In order to meet the technological requirements of different parts, different types of crank presses can be used in the production. These crank presses have their own unique structures and functions. They are classified usually according to the crank press functions and structural characteristics.
1.Classified by functions of crank press According to the function, the press can be divided into general press and common press two major categories. General press has a variety of uses, such as blanking, bending, molding, shallow drawing;The common press has a single purpose, such as drawing press, plate bending machine, plate shearing machine, automatic cold heading machine, high speed press, fine press, hot die forging press, etc.
2.Classified by physical structures of crank press According to the physical structure the crank press can be divided into two types: open press and closed press. (1)Open press Due to characteristic of the open type press that the body is “C” type, so it is also called c frame double crank press, the front and the left and right sides of which are open to facilitate the installation and adjustment of molds.However, the rigidity of the body of the c frame double crank press is poor, and it is easy to deform under load, which affects the precision of the parts and the service life of the mold. Therefore, it is only suitable for small and medium-sized presses. c frame double crank press according to its body structure, and can be divided into two types of double column open press and single column open press.
According to the structure of the working table, it is divided into two kinds: fixed bench press and descending bench press. According to the ability of fuselage to tilt, it can be divided into tilting press and not tilting press two kinds. Double column open press, fuselage back has an opening, forming two side columns in the fuselage upper part(namely double column open press). The cranks are supported on both columns and parallel to the front of the fuselage workbench.In addition, the body can be inclined along the bottom frame of the press (can be inclined press), in order to make the stamping parts by weight along the back of the body of the opening inclined plane automatic sliding down, which is conducive to the mechanization and automation of stamping processing. Single column open press, the fuselage is hollow structure, only one column in the fuselage upper part(namely single column open press). This press machine body back is closed, which works only transverse feed.The figure is a single column fixed table structure, generally used for nominal pressure than large open press;Single column drop table structure, can change the closing height of the press in a larger range, suitable for a wide range uses. (2) closed type press The machine body of the closed type is frame structure, which is open in front and back, closed on two sides, so that the operator can only approach the table from the front and back. The strength and rigidity of the machine body of the closed type press are good, so when the workpiece is loaded, the elastic deformation of the machine body is small, and the impact on the precision of the workpiece and the normal work of the mold is also small. So the closed type press is mostly large and medium-sized press.
3.classified by Press connecting rod number According to the number of connecting rod of the press, the crank press is divided into single point press, double point press, multi-point press, etc.. The slide block of the single point press is driven by one connecting rod, generally small press. the slide block of the double point press is driven by two connecting rod, generally medium press.The slide block of the multi-point press is driven by more than two connecting rods (such as the slide block of the four-point press is driven by two pairs of connecting rods), so that the slide block moves smoothly, and the machine has a large area of the bottom and the working table, and has a certain strength and stiffness, generally for the large type press. With two or two pairs of links, the sliders are not very sensitive to off-load.
4.Classified by the press slider action
According to the press slider action points, the crank press is divided into single action press, double action press and three action press. Single action press with one slide mechanism, is suitable for blanking, bending and drawing of medium and small size parts. Double action press has inside and outside two sliders. Outside sliders press material, and inside sliders deep drawing, it is suitable for large type deep drawing. Three – action press in addition to the inner and outer slider, there is a slide block, which can complete in the opposite direction of the deep.
5.Classified by the location of the transmission mechanism According to the location of the transmission mechanism, transmission mechanism on the table is called the upper drive press, and the location of the transmission mechanism under the table is called the lower drive press.
6.Classified by the characteristics of the press table According to the characteristics of the press table, the crank press is divided into fixed table press, inclinable table press, descending table press, movable table press, rotary table press, etc. 7.classified by crank According to the different crank form, crank press can be divided into crank press, fair press, crank press and fair gear press.
