DE102013210965B3 - Internal combustion engine i.e. reciprocating engine, for vehicle, has prechamber designed as measuring chamber, which comprises multiple sensors for measuring different gas properties of gas in prechamber - Google Patents

Abstract

The engine (1) has a prechamber (7) connected to a combustion chamber (2) through a connecting line (8). The prechamber is designed as a measuring chamber, which comprises multiple sensors (9) for measuring different gas properties of gas in the prechamber. The connecting line is formed such that the connection made between the prechamber and the combustion chamber is opened in an initial phase of a compression stroke during an operation of the engine and disrupted before starting of an incineration event in the combustion chamber. The sensor is designed as a temperature sensor, an oxygen sensor or a pressure sensor.

Description

The present invention relates to an internal combustion engine and a method for controlling the operation of an internal combustion engine.

In the operation of an internal combustion engine, typically a measurement of the properties of the intake gas in the intake manifold takes place. In particular, the temperature and the (charge) pressure of the intake air are determined. In addition, i.d.R. Also, an estimate of the residual gas content in the intake pressure (boost pressure) based on the exhaust gas recirculation rate or a direct measurement using an oxygen sensor in the intake manifold. In addition, a measurement of the relative humidity in the intake fresh air is required, since this is for the composition of the residual gas in the cylinder charge (mass fraction burned and water vapor content) of importance.

Although in the measurement of gas pressure and oxygen content with currently available technologies sensor signals can be obtained in a relatively short time, the speed of the temperature measurement is typically limited or impaired that in vehicle manufacturing, the use of sensor technologies with the greatest possible robustness is required. Moreover, the modeling accuracy in determining the cylinder charge is dependent on the volumetric efficiency of the engine (i.e., the ratio between actual and theoretical volumetric flow) which varies over the life of the engine.

Out EP 1 830 059 A1 An apparatus and a method for controlling the operation of an internal combustion engine are known, among others, a valve mechanism for changing the valve opening characteristic of a suction-side valve and an exhaust-side valve and a cylinder pressure sensor for measuring a cylinder pressure in the combustion chamber are provided, wherein a calculation of the sucked into the combustion chamber Air quantity is based on the intake air pressure during a valve overlap between the suction-side valve and the exhaust-side valve. Further, the exhaust pressure during this valve overlap is estimated based on the cylinder pressure measured by the cylinder pressure sensor and based on the load of the engine.

Out JP 2009203952 A Among others, an internal combustion engine having a sub-chamber is known, wherein the internal gas pressure in this sub-chamber is measured by means of a sub-chamber pressure sensor and a sub-chamber gas supply control is provided to control the opening degree of a gas pressure regulating valve or gas flow control valve based on the internal gas pressure in the sub-chamber. At this time, the sub-chamber gas supply control detects the peak value of the internal gas pressure during the compression stroke and, if necessary, changes the opening degree of the gas pressure regulating valve or the gas flow control valve when this peak value is out of an allowable range. As a result, fluctuations in the combustion process should be avoided.

Out EP 0 588 593 A2 Inter alia, an internal combustion engine with a main chamber and an antechamber is known, wherein a closable via a control valve passage opening between the main chamber and prechamber is provided. Furthermore, a control device is provided for controlling the control valve, which closes the control valve during an outlet step and an inlet step and opens the control valve during the last phase of the compression step. Further, a control means for controlling a fuel injection nozzle for the injection of fuel into the pre-chamber with the control valve closed or during the Auslassschrittes is provided.

In JP H07-310550 A a gas internal combustion engine is described, in which an antechamber and a main chamber are provided, wherein the pre-chamber is connected to the combustion chamber in each case via a connecting line.

Out DE 10 2009 050 313 A1 For example, an internal combustion engine is known in which a lean air / fuel mixture is ignited in a main chamber by igniting a rich air / fuel mixture in a pre-combustion chamber.

Out DE 10 2011 081 928 A1 a gas combustion engine with pre- and main chamber is known in which the temperature of the gas supply line is monitored in the region of a check valve.

It is an object of the present invention to provide an internal combustion engine and a method for controlling the operation of an internal combustion engine, which enable a reliable determination of gas properties during the combustion process and an operation of the internal combustion engine based thereon.

This object is achieved by the internal combustion engine according to the features of the independent patent claim 1 and the method according to the features of the independent claim 7.

An inventive internal combustion engine has a combustion chamber and an antechamber, wherein the prechamber is connected to the combustion chamber via a connecting line.

The internal combustion engine is characterized in that the prechamber is designed as a measuring chamber which has a plurality of sensors for measuring different gas properties of a gas located in the prechamber, wherein the internal combustion engine is configured such that the connection between the prechamber and combustion chamber produced by the connecting line the initial phase of a compression stroke is open during operation of the internal combustion engine, but is interrupted before the start of a combustion event in the combustion chamber. This interruption can take place automatically in particular with increasing compression of the gas in the combustion chamber.

The present invention is based in particular on the concept of measuring the gas properties directly during the combustion process during operation of an internal combustion engine. For this purpose, an antechamber is provided according to the invention, which is equipped as a measuring chamber with a plurality of sensors and is connected via a connecting line with the actual combustion chamber in connection. After closing the connecting line, in particular during the combustion process, the relevant gas properties (for example pressure, temperature, oxygen content and possibly residual gas composition) can be determined in the prechamber or measuring chamber using the sensor elements located in the prechamber.

During the compression stroke, the connection between the prechamber or measuring chamber and the combustion chamber produced by the connecting line is thus initially opened, with the result that the gas properties in the prechamber or measuring chamber coincide on the one hand with the properties of the gas flowing into the cylinder on the other. When the pressure inside the combustion chamber continues to increase due to the compression of the gas, the connection line between the prechamber and the combustion chamber is blocked or interrupted even before the combustion event takes place in the combustion chamber, whereupon the aforementioned gas properties of the combustion chamber in the prechamber or combustion chamber occur The measuring chamber located gas, which correspond to the gas properties in the combustion chamber immediately before closing the connecting line, can be measured by means of the sensor elements in the measuring chamber.

The determined gas properties can then be determined e.g. with a delay from a combustion event or during a subsequent operating cycle e.g. be used to determine the optimal settings for air path and / or fuel path actuators in the internal combustion engine and set accordingly.

The invention further relates to a method for controlling the operation of an internal combustion engine, wherein the internal combustion engine has a combustion chamber and an antechamber, wherein the pre-chamber is connected to the combustion chamber via a connecting line. In this case, the prechamber is used as a measuring chamber in which different gas properties of a gas located in the prechamber are measured during a combustion event taking place in the combustion chamber, the connection between the prechamber and the combustion chamber established by the connecting line being open in the initial phase of a compression stroke during operation of the internal combustion engine and is interrupted before the start of a combustion event in the combustion chamber.

According to one embodiment, the setting of at least one air path actuator and / or at least one fuel path actuator during a subsequent operating cycle of the internal combustion engine is determined on the basis of the determined gas properties.

Further embodiments of the invention are described in the description and the dependent claims.

The invention will be explained below with reference to a preferred embodiment with reference to the accompanying drawings.

Show it:

1 a schematic representation of an internal combustion engine during a compression stroke according to an embodiment of the invention; and

2 a schematic representation of the internal combustion engine 1 during an expansion stroke.

In the following, construction and mode of operation of an internal combustion engine according to the invention will be described with reference to an embodiment with reference to the schematic diagrams in FIG 1 and 2 explained in more detail, wherein 1 shows the operating state during a compression stroke, and wherein 2 shows the operating state during an expansion stroke.

According to 1 refers to an internal combustion engine 1 in the form of a reciprocating engine on its intake side pre-compressed air from the compressor 5 a turbocharger 4 , where the compressor 5 Fresh air is supplied via an air filter (not shown). In this case, in a known manner, the compressor 5 of the turbocharger 4 through its exhaust-side turbine 6 driven by a common shaft.

The internal combustion engine 1 has a combustion chamber 2 with movable piston inside 3 on, the condition according to 1 the compression stroke and the state according to 2 corresponds to the expansion stroke (working stroke).

Like also in 1 and 2 shown schematically, is to the combustion chamber 2 the internal combustion engine according to the invention 1 an antechamber 7 via a connecting cable 8th connected. The antechamber 7 has suitable sensor elements for measuring the relevant gas properties of the in the antechamber 7 located gas, wherein in the embodiment, in each case a sensor element for measuring pressure, temperature and oxygen content is provided.

According to 1 is the connecting cable during the compression stroke 8th between combustion chamber 2 and antechamber 7 initially opened, which has the consequence that the above-mentioned conditional parameters of the gas in the combustion chamber 2 and antechamber 7 in their values, respectively.

With increasing compression of the gas in the combustion chamber 2 and the concomitant increase in pressure in the combustion chamber 2 followed by a closing of the connecting cable 8th or interrupting the connection between antechamber 7 and combustion chamber 2 even before the ignition and the combustion event in the combustion chamber 2 occur.

During the following on the ignition expansion stroke or power stroke is according to 2 the antechamber 7 due to the closed connection line 8th from the combustion chamber 2 separated so that the above condition parameters of the in the antechamber 7 located gas, the state parameters of the gas in the combustion chamber 2 immediately before closing the connecting cable 8th correspond, by means of the sensor elements 9 can be measured. The values thus obtained for these state parameters (eg, pressure, temperature, oxygen content) may be used during the next cycle of operation (ie delayed by one combustion event) to set the optimal settings for the air path and fuel path actuators.

Claims (9)

Internal combustion engine, with a combustion chamber ( 2 ) and an antechamber ( 7 ), whereby the antechamber ( 7 ) to the combustion chamber ( 2 ) via a connecting line ( 8th ), characterized in that the antechamber ( 7 ) is designed as a measuring chamber, which has a plurality of sensors ( 9 ) for measuring different gas properties of one in the antechamber ( 7 ) gas; the internal combustion engine ( 1 ) is configured such that through the connecting line ( 8th ) established connection between antechamber ( 7 ) and combustion chamber ( 2 ) in the initial phase of a compression stroke during operation of the internal combustion engine ( 1 ) and before the start of a combustion event in the combustion chamber ( 2 ) is interrupted. Internal combustion engine according to claim 1, characterized in that the interruption of this connection with increasing compression of the in the combustion chamber ( 2 ) gas is automatically carried out. Internal combustion engine according to claim 1 or 2, characterized in that at least one of these sensors ( 9 ) is a temperature sensor. Internal combustion engine according to one of claims 1 to 3, characterized in that at least one of these sensors ( 9 ) is an oxygen sensor. Internal combustion engine according to one of claims 1 to 4, characterized in that at least one of these sensors ( 9 ) is a pressure sensor. Internal combustion engine according to one of the preceding claims, characterized in that it is configured such that on the basis of the determined gas properties, the adjustment of at least one air path actuator and / or at least one fuel path actuator during a subsequent operating cycle. Method for controlling the operation of an internal combustion engine, wherein the internal combustion engine has a combustion chamber ( 2 ) and an antechamber ( 7 ), wherein the antechamber ( 7 ) to the combustion chamber ( 2 ) via a connecting line ( 8th ), characterized in that the antechamber ( 7 ) is used as a measuring chamber in which during a in the combustion chamber ( 2 ) combustion event different gas properties of a in the antechamber ( 7 ) are measured; where the through the connecting line ( 8th ) established connection between antechamber ( 7 ) and combustion chamber ( 2 ) in the initial phase of a compression stroke during operation of the internal combustion engine ( 1 ) open and before the start of a combustion event in the combustion chamber ( 2 ) is interrupted. A method according to claim 7, characterized in that on the basis of the determined gas properties, the setting of at least one air path actuator and / or at least one fuel path actuator is set during a subsequent operating cycle of the internal combustion engine. A method according to claim 7 or 8, characterized in that the internal combustion engine is designed according to one of claims 1 to 6.

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