Roller ring assembly operation

I. Pressure setting requirements:

8-inch roller ring installation high pressure: 430-460bar, disassembly pressure is 480--680bar

Low pressure: 180-220bar

9-inch roller ring installation pressure is 430-460bar, disassembly pressure is 500--680bar

II. Precautions and causes during roller ring disassembly, accidents and preventions that may occur:

1. When disassembling the roller ring, the exit guide must be moved forward along the rolling direction to prevent the roller ring from being removed and blocked by the guide;

2. When disassembling the roller cap, pay attention to the direction of bolt rotation and determine the direction of loosening before loosening!

Note: If the bolt is rotated too tight, the bolt load will be too heavy, which will damage the bolt hardness release point and cause the thread to break soon. Note: Bolts should be replaced regularly.

3. The disassembled roller cap should not be thrown away randomly. It should be handled with care to avoid damage to the roller cap. Description: The contact surface between the roller cap and the roller ring is scratched, resulting in loose contact between the roller cap and the roller ring, water ingress, rusting of the cone sleeve or affecting the balance, resulting in large vibration and abnormal sound of the rolling mill.

4. Use the roller unloading tool correctly to avoid straining the cone sleeve and tools;

(1) The oil pipe joint must be tightened

Description: There are spring sealing beads in the convex and concave joints. Tightening the joint is to ensure smooth oil return. If it is not tightened in place, the spring sealing beads in the convex and concave joints will not be pushed open, and the pipe or tool will not be able to apply pressure, causing the roller ring to be not installed properly, resulting in the roller ring falling off, relative movement between the roller ring and the cone sleeve, and inertia knocking the cone sleeve and scratching the roller shaft. The production team generally encounters this problem. It also occurred when unloading the roll. The pipe has pressure and the tool is still active. This is why the joint must be tightened. The bead of the slipknot is not pushed open and the oil does not pass through. It is found that the bead of the slipknot is no longer moving, or it cannot be twisted when connected. The reason is that the pressure is applied every time it is tightened, causing the bead to be blocked in the oil port. In serious cases, the bead will be pushed out. On the contrary, the return oil pressure seals the bead on the other side, resulting in no oil return.

(2) Treatment of no oil return

Everyone uses the method of disassembling the slipknot to deal with it. I suggest that you try not to disassemble the slipknot to deal with it. The reason is that the time to disassemble the slipknot is longer than the time for automatic oil return. If there is no oil return, you can disassemble it. The reason is that the above joints are not tightened. The oil returns after tightening for a while (the longest time is 50 seconds). It also depends on the cleanliness of the hydraulic oil. Ensure that the joints are clean. If you want to be faster, you can use a stick to hit the inner cylinder of the tool, or you can put the tool on the roller ring to be removed, press the tool with one hand, and use a hammer to hit the tool oil port a few times to return oil. At the same time, give a certain rotational force to the hand that presses the tool. When you feel that it has been turned into place or turned to 45°±5°, you can apply pressure.

5. Pressure operation:

You must focus on the fluctuation of the pressure gauge to know the action of the cone sleeve, so as to know whether the cone sleeve is pressed in and out, so as to avoid the occurrence of pressure relief and the removal tool is not hit to the maximum stroke. The pressure operation must be more than 10 seconds.

6. Roller cap installation process:

First, check whether there are any scratches or debris on the contact surface between the roller cap and the roller ring, and finally ensure that the contact surface is flattened and pressed correctly. Sometimes it may not be put in place, which can be solved by tapping a few times. If it still cannot be solved, the inside of the roller cap should be checked. Generally, the flat mouth inside the roller cap is not suitable and has scars and burrs, which can be repaired. Note: Flattening and pressing can ensure that no water enters, the cone sleeve does not rust, the roller shaft is well balanced, the product qualification rate is high, and the sound of the finishing mill roll box is normal.

7. Requirements for tightening the left and right turning bolts:

It should not be too tight or too loose, and the spring gasket should be replaced from time to time (generally, after the spring gasket is flattened, it can be determined by hitting the wrench a few times according to the impact force of the personal tool). Note: If necessary, sealant can be applied to prevent water ingress and ensure that the cone sleeve does not rust.

8. During the empty process, the fake sleeve and the empty tube are installed, and the roller gap must be enlarged, otherwise the fake sleeve will touch the empty tube, and the roller box will be burned in serious cases.

9. When installing the fake sleeve, pay attention to check whether there are scars on both ends. The fake sleeve has a positioning end face, which is in contact with the slip ring; the flat end face is matched with the roller cap; otherwise, it will cause improper installation, inadequate installation, excessive water ingress, rust of the cone sleeve, abnormal noise in the roller box, and large vibration values.

10. When emptying, the cone surface of the roller shaft must be coated with butter to protect the cone surface from rusting, and to better clean the roller shaft next time and ensure the quality of the installed roller ring