METHOD FOR DETECTING A GAS AMOUNT

Abstract

A method for detecting the quantity of gas (m) which is supplied by means of a gas supply device to an antechamber of an internal combustion engine, whereby a targeted disturbance (u) of the gas quantity (m) supplied by the gas supply device is performed and a change (T) resulting from the target disturbance (u) in an exhaust gas temperature (T) of an exhaust gas generated in a combustion chamber connected to the antechamber is measured, whereby, by comparison with a target value of the change (Ttarget) of the exhaust gas temperature (T), the gas quantity (m) supplied by means of the gas supply device is deduced.

Claims

1. A method for detecting the quantity of gas (m) which is supplied by means of a gas supply device to an antechamber of an internal combustion engine, wherein a targeted disturbance (u) of the gas quantity (m) supplied by the gas supply device is performed and a change (T) resulting from the target disturbance (u) in an exhaust gas temperature (T) of an exhaust gas generated in a combustion chamber connected to the antechamber is measured, whereby, by comparison with a setpoint value of the change (Ttarget) of the exhaust gas temperature (T), the gas quantity (m) supplied by means of the gas supply device is deduced.

2. Method according to claim 1, whereby a gradient (dT/dm) of the exhaust gas temperature (T) with respect to the quantity of gas (m) is calculated taking account the change (m) in the quantity of gas (m) resulting from the targeted disturbance (u).

3. Method according to claim 2, whereby the calculated gradient (dT/dm) is compared with a target value of the gradient (dT/dmtarget) to make the deduction of the quantity of gas (m) supplied by means of the gas supply device.

4. Method for detecting the quantity of gas (m) which is supplied to at least two antechambers of an internal combustion engine by means of associated gas supply devices, wherein a targeted disturbance (u) of the supplied quantity of gas (m) is performed, and individually for combustion chambers connected to at least two antechambers, a change (T) of an exhaust gas temperature (T) of an exhaust gas resulting from the targeted disturbance (u) is measured, whereby, by comparing the resulting changes (T) in the exhaust gas temperatures (T), a difference between the quantities of gas (m) supplied by means of the different gas supply devices is deduced.

5. Method for equalization of the quantity of gas (m) which is supplied to at least two antechambers of an internal combustion engine by means of associated gas supply devices, wherein a targeted disturbance (u) of the supplied quantity of gas (m) is performed, and individually for combustion chambers connected to at least two antechambers, a change (T) of an exhaust gas temperature (T) of an exhaust gas resulting from the targeted disturbance (u) is measured, whereby, by comparing the resulting changes (T) in the exhaust gas temperatures (T), a difference is determined and an actuation of at least one of the at least two antechambers occurs such that the difference disappears.

6. Method according to claim 1, whereby the gas supply device(s) is or are formed as a channel or channels connected to an antechamber gas line, and the targeted disturbance (u) is performedindividually for each gas supply deviceby changing a gas pressure in the antechamber gas line and/or by changing a quantity of air supplied to the antechamber gas line.

7. Method according to claim 1, whereby the gas supply device(s) is/are formed as an active antechamber gas valve(s) connected to an antechamber gas line, and the targeted disturbance (u) is performed by changing an opening duration and/or an opening time of the antechamber gas valve(s).

8. Method according to claim 1, whereby the targeted disturbance (u) is performed in the direction of a reduced quantity of gas (m).

9. An internal combustion engine with: at least one combustion chamber an antechamber connected to the at least one combustion chamber a gas supply device for the antechamber a control unit for controlling the gas supply device, a temperature sensor assigned to the at least one combustion chamber to measure an exhaust gas temperature (T) of an exhaust gas generated in the at least one combustion chamber, whereby the temperature sensor is connected to the control unit, wherein the control unit is designed to perform a targeted disturbance (u) of the quantity of gas (m) supplied by means of the gas supply device and by means of the temperature sensor, to measure a change (T) of the exhaust gas temperature (T) resulting from the targeted disturbance (u), and by comparison with a stored target value of the change (Ttarget) in the exhaust gas temperature (T), to deduce the quantity of gas (m) supplied by means of the gas supply device.

10. An internal combustion engine with: at least two combustion chambers at least two antechambers which are each connected to one of the at least two combustion chambers a gas supply device for each of the at least two antechambers a control unit for controlling the gas supply devices, at least two temperature sensors which are each assigned to one of the at least two combustion chambers, to measure an exhaust gas temperature (T) of an exhaust gas generated in the at least one combustion chamber, whereby each temperature sensor is connected to the control unit, wherein the control unit is designed to perform, for each of the at least two antechambers, a targeted disturbance (u) of the quantity of gas (m) supplied by means of each gas supply device, and by means of the assigned temperature sensor, to measure a change (T) of the exhaust gas temperature (T) of each combustion chamber resulting from the targeted disturbance (u), and by comparison of the resulting changes (T) of the exhaust gas temperatures (T), to calculate a difference.

11. An internal combustion engine according to claim 10, whereby the control unit is designed to actuate at least one of the at least two antechambers in such a way that the difference disappears.

12. An internal combustion engine according to claim 9, whereby the gas supply device(s) is/are designed as an antechamber gas line, and the control unit is designed to perform the targeted disturbance (u) by changing a gas pressure in the antechamber gas line and/or by changing a quantity of air supplied to the antechamber gas line.

13. An internal combustion engine according to claim 9, whereby the gas supply device(s) is/are designed as (an) active antechamber gas valve(s), and the control unit is designed to perform the targeted disturbance (u) by changing an opening duration and/or an opening time of the antechamber gas valve(s).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments of the invention are discussed with reference to the figures. Description:

[0025] FIG. 1 shows schematically an internal combustion engine according to the invention

[0026] FIG. 2 shows schematically a further internal combustion engine according to the invention

[0027] FIG. 3 shows a change of the exhaust gas temperature implementing a targeted disturbance

[0028] FIG. 4 Relationship between exhaust gas temperature and quantity of gas

DETAILED DESCRIPTION

[0029] FIG. 1 shows an internal combustion engine 1 with several combustion chambers 2, each of which is connected to an antechamber 3. Each antechamber 2 has a gas supply device 4, which is designed here in the form of active antechamber gas valves 8 connected to an antechamber gas line 7. A control unit 5 (which is normally designed as a motor control device of the internal combustion engine) controls the gas supply to the antechambers 2. For each combustion chamber 2, there is a temperature sensor 6 for measuring an exhaust gas temperature T of an exhaust gas generated in the combustion chamber 2, whereby the temperature sensors 6 are connected to the control unit 5.

[0030] The control unit 5 is designed to perform a targeted disturbance u of the quantity of gas m supplied by means of the gas supply devices 4 to the individual antechambers 3 (e.g. by a slight change in the pressure in the antechamber gas line 7 or a change in an opening duration and/or an opening time of the antechamber gas valves 8) and by means of the temperature sensors 6 to measure the change T in the exhaust gas temperature T resulting from the targeted disturbance u for each combustion chamber 2. By a comparison with a stored target value of the change T.sub.target in the exhaust gas temperature T, the control unit 5 can deduce the quantity of gas m supplied by means of the gas supply device 4.

[0031] Alternatively or additionally, it could be provided that the control unit 5 is designed to determine a difference by comparing the resulting changes T in the exhaust gas temperatures T and to actuate at least one of the antechambers 3 such that the difference disappears. If the internal combustion engine has a common antechamber gas line 7 and passive gas valves which connect the individual antechambers 3 to the common antechamber gas line 7, the targeted disturbance u can only be performed globally (i.e. equally for all antechambers 3). In this case, after detecting a deviation in the quantity of gas supplied, no individual actuation can be performed in order to achieve equalization, but an exchange of the passive gas valve concerned would have to be performed. If active antechamber gas valves are provided, it is also possible to perform an equalization in the case of a common antechamber gas line 7 by individual actuation of at least one of the gas valves.

[0032] FIG. 2 shows an internal combustion engine 1 which differs from that of FIG. 1 only in that, here, the gas supply devices 4 are designed as channels which are closed with a nonreturn valve and connected to an antechamber gas line 7. The control unit 5 can vary the pressure in the antechamber gas line 7 via actuators (not shown).

[0033] FIG. 3 shows a change in the exhaust gas temperature To which occurs in the case of a targeted disturbance u.sub.1 (here in the direction of a smaller quantity of gas m), which existed before the disturbance u.sub.1, to a value T.sub.1 which results from the disturbance u.sub.1, so that the disturbance u.sub.1 is connected to a change in the exhaust gas temperature T.

[0034] FIG. 4 shows schematically a relationship between the exhaust gas temperature T of an exhaust gas produced in the combustion chamber 2 connected to the antechamber 3 and the quantity of gas m which is supplied to the antechamber 3 by means of the gas supply device 4.

[0035] The tangent existing at a point m with a slope corresponding to the gradient dT/dm can be approximated by the drawn secant with the slope g.sub.1=(T.sub.0T.sub.1)/(m.sub.0m.sub.1). If the change in the exhaust gas temperature T resulting from the disturbance u.sub.1 is known, then it is possible to calculate the quotient T/u.sub.1 and determine the point m.sub.0 at which an identical slope or an identical gradient is present. This point m.sub.0 corresponds to the quantity of gas m which is supplied to the antechamber 3 of the internal combustion engine 1 by means of the gas supply device 4.