beams 3, 4 ' On the base 2, the carriage 6 is also mounted reciprocating in the direction of the double arrow

7. Two hydraulic piston engines, 8, 9, whose cylinders are fixedly mounted on the pedestal 2 and the piston rods 10, 11 are connected, to the slide 6, are used for the reciprocating movement of the slide 6.

The carriage 6 carries two columns 12, 13 between which a transport bar 16 of austenitic material is mounted in bearings 14, 15. The conveyor bar 16 is rotatably mounted about its longitudinal axis by an adjustable angle, e.g. 90 °. .

An electric motor 17 is mounted to pivot the conveyor bar 16, which is mounted on a column 12. The conveyor bar 16 is provided with extensions distributed uniformly over its length and forming feed devices 18 which move from the rest position to the transport position when the conveyor bar 16 is rotated. The conveyor bar 16 extends through the furnace space 5A and is arranged between a pair of slide rails 20, 21 below their plane.

The sliding rails 20, 21, which are made in the form of a tube and also made of austenitic material, are fixedly mounted on two vertical beams 22, 23 on the base 2. They run parallel to each other at a distance adapted to the width of the workpieces to be heated. on the conveyor belt 25, they fall into the loading device 26 via a chute 27 arranged in front of the furnace inlet to the inclined inlet section 20A of the slide rails 20, 21 and slide thereafter onto the furnace inlet.

At the furnace outlet there is an inclined outlet section 20B of the slide rails 20, 21, after which the workpieces 24 passed through the furnace space 5A slide onto the second conveyor belt 25A, which leads them for further processing.

The hydraulic piston motors 8, 9 and the electric motor 17 are actuated by means of a common control device (not shown). Starting from the initial phase of the conveying movements, when the carriage 6 is in the starting position according to FIG. 1 and the feed device 18 on the conveying bar 16 takes up the position according to FIG. 2, the electric motor 17 is first actuated. the axis of the predetermined angle and its feed means 18 abutting from below on the workpiece 24, still resting on both slide rails 20, 21, below its center of gravity and lifting it from the second slide rail 21 to the position shown in FIG. 31 In this position, the workpiece 24 thus rests on the first slide bar 20 forming the conveyor bar and on the feed means 18 of the conveyor bar 16J.

At this stage, the hydraulic piston motors 8, 9 are actuated, which move the carriage 6 in the example shown to the right and, together with the carriage, the conveyor bar 16. The conveyor bar 16 moves the workpiece 24 with its feed devices 18. 20 until the slide 6 reaches the end position where it stops. The electric motor 17 is then started again, which rotates the conveying bar 16 back so that the feeding device. will return to the original idle position and place the workpiece 24 again on the second slide 21, which forms the storage rail. Thereafter, the slide 6 with the transport rod · 16 returns via the hydraulic piston motors 8, 9. · To the starting position. . _F

The entire partial transport cycle is then repeated as described above. The transport of the workpieces 24 through the baking space 5A is thus intermittent, and at the outlet of the furnace, the workpieces 24 slide along the inclined exit section 20B of the slide rails 20, 21 onto the second conveyor belt 25A.

The conveyor rod 16, the feed device 18 and the slide rails 20, 21 are preferably made in the form of tubes and flow through a cooling, for example water.

In a varied embodiment, prior to the furnace entrance, an additional conveyor device may be provided above the inclined inlet section 20A of the slide rails 20, 21, which transports the workpieces 24 from the inclined inlet section 20A intermittently to the furnace. At the furnace outlet, a take-off device can be provided for conveying the hot workpieces 24.

In any case, the device described has the advantage that the friction of the workpieces 24 on the slide rails 20, 21 is very small during the conveying space 5A of the furnace. In this case, it may be expedient to adapt the shape of the feeding devices 18 of the conveying bar 16 to the shape of the workpieces 24. The workpieces 24 may have a circular, square or polygonal cross-section. A further advantage is that the workpieces 24 are not forced by each other during the conveying through the furnace space 5A. However, only a slight distance can be maintained between the workpieces 24 to ensure their optimal heating and at the same time optimum utilization of the furnace space 5A. In addition, workpieces can also be transported individually.

In an alternative arrangement, the two slide rails 20, 21 passing through the furnace space 5A may be replaced by a single rail. In such a case, it is expedient for the feed bar 18 of the conveyor bar 16 to engage the individual workpieces 24 not below their center of gravity, but to convey the workpieces 24 lying on a single bar. An arrangement with two slide rails 20, 21 has the advantage that the individual workpieces 24 can be retained below their center of gravity and optionally transported in an indifferent equilibrium, sliding on one or the other conveyor slide 20, 21.

The invention is not limited to the embodiment described. For example, it is possible to replace the sliding rail 21, which serves to support the workpieces 24, by a stacking system different from the described tube and rail construction and consisting of individual stacking surfaces arranged side by side in the conveying path of the workpieces.

The invention can also be implemented in such a way that the feed means 18 are replaced by a second rod running parallel to the conveyor rod and optionally also with chilled water.

The distance of the feed devices 18 passing through the furnace space 5A along the conveying path must be chosen to correspond to the length of the workpieces to be conveyed 24. In order to avoid such a limitation, it is expedient to place the feed devices 18 closely next to each other without gaps.

Otherwise, the arrangement is realized in such a way that the feed devices 18, preferably grip the workpieces 24 below their center of gravity and lift them. This reduces the friction on the slide bar

20. However, the point of engagement of the feed devices 18 may also lie adjacent the center of gravity of the workpieces 24, provided that the conditions then allow them to slide.

Claims (1)

SUBJECT An induction continuous furnace for heating metal workpieces, with a device for intermittently conveying workpieces through the furnace chamber, through which at least one slide bar passes, through which the individual workpiece slides as it passes through the furnace chamber, the conveying device intermittently transmitting to the individual workpiece OF THE INVENTION characterized in that it is provided with a reciprocating axially movable conveyor bar (16) passing through the furnace space (5A) between the slide rails (20, 21) positioned above the conveyor bar (16) which is rotatably mounted about its longitudinal axis in the adjustable angular range i and provided with feed means (18) for conveying the workpieces (24).