JPS6149732A - Overload preventing device in case of cold roll forming - Google Patents

Abstract

PURPOSE:To prevent a damage of a roll chock, etc. by providing a hydraulic holding mechanism on at least one roll of the upper and the lower rolls, and also providing an accumulator for keeping a hydraulic pressure of a hydraulic cylinder constant. CONSTITUTION:A screw rolling reduction mechanism 7 is placed on an upper roll chock 6, and a hydraulic holding mechanism 8 for giving a pressure force is provided on a lower roll chock 6. Also, an accumulator 10 for keeping a hydraulic pressure of a hydraulic cylinder in the mechanism 8 constant is provided. An interval of upper and lower rolls 2, 3 is set in advance to the same gap as a thickness of a product of a groove shape steel, and an intermediate product 20 is bitten in between the rolls 2, 3 by a prescribed rolling reduction of a rolling reduction mechanism 7. In this case, an excessive load generated in the roll chock 6 is absorbed by the accumulator 10 connected to the hydraulic cylinder 9. In this way, a damage caused by an excessive load of the roll chock 6 or a stand is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cold roll forming device for removing distortions and bends caused during hot rolling during the production of plate materials, shaped steel, etc. In particular, the present invention relates to a cold roll forming device for removing distortions and bends caused during hot rolling during manufacturing of plate materials, shaped steel, etc. The present invention relates to a device that prevents an excessive load from being applied to a roll chock when cold roll forming a produced workpiece.

The applicant first manufactured a channel steel having parallel flange portions and a flat web portion, and in the hot rolling process, each of the pair of flange portions was inclined outward with respect to a perpendicular line, and the web portion was made convex. An intermediate product having a W-shaped cross section and a wall thickness of the flange portion and web portion that is approximately the same as the product dimensions is formed, and then cold roll forming is performed to form the convex portion of the intermediate product. We have applied for a manufacturing method that flattens the web portion of the shape.

In the above-mentioned cold roll forming, in order to flatten the convex web part, the roll gap is made in advance to be the same as the product thickness of the channel steel, and the roll chock supporting the cold forming roll shaft is Cold roll forming is performed by applying the resultant force of the rolling blade that flattens the convex-shaped web part and the force that counters the longitudinal bending that occurs when flattening the web part using a rolling machine (+#). It is something to do.

However, the wall thickness of the web portion of a hot-rolled intermediate product with a W-shaped cross section has slight variations, and the roll gap is enlarged when cold roll forming the thick web portion. As mentioned above, the roll chock that supports the roll shaft is provided with a roll gap corresponding to the target thickness by the screw lowering mechanism, and when material with a wall thickness larger than the target enters the roll gap, the roll chock part and the roll chock are There was a problem that a large load was applied to the stand that supports the web, causing damage to the bearings that make up the screw lowering mechanism and roll chock.On the other hand, when an excessive load is generated due to changes in the thickness of the web part, There are methods to increase the stiffness of the stands and rolls to counteract this load, or to provide a pressure mechanism consisting of a load cell to detect the load and an electro-hydraulic servo system to absorb this load. In the case of the latter, the equipment becomes large in size, and in the case of the latter, the equipment becomes expensive, and there is no suitable device that can cope with variations in the thickness of the web portion.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and it is possible to reduce the cost even when excessive loads occur, such as variations in the thickness of the web portion of channel steel, material biting, and biting out. Therefore, in the apparatus of the present invention, even a rolling mill suitand with low rigidity can be used.

In order to remove distortions and bends that occur during hot rolling during the production of plate materials, shaped steel, etc., the present invention comprises a plurality of cold rolls arranged parallel to each other and at least one of which is rotated by a drive device. A cold roll forming device is used which has a roll chock having a roller bearing inside that is fitted to the roll shaft formed at both ends of the cold forming roll, and a screw lowering mechanism that applies a pressing force to the roll chock. In order to cope with changes in thickness, an Akiemulator is provided that forms a closed loop with the oil that operates the hydraulic cylinder of the hydraulically driven holding mechanism and keeps the oil pressure in the hydraulic cylinder constant at all times. Even if there is slight variation in the hydraulic pressure within the hydraulic cylinder, the increase in the hydraulic pressure within the hydraulic cylinder can be absorbed by the accumulator, and an excessive load can be prevented from being applied to the roll chock or the stand.

The present invention will be explained below based on one embodiment thereof.

In this example, in the production of channel steel, a pair of flange portions are cut into perpendicular lines and inclined outward during hot rolling, the web portion is made convex, and its cross section is W-shaped, and the flange portion Next, cold roll forming will be described in which an intermediate product is formed whose web portion has approximately the same thickness as the product dimensions, and the convex web portion of this intermediate product is flattened.

1 is a plurality of rollers for flattening the convex-shaped web portion 21 of the intermediate product 20 and cold roll-forming a channel steel having a parallel flange portion 22 and a flat web portion 21;
3 is an upper roll, 3 is a lower roll, 4 is a pinch roller, and 3 is a roll shaft formed at both ends of the roller 2.3.

6 is a roll chock having a roller bearing inside that rotatably supports the roll shaft 5; 7 is a screw support mechanism that applies a pressing force to the roll chock 6 that supports the upper roll 2; 8 is a screw support mechanism that applies a pressing force to the roll chock 6 that supports the upper roll 2; , hydraulic cylinder 9 of cylinder mechanism 8
This is an accumulator that forms a closed loop with the oil inside the hydraulic cylinder 9 and keeps the oil pressure inside the hydraulic cylinder 9 constant.

Then, the cross section formed in the hot rolling process is W
In order to flatten the convex-shaped web part 21 of the intermediate product 20, the roll gap is set to be the same as the product thickness of the channel steel, and the roll chock 6 supporting the cold-forming roll shaft 5 is The screw lowering mechanism 7 applies a resultant force of the lowering blade that flattens the convex-shaped web part 21 and the force that opposes the bending in the longitudinal direction that occurs when flattening the web part 21, so that the cross section becomes W-shaped. Roll the intermediate product 20 of 2.3
It's something to fit in between. Roll 2 when biting
．． 3 gap is enlarged, and an excessive load is momentarily applied to the roll chock 6, but the increase in the oil pressure in the hydraulic cylinder 9 is adjusted by the accumulator 10, which forms a closed loop with the oil that operates the hydraulic cylinder 9 of the lowering mechanism 8. The excessive load applied to the roll chock 6 due to this is absorbed by the accumulator 10.

When forming a channel steel with a web portion 21 having a wall pressure of 0.3 mm, the gap between the rolls 2 and 3 is enlarged in the same way as described above, and an excessive load is applied to the roll chock 6. The increase in oil pressure in the hydraulic cylinder 9 is absorbed by the excessive load applied to the roll chock 6 by the accumulator 10, and even if the web portion 21
The roll chock 6 and the stand (not shown) will not be damaged even in cold roll forming of the groove-shaped sheet 14 with a large wall pressure.

As mentioned above, the present invention is applicable to cold working for removing distortions and bends caused by hot rolling during production of plates and shaped steel, even if slight variations in plate thickness occur during hot rolling. Regarding the forming of the workpiece, the roll chock or stand will not be damaged due to excessive load, and is highly practical.

[Brief explanation of the drawing]

FIG. 1 is a schematic view showing rolls and pinch rollers used in cold roll processing, and FIG. 2 is a schematic view of a cold roll forming apparatus provided with the overload prevention device of the present invention.

Claims (1)

[Claims] In a plurality of sets of cold roll forming devices arranged parallel to each other and at least one of which is rotated by a drive device, a roll shaft formed at both ends of the cold forming roll and a roll shaft rotatably supported. a roll chock having a roller bearing therein; a screw-down mechanism that applies a pressing force to the roll chock that supports the upper roll among the cold forming rolls; and a screw lowering mechanism that applies a pressing force to at least one of the upper and lower rolls. and an accumulator that forms a closed loop with the oil that operates the hydraulic cylinder of the holding mechanism and keeps the hydraulic pressure in the hydraulic cylinder constant at all times. Overload protection device.