RU2355011C2 - Jet device for controlling pneumatic cylinder - Google Patents

Abstract

FIELD: physics; control.

SUBSTANCE: present invention pertains to automation equipment and can be used in automatically controlled pneumatic systems. The outcome is achieved through that, the said jet device has a pneumatic cylinder, distributor, pneumatic amplifier, RS flip-flop, made from jet discrete monostable elements, controlled by "Start" and "Stop" buttons. The proposed device differs from existing devices in that, it has a complement flip-flop, which switches when a logic-0 level signal applied to its complementing input, as well as an AND-fluid gate and a tuning throttle. The discharge line of the distributor is connected to the input of the tuning throttle and the complementing input of the complement flip-flop. The output of the RS flip-flop, set to the logic-1 level when the "Stop" button is pressed, is connected to the set input of the complementing flip-flop. The second output of the RS flip-flop is connected to the input of the AND-element. The output of the complementing flip-flop, set to the logic-1 level when a logic-1 level signal is applied to its set input, is connected to the second input of the AND element. The output of the AND element is connected to the input of the pneumatic amplifier, and the output of the tuning throttle opens to the atmosphere.

EFFECT: simpler design, increased reliability, more functional capabilities.

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Description

The invention relates to technical means of automation and can be used in pneumatic automatic control systems.

Known schemes for controlling the cylinder at end positions using limit switches (see, for example, "Pneumatic devices and systems in mechanical engineering." Reference. Edited by E.V. Herz, M .: Mechanical Engineering, 1981, p.302, Fig. 10.29) and pressure control circuits using sequence valves (see ibid., P. 302, fig. 10.30).

Known control schemes for controlling the intermediate positions of the cylinder. Monitoring can be carried out, for example, using one moving limit switch, which is affected by stops pre-installed in predetermined positions (Copyright Certificate No. 339907, class G05b 19/44, “Hydraulic software device”, Bull. No. 17 of 01.01.72 )

Closest to the proposed invention in terms of features is an inkjet reciprocating cylinder control circuit comprising a pneumatic cylinder, a distributor, an air booster, a trigger with separate inputs, assembled on the basis of two discrete monostable inkjet elements, the Start button and the Stop button (" Inkjet logic elements and devices for automatic control of technological equipment. ”Industry Catalog. Edited by E.I. Chaplygin, Moscow: VNIITEMR, 1989, p. 47, Fig. 103).

This scheme can ensure the operation of the cylinder only in the presence of limit switches, which are installed directly in the zone of operation of the equipment. This complicates the design and reduces reliability. It should also be noted that if you want to change the stroke of the rod of the pneumatic cylinder (for example, by limiting the extension of the rod with an emphasis or by installing a pneumatic cylinder of a different size), then there is a need for readjustment of the device by changing the position of the limit switches.

The technical result of the proposed technical solution is to simplify the design, increase reliability, expand the functionality.

The specified technical result is achieved by the fact that in the jet control device of the pneumatic cylinder containing the pneumatic cylinder, distributor, pneumatic amplifier, a trigger with separate inputs, built on jet discrete monostable elements controlled by the Start and Stop buttons, an additional trigger with a counting input is installed, switching which occurs when a zero-level signal is applied to its counting input, as well as an “I” inkjet logic element and a tuning throttle, moreover, the exhaust line of the distributor soy dinene with the input of the tuning choke and the counting input of the trigger with the counting input, the output of the trigger with separate inputs, the unit level signal on which is set when the “Stop” button is pressed, connected to the installation input of the trigger with the counting input, the second output of the trigger with separate inputs is connected to the input the "And" element, the output of the trigger with a counting input, the unit level signal at which is set when the unit level signal is supplied to its installation input, is connected to the second input of the "And" element, the output of the "And »Connected to the input of the pneumatic amplifier, and the output of the tuning throttle is in communication with the atmosphere.

Introduction to the circuit of a trigger with a counting input of the logic element “I”, a tuning choke and corresponding connections allows to simplify the design and increase reliability by eliminating the limit switches from the control circuit. Changing the stroke of the rod of the pneumatic cylinder or replacing it with a pneumatic cylinder with other geometric parameters does not require readjustment of the device.

The drawing shows a jet control device pneumatic cylinder.

The device includes a pneumatic cylinder 1, the rod and piston cavities of which are connected to the distributor 2. The exhaust line of the distributor 2 is connected to the input of the adjusting throttle 3, the output of which communicates with the atmosphere, and to the counter input of the trigger with the counter input 4. Installation input of the trigger with the counter input 4 is connected to the output 5 of the trigger with separate inputs 6, and the output of the trigger with the counting input 4, the unit level signal at which is set when the unit level signal is applied to its installation input, is connected to the logic input “I” element 7. The second input of the “AND” logic element 7 is connected to the output 8 of the trigger with separate inputs 6, built on discrete monostable inkjet elements 9, 10. The output of the “AND” element 7 is connected to the input of the pneumatic amplifier 11, which controls the distributor 2. A trigger with separate inputs 6 is controlled by the “Stop” buttons 12 and “Start” 13, and when you press the “Stop” button 12 at the output 5 of the trigger with separate inputs 6, a unit level signal is set, and at output 8, a zero level signal is set. When you press the "Start" button 13 at the output 5 of the trigger with separate inputs 6, a zero level signal is set, and at the output 8 - a signal of a single level.

The jet control device of the pneumatic cylinder operates as follows.

After supplying air at the output 5 of the trigger with separate inputs 6, a signal of a single level is set, and at the output 8, a signal of zero level. As a result, the trigger is set to the initial state with a counting input 4 and a unit level signal is established at its output. After pressing the “Start” button 13, the trigger with separate inputs 6 is switched. At the output 8 of this trigger, a unit level signal is set. As a result, at the output of the element "And" 7, a signal of a unit level is formed. The pneumatic amplifier 11 will turn on by switching the distributor 2. At the same time, a zero level signal will be established at the installation input of the trigger with counter input 4. After the extension of the stem begins, a unit level signal is generated at the counting input of the trigger with the counting input 4 due to the pressure of the working medium displaced by the piston from the rod cavity of the pneumatic cylinder 1. After the extension is completed, a zero level signal is generated at the counting input of the trigger with counting input 4 and the trigger will switch. A signal of zero level will be established at its output. The pneumatic amplifier 11 is turned off, the distributor 2 is set to its original position and the retraction of the rod begins. In the process of retracting the rod at the counting input of the trigger with the counting input 4 - a signal of a single level, and after the end of retraction - a signal of zero level. A trigger with a counting input 4 will switch and a unit level signal will be established at its output. Next, the cycle repeats.

After pressing the “Stop” button 12, a trigger with separate inputs 6 switches to its initial state and a zero level signal is established at output 8. The amplifier 7 is turned off, the rod of cylinder 1 is retracted, and operation is stopped.

Using the adjusting throttle 3, the required pressure level of the signal supplied to the counting input of the trigger with the counting input 4 is set. If the pressure supplied to the pneumatic cylinder is increased, it is necessary to increase the working passage section of the throttle and vice versa.

The pneumatic cylinder jet control device has wide functionality, since the piston can be returned when stopped in any intermediate position. The intermediate position can be determined, for example, by the position of the stop, which prevents the extension of the rod. The formation of the reversal command occurs without the participation of limit switches. Exclusion from the control process of limit switches simplifies the design and increases reliability. In this case, the role of the limit switches is performed by the jet trigger with a counting input.

Claims (1)

A pneumatic cylinder control device containing a pneumatic cylinder, a distributor, a pneumatic amplifier, a trigger with separate inputs, built on discrete monostable inkjet elements, controlled by the Start and Stop buttons, characterized in that it has a trigger with a counting input, which switches when applying a zero level signal to its counting input, as well as an “I” inkjet logic element and a tuning choke, the distributor exhaust line being connected to the input of the tuning choke and a trigger input with a counting input, a trigger output with separate inputs, a unit level signal on which is set when the “Stop” button is pressed, connected to a trigger setup input with a counting input, a second trigger output with separate inputs is connected to the “AND” element output, output a trigger with a counting input, the signal of a unit level at which is set when a signal of a unit level is supplied to its installation input, is connected to the second input of the “And” element, the output of the “And” element is connected to the input of the air amplifier, and the output The adjusting throttle communicates with the atmosphere.