Strain body, force sensor device

Abstract

A strain body and a force sensor device are provided, which can suppress displacement of a portion in which a sensor chip is arranged when mounted on an object to be measured. The strain body has a strain portion including a movable portion that deforms in response to a force or a moment in a predetermined axis direction and a non-movable portion that does not deform in response to the force or the moment, and an input transmission portion that is joined to the non-movable portion and does not deform in response to the force or the moment. The input transmission portion includes a first frame portion, a plurality of first beam structures each having one end connected to the first frame portion and extending inward from the first frame portion, a first link portion in a frame shape that links the other ends of the first beam structures to each other, and a housing portion provided inward of the first link portion and capable of housing a sensor chip that detects the force or the moment.

Description

Technical Field

[0001] This invention relates to strain gauge and force sensor devices. Background Technology

[0002] A force sensor device for detecting displacement along a predetermined axial direction has been known for some time. As an example, a force sensor device is described, which includes a sensor chip and a structure disposed around the sensor chip. The structure includes an external force application plate to which an external force is applied, a base portion supporting the sensor chip, an external force buffering mechanism for fixing the external force application plate to the base portion, and a connecting rod serving as an external force transmission mechanism. The external force application plate and the actuating portion are connected by the connecting rod (for example, see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-254843 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In force sensor devices, strain gauges used in conjunction with sensor chips are fastened to robot flanges, for example, by screws. However, sometimes deformation during fastening causes displacement of the sensor chip's mounting location, resulting in an output (offset) from the sensor chip. If the sensor produces an output, there are concerns about the deterioration of the sensor chip's load-bearing capacity, the deterioration of its force characteristics, and the degradation of its time-dependent and temperature-dependent output characteristics due to its dependence on the fastened state.

[0008] The present invention is made in view of the above points, and aims to provide a strain gauge that can suppress displacement of the portion of the sensor chip that is configured when mounted on the object being measured.

[0009] Solution for solving the problem

[0010] The strain gauge 200 of the present invention includes: a strain section 220 having a movable section that deforms under a predetermined axial force or torque and a non-movable section that does not deform under the force or torque; and an input transmission section 230 that engages with the non-movable section and does not deform under the force or torque. The input transmission section 230 includes: a first frame section 231; a plurality of first beam structures 233, one end of which is connected to the first frame section 231 and extends inward from the first frame section 231; a frame-shaped first connecting section 234 that connects the other ends of each of the first beam structures 233 to each other; and a receiving section 235 disposed inside the first connecting section 234 and capable of receiving a sensor chip 100 for detecting the force or torque.

[0011] Furthermore, the reference symbols mentioned above are for ease of understanding and are merely one example, not limited to the illustrated scheme.

[0012] Invention Effects

[0013] According to the disclosed technology, it is possible to provide a strain gauge that can suppress displacement of a portion of the sensor chip configuration that occurs when it is mounted on the object being measured. Attached Figure Description

[0014] Figure 1 This is a perspective view illustrating the force sensor device of the first embodiment.

[0015] Figure 2 This is a cross-sectional perspective view illustrating the force sensor device of the first embodiment.

[0016] Figure 3 This is a top-view perspective view showing the state where a sensor chip is installed in the input transmission section.

[0017] Figure 4 This is a bottom-view perspective view showing the state where a sensor chip is installed in the input transmission section.

[0018] Figure 5 This is a three-dimensional view of the sensor chip 100 viewed from above along the Z-axis.

[0019] Figure 6 This is a top view of the sensor chip 100 viewed from above along the Z-axis.

[0020] Figure 7 This is a three-dimensional view of the sensor chip 100 viewed from the bottom along the Z-axis.

[0021] Figure 8 This is a bottom view of the sensor chip 100 viewed from below along the Z-axis.

[0022] Figure 9 It is a diagram that explains the symbols representing the forces and torques acting on each axis.

[0023] Figure 10 This is a diagram illustrating the configuration of the piezoresistive elements in sensor chip 100.

[0024] Figure 11 yes Figure 10 A magnified view of a set of detector blocks of the sensor chip shown.

[0025] Figure 12 The first figure shows an example of a detection circuit that uses various piezoresistive elements.

[0026] Figure 13 The second figure shows an example of a detection circuit that uses various piezoresistive elements.

[0027] Figure 14 This is a diagram illustrating the Fx input.

[0028] Figure 15 This is a diagram illustrating the Fy input.

[0029] Figure 16 This is a three-dimensional diagram illustrating the stress plate that constitutes the strain body.

[0030] Figure 17 This is a three-dimensional diagram illustrating the strain components that make up the strain body.

[0031] Figure 18 This is a top view illustrating the strain portion that constitutes the strain body.

[0032] Figure 19 This is a perspective view illustrating the upper surface of the input transmission section that constitutes the strain body.

[0033] Figure 20 This is a top view illustrating the input transmission part that constitutes the strain body.

[0034] Figure 21 This is a perspective view illustrating the lower surface of the input transmission section that constitutes the strain body.

[0035] Figure 22 This is a cross-sectional view illustrating the input transmission part that constitutes the strain body.

[0036] Figure 23 This is a perspective view illustrating the cover plate that constitutes the strain body.

[0037] Figure 24 This is a three-dimensional view illustrating the strain section of a comparative example.

[0038] Figure 25 This is a three-dimensional view illustrating the input transmission unit of a comparative example.

[0039] Figure 26 This is a perspective view illustrating the state in which an input transmission unit is arranged on the strain section of a comparative example.

[0040] Figure 27 This is a perspective view illustrating the state in which the input transmission unit is arranged on the strain section of this embodiment.

[0041] Figure 28 This is a diagram illustrating the measurement points in the simulation.

[0042] Figure 29 This is a comparative example. Figure 26 Contour map of the displacement of the structure.

[0043] Figure 30 It summarizes the comparative examples. Figure 26A diagram showing the displacement of each part of the structure.

[0044] Figure 31 This is the implementation method Figure 27 Contour map of the displacement of the structure.

[0045] Figure 32 This is a summary of the embodiments described in this article. Figure 27 A diagram showing the displacement of each part of the structure.

[0046] Figure 33 This is a graph representing the results of Simulation 1.

[0047] Figure 34 This is a graph representing the results of Simulation 2.

[0048] In the picture:

[0049] 1—Force sensor device; 100—Sensor chip; 101-105—Support part; 111-114—Frame part; 121-124—Connecting part; 131a, 131c, 131e, 132a, 132c, 132e, 133a, 133c, 133e, 134a, 134c, 134e—First detection beam; 131b, 131d, 131 f, 132b, 132d, 132f, 133b, 133d, 133f, 134b, 134d, 134f—Second detection beams; 131T1, 131T2, 131T3, 132T1, 132T2, 132T3, 133T1, 133T2, 133T3, 134T1, 134T2, 134T3—T-shaped beam structures; 14 1-144—Connecting parts, 151-154—Force points, 200—Strained parts, 210—Resistant plates, 211, 221, 231—Outer frame parts, 212, 222, 232—Central parts, 213, 223, 233—Beam structures, 218, 228, 238, 248—Threaded holes, 220—Strained parts, 220x—Groove, 223a—First beam, 223b—Second beam Two beams, 224—first connecting part, 229, 239—space part, 230—input transmission part, 231x—thin plate part, 233a—counterfeit part, 233b, 233c—corner part, 234—first connecting part, 234—accommodating part, 235a—vertical support part, 235b—horizontal support part, 235c—second connecting part, 235d—second connecting part, 240—cover plate. Detailed Implementation

[0050] Hereinafter, with reference to the accompanying drawings, the method for carrying out the invention will be described. In the drawings, the same symbols are used to label the same structural parts, and sometimes repeated descriptions are omitted.

[0051] <First Implementation>

[0052] (Simplified structure of force sensor device 1)

[0053] Figure 1 This is a perspective view illustrating the force sensor device of the first embodiment. Figure 2 This is a cross-sectional perspective view illustrating the force sensor device of the first embodiment. (Refer to...) Figure 1 and Figure 2 The force sensor device 1 includes a sensor chip 100 and a strain gauge 200. The force sensor device 1 is, for example, a multi-axis force sensor device mounted on the arm or finger of a robot used in machine tools or the like.

[0054] The sensor chip 100 has the function of detecting displacement along a predetermined axis in up to six axes. The strain gauge 200 has the function of transmitting the applied force and / or torque to the sensor chip 100. In the following embodiment, as an example, the sensor chip 100 is described in the case of detecting six axes, but it is not limited thereto. For example, the sensor chip 100 can also be used to detect three axes, etc.

[0055] The strain gauge 200 includes a load-bearing plate 210, a strain section 220, an input transmission section 230, and a cover plate 240. The strain section 220 is stacked on the load-bearing plate 210, the input transmission section 230 is stacked on the strain section 220, and the cover plate 240 is stacked on the input transmission section 230, forming a generally cylindrical strain gauge 200. Furthermore, the strain section 220 and the input transmission section 230 primarily function as the strain gauge 200; therefore, the load-bearing plate 210 and the cover plate 240 are provided as needed.

[0056] Furthermore, in this embodiment, for convenience, the cover plate 240 side is designated as the upper side or one side, and the force-bearing plate 210 side is designated as the lower side or the other side in the force sensor device 1. Additionally, the surface of the cover plate 240 side of each part is designated as one side or the upper surface, and the surface of the force-bearing plate 210 side is designated as the other side or the lower surface. However, the force sensor device 1 can be used in an upside-down state, or it can be configured at any angle. Furthermore, "top view" refers to viewing the object from the normal direction (Z-axis direction) of the upper surface of the cover plate 240, and "planar shape" refers to the shape of the object viewed from the normal direction (Z-axis direction) of the upper surface of the cover plate 240.

[0057] Figure 3 This is a top-view perspective view showing the state where a sensor chip is installed in the input transmission section. Figure 4 This is a bottom-view perspective view showing the state where a sensor chip is installed in the input transmission section. For example... Figure 3 and Figure 4As shown, the input transmission section 230 is provided with a receiving section 235 that protrudes from the lower surface of the input transmission section 230 toward the strain section 220. Furthermore, a sensor chip 100 is fixed to the cover plate 240 side of the receiving section 235.

[0058] Specifically, as described later, the receiving portion 235 is provided with four second connecting portions 235d protruding toward the cover plate 240 (see below). Figures 19-22 (etc.). Furthermore, the force points 151-154 between each second connection portion 235d and the sensor chip 100 (see below) Figures 5-8 The lower surface of (etc.) is connected.

[0059] Furthermore, the receiving portion 235 enters the strain section 220 side. Moreover, as described later, the strain section 220 is provided with five columnar first connecting portions 224 protruding towards the input transmission portion 230 side (see later description). Figure 17 (etc.). Furthermore, each of the first connecting portions 224 and the support portions 101-105 of the sensor chip 100 (see below) Figures 5-8 The lower surface of (etc.) is connected.

[0060] The sensor chip 100 and strain gauge 200 will be described in detail below. Furthermore, in the following description, "parallel" includes the case where two lines or edges are within a range of 0° ± 10°. Additionally, "perpendicular" or "orthogonal" includes the case where two lines or edges are within a range of 90° ± 10°. However, these are not limited to cases where specific explanations exist. Furthermore, "center" or "central" indicates the approximate center or center of the object, not a strict center or center. That is, a degree of deviation tolerable for manufacturing errors is allowed. The same applies to point symmetry or line symmetry, etc.

[0061] (Sensor Chip 100)

[0062] Figure 5 This is a three-dimensional view of the sensor chip 100 viewed from above along the Z-axis. Figure 6 This is a top view of the sensor chip 100 viewed from above along the Z-axis. Figure 7 This is a three-dimensional view of the sensor chip 100 viewed from the bottom along the Z-axis. Figure 8 This is a bottom view of the sensor chip 100 viewed from below along the Z-axis. Furthermore, in Figure 8 For convenience, surfaces of the same height are represented using the same pear-patterned texture. Furthermore, the direction parallel to one side of the upper surface of the sensor chip 100 is designated as the X-axis, the perpendicular direction as the Y-axis, and the thickness direction of the sensor chip 100 (the normal direction of the upper surface of the sensor chip 100) as the Z-axis. The X-axis, Y-axis, and Z-axis are orthogonal to each other.

[0063] Figures 5-8 The sensor chip 100 shown is a MEMS (Micro-Electro Mechanical Systems) sensor chip capable of detecting up to six axes with a single chip, 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 rectangular) of approximately 7000 μm square.

[0064] The sensor chip 100 includes five columnar support portions 101 to 105. The planar shape of the support portions 101 to 105 can be, for example, a square approximately 2000 μm in diameter. Support portions 101 to 104 are disposed at the four corners of the rectangular sensor chip 100. Support portion 105 is disposed at the center of the rectangular sensor chip 100. Furthermore, support portions 101 to 104 are representative examples of the first support portion of the present invention, and support portion 105 is a representative example of the second support portion of the present invention.

[0065] A frame portion 112 is provided between support portion 101 and support portion 102, which fixes both ends to support portion 101 and support portion 102 (connecting adjacent support portions to each other). A frame portion 113 is provided between support portion 102 and support portion 103, which fixes both ends to support portion 102 and support portion 103 (connecting adjacent support portions to each other).

[0066] A frame portion 114 is provided between support portion 103 and support portion 104, which fixes both ends to support portion 103 and support portion 104 (connecting adjacent support portions to each other). A frame portion 111 is provided between support portion 104 and support portion 101, which fixes both ends to support portion 104 and support portion 101 (connecting adjacent support portions to each other).

[0067] In other words, the four frame parts 111, 112, 113 and 114 are formed into a frame shape, and the corners that form the intersection of each frame part are the support parts 101, 102, 103 and 104.

[0068] The inner corner of the support portion 101 and the corner of the support portion 105 opposite thereto are connected by the connecting portion 121. The inner corner of the support portion 102 and the corner of the support portion 105 opposite thereto are connected by the connecting portion 122.

[0069] The inner corner of the support portion 103 and the corner of the support portion 105 opposite thereto are connected by the connecting portion 123. The inner corner of the support portion 104 and the corner of the support portion 105 opposite thereto are connected by the connecting portion 124.

[0070] That is, the sensor chip 100 has connecting portions 121 to 124 that connect the support portion 105 and the support portions 101 to 104. The connecting portions 121 to 124 are arranged at an angle relative to the X-axis direction (Y-axis direction). In other words, the connecting portions 121 to 124 are not parallel to the frame portions 111, 112, 113, and 114.

[0071] The support portions 101 to 105, the frame portions 111 to 114, and the connecting portions 121 to 124 can be formed, for example, from the active layer, the BOX layer, and the support layer of the SOI substrate, and their respective thicknesses can be set to approximately 400 μm to 600 μm.

[0072] The sensor chip 100 has four detection blocks B1 to B4. Each detection block also has three sets of T-beam structures with piezoresistive elements configured as deformation detection elements. Here, the T-beam structure refers to a structure including a first detection beam and a second detection beam extending from the center of the first detection beam in a direction orthogonal to the first detection beam and connected to the force point.

[0073] Furthermore, the detection beam refers to a beam that can be equipped with a piezoresistive element, but it may also be that the piezoresistive element is not required. That is, the detection beam can detect force or torque by configuring a piezoresistive element, but the sensor chip 100 may also have a detection beam that is not configured with a piezoresistive element and is not used for force or torque detection.

[0074] Specifically, detector block B1 has T-shaped beam structures 131T1, 131T2, and 131T3. Additionally, detector block B2 has T-shaped beam structures 132T1, 132T2, and 132T3. Furthermore, detector block B3 has T-shaped beam structures 133T1, 133T2, and 133T3. Additionally, detector block B4 has T-shaped beam structures 134T1, 134T2, and 134T3. A more detailed explanation of the beam structures follows.

[0075] Viewed from above, a first detection beam 131a is provided on the detection block B1, parallel to the side of the support portion 104 of the support portion 101, at a predetermined interval, bridging the side of the frame portion 111 near the support portion 101 and the side of the connecting portion 121 near the support portion 105. Furthermore, a second detection beam 131b is provided at the center of the long side of the first detection beam 131a, with one end connected to it, extending toward the support portion 104 in a direction perpendicular to the long side of the first detection beam 131a. The first detection beam 131a and the second detection beam 131b form a T-shaped beam structure 131T1.

[0076] Viewed from above, a first detection beam 131c is provided parallel to the side of the support portion 101 of the support portion 104, bridging the side of the frame portion 111 near the support portion 104 and the side of the connecting portion 124 near the support portion 105, separated by a predetermined interval. Furthermore, a second detection beam 131d is provided at the center of the long side of the first detection beam 131c, with one end connected to it and extending toward the support portion 101 in a direction perpendicular to the long side of the first detection beam 131c. The first detection beam 131c and the second detection beam 131d form a T-shaped beam structure 131T2.

[0077] Viewed from above, a first detection beam 131e is provided parallel to the side of the frame portion 111 of the support portion 105, bridging the side of the connecting portion 121 near the support portion 105 and the side of the connecting portion 124 near the support portion 105 at a predetermined interval. Furthermore, a second detection beam 131f is provided at the center of the long side of the first detection beam 131e, with one end connected to it, extending toward the frame portion 111 in a direction perpendicular to the long side of the first detection beam 131e. The first detection beam 131e and the second detection beam 131f form a T-shaped beam structure 131T3.

[0078] The other ends of the second detection beams 131b, 131d, and 131f are connected to each other to form a connecting portion 141. A force point 151 is provided on the lower surface of the connecting portion 141. The force point 151 is, for example, a square column. The detection block B1 is composed of the T-shaped beam structures 131T1, 131T2, and 131T3, the connecting portion 141, and the force point 151.

[0079] In detector block B1, the first detection beam 131a, the first detection beam 131c, and the second detection beam 131f are parallel, and the second detection beams 131b and 131d are parallel to the first detection beam 131e. The thickness of each detection beam in detector block B1 can be set to approximately 30μm to 50μm.

[0080] Viewed from above, a first detection beam 132a is provided on the detection block B2, parallel to the side of the support portion 101 of the support portion 102, bridging the side of the frame portion 112 near the support portion 102 and the side of the connecting portion 122 near the support portion 105. Furthermore, a second detection beam 132b is provided at the center of the long side of the first detection beam 132a, with one end connected to it, extending toward the support portion 101 in a direction perpendicular to the long side of the first detection beam 132a. The first detection beam 132a and the second detection beam 132b form a T-shaped beam structure 132T1.

[0081] Viewed from above, a first detection beam 132c is provided parallel to the side of the support portion 102 of the support portion 101, bridging the side of the frame portion 112 near the support portion 101 and the side of the connecting portion 121 near the support portion 105, separated by a predetermined interval. Furthermore, a second detection beam 132d is provided at the center of the long side of the first detection beam 132c, with one end connected to it, extending toward the support portion 102 in a direction perpendicular to the long side of the first detection beam 132c. The first detection beam 132c and the second detection beam 132d form a T-shaped beam structure 132T2.

[0082] Viewed from above, a first detection beam 132e is provided parallel to the side of the frame portion 112 of the support portion 105, bridging the side of the connecting portion 122 near the support portion 105 and the side of the connecting portion 121 near the support portion 105 at a predetermined interval. Furthermore, a second detection beam 132f is provided at the center of the long side of the first detection beam 132e, with one end connected to it, extending toward the frame portion 112 in a direction perpendicular to the long side of the first detection beam 132e. The first detection beam 132e and the second detection beam 132f form a T-shaped beam structure 132T3.

[0083] The other ends of the second detection beams 132b, 132d, and 132f are connected to each other to form a connecting portion 142. A force point 152 is provided on the lower surface of the connecting portion 142. The force point 152 is, for example, a square column. The detection block B2 is composed of the T-shaped beam structures 132T1, 132T2, and 132T3, the connecting portion 142, and the force point 152.

[0084] In detector block B2, the first detection beam 132a, the first detection beam 132c, and the second detection beam 132f are parallel, and the second detection beams 132b and 132d are parallel to the first detection beam 132e. The thickness of each detection beam in detector block B2 can be set to approximately 30μm to 50μm.

[0085] Viewed from above, a first detection beam 133a is provided on the detection block B3, parallel to the side of the support portion 102 of the support portion 103, bridging the side of the frame portion 113 near the support portion 103 and the side of the connecting portion 123 near the support portion 105, separated by a predetermined interval. Furthermore, a second detection beam 133b is provided at the center of the long side of the first detection beam 133a, with one end connected to it, extending toward the support portion 102 in a direction perpendicular to the long side of the first detection beam 133a. The first detection beam 133a and the second detection beam 133b form a T-shaped beam structure 133T1.

[0086] Viewed from above, a first detection beam 133c is provided parallel to the side of the support portion 103 of the support portion 102, bridging the side of the frame portion 113 near the support portion 102 and the side of the connecting portion 122 near the support portion 105, separated by a predetermined interval. Furthermore, a second detection beam 133d is provided at the center of the long side of the first detection beam 133c, with one end connected to it, extending toward the support portion 103 in a direction perpendicular to the long side of the first detection beam 133c. The first detection beam 133c and the second detection beam 133d form a T-shaped beam structure 133T2.

[0087] Viewed from above, a first detection beam 133e is provided parallel to the side of the frame portion 113 of the support portion 105, bridging the side of the connecting portion 123 near the support portion 105 and the side of the connecting portion 122 near the support portion 105 at a predetermined interval. Furthermore, a second detection beam 133f is provided at the center of the long side of the first detection beam 133e, with one end connected to it, extending toward the frame portion 113 in a direction perpendicular to the long side of the first detection beam 133e. The first detection beam 133e and the second detection beam 133f form a T-shaped beam structure 133T3.

[0088] The other ends of the second detection beams 133b, 133d, and 133f are connected to each other to form a connecting portion 143. A force point 153 is provided on the lower surface of the connecting portion 143. The force point 153 is, for example, a quadrangular prism. The detection block B3 is composed of the T-shaped beam structures 133T1, 133T2, and 133T3, the connecting portion 143, and the force point 153.

[0089] In detector block B3, the first detection beam 133a, the first detection beam 133c, and the second detection beam 133f are parallel, and the second detection beams 133b and 133d are parallel to the first detection beam 133e. The thickness of each detection beam in detector block B3 can be set to approximately 30μm to 50μm.

[0090] Viewed from above, a first detection beam 134a is provided on the detection block B4, parallel to the side of the support portion 103 of the support portion 104, bridging the side of the frame portion 114 near the support portion 104 and the side of the connecting portion 124 near the support portion 105. Furthermore, a second detection beam 134b is provided at the center of the long side of the first detection beam 134a, with one end connected to it, extending toward the support portion 103 in a direction perpendicular to the long side of the first detection beam 134a. The first detection beam 134a and the second detection beam 134b form a T-shaped beam structure 134T1.

[0091] Viewed from above, a first detection beam 134c is provided parallel to the side of the support portion 104 of the support portion 103, bridging the side of the frame portion 114 near the support portion 103 and the side of the connecting portion 123 near the support portion 105, separated by a predetermined interval. Furthermore, a second detection beam 134d is provided at the center of the long side of the first detection beam 134c, with one end connected to it, extending toward the support portion 104 in a direction perpendicular to the long side of the first detection beam 134c. The first detection beam 134c and the second detection beam 134d form a T-shaped beam structure 134T2.

[0092] Viewed from above, a first detection beam 134e is provided parallel to the side of the frame portion 114 of the support portion 105, bridging the side of the connecting portion 124 near the support portion 105 and the side of the connecting portion 123 near the support portion 105 at a predetermined interval. Furthermore, a second detection beam 134f is provided at the center of the long side of the first detection beam 134e, with one end connected to it, extending toward the frame portion 114 in a direction perpendicular to the long side of the first detection beam 134e. The first detection beam 134e and the second detection beam 134f form a T-shaped beam structure 134T3.

[0093] The other ends of the second detection beams 134b, 134d, and 134f are connected to each other to form a connecting portion 144. A force point 154 is provided on the lower surface of the connecting portion 144. The force point 154 is, for example, a square column. The detection block B4 is composed of the T-shaped beam structures 134T1, 134T2, and 134T3, the connecting portion 144, and the force point 154.

[0094] In detector block B4, the first detection beam 134a, the first detection beam 134c, and the second detection beam 134f are parallel, and the second detection beams 134b and 134d are parallel to the first detection beam 134e. The thickness of each detection beam in detector block B4 can be set to approximately 30μm to 50μm.

[0095] Thus, the sensor chip 100 has four detection blocks (detection blocks B1 to B4). Furthermore, each detection block is disposed in an area surrounded by adjacent support portions 101 to 104, a frame portion and connecting portion connected to the adjacent support portions, and support portion 105. Viewed from above, each detection block can, for example, be symmetrically arranged with respect to the center point of the sensor chip.

[0096] In addition, each detection block has three sets of T-beam structures. In each detection block, the three sets of T-beam structures include two sets of T-beam structures with a first detection beam arranged parallel to the connecting portion when viewed from above, and one set of T-beam structures with a first detection beam arranged parallel to the second detection beam of the two sets of T-beam structures. Furthermore, the first detection beam of the first set of T-beam structures is positioned between the connecting portion and the support portion 105.

[0097] For example, in detector block B1, the three sets of T-beam structures include T-beam structures 131T1 and 131T2, which have first detection beams 131a and 131c arranged parallel to each other between the connecting part 141 when viewed from above, and T-beam structure 131T3, which has a first detection beam 131e arranged parallel to the second detection beams 131b and 131d of T-beam structures 131T1 and 131T2. Furthermore, the first detection beam 131e of T-beam structure 131T3 is positioned between the connecting part 141 and the support part 105. Detector blocks B2 to B4 have the same structure.

[0098] Force points 151 to 154 are the locations where external forces are applied, and for example, they can be formed from the BOX layer and support layer of the SOI substrate. The lower surface of each of the force points 151 to 154 is approximately flush with the lower surface of the support portions 101 to 105.

[0099] In this way, by acquiring force or displacement from four force points 151–154, different beam deformations can be obtained for each type of force, thus enabling a sensor with good six-axis separability. The number of force points is the same as the number of displacement input points of the combined strain body.

[0100] Furthermore, in the sensor chip 100, from the viewpoint of suppressing stress concentration, it is preferable that the portion forming the inner corner is R-shaped.

[0101] The support portions 101-105 of the sensor chip 100 are connected to the non-movable portion of the strain gauge 200, and the force points 151-154 are connected to the movable portion of the strain gauge 200. However, it can function as a force sensor device even if the relationship between the movable and non-movable portions is reversed. That is, the support portions 101-105 of the sensor chip 100 can be connected to the movable portion of the strain gauge 200, and the force points 151-154 can be connected to the non-movable portion of the strain gauge 200.

[0102] Figure 9 It is a diagram that explains the symbols representing the forces and moments acting on each axis. For example... Figure 9 As shown, the force in the X-axis direction is designated as Fx, the force in the Y-axis direction as Fy, and the force in the Z-axis direction as Fz. Additionally, the torque rotating about the X-axis is designated as Mx, the torque rotating about the Y-axis as My, and the torque rotating about the Z-axis as Mz.

[0103] Figure 10 This is a diagram illustrating the configuration of the piezoresistive elements in sensor chip 100. Figure 11 yes Figure 10 A magnified view of a group of detector blocks of the sensor chip shown. Figure 10 and Figure 11 As shown, piezoresistive elements are arranged at predetermined positions on each probe block corresponding to the four force points 151-154. Furthermore, Figure 10 The configuration of the piezoresistive elements in the other probe blocks shown is similar to... Figure 11 The configuration of the piezoresistive elements in the probe block shown is the same.

[0104] Reference Figures 5-8 , Figure 10 as well as Figure 11 In the probe block B1 having a connecting portion 141 and a force point 151, the piezoresistive element MzR1' is disposed on the first probe beam 131a on the side near the second probe beam 131b, located between the second probe beam 131b and the first probe beam 131e. The piezoresistive element FxR3 is disposed on the first probe beam 131a on the side near the first probe beam 131e, located between the second probe beam 131b and the first probe beam 131e. The piezoresistive element MxR1 is disposed on the second probe beam 131b on the side near the connecting portion 141.

[0105] Furthermore, the piezoresistive element MzR2' is disposed on the first detection beam 131c on the side near the second detection beam 131d, in the portion 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 the side near the first detection beam 131e, in the portion 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 the side near the connecting portion 141.

[0106] Furthermore, the piezoresistive element FzR1' is disposed on the second detection beam 131f near the connection portion 141. The piezoresistive element FzR2' is disposed on the second detection beam 131f near the first detection beam 131e. In addition, the piezoresistive elements MzR1', FxR3, MxR1, MzR2', FxR1, and MxR2 are disposed at positions off-center from the short side direction of each detection beam.

[0107] In the probe block B2, which has a connecting portion 142 and a force point 152, a piezoresistive element MzR4 is disposed on the first probe beam 132a on the side closest to the second probe beam 132b, located between the second probe beam 132b and the first probe beam 132e. A piezoresistive element FyR3 is disposed on the first probe beam 132a on the side closest to the first probe beam 132e, located between the second probe beam 132b and the first probe beam 132e. A piezoresistive element MyR4 is disposed on the second probe beam 132b on the side closest to the connecting portion 142.

[0108] Furthermore, the piezoresistive element MzR3 is disposed on the first detection beam 132c on the side near the second detection beam 132d, 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 the side near the first detection beam 132e, 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 the side near the connecting portion 142.

[0109] Furthermore, the piezoresistive element FzR4 is disposed on the second detection beam 132f near the connection portion 142. The piezoresistive element FzR3 is disposed on the second detection beam 132f near the first detection beam 132e. In addition, the piezoresistive elements MzR4, FyR3, MyR4, MzR3, FyR1, and MyR3 are disposed at positions off-center from the short side direction of each detection beam.

[0110] In the probe block B3 having a connecting portion 143 and a force point 153, the piezoresistive element MzR4' is disposed on the first probe beam 133a on the side near the second probe beam 133b, in the portion between the second probe beam 133b and the first probe beam 133e. The piezoresistive element FxR2 is disposed on the first probe beam 133a on the side near the first probe beam 133e, in the portion between the second probe beam 133b and the first probe beam 133e. The piezoresistive element MxR4 is disposed on the second probe beam 133b on the side near the connecting portion 143.

[0111] Furthermore, the piezoresistive element MzR3' is disposed on the first detection beam 133c on the side near the second detection beam 133d, 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 the side near the first detection beam 133e, 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 the side near the connecting portion 143.

[0112] Furthermore, the piezoresistive element FzR4' is disposed on the second detection beam 133f near the connection portion 143. The piezoresistive element FzR3' is disposed on the second detection beam 133f near the first detection beam 133e. In addition, the piezoresistive elements MzR4', FxR2, MxR4, MzR3', FxR4, and MxR3 are disposed at positions off-center from the short side direction of each detection beam.

[0113] In the probe block B4 having a connecting portion 144 and a force point 154, a piezoresistive element MzR1 is disposed on the first probe beam 134a on the side near the second probe beam 134b, located between the second probe beam 134b and the first probe beam 134e. A piezoresistive element FyR2 is disposed on the first probe beam 134a on the side near the first probe beam 134e, located between the second probe beam 134b and the first probe beam 134e. A piezoresistive element MyR1 is disposed on the second probe beam 134b on the side near the connecting portion 144.

[0114] Furthermore, the piezoresistive element MzR2 is disposed on the first detection beam 134c on the side near the second detection beam 134d, 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 the side near the first detection beam 134e, 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 the side near the connecting portion 144.

[0115] Furthermore, piezoresistive element FzR1 is disposed on the second detection beam 134f near the connection portion 144. Piezoresistive element FzR2 is disposed on the second detection beam 134f near the first detection beam 134e. In addition, piezoresistive elements MzR1, FyR2, MyR1, MzR2, FyR4, and MyR2 are disposed at positions off-center from the short side direction of each detection beam.

[0116] In this way, multiple piezoresistive elements are separately arranged in each detection block in the sensor chip 100. As a result, up to six-axis detection of a predetermined axial force or torque can be performed based on the changes in the output of the multiple piezoresistive elements arranged in the predetermined beam corresponding to the input applied to the force points 151 to 154.

[0117] Furthermore, in the sensor chip 100, in addition to the piezoresistive element used for deformation detection, a dummy piezoresistive element may also be configured. The dummy piezoresistive element is used to adjust the balance of stress acting on the detection beam or resistance of the bridge circuit. For example, all piezoresistive elements, including the piezoresistive element used for deformation detection, are configured symmetrically with respect to the center point of the support portion 105.

[0118] In the sensor chip 100, multiple piezoresistive elements for detecting displacement in the X-axis and Y-axis directions are arranged on the first detection beam constituting a T-shaped beam structure. Additionally, multiple piezoresistive elements for detecting displacement in the Z-axis direction are arranged on the second detection beam constituting the T-shaped beam structure. Furthermore, multiple piezoresistive elements for detecting torque in the Z-axis direction are arranged on the first detection beam constituting the T-shaped beam structure. Additionally, multiple piezoresistive elements for detecting torque in the X-axis and Y-axis directions are arranged on the second detection beam constituting the T-shaped beam structure.

[0119] Here, the piezoresistive elements FxR1~FxR4 detect force Fx, FyR1~FyR4 detect force Fy, and FzR1~FzR4 and FzR1'~FzR4' detect force Fz. Additionally, the piezoresistive elements MxR1~MxR4 detect torque Mx, MyR1~MyR4 detect torque My, and MzR1~MzR4 and MzR1'~MzR4' detect torque Mz.

[0120] In this way, multiple piezoresistive elements are separately arranged in each detection block within the sensor chip 100. Therefore, displacement along a predetermined axial direction can be detected up to six times based on the changes in the output of the multiple piezoresistive elements arranged in the predetermined beams, corresponding to the direction (axial direction) of the force or displacement applied (transmitted) to the force points 151-154. Furthermore, by making the thickness and width of each detection beam variable, adjustments can be made to achieve uniformity of detection sensitivity, improvement of detection sensitivity, and other enhancements.

[0121] In addition, it is possible to reduce the number of piezoresistive elements and set up a sensor chip for detecting displacement of a predetermined axial direction up to five axes.

[0122] In the sensor chip 100, force and torque can be detected, for example, using the detection circuit described below. Figure 12 and Figure 13 An example of a detection circuit using various piezoresistive elements is shown. Figure 12 and Figure 13 In the diagram, numbers enclosed in squares indicate external output terminals. For example, No. 1 is the power supply terminal for the Fx, Fy, and Fz axes; No. 2 is the negative output terminal for the Fx axis; No. 3 is the GND terminal for the Fx axis; and No. 4 is the positive output terminal for the Fx axis. No. 19 is the negative output terminal for the Fy axis; No. 20 is the GND terminal for the Fy axis; and No. 21 is the positive output terminal for the Fy axis. No. 22 is the negative output terminal for the Fz axis; No. 23 is the GND terminal for the Fz axis; and No. 24 is the positive output terminal for the Fz axis.

[0123] Additionally, No. 9 is the negative output terminal for the Mx axis, No. 10 is the GND terminal for the Mx axis, and No. 11 is the positive output terminal for the Mx axis. No. 12 is the power supply terminal for the Mx, My, and Mz axes. No. 13 is the negative output terminal for the My axis, No. 14 is the GND terminal for the My axis, and No. 15 is the positive output terminal for the My axis. No. 16 is the negative output terminal for the Mz axis, No. 17 is the GND terminal for the Mz axis, and No. 18 is the positive output terminal for the Mz axis.

[0124] Next, the deformation of the detection beam will be explained. Figure 14 This is a diagram illustrating the Fx input. Figure 15 This is a diagram illustrating the Fy input. (For example...) Figure 14 As shown, when the input from the strain gauge 200 equipped with sensor chip 100 is Fx, all four force points 151-154 tend to move in the same direction (in Figure 14 In the example, the movement is to the right. Similarly, as... Figure 15 As shown, when the input from the strain gauge 200 equipped with sensor chip 100 is Fy, all four force points 151-154 tend to move in the same direction (in Figure 15 In the example, the movement is in the upward direction. That is, in the sensor chip 100, although there are four detection blocks, in any detection block, for displacement in the X-axis direction and displacement in the Y-axis direction, all force points move in the same direction.

[0125] In the sensor chip 100, there is one or more first detection beams in the first detection beam of the T-shaped beam structure that are orthogonal to the input displacement direction. The first detection beams that are orthogonal to the input displacement direction can cope with large deformations.

[0126] The beams used for detecting Fx input are first detection beams 131a, 131c, 133a, and 133c, all of which are T-shaped beam structures with a constant distance from the force point. Similarly, the beams used for detecting Fy input are first detection beams 132a, 132c, 134a, and 134c, all of which are T-shaped beam structures with a constant distance from the force point.

[0127] In the Fx and Fy inputs, the first detection beam, equipped with a piezoresistive element, undergoes significant deformation of the T-shaped beam structure, thereby effectively detecting the input force. Furthermore, the detection beam not used for input is also designed to deform significantly in response to the displacement of the Fx and Fy inputs, ensuring that the detection beam will not be damaged even with large Fx and / or Fy inputs.

[0128] Furthermore, in existing sensor chips, there exist beams that cannot deform significantly with respect to Fx and / or Fy inputs. Therefore, in the presence of large Fx and / or Fy inputs, there is a possibility that the non-deformable detection beam may be damaged. In sensor chip 100, this problem can be suppressed. That is, in sensor chip 100, the damage resistance of the beam to displacement in all directions can be improved.

[0129] Thus, the sensor chip 100 has one or more first detection beams orthogonal to the input displacement direction, and these first detection beams can deform significantly. Therefore, it is possible to effectively detect both Fx and Fy inputs, and the detection beams will not be damaged even with large Fx and / or Fy inputs. As a result, the sensor chip 100 can accommodate larger ratings, improving the measurement range or load capacity. For example, in the sensor chip 100, the rating can be set to approximately 500N, about 10 times that of the conventional rating.

[0130] In addition, the T-shaped beam structure connected from the force point in three directions in each probe block undergoes different deformations according to the input, thus enabling the detection of multi-axis forces with good separability.

[0131] In addition, the beam is T-shaped, so there are many paths from the beam to the frame or connection, which makes it easy to run wiring around the outer periphery of the sensor chip, thus increasing the flexibility of layout.

[0132] In the sensor chip 100, the first detection beams 131a, 131c, 132a, 132c, 133a, 133c, 134a, and 134c, which are arranged opposite each other with respect to the torque in the Z-axis direction, deform significantly. Therefore, piezoresistive elements can be arranged on some or all of these first detection beams.

[0133] Furthermore, regarding displacement in the Z-axis direction, the second sensing beams 131b, 131d, 131f, 132b, 132d, 132f, 133b, 133d, 133f, 134b, 134d, and 134f, which are directly connected to each force point, undergo significant deformation. Therefore, piezoresistive elements can be installed on some or all of these second sensing beams.

[0134] (Should be variant 200)

[0135] like Figure 1 and Figure 2 As shown, the strain variant 200 includes a stress plate 210, a strain section 220, an input transmission section 230, and a cover plate 240. Here, each structural part of the strain variant 200 will be described.

[0136] Figure 16 This is a three-dimensional diagram illustrating a stress-bearing plate that constitutes a strained body. For example... Figure 16 As shown, the force plate 210 is a generally disc-shaped component that receives force or torque from the object being measured. The force plate 210 has a generally annular outer frame portion 211 in plan view, a generally circular central portion 212 in plan view disposed separately from the outer frame portion 211 and located inside the outer frame portion 211, and a plurality of beam structures 213 bridging the outer frame portion 211 and the central portion 212.

[0137] By utilizing the beam structure 213 to enhance the rigidity of the load-bearing plate 210, even when force or torque is input from the object being measured, the load-bearing plate 210 itself remains almost undeformed, and the force or torque is transmitted without loss to the strain section 220 connected at the central portion 212. A threaded hole 218 is provided in the portion protruding from the inner side of the outer frame portion 211 toward the beam structure 213. The threaded hole 218 is, for example, a fastening hole that can be used to secure the load-bearing plate 210 to the object being measured with screws.

[0138] Figure 17 This is a three-dimensional diagram illustrating the strain components that make up the strain body. Figure 18 This is a top view illustrating the strained portion that constitutes the strained body. For example... Figure 17 and Figure 18 As shown, the strain section 220 is a component that is generally disk-shaped and is the part that deforms under the force of the stress plate 210.

[0139] The strain unit 220 has an outer frame portion 221 that is generally annular in plan view, a central portion 222 that is disposed separately from the outer frame portion 221 inside the outer frame portion 221 and is generally circular in plan view, and a plurality of beam structures 223 that bridge the outer frame portion 221 and the central portion 222. The outer diameter of the outer frame portion 221 is, for example, about 50 mm. The thickness of the beam structures 223 is, for example, about 3 mm to 8 mm.

[0140] Multiple beam structures 223 are arranged symmetrically with respect to the center point of the strain section 220, for example. There are, for example, four beam structures 223. Each beam structure 223 is, for example, a T-shape comprising a first beam 223a and a second beam 223b extending from the center of the first beam 223a in a direction orthogonal to the first beam 223a. The two ends of the first beam 223a are connected to the outer frame portion 221, and the end of the second beam 223b is connected to the central portion 222. For example, in top view, the strain section 220 is four-fold symmetrical with respect to the center of the outer frame portion 221.

[0141] The central portion 222 is thinner than the outer frame portion 221, and the beam structure 223 is thinner than the central portion 222. The upper surfaces of the central portion 222 and the beam structure 223 are approximately flush and lower than the upper surface of the outer frame portion 221. The lower surface of the central portion 222 protrudes slightly beyond the lower surface of the outer frame portion 221. The lower surface of the beam structure 223 is higher than both the lower surfaces of the outer frame portion 221 and the central portion 222. Only the beam structure 223 and the central portion 222 deform under the force of the load-bearing plate 210; the outer frame portion 221 remains undeformed. Specifically, the central portion 222 only moves in accordance with the deformation of the beam structure 223; the central portion 222 itself does not deform.

[0142] A groove 220x is formed on the surface of the central portion 222 on the side of the input transmission portion 230. The groove 220x is a shape in which a square groove and two orthogonal cross-shaped grooves longer than one side of the square overlap in a state of center alignment. The square groove and the cross-shaped groove have the same depth.

[0143] Five columnar first connecting portions 224 protruding toward the input transmission portion 230 are arranged on the outside of the cross-shaped groove, at the four corners of the square groove, and at the center of the square groove, in a manner that does not contact the inner wall of the groove 220x.

[0144] The first connecting portion 224 is the part that connects to the support portions 101 to 105 of the sensor chip 100. The upper surface of each first connecting portion 224 is roughly flush with the upper surface and is located lower than the upper surface of the central portion 222 and the upper surface of the beam structure 223.

[0145] A threaded hole 228 is provided in the outer frame portion 221. The threaded hole 228 is, for example, a fastening hole used to secure the strain gauge 220, the input transmission portion 230, and the cover plate 240 to the fixed side (the side of the robot, etc.) using screws. Figure 17 and Figure 18 In the example, there are four threaded holes 228 that are circular when viewed from above. The size of the threaded holes 228 is, for example, M5 according to JIS standard.

[0146] A space 229 is provided outside each threaded hole 228 of the outer frame portion 221, isolated from the threaded holes 228. The space 229 can, for example, be arc-shaped in a plan view, surrounding a portion of the threaded hole 228. In plan view, the arc-shaped opening side of the space 229 faces the outer periphery of the outer frame portion 221. 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.

[0147] From a top view, each threaded hole 228 is positioned between adjacent beam structures 223. From a top view, a space 229 is provided at least between the threaded holes 228 and the beam structures 223 adjacent to both sides of the threaded holes 228. The space 229 preferably extends through the outer frame 221, but may not. The width of the space 229 is approximately constant, for example, 0.5 mm to 1.5 mm. Alternatively, the width of the space 229 may not be constant; the width at both ends of the arc of the space 229 may be widened to 0.5 mm to 1.5 mm, and narrowed from one end of the arc to the other to, for example, 0.2 mm.

[0148] Thus, in the strain gauge 200, a space 229 is provided between the threaded hole 228 of the strain section 220 and the beam structure 223 adjacent to both sides of the threaded hole 228. This makes it difficult for forces generated when the strain gauge 200 is fastened to the test object using screws to be transmitted towards the central portion 222, and even if forces are transmitted, the inner side of the central portion 222 can easily maintain the same shape and undergo the same displacement as a whole. Furthermore, when the strain gauge 200 is mounted on the test object, deformation towards the central portion 222 can be suppressed when the strain gauge 200 experiences temperature distribution due to the heat generated by the test object.

[0149] Therefore, displacement of the first connecting portions 224 connected to the support portions 101-105 of the sensor chip 100 can be suppressed, and the displacement of the five first connecting portions 224 can be homogenized. As a result, adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force when the strain gauge 200 is fastened to the object being measured using screws or by the temperature distribution of the strain gauge 200 can be reduced.

[0150] like Figure 18 As shown, from a top view, the four threaded holes 228 include two threaded holes 228 that are centered opposite each other and sandwich the outer frame portion 221, and two other threaded holes 228 that are centered opposite each other. From a top view, the imaginary straight line L1 connecting the centers of the two threaded holes 228 that are centered opposite each other and the imaginary straight line L2 connecting the centers of the two other threaded holes 228 that are centered opposite each other are orthogonal to each other, forming an imaginary cross line.

[0151] Furthermore, from a top view, the four beam structures 223 include two beam structures 223 that are centered opposite each other and sandwich the outer frame portion 221, and two other beam structures 223 that are centered opposite each other and sandwich the outer frame portion 221. From a top view, the imaginary straight line L3 connecting the center lines of the two beam structures 223 sandwiching the outer frame portion 221 in the width direction and the imaginary straight line L4 connecting the center lines of the other two beam structures 223 sandwiching the outer frame portion 221 in the width direction are orthogonal to each other, forming an imaginary cross line.

[0152] That is, the two beam structures 223 that are opposite each other at the center of the outer frame 221 and the other two beam structures 223 that are opposite each other at the center of the outer frame 221 form a beam that is roughly cross-shaped when viewed from above.

[0153] Preferably, when viewed from above, the cross lines formed by straight lines L1 and L2 are offset from the cross lines formed by straight lines L3 and L4 by 45 degrees. That is, each beam structure 223 is preferably located in the middle of adjacent threaded holes 228. Furthermore, considering manufacturing deviations, the 45 degrees referred to here includes a range of 45 degrees ± 5 degrees.

[0154] In the outer frame portion 221, the middle portion of adjacent threaded holes 228 is the farthest from each threaded hole 228, and therefore is the least prone to deformation. Therefore, by extending the beam structure 223 from the middle portion of adjacent threaded holes 228, the force generated when the strain gauge 200 is fastened to the object being measured using screws is difficult to transmit to the central portion 222 side, and even if force is transmitted, the inner side of the central portion 222 can easily maintain the same shape and undergo the same displacement as a whole. Furthermore, when the strain gauge 200 is mounted on the object being measured, deformation on the central portion 222 side can be suppressed when the strain gauge 200 experiences temperature distribution due to the heat generated by the object being measured.

[0155] As a result, as described above, it is possible to reduce the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain 200 when it is fastened to the object being measured with screws or by the temperature distribution of the strain 200.

[0156] Furthermore, since a space is provided on the upper surface of the central portion 222, a circuit board or other electronic components such as connectors or semiconductor elements can be arranged on the upper surface of the central portion 222, for example, in a manner that does not protrude from the upper surface of the outer frame portion 221.

[0157] Figure 19 This is a perspective view illustrating the upper surface of the input transmission section that constitutes the strain body. Figure 20 This is a top view illustrating the input transmission part that constitutes the strain body. Figure 21 This is a perspective view illustrating the lower surface of the input transmission section that constitutes the strain body. Figure 22 This is a cross-sectional view illustrating the input transmission section that constitutes the strain body, showing the direction along... Figure 20 The cross-section of line L7. For example... Figures 19-22 As shown, the input transmission unit 230 is a generally disk-shaped component that transmits the deformation (input) of the strain unit 220 to the sensor chip 100.

[0158] The input transmission unit 230 has a generally annular outer frame 231 (viewed from top view), a central portion 232 disposed separately from the outer frame 231 on the inner side of the outer frame 231, and a plurality of beam structures 233 bridging the outer frame 231 and the central portion 232. The outer diameter of the outer frame 231 is, for example, about 50 mm. The plurality of beam structures 233 are, for example, symmetrically arranged with respect to the center point of the input transmission unit 230. There are, for example, four beam structures 233. Each beam structure 233 is, for example, I-shaped. In top view, the beam structures 233 of the input transmission unit 230 and the beam structures 223 of the strain unit 220 overlap at least partially.

[0159] The outer frame portion 231 is thicker and more rigid than other portions, making it the least prone to deformation. The central portion 232 has a first connecting portion 234 that is generally annular in plan view and a generally cross-shaped receiving portion 235 that extends from the lower surface of the first connecting portion 234 toward the strain portion 220. The receiving portion 235 is located inside the first connecting portion 234 and can accommodate the sensor chip 100. As for each beam structure 233, one end is connected to the outer frame portion 231 and extends inward from the outer frame portion 231, and the other ends are connected to each other through the frame-shaped first connecting portion 234.

[0160] In this way, by connecting the beam structures 233 extending from the four directions of the input transmission section 230 through the first connecting section 234, the rigidity of the receiving section 235 can be improved. This makes it difficult for the force generated when the strain gauge 200 is fastened to the object being measured using screws to be transmitted to the first connecting section 234 side, and even if force is transmitted, the inner side of the first connecting section 234 can easily maintain the same shape and undergo the same displacement as a whole. Furthermore, when the strain gauge 200 is mounted on the object being measured, deformation on the first connecting section 234 side can be suppressed if the strain gauge 200 experiences temperature distribution due to the heat generated by the object being measured.

[0161] Therefore, the displacement of the four second connecting portions 235d connected to the force points 151-154 of the sensor chip 100 can be suppressed, and the displacement of the four second connecting portions 235d can be homogenized. As a result, the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force when the strained body 200 is fastened to the object being measured using screws or the temperature distribution of the strained body 200 can be reduced.

[0162] The beam structure 233 and the first connecting portion 234 are formed to be thinner than the outer frame portion 231. The upper surfaces of the beam structure 233 and the first connecting portion 234 are positioned lower than the upper surface of the outer frame portion 231. The lower surfaces of the outer frame portion 231, the beam structure 233, and the first connecting portion 234 are substantially flush. No part of the input transmission portion 230 will deform due to applied forces or moments.

[0163] Each beam structure 233 preferably has a countersunk portion 233a, the thickness of which is thinner at the end connected to the outer frame portion 231 than at the other end connected to the first connecting portion 234. Preferably, the countersunk portion 233a is provided on the side closest to the outer frame portion 231 along the entire width direction of the beam structure 233 compared to the side of the first connecting portion 234. The thickness T1 of the central portion 232 side of the beam structure 233 is, for example, about 1.5 mm. The thickness T1 of the central portion 232 side of the beam structure 233 may also be the same as the thickness of the first connecting portion 234.

[0164] The thickness T2 of the countersunk portion 233a (the thickness of one end of the beam structure 233) is, for example, thicker than 1 mm and thinner than 1.25 mm. That is, the depth of the countersunk portion 233a, based on the upper surface of the beam structure 233, is, for example, approximately 0.25 mm to 0.5 mm. Furthermore, the length of the long side of the beam structure 233 is, for example, approximately 8 mm, and the width is approximately 4 mm. Additionally, the length of the countersunk portion 233a is, for example, approximately 5 mm.

[0165] The beam structure 233 has a countersunk portion 233a, so that when the strain gauge 200 is fastened to the object being measured using screws, even if the outer frame portion 231 deforms, the countersunk portion 233a of the beam structure 233 absorbs the deformation on the outer frame portion 231 side. Therefore, the force generated when the strain gauge 200 is fastened to the object being measured using screws is difficult to be transmitted to the first connecting portion 234 side, and even if the force is transmitted, the inner side of the first connecting portion 234 can easily maintain the same shape and undergo the same displacement as a whole. In addition, when the strain gauge 200 is installed on the object being measured, if the strain gauge 200 generates a temperature distribution due to the heat of the object being measured, deformation on the first connecting portion 234 side can be suppressed.

[0166] As a result, as described above, it is possible to reduce the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain 200 when it is fastened to the object being measured with screws or by the temperature distribution of the strain 200.

[0167] Furthermore, the corner 233b on the side of the outer frame portion 231 of the countersunk portion 233a is preferably R-shaped in cross-section. Additionally, the corner 233c on the side of the first connecting portion 234 of the countersunk portion 233a is preferably R-shaped in cross-section.

[0168] Therefore, the displacement of the four second connecting portions 235d connected to the force points 151-154 of the sensor chip 100 can be further suppressed, and the displacement of the four second connecting portions 235d can be further homogenized. As a result, the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain gauge 200 when it is fastened to the object being measured with screws or the temperature distribution of the strain gauge 200 can be further reduced.

[0169] The receiving portion 235 is provided inside the first connecting portion 234. The receiving portion 235 has four vertical support portions 235a that are connected to the first connecting portion 234 at one end and extend vertically from the lower surface of the first connecting portion 234 toward the strain portion 220, four horizontal support portions 235b that extend horizontally from the lower end of the vertical support portions 235a, and a second connecting portion 235c that connects the other ends of the horizontal support portions 235b to each other.

[0170] That is, the front ends of the four horizontal support portions 235b are connected by the second connecting portion 235c. The lower surface of the second connecting portion 235c is approximately flush with the lower surface of the horizontal support portion 235b, and its upper surface is thinner than the first layer of the horizontal support portion 235b. A through hole may also be provided at the center of the second connecting portion 235c.

[0171] Four second connecting portions 235d protruding toward the cover plate 240 are arranged on the bottom surface of the second connecting portion 235c in a manner that does not contact the inner wall of the second connecting portion 235c. Each second connecting portion 235d is approximately located on the line that bisects each horizontal support portion 235b in the short side direction. The second connecting portions 235d are the parts that connect to the force points 151 to 154 of the sensor chip 100.

[0172] The front ends of the four horizontal support portions 235b can also be separated. Even in this case, by connecting the other ends of each beam structure 233 to each other using the first connecting portion 234, it is possible to prevent the force generated when the strain gauge 200 is fastened to the object being measured using screws from being transmitted to the first connecting portion 234 side, and even if the force is transmitted, it is easy to maintain the same shape and make the same displacement as a whole for the portion inside the first connecting portion 234. In addition, when the strain gauge 200 is installed on the object being measured, deformation on the first connecting portion 234 side can be suppressed when the strain gauge 200 generates a temperature distribution due to the heat generated by the object being measured.

[0173] As a result, as described above, it is possible to reduce the force exerted when the strained body 200 is fastened to the object being measured using screws, or the adverse effects of temperature distribution on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variations of the sensor chip 100 caused by the strained body 200.

[0174] However, it is preferable to connect the horizontal support portions 235b extending in four directions via the second connecting portion 235c. This further suppresses the displacement of the four second connecting portions 235d connected to the force points 151-154 of the sensor chip 100, and further homogenizes the displacement of the four second connecting portions 235d. As a result, the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain gauge 200 when it is fastened to the object being measured using screws or by the temperature distribution of the strain gauge 200 can be further reduced.

[0175] A threaded hole 238 is provided in the outer frame portion 231. The threaded hole 238 is, for example, a fastening hole used to secure the strain gauge 220, the input transmission portion 230, and the cover plate 240 to a fixed side (such as a robot side) using screws. Figures 19-22 In the example, there are four threaded holes 238 that are circular when viewed from above. The size of the threaded holes 238 is, for example, M5 according to JIS standard.

[0176] A space portion 239 is provided outside each threaded hole 238 of the outer frame portion 231, isolated from the threaded holes 238. A portion of the upper surface of the outer frame portion 231 of the space portion 239 communicates with a thin plate portion 231x of the outer frame portion 231, which is formed to be thinner than the outer periphery. The upper surface of the thin plate portion 231x is substantially flush with the upper surface of the first connecting portion 234. By providing the thin plate portion 231x, a large space can be formed, and therefore, components such as substrates can be arranged.

[0177] The space portion 239 can, for example, be configured as an arc shape that surrounds a portion of the threaded hole 238 when viewed from above. When viewed from above, the opening side of the arc portion 239 is configured to face the outer periphery of the outer frame portion 231. In other words, in the space portion 239, the apex of the arc is located closer to the center of the outer frame portion 231 than the two ends of the arc.

[0178] From a top view, each threaded hole 238 is positioned between adjacent beam structures 233. From a top view, a space 239 is provided at least between the threaded holes 238 and the beam structures 233 adjacent to both sides of the threaded holes 238. The space 239 preferably extends through the outer frame 231, but may not. The width of the space 239 is approximately constant, for example, 0.5mm to 1.5mm. Alternatively, the width of the space 239 may not be constant; the width at both ends of the arc of the space 239 may be widened to 0.5mm to 1.5mm, and narrowed from one end of the arc to the other to, for example, 0.2mm.

[0179] Each threaded hole 238 and each threaded hole 228 are arranged to overlap in a top view, and each spatial part 239 and each spatial part 229 are arranged to overlap in a top view.

[0180] Thus, in the strain gauge 200, a space 239 is provided between the threaded hole 238 of the input transmission section 230 and the beam structure 233 adjacent to both sides of the threaded hole 238. This makes it difficult for the force generated when the strain gauge 200 is fastened to the object being measured using screws to be transmitted to the first connecting portion 234 side, and even if force is transmitted, it is easy to maintain the same shape and undergo the same displacement as a whole for the portion inside the first connecting portion 234. Furthermore, when the strain gauge 200 is installed on the object being measured, deformation on the central portion 222 side can be suppressed when the strain gauge 200 experiences temperature distribution due to the heat generated by the object being measured.

[0181] As a result, as described above, it is possible to reduce the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain 200 when it is fastened to the object being measured with screws or by the temperature distribution of the strain 200.

[0182] like Figure 20 As shown, the four threaded holes 238 include two threaded holes 238 that are centered opposite each other and sandwich the outer frame portion 231 when viewed from above, and two other threaded holes 238 that are centered opposite each other and sandwich the outer frame portion 231.

[0183] From a top view, the imaginary straight line L5 connecting the centers of the two threaded holes 238 that are opposite each other in the center of the outer frame 231 and the imaginary straight line L6 connecting the centers of the other two threaded holes 238 that are opposite each other in the center of the outer frame 231 are orthogonal to each other, forming an imaginary cross line.

[0184] In addition, the four beam structures 233 include two beam structures 233 that are centrally opposed to each other and sandwich the outer frame portion 231 when viewed from above, and two other beam structures 233 that are centrally opposed to each other and sandwich the outer frame portion 231.

[0185] From a top view, the imaginary straight line L7 connecting the center lines of the two beam structures 233 that are opposite each other in the width direction, which sandwich the outer frame 231, and the imaginary straight line L8 connecting the center lines of the other two beam structures 233 that are opposite each other in the width direction, are orthogonal to each other, forming an imaginary cross.

[0186] That is, the two beam structures 233 that are opposite each other at the center of the outer frame 231 and the other two beam structures 233 that are opposite each other at the center of the outer frame 231 form a beam that is roughly cross-shaped when viewed from above.

[0187] Preferably, when viewed from above, the cross lines formed by straight lines L5 and L6 are offset by 45 degrees from the cross lines formed by straight lines L7 and L8. That is, each beam structure 233 is preferably located in the middle of adjacent threaded holes 238. Furthermore, considering manufacturing deviations, the 45 degrees mentioned here includes a range of 45 degrees ± 5 degrees.

[0188] As described above, the rigidity of the outer frame portion 231 is higher than that of other portions. However, even within the outer frame portion 231, the middle portion of adjacent threaded holes 238 is the furthest from each threaded hole 238, making it the least prone to deformation. Therefore, by extending the beam structure 233 from the middle portion of adjacent threaded holes 238, it is possible to prevent the force generated when the strain gauge 200 is fastened to the test object using screws from being transmitted to the first connection portion 234 side. Furthermore, even if force is transmitted, it is easy to maintain the same shape and undergo the same displacement as a whole for the portion inside the first connection portion 234. In addition, when the strain gauge 200 is mounted on the test object, deformation on the first connection portion 234 side can be suppressed when the strain gauge 200 generates a temperature distribution due to the heat generated by the test object.

[0189] As a result, as described above, it is possible to reduce the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain 200 when it is fastened to the object being measured with screws or by the temperature distribution of the strain 200.

[0190] Furthermore, from a top-down view, the crosshairs formed by lines L5 and L6 intersect with the crosshairs formed by lines L1 and L2 (see reference). Figure 18 ) overlap. Additionally, from a top-down view, the crosshairs formed by lines L7 and L8 overlap with the crosshairs formed by lines L3 and L4 (see reference). Figure 18 )overlapping.

[0191] In the receiving part 235, viewed from above, two vertical support parts 235a and horizontal support parts 235b are positioned opposite each other, sandwiching the center of the outer frame part 231, and another two vertical support parts 235a and horizontal support parts 235b are positioned opposite each other, sandwiching the center of the outer frame part 231.

[0192] From a top view, the imaginary straight line connecting the center lines of the two vertical support portions 235a and the horizontal support portion 235b that are opposite each other in the width direction, which sandwich the outer frame portion 231, coincides with line L5. Furthermore, from a top view, the imaginary straight line connecting the center lines of the other two vertical support portions 235a and the horizontal support portion 235b that are opposite each other in the width direction, which sandwich the outer frame portion 231, coincides with line L6, which is orthogonal to line L5.

[0193] That is, the two vertical support parts 235a and the horizontal support part 235b that are opposite each other at the center of the outer frame part 231, and the other two vertical support parts 235a and the horizontal support part 235b that are opposite each other at the center of the outer frame part 231, form a beam that is roughly cross-shaped when viewed from above.

[0194] As described above, preferably, when viewed from above, the cross lines formed by straight lines L5 and L6 are offset by 45 degrees from the cross lines formed by straight lines L7 and L8. That is, preferably, when viewed from above, the long side direction of each horizontal support 235b is offset by 45 degrees from the long side direction of each beam structure 233.

[0195] The middle portion of the inner periphery of adjacent beam structures 233 is the farthest from the inner periphery of each beam structure 233, and therefore is the least prone to deformation. Therefore, by extending the vertical support portion 235a and the horizontal support portion 235b from the middle portion of the inner periphery of adjacent beam structures 233, the force generated when the strain gauge 200 is fastened to the object being measured using screws is difficult to transmit to the second connection portion 235c. Furthermore, even if force is transmitted, the second connection portion 235c can easily maintain the same shape and undergo the same displacement as a whole. Additionally, when the strain gauge 200 is installed on the object being measured, deformation of the second connection portion 235c can be suppressed when the strain gauge 200 experiences temperature distribution due to the heat generated by the object being measured.

[0196] As a result, as described above, it is possible to reduce the adverse effects on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 caused by the force of the strain 200 when it is fastened to the object being measured with screws or by the temperature distribution of the strain 200.

[0197] Furthermore, since a space is provided on the upper surface of the beam structure 233, a circuit board or similar device that houses electronic components such as connectors and semiconductor elements can be arranged on the upper surface of the beam structure 233, for example, in a manner that does not protrude from the upper surface of the outer frame portion 231.

[0198] Figure 23 This is a three-dimensional view illustrating the cover plate that constitutes the strain gauge. For example... Figure 23As shown, the cover plate 240 is a generally disc-shaped component that protects internal parts (such as the sensor chip 100). The cover plate 240 is thinner than the force plate 210, the strain section 220, and the input transmission section 230. A threaded hole 248 is provided in the cover plate 240. The threaded hole 248 is, for example, a fastening hole used to secure the strain section 220, the input transmission section 230, and the cover plate 240 to a fixed side (such as a robot) using screws.

[0199] Hard metal materials such as SUS (stainless steel) can be used as materials for the load-bearing plate 210, strain gauge 220, input transmission part 230, and cover plate 240. Among these, SUS630, which is hard and has high mechanical strength, is particularly preferred. It is desirable that the components constituting the strain gauge 200, especially the load-bearing plate 210, strain gauge 220, and input transmission part 230, are firmly connected or are integrally structured. As for the connection method of the load-bearing plate 210, strain gauge 220, and input transmission part 230, the use of screws, welding, etc., is considered, but regardless of the method, it is necessary to be able to withstand the force or torque input to the strain gauge 200.

[0200] In this embodiment, as an example, the stress plate 210, strain section 220, and input transmission section 230 are fabricated by metal powder injection molding, then assembled and sintered again to achieve diffusion bonding. The diffusion-bonded stress plate 210, strain section 220, and input transmission section 230 achieve sufficient bond strength. The cover plate 240 can be fastened to the input transmission section 230, for example, with screws after the sensor chip 100 or other internal components are assembled.

[0201] In strain gauge 200, when a force or torque is applied to the load-bearing plate 210, the force or torque is transmitted to the central portion 222 of strain gauge 220 connected to the load-bearing plate 210, and deformation corresponding to the input is generated through the four beam structures 223. At this time, the outer frame portion 221 and the input transmission portion 230 of strain gauge 220 do not deform.

[0202] That is, in the strain gauge 200, the load-bearing plate 210, the central portion 222 of the strain section 220, and the beam structure 223 are movable portions that deform under a predetermined axial force or moment, while the outer frame portion 221 of the strain section 220 is a non-movable portion that does not deform under force or moment. Furthermore, the input transmission portion 230, which engages with the outer frame portion 221 of the non-movable strain section 220, is also a non-movable portion that does not deform under force or moment, and the cover plate 240, which engages with the input transmission portion 230, is also a non-movable portion that does not deform under force or moment.

[0203] When the strain gauge 200 is used in the force sensor device 1, the support portions 101 to 105 of the sensor chip 100 are connected to the first connecting portion 224, which is a movable portion 222. Additionally, the force points 151 to 154 of the sensor chip 100 are connected to the second connecting portion 235d, which is a non-movable portion. Therefore, the sensor chip 100 deforms each detection beam via the support portions 101 to 105 while the force points 151 to 154 remain stationary.

[0204] However, it can also be configured such that the force points 151 to 154 of the sensor chip 100 are connected to the first connecting portion 224, which is the central portion 222, which is a movable part, and the support portions 101 to 105 of the sensor chip 100 are connected to the second connecting portion 235d, which is the receiving portion 235, which is a non-movable part.

[0205] That is, the sensor chip 100 that can be accommodated in the housing portion 235 has support portions 101-105 and force points 151-154 whose relative positions change due to force or torque. Furthermore, in the strain gauge 200, the central portion 222, which is a movable portion, has a first connecting portion 224 that extends toward the input transmission portion 230 and connects to one of the support portions 101-105 and force points 151-154. Additionally, the housing portion 235 has a second connecting portion 235d that connects to the other of the support portions 101-105 and force points 151-154.

[0206] [simulation]

[0207] Figure 24 This is a three-dimensional view illustrating the strain of a comparative example. For example... Figure 24 As shown, the strain section 220X of the comparative example is at a point where it does not have a portion equivalent to the space section 229, and is related to the strain section 220 (see reference). Figure 17 (etc.) are different.

[0208] Figure 25 This is a three-dimensional diagram illustrating the input transmission unit of a comparative example. For example... Figure 25 As shown, the comparative example's input transmission unit 230X has an outer frame portion 231X that is generally annular in plan view, an inner frame portion 232X that is generally rectangular in plan view and adjacent to the inner periphery of the outer frame portion 231X, and a receiving portion 235X provided inside the inner frame portion 232X. The inner frame portion 232X is formed to be thinner than the outer frame portion 231X, and its upper surface is positioned lower than the upper surface of the outer frame portion 231X. The input transmission unit 230X does not have portions corresponding to the beam structure 233, the first connecting portion 234, and the space portion 239.

[0209] The receiving portion 235X, like the receiving portion 235, has a vertical support portion 235a, a horizontal support portion 235b, and a second connecting portion 235d, but also has a second horizontal support portion 235e that extends horizontally from the inner side of the inner frame portion 232X and connects to the vertical support portion 235a. Furthermore, unlike the receiving portion 235, although the horizontal support portions 235b are arranged in a roughly cross shape when viewed from above, they do not intersect, and the inner peripheral ends of each horizontal support portion 235b are separated from each other. That is, the receiving portion 235X does not have a portion equivalent to the second connecting portion 235c.

[0210] Figure 26 This is a perspective view illustrating the state in which the input transmission section is arranged on the strain section of the comparative example. The receiving portion 235X of the input transmission section 230X enters the strain section 220X side. Furthermore, the first connecting portion 224 of the strain section 220X is exposed within the receiving portion 235X near the second connecting portion 235d.

[0211] Figure 27 This is a perspective view illustrating the state in which the input transmission section is arranged on the strain section in this embodiment. The receiving portion 235 of the input transmission section 230 enters the strain section 220 side. Furthermore, the first connecting portion 224 of the strain section 220 is exposed within the receiving portion 235 near the second connecting portion 235d.

[0212] Here, it is explained that... Figure 26 Structure and Figure 27 The results of the simulation of the structure were obtained. In the simulation, the Z-direction displacement of the strain section and the input transmission section was confirmed when the axial forces of each screw were inconsistent when the strain was fastened to the test object using screws. Specifically, as... Figure 27 Top view of the structure Figure 28 As shown, the Z-direction displacements of the strain section 220 at measurement points 1-5 (the upper ends of each first connection 224) and the input transmission section 230 at measurement points 1-4 (the upper ends of each second connection 235d) were confirmed when the axial forces of the threaded holes A, B, C, and D were set to 5400N, 4160N, 7720N, and 5400N, respectively. For Figure 26 The displacement in the Z direction at the same measurement point was also confirmed under the same conditions for the structure.

[0213] Figure 29 This is a comparative example. Figure 26 Contour map of the structure's displacement. Figure 30 It is a comparative example Figure 26 A diagram summarizing the displacements of each part of the structure. Figure 31 This is the implementation method Figure 27 Contour map of the structure's displacement. Figure 32 This embodiment is Figure 27The diagram summarizes the displacements of each part of the structure. In each displacement contour plot, the area below the arrow is a magnified view of the region where the sensor chip 100 is located.

[0214] according to Figures 29-32 As a result, in this embodiment Figure 27 In the structure, relative to the comparative example Figure 26 In this structure, the displacement at each measurement point of the strain section is suppressed to below 50%. Furthermore, in this embodiment... Figure 27 In the structure, relative to the comparative example Figure 26 The structure has a displacement of less than 10% in the input transmission part.

[0215] In addition, compared to the comparative example Figure 26 The structure in this embodiment Figure 27 In the structure, the difference between the displacement of the strain unit relative to the input and the displacement of the input transmission unit is small. The difference between the displacement of the strain unit relative to the input and the displacement of the input transmission unit is the input to the sensor chip 100; therefore, compared to the comparative example... Figure 26 The structure in this embodiment Figure 27 In the structure, the offset of the sensor chip 100 caused by the force when the strained object is fastened to the object being measured using screws is reduced. That is, the adverse effects of the force when the strained object is fastened to the object being measured using screws on the load-bearing capacity, force characteristics, offset temperature characteristics, and offset variation of the sensor chip 100 can be reduced.

[0216] [Simulation 1]

[0217] Here, it is explained that... Figure 26 Structure and Figure 27 The results of Simulation 1 were performed on the structure. In Simulation 1, after setting the lower surface of the load-bearing plate installed on the object under test to a steady state at 35°C, the Z-displacement difference was confirmed when the temperature rose 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 four second connecting parts 235d minus the average value of the Z-direction displacement of the upper ends of the five first connecting parts 224.

[0218] In addition, simulation 1 was passed Figure 26 Structure and Figure 27 A 1 / 4 scale model of the structure was used. Additionally, in Figure 27 In the structure, the length of the beam structure 233 is set to 8mm, the width of the beam structure 233 is set to 4mm, the length of the countersunk portion 233a is set to 5mm, the thickness T1 of the central portion 232 side of the beam structure 233 of the countersunk portion 233a is set to 1.5mm, and the thickness T2 of the countersunk portion 233a is set to 1.25mm.

[0219] Figure 33 This is a graph representing the results of Simulation 1. Figure 33 The upper side of the arrow represents the change in Z-displacement difference relative to time, and the lower side of the arrow is the contour map of the displacements at points A and B where the Z-displacement difference is largest. Furthermore, in Figure 33 The upper side of the arrow, the comparison example is Figure 26 This embodiment is a 1 / 4 scale model of the structure. Figure 27 A 1 / 4 model of the structure.

[0220] like Figure 33 As shown, in the comparative example Figure 26 In the structure, the Z-displacement difference is at its maximum, approximately 1 μm, after about 5 seconds. Thereafter, the Z-displacement difference decreases with time and stabilizes at approximately 0.1 μm. In contrast, in this embodiment… Figure 27 In the structure, the Z-displacement difference is at its maximum after approximately 5 seconds, with a value of about 0.15 μm. Afterward, the Z-displacement difference decreases with time and stabilizes at approximately -0.05 μm.

[0221] In addition, according to Figure 33 As can be seen from the contour map, in the comparative example Figure 26 In the structure, besides the large Z-displacement difference, the positional relationship between the second connecting parts 235d is also not maintained. In contrast, in this embodiment... Figure 27 In the structure, the Z displacement difference is small, and the positional relationship between the second connecting parts 235d is maintained.

[0222] Thus, relative to the comparative example Figure 26 The structure in this embodiment Figure 27 In this structure, the Z-displacement difference caused by temperature distribution can be significantly reduced, and the positional relationship between the second connecting parts 235d can be maintained. That is, compared to the comparative example... Figure 26 The structure in this embodiment Figure 27 In the structure, the offset of the sensor chip 100 generated when the strain produces a temperature distribution can be reduced.

[0223] [Simulation 2]

[0224] In Simulation 2, Figure 27 In the structure, for T2 = 1.0 mm and T2 = 1.5 mm (that is, the case without countersunk hole 233a), the same simulation as in Simulation 1 was performed, and the results were compared with those in Simulation 1 when T2 = 1.25 mm. In Simulation 2, the conditions other than T2 were the same as in Simulation 1.

[0225] like Figure 34As shown, when T2 = 1.5 mm (i.e., without the countersunk hole 233a), the maximum Z-displacement difference is approximately 0.6 μm. In contrast, when T2 = 1.0 mm, the maximum Z-displacement difference is approximately -0.5 μm. Although the displacement direction is opposite to that at T2 = 1.5 mm, the absolute value is slightly improved. Furthermore, when T2 = 1.25 mm, the maximum Z-displacement difference is approximately 0.15 μm, representing a significant improvement compared to T2 = 1.0 mm and T2 = 1.5 mm.

[0226] In this way, the thickness T2 of the countersunk portion 233a has an optimal value. It is preferable to adjust the thickness T2 of the countersunk portion 233a within a range that is thicker than 1.0 mm and thinner than 1.5 mm, and more preferably within a range that is thicker than 1.0 mm and thinner than 1.25 mm.

[0227] The preferred embodiments have been described in detail above, but are not limited to the embodiments described above. Various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0228] For example, the above embodiments describe an example of using screws to fasten the strain to the test body, but it is not limited to this. Any fastener capable of fixing the strain to the test body can be used, such as bolts, rivets, etc.

Claims

1. A strain, characterized in that, have: A strain gauge comprising a movable portion that deforms under a predetermined axial force or moment, and a non-movable portion that does not deform under the aforementioned force or moment; and The input transmission part engages with the aforementioned non-movable part and remains undeformed under the aforementioned force or torque. The above-mentioned input transmission unit includes: First frame section; Multiple first beam structures, one end of which is connected to the aforementioned first frame portion and extends inward from the aforementioned first frame portion; A frame-shaped first connecting portion connects the other ends of each of the aforementioned first beam structures to each other; and The receiving part is located inside the first connecting part and is capable of accommodating the sensor chip that detects the force or torque.

2. The strain according to claim 1, characterized in that, The aforementioned first beam structures include two first beam structures that are centrally opposed to each other and sandwich the aforementioned first frame portion when viewed from above, and two other first beam structures that are centrally opposed to each other and sandwich the aforementioned first frame portion.

3. The strain according to claim 2, characterized in that, The aforementioned receiving portion has: Four vertical support portions, one end of which is connected to the first connecting portion and extends vertically from the first connecting portion toward the strain portion side. Four horizontal support sections, which extend horizontally from the ends of the aforementioned vertical support sections; and The second connecting part connects the other ends of the aforementioned horizontal support parts to each other. Viewed from above, the two aforementioned vertical support portions and the aforementioned horizontal support portions are positioned opposite each other, sandwiching the center of the aforementioned first frame portion, and the other two aforementioned vertical support portions and the aforementioned horizontal support portions are positioned opposite each other, sandwiching the center of the aforementioned first frame portion.

4. The strain according to claim 3, characterized in that, Viewed from above, an imaginary straight line connecting the center lines of the two first beam structures facing each other in the width direction, which sandwich the center of the first frame, and an imaginary straight line connecting the center lines of the other two first beam structures facing each other in the width direction, are orthogonal to each other, forming an imaginary first cross line.

5. The strain according to claim 4, characterized in that, From a top view, an imaginary straight line connecting the center lines of the two vertical support parts and the horizontal support parts that are opposite each other in the width direction, which sandwich the center of the first frame, and an imaginary straight line connecting the center lines of the other two vertical support parts and the horizontal support parts that are opposite each other in the width direction, are orthogonal to each other, forming an imaginary second cross line.

6. The strain according to claim 5, characterized in that, Viewed from above, the first and second crosshairs are offset by 45 degrees.

7. The strain according to any one of claims 1 to 6, characterized in that, The strain section described above has: Second frame section; The central portion, which is disposed above the ground on the inner side of the second frame portion; and Multiple second beam structures bridge the aforementioned second frame section and the aforementioned central section. The aforementioned second frame portion is included in the aforementioned non-movable portion, and the aforementioned second beam structure and the aforementioned central portion are included in the aforementioned movable portion.

8. The strain according to claim 7, characterized in that, Each of the aforementioned second beam structures is a T-shape comprising a first beam and a second beam extending from the central portion of the first beam in a direction orthogonal to the first beam. The two ends of the first beam are connected to the second frame portion, and the end of the second beam is connected to the central portion.

9. The strain according to claim 7, characterized in that, The aforementioned second beam structures include two second beam structures that are centrally opposed to each other and sandwich the aforementioned second frame portion when viewed from above, and two other second beam structures that are centrally opposed to each other and sandwich the aforementioned second frame portion.

10. The strain according to claim 9, characterized in that, Viewed from above, an imaginary straight line connecting the center lines of the two second beam structures facing each other in the width direction, which sandwich the center of the second frame, and an imaginary straight line connecting the center lines of the other two second beam structures facing each other in the width direction, are orthogonal to each other, forming an imaginary third cross line.

11. The strain according to claim 7, characterized in that, Viewed from above, the second beam structure and the first beam structure overlap by at least a portion.

12. A strain, characterized in that, have: A strain gauge comprising a movable portion that deforms under a predetermined axial force or moment, and a non-movable portion that does not deform under the aforementioned force or moment; and The input transmission part engages with the aforementioned non-movable part and remains undeformed under the aforementioned force or torque. The above-mentioned input transmission unit includes: Frame; Multiple beam structures, one end of which is connected to the aforementioned frame and extends inward from the aforementioned frame; A frame-like connecting part that connects the other ends of the aforementioned beam structures to each other; and The receiving portion is located on the other end of the beam structure and inside the connecting portion, and is capable of accommodating a sensor chip for detecting the force or torque. Each of the aforementioned beam structures has a countersunk portion in which the thickness of one end is thinner than the thickness of the other end.

13. The strain according to claim 12, characterized in that, The aforementioned countersunk holes are located along the entire width of the aforementioned beam structure.

14. The strain according to claim 12 or 13, characterized in that, The corner of the aforementioned countersunk portion on the frame side is R-shaped in cross-section.

15. The strain according to claim 12, characterized in that, The corner of the aforementioned countersunk portion on the connecting side is R-shaped in cross-section.

16. The strain according to claim 12 or 15, characterized in that, The thickness of the other end of the beam structure is the same as the thickness of the connecting part.

17. The strain according to claim 12 or 13, characterized in that, The thickness of the side at one end of the aforementioned beam structure is greater than 1 mm and less than 1.25 mm.

18. The strain according to claim 12 or 13, characterized in that, The aforementioned beam structures include two beam structures facing each other at the center of the frame portion when viewed from above, and two other beam structures facing each other at the center of the frame portion.

19. The strain according to claim 18, characterized in that, Viewed from above, an imaginary straight line connecting the center lines of the two beam structures facing each other in the width direction, which sandwich the center of the frame, and an imaginary straight line connecting the center lines of the other two beam structures facing each other in the width direction, are orthogonal to each other, forming an imaginary cross.

20. A strain, characterized in that, have: A strain gauge comprising a movable portion that deforms under a predetermined axial force or moment, and a non-movable portion that does not deform under the aforementioned force or moment; and The input transmission part engages with the aforementioned non-movable part and remains undeformed under the aforementioned force or torque. The above-mentioned input transmission unit includes: First frame section; Multiple first beam structures, one end of which is connected to the aforementioned first frame portion and extends inward from the aforementioned first frame portion; A frame-shaped first connecting portion connects the other ends of the aforementioned first beam structures to each other; and The receiving portion is disposed inside the first frame portion and inside the first connecting portion, and is capable of accommodating a sensor chip for detecting the force or torque. The first frame portion is provided with a plurality of first fastening holes for fastening with the object being measured. Viewed from above, there is a first space that surrounds a portion of the aforementioned first fastening hole.

21. The strain according to claim 20, characterized in that, Viewed from above, the aforementioned first spatial section is designed in an arc shape. The vertex of the aforementioned arc is located closer to the center of the aforementioned first frame portion than both ends of the aforementioned arc.

22. The strain according to claim 20 or 21, characterized in that, From a top view, the first space portion is located between the first fastening hole and the first beam structure.

23. The strain according to claim 22, characterized in that, The plurality of the aforementioned first fastening holes include two first fastening holes that are centered opposite each other and clamp the aforementioned first frame portion when viewed from above, and another two first fastening holes that are centered opposite each other and clamp the aforementioned first frame portion. Viewed from above, an imaginary straight line connecting the centers of the two first fastening holes that are opposite each other in the center of the first frame portion, and an imaginary straight line connecting the centers of the other two first fastening holes that are opposite each other in the center of the first frame portion, are orthogonal to each other, forming an imaginary first cross line. The aforementioned first beam structures include, in a top view, two first beam structures that are centrally opposed to each other and sandwich the aforementioned first frame portion, and two other first beam structures that are centrally opposed to each other and sandwich the aforementioned first frame portion. Viewed from above, an imaginary straight line connecting the center lines of the two first beam structures facing each other in the width direction, which sandwich the center of the first frame, and an imaginary straight line connecting the center lines of the other two first beam structures facing each other in the width direction, are orthogonal to each other, forming an imaginary second cross line. Viewed from above, the first and second crosshairs are offset by 45 degrees.

24. The strain according to claim 20 or 21, characterized in that, The above-mentioned strain gauge has the following features: The second frame; and The central portion, which, along with the aforementioned second frame portion, is disposed above the ground on the inner side of the aforementioned second frame portion. The second frame portion is provided with a plurality of second fastening holes for fastening with the object being measured. From above, there is a second space that surrounds a portion of the aforementioned second fastening hole.

25. The strain according to claim 24, characterized in that, Viewed from above, the aforementioned second space is designed in an arc shape. The vertex of the aforementioned arc is located closer to the center of the aforementioned second frame portion than both ends of the aforementioned arc.

26. The strain according to claim 24, characterized in that, The aforementioned strain section includes multiple second beam structures that bridge the aforementioned second frame section and the aforementioned central section. From a top view, the aforementioned second space is located between the aforementioned second fastening hole and the aforementioned second beam structure.

27. The strain according to claim 26, characterized in that, The plurality of the aforementioned second fastening holes include two second fastening holes that are centered opposite each other and clamp the aforementioned second frame portion when viewed from above, and another two second fastening holes that are centered opposite each other and clamp the aforementioned second frame portion. Viewed from above, an imaginary straight line connecting the centers of the two second fastening holes that are opposite each other in the center of the second frame portion, and an imaginary straight line connecting the centers of the other two second fastening holes that are opposite each other in the center of the second frame portion, are orthogonal to each other, forming an imaginary third cross line. The aforementioned second beam structures include, in a top view, two second beam structures that are centrally opposed to each other and sandwich the aforementioned second frame portion, and two other second beam structures that are centrally opposed to each other and sandwich the aforementioned second frame portion. Viewed from above, an imaginary straight line connecting the center lines of the two second beam structures facing each other in the width direction, and an imaginary straight line connecting the center lines of the other two second beam structures facing each other in the width direction, are orthogonal to each other, forming an imaginary fourth cross line. Viewed from above, the third and fourth cross lines are offset by 45 degrees.

28. The strain according to claim 24, characterized in that, Viewed from above, the second fastening hole overlaps with the first fastening hole. From a top view, the aforementioned second spatial section overlaps with the aforementioned first spatial section.

29. A force sensor device, characterized in that, The strainer having any one of claims 1 to 28 and the aforementioned sensor chip.

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