Patent attributes
There is provided a flame hole formation member 7 which is inserted and mounted from above in a third plate member 6 used to form a central rich-side flame hole row 33. As the flame hole formation member 7, a pair of flame hole formation parts 71, 71 each used to form a respective lean-side flame hole row 34 are connected by bridge formation parts 72, 72 at their upper end positions, with a predetermined distance held between the flame hole formation parts 71, 71. The bridge formation part 72, 72 is fitted from above into an engagement groove 332 formed in the upper end edge of the third plate member 6, whereby the pair of the flame hole formation parts 71, 71 are assembled so as to sit astride the upper end edge of the third plate member 6.