Liquid-surface detection device

A liquid-surface detection device comprising:

• a holder configured to turn concurrently with movement of a float arm that moves based on a change in a liquid surface, wherein the holder comprises:
• an upper piece that houses a circuit board and comprises a first through-hole;
• a lower piece that comprises a second through-hole;
• and
• a holding part that connects the upper piece and the lower piece;
• a frame that comprises:
• an upper surface;
• a lower surface;
• and
• a lateral surface extending between the upper surface and the lower surface, wherein the lateral surface comprises:
• a bearing part that comprises a third through-hole;
• a first groove being disposed adjacent to the bearing part, wherein the first groove extends from the upper surface to the lower surface;
• and
• a second groove being disposed adjacent to the bearing part, wherein the second groove extends from the first groove to the bearing part,
• wherein the holder is configured to be mounted on the frame so that the bearing part of the frame is disposed between the upper piece and the lower piece of the holder,
• wherein when mounting the holder onto the frame, the first groove guides the lower piece of the holder from the upper surface to the lower surface of the frame, and the second groove further guides the lower piece of the holder from the first groove to the bearing part to align the first through-hole of the upper piece and the second through-hole of the lower piece with the third through-hole of the bearing part,
• wherein the lateral surface of the frame further comprises a first stopper surface and a second stopper surface that restrain the turning of the holder,
• wherein the upper piece of the holder further comprises a hanging part, the hanging part being a part of a lateral surface of the upper piece that extends towards the frame,
• wherein the hanging part comprises a first abutment surface and a second abutment surface abutting against the first stopper surface and the second stopper surface, respectively, when the holder turns,
• wherein when the first abutment surface is abutting the first stopper surface to restrain the turning of the holder, a first angle formed between the second abutment surface and the first stopper surface is perpendicular and a second angle formed between the second abutment surface and the second stopper surface is perpendicular, and
• wherein when the second abutment surface is abutting the second stopper surface, a third angle formed between the first abutment surface and the first stopper surface is perpendicular and a fourth angle formed between the first abutment surface and the second stopper surface is perpendicular.