RU2075617C1 - Method for optimization of operation of internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering; internal combustion engines with forced ignition system. SUBSTANCE: basing on comparing in time the position of crankshaft and sparking moment, relative intercycle and intercylinder spread of ignition advance angles within the limits of each complete operating cycle of internal combustion engine is determined. Basing on results of measurements, excess air control is adjusted to decrease excess air coefficient α in case of increased instability of ignition system operation and vice versa. In other design version, spread of ignition advance angles is determined by duration of maximum pressure in cylinders. EFFECT: improved operation of engine. 2 dwg

Description

 The inventive method of optimizing the operation of the internal combustion engine is intended for internal combustion engines with a forced ignition system.

 A known method of optimizing the operating mode of the internal combustion engine is that in idle mode, air is supplied to the intake pipe, and before the air supply starts, the ignition timing is set later than the installation angle. (See, for example, the USSR AS N 401816, class F 02 P 5/00, published on October 12, 73. in B.I. N 41: "The way ICE works in forced idle mode").

 The disadvantage of this method is that it is intended only for idle mode. In addition, this method does not have an effect with inter-cylinder spread of the ignition timing (UOZ) and uneven operation of the cylinders.

 There is also a method of optimizing the operating mode of the internal combustion engine, which is closer in technical essence to the declared one and adopted as a prototype, which consists in the fact that in the entire range of engine shaft speeds, the UOZ varies depending on the load and shaft speed, and at forced idle according to the sensor signals act on the throttle. (See, for example, the USSR AS N 1474316, class F 02 P 5/00, published on April 23, 89. in B.I. N 15: "A method for optimizing the ignition timing").

 The method, in comparison with the analogue, is more universal, however, its disadvantage is that it does not take into account the mismatch of the ignition timing in successive cycles and inter-cylinder cycles, as well as the uneven start of the working process in the cylinders. Such unevenness can lead to engine shutdown when using this method. In the general case, ignoring the actual process of cylinder operation leads to incomplete combustion of fuel, especially in private cycles and idle modes, increasing exhaust toxicity and increasing fuel consumption.

 The claimed invention is aimed at improving the specific performance of the engine, increasing the stability of its operation, reducing fuel consumption, reducing exhaust toxicity, in particular at idle.

 To achieve the specified result in the known method of optimizing the operating mode of the internal combustion engine, which consists in acting on the throttle according to the signals of the engine speed sensor and engine load, according to the invention, the maximum relative inter-cycle and inter-cylinder time spread of the ignition timing are measured, according to the measurement results, they affect the regulator of the coefficient of excess air so that with a decrease in the inter-cylinder scatter angles, the coefficient α shifts towards depletion, and and increasing the scatter angles in the direction of enrichment of the combustible mixture.

 The impact on the regulator of the composition of the mixture according to the results of measuring the time spread of the ignition timing allows you to organize the optimal value of lean lean fuel and thereby significantly reduce fuel consumption and reduce exhaust toxicity, especially in private and idle modes.

 In the known sources of information used to determine the level of technology, the combination of the claimed features is not described and, in addition, it is not obvious, since it does not follow directly from the prior art. Based on this, it can be argued that the claimed technical solution is new and non-obvious. Moreover, the claimed technical solution is feasible in an industrial environment and, therefore, is industrially applicable. Thus, the proposed method of optimizing the operating mode of the internal combustion engine meets the criteria of the invention.

 The inventive method of optimizing the operating mode of the internal combustion engine is illustrated by the drawings, with FIG. 1 and 2, where in FIG. 1 is a view of a block diagram implementing the principle of the present invention; FIG. 2 there is a second version of the structural diagram that performs the same functions, but with a slightly modified recording hardware implementation.

 The essence of the proposed method is as follows.

 The internal combustion engine 1 (Fig. 1) has sensors for the position of the crankshaft (p.c..) 2 and signals of the interrupter of the distributor of the spark of ignition (r.i.z.) 3, the number of signals coming from the sensor 2 corresponds to the number of cylinders N of engine 1, and they arrive each time the crankshaft is rotated through an angle of 360 / N. Sensor 3 is connected to a pulse counter 4. In turn, sensor 2 is connected to a pulse counter 5. Both counters 4 and 5 are also connected to a high-frequency quartz pulse generator 6, and their outputs are connected to a divider 7. The latter is connected to a comparison device 8. Device Comparison 8 is connected to the engine 1 through an adder 9, an analog converter 10 and an actuator 11. The latter has a mechanical joint with a regulator for excess air coefficient (not indicated in the drawing).

 In the embodiment of the method shown in FIG. 2, instead of an RTD sensor 3, a vibration sensor 12 is installed, connected through a high-pass filter 12 and a threshold device 14 with a counter 4.

 The way to optimize the internal combustion engine operation mode is implemented as follows. Signal from the sensor 2 acts on the pulse counters 4 and 5, and they begin to count the pulses coming from the high-frequency quartz pulse generator 6. The signal from the sensor 3 enters the pulse counter 6, turning it off. Thus, the counter 6 accumulates the number of pulses of the pulse generator 6, which is proportional to the length of time between the signal received from the sensor 2 and the sensor of the interrupter-distributor 3. The result obtained from the counter 4 goes to the divider 7. Counter 5 counts the pulses of the generator 6 between two signals, coming from the sensor 2, and the result also goes to the divider 7. The divider performs the operation of dividing the number of pulses of the counter 4 by the number of pulses received from the counter 5. And this process is repeated every time the next Ale from sensor p.k.v. 2. The result of the division is sent to the multi-channel comparison device 8. The number of channels of the device 8 is equal to the number of engine cylinders. In each channel, the results of the division received from the divider 7 are memorized, and at the end of the cycle of operation of all the engine cylinders, two values, the maximum and minimum, go to the adder 9. The latter, by the results of the difference of the signals through the analog converter 10, acts on the actuator 11. The actuator 11 acts on a mechanism that changes the coefficient of excess air.

 The process flow diagram shown in FIG. 1, continuously repeated.

 The greater the uniformity of the cylinders, the less the signal of the adder and the greater the coefficient a and vice versa. It was experimentally established that for many engines with a forced ignition system, the coefficient of excess air at idle, for example, approaches 0.95-1 or more, and this level, established experimentally for each type of ICE, can be accepted for a zero signal from the adder 9 . With increasing signal coming from the adder 9, which characterizes the uneven operation of the cylinders within each complete rotation of the crankshaft, the actuator 11 biases the regulator in the direction of decreasing a, the minimum Noe value which is also established by experiment for each type of engine.

 In the variant of the method (figure 2), the signal from the vibration sensor 12 passes through a filter 13, in which the high-frequency harmonic components are eliminated and enters the threshold device 14, where the maximum signal is allocated, the pulse characterizing the phase of the maximum pressure in the running engine 1. And this pulse arrives counter 4. Otherwise, the block diagram works similarly to that described in FIG. 1, with the difference that the number of pulses received by the divider 7 from the sensor 4 is determined by the difference between the signal from the sensor 2 and the moment of maximum pressure in the working cylinder from the threshold device 14.

 The first version of the technical solution for this method is implemented more simply, however, in the second version, the assessment of the results is more objective, since with a malfunctioning engine an ignition spark may occur, which is not recorded in the first version of the structural diagram.

 Nevertheless, with a reliably working ignition circuit, for example contactless, as experiments show, the effects are similar. Moreover, in both versions of the technological solution for this method, the spread of the angles of the ignition system, reduced to the number of revolutions of the camshaft, is practically determined.

It was experimentally established that optimization of the coefficient of excess air according to the criterion of uniformity of engine operation allows to reduce fuel consumption by 7% and the toxicity of the exhaust, in particular for carbon monoxide, is reduced by 50%
Thus, the advantages of the proposed method are as follows:
reduced fuel consumption:
exhaust emissions are reduced:
increased engine power and torque, especially in private modes of operation.

Claims (1)

 A method for optimizing the operating mode of an internal combustion engine, which consists in exposing the crankshaft rotational speed and the load to the throttle according to the signals of the sensor, characterized in that the maximum inter-cycle and inter-cylinder relative spread of the ignition angle are measured, according to the measurement results, they act on the regulator of the excess air coefficient so that with a decrease in the cross-cylinder angles of dispersion, the coefficient is shifted towards depletion of the working mixture, and with an increase in the angles of dispersion, toward the concentration Working mixture.

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