JPS63249460A - Field magnet - Google Patents

Abstract

PURPOSE:To improve accuracy in dimension, by forming holding holes, etc., at specified pitches and by inserting designated permanent magnets into a magnet base substance magnetized in the direction of thickness and into these holding holes to hold them. CONSTITUTION:A linear actuator is composed of a permanent magnet 1, an phase A pole 2 wound around with a coil 4, a phase B pole 3 wound around with a coil 5, a moving piece 6, etc. This phase A pole 2 of a stator has pole sections 21 and 22, while the phase B pole 3 of the stator has poles 31 and 32. A magnetic base substance 11 becomes the field magnet of a linear actuator, of which the whole surface is magnetized to an S-pole and the whole underside surface to an N-pole, while holding holes of specified dimension are formed in the moving direction, into which a magnetized permanent magnet 14 is inserted. Even if the permanent magnet 14 is arranged rather biasedly to a holding hole, the error is limited within the holding hole. No error is therefore accumulated, so that high pitch accuracy is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a field magnet, and *, ν, to a structure of a field magnet suitable for a linear actuator.

The same technique as this type of actuator (1.1 includes linear step motors and linear pulse motors, and the same applies to these) is also used.

[Conventional technology]

Linear pulse motors are generally manufactured by Japanese Patent Application Laid-Open No. 56-74080.
The structure is as described in the publication, and in the publication, the stator (11) is attached to the base (12) as shown in FIG.
) and a permanent magnet (13) bonded and fixed to its upper surface. Further, this permanent magnet (13) has a large number of N poles and S poles alternately magnetized along the moving direction of the mover (14).

[Problem that the invention seeks to solve]

As mentioned above, the field magnets of conventional actuators and motors obtain their magnetic poles by magnetization at minute pitches, and cannot obtain a large magnetomotive force.

Therefore, the thrust as a motor is small and cannot handle a large load, which is a factor that limits the applications of this type of motor and actuator.

[Means for solving problems]

The present invention has been made with attention to the above, and includes a magnet base in which holding holes or grooves are formed at a predetermined pitch and magnetized in the thickness direction, and a magnet base in which holding holes or grooves are formed in the magnet base. A field magnet is constructed by inserting and holding a permanent magnet that is magnetized in a direction different from the magnetization direction of the magnet, and combining the former magnet base and the latter permanent magnet.

[Effect]

As mentioned above, since the pre-magnetized magnet base and the permanent magnet are combined, there is no demagnetization effect due to single magnetization, and the magnetomotive force of the field magnet is increased.

〔Example〕

The configuration of an embodiment of the present invention will be described below.

As described above, the present invention is applied to a linear actuator and a linear step motor, so first, the basic structure of the linear actuator will be explained. In FIG. 3, 1 is a permanent magnet, 2 is an A-phase magnetic pole around which a coil 4 is wound, and 3 is a B-phase magnetic pole around which a coil 5 is wound. Reference numeral 6 denotes a movable element, which carries the above-mentioned permanent magnet, which is minutely magnetized with N poles and S poles alternately at the same pitch as the stator magnetic pole teeth. The stator A+11 magnetic pole 2 has magnetic pole parts 21 and 22, and the phase relationship between the two magnetic pole parts is such that the tooth protrusion of the magnetic pole part 21 is N i:l of the permanent magnet 1.
i, the protrusions of the teeth of the magnetic pole part 22 are aligned with the permanent magnet 1.
It is configured to coincide with the south pole of. Therefore, as shown in FIG. 1, the magnetic flux Φ^ interlinks with the coil 4. Also,
The stator B+I'I magnetic pole 3 also has magnetic poles 31° and 32, and these two magnetic pole portions also have a similar phase relationship. Furthermore, stator A
The phase relationship between the phase magnetic pole 2 and the stator B-phase magnetic pole 3 is as shown in the figure. The center of the tooth protrusion of the magnetic pole 3 is in such a relationship that it coincides with the switching point of the minute magnetic pole of the permanent magnet 1.

Therefore, when the permanent magnet 1 is in the position shown in FIG.

The magnetic flux ΦΔ interlinks with the coil 4, and the magnetic flux does not interlink with the coil 5. In addition, if the movable element 6 moves and the magnetism of the minute magnetic poles of the permanent magnet 1 facing the protrusions of the teeth of the magnetic pole parts 21 and 22 of the stator A-phase magnetic pole 2 becomes reversed, the coil 4 will be linked. The magnetic flux is in the opposite direction to Φ^. Furthermore, if the positional relationship between the stator A-phase magnetic pole 2 and the permanent magnet 1 is similar to the positional relationship between the stator B-phase magnetic pole 3 and the permanent magnet 1 in FIG. do not. In this way, the magnetic flux linkage of the coil 4 is:

The direction and size change depending on the position of the oscillator 6. Similarly, in the coil 5, the interlinkage magnetic flux changes depending on the position of the movable element 6, and the phase shifts by 90 degrees in electrical angle.

What has been described here is an example of two phases, but the same applies to three or more phases, in which case only the phase difference between each phase differs depending on the number of phases.

Further, although the permanent magnet side is used as the mover, there is no essential difference if the permanent magnet is used as the stator.

The thrust of this actuator is proportional to the amount of change in the magnetic flux linkage of the coil with respect to the above-mentioned change in the position of the movable element. In order to achieve high thrust with this linear step actuator, the pitch of the steps, i.e., the pitch of the teeth of the inductor and the pitch of the magnetic poles of the permanent magnet, must be miniaturized to provide a chain response to changes in the position of the movable element of the inductor type coil. It is necessary to increase the rate of change in alternating magnetic flux.

Therefore, miniaturization of the magnetization pitch of permanent magnets is an essential technology for increasing the thrust of linear step actuators.

The conventional permanent magnet installed in the mover is as shown in Figure 2.
It simply had N and S poles alternately magnetized. If the magnetization pitch is made minute with the structure as it is, the following problems will occur.

FIG. 4 shows the basic structure of a magnetizing device for forming the magnet shown in FIG. 2. The area of the tip 9 of the core facing the magnetic medium (permanent magnet) 7 of this magnetizing device is made minute to match the desired magnetization width, and magnetization is performed. Since the magnetic flux passes through the permanent magnet while diverging in the direction of the arrow in FIG. 4, the magnetic force of the permanent magnet 7 becomes weaker as it becomes deeper. Furthermore, in order to magnetize multiple poles at minute pitches, the core of the magnetizing device is shifted by the pitch to reverse the magnetic flux and perform magnetization. The situation is shown in FIG. As is clear from the figure, when adjacent magnetic poles are magnetized, the magnetic flux also passes through previously magnetized parts, and the magnetic force is significantly weakened.

Therefore, in the method of magnetizing permanent magnets at minute pitches in an integrated magnetic medium, a decrease in magnetic force is unavoidable, and sufficient performance cannot be obtained.

Therefore, we divided a permanent magnet into minute rectangular bodies for each magnetic pole pitch, and after magnetizing them, we glued them together as shown in Figure 2.
A method of using a micro-magnetized permanent magnet as a single sheet is also being considered. With this method, sufficient U81 force can be obtained, but the manufacturing precision and adhesion precision of the micro permanent magnet rectangular bodies are low, and when a large number of them are combined, the magnetization pitch of the permanent magnets and the height of the permanent magnets will vary. .

For this reason, sufficient performance cannot be obtained when used in an actuator.

That is, with the above method, it is not possible to arrange high magnetomotive force magnets (magnetic poles) with a small pinch and with high precision.

The present invention aims to obtain a field magnet that can provide sufficient magnetomotive force even with a minute pitch and has high dimensional accuracy. FIG. 1 is a perspective view of a field magnet showing an example of the present invention, and FIG. 6 is a developed view showing the manufacturing procedure. In FIG. 6, reference numeral 11 denotes a magnet base having a length and width necessary for a field magnet of a linear actuator. The entire surface of the magnet base 11 is magnetized to the S pole, and the entire lower surface is magnetized to the N pole. Sunao〕chi,
This magnet base 11 is magnetized in the thickness direction. Reference numeral 12 denotes a grid having a movement dimension T, and holding holes 13 having a movement direction dimension T and a width direction dimension Q are formed between the grids 12. Reference numeral 14 denotes a magnetized permanent magnet inserted into the holding hole 13, which has a dimension in the moving direction of T1 and a dimension in the width direction of Q, and can be inserted into the holding hole 13 by one circle without any gap. This permanent magnet 14 is arranged vertically in N so that it has a polarity opposite to that of the magnet base 11.

The S pole is magnetized, and one is inserted and held in each holding hole 13. FIG. 1 shows a state in which all the permanent magnets 14 are fitted into the magnet base 11, and the pitch is 1.
A field magnet in which magnetic poles N and S are alternately arranged can be obtained. The dimensional accuracy of this field magnet is determined by the manufacturing accuracy of the magnet base 11, and since the magnet base 11 can be manufactured from a plastic magnet, a highly accurate one can be obtained. Further, the permanent magnet 14 is also made of a plastic magnet.

Further, even if the permanent magnet 14 is disposed slightly off-center to the holding hole 13, the error remains within the holding hole 13, so the error does not accumulate, and very high pinch accuracy can be obtained.

In addition, since magnets with opposite magnetic poles are arranged vertically, there is no attraction force between the surfaces of the permanent magnet 14 and the magnet base 11 at the time of insertion, allowing smooth insertion, and the attraction force disappears after insertion for more than 14 minutes. Is it effective and the insertion work is easy? It becomes ↓. Further, after the insertion is completed, the suction force is applied between the two so that the two do not separate. Integration can be achieved with just this suction force, but (
(B) For the sake of safety, use adhesive to fix the parts together.

The pitch T mentioned above is from 1 nwu to several thousand, and each magnet is very small as a single unit, but since each magnet is magnetized by light, the 8 magnetic force maintains the magnetized state. It has a large magnetic force. According to experiments, the magnetomotive force is about 2 to 3 times higher than that of the alternate magnetization method in which one magnetic medium 7 is alternately magnetized with N and S as shown in Fig. 5. It was confirmed that the Furthermore, if the accuracy of forming the magnet base 11 and the permanent magnet 111 is increased and the precision of the machine is improved, the pitch '
Since F can be made small and the magnetomotive force is not reduced, the 1y resolution can also be improved.

Next, based on FIG. 9, the permanent magnet 14 is attached to the magnet base 11.
Approximate assembly machine for fitting 018 t11! I will explain the process. 21 indicates the floor or the entire base.

A slide bed 22 movable in the direction of the arrow is supported on this upper surface. This slide bed 22 is driven by a drive device (not shown) so as to move the slide bed 22 by a pinch 2T in the direction of the arrow. Reference numeral 11 denotes the aforementioned magnet base fixed on the slide bed 22 with a pair of clamps 23. A holder 24 is fixed to the base 21 and provided vertically on the magnet base 11. Reference numeral 25 denotes a guide hole formed perpendicularly to the holder 24, into which the permanent magnet 14 is inserted and held, and its lower end opening is aligned with the holding hole 13 of the magnet base 11. Reference numeral 26 denotes a cylinder provided at the upper end of the holder 24, and applies a predetermined downward force to the permanent magnet 14 with the tip of its rod 27 inserted into the guide hole 25 of the holder 24. This force is applied if holder 2
If the permanent magnet 4 is made of iron, the permanent magnet 14 will be attracted to the holder 24, but it may be larger than this attraction force. Holder 2
If cylinder 4 is made of a non-magnetic material such as aluminum or synthetic resin, this attraction force will not be generated, so the force of cylinder 2G may be small.

Then, the magnet base 11 is supported on the slide bed 22, and the permanent magnet 14 located at the lowest position in the guide hole 25 is pushed into the first holding hole 13 by the cylinder 26. Next, when the slide bed 22 is moved forward by a pitch of 2T in the direction of the arrow, the next holding hole] 3 is located between the lower ends of the guide hole 25. If the cylinder 26 is actuated at this time, the next permanent magnet 14 is dropped into this holding hole 13 and is inserted and held. In this way, the permanent magnets can be inserted and held in the holding holes one after another in the same way as a Daruma drop. In addition, in this insertion process, as mentioned above, at the beginning of insertion, the magnetism of the magnetic poles is the same and they repel each other, so they do not attract each other, and can be inserted smoothly to the middle, and after that, the polarity becomes the same, but the permanent magnet Since it is more than half inserted, it will not shift, and by applying force to it with the cylinder 26, the insertion operation can be performed reliably.

In the above-mentioned embodiment, each permanent magnet 24 is inserted and held in the holding hole 13 of the magnet body 11, but the holding hole provided in the magnet base 11 is not a perfect hole, but may be a bay. , so to speak, any holding part that has the function of holding a permanent magnet may be used. Note that the shape and depth of this holding portion can be changed arbitrarily.

Figure 8 shows the entire structure with a holding hole and a holding groove 13A.
It has an I-shaped magnet base 11A, and the magnetic pole orientation, combination direction, etc. are the same as those described in I'111. In this case, compared to FIG. 6, one root side of the comb-like shape is unnecessary, which has the effect of reducing the size. Naturally, both could be combined with the insertion device shown in FIG.

In what has been described so far, each permanent magnet 14 is an independent unit, and this is inserted and held in each holding hole 13 or holding groove 13A, so the permanent magnets are separate and the insertion work takes time. There is a problem that it takes

The solution mechanism for this problem is shown in Section 7.1. In FIG. 7, the magnet base 11B and the permanent magnet 14B are each shaped like a comb with a pitch T, and the comb teeth of each are inserted into the holding grooves 13B of the other to combine and connect them. The insertion and combination direction at this time may be performed from the side or from above, but the latter method from above is preferable in that the repulsive force is applied first and then the suction force is applied.

This figure 7 has the advantage that the combination can be completed in - times of combination operations. The polarity shown in FIG. 7 is the same as described above. Moreover, the 8 magnetic forces are exactly the same as those shown in FIG.

Incidentally, when the required dimension of the field magnet is long, it is sufficient to prepare several unit comb teeth, arrange the required number of unit teeth in a straight line, and fix them to a substrate (not shown).

Although the field magnet is widely used as a component of a mover, it is natural that it can be used as a field B1 magnet device of a stator.

【Effect of the invention〕

As described above, according to the present invention, there is provided a magnet base having retaining holes or retaining grooves formed at a predetermined pitch and magnetized in the thickness direction, and a magnet base having retaining holes or retaining grooves formed in the retaining holes or retaining grooves of the magnet base. A permanent magnet that is magnetized in a direction different from the magnetization direction is inserted and held, and the field magnet is constructed by combining the former magnet base and the latter permanent magnet, so there is no demagnetization effect due to magnetization, and the magnetomotive force is reduced. The pitch can be made as small as possible, and the accuracy of dimension Y5 can also be improved.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a field 6J & magnet showing an embodiment of the present invention, and Fig. 2 is a conventional field 1F! An oblique view of the magnet, FIG. 3 is a principle diagram of a linear actuator to which the present invention is applied, FIGS. 4 and 5 are diagrams showing a conventional method of magnetizing a field magnet, and FIG. 6 is a diagram showing the principle of a linear actuator to which the present invention is applied. 7 and 8 are perspective views showing other embodiments of the present invention, and FIG. 9 shows the field magnet shown in FIGS. 1 and 8. It is a cross section V showing an assembly machine that constitutes a magnet. Akira 1 Figure/4 E/4-m-Eternal A, 5 3rd entry B-Enchiko Tsuki 40th 52 h'l heat l''3

Claims (1)

[Claims] 1. A field magnet in which a large number of magnetic poles N and S are arranged alternately in the longitudinal direction, including a magnet base in which holding holes or holding grooves are formed at a predetermined pitch and magnetized in the thickness direction; A permanent magnet magnetized in a direction different from the magnetization direction of the magnet base is inserted and held in a holding hole or a holding groove of the magnet base, and a field magnet is constructed by combining the former magnet base and the latter permanent magnet. A field magnet featuring: 2. The field magnet according to claim 1, wherein the permanent magnets are independent and separated from each other. 3. The field magnet according to claim 1, wherein the permanent magnet has a comb-like shape in which the ends thereof are integrally connected with the same material as the permanent magnet. 4. The field magnet according to claim 1, wherein the magnet base and the permanent magnet have the same plate thickness. 5. The field magnet according to claim 1, wherein the magnet base and the permanent magnet are both made of plastic magnets.