JPS6318883Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ferrite magnetic core, and more specifically, the other end face of a so-called pot core, in which one end face of a large cylinder and a small cylinder (or small cylinder) arranged coaxially are connected by a disk. The present invention relates to a ferrite magnetic core that has a shape that forms part of a plane obliquely intersecting an axis and is extremely conveniently used as a detection end of a metal detection element.

Conventionally, a pot core type ferrite magnetic core as shown in FIG. 1 (a is a sectional view and b is a plan view) has been used in various electrical components. That is, in the figure, a ferrite magnetic core 1 has a shape in which one end surface of a large cylinder 2 and a small cylinder or small cylinder (small cylinder in the case of this figure) 3 which are arranged coaxially are connected by a disk 4. There is. Usually, a coil 5 is fitted into a ring-shaped space formed by the inner periphery of the large cylinder 2 and the outer periphery of the small cylinder 3. One example of the use of this ferrite magnetic core is at the detection end of a metal detection element as shown in FIG. That is, in the same figure, the metal detection element 11 consists of a main body 12 and a pot-core type ferrite magnetic core 1 attached to one end of the main body 12, both of which are covered with a non-magnetic thin film 13 made of resin or the like.
The main body portion is further housed in a metal housing 14. The ferrite magnetic core 1 serves as a detection end of this metal detection element 11, and its end surface serves as a detection surface A.

In this metal detection element 11, an oscillation circuit is connected to an electromagnet, and when a metal piece is present in the alternating magnetic field generated by the electromagnet, an eddy current is generated or the inductance of the electromagnet fluctuates, which causes the oscillation circuit to Metals are detected using the fluctuations in the voltage. The ferrite magnetic core 1 around which the coil 5 is wound acts as an electromagnet, and the main body 12 includes an oscillation circuit for generating an alternating magnetic field, a detection circuit for detecting voltage attenuation, a display circuit for displaying the detection results, It has a built-in power supply circuit that supplies power to each circuit.

This metal detection element 11 is used in the method shown in FIG. That is, in the same figure, the detection surface A of the metal detection element 11 is the reference surface B in the device.
By adjusting the oscillation circuit, detection circuit, etc., it is possible to separate the surface C from the detection surface A by a predetermined distance _{l 2 from} the detection surface A. Detection is possible only when there is a metal piece between the two. In this way, metal passing in the XX direction parallel to the detection surface A can be detected, and if a counting circuit is provided in the main body 12, the number of passing metal pieces can be calculated.
Also, the detection surface A is in the Y ₁ -Y ₁ direction perpendicular to the detection surface A
A metal piece close to can be accurately detected at the position of the plane C, that is, at a distance l ₁ +l ₂ from the reference plane B, which is useful for positioning, centering, etc. of the article.

However, in such a method, the detection of passage is
Only in the X direction, the direction of Y ₁ - _{Y 1} is the detection element 11
It is not possible to detect the passage because it gets in the way. Detection of passage in the Y ₂ -Y ₂ direction that avoids the detection element 11 is extremely inaccurate. Further, proximity detection is limited to the _Y1 - _Y1 direction, and distance detection in the X-X direction is inaccurate, so there is a drawback that it cannot be used for positioning, centering, etc.

The object of the present invention is to provide a ferrite magnetic core for use in the detection end of a metal detection element, which eliminates the above-mentioned drawbacks of the detection end of the conventional metal detection element and can reliably detect passage or proximity from two directions. It is an object.

The present invention achieves the above object by configuring the open end face of a pot core type ferrite magnetic core to form a part of a plane obliquely intersecting the axis thereof.

Embodiments of the present invention will be described below based on the drawings. FIG. 4 is a diagram showing an example of a ferrite magnetic core according to the present invention, in which a is a cross-sectional view and b is a front view. In the figure, the ferrite magnetic core 21 has a large cylinder 22 and a small cylinder or small cylinder (small cylinder in this figure) 23 arranged coaxially, one end surface of which is connected by a disk, and the other end surface is oblique to the axis. It has a shape cut by the intersecting plane D. The shape of other parts is the same as the conventional example shown in FIG.

This ferrite magnetic core 21 is fitted with a coil 5 and its outer surface is covered with a non-magnetic thin film 13 such as resin, and is used as the detection end of the metal detection element 11 in the same manner as the conventional example shown in FIG. be able to.

Fig. 5 is a diagram illustrating the usage of the metal detection element using the ferrite magnetic core as a detection end according to the present invention, and Fig. 6 is a diagram illustrating the relationship between the magnetic flux generated from the metal detection element and the detection situation. Here, a shows the conventional one, and b shows the one according to the present invention. In both figures, a metal sensing element 1 according to the present invention is shown.
The detection surface E of 1 is a surface formed by covering the surface D with a non-magnetic thin film 13 (see FIG. 4), and is oblique to the axis at a predetermined angle. The metal detection element 11 is mounted so that the axis of the ferrite magnetic core 21, which is its detection end, is perpendicular to the reference plane B in the device.
Therefore, the detection plane E and the reference plane B obliquely intersect at a predetermined angle. Further, a surface C that is separated by a predetermined dimension from the detection surface E similarly intersects obliquely at a predetermined angle.

If a metal piece exists between planes E and C, it will be detected because a magnetic flux F exists between them and the metal piece passes through the magnetic flux F (see FIG. 6b). As is clear from FIG. 5 and FIG. 6b, passage in the direction _X2 - _X2 , which is the X direction and the metal detection element 11 does not get in the way, can be detected, and also in an appropriate direction. Proximity in the X ₁ −X ₁ direction can also be detected with accurate dimensions. similarly
Passage in the Y ₂ -Y ₂ direction can also be detected because it passes through the magnetic flux F, and proximity in the Y ₁ -Y ₁ direction can also be detected with accurate dimensions. Also, the minute distance Δ(|X ₂ −X ₁ |, |Y ₂ −
It is also possible to determine Y ₁ |).

On the other hand, in _the conventional method shown in _FIG . If one wanted to detect both passage and proximity in a direction, a total of two metal detection elements would be required, one for each direction.

The above examples of the use of the ferrite magnetic core according to the present invention are mainly described for metal detection elements, but the ferrite magnetic core according to the present invention is used for electrical parts that require generation of a magnetic field in an oblique direction with respect to a reference plane. It is obvious that it can be used effectively.

This invention greatly improves the performance of metal detection elements, and can therefore improve the performance, downsize, and reduce costs of vending machines, automatic machine tools, and other automatic machines that use metal detection elements. It is clear that this will make an extremely large contribution.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a conventional pot core type ferrite magnetic core, where a is a cross-sectional view, b is a plan view, Figure 2 is a diagram showing the general configuration of a metal detection element, and Figure 3 is a diagram showing a conventional metal detection element. 4 is a diagram showing an example of a ferrite magnetic core according to the present invention, where a is a cross-sectional view, b is a plan view, and FIG. 5 is a diagram showing a method of using the ferrite magnetic core according to the present invention. Figure 6, which shows how to use the element, is a diagram showing the relationship between the magnetic flux generated from the metal detection element and the detection situation.
1 is a diagram showing a conventional one, and b is a diagram showing one according to the present invention. 1... Ferrite magnetic core, 5... Coil, 11...
...Metal detection element, 12... Main body, 13... Non-magnetic thin film, 14... Metal housing, 21...
Ferrite magnetic core, 22...large cylinder, 23...small cylinder, 24...disc, A, E...detection surface, B...reference surface, C, D...plane, F...magnetic flux.

Claims (1)

[Scope of utility model registration request] A large cylinder and a small cylinder or small cylinder are arranged coaxially, one end face of which is connected by a disk perpendicular to the axis, and the other end face forms part of a plane obliquely intersecting the axis. A ferrite magnetic core integrally molded from ferrite material.