JP2006167815A - Bolt fastening tool with axial force sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bolt fastening tool with an axial force sensor, reducing the cost required for measuring the axial force, reducing the time and trouble for measuring the axial force, and improving the measurement accuracy. <P>SOLUTION: This bolt fastening tool with an axial force sensor is composed of an axial force measuring device part 12 for measuring the axial force of a bolt 1 and a removable socket part 13 fitted to the bolt 1. The axial force measuring device part 12 includes: a socket fitting part 12c formed at one end of the axial force measuring device body part 12b and having a mounting part for mounting the socket part 13 fitted to the bolt 1; and the axial force sensor 11 stored in the interior of the axial force measuring device body part 12b. The socket part 13 includes: a tool fitting part 13a formed at one end of the socket body part 13 to be fitted to the socket fitting part 12c of the axial force measuring device part 12 and a bolt fitting part 13b formed at the other end of the socket body part 13 to be fitted to the bolt 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bolt tightening tool with an axial force sensor.

  Bolts are frequently used to connect various devices and structures. The bolt needs to manage the bolt axial force, that is, the tensile force acting on the bolt when tightened. When the bolt axial force is excessive, the bolt breaks, and when the bolt axial force is excessive, the bolt loosens.

  One method for managing the tightening force of the bolt is an ultrasonic axial force management method. This ultrasonic axial force management method utilizes the fact that the propagation time of ultrasonic waves becomes longer as the axial force acts on the bolt and the entire length of the bolt extends.

  However, when the axial force meter is used, the axial force of the bolt is measured through three steps of an initial value measuring step, a tightening step, and an axial force measuring step. According to this method, since the sensor is attached and detached, there is a problem that the contact state with the head of the bolt changes and the measurement accuracy decreases.

Therefore, a bolt tightening tool with an axial force sensor in which an ultrasonic sensor that measures bolt axial force using ultrasonic waves is integrated with a bolt tightening tool is disclosed (see Patent Document 1).
Japanese Patent Laid-Open No. 04-348878

  However, the conventional bolt tightening tool with an axial force sensor requires a bolt tightening tool with an axial force sensor for each bolt head size because the tightening tool and the sensor are completely integrated. . Therefore, since the sensor itself is expensive, there is a problem that the cost increases as the number of bolt types increases. In addition, since there is a variation between the axial force sensors, it is necessary to perform the calibration of the variation for each tool size, and the measurement is troublesome. Furthermore, in order to correct the axial force measurement error due to thermal expansion, the temperature of the bolt is measured with a separate temperature sensor and the numerical value is input. It was easy for human error such as input errors to the equipment to occur.

  The present invention has been made paying attention to such a conventional problem, and is a bolt with an axial force sensor that reduces the cost required for measuring the axial force, reduces the effort of measuring the axial force, and improves the measurement accuracy. The purpose is to provide a tightening tool.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention provides a bolt tightening tool with an axial force sensor comprising an axial force measuring device portion (12) for measuring the axial force of a bolt (1) and a detachable socket portion (13) fitted to the bolt (1). (10) The axial force measuring device portion (12) is formed at one end of the axial force measuring device main body portion (12b) and attaches the socket portion (13) to be fitted to the bolt (1). A socket fitting portion (12c) having a portion, and an axial force sensor (11) accommodated in the axial force measuring device main body portion (12b), wherein the socket portion (13) includes a socket main body portion ( A tool fitting portion (13a) formed at one end of 13) for fitting with the socket mounting portion (12c) of the axial force measuring device portion (12), and the other end of the socket main body portion (13). Bolt fitting part for fitting with bolt (1) Characterized in that it comprises a 13b) and.

  According to the present invention, even when measuring the sizes of different bolts, the axial force measuring device can be shared by exchanging only the socket that fits the bolt. Thereby, since the axial force sensor used for axial force measurement can be reduced, the dispersion | variation between axial force sensors is eliminated and the calibration for every axial force sensor becomes unnecessary. Therefore, the cost required for the axial force measurement can be reduced and the measurement accuracy can be improved.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a first embodiment of a bolt tightening tool with an axial force sensor according to the present invention.

  The bolt tightening tool 10 with an axial force sensor of the present embodiment holds an axial force sensor 11 that measures the axial force of the bolt 1, an exchangeable socket 13 that fits the bolt 1, and the axial force sensor 11. The tightening torque transmitting portion 12 is configured to transmit torque for tightening the bolt 1 by fitting with the socket 13.

  The axial force sensor 11 is formed in a cylindrical shape, and includes a tip end portion 11a that contacts the bolt 1 and measures the axial force, and a T-shaped sensor receiving portion 11b on the opposite side. An ultrasonic sensor that measures the axial force of the bolt 1 is built in the axial force sensor 11, and the axial force can be calculated by measuring the entire length of the bolt 1. The sensor receiving portion 11b is formed to be larger than the diameter of the through hole 12e of the tightening torque transmitting portion 12, and prevents the axial force sensor 11 from dropping from the tightening torque transmitting portion 12. Moreover, the axial force sensor 11 is provided with the lead wire 14 for connecting to the axial force meter which is not illustrated in the sensor receiving part 11b side. The sensor receiving portion 11b is provided with a fastening portion 11c for fastening with one end of a tension spring 17 described later.

  The tightening torque transmitting portion 12 includes a torque wrench fitting portion 12a for transmitting a tightening torque from a torque wrench (not shown), a body portion 12b, and a socket fitting portion 12c for fitting with the socket 13. . The tightening torque transmission part 12 is formed in a substantially cylindrical shape.

  The torque wrench fitting portion 12a is formed with a rectangular recess 12h that engages with the torque wrench. The torque wrench fitting portion 12a further has a concave hole, and is continuously formed as an axial force sensor accommodating portion 12d to be described later up to the bottom portion 12i. Torque is transmitted to the socket 13 by fitting and tightening the torque wrench on the torque wrench fitting portion 12a.

  The trunk portion 12b is formed in a columnar shape from the torque wrench fitting portion 12a toward the bottom in the axial direction. Since the outer diameter of the trunk portion 12b is slightly smaller than the torque wrench fitting portion 12a, an inclined surface is formed on the outer peripheral surface from the torque wrench fitting portion 12a toward the trunk portion 12b. A lead wire insertion opening 12f for inserting a lead wire 14 connected to the axial force sensor 11 is provided on a side surface of the body portion 12b.

  The axial force sensor housing portion 12d is formed with a through hole 12e penetrating from the bottom portion 12i toward the socket fitting portion 12c. The axial force sensor accommodating portion 12d accommodates the axial force sensor 11 coaxially.

  An annular stopper 15 having an insertion hole 15a concentric with the through hole 12e is disposed on the inner peripheral surface of the axial force sensor housing portion 12d. The stopper 15 is disposed in parallel with the bottom portion 12i and spaced from the bottom portion 12i.

  The axial force sensor accommodating portion 12d includes a disc-shaped sliding portion 16 having a sliding hole 16a at the center. The sliding portion 16 is disposed between the bottom portion 12i and the stopper 15 so as to be tiltable. The axial force sensor 11 is slidably inserted into the sliding hole 16a. The sliding portion 16 has a fastening portion 16b for fastening a tension spring 17 described later.

  The axial force sensor accommodating portion 12d accommodates the tension spring 17 coaxially. The tension spring 17 is loosely inserted into the insertion hole 15 a of the stopper 15. The tension spring 17 is inserted through the axial force sensor 11 so as to be reciprocally movable. The tension spring 17 is fixed at both ends to a fixing portion 11c provided in the sensor receiving portion 11b of the axial force sensor 11 and a fixing portion 16b provided in the sliding portion 16, respectively. Energize in the direction of 12e.

  The socket fitting portion 12c is formed in a convex shape with a square cross section that makes a business trip in the axial direction. The socket fitting portion 12c is fitted with the tool fitting portion 13a formed in the same shape of the socket 13, and transmits the tightening torque applied to the torque wrench fitting portion 12a.

  The socket 13 is formed in a cylindrical shape. The socket 13 includes a tool fitting portion 13a, and a bolt fitting portion 13b on the opposite side to the tool fitting portion 13a in the axial direction. The socket 13 includes an insertion hole 13c penetrating from the tool fitting portion 13a to the bolt fitting portion 13b, and loosely inserts the axial force sensor 11. The bolt fitting portion 13 b is formed in a rectangular concave portion such as a hexagon in order to fit the bolt 1. In addition, the bolt fitting part 13b is provided with multiple types according to the magnitude | size and shape of the volt | bolt 1. FIG.

  Next, the operation of the bolt tightening tool with the axial force sensor will be described.

  In order to use the bolt tightening tool with the axial force sensor, first, the socket 13 that matches the head of the bolt 1 to be measured for the axial force is selected. Next, the axial force sensor 11 protruding from the tightening torque transmitting portion 12 is inserted into the insertion hole 13c of the socket 13, and the tool fitting portion 13a of the socket 13 is inserted into the socket fitting portion 12c of the tightening torque transmitting portion 12 and fixed. To do. The fixing method of the tool fitting portion 13a and the socket fitting portion 12c is an insertion type with emphasis on ease of handling, but may be a screw type, a spline groove and a ring groove. Further, the bolt fitting portion 13 b of the socket 13 is fitted to the bolt head to be measured, and the torque wrench is fitted to the torque wrench fitting portion 12 a of the tightening torque transmission portion 12. At this time, the axial force sensor 11 is brought into close contact with the head of the bolt 1 by the urging force of the tension spring 17. Thereafter, the axial force measuring device is turned on, and the bolt 1 is tightened with the torque wrench. Meanwhile, since the axial force of the bolt 1 is continuously measured and displayed on the measuring device, the bolt 1 may be tightened until the desired axial force is obtained. Moreover, what is necessary is just to replace | exchange with the socket 13 and to continue a work | work, when measuring the bolt from which size differs.

  The tension spring 17 biases the axial force sensor 11 toward the socket 13 and the sliding portion 16 toward the torque wrench fitting portion 12a. Since the movement of the sliding portion 16 is restricted by the stopper 15, as a result, the axial force sensor 11 is urged toward the socket 13.

  Further, the axial force sensor 11 communicates the sliding hole 16 a of the sliding portion 16, the through hole 12 e of the tightening torque transmitting portion 12 and the insertion hole 13 c of the socket 13, and the through hole 12 e of the tightening torque transmitting portion 12 and the socket 13. These insertion holes 13c are loosely inserted. Therefore, the axial force sensor 11 can be tilted by an amount by which the sliding portion 16 can be tilted, and the stopper 15 provided in the axial force sensor housing portion 12d and the bottom portion 12i of the axial force sensor housing portion 12d allow the sliding portion 16 to move. It is determined by the regulation of tilting, and the shape and inner diameter of the through hole 12e of the tightening torque transmitting portion 12 and the insertion hole 13c of the socket 13.

  According to the present embodiment, the common axial force sensor 11 can be used by replacing the socket 13 even when the heads of the bolts 1 are different. Therefore, since an expensive measuring tool with an axial force sensor is not required for each bolt diameter, the cost required for measuring the axial force can be reduced. Furthermore, since it is not necessary to consider the variation between the sensors by making the axial force sensor 11 common, the labor of calibration can be reduced and the labor required for measuring the axial force can be reduced.

  Furthermore, since the tension spring 17 urges the axial force sensor 11 in the direction of the socket 13 by the above-described action, the axial force sensor 11 can be reliably brought into close contact with the head of the bolt 1. Further, when a push spring is employed, a member for fixing the push spring is required. However, since the tension spring 17 is employed in the present embodiment, such a member is not required. Can be simplified. Therefore, the manufacturing cost can be reduced by reducing the number of parts of the bolt tightening tool 10 with the axial force sensor.

  Since the axial force sensor 11 can tilt, the front end portion 11a of the axial force sensor 11 can be brought into close contact with the head of the bolt 1 at a right angle even if the surface of the bolt 1 is not horizontal. Therefore, even when the tool is tilted when the bolt 1 is tightened, the tip 11a is closely attached to the head of the bolt 1 by the biasing force of the tension spring 17 with respect to the axial force sensor 11 and the tilting of the axial force sensor 11. The structure is designed to reduce the effects of tool fall.

(Second Embodiment)
FIG. 2 is a view showing a second embodiment of the bolt tightening tool with an axial force sensor according to the present invention. 2A is a plan view of the axial force sensor 111, FIG. 2B is a bottom view of the axial force sensor 111, and FIG. 2C is an enlarged view of a tip portion of the axial force sensor 111.

  In the following embodiments, the same reference numerals are given to the portions that perform the same functions as those of the above-described embodiments, and overlapping descriptions are omitted as appropriate.

  As shown in FIG. 2C, the axial force sensor 111 includes a casing 111c, an ultrasonic sensor 111a, a temperature sensor 120, and an elastic body 121 that biases the temperature sensor 120 to a bolt. About another structure, it is the same as that of 1st Embodiment.

  In the axial force sensor 111, an ultrasonic sensor 111a that measures the axial force of the bolt 1 and a temperature sensor 120 that measures the temperature of the bolt 1 are accommodated in the casing 111c in parallel. The ultrasonic sensor 111 a has a cylindrical shape and is accommodated coaxially with the axial force sensor 111. The temperature sensor 120 is accommodated in the axial force sensor 111 in parallel with the ultrasonic sensor 111a. The axial force sensor 111 has a structure that protrudes from the tightening torque transmitting portion 12 as in the first embodiment. Furthermore, in this embodiment, the temperature sensor 120 is also provided with an elastic body 121 that urges the temperature sensor 120 in a direction protruding from the tightening torque transmission unit 12. The elastic body 121 is a tension spring, and the temperature sensor 120 is loosely inserted therein. A fixing portion 121b with the elastic body 121 is provided on the side surface of the temperature sensor 120. The bottom 111b of the axial force sensor 111 is also provided with a fastening part 111c with the elastic body 121, and fixes the elastic body 121 together with the fastening part 121b provided on the side surface of the temperature sensor.

  Since the ultrasonic sensor 111a calculates the axial force by measuring the entire length of the bolt 1, there is a difference in the axial force value calculated by the influence of thermal expansion due to the temperature of the bolt. Therefore, it is necessary to measure the temperature of the bolt 1 and correct an error in axial force measurement due to thermal expansion. In the present embodiment, the temperature of the bolt 1 is measured by the temperature sensor 120 inside the axial force sensor 111.

  According to this embodiment, since the temperature sensor 120 is built in the axial force sensor 111, the measurement error due to the influence of the thermal expansion of the bolt 1 can be corrected simultaneously with the axial force measurement. Therefore, by reducing the time and effort of inputting the temperature into the measuring device, it is possible to prevent the occurrence of artificial measurement errors due to misreading or input errors, and to perform accurate axial force measurement. it can. Further, similarly to the axial force sensor 111, the temperature sensor 120 is urged in a direction protruding from the tightening torque transmitting portion 12, so that the temperature sensor 120 can be securely attached to the bolt 1.

(Third embodiment)
FIG. 3 is a view showing a third embodiment of the bolt tightening tool with an axial force sensor according to the present invention.

  In the present embodiment, as shown in FIG. 3, the insertion hole 113c of the socket 113 is formed so that the diameter of the tool fitting portion 113a and the diameter of the insertion hole 113c on the tool fitting portion 113a side are substantially equal. It is formed so that the diameter gradually decreases toward 113b. The inner diameter of the opening on the bolt fitting portion 113b side of the insertion hole 113c is formed slightly wider than the axial force sensor 11 as in the first embodiment. Therefore, there is no clear boundary between the tool fitting portion 113a and the insertion hole 113c, and the bottom surface of the tool fitting portion 113a does not exist.

  When the bottom part exists in the tool fitting part 113a of the socket 113, there exists a possibility that the front-end | tip part 11a of the axial force sensor 11 may contact the edge of the insertion hole 113c, and may receive damage. According to the present embodiment, since there is no bottom portion in the tool fitting portion 113a, the tip portion 11a of the axial force sensor 11 comes into contact with the edge of the insertion hole 113c and is damaged as shown by the broken line portion in FIG. Things will disappear. Moreover, the axial force sensor 11 is supported by narrowing the opening portion of the insertion hole 113c on the bolt fitting portion 113b side, and the strength of the socket 113 can be maintained.

  Therefore, according to the present embodiment, the tip portion 11a of the axial force sensor 11 does not directly contact the end surface inside the socket 113, so that the axial force sensor 11 can be prevented from being damaged.

(Fourth embodiment)
FIG. 4 is a view showing a fourth embodiment of a bolt tightening tool with an axial force sensor according to the present invention.

  The tool fitting portion 213a of the socket 213 is formed such that the depth from the opening of the tool fitting portion 213a is longer than the axial force sensor 11 protruding from the tightening torque transmission portion 12. Further, before the tightening torque transmitting portion 12 and the socket 313 are fitted, the inner wall surface is formed so as to have a gap between the distal end portion 11a of the axial force sensor 11 and the inner wall surface, as shown by a broken line portion in FIG. To do.

  In the present embodiment, until the socket 213 and the tightening torque transmission portion 12 are coaxial and can be fitted, the front end portion 11a of the direct axial force sensor 11 has a gap between the end surface of the inner wall surface. The tip portion 11a of the axial force sensor 11 does not contact the edge of the insertion hole 213c. Further, when the socket fitting portion of the tightening torque transmitting portion 12 is inserted into the socket 213, the axial force sensor 11 is reliably guided to the insertion hole 213b.

  According to this embodiment, before the tightening torque transmission part 12 is fitted to the socket 213, there is no end face where the tip part 11a of the axial force sensor 11 directly contacts the inner wall surface of the tool fitting part 213a of the socket 213. Damage to the axial force sensor 11 can be prevented. Furthermore, in this embodiment, since the distance between the tool fitting part 213a and the bolt fitting part 213c can be taken sufficiently, the strength of the socket 213 can be sufficiently ensured.

(Fifth embodiment)
FIG. 5 is a view showing a fifth embodiment of a bolt fastening tool with an axial force sensor according to the present invention. FIG. 5A shows the socket 313 before fitting with the tightening torque transmitting portion 12, and FIG. 5B shows bolt tightening with the axial force sensor after fitting the tightening torque transmitting portion 12 and the socket 313. Attached tools are shown.

  The socket 313 includes a plate-like insertion guide 314 for the axial force sensor 11 in the tool fitting portion 313a. An elastic body 315 is coaxially provided between the insertion guide 314 and the insertion hole 313c. The insertion guide 314 has a guide insertion hole 314a for inserting the axial force sensor 11 at the center. The guide insertion hole 314a has a structure in which the inner diameter decreases in the direction of the insertion hole 313c. The elastic body 315 biases the insertion guide 314 toward the tool fitting portion 313a. The insertion hole 313c of the socket 313 is inclined so that the inner diameter becomes smaller toward the bolt fitting portion 313b.

  Next, a procedure for fitting the tightening torque transmission unit 12 and the socket 313 in this embodiment will be described. First, the axial force sensor 11 protruding from the tightening torque transmission portion 12 is inserted into the insertion hole 314 a of the insertion guide 314. Next, the tightening torque transmission part 12 is pushed into the socket 313. At this time, the insertion guide 314 slides into the socket 313, and the axial force sensor 11 is guided to the insertion hole 313 c of the socket 313.

  According to the present embodiment, the sliding insertion guide 314 can reliably guide the distal end portion 11a of the axial force sensor 11 to the insertion hole 313b of the socket 313, thereby protecting the sensor distal end portion 11a. Furthermore, since the insertion hole 314a of the insertion guide 314 and the insertion hole 313c of the socket are provided with an inclination, the insertability of the axial force sensor 11 is improved.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

It is a figure which shows 1st Embodiment of the bolt fastening tool with an axial force sensor by this invention. It is a figure which shows 2nd Embodiment of the bolt fastening tool with an axial force sensor by this invention. It is a figure which shows 3rd Embodiment of the bolt fastening tool with an axial force sensor by this invention. It is a figure which shows 4th Embodiment of the bolt fastening tool with an axial force sensor by this invention. It is a figure which shows 5th Embodiment of the bolt fastening tool with an axial force sensor by this invention, (A) shows the state of a socket single-piece | unit, (B) is the state which the tightening torque transmission part and the socket fitted. FIG.

Explanation of symbols

1 Bolt 10 Bolt Tightening Tool with Axial Force Sensor 11 Axial Force Sensor 12 Tightening Torque Transmitter (Axial Force Measuring Device)
12a Torque wrench fitting portion 12b trunk (axial force measuring device main body)
12c Socket fitting part 12d Axial force sensor storage part 12e Through-hole 13 Socket (Socket part)
13a Tool fitting part 13b Bolt fitting part 13c Insertion hole 14 Lead wire 15 Stopper 16 Sliding part 17 Tension spring (elastic body)

Claims (13)

A bolt tightening tool with an axial force sensor comprising an axial force measuring device for measuring the axial force of a bolt and a detachable socket for fitting with the bolt,
The axial force measuring unit is
A socket fitting portion formed at one end of the axial force measuring device main body portion and having a mounting portion for attaching the socket portion to be fitted with a bolt;
An axial force sensor housed inside the axial force measuring device main body,
With
The socket part is
A tool fitting portion that is formed at one end of the socket body portion and is fitted to the socket mounting portion of the axial force measuring device;
A bolt fitting part that is formed at the other end of the socket body part and is fitted with a bolt,
A bolt tightening tool with an axial force sensor. In the axial force measuring device unit,
A through hole penetrating from the inside of the axial force measuring device main body to the socket fitting portion;
The axial force sensor is inserted from the inside of the axial force measuring device main body through the through hole to the outside.
The bolt tightening tool with an axial force sensor according to claim 1. In the axial force measuring device unit,
An elastic body that biases the axial force sensor so as to protrude from the inside of the main body to the outside;
The bolt tightening tool with an axial force sensor according to claim 2. In the axial force measuring device unit,
The elastic body biases the axial force sensor by a tensile load;
The bolt tightening tool with an axial force sensor according to claim 3. In the axial force measuring device unit,
An inclination preventing member for suppressing the inclination of the axial force sensor;
The bolt tightening tool with an axial force sensor according to any one of claims 2 to 4, wherein the bolt tightening tool has an axial force sensor. In the axial force measuring device unit,
The tilt prevention member loosely inserts the axial force sensor, and a stopper member fixed in the axial force measuring device main body,
A sliding member that slidably passes through the axial force sensor, and a sliding member positioned between the stopper member and the through hole;
The bolt tightening tool with an axial force sensor according to claim 5. In the axial force measuring device unit,
Having a gap between the sliding member and the stopper member,
The bolt tightening tool with an axial force sensor according to claim 6. In the axial force measuring device unit,
The axial force sensor has a temperature sensor for measuring the temperature of the bolt,
The bolt tightening tool with an axial force sensor according to any one of claims 1 to 7. In the axial force measuring device unit,
The temperature sensor is biased by an elastic body so as to protrude from the axial force sensor,
The bolt tightening tool with an axial force sensor according to claim 8. In the socket part,
An insertion hole penetrating from the tool fitting portion through which the axial force sensor is inserted into the bolt fitting portion;
The bolt tightening tool with an axial force sensor according to any one of claims 1 to 9, wherein the bolt tightening tool has an axial force sensor. In the socket part,
The insertion hole has a smaller hole diameter from the tool fitting portion toward the bolt fitting portion,
The bolt tightening tool with an axial force sensor according to claim 10. In the socket part,
A sensor guide part provided with an insertion hole located concentrically with the insertion hole, located in the tool fitting part direction from the insertion hole;
An elastic body that urges the sensor guide portion in the tool fitting portion direction between the sensor guide portion and the insertion hole;
The bolt tightening tool with an axial force sensor according to claim 10 or 11, wherein the bolt tightening tool has an axial force sensor. In the socket part,
The length from the opening of the tool fitting portion to the insertion hole is longer than the length of the axial force sensor from the axial force measuring device,
The bolt tightening tool with an axial force sensor according to any one of claims 10 to 12, wherein the bolt tightening tool has an axial force sensor.

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