JP6422316B2 - Contact-type measuring device holding device - Google Patents

Description

  The present invention relates to a holding device for fixing a contact-type length measuring device to a support member.

  The spindle-movable contact type length measuring device is a length measuring device that measures a size and a shape by moving a movable spindle in contact with an object to be measured. In such a length measuring device, a scale having a scale is arranged on an extension line of the spindle, and position information is read by a sensor. The scale is positioned using a magnetic scale magnetized with NSNS, an optical scale with slits at equal intervals in the glass substrate, light emitting part and light receiving part, and magnetic materials such as multiple coils and iron cores. There is a transformer type for reading information, and the system is not limited.

  Further, the contact type length measuring device needs to move the spindle in the length measuring direction with high accuracy in order to measure dimensions and shapes, and has a bearing inside. As the bearing, a ball bearing or a sliding bearing in which metals are in contact with each other is used.

  A conventional example of a holding device for fixing such a length measuring device is shown in FIG. The rectangular parallelepiped holding device 102 is provided with a hole 103 for passing the length measuring device 101, a slit 104, and a hole 105. The diameter of the hole 103 is slightly larger than the outer diameter of the length measuring device 101, and the outer surface of the length measuring device 101 is fastened and fixed to the inner surface of the hole 103 by screwing a bolt 106 into the hole 105. The holding device 102 is connected to a frame or the like (not shown), and the length measuring device 101 is held at a predetermined position.

  There is also a method in which a flange is provided on a contact type length measuring device, and this flange is screwed to a plate-like support member and attached in a thrust direction by applying a force.

  Patent Document 1 describes a cylindrical fixture for fixing a cylindrical member such as a length measuring device to a plate member. In this fixture, when the outer cylinder is inserted and the nut is tightened in a state where the cylindrical fastening member formed with the split groove is attached to the plate-like member, the inclined surface of the fastening member is pressed to the center side, and the bending portion is The outer peripheral surface of the outer cylinder is tightened (see the paragraphs 0042-0048 and FIGS. 5-7 of the specification).

Japanese Patent No. 4695515

  When the contact type length measuring device of FIG. 13 is fixed, the bearing portion is fixed in the radial direction. As the fixing method, a method of fastening the sliding portion with a screw as shown in FIG. 13 or a mounting with a push screw is generally used. However, if the screw is tightened too tightly, the movement of the spindle is restricted, or the ball from the bearing is damaged by the pressure from one direction biased in the circumferential direction. There was a problem that it deteriorated and the spindle stopped moving.

  In the method of providing a flange on the length measuring device itself, no extra force is applied to the bearing part, but the flange position is determined from the beginning, so there is no degree of freedom in mounting in the length measuring direction, and positioning adjustment is difficult. There was a problem that there was.

  In the fixture described in Patent Document 1, it is necessary to process the upper end of the hole of the plate-like member into a chamfered shape in accordance with the shape of the inclined surface. For this reason, there has been a problem that the number of man-hours required for fixing the length measuring device increases.

  Therefore, an object of the present invention is to provide a holding device that can fix the length measuring device without requiring an extra man-hour for the user and without adversely affecting the bearing portion of the length measuring device.

In order to solve the above-described problems, the holding device of the present invention is in contact with one surface of a support member that is a plate-like member that fixes a cylindrical length measuring device, and the inner diameter thereof is the outer diameter of the length measuring device. A cylindrical member having a cylindrical mounting portion, and a ring-shaped elastic member provided between the inner surface of the mounting portion and the outer surface of the length measuring device, and the cylindrical member is a support member And has a cylindrical penetrating portion that protrudes to the other surface of the support member and has an inner diameter that is substantially equal to the outer diameter of the length measuring device. Larger than the diameter

  According to the present invention, the length measuring device can be fixed without requiring an extra man-hour for the user and without adversely affecting the bearing portion of the length measuring device.

FIG. 1 is a cross-sectional view of the holding device. FIG. 2 is an exploded perspective view of the holding device. FIG. 3 is a diagram showing the appearance of the length measuring device. FIG. 4 is a diagram showing the internal structure of the length measuring device. FIG. 5 is a diagram for explaining a procedure for attaching the length measuring device to the support member by the holding device. FIG. 6 is a diagram illustrating a procedure for attaching the length measuring device to the support member by the holding device. FIG. 7 is a diagram illustrating a procedure for attaching the length measuring device to the support member by the holding device. FIG. 8A and FIG. 8B are diagrams for explaining the effect of arranging two O-rings. 9A is a diagram for explaining the clearance between the length measuring device and the cylindrical member, FIG. 9B is a diagram for explaining the tilt of the length measuring device, and FIG. 9C is a diagram showing measurement errors due to the tilt. It is a figure explaining. FIG. 10 is a cross-sectional view of a first modification of the holding device. FIG. 11 is a cross-sectional view of a second modification of the holding device. FIG. 12 is a cross-sectional view of a third modification of the holding device. FIG. 13 is a perspective view of a conventional holding device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following explanation, an example in which the axis of the length measuring device is arranged in the vertical direction will be described, and the words “upper” and “lower” are used for convenience, but there is no restriction on the actual direction of the length measuring device. .

  FIG. 1 is a cross-sectional view of a holding device 10 according to an embodiment of the present invention attached to a support member 7, and FIG. 2 is an exploded perspective view of the holding device 10.

  The support member 7 is a plate-like member for fixing the length measuring device 1 and supporting it at a predetermined position. The support member 7 is provided with a hole 8 penetrating in the plate thickness direction.

  The holding device 10 includes a cylindrical member 20, a nut 30, a pressing member 40, two O-rings 50 and 51 (an example of a ring-shaped elastic member), and a collar 52.

The cylindrical member 20 is a substantially cylindrical member in which the through portion 21 and the attachment portion 22 are integrally formed and both ends are open.
The through portion 21 is between the upper surface (one surface) 7 a of the support member 7 and the lower end protruding from the lower surface (other surface) 7 b of the support member 7 in a state of being attached to the support member 7. It is a part of. The outer diameter of the penetrating portion 21 is constant and slightly smaller than the inner diameter of the hole 8 of the support member 7. The inner diameter of the penetrating portion 21 is slightly larger than the outer diameter of the stem 2 of the length measuring instrument 1 (see FIG. 3). A screw 23 is provided on most of the outer surface of the penetrating portion 21 except for the vicinity of the upper end portion. The length of the penetrating portion 21 is a length obtained by adding a slight margin to at least the total thickness of the support member 7 and the nut 30. In FIGS. 1 and 2, the length of the margin is increased so as to cope with an increase in the thickness of the support member 7.

The attachment portion 22 is a portion between the upper surface 7 a and the upper end of the support member 7 in a state of being attached to the support member 7 in the cylindrical member 20. The outer diameter of the mounting portion 22 is larger than the outer diameter of the penetrating portion 21, and a nut portion 24 having a hexagonal cross section is provided at the end portion. A screw 25 is provided on the inner surface of the nut portion 24. The boundary portion between the penetrating portion 21 and the attachment portion 22 (the lower end of the attachment portion 22) is a flat flange portion 26. The flange portion 26 abuts on the upper surface 7a, so that the vertical position of the holding device 10 is increased. Determined. The inner diameter of the attachment portion 22 is larger than the inner diameter of the penetration portion 21. The difference between the inner diameters of these two is substantially equal to or slightly smaller than the thickness of the O-rings 50 and 51. If the length is slightly small, the length measuring instrument 1 can be temporarily held by the O-rings 50 and 51, so that the operation becomes simpler.

  The nut 30 is a hexagon nut for screwing with the screw 23 to fix the cylindrical member 20 to the support member 7. The cylindrical member 20 and the support member 7 can be fixed by other methods such as adhesion and welding.

  The pressing member 40 is a member in which a flange portion 41 and a cylindrical pressing portion 42 are integrally formed, and a hole 43 having a diameter substantially equal to the outer diameter of the stem 2 is provided in the center portion. The pressing portion 42 has a cylindrical shape, and a screw that is screwed with the screw 25 of the cylindrical member 20 is provided on the outer surface thereof. The length of the pressing portion 42 in the axial direction enables the upper O-ring 50 to be pressed when the flange portion 41 and the nut portion 24 of the tubular member 20 come into contact with each other as shown in FIG. In addition, the diameter of the hole 43 may be made larger than that in the example of FIG. 1 so that a space is formed between the pressing member 40 and the stem 2.

  The O-rings 50 and 51 are elastomer-shaped annular members. The inner diameter of the O-rings 50 and 51 in a state where no external force is applied is slightly smaller than the outer diameter of the stem 2, and the outer diameter is substantially equal to the inner diameter of the mounting portion 22. As a material for the O-ring, for example, nitrile rubber, fluorine rubber, ethylene propylene rubber, silicone rubber, acrylic rubber, or the like can be used.

  The collar 52 is a cylindrical member having a small axial dimension. In this example, the inner diameter of the collar 52 is substantially equal to the outer diameter of the stem 2, and the outer diameter is slightly smaller than the inner diameter of the mounting portion 22. Since the collar 52 is a member for maintaining the interval between the two O-rings 50 and 51, it is preferable that the collar 52 be made of a hard material such as metal. You may make it hold | maintain the space | interval between O-ring 50 and O-ring 51 with members of shapes other than a cylindrical shape. Further, three or more O-rings may be arranged at intervals in the vertical direction, and a spacing member such as a collar may be provided between the O-rings as in FIG. Further, it is possible to arrange only one O-ring and omit the collar 52. Even when a plurality of O-rings are arranged, they can be arranged without any gap in the axial direction, and a member for holding a gap such as a collar can be omitted.

  In the example of FIG. 1, the O-ring 51 is disposed such that its lower end is in contact with the inner surface of the flange portion 26 and its outer peripheral portion is in contact with the inner surface of the mounting portion 22. The collar 52 is disposed such that its lower end is in contact with the upper end of the O-ring 51 and its upper end is in contact with the lower end of the O-ring 50. That is, the O-ring 50 and the O-ring 51 are arranged at an interval in the axial direction of the stem 2 by the height of the collar 52. The upper end of the O-ring 50 is positioned slightly above the lower end of the screw 25 so that when the pressing member 40 is screwed in, the O-ring 50 is pressed by the lower end of the pressing portion 42.

  FIG. 3 is a diagram showing an external appearance of an example of a length measuring device fixed to the support member 7 by the holding device 10. The length measuring device 1 includes a cylindrical stem 2, a cylindrical spindle 4 (an example of a sliding member) fitted inside the stem 2, a measuring element 5 attached to the tip of the spindle 4, and the spindle 4. And a bellows 3 for protecting a portion protruding from the stem 2. As shown in FIG. 4, a bearing 6 is provided between the stem 2 and the spindle 4, and the spindle 4 can slide in the axial direction. The spindle 4 is driven by air pressure, for example.

  When performing measurement, the stem 2 of the length measuring device 1 is fixed to a support member (not shown), and the spindle 4 is adjusted to a predetermined zero position. Then, the spindle 4 is expanded and contracted toward a workpiece (not shown), and the dimension and position of the workpiece are measured from the scale reading when the probe 5 comes into contact with the workpiece.

Next, a procedure for fixing the length measuring instrument 1 to the support member 7 by the holding device 10 will be described.
A hole 8 having a diameter larger than the outer diameter of the penetrating portion 21 and smaller than the outer diameter of the mounting portion 22 is formed in the support member 7. Since the hole 8 only needs to be able to penetrate the penetration part 21, a thread chamfering degree for removing burrs is necessary, but further C chamfering or the like is not necessary.

  Next, as shown in FIG. 5, the penetrating portion 21 is passed through the hole 8 of the support member 7 and is fastened and fixed by the nut 30. As a result, as shown in FIG. 1, the holding device 10 is fixed to the support member 7 so that the support member 7 is sandwiched between the flange portion 26 and the nut 30.

  Next, as shown in FIG. 6, the O ring 51, the collar 52, and the O ring 50 are attached to the attachment portion 22 in this order. Next, the length measuring device 1 is inserted into the tubular member 20. At this time, the length L of the portion where the inner surface of the cylindrical member 20 and the stem 2 of the length measuring device 1 overlap is set to a predetermined value or more.

  Next, as shown by an arrow A in FIG. 7, the pressing member 40 is tightened to press the O-rings 50 and 51 in the axial direction of the length measuring device 1. Thereby, the O-rings 50 and 51 are crushed in the axial direction. As a result, the length measuring device 1 is fixed. That is, the length measuring device 1 is fixed to the holding device 10 by a uniform pressing force toward the center of the cross section at any position in the circumferential direction of the cross section of the stem 2. The length measuring device has conditions such as vibration depending on the specifications, and the pressing force by the pressing member 40 is adjusted so that the length measuring device is sufficiently firmly fixed to satisfy the conditions. That is, it adjusts so that the frictional force between the pressed O-rings 50 and 51 and the inner surface of the attachment portion 22 is superior to the acceleration applied to the length measuring device 1, and the length measuring device 1 is not displaced from the holding position. .

  In the above description, the cylindrical member 20 is fixed to the support member 7 and then the length measuring instrument 1 is fixed to the cylindrical member 20. However, before the cylindrical member 20 is attached to the support member 7, Alternatively, the length measuring device 1 may be fixed to the cylindrical member 20, and finally the cylindrical member 20 may be fixed to the support member 7 by the nut 30.

  FIGS. 8A and 8B are views for explaining the effect obtained by arranging two O-rings at an interval in the axial direction of the stem 2. As shown in FIG. 8A, even if only one O-ring 50 is used, the stem 2 is adjusted by adjusting the size and material of the O-ring 50 and the pressing force by the pressing member 40 so that the stem 2 can be tightened with sufficient force. Can be fixed. However, since it is fixed at one point, it is easy to rotate around the position of the O-ring 50 as indicated by an arrow B in FIG. On the other hand, as shown in FIG. 8B, if two O-rings 50 and 51 are arranged with a space in the axial direction of the stem 2, the stem 2 rotates around the position of one O-ring. Even if it tries to do so, the other O-ring acts so as to prevent rotation, so that the stem 2 can be stably fixed without fear of rotating.

  9A to 9C are diagrams for explaining how to determine the length L described above. As shown in FIG. 9A, the hole 27 of the cylindrical member 20 and the stem 2 of the length measuring device 1 have a “clearance fit” relationship. That is, a clearance may be generated between the two by the tolerance. For example, when the hole 27 has a dimension of 8 mm and an H7 tolerance (+0.015 to 0 mm) as defined in JIS, and the stem 2 has a diameter of 8 mm and an h6 tolerance (0 to -0.009 mm), the clearance is a maximum of 0. .024 mm.

  Since there is this clearance, as shown in FIG. 9B, the stem 2 may be fixed with an inclination of the angle θ with respect to the tubular member 20. Alternatively, even if they are fixed in parallel, there is a possibility that a load will be applied and tilted when the length measuring instrument 1 comes into contact with the workpiece. Assuming that the clearance is constant, the angle θ increases as the overlapping length L decreases. In other words, when it is desired to reduce the angle θ, it is necessary to increase the overlapping length L. In FIG. 9B, the clearance is exaggerated, so that the cylindrical member 20 seems to hinder the expansion and contraction of the spindle 4, but the tilt is actually very small. It can be expanded and contracted without being obstructed.

FIG. 9C is a diagram illustrating an example of a measurement error caused by the inclination as described above. Let S be the stroke of the spindle 4 of the measuring instrument 1. As shown in FIG. 9B, when the length measuring instrument 1 is tilted and fixed by θ and the spindle 4 moves by S in the direction of arrow D in FIG. 9B, the axis of the cylindrical member 20 of the spindle 4 The amount of movement in the direction (correct measurement direction, the direction of arrow C in FIG. 9C) is S ′ = S / cos θ, and a measurement error of ΔS = S′−S occurs. The length L is determined so that the measurement error ΔS is not more than a predetermined value according to the measurement purpose. That is, the length L in the axial direction of the length measuring device 1 at the portion where the inner surface of the penetrating portion 21 and the outer surface of the stem 2 of the length measuring device 1 are in contact with the clearance between the stem 2 and the penetrating portion 21 and the stem 2. the length error ΔS measured by the slope determined from the diameter θ is determined to be equal to or less than a predetermined value. For example, when the stem 2 and the hole 27 have the above dimensions and the stroke of the stem 2 is 12 mm and the allowable error is 0.1 μm, the length L is 3 mm or more.

  The holding device 10 penetrates the hole 8 provided in the support member 7 and protrudes from the upper surface of the support member 7. The holding device 10 has a cylindrical through portion 21 whose inner diameter is substantially equal to the outer diameter of the length measuring device 1, and the inner diameter is A cylindrical member 20 having a cylindrical mounting portion 22 which is larger than the outer diameter of the length device 1 and whose outer diameter is larger than the outer diameter of the penetrating portion and whose lower flange portion 26 abuts against the upper surface 7a; O-rings 50 and 51 provided between the inner surface of the portion 22 and the outer surface of the length measuring device 1 are provided. When the length measuring device 1 is inserted into the central portion of the O-rings 50 and 51, the O-rings 50 and 51 are deformed so as to be crushed by the outer surface of the length measuring device 1 and the inner surface of the mounting portion 22. Since the O-rings 50 and 51 are made of an elastic body, the length measuring device 1 is pressed by the O-rings 50 and 51 toward the center of the cross section. Since the O-rings 50 and 51 are one member connected in a ring shape, the force pressing in the center direction is constant in any part of the outer circumference of the length measuring device 1. Therefore, the length measuring device 1 can be fixed without applying a biased pressing force to the bearing 6 arranged inside the length measuring device 1 and without adversely affecting the sliding of the spindle 4. Further, since the length measuring device 1 and the support member 7 are not in contact with each other and there is no mechanical engagement or the like, the relative position of the length measuring device 1 with respect to the support member 7 can be finely adjusted. Further, since the O-rings 50 and 51 made of elastomer are in contact with the length measuring device 1, the stem 2 of the length measuring device 1 is not damaged.

  The holding device 10 includes a pressing member 40 that presses the O-rings 50 and 51 in the axial direction of the length measuring device 1. Therefore, compared with the case where the length measuring device 1 is simply inserted into the O rings 50 and 51, the O rings 50 and 51 are greatly deformed, and the length measuring device 1 can be held more firmly.

  The holding device 10 includes two O rings 50 and 51. Therefore, the length measuring device 1 is supported at two points, and can be prevented from being rotated by an external force. A collar 52 is provided between the O-ring 50 and the O-ring 51. Therefore, the distance between the O-ring 50 and the O-ring 51 in the axial direction of the length measuring device 1 is maintained at a predetermined value, and the effect of preventing the above rotation is ensured. Further, the pressing force by the pressing member 40 can be reliably transmitted to the lower O-ring 51 that does not come into contact with the pressing portion 42 via the collar 52.

  In the holding device 10, a screw 23 is provided on an outer surface of a portion protruding from the support member 7 of the penetrating portion 21, and the support member 7 is formed by a nut 30 screwed with the screw 23 and a flange portion 26 at the lower end of the attachment portion 22. It is comprised so that may be clamped. That is, the cylindrical member 20 is not fixed to the support member 7 by friction or mechanical engagement between the inner surface of the hole 8 and the outer surface of the through portion 21. For this reason, the hole 8 only needs to be able to penetrate the penetrating portion 21 and does not require complicated processing such as chamfering.

  A screw 25 is provided on the inner surface end of the attachment portion 22, and a screw is provided on the outer periphery of the pressing portion 42 of the pressing member 40, and is configured to be screwed with the screw 25. Therefore, the pressing force by the pressing part 42 is reliably maintained at a predetermined value. Further, the pressing force can be easily adjusted by adjusting the torque when the pressing member 40 is screwed.

In the holding device 10, the length in the axial direction of the length measuring device 1 (L in FIG. 9A) of the portion where the inner surface of the penetrating portion 21 contacts the outer surface of the length measuring device 1 is the same as that of the length measuring device 1. measurement due to the slope obtained from the clearance and the diameter of the measuring machine 1 between parts 21 (theta in FIG. 9 (B)) length error (e.g., [Delta] S in FIG. 9 (C)) so that is equal to or less than a predetermined value It is stipulated in. Therefore, by adjusting L, it is possible to easily adjust the measurement error due to the inclination so as to be equal to or less than a predetermined value determined by the measurement object and purpose.

  The length measuring device 1 has a slidable spindle 4 inside and measures the position according to the sliding distance of the spindle 4. The holding device 10 can be most suitably applied to such a type of length measuring device, but may be applied to other types of length measuring devices as long as it has a cylindrical outer shape.

  In the holding device 10, O-rings 50 and 51 are used as ring-shaped elastic members. The O-ring is a general-purpose member defined in JIS. Therefore, the O-ring is easy to procure and can produce a holding device at a low cost.

  Next, a modified example of the holding device will be described. The same parts as those of the holding device 10 are denoted by the same reference numerals as those in FIG. 1 and the description thereof will be omitted. Differences from the holding device 10 will be mainly described.

  FIG. 10 is a cross-sectional view of a holding device 11 that is a first modification. The holding device 11 is different from the holding device 10 in that the pressing member 40 and the collar 52 are not provided. The inner diameter of the attachment portion 22 of the cylindrical member 20 is smaller than the holding device 10 of FIG. 1 by a length substantially equal to the thickness of the O-rings 50 and 51. Two grooves 28 and 29 having a semicircular cross section are provided on the inner surface of the attachment portion 22. The O-rings 50 and 51 are fitted in the grooves 28 and 29 on the outer half thereof, and are fixed so as not to move in the axial direction of the length measuring device 1. Therefore, the collar 52 in FIG. 1 can be omitted.

  In the holding device 11, the pressing member 40 in FIG. 1 is also omitted. Even if it does in this way, if the dimension and elastic modulus of the O-rings 50 and 51 are appropriately set, it is sufficient to push the length measuring instrument 1 while the O-rings 50 and 51 are fixed to the grooves 28 and 29. A tightening force can be obtained and the length measuring instrument 1 can be firmly fixed. Since the pressing member 40 is not disposed, it is not necessary to provide a screw at the inner surface end portion of the mounting portion 61, and it is not necessary to provide the nut portion 24 as in FIG. Therefore, the dimension which protrudes from the upper surface 7a of the support member 7 can be made small compared with the case of FIG.

  The shape of the grooves 28 and 29 is preferably a shape that is in close contact with the outside of the O-rings 50 and 51. This is because there is no space for the O-rings 50 and 51 to deform outwardly between the outer surfaces of the O-rings 50 and 51 and the surface of the groove 28, so that the tightening force is effectively transmitted to the length measuring device 1. .

  FIG. 11 is a cross-sectional view of a holding device 12 as a second modification. In the holding device 12, an elastic member 53 is used as a ring-shaped elastic member in place of the two O-rings 50 and 51 of FIG. The elastic member 53 is a cylindrical member made of elastomer, and the outer diameter in a state where no external force is applied is equal to the inner diameter of the mounting portion 22, and the inner diameter is slightly smaller than the outer diameter of the stem 2. As in the case of FIG. 1, the elastic member 53 is pressed and deformed by the pressing member 40, whereby the stem 2 is fastened and fixed. Since the ring-shaped elastic member is composed of one member, the collar 52 in FIG. 1 is not necessary. The holding device 12 has fewer parts than the holding device 10 shown in FIG.

  FIG. 12 is a cross-sectional view of a holding device 13 that is a third modification. The holding device 13 is different from the holding device 10 in that the cylindrical member 20 does not penetrate the support member 7 and the attachment portion 62 and the insertion portion 68 are integrally formed. The internal shape of the attachment portion 62 is the same as that of the attachment portion 22 in FIG. The flange portion 63 is a disk-like member that protrudes greatly to the outside. The insertion portion 68 is a cylindrical member whose inner diameter is slightly larger than the inside and outside of the stem 2 as in the penetration portion 21 of FIG. 1, but does not penetrate the lower surface 7 b side of the support member 7, and the lower end is the support member 7. The hole 8 is located near the center in the thickness direction. The flange portion 63 is provided with two bolt holes 64 penetrating in the plate thickness direction. The support member 7 is also provided with two bolt holes 65 at positions corresponding to the bolt holes 64. The cylindrical member 20 is fixed to the support member 7 by passing the bolt 66 through the bolt holes 64 and 65 and tightening the nut 67. Since the holding device 13 does not protrude toward the lower surface 7b side of the support member 7, the degree of freedom of the installation position is greater than that of the holding device 1 in FIG.

1 Measuring instrument 2 Stem 3 Bellows 4 Spindle (sliding member)
5 Measuring element 6 Bearing 7 Support member 10, 11, 12, 13 Holding device 20 Cylindrical member 21 Penetration part 22 Attachment part 30 Nut 40 Pressing member 50, 51 O-ring 52 Collar

Claims (10)

A cylindrical member provided with a cylindrical mounting portion that comes into contact with one surface of a support member, which is a plate-like member for fixing a cylindrical length measuring device, and whose inner diameter is larger than the outer diameter of the length measuring device. When,
A ring-shaped elastic member provided between the inner surface of the mounting portion and the outer surface of the length measuring device ;
The cylindrical member further has a cylindrical penetrating portion that penetrates a hole provided in the supporting member and protrudes to the other surface of the supporting member, and whose inner diameter is substantially equal to the outer diameter of the length measuring device. The holding device is characterized in that an outer diameter of the mounting portion is larger than an outer diameter of the penetrating portion . The outer surface of the portion projecting from the support member of the through portion screw is provided in claim 1, characterized in that for clamping the support member at one end of the nut and the mounting part of the screw and screwed The holding device as described. Holding apparatus according to claim 1 or claim 2, characterized in that it comprises a pressing member for pressing the elastic member in the axial length unit measuring the. The holding device according to any one of claims 1 to 3 , wherein two or more elastic members are provided. The holding device according to claim 4 , further comprising a collar provided between the elastic members. A screw is provided at the inner surface end of the mounting portion,
The holding device according to claim 3, wherein the pressing member is a member screwed with the screw. The length in the axial direction of the length measuring device at the portion where the inner surface of the penetrating portion abuts the outer surface of the length measuring device is the clearance between the length measuring device and the penetrating portion, and the diameter of the length measuring device. the length error measurement due to inclination obtained from the holding device according to any one of claims 1 to 6, characterized in that it is determined to be equal to or less than a predetermined value. The length measuring device has a slidable member therein, any claims 1 to 7, characterized in that to measure the position according to the sliding distance of the slidable member The holding device according to claim 1. The elastic member is held device according to any one of claims 1 to 8, characterized in that an O-ring. The holding device according to claim 9 , wherein an inner diameter of the O-ring is smaller than an outer diameter of the length measuring device.

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