Acceleration transducer

Patent metadata

Field	Value
Publication number	US-11747361-B2
Application number	US-202117513967-A
Country	US
Kind code	B2
Filing date	Oct 29, 2021
Priority date	Nov 2, 2020
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

An acceleration transducer defines a rectangular coordinate system with two orthogonal horizontal axes that are both normal to a vertical axis and includes a main body defining tangential side faces arranged tangentially to the vertical axis, and normal side faces arranged normally to the vertical axis. The transducer includes a converter unit, exactly three piezoelectric elements and three seismic masses. Each piezoelectric element generates piezoelectric charges transmitted to the converter unit, which is only and directly arranged on a normal side face of the main body or only on a support that is attached to a normal side face of the main body. Exactly one piezoelectric element is secured to each of the three tangential side faces, and exactly one seismic mass is secured to each of the three piezoelectric elements. Each piezoelectric element has a high sensitivity for a shear force exerted by the attached seismic mass along a principal tangential axis that is another one of the three axes for each of the three piezoelectric elements.

First claim

What is claimed is:

1. An acceleration transducer arranged in a rectangular coordinate system with three mutually orthogonal axes, one of the three axes being a transverse axis, one of the three axes being a longitudinal axis, and one of the three axes being a vertical axis, the acceleration transducer comprising:
a main body that defines a first tangential side face lying in a first plane, a second tangential side face lying in a second plane that is disposed spaced apart from and normal to the first plane, a third tangential side face lying in a third plane that is disposed spaced apart from and parallel to the first plane, and a fourth tangential side face lying in a fourth plane that is disposed spaced apart from and parallel to the second plane, wherein each of the first, second, third and fourth tangential side faces is disposed tangentially to the vertical axis;
wherein the main body further defines a lower normal side face lying in a fifth plane that is normal to each of the first, second, third and fourth planes, and wherein the main body further defines an upper normal side face lying in a sixth plane that is disposed spaced apart along the vertical axis from and parallel to the fifth plane;
exactly three piezoelectric elements, which include only a first piezoelectric element secured to the first tangential side face, a second piezoelectric element secured to the second tangential side face, and a third piezoelectric element secured to the third tangential side face, wherein each of the three piezoelectric elements defines a cuboid having a first end face opposed to a second end face, a top surface opposed to a surface bottom, and a left side surface opposed to a right side surface; wherein each of the opposed end faces is at least partially covered by an end face coating that is electrically conductive, wherein each of the top surface and the bottom surface is at least partially covered by a respective electrically conductive top surface coating or electrically conductive bottom surface coating, wherein each of the left surface and the right surface is at least partially covered by a respective electrically conductive left surface coating or electrically conductive right surface coating;
exactly three seismic masses, which include only a first seismic mass secured to the first piezoelectric element so that acceleration of the first seismic mass exerts on the first piezoelectric element a first shear force proportional to the acceleration, a second seismic mass secured to the second piezoelectric element so that acceleration of the second seismic mass exerts on the second piezoelectric element a second shear force proportional to the acceleration, and a third seismic mass secured to the third piezoelectric element so that acceleration of the third seismic mass exerts on the third piezoelectric element a third shear force proportional to the acceleration, wherein each of the three piezoelectric elements generates piezoelectric charges under the action of each respective shear force; and
a converter unit connected to each of the first piezoelectric element, the second piezoelectric element and the third piezoelectric element and configured to receive piezoelectric charges;
wherein the converter unit is arranged only on a support that is attached to either the lower normal side face of the main body or the upper normal side face of the main body or wherein the converter unit is arranged only and directly on either the lower normal side face of the main body or the upper normal side face of the main body.

2. The acceleration transducer according to claim 1 , wherein the first piezoelectric element has a high sensitivity for a shear force exerted by the first seismic mass along the longitudinal axis and generates piezoelectric charges under the action of the shear force along the longitudinal axis;
wherein the second piezoelectric element has a high sensitivity for a shear force exerted by the second seismic mass along the transverse axis and generates piezoelectric charges under the action of the shear force along the transverse axis; and
wherein the third piezoelectric element has a high sensitivity for a shear force along the vertical axis exerted by the third seismic mass and generates piezoelectric charges under the action of the shear force along the vertical axis.

3. The acceleration transducer according to claim 1 , wherein under the action of a shear force along a principal tangential axis, each of the three piezoelectric elements generates piezoelectric charges on each of the first and second end faces of each piezoelectric element; and
wherein the electrically conductive end face coating receives piezoelectric charges generated for the shear force along the principal tangential axis.

4. An acceleration transducer arranged in a rectangular coordinate system with three mutually orthogonal axes, one of the three axes being a transverse axis, one of the three axes being a longitudinal axis, and one of the three axes being a vertical axis, the acceleration transducer comprising:
a main body that defines a first tangential side face lying in a first plane, a second tangential side face lying in a second plane that is disposed spaced apart from and normal to the first plane, a third tangential side face lying in a third plane that is disposed spaced apart from and parallel to the first plane, and a fourth tangential side face lying in a fourth plane that is disposed spaced apart from and parallel to the second plane, wherein each of the first, second, third and fourth tangential side faces is disposed tangentially to the vertical axis;
wherein the main body further defines a lower normal side face lying in a fifth plane that is normal to each of the first, second, third and fourth planes, and wherein the main body further defines an upper normal side face lying in a sixth plane that is disposed spaced apart along the vertical axis from and parallel to the fifth plane;
exactly three seismic masses, which include only a first seismic mass secured to the first piezoelectric element so that acceleration of the first seismic mass exerts on the first piezoelectric element a first shear force proportional to the acceleration, a second seismic mass secured to the second piezoelectric element so that acceleration of the second seismic mass exerts on the second piezoelectric element a second shear force proportional to the acceleration, and a third seismic mass secured to the third piezoelectric element so that acceleration of the third seismic mass exerts on the third piezoelectric element a third shear force proportional to the acceleration, wherein each of the three piezoelectric elements generates piezoelectric charges under the action of each respective shear force; and
a converter unit connected to each of the first piezoelectric element, the second piezoelectric element and the third piezoelectric element and configured to receive piezoelectric charges;
wherein the converter unit is arranged only on a support that is attached to either the lower normal side face of the main body or the upper normal side face of the main body or wherein the converter unit is arranged only and directly on either the lower normal side face of the main body or the upper normal side face of the main body;
wherein each piezoelectric element defines a first end face and a second end face spaced apart from the first end face;
wherein under the action of a shear force along a principal tangential axis, each of the three piezoelectric elements generates piezoelectric charges on each of the first and second end faces of each piezoelectric element;
wherein at least one of the first and second end faces comprises an electrically conductive end face coating;
wherein the electrically conductive end face coating receives piezoelectric charges generated for the s

Assignees

• Kistler Holding Ag

Inventors

• Laffranchi Marco
• Frommenwiler Tobias
• Weber David

Classifications

• G01P15/0915 Primary

  of the shear mode type · CPC title

• G01P1/023

  for acceleration measuring devices · CPC title

• G01P15/0802

  Details · CPC title

• G01P15/09 Primary

  by piezoelectric pick-up · CPC title

• G01P15/18

  in two or more dimensions · CPC title