JP7421072B2 - Steel surface inspection equipment - Google Patents

Description

The present invention relates to a steel surface layer inspection device that inspects the surface layer of a steel material by detecting a surface hardness change portion formed on the surface layer of the steel material.

Conventionally, non-contact inspection methods have been used to detect surface flaws and internal structural defects in steel materials. For example, a current flaw detection device has been proposed as a method for inspecting walls for defects (for example, see Patent Document 1). Additionally, an inspection using ultrasonic flaw detection has been proposed as a pipeline inspection method (see, for example, Patent Document 2).

Incidentally, in recent years, sulfide stress cracking (SSC) has become a problem in steel materials exposed to a hydrogen sulfide environment. It has become clear that SSC occurs in the surface layer of steel materials exposed to sulfides such as hydrogen sulfide, starting from hardened areas of the steel material whose hardness is higher than a predetermined hardness upper limit. Furthermore, if the strength of the steel material is insufficient, the steel material may break at a softened surface layer whose hardness is lower than a predetermined lower limit of hardness in the surface layer of the steel material. Hereinafter, the surface hardening section and the surface softening section will be collectively referred to as the surface hardness changing section.

Japanese Patent Application Publication No. 2010-25801 Japanese Patent Application Publication No. 2006-112525

As a method for inspecting the surface layer of such a steel material, as described above, a method of indirectly detecting the surface hardness change part using a non-contact detection method such as Patent Documents 1 and 2 and inspecting the surface layer of the steel material is used. Can be done. However, in both Patent Documents 1 and 2, in order to scan the probe for detecting defects, it is necessary to run a wheel on which the probe scans on the surface of the steel material. For this reason, the range in which the surface hardness change portion can be detected by scanning with the probe is limited to the area where the surface of the steel material can be inspected with the probe when the wheel runs along the edge of the steel material. Therefore, there is a problem in that the vicinity of the edge of the steel material becomes a dead zone in which the surface hardness change portion cannot be detected by the probe. In order to detect surface hardness changes in this dead zone, it is necessary to perform a separate inspection using a contact inspection method, for example, which increases the number of steps required for inspection, so it is important to minimize the area of the dead zone as much as possible. was desired.

Therefore, the present invention was made in view of the above-mentioned circumstances, and it suppresses the range that becomes a dead zone in which surface layer hardness changes cannot be detected by a non-contact method, and efficiently detects surface layer hardness changes. The present invention provides a steel material surface layer inspection device that can perform the following steps.

In order to solve the above problems, the present invention employs the following means.
That is, the steel material surface layer inspection device according to one aspect of the present invention includes a support section provided with a plurality of first running wheels that can run on the surface of the steel material in a first direction, and a support section that is supported by the support section and that is capable of inspecting the steel material surface. By scanning along the surface of the steel material, either a surface hardened part where the hardness of the surface layer of the steel material exceeds a predetermined upper limit value or a surface softened part where the hardness of the surface layer of the steel material exceeds a predetermined lower limit value. and a probe for detecting a surface hardness change area on one side, and the first running wheel is configured to detect a surface hardness change area of the probe at both ends of the inspection target surface in a second direction orthogonal to the first direction. The measurement limit line is placed inside a measurement limit line that is placed a predetermined distance outside an imaginary boundary line that passes through the outermost point in the second direction along the first direction.
According to this configuration, the probe supported by the support part is scanned in the first direction along the surface of the steel material by traveling in the first direction on the surface of the steel material by the first running wheel provided on the support part. be able to. Here, a virtual boundary line that the first running wheel passes in the first direction through the outermost point in the second direction of the testable range of the probe at both ends in the second direction perpendicular to the first direction along the surface to be inspected. The measurement limit line is located inside the measurement limit line, which is located a predetermined distance outside the measurement limit line. Therefore, even if the probe travels near the edge of the steel material according to the first running theory, the surface of the steel material is inspected to a position close to the edge without being affected by the edge shape of the steel material, and the surface hardness changes are detected. can be detected.

Moreover, in the above-mentioned steel material surface layer inspection apparatus, the first running wheel may be arranged inside the virtual boundary line in the second direction.
According to this configuration, since the first running wheel is arranged inside the virtual boundary line in the second direction, the probe can be arranged at a position closer to the edge of the steel material when viewed from above.

In the above-mentioned steel material surface layer inspection device, the support portion supports the probe and is arranged on both sides of the first direction with the probe in between, and runs in the first direction along the surface of the steel material. a probe holder provided with a plurality of possible guide wheels; The probe may include support frame portions provided respectively, and a connection portion that connects the support frame portion and the probe holder and is elastically deformable downward by the weight of the probe and the probe holder.
According to this configuration, the first running wheels are provided on both sides in the first direction with the probe holder sandwiched in the support frame portion that supports the probe holder, so that the first running wheels can run stably while supporting the probe holder. can do. A probe holder that supports the probe is disposed so as to be surrounded by a support frame portion formed in a frame shape, and is supported by the support frame portion via a connecting portion. Therefore, the probe and the probe holder supporting the probe are stably supported and can be displaced in the vertical direction by elastically deforming the connecting portion in the vertical direction. The probe holder is provided with a plurality of guide wheels that are movable in the first direction. Therefore, when the probe supported by the probe holder travels in the first direction by the first running wheel, the guide wheel can scan the surface of the steel material while traveling in the first direction on the surface of the steel material. . As mentioned above, the connecting part can be elastically deformed in the vertical direction, so even if the surface of the steel material is sloped or curved, the connecting part can be elastically deformed depending on the surface condition of the steel material, and multiple The guide ring can be maintained in contact with the surface of the steel material. This allows the probe to be kept at a constant distance from the surface of the steel material, thereby suppressing fluctuations in inspection accuracy.

Moreover, in the above-mentioned steel material surface layer inspection device, the connecting portions may be arranged on both sides of the probe holder in the first direction.
According to this configuration, the probe holder is supported by the connecting portions on both sides of the probe holder in the first direction. Therefore, the probe and the probe holder supporting the probe can be stably supported, and the probe can be made to follow the surface of the steel material more suitably.

In the steel surface inspection device, the connecting portion includes a first end fixed to a side of the support frame portion and a second end fixed to a side of the probe holder, and is elastically deformable. an elastic member, a regulated portion fixed to one of the support frame portion and the probe holder, and provided on the other of the support frame portion and the probe holder, the regulated portion being movable in the vertical direction. In addition, the control unit may further include a regulating portion that regulates the movement of the regulated portion in the vertical direction when the regulated portion moves relative to the regulated portion by a predetermined amount in the vertical direction.
According to this configuration, the elastic member whose first end and second end are fixed to the support frame portion and the probe holder, respectively, is elastically deformed and can follow the surface of the steel material. On the other hand, if the probe and the probe holder that supports the probe try to move in the vertical direction by a larger amount than a predetermined amount, the regulated part is regulated by the regulating part, and this causes the probe and the probe holder to move in the vertical direction excessively. Displacement can be suppressed.

Further, in the above-mentioned steel material surface layer inspection apparatus, the second running wheel capable of traveling in the second direction and the second running wheel are moved relative to the first running wheel in the vertical direction, and the second running wheel a first state where the first running wheel is spaced apart from the surface of the steel material and can travel in the first direction by the first running wheel; and a first state where the first running wheel is spaced apart from the surface of the steel material and the second running wheel moves the The vehicle may also include a switching mechanism capable of switching to a second state in which the vehicle can travel in a second direction.
According to this configuration, the surface of the steel material can be inspected by scanning the probe in the first direction by traveling with the first running wheel in the first state in which the second running wheel is spaced apart from the surface of the steel material. Next, the switching mechanism switches the first running wheel to a second state in which it is separated from the surface of the steel material, and the second running wheel travels in the second direction, thereby moving the surface of the steel material from the position where the probe inspected the surface of the steel material to the second state. The position can be shifted in the direction. Then, after shifting its position, it switches back to the first state and runs using the first running wheel. The surface of the steel material can be inspected by scanning the probe in the first direction at a position different in the second direction from the previously inspected position.

Further, in the above-mentioned steel material surface layer inspection apparatus, the probes are arranged in a plurality of rows in the second direction, and the first probe group is arranged in the first direction. A second probe group is arranged such that it overlaps the first probe group when viewed in the first direction, and is configured by arranging a plurality of the probes side by side in the second direction. and
The probes of the first probe group and the probes of the second probe group may be arranged such that their positions are alternately shifted in the second direction.
According to this configuration, the first probe group and the second probe group are arranged so as to overlap when viewed in the first direction, and the positions of the respective probes are alternately shifted in the second direction. ing. Therefore, inspection can be performed at a pitch smaller than the array pitch of the plurality of probes in each of the first probe group and the second probe group, suppressing mutual magnetic interference between probes and detecting errors. can do.

According to the present invention, it is possible to suppress the range that becomes a dead zone in which the surface layer hardness change portion cannot be detected by a non-contact method, and to efficiently detect the surface layer hardness change portion.

It is a side view of the steel material surface layer inspection device of an embodiment. It is a front view of the steel material surface layer inspection device of an embodiment. 3 is a sectional view taken along cutting line II in FIGS. 1 and 2. FIG. It is a side view showing details of a probe holder and a connection part of a steel material surface layer inspection device of an embodiment. FIG. 1 is a block diagram of a steel material surface layer inspection device according to an embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIGS. 1 to 5. FIGS. 1 to 5 show a steel surface layer inspection apparatus of this embodiment. The steel surface layer inspection apparatus 1 of this embodiment is an apparatus that inspects a surface to be inspected 102 of the surface of a steel material 101 and detects a surface layer hardness change portion in the surface layer including the surface to be inspected 102.

The surface layer hardness change portion is a portion where hardness differs beyond a predetermined range compared to other portions of the surface layer. Such a surface layer hardness changing portion is, for example, a surface hardening portion which is a region exceeding a predetermined upper limit of hardness, or a surface layer softening portion which is a region exceeding a predetermined lower limit of hardness. When heat-treating steel materials, it may not be possible to uniformly heat or cool the steel materials due to problems with the heat treatment equipment. In such a case, the crystal structure of the manufactured steel material is non-uniform, and the hardness of the surface layer of the steel material is not uniform, resulting in a surface layer hardness change part occurring in a part of the surface layer of the steel material. In the following, a device for detecting a hardened surface portion will be described as an example of a portion where the hardness of the surface layer changes, but the present invention is not limited to this, and a device for detecting a softened surface portion may also be used.

(Surface inspection device)
As shown in FIGS. 1 to 3, the steel material surface layer inspection device 1 of this embodiment includes a probe 2 for inspecting the surface of a steel material 101, and a marking device for marking the position of the surface hardened portion detected by the probe 2. part 3, a first running wheel 4 that can run on the inspection surface 102 in a first direction P along the inspection surface 102 of the steel material 101, and a first running wheel 4 that is perpendicular to the first direction P and runs along the inspection surface 102 of the steel material 101. A second running wheel 5 that can run on the inspection target surface 102 in two directions Q is provided. Further, the steel material surface layer inspection device 1 of the present embodiment has a support part 10 that supports the probe 2, a first state in which it can run on the first running wheel 4, and a second state in which it can run on the second running wheel 5. and a switching mechanism 50 that can be switched between. Further, the steel material surface layer inspection device 1 includes a control section 80 that controls the probe 2, the marking section 3, and the switching mechanism 50, and a position for detecting the position of the steel material surface layer inspection device 1 on the inspection target surface 102 of the steel material 101. detection means 90.
Details will be explained below.

(probe)
The probe 2 of this embodiment is used for an eddy current flaw detection test. Each probe 2 has a coil 2a and a core 2b around which the coil 2a is wound (see FIG. 5). The probe 2 detects the surface hardened portion based on changes in the magnetic field generated by supplying alternating current power to the coil 2a. In this embodiment, the steel material surface layer inspection apparatus 1 includes a first probe group 2A and a second probe group 2B each composed of a plurality of probes 2. The first probe group 2A is configured by arranging a plurality of probes 2 in the second direction Q. Similarly, the second probe group 2B is configured by arranging a plurality of probes 2 in the second direction Q. As shown in FIGS. 2 and 3, the first probe group 2A and the second probe group 2B are arranged so as to overlap each other when viewed in the first direction P, and the probes 2 of each other are They are arranged at alternate positions in two directions Q. More specifically, in this embodiment, with respect to the position of the probes 2 in the first probe group 2A arranged at a predetermined arrangement pitch in the second direction Q, the probes 2 in the second probe group 2B are They are arranged at the same arrangement pitch in the second direction Q by shifting their positions in the second direction Q by half of the above arrangement pitch. Thereby, the plurality of probes 2 of the first probe group 2A and the second probe group 2B are arranged in a so-called zigzag pattern when viewed from above.

(Support part)
As shown in FIGS. 1 to 3, the support section 10 includes a support frame 11, two probe holders 30 that are supported by the support frame 11 and support the probe 2, and a connection that connects the support frame 11 and the probe holder 30. 40. Two probe holders 30 are provided corresponding to the first probe group 2A and the second probe group 2B, and openings 33 are formed in the probe holders 30. Each probe 2 directly faces the inspection target surface 102 of the steel material 101 through the opening 33, and is capable of inspecting the inspection target surface 102 of the steel material 101. Here, as shown in FIG. 3, in this embodiment, the testable range M of each probe 2 is defined in a circular shape. Note that the shape and size of the testable range M of the probes 2 are merely examples, and the shape and size of each probe 2, the magnitude and frequency of the current supplied to each probe 2, and the steel material 101 that is the subject of each probe 2. It also varies depending on the distance from the steel material 101, the electromagnetic properties of the steel material 101, etc. Further, the probes 2 of the adjacent first probe group 2A and the probes 2 of the second probe group 2B touch the boundary of the testable range M on the sides facing each other and are located at a virtual boundary passing along the first direction P. They are arranged so that the lines match. It should be noted that the probes 2 of the adjacent first probe group 2A and the probes 2 of the second probe group 2B overlap in part in the testable range M when viewed in the first direction P, and in the second direction Q. They may be arranged so that they complement each other in the testable range. At least, the first probe group 2A and the second probe group 2B are spaced apart in the first direction P so that the testable ranges M do not overlap, and the probes 2 of the first probe group 2A and the second probe group By preventing the testable ranges M of the 2B probes 2 from overlapping in the second direction Q, magnetic interference between the probes 2 can be suppressed. On the other hand, as described above, the first probe group 2A and the second probe group 2B form a virtual boundary line that touches the boundary of the testable range M of the probe 2 on the sides facing each other and passes along the first direction P. By matching or by making the testable ranges M of the probes 2 overlap in the second direction Q, it is possible to perform a thorough test in the second direction Q.

Among the plurality of probes 2 arranged as the first probe group 2A and the second probe group 2B, the probes 2-1 and 2-2 that are arranged at both ends in the second direction Q are inspectable range M. By virtual boundary lines Q1 and Q2 passing along the first direction P through the outermost point in the second direction Q among the boundaries of A measurable range in the second direction Q is defined. Note that virtual lines that pass through positions that are a predetermined distance N away from the virtual boundary lines Q1 and Q2 in the second direction Q are called measurement limit lines Q3 and Q4. When the first running wheel 4 travels near the edge of the steel material 101, if the edge of the steel material 101 is located inside the measurement limit lines Q3, Q4, the shape of the edge of the steel material 101 will change to the probes 2-1, 2-2. - Affects the measurement results of 2. The predetermined distance N that defines the measurement limit lines Q3 and Q4 depends on the shape of each probe 2, the magnitude and frequency of the current supplied to each probe 2, the separation distance of each probe 2 from the steel material 101 that is the test object, and the steel material. It is defined by the electromagnetic properties of 101, etc.

(Support frame)
As shown in FIGS. 1 to 3, the support frame 11 is made of, for example, a plurality of steel materials. The support frame 11 includes a support frame portion 12 formed to surround the probe holder 30 and support the first running wheel 4, pillar portions 15 rising from the four corners of the support frame portion 12, and connecting the upper ends of the pillar portions 15. and an upper frame portion 20 formed in a rectangular frame shape. Further, at the upper end of the column part 15, grip parts 22-1 and 22-2 are provided which protrude from both sides of the first direction P and can be gripped by the operator. When traveling on the positive side of the first direction P, the grip portion 22-1 provided on the negative side of the first direction P is used. Furthermore, when traveling in the negative side of the first direction P, the grip portion 22-2 provided on the positive side of the first direction P is used.

The support frame portion 12 includes a pair of first support members 12a and a pair of second support members 12b, and has a rectangular frame shape in plan view due to the pair of first support members 12a and the pair of second support members 12b. It is configured. The pair of first support members 12a are arranged at intervals in the first direction P, and each extends in the second direction Q to connect the column parts 15 to each other. The pair of second support members 12b are arranged at intervals in the second direction Q, and extend in the first direction P to connect the columns. In this embodiment, two first running wheels 4 are provided on each pair of first support members 12a so as to be provided on both sides of the first direction P with the pair of probe holders 30 interposed therebetween. In each of the first support members 12a, the two first running wheels 4 are arranged side by side in the second direction Q, and are positioned symmetrically with respect to the center line of the first support member 12a facing in the first direction P. It is set in. Each first running wheel 4 is provided with its rotation axis facing in the second direction Q. Further, the support frame portion 12 includes a third support member 12c that extends in the second direction Q between the pair of first support members 12a and connects the intermediate portions of the pair of second support members 12b. One probe holder 30 is arranged so as to be surrounded by a rectangular frame formed by one first support member 12a, a pair of second support members 12b, and a third support member 12c. Further, the other probe holder 30 is arranged so as to be surrounded by a rectangular frame formed by the other first support member 12a, the pair of second support members 12b, and the third support member 12c. Here, as shown in FIG. 3, the first running wheel 4 is arranged inside the measurement limit lines Q3 and Q4 when viewed in the first direction X. Further, the first running wheel 4 passes along the first direction P through the outermost point in the second direction Q in the testable range M of the probe at both ends in the second direction Q, as viewed in the first direction X. It may be arranged inside the virtual boundary lines Q1 and Q2.

(probe holder)
As shown in FIG. 3, each probe holder 30 is provided with a plurality of guide wheels 35 that can run in the first direction P. The guide ring 35 is rotatably attached to the probe holder 30 by a rotating shaft facing in the second direction Q. The guide wheels 35 are arranged on both sides of the probe 2 in the first direction P, respectively. In this embodiment, each probe holder 30 is provided with three guide wheels 35 . In each probe holder 30, on the side facing outward in the first direction P, that is, on the side opposite to the side where the pair of probe holders 30 face each other, there is one guide ring 35 located at the center of the probe holder 30 in the second direction Q. is provided. In each probe holder 30, on the side facing inward in the first direction P, that is, on the side where the pair of probe holders 30 face each other, there are two A guide wheel 35 is provided. As shown in FIGS. 1 and 2, the probe 2 is supported by a probe holder 30 that is supported by a guide ring 35 on the surface to be inspected 102, so that the probe 2 can be moved upwardly from the surface to be inspected by a certain height. are spaced apart.

(Connection part)
As shown in FIG. 3, the connecting portions 40 are provided on both sides of the first direction P with the probe holder 30 interposed therebetween. In this embodiment, three connecting parts 40 are provided corresponding to each probe holder 30. In each probe holder 30, on the side facing outward in the first direction P, that is, on the side opposite to the side where the pair of probe holders 30 face each other, there are two Two connecting portions 40 are provided to connect the probe holder 30 and the first support member 12a of the support frame portion 12. Further, in each probe holder 30, on the side facing inward in the first direction P, that is, on the side where the pair of probe holders 30 face each other, there is one connecting portion 40 at a position at the center of the probe holder 30 in the second direction Q. The probe holder 30 and the third support member 12c of the support frame portion 12 are connected to each other. That is, for each probe holder 30, on the side facing outside in the first direction P, a guide ring 35 is provided at the center in the second direction Q, and connecting portions 40 are provided on both sides of the guide ring 35, facing inside in the first direction P. On the side, a connecting portion 40 is provided at the center in the second direction Q, and guide wheels 35 are provided on both sides thereof.

As shown in FIG. 4, each connecting portion 40 includes an elastic member 42 that is fixed to the support frame portion 12 and is elastically deformable according to the weight of the probe 2 and probe holder 30. As shown in FIG. The elastic member 42 is made of rubber, for example. A first end of the elastic member 42 is fixed to the support frame 12, and a second end is fixed to the probe holder 30. Furthermore, each connecting portion 40 includes a restricted portion 44a and a restricted portion 44b that restrict relative movement of the probe holder 30 in the vertical direction with respect to the support frame portion 12.

The regulated portion 44a is formed of, for example, a piece of steel. The regulated portions 44a are provided on both sides of the probe holder 30 in the first direction P, and extend from the probe holder 30 toward the first support member 12a and the third support member 12c, respectively. The regulating portion 44b is provided on the first support member 12a and the third support member 12c in correspondence with each probe holder 30. The regulating portion 44b extends from the first support member 12a and the third support member 12c toward each probe holder 30, respectively. Further, the regulating portion 44b is formed of, for example, a piece of steel. The regulating portion 44b is disposed below the regulated portion 44a with a gap therebetween. Therefore, the probe holder 30 can move relative to the support frame 12 in the vertical direction by the amount of the gap. On the other hand, when the probe holder 30 moves downward relative to the support frame part 12 by the amount of the gap, the restricted part 44a engages with the restricting part 44b, and further downward relative movement is restricted.

(switching mechanism)
As shown in FIGS. 1 and 2, the switching mechanism 50 includes an actuator 51 fixed to the support frame 11, and supports the second running wheel 5, and is movable relative to the support frame 11 in the vertical direction by the actuator 51. A moving section 52 is provided. The actuator 51 is attached to the column part 15 of the support frame 11. The actuator 51 is a hydraulic cylinder, for example, and is capable of moving the rod downward. The moving part 52 is fixed to the rod of the actuator 51. The moving part 52 is made of steel, for example. Therefore, by moving the rod of the actuator 51 back and forth, the moving section 52 provided with the second running wheel 5 can be moved relative to the support frame 11 provided with the first running wheel 4 in the vertical direction. . Then, the switching mechanism 50 causes the second running wheel 5 to be positioned above the first running wheel 4 and separated from the inspection target surface 102, and moved in the first direction P by the first running wheel 4. A first state in which the vehicle can travel, and a second state in which the first traveling wheel 4 is located above the second traveling wheel 5 and is spaced apart from the inspection target surface 102 and can travel in the second direction Q by the second traveling wheel 5. It can be switched between two states.

(Marking part)
As shown in FIGS. 1 and 3, the marking section 3 includes mounting sections 3a-1 and 3a-2 supported by the support frame 11 at positions spaced apart from the surface to be inspected 102, and mounting sections 3a-1 and 3a-2. The marking bodies 3b-1 and 3b-2 are respectively fixed to the marking bodies 3b-1 and 3b-2 for marking the position where the surface hardened portion is detected by the probe 2. In this embodiment, the attachment part and the marking body are the attachment part 3a-1 and the marking body 3b-1 used when traveling in the positive side of the first direction P for measurement, and the attachment part 3a-1 and the marking body 3b-1 used when traveling in the negative side of the first direction P for measurement. Two sets are provided: a mounting portion 3a-2 and a marking body 3b-2, which are sometimes used. When measuring while traveling on the positive side of the first direction P, the marking body 3b-1 provided on the negative side of the first direction P is used. Furthermore, when measuring while traveling on the negative side of the first direction P, the marking body 3b-2 provided on the positive side of the first direction P is used. In addition, only two sets of attachment parts may be provided, and the marking body may be replaced on the corresponding attachment part depending on the direction of travel. Each attachment portion 3a-1, 3a-2 extends in a cantilevered manner from the support frame 11 in the first direction P so as to be spaced apart from the corresponding first probe group 2A or second probe group 2B. The attachment parts 3a-1 and 3a-2 are provided with fixing parts 3c on which corresponding marking bodies 3b-1 and 3b-2 are placed and fixed. The fixing portion 3c is formed with an opening 3d that passes through the fixing portion 3c in the vertical direction. Therefore, marking can be performed by spraying ink onto the surface to be inspected 102 through the opening 3d from the marking bodies 3b-1 and 3b-2 fixed to the fixed part 3c. Here, each marking body 3b-1, 3b-2 discharges ink such that the position in the second direction Q matches each probe 2 of the first probe group 2A or the second probe group 2B. A plurality of nozzles 3e are provided. That is, in this embodiment, since the first probe group 2A and the second probe group 2B include a total of eight probes 2, each marking body 3b-1, 3b-2 includes eight nozzles 3e. ing. Therefore, when a surface layer hardness change part is detected with a specific probe 2, the surface layer hardness change is detected by spraying ink onto the inspection target surface 102 with the corresponding nozzle 3e whose position in the second direction Q matches. It is possible to mark the surface 102 to be inspected at the position where the marking is made.

(Position detection means)
As shown in FIGS. 1, 3, and 19, the position detection means 90 includes a first proximity sensor 91 and a second proximity sensor 92 that detect the presence or absence of the inspection target surface 102, and a position with respect to the inspection target surface 102. A first position sensor 93 and a second position sensor 94 are provided. The first proximity sensor 91 and the second proximity sensor 92 detect whether or not there is the inspection target surface 102 below. The first proximity sensor 91 is provided on both sides in the second direction Q at the tip side of each attachment portion 3a-1, 3a-2. Therefore, when the steel material surface layer inspection device 1 is moved in the first direction P and the first proximity sensor 91 reaches the edge of the steel material 101, the detection result of the first proximity sensor 91 is switched from ON to OFF. It can be detected that the edge has been reached. Further, two second proximity sensors 92 are provided on both sides of the support frame 11 in the second direction Q, spaced apart in the first direction P. Therefore, when the steel material surface layer inspection device 1 is moved in the second direction Q and the second proximity sensor 92 reaches the edge of the steel material 101, the detection result of the second proximity sensor 92 switches from ON to OFF. It can be detected that the edge has been reached.

The first position sensor 93 detects the position on the surface to be inspected 102 when the steel surface inspection device 1 is moved in the first direction P, thereby making it possible to grasp the position of the probe 2 on the surface to be inspected 102. The first position sensor 93 includes a first encoder 93a fixed to the third support member 12c, and a detection wheel 93b rotatably attached to the first encoder 93a around an axis extending in the second direction Q. The detection wheel 93b is provided at an intermediate position in the first direction P between the first probe group 2A and the second probe group 2B. The detection wheel 93b contacts the surface to be inspected 102 in the first state in which it can run on the first running wheel 4, and can roll on the surface to be inspected 102 together with the first running wheel 4. Therefore, by detecting the rotational speed of the detection wheel 93b with the first encoder 93a when traveling with the first running wheel 4, it is possible to detect the position of the steel material surface layer inspection device 1 in the first direction P.

The second position sensor 94 detects the position on the surface to be inspected 102 when the steel surface inspection device 1 is moved in the second direction Q, thereby making it possible to grasp the position of the probe 2 on the surface to be inspected 102. . The second position sensor 94 is a second encoder connected to one of the rotating shafts of the second running wheel 5. Therefore, by detecting the rotational speed of the second running wheel 5 with the second encoder when traveling with the second running wheel 5, it is possible to detect the position of the steel material surface layer inspection device 1 in the first direction P. .

(control unit)
FIG. 5 shows details of the control section 80. As shown in FIG. 5, the control unit 80 includes an AC power source 81 that supplies AC power to the coil 2a of each probe 2 having a coil 2a and a core 2b, and a detection unit 82 that detects the impedance of the coil 2a of each probe 2. Equipped with. Further, the control unit 80 includes a determination unit 83 that determines whether there is a surface hardened portion based on the results of the detection unit 82, and a marking drive unit 84 that drives the marking unit 3. Each coil 2a of the plurality of probes 2 is connected in parallel to an AC power source 81, and can generate a magnetic field using an AC current supplied from the AC power source 81. When the subject is a magnetic material, eddy currents are generated in the surface layer of the subject including the surface to be inspected 102 facing the probe 2 due to changes in the magnetic field caused by the alternating current. Normally, in a steel material 101 such as the steel plate 101, the state of the surface layer portion is substantially uniform, so that the impedance detected by the coil 2a of the probe 2 is substantially constant. On the other hand, if the surface hardened portion is included in the area where eddy currents are generated, the surface hardened portion has different magnetic properties, that is, characteristics with respect to the magnetic field generated by the coil 2a, than other parts. Changes also occur. Therefore, when the probe 2 is placed near the hardened surface portion, the impedance detected from the coil 2a by the detection unit 82 changes. The determination unit 83 determines the presence or absence of a surface hardened portion based on this change in impedance. The determination method by the determination unit 83 is, for example, performed by comparing the impedance detection result with a preset upper limit value or lower limit value. The upper limit value is determined in advance by determining the correlation between hardness and impedance for each material type of the test object, and from the value of hardness to be determined as a surface hardened portion. Based on the determination result of the determination unit 83, if a surface hardened portion is detected, detection information is output to the marking drive unit 84. The marking drive section 84 drives the marking bodies 3b-1 and 3b-2 corresponding to the probe 2 from which the detection information has been acquired. Which of the marking bodies 3b-1 and 3b-2 is to be driven is changed depending on whether the marking body is moving in the positive direction or the negative direction in the first direction P. Here, upon acquiring the detection information, the marking drive unit 84 acquires the detection result from the first encoder 93a. Then, the marking drive section 84 drives the corresponding marking bodies 3b-1 and 3b-2 at the timing when the detection wheel 93b rotates by the number of rotations corresponding to the distance between the probe 2 and the marking bodies 3b-1 and 3b-2. Marking is then performed on the inspection target surface 102 of the steel plate 101. Thereby, marking can be performed at the position where the surface hardened portion is detected by the probe 2. Note that in FIG. 5, only the first probe group 2A is connected to the AC power source 81 and the detection unit 82 for simplicity of illustration, but each probe 2 of the second probe group 2B is also connected. ing. Similarly, marking bodies 3b-1 and 3b-2 corresponding to each probe 2 of the second probe group 2B are also connected to the marking drive section 84. In addition, not only the first encoder 93 a of the position detecting means 90 but also the configuration of each position detecting means 90 is connected to the control section 80 .

In the steel material surface inspection apparatus 1 of this embodiment, the probe supported by the support part 10 is moved by the first running wheel 4 provided on the support part 10 on the inspection target surface 102 of the steel material 101 in the first direction P. 2 can be scanned in the first direction P along the inspection target surface 102 of the steel material 101. Here, the first running wheel 4 is arranged inside the measurement limit lines Q3 and Q4. Therefore, even if the first running wheel 4 travels near the edge of the steel material 101, the probe 2 can reach the surface to be inspected 102 of the steel material 101 to a position close to the edge without being affected by the edge shape of the steel material 101. can be inspected to detect changes in surface hardness. Therefore, it is possible to suppress the range that becomes a dead zone in which the surface layer hardness change portion cannot be indirectly detected, and to efficiently detect the surface layer hardness change portion. Furthermore, the first running wheel 4 moves the boundaries of both ends of the second direction in the testable range M of the probes 2-1 and 2-2 at both ends of the second direction Q to the first direction P. By disposing the probe 2 inside the virtual boundary lines Q1 and Q2 that it passes along, the probe 2 can be disposed at a position closer to the edge of the steel material 101 when viewed from above.

Further, since the first running wheels 4 are provided on both sides of the first direction P with the probe holder 30 sandwiched between the support frame portion 12 that supports the probe holder 30, the probe holder 30 can be stably supported. can be run on. A probe holder 30 that supports the probe 2 is arranged so as to be surrounded by a frame-shaped support frame part 12, and is supported by the support frame part 12 via connecting parts 40 on both sides in the first direction P. There is. Therefore, the probe 2 and the probe holder 30 that supports the probe 2 are stably supported, and can be displaced in the vertical direction by elastically deforming the connecting portion 40 in the vertical direction. be. The probe holder 30 is provided with a plurality of guide wheels 35 that are movable in the first direction P. Therefore, when the probe 2 supported by the probe holder 30 travels in the first direction P by the first running wheel 4, the guide wheel 35 travels in the first direction P on the inspection target surface 102 of the steel material 101. , the inspection target surface 102 of the steel material 101 can be scanned. As described above, since the connecting portion 40 can be elastically deformed in the vertical direction, even if the surface 102 to be inspected of the steel material 101 is inclined or curved, the connection portion 40 can be connected according to the state of the surface 102 to be inspected of the steel material 101. The portion 40 is elastically deformed, and the plurality of guide wheels 35 can maintain a state in contact with the inspection target surface 102 of the steel material 101. This makes it possible to keep the probe 2 at a constant distance from the surface 102 to be inspected of the steel material 101 and suppress variations in inspection accuracy. The probe holder 30 is supported by connecting portions 40 on both sides of the probe holder 30 in the first direction P. Therefore, the probe 2 and the probe holder 30 that supports the probe 2 can be stably supported, and can be made to follow the inspection target surface 102 of the steel material 101 more suitably.

Furthermore, in the connecting part 40, the elastic member 42 whose first end and second end are fixed to the support frame part 12 and the probe holder 30, respectively, is elastically deformed, so that the surface to be inspected 102 of the steel material 101 is can be followed. On the other hand, when the probe 2 and the probe holder 30 that supports the probe 2 try to move in the vertical direction by a larger amount than a predetermined amount, the regulated part is regulated by the regulation part, and this causes the probe 2 and the probe holder to move excessively. 30 can be prevented from being displaced in the vertical direction.

In addition, as described above, the switching mechanism 50 causes the first running wheel 4 to scan the probe 2 in the first direction P by traveling from the negative side to the positive side in the first direction P to inspect the steel material 101. In addition to being able to inspect the surface 102, by traveling from the negative side to the positive side in the second direction Q with the second running wheel 5, the probe 2 can inspect the surface 102 of the steel material 101 from the inspected position. The position can be shifted in two directions Q. After shifting the position, the first state is switched again and the first running wheel 4 runs from the positive side of the first direction P to the negative side, thereby changing the previously inspected position and the second direction Q. The surface to be inspected 102 of the steel material 101 can be inspected by scanning the probe 2 in the first direction P at different positions.

Further, the first probe group 2A and the second probe group 2B are arranged apart from each other in the first direction P when viewed in the second direction Q. Furthermore, the probes 2 of the first probe group 2A and the probes 2 of the second probe group 2B are arranged apart from each other in the second direction Q when viewed in the first direction P. Therefore, mutual magnetic interference between the probes 2 is eliminated, and crosstalk noise is less likely to occur. Furthermore, each probe 2 of the first probe group 2A and each probe 2 of the second probe group 2B are arranged with their positions alternately shifted in the second direction. Therefore, when viewed in the first direction P, from the boundary of the testable range M of the probe 2-1 of the first probe group 2A to the border of the testable range M of the probe 2-2 of the second probe group 2B. Either the testable range M of the probes 2 of the first probe group 2A or the testable range M of the probes 2 of the second probe group 2B will be placed at disappears. In this embodiment, the probe group is composed of two probe groups, the first probe group 2A and the second probe group 2B, but it may be composed of three or more probe groups.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and may include design changes within the scope of the gist of the present invention. That is, in the steel surface layer inspection apparatus 1 described above, a probe for eddy current testing is used as the probe 2, but the present invention is not limited to this. Even if a probe for ultrasonic flaw detection or the like is used as the probe 2, similar effects can be obtained. Further, in the above-described steel material surface layer inspection apparatus 1, the operator holds and operates the grip part 22, but the invention is not limited to this, and the apparatus may be driven by electric power or even automatically.

1 Steel surface inspection device 2 Probe 2A First probe group 2B Second probe group 4 First running wheel 5 Second running wheel 10 Support part 12 Support frame part 30 Probe holder 35 Guide ring 40 Connection part 42 Elastic member 44a Cover Regulation part 44b Regulation part 50 Switching mechanism 101 Steel material 102 Inspection target surface M Inspection range P First direction Q Second direction Q1, Q2 Virtual boundary line Q3, Q4 Measurement limit line

Claims (7)

a support section provided with a plurality of first running wheels capable of running in a first direction on the surface of a steel material;
Supported by the support part and scanned along the surface of the steel material, a surface hardened part or a hardness of the surface layer of the steel material that exceeds a predetermined upper limit is determined by being scanned along the surface of the steel material. and a probe that detects a surface layer hardness change area that is either one of the surface layer softening areas that exceeds the lower limit,
The first running wheel passes along the first direction through the outermost point in the second direction of the testable range of the probe at both ends of the second direction perpendicular to the first direction along the inspection target surface. A steel surface layer inspection device that is placed inside a measurement limit line that is placed a predetermined distance outside a virtual boundary line. The steel surface layer inspection device according to claim 1, wherein the first running wheel is arranged inside the virtual boundary line in the second direction. The support part is
a probe holder that supports the probe and is provided with a plurality of guide wheels that are arranged on both sides of the first direction with the probe in between and can run in the first direction along the surface of the steel material;
a support frame portion formed in a frame shape so as to surround the probe holder in a plan view, and in which the first running wheels are provided on both sides of the first direction with the probe holder in between;
The steel surface layer inspection device according to claim 1 or 2, further comprising a connecting portion that connects the support frame portion and the probe holder and is elastically deformable downward by the weight of the probe and the probe holder. The steel surface layer inspection apparatus according to claim 3, wherein the connecting portions are arranged on both sides of the probe holder in the first direction. The connecting portion includes an elastic member that is elastically deformable and includes a first end fixed to a side portion of the support frame portion and a second end fixed to a side portion of the probe holder;
a regulated portion fixed to one of the support frame portion and the probe holder;
It is provided on the other of the support frame portion and the probe holder, and allows the regulated portion to move in the vertical direction, and when the regulated portion moves relative to the regulated portion by a predetermined amount in the vertical direction, The steel material surface layer inspection device according to claim 3 or 4, further comprising a regulating section that regulates vertical movement of the regulating section. a second running wheel that can run in the second direction;
The second running wheel is moved relative to the first running wheel in the vertical direction, so that the second running wheel is separated from the surface of the steel material and can be moved in the first direction by the first running wheel. Claim comprising a switching mechanism capable of switching between a first state and a second state in which the first running wheel is separated from the surface of the steel material and can run in the second direction by the second running wheel. The steel material surface layer inspection device according to any one of claims 1 to 5. a first probe group configured by arranging a plurality of the probes in the second direction;
The probes are arranged to be shifted in position from the first probe group in the first direction when viewed from above and to overlap with the first probe group when viewed from the first direction. a second probe group configured by arranging a plurality of probes in a second direction;
7. The probes of the first probe group and the probes of the second probe group are arranged with their positions alternately shifted in the second direction. The steel material surface layer inspection device described in .

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