Liquid pressure sensor esp. for detecting reducing agent solution pressure for exhaust-gas treatment in combustion engine - includes spring element for holding pressure sensor element in defined position in receptacle part for pressure sensor element

• Main Author: WEIGL, MANFRED
• Format: Patent
• Language: English; German
• Published: 16.08.2001
• Edition: 7
• Subjects: MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; TESTING

A pressure sensor (18) for detecting the pressure of s liquid, has pressure sensor (180) equipped with a pressure sensor membrane (181), a receptacle part (185,186) for accommodating the pressure sensor element (180), and at least one spring element (192), which is used for enabling the pressure sensor element (180), within a permissible working pressure range of the pressure sensor element (180), to be held in a defined position in the receptacle part (185,186). When the permissible working pressure range of the pressure sensor element (180) is exceeded, the pressure on the pressure sensor membrane (181) is limited, or the pressure sensor element (180) is specifically deflected against the spring force of the spring element (192) in the receptacle part (185,186), so that the pressure on the pressure sensor's membrane (181) is limited by the increase in volume of space lying in front of the membrane (181). The invention relates to a pressure sensor that comprises a pressure sensor element (180) that is provided with a pressure sensor membrane (181). The pressure sensor element is held in a receiving part (185, 186) in a defined position during operation within a permissible operating pressure range by a spring element (192). When the permissible working pressure range is exceeded, a relative movement, acting against the spring force, between the pressure sensor element (180) and the receiving part (185, 186) takes place, thereby increasing the volume of the space immediately upstream of the pressure sensor membrane (181). The inventive design allows for a limitation of the pressure and for an effective protection of the pressure sensor membrane (181) when the liquid is frozen. Das eine Drucksensormembran (181) aufweisende Drucksensorelement (180) wird in einem Aufnahmeteil (185, 186) mittels eines Federelementes (192) während des Betriebes innerhalb eines zulässigen Arbeitsdruckbereiches in einer definierten Position gehalten. Bei Überschreiten des zulässigen Arbeitsdruckbereiches findet eine gegen die Federkraft wirkende Relativbewegung zwischen Drucksensorelement (180) und Aufnahmeteil (185, 186) statt. Dadurch wird eine Volumenzunahme des unmittelbar vor der Drucksensormembran (181) liegenden Raumes erreicht, wodurch eine Begrenzung des Druckes erzielt und ein wirksamer Schutz der Drucksensormembran (181) bei eingefrorener Flüssigkeit erreicht wird.