| 摘要 |
<p>PURPOSE:To support a heating wire under a stable tension even when a large temperature difference or force is applied by forming a base body from a material with a coefficient of thermal expansion approximately equal to that of the heating wire supported at two points by two support pins fixedly mounted to the base body. CONSTITUTION:A detector 100 is arranged perpendicularly to the flow path of air flowing in the suction pipe of an internal-combustion engine and provided with an approximately triangular-cylinder-shaped vortex forming body 1 and a fixed member 3. A base body 6 is molded in the approximate center of the downstream side wall of the member 3. Two support pins 7a and 7b are fixed to the base body 6 and both ends of a heating wire 9 are joined to the tops of the pins 7a and 7b by soldering. Since heated and controlled by a heating electric power, the wire 9 is constituted by platinum-rhodium alloy wherein a resistance value decreases with a decrease in a temperature. The base body 6 and the pins 7a and 7b are made of iron-nickel alloy with a coefficient of expansion approximately equal to that of the wire 9 and prevent the overtension, looseness and the like of the wire 9 when an ambient temperature changes. Further, the pins 7a and 7b have a smaller elastic modulus than that of the wire 9 to prevent changes in a length in electrification and nonelectrification and the like.</p> |
