RU2536563C2 - High-pressure hydraulic press - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy, particularly to die forging and compaction. Hydraulic press comprises bed, working hydraulic cylinder, press tool, set of pressure boosters, lifting hydraulic cylinders, two hydraulic and hydraulic pressure control systems. One hydraulic system is intended for working hydraulic cylinder while another one for lifting hydraulic cylinders. Pressure boosters communicate high-pressure chambers of downstream booster with low-pressure chamber of upstream booster. Downstream booster high-pressure chamber is connected directly with press working cylinder chamber via hydraulic check valve. Controlled hydraulic valves are arranged between said high-pressure chamber and said low-pressure chambers.

EFFECT: higher working force.

2 cl, 3 dwg

Description

A high-pressure hydraulic press refers to the processing of metals by pressure, as well as to the volumetric stamping of any powder materials in mechanical engineering and in the production of other products used in industrial and civil engineering, such as bricks, slag blocks, tiles, tiles, etc.

The closest in technical essence to the proposed device is a hydraulic press (Fig. 1), containing a bed with two traverses, top 4 and bottom 5, interconnected by powerful metal columns 3, which serve for the perception of stamping forces and at the same time guides for vertical movement of the piston 2 working cylinders with a punch 7 fixed on it, a matrix 8 located on the lower beam, hydraulic cylinders 6 for raising and lowering the piston, working cylinder 1, hydraulic and distribution system emy and a multiplier (not shown) [1].

The disadvantage of this technical solution is the impossibility of creating ultra-high pressures and, as a result, pressing forces with relatively small press parameters. So, for example, the multiplier is able to increase the inlet pressure only up to 40-60 times. A further increase in the pressing force is achieved by increasing the diameter of the piston of the working cylinder, however, the overall dimensions quickly grow, and with it the mass of the press.

The objective of the present invention is to significantly increase the pressing force by using devices and materials well tested in the press technology, including the working fluid in the hydraulic system, with maximum use of the possibility of the effect of hydrostatic pressure. The use of such a hydraulic press will significantly expand the range of various products of general engineering applications manufactured by the modern and economical method of pressing.

The task is achieved by the fact that in the proposed high-pressure press for stamping metal and any powder materials containing a bed, a working hydraulic cylinder, a pressing tool, a multiplier installation, lifting hydraulic cylinders, two hydraulic systems, one of which is designed for a working hydraulic cylinder and a multiplier installation, and the second - for lifting hydraulic cylinders, and two hydraulic distribution systems, a multiplier installation made in the form of multipliers was used. In this case, the multipliers are arranged so that the high-pressure chamber of the previous multiplier is connected hydraulically to the low-pressure chamber of the subsequent multiplier, and the high-pressure chamber of the last multiplier is connected directly to the chamber of the press working cylinder through a check valve.

The role of the first multiplier is played by the multiplier M1 (Fig. 2), the second by the multiplier M2 and, finally, the third by the multiplier M3. All multipliers are arranged one after another so that the high-pressure chamber of each previous multiplier, starting from the first M1 and second M2, is connected hydraulically to the low-pressure chamber of each subsequent multiplier M2 and M3. The low-pressure chamber of the first multiplier M1 can be connected to the pressure line of the first hydraulic system using controlled hydraulic valves (in this case, valve 2), and the high-pressure chamber of the output multiplier of the device, for example, M3, can be connected hydraulically to the piston chamber of the press working cylinder with using the check valve 8 (Fig. 2). Connecting and disconnecting the multiplier installation to the pressure line of the first hydraulic system is done manually or automatically according to a special program.

In FIG. 2 shows the device in the initial position before the start of the stroke.

The work of the proposed hydraulic high-pressure press is carried out from two mutually isolated hydraulic systems, the first serving the multiplier unit and the working hydraulic cylinder of the press with high-pressure chambers. This hydraulic system has known devices for minimizing leaks, providing a low coefficient of friction in the nodes of the fluid seal. At the same time, a working fluid is used in it, which slightly changes its viscosity at ultrahigh pressures, providing the effect of hydrostatic pressure. The second hydraulic system of the usual design (not shown) serves the hydraulic cylinders for raising the punch, returning it after the end of the working stroke to its original position.

The hydraulic press in places of high pressure of the working fluid (sleeves of plunger rams of the multipliers and the working cylinder) is covered externally by prestressed bandages that prevent their expansion in the radial direction.

The hydraulic inlet to the working cylinder of the press is blocked by any known device when the piston of the working cylinder is reached with the upper position punch fixed on it, and metered filling of the working fluid from the first hydraulic system is carried out in the high pressure chambers of the multipliers. Dosed replenishment must be done due to the inevitable leakage of the working fluid through the sealing systems of the multiplier plungers.

The working stroke of the press consists of the following successive stages.

At stage "a", the working fluid from the pressure line of the hydraulic system first comes directly to the working cylinder of the press. At the same time, the hydraulic valve 1 of the distributor is open, and all other valves are closed. The piston of the press cylinder starts idling down. When the punch comes into contact with the processed material, its compaction begins. As the material is densified, its resistance increases, and the speed of the punch decreases. When the working fluid pressure becomes equal to the response pressure of the safety valve of the pumping station, stage "a" ends.

At stage "b" the multiplier installation is included in the work. The hydraulic valve 1 closes and the valves 2, 6, 11, 13, 16, 18 and 21 open, connecting the high-pressure chamber of the multiplier M3 with the check valve 8. The rest of the valves are still closed. The pressure from the multiplier installation at the output of the multiplier M3 increases, and when it exceeds the pressure in the working cylinder of the press, the check valve 8 opens and high pressure begins to flow into the working chamber of the press. The punch continues to move downward, increasing pressure on the material being worked. When the speed of the punch slows down again and becomes equal to 0, step "b" ends. In this case, the pressure on the processed material reaches its maximum value. Valve 2 closes, and the material being processed is subjected to technological exposure at maximum pressure. The working move is completed. An exemplary workflow diagram is shown in FIG. 3. On the ordinate axis, the pressure P - the working fluid on the punch is plotted, on the abscissa axis - the stroke of the punch h _n .

After the end of the working stroke, the last stage of the press working cycle begins - the press returns to its original initial position (Fig. 2) and all the multipliers of the installation return to their original position after the completion of the press working stroke. Between the multipliers are installed controlled hydraulic valves that close the entrance to the low-pressure chambers. The first hydraulic distribution system opens the valve 9 to drain; valves 6, 11, 13, 16, 18, 21 are closed, and then valves 5, 12, 17 open to drain the working fluid from the supra-piston cavity of all multipliers. Then, valves 3, 7, 10, 14, 15, 19, 20 are opened and pressure from the pressure line of the first hydraulic system is supplied to the sub-piston and plunger cavities of all multipliers, returning them to their original initial position. Finally, pressure is supplied from the pressure line of the second hydraulic system to the rams for raising the punch (not shown).

When the press punch and the multiplier pistons occupy the upper initial position, all valves are closed; the finished product is removed, the process of metered replenishment of high-pressure chambers of the multipliers is completed. A new blank is installed on the die matrix.

The high-pressure hydraulic press is ready for a new duty cycle.

Information sources

1. Rozanov B.V. Hydraulic presses. M .: Mashgiz, 1959.

Claims (2)

1. A high-pressure hydraulic press for volumetric stamping of metals and powder materials, containing a bed, a working hydraulic cylinder, a pressing tool, a multiplier installation, lifting hydraulic cylinders, two hydraulic systems, one of which is designed for a working hydraulic cylinder and a multiplier installation, and the second for lifting hydraulic cylinders , and two hydrodistribution systems, characterized in that the multiplier installation, creating ultrahigh pressures, is made in the form of multipliers, located so that the high-pressure chamber of the previous multiplier is connected hydraulically to the low-pressure chamber of the subsequent multiplier, and the high-pressure chamber of the last multiplier is connected directly to the chamber of the press working cylinder through a non-return hydraulic valve. 2. A high-pressure hydraulic press according to claim 1, characterized in that between the high-pressure chambers of the previous multiplier and the low pressure of the subsequent multiplier and so on, up to the last multiplier, controlled hydraulic valves are installed.

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