Patent ID: 7223098

Claim:
An ignition unit comprising: a bracket which is fixed to a dividing wall constituting a pan of an ignition target; a spark plug which is supported by said bracket so as to penetrate through said dividing wall and which ignites said ignition target by a spark discharge; and a main unit which has a housing containing therein a high voltage output part for said spark discharge and which is mounted onto said bracket, wherein said bracket is made of an electrically conductive material so as to constitute, together with said dividing wall, a part of a ground-side circuit from said ignition target which has received a spark discharge from said spark plug, wherein said spark plug projects to near said ignition target so that an ignition electrode part on the side of a leading end is able to issue a spark discharge to said ignition target at a position on one side through said bracket, and wherein said spark plug is supported by said bracket so that a high voltage input terminal on the side of a base end projects in a predetermined direction at a position on the other side through said bracket, wherein said main unit has a high voltage output terminal which is connected to said high voltage output pan and which projects outwardly and a ground-side connection terminal which projects in parallel with said high voltage output terminal, wherein said housing of said main unit and said bracket have sections respectively integrally formed therewith, said sections together constituting a mount mechanism for guiding an insertion operation and for holding a conductive connection state in order that both the conductive connection of said high voltage output terminal to said high voltage input terminal and the conductive connection of said ground-side connection terminal to said bracket can be established by insertion engagement of said main unit into said bracket in the projecting direction of said high voltage output terminal and said ground-side connection terminal; wherein said housing of said main unit and said bracket have sections respectively integrally formed therewith, said sections together constituting a lock mechanism for locking said main unit and said bracket in a mount state established by said mount mechanism, wherein said lock mechanism has a convex portion which is formed in one of said housing of said main unit and said bracket and which projects in a direction orthogonal to the direction of said insertion engagement, and a concave portion which is formed in the other of said housing of said main unit and said bracket and into which said convex portion is engaged from said direction orthogonal to said insertion engagement direction, and wherein said convex and concave portions are arranged so that said convex portion reaches a position of engagement into said concave portion by said insertion engagement, and that said convex portion is placed in a state in which said convex portion is engaged into said concave portion with said main unit mounted onto said bracket by said mount mechanism.