Method and device for driving an injector in an internal combustion engine

• US 6,584,961 B2
• Filed: 08/03/2001
• Issued: 07/01/2003
• Est. Priority Date: 08/04/2000
• Status: Expired due to Fees

• Current Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.), Danville Manufacturing Incorporated (Zest Anchors LLC)
• Original Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Inventors: Nepote, Andrea, Poggio, Luca, Marceca, Paolo, Carbonaro, Piero, Cagnoni, Michele
• Primary Examiner(s): Yuen, Henry C.
• Assistant Examiner(s): HUYNH, HAI H
• Application Number:
  US09/922,397
• Publication Number:
  US 20020014223A1
• Time in Patent Office: 697 Days
• Field of Search: 123/472, 123/478, 123/480, 123/490, 361/152, 361/154, 361/155, 361/156, 239/585.1, 239/585.5
• US Class Current: 123/490
• CPC Class Codes: F02D 2041/2003 using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils

Abstract

A method and device for driving an injector in an internal combustion engine in which a current wave which is variable over time, which comprises an initial section substantially of a pulse type and having a relatively high current intensity, an intermediate section during which the current intensity is rapidly reduced to substantially zero values and a final section having a substantially constant and relatively low current intensity, is caused to circulate through a control circuit of the injector.

Claims

1. A method for driving an injector (2) in an internal combustion engine (3), in which method a current wave (Iinj) which is variable over time, which comprises an initial section (T1, T2, T3) having a relatively high current intensity (Iinj) and a subsequent final section (T5) having a relatively low current intensity (Iinj), is caused to circulate through a control circuit (4) of the injector (2), the method being characterised in that the current wave (Iinj) comprises an intermediate section (T4) between the first and second sections (T1, T2, T3;

T5) during which the current intensity (Iinj) is rapidly reduced to substantially zero values;

the current intensity (Iinj) being maintained substantially constant and equal to a first predetermined value (Im) during the final section (Tb) by applying a first and second voltage value, different from one another, cyclically to the control circuit (4) of the injector (2).

2. A method as claimed in claim 1, in which the initial section (T1, T2, T3) is substantially a pulse section.

3. A method as claimed in claim 1, in which the current intensity (Iinj) is maintained substantially constant and equal to a second predetermined value (Ip) greater than the first value (Im) during at least part of the initial section (T1, T2, T3).

4. A method as claimed in claim 3, in which the initial section (T1, T2, T3) comprises a first part (T1) in which the current intensity (Iinj) rises rapidly towards the second predetermined value (Ip), a second part (T2) in which the current intensity (Iinj) is maintained substantially constant and equal to the second predetermined value (Ip) and a third part (T3) in which the current intensity (Iinj) progressively decreases.

5. A method as claimed in claim 1, in which the second voltage value is equal to zero.

6. A method as claimed in claim 1, in which the choice of switching between the first and second voltage values is carried out by means of a closed-loop control of the value of the current intensity (Iinj) so as to maintain the value of the current intensity (Iinj) within a range (Δ

Ip;

Δ

Im) centered on the predetermined value (Ip;

Im).

7. A method as claimed in claim 1, in which the control circuit (4) of the injector (2) is driven by means of a first voltage (Vtank) during the initial section (T1, T2, T3) and the control circuit (4) of the injector (2) is driven by a second voltage (Vbatt), which is equal to the battery voltage and is lower than the first voltage (Vtank), during the final section (T5).

8. A method as claimed in claim 7, in which the first voltage (Vtank) is generated by a d.c—

d.c. converter from the battery voltage.

9. A method as claimed in claim 7, in which the first voltage (Vtank) is between 60 and 90V, while the second voltage (Vbatt) is substantially equal to 12V.

10. A method as claimed in claim 1, in which a positive voltage and a zero voltage are alternately applied to the control circuit (4) during the initial and final sections (T1, T2, T3, T5), and a negative voltage is applied to the control circuit (4) during the intermediate section (T4).

11. A method for driving an injector (2) in an internal combustion engine (3), in which method a current wave (Iinj) which is variable over time, which comprises an initial section (T1, T2, T3) having a relatively high current intensity (Iinj) and a subsequent final section (T5) having a relatively low current intensity (Iinj), is caused to circulate through a control circuit (4) of the injector (2);

the current wave (Iinj) comprising an intermediate section (T4) between the first and second sections (T1, T2, T3;

T5) during which the current intensity (Iinj) is rapidly reduced to substantially zero values;

the control circuit (4) of the injector (2) being driven by means of a first voltage (Vtank) during the initial section (T1, T2, T3) and the control circuit (4) of the injector (2) being driven by a second voltage (Vbatt), which is substantially equal to the battery voltage and is lower than the first voltage (Vtank), during the final section (T5);

the first voltage (Vtank) being generated by a d.c.—

d.c. converter from the battery voltage.

12. A method for driving an injector (2) in an internal combustion engine (3), in which method a current wave (Iinj) which is variable over time, which comprises an initial section (T1, T2, T3) having a relatively high current intensity (Iinj) and a subsequent final section (T5) having a relatively low current intensity (Iinj), is caused to circulate through a control circuit (4) of the injector (2);

the current wave (Iinj) comprising an intermediate section (T4) between the first and second sections (T1, T2, T3;

T5) during which the current intensity (Iinj) is rapidly reduced to substantially zero values;

the control circuit (4) of the injector (2) being driven by means of a first voltage (Vtank) during the initial section (T1, T2, T3) and the control circuit (4) of the injector (2) being driven by a second voltage (Vbatt), which is substantially equal to the battery voltage and is lower than the first voltage (Vtank), during the final section (T5);

the first voltage (Vtank) being between 60 and 90V, while the second voltage (Vbatt) being substantially equal to 12V.

13. A method for driving an injector (2) in an internal combustion engine (3), in which method a current wave (Iinj) which is variable over time, which comprises an initial section (T1, T2, T3) having a relatively high current intensity (Iinj) and a subsequent final section (T5) having a relatively low current intensity (Iinj), is caused to circulate through a control circuit (4) of the injector (2);

the current wave (Iinj) comprising an intermediate section (T4) between the first and second sections (T1, T2, T3;

T5) during which the current intensity (Iinj) is rapidly reduced to substantially zero values;

a positive voltage and a zero voltage being alternately applied to the control circuit (4) during the initial and final sections (T1, T2, T3, T5), and a negative voltage being applied to the control circuit (4) during the intermediate section (T4).