Differential pressure detection device

A differential pressure detection device configured to detect differential pressure that is a pressure difference between a high pressure side and a low pressure side, the differential pressure detection device comprising:

• a case having a cylindrical shape and including a sliding cavity open to a first end that is one end face;
• a spool provided inside the sliding cavity, the spool being movable along a center axis of the sliding cavity inside the sliding cavity and dividing the sliding cavity into a space in the low pressure side and a space in the high pressure side;
• an elastic member provided inside the sliding cavity;
• and
• a magnetic field detection element provided inside the case,
• wherein the spool includes a first spool provided with a magnet, and a second spool having a diameter identical to an inner diameter of the sliding cavity and sliding inside the sliding cavity,
• the first spool is provided to face the space in the high pressure side, and the second spool is provided to face the space in the low pressure side,
• the elastic member includes a first elastic member provided in the first spool and configured to urge the first spool toward the space in the high pressure side, and a second elastic member provided in the second spool and configured to urge the second spool toward the space in the high pressure side,
• the magnetic field detection element is provided opposite to the magnet with a bottom surface of the sliding cavity interposed between the magnetic field detection element and the magnet,
• the first spool is lighter than the second spool in a state where the magnet is provided,
• urging force of the first elastic member is smaller than urging force of the second elastic member, and
• the first elastic member and the second elastic member are disposed in series.