The structure of the shearing machine mainly includes: transmission system, slider (tool holder), bed (frame), pressing mechanism, blocking mechanism, balancer, electric control system and other auxiliary devices. The main structural components of the shears are briefly introduced as follows:

1、 There are three types of transmission: mechanical transmission, hydraulic transmission and combined hydraulic mechanical transmission.

1. Mechanical drive plate shears.

Mechanical transmission shears are still widely used because of their good rigidity, high efficiency and few faults.

The general drive is that the motor passes through the primary belt drive and friction clutch, and then passes through the secondary gear drive to transfer the rotary motion to the eccentric shaft. Finally, the tool holder moves back and forth in the guide rail of the machine body through the crank connecting rod mechanism, and a brake is installed at one end of the eccentric shaft. The clutch and brake are mounted on a mechanically driven plate shearer. The function of the clutch and brake is to start and stop the shearer without stopping the flywheel.

There are two types of clutches for shears: rigid clutch or friction clutch.

(1) The rigid clutch has the advantages of small volume, simple structure and low cost, such as sliding pin type and claw tooth type. Its disadvantage is that it only has a single and continuous specification, and has a large impact vibration when engaged.

(2) There are many forms of friction clutch, such as single plate, multi plate and cone. The structure of friction clutch is complex, which is only used in plate shears. The advantage is that in addition to single stroke and continuous stroke, inching operation can also be carried out.

(3) The brake used with the rigid clutch is the belt brake, and the shearer with the friction clutch adopts the same brake as the clutch. >

2. Hydraulic plate shears

The proportion of hydraulic drive plate shears in plate shears is increasing, and the application of hydraulic drive in plate shears is more and more extensive. Its advantages are as follows:

(1) It is safe to work and can prevent equipment failure caused by overload.

(2) It has the advantages of simple structure, easy manufacturing, short production cycle and low cost.

(3) It is easy to operate, and can realize single stroke, continuous stroke, inching stroke, midway stop and return journey.

(4) Small vibration, stable operation, low noise, long tool life.

Its disadvantages are as follows:

(1) Less trips.

(2) The motor has high power.

(3) Hydraulic components are prone to failure, maintenance workload. The hydraulic shearing machine is a connecting platform between the cylinder piston rod and the scissors slider.

3. The sliding block is equipped with a hydraulic mechanical combined driving shear, and the lower shear is installed when working. This kind of shearer is a kind of hydraulic driven shearer, which uses mechanical mechanism to realize the parallel movement of the tool rest. It has the advantage of hydraulic drive and does not need complicated oil circuit.

2、 The bed of a frame shearer is usually composed of left and right columns, worktable and connecting beam. The left and right column and connecting beam are generally welded with A3 steel plate. In order to eliminate the stress after welding, the bed after welding should be annealed to prevent deformation after assembly. Generally, the back and lower part of the connecting beam should be made into an inclined plane, so that the sheared steel plate can slide out by itself.

The worktable is usually cast iron and bolted to the front of the bed. In order to reduce the friction of the sheared plate on the worktable, the worktable of the shearer is equipped with a supporting steel ball, and the lower end of the supporting steel ball is equipped with a spring.

3. Slider [tool holder] slider is an important part of the plate shearer, which needs enough strength and stiffness to ensure high cutting accuracy and good fracture quality of the plate after shearing.

4. In the process of shearing, the metal plate should always be pressed on the worktable, otherwise the metal plate will shift in the shearing process, resulting in the increase of the size deviation of the metal plate to be cut, so the shearing machine needs a pressing mechanism.

The pressing mechanism has two forms: mechanical pressing mechanism and hydraulic pressing mechanism.

(1) Mechanical pressing mechanism: the mechanical pressing mechanism is composed of pressing beam, spring, cam (or bump) and lever. Its characteristic is that the pressing force is large, but it is not easy to adjust, so it is suitable for cutting thick plate. Its disadvantage is that there are many pressure claws at the lower part of the beam. Due to cutting different width plates, the wear of each pressure claw will be different. Therefore, the compression force will be affected to a certain extent, which may lead to local displacement of the sheared plate due to insufficient compression force, and some parts will be pressed out of the indentation due to excessive pressure.

(2) Hydraulic pressing mechanism: the hydraulic pressing mechanism is composed of a fixed pressing beam, a group of pressing cylinders and a pump. The pressure cylinder of hydraulic shear is supplied with oil by pump, and the pressure stop of the pressure cylinder of mechanical shear is generally realized by the cam piston correction pump installed at one end of eccentric shaft.

5. The rear holder is used to ensure the required shear length. There are two types of rear material racks: manual and electric

(1) The manual baffle frame is installed at the back of the shearing machine, and the gear is rotated by the hand wheel, and then the baffle frame drives the baffle to move back and forth. In order to make the plate of the shearer fall freely, when the sliding block cuts down, the back baffle swings an angle under the action of the pressure block and the lever to separate the cut plate. This structure is simple, easy to adjust, and can ensure the size accuracy of the plate shears, so it has been widely used in small and medium-sized plate shears.

(2) Motor driven material holder: motor driven rear material holder can reduce labor intensity and shorten operation time, which has been widely used in current plate shears.

6. The balancer mechanically drives the shear. Due to the clearance of the crank connecting rod system, the weight of the moving parts and the inertial force generated in the process of motion constantly impact the eccentric shaft when the shear slider moves back and forth. In order to ensure the stability of the shear and prevent the shaft sleeve from premature wear, a balancer device is usually installed on the shear.

There are two common types of balancers: spring type and barrel type.

7、 Scissors (1) see the standard of the Ministry of mechanical industry (2) the size and deviation of the blade should comply with the national regulations on the form and size of the blade.

The use and maintenance of scissors is basically the same as that of press. The main content is to operate the scissors correctly according to the operating procedures, and use them reasonably according to the specifications of each pair of scissors. Overloading is strictly prohibited. When the scissors are broken or seriously worn, they should be replaced in time and lubricated and cleaned as required.