Device and method for detecting abnormality of cylinder pressure sensor and controller of internal combustion engine

An anomaly detection and internal pressure technology, applied in measuring devices, internal combustion engine testing, engine control, etc., can solve problems such as reduced output sensitivity, no effective means, and obstacles to measuring cylinder pressure, and achieve the effect of improving accuracy

Inactive Publication Date: 2011-08-31
TOYOTA JIDOSHA KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The impact of these impact forces and excessive pressure may be so great that the pressure sensor in the cylinder is plastically deformed.
Due to the difference in the direction and magnitude of this plastic deformation, the structure of the in-cylinder pressure sensor may change in the direction of relieving the preload of the pressure detection element.
If the preload is relaxed, the output sensitivity increased by the preload decreases, and as a result, it becomes an obstacle to the measurement of the pressure in the cylinder.
There is no effective means in the conventional technology for detecting abnormality of the in-cylinder pressure sensor caused by the disappearance of such preload.

Method used

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  • Device and method for detecting abnormality of cylinder pressure sensor and controller of internal combustion engine
  • Device and method for detecting abnormality of cylinder pressure sensor and controller of internal combustion engine
  • Device and method for detecting abnormality of cylinder pressure sensor and controller of internal combustion engine

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Embodiment approach 1

[0084] [Configuration of Embodiment 1]

[0085] (System composition of internal combustion engine)

[0086] figure 1 The configuration of the internal combustion engine as a premise in the first embodiment of the present invention is shown. In Embodiment 1, in figure 1 The internal combustion engine is equipped with the in-cylinder pressure sensor abnormality detection device of the present invention. in figure 1 In the figure, only one cylinder is shown for convenience, but the present invention can also be applied to a multi-cylinder internal combustion engine.

[0087] figure 1 The illustrated internal combustion engine has an air cleaner 1, a throttle valve 2, an air flow meter 3, and a surge tank 4 in the intake passage. The downstream of the surge tank 4 communicates with the combustion chamber through an intake pump and an intake valve. In addition, for figure 1 In the internal combustion engine, an in-cylinder pressure sensor 5, a spark plug 6 and a direct fuel injection i...

Embodiment approach 2

[0139] Hereinafter, Embodiment 2 of the present invention will be described. The second embodiment has the same hardware configuration as the first embodiment. Hereinafter, differences from Embodiment 1 will be mainly described, and descriptions of overlapping items will be omitted.

[0140] Picture 9 It is a figure for demonstrating the preload disappearance abnormality detection means concerning Embodiment 2. Picture 9 The output characteristics of 90 in the system are affected by the abnormality of the disappearance of the preload. When the preload disappearance abnormality occurs, the lower output saturation point of the in-cylinder pressure sensor 5 does not necessarily become the circuit limit value Vmin. Such as Picture 9 As with the output characteristics of 90, sometimes the lower output saturation point lies between the voltage V0 based on the zero offset and the circuit limit value Vmin. In this way, if it is assumed that there is a fluctuation at the lower output...

Embodiment approach 3

[0147] The third embodiment has the same hardware configuration as the second embodiment. Hereinafter, differences from Embodiment 2 will be described, and descriptions of overlapping items will be omitted.

[0148] In Embodiments 1 and 2, in common, the predictive determination of the preload disappearance abnormality of the in-cylinder pressure sensor 5 is performed based on the ratio of Pim and Pex. This makes use of the relationship that the exhaust pressure is sufficiently higher than the intake pressure. However, sometimes this relationship cannot be used. For example, if it is an internal combustion engine with a supercharger, the intake air pressure may be high, and Pim≥Pex. In this case, it may not be possible to perform the omen determination based on the ratio of Pim and Pex with sufficiently high accuracy.

[0149] Therefore, in Embodiment 3, in view of the above-mentioned points, the following means are adopted. Picture 12 It is a flowchart of a routine executed by...

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PUM

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Abstract

A device and a method for detecting the abnormality of a cylinder pressure sensor which can detect the abnormality of a loss of preload of the cylinder pressure sensor. The cylinder pressure sensor (5) includes a strain gauge element (20) to which a preload is applied. The device determines whether the ratio Pim / Pex of an intake pressure Pim to an exhaust pressure Pex is 1.0 or not while an internal combustion engine is operated, and when the ratio Pim / Pex is 1.0, resets a temperature drift. The device determines that the abnormality of a loss of preload occurs when V(Pim), on the basis of which Pim is calculated, matches a circuit limit value Vmin after the temperature drift is reset.

Description

Technical field [0001] The present invention relates to an abnormality detection device for an in-cylinder pressure sensor, an abnormality detection method for an in-cylinder pressure sensor, and an internal combustion engine control device. Background technique [0002] In the past, for example, as disclosed in Japanese Patent Application Laid-Open No. 2005-291091, an in-cylinder pressure sensor for measuring the in-cylinder pressure of an internal combustion engine is known. Among the in-cylinder pressure sensors, there are piezoelectric type sensors that use piezoelectric elements as pressure detection elements, and strain gauge sensors that use strain gauges as pressure detection elements. These types of in-cylinder pressure sensors are generally designed, manufactured, or installed in an internal combustion engine in a state where a preload is applied to the pressure detection element for the purpose of measuring the in-cylinder pressure with good sensitivity. Similarly, in...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F02D45/00F02D43/00
CPCG01M15/08F02D35/023F02D41/222G01L27/007Y02T10/40G01L27/00
Inventor 安田宏通
Owner TOYOTA JIDOSHA KK
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