JPH0611454Y2 - Bolt looseness detector - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a bolt looseness detection device for detecting looseness of a bolt of a steel structure such as a bridge.

[Prior art]

For example, steel structures such as bridges are fastened and assembled using a large number of bolts. At the time of assembling or completing this steel structure, or when a certain period of time has passed, it is necessary to inspect the looseness of bolts to confirm the stability of the structure.

In general, as a bolt looseness inspection method, a method of hitting the head or nut of the bolt with a hammer for hitting inspection and making a judgment by a person by the hitting at that time is used. However, this method often depends on the "intuition" of the person, and as a result, there are large individual differences, and not only a skilled person can make an accurate judgment, but also a small amount of looseness makes it impossible to make an accurate judgment. There was a problem that even a skilled person would make a different judgment.

From this, the present inventor, as a result of diligent study on loosening detection of bolts, hits the hexagonal planes of bolts and nuts in the shearing direction with a hammer having a force and / or acceleration sensor, and An acceleration sensor is attached to a flat surface facing the striking surface, and a method or device for detecting looseness of a bolt based on this force and / or a ratio of the force detected by the acceleration sensor and the acceleration detected by the acceleration sensor is previously proposed. (Japanese Patent Application No. 62-252552).

[Problems to be solved by the device]

However, in the bolt looseness detection method described above, the acceleration sensor is directly bonded to the bolt and nut, so not only does it take a lot of time to install and remove it, but also to prevent corrosion and corrosion of the bolt and nut. When the above paint is applied, it may be peeled off, in which case there is a problem that the repair is required.

[Means for Solving the Problems]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a fixing portion for engaging a nut or a bolt head is provided at the tip of the main body, and the fixing portion is arranged on the side of the fixing portion. Alternatively, a hammer is provided which strikes the hexagonal plane of the bolt head, a force and / or acceleration sensor is attached to the hammer, and an acceleration sensor is attached to the surface of the hexagonal plane of the nut or bolt facing the striking surface. Is a device for detecting looseness of a bolt, which is arranged so as to be pressed by an elastic body.

[Action]

According to the bolt loosening detection device as described above, the acceleration sensor is attached to the hexagonal plane of the bolt / nut through the material, and the material is always pulled by the elastic body to the hexagonal plane side of the bolt / nut. Since it is set,
It is easy to remove, and there is no risk of paint peeling.

〔Example〕

An embodiment of a bolt looseness detecting device according to the present invention will be described below with reference to FIGS. 1 to 16.

FIGS. 1 to 4 show a first embodiment of a bolt looseness detecting device, FIG. 1 is a side view thereof, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 2 is a view taken along the line III-III in FIG. 2, and FIG. 4 is a sectional view taken along the line IV-IV in FIG.

The bolt looseness detecting device is composed of a main body 1, an arm 2 pivotally supported at one end of the main body 1, and a fixing portion 3 that engages with the heads of bolts and nuts 19.

Specifically, a motor 6 with a reduction gear is attached to the main body 1 with a bolt 4 via an attachment member 5.
Thus, the cam 7 is rotated about the shaft 8. The cam 7 is configured to come into contact with a pressing member 9 to be described later and to push down the arm 2 against the spring force of the spring 10.

A tubular body 11 is attached to the upper surface of the main body 1, and the tubular body 11
A tension spring 10 is arranged between a lower end of a screw shaft 12 provided at the top of the and a mounting piece 13 provided at a lower part of the tubular body 11. A wing nut 14 is screwed onto the screw shaft 12, and by rotating the wing nut 14, the spring force of the spring 10 can be adjusted.

A long hole 15 is opened at the lower end of the mounting piece 13, and a pin 16 provided on the arm 2 is fitted in the long hole 15. That is,
Immediately before the hammer 17 described later hits the hexagonal plane of the bolt / nut 19, the stopper 18 contacts the lower end of the tubular body 11, and the arm 2 is not directly pulled by the spring 10.
The hammer 17 hits the head of the bolt / nut 19 in a free state. As a result, a good pulse waveform can be obtained.

As shown in FIG. 2, the fixing portion 3 attached to the tip of the main body 1 is configured to be sandwiched by two V-shaped fitting portions on both sides of the hexagonal plane of the bolt / nut 19. And open parts 20 and 21 are provided at the top and bottom.

A second member 23 having an acceleration sensor 22 is arranged in the upper open portion 20, and a hitting portion projection is provided in the lower open portion 21.
First strips 25 having 24 are respectively arranged, and the first strips 25 and the second strips 23 are attached to the mounting portion of the fixing portion 3.
The tension spring 27 that penetrates the hole formed in the
It is configured to repress integrally.

Specifically, the distance between the first contact member 25 and the second contact member 23 is arranged to be slightly smaller than the interval between the parallel portions of the hexagonal parts of the bolt / nut 19 which are opposed to each other. 25 of 1
A tension spring 27 is provided in a tensioned state between the first and second members 23 and 23 and presses the two surfaces of the bolt and nut 19 so as to hold them.

In addition, 28 is a stopper attached to the rear side surface of the fixed portion 3 by a screw 29, and this stopper 28 is the fixed portion 3
When the hexagonal part of the bolt / nut 19 is inserted inside, it functions to determine the position in the depth direction.

The second member 25 provided so as to cover the opening 21 is a hammer 17
Therefore, a hard material such as a steel plate is used for this purpose.

A grip portion 31 is attached to the lower portion of the main body 1 so that the fixing portion 3 can be accurately fitted into the bolt / nut 19. A pressing member 9 that abuts the cam 7 with a bolt 32 is attached to the arm 2, and a force sensor 33 is attached to the tip of the pressing member 9.
A hammer 17 having is provided.

In the above structure, when the looseness of the bolt / nut 19 is detected now, the hexagonal portion of the bolt / nut 19 is fitted into the fixing portion 3 having a hexagonal opening. At this time, the first strip 25 and the second strip 23 move slightly outward against the spring force of the tension spring 27, so that the first strip 25 and the second strip 23 are separated from each other. Both of them elastically contact the hexagonal plane of the bolt / nut 19.

After that, when the motor 6 is operated and the cam 7 is rotated in the direction of arrow e shown in FIG. 1, the pressing member 9 attached to the arm 2 is moved downward against the spring force of the spring 10, that is, When the arm 2 is pushed downward from the position indicated by the solid line and reaches the chain double-dashed line, the pressing member 9 is disengaged from the corner of the cam 7, and the spring force of the spring 10 causes the arm 2 to be instantaneously pulled up and attached to the tip of the arm 2. The hammer 17 hits the projection 24 provided on the first contact member 25.

At this time, the force and the acceleration detected by the force sensor 33 provided on the hammer 17 and the acceleration detected by the acceleration sensor 22 provided on the second contact member 23 are amplified by an amplifier using the peak values as signals. Then, the peak value is detected by the peak detector, introduced into the calculation unit, and the ratio of the two is calculated by this, and the result is detected by a number or displayed on the display unit or the like for detection.

Since the acceleration of the hammer 17 is proportional to the force detected by the force sensor 33, the force can be detected by attaching an acceleration sensor instead of the force sensor 33.

5 to 16 show a second embodiment of the fixing portion 3 of the bolt / nut looseness detecting device.

This fixed part 3 is a flange attached to the tip of the main body 1.
A base 36 attached to the bolt 34 by a bolt 35 and a second pad 37. More specifically, a flange 34 is attached to the tip of the main body 1 as shown in FIGS. 8 and 9.

As shown in FIGS. 10 to 12, the base 36 has a vertical member 41 having a notch 38 in the center and a screw hole 39 and a bolt hole 40, an upper horizontal member 42, and a lower horizontal member 43. Eye plate 44 and bolts and nuts attached to the lower horizontal member 43
It consists of 19 hexagonal lower locating seats 45.

Then, the lengths of the upper horizontal member 42 and the lower horizontal member 43 are determined so that the tips of the upper and lower horizontal members 42 and 43 come into contact with the side surfaces of the structure 60 when the heads of the bolts and nuts 19 are fitted to the fixing unit 3. The upper horizontal member 42 and the lower horizontal member 43 form a contact member that contacts the side surface of the structure 60. In particular, as shown in FIG. 6, a first contact member 46 that bends toward the insertion side of the bolt / nut 19 is attached to the lower portion of the base 36 by a bolt 47 (see FIG. 5). The upper positioning seat 49 for positioning the hexagonal portion of the bolt / nut 19 shown in FIGS. 14 and 15 penetrates the bolt 50 into the bolt hole 40 of the flange 34 and the base 36, and further screws of the upper positioning seat 49. The bolt 50 is screwed into the hole and attached. The upper positioning seat 49 is formed integrally with the connecting member 51, and the recess 48 is formed.

As shown in FIGS. 15 and 16, the second member 37 is provided with an eye plate 52 in the lower portion, the acceleration sensor 22 is attached in the central portion, and a recess 48 provided in the upper positioning seat 49. (See FIG. 14), and a tension spring 54 is arranged between the eye plate 52 of the second contact member 37 and the eye plate 44 provided on the base member 36.

In the bolt / nut detecting device having the fixing portion 3 configured as described above, the fixing portion 3 is moved axially in the hexagonal portion of the head of the bolt / nut 19 and fitted therein, After that, as in the first embodiment, the hammer 17 strikes the hexagonal plane of the bolt / nut 19 in the shearing direction from above the first contact member 46, and the hammer 17 is provided with a force generated by the striking force. With the force sensor 33, the acceleration is
Detected by the acceleration 22 provided in 37, the detected force and acceleration are amplified by an amplifier with the peak value as a signal,
The peak value is detected by a peak detector, introduced into a calculation unit, the ratio of the two is calculated by this, and detected by a number or by displaying it on a display unit or the like.

[Effect of device]

As is apparent from the above description, according to the bolt looseness detection device of the present invention, a force sensor is provided on a hammer that strikes the hexagonal plane of a bolt / nut in the shearing direction of the bolt / nut, and the striking surface is opposed to the hammer. It is characterized in that the second member having the acceleration sensor is attached to the hexagonal plane of the bolt / nut so as to be pressed by an elastic body such as a spring, and the following effects can be obtained.

That is, since the material on which the acceleration sensor is attached is attached to the flat surface of the hexagonal portion of the bolt / nut by the elastic body, the work of attaching / detaching the acceleration sensor is extremely easy, and the coating film on the surface of the bolt / nut is removed. It is not peeled off, and therefore complicated work such as repair work is eliminated. This is especially true for large numbers of bolts
This is effective when detecting loose nuts.

[Brief description of drawings]

1 to 16 show an embodiment of a bolt looseness detecting method and device according to the present invention, which are shown in FIGS.
1 is a side view of FIG. 1, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is III- of FIG. FIG. 4 is a sectional view taken along the line IV-IV of FIG. 5 to 16 are explanatory views of a second embodiment of the looseness detecting device for bolts and nuts, and FIG. 5 is a front view of a fixing portion,
FIG. 6 is a side view thereof, and FIG. 7 is a plan view thereof. 8 is a side view of the tip of the main body, FIG. 9 is a front view of the same, and FIG.
FIG. 11 is a front view of the base body, FIG. 11 is a side view of the same, and FIG. 12 is a plan view of the same. FIG. 13 is a front view of the upper positioning seat, FIG. 14 is a side view, and FIG.
FIG. 16 is a front view of the second material, and FIG. 16 is a front view thereof. 1 …… Main body, 17 …… Hammer 19 …… Bolt / nut hexagonal part 22 …… Accelerometer, 23 …… Second material 25 …… First material, 46 …… First material 27… … Tension spring, 33 …… Force sensor 36 …… Base, 37 …… Movable material 41 …… Vertical material, 42 …… Upper horizontal material 43 …… Lower horizontal material, 45 …… Upper positioning seat 46 …… First This material, 49 …… Upper positioning seat 53 …… Accelerometer, 55 …… Force sensor.

Claims (1)

[Scope of utility model registration request] 1. A fixing portion for engaging with a nut or bolt head is provided at a tip of a main body, and a hammer is provided on a side of the fixing portion and hits a hexagonal plane of the nut or bolt head. A force and / or acceleration sensor is attached to the hammer, and the material having the acceleration sensor attached to the surface of the hexagonal plane of the nut or bolt head opposite to the striking surface is arranged to be pressed by an elastic body. Bolt looseness detection device.