Bolt fastening management system

Abstract

This invention provides a bolt tightening management system that allows for simpler and more accurate evaluation of the quality of hydraulic tightening. [Solution] The bolt tightening management system 1 manages the tightening of bolts in multiple fastening parts 90 to which hydraulic tightening is applied by a tensioning device 50 which comprises a housing part 51 for housing bolts 93, a movable part 52 that screws with the bolts 93 and forms an oil chamber 53 between itself and the housing part 51, and a pump 55 that supplies pressurized oil to the oil chamber 53. The bolt tightening management system 1 comprises a pressure gauge 11 for measuring the pressure of the pressurized oil discharged from the pump 55, an elongation measuring instrument (dial gauge 12) for measuring the elongation of the bolts 93, which is the difference in length of the bolts 93 before and after the supply of pressurized oil, and a storage device (server 3) that stores the measured pressure and elongation values ​​so that they can be output in association with the fastening parts 90.

Description

Technical Field

[0001] The present invention relates to a bolt tightening management system.

Background Art

[0002] Patent Document 1 discloses a tensioning device used for so-called "hydraulic tightening". In order to improve the quality and reproducibility of fastening, the axial force of the bolt at the fastening part is calculated, and the calculation result is stored in the documentation module together with the identifier of the fastening part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is difficult to accurately estimate the axial force. It is preferable that the quality of hydraulic tightening can be evaluated more simply and accurately.

[0005] An object of the present invention is to provide a bolt tightening management system that can evaluate the quality of hydraulic tightening more simply and accurately.

Means for Solving the Problems

[0006] One aspect of the present invention provides a bolt tightening management system for managing bolt tightening at a plurality of fastening parts to which hydraulic tightening is applied, using a tensioning device comprising: a housing part for housing a bolt; a movable part that screws with the bolt and forms an oil chamber between itself and the housing part; and a pump that supplies pressurized oil to the oil chamber, the system comprising: a pressure gauge for measuring the pressure of the pressurized oil discharged from the pump; an elongation measuring device for measuring the elongation amount of the bolt, which is the difference in the length of the bolt before and after the supply of the pressurized oil; and a storage device that stores the measured values ​​of the pressure and the elongation amount in a manner that can be output in association with the fastening part.

[0007] According to the above configuration, when managing bolt tightening by hydraulic tightening, both the measured pressure of the pressurized oil and the amount of bolt elongation are stored in association with the fastening point. By measuring and storing the pressure and elongation, it becomes possible to estimate the axial force simply and accurately. Furthermore, the stored data can be output to an external storage device. Therefore, even if a product with multiple fastening points experiences some kind of malfunction during practical use, it becomes possible to easily review and evaluate the validity of the fastening work afterward.

[0008] The bolt tightening management system may further include a terminal device to be carried by the fastening worker, the pressure gauge and the extension measuring instrument may be wirelessly connected to the terminal device, and the measured values ​​may be wirelessly output to the terminal device.

[0009] With the above configuration, the measured values ​​are wirelessly output from the measuring instrument to the terminal device. Compared to when fastening workers manually input the measured values ​​into the terminal device, this reduces the workload on fastening workers and increases the objectivity and reliability of the data stored in the memory device.

[0010] The terminal device may determine whether the measured pressure is within a predetermined pressure tolerance range, and may output a warning if the measured pressure is outside the pressure tolerance range.

[0011] The above configuration allows for prompting fastening workers to retry the fastening process or re-examine their tools. It also makes it possible to prevent the storage device from recording pressure values ​​until the work is performed correctly, in other words, until the pressure value falls within the acceptable pressure range. This increases the validity of the data stored in the storage device.

[0012] The terminal device may determine whether the measured value of the elongation amount is within a predetermined allowable range of elongation, and may output a warning if the measured value of the elongation amount is outside the allowable range of elongation.

[0013] The above configuration allows for prompting fastening workers to retry the fastening process or re-examine their tools. It also makes it possible to prevent the storage device from recording the measured elongation amount until the work is performed correctly, in other words, until the elongation amount falls within the acceptable range. This increases the validity of the data stored in the storage device.

[0014] For at least the period from the start to the end of the hydraulic tightening, the pressure gauge is wirelessly connected to the terminal device and continuously outputs the measured value of the pressure, and the storage device may store the peak value of the measured value output from the pressure gauge during the period as the measured value of the pressure.

[0015] In the above configuration, the peak value is selected as the representative value of the pressure value stored in the memory device. Compared to storing time-series data of pressure values, the capacity of the memory device can be reduced. By adopting the peak value as the representative value, the accuracy of axial force estimation and the validity of the evaluation of bolt fastening by hydraulic tightening can be maintained at a high level.

[0016] The extension amount measuring device may be configured as a rangefinder that is fixed in position relative to the housing and measures the distance from itself to the movable part, wherein the rangefinder measures a first distance, which is the distance before the supply of the pressurized oil, and a second distance, which is the distance after the supply of the pressurized oil, and the extension amount may be measured as the difference between the first distance and the second distance.

[0017] According to the above configuration, the elongation amount of the bolt can be accurately measured.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a bolt tightening management system that can more simply and accurately evaluate the quality of hydraulic tightening.

Brief Description of the Drawings

[0019] [Figure 1] As an example of the management target of the bolt tightening management system according to the embodiment, a view showing the fastening part of the large end of the connecting rod. [Figure 2] A conceptual diagram of a tensioning device that performs hydraulic tightening applied to the management target of the bolt tightening management system according to the embodiment. [Figure 3] A block diagram of the bolt tightening management system according to the embodiment. [Figure 4] A view showing data stored in the server of the bolt tightening management system according to the embodiment. [Figure 5] A flowchart showing the processing executed in the bolt tightening management system according to the embodiment. [Figure 6] A flowchart continuing from FIG. 5. [Figure 7] A flowchart continuing from FIG. 6. [Figure 8] A flowchart continuing from FIG. 7.

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments will be described with reference to the drawings. In addition, the same or corresponding elements are denoted by the same reference numerals throughout the drawings, and redundant detailed descriptions are omitted.

[0021] The bolt tightening management system 1 (see Figure 3) according to this embodiment is a system for managing the bolt tightening of multiple fastening parts 90 (see Figure 1) to which hydraulic tightening by a tensioning device 50 (see Figure 2) is applied, and is used for quality control of products having many fastening parts 90. An example of such a product is an engine.

[0022] Figure 1 shows a fastening portion 90 provided on the large end 82 of a connecting rod 80 as an example of a target of the bolt tightening management system 1. The connecting rod 80 has a long shaft portion 81. A small end portion (not shown) through which a piston pin (not shown) is rotatably inserted is provided at one end of the shaft portion 81, and a large end portion 82 through which a crank pin (not shown) is rotatably inserted is provided at the other end of the shaft portion 81.

[0023] The large end portion 82 has a base 83 integrally formed with the shaft portion 81 and a cap 84 fastened to the base 83. Both the base 83 and the cap 84 have semicircular recesses. When the cap 84 is assembled to the base 83, the two recesses connect to form a circular hole 85. The large end portion 82 is provided with two fastening portions 90 having the same structure. The two fastening portions 90 are positioned so as to sandwich the hole 85.

[0024] Each fastening portion 90 has a female threaded hole 91 formed in the base 83, a bolt insertion hole 92 that penetrates the cap 84, a bolt 93 that is screwed into the female threaded hole 91, and a nut 94 that is screwed onto the bolt 93. One end of the bolt 93 is provided with a first male threaded portion 93a that is screwed into the female threaded hole 91, and the other end of the bolt 93 is provided with a second male threaded portion 93b that is screwed into the nut 94. The central part of the bolt 93 is provided with a hexagonal operated portion 93c. The nut 94 is, for example, a round nut. The cap 84 has a flange surface 84a through which the bolt insertion hole 92 opens.

[0025] The large end portion 82 is assembled by the following steps 1) to 3).

[0026] 1) Insert the bolt 93 into the female threaded hole 91, attach a torque wrench to the operated portion 93c protruding from the base 83, and tighten the bolt 93 with the torque wrench, screwing the first male threaded portion 93a into the female threaded hole 91. As a result, the two bolts 93 partially protrude from the base 83.

[0027] 2) With the crankpin positioned in the recess of the base 83, the two bolts 93 are inserted through the two bolt holes 92. This attaches the cap 84 to the base 83 and the crankpin to the hole 85. The operated portion 93c is housed in the bolt hole 92, and the second male threaded portion 93b protrudes from the flange surface 84a.

[0028] 3) The nut 94 is screwed onto the second male threaded portion 93b, the nut 94 is seated on the flange surface 84a, and the nut 94 is tightened to the flange surface 84a using the tensioning device 50 (see Figure 2). Two tensioning devices 50 are attached to each of the two nuts 94, and pressurized oil is supplied to and discharged from the two tensioning devices 50 simultaneously.

[0029] Referring to Figure 2, the tensioning device 50 is installed on the flange surface 84a so as to cover the bolt 93 and nut 94, with the nut 94 seated on the flange surface 84a and the second male threaded portion 93b of the bolt 93 protruding and exposed from the nut 94. The bolt 93 and nut 94, as well as the connecting rod 80, are supported, for example, by a jig 59.

[0030] The tensioning device 50 comprises a housing 51 installed on the flange surface 84a, a movable part 52 that forms a sealed oil chamber 53 between itself and the housing 51, an oil passage 54 connected to the oil chamber 53, and a pump 55 interposed in the oil passage 54 to supply pressurized oil to the oil chamber 53. The tensioning device 50 is also called a hydraulic jack.

[0031] The housing portion 51 and the movable portion 52 are coaxial and cylindrical. The housing portion 51 houses the entire nut 94 and a portion of the bolt 93. The movable portion 52 is screwed onto the bolt 93 (second male threaded portion 93b).

[0032] When pressurized oil is supplied to the oil chamber 53, the housing portion 51 does not displace, while the movable portion 52 is displaced axially toward the opposite side of the flange surface 84a. The bolt 93 extends, and the nut 94 lifts off the flange surface 84a. The nut 94 is then tightened to re-seat it on the flange surface 84a. When the pressurized oil is released from the oil chamber 53, the nut 94 is tightened firmly.

[0033] This series of operations is called hydraulic tightening. For tightening a single nut 94, the hydraulic tightening may be repeated multiple times (for example, three times). Tightening the nut 94 is performed, for example, by inserting a tool into the housing 51 through a window (not shown) provided in the housing 51, applying the tool to a recess 94a provided on the outer surface of the nut 94, and rotating the tool.

[0034] Referring to Figure 3, the bolt tightening management system 1 comprises a tablet 2, a server 3, a personal computer (PC) 4, a pressure gauge 11, a digital dial gauge 12, a digital torque wrench 13, and a torque analyzer 14.

[0035] Tablet 2 is an example of a terminal device carried by fastener workers in the production site of products such as engines. The terminal device is not limited to Tablet 2, but may be other information terminals such as smartphones.

[0036] Tablet 2 has a touch-panel display 2a. Tablet 2 is connected to server 3 and PC 4 via an internet connection. Tablet 2 is connected wirelessly to pressure gauge 11, dial gauge 12, and torque wrench 13. Known communication technologies such as Bluetooth® or Wi-Fi® can be used for wireless communication.

[0037] Server 3 is an information terminal device that stores data obtained during the fastening process and is located outside the production site. Server 3 is equipped with a storage area 3a that stores data such as drawing data 21, quality control data 22, and guidance data 23.

[0038] PC4 is connected to tablet 2 and server 3 for communication and is operated by a management worker who manages data. PC4 can be operated by the management worker and receive quality control data 22 stored in the storage area 3a of server 3. In addition, by operating PC4, the management worker can send drawing data 21 or guidance data 23 to server 3 and have it stored in the storage area 3a.

[0039] Drawing data 21 is a collection of data showing the ideal three-dimensional shape of the entire product, a sub-assembly, or an individual part, along with assembly instructions or considerations. Each data entry is assigned a drawing number. Examples of instructions or considerations include tightening torque.

[0040] The quality control data 22 is a database that links part information indicating each of the multiple fastening parts 90 provided on the product with related information associated with each of the multiple fastening parts 90. The quality control data 22 is generated automatically or manually based on the information in the drawing data 21.

[0041] Guidance data 23 is guidance information displayed on the tablet 2's display 2a during the fastening process, for the purpose of guiding the fastening procedure. Multiple pieces of guidance information are sequentially transmitted to the tablet 2 according to the fastening procedure.

[0042] Referring to Figure 4, the relevant information for quality control data 22 includes pre-recorded information that is recorded before the tightening operation and measurement result information that is recorded after the tightening operation.

[0043] Prior information may include drawing number information indicating the drawing number of the drawing data showing the fastening portion 90, standard information indicating the standards for the fastening work to be performed at the fastening portion 90, tool information indicating the tools to be used at the fastening portion 90, management item information indicating the items to be managed in the fastening work performed at the fastening portion 90, and measuring tool information indicating measuring tools for measuring the values ​​of the items to be managed.

[0044] The measurement result information shows the measured values ​​of the control items obtained by the measuring instruments indicated in the measuring instrument information. All measuring instruments entered as measuring instrument information are connected to tablet 2 in a way that allows them to communicate.

[0045] The pressure gauge 11 and dial gauge 12 are measuring instruments for measuring control items (fastening pressure and bolt elongation) in fastening work using the tensioning device 50 (hydraulic jack). The torque wrench 13 has the function of measuring tightening torque. The torque wrench 13 is both a tool and a measuring instrument for measuring tightening torque as a control item in fastening work in which it is used.

[0046] Referring to Figures 2 and 3, the pressure gauge 11 is installed, for example, in the oil passage 54 or the pump 55, and measures the pressure of the pressurized oil discharged from the pump 55, i.e., the internal pressure of the oil chamber 53. The pressure gauge 11 outputs the measurement results to the tablet 2 via wireless communication.

[0047] The dial gauge 12 is a type of rangefinder, fixed in position relative to the housing 51, and measures the distance from itself to the movable part 52 in the displacement direction of the movable part 52 (vertical direction in the plane of Figure 2). Alternatively, the dial gauge 12 may be fixed in position relative to the nut 94 and measure the distance from itself to the bolt 93 in the displacement direction of the bolt 93 (vertical direction in the plane of Figure 2). As just one example, as shown in Figure 2, the dial gauge 12 may be attached to a jig 59 and thereby fixed in position relative to the housing 51. The dial gauge 12 also outputs the measurement result to the tablet 2 via wireless communication.

[0048] The dial gauge 12, as an example of a distance measuring instrument, is used to measure the elongation of a bolt 93, which is the difference in length of the bolt 93 before and after the supply of pressurized oil. In other words, the dial gauge 12 is an example of an elongation measuring instrument that measures the elongation of a bolt 93. The dial gauge 12 measures a first distance, which is the distance before the supply of pressurized oil, and a second distance, which is the distance after the supply of pressurized oil. The elongation is obtained by subtracting the first distance from the second distance.

[0049] The dial gauge 12 may have a zeroing function. In that case, if zeroing is performed after measuring the first distance, the measurement result of the second distance will represent the value obtained by subtracting the first distance from the second distance, i.e., the amount of extension itself. The dial gauge 12 can output the measurement result of the second distance as the measurement result of the amount of extension to the tablet 2 via wireless communication.

[0050] Although detailed illustrations are omitted, the torque wrench 13 includes a rod-shaped lever section, an engagement section at the tip of the lever section that can engage with a nut, a gripping section on the opposite side of the engagement section that can be gripped by the fastening worker, a measuring section for measuring tightening torque, and a user interface section attached to the surface of the lever section. The user interface section includes a display, an alarm, and a switch. The fastening worker can set a specified value for the tightening torque by operating the switch while looking at the display. If the measured value of the tightening torque exceeds the specified value, the alarm will activate. The alarm may be a speaker that emits a beeping sound or a lamp.

[0051] The torque analyzer 14 is a device for inspecting whether the torque wrench 13 is functioning correctly, and has a dummy nut that can engage with the engagement part of the torque wrench 13. In the inspection using the torque analyzer 14, the fastening worker engages the engagement part with the dummy nut and applies a load from the torque wrench 13 to the dummy nut until the tightening torque of the torque wrench 13 reaches a specified value. If the measurement value of the torque analyzer 14 is within the acceptable range close to the specified value, the torque wrench 13 is deemed usable for fastening work. If the measurement value of the torque analyzer 14 deviates from the specified value, the torque wrench 13 is deemed unusable for fastening work.

[0052] Figure 5 is a flowchart showing the processes performed in the bolt tightening management system 1. This process is performed, as just one example, in the fastening of the large end 82 of the connecting rod 80 shown in Figure 1. Similar processes are performed in the fastening of different fastening parts 90 within the product.

[0053] Server 3 transmits guidance information and standard information corresponding to the fastening part 90 where the fastening work should be performed next, and tablet 2 receives this (step S1). Tablet 2 displays the received guidance information on display 2a (step S1). Specifically, the assembly procedure for the large end 82 described above is displayed sequentially on display 2a. First, guidance for step 1) is displayed.

[0054] The fastening worker uses a torque wrench 13 to tighten the bolt 93 to the base 83 according to the guidance (step S3). The torque wrench 13 used at this time has been determined to be in good working order through a prior inspection by a torque analyzer 14. The torque wrench 13 outputs a measured tightening torque, which the tablet 2 receives wirelessly (step S4). The tablet 2 refers to the standard information and determines whether the measured value is within the acceptable range (step S5). If it is outside the acceptable range (S5: NO), the tablet 2 displays the measured value and also displays an error (step S6). The error display can be anything that makes the fastening worker aware that the torque value is not correct, for example, the measured value or its surrounding area may be displayed in red. In response, the fastening worker repeats the tightening with the torque wrench 13 (step S3).

[0055] If the measured value is within the acceptable range (S5: YES), tablet 2 displays the measured value and also indicates that the measurement was successful (step S7). The indicator can be anything that allows the fastening worker to recognize that the fastening work was performed with the correct torque value; for example, the measured value or its surrounding area may be displayed in green. Tablet 2 then transmits the measured value to server 3, which receives it and records it in the measurement result information of quality control data 22 (step S8).

[0056] Referring to Figure 6, the tablet 2 then displays guidance regarding the next step on the display 2a (step S11). The fastening worker attaches the cap 84 and nut 94 to the bolt 93 (step S12) and installs the tensioning device 50 on the flange surface 84a (step S13). Next, the fastening worker operates the dial gauge 12 to measure the first distance (step S14). If the dial gauge 12 has a zeroing function, after measuring the first distance, the fastening worker may operate the dial gauge 12 to perform zeroing (step S15).

[0057] Referring to Figure 7, the fastening worker then activates the tensioning device 50 (step S16). The pump 55 starts up and pressurized oil is supplied to the oil chamber 53, and the pressure gauge 11 begins measuring the pressure (step S17). Upon receiving the supply of pressurized oil, the movable part 52 is displaced (step S18), and the bolt 93 extends as a result. The pressure gauge 11 outputs a measurement value, which is received by the tablet 2 (step S19). The tablet 2 refers to the standard information and determines whether the measurement value is within the acceptable range (step S20). If it is within the acceptable range, the worker decides whether to stop pulling up the bolt 93 (step S21). If pulling up should be continued (S21: NO), the pressure measurement continues with pressurized oil being supplied to the oil chamber 53. If the measurement value goes outside the acceptable range while pressurized oil is being supplied (S20: NO), the tablet 2 displays the measurement value and also displays an error (step S22). In response, the fastening worker redoes the hydraulic tightening (Step S16).

[0058] When the time comes to end the tensioning while the measured value remains within the acceptable range (S21: YES), the worker stops the tensioning device (step S23) and tightens the nut 94 (step S24). Tablet 2 displays the pressure measurement and indicates normal operation (step S25). The measurement displayed here is the peak value of the pressure gauge reading during the hydraulic tightening.

[0059] The fastening worker determines whether the number of hydraulic tightening operations has reached a specified number (for example, 3 times) (step S26). If the specified number has not been reached (S26: NO), the series of hydraulic tightening operations described above (steps S16-S21, S23-S25) are repeated. If the specified number has been reached (S26: YES), the flow shown in Figure 8 is executed.

[0060] Referring to Figure 8, tablet 2 transmits the peak value of the measurement to server 3, which receives it and records it as measurement result information for quality control data 22 (step S28).

[0061] Next, the fastening worker operates the dial gauge 12 to measure the second distance (step S29). The dial gauge 12 outputs the second distance to the tablet 2, which receives it (step S30). The tablet 2 refers to the standard information and determines whether the second distance (i.e., the elongation of the bolt 93) is within the permissible range (step S31). If it is within the permissible range, the tablet 2 displays the measured elongation amount and indicates that it is normal (step S32). Furthermore, the tablet 2 transmits the measured elongation amount to the server 3, which receives it and records it as measurement result information for the quality control data 22 (step S33). If the elongation amount is outside the permissible range (S31: NO), the tablet 2 displays the measured value and indicates an error (step S34). In response, the fastening worker performs abnormality response processing, such as checking for tightening abnormalities or component abnormalities (step S35).

[0062] In this way, the process cannot proceed to the next step unless proper fastening is performed at each fastening point 90. This results in higher product quality. Furthermore, if proper fastening is not performed, the measurement result information of the quality control data 22 cannot be written.

[0063] The management worker operating PC4 can access server 3 and download quality control data 22. Conversely, server 3 can output the quality control data stored in memory area 3a to information terminal devices outside server 3, including PC4. This makes it possible to review the validity of the fastening process afterward if any problems occur while the product is in use.

[0064] The bolt tightening management system 1 according to this embodiment manages the tightening of bolts in a plurality of fastening parts 90 to which hydraulic tightening is applied by a tensioning device 50 comprising a housing part 51 for housing bolts 93, a movable part 52 that screws with the bolts 93 and forms an oil chamber 53 between itself and the housing part 51, and a pump 55 that supplies pressurized oil to the oil chamber 53. The bolt tightening management system 1 comprises a pressure gauge 11 for measuring the pressure of the pressurized oil discharged from the pump 55, an elongation measuring instrument (dial gauge 12) for measuring the elongation of the bolts 93, which is the difference in length of the bolts 93 before and after the supply of pressurized oil, and a storage device (server 3) that stores the measured pressure and elongation values ​​so that they can be output in association with the fastening parts 90.

[0065] According to the above configuration, when managing bolt tightening by hydraulic tightening, both the measured pressure of the pressurized oil and the amount of bolt elongation are stored in association with the fastening part 90. By measuring and storing the pressure and elongation, it becomes possible to estimate the axial force simply and accurately. Furthermore, the stored data can be output to an external storage device (server 3). Therefore, even if a product equipped with multiple fastening parts 90 experiences some kind of malfunction during practical use, it becomes possible to easily review and evaluate the validity of the fastening work afterward.

[0066] The bolt tightening management system 1 further includes a terminal device (tablet 2) to be carried by the fastening worker. A pressure gauge 11 and an elongation measuring instrument (dial gauge 12) are wirelessly connected to the terminal device (tablet 2), and the measured values ​​are wirelessly output to the terminal device (tablet 2). In this way, the measured values ​​are wirelessly output from the measuring instruments to the terminal device (tablet 2). Compared to when the fastening worker manually inputs the measured values ​​into the terminal device (tablet 2), the workload of the fastening worker is reduced, and the objectivity and reliability of the data stored in the storage device (server 3) are increased.

[0067] The terminal device (tablet 2) determines whether the measured pressure is within a predetermined pressure tolerance range, and outputs a warning if the measured pressure is outside the pressure tolerance range. This prompts the fastening worker to retry the fastening work or re-check the tools. It is also possible to prevent the pressure value from being stored in the storage device (server 3) until the work is performed correctly, in other words, until the pressure value is within the pressure tolerance range. This increases the validity of the data stored in the storage device (server 3).

[0068] The terminal device (tablet 2) determines whether the measured elongation amount is within a predetermined allowable range, and outputs a warning if the measured elongation amount is outside the allowable range. In this case as well, the fastening worker can be prompted to retry the fastening work or re-examine the tools. The validity of the data stored in the storage device (server 3) is improved.

[0069] For at least the period from the start to the end of hydraulic tightening, the pressure gauge 11 is wirelessly connected to the terminal device (tablet 2) and continuously outputs pressure measurements. The storage device (server 3) stores the peak value of the pressure measurements output from the pressure gauge during the above period as the pressure measurement value. In this way, the peak value is selected as the representative value of the pressure value stored in the storage device (server 3). Compared to storing time-series data of pressure values, the storage capacity of the storage device (server 3) can be reduced. By adopting the peak value as the representative value, the accuracy of axial force estimation and the validity of the evaluation of bolt fastening by hydraulic tightening can be maintained at a high level.

[0070] The elongation measuring device is composed of a distance meter (dial gauge 12) that is fixed in position relative to the housing 51 and measures the distance from itself to the movable part 52. Alternatively, the elongation measuring device may be composed of a distance meter (dial gauge 12) that is fixed in position relative to the nut 94 and measures the distance from itself to the bolt 93. The distance meter (dial gauge 12) measures a first distance, which is the distance before the supply of pressurized oil, and a second distance, which is the distance after the supply of pressurized oil, and the elongation is measured as the difference between the first distance and the second distance. This allows for accurate measurement of the bolt's elongation.

[0071] While embodiments have been described above, the above configuration can be modified as appropriate within the scope of the present invention.

[0072] The pressure value and elongation amount are output from the measuring instrument to the terminal device via wireless communication, but these measurements may also be manually entered by the fastening worker.

[0073] For example, the fastening portion 90 may be applied to parts other than the connecting rod 80. The bolt tightening management system 1 is not limited to engines and can be applied to other products that have multiple fastening portions. [Explanation of symbols]

[0074] 1. Bolt tightening management system 2 tablets 3 Servers 3a Storage area 4. Personal Computer (PC) 11. Pressure gauge 12 Dial Gauge 13 Torque wrench 14 Torque Analyzer 21 Drawing data 22 Quality control data 23 Guidance Data 50 Tensioning device 51 Storage Unit 52 Moving parts 53 Oil room 54 Oil road 55 pumps 59 Jig 80 Connecting Rod 81. Shaft 82 Big end 83 Bass 84 caps 84a Flange surface 85 holes 90 Fastening part 91 Female threaded hole 92 Bolt insertion holes 93 volts 93a First male thread section 93b Second male thread section 93c Operated part 94 nuts 94a depression

Claims

1. A housing section for housing bolts, A movable part that screws into the bolt and forms an oil chamber between itself and the housing, A pump that supplies pressurized oil to the oil chamber, A system for managing bolt tightening at multiple fastening points to which hydraulic tightening is applied, using a tensioning device equipped with the following: A pressure gauge for measuring the pressure of the pressurized oil discharged from the pump, An elongation measuring device for measuring the elongation amount of the bolt, which is the difference in the length of the bolt before and after the supply of the pressurized oil, A storage device that stores the measured pressure and the measured elongation amount in a manner that can be output in association with the fastening portion, A bolt tightening management system equipped with [specific features / features].

2. It further includes a terminal device to be carried by the fastening worker, The pressure gauge and the extension measuring instrument are wirelessly connected to the terminal device, and the measured values ​​are wirelessly output to the terminal device. The bolt tightening management system according to claim 1.

3. The aforementioned terminal device is Determine whether the measured value of the pressure is within a predetermined pressure tolerance range. When the measured value of the pressure is outside the acceptable pressure range, a warning is issued. The bolt tightening management system according to claim 2.

4. The aforementioned terminal device is Determine whether the measured value of the elongation amount falls within a predetermined allowable range of elongation. When the measured value of the elongation amount is outside the allowable range of elongation, a warning is issued. The bolt tightening management system according to claim 2.

5. For at least the period from the start to the end of the hydraulic tightening, the pressure gauge is wirelessly connected to the terminal device and continuously outputs the measured value of the pressure. The storage device stores the peak value of the measured value output from the pressure gauge during the period as the measured value of the pressure. A bolt tightening management system according to any one of claims 1 to 4.

6. The extension amount measuring device is fixed in position relative to the housing and consists of a rangefinder that measures the distance from itself to the movable part. The rangefinder measures a first distance, which is the distance before the supply of the pressurized oil, and a second distance, which is the distance after the supply of the pressurized oil. The amount of elongation is measured as the difference between the first distance and the second distance. A bolt tightening management system according to any one of claims 1 to 4.

7. The fastening portion includes a nut that screws onto the bolt, The extension measuring device is configured as a distance measuring device that is fixed in position relative to the nut and measures the distance from itself to the bolt. The rangefinder measures a first distance, which is the distance before the supply of the pressurized oil, and a second distance, which is the distance after the supply of the pressurized oil. The amount of elongation is measured as the difference between the first distance and the second distance. A bolt tightening management system according to any one of claims 1 to 4.

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