STRUCTURE FOR PREVENTING BREAKAGE BY BACK FIRE IN INTAKE MANIFOLD

Structure for preventing breakage by back fire in an intake manifold is provided to prevent damage of welded parts between a flange shell and an insert shell by installing support posts to support the shell at its outer part. Structure for preventing breakage by back fire in an intake manifold includes a flange shell(11), a center shell(13), an insert shell(12), a runner shell(14), and support posts(16a,16b). The flange shell forms a surge tank. The center shell is installed at a periphery of the flange shell through welding. The insert shell is inserted between the flange shell and the center shell and welded to the flange shell to form the surge tank. The runner shell is installed at an outer periphery of the center shell to form a plurality of runners. The support posts support the insert shell from an explosion pressure formed between the center shell and the center shell to prevent damage of the welding parts between the flange shell and the insert shell.