JPH0130856Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is an electric circuit/magnetic circuit suitable for use in electronic devices that require both a magnetic circuit and an electric circuit, such as electric motors (hereinafter referred to as motors). The present invention relates to a substrate, and particularly to a substrate for an electric circuit/magnetic circuit that aims to reduce the magnetic resistance of a magnetic circuit.

[Conventional technology]

2. Description of the Related Art In devices that require a magnetic circuit and an electric circuit at the same time, especially motors, a technique for forming both circuits on a single substrate is widely used.

FIG. 1 is a sectional view showing an example of the structure of a direct drive motor constructed by such a method. In this figure, reference numeral 1 denotes a substrate formed by forming an electrically insulating layer 3 on the surface of a ferromagnetic metal core 2 made of enameled steel plate, cold hot rolled steel plate, silicon steel plate, etc. A typical example is a substrate. On this substrate 1, excitation coils 4, 4, . . . are arranged in a circular shape at equal intervals to form a stator 5. This stator 5
Above the permanent magnet 6, with a slight air gap,
A rotor 7 having 6... is disposed and supported by a rotating shaft (not shown). Further, a control circuit 8 is provided on the board 1 on the left side of these.

In such a configuration, a current is supplied from the control circuit 8 to the excitation coil 4 to generate a magnetic field, and the lines of magnetic force act on the permanent magnets 6 to rotate the rotor 7. In this case, the metal core 2 is included in a part of the magnetic circuit through which the magnetic lines of force pass, thereby reducing magnetic resistance.

By the way, in the conventional structure described above, since the relative magnetic permeability of each part of the thickness of the electrical insulating layer 3, the thickness of the excitation coil 4, and the thickness of the air gap between the excitation coil 4 and the permanent magnet 6 is 1, the entire magnetic circuit is The magnetic resistance of the metal core 2 increases, and the ferromagnetic properties of the metal core 2 cannot be fully utilized, resulting in a low efficiency.

[Purpose of invention]

In view of the above-mentioned circumstances, the object of this invention is to provide an electric circuit/magnetic circuit board that can form an efficient magnetic circuit.

[Structure of the idea]

In order to achieve this object, the present invention is characterized in that a protrusion that becomes the core of the coil is formed on the metal core of the substrate.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a plan view showing the configuration of an electric circuit/magnetic circuit board according to an embodiment of the present invention applied to a direct drive motor, and FIG. 3 is an enlarged cross-sectional view taken along the - line in FIG. be.

In these figures, the substrate 11 is composed of a ferromagnetic metal core 12 and an electrically insulating layer 13 made of fired enamel, and the substrate 11 has four upwardly projecting protrusions 15, 15, . . . but
They are formed in a circular shape at 90° intervals. These protrusions 15 are formed on the metal core 12 by press working or the like before firing the electrical insulating layer 13, and have a hollow truncated cone shape. As a result,
The front surface (upper side in the figure) of the substrate 11 is a convex surface, and the back surface is a concave surface. On the outer periphery of each protrusion 15, an excitation coil 16 having approximately the same thickness as the protrusion 15,
16... is wound, and its lead wires 16a, 16a
are holes 17, 17 provided near the protrusion 15.
It is soldered to printed circuits 18, 18, which are formed with a thick film on the concave side, through the concave side. Furthermore, a bearing part 19 for a rotor (not shown) is formed in the center of the four protrusions 15, through which a shaft 20 is rotatably inserted, and a permanent magnet 21 of the rotor is placed on the protrusion 15. A slight gap D (this is precisely the permanent magnet 2
1 and the top surface of the metal core of the protrusion 15).

In addition, similar protrusions 22, 22... are formed between the protrusions 15, 15..., and the eight protrusions 15, 22 are arranged on the same circumference at 45° intervals. . The functions of these protrusions 22 will be described later.

In addition, in the figure, 23 is a control circuit, and the board 11
is provided on the concave side of the excitation coil 16 to control the excitation current to the excitation coil 16.

In such a configuration, when a current is supplied from the control circuit 23 to the excitation coil 16, the protrusion 15
The rotor is rotationally driven by the interaction between the magnetic lines of force generated in the permanent magnet 21 and the permanent magnet 21.

In this case, the air gap between the protrusion 15 and the permanent magnet 21 is independent of the thickness of the excitation coil 16.
The distance is D in the figure. In other words, the conventional example (Fig. 1)
The magnetic resistance can be reduced by the thickness of the excitation coil.

In addition, a protrusion 15 is provided only at the excitation coil 16.
If the protrusion 22 is provided, the magnetic resistance will suddenly decrease at this point, which may cause torque unevenness depending on the rotation angle. However, by providing the protrusion 22, this effect can be alleviated. However, if the excitation current is appropriately controlled according to the rotation angle, it is possible to eliminate torque unevenness even without the protrusion 22.

These protrusions 15, 22 can be easily formed by press working.

Further, although an electric circuit can be formed on the electrical insulating layer 13 by thick film circuit technology, due to the printing technology,
It is difficult to form on the convex side, so it is mainly formed on the concave side. However, it is not limited to this. For example, if protrusions are formed at an appropriate processing step after the circuit is formed, it is possible to have the circuit on the convex surface side.

Note that the shapes of the protrusions 15 and 22 are not limited to the above-mentioned shapes, but are appropriately determined based on the shape of the excitation coil, the required amount of reduction in magnetic resistance, the limit value of torque unevenness, the excitation current waveform, and the like. For example, as shown in FIG. 4, a protrusion 15a without a protrusion top surface or a protrusion part with a hole in the protrusion top surface may be used.

In this way, according to this embodiment, the substrate 1 can be
The protrusion 15 provided at 1 can reduce magnetic resistance. This makes it possible to significantly improve performance at low cost.

[Effect of idea]

As explained above, the electric circuit/magnetic circuit board according to this invention has a protrusion that becomes the core of the coil formed on the metal core, so the magnetic resistance of the magnetic circuit can be easily and inexpensively reduced. can increase the energy efficiency of equipment to which it is applied.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the configuration of a conventional electric circuit/magnetic circuit board 1 applied to a direct drive motor, and FIG. 2 is an electric circuit/magnetic circuit board according to an embodiment of the present invention. 11 is a plan view showing the configuration when applied to a direct drive motor, FIG. 3 is an enlarged sectional view taken along the - line in FIG. 2, and FIG. It is a diagram. 1, 11...Substrate, 2,12...Metal core,
3, 13... Electric insulating layer, 8, 23... Control circuit (electric circuit), 15... Projection, 16... Excitation coil (coil).

Claims (1)

[Claims for Utility Model Registration] (1) An electric circuit/magnetic circuit board comprising an electric insulating layer formed on the surface of a core material made of a ferromagnetic metal and an electric circuit provided thereon, wherein the metal A board for electric and magnetic circuits, characterized in that a protrusion that becomes the core of a coil is formed on the core. (2) The electric circuit/magnetic circuit board according to claim 1, wherein the electric circuit/magnetic circuit board constitutes a stator of an electric motor.