JPH0217492Y2 - - 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]

To achieve this objective, the present invention is characterized in that a groove portion into which a coil is fitted is formed in the metal core of the substrate.

[Embodiments] Hereinafter, embodiments of the present invention will be described 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 annular grooves 15, 15, . . . They are formed in a circular shape with intervals of . These grooves 15 are
It is formed on the metal core 12 by press working or the like before sintering the electrical insulating layer 13, and as a result, the front surface (upper side in FIG. 3) of the substrate 11 has a concave surface, and the back surface has a concave surface. It has a convex surface. Each groove 1
5 is fitted with annular excitation coils 16, 16, . ing. Furthermore, four grooves 1
A bearing part 19 of a rotor (not shown) is formed in the center of the rotor (not shown), and a shaft 20 is rotatably passed through the rotor. To be precise, the permanent magnet 21 is spaced apart by a distance (which is the distance between the bottom surface of the permanent magnet 21 and the top surface of the metal core of the center portion 15a of the groove portion 15).

The control circuit 17 controls the excitation current to the excitation coil 16, and is printed on the concave side of the substrate 11 using thick film circuit technology.

In such a configuration, when a current is supplied from the control circuit 17 to the excitation coil 16, each groove 15
The rotor is rotationally driven by the interaction between the lines of magnetic force generated in the center portion 15a of the permanent magnet 21 and the permanent magnet 21.

In this case, the air gap between the center portion 15a of the groove portion 15 and the permanent magnet 21 becomes the distance D shown in FIG. 3, regardless of the thickness of the excitation coil 16. That is, the magnetic resistance can be reduced by the thickness of the excitation coil compared to the conventional example (FIG. 1).

Furthermore, since the upper surface of the center portion 15a of the groove portion 15 and the normal surface (that is, the surface on which the circuit pattern of the control circuit 17 is formed) are substantially on the same plane, the magnetic resistance between them and the permanent magnet 21 is approximately The torque is kept constant, and it is possible to prevent uneven torque from occurring depending on the rotation angle. In this case, the upper surface of the center portion 15a of the groove portion 15 may be slightly raised above the normal surface within a range that does not cause any inconvenience in forming the circuit pattern. Thereby, the distance D between the center portion 15a and the permanent magnet 21 can be further reduced.

The groove portion 15 can be easily formed by press working.

Furthermore, although an electric circuit is formed on the electrical insulating layer 13 by thick film circuit technology, it is difficult to form it on the convex side due to printing technology, and it is mainly formed on the concave side. Therefore, in the case of this embodiment, the excitation coil 1
6. The control circuit 17 is formed on the concave side where the permanent magnet 21 is provided, and the Hall element and oscillation circuit for motor control are also attached to the concave side.
The advantage is that assembly is easy.

Thus, according to this embodiment, magnetic resistance can be reduced without adding any special parts for reducing 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 groove portion in which a coil is fitted in 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.

In addition, since the circuit pattern of the control circuit can be formed on the side where the excitation coil and permanent magnet are attached (concave side), all components including the Hall element and oscillation circuit for motor control can be gathered on the concave side. The advantage is that the device is easy to assemble.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a configuration example 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, and FIG. 3 is an enlarged sectional view taken along the line -- in FIG. 1, 11...Substrate, 2,12...Metal core,
3, 13... Electric insulating layer, 8, 17... Control circuit (electric circuit), 15... Groove, 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 1. A board for electric and magnetic circuits, characterized in that a core is formed with a groove portion into which a coil is fitted. (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.