Method for regulating a common-rail injector

Patent metadata

Field	Value
Publication number	US-9995240-B2
Application number	US-201515123525-A
Country	US
Kind code	B2
Filing date	Feb 19, 2015
Priority date	Mar 6, 2014
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A method for regulating a common rail injector, the method including acquiring a signal of a sensor, which signal is proportional to a pressure in a valve space of the common rail injector; evaluating a change in the signal over time in order to detect at least one operating event of the common rail injector; and modifying at least one operating variable of the common rail injector as a function of the at least one operating event, the at least one operating variable being selected from an opening duration, a closing duration, an opening point in time, and a closing point in time of a switching valve of the common rail injector, and from an opening duration, an opening point in time, and a closing point in time of a needle valve of the common rail injector.

First claim

What is claimed is:

1. A method for regulating a common rail injector, the method comprising:
acquiring a signal of a sensor, the signal being proportional to a pressure in a valve space of the common rail injector;
evaluating a change in the signal over time to detect at least one operating event of the common rail injector; and
modifying at least one operating variable of the common rail injector as a function of the at least one operating event, wherein the at least one operating variable is selected from at least one of: (i) one of an opening duration, a closing duration, an opening point in time, and a closing point in time of a switching valve of the common rail injector, and from: (ii) one of an opening duration, an opening point in time, and a closing point in time of a needle valve of the common rail injector;
wherein the sensor is disposed in a low-pressure region of the common rail injector, and
wherein a pressure of a control space also exists in the valve space when a closure element is closed, so that in this valve position, a guidance rod inside the closure element is loaded at the end with a pressure of the control space, so that a valve space pressure is directed via the guidance rod to the sensor.

2. The method as recited in claim 1 , wherein an oscillation overlaid on the signal is filtered before evaluation of the change in the signal.

3. The method as recited in claim 1 , wherein the at least one operating event is selected from the group consisting of: a beginning of an opening of the switching valve, a force superelevation at the beginning of the opening of the switching valve, an end of the opening of the switching valve, a pressure loss in the valve space when the switching valve is open, a beginning of a closing of the switching valve, an end of the closing of the switching valve, a needle reversal of the needle valve, a pressure overshoot in the valve space in the context of the needle reversal, a valve bounce of the needle valve, a change in the pressure in the valve space upon closing of the valve needle of the needle valve, a change in the pressure in the valve space between the open and closed switching valve states when the valve needle of the needle valve is open, and a needle closing of the needle valve.

4. The method as recited in claim 1 , wherein at least one property of the common rail injector is ascertained by the evaluation of the signal.

5. The method as recited in claim 4 , wherein the at least one property of the common rail injector is selected from: a degree of carbon deposition thereof, a point in time of de-throttling of a switching valve of the common rail injector, a degree of bounce of the switching valve, and a degree of wear on the switching valve.

6. The method as recited in claim 1 , wherein at least one property of a fuel that is injected by the common rail injector is ascertained by the evaluation of the signal.

7. The method as recited in claim 6 , wherein the at least one property of the fuel is the viscosity thereof.

8. A non-transitory machine-readable storage medium having a computer program, which is executable by a processor, comprising:
a program code arrangement having program code for regulating a common rail injector, by performing the following:
acquiring a signal of a sensor, the signal being proportional to a pressure in a valve space of the common rail injector;
evaluating a change in the signal over time to detect at least one operating event of the common rail injector; and
modifying at least one operating variable of the common rail injector as a function of the at least one operating event, wherein the at least one operating variable is selected from at least one of: (i) one of: an opening duration, a closing duration, an opening point in time, and a closing point in time of a switching valve of the common rail injector, and from: (i) one of an opening duration, an opening point in time, and a closing point in time of a needle valve of the common rail injector;
wherein the sensor is disposed in a low-pressure region of the common rail injector, and
wherein a pressure of a control space also exists in the valve space when a closure element is closed, so that in this valve position, a guidance rod inside the closure element is loaded at the end with a pressure of the control space, so that a valve space pressure is directed via the guidance rod to the sensor.

9. An electronic control device for regulating a common rail injector, comprising:
an electronic control unit configured to perform the following:
acquiring a signal of a sensor, the signal being proportional to a pressure in a valve space of the common rail injector;
evaluating a change in the signal over time to detect at least one operating event of the common rail injector; and
modifying at least one operating variable of the common rail injector as a function of the at least one operating event, wherein the at least one operating variable is selected from at least one of: (i) one of: an opening duration, a closing duration, an opening point in time, and a closing point in time of a switching valve of the common rail injector, and from: (ii) one of an opening duration, an opening point in time, and a closing point in time of a needle valve of the common rail injector;
wherein the sensor is disposed in a low-pressure region of the common rail injector, and
wherein a pressure of a control space also exists in the valve space when a closure element is closed, so that in this valve position, a guidance rod inside the closure element is loaded at the end with a pressure of the control space, so that a valve space pressure is directed via the guidance rod to the sensor.

Assignees

• Bosch Gmbh Robert

Inventors

• Kober Ralph
• Rapp Holger
• Fischer Fabian
• Beier Marco
• Stein Stefan

Classifications

• F02D41/38

  of the high pressure type · CPC title

• F02M63/0071

  characterised by guiding or centering means in valves including the absence of any guiding means, e.g. "flying arrangements" · CPC title

• F02D41/40 Primary

  with means for controlling injection timing or duration · CPC title

• F02M2547/003

  Valve inserts containing control chamber and valve piston · CPC title

• F02M63/0017

  using electromagnetic operating means · CPC title