Patent ID: 8801278
Filing Date: 2014-08-12
Classification: B23K,F01N,G01K

Abstract:
1. A sensor comprising an annular mounting fixture and a tube which is inserted into a tube insertion hole of the annular mounting fixture in a loose fit fashion, a gap between an inner circumferential surface of the tube insertion hole and an outer circumferential surface of the tube is brazed so as to maintain a seal in a front-to-rear direction of the sensor, and a sensor element is provided at a front end portion in an interior of the tube, wherein the tube comprises a small-diameter tubular portion which is inserted into the tube insertion hole in a loose fit fashion and a large-diameter tubular portion which is disposed at the rear of the small-diameter tubular portion and which has a diameter larger than an inside diameter of the tube insertion hole, wherein a flow path is formed between a rear end of the tube insertion hole and a front end of the large-diameter tubular portion, so that when the tube is inserted into the tube insertion hole and the front end of the large-diameter tubular portion of the tube is locked on the rear end of the tube insertion hole, a rear end of the gap, which is defined between an inner circumferential surface of the tube insertion hole and an outer circumferential surface of the small-diameter tubular portion of the tube, is not closed by the rear end of the tube insertion hole and the front end of the large-diameter tubular portion, and so that a melted brazing filler can flow into the gap from a circumferential edge of the rear end of the tube insertion hole, and wherein the inner circumferential surface of the tube insertion hole and the outer circumferential surface of the small-diameter tubular portion of the tube are brazed together with the brazing filler which flows into the gap after having flowed through the flow path from the circumferential edge of the rear end of the tube insertion hole.