JP5656390B2 - Tube thickness measuring apparatus and tube thickness measuring method - Google Patents

Description

  The present invention relates to a pipe thickness measuring apparatus and a pipe thickness measuring method for measuring the thickness of a pipe such as a cast iron pipe.

  Conventionally, in order to measure the tube thickness, for example, as shown in FIG. 10A, the tube thickness T is measured by sandwiching the open end of the tube 71 between the spindle 72 of the micrometer 74 and the anvil 73. It was.

  The above-described tube thickness measurement is a manual measurement by an operator. As an automatic measurement, for example, as shown in FIG. The tube inner surface probe 76 and the tube outer surface probe 77 are brought into close contact with each other, the displacement amount of the tube inner surface probe 76 is detected by the inner peripheral surface displacement sensor 78, and the displacement amount of the tube outer surface probe 77 is detected by the outer peripheral surface. There is a tube thickness measuring device 80 that detects the displacement sensor 79 and automatically calculates the tube thickness T from the detected displacement amount (see Patent Document 1 below).

JP-A-10-213409

  In the conventional method, when the tube thickness is measured using the micrometer 74, as shown in FIG. 10A, the micrometer 74 is placed on a radial straight line 84 passing through the measurement point A from the tube axis 83. It is necessary to measure in a state where the spindle 72 and the anvil 73 are positioned. On the contrary, as shown in FIG. 10B, when the spindle 72 or the anvil 73 comes off the straight line 84, the measured tube thickness T1 becomes larger than the actual tube thickness T, and the accurate The problem was that it was difficult to measure the tube thickness.

Further, the tube thickness measuring apparatus 80 shown in FIG. 11 has a problem that it is difficult to accurately measure the tube thickness as described above.
An object of the present invention is to provide a tube thickness measuring apparatus and a tube thickness measuring method capable of measuring an accurate tube thickness.

In order to achieve the above object, a pipe thickness measuring device according to the first aspect of the present invention includes a pair of opposed contact portions that sandwich a pipe from an inner peripheral surface side and an outer peripheral surface side,
Expansion / contraction means for expanding / contracting the interval between the pair of contact portions;
Detecting means for detecting an interval between the pair of contact portions;
Rocking means for rocking the pair of contact portions around a rocking axis that passes between the pair of contact portions and is parallel to the tube axis ;
The swinging means swings the pair of contact portions from the outside in the tube axial direction from the opening end of the tube .

  According to this, the inner peripheral surface side and the outer peripheral surface side of the pipe are sandwiched by the pair of contact portions, the pair of contact portions swings around the swing axis by the swinging means, and the pair of contacts by the detection means. The interval between the parts is detected. The minimum value of the interval detected by the detection means is obtained, and by setting the minimum value as the thickness of the tube, the accurate tube thickness can be measured.

In the pipe thickness measuring apparatus according to the second aspect of the invention, one contact portion is provided on one frame,
The other contact portion is provided on the other frame,
One frame can be inserted into and removed from the open end of the tube.
The other frame is openable and closable with respect to the one frame in an expansion / contraction direction in which an interval between the pair of contact portions expands / contracts,
The expansion / contraction means comprises a drive device that opens and closes the other frame in the expansion / contraction direction,
The detecting means comprises a displacement meter that detects the amount of displacement of the other frame.

  According to this, one frame is inserted into the tube from the open end of the tube, and the other frame is moved in the closing direction by which the distance between the pair of contact portions is reduced by the driving device. The peripheral surface side and the outer peripheral surface side are sandwiched. The pair of contact portions swings around the swing axis by the swinging means, and the displacement amount of the other frame is detected by the displacement meter, and the distance between the pair of contact portions is based on the detected displacement amount. Is calculated, and the minimum value of the calculated interval is obtained.

In the tube thickness measuring apparatus according to the third aspect of the invention, one and the other frame are provided on a vertically movable member.
The elevating member is provided on a movable member that is movable in the direction of the tube axis.

  According to this, the movable member moves in the direction of the tube axis, and one frame is inserted into the tube from the open end of the tube. Then, when the elevating member rises, one frame rises, and one contact portion comes into contact with the inner peripheral surface of the pipe. Thereafter, the other frame moves in the closing direction in which the distance between the pair of contact portions is reduced by the driving device, and the inner peripheral surface side and the outer peripheral surface side of the pipe are sandwiched by the pair of contact portions.

In the tube thickness measuring method according to the fourth aspect of the invention, the inner peripheral surface side and the outer peripheral surface side of the tube are sandwiched between a pair of opposing contact portions,
Oscillating the pair of contact parts around the oscillation axis parallel to the tube axis passing between the pair of contact parts, and detecting the interval between the pair of contact parts;
The minimum value of the detected interval is the tube thickness.

In the pipe thickness measuring device according to the fifth aspect of the invention, a pair of opposing distance detectors are provided at a predetermined interval,
One distance detector is inserted into the tube and detects the distance to the inner peripheral surface of the tube in a non-contact manner.
The other distance detector detects the distance from the outside of the tube to the outer peripheral surface of the tube in a non-contact manner,
Oscillating means for oscillating the pair of distance detectors around the oscillating axis passing through the pair of distance detectors and parallel to the tube axis ;
The swinging means swings the pair of distance detectors from the outside in the tube axial direction from the opening end of the tube .

  According to this, one distance detector is inserted into the pipe, and the pair of distance detectors are swung around the swing axis by the swinging means, while one of the distance detectors to the inner peripheral surface of the pipe is And the other distance from the other distance detector to the outer peripheral surface of the pipe is detected.

  An accurate tube thickness can be measured by subtracting the one distance and the other distance detected as described above from the predetermined interval as the tube thickness.

The sixth invention is a pipe thickness measuring method using the pipe thickness measuring apparatus described in the fifth invention,
While oscillating a pair of distance detectors about the oscillation axis, one distance from one distance detector to the inner peripheral surface of the tube is detected and the other from the other distance detector to the outer peripheral surface of the tube Detect the distance of
The minimum value obtained by subtracting the detected one distance and the other distance from the predetermined interval is used as the tube thickness.

  As described above, according to the present invention, an accurate tube thickness can be measured.

It is a side view of the tube thickness measuring apparatus in the 1st Embodiment of this invention. It is a top view of a tube thickness measuring apparatus same as the above. FIG. 2 is an XX arrow view in FIG. 1. It is an enlarged view when a pipe | tube is pinched | interposed by a pair of contact part of a pipe thickness measuring apparatus similarly, and shows the measuring method of pipe thickness. It is a side view which shows the procedure when measuring a tube thickness using a tube thickness measuring apparatus. It is a side view of the tube thickness measuring apparatus in the 2nd Embodiment of this invention. It is a side view of the tube thickness measuring apparatus in the 3rd Embodiment of this invention. It is a side view of a tube thickness measuring apparatus and shows the state which is measuring the tube thickness. FIG. 3 is an enlarged view of a pair of distance detectors of the tube thickness measuring apparatus, showing a method for measuring the tube thickness. It is a figure which shows the measuring method when measuring a tube thickness conventionally using a micrometer. It is a figure of the conventional pipe thickness measuring apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIGS. 1 to 3, reference numeral 1 denotes a pipe thickness measuring device that measures the pipe thickness T of the cast iron pipe 2. A transport device 6 that transports the cast iron pipe 2 along the transport path 3 is installed in front of the tube thickness measuring device 1. A holding device (not shown) that holds the cast iron pipe 2 to be transported at the pipe thickness measurement position B is provided on the transport path 3. The tube thickness measurement position B is provided with a tube detection device 5 (for example, a photoelectric switch or a proximity switch) that detects the presence or absence of the cast iron tube 2 at this position.

The tube thickness measuring apparatus 1 has the following configuration.
The tube thickness measuring device 1 includes a movable member 11, an elevating member 12, a pair of upper and lower frames 13 and 14, a pair of upper and lower opposing contact portions 15 and 16, an expansion / contraction cylinder device 17, and a displacement meter 18. It has.

  The movable member 11 has a plurality of wheels 21, is supported and guided by the base frame 22, and is movable in the direction C (front-rear direction) of the tube axis 4. The movable member 11 is moved by a moving cylinder device (an example of moving means, not shown).

  The elevating member 12 is provided on the movable member 11, and includes an elevating frame 25 that is supported and guided by the elevating guide 24 and that can be raised and lowered, and a swinging means 26 provided on the elevating frame 25. In addition, the raising / lowering of the raising / lowering member 12 is performed by the raising / lowering cylinder apparatus 27 (an example of an raising / lowering means) provided in the movable member 11. FIG.

  The contact parts 15 and 16 sandwich the cast iron pipe 2 from the inner peripheral surface side and the outer peripheral surface side, and are made of a roller (rolling element) having a rotatable sphere. Among these, the upper contact portion 15 (an example of the other contact portion) is provided at the front end portion of the upper frame 13, and the lower contact portion 16 (an example of one contact portion) is provided at the front end portion of the lower frame 14. Is provided.

  The frames 13 and 14 are provided on the elevating frame 25 via the swinging means 26. The lower frame 14 (an example of one frame) can be inserted and removed from the open end of the cast iron pipe 2 into the pipe. Further, the upper frame 13 (an example of the other frame) opens / closes (rotates) in the vertical direction D (an example of an expansion / contraction direction in which the interval 37 between the pair of contact portions 15 and 16 expands / contracts) with respect to the lower frame 14. Motion) Each of the frames 13 and 14 is a square steel whose both ends are closed, and a cooling supply pipe 35 and a cooling discharge pipe 36 for allowing cooling water to pass therethrough are connected to each of the frames 13 and 14. ing.

  The lower frame 14 is provided with a lower contact detector (for example, a proximity switch, not shown) that detects that the lower contact portion 16 is in contact with the inner peripheral surface of the cast iron pipe 2. The upper frame 13 is provided with an upper contact detector (for example, a proximity switch or the like, not shown) that detects that the upper contact portion 15 is in contact with the outer peripheral surface of the cast iron pipe 2.

  The swinging means 26 passes through the pair of contact portions 15 and 16 sandwiching the cast iron pipe 2 and around the swing axis 30 parallel to the tube axis 4 and both the frames 13 and 14 and both the contact portions 15 and 16. And a swing frame 31 that can swing around a swing axis 30 and an actuator 32 that swings the swing frame 31. The lower frame 14 is horizontally attached to the lower part of the swing frame 31. Further, the upper frame 13 is attached to the swing frame 31 through the horizontal shaft 33 so as to be rotatable up and down.

  The actuator 32 is centered on a piston (not shown) provided in the cylinder body, a pinion (not shown) that meshes with a rack (not shown) formed on the piston, and the swing axis 30. And a rotatable turntable 32a. By actuating the piston with air pressure, the rack moves and the turntable 32a rotates integrally with the pinion, whereby the swing frame 31 swings, as shown in FIGS. 3 and 4A. The frames 13 and 14 and the contact portions 15 and 16 swing around the swing axis 30.

  The expansion / contraction cylinder device 17 is an example of a drive device that opens and closes the upper frame 13 in the vertical direction D (an example of the expansion / contraction direction), and also expands / contracts the space 37 between the pair of contact portions 15 and 16. It is an example. The cylinder body of the expansion / contraction cylinder device 17 is provided on the swing frame 31, and the tip of the piston rod is connected to the rear end of the upper frame 13.

  The displacement meter 18 detects a displacement amount (rotation amount) in the vertical direction of the upper frame 13 and detects a distance 37 between the pair of contact portions 15 and 16 based on the detected displacement amount. It is an example. The displacement meter 18 is an optical one, but may be a mechanical one.

  2 and 3, the elevating member 12, the frames 13, 14, the swinging means 26, the expansion / contraction cylinder device 17, the displacement meter 18, and the contact portions 15, 16 are movable together. Two sets of members 11 are provided.

Hereinafter, the operation of the above configuration will be described.
First, as shown in FIG. 5A, the movable member 11 is moved back to the standby position E in a state where the upper frame 13 is rotated upward to increase the interval 37 between the pair of contact portions 15 and 16. Keep it. Then, the cast iron pipe 2 is transported on the transport path 3 by the transport device 6 and is held at the pipe thickness measurement position B by the holding device, and the pipe detection device 5 detects the cast iron pipe 2 held at the pipe thickness measurement position B. 5B, the movable member 11 advances from the standby position E along the tube axis 4, and the lower frame 14 is inserted into the tube from the open end of the cast iron tube 2.

  Next, when the elevating member 12 is raised, the lower contact portion 16 is raised together with the lower frame 14 and comes into contact with the inner peripheral surface of the cast iron pipe 2 as shown by the phantom line in FIG. At this time, the lower contact detector detects that the lower contact portion 16 is in contact with the inner peripheral surface of the cast iron pipe 2, and the lifting member 12 stops based on this detection.

  Thereafter, when the piston rod of the expansion / contraction cylinder device 17 is shortened, the upper frame 13 is rotated downward (that is, in the closing direction), and the upper contact portion 15 is lowered to contact the outer peripheral surface of the cast iron pipe 2. The space 37 between the pair of contact portions 15 and 16 is reduced. Thereby, as shown with the continuous line of FIG. 1, the inner peripheral surface side and outer peripheral surface side of the cast iron pipe 2 are pinched | interposed by a pair of contact parts 15 and 16. FIG. At this time, the upper contact detector detects that the upper contact portion 15 has come into contact with the outer peripheral surface of the cast iron pipe 2, and based on this detection, the expansion / contraction cylinder device 17 stops, and the expansion / contraction cylinder device 17 The expansion and contraction of the piston rod is switched to the free state.

  In this state, the actuator 32 is actuated to swing the swing frame 31, whereby the pair of contact portions 15 and 16 swing together with the frames 13 and 14 as shown in FIGS. It swings about the axis 30. At this time, the swing range of the contact portions 15 and 16 is set to a range of a predetermined angle F (for example, ± 22.5 °) with reference to the vertical axis 38 orthogonal to the swing axis 30.

  While the two contact portions 15 and 16 are swung as described above, the displacement amount of the upper frame 13 is detected by the displacement meter 18, and the distance between the pair of contact portions 15 and 16 is determined based on the detected displacement amount. And the minimum value of the calculated interval 37 is obtained, and this minimum value is set as the tube thickness T of the cast iron pipe 2.

  In the pipe thickness measuring method as described above, a displacement occurs when the cast iron pipe 2 is held at the pipe thickness measuring position B, and the pipe axis 4 is brought into contact with the contact portion 15 as shown in FIG. 4, even when the position is shifted by a predetermined distance G in the direction of the conveyance path 3, the two contact portions 15, 16 are swung as described above, so that FIG. ), Both the contact portions 15 and 16 are located on a radial straight line 84 passing through the measurement point A from the tube axis 4, and the minimum value of the interval 37 between the contact portions 15 and 16 is obtained. By setting the value as the pipe thickness T of the cast iron pipe 2, the accurate pipe thickness can be measured.

  After the pipe thickness is automatically measured as described above, the piston rod of the expansion / contraction cylinder device 17 extends, so that the upper frame 13 faces upward (that is, in the opening direction) as shown by the phantom line in FIG. The upper contact portion 15 rises and is separated from the outer peripheral surface of the cast iron pipe 2, and the interval 37 between the pair of contact portions 15 and 16 is enlarged.

  Next, as shown by the solid line in FIG. 5B, when the elevating member 12 is slightly lowered, the lower contact portion 16 is lowered together with the lower frame 14 to be separated from the inner peripheral surface of the cast iron pipe 2. . Then, as shown in FIG. 5A, the movable member 11 moves back to the standby position E along the tube axis 4, and the lower frame 14 is removed from the open end of the cast iron tube 2 to the outside of the tube.

  Thereafter, the cast iron pipe 2 whose pipe thickness has been measured is transported from the pipe thickness measurement position B to the downstream side of the transport path 3, and the unmeasured cast iron pipe 2 is transported from the upstream side of the transport path 3 to the pipe thickness measurement position B. Then, the tube thickness is measured by the tube thickness measuring device 1 in the same manner as described above.

  Further, since the cast iron pipe 2 to be measured is in a high temperature state after casting, as shown in FIG. 1, cooling water is caused to flow through the frames 13 and 14 using the cooling supply and discharge pipes 35 and 36. By cooling, adverse effects such as deformation of the frames 13 and 14 due to heat can be suppressed, and accurate measurement can be performed.

  In the first embodiment, as shown in FIGS. 2 and 3, ascending / descending member 12, frames 13 and 14, swinging means 26, expansion / contraction cylinder device 17, displacement meter 18, and contact portions 15 and 16. Are provided on one common movable member 11, so that the thickness of two cast iron pipes 2 can be measured simultaneously. However, the present invention is not limited to this configuration. Multiple sets of more than one set may be provided and the thickness of three or more cast iron pipes 2 may be measured simultaneously, or only one set (single set) may be provided to reduce the thickness of the cast iron pipe 2 by one. You may measure one by one.

  In the first embodiment, the displacement amount of the upper frame 13 may be continuously detected while both the contact portions 15 and 16 are continuously swung, or both the contact portions 15 and 16 are detected. The amount of displacement of the upper frame 13 may be intermittently detected while intermittently swinging at every small angle.

  In the first embodiment, proximity switches and the like are used for the lower contact detector and the upper contact detector, respectively. However, for the lower contact detector, the lower frame 14 is a lifting cylinder device. The cylinder pressure of the elevating cylinder device 27 when the lower contact portion 16 is reliably brought into contact with the inner peripheral surface of the cast iron pipe 2 is set in advance to such a pressure that the cast iron pipe 2 does not float up. If so, a timer may be used instead of the proximity switch. In this case, the elevating cylinder device 27 is operated, and when the predetermined time measured by the timer has elapsed, the elevating cylinder device 27 is stopped. During this time, the lower contact portion 16 reliably contacts the inner peripheral surface of the cast iron pipe 2.

  Similarly, with respect to the upper contact detector, the cylinder pressure of the expansion / contraction cylinder device 17 can be made to reliably contact the outer peripheral surface of the cast iron pipe 2 by the upper frame 13 rotating downward. If the pressure is preset, a timer may be used instead of the proximity switch. In this case, the expansion / contraction cylinder device 17 is operated, and when the predetermined time measured by the timer has elapsed, the expansion / contraction cylinder device 17 is stopped. During this time, the upper contact portion 15 reliably contacts the outer peripheral surface of the cast iron pipe 2. From the viewpoint of maintenance and management of the apparatus, it is preferable to use timers for the lower and upper contact detectors as described above.

(Second Embodiment)
In the first embodiment, as shown in FIG. 1, contact portions 15 and 16 made of rollers are provided at the tips of a pair of upper and lower frames 13 and 14, but in the second embodiment, As shown in FIG. 6, contact portions 15 and 16 bent in the vertical direction are formed at the tips of the pair of upper and lower calipers 41 and 42.

  The expansion / contraction means for expanding / contracting the space 37 between the pair of contact portions 15, 16 is connected to the expansion / contraction cylinder device 17 provided on the movable member 11 and the front end portion (free end portion) of the upper caliper 41. The other end has an expansion / contraction wire 43 connected to the piston rod of the expansion / contraction cylinder device 17. The expansion / contraction wire 43 is guided by guide rollers 44 and 45 provided on the elevating member 12. Further, when the piston rod of the expansion / contraction cylinder device 17 is shortened, the upper caliper 41 opens (rotates) upward, and the interval 37 is enlarged. Further, when the piston rod of the expansion / contraction cylinder device 17 extends, the upper caliper 41 closes (rotates) downward due to its own weight, and the interval 37 is reduced.

(Third embodiment)
In the first and second embodiments, the pipe thickness measuring device 1 that measures the pipe thickness by contacting the inner and outer peripheral surfaces of the cast iron pipe 2 as shown in FIGS. 1 and 6 has been described. In this embodiment, as shown in FIGS. 7 to 9, a pipe thickness measuring device 60 that measures the pipe thickness in a non-contact manner without contacting the cast iron pipe 2 will be described. In addition, about the same member as the member demonstrated in the said 1st Embodiment, the same code | symbol is attached and description is abbreviate | omitted.

  The upper and lower frames 13 and 14 are respectively attached to the swing frame 31 in a horizontal and parallel manner. A lower distance detector 61 (an example of one distance detector) that is inserted into the cast iron pipe 2 and detects one distance L1 to the inner peripheral surface of the cast iron pipe 2 at the front end of the lower frame 14 Is provided. Further, an upper distance detector 62 (an example of the other distance detector) that detects the other distance L2 from the outside of the pipe to the outer peripheral surface of the cast iron pipe 2 is provided at the front end portion of the upper frame 13. . The distance detectors 61 and 62 irradiate the inner and outer peripheral surfaces of the cast iron pipe 2 with laser light or ultrasonic waves, receive the reflected light or reflected waves, and based on the phase difference between the inner and outer peripheral surfaces. The distance to is detected. The lower distance detector 61 and the upper distance detector 62 are opposed to each other with a predetermined interval L (a constant value) in the vertical direction. The predetermined interval L is set larger than the tube thickness T of the cast iron pipe 2.

  Further, the swinging means 26 passes both the frames 13 and 14 and the both distance detectors 61 and 62 around the swing axis 30 passing between the pair of distance detectors 61 and 62 and parallel to the tube axis 4. The swing frame 31 is swingable and has a swing frame 31 that can swing around the swing axis 30 and an actuator 32 that swings the swing frame 31.

  The pipe thickness measuring device 60 uses the pipe thickness T of the cast iron pipe 2 based on the predetermined distance L between the distance detectors 61 and 62 and the distances L1 and L2 detected by the distance detectors 61 and 62. A calculating unit 63 for calculating is provided.

Hereinafter, the operation of the above configuration will be described.
First, as shown in FIG. 7, the movable member 11 is retracted to the standby position E, the elevating member 12 is moved up and down, and the distance detectors 61 and 62 are adjusted to a height corresponding to the diameter of the cast iron pipe 2. . Then, the cast iron pipe 2 is transported on the transport path 3 by the transport device 6 and is held at the pipe thickness measurement position B by the holding device, and the pipe detection device 5 detects the cast iron pipe 2 held at the pipe thickness measurement position B. Then, the movable member 11 moves forward from the standby position E along the tube axis 4 and the lower frame 14 is inserted into the tube from the opening end of the cast iron tube 2, thereby, as shown in FIG. Is inserted between the pair of distance detectors 61 and 62.

  In this state, the actuator 32 is actuated to swing the swing frame 31, whereby the pair of distance detectors 61 and 62 together with the frames 13 and 14 are pivoted as shown in FIG. Oscillates around 30. In this way, while the distance detectors 61 and 62 are swung, the distance detectors 61 and 62 detect one distance L1 and the other distance L2. At this time, the calculation unit 63 calculates a value L3 (that is, L3 = L− (L1 + L2)) obtained by subtracting the detected one and other distances L1 and L2 from the predetermined interval L, and the minimum of these calculated values L3 is calculated. The value is the tube thickness T of the cast iron tube 2.

  In the pipe thickness measurement method as described above, a displacement occurs when the cast iron pipe 2 is held at the pipe thickness measurement position B, so that the pipe axis 4 moves from directly below the distance detectors 61 and 62 to the transport path 3. Even when the position is displaced by a predetermined distance G in the direction, by swinging the both distance detectors 61 and 62 as described above, as shown in FIG. The detectors 61 and 62 are positioned on a radial straight line 84 passing through the measurement point A from the tube axis 4 and the minimum value of the value L3 calculated as described above is set as the tube thickness T of the cast iron tube 2. Accurate tube thickness can be measured.

  After the pipe thickness is automatically measured as described above, the movable member 11 moves back to the standby position E along the pipe axis 4 and the lower frame 14 opens the cast iron pipe 2 as shown in FIG. It is pulled out of the tube from the end.

  In the third embodiment, one and the other distances L1, L2 may be continuously detected while both distance detectors 61, 62 are continuously swung, or both distance detectors 61 may be detected. , 62 may be intermittently detected while the one and the other distances L1, L2 are intermittently swung for each small angle.

  In each said embodiment, although the cast iron pipe 2 was mentioned as an example of a pipe | tube, it is not limited to the cast iron pipe 2, For example, a steel pipe, a resin pipe, etc. may be sufficient.

DESCRIPTION OF SYMBOLS 1 Pipe thickness measuring apparatus 2 Cast iron pipe 4 Pipe axis 11 Movable member 12 Lifting member 13 Upper frame (the other frame)
14 Lower frame (one frame)
15 Upper contact part (the other contact part)
16 Lower contact part (one contact part)
17 Cylinder device for expansion / contraction (expansion / contraction means, drive device)
18 Displacement meter (detection means)
26 Oscillating means 30 Oscillating axis 37 Distance between contact portions 60 Tube thickness measuring device 61 Lower distance detector (one distance detector)
62 Upper distance detector (the other distance detector)
C Tube axis direction D Vertical direction (stretching direction)
L Predetermined distance L1 One distance L2 The other distance L3 Value obtained by subtracting one distance and the other distance from the predetermined distance T

Claims (6)

A pair of opposed contact portions sandwiching the tube from the inner peripheral surface side and the outer peripheral surface side;
Expansion / contraction means for expanding / contracting the interval between the pair of contact portions;
Detecting means for detecting an interval between the pair of contact portions;
Rocking means for rocking the pair of contact portions around a rocking axis that passes between the pair of contact portions and is parallel to the tube axis ;
The tube thickness measuring apparatus characterized in that the swinging means swings the pair of contact portions from the outside in the axial direction of the tube rather than the opening end of the tube . One contact portion is provided on one frame,
The other contact portion is provided on the other frame,
One frame can be inserted into and removed from the open end of the tube.
The other frame is openable and closable with respect to the one frame in an expansion / contraction direction in which an interval between the pair of contact portions expands / contracts,
The expansion / contraction means comprises a drive device that opens and closes the other frame in the expansion / contraction direction,
2. The tube thickness measuring apparatus according to claim 1, wherein the detecting means comprises a displacement meter for detecting a displacement amount of the other frame. One and the other frame are provided on a lifting member that can be raised and lowered,
3. The pipe thickness measuring device according to claim 2, wherein the elevating member is provided on a movable member movable in the direction of the tube axis. The inner peripheral surface side and the outer peripheral surface side of the tube are sandwiched between a pair of opposing contact portions,
Oscillating the pair of contact parts around the oscillation axis parallel to the tube axis passing between the pair of contact parts, and detecting the interval between the pair of contact parts;
A tube thickness measuring method characterized in that the minimum value of the detected interval is the tube thickness. A pair of opposing distance detectors are provided at a predetermined interval,
One distance detector is inserted into the tube and detects the distance to the inner peripheral surface of the tube in a non-contact manner.
The other distance detector detects the distance from the outside of the tube to the outer peripheral surface of the tube in a non-contact manner,
Oscillating means for oscillating the pair of distance detectors around the oscillating axis passing through the pair of distance detectors and parallel to the tube axis ;
The tube thickness measuring apparatus characterized in that the swinging means swings the pair of distance detectors from the outside in the tube axial direction from the opening end of the tube . A pipe thickness measuring method using the pipe thickness measuring apparatus according to claim 5,
While oscillating a pair of distance detectors about the oscillation axis, one distance from one distance detector to the inner peripheral surface of the tube is detected and the other from the other distance detector to the outer peripheral surface of the tube Detect the distance of
A tube thickness measuring method, characterized in that a minimum value obtained by subtracting the detected one distance and the other distance from a predetermined interval is used as the tube thickness.

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