Apparatus and method for indirectly determining a temperature at a predetermined location in an internal combustion engine

• US 6,829,923 B2
• Filed: 11/07/2002
• Issued: 12/14/2004
• Est. Priority Date: 11/08/2001
• Status: Expired due to Term

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Inventors: Stutte, Thomas, Von Gregory, Jens, Sass, Heiko
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US10/289,451
• Publication Number:
  US 20030106536A1
• Time in Patent Office: 768 Days
• Field of Search: 731/16, 731/172, 731/173, 731/181, 731/19.R, 701/29, 340/438, 340/449, 374/100, 374/141, 374/144, 374/145
• US Class Current: 73/114.68
• CPC Class Codes: F01P 11/16 concerning coolant temperature F01P11/20 takes precedence
• CPC Class Codes: F01P 2023/00 Signal processing; Details thereof
• CPC Class Codes: F01P 2023/08 Microprocessor; Microcomputer
• CPC Class Codes: F01P 2025/13 Ambient temperature
• CPC Class Codes: F01P 2025/46 Engine parts temperature
• CPC Class Codes: F01P 2025/62 Load
• CPC Class Codes: F01P 2025/64 Number of revolutions
• CPC Class Codes: F02B 77/089 relating to engine temperature concerning coolant temperature F01P11/16

Abstract

An apparatus and a process are provided for determining a temperature at a predetermined location in an internal combustion engine. The temperature at a bridge between two exhaust valves of an internal combustion engine can be measured only with great effort during operation. It is proposed to measure a temperature at a location in the internal combustion engine that is easier to access and to determine the bridge temperature with the aid of a computation model on the basis of the engine rpm, the quantity of injected fuel, the temperature of the charge air, and the coolant temperature.

Claims

1. An apparatus for indirectly determining a temperature at a predetermined location in an internal combustion engine, comprising:

a sensor which can measure a component temperature mounted on the internal combustion engine;

other sensors provided to directly or indirectly detect rpm, a quantity of injected fuel, a temperature of charge air, and coolant temperature as other input variables; and

a control unit which can determine the temperature at the predetermined location from the component temperature and the other input variables.

2. The apparatus of claim 1, wherein the sensor is mounted at a location in said internal combustion engine which is accessible from outside.

3. The apparatus of claim 2, wherein said sensor is provided on a face wall of said internal combustion engine.

4. The apparatus of claim 1, wherein the control unit determines a temperature at a bridge between two exhaust valves of said internal combustion engine.

5. A method for indirectly determining a temperature at a predetermined location in an internal combustion engine, comprising:

measuring a component temperature in the internal combustion engine;

directly or indirectly determining an engine rpm, a quantity of injected fuel, a temperature of charge air, and a coolant temperature; and

calculating the temperature at a predetermined location in a control unit from a component temperature, the engine rpm, the quantity of injected fuel, the temperature of the charge air, and the coolant temperature.

6. The method of claim 5, wherein a time averaged value is used as engine rpm.

7. The method of claim 5, wherein said temperature at the predetermined location is calculated based on the following formula $T_{\mathrm{bridge}}=(\begin{array}{c}{k}_1·\end{array}$

NBKM+k2·

(NBKM)2+k3·

KM+k4·

(KM)2+k5·

TKw+k6·

(TKw)2)·

TBt+k7·

(TL1-k8)

wherein

(T_bridge)=temperature at the bridge,

(T_Bt)=measured component temperature,

(N_BKM)=engine rpm,

(KM)=quantity of injected fuel,

(T_Kw)=coolant temperature,

(T_L1)=temperature of the charge air, and

(k₁) to (k₈)=constants.

8. The method of claim 5, wherein further input variables are used in the calculation of said temperature at the predetermined location.

9. The method of claim 5, wherein the temperature at the predetermined location is used as an input variable for engine control.