U-bolt, detection device and detection method

Abstract

This U-bolt (1) comprises: a pair of shaft sections (111) which are arranged in a first direction and which extend in a second direction orthogonal to the first direction; and screw sections (12) which are provided to each of the pair of shaft sections (111) at at least one location on the vertex side and one location on the end side.

Description

[Technical field]

[0001] The present disclosure relates to U-bolts, detection devices and detection methods. [Background technology]

[0002] Conventionally, U-bolts are used to fix objects such as pipes to objects such as frames and walls. A U-bolt is a U-shaped bolt with two straight shafts connected by a bridge section. The shafts of the U-bolt are inserted into two through holes provided in the object to be fastened while the object to be fastened is sandwiched inside the U-bolt, and the two shafts are tightened with nuts from the ends of each of the two shafts, so that the object to be fastened can be sandwiched and fixed between the U-bolt and the object to be fastened. Figure 12 shows the structure when a U-bolt is used to fix an object to be fastened such as pipes to a fastened part. When a U-bolt is used to fix an object to be fastened such as pipes, the left and right nuts are tightened to fix the object to be fastened such as pipes to the fastened part. However, when the U-bolt is used outdoors for a long period of time, the nuts may loosen due to aging, causing the object to be fastened such as pipes to come off or the metal fittings of the object to be fastened to come off. Furthermore, when the nuts loosen, they may eventually come off the U-bolt and fall, causing an accident in which the nuts come into contact with people, automobiles, etc.

[0003] Non-Patent Document 1 describes research into the risk of road accessories such as lighting and signs breaking or falling due to aging, and initiatives to prevent accidents. Non-Patent Document 2 describes a performance evaluation of a super slit nut (SSN) equipped with a new anti-loosening mechanism. However, since anti-loosening nuts require accurate torque management and straight fixing to the fastened part, poor installation may occur in outdoor installation environments where the installation environment is unstable, which may reduce the effectiveness of the device. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Fumi Miyahara and 3 others, "Risk Assessment Method for Falling and Collapse of Nonstructural Road Components," Civil Engineering Technical Information 58-11, p.12-15, 2016 [Non-Patent Document 2] Satoshi Izumi and 7 others, "Functional Verification of Super Slit Nuts with Anti-Loosening Performance Using Finite Element Method," Transactions of the Japan Society of Mechanical Engineers (Series A), Vol. 71, No. 703 (March 2005) Summary of the Invention [Problem to be solved by the invention]

[0005] The purpose of this disclosure, made in consideration of such circumstances, is to provide a U-bolt that will not fall even if the nut connected to the U-bolt becomes loose, and a detection device and detection method for detecting the falling of the nut due to loosening of the nut. Note that in this specification, "nut falling" refers to the nut coming completely off the shaft, and "nut dropping" refers to the nut coming off the threaded portion on the apex side and getting caught on the threads of the threaded portion on the tip side. [Means for solving the problem]

[0006] In order to solve the above problems, the U-bolt disclosed herein is a U-bolt that fastens a fastener using a nut, and includes a pair of shanks aligned in a first direction and extending in a second direction perpendicular to the first direction, and each of the pair of shanks has a threaded portion provided at one location on the apex side and one or more locations on the tip side.

[0007] In order to solve the above problems, the detection device according to the present disclosure is a detection device that detects the descent of a nut coupled to a U-bolt that fastens a fastening object, and includes a U-bolt having a sensor that measures the distance to an object and a transmitter that transmits the measurement result by the sensor, a receiver that receives the measurement result transmitted from the transmitter, and A master unit having a control unit that determines whether the nut has dropped based on the measurement result, and an alert issuing unit that issues an alert when the control unit determines that the nut has dropped; Equipped with.

[0008] In order to solve the above problems, the detection method disclosed herein is a detection method for detecting the descent of a nut that is connected to a U-bolt that fastens a fastener, and includes the steps of measuring the distance to an object using a detection device, transmitting the measurement result, receiving the measurement result, determining whether or not the nut has descent based on the measurement result, and issuing an alert when it is determined that the nut has descent. Effect of the Invention

[0009] According to the present disclosure, it is possible to prevent the device from falling due to loosening of the nut. [Brief description of the drawings]

[0010] [Figure 1] 3A to 3C are diagrams illustrating an example of the configuration of a U-bolt according to the first embodiment. [Figure 2A] 2 shows a cross section of the threaded portion and the nut when the nut is tightened. [Figure 2B] 4 shows a cross section of the threaded portion and the nut when the nut is lowered. [Diagram 3] This is a cross-sectional view of a U-bolt in which a thread groove is provided at the apex of the threaded portion at the tip side so that it does not screw into the threads of the nut. [Figure 4A] A cross-sectional view of a U-bolt in which the start and end positions of the threads of adjacent threaded portions are aligned. [Figure 4B] This is a cross-sectional view of a U-bolt in which the start and end positions of the threads of adjacent screw portions are offset. [Diagram 5] This is a cross-sectional view of a U-bolt with three threaded portions on one side. [Figure 6] This is a cross-sectional view of a U-bolt that has a thread groove that does not screw into the threads of the nut, and the start and end positions of the threads of adjacent threaded portions are offset. [Figure 7] 13A and 13B are diagrams illustrating an example of the configuration of a U-bolt according to a second embodiment. [Figure 8] FIG. 13 is a diagram showing a structure in which a sensor is mounted by being embedded in a hole drilled in the shaft of a U-bolt. [Figure 9A] FIG. 13 is a schematic diagram showing a method for supplying power to a sensor via a wired cable. [Figure 9B] FIG. 13 is a schematic diagram showing a method of powering the sensor from a battery embedded in the stem. [Figure 10] FIG. 13 is a block diagram showing an example of the configuration of a detection device according to a third embodiment. [Figure 11] 13 is a flowchart showing an example of a detection method executed by a detection device according to a third embodiment. [Figure 12] This is a diagram showing the structure when piping is fixed with a U-bolt. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0012] (First embodiment) FIG. 1 is a diagram showing a configuration example of a U-bolt 1 according to a first embodiment of the present disclosure.

[0013] The U-bolt 1 according to this embodiment is made of a metal such as steel. As shown in Fig. 1, the U-bolt 1 includes a body portion 11 including a shaft portion 111A, a shaft portion 111B, and a bridge portion 112, and a threaded portion 12. The U-bolt 1 is a U-bolt that fastens a fastener 7 using a nut 4.

[0014] The shaft portion 111A and the shaft portion 111B are arranged in a first direction and extend in a direction perpendicular to the first direction. Hereinafter, as shown in FIG. 1, the direction in which the shaft portion 111A and the shaft portion 111B are arranged in a line is referred to as the X-axis direction (first direction), the direction in which the shaft portion 111A and the shaft portion 111B extend is referred to as the Y-axis direction (second direction), and the direction perpendicular to the X-axis direction and the Y-axis direction is referred to as the Z-axis direction (third direction). Hereinafter, the shaft portion 111A and the shaft portion 111B are collectively referred to as a pair of shaft portions 111. Hereinafter, when the shaft portion 111A and the shaft portion 111B are not distinguished from each other, they are referred to as the shaft portion 111.

[0015] The bridge portion 112 connects one end of each of the pair of shaft portions 111. The bridge portion 112 is configured to be symmetrical with respect to an imaginary straight line OY (hereinafter referred to as "imaginary line OY") extending in the Y-axis direction including the apex O of the U-shape formed by the U-bolt 1. The bridge portion 112 is provided at one end of each of the pair of shaft portions 111, and has a shape that is bent in a semicircular shape. Since the bridge portion 112 configured in this manner is provided at one end of the pair of shaft portions as described above, the U-bolt 1 forms a U-shape as a whole.

[0016] The screw portion 12 has a thread structure. The screw portion 12 is provided on each of the pair of shaft portions at one location on the apex side (the screw portion 121 on the apex side) and at one or more locations on the tip side (the screw portion 122 on the tip side). In FIG. 1, the screw portion 122 on the tip side is provided at one location.

[0017] As shown in FIG. 1, a fastening object 7 such as a pipe is placed inside the U-shaped U-bolt 1 (a space surrounded by a pair of shaft portions 111 and a bridge portion 112). With the fastening object 7 placed inside the U-bolt 1, the shaft portion 111A and the shaft portion 111B are inserted from one side of the fastening object 8 into a pair of through holes 5 provided in the fastening object 8 such as a support metal. By inserting the shaft portion 111A and the shaft portion 111B into the pair of through holes 5, respectively, the threaded portion 12 of each of the shaft portion 111A and the shaft portion 111B protrudes to the other side of the fastening object 8. The threaded portion 12 protruding from the other side of the fastening object 8 is tightened by a nut 4. The nuts 4 each have a thread that screws into the thread of the threaded portion 12. As a result, the fastening object 7 is sandwiched and fixed between the U-bolt 1 and the fastening object 8.

[0018] 2A and 2B show a structure that prevents the nut 4 from falling off by providing two threaded portions 12 of the U-bolt 1 on one side. In this specification, "dropping of the nut 4" refers to the nut 4 being completely removed from the shaft portion 111. FIG. 2A shows a cross section of the threaded portion 12 and the nut 4 when the nut 4 is fastened, and FIG. 2B shows a cross section of the threaded portion 12 and the nut 4 when the nut 4 is dropped. In this specification, "dropping of the nut 4" refers to the nut 4 being removed from the apex side threaded portion 121 and being caught on the threads of the tip side threaded portion 122 and being stopped. By providing two threaded portions 12 of the U-bolt 1 on one side, when the nut 4 loosens, it stops at the boundary portion 123 of the threaded portion, preventing the nut 4 from falling off. In this specification, "boundary portion 123 of the threaded portion" refers to the portion between the apex side threaded portion 121 and the tip side threaded portion 122, or between multiple tip side shaft portions 122. 2B(a), when the male thread of the threaded portion 122 on the tip side comes into contact with the female thread of the nut 4, the descent of the nut 4 stops. In order to ensure the fastening force of the nut 4, it is desirable to ensure that one thread has three or more turns of the thread.

[0019] 3 is a cross-sectional view of a U-bolt in which a thread groove that does not screw into the thread of a nut is provided on the apex side of the thread on the tip side. The thread groove 132 that does not screw into is cut by providing a notch only on the top surface 142 of the thread, so that the thread apex 141 remains. By providing the thread groove 132 that does not screw into, the nut 4 that has descended from the thread portion 121 on the apex side gets caught on the thread of the thread portion 122 on the tip side, and the nut 4 does not rotate any further, so the descent of the nut 4 stops.

[0020] FIG. 4A is a cross-sectional view of a U-bolt in which the start and end positions of the threads of adjacent threaded portions are aligned. FIG. 4B is a cross-sectional view of a U-bolt in which the start and end positions of the threads of adjacent threaded portions are offset. As shown in FIG. 4B, the start and end positions of the threads are offset by the distance between vertical lines a and b (i.e., the start and end positions of the threads of adjacent threaded portions 12 are not continuous when viewed from the Y-axis direction). On the other hand, as shown in FIG. 4A, if the start and end positions of the threads of adjacent threaded portions 12 are aligned along the vertical line a (i.e., the start and end positions of the threads of adjacent threaded portions 12 are continuous when viewed from the Y-axis direction), the nut 4 that has descended from the apex side may enter the threaded portion 122 on the tip side, and may eventually fall off as the nut 4 rotates. Therefore, as shown in FIG. 4B, by offsetting the start and end positions of the threads of adjacent threaded portions 12, the nut 4 is prevented from entering the threaded portion 122 on the tip side and falling off.

[0021] FIG. 5 is a cross-sectional view of a U-bolt in which threaded portions are provided at three or more locations on each of a pair of shaft portions. By providing three or more threaded portions 12 of the U-bolt 1 on one side, it is possible to prevent the nut 4 from falling and to extend the time until the nut 4 falls when it is loosened. In order to ensure the fastening force of the nut 4, it is desirable to ensure that the number of turns of the thread is three or more in one threaded portion. Also, FIG. 6 is a cross-sectional view of a U-bolt in which a thread groove that does not screw with the thread of the nut is provided, and the start and end positions of the thread of the adjacent threaded portions are shifted. As shown in FIG. 6, by shifting the start and end positions of the thread of the adjacent threaded portions, it is possible to reduce the possibility that the nut 4 that has been lowered again will rotate and fall. Furthermore, as shown in FIG. 6, by providing a thread groove 132 that does not screw with the thread of the nut 4, it is possible to stop the nut 4 from falling.

[0022] In this way, the U-bolt 1 according to the present disclosure has one threaded portion at the apex side and one or more threaded portions at the tip side of each of the pair of shaft portions 111. Therefore, the U-bolt 1 can be prevented from falling due to the nut 4 loosening.

[0023] Second embodiment FIG. 7 is a diagram showing a configuration example of a U-bolt 2 according to the second embodiment of the present disclosure.

[0024] The U-bolt 2 according to this embodiment is made of a metal such as steel. As shown in Fig. 7, the U-bolt 2 includes a main body 11 including shaft portions 111A and 111B and a bridge portion 112, a threaded portion 12, and sensors 15A and 15B. The U-bolt 2 according to this embodiment differs from the U-bolt 1 according to the first embodiment in that it further includes sensors 15A and 15B. The same components as those in the first embodiment are given the same reference numbers as those in the first embodiment, and descriptions thereof will be omitted as appropriate.

[0025] FIG. 8 is a diagram showing a structure in which a sensor is embedded and mounted in a hole opened in the U-bolt shaft. As shown in FIG. 8, the U-bolt 2 further includes a sensor 15 that is fixed to the inside of a hole 16 opened in a boundary portion 123 between adjacent threaded portions and measures a distance to an object located in the X-axis direction (first direction). In order to prevent the sensor 15 from falling off the hole 16, a stopper stp may be provided on the outer periphery of the hole 16. The stopper stp is provided by welding the same metal material as the metal constituting the shaft portion to the outer periphery of the hole 16 opened in the shaft portion. In addition, even if the stopper stp is not provided, the sensor 15 can be prevented from falling by filling the inside of the hole 16 with a resin such as an adhesive and fixing the sensor 15. In the following, when the sensor 15A and the sensor 15B are not distinguished from each other, they will be referred to as the sensor 15. In the following, the sensor 15A and the sensor 15B will be collectively referred to as a pair of sensors 15.

[0026] By mounting the sensor 15, it becomes possible to detect the descent of the nut 4 from the apex side. When the nut 4 that has descended from the apex side stops on the threaded portion 122 on the tip side, the sensor 15 reacts and detects that the nut 4 has descended. It is desirable to drill the hole 16 at a position closer to the tip side than the center of the boundary portion 123 of the threaded portion (the position of the dashed line OX). This is to make it easier for the sensor 15 to detect the nut 4 when the nut 4 descends and gets caught on the thread of the threaded portion 122 on the tip side, stopping its descent.

[0027] If a foreign object such as dead leaves adheres to the hole 16 that houses the sensor 15, the sensor 15 may erroneously detect that the nut 4 has been lowered. Therefore, as shown in Fig. 7, the sensors 15A and 15B are embedded in the boundary portion 123 of the threaded portions of both shafts in opposing directions. This allows the sensors 15A and 15B to determine whether the nut 4 has been lowered or whether a foreign object has adhered to the other sensor 15.

[0028] The sensor 15 is a sensor that measures the distance to an object by irradiating the object with ultrasonic waves, infrared rays, lasers, etc. FIG. 9A is a schematic diagram showing a method of supplying power to the sensor via a wired cable. FIG. 9B is a schematic diagram showing a method of supplying power to the sensor from a battery embedded in the shaft. Since the sensor 15 needs power supply, it is supplied with power by utilizing a method of supplying power from the outside via a wired cable c shown in FIG. 9A, a method of supplying power from a battery 18 embedded in the shaft shown in FIG. 9B, etc. Due to the structure of the U-bolt 2, power can be supplied from both the tip side and the apex side, and since the minimum outer diameter of commercially available standardized batteries is 7.9 mm, it is preferable that the diameter of the U-bolt 2 is 10 mm or more.

[0029] In this manner, the U-bolt 2 according to the present disclosure further includes a sensor 15 that detects the descent of the nut 4. Therefore, the U-bolt 2 can prevent the nut 4 from falling due to loosening, and can detect the descent of the nut 4.

[0030] (Third embodiment) FIG. 10 is a block diagram showing a configuration example of a detection device according to a third embodiment. As shown in FIG. 10, a detection device 20 according to a third embodiment includes a parent unit 30 having a receiving unit 31, a control unit 32, and an alert issuing unit 33, and a U-bolt 3 having a sensor 15 and a transmitting unit 34. The detection device 20 detects the descent of a nut coupled to a U-bolt fastened to a fastening object. The sensor 15 related to the U-bolt 3 may be the same as the sensor 15 according to the second embodiment. The detection device 20 may be composed of one parent unit 30 and multiple U-bolts 3. The same configurations as those in the second embodiment are given the same reference numbers as those in the second embodiment, and the description will be omitted as appropriate.

[0031] The master unit 30 determines whether the nut 4 has dropped based on the measurement result (the distance from the sensor 15 to the object) transmitted from the U-bolt 3, and issues an alert if it determines that the nut 4 has dropped.

[0032] The receiver 31 receives the measurement results transmitted from the transmitter of the U-bolt 3. The receiver 31 outputs the transmission results to the controller 32. The transmission of the measurement results from the transmitter 34 of the U-bolt 3 to the receiver 31 of the parent unit 30 may be performed by wired communication, wireless communication such as Wi-Fi, or a combination of these.

[0033] The control unit 32 judges whether the nut 4 has dropped based on the measurement result input from the receiving unit 21. When the control unit 32 judges that the nut 4 has dropped, it outputs the judgment result to the alert issuing unit 33. The control unit 32 can judge the case where only one nut 4A has dropped, the case where only the other nut 4B has dropped, the case where both nuts 4A and 4B have dropped, and the case where foreign matter is attached to both sensors 15A and 15B and measurement is impossible, and output the judgment result to the alert issuing unit 33. When the control unit 32 judges that the nut 4A or 4B has dropped or that no foreign matter is attached to both sensors 15A and 15B, it continues judging the measurement result.

[0034] When the control unit 32 determines that the nut is dropping, the alert issuing unit 33 receives the determination result that the nut 4 is dropping from the control unit 32 and issues an alert. The alert issuing unit 33 issues an alert A when only the nut 4A is dropping, and an alert B when only the other nut 4B is dropping. In addition, when both nuts 4A and 4B are dropping and when foreign matter is attached to both sensors 15A and 15B and measurement is impossible, an alert C is issued.

[0035] The U-bolt 3 transmits the measurement result of the sensor 15 measuring the distance to the object to the parent unit 30.

[0036] The transmitting unit 34 transmits the measurement results obtained by the sensor 15 to the receiving unit 31 of the parent device 30 .

[0037] (Detection method) FIG. 11 is a flowchart showing an example of a detection method executed by the detection device 20 according to the third embodiment.

[0038] In step S10, sensor 15A of U-bolt 3 measures the distance from sensor 15A to the object, and sensor 15B measures the distance from sensor 15B to the object.

[0039] In step S20, the transmitter 34 of the U-bolt 3 transmits the measurement result to the receiver 31 of the parent unit 30.

[0040] In step S30, the receiving unit 31 of the parent device 30 receives the measurement result and outputs it to the control unit 32.

[0041] In step S40, the control unit 32 of the parent unit 30 determines whether the nut 4A (the nut on the A side) is lowered. If the nut 4A is not lowered, the process proceeds to S50. If the nut 4A is lowered, the process proceeds to S60.

[0042] In step S50, the control unit 32 of the parent unit 30 determines whether the nut 4B (the nut on the B side) has descended. If the nut 4B has descended, the process proceeds to S80. If the nut 4B has not descended, the process returns to S10 and measurement continues.

[0043] In step S60, the control unit 32 of the parent unit 30 determines whether the nut 4B is lowered. If the nut 4B is not lowered, the process proceeds to S70. If the nut 4B is lowered, the process proceeds to S90.

[0044] In step S70, the alert issuing unit 33 of the master unit 30 issues an alert A in response to the descent of the nut 4A.

[0045] In step S80, the alert issuing unit 33 of the master unit 30 issues an alert B in response to the descent of the nut 4B.

[0046] In step S90, the alert issuing unit 33 of the master unit 30 issues an alert C due to the descent of nuts 4A and 4B or the attachment of foreign matter to both sensors 15A and 15B.

[0047] Thus, the detection device 20 according to the present disclosure includes a U-bolt 3 equipped with a sensor 15 that detects the descent of the nut 4, and a parent unit 30 that determines whether the nut 4 has been descent and issues an alert when the nut 4 has been descent. Therefore, the detection device 20 can detect the descent of the nut 4 due to loosening and issue an alert, thereby notifying the worker of the descent of the nut 4, etc.

[0048] Although the above-mentioned embodiment has been described as a representative example, it is obvious to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be interpreted as being limited by the above-mentioned embodiment, and various modifications or changes are possible without departing from the scope of the claims. [Explanation of symbols]

[0049] 1,2,3 U-bolt 4,4A,4B Nut 5 Through hole 6 Washer 7. Contracts 8 Object to be fastened 11 Main body 111,111A,111B Shaft part 112 Bridge Section 12 Threaded part 121 Threaded part on the apex side 122 Threaded part at the tip 123 Boundary of thread 13 Thread groove 131 Thread groove that mates with the nut thread 132 Thread groove that does not engage with the nut thread 14 Threads 141 Top of the Thread 142 Thread top 143 Underside of thread 15, 15A, 15B Sensor 16 Drilled Hole 17 Batteries 20 Detection Device 30 Parent Unit 31 Receiving section 32 Control section 33 Alert Issue Department 34 Transmitter

Claims

1. A U-bolt that fastens objects using a nut, A pair of shaft portions aligned in a first direction and extending in a second direction perpendicular to the first direction; Each of the pair of shaft portions has a threaded portion provided at one location on the apex side and at one or more locations on the tip side; a sensor that is fixed to the inside of a hole formed at a boundary between adjacent threaded portions and that measures a distance to an object located in the first direction; A U-bolt equipped with

2. The threaded portion at the tip end is provided with a thread groove that does not screw into the thread of the nut, 2. The U-bolt according to claim 1, wherein the non-threaded groove is provided on the apex side of the threaded portion on the tip side.

3. The U-bolt according to claim 1 or 2, wherein the start and end positions of the threads of adjacent threaded portions are offset from each other.

4. A U-bolt according to any one of claims 1 to 3, further comprising a transmitter for transmitting a measurement result by the sensor; a receiving unit that receives the measurement result transmitted from the transmitting unit; A control unit that determines whether the nut has dropped or not based on the measurement result; A parent unit having an alert issuing unit that issues an alert when the control unit determines that the nut is lowered; A detection device comprising:

5. A step in which a U-bolt according to any one of claims 1 to 3 transmits a measurement result of the distance; A step of a parent device receiving the measurement result; A step in which the parent machine determines whether or not the nut has dropped based on the measurement result; When it is determined that the nut is lowered, the parent unit issues an alert; A detection method comprising:

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