JPS62114461A - Linear pulse motor - Google Patents

Abstract

PURPOSE:To enhance a static thrust and precision, by forming two rugged rows of a stator with positionally shifted phase, and by arranging the rows in a specific manner. CONSTITUTION:A mover 1 is organized with a permanent magnet 2, U-formed magnetic members 3, 4 fitted on the both sides of the magnet 2, and exciting coils 5, 6 wound up respectively on the members 3, 4. On a stator 8, two rugged rows 9, 10 shifted positionally by 1/4 pitch (phase, 90 deg.) against one pitch of the rugged sections are formed. The rugged rows 9, 10 consist of a plurality of concave sections and convex sections repeated at a specified pitch. Besides, on the mover 1, vertically to the advancing direction, the magnetic member 3, the permanent magnet 2, and the magnetic member 4 are arranged, and the rugged section of the magnetic member 3 approaches the confronts the rugged row 9 and the rugged section of the magnetic member 4 approaches the confronts the rugged row 10, respectively. Then, the unbalance of a magnetic circuit between magnetic pole teeth is remedied, and the distortion or the like of the mover 1 can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a linear pulse motor in which a mover moves a certain distance in response to a human pulse.

[Conventional technology]

FIG. 2 shows a schematic diagram of a conventional linear pulse motor. The movable element 20 includes magnetic materials 21 and 22 that are formed with unevenness and have low coercive force and high saturation magnetic flux density, a permanent magnet 24 mounted between them and magnetized like magnetization 23, and magnetic materials 21 and 22.
22 and excitation coils 25 and 26 wound respectively. The magnetic materials 21 and 22 and the permanent magnets 24 are arranged in the direction in which the mover 20 moves. On the other hand, the stator 27 is formed with a row of concavities and convexities 28 corresponding to the magnetic materials 21 and 22 of the movable element 20, and is made of a magnetic material having low coercive force and high saturation magnetic flux density. The unevenness of the movable element 20 is formed in combination with the unevenness row 28 of the stator 27 to obtain a desired step pitch.

FIG. 3 is a sectional view showing the operating principle of the conventional linear pulse motor shown in FIG. 2. The excitation coil 25 is connected so that the polarities of the magnetic pole teeth (2) and (2) constituting the convex portion of the magnetic material 21 are opposite to each other. Similarly, the excitation coil 26 is connected to the magnetic pole teeth ■ and ■ constituting the convex portion of the magnetic material 22.
are connected so that their polarities are opposite to each other.

When a current is applied to the excitation coil 25 in the direction shown by the arrow in the magnetic material 21 to excite it, the magnetic field of the electromagnet is added to the magnetic field of the permanent magnet 24 at the magnetic pole tooth ■, and the magnetic field is strengthened. The magnetic field of the magnetic field and the magnetic field of the electromagnet cancel each other out, and the mover 20 stops at the position shown in FIG. 3(a). At this time, the magnetic force of the magnetic material 22 is balanced.

Next, as shown in FIG. 30)), when a current is passed through the excitation coil 26 in the direction of the arrow, the magnetic field is strengthened at the magnetic pole (2) and canceled at the magnetic pole (2), so that the mover stops at the position shown. In other words, one step pitch (
(equivalent to 1/4 pitch of the row of protrusions and recesses on the stator 27). Below, in the same manner, Figure 3 (C) and (d)
The movable element 20 moves as shown in FIG.

[Problem that the invention seeks to solve]

In a conventional linear pulse motor, as shown in Figure 3, there is a magnetic circuit through which magnetic flux passes when exciting magnetic pole teeth ■ and magnetic pole teeth ■, and a magnetic circuit through which magnetic flux passes when exciting magnetic pole teeth ■ and magnetic pole teeth ■. Since the magnetic circuits are different, the magnetic resistance when exciting the magnetic pole teeth ■ and ■ is different from the magnetic resistance when exciting the magnetic pole teeth ■ and ■.

Therefore, if the same current is applied to the excitation coils 25 and 26, an imbalance in thrust will occur, so it is necessary to check the current values in advance and determine so that the same thrust will be generated.

Furthermore, due to the difference in magnetic resistance, the attractive force due to magnetic coupling near both ends of the permanent magnet 24 and the attractive force near both ends of the mover 20 are different, resulting in distortion near the center, which causes the mover 20 and stator to become distorted. This causes an imbalance in the gap between the two. Therefore, there is a problem in that the error in the step pitch increases, and furthermore, the adhesive between the permanent magnet 24 and the magnetic materials 21 and 22 on both sides peels off.

[Purpose of the invention]

The purpose of the present invention is to solve the above-mentioned problems.
An object of the present invention is to provide a linear pulse motor that realizes a highly accurate step pitch.

[Structure of the invention]

The present invention provides a stator made of a magnetic material on which a row of projections and recesses are formed to correspond to a step pitch, a permanent magnet, and projections and recesses that are attached to both sides of the permanent magnet and magnetically couple with the row of projections and recesses of the stator. In a linear pulse motor, the linear pulse motor is configured by: two magnetic materials formed with a movable element, and an excitation coil wound around these magnetic materials; The two magnetic materials of the stator are composed of two rows of concavo-convex rows, and the concavities and convexities of one magnetic material closely oppose one of the concavo-convex rows, and the concave-convex rows of the other magnetic material closely oppose the other concave-convex row. It is characterized by being arranged as follows.

〔Example〕

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

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

The movable element 1 is composed of a permanent magnet 2, U-shaped magnetic members 3 and 4 attached to both sides thereof, and excitation coils 5 and 6 respectively wound around these magnetic members.

Further, the permanent magnet 2 is magnetized in the direction of magnetization 7. That is, it is magnetized so that the direction of magnetization is perpendicular to the direction in which the movable element 1 moves.

On the stator 8, two rows of protrusions and recesses 9° and 10 are formed with a 1/4 pitch, that is, a phase shift of 90° for each pitch of the protrusions and recesses. FIG. 4 shows a partial plan view of the stator 8.

The concavo-convex row 9 is a plurality of concave portions 9a that are repeated at a predetermined pitch.
Similarly, the concavo-convex row 10 consists of a plurality of concave portions 10a and convex portions 10b repeated at the predetermined pitch. As described above, these rows of recesses and recesses 9 and 10 are arranged with a shift of 1/4 pitch from one pitch of the recesses and recesses.

In this embodiment, the edges of the opposing recesses 9a and 10a of the concavo-convex rows 9 and the concavo-convex rows 10 are formed to have rounded edges, and the reason for this will be described later.

In FIG. 1, the mover 1 is arranged perpendicularly to the moving direction of the mover 1 with the magnetic material 3. Permanent magnet 2. The magnetic materials 4 are arranged such that the concave and convex portions of the magnetic material 3 are close to and opposite to the concave and convex rows 9 of the stator 8 , and the concave and convex portions of the magnetic material 4 are arranged to be close to and opposite to the concave and convex rows 10 of the stator 8 .

In the linear pulse motor configured as above, the mover 1
The magnetic flux from the stator 8 is perpendicular to the moving direction of the mover 1.
pass through the interior of In that case, the shortest magnetic path is one that passes near the surface of the stator 8 from the convex portion 9b to the convex portion 10b. Therefore, in order to allow this magnetic flux to pass through smoothly, it is necessary to
In order to prevent leakage due to magnetic saturation, la and llb are formed to have roundness, that is, a round groove, as described above.

FIG. 5 shows a cross-sectional view of the linear pulse motor of this embodiment, and FIG. 5(a) shows the magnetic material 3 of the movable element 1 and the concavo-convex array 9 of the stator 8 facing it. FIG. 5 is a cross-sectional view of the magnetic material 4 of the movable element 1 and the concavo-convex array 10 of the stator 8 facing thereto. The magnetic pole teeth of the U-shaped magnetic material 3 are denoted by ■ and ■ as shown in the figure, and the magnetic pole teeth of the U-shaped magnetic material 4 are denoted by ■ and ■ as illustrated. In addition, 5°6 in the figure indicates the magnetic material 3 as explained in FIG.
．． The excitation coils are wound around the coils 4 and 4 respectively. The excitation coil 5 is wound so that the polarities of the magnetic pole teeth ■ and ■ are opposite to each other, and the excitation coil 6 is wound so that the polarities of the magnetic pole teeth ■ and ■ are opposite to each other. There is.

The operating principle of this embodiment is the same as that of a normal linear pulse motor driven by a phase shift of the magnetic pole teeth, but the magnetic coupling makes it possible for the conventional linear pulse motor shown in Fig. 2 to advance the mover. In contrast, in the present invention, the movable member is formed perpendicularly to the moving direction of the mover. That is, the magnetic flux emitted from the magnetic pole teeth ■ or ■ passes through the stator 8 and enters the magnetic pole teeth ■ and ■. Further, the magnetic flux coming out from the magnetic pole teeth ■ or ■ passes through the stator 8 and enters the magnetic pole teeth ■ and ■. Since there is no significant difference in the magnetic circuits through which these magnetic fluxes pass, there is no significant difference in magnetic resistance.

Therefore, even if the same current is applied to the excitation coils 5 and 6, an imbalance in thrust does not occur, so that the applied current supply circuit can be configured very easily. Therefore, the step pitch error depends only on mechanical accuracy. Furthermore, since there is no large difference in magnetic resistance, peeling of the adhesive due to unbalanced attractive force, which was a problem in the conventional example, does not occur. Furthermore, as described above, the recesses 9a, 1Qa(7) edges lla, ll of the stator 8
Since b is formed with a round groove, there is no leakage of magnetic flux due to magnetic saturation (magnetic flux passes through smoothly, so a very strong static thrust can be achieved).

It is preferable that the magnetic materials 3 and 4 constituting the mover l of this embodiment have a low coercive force, such as pure iron, and a saturation magnetic flux density as high as possible. Furthermore, the permanent magnet 2 used has an energy product greater than that of a rare magnet. In this case, the miniaturization of linear pulse motors.

For thinning, for example, NEOMAX30 (product name)
If the energy product is approximately 7 mm, a static thrust of nearly 400 g can be obtained if the combined height of the stator and mover is 7 mm. Like the movable element 1, the stator 8 is also desirably made of a material close to pure iron. The two rows of unevenness rows 9° and 10 on the stator 8 can be formed by etching, etc., and there is no major problem when the step pitch is large, but as the step pitch becomes smaller, the deterioration of feeding accuracy becomes a serious problem. becomes. To solve this problem, a method such as wire electrical discharge machining or electromagnetic wave machining can form irregularities with very high accuracy.

Although one embodiment of the present invention has been described above, it goes without saying that those skilled in the art can make various modifications and changes within the scope of the present invention.

〔Effect of the invention〕

As explained above, the linear pulse motor of the present invention has the following features:
It improves the unbalance of the magnetic circuit between the magnetic pole teeth, which was a problem in the past, and also eliminates the distortion of the mover due to the unbalance of the attractive force or the peeling of the adhesive between the permanent magnet and the magnetic material. It is possible to realize a highly accurate step pitch.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention, FIG. 2 is a schematic perspective view of a conventional linear pulse motor, and FIG. 3 is a diagram explaining the operating principle of the linear pulse motor shown in FIG. 4 is a schematic plan view of a part of the stator in the embodiment of FIG. 1, and FIG. 5 is a sectional view of the linear pulse motor of FIG. 1. 1...Mover 2...Permanent magnet 3.4...Magnetic material 5.6...Exciting coil 8
..... Stator 9.10 ..... Concave and convex rows 9a, 10a ..... Concave portions 9b, 10b ..... Convex portions 11a, llb ..... Concave edges agent
Patent attorney Yoshiyuki Iwasa (a) (b) (C) (d) Figure 3

Claims (2)

[Claims] (1) A stator made of a magnetic material on which a row of projections and recesses are formed to correspond to the step pitch, a permanent magnet, and projections and recesses attached to both sides of the permanent magnet that magnetically couple with the row of projections and recesses of the stator. In a linear pulse motor, the linear pulse motor includes a movable element made up of two magnetic materials and an excitation coil wound around these magnetic materials. The two magnetic materials of the stator are arranged such that the projections and recesses of one magnetic material are closely opposed to one row of recesses and recesses, and the recesses and recesses of the other magnetic material are closely opposed to the other row of recesses and recesses. A linear pulse motor characterized by being arranged in. (2) The linear pulse motor according to claim 1, wherein opposing edges of the concave portions of the two rows of concavo-convex rows are rounded.