JPS6255930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing excessive diameter expansion of an uncoiler that supports a coil of a metal stop or other strip material, and in particular, a method for preventing excessive diameter expansion of an uncoiler whose diameter is expanded by a hydraulic cylinder. The present invention relates to a method for preventing an uncoiler drum from being excessively expanded in diameter as the number of turns of a coil on the drum decreases due to unwinding of material.

Conventionally, uncoilers have been installed not only in metal strip processing lines such as rolling mills, continuous annealing furnaces, slitters, and recoiling lines, but also in non-metal strip processing lines to unwind the coil and feed out the strip material. .

Such an uncoiler includes, for example, the one shown in FIG. The piston rod 4 is configured to expand or contract the diameter by moving it back and forth with respect to the drum 1.

In such an uncoiler, when loading the coil 5 into the uncoiler drum 1, the diameter of the uncoiler drum 1 is reduced, and after loading, the electromagnetic switching valve 6 is switched to the B position, and the cylinder device 2 is switched by the switching valve 6.
The cylinder chamber 7 on the reduced diameter side is connected to the tank T via the supply/discharge pipe 8, and the cylinder chamber 9 on the enlarged diameter side is connected to the supply/discharge pipe 10.
Then, hydraulic pressure is introduced from the hydraulic source P, and the diameter of the drum is expanded against the coil's inner surface tightening force, and the drum 1 is completely brought into close contact with the inner diameter surface of the coil 5, and the coil 5 is placed on the drum 1. It is fixed at

However, the conventional uncoiler drum 1 sufficiently expands in diameter in its initial state (when the coil's own weight is at its maximum).
Because the structure is such that the pressure that fixes the coil 5 to the drum 1 continues to push the inner diameter surface of the coil until the end, the number of turns remaining in the coil decreases and the inner winding force of the coil decreases. The coil becomes loose due to the force of the drum trying to expand its diameter, causing relative sliding between each winding of the coil and between the coil and the drum, resulting in the problem of scratches occurring on the coil surface. be.

An object of the present invention is to prevent the occurrence of the coil surface flaws due to the above-mentioned relative sliding when the number of turns of the coil on the drum decreases due to the coil being unwound as mentioned above. be.

Therefore, according to the present invention, the diameter of the drum is expanded by a hydraulic cylinder device against the internal winding force of the coil mounted on the drum of the uncoiler, the coil is fixed on the drum, and the strip is removed from the coil. When the number of turns of the coil on the drum decreases to a predetermined amount when unwinding the drum, the switching valve installed in the supply/discharge pipe to the expansion side cylinder chamber and diameter contraction side cylinder chamber of the hydraulic cylinder device is set to the neutral position. Then, the hydraulic pressure in the supply/discharge pipeline between the two cylinder chambers and the switching valve is balanced via a pilot check valve, thereby overcoming the internal winding force of the coil on the drum and expanding the diameter of the drum. It is characterized by preventing

As a result, according to the present invention, when the number of coil turns on the drum of the uncoiler decreases, excessive expansion of the diameter of the drum is prevented by removing the force that tends to further expand the diameter of the drum. Relative sliding of the coil strip does not occur, and surface defects such as slip defects on the surface of the strip caused by this relative sliding can be eliminated.

The invention will now be explained with reference to the drawings.

FIG. 2 shows an example of a device for carrying out the present invention, in which a pilot check valve 1 is connected to supply and discharge pipes 8 and 10 between an electromagnetic switching valve 11 and a hydraulic cylinder device 2.
2 and 13 respectively, and the uncoiler drum 1
After the coil 5 is inserted and fixed, the electromagnetic switching valve 11 is set to neutral to prevent the diameter from expanding any further, especially when the number of turns of the coil 5 is running low, so as not to generate force on the drum 1 to further expand the diameter. It is configured to be changed and held at position N.

14 in FIG. 2 is a pilot check valve 12 installed in the middle of the hydraulic supply/discharge circuits 8 and 10;
This is an internal pilot hydraulic line for opening 13.

This internal pilot hydraulic line 14 receives pressure supplied via the electromagnetic switching valve 11. For example, when the electromagnetic switching valve 11 is switched to position A, the hydraulic pressure of the hydraulic source P is applied to the diameter-reducing side of the hydraulic cylinder 2. It is applied to the cylinder chamber 7 through the supply and discharge pipe 8, and
It also acts on the pilot hydraulic line 14b. Therefore, the pilot check valve 13 is opened and the oil in the cylinder chamber 9 on the enlarged diameter side of the hydraulic cylinder 2 is returned to the T pipe through the hydraulic supply and discharge pipe 10 and the pilot check valve 13.

In this way, the hydraulic pressure that opens the pilot check valve 13 via the pilot hydraulic line 14b is equal to the hydraulic pressure (atmospheric pressure) in the cylinder chamber 9 on the expanded diameter side.
Since it is sufficiently larger, the pilot check valve 13
will be released.

However, when the number of turns of the coil on the drum decreases to a predetermined amount, when the solenoid valve 11 is brought to the neutral position N, the hydraulic supply/discharge pipes 8, 10 are affected by the hydraulic pressure to open the pilot check valves 12, 13. Since the back pressure is large, the pilot check valves 12 and 13 do not open. Therefore, no hydraulic pressure flows into or out of both cylinder chambers, the position of the piston is maintained in an equilibrium state, and the diameter of the drum of the uncoiler does not expand or contract.

As shown in FIG. 2, by switching the electromagnetic switching valve 11 to the neutral position N, excessive expansion of the diameter of the uncoiler drum 1 can be prevented. Furthermore, if you set this position N too early (at the stage when the coil is at its own weight), there is a risk that the drum will start to contract in diameter due to leaks at the rotary joint and other parts, causing the coil 5 to fall out during uncoiling. The switching point needs to be set according to each state (condition).
Also, the reason why pilot check valves 12 and 13 are provided in the supply/discharge pipeline between the electromagnetic switching valve 11 and the hydraulic cylinder device 2 is that when the electromagnetic switching valve 11 is in the neutral state N, the electromagnetic switching valve 11 and the cylinder device 2 This is to minimize the amount of movement of the piston rod 4 when back pressure remains in the conduit between the piston rod and the coil's internal winding force is overcome by the back pressure. As described above, according to the present invention, the purpose can be achieved using inexpensive means such as an electromagnetic switching valve and a pilot check valve, and the over-diameter expansion phenomenon that occurs in the conventional method does not occur, so that scratches do not occur on the surface of the strip. Problems that may occur can be resolved.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic control circuit diagram of a conventional device, and FIG. 2 is a hydraulic control circuit diagram according to the present invention. DESCRIPTION OF SYMBOLS 1... Uncoiler drum, 2... Hydraulic cylinder device, 5... Coil, 8, 10... Hydraulic supply/discharge circuit, 11
...Solenoid switching valve, 12, 13...Pilot check valve, 14...Internal pilot hydraulic line.

Claims (1)

[Claims] 1. When unwinding the strip material from the coil by expanding the diameter of the drum using a hydraulic cylinder device against the internal winding force of the coil mounted on the drum of the uncoiler and fixing the coil on the drum, When the number of turns of the coil decreases to a predetermined amount, the switching valve provided in the supply/discharge pipe to the cylinder chamber on the expanding diameter side and the cylinder chamber on the contracting diameter side of the hydraulic cylinder device is set to the neutral position, and both the cylinder chambers and the The oil pressure in the supply/discharge pipe between the switching valve and the switching valve is balanced through a pilot check valve, thereby overcoming the internal winding force of the coil on the drum and preventing the drum from expanding in diameter. A method to prevent excessive diameter expansion of an uncoiler.