SU112652A1 - Device for semi-automatic control of hydraulic press - Google Patents

Description

The known devices for automatic and semi-automatic control of a hydraulic press equipped with electrically controlled hydraulic valves using intermediate relays, limit switches, a time relay, a thermostat and a push-button station mounted according to a contactor circuit do not have the ability to automatically perform any number of universal pressings in various combinations x

A special feature of the proposed device is the use of such an electrical circuit, according to which the closed contact of the limit switch and the time-delayed contacts connected to each other and solenoids of hydraulic valves are connected in parallel to the power supply circuit of the closing press of the solenoids, and the time-relay contacts and the open contact of the limit switch, or the contact of the intermediate relay operating with it, is connected in series to the power supply circuit Solenoid press connectors.

Thanks to the use of the above-mentioned control circuit and the cam of the elongated shape installed on the bottom plate of the cam press, which does not come out of engagement with the limit switch lever at the most large mold connector, it was possible to carry out at a low pressure both the preliminary closing of the press and automatic execution of any number of universal subpressions in various combinations.

The drawing shows a circuit diagram of a device whose operation is carried out as follows.

When a normally open contact of control button 1 is closed, intermediate relay 2 will be energized, contact 3 of which will close, providing power to the electrical equipment of the circuit.

No. 112652-2 -

Lowering the movable plate of the press (not indicated in the drawing) occurs after pressing button 4. At this, intermediate relay 5 is energized and its contacts 6 are closed, and contact 7 is opened, solenoid 8 is powered, the corresponding hydraulic valves are opened (no drawing is shown ) and will lower the movable plate under low pressure working fluid.

A few millimeters before the mold is fully closed (not shown in the drawing), contacts 9a and 96 of the limit switch are switched. At the same time, the time relay 10, which may be electronic or motor type, will start operating the high pressure hydraulic valve solenoid 11 Further lowering of the movable pressure plate (i.e. closing of the mold) takes place under high pressure.

The solenoid // is turned on only for the time when the normally open contact 9a is closed. However, only a cam (not shown) mounted on a movable press nylon, which can be lowered under low pressure in an alternate order, can reach the limit switch. Due to the elongated shape of the cam, the limit switch is held in a switched state during pressing and pressing. .

The normalyio closed co-tact 96 of the limit switch is set in the power circuit of relay 2 in order to eliminate the possibility of violation of the pressing mode by successive pressing buttons 12 and 1.

At the time of the final closing of the press-form node, the contacts 13a and 136 of the other limit switch are switched on by high pressure (not shown). At the same time, intermediate relay 14 will be energized, contacts of which 15, 16 and 17 are closed. Due to the closure of the contacts 16, the time relays 18, 19 and 20 are activated.

Contacts 21 and 22 of relay 18 and 19 are open, and contacts 23 and 24 are closed, thanks to which they block pe.ie / 6, 19 and 20.

In rezu; By opening the contact 136, the solenoids 6 and // will be de-energized, and as a result of the contact closure 15, the solenoids 25 and 26 will receive power, and the mold will be disconnected. The connector continues until the contacts 13a and 756 of the coaxial switch are reset. When this.m the relay 14 is de-energized, its contact 15 is opened, as a result the solenoids 25 and 26 are de-energized and the mold connector is stopped. Since the contacts / 7, 21 and 22 are open, when the contact 136 is closed, only the soleoid 8 will be powered and the subsequent closure of the press form will occur under low pressure.

The connectors and the clamping lugs, i.e., push-downs, continue until the time relay 18 is activated. At the same time, its contacts 27 and 28 are switched with a time delay. After closing the mold under low pressure and switching the contacts 13a and 136, the solenoids 25 and 26 are de-energized, and as a result of the contact closure 17, besides the solenoid 8, the solenoid // will also be powered. The mold will be closed by a high pressure node until a pause has elapsed, preset on time relay 19. After a pause, relay 19 will work, contacts 29 and 30 of which will switch over time. When contact 30 is opened, de-energize time relay 18, all contacts of which switch to the initial position. As a result of the return of the contacts 27 vi 28 ′, the initial position of the pre-pressings will occur again, and the press closures of the mold during the pressing are performed under low pressure.

The crimping is stopped after the time relay 20 is activated, the contacts of which 31 w-32 and the time delay are switched. At the same time, the first solenoid 8 will receive power, and after the mold is closed, the solenoid // will also turn on and iodine pressure will begin. Solenoids 25 and 26 do not receive power due to open contact 32 (although contact 15 is closed).

After the shutter speed has expired, the iodine pressed will trigger the time relay 10, the contacts 33, 34 and 35 of which switch. When the contact 33 is closed, the relay 10 is blocked. Due to the opening of the contact 34, intermediate relay 5 is de-energized, contacts b and 7 of which switch to the initial position. In this case, the solenoids 8 11 will be de-energized and the solenoids 25 and 26 will receive power. The movable plate of the press will rise to the initial upper position.

As a result of contact closure 35, intermediate relay 36 (whose contacts 37 are switched) will be energized, and lamp 38 will come on, signaling that the end of the shutter speed is idle. However, the signal lamp 38 will only illuminate if the press connector does not occur due to a malfunction of the hydraulic valves or the device. In this case, the rise of the movable plate impedes the path of pressing the / button (i.e., opening its normally closed contact).

When the moving plate reaches its initial upper position, the contacts of the limit switch 39 are switched.

In this case, the solenoid 40 will receive power and the ejector will rise, which will switch the contacts of the limit switch 41, and the solenoid 42 of the pneumatic valve will turn on.

Intermediate relay 43a with contacts 436 is used for the avapiip of the movable plate lifting from any position (except the original top) and for blocking the electrical circuit that does not allow the press operator to control the press after the emergency lifting of the plate.

We bring the circuit back to the original position by opening the locked control panel door, which causes the door lock contacts 44 to open. Contacts 45 relate to the press mode switch, and contacts 46 to the sub-press type switch. The contacts 47 of the thermostats serve for emergency lifting of the movable press plate in case of overheating of the mold. Using the limit switch 48, control of the delayed closing of the press form is carried out.

Subject invention

Claims (4)

1. A device for semi-automatic control of a hydraulic press, equipped with hydraulic valves, consisting of intermediate relays, limit switches, a time relay, a thermostat and a push-button station simulated according to a contactor circuit, characterized in that, in order to automatically perform any number of universal prepressors on low pressure, in the electrical circuit of the device connected to each other and solenoids of hydraulic valves, the closed contact of the limit switch and opened with the withdraw For which time the relay contacts are temporally connected in parallel to the power supply circuit of the closing solenoids press, and the timed contacts and the open contact of the limit switch, or the intermediate relay contact that is synchronously active, are connected in series to the power supply circuit of the solenoid press controls 112652 2. The device according to claim 1, characterized in that, in order to automatically perform the closing of the molds at low pressure prepressions, the solenoid power supply circuit includes time-delayed contacts closed as well as an open contact of the intermediate relay operating synchronously with open contact of the prepress switch limit switch. 3. The device according to paragraphs. 1 and 2, characterized in that, in order to ensure the pre-closing of the press at low pressure in the forced order, the open contact of the limit switch is connected in series with the solenoid of the high pressure hydraulic valve solenoid. 4. Device on PP. 1, 2 and 3, characterized in that, in order to keep the contacts of the limit switches in the switched state when the contacts are pressed in, the elongated cam is mounted on the movable press plate, which does not break out of engagement with the limit switch lever at the largest mold connector.