JP2961563B2 - Method of manufacturing magnetic wire for pulse generation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic wire having a distribution of coercive force in a wire diameter direction and having an easy direction of magnetization in a wire axis direction, and in particular, a magnetic wire which generates a pulse voltage by a change in an external magnetic field. It is about.

[0002]

2. Description of the Related Art A magnetic wire having a coercive force distribution in a wire diameter direction and an easy magnetization direction in a wire axis direction is used as a magnetic wire for generating a pulse voltage by an external magnetic field.
Conventionally, this method of manufacturing a magnetic wire has a relatively large coercive force in the outer layer of the wire by applying a circumferential strain or torsion stress around the linear axis by applying tension in the longitudinal direction and then elongating the wire. Manufacturing method (Japanese Patent Publication No. 55-15797), in which a torsional stress is applied to a magnetic wire having a relatively high coercive force around a line axis, and the vicinity of the core is uniaxially anisotropic in the axial direction. And a method of manufacturing a magnetic wire having a soft magnetic property continuously or stepwise in the radial direction and having a small coercive force in an outer layer and a large coercive force in an inner layer (Japanese Patent Publication No. 59-121).
No. 42 gazette).

[0003]

In these prior arts, annealing and cooling are performed while applying tension to a wire drawn into a predetermined product shape in order to apply different coercive forces in the wire diameter direction within the same wire. A magnetic wire having a coercive force different between the inner layer portion and the outer layer portion is obtained in which work hardening is repeatedly generated on the surface portion and distortion remaining due to tension is different between the inner layer portion and the outer layer portion. In this method, it is necessary to repeat heating and cooling of the wire in the work hardening treatment, and it is difficult to control the temperature thereof, and it has not yet been possible to obtain stable magnetic properties. Further, according to the method disclosed in Japanese Patent Publication No. 59-12142, a magnetic wire in which torsional stress is alternately applied under tension in a reverse direction, and then heat treatment is performed at a relatively low temperature to suppress the secular change in shape and characteristics is achieved. It is obtained. In this method, it is difficult to perform the twisting process on a continuous wire, and the mass productivity is poor, and it is difficult to continuously apply heat treatment to the wire.

In the conventional method of twisting a wire, a method of twisting from one end in a state of being stationary in the axial direction as shown in FIG. 2 is used. Therefore, twisting due to variation in the diameter and hardness of the wire. It is not uniform in some places, and the twist interval is not constant. Further, when used in a pulse generating element or the like, there is a problem that the variation of output pulses in product characteristics is increased.

[0005] Therefore, a technical object of the present invention is to make the twist pitch applied to the wire uniform and to continuously produce a magnetic wire for pulse generation in order to minimize large variations in output pulse characteristics. The object of the present invention is to provide a method for manufacturing a magnetic wire having a stable output pulse.

[0006]

According to the present invention, there is provided a method of manufacturing a magnetic wire having a distribution of coercive force in a wire diameter direction and having an easy magnetization direction in a wire axis direction, wherein the wire material is axially moved in the wire direction. A method for manufacturing a magnetic wire for pulse generation, characterized in that a twist is continuously applied in only one direction while being fed.

Further, according to the present invention, there is provided a method of manufacturing a magnetic wire for pulse generation, wherein a heat treatment is continuously performed after twisting in the method of manufacturing a magnetic wire for pulse generation.

The present invention is a method of manufacturing a magnetic wire that generates an output pulse due to a steep change in magnetic flux density (large Barkhausen jump), which has stable characteristics and excellent mass productivity. The cause of the large Barkhausen jump is considered to be the distribution of magnetic anisotropy in the radial direction of the wire (Japanese Patent Publication No. 59-12142).

The components of the magnetic anisotropy include the crystal magnetic anisotropy derived from the crystal structure and the induced magnetic anisotropy derived from the rearrangement of the atomic structure by a strong working such as rolling. Since the former is determined by the crystal structure, it is almost impossible to have a distribution within the same line. In the latter induced magnetic anisotropy, it is not suitable for stable production to have a distribution of a processing rate in a narrow wire diameter with respect to a magnetic anisotropy generated by strong working. Therefore, the next conceivable method is to introduce uniaxial induced magnetic anisotropy due to magnetostriction and external stress or strain. The material to which the method of the present invention can be applied is a material having a relatively large coercive force and a large magnetostriction, which is called a semi-hard material. The induced magnetic anisotropy due to the magnetostriction can introduce anisotropic energy proportional to the applied stress or strain, thereby facilitating the control.

[0010] Since the magnetic wire aimed at by the present invention needs to have uniaxial magnetic anisotropy distributed in the wire diameter direction, torsion stress is required as stress or strain applied to the wire. However, it is difficult to introduce a torsional stress or a torsional strain uniformly in a linear axis direction with a long object. However, by twisting the wire in a minimum distance while feeding the wire in the axial direction, the twist pitch width can be controlled uniformly even if the wire diameter and the hardness vary greatly. Also,
By applying the twist while feeding the wire, the heat treatment can be continuously performed after the twist, and this is a method of manufacturing a magnetic wire for pulse generation that is extremely rich in mass productivity.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings.

Co = 50 wt%, V = 10 wt%, residual F
e is vacuum-melted and hot-worked to φ5mm
Process into the material. Next, the wire was heated at 850 ° C. for 3 hours.
Annealed in hydrogen for 0 minutes and water-quenched. Then φ
The wire was drawn to 0.25 mm to obtain a wire. In order to twist the wire, a wire twisting device shown in FIG. 1 is used.

Here, the wire twisting device shown in FIG. 1 will be briefly described. The rotation of the motor 10 is transmitted by the rotating shaft 7, and the rotation rotates the rotating portion spur gear 2 around the fixed portion spur gear 1. Further, the rotation is passed through the worm gear 3 and the wire feed drum 5 rotates to feed the wire 16 at a constant speed. The fed wire is adjusted to the center of the rotating body by the rotating unit guide roller 8. The wire is fixed by the guide roller 9 for twisting the rotating portion with a V-groove, and immediately thereafter, the rubber roller 12 for twisting is passed.
A twist is applied to the wire by the rotation of the rotating unit main body. The twist applied to the wire is held by a twist holding rubber roller 13. The heat treatment is performed using a heat treatment furnace 15 between the twist rubber roller 12 and the twist guide rubber roller 13 that keep the twist constant. Also,
The winding of the wire is performed using a winding drum 14 that can be wound with a constant tension. Using the above apparatus, a pulse generating magnetic wire is manufactured by the manufacturing method according to the present invention.

The above-mentioned 10 V-5 of φ0.25 mm
Using a wire twisting apparatus shown in FIG. 1, a 0 Twist-Fe wire was used to form a magnetic wire for pulse generation at a set twist pitch of 3 mm and a heat treatment temperature of 300 ° C.

As a comparative example, using a conventional wire twisting device as shown in FIG. 2, a wire 16 made in the same manner as in the embodiment is tensioned by a weight 14 and twisted by a motor 17 at a twist pitch of 3 mm. Add. In addition, since both ends of the wire are fixed, it is difficult to uniformly heat-treat the entire wire. Instead, a DC current corresponding to a temperature of 300 ° C. is passed for about 30 seconds (actually when a furnace is used). The same time as the heat treatment on the wire). Note that the wire is colored with oil-based ink in the axial direction so that the twisting state of the wire can be recognized in advance.
The distribution of the twist pit width was measured for m, and the average value and its variation were determined. The results are shown in Table 1.

[0016]

[Table 1]

Further, the output pulse voltage was measured by cutting 20 wires into a length of 30 mm, using an exciting coil and a detecting coil (2,000 turns of the detecting coil, 13 mm in length) shown in FIG. The variation in pulse voltage was determined.
The output pulse was measured with an asymmetrical AC magnetic field of +80 (Oe) and -35 (Oe) and a fluctuation number of 500 (Hz). The results are shown in Table 2.

[0018]

[Table 2]

It can be seen that the use of the method of manufacturing a magnetic wire for pulse generation according to the present invention makes the twist pitch width clearly uniform as compared with the conventional method, and that the output pulse characteristics vary greatly. Has become smaller.

When the twist is applied to the wire, in order to make the twist uniform, the distance of the twist portion between the V-grooved rotating portion twist guide roller 9 and the twist rubber roller 12 shown in FIG. Is desirable. It has a uniform twist pitch because the transmission of the twist occurs over a minimum distance.

FIG. 4 shows the relationship between the heat treatment temperature and the output pulse voltage with respect to the heat treatment temperature after the twist processing. According to this, the output pulse becomes maximum around 400 ° C. In a sample that has been heat-treated at a temperature of 200 ° C. or lower, the output pulse has a peak or a pulse waveform largely oscillates up and down. Further, when the heat treatment is performed at 500 ° C. or more, the distortion due to the twist applied to the wire is removed, and the level of the output pulse starts to drop sharply.
The heat treatment temperature was limited to 200 ° C or more and 500 ° C or less. Desirably, a heat treatment around 300 ° C. is good.

Next, a second embodiment of the present invention will be described with reference to the drawings.

An alloy consisting of 14 wt% of Ni and the balance of Fe is melted in a vacuum to obtain a wire diameter of 0.25 mm by the same working process as in the first embodiment, and then annealed in hydrogen at 600 (° C.). I got a strand. Next, twisting in one direction was performed using the apparatus shown in FIG. 1 as in the first embodiment. The twist pitch width in one direction is 1 (mm).
Further, the heat treatment was continuously performed after the twist processing. This heat treatment temperature is 270 (° C.).

As a comparative example, a material was prepared by twisting the wire and heat-treating it with a direct current as in the first embodiment.

Next, as shown in FIG. 3, the exciting coil and the detecting coil (the number of turns of the detecting coil is 2,000 and the length is 13) are cut in the same manner as in the first embodiment.
mm), the output pulse voltage was measured, and the variation of the pulse voltage was determined. Output pulse measurement is +80 (O
e), asymmetrical AC magnetic field of -20 (Oe), variation number 50
The measurement was performed at 0 (Hz). Table 3 shows the results.

[0026]

[Table 3]

[0027]

As described above, according to the present invention, by twisting the wire while feeding it at a very short distance, the twist pitch of the wire can be processed uniformly, and thereby the variation in the characteristics of the output pulse is greatly reduced. It has become smaller. Further, by applying a twist while feeding the wire, a heat treatment can be continuously performed, which is a manufacturing method excellent in mass productivity. The application of this material is to enable mass production of sensors and pulsars that can be used in many industrial fields such as the automobile industry and automation equipment industry, such as rotation sensors, vehicle speed sensors, proximity switches, etc., and its effectiveness is extremely large. It is.

[Brief description of the drawings]

FIG. 1 shows a wire twisting device used in an embodiment of the present invention. FIG. 1 (a) is a top view, and FIG. 1 (b) is a side view.

FIG. 2 is a side view showing an example of a conventional device used when twisting a wire.

FIG. 3 shows an arrangement of an exciting coil, a detecting coil, and a magnetic wire for pulse generation in which an output pulse voltage is measured.

FIG. 4 is a correlation diagram showing a relationship between a heat treatment temperature and an output pulse.

[Description of Signs] 1 Fixed part spur gear 2 Rotating part spur gear 3 Worm gear 4 Feed drum driving gear 5 Feed drum 6 Rotating part main body 7 Rotating shaft 8 Rotating part guide roller 9 Rotating part twist guide roller with V groove 10 Motor DESCRIPTION OF SYMBOLS 11 Rotation transmission shaft 12 Twist rubber roller 13 Twist holding rubber roller 14 Winding drum 15 Heat treatment furnace 16 Wire 17 Motor 18 Weight 19 Excitation coil 20 Detection coil 21 Pulse generation element 22 Resistance 23 Power supply 24 Oscilloscope

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-43502 (JP, A) JP-A-53-137641 (JP, A) JP-A-63-277983 (JP, A) JP-A-54-1979 57643 (JP, A) JP-B 55-15797 (JP, B2) JP-B 59-12142 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01R 33/00-33 / 18

Claims (4)

(57) [Claims] 1. A method of manufacturing a magnetic wire having a distribution of coercive force in a wire diameter direction and having an easy magnetization direction in a wire axis direction, wherein the wire material is continuously twisted in only one direction while being fed in the axial direction. A method for manufacturing a magnetic wire for pulse generation, comprising: 2. The method according to claim 1, wherein the heat treatment is performed continuously after the twisting. 3. The manufacturing method according to claim 2, wherein the heat treatment temperature when the Fe—Co—V alloy is used as the magnetic wire is 200 ° C. or more and 500 ° C. or less. Of producing a porcelain wire for pulse generation. 4. The pulse according to claim 2, wherein the heat treatment temperature when the Fe—Ni alloy is used as the magnetic wire is 200 ° C. or more and 300 ° C. or less. Method for producing porcelain wire for generation.