Attachment device and physical quantity detection device

Abstract

To provide a mounting device or the like capable of improving magnetic attraction force with respect to measuring objects of various shapes.SOLUTION: The attachment device 100 is a device for attaching the physical quantity sensor 50 to the measurement target 1. The attachment device 100 includes a base 110 on which the physical quantity sensor 50 is mounted, a magnet 120 having an attraction surface 121 that is attracted to the measurement target 1, and an attraction yoke 130 having attraction ends 131 and 132 that are attracted to the measurement target 1 by the magnetic force of the magnet 120. The attraction yoke 130 is displaced relative to the magnet 120 in the first direction (z direction) along the normal line of the attraction surface 121, so that at least a part of the attraction surface 121 of the magnet 120 and the attraction ends 131 and 132 of the attraction yoke 130 are attracted to the measurement target 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mounting device, a physical quantity detection device, and the like. [Background technology]

[0002] Patent document 1 discloses a technology in which an acceleration sensor is fixed to a magnet via the yoke in an attachment device that includes a sensor holder having a first pair of legs and a yoke having a second pair of legs, and the tip of the first pair of legs abuts against an object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-195173 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the acceleration sensor is fixed to the object by the magnetic attraction force of a magnet, but the distance between the magnet and the object changes depending on the shape of the object, making it difficult to improve the magnetic attraction force for measurement objects of various shapes. [Means for solving the problem]

[0005] One aspect of the present disclosure relates to an attachment device for attaching a physical quantity sensor to a measurement object, the attachment device including: a base on which the physical quantity sensor is mounted; a magnet having an adhesive surface that is attached to the measurement object; and an adhesive yoke having an adhesive end that is attached to the measurement object by the magnetic force of the magnet, wherein the adhesive yoke is displaced relative to the magnet in a first direction along a normal to the adhesive surface, so that at least a portion of the adhesive surface of the magnet and the adhesive end of the adhesive yoke are attached to the measurement object.

[0006] Another aspect of the present disclosure relates to a physical quantity detection device including the above-described mounting device and the physical quantity sensor. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view illustrating an outline of a physical quantity detection device. [Figure 2] FIG. [Figure 3] AA cross-sectional view of the mounting device. [Figure 4] FIG. 2 is a perspective view showing a state in which the attachment device is attached to a measurement object. [Figure 5] 1 is a cross-sectional view of the mounting device and the object to be measured, taken along a plane parallel to the yz plane. [Figure 6] 1 is a cross-sectional view of a mounting device attached to a planar measurement object, taken along a plane parallel to the yz plane. [Figure 7] FIG. 10 is a diagram illustrating the attachment of the suction yoke and magnet. DETAILED DESCRIPTION OF THE INVENTION

[0008] Preferred embodiments of the present disclosure will be described in detail below. Note that the embodiments described below do not unduly limit the scope of the claims, and not all of the configurations described in the embodiments are necessarily essential components.

[0009] 1.Configuration example Fig. 1 is a cross-sectional view illustrating an outline of a physical quantity detection device 200. The physical quantity detection device 200 includes a physical quantity sensor 50 and an attachment device 100. Fig. 1 illustrates a state in which the physical quantity detection device 200 is attached to a measurement object 1, but the physical quantity detection device 200 is detachable from the measurement object 1.

[0010] The measurement target 1 includes, for example, a vibration source that generates vibrations due to mechanical operation. The physical quantity sensor 50 detects vibrations in the measurement target 1 caused by the vibration source. Examples of the vibration source include a motor, engine, or turbine. Alternatively, the measurement target 1 may not include a vibration source, but vibrations may be applied from outside the measurement target 1, and the physical quantity sensor 50 may detect the vibrations. The measurement target 1 may be, for example, the vibration source itself, i.e., a motor, engine, or turbine. Alternatively, the measurement target 1 may be a machine, device, or apparatus that includes a vibration source, such as a printer, air conditioner, robot, pump, belt conveyor, or processing equipment, or other household or industrial equipment; a moving object such as an automobile or airplane; or industrial equipment such as a power generator or manufacturing plant. Alternatively, the measurement target 1 may be a structure that vibrates due to external forces, such as a building, road, or bridge.

[0011] In FIG. 1, the three orthogonal directions are the x-direction, y-direction, and z-direction. The direction of the arrow is sometimes referred to as the +x-direction, and the opposite direction is sometimes referred to as the -x-direction. FIG. 1 shows a cross-sectional view of a cross section parallel to the yz-plane. An example of the measurement target 1 is a cylindrical object with a central axis parallel to the x-direction, such as a bearing for a rotating machine such as a motor. However, the shape of the measurement target 1 is not limited to this. It may have any shape that allows the physical quantity sensor 50 to be stably supported relative to the measurement target 1 by the mechanism of the mounting device 100 of this embodiment, which will be described later. An example of a non-cylindrical shape of the measurement target 1 may be a shape with irregularities at regular or irregular intervals in the yz-plane cross section. In this case, by mounting the mounting device 100 so that the protrusions of the measurement target 1 are located near the center of the mounting device 100, it is clear that stable mounting is possible, similar to the mounting of the measurement target 1 to a cylinder, as will be described later.

[0012] The physical quantity sensor 50 is a sensor that detects a physical quantity transmitted from the measurement target 1 via the mounting device 100. As a specific example, the physical quantity sensor 50 detects acceleration, velocity, displacement, angular acceleration, angular velocity, or angle, and outputs a signal indicating the detected physical quantity. These physical quantities can also be considered information representing the vibration of the measurement target 1, and the physical quantity sensor 50 can also be called a vibration sensor. The physical quantity sensor 50 may be a sensor that detects one type of physical quantity, or a sensor that detects multiple types of physical quantities. Furthermore, the physical quantity sensor 50 may be a sensor that detects a physical quantity on one axis, or a sensor that detects physical quantities on two or more axes.

[0013] The physical quantity sensor 50 may be, for example, an acceleration sensor or gyro sensor using a quartz crystal oscillator as a detection element, or an acceleration sensor or gyro sensor using a MEMS as a detection element. The physical quantity sensor 50 may also be an inertial measurement unit (IMU) that combines an acceleration sensor and a gyro sensor. The physical quantity sensor 50 may detect velocity or displacement by integrating acceleration detected by a detection element, or may use a detection element that detects velocity, etc. The physical quantity sensor 50 may detect angular acceleration or angle by differentiating or integrating angular velocity detected by a detection element, or may use a detection element that detects angular acceleration, etc. An example of an acceleration sensor is a sensor that detects acceleration by measuring the vibration frequency, which changes in response to stress applied to a quartz crystal oscillator. An example of a gyro sensor is a sensor that detects angular velocity by detecting the Coriolis force applied to a quartz crystal oscillator. Another example of an acceleration sensor or gyro sensor is a sensor in which a mass and electrodes are formed by MEMS and that detects acceleration or angular velocity by detecting the electrostatic capacitance between the electrodes, which changes in response to the inertial force applied to the mass.

[0014] The mounting device 100 is a device for mounting the physical quantity sensor 50 to the measurement object 1. As a specific example, the measurement object 1, such as the motor described above, has a ferromagnetic material on at least a portion of its surface. The mounting device 100 is mounted by being attracted to the ferromagnetic material on the surface of the measurement object 1 by magnetic force. The ferromagnetic material may be covered with an exterior such as plastic, or may be coated with paint or the like. The mounting device 100 includes a base 110, a magnet 120, and an attraction yoke 130.

[0015] The base 110 is a plate-like member whose thickness direction is the z direction and is made of a hard material such as metal or resin. A physical quantity sensor 50 is mounted on the surface of the base 110 on the +z direction side. The base 110 and the physical quantity sensor 50 are detachably fixed with screws, adhesive, adhesive tape, or the like. A magnet 120 is fixed to the surface of the base 110 on the -z direction side. The base 110 and the magnet 120 are fixed with screws, adhesive, adhesive tape, or the like. Note that "fixing" two objects A and B means that A and B are fixed so that their relative positions do not move, and is not limited to A and B being fixed in direct contact with each other. For example, the base 110 and the magnet 120 may be fixed with a fixing yoke (described later) present between them, that is, the base 110 and the magnet 120 may not be in direct contact with each other.

[0016] The magnet 120 has an attraction surface 121 that attracts the measurement target 1 by magnetic force. The attraction surface 121 is the surface opposite to the surface fixed to the base 110, i.e., the surface on the -z direction side of the magnet 120. The attraction surface 121 is assumed to be flat, but may also be a curved surface that is convex or concave in the -z direction. The attraction surface 121 basically exposes the magnet itself. However, a portion of the attraction surface 121 may be a non-magnetic member such as a screw or a hole, or the surface of the attraction surface 121 may be coated with a thin resin or the like. The magnet 120 is, for example, rectangular or plate-shaped, and is, for example, rectangular or square when viewed in the z direction. The magnet 120 is, for example, a neodymium magnet, an alnico magnet, a ferrite magnet, or the like. The magnetic pole direction may be arbitrary. For example, the attraction surface 121 may have one of a south pole and a north pole, and the other of a south pole and a north pole may be on the opposite surface.

[0017] The "yoke" of the attraction yoke 130 strengthens the attraction force of the magnet 120 by concentrating the magnetic flux of the magnet 120 within the yoke. The attraction yoke 130 is a frame-shaped member that surrounds the side of the magnet 120 and is made of a ferromagnetic material that becomes magnetized by the magnetic force of the magnet 120. The sides of the magnet 120 refer to the four sides of the magnet 120: the +x, -x, +y, and -y directions. Because FIG. 1 is a cross-sectional view, only the +y and -y directions are shown. The attraction yoke 130 has a rectangular or square shape similar to the outer shape of the magnet 120 when viewed in the z direction, and is arranged to surround the immediate outside of the magnet 120. In other words, the side of the magnet 120 and the inner surface of the attraction yoke 130 are in contact. The attraction yoke 130 is not fixed to the magnet 120 and can be displaced in the +z or -z direction along the side of the magnet 120. The +z direction or the -z direction can also be said to be a direction along the normal to the attraction surface 121, and this is referred to as the first direction. At this time, it can also be said that the attraction yoke 130 is displaced relative to the magnet 120 in the first direction.

[0018] As described above, the suction yoke 130 has four faces, namely, the +x side, the −x side, the +y side, and the −y side. The first suction end 131 is provided on the +y side face, and the second suction end 132 is provided on the −y side face. The first and second suction ends 131 and 132 are sometimes collectively referred to as suction ends 131 and 132. The suction ends 131 and 132 are the −z side ends of the two faces, the +y side and the −y side, that contact the object to be measured 1. When viewed in the z direction, the suction ends 131 and 132 are provided on two of the four sides of the rectangular or square suction yoke 130 that are parallel to the central axis of the cylinder that is the object to be measured 1, that is, on two sides along the x direction. The linear suction ends 131 and 132 on these two sides contact the object to be measured 1.

[0019] As shown in the upper diagram of FIG. 1 , a portion of the suction surface 121 is attached to the measurement target 1 at position P3 on the suction surface 121. Furthermore, as the suction ends 131 and 132 of the suction yoke 130 are displaced to protrude from the suction surface 121 in the −z direction, the first suction end 131 contacts the measurement target 1 at position P1, and the second suction end 132 contacts the measurement target 1 at position P2. The distance by which the suction ends 131 and 132 protrude from the suction surface 121 at this time is designated ΔZ1. The lower diagram of FIG. 1 illustrates a case in which the radius of the cylinder serving as the measurement target 1 is larger than that in the upper diagram, i.e., the cylinder has a more gently curved surface. In this case, the protrusion distance ΔZ2 of the suction ends 131 and 132 in the lower diagram is smaller than the protrusion distance ΔZ1 of the suction end 131 in the upper diagram. Similarly, the mounting device 100 attaches to the measurement target 1 at positions P1 to P3.

[0020] As described above, the mounting device 100 of this embodiment is a device for mounting the physical quantity sensor 50 to the measurement object 1. The mounting device 100 includes a base 110 on which the physical quantity sensor 50 is mounted, a magnet 120 having an attraction surface 121 that attracts the measurement object 1, and an attraction yoke 130 having attraction ends 131 and 132 that attract the measurement object 1 by the magnetic force of the magnet 120. The attraction yoke 130 is displaced relative to the magnet 120 in a first direction (+z direction or −z direction) along the normal to the attraction surface 121, so that at least a portion of the attraction surface 121 of the magnet 120 and the attraction ends 131 and 132 of the attraction yoke 130 attract the measurement object 1.

[0021] According to this embodiment, the attraction yoke 130 is freely displaceable in the first direction (+z direction or −z direction), so that the attraction yoke 130 is always attracted to the measurement object 1 at positions P1 and P2 regardless of the radius of the cylinder, and the attraction surface 121 of the magnet 120 is attracted to the measurement object 1 at position P3. This allows the mounting device 100 to be stably fixed to the measurement object 1. Furthermore, because the magnet 120 is in contact with the measurement object 1 at least at position P3, the distance between the magnet 120 and the measurement object 1 does not increase.

[0022] Specifically, as the distance between the magnet 120 and the object to be measured 1 increases, the magnetic field (magnetic flux density) weakens inversely proportional to the square of the distance between the magnet 120 and the object to be measured 1, weakening the magnetic field (magnetic flux density) and the magnetic attraction of the magnet 120. For example, the larger the diameter of a motor, the greater the motor's output and the greater the vibration. In FIG. 1, if the attraction yoke 130 did not move up and down, the larger the motor's diameter, the greater the distance between the magnet 120 and the object to be measured 1, making it more likely that the mounting device 100 would come off the object to be measured 1 or move due to vibration. In this regard, according to this embodiment, the movement of the attraction yoke 130 allows the mounting device 100 to be attached to the object to be measured 1 with the magnet 120 and the object to be measured 1 always in contact. This allows the mounting device 100 to be fixed to the object to be measured 1 with a strong magnetic force.

[0023] Furthermore, in this embodiment, the magnet 120 may be fixed to the base 110. That is, the attraction yoke 130 may not be fixed to the base 110, but may be provided so as to be displaceable in the +z direction or the −z direction relative to the base 110. However, this is not limited thereto, and the attraction yoke 130 may be configured to be fixed to the base 110. That is, the magnet 120 may not be fixed to the base 110, but may be provided so as to be displaceable in the +z direction or the −z direction relative to the base 110. For example, a recess of the same shape as the magnet 120 is provided on the surface of the base 110 on the −z direction side. Then, when the magnet 120 is displaced in the +z direction, an upper part of the magnet 120 fits into the recess of the base 110, and the attraction surface 121 of the magnet 120 is displaced further in the +z direction than the attraction ends 131, 132 of the attraction yoke 130. In this way, the protruding distance of the suction ends 131 and 132 from the suction surface 121 can be freely changed according to the curved surface of the cylinder that is the measurement object 1.

[0024] 2. Detailed configuration example 2 to 5 show a detailed configuration example of one example of the mounting device 100 described in FIG. 1. The physical quantity sensor 50 is not shown here. FIG. 2 is a view of the mounting device 100 as seen from the back side, i.e., the -z direction side. FIG. 3 is an AA cross-sectional view of the mounting device 100 in FIG. 2. The AA cross-section is parallel to the yz plane. FIG. 4 is a perspective view of the mounting device 100 in FIGS. 2 and 3 attached to the measurement target 1. FIG. 5 is a cross-sectional view of the mounting device 100 and the measurement target 1 in FIG. 4, taken along a cross-section parallel to the yz plane. Hereinafter, the +z direction will also be referred to as the top and the -z direction will also be referred to as the bottom. The width of a member in the z direction will also be referred to as the height. The surface on the -z direction side will also be referred to as the back side, and the surface on the +z direction side will also be referred to as the front side. The surfaces on the +x direction side, the -x direction side, the +y direction side, and the -y direction side will also be referred to as the side faces.

[0025] The mounting device 100 includes a base 110, a magnet 120, an attraction yoke 130, a fixing yoke 140, and a screw 150. Here, an example in which the magnet 120 is fixed to the base 110 will be described, but as described above, a configuration in which the attraction yoke 130 is fixed to the base 110 may also be used.

[0026] The base 110 has a plate-like or rectangular parallelepiped shape. The top and bottom surfaces of the base 110 are parallel to the xy plane. The side surfaces of the base 110 on the +x direction side and the -x direction side are parallel to the yz plane. The side surfaces of the base 110 on the +y direction side and the -y direction side are parallel to the xz plane. The thickness of the base 110 in the z direction is smaller than the width in the x direction and the width in the y direction. The widths of the base 110 in the x direction and the y direction may be the same or different. When viewed in the z direction, a screw hole 115 for fixing the magnet 120 is provided in the center of the base 110. Furthermore, when viewed in the z direction, screw holes 111 to 113 for fixing the physical quantity sensors 50 are provided at three locations on the base 110. For example, screw holes 111 and 112 are provided at both ends of one of two opposing sides of the base 110, and a screw hole 113 is provided near the center of the other side. By inserting screws from bottom to top through the screw holes 111 to 113 to fasten the physical quantity sensor 50, the base 110 and the physical quantity sensor 50 are fixed. Note that the number and positions of the screw holes are not limited to those described above.

[0027] The magnet 120 has a plate-like or rectangular parallelepiped shape. The top and bottom surfaces of the magnet 120 are parallel to the xy plane. The +x and -x side surfaces of the magnet 120 are parallel to the yz plane. The +y and -y side surfaces of the magnet 120 are parallel to the xz plane. The thickness of the magnet 120 in the z direction is smaller than its width in the x and y directions. The width of the magnet 120 in the x and y directions may be the same or different. A screw hole 115 is provided in the center of the magnet 120 when viewed in the z direction. A screw 150 is inserted from below the screw hole in the magnet 120 into the screw hole 115 in the base 110, and the magnet 120 is screwed to the base 110, thereby fixing the base 110 and the magnet 120 together.

[0028] 1, the attraction yoke 130 may be fixed to the base 110, allowing the magnet 120 to move up and down. In this case, the positions of the magnet 120 and the base 110 move relatively in the z direction by tightening or loosening the screw 150. In other words, the up and down positions of the magnet 120 can be adjusted by tightening or loosening the screw 150.

[0029] The fixed yoke 140 is fixed to the magnet 120 and is arranged to cover the top and side surfaces of the magnet 120. The position of the lower end of the fixed yoke 140 in the z direction is the same as the position of the attraction surface 121 of the magnet 120. The fixed yoke 140 is a ferromagnetic material that becomes magnetized by the magnetic force of the magnet 120. The fixed yoke 140 includes an upper plate in contact with the surface of the magnet 120 facing the +z direction, a first horizontal plate in contact with the side surface of the magnet 120 facing the +x direction, a second horizontal plate in contact with the side surface of the magnet 120 facing the -x direction, a third horizontal plate in contact with the side surface of the magnet 120 facing the +y direction, and a fourth horizontal plate in contact with the side surface of the magnet 120 facing the -y direction. The upper plate is parallel to the xy plane. The first and second horizontal plates are parallel to the yz plane. The third and fourth horizontal plates are parallel to the xz plane. The upper plate has holes for inserting screws 150. These five plates may be integrally configured as fixed yoke 140 without being separated, or fixed yoke 140 may be configured by combining five separate plates. Note that holes other than the holes for inserting screws 150 may also be provided in each plate. For example, FIGS. 3 and 5 show an example in which two holes are provided in the upper plate. These holes are for pushing magnets 120 out of fixed yoke 140 and removing them.

[0030] The suction yoke 130 includes a first frame plate in contact with the first horizontal plate of the fixed yoke 140, a second frame plate in contact with the second horizontal plate, a third frame plate in contact with the third horizontal plate, and a fourth frame plate in contact with the fourth horizontal plate. The first and second frame plates are parallel to the yz plane. The third and fourth frame plates are parallel to the xz plane. These four plates may be integrally configured as the suction yoke 130 without being separated, or the suction yoke 130 may be configured by combining the four separate plates. The +z direction ends of the first to fourth frame plates are located at the same position in the z direction; in other words, they are located within the same xy plane. The first suction end 131 is the -z direction end of the third frame plate on the +y direction side, and the second suction end 132 is the -z direction end of the fourth frame plate on the -y direction side. The height of the third and fourth frame plates having these suction ends 131 and 132 is higher than the height of the first frame plate on the +x-direction side and the second frame plate on the -x-direction side. That is, the suction ends 131 and 132 protrude further in the -z direction than the ends of the first and second frame plates on the -z direction side. As shown in the perspective view of Figure 4, because the suction ends 131 and 132 protrude, when the suction ends 131 and 132 are attached to the measurement target 1, the ends of the first and second frame plates do not interfere with the measurement target 1, and the suction surface 121 of the magnet 120 can be attached to the measurement target 1.

[0031] The suction ends 131 and 132 of the suction yoke 130 have a curved surface that is convex in the -z direction. Specifically, as shown in FIG. 3 , in a cross section parallel to the yz plane, the suction ends 131 and 132 have a semicircular shape that is convex in the -z direction. If the suction ends 131 and 132 were rectangular, the inner corner of the suction end 131 would always be in contact with the cylindrical object to be measured 1. In this case, the angle formed between the ends of the suction ends 131 and 132 and the cylinder varies depending on the radius of the cylinder. This may result in a change in the suction force of the suction yoke 130. In this regard, according to this embodiment, as can be seen from FIG. 1 and other figures, regardless of whether the curve of the object to be measured 1 is steep or gentle, a point on the semicircle of the suction ends 131 and 132 will be in contact with the object to be measured 1. In this case, the suction end 131 and the cylinder of the object to be measured 1 are in contact with each other at a tangent to the circle, so the angle formed between the suction end 131 and the object to be measured 1 is always constant. This allows the chucking force of the chucking yoke 130 to be constant regardless of the shape of the object 1 to be measured.

[0032] 6 is a cross-sectional view of the mounting device 100 mounted on a planar measurement object 1, taken along a cross section parallel to the yz plane. When the mounting device 100 is mounted on the planar measurement object 1, the suction ends 131 and 132 of the suction yoke 130 are attracted to the measurement object 1, and the entire suction surface 121 of the magnet 120 is attracted to the measurement object 1. In other words, the mounting device 100 can be mounted not only on a measurement object 1 having a curved surface such as a cylinder, but also on a flat surface.

[0033] As described above, the attraction yoke 130 has first to fourth frame plates, and the third and fourth frame plates have attraction ends 131 and 132. The height of the third and fourth frame plates is equal to or less than the height from the attraction surface 121 of the magnet 120 to the upper surface of the upper plate of the fixed yoke 140. As a result, when the attraction ends 131 and 132 are attracted to the planar measurement object 1, the attraction surface 121 of the magnet 120 and the attraction ends 131 and 132 are at the same height, and the attraction surface 121 and the attraction ends 131 and 132 are attracted to the planar measurement object 1.

[0034] 7 is a diagram illustrating the fixation of the attraction yoke 130 and the magnet 120. The following describes an example in which the magnet 120 is fixed to the base 110, but this method can also be applied to a case in which the attraction yoke 130 is fixed to the base 110.

[0035] Screw holes 135 and 136 are provided in the attraction yoke 130. FIG. 7 shows an example in which the screw holes 135 and 136 are provided in the third frame plate on the +y direction side. The screw holes 135 and 136 are through holes with threads cut into the inside, allowing screws 165 and 166 to be inserted in the y direction. When the screws 165 and 166 are turned in the tightening direction, the tips of the screws 165 and 166 come into contact with the side surface of the fixed yoke 140. When the screws 165 and 166 are further turned in the tightening direction, the tips of the screws 165 and 166 press the side surface of the fixed yoke 140 in the −y direction, applying a force in the +y direction to the attraction yoke 130. This presses the fourth frame plate on the −y direction side of the attraction yoke 130 against the side surface of the fixed yoke 140, and the attraction yoke 130 is fixed to the magnet 120.

[0036] When mounting the mounting device 100 to the measurement target 1, the screws 165 and 166 are first loosened before mounting. At this time, the attraction yoke 130 moves in the -z direction, and the attraction ends 131 and 132 are attracted to the measurement target 1. Then, by tightening the screws 165 and 166 in this state, the attraction yoke 130 and the magnet 120 are fixed as described above, and the stable mounting state described in FIG. 1 etc. is maintained.

[0037] In the above-described embodiment, the mounting device 100 may include a fixed yoke 140 provided between the magnet 120 and the attraction yoke 130 .

[0038] The attraction yoke 130 is frame-shaped because it moves in the z-direction relative to the magnet 120, and does not cover the top surface of the magnet 120. By including the fixed yoke 140 provided between the magnet 120 and the attraction yoke 130, the top and side surfaces of the magnet 120 are covered by the yoke, thereby strengthening the attraction force of the magnet 120.

[0039] As described with reference to FIG. 6 and other figures, the length in the first direction of the attraction yoke 130 (height in the z direction) may be equal to or less than the length in the first direction of the fixed yoke 140 (height in the z direction).

[0040] According to this embodiment, when the upper end of the attraction yoke 130 abuts the base 110, the positions of the attraction ends 131, 132 in the z direction are the same as or above the lower end of the fixed yoke 140. As a result, not only when the mounting device 100 is mounted on a measurement target 1 having a curved surface as in FIG. 4, but also when the mounting device 100 is mounted on a measurement target 1 having a flat surface as in FIG. 6, the attraction surface 121 of the magnet 120 and the attraction ends 131, 132 of the attraction yoke 130 can be attracted to the measurement target 1. In this way, the mounting device 100 of this embodiment can be mounted on measurement targets 1 of various shapes.

[0041] In this embodiment, the fixed yoke 140 may be provided so as to cover the surfaces of the magnet 120 excluding the attraction surface 121 .

[0042] According to this embodiment, the fixed yoke 140 concentrates the magnetic flux inside the fixed yoke 140 on the surfaces of the magnet 120 excluding the attraction surface 121, thereby increasing the attraction force of the magnet 120.

[0043] In this embodiment, the attraction yoke 130 may be displaced by sliding on the outer surface (side surface) of the fixed yoke 140 .

[0044] According to this embodiment, the attraction yoke 130 slides on the outer surface (side surface) of the fixed yoke 140, so that the attraction yoke 130 can be displaced relative to the magnet 120 in the first direction (z direction).

[0045] In this embodiment, the attraction yoke 130 may be attracted to the fixed yoke 140 by magnetic force.

[0046] According to this embodiment, the fixed yoke 140 is magnetized by the magnetic force of the magnet 120, and the attracting yoke 130 is magnetized by the magnetic force of the magnet 120 and the fixed yoke 140. As a result, an attractive force due to the magnetic force acts between the fixed yoke 140 and the attracting yoke 130. After the attracting yoke 130 moves so that the attracting ends 131 and 132 are attracted to the measurement target 1, the position of the attracting yoke 130 is fixed or becomes difficult to move due to the attractive force between the fixed yoke 140 and the attracting yoke 130.

[0047] In this embodiment, the direction perpendicular to the first direction (z direction) may be the second direction (+y direction), and the direction opposite to the second direction (+y direction) may be the third direction (-y direction). In this case, the attraction yoke 130 may have, as attraction ends, a first attraction end 131 provided in the second direction (+y direction) of the magnet 120 and a second attraction end 132 provided in the third direction (-y direction) of the magnet 120.

[0048] According to this embodiment, the attraction surface 121 of the magnet 120 and the first attraction end 131 and second attraction end 132 of the attraction yoke 130 attract the measurement object 1, so that the measurement object 1 is attracted to the measurement object 1 at three points. This allows the mounting device 100 to be stably attracted to the measurement object 1.

[0049] In this embodiment, a direction perpendicular to the first direction (z direction) and the second direction (+y direction) may be defined as a fourth direction (x direction). In this case, the first suction end 131 and the second suction end 132 may be suction ends along the fourth direction (x direction).

[0050] According to this embodiment, the attachment device 100 is attached to the measurement object 1 so that the first suction end 131 and the second suction end 132 along the fourth direction are parallel to the central axis of the cylindrical measurement object 1. This brings the entire first suction end 131 and the second suction end 132 along the fourth direction into contact with the cylindrical side surface, and the attachment device 100 stably attaches to the measurement object 1.

[0051] In this embodiment, the first suction end 131 and the second suction end 132 may have a curved surface facing the measurement target 1 in a cross section (cross section parallel to the yz plane) perpendicular to the fourth direction (x direction). Specifically, as described above, the first suction end 131 and the second suction end 132 have a curved surface that is convex in the -z direction.

[0052] 1 and other figures, according to this embodiment, regardless of whether the curve of the measurement target 1 is steep or gentle, one point on the semicircle of the suction tips 131 and 132 comes into contact with the measurement target 1. In this case, the angle formed between the suction tips 131 and the measurement target 1 is constant regardless of the shape of the measurement target 1, so the suction force of the suction yoke 130 can be made constant.

[0053] As described in FIG. 7, the mounting device 100 may also include fixing members (screws 165, 166) that fix the adsorption yoke 130, which is displaceable relative to the magnet 120 in the first direction (z direction), to the magnet 120 at any position.

[0054] According to this embodiment, the mounting device 100 is mounted to the measurement target 1 in a state where the magnet 120 and the attraction yoke 130 are not fixed relative to each other by a fixing member, and after mounting, the magnet 120 and the attraction yoke 130 can be fixed relative to each other by a fixing member. As a result, after the attraction yoke 130 moves in the −z direction during mounting and the attraction ends 131 and 132 are attracted to the measurement target 1, the position of the attraction yoke 130 can be fixed in that state.

[0055] Although the present embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader or equivalent meaning may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of the present embodiment and modifications are also included within the scope of the present disclosure. Furthermore, the configurations and operations of the physical quantity detection device, physical quantity sensor, mounting device, base, magnet, attraction yoke, and fixed yoke are not limited to those described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0056] 1...measurement object, 50...physical quantity sensor, 100...mounting device, 110...base, 111 to 113, 115...screw hole, 120...magnet, 121...attraction surface, 130...attraction yoke, 131...first attraction end, 132...second attraction end, 135, 136...screw hole, 140...fixing yoke, 150, 165, 166...screw, 200...physical quantity detection device

Claims

1. An attachment device for attaching a physical quantity sensor to a measurement target, a base on which the physical quantity sensor is mounted; a magnet having an attraction surface that attracts the object to be measured; an attraction yoke having an attraction end that attracts the object to be measured by the magnetic force of the magnet; Including, The attachment device is characterized in that the suction yoke is a yoke that is displaced relative to the magnet in a first direction along the normal to the suction surface, so that at least a portion of the suction surface of the magnet and the suction end of the suction yoke are attracted to the object to be measured.

2. 2. The mounting device according to claim 1, The attachment device further comprises a fixed yoke provided between the magnet and the attraction yoke.

3. 3. The mounting device according to claim 2, An attachment device, characterized in that the length of the suction yoke in the first direction is equal to or less than the length of the fixed yoke in the first direction.

4. 3. The mounting device according to claim 2, The mounting device is characterized in that the fixed yoke is provided so as to cover the surfaces of the magnet excluding the attraction surface.

5. 3. The mounting device according to claim 2, The attachment device is characterized in that the suction yoke is displaced by sliding on the outer surface of the fixed yoke.

6. 3. The mounting device according to claim 2, The attachment device is characterized in that the attraction yoke is attracted to the fixed yoke by magnetic force.

7. 2. The mounting device according to claim 1, When a direction perpendicular to the first direction is defined as a second direction and a direction opposite to the second direction is defined as a third direction, an attachment device characterized in that the suction yoke has, as the suction ends, a first suction end provided in the second direction of the magnet and a second suction end provided in the third direction of the magnet.

8. 8. The mounting device according to claim 7, When a direction perpendicular to the first direction and the second direction is defined as a fourth direction, The attachment device is characterized in that the first suction end and the second suction end are suction ends along the fourth direction.

9. 9. The mounting device according to claim 8, The mounting device is characterized in that the first suction end and the second suction end have curved surfaces that face the object to be measured in a cross section perpendicular to the fourth direction.

10. 2. The mounting device according to claim 1, The mounting device is characterized in that the magnet is fixed to the base.

11. 2. The mounting device according to claim 1, The attachment device is characterized in that the suction yoke is fixed to the base.

12. 2. The mounting device according to claim 1, a fixing member that fixes the attraction yoke, which is displaceable relative to the magnet in the first direction, to the magnet at an arbitrary position;

13. A mounting device according to any one of claims 1 to 12; the physical quantity sensor; A physical quantity detection device comprising:

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