SU789660A1 - Apparatus for determining ignition advance angle - Google Patents

Description

one

The invention relates to measurement technology and can be used. It is designed to determine the ignition advance angle in multiple engines of internal combustion engines. five

There are several types of devices for determining the advance angle of ignition. One of such devices contains a sensor for determining the top dead center, a spark plug and an upper dead point sensor pulse generators, a time pulse generator, ignition advance angle and crankshaft rotation speed recorder corresponding to the measured angle, button, controllers. triggers and match items 1).

The disadvantage of this device is the impossibility of simultaneously measuring its ignition advance angle in each cylinder of a multi-cylinder engine.

The closest to the proposed technical entity is a device containing a top dead center and crankshaft speed sensors, pulse formers of both sensors, the inputs of which are connected to the outputs coot-) 0

sensors, an ignition pulse driver connected to the low-voltage terminal of the distributor interruption, triggers, pulse frequency divider and crankshaft rotation speed meter and zeshigani front angle 2,

Disadvantages of this device. low accuracy and great laboriousness of determining the ignition advance angle in each cylinder of a multi-cylinder engine due to the use of a loop oscilloscope in it, which is due to the large laboriousness of deciphering the oscillograms and loss of accuracy due to both errors in the processing of the results, and the inability to maintain constant the speed of movement of the photosensitive paper.

The purpose of the invention is to improve the accuracy and reduce the complexity of determining the angle of ignition advance in each cylinder of the engine.

The goal is achieved by the fact that, in a known device for determining the ignition advance angle, comprising sensors for the top dead center and rotational speed of the crankshaft, pulse formers of both sensors, whose inputs are connected to the outputs of the respective sensors, igniter pulse former connected to the distributor-distributor terminal , triggers, pulse frequency divider and crankshaft speed and crankshaft rotation angle meters, the ignition pulse switch is entered, and The ignition advance angle is made in the form of a block of digital meters, one inputs of which are connected to the corresponding outputs of the pulse switch, ignition, and the second to the output of the impulse generator of the top dead center sensor, two elements of coincidence, one input of the first of them is connected to the output of the pulse former - burning, the output is connected to the ignition pulse tator, one input of the second coincidence element is connected to the output of the rotation speed sensor pulse generator, and the output is connected to a pulse frequency divider, connected to two digital outputs to a digital rotational speed meter, crankshaft, a spark plug pulse former whose input is connected to a spark plug, and the output is connected via a start button to the input of the first trigger, and the output of the first trigger is connected to one input of the second trigger, the second input is connected with one output, the pulse frequency divider, and the output with the second inputs of both elements coincide.

FIG. 1 is a block diagram of a device for determining the ignition advance angle; in fig. 2 is a schematic diagram of the sensors of the top dead center and the rotational speed of the crankshaft.

The device for determining the ignition advance angle contains the upper dead center sensors 1 (Fig. 1) and the crankshaft speed sensor 2, the formers 3 and 4 pulses of both sensors, the inputs connected to the outputs of the respective sensors, the driver 5 ignition pulses connected to the low voltage terminal b distributor interrupter, triggers 7 and 8, pulse frequency divider 9, digital crankshaft speed, digital speed meter 10, digital ignition angle meters 11, ignition pulse switch 12 , The outputs of which are connected with one of the inputs of digital meters 11, spark advance, the second inputs of which are connected to the output shaper 3 imiulsov; top dead center, elements 13 and 14 match, one inputs of which are connected respectively to the outputs of the driver 5 ignition pulses and the driver 4 rotational speeds, the second inputs to the output of the trigger 8, and the outputs respectively to the input of the switch 12 ignition pulses and to the input a pulse frequency divider 9 connected by two of its outputs to a digital crankshaft speed meter 10, a driver of 15 spark plug pulses whose input is connected to a spark plug 16, and an output through the start button 17 dinen with the input of the trigger 7, the output of which is connected to one of the inputs of the trigger. 8, the second input of which is connected to one of the outputs of the pulse frequency divider 9.

The top dead center sensor 1 is designed to emit pulses corresponding to a position more pronounced in the engine cylinders at the top dead center of the compression stroke end, and is made in the form of a shaft 18 (Fig. 2) with a disk 19 with holes 20 fixed on it, one side of which sources of light 21 are located and, on the other, sensitive elements 22, in which FD-2 type photodiodes are used. The outputs of the sensitive elements 22, corresponding to a certain number of cylinders of the engine under test, are connected to the inputs of the switch 23, which has four inputs and one output.

The holes in the ia disk are located for an eight-cylinder engine through 90, for a six-cylinder engine through 120, for a four-cylinder engine through 180, for a two-cylinder engine through 360 °.

The sensor body with sensing elements 2 located on it and sources of light 21 can freely move relative to the axis of the disk 19, which is necessary to align the holes 20 of the disk 19 with the sources of light 21 and the sensitive elements 22 during the installation of the sensor.

The crankshaft speed sensor 2 is structurally aligned with the top dead center sensor 1 and has one hole 24 on the disk 19, a light source 25 and a sensitive element 26. The hole 24 is located at the same radius with the holes O of the top dead center sensor 1 corresponding to the position of the piston of the first cylinder of the engine at the top dead center of the end of the compression stroke. Sensor 2 serves to output pulses in the course of rotation of the engine crankshaft, the frequency of which is proportional to the angular velocity. During one revolution of the crankshaft, the sensor generates a single pulse in exactly the same phase of rotation. The formers 3 and 4 are designed to amplify, limit amplitude de and form, the duration of the signals received at their inputs of the upper point sensor 1 and the crankshaft speed sensor 2, respectively. Both drivers are similarly made, and each of them is a single-stage electronic amplifier equipped with emitter followers at the input and output. Pulse generator 5 is ignited to form signals corresponding to the tripping points of the distributor distributor, and is a two-stage electronic amplifier, at the input of the first stage of which a capacitive-rheostat filter is installed to eliminate the high-frequency component of the discharge. Triggers 7 and 8 are designed to start the device and stop it after the end of the measurement cycle, equal to two revolutions of the engine crankshaft. In addition, both triggers together allow only one pulse from the spark plug to be transmitted, regardless of the duration of pressing the start button 17. The pulse frequency divider 9 is used to limit the cycle of operation of the device to determine the ignition advance angle by two turns of the crankshaft of the engine. It consists of two triggers connected in series with counting inputs, with the input of the second trigger connected to the single output of the first trigger. The digital crankshaft speed meter 10 is designed to measure the duration of two revolutions of the engine crankshaft that make up its cycle of operation, during which the timing of ignition advance is measured. It is made in the form of a six-bit electronic scaler and a time pulse generator, with a matching element set at the input of the scaler, controlled by a trigger with separate inputs. Digital ignition timing meters 11 are used to measure time intervals that are proportional to the ignition advance angles in the respective cylinders of the engine, from the moment the ignition pulses appear to the upper dead point 1 pulses. All gauges are four-bit and structurally similar to gauge 10 of the crankshaft rotation speed. To display the measurement results, digital meters 10 and 11 are equipped with one decoder and one six-bit indicating device connected to its output, made on the basis of digital indicators. The outputs of the triggers of the counting devices of both meters through one of the inputs of the coincidence elements are connected to the corresponding inputs of the decoder, and the second inputs of the coincidence elements are connected to the source of the control positive voltage plus 1.5 V at the inputs of the elements of the matching voltage it is disconnected from the decoder, and in the absence of it it is connected, indicating its state on the digital-digital indicators. The ignition pulse switch 12 is designed to distribute the impulse chopper distributor pulses arriving at its input to the corresponding inputs of the ignition angle meters 11. He has one. . an entrance and eight exits (for the eight-cylinder engine) and it is executed in the form of a binary electronic Counter with a decoder. The coincidence elements 13 and 14 are used for communicating and dissociating, respectively, the generator 5 of the pulses of the distributor distributor with the switch 12 of the ignition pulses and the generator of 4 rotational speeds with a frequency divider 9 pulses. Both of them are controlled by the trigger 8 and are made in the form of a transistor matching circuit for two inputs, giving positive signals at the output if there are impedance signals on its inputs. The ignition pulse shaper 15 serves to generate signals corresponding to the discharge process in the spark plug of the first cylinder of the engine, and is designed as a two-stage electronic amplifier, at the input of the first stage of which are installed series-connected damping resistance and a neon lamp. A device for determining the ignition advance angle operates as follows. Before starting the measurement, the piston of the first cylinder of the engine is set to the position corresponding to the top dead center of the end of the compression stroke. After that, the top dead center sensor 1 and the crankshaft rotation speed sensor 2 are installed, and the sensor housing moves relative to its axis with the sensitive elements 22 and light sources 21 located on it until they coincide with the corresponding holes 20 located along with other holes in disk 19 on one radius. The device is connected to the output of the spark plug 16 of the first engine cylinder, the upper dead sensor and the crankshaft speed sensor 21 and the low-voltage terminal 6 of the distributor chopper. The switch 23 is set to the number of cylinders of the engine being tested (in Fig. 2 the switch corresponds to an eight-cylinder engine). After supplying the device voltages to the inputs of the formers 3, 4, 5 and 15, the pulses are continuously received when the engine is running, where they are amplified, limited in amplitude and formed in duration. . The damping pulse (not shown) of the device nodes is reset to the initial state shown in FIG. 1, in which all the triggers are in position, the elements 13 and 14 of the match are closed and. the pulses from the formers 5 and 4 do not pass through them. The pulses from the output of the former 3 upper dead center impulses are fed to the inputs of the digital ignition angle meters 11 and keep them in the closed state. When the start button 17 is pressed, the pulse from the spark plug of the first cylinder, having passed through the former 15, enters the input of the trigger 7 and turns it into a state. The signal appearing at its output is fed to the input of the second trigger and also puts it into a state. As a result, the elements 13 and 14 of the match are covered. Since trigger -7 only changes its state once, regardless of how long the button 17 is pressed, trigger 8 retains its new position until a signal is sent to its second input. Thus, triggers 7 and 8 allow only one si from the spark plug to be passed, and the rest to be delayed by trigger 7. The pulse from the output of the driver 5 after the open element 13 coincides and is fed to the input of the switch 12 by the ignition pulse, which outputs a signal at its output , opening the first digital ignition timing indicator 11, which begins to sum up the time pulses. As the engine crankshaft rotates, there comes a moment when the piston of the first cylinder of the engine is in the position of the upper measure of the end point of the compression stroke. At the same time, the corresponding aperture 20 on the upper dead center sensor disk 19 is located opposite the corresponding light source 21. The corresponding sensor element 22 is illuminated, the signal from the output of which is fed to the input of the imager 3 upper dead center pulses and closes the first digital ignition angle meter 11. At the same time, a sensitive element 26 is illuminated by a source 25 of light through an opening 24 on the disk 19. The signal released by its output is the input of the driver. 4 pulses of rotational speed, an open coincidence element 14 passes and opens a digital meter of rotational speed 10. With the arrival of the next ignition pulse from the imaging unit 5, which corresponds to the ignition time in the next cylinder order (in this case in the fifth), the engine passes the open coincidence element 13 and enters the input of the ignition impulse switch 12. The switch generates a signal that opens the second digital frontal angle meter 11. At the time of the emergence of the next-signal upper dead center pulse output from the former 3, the second digital advance angle meter 11 also closes. The described process of operation of the device for determining the ignition advance angle proceeds similarly through other engine cylinders in a sequence determined by the order of its operation (for an eight-cylinder engine, in the sequence 1-5-4-2-6-3-7-8). At the end of the engine cycle equal to two crankshaft revolutions, the last digital ignition angle meter 11 closes with an impulse from the output of the imager 3 upper dead center pulses, and a digital rotation speed meter 10 closes with the impulse from the output of the imager 4 impulses of rotation. In this case, the signal from the output of the pulse frequency divider 9 is fed to the input of the trigger 8 and converts it to the initial state, as a result of which the elements 13 and 14 coincide are closed, preventing it; The most direct passage through them of pulses from the output of the formers 4 and 5. At this the measurement cycle is terminated. By pressing the corresponding buttons, the counting devices of the meters 10 and 11 are alternately connected with the decoder, as a result of which their status is indicated on the digital

Indicators of the indicating device. .

Thus, at the end of two revolutions of the engine crankshaft during which one full cycle of its operation takes place, digital gauges 11 record the number of time pulses corresponding to the time intervals from the ignition points in the corresponding cylinders to the piston reaching points in accordance with the order of engine operation. of the same cylinders of the upper dead end of the compression stroke and the projection angle of the ignition advance angle, and on the digital meter 10 - the number of time pulses corresponding to the length flax two revolutions of the engine crankshaft and proportional to the speed of rotation.

An introduction to the proposed ignition pulse commutator device, two coincidence elements, a spark plug pulse generator, a start button, and an ignition angle gauge as a block of digital meters and the use of a digital crankshaft speed meter, connected to one another and with other device nodes allows for one. the engine cycle makes a digital measurement of the angles of one ignition in all cylinders and axes of a multi-cylinder engine with simultaneous measurement of the rotational speed of the NIN of the crankshaft, which can be considered as a constant value. This leads to a decrease in labor intensity and an increase in the accuracy of determining the angle of ignition advance.

Knowing the ignition advance angles in each cylinder of the engine makes it possible to determine the asynchronism of the alternation of sparks and the continuity of the sparking, which have a significant effect on the efficiency of the ignition system.

In addition, a more accurate determination of the advance angle of the ignition allows it to be more accurately mounted on the engine and thereby reduce fuel consumption, increase engine power and improve performance: vehicle efficiency.

Claims (2)

1. Authors certificate of the USSR 544118, cl. F 02 R 17/00, 1975. 2. Authors certificate of the USSR 144625, cl. F 02 R 17/00, 1960 5 (prototype) ..