| 摘要 |
PURPOSE:To improve the durability of an intake air heater, by eliminating direct contact of intake air to ceramic heating elements having a positive temperature resistance coefficient, by way of arranging, in an intake passage, heat radiation blocks which about on the heating elements and heat the intake air by receiving the heat thereof. CONSTITUTION:Four sheets of PTC element 1, made of ceramic sintered body and formed in a rectangular flat plate-shape, are disposed in two columns by making two sheets a set, respectively, and three intermediate heat radiation blocks 2 and each one outside heat radiation block 2 are disposed in the central parts between two columns of PTC element 1 and on both outside parts thereof, respectively. Each heat radiation block 2 is composed of a heat radiation fin 2a, which is made by forming a cupper or aluminum plate in a meandering- shape, and a pair of heat transmission plates 2b, which are attached to both sides of the fin 2a. Then, the PTC elements 1 and the heat radiation blocks 2, both of which are formed respectively in one body, are contained in a case 3 made of heat resistant resin or the like, and further they are housed in an aluminum housing 4, thereby constituting a desired intake heater 10. |
