Air conditioning unit for vehicle

An air conditioning unit that is configured to perform an air conditioning for a vehicle compartment, comprising:

• an air conditioning case that defines a warm air passage, a cool air passage, and a downstream space therein,
• the warm air passage allowing air to flow therethrough and to be heated in a heater,
• the cool air passage allowing air to flow therethrough while bypassing the heater,
• the downstream space defined on a downstream side of the warm air passage and on a downstream side of the cool air passage,
• the warm air passage and the cool air passage being connected to each other in the downstream space;
• and
• a case interior member in the air conditioning case, wherein
• the cool air passage is in fluid communication with the downstream space in a cool air flow direction,
• the case interior member includes
• a tunnel member that defines a tunnel channel therein passing through the tunnel member in a direction intersecting with the cool air flow direction and
• a tunnel exterior guide wall that is configured to guide an air to flow from the warm air passage to an outside of the tunnel channel in the downstream space,
• the tunnel member is open to the warm air passage at an upstream end of the tunnel channel, and includes a tunnel guide wall that faces the tunnel channel and that is configured to guide an air flowing through the tunnel channel,
• in the downstream space, the air from the cool air passage flows outside the tunnel member across the tunnel member from the cool air passage to a side of the tunnel member away from the cool air passage along the cool air flow direction, and joins the air flowing from the warm air passage into the outside of the tunnel member,
• the tunnel exterior guide wall includes an exterior-wall downstream end that is located most downstream in the tunnel exterior guide wall in a first flow direction along which the air flows from the warm air passage into the downstream space along the tunnel exterior guide wall,
• the tunnel guide wall includes a tunnel-wall downstream end in a second flow direction along which the air flows along the tunnel guide wall in the tunnel channel,
• the tunnel exterior guide wall around the exterior-wall downstream end extends along a first direction,
• the tunnel guide wall around the tunnel-wall downstream end extends along a second direction, and
• the first direction is closer to a direction, which is opposite to the cool air flow direction along which the air flowing from the cool air passage into the downstream space, as compared to the second direction, wherein
• the air conditioning case includes a case wall that extends from the tunnel exterior guide wall,
• the case wall includes a notch, a first case wall portion, and a second case wall portion different from the first case wall portion,
• the first case wall portion abuts on the second case wall portion on a boundary extending from the notch,
• the tunnel exterior guide wall is fixed to the case wall with the notch engaged with the tunnel exterior guide wall, and
• one wall of the tunnel exterior guide wall and the case wall includes a protrusion, the protrusion is
• positioned on one side of a surface of an other wall of the tunnel exterior guide wall and the case wall in a thickness direction of the one wall and
• formed to protrude from a boundary between the one wall and the other wall toward the other wall and to extend along the surface of the other wall.