DE-102012223326-B4 - Composition for a sensor element, temperature sensor and method for manufacturing the temperature sensor

Abstract

Composition for a sensor element (10) comprising Y 2 O 3 , Al 2 O 3 , MnO 2 , NiO and Fe 2 O 3 and further ZrO 2 and intended to be used in a temperature sensor (1), wherein a molar concentration of Zr used in the composition for the sensor element (10) is 0.2-0.5, and wherein a molar concentration of the metallic elements yttrium, aluminium, manganese, nickel and iron used in the composition for the sensor element (10) is accordingly 0.2-0.5, 0.01-0.1, 0.1-0.3, 0.1-0.3 and 0.03-0.1.

Inventors

• Na-Yun Ko
• Tae Seung Lee
• Jin-Seong Park
• Woon-Young Lee

Assignees

• HYUNDAI MOTOR COMPANY

Dates

Publication Date

20260513

Application Date

20121217

Priority Date

20120518

Claims (5)

1. A composition for a sensor element (10) comprising Y2O3 , Al2O3 , MnO2 , NiO and Fe2O3 and further ZrO2 , and intended for use in a temperature sensor (1), wherein the molar concentration of Zr used in the composition for the sensor element (10) is 0.2-0.5, and wherein the molar concentrations of the metallic elements yttrium, aluminium, manganese, nickel and iron used in the composition for the sensor element (10) are accordingly 0.2-0.5, 0.01-0.1, 0.1-0.3, 0.1-0.3 and 0.03-0.1.
2. Temperature sensor (1) comprising: a sensor element (10) comprising a composition for a sensor element (10) of Y 2 O 3 , Al 2 O 3 , MnO 2 , NiO and Fe 2 O 3 and ZrO 2 ; and a plurality of connecting wires (20) inserted in parallel into the sensor element (10), wherein a molar concentration of the Zr used in the composition for the sensor element (10) is 0.2-0.5, and wherein a molar concentration of the metallic elements yttrium, aluminium, manganese, nickel and iron used in the composition for the sensor element (10) is accordingly 0.2-0.5, 0.01-0.1, 0.1-0.3, 0.1-0.3 and 0.03-0.1.
3. A method for manufacturing a temperature sensor (1), comprising: weighing out a composition of Y₂O₃ , Al₂O₃ , MnO₂ , NiO , Fe₂O₃ , and ZrO₂ for a sensor element (10); mixing the composition; calcining the mixture at about 1,000 °C to 1,400 °C for 30 minutes to 5 hours; pulverizing the calcined mixture to obtain a powder; placing the powdery mixture into a mold; parallel insertion of a plurality of lead wires (20) into the powdery mixture; and compression molding the powdery mixture. and sintering of the molded material at about 1,300 °C to 1,500 °C for 30 min to 5 hours, wherein a molar concentration of Zr used in the composition for the sensor element (10) is 0.2-0.5, and wherein a molar concentration of the metallic elements yttrium, aluminium, manganese, nickel and iron used in the composition for the sensor element (10) is 0.2-0.5, 0.01-0.1, 0.1-0.3, 0.1-0.3 and 0.03-0.1.
4. Method for manufacturing a temperature sensor (1) according to Claim 3 , whereby the calcination is carried out at 1,200 °C for 2 hours.
5. Method for manufacturing a temperature sensor (1) according to Claim 3 , whereby the sintering is carried out at 1,400 °C for one hour.

Description

Cross-reference to a related registration Pursuant to 35 USC § 119, the application claims priority from Korean patent application no. 10-2012-53210 , which was filed with the Korean Patent Office on May 18, 2012, and to whose entire disclosure reference is hereby made in full. background 1. Field of the invention The present invention relates to a composition for a sensor element, a temperature sensor, and a method for manufacturing the temperature sensor comprising the composition for the sensor element. More specifically, the present invention relates to a composition for a sensor element with improved accuracy and thermal stability when measuring temperature, and to a temperature sensor in which wires are inserted into a sensor element and which comprises the same composition and exhibits heat resistance, impact resistance, vibration resistance, durability, and the like, enabling temperature measurements at high temperatures and under vibration conditions, and to a method for manufacturing the temperature sensor. 2. Description of the state of the art As restrictions on harmful emissions from vehicles increase, exhaust emission control systems for vehicles have recently been developed. Diesel vehicles, in particular, produce nitrogen oxides ( NOx ) and similar pollutants during fuel combustion. Diesel vehicles can emit particulate matter (PM) of less than 0.005 g per 1 km, and to regulate these emissions, a diesel particulate filter (DPF) system can be used as an exhaust emission control device. Installed in the exhaust system, the DPF collects the particulate matter in the exhaust gas using a catalytic filter and controls a regeneration process that burns off the collected PM when certain conditions are met. The regeneration process is carried out at a temperature optimized for maximum effectiveness (e.g., the temperature at which the particulate matter collected in the filter is burned). To perform this process, a precise and durable temperature sensor must be integrated into the DPF system. This temperature sensor is also incorporated into a combustion chamber and related components commonly used in vehicles to accurately monitor the temperature at any given ambient temperature, ensuring reliable and long-lasting vehicle operation. A temperature sensor is a device designed to measure temperature based on changes in material density, resistance, electromotive force, and the like, as a function of temperature. Temperature sensors include thermocouples, resistance temperature detectors, thermistors (NTC thermometers), and similar devices. A thermocouple thermometer is a thermometer that utilizes the thermal electromotive force of a thermocouple. It measures temperature based on the value of the thermal electromotive force generated at one junction when the two ends of two metal wires are connected and the other junction is held at a specific, fixed temperature. A resistance liquid thermometer is also a device that measures temperature based on resistance, utilizing a change in the electrical resistance of a metal or semiconductor as a function of temperature. A thermistor thermometer is generally manufactured by sintering metal oxides, and the thermistor is a device whose electrical resistance changes with temperature. Thermistor thermometers are divided into PTC (Positive Temperature Coefficient) thermistors and NTC (Negative Temperature Coefficient) thermistors. A PTC thermistor increases its resistance in response to a temperature increase, while an NTC thermistor decreases its resistance in response to a temperature increase. The temperature sensor used for the exhaust system of a vehicle should be operated at a temperature of approximately 500 °C or higher and should have thermal shock resistance, which is resistant to repeated temperature changes between a high temperature and room temperature, and vibration and impact resistance, which is resistant to extreme vibrations often generated while driving the vehicle. Conventional temperature sensors generally comprise a sensing element and connecting wires, and the sensing element is usually made of metals or metal oxides. The metal oxides are typically insulators; however, when transition metal oxides are mixed with them and sintered, they exhibit the conductivity of semiconductors. In particular, a temperature sensor used at high temperatures and manufactured by a ceramic process involving mixing a sensing element composition containing transition metal oxides , such as Fe₂O₃ , NiO, Cr₂O₃ , MnO₂ , and the like, calcining, and sintering the composition, may experience a decrease in temperature measurement accuracy due to errors caused by a decline in thermal stability at 500 °C or above and by the low resistance of only a few ohms. The conventional temperature sensor is also manufactured by printing or coating paste electrodes made of silver (Ag), gold (Au), platinum (Pt) and the like onto the surface of the sensor element and by attaching lead wires