JP5149562B2 - Nondestructive measuring method and nondestructive measuring device - Google Patents

Description

  The present invention relates to a quenching depth nondestructive measurement method and apparatus for measuring a quenching depth without destroying a measurement object, and in particular, a quenching depth of a surface change portion existing in the measurement object. It is for measuring.

  As a non-destructive measurement method for measuring without quenching the object to be measured when the quenching depth is measured for what has been quenched by induction hardening or the like, for example, it is disclosed in Patent Document 1 below. There are methods. From the relationship between the hardness distribution of the hardened surface and the magnetic permeability distribution, the change in hardness is detected through the change in the magnetic permeability as the medium, and the surface hardness and the quenching depth of the hardened measurement object (hardened layer) This is a non-destructive measurement method. FIG. 8 is a diagram showing a nondestructive measuring apparatus described in the same document.

The detection coil body 101 is a sensor for measuring the quenching surface hardness and the quenching depth, and an excitation coil 111 and a detection coil 112 are provided in the case 102 with a common central axis. . And it sets to the axial part 201 of the measuring object 200 with a level | step difference as shown in figure. When the AC excitation signal V1 from the AC power supply 104 is applied to the excitation coil 111, an eddy current is induced in the shaft portion 201, and the measurement device 103 detects a detection signal (voltage signal) obtained from the detection coil 112. In addition to the magnitude of V2, the phase difference Φ between the signal V2 and the signal V1 is detected. The quenching surface hardness is measured based on the detection signal V2, and the quenching depth is measured based on the phase difference Φ, and each measurement result is displayed on the display 131.
JP 2004-108873 A

  In the case of the conventional nondestructive measurement method and apparatus described above, even if there is a step in the shaft portion 201 of the measurement object 200, the quenching depth can be measured by arranging the detection coil 112 on the surface change portion. is there. However, in the conventional configuration in which the shaft portion 201 is placed in the excitation coil 111 or the detection coil 112, the measurement object is limited, and it corresponds to a measurement object having a complicated shape such as a crankshaft. Can not. In addition, when it is necessary to measure a plurality of locations, the coil is designed in accordance with the thickest part in the conventional apparatus, so that the distance between the measurement location and the coil increases depending on the measurement location, and the measurement varies. It will occur.

  In the conventional measuring method, the frequency of the AC power source 104 is switched to a plurality of stages, the characteristic having the highest correlation such as the quenching depth is obtained as a calibration curve, and the quenching depth is measured. However, since a method is used in which the magnetic field is generated and discriminated in the entire measurement object 200, it will not be established if there is no correlation between the quenching depth of the changing portion due to the shaft 201 and the step. Further, if the correlation is shifted due to breakage or deformation of the hardened coil, it becomes more difficult to measure the changed portion. When automatic measurement is to be performed, it is necessary to collect a large amount of prior data and to create a complicated calibration curve.

  Therefore, the present invention provides a nondestructive measuring method and a nondestructive measuring apparatus capable of easily and accurately measuring the quenching depth of the surface change portion existing in the measurement object in order to solve such a problem. For the purpose.

The nondestructive measurement method according to the present invention measures the quenching depth of the measurement object with respect to a surface change portion between adjacent different surfaces present in the measurement object, and the adjacent different surfaces. Is a vertical plane and a horizontal plane that are substantially orthogonal to each other, and a first sensor and a second sensor are arranged with respect to the vertical plane and the horizontal plane across the surface change portion, and this arrangement is arranged on the vertical plane. By bringing the tip of the first sensor into contact and then bringing the tip of the second sensor into contact with the lateral surface, and performing electrical processing between the first sensor and the second sensor The obtained electrical output is a measured value of one potential difference , while the correlation between the quenching depth and the measured value of the potential difference according to the shape of one or more surface change portions existing in the measurement object is shown. one of the calibration curve data is previously obtained, the one Measured value of the potential difference between comparing the calibration curve data and obtaining the hardening depth for the surface variation portion.

In the nondestructive measurement method according to the present invention, the first sensor may be a first current probe and a first measurement probe in which a tip is brought into contact with the vertical surface sandwiching the surface change portion. A sensor is a second current probe and a second measurement probe whose tips are brought into contact with the lateral surfaces sandwiching the surface change portion, and the current supplied from the first current probe is converted into the measurement object. A current is passed back through the second current probe, and a potential difference at a position where the surface change portion is sandwiched between the first measurement probe and the second measurement probe is obtained as a measurement value. It is preferable that the quenching depth is obtained for the surface change portion by comparing with the calibration curve data .

The nondestructive measuring apparatus according to the present invention measures the quenching depth of the measurement object with respect to a surface change portion between adjacent different surfaces present in the measurement object, and the adjacent different surfaces. Are a vertical plane and a horizontal plane that are substantially orthogonal to each other, and a first sensor and a second sensor that are disposed with their tips in contact with the vertical plane and the horizontal plane across the surface change portion, and the vertical plane After bringing the tip of the first sensor into contact, an electrical process is performed between the first sensor and the second sensor, and a drive mechanism for bringing the tip of the second sensor into contact with the lateral surface. Processing means for obtaining an electrical output of one potential difference, the processing means depending on the shape of one or more surface change portions existing in the object to be measured, and the quenching depth and the electrical output. one calibration curve showing the correlation between the measured value of the potential difference is Is obtained by storing over data, characterized in that by comparing the measured values of the one of the potential difference between said calibration curve data and requests the hardening depth for the surface variation portion.

In the nondestructive measurement apparatus according to the present invention, the first sensor is a first current probe and a first measurement probe whose tips are brought into contact with the vertical surface sandwiching the surface change portion. A sensor is a second current probe and a second measurement probe whose tips are brought into contact with the lateral surfaces sandwiching the surface change portion, wherein the processing means passes through the measurement object from the first current probe. A current is passed back through the second current probe, and a potential difference at a position where the surface change portion is sandwiched between the first measurement probe and the second measurement probe is obtained as a measurement value. It is preferable that the quenching depth is determined for the surface change portion by comparing with the calibration curve data.
The nondestructive measuring apparatus according to the present invention includes a current probe constituting the first sensor or the second sensor and a cover for guiding the movement of the probe to the measurement probe, and the surface of the measurement object. It is preferable that all the probes pressed against are brought into contact so that their tips are positioned in a straight line.

  According to the present invention, the first sensor and the second sensor are arranged and measured on different surfaces adjacent to each other with the surface change portion interposed therebetween, so that the whole has a complicated shape such as a crankshaft, for example. Even if it is a thing, each measurement location can be measured easily. Further, since the first sensor and the second sensor are arranged and measured so as to correspond to the respective surfaces sandwiching the surface change portion, it is possible to obtain an accurate quenching depth.

Next, an embodiment of a nondestructive measuring method and a nondestructive measuring apparatus according to the present invention will be described below with reference to the drawings. In the present embodiment, for example, a case where a crankshaft as shown in FIG. 1 is a measurement object and the quenching depth is measured will be described. FIG. 1 shows a crankshaft 1 for a four-cylinder engine, which is an integrally formed product by forging. An orthogonal arm A is connected to the journal J arranged through the central axis X, and the arms A arranged opposite to each other are connected by pins P, respectively. The crankshaft 1 is quenched by local heating such as high frequency induction heating or laser heating.

  In the crankshaft 1, the arm A and the pin P or the journal J are connected as described above, and the connecting portion is a surface changing portion between adjacent different surfaces as indicated by an arrow C, for example. FIG. 2 is a cross-sectional view showing such a surface changing portion, specifically, a connecting portion (an arrow C portion) between the arm A and the pin P of the crankshaft 1 shown in FIG. In this surface change portion, the vertical surface Y of the arm A and the horizontal surface X of the pin P that are substantially orthogonal to each other are continuous, and an R portion 2 formed of a curved surface is formed. Further, the hardened and hardened layer 3 is also formed in the R portion 2 as shown in FIG.

In the nondestructive measuring method and apparatus of this embodiment, the quenching depth H of the hardened and hardened layer 3 formed by the quenching process is measured for the surface change portion such as the R portion 2. In particular, in the following embodiment, a nondestructive measurement method and a nondestructive measurement apparatus that employ a potential difference method will be described.

First, a nondestructive measuring apparatus adopting the potential difference method as the first embodiment will be described. FIG. 3 is a diagram conceptually showing the nondestructive measuring apparatus.
The nondestructive measuring apparatus 10 has a sensor 18 that enters a portion where the R portion 2 exists as shown in FIG. The sensor 18 includes a probe that comes into contact with the crankshaft 1 that is an object to be measured, and is configured to face in two directions with the R portion 2 interposed therebetween. That is, the current probe 11a or 11b and the measurement probe 12a or 12b are provided so that the tip contacts the vertical surface Y and the horizontal surface X substantially orthogonal to each other.

  The two current probes 11a and 11b are connected to a constant current source 13, and the current supplied from the constant current source 13 flows through the crankshaft 1 from the current probe 11a on the input side, and the current probe on the output side. The current returns to the constant current source 13 through the needle 11b. On the other hand, the two measurement probes 12 a and 12 b measure the potential difference and are connected to the potential difference measuring device 14. Accordingly, the two measurement probes 12a and 12b are arranged between the current probes 11a and 11b, and are configured to measure a potential difference particularly at a position sandwiching the R portion 2.

The nondestructive measuring apparatus 10 further includes a drive mechanism 17 that moves the sensor 18 to a predetermined position. In addition to the drive mechanism 17, an arithmetic controller 15 is connected to the constant current source 13 and the potential difference measuring instrument 14. A display 19 is connected to the device 15.
The arithmetic control unit 15 performs energization control by the constant current source 13 in addition to drive control for the drive mechanism 17, and calculates the quenching depth H from the potential difference detected by the potential difference measuring unit 14 based on the measurement data. It is a thing.

  FIG. 6 is a diagram showing a calibration curve obtained from the measurement data, and shows the correlation between the quenching depth and the potential difference. Since the quench hardened layer 3 has a high resistivity, as can be seen from the figure, the quenching depth increases in proportion to the magnitude of the potential difference. This calibration curve is created from the measured values of the quenching depth of two or more levels for the workpiece having the same shape as the crankshaft 1. The arithmetic controller 15 stores such a calibration curve (calibration curve data), and is configured to perform conversion processing based on the actually measured potential difference value and display the quenching depth on the display 19. ing.

  By the way, the four probes 11a, 11b, 12a, 12b are in the sensor body 16, and as shown in FIG. 3, the probes 11a, 12a are orthogonal to the vertical surface Y, and the probes 11b, 12b are lateral. It is provided so as to be orthogonal to the plane X. The two sets of the probes 11a and 12a and the probes 11b and 12b which are orthogonal to each other have a certain length, and actually intersect with each other in a direction penetrating the drawing. FIG. 4 is a diagram showing such a state, and shows the positions of the probes 11a, 11b, 12a, and 12b at the time of measurement from the direction of the arrow M in FIG.

The probes 11a, 11b, 12a, and 12b of the sensor 18 are always in a constant state when the tip of the non-destructive measuring apparatus 10 comes into contact with the measurement object in order to perform accurate measurement based on the calibration curve data. That is, as shown in FIG. 4, it is necessary to be positioned on a straight line (measurement line L).
However, while the probes 11b and 12b are orthogonal to the measurement line L, the probes 11b and 12b are inclined. Then, when the probes 11a and 12a contact the vertical surface Y from an oblique direction, the tip may slip due to the pressing force and may come off from the measurement line L. Therefore, in the present embodiment, the probe 11a, 12a is configured to reliably contact at a fixed position. Here, FIG. 5 is a diagram showing a part of the configuration in a simplified manner.

  Positioning covers 21 are provided on the inclined probes 11a and 12a, and after the positioning cover 21 is pressed against the vertical surface Y, the probes 11a and 12a jump out of the positioning cover 21 and vertically A configuration that causes a movement to come into contact with the surface Y is employed. Although a detailed mechanism is omitted, the sensor 18 is configured so that the sensor body 16 can move along the vertical surface Y and the horizontal surface X, and further, each set of the probes 11a and 12a and the probes 11b and 12b. Are configured to be capable of moving in the axial direction independently of each other.

  Next, a nondestructive measurement method using the nondestructive measurement apparatus 10 will be described. First, as shown in FIG. 1, the sensor 18 is arranged at a measurement location, and measurement preparation is performed. For this purpose, the driving mechanism 17 is controlled by the arithmetic controller 15, and as shown in FIG. 5, the sensor main body 16 is lowered so as to approach the lateral surface X to a certain position, and then the lateral movement is made so that the positioning cover 21 is moved. It is pressed against the vertical surface Y. Further, the probes 11b and 12b jump out in the descending direction and the tip contacts the lateral surface X. The probes 11a and 12a move in the lateral direction as guided by the positioning cover 21, and the tips are laterally moved. Contact surface X.

  Subsequently, the energization control of the constant current source 13 is performed by the arithmetic controller 15, and current is supplied to the current probe 11a. Then, a current flows in the R portion 2 of the crankshaft 1 from the current probe 11a on the input side, and returns to the constant current source 13 via the current probe 11b on the output side. At that time, the potential difference measuring unit 14 measures the potential difference at the position where the R portion 2 is sandwiched between the two measurement probes 12a and 12b. In the arithmetic controller 15, the value of the potential difference obtained by the potential difference measuring device 14 is compared with the calibration curve data stored in advance, and the quenching depth H is obtained by a conversion process. Then, the obtained quenching depth H is displayed on the display 19.

Therefore, according to the nondestructive measurement method and the nondestructive measurement apparatus of the present embodiment, the probes 11a, 11b, 12a, and 12b are brought into contact with different surfaces adjacent to the surface change portion such as the R portion 2. Therefore, even if the crankshaft 1 has a complicated shape as a whole, each measurement point can be easily measured. Further, since the probes 11a, 11b, 12a, and 12b are directly contacted for measurement, an accurate quenching depth H can be obtained. Furthermore, even if the probes 11a and 12a are in contact with the surface of the object to be measured from an oblique direction, the tip of the probe 11a, 12a is always measured by the positioning cover 21.
Since it is located above, stable measurement is possible.

Next, a reference embodiment according to the present invention will be described. FIG. 7 is a diagram conceptually showing a nondestructive measuring apparatus of a reference form . The same components as those in the first embodiment will be described with the same reference numerals.
The nondestructive measuring device 30 is for measuring the quenching depth of the R portion 2 of the crankshaft 1 as in the first embodiment, and is an excitation that generates an eddy current in the surface layer of such a surface change portion. A coil 31 and a detection coil 32 for detecting eddy currents formed on the surface layer are provided. And the exciting coil 31 and the detection coil 32 are provided with respect to the ferrite core 33 of a high magnetic permeability material.

  The excitation coil 31, the detection coil 32, and the ferrite core 33 are integrally configured by a sensor body 34. The excitation coil 31 and the detection coil 32 are provided so as to face one of the vertical surface Y and the horizontal surface X that are substantially orthogonal to each other with the R portion 2 interposed therebetween. A current generator 36 is connected to the excitation coil 31, and an amplifier 37 that amplifies the detection current is connected to the other detection coil 32. A control calculator 38 for calculating the current value obtained via the current control and the amplifier 37 is connected to the control calculator 38. The control calculator 38 has a display 39 for displaying the measurement result. It is connected.

  In this nondestructive measuring device 30, a sensor 35 is arranged with respect to the crankshaft 1 in the same manner as the sensor 18 shown in FIG. 1. Specifically, the excitation coil 31 is disposed on the vertical surface Y and the detection coil 32 is disposed on the horizontal surface X so as to sandwich the R portion 2. An alternating current is passed through the exciting coil 31, thereby forming a magnetic field along the axial direction of the exciting coil 31. An eddy current is formed in the surface layer of the crankshaft 1 by electromagnetic induction based on the magnetic field, and the eddy current newly forms a magnetic field in the vicinity of the surface of the R portion 2. A magnetic field generated by an electric current is detected.

At this time, since the hardened and hardened layer 3 of the R portion 2 has a high magnetic permeability, a large amount of magnetic flux is allowed to pass therethrough. Therefore, in the present embodiment , since the calculator 38 stores in advance calibration curve data (not shown) indicating the correlation between the current values corresponding to the quenching depth, the current value obtained via the detection coil 32 is stored. Is converted by the calculator 38 based on the calibration curve data, and the quenching depth H determined there is displayed on the display 39.

Therefore, according to the nondestructive measurement method and the nondestructive measurement apparatus of the present embodiment , the exciting coil 31 and the detection coil 32 are arranged opposite to each other on different surfaces with respect to the surface change portion such as the R portion 2. Therefore, even if the entire object to be measured has a complicated shape such as the crankshaft 1, the measurement can be easily performed.

  As mentioned above, although one embodiment was described about the nondestructive measuring method and nondestructive measuring device concerning the present invention, the present invention is not limited to these but can be variously changed in the range which does not deviate from the meaning.

It is the figure which showed the crankshaft which is a measuring object. It is the expanded sectional view which showed the connection part (arrow C part) of the arm and pin of the crankshaft shown in FIG. It is the figure which showed notionally the nondestructive measuring apparatus of 1st Embodiment. The position at the time of measurement of a probe is shown from the arrow M direction of FIG. It is the figure which showed arrangement | positioning of a current probe and a measurement probe. It is the figure which showed the calibration curve. It is the figure which showed the nondestructive measuring apparatus of the reference form notionally. It is the figure which showed notionally the conventional nondestructive measuring apparatus.

DESCRIPTION OF SYMBOLS 1 Crankshaft 2 R part 11a, 11b Current probe 12a, 12b Measurement probe 13 Constant current source 14 Potential difference measuring device 15 Computation controller 16 Sensor main body 17 Drive mechanism 18 Sensor 19 Display 21 Positioning cover H Hardening depth

Claims (5)

It is a non-destructive measurement method for measuring the quenching depth of the measurement object with respect to the surface change portion between adjacent different surfaces present in the measurement object,
The different surfaces adjacent to each other are substantially perpendicular vertical and horizontal surfaces,
A first sensor and a second sensor are arranged on the vertical surface and the horizontal surface with the surface change portion interposed therebetween, and this arrangement is performed after the tip of the first sensor is brought into contact with the vertical surface, By bringing the tip of the second sensor into contact with the lateral surface;
The electrical output obtained by performing electrical processing between the first sensor and the second sensor is a measured value of one potential difference ,
On the other hand, one calibration curve data indicating the correlation between the quenching depth and the measured value of the potential difference according to the shape of one or more surface change portions present in the measurement object is obtained in advance,
Nondestructive measurement method characterized by determining the hardening depth for the surface variation portion by comparing the calibration curve data and the measured values of the one of the potential difference. In the nondestructive measuring method according to claim 1,
The first sensor is a first current probe and a first measurement probe whose tips are brought into contact with the vertical surface sandwiching the surface change portion, and the second sensor is the horizontal probe sandwiching the surface change portion. A second current probe and a second measurement probe, the tip of which contacts the surface,
The current supplied from the first current probe passes through the measurement object so as to return from the second current probe, and the surface change portion is caused by the first measurement probe and the second measurement probe. A non-destructive measurement method characterized by obtaining a potential difference at a position sandwiching a gap as a measured value and comparing the measured value with the calibration curve data to obtain a quenching depth for the surface change portion. It is a non-destructive measuring device that measures the quenching depth of the measurement object with respect to the surface change portion between adjacent different surfaces present in the measurement object,
The different surfaces adjacent to each other are substantially perpendicular vertical and horizontal surfaces,
A first sensor and a second sensor arranged with their front ends in contact with the vertical surface and the horizontal surface across the surface change portion; and after contacting the front end of the first sensor with the vertical surface, A driving mechanism for bringing a tip of the second sensor into contact with a lateral surface; and processing means for obtaining an electrical output of one potential difference by performing electrical processing between the first sensor and the second sensor. Have
The processing means is one calibration curve showing a correlation between a quenching depth and a measured value of a potential difference as the electrical output according to the shape of one or more surface change portions present in the measurement object. is obtained by storing the data, non-destructive measuring apparatus characterized by comparing the measured values of the one of the potential difference between said calibration curve data and requests the hardening depth for the surface variation portion. In the nondestructive measuring device according to claim 3 ,
The first sensor is a first current probe and a first measurement probe whose tips are brought into contact with the vertical surface sandwiching the surface change portion, and the second sensor is the horizontal probe sandwiching the surface change portion. A second current probe and a second measurement probe, the tip of which contacts the surface,
The processing means causes a current to flow from the first current probe so as to return from the second current probe through the measurement object, and the surface change portion is defined by the first measurement probe and the second measurement probe. A non-destructive measurement characterized in that a potential difference at a sandwiched position is obtained as a measured value and the measured value and the calibration curve data are compared to obtain a quenching depth for the surface change portion. apparatus. In the nondestructive measuring device according to claim 4 ,
The current probe and the measurement probe constituting the first sensor or the second sensor have a cover for guiding the movement of the probe, and the entire probe pressed against the surface of the measurement object has its tip A non-destructive measuring device characterized in that they are brought into contact so as to be positioned on a straight line.

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