RU1781468C - Hydraulic actuator - Google Patents

Abstract

The invention relates to mechanical engineering, namely to forging and pressing equipment, and can be used in hydraulic drives of press and assembly plants, power tables of machine tools and other hydraulic machines, In order to simplify the design, reduce weight and reduce the dimensions in the rod 4 of the power cylinder 1, made hollow, the piston rod 5 is installed with the formation of the return cavity 6, in communication with the first output 9 of the valve 8 and the control cavity 10 of the hydraulic lock 7. The latter is connected to the pc kovoy cavity 3 of the power guide rolitsilinda 1-1 and the control cavity 12 emogo Hydraulic valve 13 is connected to a second output 11 and the piston 8 Hydrodistributor cavity 2 of the power cylinder 1. 1-yl.

Description

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The invention relates to mechanical engineering, in particular to forging equipment, and can be used in hydraulic drives of press and assembly plants, power tables of modular machines and other hydroficated machines.

The purpose of the invention is to simplify the design and reduce weight.

The drawing shows a General view of the hydraulic drive.

The hydraulic actuator contains a power cylinder 1 with piston 6 and rod 3 cavities and a hollow rod 4, in the sleeve surface of which the piston rod 5 is placed with the formation of the return cavity 6. The piston cavity 2 and the rod cavity 3 can be interconnected the time of the accelerated movements of the rod 4 through the hydraulic lock 7 and separation during the working stroke of the rod 4. The hydraulic distributor 8 is connected to the return cavity 6 and to the control cavity 10 of the hydraulic lock 7 by one of its outputs 9, and the second output 11 to the piston cavity 2 of the power g drotsilindra 1 and to the control cavity 12 of the valve 13. Hydraulic emogo emy Hydraulic valve. 13 is connected by its input 14 to the rod cavity, 3 of the power hydraulic cylinder 1, and by the output 15 7 to the hydraulic tank 16. The control valve 8 is equipped with electromagnets 17 and 18. The pump 19 is connected by its output to the input 20 of the control valve 8.

The hydraulic actuator operates as follows.

In the initial position, the electromagnets 17 and. 18 directional control valves 8 are de-energized. The stem 4 of the power hydraulic cylinder is 1 watt nut and is in the far right (according to the drawing) position.

 When the electromagnet 18 of the control valve 8 is turned on, the working fluid from the pump 19 enters the cylinder outlet 11 and then into the piston cavity 2 of the power hydraulic cylinder 1. In this case, the working fluid from the rod cavity 3 is forced out through the hydraulic lock 7 into the piston cavity 2.

The summation of these two costs gives the necessary speed of movement of the rod 4 with accelerated approach. Accelerated motion here is no different from differential. At the same time, the working fluid is displaced from the return cavity 6 through the cylinder outlet 9 and then through the valve 8 to the drain to the tank 16. When the rod 4 contacts the workpiece, the pressure in the piston cavity 2 increases, the hydraulic lock 7 divides the cavities 2 and 3. The hydraulic valve 13 under the action of pressure arising in the control cavity 12. will open, communicating with the stock cavity 3 with a drain in the hydraulic tank 16 - there is a further movement of the rod 4 by

working stroke, i.e. processing of the workpiece will occur.

After that, the electromagnet 17 of the control valve 8 is turned on, while the piston cavity 2 of the power hydraulic cylinder 1,

0, the control cavity 12 of the hydraulic control valve 13 is communicated through the control valve 8 with a drain to the hydraulic tank 16, and the return cavity b and the control cavity 10 of the hydraulic lock 7 communicate with the pump 19, an accelerated outlet occurs. This is primarily achieved due to the fact that the hydrically controlled valve 13 at this time disconnects the rod cavity 3 from the drain, and the hydraulic lock 7 is forced open by the pressure in the control cavity 10, therefore, the working fluid is displaced back from the piston cavity 2 into the stock cavity. Since the volume of the piston cavity 2 is greater than the volume

5 of the rod cavity 3, then the difference in the volumes of the working fluid is displaced along the cylinder outlet 11 and through the hydraulic unit. Limiter 8 to drain into the hydraulic tank 16.

Claims (1)

At the end of the accelerated tap, the electromagnet 17 is turned off - the cycle is completed. The introduction of the hydraulic drive allows to save production space by reducing the size of the hydraulic drive, because in the proposed hydraulic actuator there is no additional tank and oversized valve (its role is played by a compact hydraulic lock). The role of the filling tank is played by the rod cavity of the power hydraulic cylinder, and the volume difference between the piston and rod cavities is performed by the flow rate received from the pump. SUMMARY OF THE INVENTION A hydraulic actuator comprising a pump, a discharge and a drain hydraulic line, a power hydraulic cylinder with a piston and rod cavities and a hollow rod, a hydraulic valve connected to one of the outlets with a piston cavity of the power hydraulic cylinder, a hydraulic lock connected to the input to 0 of the piston cavity of the power hydraulic cylinder, and a hydraulically controlled valve connected by an inlet to the rod cavity of the power hydraulic cylinder, characterized in that, in order to simplify the design and reduce weight, a piston rod is installed in the hollow rod of the power hydraulic cylinder with the formation of a return cavity connected to the second the output of the valve, while the hydraulic lock is connected by the output to the rod cavity of the power hydraulic the cylinder, and the control cavity of the hydraulic outlet of the control valve and the piston-controlled valve is connected to the second cavity of the power hydraulic cylinder.