SU1149293A1 - Device for monitoring rotation of shaft - Google Patents

Abstract

A device for controlling the rotation of the shaft, containing a toothed disk, a position sensor with direct and inverse outputs and an element I, o and which is so that, in order to increase the reliability of the control, an additional position sensor with a direct output and three time relays are introduced , the inverse output of the position sensor is connected to the input of the first time relay, the direct output of the position sensor is connected to the input of the second time relay and one input of the I element, the direct output of the additional position sensor is connected to the input of the third time relay, output D which is connected to another input of the element I, an additional position sensor is installed with respect to the position sensor at a distance smaller than the pitch of the teeth of the disk, the outputs of the first and second time relay L and element And form the device output. i4 f 1chE se so

Description

The invention relates to the control automation and is intended for use in the systems of automatic measuring equipment, in particular, as part of the means of controlling conveyors for various purposes. The aim of the invention is to increase the reliability of the control. FIG. 1 is a block diagram of the device for controlling shaft rotation in FIG. 2 is a timing diagram explaining its principle of operation when the shaft rotates at a normal speed in a given direction (clockwise in FIG. 1) V in FIG. 3 is a timing chart with a slower rotational speed; in fig. 4 shows a timing diagram for stopping rotation of a cog tgr disk in the position of the scientific research institute as shown in FIG. 1 in FIG. 5 is a timing diagram for the reverse of rotation (in FIG. 1, the reverse of rotation corresponds to the direction counterclockwise) with a normal speed in FIG. 6 is a timing diagram for oscillatory rotation; a gear disk; FIG. 7 The relay circuit diagram in FIG. 5 | 8 - time diagram of the time relay. FIG. I and 7 of the connection of the elements are indicated by capital letters. The device for controlling the rotation of the shaft (Fig. T) contains a toothed disk 1 mounted on a rotating shaft (Fig. 1 shows a part of the disk and the shaft is not shown), position sensor 2 with direct and inverse outputs, additional position sensor 3 with right my output, time relay 4-6, element I 7 The relay shown in FIG. 7, the relay time | Ne contains elements 8-13 AND –NE, resistors 14-16, capacitors 17 and 18. The gear disk 1 is made in increments Scar .. The device works as follows. The sensors 2 and 3 of the position emit signals, the levels of which are relayed when the teeth of the disk 1 pass in their working areas. When the tooth of disk 1 is in the working area of sensors 2 and 3 of the direct output, a signal appears that is logical unit, and on the inverse output of sensor 2 - a signal of logical zero. Sensors 2 and 3 are located relative to each other at a distance smaller than a pitch of 19. A tooth (for example, 0.75 pitch). The relays 4-6 times delay the signal edge by the given values of t, tj and tf, respectively. The cuts of the input and output signals are cvv screen. If the input signal disappears during the hold time, then no output signal appears at all. The proposed time relay function is implemented, for example, by elements of the time T-303 or T-304 of the Logic system. I The required function can be implemented using a time relay (Fig. 7), built on the basis of a known one-shot. Elements 8 and 9 form an RS-flip-flop, elements AND-NOT 10 and 11 are inverters, and element IS-HE 12 together with a differentiating circuit (capacitor 17 and resistor 15) form a narrow pulse driver on the front of the input signal (7 relays. When the presence of a single signal at the output To the RS-trigger at the output of element 8 is set to zero level of the output voltage. The voltage at the voltage of the element AND-NE 10 takes a single level. The capacitor t8 through the resistor 16 is charged, creating a high voltage level at the input of the element AND -NOT 9. Because on the other the input level of the element AND-NOT 9 operates at a zero signal level, then the voltage at the output of the IEN 9 element is equal to Logical unit 1. With the arrival of the signal at the input of the time relay at the generator of the narrow pulse (capacitor 17, resistor 15 and element IS-NOT 12) a narrow the logical zero signal leading to the flip-flop of the RS flip-flop.The output of the N-8 element is set to the level of the logical unit, and the output of the N-10 element is the logical zero. The voltage on the capacitor 18 cannot change in the jumps, so after tipping the RS-trngger, the capacitor 18 continues to create at the input L of element 9 a high voltage level exceeding the threshold value. In this case, the capacitor 18 is discharged through the resistor 16, and the voltage across it decreases. When it decreases to a voltage corresponding to the switch-off threshold of the N-9 element, for example, the SRI on the drive of this element will again take the level of the logical unit, returning the RS flip-flop to the original state. The voltage on the capacitor 1-8 is restored to its original level by charging the resistor 16 with a voltage of 1.0 through a resistor through the resistor. At the output O of the time relay, a signal is generated whose duration is equal to the output. .- t where t is the duration of the input signal ta is the delay time. The signals (Fig. 1) from the inverse output A and the direct output B, the position sensor 2 are fed to the inputs of time relays 4 and 5. The signal from the direct output B of sensor 3 is the position of flow from to the input of time relay 6. Output B of position 2 sensor and output G of time relay 6 are connected to inputs of logic element 7. And outputs E and D of time relay 4 and 5 and output W of logic element 7 are outputs of the device. Operation of the device in a given direction of rotation with a normal speed is explained in the time diagram in FIG. 2. When the toothed disk 1 is rotated, the outputs A, B, and C show signals with a pulse duration td, tg, and tg, respectively. At the same time t tg. The signal at output B is lagging behind the signal at output B by an amount equal to 00 (1 - i) (t, + t), (1) where J is the distance between position sensors 2 and 3 h is the tooth pitch. The signal in the code D is absent under the condition tA t 1d + c. (2) The signal at output E is absent under the condition tb ty t + tp. (3) There is no signal at output F, ec does not simultaneously send signals from outputs B and D to the inputs of the logic element I 7, t. its tg (4) te -06 tj 3 .4 The diagram in FIG. 2 is kept unchanged if the position sensor 3 is placed against a predetermined direction of rotation over a distance mh, with m 1,2,3, .. ,, (n-1), where n is the number of teeth of the disk. When the rotational motion of the shaft with a slow speed (Fig. 3) Cd t and t g tj, i.e. the conditions specified by the left frequent inequalities (2) and (3) are violated. At outputs D and E, warning pulses appear, the duty ratio of which depends on the speed of rotation of the shaft. When the rotation is stopped (fig. 4), for example, in the position shown in fig. 1, output B is a constant signal at the source. From the output E with a delay t also follows a constant signal. When reverse rotation with normal speed (Fig. 5), the signal at the output B is lagging behind the signal at the output B by the value of Oi i (t.A-b C). In this case, oi) i.e. violates the condition specified by the right-hand side of inequality (4). The pulse at the output of G partially coincides with the signal at the output of B, as a result of which, at the output of the logic element And 7, warning pulses appear. The operation of the device in the case of oscillating rotation of the shaft is illustrated in FIG. 6. The gear disk 1 oscillates with an amplitude equal to the step 19 of the tooth, and in FIG. 1 disk 1 is shown in the leftmost position of these oscillations. From this position, the disk 1 moves to the tooth pitch against the specified direction of rotation (i.e., counterclockwise), then the disk 1 moves to the schag in the specified direction (i.e., clockwise), etc. The diagram in FIG. 6 for definiteness is shown with oscillatory rotation at normal speed. From the output of the device, follow the warning pulses. Thus, the device provides warning signals for reverse rotation as well as for oscillating rotation of the toothed disk.

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Claims (1)

DEVICE FOR CONTROL OF SHAFT ROTATION, containing a toothed disk, a position sensor with direct and inverse outputs and an element And, about τη and that, with the aim of 1 to increase the reliability of control, an additional position sensor with a direct output and three time relays are introduced into it, the inverse output of the position sensor is connected to the input of the first time relay, the direct output of the position sensor is connected to the input of the second time relay and one input of the AND element, direct the output of the additional position sensor is connected to the input of the third time relay, the output of which is connected to another input of the And element, the additional position sensor is installed relative to the position sensor at a distance less than a step On the other hand, the outputs of the first and second time relays and the AND element form the output of the device. 1 1149293