JP3039841B2 - Steel plate magnetostriction detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a magnetostriction characteristic of a steel sheet such as an electromagnetic steel sheet, a high silicon steel sheet, and an amorphous steel sheet.

[0002]

2. Description of the Related Art Conventionally, when an electromagnetic steel plate is processed into an iron core of a transformer and used, a compressive stress is applied to the material. Therefore, when measuring the magnetostriction of an electromagnetic steel sheet, it is often performed in a state where the test piece is excited and a compressive stress is applied. When measuring the magnetostriction of such a steel sheet, an apparatus as shown in FIG. 3 is generally used.

That is, the test piece S is formed in a rectangular shape, and both ends in the longitudinal direction are mounted on a pair of support tables 1a and 1b. One end of the test piece S is fixed by a fixing device 2 provided immediately above the support 1a. The fixing device 2 includes a fixing portion 2a and a holding cylinder 2b that allows the fixing portion 2a to move up and down. Between the supports 1a and 1b,
Exciter 4 composed of primary coil 3a and secondary coil 3b
, And an exciting current is supplied from the power supply 5 to the primary coil 3a to excite the test piece S. Test piece S at this time
The induced voltage (magnetic flux density) is detected by the secondary coil 3b and input to the measurement calculation device 6.

A predetermined stress is applied to the end surface of the test piece S on the side of the support 1b by a stress applying device 7 through a stress applying cylinder 8 and a lever 9. Further, the target 10 is pressed on the upper surface of the test piece S immediately above the support 1b by pressing means (not shown), and the laser light LB from the laser light source 12 of the laser head 11 is irradiated on the target 10 via the collective lens 13. Is done. Then, the reflected light is detected by a reflected light detector 14 built in the laser head unit 11 and input to the measurement operation device 6.

Therefore, when a compressive stress is applied by a stress applying device 7 to a test piece S placed on the supporting tables 1a and 1b and fixed at one end by a fixing device 2 while being excited by an exciting device 4, the test piece S The magnetostriction inside S changes, and the target 10 fixed to the test piece S is slightly displaced. When the target 10 is irradiated with the laser beam LB from the laser light source 12 and the reflected light is detected by the reflected light detector 14, the minute displacement can be detected as a Doppler effect, thereby reducing the magnetostriction characteristics of the test piece S. It can be detected.

[0006]

However, in the conventional method as described above, the laser beam LB must travel straight toward the target 10 and the reflected light from the target 10 must be received on the same path. Therefore, it is necessary to irradiate the laser beam LB oscillated from the laser light source 12 in a direction parallel to the test piece S. Therefore, the stress applying device 7, which is a mechanism for applying a compressive stress, has a complicated structure using the lever 9 as shown in the figure, and there is a problem that miniaturization is difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a magnetostriction detecting apparatus for a steel sheet which is reduced in size.

According to the present invention, there is provided a pair of supports on which both longitudinal ends of a steel plate test piece are placed, and one end in the longitudinal direction of the test piece provided just above one side of the support base. A fixing means comprising a fixing portion for fixing and a holding cylinder which can be raised and lowered, a target pressed on the upper surface of a test piece located on the upper side on the other side of the support, and a test provided between the pair of supports. Exciting means having a primary coil for exciting the specimen and a secondary coil for detecting the magnetic flux density thereof, and being attached to the fixing means side, the fixing part of the fixing means corresponding to the center of the test piece width direction. Irradiate the target with laser light parallel to the longitudinal direction of the test piece through the perforated opening,
A laser head portion that receives the reflected light, and a stress applying unit that is provided on the opposite side of the fixing unit, applies a compressive stress to an end surface of the test piece in a horizontal direction, and detects a magnitude of the compressive stress, it is made of a magnetostrictive detector of the steel sheet according to claim.

[0009]

[Work] The present inventor paid attention to the straightness of a laser beam used for detecting magnetostriction and the long distance of detection of reflected light, and detected magnetostriction in a state where a compressive stress was applied to a test piece and the test piece was excited. As a result of examining the structure to be realized, a means capable of simplifying and miniaturizing the detection structure was found, and the present invention was completed.

That is, according to the present invention, as a result of disposing the laser head on the fixing means side, the stress applying means provided on the opposite side of the fixing means can be arranged at the same level as the test piece. Thus, the configuration of the device can be made compact and small.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view showing an embodiment of the present invention. In the drawings, the same members as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted. First, a laser head unit 11 incorporating a laser light source 12 for irradiating a laser beam LB and a reflected light detector 14 for detecting magnetostriction by reflected light.
Is arranged on the side of the fixing device 2. At this time, in order to irradiate the target 10 with the laser beam LB, the fixing portion 2a of the fixing device 2 is provided with an opening at a height corresponding to the laser beam irradiation position of the target 10, for example, near the center in the width direction of the test piece S. Fifteen
Have been drilled.

On the other hand, the stress applying device 7 for applying a compressive stress to the end face of the test piece S is configured such that the stress applying cylinder 8, the stress detector 16 such as a load cell, and the compressive stress jig 17 are aligned. , On the side of the fixed base 1b. Thereby, a compressive stress can be applied to the end face of the test piece S from a horizontal direction, so that it is not necessary to use a lever or the like as in the conventional apparatus, and the structure is extremely simplified. The positions of the pair of supports 1a and 1b and the target 10 have the same structure as the conventional example.

FIG. 2 is a perspective view showing the arrangement of main components of the magnetostriction detecting device of the present invention. As can be seen from FIG.
And can be made compact and compact.
For example, when measuring a test piece S having a length A of 400 mm,
The length B of the base 18 may be about 1200 mm. Next,
A measurement procedure using this device will be described. Both ends of the test piece S are placed on the pair of support tables 1a and 1b. The holding cylinder 2b of the fixing device 2 is operated to lower the fixing portion 2a to fix the end of the test piece S. The target 10 is pressed on the upper surface of the test piece S. When the exciting device 4 is turned on, the primary coil 3
Excitation current is passed through a to excite the test piece S. The magnetic flux density of the test piece S is input to the measurement operation device 6 via the secondary coil 3b. The compressing stress is applied to the end face of the test piece S by operating the stress applying cylinder 8 of the stress applying device 7. The compressive stress at this time is detected by the stress detector 16 and input to the measurement arithmetic unit 6. The laser head unit 11 is turned on, the target 10 is irradiated with the laser beam LB from the laser light source 12, the reflected light is detected by the reflected light detector 14, and the measured and calculated amount is calculated as a minute displacement.
To enter. The measurement operation device 6 performs an operation process using the input magnetic flux density, the compressive stress value, and the minute displacement amount to obtain and output a magnetostriction.

Although the above embodiment has been described as applying a compressive stress to the test piece S, the present invention is not limited to this, and it is also possible to apply a tensile stress.

[0015]

As described above, according to the present invention,
Since the laser head is arranged on the fixing means side and the stress applying means is arranged at the same level as the test piece, the configuration of the apparatus can be made compact and small.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a perspective view of the device of the present invention.

FIG. 3 is a side view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1a, 1b Support base 2 Fixing device (fixing means) 2a Fixing part 2b Holding cylinder 3a Primary coil 3b Secondary coil 4 Exciting device (exciting device) 5 Power supply 6 Measurement / calculation device 7 Stress applying device (stress applying device) 8 Stress Applied cylinder 9 Lever 10 Target 11 Laser head 12 Laser light source 13 Collective lens 14 Reflected light detector 15 Opening 16 Stress detector 17 Jig for compressive stress 18 Base S Test piece LB laser beam

Claims (1)

(57) [Claims] 1. A pair of supports on which both ends in the longitudinal direction of a test piece of a steel plate are placed, and one end in the longitudinal direction of the test piece fixed on one side of the support and fixed on one side of the support. Fixing means comprising a fixing portion and a vertically movable holding cylinder; a target pressed on the upper surface of a test piece located on the upper side on the other side of the support; and a test piece provided between the pair of supports. Exciting 1
An exciting means provided with a secondary coil and a secondary coil for detecting its magnetic flux density; and an opening attached to the fixing means side and formed in a fixing portion of the fixing means so as to correspond to a central portion in a test piece width direction. A laser head that irradiates the target with laser light parallel to the longitudinal direction of the test piece through the portion, and receives the reflected light thereof; the pressure Chijimi応 force is applied from the magnetic strain detector of steel plate and the stress applying means for detecting the magnitude of the pressure Chijimi応 force, characterized in that it consists of.