Patent ID: 7790083

Claim:
A method for manufacturing a throttle valve unit having a housing part and a valve flap part that is able to move in relation to the housing part, the method comprising including the following process steps: a) injection molding the housing part of the throttle valve unit out of a first plastic material in a first cavity, b) transferring the molded housing part obtained according to process step a) to a second cavity spatially separate from the first cavity, c) injection molding the movable valve flap part of the throttle valve unit out of a second plastic material inside the molded housing part in the second cavity, the first and second plastic materials being injected into the first and second cavities, respectively, through injection points positioned in the cavities in such a way that the flow orientation of chain molecules of the plastic materials and their reinforcing and filler materials are used to influence the shrinkage behavior of the housing part and the valve flap part during the cooling phase so that the second plastic material of the valve flap part shrinks away from the housing part in the intended manner in order to provide the desired gap between the housing part and flap part, and d) inserting bushes into openings of the molded housing part or applying a third material into the gap.