| 摘要 |
PURPOSE:To detect combustion pressure, by forming a space between the inner housing and the outer housing of a glow plug, enclosing a pressure sensitive element in the space through a heat insulating material, thereby preventing the deterioration of the function of the pressure sensitive element. CONSTITUTION:Heater wires 1 are enclosed in a sheath 2. The sheath 2 is provided in an inner housing 4. Meanwhile, a pressure sensitive part is provided in the space between the outer surface of the inner housing 4 and the inner surface of an outer housing 5, and provided with a structure with an L shaped cross section, wherein an output electrode 13 and a pressure sensitive element 14 are laminated through a ring shaped heat insulating material 12. When the combustion pressure in a cylinder is applied to the inner housing 4, the force is transmitted to the heat insulating material 12, the output electrode 13, and the pressure sensitive element 14. Therefore, the electric charge corresponding to the force is generated in the pressure sensitive element 14 and guided to the outside by a lead wire 19 from the output electrode 13. |
