The invention relates to a fresh air supply device which is connected upstream of a blower of a heating or air conditioning unit in a motor vehicle. The blower is accommodated by a housing, with the fresh air entering into a gap between the windscreen and the adjacent vehicle bonnet or hood and, while being deflected and, associated therewith, while water and foreign bodies are separated, being supplied underneath the bonnet to a filter and then entering on the intake side into the blower. The filter can be exchanged by pulling it out upwards.
A fresh air supply device of this type with a high rate of separation is known from the German Patent Specification No. 3330951. The air intake path is long and runs over a broad stretch beneath the hood, which hood is frequently heated up by waste heat from the engine and/or direct solar irradiation, so that the fresh air heats up undesirably at least in the summer months.
It is an object of the invention, while retaining easy exchangeability of the filter, to prevent unintentional heating up of the fresh air in the intake tract due to heat transfers from the vehicle engine space hood to the fresh air.
This object is achieved according to the invention by providing thermal insulation in the space between the top of an air scoop for the fresh air and the bottom of the vehicle hood.
Good thermal insulation is achieved if the intake scoop is made of thermally insulating material according to certain preferred embodiments of the invention.
According to other preferred embodiments of the invention the upper side of the intake scoop is thermally insulated relative to the hood.
So that the filter can easily be reached, the intake scoop is pivotably mounted in certain preferred embodiments.
An additional saving in space and weight is made if the intake scoop is formed at least in part by wall areas of the hood according to certain preferred embodiments.
Moreover, when the hood is swung away, ingress of foreign bodies and water is impossible if, when the hood is swung away, a support part accommodating the filter is covered by a pivoted lid articulated on the supporting part according to certain preferred embodiments.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.