Strain body, force sensor device

Abstract

The present application provides a strain body capable of having both high load and displacement. The strain body has: a strain portion having a movable portion that deforms in response to a predetermined axial force or torque, and a non-movable portion that does not deform in response to the force or torque; and an input transmission portion that is joined to the non-movable portion and does not deform in response to the force or torque, the input transmission portion having a housing portion that houses a sensor chip that detects the force or torque, and transmits deformation of the strain portion to the sensor chip.

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 can be described as follows: it comprises a sensor chip, an external force application plate disposed around the sensor chip and applying an external force, a pedestal portion supporting the sensor chip, an external force buffer mechanism for fixing the external force application plate to the pedestal portion, and a connecting rod serving as an external force transmission mechanism, wherein the external force application plate and the action portion are connected by the connecting rod (for example, see Patent Document 1).

[0003] Existing patent literature

[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] However, the strain gauges used in existing force sensor devices are structures where the force-bearing structure and the displacement-transmitting structure are integrated or in close contact. Therefore, the trade-off between displacement and load is relatively close, making it particularly difficult to improve the load-bearing capacity.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to provide a strain gauge that can achieve both high load-bearing capacity and high displacement.

[0009] Solution for solving the problem

[0010] The variant 200 includes: a strain section 220 having a movable part that deforms under a predetermined axial force or torque and a non-movable part that does not deform under the force or torque; and an input transmission section 230 that engages with the non-movable part and does not deform under the force or torque, the input transmission section 230 having a housing section 235 capable of housing a sensor chip 100 that detects the force or torque, and transmitting the deformation of the strain section 220 to the sensor chip 100.

[0011] Furthermore, the symbols mentioned above are for ease of understanding and are merely an example, not a limitation on the way they are illustrated.

[0012] The effects of the invention are as follows.

[0013] According to the publicly available technology, it is possible to provide a strain gauge that can achieve both high load-bearing capacity (load resistance) and displacement. 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 perspective view of the lower surface showing the state in which 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 This is a diagram illustrating the symbols for the forces and torques applied to each axis.

[0023] Figure 10 This is a diagram illustrating the configuration of the piezoelectric resistor element in sensor chip 100.

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

[0025] Figure 12 Figure 1 shows an example of a detection circuit using various piezoelectric resistor elements.

[0026] Figure 13 Figure 2 shows an example of a detection circuit using various piezoelectric resistor 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 16This is the simulation result when the sensor chip has an Fx input.

[0030] Figure 17 This is the simulation result when the sensor chip has an Mz input.

[0031] Figure 18 This is the simulation result when the sensor chip has an Fz input.

[0032] Figure 19 Is with Figure 18 The corresponding partial 3D view.

[0033] Figure 20 This is a three-dimensional diagram illustrating the stress plate that constitutes the strain body.

[0034] Figure 21 This is a three-dimensional diagram illustrating the strain components that make up a strained body.

[0035] Figure 22 This is a perspective view illustrating the upper surface of the input transmission section that constitutes the strain body.

[0036] Figure 23 This is a perspective view illustrating the lower surface of the input transmission section that constitutes the strain body.

[0037] Figure 24 This is a side view illustrating the input transmission part that constitutes the strain body.

[0038] Figure 25 This is a three-dimensional diagram illustrating the cover plate that constitutes the strain body.

[0039] Figure 26 These are simulation results under the condition that the strain gauge has an Fx input.

[0040] Figure 27 These are simulation results under the condition that the strain gauge has an Mz input.

[0041] Figure 28 This is a top view of the sensor chip 100A viewed from above along the Z-axis.

[0042] Figure 29 This is a partial top view of the sensor chip 100B viewed from above along the Z-axis.

[0043] Figure 30 This is a partial top view of the sensor chip 100C viewed from above along the Z-axis.

[0044] Figure 31 This is a three-dimensional view of strain 200A.

[0045] Figure 32 This is a sectional perspective view of strain 200A.

[0046] Figure 33 This is a three-dimensional diagram illustrating the input transmission part that constitutes the strain body.

[0047] Figure 34 This is a three-dimensional diagram illustrating the cover plate that constitutes the strain body.

[0048] Figure 35 This is a side view of strain 200B.

[0049] Figure 36 This is a perspective view illustrating the lower surface of the strain section that constitutes the strain body.

[0050] Symbol Explanation

[0051] 1—Force sensor device; 100, 100A, 100B, 100C—Sensor chip; 101~105—Support part; 111~114—Frame part; 121~124—Connecting part; 131a, 131c, 131e, 131g, 132a, 132c, 132e, 133a, 133c, 133e, 134a, 134c, 134e—The first... Beams for inspection: 131b, 131d, 131f, 131h, 132b, 132d, 132f, 133b, 133d, 133f, 134b, 134d, 134f — Beams for inspection: 131T1, 131T2, 131T3, 131T4, 132T1, 132T2, 132T3, 133T1, 133T2, 133T 3. 134T1, 134T2, 134T3—T-shaped beam construction; 141~144—Connection parts; 151~154—Force points; 200, 200A, 200B—Strain gauges; 210—Load-bearing plate; 211, 221, 231—Outer frame; 212, 222, 232—Central section; 213, 223, 233—Beam construction; 218, 228, 238… 248—Through hole; 220, 220B—Strain section; 220x, 235x—Groove; 224—First connecting part; 225—Protrusion; 230, 230A—Input transmission part; 234—Inner frame part; 235—Storage part; 235a—Vertical support part; 235b—Horizontal support part; 235c—Second connecting part; 240, 240A—Cover plate; 241—Inner cover part. Detailed Implementation

[0052] Hereinafter, the method of carrying out the invention will be described with reference to the accompanying drawings. In each drawing, the same symbol is used to mark the same component, and there are cases where repeated descriptions are omitted.

[0053] <First Implementation>

[0054] (Brief structure of force sensor device 1)

[0055] 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, fingers, or other parts of a robot used in machine tools or similar applications.

[0056] The sensor chip 100 has the function of detecting displacement in a predetermined axial direction 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, the sensor chip 100 is described as detecting six axes as an example, but it is not limited to this. For example, the sensor chip 100 can also be used to detect three axes, etc.

[0057] 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, thus forming a generally cylindrical strain gauge 200. Furthermore, since the strain section 220 and the input transmission section 230 primarily perform the functions of the strain gauge 200, the load-bearing plate 210 and the cover plate 240 are provided as needed.

[0058] Furthermore, in this embodiment, for ease of explanation, in the force sensor device 1, the cover plate 240 side is designated as the upper side or one side, and the force plate 210 side is designated as the lower side or the other side. Also, the surface of the cover plate 240 side of each part is designated as one surface or upper surface, and the surface of the force plate 210 side is designated as the other surface or lower surface. However, the force sensor device 1 can be used in an upside-down state, or can be configured at any angle. Furthermore, "top view" refers to the view of the object from the normal direction (Z-axis direction) of the upper surface of the cover plate 240, and "top view shape" refers to the shape of the object when viewed from the normal direction (Z-axis direction) of the upper surface of the cover plate 240.

[0059] 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-side perspective view showing the state where a sensor chip is mounted on the input transmission section. (See image below.) Figure 3 and Figure 4As shown, the input transmission section 230 is provided with a storage 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 storage section 235.

[0060] Specifically, as will be explained below, the storage section 235 is provided with four second connecting portions 235c protruding toward the cover plate 240 (see below). Figures 22-24 (etc.). Furthermore, the contact points 151 to 154 between each second connection portion 235c and the sensor chip 100 (refer to the following...) Figures 5-8 The lower surface of (etc.) is connected.

[0061] Furthermore, the receiving portion 235 extends into the strain section 220 side. Moreover, as will be explained below, the strain section 220 is provided with five columnar first connecting portions 224 protruding towards the input transmission portion 230 side (see below). Figure 21 (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.

[0062] The sensor chip 100 and strain gauge 200 will now be described in detail. Furthermore, in the following description, "parallel" includes the case where two lines, edges, etc., are within a range of 0° ± 10°. And, "perpendicular" or "orthogonal" includes the case where two lines, edges, etc., are within a range of 90° ± 10°. However, these are not limitations unless specifically stated otherwise. Also, "center" or "central" indicates the approximate center or center of the object, not a strict center or center. That is, a degree of manufacturing error is allowed. This also applies to point symmetry and line symmetry.

[0063] (Sensor Chip 100)

[0064] 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, Figure 8 For ease of explanation, surfaces of the same height are shown using the same pear-skin pattern. Furthermore, here, 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.

[0065] 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 top view shape of the sensor chip 100 can be, for example, a rectangle (square or elongated shape) of approximately 7000 μm square.

[0066] The sensor chip 100 includes five columnar support portions 101 to 105. The top view shape of the support portions 101 to 105 can be, for example, a square approximately 2000 μm in size. 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.

[0067] A frame portion 112 is provided between the support portion 101 and the support portion 102, with both ends fixed to the support portion 101 and the support portion 102 (connecting adjacent support portions to each other). A frame portion 113 is provided between the support portion 102 and the support portion 103, with both ends fixed to the support portion 102 and the support portion 103 (connecting adjacent support portions to each other).

[0068] A frame portion 114 is provided between the support portion 103 and the support portion 104, with both ends fixed to the support portion 103 and the support portion 104 (connecting adjacent support portions to each other). A frame portion 111 is provided between the support portion 104 and the support portion 101, with both ends fixed to the support portion 104 and the support portion 101 (connecting adjacent support portions to each other).

[0069] In other words, the four frame parts 111, 112, 113 and 114 are formed into a frame shape, and the corners that constitute the intersection of each frame part become the support parts 101, 102, 103 and 104.

[0070] 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.

[0071] 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.

[0072] That is, the sensor chip 100 has connecting portions 121 to 124 that connect the support portion 105 to the support portions 101 to 104. The connecting portions 121 to 124 are arranged at an angle relative to the X-axis direction (Y-axis direction). In other words, the connecting portions 121 to 124 are not arranged parallel to the frame portions 111, 112, 113, and 114.

[0073] 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.

[0074] The sensor chip 100 has four detection blocks B1 to B4. Furthermore, each detection block has three sets of T-shaped beam structures with piezoelectric elements configured as strain detection elements. Here, the T-shaped 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.

[0075] Specifically, detection block B1 has T-shaped beam structures 131T1, 131T2, and 131T3. Detection block B2 has T-shaped beam structures 132T1, 132T2, and 132T3. Detection block B3 has T-shaped beam structures 133T1, 133T2, and 133T3. Detection block B4 has T-shaped beam structures 134T1, 134T2, and 134T3. A more detailed explanation of the beam structures follows.

[0076] In detection block B1, when viewed from above, a first detection beam 131a is provided, parallel to the side of the support portion 104 of the support portion 101, and is spaced apart by a predetermined interval in a manner that bridges 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, one end of which is connected to the central portion of the first detection beam 131a in the longitudinal direction, and extends toward the support portion 104 in a direction perpendicular to the longitudinal direction of the first detection beam 131a. The first detection beam 131a and the second detection beam 131b form a T-shaped beam structure 131T1.

[0077] In a top view, 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, spaced apart by a predetermined interval. A second detection beam 131d is provided, with one end connected to the central portion of the first detection beam 131c along its length, extending towards the support portion 101 and in a direction perpendicular to the length direction of the first detection beam 131c. The first detection beam 131c and the second detection beam 131d form a T-shaped beam structure 131T2.

[0078] In a top view, a first detection beam 131e is provided, parallel to the edge of the frame portion 111 of the support portion 105, and is spaced apart by a predetermined interval in a manner that bridges the side of the connecting portion 121 near the support portion 105. A second detection beam 131f is provided, with one end connected to the central portion of the first detection beam 131e in the longitudinal direction and extending toward the frame portion 111 in a direction perpendicular to the longitudinal direction of the first detection beam 131e. The first detection beam 131e and the second detection beam 131f form a T-shaped beam structure 131T3.

[0079] The other ends of the second detection beams 131b, 131d, and 131f are connected to form a connecting portion 141, and a force point 151 is provided on the lower surface of the connecting portion 141. The force point 151 is, for example, a quadrangular prism. The detection block B1 is constituted by the T-shaped beams 131T1, 131T2, 131T3, the connecting portion 141, and the force point 151.

[0080] In detection 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 detection block B1 can be set to approximately 30μm to 50μm.

[0081] In detection block B2, when viewed from above, a first detection beam 132a is provided, 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, separated by a predetermined interval. A second detection beam 132b is provided, with one end connected to the central portion of the first detection beam 132a along its length, extending towards the support portion 101 and in a direction perpendicular to the length of the first detection beam 132a. The first detection beam 132a and the second detection beam 132b form a T-shaped beam structure 132T1.

[0082] In a top view, 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, spaced apart by a predetermined interval. A second detection beam 132d is provided, with one end connected to the central portion of the first detection beam 132c along its length, extending towards the support portion 102 and perpendicular to the length direction of the first detection beam 132c. The first detection beam 132c and the second detection beam 132d form a T-shaped beam structure 132T2.

[0083] In a top view, a first detection beam 132e is provided, parallel to the edge of the frame portion 112 of the support portion 105, and is spaced apart by a predetermined interval in a manner that bridges the side of the connecting portion 122 near the support portion 105. Furthermore, a second detection beam 132f is provided, one end of which is connected to the central portion of the first detection beam 132e in the longitudinal direction, and extends toward the frame portion 112 in a direction perpendicular to the longitudinal direction of the first detection beam 132e. The first detection beam 132e and the second detection beam 132f form a T-shaped beam structure 132T3.

[0084] The other ends of the second detection beams 132b, 132d, and 132f are connected to form a connecting portion 142, and a force point 152 is provided on the lower surface of the connecting portion 142. The force point 152 is, for example, a quadrangular prism. The detection block B2 is constituted by the T-shaped beam structures 132T1, 132T2, 132T3, the connecting portion 142, and the force point 152.

[0085] In detection block B2, the first detection beam 132a, the first detection beam 132c, and the second detection beam 132f are parallel, while the second detection beams 132b and 132d are parallel to the first detection beam 132e. The thickness of each detection beam in detection block B2 can be set to approximately 30μm to 50μm.

[0086] In detection block B3, when viewed from above, a first detection beam 133a is provided, parallel to the side of the support portion 102 of the support portion 103, and is spaced apart by a predetermined interval in a manner that bridges 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. Furthermore, a second detection beam 133b is provided, one end of which is connected to the central portion of the first detection beam 133a in the longitudinal direction, and extends toward the support portion 102 in a direction perpendicular to the longitudinal direction of the first detection beam 133a. The first detection beam 133a and the second detection beam 133b form a T-shaped beam structure 133T1.

[0087] In a top view, 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, spaced apart by a predetermined interval. A second detection beam 133d is provided, with one end connected to the central portion of the first detection beam 133c along its length, extending towards the support portion 103 and perpendicular to the length direction of the first detection beam 133c. The first detection beam 133c and the second detection beam 133d form a T-shaped beam structure 133T2.

[0088] In a top view, a first detection beam 133e is provided, parallel to the edge of the frame portion 113 of the support portion 105, and is spaced apart by a predetermined interval in a manner that bridges the side of the connecting portion 123 near the support portion 105. Furthermore, a second detection beam 133f is provided, one end of which is connected to the central portion of the first detection beam 133e in the longitudinal direction, and extends toward the frame portion 113 in a direction perpendicular to the longitudinal direction of the first detection beam 133e. The first detection beam 133e and the second detection beam 133f form a T-shaped beam structure 133T3.

[0089] The other ends of the second detection beams 133b, 133d, and 133f are connected to form a connecting portion 143, and 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 constituted by the T-shaped beam structures 133T1, 133T2, 133T3, the connecting portion 143, and the force point 153.

[0090] In detection block B3, the first detection beam 133a, the first detection beam 133c, and the second detection beam 133f are parallel, while the second detection beams 133b and 133d are parallel to the first detection beam 133e. The thickness of each detection beam in detection block B3 can be set to approximately 30μm to 50μm.

[0091] In detection block B4, when viewed from above, a first detection beam 134a is provided, parallel to the side of the support portion 103 of the support portion 104, and is spaced apart by a predetermined interval in a manner that bridges 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, one end of which is connected to the central portion of the first detection beam 134a in the longitudinal direction, and extends toward the support portion 103 in a direction perpendicular to the longitudinal direction of the first detection beam 134a. The first detection beam 134a and the second detection beam 134b form a T-shaped beam structure 134T1.

[0092] In a top view, a first detection beam 134c is provided, spaced apart by a predetermined interval, 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, and parallel to the edge of the support portion 103 on the support portion 104 side. Furthermore, a second detection beam 134d is provided, one end of which is connected to the central portion of the first detection beam 134c in the longitudinal direction, and extends toward the support portion 104 in a direction perpendicular to the longitudinal direction of the first detection beam 134c. The first detection beam 134c and the second detection beam 134d form a T-shaped beam structure 134T2.

[0093] In a top view, a first detection beam 134e is provided, parallel to the edge of the frame portion 114 of the support portion 105, and is spaced apart by a predetermined interval in a manner that bridges 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. Furthermore, a second detection beam 134f is provided, one end of which is connected to the central portion of the first detection beam 134e in the longitudinal direction, and extends toward the frame portion 114 in a direction perpendicular to the longitudinal direction of the first detection beam 134e. The first detection beam 134e and the second detection beam 134f form a T-shaped beam structure 134T3.

[0094] The other ends of the second detection beams 134b, 134d, and 134f are connected to form a connecting portion 144, and a force point 154 is provided on the lower surface of the connecting portion 144. The force point 154 is, for example, a quadrangular prism. The detection block B4 is constituted by the T-shaped beam structures 134T1, 134T2, 134T3, the connecting portion 144, and the force point 154.

[0095] In detection block B4, the first detection beam 134a, the first detection beam 134c, and the second detection beam 134f are parallel, while the second detection beams 134b and 134d are parallel to the first detection beam 134e. The thickness of each detection beam in detection block B4 can be set to approximately 30μm to 50μm.

[0096] 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 a connecting portion connected to the adjacent support portions, and support portion 105. When viewed from above, each detection block can, for example, be arranged in a point-symmetrical manner with respect to the center of the sensor chip.

[0097] Furthermore, each detection block has three sets of T-beam structures. In each detection block, the three sets of T-beam structures, when viewed from above, include two sets of T-beam structures with a first detection beam arranged parallel to each other across the connecting portion, 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. Moreover, the first detection beam of the first set of T-beam structures is positioned between the connecting portion and the support portion 105.

[0098] For example, in detection block B1, the three sets of T-beam structures, when viewed from above, include: T-beam structures 131T1 and 131T2, which are arranged parallel to each other with first detection beams 131a and 131c separated by a connecting portion 141; 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 portion 141 and the support portion 105. Detection blocks B2 to B4 have the same structure.

[0099] Force points 151 to 154 are the locations where external forces are applied, and can be formed, for example, by the BOX layer and support layer of the SOI substrate. The lower surfaces of each of the force points 151 to 154 are approximately coplanar with the lower surfaces of the support portions 101 to 105.

[0100] By introducing force or displacement from four force points 151–154, the deformation of the beam, which varies according to each type of force, can be obtained, 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.

[0101] Furthermore, in the sensor chip 100, from the viewpoint of suppressing stress concentration, the portion forming the inner corner is preferably arc-shaped (R-shaped).

[0102] 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 also 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.

[0103] Figure 9 This is a diagram illustrating the symbols for the forces and moments applied to each axis. For example... Figure 9As 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. Furthermore, the torque rotating about the X-axis is designated as Mx, the torque rotating about the Y-axis is designated as My, and the torque rotating about the Z-axis is designated as Mz.

[0104] Figure 10 This is a diagram illustrating the configuration of the piezoelectric resistor element in sensor chip 100. Figure 11 yes Figure 10 The image shows a magnified view of a set of detection blocks of the sensor chip. (See attached image.) Figure 10 and Figure 11 As shown, piezoelectric elements are arranged at predetermined positions in each detection block corresponding to the four force points 151-154. Furthermore, Figure 10 The configuration of the piezoelectric resistor elements in the other detection blocks shown is similar to... Figure 11 The piezoelectric resistor elements in one of the detection blocks shown are configured identically.

[0105] Reference Figures 5-8 , Figure 10 as well as Figure 11 In the detection block B1, which has a connecting portion 141 and a force point 151, the piezoelectric resistor element MzR1' is disposed in the first detection beam 131a on the side closer to the second detection beam 131b, located between the second detection beam 131b and the first detection beam 131e. The piezoelectric resistor element FxR3 is disposed in the first detection beam 131a on the side closer to the first detection beam 131e, located between the second detection beam 131b and the first detection beam 131e. The piezoelectric resistor element MxR1 is disposed in the second detection beam 131b on the side closer to the connecting portion 141.

[0106] Furthermore, the piezoelectric element MzR2' is disposed in the first detection beam 131c on the side closer to the second detection beam 131d, in the portion located between the second detection beam 131d and the first detection beam 131e. The piezoelectric element FxR1 is disposed in the first detection beam 131c on the side closer to the first detection beam 131e, in the portion located between the second detection beam 131d and the first detection beam 131e. The piezoelectric element MxR2 is disposed in the second detection beam 131d on the side closer to the connecting portion 141.

[0107] Furthermore, the piezoelectric element FzR1' is disposed in the second detection beam 131f on the side near the connecting portion 141. The piezoelectric element FzR2' is disposed in the second detection beam 131f on the side near the first detection beam 131e. In addition, the piezoelectric elements MzR1', FxR3, MxR1, MzR2', FxR1, and MxR2 are disposed at positions offset from the center of each detection beam along its length.

[0108] In the detection block B2, which has a connecting portion 142 and a force point 152, a piezoelectric resistor element MzR4 is disposed in the first detection beam 132a on the side closer to the second detection beam 132b, located between the second detection beam 132b and the first detection beam 132e. A piezoelectric resistor element FyR3 is disposed in the first detection beam 132a on the side closer to the first detection beam 132e, located between the second detection beam 132b and the first detection beam 132e. A piezoelectric resistor element MyR4 is disposed in the second detection beam 132b on the side closer to the connecting portion 142.

[0109] Furthermore, the piezoelectric element MzR3 is disposed in the first detection beam 132c on the side closer to the second detection beam 132d, in the portion located between the second detection beam 132d and the first detection beam 132e. The piezoelectric element FyR1 is disposed in the first detection beam 132c on the side closer to the first detection beam 132e, in the portion located between the second detection beam 132d and the first detection beam 132e. The piezoelectric element MyR3 is disposed in the second detection beam 132d on the side closer to the connecting portion 142.

[0110] Furthermore, the piezoelectric element FzR4 is disposed in the second detection beam 132f on the side near the connecting portion 142. The piezoelectric element FzR3 is disposed in the second detection beam 132f on the side near the first detection beam 132e. In addition, the piezoelectric elements MzR4, FyR3, MyR4, MzR3, FyR1, and MyR3 are disposed at positions offset from the center of each detection beam along its length.

[0111] In the detection block B3, which has a connecting portion 143 and a force point 153, the piezoelectric element MzR4' is disposed in the first detection beam 133a on the side closer to the second detection beam 133b, in the portion located between the second detection beam 133b and the first detection beam 133e. The piezoelectric element FxR2 is disposed in the first detection beam 133a on the side closer to the first detection beam 133e, in the portion located between the second detection beam 133b and the first detection beam 133e. The piezoelectric element MxR4 is disposed in the second detection beam 133b on the side closer to the connecting portion 143.

[0112] Furthermore, the piezoelectric element MzR3' is disposed in the first detection beam 133c on the side closer to the second detection beam 133d, in the portion located between the second detection beam 133d and the first detection beam 133e. The piezoelectric element FxR4 is disposed in the first detection beam 133c on the side closer to the first detection beam 133e, in the portion located between the second detection beam 133d and the first detection beam 133e. The piezoelectric element MxR3 is disposed in the second detection beam 133d on the side closer to the connecting portion 143.

[0113] Furthermore, the piezoelectric element FzR4' is disposed in the second detection beam 133f on the side near the connecting portion 143. The piezoelectric element FzR3' is disposed in the second detection beam 133f on the side near the first detection beam 133e. In addition, the piezoelectric elements MzR4', FxR2, MxR4, MzR3', FxR4, and MxR3 are disposed at positions offset from the center of each detection beam along its length.

[0114] In the detection block B4, which has a connecting portion 144 and a force point 154, a piezoelectric resistor element MzR1 is disposed in the first detection beam 134a on the side closer to the second detection beam 134b, located between the second detection beam 134b and the first detection beam 134e. A piezoelectric resistor element FyR2 is disposed in the first detection beam 134a on the side closer to the first detection beam 134e, located between the second detection beam 134b and the first detection beam 134e. A piezoelectric resistor element MyR1 is disposed in the second detection beam 134b on the side closer to the connecting portion 144.

[0115] Furthermore, the piezoelectric element MzR2 is disposed in the first detection beam 134c on the side closer to the second detection beam 134d, located between the second detection beam 134d and the first detection beam 134e. The piezoelectric element FyR4 is disposed in the first detection beam 134c on the side closer to the first detection beam 134e, located between the second detection beam 134d and the first detection beam 134e. The piezoelectric element MyR2 is disposed in the second detection beam 134d on the side closer to the connecting portion 144.

[0116] Furthermore, the piezoelectric element FzR1 is disposed in the second detection beam 134f on the side near the connecting portion 144. The piezoelectric element FzR2 is disposed in the second detection beam 134f on the side near the first detection beam 134e. In addition, the piezoelectric elements MzR1, FyR2, MyR1, MzR2, FyR4, and MyR2 are disposed at positions offset from the center of each detection beam along its length.

[0117] Thus, in the sensor chip 100, multiple piezoelectric elements are separately arranged in each detection block. Therefore, based on the changes in the output of the multiple piezoelectric elements arranged on the predetermined beam corresponding to the input applied to force points 151 to 154, it is possible to detect a predetermined axial force or torque on all six axes.

[0118] Furthermore, in the sensor chip 100, in addition to the piezoelectric resistor element used for strain detection, a dummy piezoelectric resistor element may also be configured. The dummy piezoelectric resistor element is used to adjust the balance of the stress applied to the detection beam and the resistance of the bridge circuit. For example, all piezoelectric resistor elements, including the piezoelectric resistor element used for strain detection, are arranged symmetrically with respect to the center of the support portion 105.

[0119] In the sensor chip 100, a plurality of piezoelectric elements for detecting displacement in the X-axis direction and displacement in the Y-axis direction are arranged on the first detection beam constituting a T-shaped beam structure. Furthermore, a plurality of piezoelectric elements for detecting displacement in the Z-axis direction are arranged on the second detection beam constituting a T-shaped beam structure. Additionally, a plurality of piezoelectric elements for detecting torque in the Z-axis direction are arranged on the first detection beam constituting a T-shaped beam structure. And, a plurality of piezoelectric elements for detecting torque in the X-axis direction and torque in the Y-axis direction are arranged on the second detection beam constituting a T-shaped beam structure.

[0120] Here, the piezoelectric resistor elements FxR1~FxR4 detect force Fx, FyR1~FyR4 detect force Fy, and FzR1~FzR4 and FzR1'~FzR4' detect force Fz. Furthermore, the piezoelectric resistor elements MxR1~MxR4 detect torque Mx, MyR1~MyR4 detect torque My, and MzR1~MzR4 and MzR1′~MzR4′ detect torque Mz.

[0121] In this way, multiple piezoelectric elements are separately arranged in each detection block within the sensor chip 100. Therefore, based on the changes in the output of the multiple piezoelectric elements arranged on the predetermined beams corresponding to the direction (axial direction) of the force or displacement applied to (transmitted to) force points 151-154, a predetermined axial displacement can be detected up to six axes. Furthermore, by making the thickness and width of each detection beam variable, adjustments such as uniformity of detection sensitivity and improvement of detection sensitivity can be achieved.

[0122] In addition, it can also be used as a sensor chip to detect the displacement of a predetermined axial direction up to five axes by reducing the number of piezoelectric resistor elements.

[0123] 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 piezoelectric resistor elements is shown. Figure 12 and Figure 13 In the diagram, the numbers enclosed in squares indicate the 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.

[0124] Furthermore, No. 9 is the negative output terminal of the Mx axis, No. 10 is the GND terminal of the Mx axis, and No. 11 is the positive output terminal of the Mx axis. No. 12 is the power terminal for the Mx, My, and Mz axes. No. 13 is the negative output terminal of the My axis, No. 14 is the GND terminal of the My axis, and No. 15 is the positive output terminal of the My axis. No. 16 is the negative output terminal of the Mz axis, No. 17 is the GND terminal of the Mz axis, and No. 18 is the positive output terminal of the Mz axis.

[0125] Next, the deformation of the beam used for testing 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, there are four detection blocks, but 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.

[0126] Figure 16 This is the simulation result when the sensor chip has an Fx input. Figure 14 In the case of Fx input as indicated by the arrow, each detection beam is as follows: Figure 16 The deformation is shown. In particular, it can be seen that in each test block, the first test beam (the beam with the horizontal line of the T-shape) of the T-shaped beam structure deforms more significantly.

[0127] In the sensor chip 100, among the first detection beams constructed with a T-shaped beam, there is one or more first detection beams orthogonal to the input displacement direction. The first detection beams orthogonal to the input displacement direction are as follows: Figure 16 The surface shown is capable of handling large deformations. Furthermore, Figure 16 In the process, the first detection beam orthogonal to the input displacement direction is... Figure 6 The first testing beams 131a, 131c, 132e, 133a, 133c and 134e are shown in the figure.

[0128] The beams used in the Fx input detection are the first detection beams 131a, 131c, 133a, and 133c, all of which are T-shaped beams constructed with the force point at a fixed distance from the point of force application. Similarly, the beams used in the Fy input detection are the first detection beams 132a, 132c, 134a, and 134c, all of which are T-shaped beams constructed with the force point at a fixed distance from the point of force application.

[0129] In both Fx and Fy inputs, the first detection beam, constructed with a T-shaped beam and incorporating a piezoelectric element, deforms significantly, thereby enabling effective detection of the input force. Furthermore, the beam not used in input detection is also designed to deform significantly in response to the displacement of the Fx and Fy inputs, ensuring that the detection beam is not damaged even with large Fx and / or Fy inputs.

[0130] Furthermore, in existing sensor chips, there are beams that cannot deform significantly with respect to Fx and / or Fy inputs. Therefore, there is a concern that these non-deformable detection beams may be damaged in the presence of large Fx and / or Fy inputs. In sensor chip 100, this problem can be suppressed. That is, sensor chip 100 can improve the resistance to damage of beams subjected to displacement in various directions.

[0131] 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 considerably. Therefore, both Fx and Fy inputs can be effectively detected, and the detection beams will not be damaged even with large Fx and / or Fy inputs. As a result, the sensor chip 100 can handle larger rated values, improving its measurement range and load-bearing capacity. For example, in the sensor chip 100, the rated value can be approximately 10 times that of the prior art, i.e., 500N.

[0132] Furthermore, in each detection block, the T-shaped beam structure connected from the force point in three directions undergoes different deformations according to the input, thus enabling the detection of multiaxial forces with good separation.

[0133] Furthermore, since the beam is T-shaped, there are many paths from the beam to the frame and connecting parts, making it easy to lay out wiring to the outer periphery of the sensor chip, thus increasing the flexibility of layout.

[0134] Figure 17 This is the simulation result when the sensor chip has an Mz input. For example... Figure 17 As shown, the first detection beams 131a, 131c, 132a, 132c, 133a, 133c, 134a, and 134c, which are arranged opposite each other at each force point, deform considerably in response to the torque in the Z-axis direction. Therefore, piezoelectric resistor elements can be arranged on some or all of the aforementioned first detection beams.

[0135] Figure 18 This is the simulation result when the sensor chip has an Fz input. Figure 19 Is with Figure 18 The corresponding partial 3D image. For example... Figure 18 and Figure 19 As shown, for displacement in the Z-axis direction, the second detection beams 131b, 131d, 131f, 132b, 132d, 132f, 133b, 133d, 133f, 134b, 134d, and 134f, which are directly connected to each force point, deform significantly. Therefore, piezoelectric resistor elements can be arranged in part or all of the aforementioned second detection beams.

[0136] (Should be variant 200)

[0137] like Figure 1 and Figure 2 As shown, the strain variant 200 includes a force-bearing plate 210, a strain section 220, an input transmission section 230, and a cover plate 240. Here, each component of the strain variant 200 will be described.

[0138] Figure 20 This is a three-dimensional diagram illustrating the stress plate that constitutes the strain body. For example... Figure 20As shown, the force plate 210 is a generally disk-shaped component and is used to input force and torque from the object being measured. The force plate 210 has an outer frame portion 211 that is generally annular when viewed from above, a central portion 212 that is disposed separately from the outer frame portion 211 and is generally circular when viewed from above, 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. The beam structures 213 increase the strength of the force plate 210, ensuring that even when force and torque are input from the object being measured, the force plate 210 itself hardly deforms, and deformation (displacement) is transmitted to the strain portion 220 connected to the central portion 212 without loss. A through hole 218 is provided in the portion protruding from the inner side of the outer frame portion 211 toward the beam structure 213. The through hole 218 can be used, for example, when the force plate 210 is fastened to the object being measured using a threaded fitting.

[0139] Figure 21 This is a three-dimensional diagram illustrating the strain components that make up a strained body. For example... Figure 21 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.

[0140] The strain section 220 has an outer frame portion 221 that is generally annular when viewed from above, a central portion 222 that is disposed separately from the outer frame portion 221 and is generally circular when viewed from above, located inside the outer frame portion 221, and a plurality of beam structures 223 bridging the outer frame portion 221 and the central portion 222. The plurality of beam structures 223 are arranged, for example, point-symmetrically with respect to the center of the strain section 220. For example, there are four beam structures 223. Each beam structure 223 is, for example, a T-shaped structure including 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 outer frame portion 221, and the end of the second beam is connected to the central portion 222.

[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 coplanar and are located 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 located higher than both the lower surfaces of the outer frame portion 221 and the lower surface of the central portion 222. Only the beam structure 223 and the central portion 222 deform under the force of the load-bearing plate 210; the outer frame portion 221 remains undeformed. However, the central portion 222 only follows the deformation of the beam structure 223 and does not deform itself.

[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 formed by overlapping a square groove and a cross-shaped groove in a top view, with the center aligned. The cross-shaped groove is formed by two elongated grooves, each longer than one side of the square, intersecting each other. The square groove and the cross-shaped groove in the top view have the same depth.

[0143] Five columnar first connecting portions 224, protruding toward the input transmission section 230, are arranged on the outer side of the cross-shaped groove, at the four corners of the square groove, and at the center of the square groove, without contacting the inner wall of the groove 220x. The first connecting portions 224 are connected to the support portions 101-105 of the sensor chip 100. The upper surfaces of each first connecting portion 224 are substantially coplanar and are located lower than the upper surface of the central portion 222 and the upper surface of the beam structure 223. A through hole 228 is provided in the outer frame portion 221. The through hole 228 can be used, for example, to fasten the strain section 220, the input transmission section 230, and the cover plate 240 to the fixed side (the side of the robot, etc.) using threaded fasteners.

[0144] Furthermore, since a space is provided on the upper surface side of the central portion 222, a circuit board or other electronic device such as a connector or semiconductor element can be mounted on the upper surface side of the central portion 222, for example, in a manner that does not protrude from the upper surface of the outer frame portion 221.

[0145] Figure 22 This is a perspective view illustrating the upper surface of the input transmission section that constitutes the strain body. Figure 23 This is a perspective view illustrating the lower surface of the input transmission section that constitutes the strain body. Figure 24 This is a side view illustrating the input transmission part that constitutes the strain body. (Example) Figures 22-24 As shown, the input transmission unit 230 is a component that is generally in the shape of a disk, and it is the part that transmits the deformation (input) of the strain unit 220 to the sensor chip 100.

[0146] The input transmission unit 230 has an outer frame portion 231 that is generally annular when viewed from above, a central portion 232 disposed separately from the outer frame portion 231 on the inner side of the outer frame portion 231, and a plurality of beam structures 233 bridging the outer frame portion 231 and the central portion 232. The plurality of beam structures 233 are arranged, for example, symmetrically with respect to the center of the input transmission unit 230. For example, there are four beam structures 233. Each beam structure 233 is, for example, I-shaped.

[0147] The central portion 232 has an inner frame portion 234 that is generally annular when viewed from above and is connected to the beam structure 233, and a generally cross-shaped receiving portion 235 that extends from the lower surface of the inner frame portion 234 toward the strain portion 220. The receiving portion 235 has four vertical support portions 235a that extend vertically from the lower surface of the inner frame portion 234 toward the strain portion 220, and four horizontal support portions 235b that extend horizontally from the lower end of the vertical support portions 235a and intersect at the center of the inner frame portion 234.

[0148] The beam structure 233 and the inner frame portion 234 are formed to be thinner than the outer frame portion 231. The upper surfaces of the beam structure 233 and the inner frame portion 234 are located at a lower position 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 inner frame portion 234 are substantially coplanar. No part of the input transmission portion 230 will deform due to the applied force or torque.

[0149] Viewed from above, the four vertical support sections 235a and the four horizontal support sections 235b are arranged symmetrically with respect to the center of the input transmission section 230. Viewed from above, the length direction of each horizontal support section 235b is not the same as the length direction of each beam structure 233. For example, viewed from above, the length direction of each horizontal support section 235b is offset from the length direction of each beam structure 233 by 45 degrees.

[0150] A groove 235x is provided near the center of the roughly cross-shaped storage section 235, and four second connecting portions 235c protruding toward the cover plate 240 are arranged on the bottom surface of the groove 235x in a manner that does not contact the inner wall of the groove 235x. Each second connecting portion 235c is located approximately on the line that bisects each horizontal support portion 235b in the length direction. The second connecting portions 235c are the portions that connect to the force points 151 to 154 of the sensor chip 100. A through hole 238 is provided in the outer frame portion 231. The through hole 238 can be used, for example, when the strain section 220, the input transmission section 230, and the cover plate 240 are fastened to the fixed side (the side of the robot, etc.) using threaded parts.

[0151] Furthermore, since a space is provided on the upper surface of the beam structure 233, a circuit board on which electronic devices such as connectors and semiconductor components are mounted can also 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.

[0152] Figure 25 This is a three-dimensional diagram illustrating the cover plate that constitutes the strain gauge. For example... Figure 25As shown, the cover plate 240 is a generally disk-shaped component that protects internal devices (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 through hole 248 is provided in the cover plate 240. The through hole 248 can be used, for example, to fasten the strain section 220, the input transmission section 230, and the cover plate 240 to a fixed side (the side of a robot, etc.) using threaded fasteners.

[0153] For the materials used in the load-bearing plate 210, strain gauge 220, input transmission part 230, and cover plate 240, hard metal materials such as SUS (stainless steel) can be used. Among these, SUS630, which is hard and has high mechanical strength, is particularly preferred. In the components constituting the strain gauge 200, it is particularly preferable that the load-bearing plate 210, strain gauge 220, and input transmission part 230 are firmly connected or formed as a single unit. As for the connection method of the load-bearing plate 210, strain gauge 220, and input transmission part 230, fastening with threaded parts, welding, etc., are considered, but regardless of the method, it must be able to fully withstand the forces and torques input to the strain gauge 200.

[0154] 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 joined together 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. After mounting the sensor chip 100 and other internal components, the cover plate 240 can be fastened to the input transmission section 230, for example, using threaded fasteners.

[0155] In strain gauge 200, if 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 in the four beam structures 223. At this time, the outer frame portion 221 of strain gauge 220 and the input transmission portion 230 do not deform.

[0156] 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.

[0157] When the strain gauge 200 is used in the force sensor device 1, the support portions 101-105 of the sensor chip 100 are connected to the first connecting portion 224 located in the central portion 222, which is a movable portion. Furthermore, the force points 151-154 of the sensor chip 100 are connected to the second connecting portion 235c located in the storage portion 235, which is a non-movable portion. Therefore, the sensor chip 100 operates such that the force points 151-154 remain stationary while each detection beam deforms via the support portions 101-105.

[0158] 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 provided in 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 235c provided in the storage portion 235 which is a non-movable part.

[0159] That is, the sensor chip 100 that can be housed in the housing section 235 has support sections 101-105 and force points 151-154 whose relative positions change when subjected to force or torque. Furthermore, in the strain gauge 200, the central section 222, which is a movable section, has a first connecting section 224 that extends toward the input transmission section 230 and connects to one of the support sections 101-105 and force points 151-154. The housing section 235 also has a second connecting section 235c that connects to the other of the support sections 101-105 and force points 151-154.

[0160] Figure 26 These are simulation results under the condition that the strain gauge has an Fx input. Figure 27 These are simulation results under the condition that the strain gauge has an Mz input. For example... Figure 26 and Figure 27 As shown, it can be confirmed that in any case, the outer frame 221 of the strain unit 220 does not deform, while the four T-shaped beam structures 223 deform. The same applies to other input cases.

[0161] In this way, the strain gauge 200 converts the input force and torque into displacement and transmits it to the mounted sensor chip 100. Currently, in strain gauges with the same function, the structure that receives the force and torque and the structure that transmits the displacement are integrated or in close contact. Therefore, the trade-off between displacement and load-bearing capacity is relatively tight, making it particularly difficult to achieve a large load-bearing capacity (load capacity).

[0162] In the strain gauge 200, since the strain section 220 subjected to force and torque and the input transmission section 230 that transmits displacement to the sensor chip 100 are separate structures, it is possible to achieve both high load-bearing capacity and high displacement.

[0163] <Modification 1 of the First Embodiment>

[0164] In Variation 1 of the first embodiment, an example is shown where the sensor chip has a different construction from that of the first embodiment. Furthermore, in Variation 1 of the first embodiment, there are instances where descriptions of components identical to those in the already described embodiment are omitted.

[0165] Figure 28 This is a top view of the sensor chip 100A viewed from above along the Z-axis. (Example) Figure 28 As shown, the structure of the detection beam for sensor chip 100A is similar to that of sensor chip 100 (refer to...). Figure 6 (etc.) are the same. However, the shape of the space around the detection beam is different from that of the sensor chip 100. That is, in the sensor chip 100A, the opening width of the space on both sides of each detection beam is uniform when viewed from above.

[0166] Typically, the beam structure of a sensor chip is formed from a silicon wafer using semiconductor processes. However, in this case, a deep etching process based on dry etching is used. As with the shape of sensor chip 100, there are concerns about increased processing difficulty and decreased processing quality when the opening width of the etched area divided by the detection beam is large and uneven.

[0167] In the sensor chip 100A, etched areas are formed on both sides of each detection beam in a narrow slit shape with a uniform opening width. This reduces the processing difficulty when performing deep etching using dry etching, thus improving processing quality. Furthermore, Figure 28 The four circular openings in the design are clearance portions that prevent the sensor chip 100A from contacting the strain gauge 200 when it is mounted on the strain gauge 200. Therefore, if only the efficiency of dry etching is considered, the four circular openings may not be provided.

[0168] Figure 29 This is a partial top view of the sensor chip 100B viewed from above along the Z-axis. (Example) Figure 29 As shown, in the detection block B1, the ends of two T-shaped beams of the second detection beam in the sensor chip 100B are connected to each other. This is similar to the sensor chip 100 in which the ends of three T-shaped beams of the second detection beam are connected to each other (see reference). Figure 6 The sensor chip 100B differs from the sensor chip 100 in that it does not have the first detection beams 131e, 132e, 133e, and 134e, or the second detection beams 131f, 132f, 133f, and 134f. The structure of the detection blocks B2 to B4 is also the same as that of the detection block B1.

[0169] Figure 30 This is a partial top view of the sensor chip 100C viewed from above along the Z-axis. (Example) Figure 30As shown, the sensor chip 100C has four T-shaped beams at the ends of its second detection beams connected to each other in the detection block B1. This is similar to the sensor chip 100 with three T-shaped beams at the ends of its second detection beams connected to each other (see reference). Figure 6 The sensor chip 100C differs from the sensor chip 100 in that it also has a T-shaped beam structure 131T4, which includes a first detection beam 131g and a second detection beam 131h. The T-shaped beam structure 131T4 is configured to face the T-shaped beam structure 131T3 across the connecting portion 141. The structures of detection blocks B2 to B4 are also the same as those of detection block B1.

[0170] Thus, in the sensor chip, the T-beam structure is not limited to three; it can be two, as in sensor chip 100B, or four, as in sensor chip 100C. In either case, each detection block has two or more sets of T-beam structures, allowing either the first or second detection beam constituting the T-beam structure to deform considerably. Therefore, both Fx and Fy inputs can be effectively detected, and the detection beams will not be damaged even with large Fx and / or Fy inputs. That is, the damage resistance of the beams to displacements in various directions can be improved in any type of sensor chip. As a result, sensor chips capable of handling larger ratings and improving measurement range and load-bearing capacity can be realized.

[0171] However, with two T-beams, it is difficult to detect displacement in six axes. Furthermore, while a structure with more T-beams is advantageous in terms of easier separation of multi-axial forces, it is disadvantageous as chip size tends to increase. Considering these factors, having three T-beams is preferable for detecting displacement in six axes.

[0172] <Modification 2 of the First Embodiment>

[0173] In Variation 2 of the first embodiment, an example of a strain with a construction different from that of the first embodiment is shown. Furthermore, in Variation 2 of the first embodiment, there are cases where descriptions of components identical to those in the already described embodiment are omitted.

[0174] Figure 31 This is a three-dimensional view of strain 200A. Figure 32 This is a sectional perspective view of strain 200A. (Refer to...) Figure 31 and Figure 32The strain gauge 200A includes a load-bearing plate 210, a strain section 220, an input transmission section 230A, and a cover plate 240A. The strain section 220 is stacked on the load-bearing plate 210, the input transmission section 230A is stacked on the strain section 220, and the cover plate 240A is stacked on the input transmission section 230A, forming a generally cylindrical strain gauge 200A. The central portion of the cover plate 240A can be opened and closed via an inner cover portion 241. Furthermore, the load-bearing plate 210 and the strain section 220 are the same as those in the strain gauge 200.

[0175] Figure 33 This is a perspective view illustrating the upper surface of the input transmission section that constitutes the strain body. (Example) Figure 33 As shown, the basic structure of the input transmission unit 230A is the same as that of the input transmission unit 230. However, the input transmission unit 230A is formed to be thinner than that of the input transmission unit 230.

[0176] Figure 34 This is a three-dimensional diagram illustrating the cover plate that constitutes the strain gauge. For example... Figure 34 As shown, the cover plate 240A is a generally disk-shaped component that protects internal devices (such as the sensor chip 100). The cover plate 240A is, for example, thicker than the force plate 210, strain section 220, and input transmission section 230A, and has a larger internal space on the input transmission section 230A side. Through holes 248 and 249 are provided in the cover plate 240A. The through hole 249 extends from the inner cover portion 241 (see reference). Figure 31 ) Blockade.

[0177] In this way, the segmentation positions of the components constituting the strain body can be changed taking into account factors such as the internal space of the strain body and its assembly properties. Figures 31-34 In the example shown, with Figure 1 The separation position between the input transmission section and the cover plate has been changed, but in this case, there is a larger internal space on the cover plate 240A side, so more devices can be installed.

[0178] <Modification 3 of the First Embodiment>

[0179] In Variation 3 of the first embodiment, other examples of strain bodies with constructions different from those of the first embodiment are shown. Furthermore, in Variation 3 of the first embodiment, descriptions of components identical to those in the already described embodiment are omitted.

[0180] Figure 35 This is a side view of strain variant 200B. (Refer to...) Figure 35The strain gauge 200B includes a load-bearing plate 210, a strain section 220B, an input transmission section 230, and a cover plate 240. The strain section 220B is stacked on the load-bearing plate 210, the input transmission section 230 is stacked on the strain section 220B, and the cover plate 240 is stacked on the input transmission section 230, forming the strain gauge 200B in a generally cylindrical shape. Furthermore, the load-bearing plate 210, the input transmission section 230, and the cover plate 240 are the same as those in the strain gauge 200.

[0181] Figure 36 This is a perspective view illustrating the lower surface of the strain section that constitutes the strained body. That is, Figure 36 In the middle, strain gauge 220B and Figure 35 Compared to upside down. For example... Figure 35 and Figure 36 As shown, the strain section 220B has a protrusion 225 that protrudes toward the force-bearing plate 210. The protrusion 225 is approximately circular in plan view, shaped to contact the central portion 212 of the force-bearing plate 210. The amount by which the protrusion 225 protrudes from the lower surface of the strain section 220B is, for example, about 0.5 mm. The protrusion 225 engages with the central portion 212 of the force-bearing plate 210, for example, by diffusion bonding, but can also be engaged by threaded fastening or welding. Furthermore, the height of the protrusion 225, after engaging the strain section 220B with the force-bearing plate 210, forms a gap between the strain section 220B and the force-bearing plate 210.

[0182] For the load-bearing plate 210 to be displaced under stress, a gap is required between it and the strain portion 220B. In the strain gauge 200B, a protrusion 225 is provided in the strain portion 220B, thereby making it easy to create a gap between the load-bearing plate 210 and the strain portion 220B. That is, by providing the protrusion 225 in the strain portion 220B and controlling the height of the protrusion 225, the gap between the strain portion 220B and the load-bearing plate 210 can be controlled. For example, before the strain portion 220B and the load-bearing plate 210 are joined, the height of the protrusion 225 can be precisely controlled by grinding or the like, thereby allowing arbitrary control of the gap after joining. Furthermore, in the method of providing the protrusion 225 in the strain portion 220B, it is also possible to form a narrow gap that is difficult to achieve in machining processes such as joining and wire cutting. Moreover, when the strain portion 220B and the load-bearing plate 210 are joined by diffusion bonding, a joint strength equivalent to the material strength can be obtained.

[0183] Furthermore, the protrusion can be provided on the side of the stress plate 210, or on both the strain portion 220B and the stress plate 210. In either case, the protrusion is provided between the strain portion 220B and the stress plate 210, and functions as a gap defining portion that defines the gap between the strain portion 220B and the stress plate 210.

[0184] 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.

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 such force or moment; and The input transmission part engages with the aforementioned non-movable part and remains undeformed when subjected to the aforementioned force or torque. The input transmission unit described above includes a housing section capable of accommodating a sensor chip that detects the force or torque described above, and transmits the deformation of the strain portion to the sensor chip described above. The sensor chip that can be housed in the aforementioned housing portion has a first portion and a second portion whose relative positions change due to the aforementioned force or torque. The movable part includes a first connecting part that extends toward the input transmission part and connects to one of the first part and the second part. The aforementioned storage section includes a second connecting portion that connects to the other side of the aforementioned first part and the aforementioned second part. The strain section described above has: First frame section; The first central portion of the first frame portion is disposed above the ground on the inner side of the first frame portion; and The structure consists of multiple first beams that bridge the aforementioned first frame portion and the aforementioned first central portion. The aforementioned first frame portion is included within the aforementioned non-movable portion, and the aforementioned first beam structure and the aforementioned first central portion are included within the aforementioned movable portion. The aforementioned storage section enters the aforementioned movable section on the strain section side.

2. The strain according to claim 1, characterized in that, Each of the aforementioned first beam structures is a T-shaped structure 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 first frame portion, and the end of the second beam is connected to the first central portion.

3. The strain according to claim 1 or 2, characterized in that, When viewed from above, each of the aforementioned first beam structures is arranged in a point-symmetrical configuration with respect to the center of the aforementioned strain section.

4. The strain according to claim 1 or 2, characterized in that, It has four of the aforementioned first beam structures.

5. The strain according to claim 1 or 2, characterized in that, The above-mentioned input transmission unit has: Second frame section; The second central portion, located on the inner side of the second frame portion and partially above the ground, is also located therefrom. The structure consists of multiple second beams that bridge the aforementioned second frame section and the aforementioned second central section. The aforementioned second central portion includes a third frame portion connected to the aforementioned second beam structure and the aforementioned receiving portion extending from the aforementioned third frame portion toward the aforementioned strain portion side.

6. The strain according to claim 5, characterized in that, The aforementioned storage section has four vertical support sections extending vertically from the aforementioned third frame section toward the aforementioned strain section side, and four horizontal support sections extending horizontally from the ends of the aforementioned vertical support sections and intersecting at the center of the aforementioned third frame section.

7. The strain according to claim 6, characterized in that, When viewed from above, the aforementioned third frame is ring-shaped, and the four aforementioned horizontal support sections are cross-shaped.

8. The strain according to claim 1 or 2, characterized in that, The strain section and the input transmission section are diffusely bonded.

9. The strain according to claim 1 or 2, characterized in that, A force-receiving plate is joined on the side of the strain section opposite to the input transmission section, so that the force or torque is input from the object being measured.

10. The strain according to claim 9, characterized in that, A gap defining part is provided between the strain section and the stress plate to define the gap between the strain section and the stress plate.

11. The strain according to claim 1 or 2, characterized in that, A cover plate protecting the internal components is joined to the opposite side of the input transmission section from the strain section.

12. A force sensor device, characterized in that, It has the strain as described in any one of claims 1 to 11 and the aforementioned sensor chip.

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