RU2366578C2 - Hydraulic press to form axially symmetric parts by rolling - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: press bed guides accommodates slide with inclined rotary unit. Aforesaid unit accommodates top punch attached thereto. The bed lower crosspiece accommodates lower drive rotary unit with bottom die. Operating and return hydraulic cylinders are arranged at the bed top crosspiece. Lower rotary unit rotational axis is shifted relative to operating cylinder axis by, approximately, 2/3 of the maximum radius of formed product.

EFFECT: higher reliability.

2 dwg

Description

The invention relates to the field of forging and pressing engineering, and in particular to equipment for stamping.

Known designs of hydraulic presses for stamping, for example, railway wheels. On these presses, a traditional stamping scheme is implemented with stamps completely overlapping the entire surface of the workpiece, which determines the occurrence of high contact friction forces, zones of difficult deformation, stagnant zones, which in turn leads to low forgings accuracy and large subsequent metal losses to the chips.

Another construction of the press is known, comprising a traditional bed with a slave cylinder, a slider and a table on which a rotary block with a lower die rotates in bearings coaxially with the slave cylinder. A stamp having a conical shape of the working surface is also mounted on the slider with the possibility of rotation.

The disadvantage of this design is that the press frame perceives large eccentric loads at the end of the course of deformation of the forgings.

The objective of the present invention is to provide a simple and reliable design of the press, ensuring reliable operation of the press with minimal eccentric loads on the bed with the greatest working forces of forging deformation.

This task is achieved by the fact that in the lower cross member of the bed, the axis of rotation in the bearings of the block with the lower die is offset relative to the axis of the press by an amount commensurate with the radius of the stamped forging.

Figure 1 presents a diagram of a hydraulic press for stamping with rolling axisymmetric products, and figure 2 is a layout of the axes of the press and the lower rotary unit.

The hydraulic press (Fig. 1) contains a bed, in the guides of which there is a slider 2, which carries the upper stamp 3 of a conical shape, which in turn is located on the rotary block 4 and in the bearings 5, is in the slider at a certain angle with respect to the axis of the slider 2 .

In the upper cross member of the bed 1, a working hydraulic cylinder 6 and return cylinders 7 are strengthened, the plunger of which is connected to the slider 2.

In the lower cross member of the bed 1, a block 9 is rotatably mounted in bearings 8, on which a lower stamp 10 is mounted. The axis of the block is offset with respect to the axis of the press itself and its hydraulic cylinder 6.

In the lower stamp 10 is placed the workpiece 11.

The rotary block 9 with the lower stamp 10 is connected to the rotation drive 12, which may be electromechanical, hydraulic. The upper rotary unit 4 may also have a rotation drive. The slider 2 is located in the guides of the frame 1 of the press. Press works as follows.

In the initial position, the slider 2 with the upper stamp 3 under the influence of return cylinders 7 is in the upper position.

After loading the workpiece 11 into the lower die 10, the block 9 with the lower die 10 is rotated from the drive 12, and the slider 2 with the upper block 4 and the upper cone-shaped stamp 3 is lowered down to contact the upper end face of the workpiece 11.

From the moment of contact of the stamp 3 with the end face of the rotating workpiece 11 due to friction, the block 4 with the stamp 3 comes into rotation and further deformation of the workpiece 11 occurs during the rolling force impact of the stamp 3 with the workpiece. Power effects creates a working hydraulic cylinder 6.

If necessary, the block 4 can receive rotation from the rotation drive.

In the process of stamping with rolling, the center of pressure at the local contact spot between the conical stamp 3 and the workpiece 11 is shifted to the periphery of the workpiece. This determines the occurrence of the eccentricity of the application of the resultant deformation-stamping force on dies 3 and 10, which, in turn, leads to eccentric loading of the bed and the entire press.

It is possible to eliminate the noted eccentric loading of the press if the axis of the lower rotary block 9 is shifted relative to the axis of symmetry of the press and the axis of the working cylinder 6 by a value of e, approximately equal to 2/3 of the largest radius of the stamped forgings (figure 2).

This design of the press allows stamping of axisymmetric parts with a force of Rd provided that the eccentric moment is M = 0 (M = Rd · e) at Rd = max.

After the end of the stamping stroke, the return cylinders 7 raise the slider 2 with the rotary block 4 and the upper stamp 3 in the lower position. The rotation drive 12 of the lower block 9 is stopped, and the forging is removed from the lower die 10 (an ejector can be located in block 9).

The cycle is over.

Claims (1)

Hydraulic press for stamping with rolling in axisymmetric parts, containing a bed with upper and lower crossbars and guides, a slider with an inclined rotary block located in the guides of the frame, on which a upper stamp is mounted, a lower drive rotary block with a lower stamp located in the lower cross beam and fixed in the upper cross member of the bed working and return hydraulic cylinders, characterized in that the axis of rotation of the lower drive rotary unit is offset from the axis of the working hydro cylinder parallel to it by an amount approximately equal to 2/3 of the largest radius of the stamped part.

Images