Measuring apparatus
Patent Information
- Application Number
- JP2024081058
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-11-28
Smart Images
Figure 2025174587000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates primarily to a retrofittable measuring device for measuring torque on a shaft to be measured. [Background technology]
[0002] As a technique relating to a retrofittable measuring device for measuring the torque of a rotating shaft, a torque transducer shown in FIG. 8 is known (for example, Patent Document 1). Figure 8a1 shows the configuration of the torque converter as viewed from the radial direction of the rotating shaft, and Figure 8a2 shows the configuration of the torque converter as viewed from the axial direction of the rotating shaft. This torque converter comprises a first mounting base 813 consisting of a first upper base 811 and a first lower base 812 that clamp the rotating shaft 800, a second mounting base 823 consisting of a second upper base 821 and a second lower base 822 that clamp the rotating shaft 800 at a position spaced a predetermined distance axially from the first mounting base 813, a beam-shaped strain-flexing part 830 whose both ends are fixed to the first mounting base 813 and the second mounting base 823, respectively, and a strain gauge 831 attached to the middle part of the circumferential side of the strain-flexing part 830. The torque of the rotating shaft 800 can be detected from the change in resistance value of the strain gauge 831 that accompanies strain in the strain-flexing part 830. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Publication No. 3029548 Summary of the Invention [Problem to be solved by the invention]
[0004] When configuring a measuring device using the torque converter shown in Figures 8a1 and 8a2, in addition to the configuration shown, various electrical / electronic devices such as a bridge circuit that converts changes in the resistance value of the strain gauge 831 into a voltage value, a transmission device that transmits the converted voltage value to the outside via wireless or other means, and a battery that supplies power to these devices must be arranged in a form that rotates together with the torque converter so that their relative positional relationship with the torque converter does not change.
[0005] Therefore, it is conceivable to provide a housing fixed to the torque converter and fix the electric / electronic device inside the housing. Depending on the environment in which the torque converter is used, it may be desirable to provide a housing that covers the torque converter to protect it. However, for example, if a housing 850 covering the torque converter is connected to the first mounting base 813 or the second mounting base 823, as shown in Figure 8b1, which shows the external appearance, and Figure 8b2, which shows a cross section taken along a plane including line AA in Figure 8b1 and the central axis BB of the rotating shaft 800, the rigidity of the housing 850 will hinder the deformation of the strain-flexing part 830, resulting in a relatively large decrease in the accuracy of torque measurement.
[0006] The cross section of the torque converter shown in FIG. 8b2 corresponds to the cross section taken along line CC in FIG. 8a2. Therefore, an object of the present invention is to provide a housing for a measurement device that can be retrofitted to measure torque, stress, or strain on a shaft to be measured, while keeping the decrease in measurement accuracy relatively small. [Means for solving the problem]
[0007] To achieve the above object, the present invention provides a measurement device fixed to an axis to be measured, comprising: a strain detection device detachably fixed to the axis to be measured and detecting strain associated with deformation of the axis to be measured; and a housing detachably fixed to the axis to be measured. Here, when the strain detection device and the housing are fixed to the axis to be measured, the housing is fixed to the axis to be measured by sandwiching the axis to be measured at both ends in the axial direction of the axis to be measured, the strain detection device is disposed between the both ends of the housing and spaced apart from the both ends in the axial direction, and the housing has a shape that covers the periphery of the strain detection device in a non-contact manner.
[0008] In such a measuring device, the housing may have a hollow cylindrical shape and include a first housing portion and a second housing portion formed by dividing the housing in half so that the circumference of the cylindrical shape is divided into two. The first housing portion and the second housing portion have V-groove-shaped recesses provided in portions corresponding to the centers of the two walls that correspond to the two bottoms of the cylindrical shape. Here, the two walls correspond to the two end portions. Next, the first housing portion and the second housing portion are at least partially separable so that the measurement target shaft and the strain sensor fixed to the measurement target shaft can be inserted into the hollow from outside the housing. The measurement target shaft is sandwiched between the recesses in the walls of the first housing portion and the second housing portion that correspond to the same bottom of the cylindrical shape, thereby fixing the housing to the measurement target shaft.
[0009] In the above-described measuring device, it is preferable that the surfaces at both ends of the housing that hold the shaft to be measured are flat. According to the above-described measuring device, the housing is arranged in a non-contact manner with the strain detection device, so that the influence of the rigidity of the housing, etc. does not directly affect the strain detection device, and the reduction in the measurement accuracy of the strain detection device due to the arrangement of the housing can be suppressed. To achieve the above object, the present invention provides a measurement device fixed to an axis to be measured, the measurement device comprising a strain detector detachably fixed to the axis to be measured and a housing detachably fixed to the axis to be measured. The strain detector comprises a first gripping portion fixed to the axis to be measured by clamping the axis to be measured, a second gripping portion fixed to the axis to be measured by clamping the axis to be measured at a position axially separated from the first gripping portion, and a strain-flexing portion to which a strain gauge is fixed, connecting the first gripping portion and the second gripping portion. Furthermore, when the strain detector and the housing are fixed to the axis to be measured, the strain detector is disposed between both ends of the housing in the axial direction, and the housing is connected to the first gripping portion and has a shape that covers the strain detector without contacting the second gripping portion and the strain-flexing portion.
[0010] According to this type of measuring device, the housing is connected to the first gripping part of the strain detector, so the housing and the strain detector can be integrated, making the measuring device easy to handle. Also, because the housing is not connected to the second gripping part, the rigidity of the housing does not have a strong effect on the strain-generating part connecting the first gripping part and the second gripping part, and the measurement accuracy of the strain detector does not decrease significantly.
[0011] Here, in such a measuring device, when the strain detection device and the housing are fixed to the axis to be measured, the housing may be fixed to the axis to be measured by connecting with the first gripping portion. Alternatively, in such a measuring device, when the strain detection device and the housing are fixed to the shaft to be measured, at least the end of the housing on the second gripping portion side may clamp the shaft to be measured. Furthermore, in such a measuring device, the first gripping unit may include a first block and a second block that sandwich the shaft to be measured when the strain detector and the housing are fixed to the shaft to be measured. A first connecting unit that connects the housing to the first block and a second connecting unit that connects the housing to the second block may be provided, and the first gripping unit may be fixed to the shaft to be measured by clamping the shaft to be measured between the first block and the second block with a force applied to the first block via the first connecting unit and a force applied to the second block via the second connecting unit.
[0012] In this case, the first connecting portion may be a first feed screw mechanism that moves the first block in the radial direction of the shaft to be measured when the strain detection device and the housing are fixed to the shaft to be measured. Furthermore, the second connecting portion may be a second feed screw mechanism that moves the second block in the radial direction of the shaft to be measured when the strain detection device and the housing are fixed to the shaft to be measured. Alternatively, the present invention also provides a method for mounting a measuring device on a shaft to be measured, the method comprising the steps of: fixing a strain detection device, which detects strain associated with deformation of the shaft to be measured, to the shaft to be measured; attaching a predetermined positioning jig between the housing and the strain detection device to position the housing so that the housing covers the periphery of the strain detection device in a non-contact manner; clamping the shaft to be measured between both axial ends of the housing in the axial direction of the shaft to be measured and fixing the housing to the shaft to be measured; and removing the positioning jig. [Effects of the Invention]
[0013] As described above, according to the present invention, a housing for a retrofittable measuring device that measures torque, stress, or strain on a shaft to be measured can be provided while keeping the decrease in measurement accuracy relatively small. [Brief explanation of the drawings]
[0014] [Figure 1] 1 is a diagram showing a configuration of a distortion detection device according to an embodiment of the present invention; [Figure 2] 1 is a diagram showing a configuration of a housing according to a first embodiment of the present invention. [Figure 3] 1 is a diagram showing a usage form of a measurement device according to a first embodiment of the present invention. [Figure 4] 1 is a diagram showing a usage form of a measurement device according to a first embodiment of the present invention. [Figure 5] FIG. 4 is a diagram showing the configuration of a measurement device according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing another example of the configuration of the measurement device according to the second embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing the configuration of a measurement device according to a third embodiment of the present invention. [Figure 8] 1 shows a diagram illustrating the configuration of a known torque converter and the problem to be solved by the present invention; DETAILED DESCRIPTION OF THE INVENTION
[0015] A first embodiment of the present invention will be described below. The measurement device of the first embodiment is configured by combining a strain detector with a housing. First, the configuration of a strain detector 1 is shown in FIGS. For convenience, front, back, top, bottom, left and right are defined as shown in the figures, with Fig. 1a1 showing the front of the strain detection device 1, Fig. 1a2 showing the top of the strain detection device 1, Fig. 1a3 showing the left side of the strain detection device 1, and Fig. 1a4 showing the right side of the strain detection device 1. Also, Fig. 1b shows an oblique view of the strain detection device 1. The rear of the strain detection device 1 is bilaterally symmetrical to the front, and the bottom of the strain detection device 1 appears almost identical to the top.
[0016] As shown in the figure, the strain detection device 1 has a first gripping portion 11 having a hollow space that is open in the front-to-back direction, a second gripping portion 12 having a hollow space that is open in the front-to-back direction, and four strain-generating portions 13 that connect the first gripping portion 11 and the second gripping portion 12 in the front-to-back direction. The first gripping unit 11 has a first upper block 111 and a first lower block 112 connected to the lower part of the first upper block at the left and right ends. The left ends of the first upper block 111 and the first lower block 112 are connected vertically by a first hinge 113, and the right ends of the first upper block 111 and the first lower block 112 are connected by a first bolt 115 with a first spacer 114 sandwiched between them.
[0017] Here, the first spacer 114 is provided with a front positioning hole 1141 having an opening on the front surface of the first spacer 114 . The central portion in the left-right direction of the lower surface of the first upper block 111 is recessed upward in a V-shaped groove, and the central portion in the left-right direction of the upper surface of the first lower block 112 is recessed downward in a V-shaped groove. The space between these two V-shaped recesses forms the hollow of the first gripping portion 11. The second gripping unit 12 has the same configuration as the first gripping unit 11. That is, the second gripping unit 12 has a second upper block 121 and a second lower block 122 connected at the left and right ends to the lower part of the second upper block 121. The left ends of the second upper block 121 and the second lower block 122 are connected vertically by a second hinge 123, and the right ends of the second upper block 121 and the second lower block 122 are connected by a second bolt 125 with a second spacer 124 sandwiched between them.
[0018] Here, second spacer 124 is provided with rear positioning hole 1241 that opens on the rear surface of second spacer 124 . The center portion in the left-right direction of the lower surface of the second upper block 121 is recessed upward in a V-shaped groove, and the center portion in the left-right direction of the upper surface of the second lower block 122 is recessed downward in a V-shaped groove. The second gripping portion 12 is hollow between these two V-shaped recesses. Next, two of the four strain-generating sections 13 are suspended in the form of beams extending in the front-to-back direction between the first upper block 111 and the second upper block 121, and the remaining two are suspended in the form of beams extending in the front-to-back direction between the first lower block 112 and the second lower block 122. Furthermore, the four strain-flexing parts 13 have the shape of a thin flat plate in the tangential direction, with a plane perpendicular to the tangential direction at the position of the strain-flexing part 13 of a circle that passes through the strain-flexing part 13 and has its center at an axis that passes through the center in the vertical and horizontal directions of the hollow of the first gripping part 11 and the hollow of the second gripping part 12 in the front-to-back direction, and a strain gauge is attached to the plane perpendicular to the tangential direction. Note that the number of strain gauges attached to each strain-flexing part 13 and their positions in the front-to-back direction may be set arbitrarily.
[0019] The set of the first upper block 111, the second upper block 121, and the strain-flexing part 13 between the first upper block 111 and the second upper block 121 is called the upper structure part, and the first bolt 115 and the second bolt 125 are removable. As shown in Figure 1c, when the first bolt 115 and the second bolt 125 are removed, the upper structure part can rotate relative to the remaining part around the rotation axes of the first hinge 113 and the second hinge 123, thereby opening the hollows of the first gripping part 11 and the second gripping part 12 to the outside.
[0020] Then, with the hollows of the first holding portion 11 and the second holding portion 12 open to the outside, the blocks are arranged so that the rotating shaft 100 to be measured is located between the first upper block 111 and the first lower block 112, and between the second upper block 121 and the second lower block 122.Then, as shown in Figure 1d, the first upper block 111 and the first lower block 112 are fastened with a first bolt 115, and the second upper block 121 and the second lower block 122 are fastened with a second bolt 125, thereby clamping the rotating shaft 100 between the four V-groove-shaped recesses, and the strain detection device 1 can be fixed to the rotating shaft 100.
[0021] The rotating shaft 100 to be measured may be, for example, a drive shaft of an automobile. Next, when the strain detection device 1 is fixed to the rotating shaft 100 using the four V-groove-shaped recesses, the surface that abuts against the rotating shaft 100 to be measured is a curved surface with the central part in the front-to-back direction bulging out toward the rotating shaft 100, as shown in Figure 1e, which is a cross section of line DD in Figure 1d, and the four V-groove-shaped recesses abut against the rotating shaft 100 to be measured in a manner that is close to point contact.
[0022] The first hinge 113, the second hinge 123, the first spacer 114, and the second spacer 124 may be provided interchangeably with different lengths in the vertical direction to accommodate a wider range of different diameters of the rotating shaft 100. In addition, the left ends of the first upper block 111 and the first lower block 112 and the left ends of the second upper block 121 and the second lower block 122 may be connected using spacers and bolts instead of hinges, as with the right ends. Next, the configuration of the housing 2 is shown in FIGS. 2a and 2b. For convenience, the front, back, top, bottom, left and right are defined as shown in the figures, with Fig. 2a1 showing the front of the housing 2, Fig. 2a2 showing the top of the housing 2, Fig. 2a3 showing the left side of the housing 2, and Fig. 2a4 showing the right side of the housing 2. Also, Fig. 2b shows a perspective view of the housing 2. The rear of the housing 2 is bilaterally symmetrical to the front, and the bottom of the housing 2 appears almost identical to the top.
[0023] As shown in the figure, the housing 2 has an upper housing 21 and a lower housing 22 that are connected vertically. The housing 2 has a hollow cylindrical shape with the axial direction (height direction) extending in the front-to-rear direction as a whole, and openings are provided in the centers of the front and rear walls that correspond to the two bottoms of the cylindrical shape. The upper housing 21 forms the upper half of the housing 2 , and the lower housing 22 forms the lower half of the housing 2 . The left ends of the upper housing 21 and the lower housing 22 are connected vertically by two hinges 23 provided at the front wall and the rear wall. The right ends of the upper housing 21 and the lower housing 22 are connected vertically at two points by two bolts 24. The left-right central portions of the front and rear walls of upper housing 21 are recessed upward in a V-shaped groove, and the left-right central portions of the front and rear walls of lower housing 22 are recessed downward in a V-shaped groove. The space between the V-groove-shaped recesses in the front walls of upper housing 21 and lower housing 22 forms an opening in the center of the front wall of cylindrical housing 2, and the space between the V-groove-shaped recesses in the rear walls of upper housing 21 and lower housing 22 forms an opening in the center of the rear wall of cylindrical housing 2.
[0024] 2c shows a perspective view of lower housing 22, there are cavities between the front wall, rear wall, and side walls of lower housing 22. Similarly, there are cavities between the front wall, rear wall, and side walls of upper housing 21. The cavities in lower housing 22 and upper housing 21 form a cylindrical hollow inside housing 2.
[0025] A front pin hole 221, which is a through hole, is provided in the upper right end of the front wall of the lower housing 22, and a rear pin hole 222, which is a through hole, is provided in the upper right end of the rear wall of the lower housing 22. The two bolts 24 are removable, and as shown in Figure 2d, when the two bolts 24 are removed, the upper housing 21 can rotate relative to the lower housing 22 around the rotation axis of the hinge 23, opening the hollow inside the housing 2 and the openings in the front and rear walls to the outside.
[0026] Then, with the hollow and the openings in the front and rear walls open to the outside, the housing 2 is positioned so that the rotating shaft 100 is located between the upper housing 21 and the lower housing 22, and then, as shown in Figure 2e, the upper housing 21 and the lower housing 22 are fastened together with two bolts 24, thereby fixing the housing 2 to the rotating shaft 100 in a form in which the rotating shaft 100 is sandwiched between the four V-groove-shaped recesses in the front and rear walls.
[0027] Here, when the housing 2 is fixed to the rotating shaft 100 using the four V-groove-shaped recesses in the housing 2, the surface that comes into contact with the rotating shaft 100 to be measured is a roughened flat surface so as not to easily slide against the rotating shaft 100, which generates rotational angular acceleration. Note that by setting the friction coefficient of the contact surface of either the front wall or the rear wall lower than the friction coefficient of the other, either the front wall or the rear wall of the housing 2 will slide against the rotating shaft 100 when a force torque acts on the housing 2, thereby suppressing disturbances caused by forces acting between the housing 2 and the rotating shaft 100 and preventing damage to the housing 2.
[0028] The following describes how to use a measurement device having such a strain detector 1 and housing 2. Measurement using the measurement device is performed by fixing the strain detector 1 and the housing 2 to the rotating shaft 100 to be measured. First, as shown in Figures 3a1 and 3a2, the first upper block 111 and the first lower block 112 are tightly fastened together with the first bolt 115, and the second upper block 121 and the second lower block 122 are tightly fastened together with the second bolt 125, as described above, thereby fixing the strain detection device 1 to the rotating shaft 100, which is the first state. 3a1 shows the first state when viewed in the radial direction of the rotating shaft 100, and FIG. 3a2 shows the first state when viewed in the axial direction of the rotating shaft 100. FIG.
[0029] Next, the housing 2 is opened and placed around the strain detection device 1, and then the housing 2 is closed so that the strain detection device 1 fits into the hollow interior, as shown in Figures 3b1 and b2, which is the second state. 3b1 shows the second state when viewed in the radial direction of the rotating shaft 100, and FIG. 3b2 shows the second state when viewed in the axial direction of the rotating shaft 100. FIG. Here, this second state is a state in which the strain detector 1 fixed to the rotary shaft 100 is accommodated in the hollow interior of the housing 2, as shown in FIG. 3b3. Next, as shown in Figures 4a1 and 4a2, the front positioning pin 3, which has passed through the front pin hole 221 of the housing 2, is fitted into the front positioning hole 1141 of the strain detection device 1, and the rear positioning pin 4, which has passed through the rear pin hole 222 of the housing 2, is fitted into the rear positioning hole 1241 of the strain detection device 1, thereby positioning the housing 2 relative to the strain detection device 1, which is the third state.
[0030] Figure 4a1 shows the third state as viewed radially of the rotating shaft 100, and Figure 4a2 shows the third state as viewed axially of the rotating shaft 100, with the housing 2 being translucent. Here, the size and shape of the hollow space of the strain detector 1 and the housing 2 are determined so that the strain detector 1 can be accommodated in the hollow space of the housing 2 without contacting the housing 2, as shown in the drawing. In addition, the dimensions and arrangement of the front pin hole 221, front positioning hole 1141, rear pin hole 222, and rear positioning hole 1241 are determined so that by fitting the front positioning pin 3, which passes through the front pin hole 221 of the housing 2, into the front positioning hole 1141 of the strain detection device 1, and fitting the rear positioning pin 4, which passes through the rear pin hole 222 of the housing 2, into the rear positioning hole 1241 of the strain detection device 1, a gap is created between the housing 2 and the strain detection device 1, and the two are positioned in a position where they are not in contact with each other.
[0031] As shown in the figure, a circuit board CB is mounted in a space within the hollow housing 2 that does not interfere with the strain detection device 1, and is equipped with various electrical / electronic devices, such as a bridge circuit that converts changes in the resistance value of the strain gauges into a voltage value, a transmission device that transmits the converted voltage value to the outside via wireless or other means, and a battery that supplies power. The strain gauges of the strain detection device 1 are connected to the circuit board CB by cables. The cables connecting to the strain gauges may be detachably attached to the circuit board CB or to the strain detection device 1 using a connector. Alternatively, to prevent the housing 2 or the strain detection device 1 from accidentally falling off from the other when removing the measuring device and cutting the cables connecting to the strain gauges, the strain detection device 1 may be constructed including a magnetic material, and a magnet for attracting the strain detection device 1 may be provided in a space within the hollow housing 2 that does not interfere with the strain detection device 1.
[0032] After the housing 2 is positioned relative to the strain detection device 1 to achieve the third state, the upper housing 21 and the lower housing 22 are then fastened together with two bolts 24, as shown in Figures 4b1 and 4b2, to achieve the fourth state. 4b1 shows the fourth state when viewed in the radial direction of the rotary shaft 100, and FIG. 4b2 shows the fourth state when viewed in the axial direction of the rotary shaft 100. FIG. 4c1 and 4c2, the state in which the front positioning pin 3 and the rear positioning pin 4 are removed is defined as a fifth state. 4c1 shows the fifth state when viewed in the radial direction of the rotating shaft 100, and FIG. 4c2 shows the fifth state when viewed in the axial direction of the rotating shaft 100. FIG. Here, this fifth state is the state when the measurement is performed in the measurement device. In this fifth state, when torque is applied to the rotating shaft 100 and the rotating shaft 100 twists while rotating, a torsion angle is generated between the first gripping part 11 and the second gripping part 12 fixed to the rotating shaft 100, and a strain corresponding to the torsion angle is generated in the strain-flexing part 13. This strain then changes the resistance value of the strain gauge, and the amount of this change is detected by the circuit board CB and wirelessly transmitted from the circuit board CB to an external measuring device. The measuring device then measures the torque, strain, and stress of the rotating shaft 100 from the amount of change in the resistance value of the strain gauge.
[0033] The first embodiment of the present invention has been described above. According to the first embodiment, the housing 2 is arranged out of contact with the strain detection device 1, so that the influence of the rigidity of the housing 2, etc. does not directly act on the strain-generating part 13, and the reduction in the measurement accuracy of the strain detection device 1 due to the arrangement of the housing 2 can be suppressed. Next, a second embodiment of the present invention will be described. FIG. 5a shows a measuring device according to a second embodiment. 5a1 shows the front of the measuring device, FIG. 5a2 shows the top of the measuring device, FIG. 5a3 shows the left side of the measuring device, and FIG. 5a4 shows the right side of the measuring device. As shown in Figure 5b1, which shows the front of the measuring device with a semi-transparent housing 2, and Figure 5b2, which shows the right side of the measuring device with a semi-transparent housing 2, the measuring device of this second embodiment differs from the measuring device of the first embodiment in the following four points. The first point is that with the strain detection device 1 housed in the housing 2, the first upper block 111 of the first holding portion 11 of the strain detection device 1 is connected to the upper housing 21 with the first connecting bolt 5, and the first lower block 112 of the first holding portion 11 of the strain detection device 1 is connected to the lower housing 22 with the second connecting bolt 6.
[0034] The second point is that the upper housing 21 is provided with a first through hole 211 for performing the operation of attaching and detaching the first bolt 115 to the first holding portion 11 from the outside of the housing 2, and a second through hole 212 for performing the operation of attaching and detaching the second bolt 125 to the second holding portion 12. The third point is that the shapes of the V-groove-shaped recesses of the upper housing 21, the first upper block 111, and the second upper block are made to match, and the shapes of the V-groove-shaped recesses of the lower housing 22, the first lower block 112, and the second lower block are made to match. The fourth point is that the rotation axes of the first hinge 113 and the second hinge 123 of the strain detector 1 are aligned with the rotation axes of the two hinges 23 of the housing 2 . In such a measuring device, as shown in Figure 5c, when the first bolt 115 and the second bolt 125 of the strain detection device 1 and the two bolts 24 of the housing 2 are removed, the upper housing 21 and the above-mentioned upper structural part of the strain detection device 1 can rotate relative to the remaining parts around the rotation axes of the first hinge 113, the second hinge 123, and the two hinges 23, thereby opening the hollows of the first gripping part 11 and the second gripping part 12 to the outside.
[0035] Then, with this hollow space open, the measuring device is positioned so that the rotating shaft 100 to be measured is located between the first upper block 111 and the first lower block 112, and between the second upper block 121 and the second lower block 122.Then, as shown in Figures 5d1 and d2, the upper housing 21 and the lower housing 22 are fastened with two bolts 24, and the first upper block 111 and the first lower block 112 of the strain detection device 1 are fastened with a first bolt 115 passed through the first through hole 211, and the second upper block 121 and the second lower block 122 of the strain detection device 1 are fastened with a second bolt 125 passed through the second through hole 212, thereby fixing the measuring device to the rotating shaft 100.
[0036] According to the second embodiment, the housing 2 is connected to the first gripping part 11 of the strain detection device 1, so the housing 2 and the strain detection device 1 can be integrated, making it easier to handle the measurement device. Furthermore, because the housing 2 is not connected to the second gripping part 12, the rigidity of the housing 2 does not have a direct, strong effect on the strain-flexing part 13 connecting the first gripping part 11 and the second gripping part 12, and the measurement accuracy of the strain detection device 1 does not decrease significantly.
[0037] The second embodiment of the present invention has been described above. In the second embodiment described above, when the strain detector 1 is fixed to the rotating shaft 100, the housing 2 is fixed to the rotating shaft 100 via the first grip portion 11 of the strain detector 1. Therefore, as shown in Figures 6a1 and 6a2, the central openings in the front and rear walls of the housing 2 may be shaped so that they do not come into contact with the rotating shaft 100 even when the upper housing 21 and the lower housing 22 are closed, and the housing 2 may be fixed to the rotating shaft 100 only via the first gripping portion 11. Alternatively, as shown in Figures 6b1 and 6b2, only the central opening in the rear wall of the housing 2 may be shaped so that it does not come into contact with the rotating shaft 100 even when the upper housing 21 and the lower housing 22 are closed, and the front end of the housing 2 may be fixed to the rotating shaft 100 by being sandwiched between two V-groove-shaped recesses in the front wall, while the first gripping portion 11 is fixed to the rotating shaft 100 by the front part of the housing 2.
[0038] Furthermore, the second embodiment described above can also be configured so that the first upper block 111 and the first lower block 112, which are respectively connected to the upper housing 21 and the lower housing 22, can be fixed to the rotating shaft 100 simply by fastening the two bolts 24 of the upper housing 21 and the lower housing 22, by appropriately setting the shapes and arrangements of the upper housing 21 and the lower housing 22 and the first upper block 111 and the first lower block 112.
[0039] For example, as shown in Figure 6c, the fastening position of the front bolt 24 is set to a position between the front wall of the housing 2 and the first gripping portion 11 in the fore-and-aft direction, and the first upper block 111 and the first lower block 112 are not fastened together by the first bolt 115 using the first through hole 211, but the strain detection device 1 and the housing 2 are fixed to the rotating shaft 100 by only firmly fastening the upper housing 21 and the lower housing 22 together by the two bolts 24 and firmly fastening the second upper block 121 and the second lower block 122 by the second bolt 125 using the second through hole 212.
[0040] The third embodiment will be described below. The measuring device according to the third embodiment differs from the measuring device according to the first embodiment in the following four points. The first point is that the strain detector 1 used is the strain detector 1 shown in a perspective view in FIG. 7a. The strain detection device 1 in Figure 7a is the strain detection device 1 of the first embodiment shown in Figure 1, with the first hinge 113 and first spacer 114 of the first holding portion 11 removed, and with a screw hole 116 that functions as a feed screw nut in the center of the left-right direction of the first upper block 111, and a screw hole 117 that functions as a feed screw nut in the center of the left-right direction of the first lower block 112.
[0041] The second point is that, as shown in Figure 7b, with the strain detection device 1 housed in the housing 2, the first upper block 111 of the first holding portion 11 of the strain detection device 1 is connected to the upper housing 21 by a feed screw 7 threaded into the threaded hole 116 for the feed screw in the first upper block 111, and the first lower block 112 of the first holding portion 11 of the strain detection device 1 is connected to the lower housing 22 by a feed screw 8 threaded into the threaded hole 117 for the feed screw in the first lower block 112.
[0042] The third point is that, as shown in Figure 7b, the central openings in the front and rear walls of the housing 2 are shaped so that they do not come into contact with the rotating shaft 100 even when the upper housing 21 and the lower housing 22 are closed, so that the housing 2 can be fixed to the rotating shaft 100 only via the first gripping portion 11. The fourth point is that, as shown in FIG. 7d, a rear right through-hole 213 is provided in the upper housing 21 to allow the second bolt 125 to be attached to and detached from the second grip portion 12 from outside the housing 2. According to this measuring device, as with the measuring device of the second embodiment, when the second bolt 125 of the strain detection device 1 and the two bolts 24 of the housing 2 are removed, the upper housing 21 and the above-mentioned upper structural part of the strain detection device 1 can rotate relative to the remaining parts around the rotation axes of the two hinges 23, thereby opening the hollows of the first gripping part 11 and the second gripping part 12 to the outside.
[0043] Also, as shown in Figure 7c, by rotating the lead screw 7 of the upper housing 21, the first upper block 111 can be moved up and down by the lead screw mechanism formed by the lead screw 7 and the screw hole 116, and by rotating the lead screw 8 of the lower housing 22, the first lower block 112 can be moved up and down by the lead screw mechanism formed by the lead screw 8 and the screw hole 117. Furthermore, with the hollows of the first gripping unit 11 and the second gripping unit 12 open, the measuring device is positioned so that the rotating shaft 100 to be measured is located between the first upper block 111 and the first lower block 112 and between the second upper block 121 and the second lower block 122. Thereafter, the housing 2 is closed and the upper housing 21 and the lower housing 22 are fastened together with two bolts 24. As shown in FIG. 7d, the lead screw 7 of the upper housing 21 and the lead screw 8 of the lower housing 22 are rotated so that the first upper block 111 and the first lower block 112 tightly grip the rotating shaft 100, thereby fixing the first gripping unit 11 to the rotating shaft 100 as shown in FIG. 7e. By fixing the rotating shaft 100 to the first gripping unit 11, the housing 2 is also fixed to the rotating shaft 100.
[0044] In addition, the second gripping portion 12 can be fixed to the rotating shaft 100 by fastening the second upper block 121 and the second lower block 122 of the strain detection device 1 with a second bolt 125 passed through the rear right through hole 213. The third embodiment of the present invention has been described above. In this third embodiment, one of the connections between the first upper block 111 of the first gripping portion 11 and the upper housing 21 and the first lower block 112 of the first gripping portion 11 and the lower housing 22 may be a fixed connection using a bolt or the like instead of using a feed screw mechanism. According to the third embodiment, the housing 2 and the strain detector 1 can also be integrated, making it easier to handle the measurement device. Furthermore, since the housing 2 is connected only to the first gripping part 11 and not to the second gripping part 12, the rigidity of the housing 2 does not have a direct or strong effect on the strain-flexing part 13 connecting the first gripping part 11 and the second gripping part 12, and the measurement accuracy of the strain detector 1 does not decrease significantly.
[0045] The embodiments of the present invention have been described above. [Explanation of symbols]
[0046] 1... strain detection device, 2... housing, 3... front positioning pin, 4... rear positioning pin, 5... first connecting bolt, 6... second connecting bolt, 7... feed screw, 8... feed screw, 11... first gripping portion, 12... second gripping portion, 13... strain-flexing portion, 21... upper housing, 22... lower housing, 23... hinge, 24... bolt, 100... rotating shaft, 111... first upper block, 112... first lower block, 113... first hinge, 114... first spacer, 115... first bolt, 116... screw hole, 117... screw hole, 121... second upper block, 122... Second lower block, 123...second hinge, 124...second spacer, 125...second bolt, 211...first through hole, 212...second through hole, 213...rear right through hole, 214...rear left through hole, 221...front pin hole, 222...rear pin hole, 800...rotating shaft, 811...first upper base, 812...first lower base, 813...first mounting base, 821...second upper base, 822...second lower base, 823...second mounting base, 830...strain-flexing part, 831...strain gauge, 850...housing, 1141...front positioning hole, 1241...rear positioning hole.
Claims
1. A measuring device fixed to a shaft to be measured, a strain detector that is detachably fixed to the shaft to be measured and detects strain caused by deformation of the shaft to be measured; a housing detachably fixed to the measurement object shaft, A measuring device characterized in that, when the strain detection device and the housing are fixed to the axis to be measured, the housing is fixed to the axis to be measured by clamping the axis to be measured at both axial ends of the axis to be measured, the strain detection device is arranged between the both ends of the housing and spaced apart from the both ends in the axial direction, and the housing has a shape that covers the periphery of the strain detection device in a non-contact manner.
2. 2. The measuring device according to claim 1, the housing has a hollow cylindrical shape and includes a first housing portion and a second housing portion having a shape obtained by dividing the housing into two such that a circumference of the cylindrical shape is divided into two, the first housing portion and the second housing portion have V-groove-shaped recesses provided in portions of two walls corresponding to two bottoms of the cylindrical shape, the V-groove-shaped recesses being provided in portions corresponding to central portions of the bottoms, The two ends are the two walls, the first housing portion and the second housing portion are at least partially separable so that the shaft to be measured and the strain sensor fixed to the shaft to be measured can be inserted into the hollow from outside the housing; A measuring device characterized in that the housing is fixed to the axis to be measured by clamping the axis to be measured between the wall of the first housing part and the recess in the wall of the second housing part, which are at the same bottom of the cylindrical shape.
3. 3. The measuring device according to claim 1 or 2, A measuring device characterized in that the surfaces at both ends of the housing that clamp the shaft to be measured are flat.
4. A measuring device fixed to a shaft to be measured, a strain detector detachably fixed to the shaft to be measured and a housing detachably fixed to the shaft to be measured, the strain detection device comprises a first gripping portion that is fixed to the shaft to be measured by clamping the shaft to be measured, a second gripping portion that is fixed to the shaft to be measured by clamping the shaft to be measured at a position spaced apart from the first gripping portion in the axial direction of the shaft to be measured, and a strain-flexing portion that connects the first gripping portion and the second gripping portion and has a strain gauge fixed thereto; A measuring device characterized in that, when the strain detection device and the housing are fixed to the axis to be measured, the strain detection device is arranged between both ends of the housing in the axial direction, and the housing is connected to the first gripping portion and has a shape that covers the strain detection device in a non-contact manner with the second gripping portion and the strain-generating portion.
5. 5. The measuring device according to claim 4, A measuring device characterized in that, when the strain detection device and the housing are fixed to the axis to be measured, the housing is fixed to the axis to be measured by connecting with the first gripping portion.
6. 5. The measuring device according to claim 4, A measuring device characterized in that, when the strain detection device and the housing are fixed to the shaft to be measured, at least the end of the housing on the second gripping portion side clamps the shaft to be measured.
7. 5. The measuring device according to claim 4, the first gripping unit includes a first block and a second block that sandwich the shaft to be measured in a state in which the strain detection device and the housing are fixed to the shaft to be measured, a first connecting portion that connects the housing and the first block, and a second connecting portion that connects the housing and the second block, wherein the first gripping portion is fixed to the shaft to be measured by clamping the shaft to be measured between the first block and the second block with a force applied to the first block via the first connecting portion and a force applied to the second block via the second connecting portion.
8. 8. The measuring device according to claim 7, A measuring device characterized in that the first connecting part is a first feed screw mechanism that moves the first block in the radial direction of the shaft to be measured when the strain detection device and the housing are fixed to the shaft to be measured.
9. 9. The measuring device according to claim 8, A measuring device characterized in that the second connecting part is a second feed screw mechanism that moves the second block in the radial direction of the shaft to be measured when the strain detection device and the housing are fixed to the shaft to be measured.
10. A method for attaching a measuring device to a shaft to be measured, comprising: a step of fixing a strain detection device to the shaft to be measured, the strain detection device detecting a strain caused by deformation of the shaft to be measured; a step of positioning the housing at a position where the housing covers the periphery of the strain detection device in a non-contact manner by attaching a predetermined positioning jig between the housing and the strain detection device; a step of clamping the shaft to be measured between both axial ends of the housing in the axial direction of the shaft to be measured and fixing the housing to the shaft to be measured; and removing the positioning jig.