JPS6231582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse transmitter that uses a magnetically sensitive element made of a specially treated ferromagnetic material. It is an object of the present invention to provide a pulse oscillator that can induce a steep pulse electromotive force with a high S/N ratio simply by having the following.

Conventionally, there have been several means for generating a signal voltage by the magnetic field of a magnet, one of which is the device disclosed in Japanese Utility Model Publication No. 50-36163. This generates a signal voltage in the coil by the change in magnetic flux when the magnetic fluxes of two fixed and rotating magnets differentially interact with each other. Therefore, there was a drawback that no signal voltage was generated during extremely low speed rotation.

Further, as a magnetic material having portions having different coercive forces like the magnetically sensitive element used in the present invention, there is a material disclosed in, for example, Japanese Patent Laid-Open No. 51-51792. However, this does not have the property of causing changes in magnetic flux due to magnetic behavior based on magnetic interactions between parts with different coercive forces, and is not a composite ferromagnetic material with uniaxial magnetic anisotropy. Therefore, it has not been possible to generate steep pulses using changes in the magnetic flux of the magnetic material.

The pulse transmitter of the present invention has uniaxial magnetic anisotropy, and can shift only the magnetization direction of the portion with a relatively small coercive force to either the positive direction or the negative direction in response to the direction of action of an external magnetic field, and An output coil for pulsed electromotive force is placed near a magnetosensitive element made of a composite ferromagnetic material treated so that dislocation occurs rapidly in the magnetization direction of the portion with a large coercive force. , and is characterized by having only one magnet placed close to and spaced from them.

In order to understand the present invention, the properties of the magnetically sensitive element will first be outlined.

For example, alloys such as iron-cobalt-vanadium and amorphous ferromagnetic wires are twisted mechanically, with less twisting near the core and more twisting toward the outer periphery. Processed to have a portion with a relatively large coercive force near the wire core, a portion with a relatively low coercive force closer to the outer periphery, and to have uniaxial magnetic anisotropy in the wire axis direction as a whole. It becomes a composite ferromagnetic wire or magnetically sensitive element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and embodiments of the present invention will be described below with reference to the drawings.

In Fig. 1, reference numeral 1 denotes the above-mentioned magnetic sensing element, and around it there is an output coil 2, either directly or via a bobbin.
is wrapped. Of course, the output coil 2 may simply be placed near the magnetically sensitive element 1.

This magnetically sensitive element 1 is fixed, and one permanent magnet 3 shown by a dotted line is moved in the direction of the axis in the direction of the arrow so as to be parallel to and close to the magnetically sensitive element 1, and then a permanent magnet 3 shown by a solid line When separated like the magnets 3, a steep pulse electromotive force is induced in the output coil 2.

In this case, the external magnetic field on which the permanent magnet 3 acts is
These are external magnetic lines of force that originate from the north pole and reach the south pole.

The magnetic field distribution is as shown in the figure, with the N pole on the right side and
When placed so that the left side is the south pole, the situation is as follows.

The external magnetic field lines emitted from the north pole to the right change direction to the left while detouring, then bypass the midsection of the permanent magnet, reach the left side of the south pole, change direction again to the right, and reach the south pole. do.

Therefore, the magnetic field that acts on the magnetically sensitive element 1 while the permanent magnet 3 approaches its S pole in parallel and moves away from its N pole initially has a strong rightward direction near the S pole where the lines of magnetic force are concentrated. The first magnetic field H ₁ is weaker, then the weaker one near the middle (because it is far from the magnetic pole)
There is a second magnetic field H ₂ directed to the left, and a third magnetic field H ₃ directed to the right which is strong again near the north pole.

At this time, the magnetically sensitive element 1, which has been oriented in the right direction by a sufficiently strong external magnetic field (orienting magnetic field), causes the following magnetic behavior inside it.

First, a strong rightward first magnetic field _H1 is applied from the outside, but since this is in the same direction as the above-mentioned orientation magnetic field, the wire core remains oriented with the polarity NS as shown. The outer periphery is also magnetized in the right direction.

Next, when it comes to the stage where the second magnetic field H ₂ acts,
The direction of magnetization is reversed only in the outer periphery where the coercive force is small. The magneto-sensitive element is a composite ferromagnetic material with uniaxial magnetic anisotropy, and can maintain an equilibrium state with the outer peripheral part parallel to its easy axis in a direction 180 degrees different from the core part.

When the third magnetic field H ₃ is subsequently applied, the magnetization direction of the outer circumferential portion is reversed to the right again, but the reversal speed at this time is extremely rapid. This is because the outer periphery is stimulated by the magnetic field _H3 , and as soon as the above-mentioned equilibrium state collapses and begins to reverse, the exchange interaction with the orientation magnetism of the core becomes dominant. Therefore, it is considered that the reversal of the magnetization direction is achieved especially quickly and all at once.

Therefore, in response to the sudden change in magnetic flux at this time, a steep and large pulse electromotive force is induced in the output coil.

In any case, when at least the second magnetic field H ₂ in the left direction and the third magnetic field H ₃ in the right direction act sequentially on the magnetically sensitive element that has been oriented and magnetized in the right direction, a pulse is generated in the output coil. Electricity is induced.

The permanent magnet 3 shown in FIG. 1 may be replaced with an electromagnet 3' as shown in FIG. Also permanent magnet 3
Even if the sensor is tilted as shown in FIG. 3 and moved in the direction of the arrow, a pulse is induced at the position shown based on the same principle of operation as described above. Furthermore, as shown in FIG. 4, when the magnet 3 is placed at a position perpendicular to the magnetically sensitive element 1 and moved, a pulse is generated at the position shown. All of the above pulses are positive pulses, but when the polarity of the magnet is reversed from that in FIG. 4 as shown in FIG. 5, a negative pulse is generated at the time shown.

In these cases, the magnet 3 does not necessarily have to be rod-shaped, and in order to effectively achieve the above principle, a curved or U-shaped magnet can be used depending on the place of application.

Further, in the above description, the magnetically sensitive element 1 is fixed, but the magnet 3 may be fixed and the magnetically sensitive element 1 and the output coil 2 may be moved.

Next, an embodiment of the present invention will be explained with reference to FIGS. 6 to 8.

FIG. 6 shows a press-type embodiment based on the principle of FIG. Since it moves in parallel, it induces a pulse at this time. When the pressing part 4 is released, the magnet 3 becomes the spring 6.
is returned to its original position.

FIG. 7 shows a rotary embodiment using the principle of FIG. 4 or 5, in which the rotating part 7 is rotated by manual or other external force, and the rotor 9 is fixed to a shaft 8.
It is a method of turning. In this case, if the magnet 3 is attached to the rotor 9 and one or more magnetically sensitive elements 1 and the output coil 2 are fixed to the stator 10, the magnet 3 of the rotor 9 will rotate and connect to the magnetically sensitive element 1. When moving close to each other, a pulse is triggered. A positive pulse can be generated when the rotor 9 rotates clockwise, and a negative pulse can be generated when the rotor 9 rotates counterclockwise.

Therefore, as shown in FIG. 8, when a plurality of pairs of magnetically sensitive elements 1 and output coils 2 are designated as A, B, C, and D, for example, if only two pairs, A and C, are arranged, the rotation direction It can be applied to an indicator, etc., and can be operated as a multiple pulse transmitter when a configuration is adopted in which four or more sets of A to D are provided.

As described above, according to the present invention, a steep pulse with a good S/N ratio can be obtained even without a power source. Furthermore, regardless of the rate of change of the flux linkage, for example, even if the magnet approaches and moves away from the magnetically sensitive element at an extremely low speed, the second and third magnetic fields H ₂ and 3 with predetermined magnitudes and directions, as described above,
As long as the magnetic field H ₃ acts sequentially and stimulates the outer circumferential portion, a rapid reversal phenomenon is induced due to the control of the orientation magnetism of the core portion. Therefore, a pulse electromotive force of a certain magnitude or more can always be obtained. Because it has such many characteristics, it can be widely used in various mechanical devices, automatic control equipment, and other applications.

[Brief explanation of the drawing]

FIGS. 1 to 5 are diagrams of the basic configuration of the present invention,
6 and 7 are diagrams showing the embodiment, and FIG. 8 is a plan view of FIG. 7. 1: Magnetic sensing element, 2: Output coil, 3: Magnet,
3': Electromagnet, 4: Pressing part, 5: Shaft, 6: Spring, 7: Rotating part, 8: Shaft, 9: Rotor, 1
0: Stater.

Claims (1)

[Claims] 1 Having uniaxial magnetic anisotropy, only the magnetization direction of the portion with a relatively small coercive force can be shifted to the positive or negative direction in response to the direction of action of an external magnetic field, and the magnetization direction of the portion with a large coercive force In this method, an output coil for pulsed electromotive force is placed near a magnetosensitive element made of a composite ferromagnetic material treated to allow rapid dislocation, and only one magnet is placed close to and separated from the magnetically sensitive element. A pulse transmitter characterized by comprising: