JP2014095671A - Torque measuring equipment for reference - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide torque measuring equipment for reference that actualizes high-precision traceability for torque measurement.SOLUTION: Torque measuring equipment for reference includes: a torque detection part 8 which detects relative torsion on an axis generated between both ends of a strain element; a strain element support part 7 which supports the strain element so that one end part of the strain element is free and the other end of the strain element is fixed; and bearing means 5 of suspending and supporting a shaft 52 arranged in a bearing casing 51 with a fluid film in a radial direction and in a thrust direction. The strain element support part 7 is fixed to the bearing casing 51 of the bearing means 5, and the shaft 52 is connected to one end part of the strain element movably in an axial direction and immovably on the axis so as to impart reference torque between the bearing casing 51 of the bearing means 5 and the shaft 52.

Description

  The present invention relates to a reference torque driver and a reference torque wrench used for calibration of a torque driver tester and a torque wrench tester, a reference torque meter that mediates between a torque standard machine and a torque meter reference machine in order to establish traceability of torque measurement, etc. The present invention relates to a reference torque measuring device.

  The traceability of the torque measurement has a hierarchical structure from the highest level to the lowest level: specified standard device, specified secondary standard device, practical standard, common reference standard, second level calibration target, third level calibration or test It is set as a target (Non-Patent Document 1).

  A manual torque driver and a manual torque wrench are shown as the third level calibration or test object. In addition, there is a torque standard machine in the specific standard device at the top of the hierarchical structure. Taking the traceability of a manual torque driver as an example, the torque standard machine and the practical standard torque meter reference machine are used as a reference torque meter. To establish traceability of torque measurement. Also, the traceability of torque measurement has been established by mediating the standard torque meter standard machine and the torque driver tester that is the calibration target of the second layer with the reference torque driver.

  On the other hand, with regard to the traceability of manual torque wrenches, torque measurement traceability is established by mediating a torque standard machine and a practical standard torque wrench reference machine with a reference torque wrench. The traceability of torque measurement is established by mediating a standard torque wrench standard machine and a torque wrench tester, which is the calibration target of the second layer, with a reference torque wrench.

JCT20902 Technical Requirements Application Guidelines (Torque Tester and Torque Wrench Tester (2nd edition), pages 5/32 to 7/32)

  By the way, the reference torque driver, the reference torque meter, and the reference torque wrench are configured to detect relative torsion between the input shaft and the output shaft by the torsion detection unit, and the input shaft (load side) and the output shaft ( Bearings such as ball bearings are used for smooth rotation relative to the measurement side.

  Further, when the reference torque driver is twisted, two forces acting in a direction in which the torsional force is orthogonal to the central axis of rotation and in opposite directions are applied. In this case, the direction and magnitude of the force in both directions are theoretically the same, but in reality they are different. Therefore, the axis of rotation of the reference torque driver produces a parasitic component that is inclined with respect to the theoretical axis. In addition, it may receive lateral force and bending moment.

  However, when these parasitic force, lateral force, and bending moment are applied to a ball bearing or the like, the torque transmitted due to the influence of the friction of the ball bearing, the influence of the lubrication state, corrosion, or the like changes.

  The present invention eliminates factors that affect measurement uncertainty as much as possible, and realizes reference torque measurement for reference torque drivers, reference torque wrenches, reference torque meters, etc. that realizes highly accurate torque measurement traceability. The purpose is to provide equipment.

The configuration for solving the problems of the present invention is as follows.
(1) A torque detector for detecting relative torsion around the axis generated between both ends of the strain generating body by a strain gauge, and one end of the strain generating body as a free end, and the other end of the strain generating body is fixed. A strain body supporting portion for supporting the strain body, and a bearing means for floatingly supporting the shaft disposed in the bearing casing with a fluid film in the radial direction and the thrust direction,
The strain body supporting portion is fixed to a bearing casing of the bearing means, the shaft is connected to one end portion of the strain body so as to be axially movable and immovable around an axis, and A reference torque measuring device for applying a reference torque between a bearing casing and the shaft.
(2) The reference torque device according to (1) above, wherein the shaft center of the bearing means and the shaft center of the strain generating body are matched.
(3) The reference torque device according to (1) or (2), wherein the strain body is formed in a rotationally symmetric shape with a central axis as a center.
(4) The strain body has a predetermined angle around a plurality of strain body bodies formed of an elastic body with one end portion disposed at the central shaft portion as a common connecting portion. The strain body main body portion is bent at a right angle in a predetermined direction from the first elastic body portion that is expended outward in the radial direction from the connecting portion, and the second elastic body portion The third elastic body portion is bent at a right angle in the predetermined rotation direction, and a fixing portion fixed to the strain generating body support portion is provided at the tip of the third elastic body portion, and the whole is made into a single winding shape. The reference torque device according to (3) above.
(5) The above-described (1) to (4), wherein a serration hole is formed in a central shaft portion of the strain body, and a serration shaft portion connected to the serration hole portion is provided on the shaft. The torque measuring device for reference according to any one of the above.
(6) Stopper means for restricting the amount of twisting of the strain generating body inside the region surrounded by the first elastic body portion, the second elastic body portion, and the third elastic body portion. The reference torque measuring device according to the above (4) or (5), wherein the reference torque measuring device is provided.
(7) a first shaft portion fixed to the bearing casing, and a second shaft portion fixed to the shaft on the opposite side of the first shaft portion and on the same axis as the first shaft portion. The second shaft portion further includes an engagement portion that engages with a sensor shaft of a torque driver tester or a torque driver checker, and is a reference torque driver used for calibration of the torque driver tester or torque driver checker. The reference torque measuring device according to any one of (1) to (6) above, characterized in that:
(8) A first shaft portion fixed to the bearing casing, and a third shaft portion fixed to the shaft on the opposite side of the first shaft portion and on the same axis as the first shaft portion. In order to establish torque traceability, it is a reference torque meter that mediates the upper level torque standard machine and the lower level torque meter reference machine, and the upper level torque meter reference machine and the lower level torque test machine. The torque measuring instrument for reference according to any one of (1) to (6) above.
(9) A lever that is integrally fixed to the bearing casing and extends in a direction perpendicular to the shaft center of the bearing casing, and a second shaft portion that is fixed to the shaft on the opposite side of the lever. The reference torque wrench having an engagement portion that engages with a sensor shaft of a torque wrench tester or a torque wrench checker on the second shaft portion, according to any one of (1) to (6), Torque measuring device for reference.
(10) A lever that is integrally fixed to the bearing casing and extends in a direction perpendicular to the axis of the bearing casing, and a second shaft portion that is fixed to the shaft on the opposite side of the lever. Any one of (1) to (6) above, wherein a reference torque wrench mediates between a higher-level torque standard machine and a lower-level torque wrench reference machine in order to establish torque traceability. Torque measuring device for reference.

  According to the first, seventh, eighth, ninth, and tenth aspects of the present invention, a parasitic component force such as a bending load generated when a torque is applied is received in the radial direction and the thrust direction by the use of a bearing means such as an air bearing. There is no influence of parasitic force on the detection part. In particular, a strain generating body having a small torque capacity is used as the torque driver, and high precision measurement can be performed for a reference torque driver and a reference torque meter that are easily affected by the parasitic component force.

  According to the invention which concerns on Claim 2, a difference does not arise in the measured value which a torque detection part detects by the position around the axis | shaft of the reference torque apparatus.

  According to the third aspect of the present invention, since the mass balance of the strain generating body is good, for example, when the reference torque device is arranged in the horizontal direction, the reference torque regardless of the position of the strain generating body around the horizontal axis. There is no variation in measurement values due to changes in the attitude of the device.

  According to the invention of claim 4, the rotational symmetry of the strain generating body can be obtained with a simple configuration, and the length of the strain generating body can be increased to achieve a good mass balance. At the same time, a large amount of deformation in the rotational direction of the strain generating body is obtained at the time of torque load, and it is possible to install an overload prevention or damage preventing mechanism for the strain generating body.

  According to the fifth aspect of the present invention, even if the relative positional relationship between the strain generating body and the central axis changes due to the deformation due to the weight of the strain generating body caused by the change in the posture of the reference torque device or the clearance change of the bearing means, the serration Since the connection is made, the connection state between the strain generating body and the central shaft becomes free in the no-load state, and the change in the relative positional relationship is corrected.

  According to the sixth aspect of the present invention, the strain body can be prevented from being damaged, and the damage prevention mechanism can be made compact.

The torque driver tester tester which shows 1st Embodiment is shown, (a) is a front view, (b) is a right view of (a). The front view of the reference torque driver by this invention which shows 2nd Embodiment. FIG. 3 is an AA arrow view of FIG. 2. Sectional drawing along the BB line of FIG. 3 and sectional drawing of an air bearing. The figure which shows the attachment state of a strain body in the AA arrow line view of FIG. 5A is a top view of the strain-generating body, and FIG. The front view of the reference torque meter by this invention which shows 3rd Embodiment. The front view of the reference torque wrench by this invention which shows 4th Embodiment. The top view of the strain body which shows 5th Embodiment. The front view of the torque wrench tester which shows 6th Embodiment. FIG. 11 is a top view of FIG. 10. (A)-(c) is a figure explaining the lateral load and bending moment which are added to the strain body of a reference torque wrench.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment FIG. 1A is a front view of a torque driver tester showing a first embodiment, showing a state in which a reference torque driver is set, and FIG. 1B is a right front view of FIG.

  In the hierarchical structure of calibration in the traceability of torque measurement, a manual torque driver which is a third level calibration target is calibrated, while the torque driver tester 100 is calibrated by the reference torque driver 1.

  The torque driver tester 100 is configured such that a loading device 103 is attached to a tester main body 101 via an attachment stand 102. A sensor shaft 104 is spent on the tester body 101 along the vertical axis direction. A sensor such as a strain gauge is attached to the sensor shaft 104, and a signal corresponding to the torsion torque applied to the sensor shaft 104 is output to a torque detection circuit (not shown), and the torque value is displayed on the display unit 105.

  The loading device 103 includes an annular base 106 fixed to the mounting stand 102, an operation ring portion 108 that is rotatably mounted on the annular portion 107 of the base 106, and an operation ring portion 108 that holds the loading device 103. The holding portion 109 is provided. Here, assuming that the vertical axis of the sensor shaft 104 is the Z-axis, and the two axes orthogonal to each other in the horizontal direction are the X-axis and the Y-axis, the center of the annular portion 107, the operation ring portion 108, and the grip portion 109 is Located on the Z axis, the operation ring portion 108 rotates about the Z axis around the Z axis. A helical gear portion (not shown) is attached to the outer peripheral portion of the operation ring portion 108, and a worm gear portion (not shown) formed on a rotating shaft 110 that is rotatably provided on the base 106 is this helical gear portion. Are engaged. Then, by rotating the dials 111 provided at both ends of the rotating shaft, the operation ring portion 108 is rotated around the Z axis.

  The grip portion 109 grips a grip portion of a torque driver (not shown) mounted along the vertical direction or the first shaft portion 2 of the reference torque driver 1 and rotates integrally around the Z axis. In this embodiment, the grip portion 109 is provided with support shaft portions 112 at four locations in the X-axis and Y-axis directions on the outer peripheral portion, and is attached to the shaft hole portion 113 of the operation ring portion 108. Each shaft hole portion 113 has a gap with respect to the support shaft portion 112 so that the grip portion 109 can rotate around the X axis and the Y axis to be inclined.

  When the angular shaft portion 3 of the reference torque driver 1 is engaged with the sensor shaft 104 and the input portion 2 of the reference torque driver (or torque driver) 1 is gripped by the grip portion 109 and the dial 111 is rotated, the operation ring portion 108 rotates and the gripping part 109 rotates. Then, a torsional stress generated between the input unit 2 and the angular shaft unit 3 of the reference torque driver 1 is detected by a torque detection unit (not shown). Based on the torsional force detected by the torque detection unit of the reference torque driver 1, a torque value is calculated by a torque value calculation circuit (not shown) and the torque value is displayed on a display unit (not shown). The torque value is also displayed on the display unit 105 of the torque driver tester 100. The torque driver tester 100 is calibrated based on the torque value of the reference torque driver 1 which is a higher standard.

  When the reference torque driver 1 is twisted by the rotation of the grip portion 109 around the Z axis, the torsional force acts, for example, in a direction parallel to the Y axis and in the opposite direction. In this case, the direction and magnitude of the force in both directions are theoretically the same, but are actually different. Therefore, the axis of the reference torque driver 1 in the Z-axis direction is the axis of the torque driver tester 100 in the Z-axis direction. Lean against. In order to allow such an inclination, the grip portion 109 can be inclined with respect to the Z axis of the torque driver tester 100.

  Note that the present invention can also be applied to calibration of a torque driver checker that is a device in which the loading device 103 and the mounting stand 102 are removed from the torque driver tester 100.

Second Embodiment FIGS. 2 to 6 are front views of a reference torque driver according to the present invention showing a second embodiment, FIG. 3 is a view taken along the line AA in FIG. 2, and FIG. 4 is a BB line in FIG. FIG. 5 is a cross-sectional view taken along the line AA and a cross-sectional view of the air bearing, and FIG. 5 is a view taken along the line AA of FIG. 6 shows the strain body of FIG. 5, (a) is a top view of the strain body, and (b) is a view as seen from the arrow C of (a).

  The reference torque driver 1 includes a first shaft portion 2 formed into an axial shape, a second shaft portion 4 formed with a square shaft portion 3 at the rear end, an air bearing 5 that is a fluid bearing, and a first shaft portion 2. The cover 6 fixed to the rear end, the strain-generating body support 7, and the torque detector 8 having the strain-generating body 81 supported by the strain-generating body support 7 are the same. Each axis is arranged so as to coincide with the axis L.

  The strain body support base 7 has a strain body 81 disposed on one end surface side of a base body portion 71 formed in a disk shape, and mounting leg portions 72 from the other end surface side of the base body portion 71 toward the rear in the axial direction. Has been spent. The cover portion 6 is formed in a disk shape having a concave cross section, is disposed on one end surface side of the base body portion 71 so as to cover the torque detection portion 8, and is fixed to the base body portion 71 by a bolt 61. An insertion hole 73 into which a later-described connecting shaft 54 is inserted with a gap is formed in the axis of the base body 71.

  The air bearing 5 includes a bearing housing 51 formed in a cylindrical shape, a shaft 52 penetratingly disposed in the bearing housing 51 with a gap, and a disk-shaped first flange fixed to both axial ends of the shaft 52. It has a portion 53A and a second flange portion 53B. The first flange portion 53A and the second flange portion 53B are fixed to both ends of the shaft 52 penetrating the bearing housing 51 in the axial direction with a gap from the axial end surface of the bearing housing 51.

  Radial bearing pads 511 are disposed on the inner peripheral surface of the bearing housing 51, and thrust bearing pads 512 are disposed on both end surfaces in the axial direction. The bearing housing 51 is formed with an air passage 514 for supplying compressed air from the air supply port 513 to the radial bearing pad 511 and the thrust bearing pad 512, and the air blown from the radial bearing pad 511 toward the shaft 52 is externally supplied. An exhaust port 515 for exhausting the air is formed. The thrust bearing pad 512 is disposed to face the inner end surfaces of the first flange portion 53A and the second flange portion 53B.

  When the compressed air is supplied from the air supply port 513 to the air passage 514 through the hose (not shown) that is thinner than the compressed air source (not shown), the shaft 52 is connected to the radial bearing pad 511. The suspension is supported by the compressed air ejected from the thrust bearing pad 512. Therefore, even if the shaft 52 is arranged in the horizontal direction, the vertical direction, and an arbitrary inclination between the horizontal direction and the vertical direction, and even if a parasitic component force generated when a torque is applied occurs, the shaft 52 and the first flange portion 53A. Further, the second flange portion 53B does not contact the bearing housing 51. For this reason, a rotational force (torque) can be transmitted without loss from one end side of the shaft 52 to the other end side.

  In the present embodiment, the bearing housing 51 and the strain body support base 7 are fixed and integrated by a bolt 74 via a mounting leg 72.

  The connecting shaft 54 is integrally fixed to one end face of the first flange portion 53A via a disk-shaped first mounting flange 54A. The first mounting flange 54A fixes the connecting shaft 54 along the axis L at the center thereof, and the first mounting flange 54A is fixed to one end surface of the first flange portion 53A by a bolt 55.

  The connecting shaft 54 passes through the insertion hole 73, and a through end that passes through the insertion hole 73 is serrated to form a serration connecting portion 56.

  The second shaft portion 4 is integrally fixed to the other end surface of the second flange portion 53B via a disk-shaped second mounting flange 54B. The second mounting flange 54B fixes the second shaft portion 4 to the center along the axis L, and the second mounting flange 54B is fixed to the other end surface of the second flange portion 53B by a bolt 57.

  As shown in FIG. 6, the torque detection unit 8 includes a strain body 81 formed in a rotationally symmetric shape of 180 degrees around the axis L, and strain gauges 82 and 83 attached to the strain body 81. doing. FIG. 6 shows a normal state where no external force is applied to the strain body 81. The strain generating body 81 includes a first strain body main body portion 84, a second strain body main body portion 85, a first strain body main body portion 84, and a second strain body main body that are formed of a metal strip member having a constant width. A central connecting portion 86 formed at one end of the portion 85, and a first fixing portion 87 and a second fixing portion 88 formed at the other ends of the first strain body main body portion 84 and the second strain body main body portion 85, respectively. Have. The first strain body main body portion 84 and the second strain body main body portion 85 are formed in a rotationally symmetric shape of 180 degrees around the axis L with the central connection portion 86 as a common connection portion.

  The first strain body main body 84 and the second strain body main body 85 are bent from the three straight elastic bodies 89A, 89B, 89C clockwise by an angle of 90 degrees, and are spent from the central extinction section 86. The first fixing portion 87 and the second fixing portion 88 bent at an angle of 90 degrees clockwise from the third linear elastic body portion 89C are arranged at positions symmetrical to the first linear elastic body portion 89A. To do. In addition, the first fixing portion 87 of the first strain body main body portion 84 is disposed outside the second linear elastic body portion 89B of the second strain body main body portion 85, and similarly, the second strain body main body portion. The 85 second fixing portion 88 is disposed outside the second linear elastic body portion 89 </ b> B of the first strain body main body portion 84.

  The first linear elastic body portion 89A is shorter in length than the parallel third linear elastic body portion 89C, the second linear elastic body portion 89B is longer than the first linear elastic body portion 89A, and the third It is shorter than the linear elastic body part 89C.

  The strain gauge 82 of the first strain body main body 84 and the strain gauge 83 of the second strain body main body 85 are respectively a third linear elastic body portion 89C, and are a first fixing portion 87 and a second fixing portion. Affixed as close to 88 as possible. This is due to the largest distortion at this position. The strain gauges 82 and 83 are attached to both surfaces or one surface of the third linear elastic body portion 89C.

  The central connection portion 86 is formed with a serration connection hole 90 for serration connection with the serration connection portion 56 of the connection shaft 54 at the axial center position. The serration connection portion 56 and the central connection portion 86 are relatively aligned with each other along the axis L direction. It can be moved freely, and it rotates integrally around the axis.

  The central connecting portion 86 is formed with a stopper piece 91A and a dummy stopper piece 91B in parallel with each second linear elastic body 89B. In the present embodiment, the stopper piece 91A is used to regulate the twist angle of the strain body 81, and the dummy stopper piece 91B is provided to maintain the rotational symmetry of the strain body 81 at an angle of 180 degrees. ing.

  Bolt holes 92 are formed in the first fixing portion 87 of the first strain body main body 84 and the second fixing portion 88 of the second strain body main body 85. The strain body 81 is fixed to the base body 71 by inserting a bolt 94 through the bolt hole 92 with the spacer 93 inserted between the base body 71 and the first fixing part 87 and the second fixing part 88. Has been.

  In the reference torque driver 1 configured as described above, when torque is applied around the right twist, the connecting shaft 54 and the central connecting portion 86 of the strain generating body 81 rotate relatively around the axis L. The strain generating body 81 contracts like a single wound spring. At that time, the stopper shaft portion 95A attached to the base body portion 71 and the stopper piece portion 91A come into contact with each other to restrict the contraction of the strain body 81 and prevent the breakage. The stopper shaft portion 95A is disposed between the stopper piece portion 91A and the second linear elastic body portion 89B of the first strain body main body portion 84. In addition, a stopper shaft portion 95B for counterclockwise turning is arranged at a symmetrical position on the opposite side across the stopper piece portion 91A. When torque is applied around the left twist, the strain body 81 expands. The stopper shaft portion 95B and the stopper piece portion 91A come into contact with each other around the left twist, thereby restricting the expansion of the strain body 81 and preventing damage.

  The reference torque driver 1 configured as described above connects the first shaft portion 2 and the second shaft portion 4 via a strain body 81. The strain body 81 is elastically deformed by the relative twisting of the first shaft portion 2 and the second shaft portion 4, and the strain generated by the elastic deformation of the strain body 81 is detected by the strain gauges 82 and 83, not shown. The torque value is calculated by the torque value calculation circuit.

  When the torque driver tester 100 shown in FIG. 1 is calibrated, the reference torque driver 1 is mounted at a predetermined position along the vertical direction, and compressed air is supplied to the air bearing 5. Then, the loading device 103 is rotated to cause the reference torque driver 1 to generate a twisting torque around the Z axis. Here, even if a torque in the rotational direction is applied to the reference torque driver 1, the reference torque driver 1 is tilted with respect to the Z axis due to a parasitic component such as a bending load as described above. On the other hand, the axis L of the reference torque driver 1 is inclined.

  However, in the air bearing 5, the shaft 52 integral with the second shaft portion 4 is floatingly supported in the radial direction and the thrust direction via a thin film of air with respect to the bearing housing 51 integral with the first shaft portion 2. Therefore, even if this parasitic component force is generated, the first shaft portion 2 and the second shaft portion 4 are relatively twisted without mechanical frictional contact between the shaft 52 and the bearing housing 51. Therefore, the reference torque driver 1 can apply torsional torque excluding the parasitic component force to the sensor shaft 104 of the torque driver tester 100, and the strain generating body 81 is not affected by the parasitic component force. It can be elastically deformed to obtain a highly accurate torque value.

  Further, since the strain generating body 81 and the connecting shaft 54 are serrated and connected, the strain generating body 81 has a cantilever support beam structure with the first fixing portion 87 and the second fixing portion 88 as fulcrums. For this reason, in the stationary state, the central connecting portion 86 positioned at the central portion of the strain generating body 81 is bent without being restricted by a predetermined amount. Therefore, by measuring the state where the central connecting portion 86 is bent as a stationary state, the influence of the bending of the strain generating body 81 is eliminated, and high-precision measurement is possible. Even if the shaft 52 moves in the thrust direction during floating support, the serration connecting portion 56 only moves in the Z-axis direction with respect to the central connecting portion 86 of the strain generating body 81, so that it bends to the strain generating body 81. No external force is generated that causes

  On the other hand, when the reference torque driver 1 is used in a horizontal state, the reference torque driver 1 is in a support state of the both-end support beams, and bending occurs. At that time, since the air bearing 5 floats and supports the shaft 52 by the compressed air in the bearing housing 51, direct contact between the shaft 52 and the bearing housing 51 in the radial direction is prevented. Therefore, the torsion torque according to the relative torsion between the first shaft portion 2 and the second shaft portion 4 is transmitted to the strain body 81 without loss.

  In addition, the strain body 81 is formed in a rotationally symmetric shape with an angle of 180 degrees around the axis L. For this reason, when the axial center L of the reference torque driver 1 is set in the horizontal direction and the reference torque driver 1 is twisted in an angle range of, for example, 0 degrees to 10 degrees with respect to the axial center L, the strain generating body 81 The bending amount of the first strain body main body 84 changes between the first fixed portion 87 and the central connecting portion 86 according to the change of the rotation angle. At this time, since the second strain body main body 85 also rotates, it is output from the first strain gauge 82, but the changing portion of the deflection amount is canceled out. Therefore, highly accurate measurement can be performed. Even if the axis L of the reference torque driver 1 is used at an arbitrary angle between a vertical attitude parallel to the axis Z and a horizontal attitude parallel to the X axis (or Y axis), the above-described deflection amount is obtained. The change of is canceled out, and high-precision measurement is possible as well.

  The strain body 81 is formed by turning the first strain body main body 84 from the first linear elastic body portion 89A, the second linear elastic body portion 89B, and the third linear elastic body portion 89C by 90 degrees clockwise. Are bent to form a single winding structure, and a two-strand structure is formed together with the second strain body main body 85. For this reason, even if the 1st strain body main-body part 84 (2nd strain body main-body part 85) is long, it can attain space saving which can be arrange | positioned in a narrow place. In addition, since the first strain body main body 84 (second strain body main body 85) is long, the relative torsion angle between the first shaft portion 2 and the second shaft portion 4 is increased. Even in this case, torque can be measured effectively. For this reason, it is suitable for a reference torque driver used for calibration of a torque driver tester used for high-precision minute torque measurement.

  According to the strain body 81 of the present embodiment, since the mass balance is good, even if the reference torque driver is tilted, the indicated value does not change and no error occurs.

  In addition, overload is easily applied during calibration of minute torque, and overload is mistakenly applied when attaching to a torque driver tester or the like, but by providing a stopper, damage to the strain generating body can be prevented in advance. .

  Furthermore, since a stopper for preventing overload is arranged inside the strain generating body 81, it is possible to realize a lightweight and compact design. In particular, the light weight reduces the load applied to the torque driver tester, torque standard machine, torque reference machine, etc., and is effective for high-accuracy measurement.

Third Embodiment FIG. 7 is a front view of a reference torque meter according to the present invention showing a third embodiment.

  The reference torque meter 200 of this embodiment has the same basic configuration as the reference torque driver 1 shown in FIGS. 2 to 6, except that the third shaft portion 201 is replaced with the second shaft portion 4. This is a point fixed to the shaft 52 of the air bearing 5. The third shaft portion 201 is fixed to the shaft center portion of the disc-shaped mounting flange 202, and is fixed to the other end surface of the shaft 52 by a bolt 203.

  According to this embodiment, the same effect as the first embodiment can be obtained.

Fourth Embodiment FIG. 8 is a front view of a reference torque wrench according to the present invention showing a fourth embodiment.

  The reference torque wrench has a torque converter in the shape of a torque wrench accompanied by a lever, but inevitably transmits torque with lateral force and bending moment, so the effects of these lateral force and bending moment are torqued. It is important not to affect the transducer.

  The reference torque wrench 300 of the present embodiment has the same basic configuration as the reference torque driver 1 shown in FIGS. 2 to 6, except that the lever 301 is replaced with the cover portion 6 instead of the first shaft portion 2. This is a fixed point. The lever 301 is fixed in a direction orthogonal to the axis L. According to this embodiment, the same effect as the first embodiment can be obtained.

Fifth Embodiment FIG. 9 is a top view of a strain generating body showing a fifth embodiment.

  In the strain generating body 400 of the present embodiment, a large-diameter ring-shaped outer peripheral annular portion 401 that forms a fixing portion and a small-diameter central coupling portion 402 are arranged on the same axis L, and the outer periphery of the central coupling portion 402 Four linear elastic body portions 403 are fixed radially from the axis L at intervals of 90 degrees between the inner periphery of the outer peripheral annular portion 401. That is, the strain body 400 is formed rotationally symmetric at an angle of 90 degrees about the central axis L. Further, a serration hole is provided at the center of the central connecting portion 402. A strain gauge (not shown) is attached to each linear elastic body 403 on one side or both sides.

In each of the above-described embodiments, the strain generating body is not limited to the shape of each of the above-described embodiments, and may have a rotationally symmetric shape such as 45 °, even if it is not a 90 ° or 180 ° rotationally symmetric shape. There may be.
Sixth Embodiment FIG. 10 is a front view of a torque wrench tester, and FIG. 11 is a top view of FIG.

  In the hierarchical structure of calibration in the traceability of torque measurement, the torque wrench tester 500 calibrates the manual torque wrench that is the third level calibration target, while the torque wrench tester 500 is used for the reference torque shown in FIG. Calibration is performed by the wrench 300.

  The torque wrench tester 500 is attached to a tester main body 501 so that a swivel base 502 can turn around a vertical axis Z. A sensor shaft 503 having the shaft center Z as the shaft center is attached to the tester body 501. The sensor shaft 503 is connected to an intermediate shaft 503A centered on the shaft center Z. A sensor such as a strain gauge is attached to the sensor shaft 503, and a signal corresponding to the torque applied to the sensor shaft 503 is output to a torque detection circuit (not shown). Then, the torque value is displayed on the display unit 504. The square shaft portion 3 of the reference torque wrench 300 is fitted to the upper end portion of the intermediate shaft 503A.

  A vertical shaft portion 505 that stands upward is attached to the swivel base 502. In the reference torque wrench 300, the square shaft portion 3 formed at the tip of the second shaft portion 4 engages with the sensor shaft 503, and the axis L of the reference torque wrench 500 coincides with the axis Z of the sensor shaft 503. Let In this attached state, the reference torque wrench 300 abuts the lever 301 on a cylindrical abutting portion 506 provided on the vertical shaft portion 505.

  A base 508 having a rectangular frame 507 is fixed below the swivel base 502 as shown in FIG. Between a pair of opposing frame bodies 507a and 507b of the rectangular frame portion 507, a drive screw shaft portion 509 having a screw portion formed on the outer peripheral surface is rotatably attached and cannot be moved in the axial direction. A handle portion 510 is attached to one end of the drive screw shaft portion 509.

  A nut portion (not shown) that engages with the drive screw shaft portion 509 is attached to the lower surface side of the swivel base 502. The nut portion is movable in the radial direction of the swivel base 502 and is rotatable around a vertical axis. Therefore, when the handle portion 510 is rotated in a predetermined direction, the nut portion is screwed in the predetermined direction while meshing with the drive screw shaft portion 509, and the swivel base 502 is turned.

  Since the lever portion 301 is rotated in a predetermined direction via the contact portion 506 by the vertical shaft portion 505 that turns integrally with the turntable 502, the torque value is measured by the reference torque wrench 300 and the sensor shaft 503. The torque wrench tester 500 is calibrated based on the torque value measured by the reference torque wrench 300.

  The torque wrench tester 500 can be applied to calibration of a torque wrench checker that is a device in which the load mechanism (the swivel base 502, the base 508, the handle portion 510, the vertical shaft portion 505, and the intermediate shaft 503A) is removed.

  Here, with reference to FIG. 12, the lateral load and bending moment applied to the strain body 81 of the reference torque wrench 300 when torque is applied to the torque wrench tester 500 by the reference torque wrench 300 will be described. The vertical direction is defined as the Z axis, and the two axes orthogonal to the Z axis are defined as the X axis and the Y axis.

  First, the lateral load will be described. In FIG. 12A, a lateral load corresponding to the reference torque applied in the Y-axis direction indicated by the arrow is applied to the force point of the lever 301 of the reference torque wrench 300. If the air bearing 5 is not used for the reference torque wrench 300, as shown in FIG. 12C, the strain body 81 of the reference torque wrench 300 has a torque around the Z axis and a Y axis direction. Lateral load is applied. Since the strain generating body 81 is deformed by the lateral load in the Y-axis direction, the strain gauge 82 is additionally subjected to the deformation of the strain generating body 81 due to the lateral load.

  Next, the bending moment applied to the strain body 81 will be described. As shown in FIGS. 12B and 12C, when the torque wrench 300 for reference position of the torque wrench tester 500 is set, the height position of the force point in the Z-axis direction and the Z-axis at the center of the strain gauge 82 Let H be the difference from the height position in the direction. If the air bearing 5 is not used in the reference torque wrench 300, the H is deformed by applying a lateral load × H bending moment in the direction indicated by the arrow in FIG. The gauge 82 is additionally subjected to the deformation of the deformation body 81 due to the bending moment.

  By the way, as shown in FIG. 12B, the angular shaft portion 3 of the reference torque wrench 300 is engaged with the intermediate shaft 503A of the torque wrench tester 500. Engage with 503A. Due to the play, the shaft center L of the reference torque wrench 300 is inclined with an angle θ with respect to the shaft center Z of the torque wrench tester 500. If the air bearing 5 is not used in the reference torque wrench 300, a parasitic component force is generated and deformed in the strain generating body 81 when the torque is applied due to this θ. The distortion of the deformation of the body 81 is added.

  When the air bearing 5 is used, the strain caused by the deformation of the extra strain generating body 81 is absorbed by the radial air gap between the shaft 52 and the bearing housing 51 and is not applied to the strain gauge 82.

  Furthermore, it is assumed that a ball bearing is used for the reference torque wrench 300 without using the air bearing 5. Ball bearings are deformed and worn over time, and play occurs. Also, the viscosity of the lubricant applied to the ball bearing varies depending on the temperature. Such backlash and changes in viscosity are not constant, and the frictional force of the bearing changes. For this reason, for example, the frictional force may be different between morning and afternoon within a day, and the frictional force may be different before and after a period such as one month or six months later.

  When the air bearing 5 is used, since the shaft 52 and the bearing housing 51 are held by the radial air gap, the frictional force based on the air gap does not change. A constant torque is applied.

  It is possible to measure the reference torque with high accuracy by eliminating the influence of the lateral load, the bending moment and the parasitic component force on the deformation of the strain body 81 and the instability of the bearing.

DESCRIPTION OF SYMBOLS 100 Torque driver tester 101 Tester main body 102 Mounting stand 103 Loading apparatus 104 Sensor shaft 105 Display part 106 Base 107 Ring part 108 Operation ring part 109 Holding part 110 Rotating shaft 111 Dial 112 Supporting shaft part 113 Shaft hole part 1 Reference torque Driver 2 First shaft portion 3 Square shaft portion 4 Second shaft portion 5 Air bearing 51 Bearing housing 52 Shaft 53A First flange portion 53B Second flange portion 54 Connection shaft 54A First mounting flange 54B Second mounting flange 55 Bolt 56 Serration Connecting part 57 Bolt 511 Radial bearing pad 512 Thrust bearing pad 513 Air supply port 514 Ventilation path 515 Exhaust port 6 Cover part 61 Bolt 7 Strain body support base 71 Base body part 72 Mounting leg part 73 Insertion hole 74 Bolt 8 G Detecting part 81 Straining body 82, 83 Strain gauge 84 First straining body main body 85 Second straining body main body 86 Central connecting part 87 First fixing part 88 Second fixing part 89A, 89B, 89C Linear elasticity Body 90 Serration connecting hole 91A Stopper piece 91B Dummy stopper piece 92 Bolt hole 93 Spacer 94 Bolt 95A Stopper shaft 95B Stopper shaft 200 Reference torque meter 201 Third shaft 202 Mounting flange 203 Bolt 300 Reference torque wrench 301 Lever 400 strain generating body 401 outer peripheral annular portion 402 central connecting portion 403 linear elastic body portion 500 torque wrench tester

Claims (10)

A torque detector for detecting relative torsion around the axis generated between both ends of the strain generating body with a strain gauge;
One end portion of the strain body is a free end, the other end of the strain body is fixed, and a strain body support portion that supports the strain body,
Bearing means for floatingly supporting the shaft disposed in the bearing casing by a fluid film in the radial direction and the thrust direction;
Have
The strain body supporting portion is fixed to a bearing casing of the bearing means, and the shaft is connected to one end portion of the strain body so as to be axially movable and immovable around an axis, or moved axially and around the axis. A reference torque measuring device, wherein the reference torque measuring device is fixed to be impossible and a reference torque is applied between a bearing casing of the bearing means and the shaft.   2. The reference torque device according to claim 1, wherein the shaft center of the bearing means and the shaft center of the strain-generating body are matched.   The reference torque device according to claim 1 or 2, wherein the strain body is formed in a rotationally symmetrical shape with a central axis as a center.   The strain body is arranged with a predetermined angle around a plurality of strain body bodies formed of an elastic body with one end portion disposed at the central shaft portion as a common connecting portion. The strain body main body portion is bent from the first elastic body portion to the outer side in the radial direction from the connecting portion by bending the second elastic body portion at a right angle in a predetermined direction, and from the second elastic body portion to the third elastic body portion. The elastic body part is bent at a right angle in the predetermined rotation direction, and a fixing part fixed to the strain generating body support part is provided at the tip of the third elastic body part, and the whole is made into one winding shape. Item 4. The reference torque device according to Item 3.   The serration hole part is formed in the center axis | shaft part of the said strain body, and the serration shaft part connected with the said serration hole part was provided in the said shaft, The Claim 1 characterized by the above-mentioned. Torque measuring device for reference. The strain body support portion is provided with stopper means for restricting the amount of twist of the strain body inside a region surrounded by the first elastic body portion, the second elastic body portion, and the third elastic body portion. The reference torque measuring device according to claim 4 or 5, wherein   A first shaft portion fixed to the bearing casing; and a second shaft portion fixed to the shaft opposite to the first shaft portion and on the same axis as the first shaft portion; The second shaft portion further includes an engaging portion that engages with a sensor shaft of a torque driver tester or a torque driver checker, and is a reference torque driver used for calibration of the torque driver tester or the torque driver checker. The reference torque measuring device according to any one of claims 1 to 6.   A first shaft portion fixed to the bearing casing, and a third shaft portion fixed to the shaft on the opposite side of the first shaft portion and on the same axis as the first shaft portion; In order to establish the traceability of torque, the reference torque meter is used as an intermediary between the upper level torque standard machine and the lower level torque meter reference machine, and the higher level torque meter reference machine and the lower level torque test machine. Item 7. The reference torque measuring device according to any one of Items 1 to 6.   A lever that is integrally fixed to the bearing casing and extends in a direction perpendicular to the axis of the bearing casing; and a second shaft portion that is fixed to the shaft on the opposite side of the lever. The reference torque measuring device according to any one of claims 1 to 6, wherein the reference torque wrench has an engagement portion that engages with a sensor shaft of a torque wrench tester or a torque wrench checker on two shaft portions. . A lever that is integrally fixed to the bearing casing and extends in a direction perpendicular to the axis of the bearing casing; and a second shaft portion that is fixed to the shaft on the opposite side of the lever. 7. The reference torque measuring device according to claim 1, wherein the reference torque wrench is a reference torque wrench that mediates between a higher-level torque standard machine and a lower-level torque wrench reference machine in order to establish traceability. .

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