A lighting unit, such as a tail light, to be attached to a vehicle includes a frame supporting a bulb socket. A continuous or loop-shaped sealing wall protrudes from a rear surface of the frame so as to surround the bulb socket. A sheet-like sealing member is attached to an end of the sealing wall so as to cover an opening defined by the sealing wall. A bulb, serving as a light source, is connected to the bulb socket. When the lighting unit is attached to a vehicle body panel, the sealing member is sandwiched between the sealing wall and a lighting unit attachment wall portion of the vehicle body panel. Thus, sealing is achieved to prevent, for example, water from entering a space inside the sealing wall. The sealing member and the vehicle body panel each have a bulb socket hole for preventing interference with the bulb socket (refer to Japanese Unexamined Patent Application Publication No. 8-183387, for example).
Before attachment of the lighting unit to the vehicle body panel, the sealing member is temporarily fixed to the frame and the sealing member is in contact with the whole of the end of the sealing wall. The sealing member is not securely fastened to the end of the sealing wall. Temporarily fixed points of the sealing member are positioned inside the sealing wall. Unfortunately, end part of the sealing member may be partly turned when the lighting unit is attached to the vehicle body panel. If the lighting unit is attached to the vehicle body panel while the sealing member is partly turned, the sealing member will fail to cover part of the end of the sealing wall, thus leading to incomplete sealing. Water may enter the space inside the sealing wall through that part.
According to a related-art approach to preventing such turn, a pointed pin (hereinafter, referred to as an “anti-turn pin”) is provided inside the sealing wall so as to rise from the rear surface of the frame such that the pin is to be positioned in the vicinity of part of the sealing member which tends to be turned. To temporarily fix the sealing member to the frame, the tip of the anti-turn pin pierces through the sealing member to make the sealing member difficult to turn.
According to another approach, the end of the sealing wall to be positioned in the vicinity of part of the sealing member which tends to be turned is covered with a double-faced tape. The end of the sealing wall is partly bonded to the sealing member with the double-faced tape to make the sealing member difficult to turn.
In the case where the tip of the anti-turn pin pierces through the sealing member to make the sealing member difficult to turn, the tip of the anti-turn pin projects through the sealing member. It is necessary to form a hole in the lighting unit attachment wall portion of the vehicle body panel in order to prevent the tip of the anti-turn pin from interfering with the lighting unit attachment wall portion of the vehicle body panel. Disadvantageously, the cost is increased because the step of hole formation is additionally performed. To use the bulb socket hole in the lighting unit attachment wall portion as a hole to prevent interference with the anti-turn pin, the bulb socket hole has to be increased so as to cover the position of the anti-turn pin, so that the bulb socket hole has an increased area. Unfortunately, this results in a reduction in stiffness of the vehicle body panel.
In the case where the end of the sealing wall is partly bonded to the sealing member with the double-faced tape in order to make the sealing member difficult to turn, the cost is increased because the double-faced tape is additionally used. Furthermore, this case requires an additional troublesome task.