Piezoelectric sensor

A piezoelectric sensor, comprising:

• a charge output element comprising a first end surface and a second end surface opposite to each other in a length direction, the charge output element comprising a base and a connecting member extending from the base in a height direction, wherein a piezoelectric member and a mass are sleeved on the connecting member, the piezoelectric member and the mass are fixed to the connecting member via a pretensioning member, and the mass is disposed closer to the first end surface relative to the piezoelectric member;
• a connector, disposed above the first end surface of the charge output element with a predetermined distance from the first end surface in the length direction, wherein the connector comprises a connector housing and a conductive terminal, which is inserted into an interior of the connector housing and connected to the connector housing by a first insulating layer;
• and
• a case, provided with openings on both ends and formed as a hollow member having a receiving portion, the charge output element is contained in the receiving portion, wherein one opening end of the case is connected with the connector housing by a second insulating layer, and the other opening end of the case is connected with the base.