Glow plug

Abstract

Breakage in a short period is suppressed by improving a heat dissipation property. In a glow plug that includes: a heater element ( 10 ) that is inserted in a combustion chamber of an internal combustion engine; a housing ( 14 ) that supports the heater element in a state where a heating section of the heater element is projected; a resilient body ( 31 ) that couples the heater element and the housing to divide a space between the heater element and the housing into a tip side and a rear end side of the housing; and a pressure sensor ( 15 ) that is provided in a space on the rear end side of the resilient body in the housing to detect a pressure in the combustion chamber from displacement of the heater element, a space ( 142 ) on the tip side of the resilient body in the housing is filled with a heat transfer material ( 22 ) that is melted by heat transferred from the heater element.

1 . A glow plug comprising:
 a heater element that is inserted in a combustion chamber of an internal combustion engine;   a housing that supports the heater element in a state where a heating section of the heater element is projected;   a resilient body that couples the heater element and the housing and divides a space between the heater element and the housing into a tip side and a rear end side of the housing; and   a pressure sensor that is provided in a space on the rear end side of the resilient body in the housing to detect a pressure in the combustion chamber from displacement of the heater element,   wherein the space on the tip side of the resilient body in the housing is filled with a heat transfer material that is melted by heat transferred from the heater element.   
     
     
         2 . The glow plug according to  claim 1  characterized in that
 the housing has an opening at a tip thereof, in which the heater element is inserted, and 
 includes a sealing member that seals a clearance between the heater element, which is inserted from the opening, and an opening edge. 
 
     
     
         3 . The glow plug according to  claim 1  characterized in that the heat transfer material is metal that is melted at 100° C. or lower. 
     
     
         4 . The glow plug according to  claim 1  characterized in that a step is formed on an inner surface on the tip side of the resilient body in the housing. 
     
     
         5 . The glow plug according to  claim 2  characterized in that the heat transfer material is metal that is melted at 100° C. or lower. 
     
     
         6 . The glow plug according to  claim 5  characterized in that a step is formed on an inner surface on the tip side of the resilient body in the housing.