Fail-safe controller for direct injection engine
AssigneeDenso Corporation
InventorHiroshi Katsurahara
Life of this patent
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Abstract
A fuel pressure varies according to whether a fuel pressure sensor and a high-pressure pump have a malfunction or not. In view of this, a first threshold Perr1 is defined for determining whether the fuel pressure sensor has a malfunction and a second threshold Perr2 is defined for determining whether the high-pressure pump has a malfunction. The second threshold Perr2 is greater than the first threshold Perr1. By comparing a detection value of the fuel pressure sensor with the first and the second threshold, a malfunction in the fuel pressure sensor and a malfunction in the high-pressure pump are distinguished from each other. A first fail-safe control or a second fail-safe control is executed according to a portion having a malfunction.
Claims6
A fail-safe controller for a direct injection engine, the direct injection engine including:
- a feed pump pumping up a fuel in a fuel tank;
- a high-pressure pump pressurizing the fuel pumped up by the feed pump, the high-pressure pump introducing the pressurized fuel into a delivery pipe;
- a fuel pressure sensor detecting a fuel pressure in the delivery pipe;
- and
- a fuel injector directly injecting the fuel accumulated in the delivery pipe into a cylinder of the direct injection engine,
- the fail-safe controller comprising:
- a malfunction detecting means for detecting a malfunction in the fuel pressure sensor by comparing a detection value of the fuel pressure sensor with a first threshold, and for detecting a malfunction in the high-pressure pump by comparing the detection value of the fuel pressure sensor with a second threshold which is greater than the first threshold;
- and
- a fail-safe control means for executing a first fail-safe control in which the direct injection engine is kept running when the malfunction detecting means detects malfunction in the fuel pressure sensor, and for executing a second fail-safe control in which the direct injection engine is turned off when the malfunction detecting means detects a malfunction in the high-pressure pump.
Dependencies are inferred from the claim text.