System for method for controlling engine knock of a variable displacement engine

Patent metadata

Field	Value
Publication number	US-2017356367-A1
Application number	US-201715428433-A
Country	US
Kind code	A1
Filing date	Feb 9, 2017
Priority date	Jun 9, 2016
Publication date	Dec 14, 2017
Grant date	—

Abstract

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

First claim

1 . A method for operating an engine, comprising:
operating the engine with a first group of combusting cylinders in response to a first condition; operating the engine with a second group of combusting cylinders in response to a second condition; adjusting spark timing of a cylinder in response to an indication of knock via a first group of sensors during the first condition; and adjusting spark timing of the cylinder in response to an indication of knock via a second group of sensors during the second condition.

2 . The method of claim 1 , where the first condition is one or more cylinders deactivated via ceasing fuel flow and not air flow to the one or more cylinders.

3 . The method of claim 1 , where the second condition is one or more cylinders deactivated via ceasing fuel flow and air flow to the one or more cylinders.

4 . The method of claim 1 , further comprising switching between combusting air and fuel in the first group of combusting cylinders and combusting air and fuel in the second group of combusting cylinders while engine speed and load are substantially constant.

5 . The method of claim 1 , where the first condition is a first group of deactivated cylinders being deactivated for a threshold number of engine rotations.

6 . The method of claim 1 , where the second condition is a second group of deactivated cylinders being deactivated for a threshold number of engine rotations.

7 . A method for operating an engine, comprising:
adjusting spark supplied to a cylinder in response to output of a first knock sensor when a first group of cylinders is deactivated via ceasing fuel flow and not air flow to the first group of cylinders; and adjusting spark supplied to the cylinder in response to output of a second knock sensor when the first group of cylinders is deactivated via ceasing fuel flow and air flow to the cylinder.

8 . The method of claim 7 , further comprising combusting air and fuel in a second group of cylinders in response to a driver demand torque at a first engine speed and load.

9 . The method of claim 8 , further comprising combusting air and fuel in a third group of cylinders in response to an actual total number of engine revolutions the first group of cylinders is deactivated.

10 . The method of claim 7 , further comprising adjusting a ratio of direct injection fuel amount to port injection fuel amount of the cylinder in response to output of the first and second knock sensors.

11 . The method of claim 7 , where the cylinder is active and combusting air and fuel.

12 . The method of claim 7 , where the second knock sensor is different than the first knock sensor, and where adjusting spark includes adjusting spark timing.

13 . The method of claim 7 , further comprising adjusting an engine knock threshold responsive to the first knock sensor being a basis for detecting knock in the cylinder.

14 . The method of claim 13 , further comprising adjusting the engine knock threshold responsive to the second knock sensor being the basis for detecting knock in the cylinder.

15 . A vehicle system, comprising:
an engine; and a controller including non-transitory executable instructions, which when executed by the controller, cause the controller to vary an actual total number of cylinders combusting air and fuel in the engine at an engine speed and load, varying which cylinders combust air and fuel at the engine speed and load, and adjust spark timing of the engine in response to output of a first knock sensor when a cylinder is deactivated via ceasing fuel injection and not air flow to the cylinder, and further instructions to adjust spark timing of the engine in response to output of a second knock sensor when the cylinder is deactivated via ceasing fuel injection and air flow to the cylinder.

16 . The vehicle system of claim 15 , where the first knock sensor and the second knock sensor are selected based on output of an engine knock sensor to activated cylinder map.

17 . The vehicle system of claim 15 , where the first knock sensor and the second knock sensor are selected based on output of an engine knock sensor to deactivated cylinder map.

18 . The vehicle system of claim 15 , further comprising additional instructions to vary the actual total number of cylinders in response to an actual total number of engine revolutions.

19 . The vehicle system of claim 15 , further comprising additional instructions to vary which cylinders combust air and fuel in response to an actual total number of engine revolutions.

20 . The vehicle system of claim 19 , further comprising additional instructions to adjust a knock sensitivity threshold for a cylinder to a first level in response to sensing knock via the first knock sensor, and additional instructions to adjust the knock sensitivity threshold for the cylinder to a second level in response to sensing knock via the second knock sensor.

Assignees

• Ford Global Tech Llc

Inventors

• Glugla Chris Paul

Classifications

• F02D2250/18

  Control of the engine output torque · CPC title

• F02D2041/0012

  with selective deactivation of cylinders · CPC title

• F02P5/152 Primary

  dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L23/22) · CPC title

• F02P5/045

  combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02) · CPC title

• F02D13/04

  using engine as brake · CPC title