Vehicle heating appliance with overheating checking device

US5788148A · kind A · utility

Assignee

• J. Eberspaecher GmbH & Co. KG · DE

Inventors

• Erwin Burner · Adelberg, DE
• Jurgen Epple · Waldenbuch, DE
• Michael Humburg · Göppingen, DE
• Johannes Koch · Braunschweig, DE

Key dates

• Filing date: Jun 28, 1996
• Grant date: Aug 4, 1998
• Expiry date: Jun 28, 2016

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F23N2241/14
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

In a vehicle heating appliance, an overhead state is detected by an overheating temperature sensor by means of a microprocessor. The overheating temperature sensor supplies a signal (UTF) to the microprocessor, and when the signal (UTF) exceeds a threshold value, the microprocessor blocks the transmission of driving signals to a driving transistor (Tr) for the fuel dosing pump. A circuit connected in parallel to the microprocessor with a threshold value switch acts as a redundant switching-off device. The output signal of the threshold value switch is applied to an AND-gate whose output is connected to the base of the driving transistor (Tr) and whose other input receives the driving signals from the microprocessor. When the signal UFT exceeds the threshold value of the threshold switch, the AND-gate blocks all signal transmission from the microprocessor to the driving transistor, so that the fuel dosing pump is stopped. The danger of overheating is detected in that the signal supplied by the overheating temperature sensor exceeds an overheating temperature threshold value. Preferably the microprocessor calculates a differential value from the signal supplied by the overheating tem…