There are many kinds of pliers, and they are widely used. They are an indispensable
Hand Tool for clamping and cutting workpieces in various industries such as assembly, repair and installation. However, it has a common basic structure, that is, any hand pliers is composed of three parts: a pliers head, a pin and a pliers handle. The basic principle of pliers is to use two levers to cross connect the two ends at a point in the middle with pins so that the two ends can move relatively. As long as the tail end is operated by hand, the other end can pinch the object. In order to reduce the force used by the user during operation, according to the lever principle of mechanics, the tong handle is usually made longer than the tong head, so that a strong clamping force can be obtained with a small force to meet the use requirements.
The three parts of the pliers are as follows:
A pair of handles for holding. The clamp handle designed according to the principle of ergonomics is convenient for more safe and comfortable holding. Connecting axis, which is the connecting axis point of the pliers. The connection point must move smoothly without any looseness, so that the pliers can be easily opened or closed with one hand. The tong head is equipped with a clamping jaw or a cutting edge. The cutting edge of the tong head is finely ground into a proper shape. The two cutting edges (with springs) must be very sharp and close to each other accurately to cut the wire easily.
This converts a small external force (such as the hand force applied on the pliers arm) into a large power, so that the pliers can effectively clamp or shear. When the external force applied to the tong arm increases with the leverage ratio, the force of the tong mouth generates an external force for clamping movement. If a large external force is to be generated, the distance from the center of the riveting position of the pliers to the handle must be as long as possible, and the distance from the clamping opening or shear opening to the riveting center must be as short as possible. However, many pliers will not greatly increase the hand power, because they only make it easier to operate in difficult places, such as the assembly of electronic equipment and the application of electronics and precision engineering.
Pliers are usually forged from alloy and non alloy structural steel. The general pliers are made of high-quality carbon structural steel with a carbon content of 0.45%. High quality and heavy duty pliers are made of high carbon content and / or alloying elements such as chromium or vanadium.
The origin of pliers in Europe can be traced back to more than 1000 years B.C., when people began to cast iron. During the casting process, pliers can be used to hold hot iron pieces. The shape of the forging pliers in the past has remained unchanged. The types of pliers are expanding with the development of handicraft, commerce and industrialization. There are 100 kinds of universal pliers. Special applications of pliers are also increasing. Of course, these special pliers are not always available in the general scope. It is the only one in Germany, with a monthly output of more than 1 million pliers, about 50% of which are exported. Most of them are general-purpose pliers, such as shear pliers, wire pliers and water pump pliers.
As for functions, the differences are as follows:
① Shears can be used for cutting or trimming (side shears, front shears, trimmers, etc.).
② Wire pliers can be used for cutting and clamping (wire pliers, crane nose pliers, electronic pliers, etc.).
Regarding the splicing structure, the differences are as follows:
① Butt splices, e.g. carpenter's pliers. The tongs are butted and installed on top of each other, without milling and riveting.
② Single scissor type splicing, such as wire pliers. The butt joint is milled and half of the thickness is milled so that the two pliers are inserted and installed.
③ Sleeve type splicing: one handle is provided with a groove, and the other handle passes through the groove and is spliced at the joint. The casing type twisted pliers - except for the water pump pliers - are difficult to manufacture because of the use of hard alloy steel, so the manufacturing cost is high. Therefore, compared with the first two splicing methods, it is relatively minor.
type
Pliers can be divided into: clamping and twisting type; Shear type; Clamp torsion shear type. It can be divided into: hydraulic tong; Crimping pliers; Hydraulic wire clamp; Wire stripper; Rechargeable hydraulic cable clamp. According to the shape, it can be divided into: pointed mouth; Flat mouth; Round mouth; Curved mouth; Oblique mouth; Needle mouth; Top cutting; Wire pliers; Flower gill forceps, etc. According to the use, it can be divided into DIY, industrial grade pliers, special pliers, etc. According to the structural form, it can be divided into two types: through gill and folded gill. The general specifications are: 4.5 "(mini pliers), 5", 6 ", 7", 8 ", 9.5", etc.
The main categories are as follows:
Wire pliers
Fig. 1 wire pliers
Fig. 1 wire pliers
The wire clamp is a kind of clamp and cutting tool. Its shape is shown in Figure 1 on the right.
The wire Tong is composed of a tong head and a tong handle. The tong head includes a jaw, a tooth mouth, a knife edge, and a guillotine mouth. The functions of each part of the pliers are: ① the tooth mouth can be used to fasten or loosen the nut; ② The knife edge can be used to cut the rubber or plastic insulation layer of the flexible wire, and can also be used to cut the wire and iron wire; ③ The guillotine can be used to cut hard metal wires such as wires and steel wires; ④ The insulated plastic pipe of the pliers has a withstand voltage of more than 500V, and it can cut the wire with electricity. During use, do not litter. So as not to damage the insulating plastic pipe. Wire pliers commonly used by electricians include 150mm, 175mm, 200mm and 250mm.
Needle nose pliers
Pointed nose pliers, also known as trimming pliers, are mainly used to cut single strand and multi strand wires with small wire diameter, bend the single strand wire joint, peel the plastic insulation layer, etc. it is also one of the commonly used tools for electricians (especially for internal electricians). It is composed of a pointed head, a knife edge and a tong handle. The handle of the pointed nose pliers for electricians is sleeved with an insulating sleeve with a rated voltage of 500V. Due to the sharp head of the pointed nose pliers, the operation method of using the pointed nose pliers to bend the wire connector is as follows: first turn the wire head to the left, and then bend it to the right against the screw in a clockwise direction.
Wire stripper
Fig. 2 stripping pliers
Fig. 2 stripping pliers (2 pieces)
The wire stripper is one of the tools commonly used by the electricians for internal line, motor repair and instrument and meter repair. Its appearance is shown in Fig. 2. It is composed of a knife edge, a wire pressing edge and a clamp handle. The handle of the stripping pliers is sleeved with an insulating sleeve with a rated working voltage of 500V.
Wire stripping pliers are suitable for stripping plastic, rubber insulated wires and cable cores.
Pipe clamp
Used to fasten or disassemble various pipes, pipe accessories or round parts. Common tools for pipeline installation and repair. Its inlay can be forged and cast. In addition, it is made of aluminum alloy, which is characterized by light weight, light use and not easy to rust.
Side mouth pliers
Side mouth pliers are sometimes called oblique mouth pliers. When cutting the wire, especially when cutting off the excess wire head after the wire is wound on the welding point and the long lead wire after the printed circuit board is placed with the plug-in, the use of the offset pliers is the best tool. Side cutters are also often used to cut insulating sleeves and nylon cable ties instead of ordinary scissors. Side mouth pliers with 160mm body length and plastic insulated handle are most commonly used. [2]
Features: editing and broadcasting
Pliers generally include wire pliers, pointed nose pliers and diagonal pliers. It is used for clamping or bending thin sheet shaped and cylindrical metal parts and cutting metal wires, and its side edge can also be used for cutting thin metal wires.
Material: the pliers are made of high-quality chrome vanadium steel.
Forging: the hot forging forming technology of die forging is adopted.
Heat treatment: computer controlled heat treatment technology is adopted to ensure the stability of hardness.
Surface treatment: surface polishing treatment.
Features: the cutting edge is subject to special heat treatment process to maintain the stability of long-term cutting work.
Hardness: hrc40-48.
Shears: meet DIN standards.
matters needing attention
① The pliers are operated with the right hand. Put the jaw inward to facilitate the control of the cutting position. Put your little finger in the middle of the two handles to hold the handle and open the clamp head, so that the handle can be separated flexibly.
② The knife edge of the pliers can be used to cut the rubber or plastic insulation layer of the flexible wire.
③ The knife edge of the pliers can also be used to cut electric wires and iron wires. When cutting No. 8 galvanized iron wire, the blade shall be used to cut back and forth around the surface for several times, and then the iron wire shall be broken with a gentle pull.
④ The guillotine can also be used to cut hard metal wires such as wires and steel wires.
⑤ The insulated plastic pipe of the pliers has a withstand voltage of more than 500V, and it can cut the wire with electricity. Do not throw it around in use to avoid damaging the insulating plastic pipe.
⑥ Never use pliers as a hammer.
⑦ Do not use pliers to cut the double stranded live wire, which will cause short circuit.
⑧ When winding the holding hoop to fix the cable with pliers, the teeth of the pliers shall clamp the iron wire and wind it clockwise.
⑨ It is mainly used for cutting single strand and multi strand wires with thin wire diameter, bending single strand wire joints, stripping plastic insulation layer, etc.
