Fuel injection device

Patent metadata

Field	Value
Publication number	US-9897032-B2
Application number	US-201514933588-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 6, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

There is provided a fuel injection device. Based on a current intake air pressure and a previous intake air pressure of an engine at the predetermined crank position, an intake air pressure variation of the engine at the predetermined crank position is calculated as a measured intake air pressure variation. Based on the current rotational speed and the previous rotational speed of the engine at the predetermined crank position, and a fully-closed-state intake air pressure conversion data item, the fully-closed-state intake air pressure variation of the engine at the predetermined crank position is calculated. The measured intake air pressure variation is corrected based on the fully-closed-state intake air pressure variation. Based on the corrected measured intake air pressure variation, the current rotational speed at the predetermined crank position, and the transient fuel injection quantity conversion data item, the transient fuel injection quantity at the predetermined crank position is determined.

First claim

What is claimed is:

1. A fuel injection device for performing fuel injection in an engine, comprising:
a crank position detecting unit configured to detect a position of a crank of the engine;
a speed measuring unit configured to measure a rotational speed of the engine;
an intake air pressure measuring unit configured to measure an intake air pressure of the engine;
a fuel injecting unit configured to inject fuel in the engine;
a storage unit; and
a control unit configured to determine a transient fuel injection quantity which is a quantity of transient fuel injection which is fuel injection during transient driving, and to control the transient fuel injection of the fuel injecting unit,
wherein if a variation in the intake air pressure for one cycle of the engine is referred to as an intake air pressure variation, and the intake air pressure of the engine when a throttle valve for opening and closing an intake passage of the engine is in a fully closed state is referred to as fully-closed-state intake air pressure, and a variation in the fully-closed-state intake air pressure for one cycle of the engine is referred to as a fully-closed-state intake air pressure variation, in the storage unit, a transient fuel injection quantity conversion data item defining a relation of the intake air pressure variation of the engine, the rotational speed of the engine, and the transient fuel injection quantity of the engine at a predetermined crank position in advance, and a fully-closed-state intake air pressure conversion data item defining a relation between the rotational speed of the engine and the fully-closed-state intake air pressure of the engine in the predetermined crank position in advance are stored,
wherein the control unit recognizes the predetermined crank position on the basis of detection of the crank position detecting unit,
wherein the control unit recognizes a current rotational speed of the engine measured at the predetermined crank position by the speed measuring unit, and a previous rotational speed of the engine measured one cycle before by the speed measuring unit,
wherein the control unit recognizes a current intake air pressure of the engine measured at the predetermined crank position by the intake air pressure measuring unit, and a previous intake air pressure of the engine measured one cycle before by the intake air pressure measuring unit,
wherein on the basis of the current intake air pressure and the previous intake air pressure of the engine at the predetermined crank position, the control unit calculates the intake air pressure variation of the engine at the predetermined crank position, as a measured intake air pressure variation,
wherein on the basis of the current rotational speed and the previous rotational speed of the engine at the predetermined crank position, and the fully-closed-state intake air pressure conversion data item, the control unit calculates the fully-closed-state intake air pressure variation of the engine at the predetermined crank position,
wherein the control unit corrects the measured intake air pressure variation on the basis of the fully-closed-state intake air pressure variation, and
wherein on the basis of the corrected measured intake air pressure variation, the current rotational speed of the engine at the predetermined crank position, and the transient fuel injection quantity conversion data item, the control unit determines the transient fuel injection quantity of the engine at the predetermined crank position.

2. The fuel injection device according to claim 1 , wherein the predetermined crank position is set as a plurality of predetermined crank positions in the one cycle, and in the storage unit, a plurality of different transient fuel injection quantity conversion data items determined for the plurality of predetermined crank positions, and a plurality of different fully-closed-state intake air pressure conversion data items determined for the plurality of predetermined crank positions are stored.

3. The fuel injection device according to claim 2 , wherein one of the plurality of predetermined crank positions is set in an intake stroke of the engine, and another one is set in an expansion stroke or exhaust stroke of the engine.

4. The fuel injection device according to claim 2 , wherein two of the plurality of predetermined crank positions are set at different positions in an intake stroke of the engine, respectively.

5. The fuel injection device according to claim 1 , wherein the control unit controls the fuel injecting unit to perform the transient fuel injection at each of the plurality of predetermined crank positions.

6. The fuel injection device according to claim 5 , wherein if a certain crank position in the one cycle of the engine is referred to as a reference crank position, and a range corresponding to one cycle from the reference crank position is referred to as a reference cycle, and a crank position at which the transient fuel injection is performed in the reference cycle is referred to as a performance crank position, and crank positions at which the transient fuel injection has been already performed in the reference cycle are referred to as performance completion crank positions, the control unit subtracts a sum of transient fuel injection quantities of the transient fuel injection performed at the performance completion crank positions from the transient fuel injection quantity determined on the basis of the corrected measured intake air pressure variation, the rotational speed of the engine, and the transient fuel injection quantity conversion data items at the performance crank position, thereby obtaining a transient fuel injection quantity, and sets the obtained transient fuel injection quantity as the transient fuel injection quantity for transient fuel injection to be performed at the performance crank position.

7. A fuel injection device for performing fuel injection in an engine, comprising:
a crank position detecting unit configured to perform a position of a crank of the engine;
a speed measuring unit configured to measure a rotational speed of the engine;
an intake air pressure measuring unit configured to measure an intake air pressure of the engine;
a fuel injecting unit configured to inject fuel in the engine;
a storage unit; and
a control unit configured to determine a transient fuel injection quantity which is a quantity of transient fuel injection which is fuel injection during transient driving, and to control the transient fuel injection of the fuel injecting unit,
wherein if a variation in the intake air pressure for one cycle of the engine is referred to as an intake air pressure variation, in the storage unit, a transient fuel injection quantity conversion data item defining a relation of the intake air pressure variation of the engine, the rotational speed of the engine, and the transient fuel injection quantity of the engine at a predetermined crank position in advance is stored,
wherein the control unit recognizes the predetermined crank position on the basis of detection of the crank position detecting unit,
wherein the control unit recognizes a current rotational speed of the engine measured at the predetermined crank position by the speed measuring unit,
wherein the control unit recognizes a current intake air pressure of the engine measured at the predetermined crank position by the intake air pressure measuring unit, and a previous intake air pressure of the engine measured one cycle before by the intake air pressure measuring unit,
wherein on the basis of the current intake air pressure and the previous intake air pressure of the engine at the predetermined crank position, the control unit calculates the intake air pressure variation of the engine at the pr

Assignees

• Suzuki Motor Corp

Inventors

• Sugimoto Kenta
• Shimatani Kazuyoshi

Classifications

• F02D41/1498

  measuring engine roughness · CPC title

• F02D41/10

  for acceleration · CPC title

• F02D41/0097

  using means for generating speed signals · CPC title

• F02D2200/0406

  Intake manifold pressure · CPC title

• F02D41/3005 Primary

  Details not otherwise provided for · CPC title