Engine intake control device

摘要

An engine intake control device includes an intake manifold (M) made of a synthetic resin, and a butterfly-type switching valve (V) which is mounted in the intake manifold (M) and capable of switching over an interior of the intake manifold (M) between a low-speed intake mode that is adapted for low-speed driving of an engine (E) and a high-speed intake mode that is adapted for high-speed driving of the engine (E). The switching valve (V) includes: a valve case (15) which has a plurality of valve holes (16) and is fastened to an inner wall of the intake manifold (M) at two spots at its opposite ends; a valve stem (17) which is rotatably supported by the valve case (15) ; and a plurality of valve plates (19) which is mounted on the valve stem (17) so as to open and close the valve holes (16). Rigidity of the valve case (15) between the plurality of fastening spots is made larger than rigidity of the intake manifold (M) between the spots. Thus, parallel assembling of the intake manifold (M) and the switching valve (V) becomes possible, and the assemblability becomes excellent. Furthermore, it is possible to always secure a good operating state of the switching valve (V), in a state in which the switching valve (V) is mounted in the intake manifold (M).