JP2003047231A - Pulse motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse motor which can reduce cogging and enables the dimensional reduction, the weight reduction, and the increase of an output. SOLUTION: This pulse motor has a planar lattice platen, zero-pitch cores and 1/2-pitch cores having salient poles on their one side surfaces facing the platen respectively, coils wound on the zero-pitch cores and the 1/2 pitch cores, and bias permanent magnets whose one side surfaces are brought into contact with the other side surfaces of the zero-pitch cores and the 1/2-pitch cores and which are magnetized in the protruding directions of the salient poles. The zero-pitch cores and the 1/2-pitch cores are arranged so as to have the fluxes of the bias permanent magnets and the exciting fluxes of the coils perpendicular to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse motor capable of reducing cogging, reducing the size and weight, and increasing the output. The present invention is particularly applicable to a prober, a handler,
The present invention relates to a pulse motor suitable for a two-dimensional positioning device used for steppers and the like.

[0002]

2. Description of the Related Art FIG. 7 is an explanatory view of the structure of a main part of a conventional example generally used in the past, FIG. 8 is a side view of FIG. 7, FIG. 9 is a plan view of FIG. 7, and FIG. FIG. In the figure, the lattice platen 1 has a plate shape, and teeth are formed at a constant pitch along the X-axis direction and the Y-axis direction.

In this case, teeth are formed at a constant pitch along the X-axis direction. The lattice platen 1 is formed by cutting grooves on a flat surface in a lattice pattern, and is made of a magnetic material.

The zero pitch core 2 and the half pitch core 3 are
The salient poles 4A, 4B, 4C, 5A, 5B, 5C that are long in the direction orthogonal to the thrust direction are formed on one surface facing the lattice platen 1, respectively.

The zero pitch core 2 has salient poles 4A, 4B, 4
According to the arrangement order of C, the A-phase coil 6A, the B-phase coil 6
The B and C phase coils 6C are wound. 1/2 pitch core 3
An A-phase coil 7A, a B-phase coil 7B, and a C-phase coil 7C are wound on the coil in the order of the salient poles 5A, 5B, and 5C.

Teeth are formed by the pitch P at the tips of the salient poles 5A, 5B and 5C. These teeth are grid platen 1
It is arranged at a position facing the 0 tooth. Salient poles 5A, 5
The teeth of B and 5C are out of phase with each other by P / 3.

Sine wave currents whose phases are shifted by 120 ° are applied to the A-phase coil 5A, the B-phase coil 5B and the C-phase coil 5C. The 1/2 pitch core 3 has the same structure as the zero pitch core 2.

However, the 1/2 pitch core 3 is arranged such that the teeth of the salient poles are out of phase with each other by P / 2 with respect to the zero pitch core 2. The A-phase coil 7A, the B-phase coil 7B, and the C-phase coil 7C are also supplied with sinusoidal currents whose phases are shifted by 120 °.

The bias magnet 8 is provided with one surface in contact with the other surface of the zero pitch core 2 and has salient poles 4A, 4B, 4C, 5
It is magnetized in the protruding directions of A, 5B and 5C. York 9
Is provided so that one surface is in contact with the other surface of the 1/2 pitch core 3. One surface of the yoke 11 is provided in contact with the other surface of the bias magnet 8 and the other surface of the yoke 9.

In the above structure, the A-phase coils 6A, 7
3 for A and B phase coils 6B and 7B and C phase coils 6C and 7C
By passing the sinusoidal current of the phase,
The 1/2 pitch core 3 moves in the X1 ← → X2 direction.

[0011]

However, in such a device, (1) there is a magnetic imbalance by the bias magnet 8 in each phase of the zero pitch core 2 and the 1/2 pitch core 3. That is,
As shown in FIG. 10, for example, in the case of exciting the B-phase coils 6B and 7B, the salient poles 4A, 4B, 4C, 5A and 5
The magnetic flux density in B and 5C is examined.

The magnetic flux passing through the 4C phase of the salient pole 4C of the zero pitch core 2 and the salient pole 5A of the 1/2 pitch core 3 has a high magnetic flux density as seen from the magnetic path. The magnetic flux passing through the salient poles 5C has a low magnetic flux density.

That is, a high magnetic flux density region J1 and a low magnetic flux density region J2 are generated, and each salient pole 4A, 4B, 4C, 5A, 5 is formed.
Magnetic imbalance occurs in B and 5C, which leads to an increase in cogging.

(2) Since the magnetic flux generated by the bias magnet 8 and the magnetic flux generated by the excitation of the coils 6A, 6B, 6C, 7A, 7B, 7C are in the same direction, the platen 1 is likely to be magnetically saturated at an early stage. Therefore, the size and weight of the components are likely to increase.

An object of the present invention is to solve the above problems, and an object of the present invention is to provide a pulse motor capable of reducing cogging, downsizing, weight reduction and high output.

That is, the purpose is as follows. (1) By making the exciting magnetic flux direction of the coil and the magnetic flux direction of the bias magnet orthogonal to each other, the magnetic poles of the salient poles of the zero pitch core 2 and the 1/2 pitch core 3 are magnetically balanced by the bias magnet and cogging is reduced.

(2) The magnetic flux of the bias magnet and the exciting magnetic flux of the coil are made orthogonal to each other to obtain a magnetic saturation margin, and
Aim for higher output and lighter weight of components.

[0018]

In order to achieve such an object, according to the present invention, in a pulse motor according to a first aspect of the present invention, a planar grid platen and one surface side facing the grid platen are provided. (Long in the direction orthogonal to the thrust direction)
A zero pitch core and a 1/2 pitch core having salient poles formed respectively, a coil wound around the zero pitch core and the 1/2 pitch core, and one surface contacting the other surface of the zero pitch core and the 1/2 pitch core. A pulse motor provided with a bias magnet magnetized in the protruding direction of the salient poles, wherein the magnetic flux of the bias permanent magnet and the coil exciting magnetic flux are arranged so as to be orthogonal to each other, and 1 / 2
And a pitch core.

According to a second aspect of the present invention, in the pulse motor according to the first aspect, the zero pitch core and the ½ pitch core are arranged to face each other in a direction orthogonal to the thrust direction.

[0020]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. 1 is a cross-sectional view taken along the line BB shown in FIG. 3, which is an explanatory view of a main part of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a plan view of FIG. 1, and FIGS. It is operation | movement explanatory drawing of FIG.
In the figure, the same symbols as those in FIG. 7 represent the same functions.
Only parts different from FIG. 7 will be described below.

In the figure, the zero pitch core 2 and the 1/2 pitch core 3 are the magnetic fluxes of the bias permanent magnets 81 and 82, and the coils 61A, 61B and 61C wound around the zero pitch core 2 and the 1/2 pitch core 3, respectively. 62A, 62B, 62C, 7
1A, 71B, 71C, 72A, 72B, 72C are arranged so that the exciting magnetic fluxes are orthogonal to each other.

In this case, the zero pitch core 2 and the 1/2 pitch core 3 are arranged to face each other in the direction orthogonal to the thrust direction X1 ← → X2.

The bias magnets 81, 82 are provided so that one surface is in contact with the other surface of the zero pitch core 2 and the salient poles 41A, 41 are provided.
B, 41C, 42A, 42B, 42C are magnetized in the protruding direction.

The yokes 91 and 92 are provided so that one surface is in contact with the other surface of the 1/2 pitch core 3. York 111,1
12 is the other surface of the bias magnets 81 and 82 and the yoke 9
One surface is provided in contact with the other surface of 1, 92, respectively.

In the embodiment of FIG. 1, two units are used in order to obtain the same thrust as that of FIG.

In the above configuration, as shown in FIGS. 4 to 6, for example, B-phase coils 61B, 62B, 71B, 72B.
The magnetic flux density at each salient pole will be examined in the case of excitation. As shown in FIGS. 5 and 6, the bias magnets 81 and 82
High magnetic flux density area J1 and low magnetic flux density area J
2 and 2 occur.

However, the B-phase coils 61B, 62B, 71
Since the exciting magnetic flux directions of B and 72B are orthogonal to each other as shown in FIG. 4, each salient pole 41A, 41B, 41C, 42A,
42B, 42C, 51A, 51B, 51C, 52A, 5
No magnetic imbalance occurs in 2B and 52C.

As a result, a pulse motor which can reduce cogging can be obtained. For example, as a specific example, the cogging Fcog of the conventional apparatus shown in FIG. 7 can be reduced to 10 N, while the cogging Fcog of the apparatus of the present invention can be reduced to 5 N.

Magnetic flux generated by the bias magnets 81, 82 and coils 61A, 61B, 61C, 62A, 62B, 62.
Since the magnetic flux due to the excitation of C, 71A, 71B, 71C, 72A, 72B is in the orthogonal direction, magnetic saturation can be improved, a low ampere turn can be obtained, and a pulse motor capable of high output can be obtained.

The magnetic flux generated by the bias magnets 81, 82 and the coils 61A, 61B, 61C, 62A, 62B, 62.
Since the magnetic flux due to the excitation of C, 71A, 71B, 71C, 72A, 72B is in the orthogonal direction, the magnetic saturation can be improved, the platen 1 and the like can be made smaller and lighter, and the pulse motor that can be made smaller and lighter as a whole is provided. can get.

Since the unit in which the zero-pitch core 2 and the 1 / 2-pitch core 3 are arranged so as to face each other in the direction orthogonal to the thrust direction can be constructed, it is easy to increase the number of units and increase the thrust. A pulse motor having is obtained.

The above description merely shows specific preferred embodiments for the purpose of explaining and exemplifying the present invention. Therefore, the present invention is not limited to the above-mentioned embodiment, and many modifications are made without departing from the essence thereof.
It also includes deformation.

[0033]

As described above, according to the first aspect of the present invention.
According to the above, there are the following effects. Since it was possible to make the direction of the coil excitation magnetic flux and the direction of the bias magnet magnetic flux at right angles,
The magnetic balance between the zero bitch core and the 1/2 pitch core can be obtained, and a pulse motor with reduced cogging can be obtained.
Moreover, since cogging can be reduced, a pulse motor that can reduce slider pitching can be obtained.

Since the direction of the coil exciting magnetic flux and the direction of the bias magnet magnetic flux can be made perpendicular to each other, the magnetic saturation can be improved,
A pulse motor capable of obtaining a low ampere turn and a high output can be obtained.

Since the coil exciting magnetic flux direction and the bias magnet magnetic flux direction can be made to be at right angles, the magnetic saturation can be improved,
It is possible to reduce the size and weight of the platen and the like, and obtain a pulse motor that can reduce the size and weight of the entire device.

According to the second aspect of the present invention, there are the following effects. Since a unit in which the zero pitch core and the 1/2 pitch core are arranged so as to face each other in the direction orthogonal to the thrust direction can be configured, it is easy to add units and a pulse motor with flexibility that can easily increase thrust is obtained. To be

Therefore, according to the present invention, it is possible to realize a pulse motor capable of reducing cogging, reducing the size and weight, and increasing the output.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view of FIG.

FIG. 4 is an operation explanatory diagram of FIG. 1.

5 is an operation explanatory diagram of FIG. 1. FIG.

FIG. 6 is an operation explanatory diagram of FIG. 1.

FIG. 7 is an explanatory diagram of a main part configuration of a conventional example that is generally used in the past.

FIG. 8 is a side view of FIG. 7.

9 is a plan view of FIG. 7. FIG.

10 is an explanatory diagram of the operation of FIG.

[Explanation of symbols]

1 lattice platen 2 Zero pitch core 3 1/2 pitch core 41A salient pole 41B salient pole 41C salient pole 42A salient pole 42B salient pole 42C salient pole 51A salient pole 51B salient pole 51C salient 52A salient pole 52B salient pole 52C salient pole 61A Phase A coil 61B B-phase coil 61C C phase coil 62A A phase coil 62B B-phase coil 62C C phase coil 71A A phase coil 71B B-phase coil 71C C phase coil 72A A phase coil 72B B phase coil 72C C phase coil 81 Bias Magnet 82 Bias magnet 91 York 92 York 111 York 112 York G1 B-phase excitation magnetic flux G2 Magnetic flux for bias J1 High magnetic flux density area J2 Low magnetic flux density area

Claims (2)

[Claims] 1. A planar lattice platen, a zero pitch core and a 1/2 pitch core each having a salient pole (long in the direction orthogonal to the thrust direction) formed on one surface facing the lattice platen, and the zero pitch core. A coil wound around a pitch core and a ½ pitch core; and a bias magnet magnetized in the protruding direction of the salient pole, one surface of which is in contact with the other surface of the zero pitch core and the ½ pitch core. A pulse motor comprising: the zero pitch core and the ½ pitch core arranged such that the magnetic flux of the biasing permanent magnet and the coil exciting magnetic flux are orthogonal to each other. 2. The pulse motor according to claim 1, wherein the zero pitch core and the ½ pitch core are arranged to face each other in a direction orthogonal to the thrust direction.