RU1810614C - Piston extreme position sensor - Google Patents

Abstract

SUMMARY OF THE INVENTION: In a cylinder with piston and rod cavities, a side hole is made at a controlled point. The output signal generating unit comprises a FORBID logic element whose inverse input is connected to the extreme point of the stock cavity. One outlet of the distributor is in communication with the rod cavity through a throttle with a check valve; another outlet is communicated with the piston cavity through a closed loop. One input of the AND gate is connected to the side hole, the second input to the output of the FORBID element, the direct input of which is connected to a closed loop. 1 ill.

Description

The invention relates to automation and can be used in various industries.

The purpose of the invention is to increase the reliability of the sensor when the piston reaches its extreme position by eliminating the occurrence of false signals during depressurization of the lines.

 This goal is achieved in that the node for generating the output signal co. also holds the logical element And, the throttle with a check valve, a closed circuit of highways with a built-in throttle and two check valves and a distributor, one output of which is communicated by a highway with a cavity for emptying the cylinder through a throttle with a check valve, and the other output - with a filling cavity through a closed a circuit, and one input of the AND gate connected to the cylinder cavity at a controlled point of the extreme position of the piston,

and the second input is to the output of the FORBID logic element, the direct input of which is connected to a closed circuit, and the inverse input to the extreme point of the empty cavity.

The drawing shows a diagram of the sensor reaching the extreme position.

The piston reaches its extreme position and includes a ram 1 with an opening 2 in the side wall. Rodless cavity 3 of cylinder 1 is connected to a source of compressed gas (not shown) by line 4 through a closed housing 5 and distributor 6. Closed loop 5 contains a check valve 7, a throttle 8, a check valve 9, which are in series. communicated by line 10 with a direct input of a logic element (for example, a pneumatic valve) FORBID 11. The rod cavity 12 of cylinder 1 is connected by line 13 through a throttle to a check valve 14 and a distributor 6 sec

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the atmosphere. In addition, the cavity 12 is communicated by the highway 15 through the highway 13 with an inverse input of the element 11, the output of which is communicated by the highway 16 with the control input of the logic element And 17, the second input of which is communicated by the highway 18 with the hole 2. In the cylinder 1 there is a piston 19 with a rod.

The sensor operates as follows.

Compressed air from the distributor 6 along the line 4 through the check valve 7 of the closed circuit 5 enters the rodless cavity 3 of the power cylinder 1, after which the piston 19 with the rod begins to move to the leftmost position towards the hole 2. At the same time, compressed air enters through the throttle 8 through line 10 to the direct input of the logic element 11. From the rod cavity 12, compressed air is displaced by the piston 19 along the line 13 through the throttle 14 and the distributor 6 into the atmosphere. At the same time, compressed air through line 15 enters the inverse (control) input of element 11, supporting it in the on state, while at the output of element 11, and therefore in the line 16 and at the control input of logic element 17, there is no compressed air pressure therefore, despite the fact that the compressed air displaced by the piston 19 from the cavity 12 enters through the opening 2 along the line 18 to the second input of the element 17, the pressure of the compressed air is 0 at the output of the element 17 (Pout. 0). When the piston 19 is in its leftmost position (the stem is extended), the hole 2 will be behind the piston in the rodless cavity 3, where the maximum pressure of compressed air is set, while in the end cavity 12 the pressure is 0. The pressure in line 15 and the inverse input of element 11 is also set equal to 0, while element 11 is switched and line 10 is connected to line 16, and compressed air from line 10 enters through line 11 to line 16 and to the control input of element 17. Logic element 17 switches whenIn this way, the highway 18 is connected to the outlet of the element 17. Compressed air from the cavity 3 of the cylinder 1 through the hole 2 along the highway 18 through the element 17 enters its outlet (Pry. -1). The return stroke of the piston 19 of the cylinder 1 will occur if the distributor 6 switches, while the line 4 communicates with the atmosphere and the line 13 communicates with a source of compressed air. Compressed air through line 13 through the check valve throttle 14 enters the cavity 12. At the same time, compressed air through

line 15 is fed to the inverse input of element 11, switching it. The line 16 communicates through the element 11 with the atmosphere, while the pressure of the compressed air at the control inlet of the element 17 becomes 0. The element 17 is switched off, locking the line 18 and communicating the output with the atmosphere (Burst. 0). When the piston 19 is moved to the extreme right position, compressed air from the cavity 3 along the line 4 through the throttle 8, the check valve 9 and the distributor 6 is released into the atmosphere. The piston 19 may be in its rightmost position for an arbitrarily long time, while the motorways 5 and 18 are under pressure from compressed air. In the case of depressurization of the line 15, the appearance of a false signal at the output of element 17 will not occur, because highway 16 connects to the highway

0 10 through element 11, and line 10 through the check valve-9, line 4 and distributor 6 are in communication with the atmosphere. The most dangerous moment from the point of view of the occurrence of false (premature)

5, the signal at the output of element 17 (Pout 1) occurs when the piston 19 moves from the extreme right to the extreme left, i.e. when the piston moves to a controlled point 2. At this time, the pressure in the cavity 12 and

0 line 15 drops, and the pressure in the cavity 3 increases spasmodically.

The throttle 8 slows down the increase in pressure in the line 10, preventing the breakdown of compressed air through the element 11 in

5 to line 16 and to the control input of element 17, in the case of partial depressurization of line 15, element 11 is in a position called a short circuit, i.e. his entrance

0 outlet and atmospheric opening are in communication. If the flow rate of compressed air along the line 10 is equal to leaks through the atmospheric opening of the element 11, then the pressure in the line 16 is 0 (Pout.0);

5 The flow rate in line 10 is determined by the throttle setting 8. When the line 15 is completely depressurized, the pressure in line 16 rises, but drops sharply. the pressure in the cavity 12 and line 18, with

0 this, the speed of the piston when moving towards the hole 2 increases just as quickly.

Thus, the design of the sensor reaches the extreme position of the piston ensures its reliable operation, with

In this case, the depressurization of any of its lines or the pressure drop in the cylinder cavities in the case of rapid movement of the piston (high-speed actuators) does not lead to the appearance of a false signal at the output of the sensor.

The economic effect of using the proposed piston extreme position sensor can be calculated after use.

Claims (1)

SUMMARY OF THE INVENTION A piston reaching the extreme position of a piston, comprising a cylinder with a rod and piston cavities, in the housing of which a side hole is made at a controlled point, and an output signal generating unit including a logic element BAN, whose inverse input is connected to the rod end point cylinder cavities the fact that, in order to increase the reliability of the sensor, it is equipped with a logical element And, a throttle with a check valve, a closed loop with two check valves and a throttle connected in series, and a distributor, one output of which is connected, with the rod cavity of the cylinder through a throttle with a check valve, and the other exit - with the piston cavity of the cylinder through a closed loop, with one input of the logical element And connected to the side hole at the controlled point, and the second input - to the output of the logical element FORBID, direct th input which is connected to a closed loop.