SU1277301A1 - D.c.electric drive - Google Patents

Abstract

The invention relates to electrical engineering, in particular to devices for measuring the dead strokes of electric drive mechanisms. The purpose of the invention is to simplify the sensor for monitoring the dead stroke of a mechanical transmission during operation of the electric drive. The electric drive contains controlled mechanical transmission 1, load 2 of a direct current motor 3, sensor 4, the output of which is connected to the input of the pulse shaper 5, whose input is connected to the input of switch 6. The output of switch 6 is connected to one of the inputs of logic circuit 7. Output pulse generator 8 is connected to the second input of the logic circuit And 7, the output of which is connected to the counting circuit 9 from the board. The invention makes it possible to control the dead course of the mechanisms with direct current electric drive without dismantling (from them with the products in which they perform their working functions. 2 or more. Vj vj with

Description

The invention relates to electrical engineering, in particular to devices for measuring the dead strokes of electric drive mechanisms without removing them from the products in which they perform working functions, and can be used in all popular economic sectors for the built-in (in-dash) control of the dead run of mechanical gears.

The purpose of the invention is to simplify the sensor for monitoring the dead stroke of a mechanical transmission during operation of the electric drive.

FIG. 1 shows a block diagram of an electric drive with a device for in-built monitoring of the dead stroke of mechanisms; 2, time diagrams of the device operation.

The actuator contains a controlled mechanical transmission 1, the load 2 of the drive motor 3 DC, the sensor 4, the output of which is connected to the input of the driver 5 pulses, the output of which is connected to the input of the switch 6, the output of the switch 6 is connected to one of the inputs of the logic circuit And 7, generator 8 pulses, the output of which is connected to the second input of the logic circuit And 7, In addition, the drive contains a counting circuit 9 from the board, the input of which is connected to the output of the logic circuit And 7.

The load 2, the mechanical gear 1 and the drive of the engine 3 are at the same time the elements of the system in which the work functions are controlled by the mechanical gear 1,

As the sensor 4, a low-resistance active is used, connected in series to the main winding of the drive motor 3. The resistance value of the sensor 4 is selected one to two times less than the resistance of the winding of the engine core 3, therefore the sensor 4 has almost no effect on the operating mode of the engine 3 The role of pulse generator 5 is performed by a differentiating circuit and a pulse amplifier-limiter, and switch 6 and pulse generator 8 are triggered and blocking oscillator, respectively. The logic circuit And 7 performed on the diodes. The counting circuit 9 includes a binary counter, a decoder that converts binary numbers to a decimal form, and a display board,

The device works as follows.

Before starting the measurement process, the dead stroke of the mechanical transmission 1 is set to the maximum position. The generator 8 pulses produces pulses with a period of following T; (Fig. 2d), which are fed to one of the inputs of the logic circuit And 7, At the second input of the logic circuit And 7 there is no signal and it is closed.

At time t, (FIG. 2), the driving motor 3 starts up. A start-up current pulse occurs in the winding of the core 3, which triggers a voltage pulse on the U8 sensor 4 and, (time t, fig 2a), the front of the voltage sensor pulse 4 is fed to a pulse shaper 5, differentiated, amplified, and limited. The generated voltage pulse of the driver 5 (time t, fig 26) is fed to the input of switch 6 and brings it to a state characterized by a high potential at the output (time t, figure 2b). From the output of switch b high potential is given to the second input of the logic circuit AND 7, which from the moment of time t passes pulses produced by the generator 8 pulses, to the counting circuit 9, the latter starts counting the pulses,

In the time interval ttt (Fig 2), the motor 3 comes into rotation, the starting current and voltage on the sensor 4 decrease exponentially (the interval ttt, fig 2a) on the low-speed shaft of the mechanical transmission 1 does not move, since Dead Run is not yet selected . The counting circuit 9 produces a count of pulses coming from the generator of 8 pulses through an open circuit And 7 "The input signal of the counting circuit 9 is shown in FIG. 2e,

Claims (1)

At the time t- (FIG. 2), the dead stroke is selected to rotate the low-speed shaft of the mechanical transmission 1, the load on the engine 3 rises abruptly, which causes a current pulse of the core of the engine 3 and a voltage pulse on the sensor U (time moment t, FIG. 2a), the voltage pulse of the sensor 4 is supplied 3 to the pulse shaper 5, (the voltage at the output U ,,), which produces the second pulse (time t, Fig. 26). This pulse from the imaging unit 5 is fed to the switch 6 and transfers it to the zero potential state at the output (time t, Fig. 2c). The zero output potential of the switch 6 (U) is applied to the AND 7 gate and closes it. The receipt of pulses from the generator 8 pulses (U | :) at the input of the counting circuit 9 is stopped (time t, Fig. 2e). The display of the counting circuit 9 (U) shows the number of pulses n counted during the dead run selection At. Since the pulse repetition period T produced by the pulse generator 8 is known, 2 and the mathematical expression used for which at a known value of at calculate the amount of backlash. The differential equation of motion of the engine 3 has the form V-3P (t). S .. (2) where J (t) is the current angular rotational speed of the engine 3 in a transient mode; Yats - nominal speed of rotation of engine 3 in steady state; The total electromechanical time constant of the engine 3. The values of 2 and T. are in the technical documentation and reference books, in addition, they are quite simple to determine experimentally. Substituting the expression (1) into the expression (2) and deciding it, get the calculation formula for the dead stroke of SLBODPT + T 5 (), 3, (3). Represent the expression (3) in the form of convenient for practical solutions. In technical documentation14 and reference books, the nominal rotational speed L is given in rpm dimensions. When calculating the dead stroke oL by the formula (3), it is necessary to substitute 9. (r / min) into it; , (with); T is the pulse repetition period of the pulse generator 8 (s); n is the number of pulses, taken from the information board of the counting circuit 9 (the value is dimensionless). After calculating the backlash 1, the device is reset, and, if necessary, go to the next control position of the mechanical gear I. In each control position, before measurement, it is necessary to set the maximum backlash. The proposed device allows controlling the dead stroke of DC-powered mechanisms without dismantling them from the products in which they perform their working functions. Invention A direct current drive comprising an electric motor connected to a load via a mechanical transmission, a dead-stroke control sensor of a mechanical transmission integrated in an electric motor, a switch connected to an input of the logic circuit AND whose output is connected to a counting circuit characterized in that the purpose of simplifying the sensor for monitoring the dead stroke of a mechanical transmission during the operation of an electric drive, it is equipped with a pulse generator, a pulse generator, the sensor control is made in de active resistor connected in series to the motor an anchor chain, wherein the input pulse shaper connected to the output of the control sensor, and its output is connected to the switch, wherein the pulse generator output is connected to the second input p logic I.