JPH01298945A - Permanent magnet type linear pulse motor - Google Patents

Abstract

PURPOSE:To increase a thrust by forming a slit on a part adjacent to the unmagnetized part of the magnet. CONSTITUTION:A permanent magnet type linear pulse motor has a slider R and a scale 9. Permanent magnets 5-8 multipolarly magnetized are provided at the slider R. A plurality of slits 10a1-10a12 are formed on the boundary of the poles 1-4 adjacent to the unmagnetized parts M1, M2, M3 of the magnets 5-8. Magnetic flux density of the pole is reduced by the slits 10a1-10a12, and the magnetic flux density in the gap can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a permanent magnet type linear pulse motor whose thrust can be increased by simple structural improvements.

[Prior Art] As a permanent magnet type linear pulse motor, one is known in which a multi-pole magnetized permanent magnet is provided at the tip of each magnetic pole constituting an electromagnet on the slider side.

FIGS. 4(a) to 4(d) are front views showing the configuration and operating principle of conventional devices, respectively.

In the figure, R is a slider and 9 is a scale.

The slider R has magnetic poles 1 to 4 of four electromagnets each having excitation coils 1a to 4a. At the tip of each of these magnetic poles, there is a minute length corresponding to a tooth slot with a scale of 9ftm.
It is provided with multi-thin permanent magnets 5 to 8. On the other hand, the scale 9 is disposed opposite the permanent magnets 5 to 8 of the slider H at a predetermined interval, and is configured to have inductor teeth on the opposing surface.

In addition, (a) to (d) indicate the original burial that generates a moving magnetic field, so in the figures after (b), the coil is not shown, and the coil that is magnetized by 9w1 and the passing magnetic flux are described with emphasis by symbols. That's what I do.

[Problems to be Solved by the Invention] Since the above-mentioned permanent magnets 5 to 8 have multiple poles, it is theoretically possible to attach a permanent magnet having such multiple poles to each of the magnetic poles 1 to 4. 2 Although it is possible to do so, the production efficiency is poor with this manufacturing method.

In reality, each permanent magnet is constructed by means of multipolar magnetization.

By the way, when magnetizing a permanent magnet with multiple poles in this way, especially for high-performance rare earth magnets, for example, as shown in Fig. 5 (
b) as shown with a hatch.

Adjacent N[! , unmagnetized portions M1 to M at each boundary of the S pole,
will definitely occur. Therefore, the configuration shown in FIG. 5(a) is magnetically equivalent to the configuration shown in FIG. 5(b).

Therefore, the magnetic flux caused by the magnetomotive force of the coil that passes through the unmagnetized portion of the permanent magnet does not contribute to the thrust of the linear pulse motor.

That is, when the permanent magnet has an unmagnetized portion.

When the coil is excited, in addition to the magnetic flux due to the magnetic poles of the permanent magnet shown in Figure 5 (a), when the magnetic flux due to the magnetomotive force of the coil flows, the combined magnetic flux is as shown in the same figure (b). Including unmagnetized portions M1 to M.

It flows from the magnetic pole on the slider side to the scale 9 side.

As a result, leakage magnetic flux as shown by Ll+L2 is generated,
The magnetic saturation of the magnetic pole part was accelerated, causing a reduction in the thrust of the linear pulse motor.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a permanent magnet type linear pulse motor equipped with a multi-pole magnetized permanent magnet on the slider side or the scale side. This invention relates to a permanent magnet type linear pulse motor in which a slit is formed in a portion adjacent to a magnetic portion.

[Example] First and second embodiments of the present invention shown in FIGS. 1 and 2 below
Each example will be explained. In each figure, components equivalent to those in FIG. 4 are designated by the same reference numerals.

FIG. 1 shows a first embodiment of the invention. In the figure, 10a+ to 10a+2 are slits, respectively, and unmagnetized portions M + of one permanent magnet 5 to 8.

A plurality of (for example, three each) are formed at the boundary between M 2 and M 3 and adjacent magnetic poles 1 to 4.

FIGS. 2(a) to 2(c) show a second embodiment of the present invention. In this case, the permanent magnet 11 is provided not on the slider side but on the scale side, and this permanent magnet 11 is placed on the scale side as shown in the figure. , N, S, N, S, etc., and use a plurality of permanent magnet plates as intermediate layers adjacent to the boundary portions of each unmagnetized magnetic pole of each permanent magnet plate 11. Slit S+.

S2. Using a slit plate formed with S*, S4..., a permanent magnet plate 11. Slit plate 12. Board 13
The scale 9' is constructed by adhering the two parts together with adhesives Zl and Z2. In addition.

In this case, the slits may be formed in the slit plate by a half-etching method.

[Function] In the permanent magnet type linear pulse motor according to the present invention, slits are provided in the magnetic flux path adjacent to the unmagnetized portions that occur at the boundaries of each magnetic pole of the permanent magnet as described above.
In terms of the magnetic circuit, FIG. 3(A) has the configuration shown in FIG. 3(B).

Therefore, the composite magnetic flux based on the magnetomotive force of the permanent magnet and the magnetomotive force of the coil flows as shown in the same figure (b), and the leakage magnetic flux that conventionally passed through the unmagnetized parts M1 to M, L2
are the slits 10a, -10ai (in the case of the second embodiment shown in FIG. 2, the slits S1+S2.S3.
), the flow stops due to the presence of

[Effects of the Invention] As described above, the permanent magnet type linear pulse motor of the present invention differs from conventional ones in that a slit is provided at the boundary portion of the slider or scale adjacent to the unmagnetized portion that occurs at each magnetic pole boundary of the permanent magnet. 1 with a simple configuration that only requires installation.
It has the following excellent features.

■Unnecessary magnetic flux that leaked from the unmagnetized parts of the permanent magnet in conventional magnets is eliminated, so the magnetic flux density at the magnetic poles can be reduced (the magnetic flux density at the gap is increased), and the linear pulse motor Thrust can be increased.

■The same reluctance force acts on the slit part as in the case of a normal linear pulse motor with a permanent magnet attached to the bottom surface, so the thrust of the linear pulse motor increases at this point as well, and in the end, the overall linear The thrust of the pulse motor can be significantly increased.

[Brief explanation of the drawing]

1 and 2 show first and second embodiments of the present invention, of which FIG. 1 is a front view. Figure 2 (A) is a front view, and Figure 2 (B) is an exploded perspective view. Figure (C) is a partial sectional view. Furthermore, FIGS. 3(A) and 3(B) are partial front views for explaining the operation of the first embodiment of the present invention, and FIGS. 4 and 5 are respectively for the conventional example. Figures 4(a) to 4(d) are front views showing the structure and principle thereof. FIGS. 5(a) and 5(b) are partial front views showing the operation, respectively. 1-4: Magnetic poles 5-8: Permanent magnet 11: Permanent magnet plates 10a1-10a+2 Nislit S+, S2. S 3. S4... Nislit 12; Slit plate 13 Two substrates M1 to M3: Unmagnetized portion 9.9° Niscale R Nislider

Claims (1)

[Scope of Claims] 1. In a permanent magnet type linear pulse motor comprising a multi-pole magnetized permanent magnet at the tip of each magnetic pole constituting the electromagnet on the slider side, the permanent magnet is adjacent to the non-magnetized portion of the permanent magnet. A permanent magnet type linear pulse motor characterized by having slits formed in its parts. 2. In a permanent magnet type linear pulse motor, which is equipped with a multi-pole magnetized permanent magnet on the scale side surface facing each magnetic pole that constitutes the electromagnet of the slider, a slit is provided in the part adjacent to the unmagnetized part of this permanent magnet. A permanent magnet type linear pulse motor characterized by forming a permanent magnet type linear pulse motor. 3. A permanent magnet type linear pulse motor according to claim 2, wherein the slits are formed by half etching.