Exhaust heating apparatus

Abstract

An exhaust heating apparatus has a housing defining a firing chamber jointed to an exhaust pipe, a fuel supply valve for injecting fuel to the firing chamber communicated with the exhaust passage through a junction port, a glow plug for igniting the injected fuel. A part of the exhaust gas flowing in the exhaust passage flows into the firing chamber and again flowing out to the exhaust passage together with a combustion gas generated in the firing chamber. An angle between a wall surface in the exhaust pipe positioned upstream of the junction port and an upstream wall surface in the housing, and an angle between a wall surface in the exhaust pipe positioned downstream of the junction port and a downstream wall surface in the housing, are set to an obtuse angle, respectively.

1 . An exhaust heating apparatus comprising:
 a housing defining a firing chamber, the housing being jointed to the halfway of an exhaust pipe defining an exhaust passage, the exhaust pipe being connected to an internal combustion engine;   a fuel supply valve for injecting fuel to the firing chamber communicated with the exhaust passage through a junction port formed on a wall of the exhaust pipe; and   ignition means including a heat generating portion for igniting the fuel injected into the firing chamber,   wherein a part of the exhaust gas flowing in the exhaust passage flows from the junction port into the firing chamber and again flows out from the junction port to the exhaust passage together with a combustion gas generated in the firing chamber, characterized in that   an angle between a wall surface in the exhaust pipe positioned upstream of the junction port in the exhaust passage and adjacent to the junction port, and an upstream wall surface in the housing positioned upstream of the exhaust passage, is set to an obtuse angle, and   an angle between a wall surface in the exhaust pipe positioned downstream of the junction port in the exhaust passage and adjacent to the junction port, and a downstream wall surface in the housing positioned downstream of the exhaust passage, is set to an obtuse angle.   
     
     
         2 . An exhaust heating apparatus as claimed in  claim 1 , wherein the housing further defines a fuel injection chamber communicated with the firing chamber, the fuel injection chamber being further recessed from a section of the upstream wall surface of the housing at a distance from the junction port, and wherein the fuel supply valve injects the fuel into the firing chamber through the fuel injection chamber. 
     
     
         3 . An exhaust heating apparatus as claimed in  claim 1 , wherein a posture of the fuel supply valve is set to the downstream wall surface in the housing such that the fuel injected from the fuel supply valve collides with the downstream wall surface in the housing and plashes toward the exhaust passage through the junction port. 
     
     
         4 . An exhaust heating apparatus as claimed in  claim 1 , wherein the heat generating portion of the ignition means is arranged in the vicinity of the downstream wall surface in the housing. 
     
     
         5 . An exhaust heating apparatus as claimed in  claim 1 , wherein an exhaust emission purifier is jointed to the exhaust pipe, the exhaust emission purifier being positioned downstream of the housing in the exhaust passage.