SU1362657A1 - System for controlling shock dampening in hydraulic press - Google Patents

Abstract

The invention relates to the field of mechanical engineering, namely to hydraulic presses. The purpose of the invention is to increase reliability. The goal is achieved by executing the pressure regulator in the form of interconnected and with the control cavity of the drain valve of the return cavity of the power cylinder of the accumulator, four-way pilot, hydraulic lock, non-return valve, OR logic element and adjustable throttles. The latter allows fluid to be bypassed from the working into the return cavity of the ram when the process load is instantaneously reduced and dynamic loads are reduced when performing separation operations on the press. 1 il. with S (L

Description

The invention relates to mechanical engineering, namely to hydraulic presses.,

The purpose of the invention is to increase reliability by reducing dynamic loads when performing separation operations.

The drawing is a schematic diagram of the control system.

The control system contains a pump 1 connected by a pressure line to the working 2 and return 3 cavities of the power cylinder and through the distribution block 4, including pressure valves 5 and 6 with the control valves 7 and 8, and drain valve 9 from the cavity 3 of the power cylinder cavity 10 of his control. On the lines x of the pump 1 and the cavity 3 of the power cylinder installed safety valves 11 and 12.

The pressure regulator 13 comprises a battery 14, a four-way pilot 15 with control cavities 16 and 17, a hydraulic lock 18 with a servo drive, a check valve 19, an OR 20 logic element, and an adjustable throttle 21. The hydraulic lock 18 is connected with its input to the trunk 2 of the power cylinder and the pilot cavity 17 of the pilot 15 and the output from one of the four inputs of the pilot 15, and its servo drive is connected to the OR element 20 and to the distributor 7. The battery 14 is connected to the second output of the pilot 15 and to its control cavity 16. Third exit pilot 15 through the element IL 20 is connected to the control cavity 10 of the drain valve 9, and its fourth outlet is connected through a check valve 19 to a cavity of 3 cimoBoro cylinders and through an adjustable choke 21 to a drain line and tank 22. A tank 23 with a valve 24 is installed above the working cavity 2 of the power cylinder filling. The tool 25 is fixed on the slider 26. The workpiece 27 and the tool 28 is installed on the table 29 of the press.

The control system operates as follows.

 The movement of the slider 26 downward along the approach stroke is carried out by the action of its own weight with the filling valve 24 open. Upon transition to the operating speed, the valve 24 is closed. The distributor 8 is turned on, and the working fluid from the pump

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Sa 1 enters through the valve 6 into the working cavity 2 of the cylinder and is expelled from the return cavity 3 through the valve 9. After the tool 25 contacts the workpiece 27, the pressure c increases. cavities 2 and synchronously in cavity 16 and 17 of the pilot 15, and tarszhe in the battery 14 until the maximum technological load is reached, after which the pressure in the working cavity 2 and control space 16 pilot 15 is correspondingly reduced. The pressure in the accumulator 14 and the pilot control cavity I7 is maintained at the maximum level reached. Due to the pressure difference in the cavities 16 and 17 of the control, the pilot valve 15 is moved from the source to the other extreme position. In this case, the battery 14 communicates through the element 1Sh 20 with the cavity 10 of the valve 9, and the cavity

2-cylinder through a return valve 19 with a return cavity 3 and through an adjustable throttle 21 — with a tank 22. The significant pressure drop between pilot 2 and return 3 a cylinder that is available by the time pilot 15 is switched off. Rapid growth occurs pressure in the return cavity 3 by closing the valve 9 and the flow of working fluid into it through the check valve 19 from the working cavity 2. The pressure in the working cavity 2 is reduced. The gradient of pressure decrease in the working cavity 2 is set by adjusting adjustable throttles 21. The speed of movement of the slider 26 drops, which allows to increase the time interval between the point of maximum process load and the moment of the beginning of cleavage. This achieves the ability to set the pressure in the return cavity.

3 at the beginning of the chip even for relatively fragile materials. As the differential pressure between working 2 and return 3 cavities decreases, the check valve 19 closes. The pressure in the return cavity 3 is limited by the setting of the safety valve 12. With further movement of the slide 26, shock damping is achieved by increasing the back pressure of the return cavity 3 and reducing the pressure in the working cavity 2.

During the return stroke of the slider 26, the valve 8 is turned on and the valve 5 is turned off and the valve 17 is turned off. The fluid from pump 1 enters cavity 3 and is forced into tank 23 from cavity 2 of the power cylinder. After the upper position of the slider 26 is reached, the finished part is removed and the workpiece is loaded.

The economic effect of the implementation is achieved by increasing reliability.

Claims (1)

Invention Formula The shock damping control system on a hydraulic press, holding the pump connected to the working and return cavity of the power cylinder through a distribution unit with drain and pressure lines, including a drain valve with its control cavity, a pressure regulator with a battery, characterized by that, with a view increase reliability by reducing dynamic loads during separation operations, the pressure regulator is made in the form of a four-way pilot with two control cavities, a hydraulic lock with a servo actuator, a check valve, an SCHO logic element and an adjustable Q throttles, in this case, a hydraulics amok connectionH by its platoon with the working cavity of the power cylinder and one of the control cavities of the four-way pilot, and its servo drive is connected to the distribution unit and through the logical element OR to the control valve of the drain valve, the four-way pilot is connected with its first output with the logical element OR, with the second output with the release of the hydraulic lock and the third output through the non-return valve with the return cavity of the cylinder power and the adjustable throttle with the drain main, and the battery is connected to the second control cavity and the fourth inlet of the four-way pressure regulator pilot. 23G oBMoiigvaiarMMOiMMMBacnaaK o, g. . dxfflh 4 || g