SU741183A1 - Phase-selective device - Google Patents

Description

one

The resolution relates to instrument making, in particular to electronic devices of test equipment and technical diagnostics of machines and can be used to selectively record the parameters of the studied processes.

A phase-selector device is known that contains a rotational frequency sensor, connected via a formation cascade with a frequency multiplier, a control unit associated with the output to the installation input of the counter, and an input with the output of the specified counter and input of the metering trigger. The frequency multiplier in this device is made on the basis of a time ratio meter; the inputs are connected to the trigger outputs. In the 20th unit, the introduction of a frequency multiplier allows an increase in the number of pulses arriving at the counter input during the period of the process under study. 1.25

The disadvantage of such devices is the low accuracy of phase selection. caused by non-frequency of the pulse frequency from the output of the speed sensor, for example 30

due to uneven rotation of the crankshaft dvigatel.p internal combustion in certain parts of the cycle of its work. When accelerating or decelerating the frequency of rotation of the crankshaft, the number of pulses generated by the frequency multiplier during each of the periods of impulses. , successively, dogddkost phase

The purpose of the invention is to improve the accuracy of phase separation.

The goal is achieved by the fact that a phase-selection device containing a series-connected rotational speed sensor, a driver and a frequency multiplier, as well as a control unit connected by its output to the installation input of the counter, and the input to the output of the above-mentioned counter and input of the countable trigger, equipped with a valve, two logical elements OR frequency divider.

acceleration and deceleration latches and a pulse generator, the output of which is connected to the first inputs of the OR elements, the output of the frequency multiplier is connected to the signal input of the valve, the valve output is connected to the second inputs of the OR elements, the output of the first OR element is connected to the counter, the output of the second OR element is connected with a frequency divider, the output of the frequency divider is connected to the reference, the two inputs of both latches, the signal inputs of which are connected to the output stage of the shaping stage, the output of the acceleration latch is connected to the control th input of the pulse generator, delay latch output is connected to a steering valve input, and the other control input of which is connected to the output of the shaper.

The drawing shows the functional scheme of the device.

The device contains a rotational speed sensor 1 4aic with a driver 2 at the output connected through a frequency multiplier 3 to the signal input of valve 4. The output of valve 4 is through logic elements 5 and b OR connected to the inputs of frequency divider 7 and counter 8, respectively. The frequency divider 7 is connected to the reference inputs of deceleration latches 9 and acceleration 10. The signal inputs of the latter are connected to the output of the imaging unit 2, the output of the counter 8 is connected to the control unit 11, the output of the acceleration latch 10 is connected to the control input of the generator 12 pulses, the latch output 9. Connected to one of the control inputs of valve 4.

The output of the counter 8 is connected to the input of the counting trigger 13, to the other inputs of the control unit 11, respectively, the trigger synchronization signals as well as the number codes defining the operation program of the device are supplied. The output of the control unit 11 is connected to the installation input of the counter 8.

The device operates as follows 3 ohm.

On the Start command supplied to the input of the control unit 11, the code of the number specifying the registration start phase is recorded in the counter 8 from the programming input.

The speed from the output of the rotational speed sensor 1, formed over the duration tX of the driver 2, is multiplied4. frequency multiplier 3 frequency and after 4, open pr one of the control inputs pulse from the output of the imager 2 ,. arrive at the inputs of the frequency divider 7 and the counter8, respectively, through the logic elements 5 and 6 OR.

Img: the pulses formed at the output of the frequency divider 7 are generated by. duration7

The division factor of the frequency divider 7 is equal to the multiplier factor 3 frequencies, as a result of which, at a constant rotation frequency, the reference and signal inputs of the acceleration latches 10 and the slowdown 9 are impulses from the outputs of the imaging unit 2 and the divider 7 simultaneously. In this case, the latches 9 and 10 do not work, and at the output of the counting trigger 13 in a known manner, a strobe pulse is formed, the phase of the beginning and end of which is set by the programming input of the control unit 11.

As the rotational speed of the engine increases at any part of the engine cycle (acceleration of rotation) at the signal input of the acceleration latch 10, the rotational speed pulses from the output of Former 2 appear earlier than the pulses on. the reference input from the output of the divider 7, due to the inertia of the multiplier 3 frequency. The acceleration latch 10 is triggered and generates at its output a signal that unlocks the pulse generator for 12 pulses for the duration of the signal. From the output of the latter, pulses through elements 5, 6 OR arrive at the inputs of counter 8 and frequency divider 7 until a pulse fails at the output of frequency divider 1 to reset the acceleration latch 10 to the initial position, as a result of which the pulse at the output of the counting trigger 13 is Wits earlier than necessary as the rotational speed has increased.

When the acceleration latch 10 is triggered by a signal from its output, the deceleration latch 9 is blocked. When the acceleration latch 10 is reset to the initial state by a pulse from the output of the divider 7, the deceleration latch 9 does not turn on, since its delay element delays the falling edge of the output pulses of the acceleration latch 10 by a time longer than the duration of the pulses from the output of the divider 7.

When a frequency of the engine rotates (deceleration) on a part of the engine cycle, deceleration latch 9 is triggered, since at the reference input its pulses from the output of the divider T appear earlier than at the signal input. The output signal of the deceleration latch 9 is fed to the second control input of the valve 4 and closes it until the frequency pulse appears at the output of the driver 2. As a result, a smaller number of pulses from the output of the multiplier 3 frequencies arrive at counter 6 and a strobe pulse will be formed later, as it should be when slowing down.

When a pulse appears at the output of the former 2, the deceleration latch 9 is reset by the signal input to the initial state. In this case, the latch 10 of the acceleration does not work because it is blocked by the blocking input by a signal from the output of the deceleration latch 9, which is delayed by the delay element by its delay element for a time longer than the rotational speed impulse. In order for the device to function normally with uniform rotation, the condition G / x must be met.

Thus, the device provides an automatic analysis of rotational unevenness, for example, inside the cycle of the internal combustion engine, and corrects the phase of the beginning and end of the strobe pulse, which improves the accuracy of the formation of the beginning and end of registration of the monitored parameters. The introduction of new elements — a valve, two logical elements OR, a frequency divider with a division factor equal to the multiplier of the frequency multiplier, acceleration and deceleration clamps, two delay elements, a pulse generator — distinguishes the proposed device from the well-known device, because it allows to increase the accuracy of phase selection the frequency of rotation during the period of the process being studied.

Claims (1)

1. USSR author's certificate, cl. G 01 R 25/00, 1972. Hpt leJ //