JP2000009594A - Slack detector for fastener, cap member and fixing method therefor and slack alarm system for fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap member for slack detector of fastener in which a sensor for detecting slack of bolt and nut can be fixed easily and surely even to an existing bolt. SOLUTION: The cap member for slack detector of fastener is provided with a first screw hole 11, a second screw hole 12, and a space section 13. The first screw hole 11 is screwed with the forward end of the bolt in a fastener comprising a bolt and a nut. The second screw hole 12 is screwed with a proximity sensor 2 for detecting the distance to the forward end of the bolt 5. In the space section 13, forward end of the bolt 5 screwed into the first screw hole 11 faces the forward end of the proximity sensor 2 screwed into the second screw hole 12. When a nut (not shown) screwed over the bolt 5 turns in the loosening direction, the cap member 1 also turns in the loosening direction to enlarge the distance between the forward end of the bolt 5 and the forward end of the proximity sensor 2. When they are separated more than a specified distance, the fact is notified by the output from the proximity sensor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap member for a fastener looseness detecting device, a fastener looseness detecting device, and a fastener loosening detecting device, which are suitable for detecting the looseness of a fastening by a bolt and a nut. And an alarm system for detecting looseness of a fastener.

[0002]

2. Description of the Related Art For example, when installing a steel tower, an anchor bolt is embedded on a concrete base so that its screw portion protrudes, and a through hole formed in a flange portion of a steel tower leg is fixed to the anchor bolt. A method of establishing a fixed state between these anchor bolts, the flange portion of the tower and the nut by screwing a nut to the screw portion of the anchor bolt and tightening the nut, or
A pillar with a through hole is projected from the concrete base, and this pillar is overlapped with the flange of the tower leg, and bolts are inserted into both through holes with the positions of the through holes aligned. Then, a method is adopted in which a nut is screwed into the threaded portion of the bolt and tightened to thereby establish a fixed state between the column, the flange portion of the tower, the nut and the bolt. Of course, a fastening structure using bolts and nuts is adopted not only for installation of such a large building such as a steel tower, but also for machinery, equipment, and vehicles.

[0003] In the fastening with the bolts and nuts, loosening is not allowed, and as a countermeasure, a method of completely fixing the fastener and the member to be fastened by welding, an adhesive or the like has been conventionally used as a countermeasure. There are adopted a method in which a maintenance inspector performs inspection and maintenance, and a method in which a looseness detecting device is attached to detect looseness without manual operation.

[0004]

However, in the above-mentioned method, it is necessary to take a process such as burning out the fastener at the time of replacement of the fastener or replacement of parts, which is inferior in workability of replacing the fastener and parts. There is a disadvantage that. In addition, the above method requires labor and maintenance and inspection costs are high. Furthermore, it is desired that maintenance and inspection work under severe environments be minimized. On the other hand, according to the above-described looseness detection method, the disadvantages when the above methods and the above methods are adopted are eliminated.

As a conventional technique relating to looseness detection, Japanese Patent Application Laid-Open No. 01-13433 (IPC: G01M 13/0) has been proposed.
No. 0) discloses a rod-shaped fixing device and a method of using the same. In this technology, a sensor (vibrator) is fixed to the tip surface of a bolt, and the vibrator is electrically connected to a measuring device. Looseness due to repeated load over time is detected in the initial set state. It is possible to do.
However, since the vibrator is fixed to the tip of the bolt with an adhesive, the workability of attaching and replacing the sensor is poor. Further, this publication discloses that the sensor is fixed by processing the tip of the bolt, but it is not easy to perform such processing on the existing bolt. Installation becomes extremely difficult.

Further, as a conventional technique for detecting looseness,
JP-A-07-280762 and JP-A-07-2
No. 79936 (IPC: G01N 27/00) discloses a looseness detecting device. In this technique, first, a cap member having a hexagonal recess having a shape somewhat larger than a hexagonal nut mounted on a threaded portion of a bolt is attached to the tip of the threaded portion of the bolt. At the time of this installation,
A gap is uniformly formed between the outer surface of the hexagon nut and the inner wall surface of the hexagonal recess. When the hexagon nut loosens and turns a little, the outer surface of the hexagon nut comes into contact with the inner wall surface of the hexagonal recess, so by detecting the electrical conduction state due to this contact,
Detect looseness. However, such a technique is not preferable because the cap member and the bolt are used as current paths. In addition, if the cap member is simply mounted without cutting the screw hole, it is considered that the cap member itself may be detached from the bolt or may be erroneously detected to be loose due to rotation, and when the screw hole is cut in the cap member. It is necessary to temporarily remove the hexagon nut from the bolt when installing it on the existing nut / bolt, to install this hexagon nut in the hexagonal recess, and to screw these hexagon nut and cap member integrally to the bolt. However, there is a drawback that the work of attaching to the existing bolts is complicated.

In view of the above circumstances, the present invention can easily and reliably mount a sensor for detecting the looseness of the fastening by a bolt and a nut, and can easily and securely mount the sensor on an existing bolt. An object of the present invention is to provide a cap member for a looseness detection device for a fastener, a looseness detection device for a fastener, and a method for mounting the looseness detection device for a fastener, which can be securely mounted. It is another object of the present invention to provide a fastener looseness detection alarm system using the fastener looseness detection device.

[0008]

According to the present invention, there is provided a cap member for a looseness detecting device for a fastener, wherein a tip of the bolt is screwed into a fastener comprising a bolt and a nut. A screw hole, a second screw hole into which a sensor for detecting contact or distance with the tip of the bolt is screwed, a tip of the bolt screwed into the first screw hole, and the second screw hole.
And a space for facing the tip of the sensor screwed into the screw hole.

Since the cap member having the above-described structure is realized by a relatively simple structure including the first screw hole, the second screw hole, and the space, the manufacturing thereof is easy and the cost can be easily reduced. It has the advantage that. Then, just by screwing the tip of the bolt into the first screw hole and screwing the sensor into the second screw hole, the sensor is attached to the bolt. Compared to the case of processing into a shape and attaching the sensor,
The workability of mounting the sensor can be significantly improved. In addition, as compared with the case where the sensor is attached to the tip of the bolt with an adhesive, the reliability of attachment and the maintainability such as replacement of the sensor are remarkably improved. Further, a sensor can be easily and reliably attached to a bolt already provided on a steel tower or the like at the existing site.

[0010] In the cap member, it is preferable that a center line of the first screw hole and a center line of the second screw hole are parallel to each other. According to this, even if the amount of insertion of the tip of the bolt into the space of the cap member is slightly different in each cap member, by adjusting the amount of screwing of the sensor into the second screw hole, the tip of the sensor can be removed. The contact or distance with the tip of the bolt can be easily adjusted.

Preferably, the cap member is formed of a resin material. For example, when the sensor detects contact or approach to a metal bolt, erroneous detection and the like are reduced as compared with the case where the cap member is formed of metal.

A looseness detecting device for a fastener according to the present invention comprises the above-mentioned cap member, a sensor screwed into the second screw hole, and a nut for fixing the sensor. .

Further, according to the method of mounting the looseness detecting device for a fastener according to the present invention, a bolt is fitted into a through hole of a member to be fastened, and one or two or more nuts are screwed into the bolt to cover the bolt. After establishing the fixed state of the fastening member and the nut,
The tip of the bolt is screwed into the first screw hole of the cap member to establish a fixed state of the cap member, and the contact state or the distance between the tip of the sensor and the tip of the bolt is adjusted. And

Further, the fastener looseness detection alarm system of the present invention receives the above-described fastener looseness detection device and an output signal of the sensor, and the output signal is used to determine whether the sensor is in non-contact with the tip of the bolt or not. And control means for outputting an alarm signal when the distance is greater than a predetermined distance.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in the perspective view of FIG. 1, the looseness detecting device of this embodiment includes a cap member 1, a proximity sensor 2, and a nut 3 for fixing the proximity sensor 2 to the cap member 1. And is provided.

As shown in the sectional view of FIG. 2, the cap member 1 has a first screw hole 11 into which the tip of a screw portion 5a of the bolt 5 is screwed, and a second screw hole into which the proximity sensor 2 is screwed. A hole 12 and a screw portion 5a screwed into the first screw hole 11
Sensor 2 screwed into the tip of the second and the second screw hole 12
And a space portion 13 for facing the front end of the head. The first screw hole 11 and the second screw hole 12 are formed such that their respective center lines coincide with each other. The cap member 1 is formed of a resin material such as polycarbonate, and has a flat outer surface, a cylindrical upper portion, and a hexagonal nut lower portion. are doing.

FIG. 3 shows a state in which the fastening member 22 is fixed to the anchor bolt 5 which is embedded in the concrete base 21 and projects the screw portion 5a with the first and second nuts 23 and 24, and the above-described looseness detection is performed. FIG. 4 is a perspective view showing a state where the device is attached to a tip of an anchor bolt 5. FIG. 4 is a sectional view of the same. In order to realize such an attached state, first, the through hole 22a of the member to be fastened 22 is fitted to the screw portion 5a of the anchor bolt 5. Next, the screw portion 5a
By screwing the first nut 23 to the anchor bolt 5 and tightening it, the anchor bolt 5, the member 22 to be fastened and the first
A fixed state with the nut 23 is established. Further, the screw portion 5a
Then, the second nut 24 is screwed together to fasten the double nut. Then, the cap member 1 is screwed to the tip of the screw portion 5a, tightened, and the lower surface thereof is pressed against the upper surface of the second nut 24 to establish a fixed state of the cap member 1 with respect to the anchor bolt 5. If a sealing tape is attached to the screw portion 5a of the bolt 5 when screwing the cap member 1, the cap member 1
The looseness of itself can be suppressed. Next, the embedding amount of the proximity sensor 2 in the second screw hole 12 is adjusted, and the distance between the tip of the proximity sensor 2 and the tip of the screw portion 5a is adjusted. After the adjustment, the proximity sensor 2 is fixed to the cap member 1 by the nut 3.
Fixed to.

When the fastening force of the first and second nuts 23 and 24 to the anchor bolt 5 is loosened by vibration or the like or loosened by anyone, the cap member 1 is also moved in the loosening direction by the second nut 24 rotating in the loosening direction. Rotation, bolt 5
The distance between the tip of the screw portion 5a and the tip of the proximity sensor 2 increases. When this distance exceeds a specified value (2 mm in this embodiment), the proximity sensor 2
As a result, a signal to that effect (abnormal signal) is output. Further, when the cap member 1 is loosened intentionally by someone, the second nut 2
Even if the user tries to loosen the cap member 1, the distance between the tip of the screw portion 5a of the bolt 5 and the tip of the proximity sensor 2 increases by the turning operation for removing the cap member 1, so that the proximity sensor 2 may detect an abnormality. it can. Similarly, if the cap member 1 or the second nut 24 is to be loosened after removing the proximity sensor 2 when the proximity sensor 2 is loosened intentionally, the screw 5a of the bolt 5 is turned by the turning operation for removing the proximity sensor 2. Since the distance between the tip of the proximity sensor 2 and the tip of the proximity sensor 2 increases, the abnormality can be detected by the proximity sensor 2 even in such a case.

The cap member 1 configured as described above includes a first screw hole 11, a second screw hole 12, and a space 13.
Since it is realized with a relatively simple structure consisting of the following, there is an advantage that its manufacture is easy and cost reduction can be easily achieved. And if such a cap member 1 is used,
Just by screwing the tip of the screw portion 5a of the anchor bolt 5 into the first screw hole 11 and screwing the proximity sensor 2 into the second screw hole 12, the proximity sensor 2 is connected to the anchor bolt 5
Therefore, the workability of mounting the sensor is remarkably improved as compared with the case where the tip itself of the anchor bolt 5 is processed into a predetermined shape and the sensor is mounted. Compared with the case where the sensor is attached to the part by an adhesive, the reliability of the attachment and the maintainability such as replacement of the sensor are remarkably improved. Further, the sensor can be easily and reliably attached to the anchor bolts 5 already embedded on the concrete base 21 for supporting the tower or the like at the site.

In this embodiment, since the center line of the first screw hole 11 and the center line of the second screw hole 12 are aligned, the bolt 5 is inserted into the space 13 of the cap member 1. Of the proximity sensor 2 to the second screw hole 12 even if the penetration amount of
The distance between the tip of the proximity sensor 2 and the tip of the bolt 5 can be easily adjusted by adjusting the screwing amount of the bolt. Further, since the cap member 1 is formed of a resin material, erroneous detection is reduced as compared with the case where the cap member is formed of metal. Further, since a part of the cap member 1 is formed in a hexagonal nut shape, the cap member 1 can be easily tightened to the bolt 5 by a spanner which is a general tool.

FIG. 5 is a block diagram exemplifying a schematic configuration of a loosening detection / warning system of a fastener. The components surrounded by the alternate long and short dash line in this figure are provided in a control box (not shown). The power supply switching unit 31 is connected to the AC1
The DC power obtained by rectifying the 00V power supply is supplied to the control unit 32 through the power supply line 34, and the DC power is stored in the battery 33 through the battery power supply line 35. When the supply of the AC 100 V power is cut off, an abnormal signal is supplied to the control unit 32 through the signal line 36 and the DC power from the battery 33 is supplied to the control unit 3.
Feed to 2. Further, when a disconnection of the battery power supply line 35 or a voltage drop of the DC power from the battery 33 occurs, an abnormal signal is given to the control unit 32 through the signal line 36.

The control section 32 receives a signal from the proximity sensor 2. If a plurality of proximity sensors 2 are provided, a signal is received from each of them. Not only signal detection from the proximity sensor 2 but also disconnection or short circuit of the signal line 38 connecting the proximity sensor 2 and the control unit 32 is detected. Further, the control unit 32 also detects whether or not the door has been pryed open without using, for example, a predetermined key by the switch 37 that detects the opening and closing of the door of the control box. Then, the control unit 32 performs the above-described abnormality related to the power supply and the proximity sensor 2.
When an abnormality related to looseness, an abnormality related to the signal line 38, and an abnormality related to the door of the control box are detected, an alarm device (not shown) sounds an alarm,
Alternatively, the communication device 39 sends an abnormal signal to the central monitoring center. At the central monitoring center, a maintenance and inspection person may be dispatched to the site when an abnormal signal is received, and it is not always necessary to dispatch a maintenance inspector periodically.

In this embodiment, the cap member made of a resin material has been described. However, the present invention is not limited to this.
For example, the cap member may be formed of a metal material, and a structure in which an insulating material such as a resin is coated on a portion where the property as a metal is undesired may be employed. Although the example using the proximity sensor has been described, the invention is not limited thereto, and for example, a contact / non-contact detection sensor may be used. Further, the case where the member 22 to be fastened is fixed to the anchor bolt 5 embedded in the concrete base 21 has been described as an example. However, the present invention is not limited to this, and the technology of the present application may be applied to all cases where fastening with the bolt and nut is performed. Is possible.

[0025]

As described above, since the cap member of the present invention is realized with a relatively simple structure including the first screw hole, the second screw hole, and the space portion, the manufacturing thereof is performed. There is an advantage that it is easy and cost reduction can be easily achieved.
In addition, it is excellent in the workability of mounting the sensor and the maintenance performance such as replacement of the sensor, and also has an effect that the sensor can be easily mounted on the existing bolt at the existing site. And the above-mentioned effect is also exerted about the fastener looseness detection device using the cap member, the fastening device looseness detection device mounting method, and the fastener looseness detection alarm system.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a looseness detecting device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view showing a cap member for a looseness detection device according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a state in which the looseness detecting device according to the embodiment of the present invention is attached to the tip of an anchor bolt provided on a concrete base.

FIG. 4 is a longitudinal sectional side view showing a state in which the looseness detecting device according to the embodiment of the present invention is attached to the tip of an anchor bolt provided on a concrete base.

FIG. 5 is a block diagram showing a schematic configuration of a looseness detection alarm system using the looseness detection device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap member 2 Proximity sensor 3 Nut 5 Bolt 5a Screw part 11 1st screw hole 12 2nd screw hole 13 Space part 21 Concrete base 22 Fastened member 23 1st nut 24 2nd nut

Claims (6)

[Claims] A first screw hole into which a tip of the bolt is screwed in a fastener comprising a bolt and a nut; a second screw hole into which a sensor for detecting contact or distance with the tip of the bolt is screwed; A loose part for detecting a looseness of a fastener, wherein a space for allowing a tip of a bolt screwed into the first screw hole and a tip of a sensor screwed to the second screw hole to face each other is formed. Device cap member. 2. A center line of the first screw hole and a center line of the second screw hole are parallel to each other.
4. The cap member for a looseness detecting device for a fastener according to claim 1. 3. A cap member for a looseness detecting device for a fastener according to claim 1, wherein the cap member is formed of a resin material. 4. A cap member according to claim 1, comprising a sensor screwed into said second screw hole, and a nut for fixing said sensor. Looseness detector for fasteners. 5. A bolt is fitted into a through hole of a member to be fastened,
The first screw of the cap member in the looseness detecting device for a fastener according to claim 4, wherein one or two or more nuts are screwed into the bolt to establish a fixed state between the bolt, the member to be fastened, and the nut. A looseness detecting device for a fastener, wherein a tip of the bolt is screwed into a hole to establish a fixed state of the cap member, and a contact state or a distance between the tip of the sensor and the tip of the bolt is adjusted. Mounting method. 6. A case where a looseness detecting device for a fastener according to claim 4 and an output signal of the sensor are inputted, and the output signal indicates non-contact between the sensor and a bolt tip or a separation of a predetermined distance or more. Control means for outputting an alarm signal to
A loosening detection alarm system for fasteners, comprising: