Strain-generating body, force sensor device

Abstract

To provide a strain body capable of suppressing displacement of a portion where a sensor chip is arranged, which is generated when attached to an object to be measured.SOLUTION: This strain body includes: a strain-generating part which includes a movable part deformed by receiving a predetermined axial force or moment, and a non-movable part not deformed by receiving the force or the moment; and an input transmission part which is joined to the non-movable part and not deformed upon receipt of the force or the moment. The input transmission part includes: a first frame part; a plurality of beam structures whose one end is connected to the frame part and extends inwardly from the frame part; and a housing part which is provided on the other end side of the beam structure and in which a sensor chip for detecting the force or the moment can be housed. Each of the beam structures has a counterbore part for making the thickness at the one end side thinner than that at the other end side.SELECTED DRAWING: Figure 22

Description

[Technical field]

[0001] The present invention relates to a strain generating body and a force sensor device. [Background technology]

[0002] Conventionally, force sensor devices that detect displacement in a predetermined axial direction have been known. One example is a force sensor device that includes a structure consisting of a sensor chip, an external force application plate that is arranged around the sensor chip and to which an external force is applied, a base that supports the sensor chip, an external force buffering mechanism that fixes the external force application plate to the base, and a connecting rod that is an external force transmission mechanism, and in which the external force application plate and an action part are connected by the connecting rod (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-254843 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a force sensor device, the strain body used in combination with the sensor chip is fastened to the object to be measured, such as a robot flange, by means of screws, but when fastened, the strain body is overheated by the heat generated by the object to be measured, causing a temperature distribution in the strain body. When a temperature distribution occurs in the strain body, the expansion and deformation of the strain body displaces the part where the sensor chip is placed, and an output (offset) may occur in the sensor chip.

[0005] The present invention has been made in view of the above-mentioned points, and has an object to provide a strain body that can suppress displacement of a portion where a sensor chip is disposed, which occurs when the strain body is attached to an object to be measured. [Means for solving the problem]

[0006] The present strain-generating body (200) has a strain-generating part (220) including a movable part that deforms when subjected to a predetermined axial force or moment, and a non-movable part that does not deform when subjected to the force or moment, and an input transmission part (230) that is joined to the non-movable part and does not deform when subjected to the force or moment, the input transmission part (230) including a frame part (231), a plurality of beam structures (233) having one end connected to the frame part (231) and extending inward from the frame part (231), and an accommodating part (235) provided on the other end side of the beam structure (233) and capable of accommodating a sensor chip (100) that detects the force or moment, and each of the beam structures (233) has a countersunk part (233a) that makes the thickness of the one end side thinner than the thickness of the other end side.

[0007] The reference symbols in parentheses are given for ease of understanding, are merely examples, and are not intended to be limiting of the embodiments shown in the drawings. Effect of the Invention

[0008] According to the disclosed technique, it is possible to provide a strain body that can suppress the displacement of the portion where the sensor chip is disposed, which occurs when the strain body is attached to an object to be measured. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view illustrating a force sensor device according to a first embodiment; [Diagram 2] 1 is a cross-sectional perspective view illustrating a force sensor device according to a first embodiment; [Diagram 3] 1 is a top perspective view showing a state in which a sensor chip is attached to an input transmission section; FIG. [Figure 4] 1 is a bottom perspective view showing a state in which the sensor chip is attached to an input transmission section; FIG. [Diagram 5] 1 is a perspective view of the sensor chip 100 as viewed from above in the Z-axis direction. [Figure 6] 1 is a plan view of the sensor chip 100 as viewed from above in the Z-axis direction. [Figure 7]2 is a perspective view of the sensor chip 100 as viewed from below in the Z-axis direction. FIG. [Figure 8] 1 is a bottom view of the sensor chip 100 as viewed from below in the Z-axis direction. [Figure 9] FIG. 2 is a diagram illustrating symbols indicating forces and moments acting on each axis. [Figure 10] 2 is a diagram illustrating an example of the arrangement of piezoresistance elements of the sensor chip 100. FIG. [Figure 11] 11 is a partial enlarged view of a pair of detection blocks of the sensor chip shown in FIG. 10. [Figure 12] FIG. 1 is a diagram (part 1) showing an example of a detection circuit using piezoresistance elements. [Figure 13] FIG. 2 is a diagram (part 2) showing an example of a detection circuit using piezoresistance elements. [Figure 14] FIG. 13 is a diagram illustrating an Fx input. [Figure 15] FIG. 13 is a diagram illustrating an Fy input. [Figure 16] FIG. 4 is a perspective view illustrating a force-receiving plate that constitutes the strain body. [Figure 17] FIG. 2 is a perspective view illustrating a strain-generating portion that configures a strain-generating body. [Figure 18] FIG. 1 is a plan view illustrating a strain-generating portion that constitutes a strain-generating body; [Figure 19] FIG. 2 is a perspective view of the upper surface side illustrating an input transmission portion that configures the strain body. [Figure 20] FIG. 4 is a plan view illustrating an input transmission portion that configures the strain body. [Figure 21] FIG. 4 is a perspective view of the lower surface side illustrating an input transmission portion that configures the strain body. [Figure 22] 4 is a cross-sectional view illustrating an input transmission portion that configures the strain body. FIG. [Diagram 23] FIG. 4 is a perspective view illustrating a cover plate that constitutes a strain generating body. [Figure 24] FIG. 11 is a perspective view illustrating a strain-flexing part according to a comparative example. [Diagram 25] 11 is a perspective view illustrating an input transmission section according to a comparative example; FIG. [Figure 26]13 is a perspective view illustrating a state in which an input transmission part is disposed on a strain-flexing part according to a comparative example. FIG. [Figure 27] 10 is a perspective view illustrating a state in which an input transmission part is disposed on a strain-flexing part according to the present embodiment; FIG. [Figure 28] FIG. 13 is a diagram showing the results of simulation 1. [Figure 29] FIG. 13 is a diagram showing the results of simulation 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated explanations may be omitted.

[0011] First embodiment (Schematic configuration of the force sensor device 1) Fig. 1 is a perspective view illustrating a force sensor device according to a first embodiment. Fig. 2 is a cross-sectional perspective view illustrating the force sensor device according to the first embodiment. With reference to Figs. 1 and 2, the force sensor device 1 has a sensor chip 100 and a strain body 200. The force sensor device 1 is a multi-axis force sensor device mounted on, for example, the arms or fingers of a robot used in machine tools or the like.

[0012] The sensor chip 100 has a function of detecting displacement in a predetermined axial direction in up to six axes. The strain body 200 has a function of transmitting an applied force and / or moment to the sensor chip 100. In the following embodiments, as an example, a case where the sensor chip 100 detects six axes will be described, but the present invention is not limited thereto, and the sensor chip 100 can also be used in a case where it detects three axes, for example.

[0013] The flexure body 200 has a force receiving plate 210, a strain generating section 220, an input transmission section 230, and a cover plate 240. The strain generating section 220 is laminated on the force receiving plate 210, the input transmission section 230 is laminated on the strain generating section 220, and the cover plate 240 is laminated on the input transmission section 230, thereby forming the substantially cylindrical flexure body 200 as a whole. Note that since the function of the flexure body 200 is mainly performed by the strain generating section 220 and the input transmission section 230, the force receiving plate 210 and the cover plate 240 are provided as necessary.

[0014] In this embodiment, for convenience, in the force sensor device 1, the cover plate 240 side is referred to as the upper side or one side, and the force receiving plate 210 side is referred to as the lower side or the other side. Also, the surface of each part facing the cover plate 240 is referred to as one side or upper side, and the surface facing the force receiving plate 210 is referred to as the other side or lower side. However, the force sensor device 1 can be used upside down or placed at any angle. Also, a planar view refers to viewing an object from the normal direction (Z-axis direction) of the upper surface of the cover plate 240, and a planar shape refers to the shape of an object viewed from the normal direction (Z-axis direction) of the upper surface of the cover plate 240.

[0015] Fig. 3 is a top perspective view showing a state in which the sensor chip is attached to the input transmission section. Fig. 4 is a bottom perspective view showing a state in which the sensor chip is attached to the input transmission section. As shown in Figs. 3 and 4, the input transmission section 230 is provided with a housing section 235 that protrudes from the bottom surface of the input transmission section 230 toward the strain-generating section 220. The sensor chip 100 is fixed to the cover plate 240 side of the housing section 235.

[0016] Specifically, as described later, four second connection parts 235d (see FIGS. 19 to 22, etc., described later) protruding toward the cover plate 240 are arranged in the accommodation part 235. Each of the second connection parts 235d is connected to the lower surface of the force points 151 to 154 (see FIGS. 5 to 8, etc., described later) of the sensor chip 100.

[0017] The accommodation section 235 is recessed into the strain-flexing section 220. As described later, five columnar first connection sections 224 (see FIG. 17, etc., described later) protruding toward the input transmission section 230 are disposed on the strain-flexing section 220. Each of the first connection sections 224 is connected to the lower surface of the support sections 101-105 (see FIG. 5-8, etc., described later) of the sensor chip 100.

[0018] The sensor chip 100 and the strain body 200 will be described in detail below. In the following description, "parallel" includes cases where two straight lines or sides are in the range of 0°±10°. Furthermore, "perpendicular" or "orthogonal" includes cases where two straight lines or sides are in the range of 90°±10°. However, this does not apply unless there is a special explanation for each case. Furthermore, "center" or "middle" refers to the approximate center or center of an object, not the exact center or center. In other words, variations on the order of manufacturing errors are allowed. The same applies to point symmetry and line symmetry.

[0019] (Sensor chip 100) FIG. 5 is a perspective view of the sensor chip 100 viewed from above in the Z-axis direction. FIG. 6 is a plan view of the sensor chip 100 viewed from above in the Z-axis direction. FIG. 7 is a perspective view of the sensor chip 100 viewed from below in the Z-axis direction. FIG. 8 is a bottom view of the sensor chip 100 viewed from below in the Z-axis direction. In FIG. 8, for convenience, surfaces at the same height are shown with the same matte pattern. In this case, the direction parallel to one side of the upper surface of the sensor chip 100 is the X-axis direction, the direction perpendicular to the side is the Y-axis direction, and the thickness direction of the sensor chip 100 (the normal direction to the upper surface of the sensor chip 100) is the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually orthogonal.

[0020] 5 to 8 is a MEMS (Micro Electro Mechanical Systems) sensor chip capable of detecting up to six axes per chip, and is formed from a semiconductor substrate such as an SOI (Silicon On Insulator) substrate. The planar shape of the sensor chip 100 can be, for example, a rectangle (square or oblong) with sides of about 7000 μm.

[0021] The sensor chip 100 includes five columnar support parts 101-105. The planar shape of the support parts 101-105 may be, for example, a square of about 2000 μm on each side. The support parts 101-104 are disposed at the four corners of the rectangular sensor chip 100. The support part 105 is disposed in the center of the rectangular sensor chip 100. The support parts 101-104 are a representative example of a first support part according to the present invention, and the support part 105 is a representative example of a second support part according to the present invention.

[0022] Between supporting portion 101 and supporting portion 102, there is provided a frame portion 112 whose both ends are fixed to supporting portion 101 and supporting portion 102 (connecting adjacent supporting portions). Between supporting portion 102 and supporting portion 103, there is provided a frame portion 113 whose both ends are fixed to supporting portion 102 and supporting portion 103 (connecting adjacent supporting portions).

[0023] Between the supporting parts 103 and 104, there is provided a frame part 114 whose both ends are fixed to the supporting parts 103 and 104 (connecting adjacent supporting parts). Between the supporting parts 104 and 101, there is provided a frame part 111 whose both ends are fixed to the supporting parts 104 and 101 (connecting adjacent supporting parts).

[0024] In other words, the four frame portions 111, 112, 113, and 114 are formed in a frame shape, and the corners forming the intersections of the frame portions become the support portions 101, 102, 103, and 104.

[0025] An inner corner of support part 101 and an opposing corner of support part 105 are connected by connecting part 121. An inner corner of support part 102 and an opposing corner of support part 105 are connected by connecting part 122.

[0026] An inner corner of support part 103 and an opposing corner of support part 105 are connected by connecting part 123. An inner corner of support part 104 and an opposing corner of support part 105 are connected by connecting part 124.

[0027] That is, the sensor chip 100 has connecting portions 121 to 124 that connect the support portion 105 to the support portions 101 to 104. The connecting portions 121 to 124 are disposed obliquely with respect to the X-axis direction (Y-axis direction). That is, the connecting portions 121 to 124 are disposed non-parallel to the frame portions 111, 112, 113, and 114.

[0028] The supporting portions 101 to 105, the frame portions 111 to 114, and the connecting portions 121 to 124 can be formed, for example, from an active layer, a BOX layer, and a supporting layer of an SOI substrate, and each can have a thickness of, for example, about 400 μm to 600 μm.

[0029] The sensor chip 100 has four detection blocks B 1 ~B 4 Each detection block has three T-shaped beam structures in which piezoresistance elements, which are strain detection elements, are arranged. Here, the T-shaped beam structure refers to a structure including a first detection beam and a second detection beam that extends from the center of the first detection beam in a direction perpendicular to the first detection beam and connects to the force point.

[0030] The detection beam refers to a beam on which a piezoresistance element can be arranged, but does not necessarily have to be arranged. In other words, the detection beam can detect force or moment by arranging a piezoresistance element, but the sensor chip 100 may have a detection beam that does not have a piezoresistance element arranged thereon and is not used for detecting force or moment.

[0031] Specifically, detection block B 1 The T-shaped beam structure 131T 1 , 131T 2 , and 131T 3 In addition, detection block B 2 The T-shaped beam structure 132T 1 , 132T 2 , and 132T 3 In addition, detection block B 3 The T-shaped beam structure 133T 1 , 133T 2 , and 133T 3 In addition, detection block B 4 The T-shaped beam structure 134T 1 , 134T 2 , and 134T 3 The beam structure is described in more detail below.

[0032] Detection Block B 1 In plan view, a first detection beam 131a is provided parallel to the side of the support portion 101 on the support portion 104 side of the support portion 101 at a predetermined interval so as to bridge the side of the frame portion 111 closer to the support portion 101 and the side of the connecting portion 121 closer to the support portion 105. In addition, a second detection beam 131b is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 131a, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 131a toward the support portion 104 side. The first detection beam 131a and the second detection beam 131b form a T-shaped beam structure 131T. 1 It is formed.

[0033] In plan view, a first detection beam 131c is provided parallel to the side of the support portion 104 on the support portion 101 side at a predetermined interval so as to bridge the side of the frame portion 111 closer to the support portion 104 and the side of the connecting portion 124 closer to the support portion 105. In addition, a second detection beam 131d is provided which has one end connected to the center portion in the longitudinal direction of the first detection beam 131c and extends in a direction perpendicular to the longitudinal direction of the first detection beam 131c toward the support portion 101 side. The first detection beam 131c and the second detection beam 131d form a T-shaped beam structure 131T. 2 It is formed.

[0034] In plan view, a first detection beam 131e is provided parallel to the side of the support portion 105 on the frame portion 111 side at a predetermined interval so as to bridge the side of the connecting portion 121 closer to the support portion 105 and the side of the connecting portion 124 closer to the support portion 105. In addition, a second detection beam 131f is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 131e, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 131e toward the frame portion 111 side. The first detection beam 131e and the second detection beam 131f form a T-shaped beam structure 131T. 3 It is formed.

[0035] The other ends of the second detection beam 131b, the second detection beam 131d, and the second detection beam 131f are connected to each other to form a connection portion 141, and a force point 151 is provided on the lower surface side of the connection portion 141. The force point 151 is, for example, a square prism shape. 1 , 131T 2 , and 131T 3 The connection portion 141 and the force point 151 form a detection block B 1 It is composed of:

[0036] Detection Block B 1 In the detection block B, the first detection beam 131a, the first detection beam 131c, and the second detection beam 131f are parallel to each other, and the second detection beams 131b and 131d and the first detection beam 131e are parallel to each other. 1 The thickness of each of the detection beams can be, for example, about 30 μm to 50 μm.

[0037] Detection Block B 2 In plan view, a first detection beam 132a is provided parallel to the side of the support portion 102 on the support portion 101 side at a predetermined interval so as to bridge the side of the frame portion 112 closer to the support portion 102 and the side of the connecting portion 122 closer to the support portion 105. In addition, a second detection beam 132b is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 132a, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 132a toward the support portion 101 side. The first detection beam 132a and the second detection beam 132b form a T-shaped beam structure 132T.1 It is formed.

[0038] In plan view, a first detection beam 132c is provided parallel to the side of the support portion 101 on the support portion 102 side of the support portion 101 at a predetermined interval so as to bridge the side of the frame portion 112 closer to the support portion 101 and the side of the connecting portion 121 closer to the support portion 105. In addition, a second detection beam 132d is provided which has one end connected to the center portion in the longitudinal direction of the first detection beam 132c and extends in a direction perpendicular to the longitudinal direction of the first detection beam 132c toward the support portion 102 side. The first detection beam 132c and the second detection beam 132d form a T-shaped beam structure 132T. 2 It is formed.

[0039] In plan view, a first detection beam 132e is provided parallel to the side of the support portion 105 on the frame portion 112 side at a predetermined interval so as to bridge the side of the connecting portion 122 closer to the support portion 105 and the side of the connecting portion 121 closer to the support portion 105. In addition, a second detection beam 132f is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 132e, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 132e toward the frame portion 112 side. The first detection beam 132e and the second detection beam 132f form a T-shaped beam structure 132T. 3 It is formed.

[0040] The other ends of the second detection beam 132b, the second detection beam 132d, and the second detection beam 132f are connected to each other to form a connection portion 142, and a force point 152 is provided on the lower surface side of the connection portion 142. The force point 152 is, for example, a square prism shape. 1 , 132T 2 , and 132T 3 The connection portion 142 and the force point 152 form a detection block B 2 It is composed of:

[0041] Detection Block B 2 In the detection block B, the first detection beam 132a, the first detection beam 132c, and the second detection beam 132f are parallel to each other, and the second detection beams 132b and 132d and the first detection beam 132e are parallel to each other. 2The thickness of each of the detection beams can be, for example, about 30 μm to 50 μm.

[0042] Detection Block B 3 In plan view, a first detection beam 133a is provided parallel to the side of the support portion 103 on the support portion 102 side with a predetermined gap therebetween, so as to bridge the side of the frame portion 113 closer to the support portion 103 and the side of the connecting portion 123 closer to the support portion 105. In addition, a second detection beam 133b is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 133a, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 133a toward the support portion 102 side. The first detection beam 133a and the second detection beam 133b form a T-shaped beam structure 133T. 1 It is formed.

[0043] In plan view, a first detection beam 133c is provided parallel to the side of the support portion 102 on the support portion 103 side of the support portion 102 at a predetermined interval so as to bridge the side of the frame portion 113 closer to the support portion 102 and the side of the connecting portion 122 closer to the support portion 105. In addition, a second detection beam 133d is provided which has one end connected to the center portion in the longitudinal direction of the first detection beam 133c and extends in a direction perpendicular to the longitudinal direction of the first detection beam 133c toward the support portion 103 side. The first detection beam 133c and the second detection beam 133d form a T-shaped beam structure 133T. 2 It is formed.

[0044] In plan view, a first detection beam 133e is provided parallel to the side of the support portion 105 on the frame portion 113 side at a predetermined interval so as to bridge the side of the connecting portion 123 closer to the support portion 105 and the side of the connecting portion 122 closer to the support portion 105. In addition, a second detection beam 133f is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 133e, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 133e toward the frame portion 113 side. The first detection beam 133e and the second detection beam 133f form a T-shaped beam structure 133T. 3 It is formed.

[0045] The other ends of the second detection beam 133b, the second detection beam 133d, and the second detection beam 133f are connected to each other to form a connection portion 143, and a force point 153 is provided on the lower surface side of the connection portion 143. The force point 153 is, for example, a square prism shape. 1 , 133T 2 , and 133T 3 The connection portion 143 and the force point 153 form a detection block B 3 It is composed of:

[0046] Detection Block B 3 In the detection block B, the first detection beam 133a, the first detection beam 133c, and the second detection beam 133f are parallel to each other, and the second detection beams 133b and 133d are parallel to the first detection beam 133e. 3 The thickness of each of the detection beams can be, for example, about 30 μm to 50 μm.

[0047] Detection Block B 4 In plan view, a first detection beam 134a is provided parallel to the side of the support portion 104 on the support portion 103 side of the support portion 104 at a predetermined interval so as to bridge the side of the frame portion 114 closer to the support portion 104 and the side of the connecting portion 124 closer to the support portion 105. In addition, a second detection beam 134b is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 134a, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 134a toward the support portion 103 side. The first detection beam 134a and the second detection beam 134b form a T-shaped beam structure 134T. 1 It is formed.

[0048] In plan view, a first detection beam 134c is provided parallel to the side of the support portion 103 on the support portion 104 side of the support portion 103 at a predetermined interval so as to bridge the side of the frame portion 114 closer to the support portion 103 and the side of the connecting portion 123 closer to the support portion 105. In addition, a second detection beam 134d is provided which has one end connected to the center portion in the longitudinal direction of the first detection beam 134c and extends in a direction perpendicular to the longitudinal direction of the first detection beam 134c toward the support portion 104 side. The first detection beam 134c and the second detection beam 134d form a T-shaped beam structure 134T. 2 It is formed.

[0049] In plan view, a first detection beam 134e is provided parallel to the side of the support portion 105 on the frame portion 114 side at a predetermined interval so as to bridge the side of the connecting portion 124 closer to the support portion 105 and the side of the connecting portion 123 closer to the support portion 105. In addition, a second detection beam 134f is provided, one end of which is connected to the center portion in the longitudinal direction of the first detection beam 134e, and which extends in a direction perpendicular to the longitudinal direction of the first detection beam 134e toward the frame portion 114 side. The first detection beam 134e and the second detection beam 134f form a T-shaped beam structure 134T. 3 It is formed.

[0050] The other ends of the second detection beam 134b, the second detection beam 134d, and the second detection beam 134f are connected to each other to form a connection portion 144, and a force point 154 is provided on the lower surface side of the connection portion 144. The force point 154 is, for example, a square prism shape. 1 , 134T 2 , and 134T 3 The connection portion 144 and the force point 154 form a detection block B 4 It is composed of:

[0051] Detection Block B 4 In the detection block B, the first detection beam 134a, the first detection beam 134c, and the second detection beam 134f are parallel to each other, and the second detection beams 134b and 134d and the first detection beam 134e are parallel to each other. 4 The thickness of each of the detection beams can be, for example, about 30 μm to 50 μm.

[0052] In this way, the sensor chip 100 has four detection blocks (detection block B 1 ~B 4 ). Each detection block is disposed in an area surrounded by adjacent support parts among support parts 101 to 104, frame parts and connecting parts connecting to the adjacent support parts, and support part 105. In a plan view, each detection block can be disposed, for example, point-symmetrically with respect to the center of the sensor chip.

[0053] Each detection block has three T-shaped beam structures. In each detection block, the three T-shaped beam structures include, in a plan view, two T-shaped beam structures in which first detection beams are arranged in parallel with a connection portion therebetween, and one T-shaped beam structure including a first detection beam arranged in parallel with a second detection beam of the two T-shaped beam structures. The first detection beam of the one T-shaped beam structure is arranged between the connection portion and the support portion 105.

[0054] For example, detection block B 1 The three sets of T-shaped beam structures are, in plan view, a T-shaped beam structure 131T in which a first detection beam 131a and a first detection beam 131c are arranged in parallel with each other with a connection portion 141 interposed therebetween. 1 and 131T 2 and T-shaped beam structure 131T 1 and 131T 2 The T-shaped beam structure 131T includes a first detection beam 131e arranged parallel to the second detection beams 131b and 131d. 3 and T-beam structure 131T 3 The first detection beam 131e is disposed between the connection portion 141 and the support portion 105. Detection block B 2 ~B 4 has a similar structure.

[0055] The force points 151-154 are points to which an external force is applied, and can be formed, for example, from the BOX layer and support layer of an SOI substrate. The lower surfaces of the force points 151-154 are approximately flush with the lower surfaces of the support portions 101-105.

[0056] In this way, by inputting force or displacement from the four force points 151 to 154, different deformations of the beam can be obtained for each type of force, and a sensor with good six-axis separation can be realized. The number of force points is the same as the number of displacement input points of the combined strain generating body.

[0057] In the sensor chip 100, from the viewpoint of suppressing stress concentration, it is preferable that the portions forming the interior angles have an R-shape.

[0058] Supporting parts 101-105 of sensor chip 100 are connected to the non-movable parts of flexure body 200, and force points 151-154 are connected to the movable parts of flexure body 200. However, even if the relationship between movable and non-movable is reversed, it still functions as a force sensor device. In other words, supporting parts 101-105 of sensor chip 100 may be connected to the movable parts of flexure body 200, and force points 151-154 may be connected to the non-movable parts of flexure body 200.

[0059] Fig. 9 is a diagram explaining the symbols indicating the forces and moments acting on each axis. As shown in Fig. 9, the force in the X-axis direction is Fx, the force in the Y-axis direction is Fy, and the force in the Z-axis direction is Fz. Also, the moment of rotation about the X-axis is Mx, the moment of rotation about the Y-axis is My, and the moment of rotation about the Z-axis is Mz.

[0060] Fig. 10 is a diagram illustrating an example of the arrangement of piezoresistance elements of the sensor chip 100. Fig. 11 is a partial enlarged view of a set of detection blocks of the sensor chip shown in Fig. 10. As shown in Figs. 10 and 11, piezoresistance elements are arranged at predetermined positions of each detection block corresponding to four force points 151 to 154. The arrangement of the piezoresistance elements in the other detection blocks shown in Fig. 10 is similar to the arrangement of the piezoresistance elements in one detection block shown in Fig. 11.

[0061] 5 to 8, 10, and 11, a detection block B having a connection portion 141 and a force point 151 is 1 In the figure, the piezoresistive element MzR1' is disposed on the first detection beam 131a on a side closer to the second detection beam 131b in a portion located between the second detection beam 131b and the first detection beam 131e. The piezoresistive element FxR3 is disposed on the first detection beam 131a on a side closer to the first detection beam 131e in a portion located between the second detection beam 131b and the first detection beam 131e. The piezoresistive element MxR1 is disposed on a side closer to the connection portion 141 in the second detection beam 131b.

[0062] In addition, the piezoresistive element MzR2' is disposed on the first detection beam 131c on a side closer to the second detection beam 131d in a portion located between the second detection beam 131d and the first detection beam 131e. The piezoresistive element FxR1 is disposed on the first detection beam 131c on a side closer to the first detection beam 131e in a portion located between the second detection beam 131d and the first detection beam 131e. The piezoresistive element MxR2 is disposed on the second detection beam 131d on a side closer to the connection portion 141.

[0063] Moreover, the piezoresistive element FzR1' is disposed on a side of the second detection beam 131f closer to the connection portion 141. The piezoresistive element FzR2' is disposed on a side of the second detection beam 131f closer to the first detection beam 131e. Note that the piezoresistive elements MzR1', FxR3, MxR1, MzR2', FxR1, and MxR2 are disposed at positions offset from the longitudinal center of each detection beam.

[0064] Sensing block B having connection portion 142 and force point 152 2 In the figure, the piezoresistive element MzR4 is disposed on the first detection beam 132a on a side closer to the second detection beam 132b in a portion located between the second detection beam 132b and the first detection beam 132e. The piezoresistive element FyR3 is disposed on the first detection beam 132a on a side closer to the first detection beam 132e in a portion located between the second detection beam 132b and the first detection beam 132e. The piezoresistive element MyR4 is disposed on the second detection beam 132b on a side closer to the connection portion 142.

[0065] The piezoresistive element MzR3 is disposed on the first detection beam 132c on a side closer to the second detection beam 132d in a portion located between the second detection beam 132d and the first detection beam 132e. The piezoresistive element FyR1 is disposed on the first detection beam 132c on a side closer to the first detection beam 132e in a portion located between the second detection beam 132d and the first detection beam 132e. The piezoresistive element MyR3 is disposed on the second detection beam 132d on a side closer to the connection portion 142.

[0066] Furthermore, the piezoresistive element FzR4 is disposed on the second detection beam 132f on a side closer to the connection portion 142. The piezoresistive element FzR3 is disposed on the second detection beam 132f on a side closer to the first detection beam 132e. Note that the piezoresistive elements MzR4, FyR3, MyR4, MzR3, FyR1, and MyR3 are disposed at positions offset from the longitudinal center of each detection beam.

[0067] Sensing block B having connecting portion 143 and force point 153 3 In the figure, the piezoresistive element MzR4' is disposed on the first detection beam 133a on a side closer to the second detection beam 133b in a portion located between the second detection beam 133b and the first detection beam 133e. The piezoresistive element FxR2 is disposed on the first detection beam 133a on a side closer to the first detection beam 133e in a portion located between the second detection beam 133b and the first detection beam 133e. The piezoresistive element MxR4 is disposed on the second detection beam 133b on a side closer to the connection portion 143.

[0068] The piezoresistive element MzR3' is disposed on the first detection beam 133c on a side closer to the second detection beam 133d in a portion located between the second detection beam 133d and the first detection beam 133e. The piezoresistive element FxR4 is disposed on the first detection beam 133c on a side closer to the first detection beam 133e in a portion located between the second detection beam 133d and the first detection beam 133e. The piezoresistive element MxR3 is disposed on the second detection beam 133d on a side closer to the connection portion 143.

[0069] Moreover, the piezoresistive element FzR4' is disposed on the second detection beam 133f on a side closer to the connection portion 143. The piezoresistive element FzR3' is disposed on the second detection beam 133f on a side closer to the first detection beam 133e. Note that the piezoresistive elements MzR4', FxR2, MxR4, MzR3', FxR4, and MxR3 are disposed at positions offset from the longitudinal center of each detection beam.

[0070] Sensing block B having connection portion 144 and force point 154 4 In the figure, the piezoresistive element MzR1 is disposed on the first detection beam 134a on a side closer to the second detection beam 134b in a portion located between the second detection beam 134b and the first detection beam 134e. The piezoresistive element FyR2 is disposed on the first detection beam 134a on a side closer to the first detection beam 134e in a portion located between the second detection beam 134b and the first detection beam 134e. The piezoresistive element MyR1 is disposed on the second detection beam 134b on a side closer to the connection portion 144.

[0071] The piezoresistive element MzR2 is disposed on the first detection beam 134c on a side closer to the second detection beam 134d in a portion located between the second detection beam 134d and the first detection beam 134e. The piezoresistive element FyR4 is disposed on the first detection beam 134c on a side closer to the first detection beam 134e in a portion located between the second detection beam 134d and the first detection beam 134e. The piezoresistive element MyR2 is disposed on the second detection beam 134d on a side closer to the connection portion 144.

[0072] Moreover, the piezoresistive element FzR1 is disposed on a side of the second detection beam 134f closer to the connection portion 144. The piezoresistive element FzR2 is disposed on a side of the second detection beam 134f closer to the first detection beam 134e. The piezoresistive elements MzR1, FyR2, MyR1, MzR2, FyR4, and MyR2 are disposed at positions offset from the longitudinal center of each detection beam.

[0073] In this way, multiple piezoresistance elements are arranged separately in each detection block in the sensor chip 100. This makes it possible to detect forces or moments in predetermined axial directions along up to six axes based on changes in output of multiple piezoresistance elements arranged on predetermined beams in response to inputs applied to the force points 151 to 154.

[0074] In addition to the piezoresistance elements used for detecting strain, dummy piezoresistance elements may be arranged in the sensor chip 100. The dummy piezoresistance elements are used to adjust the balance of the stress applied to the detection beam and the resistance of the bridge circuit. For example, all the piezoresistance elements including the piezoresistance elements used for detecting strain are arranged so as to be point-symmetric with respect to the center of the support part 105.

[0075] In the sensor chip 100, a plurality of piezoresistance elements for detecting displacement in the X-axis direction and the Y-axis direction are arranged on a first detection beam constituting a T-shaped beam structure. A plurality of piezoresistance elements for detecting displacement in the Z-axis direction are arranged on a second detection beam constituting the T-shaped beam structure. A plurality of piezoresistance elements for detecting moment in the Z-axis direction are arranged on the first detection beam constituting the T-shaped beam structure. A plurality of piezoresistance elements for detecting moment in the X-axis direction and the Y-axis direction are arranged on the second detection beam constituting the T-shaped beam structure.

[0076] Here, the piezoresistive elements FxR1-FxR4 detect a force Fx, the piezoresistive elements FyR1-FyR4 detect a force Fy, the piezoresistive elements FzR1-FzR4 and FzR1'-FzR4' detect a force Fz, the piezoresistive elements MxR1-MxR4 detect a moment Mx, the piezoresistive elements MyR1-MyR4 detect a moment My, and the piezoresistive elements MzR1-MzR4 and MzR1'-MzR4' detect a moment Mz.

[0077] In this way, in the sensor chip 100, a plurality of piezoresistance elements are arranged separately in each detection block. This makes it possible to detect a displacement in a predetermined axial direction in up to six axes based on a change in output of a plurality of piezoresistance elements arranged in a predetermined beam according to the direction (axial direction) of the force or displacement applied (transmitted) to the force points 151 to 154. In addition, by varying the thickness and width of each detection beam, it is possible to make the detection sensitivity uniform or to adjust the detection sensitivity to be improved.

[0078] It is also possible to reduce the number of piezoresistance elements and form a sensor chip that detects displacement in five or fewer predetermined axial directions.

[0079] In the sensor chip 100, the force and moment can be detected, for example, by using a detection circuit described below. An example of a detection circuit using each piezoresistance element is shown in Fig. 12 and Fig. 13. In Fig. 12 and Fig. 13, the numbers enclosed in squares indicate external output terminals. For example, No. 1 is a power supply terminal for the Fx-axis, Fy-axis, and Fz-axis, No. 2 is a negative Fx-axis output terminal, No. 3 is a GND terminal for the Fx-axis, and No. 4 is a positive Fx-axis output terminal. No. 19 is a negative Fy-axis output terminal, No. 20 is a GND terminal for the Fy-axis, and No. 21 is a positive Fy-axis output terminal. No. 22 is a negative Fz-axis output terminal, No. 23 is a GND terminal for the Fz-axis, and No. 24 is a positive Fz-axis output terminal.

[0080] Additionally, No. 9 is the Mx-axis output negative terminal, No. 10 is the Mx-axis GND terminal, and No. 11 is the Mx-axis output positive terminal. No. 12 is the power supply terminal for the Mx, My, and Mz axes. No. 13 is the My-axis output negative terminal, No. 14 is the My-axis GND terminal, and No. 15 is the My-axis output positive terminal. No. 16 is the Mz-axis output negative terminal, No. 17 is the Mz-axis GND terminal, and No. 18 is the Mz-axis output positive terminal.

[0081] Next, the deformation of the detection beam will be described. FIG. 14 is a diagram for explaining the Fx input. FIG. 15 is a diagram for explaining the Fy input. As shown in FIG. 14, when the input from the flexure body 200 on which the sensor chip 100 is mounted is Fx, all of the four force points 151 to 154 tend to move in the same direction (rightward in the example of FIG. 14). Similarly, as shown in FIG. 15, when the input from the flexure body 200 on which the sensor chip 100 is mounted is Fy, all of the four force points 151 to 154 tend to move in the same direction (upward in the example of FIG. 15). That is, although there are four detection blocks in the sensor chip 100, in each detection block, all of the force points move in the same direction in response to displacement in the X-axis direction and displacement in the Y-axis direction.

[0082] In the sensor chip 100, the first detection beams of the T-shaped beam structure have one or more first detection beams perpendicular to the input displacement direction, and the first detection beams perpendicular to the input displacement direction can accommodate large deformation.

[0083] The beams used to detect the Fx input are first detection beams 131a, 131c, 133a, and 133c, all of which are first detection beams with a T-shaped beam structure located a certain distance away from the point of force. The beams used to detect the Fy input are first detection beams 132a, 132c, 134a, and 134c, all of which are first detection beams with a T-shaped beam structure located a certain distance away from the point of force.

[0084] In the case of the Fx input and the Fy input, the first detection beam of the T-shaped beam structure in which the piezoresistance element is arranged is largely deformed, so that the input force can be effectively detected. Also, since the beams not used for input detection are designed to be largely deformable following the displacement of the Fx input and the Fy input, the detection beam will not be destroyed even if there is a large Fx input and / or Fy input.

[0085] In addition, in the conventional sensor chip, since there is a beam that cannot be significantly deformed in response to the Fx input and / or Fy input, there is a risk that the detection beam that cannot be deformed will be destroyed in the case of a large Fx input and / or Fy input. The sensor chip 100 can suppress such a problem. That is, the sensor chip 100 can improve the destruction resistance of the beam against displacement in various directions.

[0086] In this way, the sensor chip 100 has one or more first detection beams perpendicular to the displacement direction of the input, and the first detection beams perpendicular to the displacement direction of the input can be greatly deformed. Therefore, the Fx input and the Fy input can be effectively detected, and the detection beams are not broken even if there is a large Fx input and / or Fy input. As a result, the sensor chip 100 can also handle a large rating, and the measurement range and load resistance can be improved. For example, the sensor chip 100 can have a rating of 500 N, which is about 10 times that of the conventional sensor chip.

[0087] In addition, the T-shaped beam structure in each detection block, which is connected in three directions from the force point, deforms differently depending on the input, making it possible to detect multi-axial forces with good separation.

[0088] In addition, because the beam is T-shaped, there are many paths from the beam to the frame and connecting parts, making it easy to route wiring to the outer periphery of the sensor chip, improving layout freedom.

[0089] In the sensor chip 100, the first detection beams 131a, 131c, 132a, 132c, 133a, 133c, 134a, and 134c arranged opposite each force point are significantly deformed by the moment in the Z-axis direction. Therefore, piezoresistance elements can be arranged on some or all of these first detection beams.

[0090] In response to the displacement in the Z-axis direction, the second detection beams 131b, 131d, 131f, 132b, 132d, 132f, 133b, 133d, 133f, 134b, 134d, and 134f directly connected to the respective force points are largely deformed. Therefore, piezoresistance elements can be disposed on some or all of these second detection beams.

[0091] (Strain body 200) 1 and 2, the strain generating body 200 has a force receiving plate 210, a strain generating portion 220, an input transmitting portion 230, and a cover plate 240. Here, each component of the strain generating body 200 will be described.

[0092] Fig. 16 is a perspective view illustrating a force receiving plate constituting a strain generating body. As shown in Fig. 16, the force receiving plate 210 is a member having a substantially disk shape overall, and is a member to which a force or moment is input from an object to be measured. The force receiving plate 210 has an outer frame portion 211 having a substantially ring shape in a plan view, a central portion 212 having a substantially circular shape in a plan view that is spaced apart from the outer frame portion 211 and disposed inside the outer frame portion 211, and a plurality of beam structures 213 that bridge the outer frame portion 211 and the central portion 212.

[0093] By improving the rigidity of force receiving plate 210 with beam structure 213, even when a force or moment is input from the object to be measured, force receiving plate 210 itself undergoes almost no deformation, and the force or moment is transmitted without loss to strain generating part 220 connected at central part 212. Screw holes 218 are provided in the part protruding from the inside of outer frame part 211 towards beam structure 213. Screw holes 218 are, for example, fastening holes that can be used when fastening force receiving plate 210 to the object to be measured with screws.

[0094] Fig. 17 is a perspective view illustrating a strain-generating portion constituting the strain body. Fig. 18 is a plan view illustrating a strain-generating portion constituting the strain body. As shown in Figs. 17 and 18, the strain-generating portion 220 is a generally disk-shaped member, and is a portion that deforms when it receives a force from the force-receiving plate 210.

[0095] The strain-flexing part 220 has an outer frame part 221 that is substantially ring-shaped in a plan view, a central part 222 that is substantially circular in a plan view and disposed inside the outer frame part 221 and spaced apart from the outer frame part 221, and a plurality of beam structures 223 that bridge the outer frame part 221 and the central part 222. The outer diameter of the outer frame part 221 is, for example, about 50 mm. The thickness of the beam structure 223 is, for example, about 3 mm to 8 mm.

[0096] The multiple beam structures 223 are arranged, for example, point-symmetrically with respect to the center of the strain-flexing portion 220. There are, for example, four beam structures 223. Each beam structure 223 is, for example, T-shaped including a first beam 223a and a second beam 223b extending from a central portion of the first beam 223a in a direction perpendicular to the first beam 223a. Both ends of the first beam 223a are connected to the outer frame portion 221, and an end of the second beam 223b is connected to the central portion 222. For example, in a plan view, the strain-flexing portion 220 is four-fold symmetric with respect to the center of the outer frame portion 221.

[0097] The central portion 222 is formed thinner than the outer frame portion 221, and the beam structure 223 is formed even thinner than the central portion 222. The upper surface of the central portion 222 and the upper surface of the beam structure 223 are substantially flush with each other and are located lower than the upper surface of the outer frame portion 221. The lower surface of the central portion 222 protrudes slightly from the lower surface of the outer frame portion 221. The lower surface of the beam structure 223 is located higher than the lower surface of the outer frame portion 221 and the lower surface of the central portion 222. Only the beam structure 223 and the central portion 222 are deformed by receiving a force from the force receiving plate 210, and the outer frame portion 221 is not deformed. However, the central portion 222 only moves following the deformation of the beam structure 223, and the central portion 222 itself is not deformed.

[0098] A groove 220x is formed on the surface of the central portion 222 facing the input transmission portion 230. The groove 220x has a shape in which a square groove in a plan view and a cross-shaped groove in which two elongated grooves longer than one side of the square intersect at right angles are overlapped with their centers aligned. The square groove in a plan view and the cross-shaped groove in a plan view have the same depth.

[0099] Outside the cross-shaped groove, at the four corners of the square groove and at the center of the square groove, five columnar first connection parts 224 protruding toward the input transmission part 230 are arranged so as not to come into contact with the inner wall of the groove 220x. The first connection parts 224 are parts that are connected to the support parts 101 to 105 of the sensor chip 100. The upper surface of each of the first connection parts 224 is substantially flush with the surface, and is located lower than the upper surface of the central part 222 and the upper surface of the beam structure 223.

[0100] The outer frame portion 221 is provided with screw holes 228. The screw holes 228 are fastening holes that can be used, for example, when fastening the strain-flexing portion 220, the input transmission portion 230, and the cover plate 240 to a fixed side (the side of a robot or the like) with screws. In the example of Fig. 17 and Fig. 18, four screw holes 228 that are circular in plan view are provided. The size of the screw holes 228 is, for example, JIS standard M5.

[0101] A space 229 is provided outside each screw hole 228 of the outer frame portion 221 and separated from the screw hole 228. The space 229 can be provided, for example, in an arc shape so as to surround a part of the screw hole 228 in a plan view. The space 229 is disposed so that an opening side of the arc faces the outer periphery of the outer frame portion 221 in a plan view. In other words, in the space 229, the apex of the arc is located closer to the center of the outer frame portion 221 than both ends of the arc.

[0102] Each screw hole 228 is disposed between adjacent beam structures 223 in plan view. In plan view, the space 229 is provided at least between the screw hole 228 and the beam structures 223 adjacent to both sides of the screw hole 228. The space 229 preferably penetrates the outer frame portion 221, but does not have to penetrate the outer frame portion 221. The width of the space 229 is approximately constant, for example, 0.5 mm to 1.5 mm. Note that the width of the space 229 does not have to be constant, and the width of both ends of the arc of the space 229 may be widened to 0.5 mm to 1.5 mm, and the distance from one end of the arc to the other end may be narrowed to, for example, 0.2 mm.

[0103] In this manner, in the strain-generating body 200, a space 229 is provided in the strain-generating portion 220 between the screw hole 228 and the beam structure 223 adjacent to both sides of the screw hole 228. This makes it possible to make it difficult for the force generated when fastening the strain-generating body 200 to the object to be measured with a screw to be transmitted to the center portion 222 side, and even if the force is transmitted, the inside of the center portion 222 tends to maintain the same shape and to cause the same overall displacement. Furthermore, when the strain-generating body 200 is attached to the object to be measured, if a temperature distribution occurs in the strain-generating body 200 due to the effect of heat generated by the object to be measured, deformation on the center portion 222 side can be suppressed.

[0104] Therefore, it is possible to suppress the displacement of the first connection parts 224 connected to the support parts 101 to 105 of the sensor chip 100, and to equalize the displacement of the five first connection parts 224. As a result, it is possible to reduce adverse effects on the load resistance, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0105] 18, the four screw holes 228 include two screw holes 228 that face each other across the center of the outer frame portion 221 in a plan view, and two other screw holes 228 that face each other across the center of the outer frame portion 221. A virtual straight line L that connects the centers of the two screw holes 228 that face each other across the center of the outer frame portion 221 in a plan view 1 and an imaginary straight line L connecting the centers of the other two screw holes 228 that face each other across the center of the outer frame portion 221. 2 are perpendicular to each other to form an imaginary crosshair.

[0106] Further, the four beam structures 223 include two beam structures 223 that face each other across the center of the outer frame portion 221 in a plan view, and two other beam structures 223 that face each other across the center of the outer frame portion 221 in a plan view. A virtual straight line L connecting the center lines in the width direction of the two beam structures 223 that face each other across the center of the outer frame portion 221 in a plan view 3 and an imaginary straight line L connecting the center lines in the width direction of two other beam structures 223 that face each other across the center of the outer frame portion 221. 4 are perpendicular to each other to form an imaginary crosshair.

[0107] That is, two beam structures 223 facing each other across the center of outer frame portion 221 and other two beam structures 223 facing each other across the center of outer frame portion 221 form a beam that is generally cross-shaped in plan view.

[0108] In plan view, straight line L 1 and L 2 The crosshairs formed by and the straight line L 3 and L 4 It is preferable that the cross lines formed by the beam structures 223 are shifted by 45 degrees from each other. That is, it is preferable that each beam structure 223 is provided in the middle of the adjacent screw holes 228. Note that, taking into consideration manufacturing variations and the like, the "45 degrees" mentioned here includes a range of 45 degrees ±5 degrees.

[0109] In the outer frame portion 221, the intermediate portions between adjacent screw holes 228 are the furthest from each screw hole 228, and are therefore the least likely to deform. Therefore, by extending the beam structure 223 from the intermediate portions between adjacent screw holes 228, it is possible to make it difficult for the force generated when fastening the flexure body 200 to the object to be measured with screws to be transmitted to the center portion 222 side, and even if the force is transmitted, it is easy for the same overall displacement to occur while the inside of the center portion 222 maintains the same shape. Furthermore, when the flexure body 200 is attached to the object to be measured, if a temperature distribution occurs in the flexure body 200 due to the effect of heat generated by the object to be measured, deformation on the center portion 222 side can be suppressed.

[0110] As a result, as described above, it is possible to reduce adverse effects on the load-bearing capacity, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0111] In addition, since a space is provided on the upper surface side of the central portion 222, a circuit board or the like on which electronic components such as connectors and semiconductor elements are mounted may be placed on the upper surface side of the central portion 222 so as not to protrude from the upper surface of the outer frame portion 221.

[0112] Fig. 19 is a perspective view of the upper surface side illustrating an input transmission section constituting the flexure body. Fig. 20 is a plan view illustrating an input transmission section constituting the flexure body. Fig. 21 is a perspective view of the lower surface side illustrating an input transmission section constituting the flexure body. Fig. 22 is a cross-sectional view illustrating an input transmission section constituting the flexure body, and is a cross-sectional view of L in Fig. 20. 7 19 to 22, the input transmission section 230 is a generally disk-shaped member, and is a section that transmits the deformation (input) of the strain-flexing section 220 to the sensor chip 100. As shown in FIG.

[0113] The input transmission section 230 has an outer frame section 231 that is substantially ring-shaped in a planar view, a central section 232 that is spaced apart from the outer frame section 231 and disposed inside the outer frame section 231, and a plurality of beam structures 233 that bridge the outer frame section 231 and the central section 232. The outer diameter of the outer frame section 231 is, for example, about 50 mm. The plurality of beam structures 233 are, for example, disposed point-symmetrically with respect to the center of the input transmission section 230. The number of beam structures 233 is, for example, four. Each beam structure 233 is, for example, I-shaped. The beam structure 233 of the input transmission section 230 and the beam structure 223 of the strain-flexing section 220 at least partially overlap with each other in a planar view.

[0114] The outer frame portion 231 is formed thicker than the other portions and has high rigidity, and is therefore the least likely to deform. The central portion 232 has a first connecting portion 234 that is substantially ring-shaped in a plan view, and a substantially cross-shaped housing portion 235 that extends from the lower surface of the first connecting portion 234 toward the strain-generating portion 220. The housing portion 235 is provided inside the first connecting portion 234 and is capable of housing the sensor chip 100. One end of each of the beam structures 233 is connected to the outer frame portion 231, and the other ends extend inward from the outer frame portion 231 and are connected to each other by the frame-shaped first connecting portion 234.

[0115] In this way, by connecting the beam structures 233 extending from the four directions of the input transmission section 230 with the first connecting section 234, the rigidity of the accommodation section 235 can be increased. This makes it possible to make it difficult for the force generated when the flexure body 200 is fastened to the object to be measured with screws to be transmitted to the first connecting section 234 side, and even if the force is transmitted, the inside of the first connecting section 234 tends to maintain the same shape and to cause the same overall displacement. Furthermore, when the flexure body 200 is attached to the object to be measured, if a temperature distribution occurs in the flexure body 200 due to the effect of heat generated by the object to be measured, deformation on the first connecting section 234 side can be suppressed.

[0116] Therefore, it is possible to suppress and equalize the displacement of the four second connection parts 235d connected to the force points 151 to 154 of the sensor chip 100. As a result, it is possible to reduce adverse effects on the load resistance, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and the temperature distribution of the strain body 200.

[0117] Beam structure 233 and first connecting portion 234 are formed thinner than outer frame portion 231. The upper surfaces of beam structure 233 and first connecting portion 234 are located lower than the upper surface of outer frame portion 231. The lower surface of outer frame portion 231, the lower surface of beam structure 233, and the lower surface of first connecting portion 234 are approximately flush with each other. None of the parts of input transmission portion 230 are deformed by the force or moment they receive.

[0118] Each beam structure 233 preferably has a countersunk portion 233a that makes the thickness of one end connected to the outer frame portion 231 thinner than the thickness of the other end connected to the first connecting portion 234. The countersunk portion 233a is preferably provided over the entire width of the beam structure 233 on the side closer to the outer frame portion 231 than the first connecting portion 234 side. 1 The thickness T of the beam structure 233 on the side of the central portion 232 is, for example, about 1.5 mm. 1 may be the same as the thickness of the first connecting portion 234.

[0119] Thickness of the counterbore 233a (thickness on one end of the beam structure 233) T 2 For example, the thickness of the countersunk portion 233a is thicker than 1 mm and thinner than 1.25 mm. That is, the depth of the countersunk portion 233a based on the top surface of the beam structure 233 is, for example, about 0.25 mm to 0.5 mm. The length of the beam structure 233 in the longitudinal direction is, for example, about 8 mm, and the width is, for example, about 4 mm. The length of the countersunk portion 233a is, for example, about 5 mm.

[0120] Since the beam structure 233 has the countersunk portion 233a, even if the outer frame portion 231 side is deformed when the flexure body 200 is fastened to the object to be measured with a screw, the countersunk portion 233a of the beam structure 233 absorbs the deformation of the outer frame portion 231 side. Therefore, the force generated when the flexure body 200 is fastened to the object to be measured with a screw can be made less likely to be transmitted to the first connecting portion 234 side, and even if the force is transmitted, the inside of the first connecting portion 234 tends to maintain the same shape and to cause the same overall deformation. Furthermore, if a temperature distribution occurs in the flexure body 200 due to the heat generated by the object to be measured when the flexure body 200 is attached to the object to be measured, deformation on the first connecting portion 234 side can be suppressed.

[0121] As a result, as described above, it is possible to reduce adverse effects on the load-bearing capacity, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0122] It is preferable that a corner 233b of the countersunk portion 233a on the outer frame portion 231 side is rounded in cross section. It is also preferable that a corner 233c of the countersunk portion 233a on the first connecting portion 234 side is rounded in cross section.

[0123] This makes it possible to further suppress the displacement of the four second connection parts 235d connected to the force points 151 to 154 of the sensor chip 100, and to further uniformize the displacement of the four second connection parts 235d. As a result, it is possible to further reduce adverse effects on the load resistance, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0124] The accommodation section 235 is provided inside the first connecting section 234. The accommodation section 235 has one end connected to the first connecting section 234, and has four vertical support sections 235a extending vertically from the lower surface of the first connecting section 234 toward the strain-flexing section 220, four horizontal support sections 235b extending horizontally from the lower end sections of the vertical support sections 235a, and second connecting sections 235c connecting the other ends of the horizontal support sections 235b to each other.

[0125] That is, the tip sides of the four horizontal support parts 235b are connected by the second connecting part 235c. The lower surface of the second connecting part 235c is substantially flush with the lower surfaces of the horizontal support parts 235b, and the upper surface is one step lower and thinner than the horizontal support parts 235b. A through hole may be provided in the center of the second connecting part 235c.

[0126] Four second connection parts 235d protruding toward the cover plate 240 are disposed on the bottom surface of the second coupling part 235c so as not to come into contact with the inner wall of the second coupling part 235c. Each second connection part 235d is located approximately on a line that bisects each horizontal support part 235b in the longitudinal direction. The second connection parts 235d are portions that are connected to the force points 151 to 154 of the sensor chip 100.

[0127] The tip sides of the four horizontal support parts 235b may be separated. In this case, by connecting the other ends of the beam structures 233 to each other with the first connecting parts 234, it is possible to make it difficult for the force generated when the flexure body 200 is fastened to the object to be measured with screws to be transmitted to the first connecting parts 234 side, and even if the force is transmitted, the inside of the first connecting parts 234 tends to maintain the same shape and to cause the same overall displacement. In addition, when the flexure body 200 is attached to the object to be measured, if a temperature distribution occurs in the flexure body 200 due to the effect of heat generated by the object to be measured, deformation on the first connecting parts 234 side can be suppressed.

[0128] As a result, as described above, it is possible to reduce adverse effects on the load-bearing capacity, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0129] However, it is preferable to connect the horizontal support parts 235b extending from the four directions with the second connecting parts 235c. This can further suppress the displacement of the four second connecting parts 235d connected to the force points 151 to 154 of the sensor chip 100, and can further uniformize the displacement of the four second connecting parts 235d. As a result, it is possible to further reduce adverse effects on the load resistance, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with screws and the temperature distribution of the strain body 200.

[0130] The outer frame portion 231 is provided with screw holes 238. The screw holes 238 are fastening holes that can be used, for example, when fastening the strain-flexing portion 220, the input transmission portion 230, and the cover plate 240 to a fixed side (the side of a robot or the like) with screws. In the example of Figs. 19 to 22, four screw holes 238 that are circular in plan view are provided. The size of the screw holes 238 is, for example, JIS standard M5.

[0131] A space 239 is provided outside each screw hole 238 of the outer frame portion 231, separated from the screw hole 238. In the space 239, a part of the upper surface side of the outer frame portion 231 communicates with a thin plate portion 231x formed thinner than the outer periphery side of the outer frame portion 231. The upper surface of the thin plate portion 231x and the upper surface of the first connecting portion 234 are substantially flush with each other. By providing the thin plate portion 231x, a large space can be formed, making it possible to arrange components such as a board.

[0132] Space portion 239 can be provided, for example, in an arc shape in a plan view so as to surround a part of screw hole 238. Space portion 239 is disposed in a plan view so that an opening side of the arc faces the outer periphery of outer frame portion 231. In other words, in space portion 239, the apex of the arc is located closer to the center of outer frame portion 231 than both ends of the arc.

[0133] Each screw hole 238 is disposed between adjacent beam structures 233 in plan view. In plan view, the space 239 is provided at least between the screw hole 238 and the beam structures 233 adjacent to both sides of the screw hole 238. The space 239 preferably penetrates the outer frame portion 231, but does not have to penetrate the outer frame portion 231. The width of the space 239 is approximately constant, for example, 0.5 mm to 1.5 mm. Note that the width of the space 239 does not have to be constant, and the width of both ends of the arc of the space 239 may be widened to 0.5 mm to 1.5 mm, and the distance from one end of the arc to the other end may be narrowed to, for example, 0.2 mm.

[0134] Each screw hole 238 and each screw hole 228 are provided so as to overlap in a plan view, and each space portion 239 and each space portion 229 are provided so as to overlap in a plan view.

[0135] In this manner, in the input transmission section 230 of the flexure body 200, a space 239 is provided between the screw hole 238 and the beam structure 233 adjacent to both sides of the screw hole 238. This makes it possible to make it difficult for the force generated when the flexure body 200 is fastened to the object to be measured with a screw to be transmitted to the first connecting section 234 side, and even if the force is transmitted, the inside of the first connecting section 234 tends to maintain the same shape and to cause the same overall displacement. Furthermore, when the flexure body 200 is attached to the object to be measured, if a temperature distribution occurs in the flexure body 200 due to the effect of heat generated by the object to be measured, deformation on the side of the central section 222 can be suppressed.

[0136] As a result, as described above, it is possible to reduce adverse effects on the load-bearing capacity, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0137] As shown in FIG. 20, the four screw holes 238 include two screw holes 238 that face each other across the center of the outer frame portion 231 in a plan view, and two other screw holes 238 that face each other across the center of the outer frame portion 231.

[0138] In a plan view, a virtual straight line L connecting the centers of two screw holes 238 facing each other across the center of the outer frame portion 231 5 and an imaginary straight line L connecting the centers of the other two screw holes 238 that face each other across the center of the outer frame portion 231. 6 are perpendicular to each other to form an imaginary crosshair.

[0139] Further, the four beam structures 233 include two beam structures 233 opposing each other across the center of the outer frame portion 231, and other two beam structures 233 opposing each other across the center of the outer frame portion 231, in a plan view.

[0140] In a plan view, a virtual straight line L connecting the center lines in the width direction of two beam structures 233 facing each other across the center of the outer frame portion 231 7 and an imaginary straight line L connecting the center lines in the width direction of two other beam structures 233 that face each other across the center of the outer frame portion 231. 8 are perpendicular to each other to form an imaginary crosshair.

[0141] That is, two beam structures 233 facing each other across the center of outer frame portion 231 and the other two beam structures 233 facing each other across the center of outer frame portion 231 form a beam that is generally cross-shaped in plan view.

[0142] In plan view, straight line L 5 and L 6 The crosshairs formed by and the straight line L 7 and L 8 It is preferable that the cross lines formed by the beam structures 233 are shifted by 45 degrees from each other. That is, it is preferable that each beam structure 233 is provided in the middle of the adjacent screw holes 238. Note that, taking into consideration manufacturing variations and the like, the 45 degrees mentioned here includes a range of 45 degrees ±5 degrees.

[0143] As described above, the outer frame portion 231 has higher rigidity than other portions, but the intermediate portions of the adjacent screw holes 238 in the outer frame portion 231 are the furthest from the respective screw holes 238 and are therefore the least likely to deform. Therefore, by extending the beam structure 233 from the intermediate portions of the adjacent screw holes 238, it is possible to make it difficult for the force generated when the flexure body 200 is fastened to the object to be measured with screws to be transmitted to the first connecting portion 234 side, and even if the force is transmitted, the inside of the first connecting portion 234 tends to maintain the same shape and to undergo the same overall displacement. In addition, when the flexure body 200 is attached to the object to be measured and a temperature distribution occurs in the flexure body 200 due to the effect of heat generated by the object to be measured, deformation on the first connecting portion 234 side can be suppressed.

[0144] As a result, as described above, it is possible to reduce adverse effects on the load-bearing capacity, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0145] In addition, in plan view, the straight line L 5 and L 6 The crosshairs formed by the line L 1 and L 2 Also, in plan view, the straight line L 7 and L 8 The crosshairs formed by the line L 3 and L 4 overlaps with the crosshairs formed by the arrows (see Figure 18).

[0146] In the storage section 235, in a plan view, two vertical support sections 235a and horizontal support sections 235b face each other across the center of the outer frame section 231, and the other two vertical support sections 235a and horizontal support sections 235b face each other across the center of the outer frame section 231.

[0147] In a plan view, a virtual line connecting the center lines in the width direction of the two vertical support parts 235a and the two horizontal support parts 235b facing each other across the center of the outer frame part 231 is a line L. 5In addition, in a plan view, a virtual line connecting the center lines of the other two vertical support parts 235a and the horizontal support part 235b that face each other across the center of the outer frame part 231 is a line L 5 A straight line L perpendicular to 6 Matches.

[0148] In other words, the two vertical support portions 235a and the horizontal support portion 235b that face each other across the center of the outer frame portion 231, and the other two vertical support portions 235a and the horizontal support portion 235b that face each other across the center of the outer frame portion 231, form a beam that is approximately cross-shaped when viewed in a plane.

[0149] As mentioned above, in plan view, the straight line L 5 and L 6 The crosshairs formed by and the straight line L 7 and L 8 That is, in a plan view, the longitudinal direction of each horizontal support portion 235b and the longitudinal direction of each beam structure 233 are preferably shifted by 45 degrees.

[0150] The intermediate portion of the inner circumferential end of the adjacent beam structures 233 is the farthest position from the inner circumferential end of each beam structure 233, and is therefore the least likely to deform. Therefore, by extending the vertical support portion 235a and the horizontal support portion 235b from the intermediate portion of the inner circumferential end of the adjacent beam structures 233, it is possible to make it difficult for the force generated when the flexure body 200 is fastened to the object to be measured with a screw to be transmitted to the second connecting portion 235c, and even if the force is transmitted, the second connecting portion 235c tends to maintain the same shape and to displace the same as a whole. In addition, when the flexure body 200 is attached to the object to be measured, if a temperature distribution occurs in the flexure body 200 due to the heat generated by the object to be measured, the deformation of the second connecting portion 235c can be suppressed.

[0151] As a result, as described above, it is possible to reduce adverse effects on the load-bearing capacity, force sense characteristics, offset temperature characteristics, and offset fluctuation of the sensor chip 100 caused by the force when fastening the strain body 200 to the object to be measured with a screw and by temperature distribution in the strain body 200.

[0152] In addition, since a space is provided on the upper surface side of the beam structure 233, a circuit board or the like on which electronic components such as connectors and semiconductor elements are mounted may be placed on the upper surface side of the beam structure 233 so as not to protrude from the upper surface of the outer frame portion 231.

[0153] Fig. 23 is a perspective view illustrating a cover plate constituting the strain generating body. As shown in Fig. 23, the cover plate 240 is a member that is generally disk-shaped and protects internal components (such as the sensor chip 100). The cover plate 240 is formed thinner than the force receiving plate 210, the strain generating portion 220, and the input transmitting portion 230. The cover plate 240 is provided with a screw hole 248. The screw hole 248 is, for example, a fastening hole that can be used when fastening the strain generating portion 220, the input transmitting portion 230, and the cover plate 240 to a fixed side (such as a robot side) with a screw.

[0154] The materials for the force receiving plate 210, the strain generating part 220, the input transmission part 230, and the cover plate 240 may be, for example, a hard metal material such as SUS (stainless steel). Of these, it is preferable to use SUS630, which is particularly hard and has high mechanical strength. Of the members constituting the strain generating body 200, it is particularly desirable that the force receiving plate 210, the strain generating part 220, and the input transmission part 230 are firmly connected or have an integral structure. Methods for connecting the force receiving plate 210, the strain generating part 220, and the input transmission part 230 include fastening with screws, welding, etc., but any method must be able to fully withstand the force and moment input to the strain generating body 200.

[0155] In this embodiment, as an example, the force receiving plate 210, the strain generating portion 220, and the input transmitting portion 230 are produced by metal powder injection molding, and then they are combined and sintered again to form a diffusion bond. The diffusion bonded force receiving plate 210, the strain generating portion 220, and the input transmitting portion 230 can obtain a necessary and sufficient bonding strength. After the sensor chip 100 and other internal components are mounted, the cover plate 240 may be fastened to the input transmitting portion 230 by, for example, screws.

[0156] In the strain-generating body 200, when a force or moment is applied to the force-receiving plate 210, the force or moment is transmitted to the central portion 222 of the strain-generating part 220 connected to the force-receiving plate 210, and deformation according to the input occurs in the four beam structures 223. At this time, the outer frame portion 221 and the input transmission portion 230 of the strain-generating part 220 do not deform.

[0157] That is, in the strain-generating body 200, the force-receiving plate 210 and the central portion 222 and beam structure 223 of the strain-generating part 220 are movable parts that deform when subjected to a force or moment in a predetermined axial direction, and the outer frame part 221 of the strain-generating part 220 is a non-movable part that does not deform when subjected to a force or moment. Also, the input transmission part 230 that is joined to the outer frame part 221 of the strain-generating part 220, which is a non-movable part, is a non-movable part that does not deform when subjected to a force or moment, and the cover plate 240 that is joined to the input transmission part 230 is also a non-movable part that does not deform when subjected to a force or moment.

[0158] When the strain body 200 is used in the force sensor device 1, the support parts 101-105 of the sensor chip 100 are connected to a first connection part 224 provided in the center part 222, which is a movable part. In addition, the force points 151-154 of the sensor chip 100 are connected to a second connection part 235d provided in the accommodation part 235, which is a non-movable part. Therefore, in the sensor chip 100, the force points 151-154 do not move, and each detection beam is deformed through the support parts 101-105.

[0159] However, the configuration may also be such that the force points 151-154 of the sensor chip 100 are connected to a first connection portion 224 provided in the central portion 222, which is the movable portion, and the support portions 101-105 of the sensor chip 100 are connected to a second connection portion 235d provided in the accommodating portion 235, which is the non-movable portion.

[0160] That is, the sensor chip 100 that can be accommodated in the accommodation portion 235 has the support portions 101-105 and the force points 151-154 whose relative positions change when subjected to a force or moment. In the strain body 200, the central portion 222, which is the movable portion, has a first connection portion 224 that extends toward the input transmission portion 230 and is connected to one of the support portions 101-105 and the force points 151-154. The accommodation portion 235 also has a second connection portion 235d that is connected to the other of the support portions 101-105 and the force points 151-154.

[0161] [simulation] Fig. 24 is a perspective view illustrating a strain-flexing part according to a comparative example. As shown in Fig. 24, the strain-flexing part 220X according to the comparative example differs from the strain-flexing part 220 (see Fig. 17 and the like) in that it does not have a portion corresponding to the space 229.

[0162] 25 is a perspective view illustrating an input transmission section according to a comparative example. As shown in FIG. 25, the input transmission section 230X according to the comparative example has an outer frame section 231X having a substantially ring shape in a plan view, an inner frame section 232X having a substantially rectangular shape in a plan view adjacent to the inner circumference of the outer frame section 231X, and a storage section 235X provided inside the inner frame section 232X. The inner frame section 232X is formed thinner than the outer frame section 231X, and the upper surface is located at a lower position than the upper surface of the outer frame section 231X. The input transmission section 230X does not have a portion corresponding to the beam structure 233, the first connecting section 234, and the space section 239.

[0163] The storage section 235X has the vertical support section 235a, the horizontal support section 235b, and the second connection section 235d, similar to the storage section 235, but further has a second horizontal support section 235e that extends horizontally from the inner surface of the inner frame section 232X and is connected to the vertical support section 235a. Also, unlike the storage section 235, the horizontal support sections 235b are arranged in a substantially cross shape in a plan view, but do not intersect with each other, and the inner circumferential ends of each horizontal support section 235b are spaced apart from each other. That is, the storage section 235X does not have a portion equivalent to the second connection section 235c.

[0164] 26 is a perspective view illustrating a state in which an input transmission part is disposed on a strain-flexing part according to a comparative example. The accommodation part 235X of the input transmission part 230X is inserted into the strain-flexing part 220X side. The first connection part 224 of the strain-flexing part 220X is exposed in the accommodation part 235X near the second connection part 235d.

[0165] 27 is a perspective view illustrating a state in which an input transmission part is disposed on a strain-flexing part according to this embodiment. The accommodation part 235 of the input transmission part 230 is inserted into the strain-flexing part 220. The first connection part 224 of the strain-flexing part 220 is exposed in the accommodation part 235 near the second connection part 235d.

[0166] [Simulation 1] Here, the results of Simulation 1 performed on the structure of Fig. 26 and the structure of Fig. 27 will be described. In Simulation 1, the Z displacement difference was confirmed when the lower surface of the force receiving plate attached to the object to be measured was kept in a steady state at 35°C, and then raised to 40°C at a rate of 1°C / s. Here, the Z displacement difference is the average value of the Z direction displacement of the upper ends of the five first connecting parts 224 subtracted from the average value of the Z direction displacement of the upper ends of the four second connecting parts 235d.

[0167] Simulation 1 was performed using a 1 / 4 model of the structure of Fig. 26 and the structure of Fig. 27. In the structure of Fig. 27, the length of beam structure 233 is 8 mm, the width of beam structure 233 is 4 mm, the length of countersunk portion 233a is 5 mm, and the thickness T 1 1.5 mm, and the thickness of the counterbore 233a T 2 was set to 1.25 mm.

[0168] Fig. 28 is a diagram showing the results of simulation 1. The upper side of the arrow in Fig. 28 shows the change in the Z displacement difference with respect to the elapsed time, and the lower side of the arrow is a displacement contour diagram of points A and B where the Z displacement difference is maximum. Note that, in the upper side of the arrow in Fig. 28, the comparative example is a 1 / 4 model of the structure in Fig. 26, and this embodiment is a 1 / 4 model of the structure in Fig. 27.

[0169] As shown in Fig. 28, in the structure of Fig. 26 according to the comparative example, the Z displacement difference is maximum when the elapsed time is about 5 s, and the value is about 1 µm. Thereafter, the Z displacement difference decreases with the elapsed time, and stabilizes at about 0.1 µm. In contrast, in the structure of Fig. 27 according to the present embodiment, the Z displacement difference is maximum when the elapsed time is about 5 s, and the value is about 0.15 µm. Thereafter, the Z displacement difference decreases with the elapsed time, and stabilizes at about -0.05 µm.

[0170] Also, from the contour diagram of Fig. 28, it can be seen that in the structure of Fig. 26 according to the comparative example, the Z displacement difference is large and the mutual positional relationship of the second connection parts 235d is not maintained. In contrast, in the structure of Fig. 27 according to the present embodiment, the Z displacement difference is small and the mutual positional relationship of the second connection parts 235d is also maintained.

[0171] 27 according to this embodiment can significantly reduce the Z displacement difference that occurs when a temperature distribution occurs, and can maintain the relative positional relationship of the second connecting parts 235d, compared to the structure of Fig. 26 according to the comparative example. That is, the structure of Fig. 27 according to this embodiment can reduce the offset of the sensor chip 100 that occurs when a temperature distribution occurs in the strain element, compared to the structure of Fig. 26 according to the comparative example.

[0172] [Simulation 2] In Simulation 2, in the structure of FIG. 2 = 1.0 mm, T 2 = 1.5 mm (i.e., when there is no counterbore 233a), a simulation similar to that of Simulation 1 was performed. 2 = 1.25 mm. In Simulation 2, T 2 All other conditions are the same as in Simulation 1.

[0173] As shown in Figure 29, T 2 = 1.5 mm (i.e., when there is no counterbore 233a), the maximum value of the Z displacement difference is about 0.6 μm.2 At T = 1.0 mm, the maximum Z displacement difference is about -0.5 μm. 2 Although the displacement direction is opposite to that of T = 1.5 mm, the absolute value is slightly improved. 2 At T = 1.25 mm, the maximum Z displacement difference is about 0.15 μm. 2 = 1.0 mm and T 2 = 1.5 mm, the Z displacement difference is significantly improved.

[0174] In this way, the thickness T of the countersunk portion 233a 2 There is an optimum value for the thickness T 2 It is preferable to adjust the thickness in the range of more than 1.0 mm to less than 1.5 mm, and more preferably to adjust the thickness in the range of more than 1.0 mm to less than 1.25 mm.

[0175] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0176] For example, in the above-described embodiment, an example has been described in which the strain-generating body is fastened to the object to be measured with a screw, but this is not limited thereto, and various fasteners such as bolts and rivets that can fix the strain-generating body to the object to be measured can be used. [Explanation of symbols]

[0177] 1 Force sensing device, 100 Sensor chip, 101 - 105 Support parts, 111 - 114 Frame parts, 121 - 124 Connection parts, 131a, 131c, 131e, 131g, 132a, 132c, 132e, 133a, 133c, 133e, 134a, 134c, 134e First detection beams, 131b, 131d, 131f, 131h, 132b, 132d, 132f, 133b, 133d, 133f, 134b, 134d, 134f Second detection beams, 131T1, 131T2, 131T3, 131T4, 132T1, 132T2, 132T3, 133T1, 133T2, 133T3, 134T1, 134T2, 134T3 T-shaped beam structures, 141 - 144 Connection parts, 151 - 154 Force points, 200 Distortion body, 210 Load-bearing plate, 211, 221, 231 Outer frame parts, 212, 222, 232 Central parts, 213, 223, 233 Beam structures, 218, 228, 238, 248 Screw holes, 220 Distortion part, 220x Groove, 223a First beam, 223b Second beam, 224 First connection part, 229, 239 Space parts, 230 Input transmission part, 231x Thin plate part, 233a Counterbore part, 233b, 233c Corner parts, 234 First connection part, 235 Accommodation part, 235a Vertical support part, 235b Horizontal support part, 235c Second connection part, 235d Second connection part, 240 Cover plate

Claims

1. a strain-generating part including a movable part that is deformed when subjected to a force or moment in a predetermined axial direction, and a non-movable part that is not deformed when subjected to the force or moment; an input transmission part that is joined to the non-movable part and does not deform when receiving the force or the moment, The input transmission unit is A frame portion and a plurality of beam structures each having one end connected to the frame and extending inwardly from the frame; a housing portion provided on the other end side of the beam structure and capable of housing a sensor chip that detects the force or the moment; Each of the beam structures is a flexure body having a countersunk portion that makes the thickness of the one end side thinner than the thickness of the other end side.

2. The flexure body according to claim 1 , wherein the countersunk portion is provided over the entire width of the beam structure.

3. 3. The flexure body according to claim 1, wherein a corner of the countersunk portion on the side of the frame portion is rounded in cross section.

4. A frame-shaped connecting portion is provided to connect the other ends of the beam structures to each other, The flexure body according to claim 1 , wherein the housing portion is provided inside the connecting portion.

5. The flexure body according to claim 4 , wherein a corner of the countersunk portion on the side of the connecting portion is rounded in cross section.

6. The flexure body according to claim 4 or 5, wherein a thickness of the other end of the beam structure is the same as a thickness of the connecting portion.

7. The flexure body according to claim 1 , wherein the thickness of the one end of the beam structure is greater than 1 mm and less than 1.25 mm.

8. The plurality of beam structures include 8. The flexure body according to claim 1, comprising, in a plan view, two beam structures facing each other across a center of the frame portion, and two other beam structures facing each other across the center of the frame portion.

9. 9. The flexure body according to claim 8, wherein, in a plan view, an imaginary straight line connecting center lines in a width direction of two of the beam structures opposing each other across the center of the frame portion and an imaginary straight line connecting center lines in a width direction of another two of the beam structures opposing each other across the center of the frame portion intersect at right angles to each other to form an imaginary cross line.

10. A force sensor device comprising: the strain element according to claim 1; and the sensor chip.

Images