Bolt tilt inspection tool

Abstract

To be possible to accurately and easily confirm that an inclination of a placed bolt is within an allowable range regardless of a condition of a placed surface of the bolt.SOLUTION: A bolt inclination inspection device 10 includes an annular body 11 in which a contact surface 13 is positioned to mimic a placed surface 52 of a bolt 61 and a projection portion 14 that projects in a reverse direction to the contact surface 13 of the annular body 11. The inclination surface 13 that inclines outward to a projection direction of the projection portion 14 from an edge of a center hole 12 of the annular body 11 is formed on the projection portion 14, and an inclination angle of the inclination surface 13 is set at an allowable inclination angle of the bolt 61.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bolt inclination inspection tool used to inspect the inclination of bolts driven into natural ground, concrete, etc. [Background technology]

[0002] Conventionally, at civil engineering and construction sites, the axial force of a driven bolt in the axial direction is measured using a load cell, an axial force meter, or the like, as in Patent Document 1. When measuring this axial force, for example, as shown in FIG. 3(a), washers 103 and 104 are extrapolated to bolt 102 driven into natural ground 101, and a load cell 105 is placed between washers 103 and 104 and extrapolated to bolt 102. Then, nut 106 threaded onto bolt 102 is tightened outside washer 104, and strain caused by threading of nut 106 is measured by load cell 105 between washer 103 and washer 104, and the axial force of bolt 102 is obtained from the measured strain. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-75903 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when measuring the axial force of a bolt 102 driven into the natural ground 101, if the bolt 102 is driven at an excessive inclination relative to the natural ground 101, the axial force cannot be measured accurately (see FIG. 3(b)). For this reason, as shown in FIG. 4, an L-shaped curved ruler 107, which is a common tool, is applied to the part of the bolt 102 that protrudes from the natural ground 101 to check whether the inclination of the driven bolt 102 is within the allowable range. If the surface on which the bolt 102 is driven is a vertical or horizontal plane, checking the inclination with this curved ruler 107 can provide a fairly accurate check.

[0005] However, when the inner circumferential surface or slope of a tunnel is the casting surface for the bolt 102, the casting surface is curved or inclined, so the L-shaped curved ruler 107 must be placed at an angle to the casting surface, or it can easily be placed at an angle. If the L-shaped curved ruler 107 cannot be placed horizontally or perpendicular to the casting surface, for example, the bolt axis X1 may be mistakenly recognized as being perpendicular to the casting surface, even if it is tilted relative to the bolt axis X or the casting surface where it should be. Therefore, there is a need for a tool that can accurately confirm that the tilt of the driven bolt 102 is within the allowable range, regardless of the condition of the casting surface for the bolt 102.

[0006] The present invention has been proposed in consideration of the above-mentioned problems, and aims to provide a bolt tilt inspection tool that can accurately and easily confirm that the tilt of a driven bolt is within the acceptable range, regardless of the condition of the bolt driving surface. [Means for solving the problem]

[0007] The bolt tilt inspection tool of the present invention comprises a ring-shaped body whose contact surface is arranged to conform to the installation surface of the bolt, and a protrusion that protrudes in the opposite direction from the contact surface of the ring-shaped body, and is characterized in that the protrusion has an inclined surface that slopes outward from the edge of the central hole of the ring-shaped body in the protruding direction of the protrusion, and the inclination angle of the inclination surface is set to the allowable inclination angle of the bolt. With this, the contact surface of the annular body is positioned to follow the bolt's driving surface, making it possible to accurately check the inclination of the bolt's axis. Furthermore, simply by extrapolating the center hole of the annular body onto the driven bolt and positioning the annular body's contact surface to follow the bolt's driving surface, the inclination of the bolt's axis can be easily checked. In other words, regardless of the condition of the bolt's driving surface, the annular body's contact surface comes into planar contact with the bolt's driving surface, making it possible to accurately and easily check whether the inclination of the driven bolt is within the allowable range.

[0008] The bolt tilt inspection tool of the present invention is characterized in that the protrusion is formed in a cylindrical shape that stands up from the periphery of the central hole, and the inclined surface is provided on the inner surface of the cylindrical protrusion. With this, by simply extrapolating the center hole of the annular body to the installed bolt and positioning the contact surface of the annular body to match the installed surface of the bolt, it is possible to check whether the inclination of the bolt is within the acceptable range over the entire circumference of the installed bolt, thereby efficiently checking the inclination of the bolt over the entire circumference.

[0009] The bolt tilt inspection tool of the present invention is characterized in that the protrusion is formed in a plate shape extending radially of the annular body, and the inclined surface is provided on the center hole side of the plate-shaped protrusion. This not only makes it possible to confirm that the inclination of the driven bolt is within the allowable range, but also makes it possible to easily check the exact angle of inclination of the bolt from directly to the side of the driven bolt, thereby improving the visibility of the inclination state of the bolt. [Effects of the Invention]

[0010] The bolt inclination inspection tool of the present invention makes it possible to accurately and easily confirm that the inclination of a driven bolt is within the allowable range, regardless of the condition of the bolt driving surface. [Brief explanation of the drawings]

[0011] [Figure 1] 1A is a perspective view of a bolt tilt inspection tool according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional explanatory view of the tool in use. [Figure 2] 1A is a perspective view of a bolt tilt inspection tool according to a second embodiment of the present invention, and FIG. 1B is a cross-sectional explanatory view of the tool in use. [Figure 3] (a) is a cross-sectional view illustrating conventional bolt axial force measurement, and (b) is a cross-sectional view illustrating a state in which the bolt is excessively tilted during conventional bolt axial force measurement. [Figure 4] FIG. 10 is an explanatory perspective view illustrating a conventional method for checking the inclination of a driven bolt using a curved ruler. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Bolt tilt inspection tool of the first embodiment] 1, a bolt inclination inspection tool 10 according to a first embodiment of the present invention comprises a flange-shaped annular body 11 and a cylindrical protrusion 14 formed to rise from the periphery of a central hole 12 of the annular body 11. The annular body 11 is extrapolated to the protruding portion of a bolt 61, which is a rock bolt that is driven so that a portion of the bolt is buried in the natural ground 51 and the remaining portion protrudes from a pouring surface 52 to the outside of the natural ground 51, and a contact surface 13 is arranged to follow the pouring surface 52 of the bolt 61. The contact surface 13 is formed flat and flush overall, and is in surface contact with the pouring surface 52 when the pouring surface 52 is flat.

[0013] The cylindrical protrusion 14 is provided so as to protrude in the opposite direction from the contact surface 13 of the annular body 11. The protrusion 14 is also formed with an inclined surface 15 that slopes outward from the edge of the central hole 12 of the annular body 11 in the protruding direction of the protrusion 14, and in the first embodiment, a tapered inclined surface 15 is provided around the inner peripheral surface of the cylindrical protrusion 14. Furthermore, in the first embodiment, the peripheral surface of the central hole 12 is also inclined at the same inclination angle as the inclined surface 15, and is formed continuously with the inclined surface 15 of the protrusion 14.

[0014] The inclination angle of the inclined surface 15 of the protrusion 14 and the inclined surface of the circumferential surface of the central hole 12 connected thereto relative to the normal to the contact surface 13 is set to the allowable inclination angle of the inclination of the bolt 61. In the first embodiment, the inclination angle of the inclined surface 15 of the protrusion 14 and the inclined surface of the circumferential surface of the central hole 12 connected thereto is set to the allowable inclination angle of the inclination of the bolt 61 over the entire circumference.

[0015] When using the bolt inclination inspection tool 10 of the first embodiment, prior to measuring the axial force of the driven bolt 61, the annular body 11 and protruding portion 14 of the bolt inclination inspection tool 10 are extrapolated onto the protruding portion of the bolt 61, and the contact surface 13 is positioned to match the driving surface 52 of the bolt 61. Then, if it can be confirmed that the bolt 61 is not pressed against the inclined surface 15, which is the inner surface of the protruding portion 14, it can be determined that the inclination of the driven bolt 61 is within the allowable inclination angle range.

[0016] According to the bolt inclination inspection tool 10 of the first embodiment, the contact surface 13 of the annular body 11 is positioned to conform to the driving surface 52 of the bolt 61, allowing for accurate confirmation of the inclination of the axial center of the driven bolt 61. Furthermore, simply by extrapolating the center hole 12 of the annular body 11 to the driven bolt 61 and positioning the contact surface 13 of the annular body 11 to conform to the driving surface 52 of the bolt 61, the inclination of the bolt axial center can be easily confirmed. That is, regardless of the state of the driving surface 52 of the bolt 61, the contact surface 13 of the annular body 11 comes into planar contact with the driving surface 52 of the bolt 61, allowing for accurate and easy confirmation of whether the inclination of the driven bolt 61 is within the allowable range. Furthermore, simply by positioning the tool in this manner, it is possible to confirm whether the inclination of the driven bolt 61 is within the allowable range over the entire circumference of the driven bolt 61, allowing for efficient confirmation of the inclination of the bolt 61 over the entire circumference.

[0017] [Bolt tilt inspection tool of the second embodiment] 2, a bolt tilt inspection tool 20 according to a second embodiment of the present invention includes an annular body 21, which is a plate-like ring, and a protrusion 24 formed in a plate shape that extends in the radial direction of the annular body 21. In the illustrated example, the lower part of the protrusion 24 on the annular body 21 side is formed to have the same length as the radius of the annular body 21, and the lower inner end of the protrusion 24 forms part of the periphery of the center hole 22.

[0018] The annular body 21 is extrapolated to the protruding portion of the bolt 61, which is a rock bolt that is driven so that a portion of it is buried in the natural ground 51 and the remaining portion of it protrudes from the pouring surface 52 to the outside of the natural ground 51, and the contact surface 23 is arranged to follow the pouring surface 52 of the bolt 61. The contact surface 23 is formed flat and flush overall, and is in surface contact with the pouring surface 52 when the pouring surface 52 is flat.

[0019] The plate-like protrusion 24 is provided so as to protrude in the opposite direction from the contact surface 23 of the annular body 21. The protrusion 24 is formed with an inclined surface 25 that slopes outward from the edge of the central hole 22 of the annular body 21 in the protruding direction of the protrusion 24, and in the second embodiment, a sloped inclined surface 25 is provided on the plate-like protrusion 24 on the side of the central hole 22. Furthermore, in the second embodiment, the peripheral surface of the central hole 22 at a position corresponding to the protrusion 24 is inclined at the same inclination angle as the inclined surface 25, and is formed continuously with the inclined surface 25 of the protrusion 24.

[0020] The inclination angle of the sloped inclined surface 25 of the protrusion 24 and the inclined surface formed by part of the peripheral surface of the central hole 22 connected to it with respect to the normal to the contact surface 23 is set to the allowable inclination angle of the inclination of the bolt 61.

[0021] When using the bolt inclination inspection tool 20 of the second embodiment, prior to measuring the axial force of the driven bolt 61, the annular body 21 of the bolt inclination inspection tool 10 is extrapolated onto the protruding portion of the bolt 61, and the contact surface 23 is positioned to match the driving surface 52 of the bolt 61. If it is confirmed that the bolt 61 is not pressed against the inner inclined surface 15 of the protruding portion 24, it is determined that the inclination of the driven bolt 61 is within the allowable inclination angle range. Furthermore, the bolt inclination inspection tool 20 is sequentially rotated circumferentially around the annular body 21, and if it is confirmed over the entire circumference that the bolt 61 is not pressed against the inner inclined surface 15 of the protruding portion 24, it is determined that the inclination of the driven bolt 61 is within the allowable inclination angle range over the entire circumference.

[0022] According to the bolt inclination inspection tool 20 of the second embodiment, the contact surface 23 of the annular body 21 is positioned to conform to the driving surface 52 of the bolt 61, allowing the inclination of the axial center of the driven bolt 61 to be accurately confirmed. Furthermore, the inclination of the bolt axial center can be easily confirmed by simply extrapolating the center hole 22 of the annular body 21 to the driven bolt 61 and positioning the contact surface 23 of the annular body 21 to conform to the driving surface 52 of the bolt 61. That is, regardless of the state of the driving surface 52 of the bolt 61, the contact surface 23 of the annular body 21 comes into planar contact with the driving surface 52 of the bolt 61, allowing accurate and easy confirmation that the inclination of the driven bolt 61 is within the allowable range. Furthermore, the detailed inclination angle of the bolt 61 can be easily confirmed from directly beside the driven bolt 61, improving the visibility of the inclination state of the bolt 61.

[0023] [Scope of the invention disclosed herein] The inventions disclosed in this specification include, in addition to the individual inventions and embodiments listed as inventions, those specified by modifying partial contents of these with other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects can be obtained and creating a generic concept. The inventions disclosed in this specification also include the following contents and modifications.

[0024] For example, in the above embodiment, an example was described in which a bolt 61 is driven into the natural ground 51 of a tunnel or the like and the bolt inclination inspection tools 10, 20 are used to check the inclination of this bolt 61, but the bolt inclination inspection tools 10, 20 can also be suitably used to check the inclination of a bolt driven into concrete, and the bolt inclination inspection tools 10, 20 may also be used to check the inclination of bolts other than rock bolts. Furthermore, the bolt inclination inspection tool of the present invention can be used for any bolt driven in the civil engineering or construction fields.

[0025] Furthermore, the plate-shaped protrusions 24 in the bolt inclination inspection tool 20 of the second embodiment can be provided at intervals in multiple locations around the circumference of the annular body 21, and by providing the plate-shaped protrusions 24 spaced apart in multiple locations around the circumference of the annular body 21, it is possible to inspect the inclination of the bolt 61 in multiple directions corresponding to the multiple locations. When providing the plate-shaped protrusions 24 spaced apart in multiple locations around the circumference of the annular body 21, they can be configured to be provided around the entire circumference of the annular body 21, or only in a local fan-shaped region around the circumference of the annular body 21. [Industrial Applicability]

[0026] The present invention can be used, for example, when inspecting the inclination of rock bolts or anchor bolts driven into the natural ground or concrete. [Explanation of symbols]

[0027] 10, 20... Bolt tilt inspection tool 11, 21... Annular body 12, 22... Center hole 13, 23... Contact surface 14, 24... Protrusion 15, 25... Inclined surface 51... Ground 52... Pouring surface 61... Bolt 101... Ground 102... Bolt 103, 104... Washer 105... Load meter 106... Nut 107... Curved ruler X...Original bolt axis X1...Bolt axis

Claims

[Claim 1] An annular body having a contact surface arranged to follow the installation surface of the bolt; a protrusion protruding in a direction opposite to the contact surface of the annular body, an inclined surface is formed on the protruding portion, the inclined surface inclining outward from the edge of the central hole of the annular body toward the protruding direction of the protruding portion; The inclination angle of the inclined surface is set to an allowable inclination angle of the bolt, the protruding portion is formed in a plate shape extending in a radial direction of the annular body, A bolt tilt inspection tool, characterized in that the inclined surface is provided on the central hole side of the plate-shaped protrusion.

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