SU1737344A1 - Electronic tachometer - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the rotational speed of a crankshaft of an internal combustion engine and monitor the performance of candles. The purpose of the invention is to increase the reliability of measurements and the information content of the control. The goal is achieved due to the fact that the counters 3 1-3.N count the actually occurring burning in candles for a cycle of 100 pulses from 2.1-2.N signal conditioners, from inductive sensors 1.1-1.N appropriate candles. This allows you to continuously monitor the performance of the spark while the vehicle is moving and to judge the correctness of the tachometer itself connected to the output of the AND-NE element 10, whose input receives all the pulses from the outputs of the 2.1-2.N. Shaping the tachometer allows you to reduce fuel consumption. 2 Il.

Description

H O)

Xi

s

The invention relates to a measurement technique and can be used to measure the frequency of rotation of an engine shaft, as well as constant monitoring of the performance of candles and initiating a percentage ratio of the number of actually ignited candles in candles per cycle of one hundred ignitions.

A known electronic tachometer contains N inductive sensors, the outputs of which are connected to the corresponding inputs of N pulse formers, the outputs of which are connected to the corresponding inputs of the NAND circuit, the output of which is connected to a measuring instrument, and this tachometer contains RS-triggers, R-in RS-flip-flop dyes are connected to the corresponding N inputs — from the first drivers,

a S - inputs - with corresponding outputs

N

- to the remaining formers, outputs

each R-flip-flop is connected to the inputs of the indicators (1).

This device allows you to measure the frequency of rotation of the shaft, as well as to judge the errors in the measurements, i.e. when the indicators are on, the tachometer is correct. An off indicator indicates the absence of electrical discharges in the candle.

The disadvantage of this electronic tachometer is that it can only detect a completely inoperative candle, i.e. if the candle is intermittent (more than 50% but less than 100% of spark formation occurs in it), the electronic tachometer cannot determine this due to the rapid blinking of the indicator. This leads to an error in measuring the frequency of rotation of the engine shaft, as well as the impossibility of diagnosing the performance of candles that work with small interruptions. This entails gas overuse.

The purpose of the invention is to increase the reliability of measurements of the engine shaft revolutions and the information content of monitoring the performance of candles, as well as a constant indication of the percentage of the number of ignitions in candles during a cycle of 100 per candle (norm).

Figure 1 shows the block diagram of the proposed electronic tachometer; Fig. 2 shows timing diagrams for tachometer operation; where figa signal from the output of the pulse shaper from the contacts of the chopper; Fig.26, 2b, 2g, 2d - signals at the outputs of the formers from the inductive sensors of the first, second, third and fourth candles, respectively; 2e — write pulse from the write pulse and reset pulser; FIG. 2g shows the reset pulse from the write and reset pulse generator.

The electronic tachometer contains in series inductive sensors 1.1-1.N, pulse former 2.1-2.N, where N is the number of engine cylinders, counters per one hundred 3.1-3.N, memory blocks 4.14 .N, decoders 5.1-5.N and digital indicators 6.1-6.N, as well as serially connected shaper 7 pulses from the contacts of the chopper, pulse divider by the number N x 100, shaper 9 pulses of write and reset, the outputs of which are connected respectively to the combined write inputs of N memory blocks 4.1-4 .N and the combined reset inputs of N counters per hundred 3. 1-3.N. Shaper Outputs

pulses 2.1-2.P are connected to the corresponding inputs of the element AND-NOT 10, the output of which is connected to the measuring device 11.

A description of the operation of the device is given for

four-cylinder engine.

Inductive sensors 1.1-1.N separate the signal induced in the high-voltage wires going to the plugs, which are then generated by the 2.1-2.N drivers in

standard pulses that arrive at the counters 3.1-3.N and to the corresponding inputs of the NAND 10 circuit, the output of which is connected to the measuring device 11.

The state of the 3.1-3.N counters is stored in

memory for the previous cycle. Decoders 5.1-5.N decipher the state of the 4.1-4.N memory blocks, which are highlighted with indicators 6.1-6.N.

Shaper 7 pulses in the contacts of the chopper generates pulses, which are then divided by the number N x 100 by divider 8 (for a four-cylinder engine by 400).

At the end of the N × 100 pulse, the driver 9 emits two pulses separated by time.

During the time of dividing divider 8 by the number of four hundred in the counters 3.1-3.

occurred arson in the respective candles. This information in terms of numbers represents the percentage of each candle of a cycle of 100 ignitions triggered.

After the end of the cycle (rate 100 ignited by each candle), the content of the state of the counters 3.1-3.N is recorded in the memory blocks 4.1-4.N of the write and reset pulses 9. After the action of the write pulse, the reset pulse zeroed the counters 3.1-3.N and A new cycle of accumulation of information in the counters 3.1-3.N begins. The information recorded in the memory block 4.1-4.N is decrypted by the decoder 5.1-5.N and highlighted with the digital indicators 6.1-6.N according to the percentage response of each candle.

The indication time at the crankshaft rotation speed of 6000 rpm is about 2 seconds, which is quite enough to avoid the flickering of figures.

The pulses from the pulse shaper 2.1-2.N are combined into one pulse sequence using an AND-NOT 10 circuit. The output of the NAND circuit is connected to a measuring device that changes the frequency of rotation of the shaft.

The electronic tachometer makes it possible to measure engine rpm with great accuracy, as well as continuously monitor spark sparking in the percentage as a direct result of vehicle movement, detect a candle that works intermittently, and ultimately save fuel.

Claims (1)

Invention Formula Electronic tachometer containing N series-connected inductive sensors and pulse shapers, where N is the number of engine cylinders, the AND-NOT element, the driver of the pulses and contacts of the chopper and N indicators, while the outputs of the drivers are connected to the corresponding inputs of the NAND element, to the output of which a measuring device is connected, characterized in that, in order to increase the reliability of measurements and informativeness of the control, n counters per hundred, N memory blocks, N decoders, pulse divider are introduced into it on the number N x 100 and the driver write and reset pulses, while the counting inputs each of the counters is connected to the outputs of the pulse formers, respectively, and each of the outputs through the serially connected memory block and the decoder is connected to the input of the corresponding indicator, and the output of the pulse former from the breaker contacts is connected through an impulse divider number N x 100 to the pulse former input write and reset, the outputs of which are connected, respectively, with the combined write inputs of N blocks and the combined reset inputs of N counters per hundred. thirty schich- ichtgt