Rolling Mill:

Equipment for achieving the metal rolling process

Rolling mill is the equipment used to achieve the metal rolling process, which generally refers to the equipment used to complete the entire process of rolling material production

Rolling mills can be divided into two rolls, four rolls, six rolls, eight rolls, twelve rolls, eighteen rolls, etc. according to the number of rolls; According to the arrangement of the rollers, they can be divided into "L" type, "T" type, "F" type, "Z" type, and "S" type.

The ordinary rolling mill mainly consists of a roller, a frame, a roller pitch adjustment device, a roller temperature adjustment device, a transmission device, a lubrication system, a control system, and a roller dismantling device. In addition to the main components and devices of ordinary rolling mills, precision rolling machines have added devices to ensure rolling accuracy.

Brief introduction:

Equipment for achieving the metal rolling process. It refers to the equipment that completes the entire process of rolling production, including the unwinding machine, rolling system, driving system, hydraulic system, control system, roll dismantling device, etc. But generally speaking, the rolling mill only refers to the main equipment. It is said that there were rolling mills in Europe in the 14th century, but it is recorded that in 1480, the Italian Leonardo da Vinci designed a sketch of the rolling mill. In 1553, the Frenchman Brulier rolled gold and silver plates to make coins. Subsequently, rolling mills emerged in Spain, Belgium, and the United Kingdom.

Naming method:

Name according to rolling variety, rolling mill type, and nominal size. The principle of "nominal size" for profile rolling mills is named after the pitch diameter of the herringbone gear on the gear seat; The blooming mill is named after the nominal diameter of the roller; The plate and strip rolling mill is named after the length of the working roll body; The steel pipe rolling mill is named after the maximum pipe diameter produced. Sometimes named after the inventor of the rolling mill.

Componenets:

Working seat:

It is composed of roll, mill memorial archway, bearing pedestal, bearing, self coiling or unwinding platform, base, roll adjusting device, upper roll balancing device and roll changing device.

Roll:

It is a component that causes plastic deformation of metal.

Roller bearings:

Support the rollers and maintain their fixed position in the frame. The working load of roller bearings is heavy and varies greatly, so it is required that the friction coefficient of the bearings be small, have sufficient strength and stiffness, and be easy to replace the rollers, such as cylindrical roller bearings. Different types of roller bearings are used for different rolling mills. Cylindrical roller bearings have high rigidity, low friction coefficient, high pressure resistance, and are convenient for roller disassembly, but their prices are relatively high. Rolling bearings have high rigidity and low friction coefficient, but their load-bearing capacity is small and their overall dimensions are large. They are mostly used for working rolls in plate and strip mills. There are two types of sliding bearings: semi dry friction and liquid friction. Semi dry friction roller bearings are mainly made of bakelite, copper tile, and nylon tile bearings, which are relatively inexpensive and are mostly used in profile rolling mills and billets. There are three types of liquid friction bearings: dynamic pressure, static pressure, and static dynamic pressure. The advantage is that the friction coefficient is relatively small, the pressure bearing capacity is large, the working speed is high, and the rigidity is good. The disadvantage is that the oil film thickness changes with speed. Liquid friction bearings are commonly used for support rolls of plate and strip mills and other high-speed rolling mills.

Body frame:

It is composed of two pieces of "notched memorial archway" to install the roller bearing block and roller adjustment device, which shall have sufficient strength and rigidity to bear the rolling force. There are two main types of racks: closed and open. The closed frame is an integral framework with high strength and stiffness, mainly used for blooming mills and strip mills with high rolling force. A roller changing guide rail can be installed below the mouth frame, and it is composed of an external roller changing car for easy roller changing.

Stand:

Used to install a rack and fix it on the foundation, also known as a baseboard. Bear the gravity and overturning torque of the working machine base, while ensuring the accuracy of the installation dimensions of the working machine base.

Roll adjustment device:

Used to adjust the roll gap to achieve the required cross-sectional size of the rolled piece. The upper roller adjustment device, also known as the "press down device", has three types: manual, electric, and hydraulic. Manual screwdown devices are often used on profile mills and small mills. The electric screwdown device includes components such as an electric motor, reducer, brake, screwdown screw, screwdown nut, screwdown position indicator, spherical pad, and pressure gauge. Its transmission efficiency is low, the rotational inertia of the moving part is large, the reaction speed is slow, and the adjustment accuracy is low. Since the 1970s, after the adoption of AGC (Automatic Thickness Control) system in plate and strip mills, hydraulic screwdown devices have been used in new strip cold and hot rolling mills and thick plate mills, which have the advantages of small plate thickness deviation and high product qualification rate.

Upper roll balancing device:

A device used to lift the upper roller and prevent impact when the rolled piece enters or exits the roller. The forms include: spring type, commonly used on profile rolling mills; heavy hammer type, commonly used on blooming mills with large roll movement; hydraulic type, commonly used on four high plate and strip rolling mills.

To improve the operation rate, it is required that the rolling mill change the rolls quickly and conveniently. There are four types of roller changing methods: C-hook type, sleeve type, trolley type, and whole frame roller changing type. The first two methods of changing rolls rely on crane assistance, while the entire frame requires two sets of frames for changing rolls. This method is often used for small rolling mills. Small car roll changing is suitable for large rolling mills and is beneficial for automation. Nowadays, fast automatic roll changing devices are used on rolling mills, and a roll change only takes 5-8 minutes.

Transmission:

It consists of an electric motor, a reducer, a gear seat, and a connecting shaft. The gear seat distributes the transmission torque to two or several rollers.

Auxiliary equipment includes equipment for a series of auxiliary processes during the rolling process. Equipment such as raw material preparation, heating, steel turning, shearing, straightening, cooling, flaw detection, heat treatment, pickling, etc.

Hoisting and transportation equipment, such as cranes, transport vehicles, roller tracks, and transfer machines.

Accessory equipment:

There are equipment for power supply, distribution, rolling mill, lubrication, water supply and drainage, fuel supply, compressed air, hydraulic pressure, removal of iron oxide scale, machine repair, electrical repair, acid discharge, oil, water, acid recovery, and environmental protection.