Among vehicle air conditioners that air-condition a vehicle cabin, there is a known vehicle air conditioner in the related art in which an opening is provided in a toe board that separates a vehicle engine compartment and the vehicle cabin; an expansion valve provided in an air conditioning unit (HVAC unit: Heating Ventilation and Air Conditioning Unit) is disposed so as to face the opening, and devices disposed in the engine compartment, such as a compressor, a condenser, etc., are connected with an evaporator in the air conditioning unit disposed in the vehicle cabin with a refrigerant pipe via the expansion valve.
In such a vehicle air conditioner, an expansion-valve cover that covers the outer circumference of the expansion valve is provided so as to bridge mating surfaces of top and bottom divided cases that form the air conditioning unit, and the expansion-valve cover is installed in close contact with the toe board at the periphery of the opening thereof with a dash-side gasket sandwiched therebetween, thus preventing infiltration of water that would otherwise pour into the vehicle cabin via the opening from the engine compartment, for example, rain water, water splashed when driving on a flooded road, and so on; however, water enters the expansion-valve cover, inside which the expansion valve is disposed, from the engine compartment via the opening in the toe board. Therefore, if the mating surfaces of the expansion-valve cover and those of the top and bottom divided cases of the air conditioning unit face the portion where the expansion valve is disposed, water may infiltrate the vehicle cabin by being conveyed through the mating surfaces.
Therefore, a rubber water-proofing cover is installed at the portion where the expansion valve is disposed to prevent water from infiltrating the vehicle cabin. Patent Literature 1 discloses a waterproofing structure in which the opening in the toe board is sealed with a waterproofing cover formed of a pair of divided members that sandwich and hold a refrigerant pipe connected to the expansion valve and that are bonded together with a gasket material. In addition, Patent Literature 2 discloses a vehicle air conditioner in which mating surfaces of top and bottom cases, which cover the outer circumference of an expansion valve, are fitted with each other by means of fitting ribs, front surfaces thereof are placed in close contact with a toe board with a front gasket therebetween, and a rear gasket is also provided, via ribs, at a rear opening, through which an indoor-side pipe passes, thus achieving both prevention of flooding of the vehicle cabin and ease of replacing the expansion valve.