Asynchronous High-Pressure Pump Control for Direct Injection

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Solution Overview

Problem

In direct injection engines, the existing high-pressure pump control systems often result in insufficient injection pressure after the engine starting period when using normally-open valves, leading to excess hydrocarbons in the exhaust, and excessive pressure when using normally-closed valves, causing premature fuel injection and thermal damage.

Innovation Solution

An asynchronous starting system that actuates the control valve when the crankshaft starts to rotate, maintaining activation until synchronous pump control is initiated, or until a temperature threshold is reached to prevent thermal damage, thereby eliminating the pressurization period and reducing hydrocarbons in the exhaust.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If the control valve is activated based on camshaft position relative to crankshaft position (synchronous control), then the injection pressure can be precisely controlled during normal operation, but the injection pressure is insufficient after engine starting when using normally-open valves

Engineering Contradiction:

Improveinjection pressureVSAvoidpressure control reliability during starting

Core Design Contradiction:

Stress or pressureVSReliability

Solution Approach 1:

The control valve is activated in advance based on crankshaft rotation detection before synchronous control is established. This preliminary activation ensures fuel pressure builds up during the starting period, preventing insufficient injection pressure when the engine first starts rotating.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses the crankshaft's own rotation signal to trigger control valve activation, creating a self-regulating mechanism that automatically adjusts fuel pressure based on engine starting conditions without requiring external intervention or complex sensing.

Inventive Principle:

Principle #25Self-service

2Stress or pressure

If the control valve is activated based on camshaft position relative to crankshaft position (synchronous control), then the injection pressure can be precisely controlled during normal operation, but excess hydrocarbons are released in the exhaust during starting

Engineering Contradiction:

Improveinjection pressureVSAvoidhydrocarbon emissions

Core Design Contradiction:

Stress or pressureVSObject-generated harmful factors

Solution Approach 1:

The control valve is activated in advance during engine starting to build sufficient fuel pressure before injection begins. This prevents incomplete combustion caused by insufficient pressure, thereby reducing hydrocarbon emissions in the exhaust during the starting period.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors crankshaft position and fuel pressure conditions, using this feedback to maintain control valve activation during starting. This closed-loop control ensures injection pressure remains within the optimal range, preventing both insufficient pressure and excessive pressure conditions that would increase emissions.

Inventive Principle:

Principle #23Feedback

3Stress or pressure

If the control valve is activated based on camshaft position relative to crankshaft position (synchronous control), then the injection pressure can be precisely controlled during normal operation, but thermal damage occurs to the control valve due to excessive pressure

Engineering Contradiction:

Improveinjection pressureVSAvoidthermal damage to control valve

Core Design Contradiction:

Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The control valve is activated at the appropriate time based on crankshaft rotation detection, allowing fuel pressure to build gradually during starting rather than experiencing sudden excessive pressure spikes. This controlled pressurization prevents thermal damage to the control valve while still achieving sufficient injection pressure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from crankshaft position sensing to regulate control valve activation duration and intensity, maintaining fuel pressure within safe operating limits. This prevents excessive pressure conditions that would cause thermal damage while ensuring sufficient pressure for proper injection.

Inventive Principle:

Principle #23Feedback

4Stress or pressure

Engineering Contradiction:

Improveinjection pressureVSAvoidinjection timing accuracy

Core Design Contradiction:

Stress or pressureVSLoss of time

Solution Approach 1:

The control valve is activated based on crankshaft rotation detection before synchronous control is fully established, ensuring fuel pressure is ready but injection is delayed until the appropriate timing. This prevents premature injection while maintaining pressure readiness, improving timing accuracy during the starting transition period.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8033268B2Asynchronous control of high-pressure pump for direct injection engines

Publication Date: 2011.10.11 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An engine control system includes a starting module, a position module, and a deactivation module. The starting module determines when a crankshaft starts to rotate and activates a control valve of a fuel pump when the crankshaft starts to rotate. The position module determines a position of the crankshaft and determines a position of a camshaft based on the position of the crankshaft. The camshaft drives the fuel pump. The deactivation module deactivates the control valve when the position module determines the position of the camshaft.