Ultrasonic wave propagating member

Abstract

Provided is an ultrasonic wave propagating member capable of improving durability while ensuring measurement accuracy. An ultrasonic wave propagating member (6A) includes: an ultrasonic wave propagating portion (10A) having a first contact surface (11a) that contacts a bolt (2A) as an example of a measurement target, and a second contact surface (11b) provided on the opposite side of the first contact surface (11a) and contacting a front surface (5b) of an ultrasonic probe (5); and a holding portion (20A) that holds the ultrasonic wave propagating portion (10A) and has a third contact surface (23a) that contacts the bolt (2A) on the radially outer side compared to the first contact surface (11a), the ultrasonic wave propagating portion (10A) being softer than the holding portion (20A).

Description

Technical Field

[0001] The present invention relates to a component for propagating ultrasonic waves generated by an ultrasonic probe toward a measured object. Background Technology

[0002] When measuring the bolt (tightening) axial force during bolt tightening, the following operation is performed: an elastic mechanism is provided to fill the gap between the ultrasonic probe and the bolt head (see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-20749

[0006] Because this elastic component is used in a state of compression deformation under load between the ultrasonic probe and the object being measured (bolt), it is difficult to balance measurement accuracy and durability. Summary of the Invention

[0007] The present invention was made in view of the above-mentioned matters, with the objective of providing an ultrasonic propagation component that can improve durability while ensuring measurability.

[0008] To address the aforementioned issues, the ultrasonic propagation component of the present invention is characterized by comprising: an ultrasonic propagation section having a first contact surface that contacts the object being measured, and a second contact surface disposed on the opposite side of the first contact surface and in contact with the front end face of the ultrasonic probe; and a holding section that holds the ultrasonic propagation section and has a third contact surface that contacts the object being measured radially outward compared to the first contact surface, wherein the ultrasonic propagation section is more flexible than the holding section.

[0009] Invention Effects

[0010] According to the present invention, durability can be improved while ensuring the measurability of the ultrasonic wave propagation component. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating the fastening device according to the first embodiment of the present invention.

[0012] Figure 2 (a) and (b) are schematic three-dimensional diagrams representing the ultrasonic wave propagation components.

[0013] Figure 3 This diagram illustrates the state after the fastening device is installed with the bolts.

[0014] Figure 4 This is a schematic diagram illustrating the fastening device according to the second embodiment of the present invention.

[0015] Figure 5 This diagram illustrates the state after the fastening device is installed with the bolts.

[0016] Explanation of reference numerals in the attached figures

[0017] 1A, 1B Fastening devices (bolt axial force measuring devices)

[0018] Bolts 2A and 2B (objects of measurement)

[0019] 2a Head

[0020] 2b concave part

[0021] 2b1 bottom surface

[0022] 2b2 Inner circumferential surface

[0023] 2c concave part

[0024] 2c1, 2c2 bottom surface

[0025] 2c3 inner circumferential surface

[0026] 4. Socket

[0027] 5. Ultrasonic probe

[0028] 5a External thread section (fixed section)

[0029] 5b Front end face (lower surface)

[0030] 6A, 6B Ultrasonic Propagation Components

[0031] 10A, 10B Ultrasonic Propagation Section

[0032] 10a R section

[0033] 11 Main Body

[0034] 11a First contact surface (lower surface)

[0035] 11b Second contact surface (upper surface)

[0036] 12 First Extension Setting Section

[0037] 13 Second Extension Installation Section

[0038] 14. Protrusion

[0039] 20A, 20B Holding Section

[0040] 21 Main body

[0041] 22 First Extension Setting Section

[0042] 23 Second Extension Installation Section

[0043] 23a Third contact surface (lower surface)

[0044] 23b Fourth contact surface (outer peripheral surface)

[0045] 23c Chamfered part Detailed Implementation

[0046] Hereinafter, embodiments of the present invention will be described using a bolt as the object of measurement and an ultrasonic probe to measure the bolt's axial force as an example, with appropriate reference to the accompanying drawings. Identical components will be labeled with the same reference numerals, and repeated descriptions will be omitted. Furthermore, the object of measurement in the present invention is not limited to bolts; the ultrasonic propagation component of the present invention can be used in combination with devices that use ultrasonic probes to measure the dimensions, axial force, etc., of the object of measurement.

[0047] <First Implementation>

[0048] like Figure 1 As shown, the fastening device (nut tightening device) 1A of the first embodiment of the present invention is also a bolt axial force measuring device for measuring the bolt (fastening) axial force generated when fastening bolt 2A. The bolt axial force measuring device fastens bolt 2A by rotating the fastening device 1A mounted on bolt 2A through a control unit (not shown) that drives a drive unit (motor, etc.) (not shown). The control unit of the bolt axial force measuring device calculates the bolt axial force based on the echo of the ultrasonic pulse during bolt tightening. The fastening device 1A includes a rotating shaft 3, a socket 4, an ultrasonic probe 5, and an ultrasonic wave propagation component 6A.

[0049] <Rotation axis>

[0050] The rotating shaft 3 is a cylindrical component that rotates at a predetermined torque and rotational speed (rotational angular velocity) under the control of a control unit (not shown).

[0051] <Chengkou>

[0052] The socket 4 is a cylindrical component externally fitted into the rotating shaft 3 and the bolt 2A. The base end (upper end) of the socket 4 is externally fitted and fixed to the front end (lower end) of the rotating shaft 3 in a detachable manner. The front end (lower end) of the socket 4 can be externally fitted into the head 2a of the bolt 2A.

[0053] <Ultrasonic probe>

[0054] The ultrasonic probe 5 is a generally cylindrical component mounted within the socket 4 at the front end (lower end) of the rotating shaft 3. The ultrasonic probe 5 includes a piezoelectric element that oscillates ultrasonic pulses and detects the echoes of the oscillating ultrasonic pulses. The ultrasonic probe 5 can also be mounted at the front end of the rotating shaft 3 via a support member (not shown), an elastic helical spring, or the like. An external thread 5a is formed on the outer peripheral surface of the ultrasonic probe 5. The front end face (lower end face) 5b of the ultrasonic probe 5 can contact the base end face (upper surface) of the main body of the ultrasonic propagation section 10A, which will be described later. Furthermore, on the outer peripheral surface of the ultrasonic probe 5, the portion closer to the front end (lower side) than the external thread 5a does not have an external thread 5a, but instead has a small-diameter portion 5c with a smaller diameter than the external thread 5a. On the outer peripheral surface of the ultrasonic probe 5, the portion closer to the base end (upper side) than the external thread 5a does not have an external thread 5a, but instead has a large-diameter portion 5d with a larger diameter than the external thread 5a. The diameter of the large diameter portion 5d is set to be larger than the diameter of the internal thread portion 21a and smaller than the diameter of the radial inner end of the hole portion 21b.

[0055] <Ultrasonic propagation components>

[0056] The ultrasonic wave propagation component 6A is a generally bottomed cylindrical resin component installed within the socket 4 at the front (lower) end of the ultrasonic probe 5. The ultrasonic wave propagation component 6A fills the gap between the ultrasonic probe 5 and the head 2a of the bolt 2A, and propagates the ultrasonic pulses oscillating from the ultrasonic probe 5 to the bolt 2A, or propagates the echoes of the ultrasonic pulses from the bolt 2A to the ultrasonic probe 5. Figure 1 and Figure 2 As shown in (a) and (b), the ultrasonic wave propagation component 6A of the first embodiment of the present invention includes an ultrasonic wave propagation section 10A and a holding section 20A.

[0057] <Ultrasound Propagation Department>

[0058] The ultrasonic wave propagation section 10A is a component that enables ultrasonic pulses to propagate between the ultrasonic probe 5 and the bolt 2A. The ultrasonic wave propagation section 10A is formed of a material softer than the holding section 20A. Specifically, it is formed of a soft material that can be compressed and deformed axially (vertically) within its elastic deformation range when mounted on the bolt 2A; in this embodiment, it is formed of an elastomer. The ultrasonic wave propagation section 10A integrally comprises a main body section 11, a first extension section 12, a second extension section 13, and a protrusion section 14.

[0059] The main body 11 is a circular plate-shaped portion that transmits ultrasonic pulses. The front end face (lower surface) of the main body 11 forms a first contact surface 11a that contacts the bottom surface 2b1 of the recess 2b, which is circular when viewed from above, formed in the head 2a of the bolt 2A. The base end face (upper surface) of the main body 11, located on the opposite side of the first contact surface 11a, forms a second contact surface 11b that contacts the front end face (lower end face) 5b of the ultrasonic probe 5.

[0060] The first extension portion 12 is a portion that extends radially outward from the radially outer end of the main body portion 11. The first extension portion 12 is provided in such a way that it tends to extend upward as it extends radially outward.

[0061] The second extension portion 13 is a portion that extends radially outward from the radially outer end of the first extension portion 12. The second extension portion 13 extends in a direction orthogonal to the axial direction of the rotating shaft 3, the socket 4, and the ultrasonic probe 5.

[0062] The protrusion 14 is a portion extending upward from the radially outer end of the second extended portion 13. The protrusion 14 has an arc shape when viewed from above. In this embodiment, four protrusions 14 are formed at equal intervals in the circumferential direction.

[0063] <Maintenance Section>

[0064] The retaining part 20A is a component that holds the ultrasonic wave propagating part 10A relative to the ultrasonic probe 5. The retaining part 20A is formed of a material harder than the ultrasonic wave propagating part 10A. Specifically, it is formed of a hard material capable of positioning relative to the bolt 2A when mounted on it; in this embodiment, it is formed of polypropylene. The retaining part 20A integrally comprises a main body part 21, a first extension part 22, and a second extension part 23. Furthermore, the material of the retaining part 20A is not limited to polypropylene; any material harder than the ultrasonic wave propagating part 10A (having greater hardness) and capable of performing functions such as holding the ultrasonic wave propagating part 10A, fixing it relative to the ultrasonic probe 5, or positioning it relative to the recess 2b of the bolt 2A is acceptable.

[0065] The main body 21 is a cylindrical portion. An internal thread 21a is formed on the inner circumferential surface of the main body 21. The internal thread 21a is an example of a fixing portion that is fixed to the outer circumferential surface of the ultrasonic probe 5. An arc-shaped hole 21b extending vertically through the main body 21 is formed. In this embodiment, four holes 21b, corresponding to the four protrusions 14, are formed at equal intervals in the circumferential direction.

[0066] The first extension portion 22 is an annular portion extending downward from the radially inner end of the main body portion 21. The first extension portion 22 extends radially inward as it extends downward. The first extension portion 22, by virtue of its shape, serves to position the front end of the ultrasonic probe 5. The lower surface of the first extension portion 22 contacts the upper surface of the main body portion 11 of the ultrasonic propagation portion 10A, thereby stabilizing the compression deformation of the main body portion 11.

[0067] The second extension portion 23 is an annular portion extending downward from the radially outer end of the main body portion 21. The second extension portion 23 extends further downward than the first extension portion 22. The front end face (lower surface) of the second extension portion 23 forms a third contact surface 23a that contacts the bottom surface 2b1 of the recess 2b of the bolt 2A. This third contact surface 23a is located radially outward compared to the first contact surface 11a and the second contact surface 11b of the ultrasonic wave propagation portion 10A. The outer peripheral surface of the second extension portion 23 forms a fourth contact surface 23b that contacts the inner peripheral surface 2b2 of the recess 2b of the bolt 2A.

[0068] <Assembly Method for Ultrasonic Wave Propagation and Holding Parts>

[0069] The ultrasonic wave propagating part 10A is inserted (pressed) into the hole 21b of the retaining part 20 from below via the protrusion 14, or is simultaneously formed (integratedly formed) and fixed to the retaining part 20A in this state. In the assembled state, the upper surface of the main body 11, the inner peripheral surface of the first extension part 12, and the upper surface of the second extension part 13 are in contact with the lower surface of the first extension part 22, the outer peripheral surface of the first extension part 22, and the lower surface of the main body 21, respectively. The lower surface of the second extension part 23, i.e., the third contact surface 23a, is located between the lower surface of the main body 11, i.e., the first contact surface 11a, and the upper surface of the main body 11, i.e., the second contact surface 11b, in the axial direction of the ultrasonic probe 5. That is, before being installed with the bolt 2A, the third contact surface 23a is located above the first contact surface 11a and below the second contact surface 11b.

[0070] <Assembly Method of Ultrasonic Propagation Components and Ultrasonic Probe>

[0071] The ultrasonic propagation component 6A is fixed to the ultrasonic probe 5 by screwing an internal thread 21a formed on the inner circumferential surface of the main body 21 with an external thread 5a formed on the outer circumferential surface of the ultrasonic probe 5. In the assembled state, the front end face (lower surface) 5b of the ultrasonic probe 5 contacts the upper surface of the main body 11, i.e., the second contact surface 11b. Furthermore, the small-diameter portion 5c of the ultrasonic probe 5 contacts the lower end of the inner circumferential surface of the first extension portion 22 (the portion without the internal thread 21a). Additionally, the surface (downward-facing surface) of the boundary between the external thread 5a and the large-diameter portion 5d of the ultrasonic probe 5 contacts the base end face (upper surface) of the main body 21. Through these contacts, the ultrasonic probe 5 and the ultrasonic propagation component 6A are positioned relative to each other.

[0072] <Method for installing bolts>

[0073] The socket 4 is externally fitted into the head 2a of the bolt 2A. Here, the ultrasonic wave propagating component 6A is inserted into the recess 2b formed in the head 2a of the bolt 2A, thereby being mounted on the bolt 2A. The outer peripheral surface of the second extension portion 23, i.e., the fourth contact surface 23b, contacts the inner peripheral surface 2b2 of the recess 2b. This allows for proper positioning of the ultrasonic wave propagating component 6A and the ultrasonic probe 5 in a direction orthogonal to the axis. Furthermore, the lower surface of the main body 11, i.e., the first contact surface 11a, and the lower surface of the second extension portion 23, i.e., the third contact surface 23a, contact the bottom surface 2b1 of the recess 2b. Here, the main body 11 and the first extension portion 12 are compressed and deformed until the first contact surface 11a, which is the lower surface, becomes the same height as the third contact surface 23a.

[0074] The outer peripheral surface of the first extension portion 12 is tapered, tapering downwards, which makes it easy for the main body portion 11 and the first extension portion 12 to be compressed and deformed in the vertical direction. A clearance is ensured between the outer peripheral surface of the first extension portion 12 and the inner peripheral surface of the second extension portion 23 when the main body portion 11 and the first extension portion 12 are compressed and deformed.

[0075] In this state, a control unit (not shown) drives a drive unit (motor, etc., not shown) to rotate the rotating shaft 3 and the socket 4. This causes the bolt 2A to engage with the hole (not shown) and be secured. Here, the control unit (not shown) drives the ultrasonic probe 5 to oscillate ultrasonic pulses. The ultrasonic pulses propagate to the bolt 2A via the main body 11 of the ultrasonic propagation unit 10A. The ultrasonic probe 5 detects the echo from the head 2a (bottom surface 2b1 of the recess 2b) of the bolt 2 and the echo from the front end face (lower surface) of the shaft portion of the bolt 2A, and outputs the detection results to the control unit (not shown).

[0076] The control unit (not shown) calculates the bolt axial force based on the detection results.

[0077] The ultrasonic wave propagation component 6A according to the first embodiment of the present invention includes: an ultrasonic wave propagation section 10A having a first contact surface 11a that contacts the object to be measured (bolt 2A) and a second contact surface 11b provided on the opposite side of the first contact surface 11a and in contact with the front end surface 5b of the ultrasonic probe 5; and a holding section 20A that holds the ultrasonic wave propagation section 10A and has a third contact surface 23a that contacts the object to be measured radially outward compared to the first contact surface 11a, wherein the ultrasonic wave propagation section 10A is more flexible than the holding section 20A.

[0078] Therefore, since the ultrasonic propagating part 10A of the ultrasonic propagating component 6A is more flexible than the holding part 20B, the compression deformation of the main body part 11 and the first extension part 12 of the ultrasonic propagating part 10A can be appropriately set by the third contact surface 23a of the holding part 20B, and the durability of the ultrasonic propagating part 10A can be improved while ensuring the measurability.

[0079] In the ultrasonic wave propagation component 6A, when it is installed before the object being measured, the first contact surface 11a is located on the object side compared to the third contact surface 23a.

[0080] Therefore, the ultrasonic wave propagation component 6A can appropriately set the compression deformation of the main body 11 and the first extension part 12 of the ultrasonic wave propagation part 10A according to the amount of protrusion of the first contact surface 11a relative to the third contact surface 23a, and can improve the durability of the ultrasonic wave propagation part 10A while ensuring measurability.

[0081] In the ultrasonic wave propagation component 6A, the holding part 20A has a fixing part that is fixed to the outer peripheral surface of the ultrasonic wave probe 5.

[0082] Therefore, since the ultrasonic wave propagation component 6A is fixed to the ultrasonic wave probe 5 by a retaining part 20A that is harder than the ultrasonic wave propagation component 10A, the stability relative to the ultrasonic wave probe 5 can be improved, which helps to make accurate measurements.

[0083] In the ultrasonic wave propagation component 6A, the fixing part is an internal threaded part 21a that engages with the external threaded part 5a formed on the outer peripheral surface of the ultrasonic probe 5.

[0084] Therefore, since the ultrasonic propagation component 6A is fixed to the ultrasonic probe 5 by the retaining part 20A through threaded engagement, the fixation relative to the ultrasonic probe 5 can be further improved, which helps to make the measurement more accurate.

[0085] In the ultrasonic wave propagation component 6A, the first contact surface 11a and the third contact surface 23a are in contact with the bottom surface 2b1 of the recess 2b formed on the measuring object (the head 2a of the bolt 2A), and the holding part 20A has a fourth contact surface 23b that is in contact with the inner peripheral surface 2b2 of the recess 2b.

[0086] Therefore, the ultrasonic propagation component 6A can improve the positioning and fixation relative to the object being measured, and contribute to accurate measurement.

[0087] In the ultrasonic wave propagation component 6A, the ultrasonic wave propagation part 10A is formed of an elastomer.

[0088] Therefore, the ultrasonic propagation component 6A can improve the tightness relative to the object being measured and the ultrasonic probe 5, and contribute to accurate measurement.

[0089] In the ultrasonic wave propagation component 6A, the retaining part 20A is formed of polypropylene.

[0090] Therefore, since the retaining part 20A of the ultrasonic wave propagation component 6A is made of polypropylene, which is harder than the ultrasonic wave propagation part 10A, it is possible to suppress excessive compression of the ultrasonic wave propagation part 10A and set the load within an appropriate range.

[0091] <Second Implementation>

[0092] Next, the fastening device of the second embodiment of the present invention will be described, focusing on the differences from the first embodiment. For example... Figure 4 As shown, in the recess 2c of bolt 2B, the bottom surface 2c1 on the radially central side is deeper than the bottom surface 2c2 on the radially outer side. In the second embodiment of the present invention, the fastening device 1B replaces the ultrasonic wave propagation component 6A with an ultrasonic wave propagation component 6B, which has an ultrasonic wave propagation portion 10B and a holding portion 20B.

[0093] In the ultrasonic wave propagation section 10B, the boundary portion (corner) between the outer peripheral surface of the first extension section 12 and the lower surface of the second extension section 13 is an R-shaped R-section 10a. This prevents cracks from forming due to compression deformation of the main body section 11 and the first extension section 12.

[0094] In the ultrasonic wave propagation section 10B, the protrusion 14 has a shape that tapers radially towards the top. Furthermore, in the holding section 20B, the hole 21b formed in the main body section 21 has a shape corresponding to the protrusion 14.

[0095] In the ultrasonic wave propagation section 10B, the boundary portion between the third contact surface 23a and the fourth contact surface 23b becomes a chamfered portion 23c. Thus, the chamfered portion 23c serves as a guide portion, making it easier to install the ultrasonic wave propagation component 6B relative to the recess 2c of the bolt 2B.

[0096] <Method for installing bolts>

[0097] The socket 4 is externally fitted into the head 2a of the bolt 2B. Here, the ultrasonic wave propagation component 6B is inserted into the recess 2c formed in the head 2a of the bolt 2B, thereby being mounted on the bolt 2B. The outer peripheral surface of the second extension portion 23, i.e., the fourth contact surface 23b, contacts the inner peripheral surface 2c3 of the recess 2c. This allows for proper positioning of the ultrasonic wave propagation component 6B and the ultrasonic probe 5 in a direction orthogonal to the axis. Furthermore, the lower surface of the main body 11, i.e., the first contact surface 11a, contacts the bottom surface 2c1 of the recess 2c, and the lower surface of the second extension portion 23, i.e., the third contact surface 23a, contacts the bottom surface 2c2 of the recess 2c. Here, the main body 11 is compressed and deformed only by an amount corresponding to the height difference between the bottom surfaces 2c1 and 2c2. Between the outer peripheral surface of the first extension portion 12 and the inner peripheral surface of the boundary formed in the bottom surfaces 2c1 and 2c2 of the recess 2c, a clearance is ensured for the main body 11 and the first extension portion 12 during compression and deformation. Furthermore, the bottom surface of the second extension portion 13 is set higher than the third contact surface 23a (set at a position away from the bolt 2B), ensuring a gap between the bottom surface of the second extension portion 13 and the bottom surface 2c2 of the recess 2c when the socket 4 and the ultrasonic transducer 6B are installed on the bolt 2B. This allows for proper positioning based on the third contact surface 23a.

[0098] The above describes the embodiments of the present invention, but the present invention is not limited to the above embodiments, and appropriate modifications can be made without departing from the spirit of the present invention.

Claims

1. An ultrasonic wave propagating member characterized by comprising: Possessing: an ultrasonic wave propagation portion having a first contact surface that contacts a measurement object and a second contact surface that is on the opposite side of the first contact surface and contacts a front end surface of an ultrasonic probe; and a holding portion that holds the ultrasonic wave propagation portion and has a third contact surface that contacts the measurement object on the radially outer side compared to the first contact surface, the ultrasonic wave propagation portion is softer than the holding portion, a protruding portion that is fixed from below by being inserted into a hole portion of the holding portion, the first contact surface and the third contact surface contact a bottom surface of a recess formed in the measurement object, the holding portion has a fourth contact surface that contacts an inner peripheral surface of the recess.

2. The ultrasonic wave propagation member according to claim 1, characterized by In a state before being mounted to the measurement object, the first contact surface is located on the measurement object side compared to the third contact surface.

3. The ultrasonic wave propagation member according to claim 1, characterized by The holding portion possesses a fixing portion that is fixed to an outer peripheral surface of the ultrasonic probe.

4. The ultrasonic wave propagation member according to claim 3, characterized by The fixing portion is an internal thread portion that is screwed with an external thread portion formed in the outer peripheral surface of the ultrasonic probe.

5. The ultrasonic wave propagating member according to claim 1, wherein The ultrasonic wave propagation portion is formed of an elastomer.

6. The ultrasonic wave propagation member according to claim 5, characterized by The holding portion is formed of polypropylene.

7. An ultrasonic wave propagating member characterized by comprising: Possessing: an ultrasonic wave propagation portion having a first contact surface that contacts a measurement object and a second contact surface that is on the opposite side of the first contact surface and contacts a front end surface of an ultrasonic probe; and a holding portion that holds the ultrasonic wave propagation portion and has a third contact surface that contacts the measurement object on the radially outer side compared to the first contact surface, the ultrasonic wave propagation portion is softer than the holding portion, a protruding portion that is fixed from below by being inserted into a hole portion of the holding portion, the protruding portion is integrally formed in a state of being inserted into the hole portion of the holding portion, the first contact surface and the third contact surface contact a bottom surface of a recess formed in the measurement object, the holding portion has a fourth contact surface that contacts an inner peripheral surface of the recess.

8. An ultrasonic wave propagating member characterized by comprising: Possessing: an ultrasonic wave propagation portion having a first contact surface that contacts a measurement object and a second contact surface that is on the opposite side of the first contact surface and contacts a front end surface of an ultrasonic probe; and a holding portion that holds the ultrasonic wave propagation portion and has a third contact surface that contacts the measurement object on the radially outer side compared to the first contact surface, the ultrasonic wave propagation portion is softer than the holding portion, the ultrasonic wave propagation portion has a protruding portion that is provided extending upward from the front end surface of the ultrasonic wave propagation portion on a radially outer end portion of the ultrasonic wave propagation portion and is disposed in a hole portion of the holding portion, the first contact surface and the third contact surface contact a bottom surface of a recess formed in the measurement object, the holding portion has a fourth contact surface that contacts an inner peripheral surface of the recess.

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