Patent ID: 8966996
Filing Date: 2015-03-03
Classification: G01L

Abstract:
1. A force sensor detecting force or moment with regard to at least one axis, among force in a direction of each coordinate axis and moment around each coordinate axis, in an XYZ three-dimensional orthogonal coordinate system, the force sensor comprising: a force receiving ring which is arranged on an XY-plane so that a Z-axis is given as a central axis and receives exertions of force or moment to be detected; a detection ring which is arranged on the XY-plane so that the Z-axis is given as a central axis and also arranged so as to be inside or outside the force receiving ring, at least a part of the detection ring undergoing elastic deformation by exertions of force or moment to be detected; a supporting substrate which has an upper surface parallel to the XY-plane and is arranged at certain intervals below the force receiving ring and the detection ring; a connection member which connects the detection ring to the force receiving ring at a predetermined exertion point; a fixing member which fixes the detection ring to the supporting substrate at a predetermined fixing point; a detection element which electrically detects elastic deformation of the detection ring; and a detection circuit which detects a detection value of force in a predetermined coordinate axis direction or moment around a predetermined coordinate axis which is exerted on the force receiving ring, with the supporting substrate being fixed, on the basis of detection result of the detection element; wherein a projection image of the exertion point on the XY-plane and a projection image of the fixing point on the XY-plane are formed at mutually different positions; four exertion points and four fixing points are arranged on an annular channel along a contour of the detection ring in an order of a first exertion point, a first fixing point, a second exertion point, a second fixing point, a third exertion point, a third fixing point, a fourth exertion point and a fourth fixing point; vicinity of the first exertion point on the detection ring constitutes a first diaphragm thinner in thickness than other parts, vicinity of the second exertion point on the detection ring constitutes a second diaphragm thinner in thickness than other parts, vicinity of the third exertion point on the detection ring constitutes a third diaphragm thinner in thickness than other parts, vicinity of the fourth exertion point on the detection ring constitutes a fourth diaphragm thinner in thickness than other parts; four connection members are respectively connected to the first to the fourth diaphragms; and the detection element electrically detects elastic deformation of the first to the fourth diaphragms.