Fuel octane responsive internal combustion engine ignition system
First Claim
1. In an internal combustion engine having a combustion chambera first sensor for sensing a parameter which varies with the presence of knocking phenomena in the combustion chamber of said engine;
- a second sensor for sensing the load on said engine;
a third sensor responsive to the rotational speed of said engine;
a spark generating arrangement for producing a spark in said combustion chamber; and
a control circuit responsive to the outputs of said first, second and third sensors for controlling the timing at which said spark is generated, said control circuit including control means for;
(a) causing said spark to be initially generated according to a first schedule suitable for fuel having a first octane value,(b) sensing said engine entering a predetermined mode of operation;
(c) advancing the ignition timing until said first sensor detects said knocking phenomena;
(d) comparing the conditions under which said knocking occurs with pre-recorded data,(e) determining the octane value of the fuel being combusted in said combustion chamber, and(f) causing said spark to be generated according to a second schedule suitable for fuel having a second octane value higher than said first octane value in the event that the octane value of the fuel being combusted in said combustion chamber is determined to be higher than that for which said first schedule is suited.
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Accused Products
Abstract
In order to simultaneously prevent engine damage due to violent knocking and maintain good fuel economy, an ignition control system firstly controls the ignition timing according to a first schedule suited for fuel having a first octane rating until the engine enters a preselected mode of operation. At this time the ignition is advanced until knocking occurs. The conditions under which the knocking is generated are compared with prememorized data and if this reveals that the octane value of the fuel is higher than that for which the first schedule is suited control is switched to a second schedule designed for fuel having a second and higher octane value.
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Citations
9 Claims
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1. In an internal combustion engine having a combustion chamber
a first sensor for sensing a parameter which varies with the presence of knocking phenomena in the combustion chamber of said engine; -
a second sensor for sensing the load on said engine; a third sensor responsive to the rotational speed of said engine; a spark generating arrangement for producing a spark in said combustion chamber; and a control circuit responsive to the outputs of said first, second and third sensors for controlling the timing at which said spark is generated, said control circuit including control means for; (a) causing said spark to be initially generated according to a first schedule suitable for fuel having a first octane value, (b) sensing said engine entering a predetermined mode of operation; (c) advancing the ignition timing until said first sensor detects said knocking phenomena; (d) comparing the conditions under which said knocking occurs with pre-recorded data, (e) determining the octane value of the fuel being combusted in said combustion chamber, and (f) causing said spark to be generated according to a second schedule suitable for fuel having a second octane value higher than said first octane value in the event that the octane value of the fuel being combusted in said combustion chamber is determined to be higher than that for which said first schedule is suited. - View Dependent Claims (2, 3, 4)
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5. A method of controlling an internal combustion engine which has a combustion chamber comprising the steps of:
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(a) sensing a parameter which varies with the presence of knocking phenomena in said combustion chamber; (b) sensing the load on said engine; (c) periodically outputting a first signal and a plurality of second signals; (d) producing a spark in said combustion chamber; and (e) controlling the timing at which said spark is generated via the steps of; (f) causing said spark to be initially generated according a schedule suitable for fuel having a first octane value; (g) sensing the engine entering a predetermined mode of operation; (h) advancing the ignition timing until knocking occurs in said combustion chamber; (i) comparing the conditions under which said knocking occurs with pre-recorded data; (j) determining the octane value of the fuel being combusted in said combustion chamber; and (k) causing said spark to be generated according to a second schedule suitable for fuel having a second octane value higher than said first octane rating in the event that said step of determining indicates an octane value higher than that for which said first schedule is suited. - View Dependent Claims (6, 7, 8, 9)
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Specification