JP2014225075A - Intelligent fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a threaded fastener having an intellectual characteristic and to provide a new advantage for the mounting and the tracking monitoring of a structure mutually fastened using the threaded fastener.SOLUTION: An intelligent fastener having a head and a threaded shank with a male-screw for engaging with a structural component is provided. The head has a recess formed on upper surface thereof for mounting an RFID tag having a memory including information unique to a fastener such as an identification code of the fastener, a designated torque value, and other information, an antenna for enabling two-way communication with an RFID tag reader, and a torque value sensor for measuring torque applied to the faster by a fastener mounting tool. When fasteners are mounted, the RFID tag reader is used to measure the existing torque on a group of fasteners and scan information stored in the memory of each fastener.

Description

  The present invention relates to a threaded fastener. More specifically, the present invention relates to industrial threaded fasteners having intelligent properties.

  Threaded fasteners have been used for a long time to fasten countless types of machine parts together. Some examples of different types of mechanical parts that are fastened together by threaded fasteners include structural members such as bridge girders, support beams in buildings, and aircraft structural members. Normally, during installation, each threaded fastener is inserted into the opening of the part to be captured, and the designation of the mating part, such as a nut fixed to this mating part or a threaded opening formed in this mating part, is specified. Screw into the part. In many applications, each fastener must be tightened with a screw to a specified amount of torque within a narrow specified tolerance range. Typically, this specified tolerance is part of a specification created for a given project and can be used in document form or on a portable computer that can be carried to the field (flash drive or other computer). Provided in electronic form (stored in a readable memory or the like). Typically, both manual torque wrenches and electric torque tools are used to tighten fasteners to values within a specified torque range. Normally, the installer must tighten the fastener after referring to the specifications to determine the correct allowable torque value range. The installer manually creates a record of each installed fastener for each installation location and torque value and submits such records to an inspector or other person or office responsible for maintaining project data. Ideally. However, this is not always done.

  In many projects, it is necessary to check whether the installed fasteners have the correct torque values immediately after installation and periodically thereafter to ensure the safety of the entire structural assembly. This inspection and check must be performed by a qualified person (usually a trained inspector) who has a certified copy of the official specification, and the inspector usually attaches a torque wrench to each attached fastener. It is performed manually by applying an electric torque tool or a torque measuring device. Also, inspectors typically conduct visual surveys to determine if any fasteners are missing. The results of these inspections and checks must be reported to the designated person or office that maintains the inspection records for future reference.

US Patent Application Publication No. 2007/0222583

  This inspection process must be done manually and visually for each individual fastener, which is very time consuming and fails to accurately apply the correct torque specifications to one or more fasteners. It is prone to human error, such as failing to accurately measure torque for a given fastener, or failing to signal that a fastener is not present at a specified fastener location. Further, as described above, the first fastener installation record is not always created, and the person in charge of maintaining and managing the integrity and safety of the fastening structure is inconvenienced.

  The present invention provides unprecedented advantages for threaded fasteners with intelligent properties that facilitate fastener installation and tracking checks, and for mounting and tracking monitoring of structures that are fastened together using threaded fasteners. An intelligent fastener system and method.

  Viewed from an individual device perspective, the present invention includes an intelligent fastener that includes a body member having a head portion and a male threaded shank portion extending from the head portion, the head portion comprising a lower surface, There is a through hole formed through the top surface and the head portion, and a recess is formed in the top surface. The intelligent fastener is mounted in the recess, and the RFID tag is mounted in the recess. And a sensor having a body portion mounted in the recess and coupled to the RFID tag, wherein the sensor has an arm portion extending away from the sensor body portion and terminating at an end portion. This arm part is slidably received in the through hole, and the end part of the arm part is inserted into the opening part of the workpiece with the opening part. When extending downwardly from the lower surface so as to contact the surface of the workpiece.

  The RFID tag has a memory that stores fastener-specific information such as a unique identification code, the specified torque value of the fastener, the installation date, the location where the fastener was installed, the first installation date, and the most recent inspection date of the fastener. Have.

  In a preferred embodiment, the sensor comprises a two-state microswitch that provides a binary torque state signal.

From a system point of view, the present invention is a fastener mounting and inspection system that includes:
A fastener having a main body member including a head portion and a male threaded shank portion extending from the head portion, the head portion having a bottom surface, a top surface, and a through hole formed through the head portion, This fastener mounting and inspection system includes an RFID tag having a memory for storing fastener-specific information mounted in the recess, and an antenna mounted in the recess and coupled to the RFID tag. And a sensor coupled to the RFID tag, the sensor having an arm portion that extends away from the sensor body portion and terminates at an end portion. Part is slidably received in the through-hole, and the end of the arm part is in contact with the surface of the workpiece when the fastener is inserted into the opening of the workpiece with the opening. It extends below the lower surface to so that,
An RFID tag reader is further provided for calling the RFID tag and receiving information from the RFID tag.

  The information stored in the RFID tag memory includes the fastener's unique identification code, the fastener's specified torque value, the fastener's first installation date, the location where the fastener was installed, and the fastener's last inspection date. The information stored in the RFID tag memory can be updated at an appropriate time using an RFID tag reader, and the updated information can be transmitted to the RFID tag.

  The sensor preferably comprises a two-state microswitch for sensing the torque condition of the fastener.

  The system further includes a fastener installation tool for screwing the fastener into the threaded opening to a specific torque value. For this purpose, the fastener mounting tool comprises a torque control unit coupled to the RFID tag reader for limiting the torque applied to the fastener by the fastener mounting tool.

  Fasteners made according to the present invention offer several advantages over known threaded fasteners. First, it is very easy to first install the fastener to the correct torque specification by providing the correct torque information in the fastener's RFID tag that can be extracted by the mounting tool when the installer is ready to install the fastener. become. The attachment tool can also automatically drive the fastener to the correct torque value and immediately check the torque value after attaching the fastener to ensure that the fastener is correctly attached. In addition, scan inspection techniques can be used to quickly check the integrity of a set of fasteners at any time, and the installation tool can be used to take any necessary corrective action. In addition, this scan inspection technique eliminates the need to manually check the current value of each attached fastener, greatly reducing the time required to perform the inspection process. In addition, the fastener identification code, type, specified torque value, installation location, installation date, and inspection date information are provided in the fastener in a form that can be read by the associated tag reader for future maintenance. A complete history of fastener installation projects can be collected and stored on the host computer. Finally, all these benefits come at a relatively low additional cost per fastener.

  For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken together with the accompanying figures.

1 is a perspective view of a preferred embodiment of a threaded fastener having intellectual properties and incorporating the present invention. FIG. FIG. 3 is a top view showing the orientation of intelligent components of the fastener of FIG. 1. FIG. 2 is a schematic diagram showing intelligent components of the fastener of FIG. 1. FIG. 2 is a side view in which the fastener of FIG. 1 is partially sectioned, with a threaded shaft inserted through an opening of a capture structural member and the threaded shaft threaded onto a mating thread portion of another structural member. It is the schematic of the electric fastener attachment tool used in fastener attachment and torque adjustment. FIG. 2 is a block diagram illustrating an initial attachment process of the fastener of FIG. 1. It is a schematic diagram showing a plurality of attached fasteners and a scan inspection process.

  Referring now to the drawings, FIGS. 1 and 2 show a single fastener according to the present invention. As can be seen from these figures, the fastener, generally designated by reference numeral 10, has a head 12 and a threaded shank 13 that terminates at a free end 14. The fastener head 12 has a central recess defined by a recessed top surface 15 and a boundary wall 16 that is deep enough to accommodate the RFID chip 17, the antenna 18, and the upper body portion 19 of the microswitch 20. And has a boundary dimension. Elements 17, 18 and 19 are all supported by the recessed upper surface 15 of the head 12. The remainder of the microswitch 20 includes a switch activation arm 22 that extends downward through a through hole 23 formed in the head 12 and terminates at a free end 23. The free end 23 of the switch activation arm 22 terminates below the lower surface 24 (shown in FIG. 4) of the head 12 by a predetermined level for the purpose described below. The relative diameter dimensions of the through hole 23 and the switch activation arm 22 are selected so that the switch activation arm 22 can slidably reciprocate within the through hole 23.

  Referring to FIG. 3, the components that provide the intelligent characteristics of fastener 10 include microswitch 20, RFID chip 17, and antenna 18. RFID chip 17 is a conventional RFID chip, commonly referred to in the art as an RFID tag, and is bi-directional with an associated RFID tag reader via antenna 18 commercially available from Atmel, Inc., San Jose, California. It is preferably an Atmel type ATA5570 integrated circuit incorporating the usual components necessary to enable communication. The RFID chip 17 further includes a read / write memory section that stores some information about the fastener 10 and allows this information to be retrieved in response to a call by an associated RFID tag reader. This type of information is described in more detail below. The RFID chip 17 also incorporates a power transfer circuit component necessary to supply power to the integrated circuit component from an electromagnetic calling signal received via an antenna 18 from an associated RFID tag reader. Such components are well known and will not be further described to avoid redundancy.

  The microswitch 20 has two conductors 26 and 27 (shown in FIGS. 2 and 3) coupled to the data input of the RFID chip 17. This allows the RFID chip to monitor the binary state of the microswitch 20, i.e., either closed or open. In the preferred embodiment, the microswitch 20 functions as a binary torque value sensor for sensing whether the fastener 10 is tightened to the correct torque value.

  FIG. 4 shows a fastener partially attached to two structural members incorporating the present invention. In this figure, elements 17, 18 and 20 are indicated by phantom lines. As can be seen from this figure, the threaded shaft 13 is inserted into the opening 31 of the first structural member 30 to be captured and is also screwed into the threaded portion 33 of another structural member 34. . In a sufficiently thick structural member 34, the threaded portion 33 of the structural member 34 can have a threaded opening formed in the structural member 34 as shown, or on the opposite surface of the structural member 34 (weld (E.g.) can have a separate threaded nut permanently secured. In any case, the purpose of the threaded portion 33 is to give an appropriate amount of tightening force between the first structural member 30 and the additional structural member 34 when the fastener 10 is screwed sufficiently deep. .

  As described above, the fastener 10 must be tightened to a torque value that is typically within a narrow range defined by the project specifications. The fastener 10 is in the state of the microswitch 20 when the free end 23 of the arm 22 of the microswitch 20 is engaged with the upper surface 35 of the structural member 30 and driven to the upper calibration position in FIG. (Closed or opened by parameter). This change in state can be detected by the RFID chip 17 and stored in memory for later use. The fastener torque value can be checked after the fastener 10 is installed by calling the RFID tag 17 with the associated RFID tag reader. When the torque is below the lower limit value defined in the specification, the axial position of the micro switch arm 22 is sufficiently changed so that the state of the micro switch 20 returns to a state outside the torque range. This change in switch state can be detected by the RFID tag 17, stored in memory, and sent to the associated RFID tag reader when called.

  FIG. 5 is a schematic diagram of an electric fastener installation tool, indicated by reference numeral 40, used when initially installing the fastener 10 and later adjusting the fastener 10 to the correct torque. As can be seen from this figure, the tool 40 is used for tightening the fastener 10, a real-time clock 41 for providing real-time attachment information, an RFID tag reader 42 for reading information from the RFID tag 17 of the fastener to be attached, and the fastener 10. It is preferable to include a driver unit 43 for applying a driving force to the driver bit 44 and a torque control unit 45 for controlling the driver unit 43 to tighten the fastener 10 to a specified torque value. The attachment tool 40 has a power input and data communication conductors that allow connection to the host computer 47 and portable computer 48. The real-time clock 41 is a conventional circuit for providing real-time information. The RFID tag reader 42 is a conventional device that can generate a call signal for a specific RFID tag and receive and process information from the responding RFID tag 17. The driver unit 43 is a conventional electromechanical device used to apply a rotational driving force to the driver bit 44. The driver bit 44 is a conventional driver bit having a configuration adapted to the shape of the head 12 (for example, a hexagonal head) of the fastener 10. The torque control unit 45 is a conventional unit that can control the maximum amount of torque generated by the drive unit 43.

  FIG. 6 is a block diagram illustrating the use of tool 40 in attaching fastener 10 and adjusting torque settings. As can be seen from this figure, the RFID tag reader 42 is disposed in the vicinity of the fastener 10 and within the reception range thereof. Thereafter, the RFID tag reader 42 operates to generate a call signal to be sent to the fastener 10. Upon receiving this call signal, the RFID tag 17 of the fastener 10 responds by sending the required information to the RFID tag reader 42. Next, the RFID tag reader 42 examines the received information including the unique identification code of the fastener 10 and the desired torque value of the fastener 10. Next, the RFID tag reader 42 supplies this desired torque value to the torque control unit 45. When the torque control unit 45 receives the torque value, the torque control unit 45 controls the operation of the drive unit 43 using the torque value. The driver bit 44 is moved onto the head 12 of the fastener 10 and the driver unit 43 is activated. When the driver bit 44 is rotated by the driver unit 43, the fastener 10 is screwed into the threaded opening 33 of the structural member 34 (FIG. 4), and the torque control unit 45 indicates that the torque acting on the fastener 10 has reached a specific value. The structural members 30, 34 are pulled together until they are sensed. Thereafter, the operation of the drive unit 43 is ended by the torque control unit 45. Thereafter, the RFID tag reader 42 calls the RFID tag 17 of the fastener 10, transmits the attachment date information from the real time clock 41 to the RFID tag 17, and the RFID tag stores this information in the memory.

  After initial installation, the actual torque value of the fastener 10 currently installed can be checked by operating the RFID tag reader 42 to call the RFID tag 17 of the fastener 10. When the RFID tag reader 42 receives a response, the received information includes a unique identification code for the fastener 10, a desired torque value for the fastener, and the status of the microswitch 20. If the state of the microswitch 20 indicates that the torque value is not correct, the first attachment process can be repeated until this torque value is correct. If the first installation process fails after one or more trials, the installer should examine the fastener and replace it if a failure is found, and the threaded opening 33 of the structural member 34. The cause of the failure can be identified by taking action such as examining to determine if it is damaged.

  After the installation process is successfully completed, the information received by the RFID tag reader 42 from the RFID tag 17 of the currently installed fastener 10 is stored in the host computer 47 for further processing and / or for later retrieval. Can be sent. This information typically includes a unique identification code for the fastener 10, the desired torque value, whether the fastener torque value is within specification, the date and (optionally) time of installation, and the location of the fastener installation. The information received by the RFID tag reader 42 is transmitted to the host computer 47 for further processing and / or for later retrieval at any stage of the mounting process. Similarly, the host computer 47 updates the data in the RFID tag 17, performs a search operation for specific data from the RFID tag 17, or groups of RFID tags 17 that exist in different fasteners 10. Data and instructions for taking other measures such as scanning can be sent to the RFID tag reader 42.

  Once a group of fasteners 10 has been successfully installed, the integrity of this installation can be quickly checked at any time using the scan inspection technique shown in FIG. Typically, this scan inspection process is performed by an installer who has received more specialized training than the fastener installer. Also, the first scan inspection is usually performed immediately after the entire installation is completed or immediately after a predetermined series of fasteners are installed. FIG. 7 shows an array of twelve fasteners 10aa, 10ab,..., 10cd, each mounted at a different location along the structural panel 30. Manually scan a portable RFID tag reader 50 capable of calling individual RFID tags 17 supported on individual fasteners 10aa, 10ab,..., 10cd in the desired direction (left to right in FIG. 7) across the array. To do. The RFID tag reader 50 may have an antenna that defines a transmission / reception area surrounding a plurality of fasteners 10aa, 10ab,..., 10cd so that a plurality of (three in the embodiment of FIG. 7) fasteners can be scanned simultaneously. preferable. Each responding fastener 10aa, 10ab,..., 10cd supplies the required information to the RFID tag reader 50 and uses the dedicated display or portable computer monitor built into the RFID tag reader 50 to inspect this information. Can be displayed.

  Typically, this required information includes the unique identification code of each fastener that responds to the paging signal generated by the RFID tag reader 50, the physical location of each responding fastener on the panel 30, the status of the torque microswitch 20, and the initial Includes installation date. If no response is received for a given fastener 10aa, 10ab,..., 10cd call, this means that a fastener is currently missing or that an intelligent circuit component is not operational. . Either state can be corrected immediately or on a subsequent scheduled date by simply replacing the missing or inoperable fasteners 10aa, 10ab,..., 10cd. If the information received from responding fasteners 10aa, 10ab,..., 10cd indicates that the torque is out of specification, the inspector may use the mounting tool 40 described above in connection with FIG. You can try to fix this problem. All information received by the RFID tag reader 50 can be shared with the host computer 47 and used for maintenance, history, and other suitable purposes. The RFID tag reader 50 transmits an inspection date and an installation location to each normally called RFID tag 17, and these RFID tags store this information in a memory.

  The basic type of information that can be stored in the RFID tag 17 of the fastener 10 includes a specific fastener identification code, which is a serial number in the form of a series of numbers or combinations of different characters within a group of characters, The fastener type designation, the specified torque value of the fastener, the fastener installation location, the first installation date, and the most recent inspection date can be used. It will be apparent to those skilled in the art that other types of information may be stored in the RFID tag 17 depending on the requirements of a given application.

  Note that there are three possible states for the microswitch 20 of each fastener 10. The state “1” can mean that the fastener torque is within the specification value, and the state “0” can mean that the fastener torque is not within the specification value. If the RFID tag reader 50 does not receive the microswitch value during a call, it is interpreted as a fastener 10 missing, which can be verified by visual inspection or the microswitch is inoperable. In this case, a new fastener 10 can be attached as a replacement.

  As is apparent from the foregoing, a threaded fastener having an intelligent component incorporating the present invention described above provides several advantages over known threaded fasteners. First, it is very easy to first install the fastener to the correct torque specification by providing the correct torque information in the fastener's RFID tag that can be extracted by the mounting tool when the installer is ready to install the fastener. become. The attachment tool can also automatically drive the fastener to the correct torque value and immediately check the torque value after attaching the fastener to ensure that the fastener is correctly attached. In addition, scan inspection techniques can be used to quickly check the integrity of a set of fasteners at any time, and the installation tool can be used to take any necessary corrective action. In addition, this scan inspection technique eliminates the need to manually check the current value of each attached fastener, greatly reducing the time required to perform the inspection process. In addition, the fastener identification code, type, specified torque value, installation location, installation date, and inspection date information are provided in the fastener in a form that can be read by the associated tag reader for future maintenance. A complete history of fastener installation projects can be collected and stored on the host computer. Finally, all these benefits come at a relatively low additional cost per fastener.

  While the preferred embodiment of the present invention has been fully and fully disclosed, various modifications, alternative constructions and equivalents will occur to those skilled in the art. For example, although the present invention has been described with reference to a particular RFID tag 17, other FRID tags can be used according to the requirements of a particular application. Also, although the torque value sensor has been described as a simple microswitch with two operating states, ie a binary device, other types of torque that measure variable values, such as variable resistance or variable capacitance, as required A sensor can also be employed. Such sensors can also be incorporated into fastener 10 by using complementary variable signal processing techniques, such as the signal processing techniques described in US Patent Application Publication No. 2007/0222583 A1, the disclosure of this patent application is Which is incorporated herein by reference. Therefore, the above description should not be taken as limiting the invention, which is defined by the appended claims.

Claims (20)

Intelligent fastener,
A main body member having a head portion and a male threaded shank portion extending from the head portion;
The head portion has a lower surface, an upper surface, and a through hole formed through the head portion,
A recess is formed on the upper surface, and the intelligent fastener is
An RFID tag mounted in the recess,
An antenna mounted in the recess and coupled to the RFID tag;
A sensor having a body mounted in the recess and coupled to the RFID tag;
The sensor further includes an arm portion that extends away from the sensor body portion and terminates at an end portion, the arm portion being slidably received in the through hole, and the end of the arm portion. The portion extends below the lower surface so that the fastener can contact the surface of the workpiece when inserted into the opening of the workpiece with an opening.
Intelligent fastener characterized by that. The RFID tag has a memory for storing information unique to the fastener.
The intelligent fastener according to claim 1. At least a portion of the information is stored in a readable portion of the memory;
The intelligent fastener according to claim 2. The information includes a unique identification code of the fastener;
The intelligent fastener according to claim 2. The information includes a specified torque value of the fastener,
The intelligent fastener according to claim 2. The information includes an installation date of the fastener,
The intelligent fastener according to claim 2. The information includes a location where the fastener is installed,
The intelligent fastener according to claim 1. The information includes an inspection date of the fastener,
The intelligent fastener according to claim 1. The sensor comprises a two-state microswitch,
The intelligent fastener according to claim 1. Fastener installation and inspection system,
A fastener having a body member including a head portion and a male threaded shank portion extending from the head portion;
The head portion has a lower surface, an upper surface, and a through hole formed through the head portion,
A recess is formed on the top surface, and the system includes:
An RFID tag that is mounted in the recess and has a memory for storing information unique to the fastener;
An antenna mounted in the recess and coupled to the RFID tag;
A sensor having a body mounted in the recess and coupled to the RFID tag;
The sensor further includes an arm portion that extends away from the sensor body portion and terminates at an end portion, the arm portion being slidably received in the through hole, and the end of the arm portion. The portion extends below the lower surface so that the fastener can contact the surface of the workpiece when inserted into the opening of the workpiece with the opening,
An RFID tag reader for calling the RFID tag and receiving the information from the RFID tag;
Fastener mounting and inspection system characterized by that. The information includes a unique identification code of the fastener;
The system according to claim 10. The information includes a specified torque value of the fastener,
The system according to claim 10. The information includes an installation date of the fastener,
The system according to claim 10. The information includes a location where the fastener is installed,
The system according to claim 10. The information includes an inspection date of the fastener,
The system according to claim 10. The sensor comprises a two-state microswitch,
The system according to claim 10. The RFID tag reader includes a transmitter for storing information in the memory of the RFID tag;
The system according to claim 10. The RFID tag reader includes a transmitter for updating the information stored in the memory of the RFID tag;
The system according to claim 10. A fastener installation tool for screwing the fastener into the threaded opening to a specified torque value;
The system according to claim 10. The information includes a specified torque value of the fastener, and the fastener mounting tool is a torque coupled to the RFID tag reader for limiting the torque applied by the fastener mounting tool to the fastener to the torque value. Including control unit,
The system of claim 19.

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