Alligator scissors and their uses

Principle of operation

The hydraulic shear system is similar in principle to variations of the manual or electric type. The difference is characterized by the way the force is applied to the separating element. Instead of a gearbox or manual mechanism, a hydraulic cylinder or pump plays this role. This design has many advantages.

• The high efficiency of conversion of efforts allows the development of a force for the blade equal to several tons. In this case, the dead weight of the tool varies from 1 to 4 kg.
• The mobility and autonomy of the device is higher in comparison with manual or electrical devices.
• The cut quality is better as the cut is longer.
• The hydraulic drive is safer than other options.
• The guillotine type of knives is considered an improvement over lever tools.
• The blade moves at a low speed, so the work process is easier to control.

These are the main advantages of a hydraulic tool. Fast and accurate work is essential when cutting sheet metal. This factor is especially relevant for detailed cutting of thick sheets.

User manual

Before using the product, you must follow a number of the following recommendations.

• Each tool comes complete with accompanying documentation, which must be studied in advance.
• Newer models usually have a protective lubricant that needs to be removed from the blades.
• The cylinder must be checked for oil level, and the entire pneumatic structure must be correctly combined into a single system. If there is no oil in the pump, it should be topped up using only suitable technical grades. Recommendations for the choice of lubricant are contained in the manufacturer's technical documentation.

When using the product, you must adhere to the following rules:

• the standard characteristics of the tool must correspond to the thickness of the processed material or be more;
• replacement of lubricants in the pump should be done at least once a year;
• in the event of an emergency, cutting should be stopped immediately;
• most of the hydraulic type tools are subject to repair, after which their reuse is allowed.

It is also important to know the general safety rules. When using the tool, it is important to consider:

• the correct position of the tool, especially its working part;
• features of treatment with anti-corrosion compounds during long-term storage;
• mandatory cleaning of moving parts before starting work.

An overview of the model of the hydraulic shears for metal, see below.

Peculiarities

Hydraulic shears are successful in cutting rebar, which is needed for concrete structures. Steel products will also not become an obstacle for this type of equipment. The technical structure of the hydraulic shear seems to be complicated, but in reality it is simple. The tool is popular not only in construction work, but also in industrial production.

The hydraulic cylinders are responsible for this setting. Because of them, automatic systems are usually very large. The length of the cutting edge of these types reaches eight or more meters.

If a large device is not necessary, you can choose the option with manual control parameters. The scope of use of such equipment is already, but scissors can be used, for example, for cutting a cable. The force is transmitted to the object by pressure generated by an internal pump.

At the same time, manual devices are characterized by compact dimensions and increased mobility.

In the field of production of various materials, hand scissors with an external pump are used. The tool is suitable for cutting products with particularly large dimensions. Pressure is supplied to the tool through a long flexible tube. This distinctive feature allows you to place the separating part at absolutely any angle. Labor is also simplified due to the possibility of connecting any pumping device.

Working with metal is possible without a special separating device. One-time undercuts or cutting of thin rods are allowed with the help of a grinder. An electric jigsaw and conventional metal cutters are also suitable. We will talk about the scope of application of hydraulic shears and the principles of operation of the device further.

Description

Alligator shears Q43-5000 is ideal equipment for small and medium scale metal recycling plants, metallurgical plants, scrap metal recycling plants, etc. The machine is used for cold cutting scrap metal to sizes suitable for furnace smelting. The processed materials include various shapes and structural steels of round, square, iron angles, H-beams, plate steel, steel pipes, and so on. If necessary, a diesel engine is used to drive the equipment (in the absence of a power source at the facility).

Alligator shears are suitable for automatic operation, have different blade lengths and maximum cutting force, etc. The equipment has push-button control, automatic cutting mode and manual feed. Customers from Russia, Ukraine and other countries widely use this type of machine. In addition, we design and manufacture equipment with special characteristics to meet the specific requirements of users.

Wanshida Hydraulic Equipment Factory, is a professional scrap metal recycling equipment manufacturer. We produce hydraulic balers for scrap metal, mechanical alligator shears for cutting scrap metal, briquetting presses for metal shavings, crushers for crushing metals, shear presses with horizontal cut, as well as shear presses with a baling chamber. This equipment is widely used in metallurgy, waste management, renewable resource recycling, metal processing and some other fields.

Our advanced production equipment and control equipment, under the guidance of 5 senior engineers and 3 foreign engineers, enable us to fulfill your order with high efficiency and meet your requirements for the purchased equipment.

Varieties

Regardless of the principle of work, the tools are divided into:

• knife;
• nibbling.

The first version of the product is equipped with two single-edged knives. Only the edges of the material to be cut can be cut with these scissors. The middle of the workpiece can be cut with punching (nibbling) shears.

The following types of hydraulic shears are known.

Manual ones are used for ropes and fittings. The tool has been successfully used in rescue operations. Scissors are used when cutting large quantities of rods and wires. The system of manual hydraulic shears is different in the design of the sharp part.Professional tools are guillotine and edging. If the first option can easily cope with bundles of wire and cables, then the second is useful in processing sheet metal.

Composition of units and principle of operation

Crank shears for cutting metal have a fairly uniform structure, which includes the following units:

• AC drive motor;
• the drive shaft on which the switching system is located;
• intermediate gear transmission;
• flywheel;
• crank or eccentric shaft;
• a connecting rod with a slider, to which movable knives are attached;
• clamping mechanism for the original workpiece;
• back-up unit for the cut-off part of the bar (strip, rolled section);
• an adjustable roller table for feeding the raw material;
• back emphasis;
• bed.

The process of a single cycle of cutting metal on combined press-shears occurs in the following sequence. The operator, including the roller conveyor, introduces the cut profile into the working area of ​​the shear press, after which the required billet length is set using the back stop. After that, the material is fixed in the required position with a clamping device, and is supported by a compensator, which ensures the constancy of the horizontal axis of the bar / strip during the cutting process. After that, the electric motor of the combined shear press is switched on to the working stroke. The engagement clutch is triggered (for large standard sizes it is pneumo-electric multi-disc, for scissors with a force of less than 800 kN, the unit can also contain one pressure plate), and the band brake releases the shaft, which transfers the required torque to the crank shaft through a gear transmission. The crank mechanism located there converts the rotation into translational movement of the slider with the working knife. The cut product falls down the slide onto the receiving tray, and from there - into the box for cut blanks. At this time, the crank mechanism returns to its original - upper - position. The engagement system is triggered, and the shaft is secured by synchronous engagement of the band-type brake.

Operations performed on press-shears NG5224

With the automatic operation of the combined shears, during the return stroke of the slider, the next workpiece is pushed and fixed in the cutting zone.

Hydraulically driven shears (for example, from the Hecka Multicrop series) are powered by a hydraulic power cylinder that controls the reciprocating movement of the slider. Such equipment is less efficient, but it provides the ability to hold the slider at the lowest point. In some cases, this improves the quality of the cut. Geka scissors are distinguished by the presence of the option of angular cutting of the profile, as well as the possibility of subsequent bending.

Slightly different kinematics are possessed by press-shears for cutting metal of the alligator type, as well as reinforcing shears designed for mechanized separation of bars made of reinforcing steel. There are less torques, therefore, instead of a friction clutch, a structurally simpler rigid clutch with pivot keys is provided in the scheme. In addition to unpretentious maintenance, it does not require a continuous supply of compressed air at a pressure of more than 5 ... 6 at. The slider itself does not reciprocate, but swing movements. With a slightly worse quality of the cut (for scrap this circumstance is not of particular importance), the height of the working space between the movable and fixed knives increases, which makes it easier to cut the scrap metal.

Selection recommendations

The performance and specifications of most hydraulic variations are versatile

When machining workpieces, it is important to consider the thickness of the material. The shape of the working part of the product is selected based on the scope of its use

When choosing, special attention must be paid to the dimensions and weight of the scissors themselves.

Hydraulic tools have basic operational parameters that you can rely on when choosing tools for cutting metal, rubber, concrete, tires:

• the maximum possible indicator of the cutting force, calculated in kN or tons;
• the gap between the cutting blades in mm;
• unclamping force, calculated in kN;
• tractive effort in kN;
• parameter of thrust movement in mm.

Combined scissors designed for opening structures are equipped with an additional pedal. It relieves pressure in the working pump. If the tool has been idle for a long time, this part may not work properly.

Classic hydraulic shears can cut a profile with a cross section of about 100 mm. The tool is suitable not only for rolled metal, but can also be used as attachments to an excavator. There are firefighters or cable hydraulic shears, they are used by the corresponding services. A tool with knives, working like a guillotine, is needed to cut rebar, wire or cable. The cuts made with such products are of good quality, even if the cables are thick enough. These device options differ in the way the blades are closed.

To choose scissors for your home, you need to consider:

• location of cutting edges;
• the shape of the blades;
• cutting feature of the tool;
• model power;
• convenience for use in a specific situation;
• the presence of basic protection.