JP5415819B2 - Linear motor and linear motor device - Google Patents

Description

The present invention relates to a linear motor and a linear motor device having a linear motor.
More specifically, the present invention relates to a linear motor that enables position detection with a simple configuration, and a linear motor device having the linear motor.

Linear motors having various configurations have been proposed (for example, see Patent Document 1).
An example of a linear motor will be described with reference to FIGS. 1 (A), (B), and (C).
The linear motor 1 illustrated in FIG. 1 is called a magnet movement type linear motor, and a mover 2 having a permanent magnet (magnet) 10 mounted thereon is parallel to a stator 3 fixed to a base member 4. Moving.

The linear motor 1 includes a stator 3A, 3B, 3C provided on the base member 4 via pedestals 13A, 13B, 13C, and a single movable element arranged to face the stators 3A, 3B, 3C. 2.
In this example, a linear motor including three stators 3A, 3B, and 3C provided on the base member 4 via pedestals 13A, 13B, and 13C with a gap Z in the longitudinal direction of the linear motor 1 is illustrated. Illustrated. Note that at least one stator 3 is sufficient. For the sake of simplicity, a linear motor provided with one stator 3 will be described below.
Each stator 3 is provided with three electromagnetic coils of three phases, that is, a U phase, a V phase, and a W phase, to which currents different in phase by 120 ° are applied via a pedestal 13.

A pair of magnetic poles composed of adjacent S magnetic poles and N magnetic poles formed of permanent magnets (magnets) 10 are linearly formed in the movable element 2 along the longitudinal direction of the linear motor 1. Arranged (or mounted, mounted).
The mover 2 faces the stator 3 and is attached so as to be movable in parallel to the stator 3.

In the longitudinal direction of the linear motor 1, the width (arrangement interval) of a pair of magnetic poles composed of adjacent S magnetic poles and N magnetic poles (or N magnetic poles and S magnetic poles) is defined as a pitch Pa.
Two adjacent pairs of magnetic poles, that is, the width of four magnetic poles (2 × Pa) and the width of three parallel arranged U-phase, V-phase, and W-phase electromagnetic coils (along the longitudinal direction of the base member 4) Length) Pc is substantially equal. That is, Pc = 2 × Pa. The positional relationship between the magnetic poles of the mover 2 and the electromagnetic coils of the stator 3 is based on the operating principle of the linear motor 1.

  By applying currents having different phases by 120 ° to the three U-phase electromagnetic coils, V-phase electromagnetic coils, and W-phase electromagnetic coils in one stator 3, the 120 ° phase generated in these electromagnetic coils Due to the interaction between the shifted electromagnetic force and the magnetic force of the plurality of pairs of the S magnetic pole and the N magnetic pole disposed on the mover 2, the mover 2 moves in parallel with the stator 3.

Such a linear motor is applied to, for example, a transport device. For example, if the transfer object is placed on the mover 2, the transfer object can be moved along with the movement of the mover 2.
In such a transport apparatus, positioning control is performed. For example, the position of the mover 2 is detected, and the positioning control of the conveyance target is performed.

A method for detecting such a position and magnetic pole will be described with reference to FIG.
In order to detect the position of the mover 2 with respect to the base member 4 or the stator 3, the linear scale 5 is provided in the mover 2 in the linear motor illustrated in FIG. A head 6 is provided. The linear scale head 6 is fixed to the linear motor 1.
The linear scale 5 is provided with, for example, a magnetic scale that generates a magnetic signal at a predetermined interval.
The linear scale head 6 moves with the movement of the mover 2 and detects the scale of the linear scale 5. Thereby, the position of the mover 2 that moves relative to the stator 3 can be detected.

In FIG. 1, a U-phase electromagnetic coil, a V-phase electromagnetic coil, a W-phase electromagnetic coil on the stator 3 side, and a magnet 10 mounted on the mover 2, more specifically, two adjacent pairs In order to detect the positional relationship between the S magnetic pole and the N magnetic pole, Hall elements 7U, 7V, and 7W having characteristics sensitive to the magnetic field of the magnetic pole are provided in each of the U-phase electromagnetic coil, the V-phase electromagnetic coil, and the W-phase electromagnetic coil. ing.
The three Hall elements 7U, 7V, and 7W detect the strength of the magnetic field of two pairs of S magnetic poles and N magnetic poles arranged in the movable element 2, in other words, four magnets.
Each Hall element generates a signal indicating an amplitude according to the strength of the magnetic field of the S magnetic pole or the N magnetic pole, in other words, the distance from the S magnetic pole or the N magnetic pole.

  Since the pitch of the two pairs of magnetic poles adjacent to each other at a pitch of (2 × Pa) and the distance between three adjacent U-phase electromagnetic coils, V-phase electromagnetic coils, and W-phase electromagnetic coils are known, these U-phase electromagnetic coils When the detection signals of the three Hall elements 7U, 7V, 7W provided corresponding to the V-phase electromagnetic coil and the W-phase electromagnetic coil are processed, these U-phase electromagnetic coil, V-phase electromagnetic coil, W-phase electromagnetic coil And the positional relationship between two adjacent pairs of magnetic poles can be detected.

  The above-described example is a magnet-movable linear motor in which the S magnetic pole and the N magnetic pole move. However, in contrast to the linear motor described above, a linear motor in which the side on which the electromagnet coil is mounted moves is also known. Yes.

Japanese Patent No. 2815655

The linear motor 1 described above encounters the following problems, for example.
(A) The linear scale head 6 and the linear scale 5 which are magnetic position detecting means are expensive. As a result, the price of the linear motor increases.
(B) Since the three hall elements 7U, 7V, and 7W are provided for each stator 3 in addition to the linear scale 5 and the linear scale head 6, the apparatus configuration for position detection and magnetic pole detection is provided. It is complicated.
(C) Furthermore, the linear scale head 6 and the linear scale 5 that moves together with the mover 2 occupy a considerable place (space) in the linear motor 1, which hinders the miniaturization of the linear motor. ing.
(D) Since the linear scale 5 and the linear scale head 6 are magnetic detection means, it is necessary to take a shielding measure to prevent the influence of the magnetic field of the permanent magnet provided on the mover 2. This hinders downsizing and hinders heat dissipation.
(E) Similarly to the above, it is necessary to take measures to prevent the three Hall elements 7U, 7V, and 7W from being affected by the electromagnetic coil mounted on the stator 3.

From the above, a linear motor that can overcome the above-described problems and obtain position information and magnetic pole information is desired.
It is also desired to provide a linear motor device using such a linear motor.
In particular, it is desired to provide a linear motor and a linear motor device that can detect an absolute position of a movable part with respect to a fixed part of the linear motor even when the linear motor is in an initial state.

According to the present invention, a linear motor comprising:
A stator, a mover disposed in a longitudinal direction of the linear motor and in a first axis direction that is a moving direction of the mover, and arranged to be movable relative to the stator , along the first axis direction disposed adjacent alternately, and a different first and second magnetic poles of the magnetization characteristics, spaced apart and pole group, and the pole group in a second axial direction orthogonal to the first axis direction A pair of first and second magnetically sensitive elements disposed at positions sensitive to the magnetic field of the magnetic pole group and spaced apart along the first axis direction; and the second axis And at least one pair of third and fourth magnets disposed at positions that are spaced apart from the magnetic pole group in the direction and that are sensitive to the magnetic field of the magnetic pole group and that are spaced apart along the first axial direction. and a sensitive element,
When the width of the arrangement of the pair of adjacent first magnetic poles and second magnetic poles is defined as one magnetic pole pitch , the first and second magnetic sensitive elements are a distance of 1/4 of the one magnetic pole pitch. the spaced apart are disposed, the third and fourth magnetic sensitive element is disposed spaced apart only the distance equal to the one magnetic pole pitch,
The first magnetic sensitive element and the third magnetic sensitive element are spaced apart by a distance equal to at least one magnetic pole pitch in the direction in which the fourth magnetic sensitive element is disposed. A linear motor is provided.
The position of the mover relative to the stator can be detected using detection signals having a 90-degree phase difference from the first and second magnetically sensitive elements. On the other hand, the absolute position of the mover can be calculated using the detection signals of the third and fourth magnetically sensitive elements.

As a first embodiment of the linear motor, the stator is fixed to the base member, said stator includes three electromagnetic coils the first axial current whose phases are shifted by 120 ° are applied The magnetic pole group is disposed on the movable element so as to face the electromagnetic coil and in the first axial direction, and the first and second magnetic elements are arranged in parallel with each other. The sensitive element and the third and fourth magnetic sensitive elements are disposed on the base member so as to be spaced apart from each other at a position not sensitive to the magnetic field of the electromagnetic coil .
On the other hand, as a second form of the linear motor, the magnetic pole group is provided in the stator, and three electromagnetic coils to which currents whose phases are shifted by 120 ° are applied to the mover are described above. The first and second magnetic sensitive elements, and the third and fourth magnetic sensitive elements are arranged in parallel along the first axial direction, and the movable element is sensitive to the magnetic field of the electromagnetic coil. It is arranged at a position not to be.
Preferably, each of the first to fourth magnetic sensitive elements includes a Hall element or a magnetoresistive change element sensitive to the magnetic field of the magnetic pole.

According to the present invention, the above linear motor, the movable element, when the time one cycle of movement by one pole pitch, based on the detection signal of the first and second magnetically sensitive element, said one A position information generating circuit for detecting a relative position of the pair of adjacent first magnetic pole, second magnetic pole, and the first and second magnetically sensitive elements within a period; and the third and second There is provided a linear motor device having an absolute position information generation circuit for detecting an absolute position of the mover relative to the stator from a relative position generated by the position information generation circuit based on a detection signal of the magnetic sensing element of 4. The
Preferably, the linear motor includes the absolute position detection signal output from the absolute position information generation circuit , the magnet constituting the magnetic pole group mounted on the mover , or the mount mounted on the stator. It further includes a magnetic pole information generation circuit that generates magnetic pole information based on the positional relationship with the magnets constituting the magnetic pole group .

According to the present invention, the relative position between the mover and the stator can be detected by providing the first and second magnetically sensitive elements.
In the present invention, it is not necessary to provide a linear scale head and a linear scale, and according to the present invention, the problems and problems associated with the provision of this are solved.

  In addition, according to the present invention, it is possible to provide a linear motor device that can obtain position information and / or magnetic pole information between the mover and the stator by providing the third and fourth magnetic sensitive elements.

FIG. 1 is a diagram showing a position detection method in a linear motor, FIG. 1 (A) is an upper plan view of the linear motor, FIG. 1 (B) is a sectional view of the linear motor, and FIG. It is the elements on larger scale of 1 (B). FIG. 2 is a diagram illustrating a linear motor provided with position detecting means as an embodiment of the present invention. FIG. 2 (A) is an upper plan view of the linear motor of the present embodiment, and FIG. FIG. 2 is a cross-sectional view of the linear motor, and FIG. 2C is a partially enlarged view of FIG. FIG. 3 is a diagram showing a circuit configuration for generating position information and magnetic pole information from the detection signal detected by the position detecting means illustrated in FIG. 4A shows waveforms of detection signals of the A-phase and B-phase Hall elements when the mover moves to the left side L in FIGS. 2 and 3, and FIG. 4B shows the mover shown in FIG. FIG. 3 shows waveforms of detection signals of the A-phase and B-phase Hall elements when moving to the right R in FIG. 5A and 5B are diagrams showing a configuration example of the position / magnetic pole information generation circuit. FIG. 6 is a diagram illustrating a linear motor provided with position detecting means as a second embodiment of the present invention, and FIG. 6 (A) is a top plan view of the linear motor of the second embodiment . (B) is a sectional view of the linear motor, and FIG. 6 (C) is a partially enlarged view of FIG. 6 (B). FIG. 7 is a diagram showing the arrangement of the A-phase and B-phase Hall elements 17A and 17B and the third and fourth Hall elements in FIG. FIG. 8A is a waveform diagram of the A-phase and B-phase signals of the A-phase and B-phase Hall elements 17A and 17B when, for example, the mover 2 moves to the left in FIG. 8B and 8C are waveform diagrams of the detection signal HD1 of the third Hall element 19A and the detection signal HD2 of the fourth Hall element 19B. FIG. 9 is a diagram showing a circuit configuration for generating position information and magnetic pole information according to the second embodiment. FIG. 10 is a diagram for explaining an operation example of the second embodiment. FIG. 11 is a diagram for explaining another operation example of the second embodiment.

  Embodiments of a linear motor and a linear motor device according to the present invention will be described below with reference to the accompanying drawings.

First Embodiment A first embodiment of a linear motor and a linear motor device according to the present invention will be described with reference to FIGS.
2A, 2B, and 2C are diagrams illustrating the linear motor 1A according to the first embodiment. 2A is a top plan view of the linear motor according to the first embodiment, FIG. 2B is a sectional view of the linear motor, and FIG. 2C is a partially enlarged view of FIG. 2B. is there.
FIG. 3 is a diagram illustrating the position / magnetic pole information generation circuit 20, the servo control unit 21, and the amplification drive circuit 22 of the first embodiment.

A linear motor 1A illustrated in FIGS. 2A to 2C includes a stator 3 mounted on a base member 4 and a single movable element 2 disposed to face the stator 3.
Also in the present embodiment, as described with reference to FIG. 1, a plurality of stators 3, for example, three stators 3A, 3B, 3C can be provided. For example, if a plurality of stators are provided in the movable range of the mover 2 with a predetermined interval Z (for example, the width of one stator), the mover 2 can be moved smoothly and over a wide range. Furthermore, it is provided to give a sufficient propulsive force to the mover 2.
Basically, only one stator 3 needs to be provided. For the sake of simplicity, a linear motor provided with one stator 3 will be described below.

The linear motor 1A has two Hall elements mounted on the sensor substrate 18 fixed to the base member 4, that is, an A-phase Hall element 17A and a B-phase Hall element 17B.
The Hall element is an example of a magnetic sensitive element that is sensitive to the magnetic field of the present embodiment, and detects the magnetic field of the S magnetic pole and the N magnetic pole mounted on the mover 2. The magnetic field strength of the S magnetic pole and the N magnetic pole depends on the distance between the Hall element, the S magnetic pole, and the N magnetic pole.
The adjacent S magnetic pole and N magnetic pole, or the adjacent N magnetic pole and S magnetic pole correspond to the first and second magnetic poles which are adjacent and have different magnetization characteristics in the present invention.

In addition to the linear motor 1A illustrated in FIGS. 2A to 2C, the linear motor device 10A according to the first embodiment includes a position / magnetic pole information generation circuit 20 and a servo control unit 21 illustrated in FIG. And an amplification drive circuit 22.
The position / magnetic pole information generation circuit 20 generates information indicating the position of the mover 2 and information indicating the position of the magnetic pole based on the detection signals of the A-phase and B-phase Hall elements 17A and 17B.
The servo control unit 21 performs movement and positioning control of the mover 2 based on the position information and magnetic pole information generated by the position / magnetic pole information generation circuit 20.
The amplification drive circuit 22 applies a current for exciting the U-phase electromagnetic coil, V-phase electromagnetic coil, and W-phase electromagnetic coil mounted on the stator 3 in accordance with a control signal from the servo control unit 21.

In the present embodiment, for convenience, the one having the configuration illustrated in FIGS. 2A to 2C is referred to as a linear motor 1A, and the linear motor illustrated in FIGS. 2A to 2C is illustrated in FIG. A circuit to which the position / magnetic pole information generation circuit 20, the servo control unit 21, and the amplification drive circuit 22 illustrated in FIG.
Of course, the position / magnetic pole information generation circuit 20, the servo control unit 21, and the amplification drive circuit 22 can also be called a linear motor.

The stator 3 is fixed to the base member 4 via a pedestal 13.
A three-phase electromagnetic coil, a U-phase electromagnetic coil, a V-phase electromagnetic coil, and a W-phase electromagnetic coil, to which currents different in phase by 120 ° are applied from the amplification drive circuit 22 is applied to the stator 3 in the longitudinal direction of the linear motor 1A. Are juxtaposed in a straight line.

The mover 2 is movably attached to the stator 3 in the linear motor 1A.
The mover 2 includes a first magnetic pole and a second magnetic pole, which are composed of permanent magnets (magnets) 10 and have different magnetization characteristics, for example, an S magnetic pole and an N magnetic pole (or an N magnetic pole and an S magnetic pole). A plurality of pairs of magnetic poles as a pair of magnetic poles are arranged linearly along the longitudinal direction of the linear motor 1A.
The length X of the plurality of pairs of magnetic poles is defined according to the moving range of the mover 2, for example.

The A-phase and B-phase Hall elements 17A and 17B are sensitive to the magnetic field strength of a pair of adjacent magnetic poles disposed on the mover 2, for example, the S magnetic pole and the N magnetic pole. A signal having a corresponding amplitude is output.
When the distance (interval) between the S magnetic pole and the A phase Hall element 17A is short, the A phase Hall element 17A outputs a signal having a large amplitude, and when the distance (interval) between the S magnetic pole and the A phase Hall element 17A is separated, The A-phase Hall element 17A outputs a signal having a small amplitude. Further, when the S magnetic pole mounted on the mover 2 moves together with the mover 2, the change in the amplitude changes with time. The amplitude change usually changes in a triangular wave shape (sine wave shape or cosine wave shape) according to the movement of the mover 2 (moving speed and direction).

In this specification, the width (length) of a pair of adjacent magnetic poles (for example, an S magnetic pole and an N magnetic pole, or an N magnetic pole and an S magnetic pole) is referred to as a magnetic pole pitch Pa.
One stator on which three electromagnetic coils, that is, a U-phase electromagnetic coil, a V-phase electromagnetic coil, and a W-phase electromagnetic coil are mounted for two pairs of magnetic pole pitches, that is, a width of (2 × Pa). 3 corresponds to the same width (length in the longitudinal direction). The width Pc of the stator 3 is substantially equal to (2 × Pa). This pitch (width) relationship is based on the driving principle of the linear motor.
The interval (pitch) Pb between the A-phase Hall element 17A and the B-phase Hall element 17B is separated by ¼ of the pitch Pa of a pair of magnetic poles (S magnetic pole and N magnetic pole).
If the pitch Pa of the pair of magnetic poles (S magnetic pole and N magnetic pole) moves is 360 ° and one period, the pitch between the adjacent A phase Hall element 17A and B phase Hall element 17B is Pa / 4. The angle corresponds to 90 °.

Based on the control of the servo control unit 21, when an alternating current having a phase difference of 120 ° is applied from the amplification drive circuit 22 to the U-phase electromagnetic coil, V-phase electromagnetic coil, and W-phase electromagnetic coil of the stator 3, the U-phase electromagnetic The electromagnetic force generated by the coils, the V-phase electromagnetic coil, and the W-phase electromagnetic coil is shifted in phase by 120 °, and the magnetic force of the magnet 10 mounted on the mover 2 interacts with the stator 3. A propulsive force that moves the mover 2 in parallel is generated. As a result, the mover 2 moves relative to the stator 3.
Since the sensor substrate 18 is fixed to the stator 3, the A-phase and B-phase Hall elements 17A and 17B attached to the sensor substrate 18 are also fixed. Therefore, the mover 2 also moves relative to the A-phase and B-phase Hall elements 17A and 17B.

When the mover 2 moves relative to the stator 3, a signal whose amplitude pulsates according to a change in the distance between the S magnetic pole and the N magnetic pole is output from the A phase Hall element 17A and the B phase Hall element 17B, respectively. Is done.
Since the A-phase hall element 17A and the B-phase hall element 17B are separated by a distance of Pa / 4, there is a 90 ° phase shift between the A-phase hall element 17A and the B-phase hall element 17B. In response to this, a signal that is 90 ° out of phase is generated. The signal is a signal having an amplitude corresponding to the position of the Hall element and the magnetic pole, in other words, the rotational position of the magnetic pole at that time, that is, the phase at that time.

The waveform signals (phase data) are illustrated in FIGS. 4 (A) and 4 (B).
4A shows waveforms of detection signals of the A-phase Hall element 17A and the B-phase Hall element 17B when the mover 2 moves to the left side L in FIGS. 2 and 3, and FIG. These show the waveforms of the detection signals of the A-phase Hall element 17A and the B-phase Hall element 17B when the mover 2 moves to the right R.

As illustrated in FIG. 4A, when the mover 2 moves to the left L with respect to the base member 4, the magnetic field of the S magnetic pole acts on the A-phase Hall element 17A first. A phase A signal of a sine wave signal is output. As the S magnetic pole approaches the A phase Hall element 17A, the amplitude of the detection signal of the A phase Hall element 17A increases. As the S magnetic pole moves away from the A phase Hall element 17A, the detection signal of the A phase Hall element 17A increases. The amplitude decreases.
When the mover 2 moves to the left L, the magnetic field of the S magnetic pole is strong and acts on the B-phase Hall element 17B, and the B-phase Hall element 17B outputs a B-phase signal of a cosine wave signal.
As described above, the detection signals of the A-phase and B-phase Hall elements 17A and 17B maintain the phase of 90 °, and the signal whose amplitude changes as a sine wave signal or a cosine wave signal as the mover 2 moves. Become.

  When the direction of movement of the mover 2 is to the right, the A-phase signal from the A-phase Hall element 17A and the B-phase signal of the B-phase Hall element 17B are output contrary to FIG.

The following can be understood from the waveform diagrams of FIGS.
(A) The phase of the A phase signal output from the A phase Hall element 17A and the phase of the B phase signal output from the B phase Hall element 17B are 90 ° out of phase.
(B) Depending on the direction of movement of the mover 2, the phase of the A-phase signal and the phase of the B-phase signal are advanced or the phase is delayed. For example, if the phase of the A-phase signal is ahead of the phase of the B-phase signal, the mover 2 has moved to the left, and if the phase is reversed, the mover 2 has moved to the right. And the B phase signal, the direction of movement of the mover 2 can be determined by confirming the phase advance or phase relationship.
(C) If the period during which the mover 2 moves by the distance between one pair of magnetic poles is 360 ° and one cycle, the phase data of the A-phase signal and the B-phase signal (the amplitude of the A-phase signal in the current phase) Further, the position (or angle) of the movable element 2 with respect to the stator 3 or the base member 4 in one cycle can be determined from the data indicating the relative relationship between the B-phase signal and the amplitude of the phase at that time.
That is, the moving distance of the mover 2 within one cycle can be detected from the phase data indicating the relationship between the A phase signal from the A phase Hall element 17A and the B phase signal from the B phase Hall element 17B.
(D) The moving distance of the mover 2 over a plurality of cycles in the linear motor is, for example, as shown in FIG. 4A when the point where the A-phase signal zero-crosses from “negative” to “positive” is detected. You can see that it has entered the cycle. Since the distance of one cycle is known in advance as the magnetic pole pitch Pa, if the distance of the magnetic pole pitch Pa is added every time one cycle is exceeded, the entire moving distance of the mover 2 can be determined.
(E) The distance D between the A-phase Hall element 17A or the B-phase Hall element 17B and the stator 3 is known in advance. For example, the distance D from the center of the A-phase Hall element 17A to the center position of the stator 3 (the center of the V-phase electromagnetic coil) is known in advance. In the present embodiment, for example, the distance D is the same as the width of a pair of magnetic poles.
Of course, the width of each coil in the stator 3, that is, the U-phase electromagnetic coil, the V-phase electromagnetic coil, and the W-phase electromagnetic coil is also known in advance.
Since the moving distance of the mover 2 within one cycle is known from the phase data indicating the relationship between the A phase signal from the A phase Hall element 17A and the B phase signal from the B phase Hall element 17B, the mover 2 is mounted on the mover 2. The positional relationship of the magnetic poles with respect to the coils of the stator 3 can be understood as [(two pairs of S magnetic poles and N magnetic poles) + left and right magnetic poles] facing the respective coils of the stator 3.

  In the present embodiment, the relationship between the position of the mover 2 and the magnetic pole with respect to the base member 4 (stator 3) is detected based on the above knowledge.

Position / Pole Information Generation Circuit The position / pole information generation circuit 20 generates a position detection signal and pole information based on the above knowledge.
Note that the position information generation circuit and the magnetic pole information generation circuit can be separated, but in this embodiment, an example in which the position information generation circuit and the magnetic pole information generation circuit are configured as one circuit will be described.
FIG. 5 is a diagram illustrating a configuration example as an example of the position / magnetic pole information generation circuit 20.
The position / magnetic pole information generation circuit 20 includes an orientation detection unit 201 and a position calculation unit 203 that function as a position information generation circuit.
The position / magnetic pole information generation circuit 20 further includes a magnetic pole information generation unit 205.

Direction Detection Unit The direction detection unit 201 includes a zero cross (ZC) detection unit 2011, a level determination unit 2012, and a direction detection signal holding circuit 2013.

For example, in FIG. 4A, the zero-cross detection unit 2011 indicates that the A-phase signal detected by the A-phase Hall element 17A is “negative” in FIG. 4B. ”Is detected to change to a“ positive ”value beyond the 0 level.
For example, in FIG. 4A, this zero-cross detection means that the A-phase Hall element 17A has output an A-phase signal that changes as described above in response to the strength of the magnetic field of the S magnetic pole. In other words, it means that the S magnetic pole approaches the A-phase Hall element 17A, and the A-phase Hall element 17A is sensitive to the strength of the positive magnetic field.
In this way, the zero cross detection unit 2011 detects that the mover 2 has moved relative to the A-phase and B-phase Hall elements 17A and 17B by a distance of a pair of magnetic poles (adjacent S magnetic pole and N magnetic pole). To do. That is, the zero cross detection unit 2011 detects that the mover 2 has moved 360 degrees for one cycle.

The level determination unit 2012 determines the level of the B phase signal detected from the B phase Hall element 17B in response to the zero cross detection in the zero cross detection unit 2011.
If the B-phase signal is “negative level” at the time when the A-phase signal is zero-crossed, it means that the mover 2 has moved to the left as illustrated in FIG. On the other hand, if the B phase signal is “positive level” when the A phase signal crosses zero, it means that the mover 2 has moved to the right as illustrated in FIG. 4B.

For example, if the moving direction of the mover 2 is the left side, the level determination unit 2012 sets 2-bit “10” in the direction detection signal holding circuit 2013, and vice versa, holds the 2-bit “01” in the direction detection signal. Set in the circuit 2013.
The direction detection signal holding circuit 2013 is composed of, for example, a 2-bit flip-flop, and holds data in accordance with an instruction from the level determination unit 2012.
When the orientation is not determined in the initial state, the value of the orientation detection signal holding circuit 2013 is “00”, and when the orientation is indefinite, “11”.
Thus, the direction detection signal holding circuit 2013 is configured to indicate not only the direction of movement of the mover 2 but also an indeterminate or undecided state.
A 2-bit direction signal d is output from the direction detection signal holding circuit 2013 to the servo control unit 21.

Position Calculation Unit The position calculation unit 203 can take various configurations, an example of which will be described below.
The position calculation unit 203 includes a phase data calculation unit 2031 and a position calculation unit 2032.
The phase data calculation unit 2031 obtains phase data, for example, an amplitude difference between the detection signal (A phase signal) of the A phase Hall element 17A and the detection signal (B phase signal) of the B phase Hall element 17B.
For example, from the waveform diagram illustrated in FIG. 4A when the mover 2 moves to the left with respect to the A-phase and B-phase Hall elements 17A and 17B, the half width of one magnetic pole, The difference in amplitude between the A-phase signal and the B-phase signal in the range of 0 to 90 ° is as follows.
The reverse occurs when the mover 2 moves to the right.

Range of 0 to 90 degrees (a) When the A phase Hall element 17A is positioned between the N magnetic pole and the S magnetic pole, the amplitude of the A phase signal from the A phase Hall element 17A is "0", and the B phase The B phase signal from the Hall element 17B is “negative” and has a maximum amplitude. Therefore, as the phase data, for example, the amplitude difference between the phase at that time (A-phase signal-B-phase signal) is the maximum value of “positive”.
(B) When the A-phase Hall element 17A approaches the center of the S magnetic pole, the A-phase signal from the A-phase Hall element 17A increases from “0”, and the B-phase signal from the B-phase Hall element 17B Becomes a small value of “negative” from the maximum value of “negative”. Therefore, as the phase data, for example, the amplitude difference of (A phase signal−B phase signal) of the phase at that time becomes a smaller “positive” value than in the case of (a).
(C) When the A-phase Hall element 17A is positioned at the center of the S magnetic pole, the amplitude of the A-phase signal from the A-phase Hall element 17A becomes “positive” maximum, and the B-phase signal from the B-phase Hall element 17B is “0”. Therefore, as the phase data, for example, the phase data (amplitude difference) of the phase at that time (A-phase signal−B-phase signal) is the maximum value of “positive”.
As described above, the phase data of the A-phase signal and the B-phase signal in the range of 0 to 90 ° (for example, the phase difference at that time) can be calculated in advance. The angle at that time, that is, the positional relationship between the mover 2 and the A-phase and B-phase Hall elements 17A and 17B can also be calculated in advance.

  The position calculating unit 2032 calculates the amplitude difference of (A phase signal−B phase signal) as phase data calculated by the phase data calculating unit 2031 based on the phase data and position data obtained by calculation in advance. Then, the position of the mover 2 at that time is obtained.

First Configuration Example of Position Calculation Unit As a first example of the position calculation unit 2032, a case where a nonlinear output circuit 2032A is used will be described with reference to FIG.
The nonlinear output circuit 2032A can be configured as, for example, a nonlinear function generation circuit. For example, the nonlinear output circuit 2032A is configured to output a position detection signal P0 corresponding to an angular position corresponding to the amplitude difference or a position within one pitch Pa. When the amplitude difference signal (analog voltage signal) output from the amplitude difference calculation unit 2031 is input to the nonlinear output circuit 2032A, the nonlinear output circuit 2032A has an angular position corresponding to the amplitude difference signal or within one pitch Pa. A signal P0 corresponding to the position is output.

Second Configuration Example of Position Calculation Unit As a second example of the position calculation unit 2032, a case where an A / D converter 2032 a and a ROM 2032 b are used is described in FIG.
In the ROM 2032b, as with the nonlinear output circuit 2032A, phase data (amplitude difference) is used as a parameter, and the angular position at that time or the position within one magnetic pole pitch Pa is stored as a table.
The A / D converter 2032a converts the phase data (amplitude difference signal) output from the phase data calculation unit 2031 into a digital signal.
When the ROM 2032b receives phase data (amplitude difference signal) that has been digitally converted as an address, a signal corresponding to an angular position corresponding to the phase data or a position within one pitch Pa by a table lookup method. P0 is output.

  As described above, using the phase data calculation unit 2031 and the nonlinear output circuit 3032A, or the A / D converter 2032a and the POM 2032b, a position in the range of 0 to 90 ° can be detected.

More than the expansion of the angle (position), the calculation of the position of 0 to 90 ° (first zone) has been described, but 90 to 180 ° (second zone), 180 to 270 ° (third zone), 270 to 360 ° ( 4th zone).
Thus, both the A phase signal detected by the A phase Hall element 17A and the B phase signal detected by the B phase Hall element 17B have a phase of 90 ° and change as a sine wave signal or a cosine wave signal. The position data with respect to the amplitude difference can be 0 to 90 °.
Therefore, for the second to fourth zones, the position data corresponding to the zone is obtained by using the analog zone conversion circuit 2032B in FIG. 5A or the digital zone conversion circuit 2032c in FIG. 5B. Is added.

  Zone switching can be detected using the zero-cross detection signal ZC detected by the zero-cross detection unit 2011 in the direction detection unit 201 and the direction detection signal d. For example, each time the zero-cross detection signal ZC is input, the zone conversion circuit 2032B or the zone conversion circuit 2032c determines the zone in consideration of the movement direction of the mover 2 indicated by the direction detection signal d at that time. The addition value to be counted or the counter value is updated, and angle data or position data corresponding to the zone at that time is added as a bias.

  As described above, the position of one cycle of the mover 2 that moves relative to the stator 3 can be detected.

  In FIG. 5A, since the position signal P1 output from the zone conversion circuit 2032B in the analog format is in the analog format, if the servo control unit 21 or the like needs the position data P in the digital format, it is necessary. Accordingly, the position calculation unit 2032 adds an A / D converter 2032C after the zone conversion circuit 2032B.

  On the other hand, in FIG. 5B, the position signal P1 output from the zone conversion circuit 2032c in the digital format is in the digital format. Therefore, if the position data P in the analog format is required in the servo control unit 21 or the like, If necessary, the position calculation unit 2032 adds a D / A converter 2032d to the subsequent stage of the zone conversion circuit 2032c.

Since the servo control unit 21 is usually configured by using a computer in many cases, the position signal P0 of 0 to 90 ° from the nonlinear output circuit 2032A in FIG. 5A or FIG. It is also possible to input the position signal P0 of 0 to 90 ° from the ROM 2032b in the servo control unit 21 to process the zone conversion circuits 2032B and 2032c.
In such a case, the zone conversion circuits 2032B and 2032c are unnecessary.

Magnetic pole information generation unit The magnetic pole information generation unit 205 knows in advance the position detection signal P (or angle information) calculated by the position calculation unit 2032, for example, the center of the A-phase Hall element 17A and the stator 3 Magnetic poles such as a positional relationship between a U-phase electromagnetic coil, a V-phase electromagnetic coil, a W-phase electromagnetic coil fixed to the stator 3 and a magnetic pole pair mounted on the mover 2 based on the distance D to the position Generate information.

The servo control unit 21, based on the position detection signal P detected by the position / magnetic pole information generation circuit 20 and the magnetic pole information, for example, a U-phase electromagnetic coil, a V-phase electromagnetic coil, W, Controls the current applied to the phase electromagnetic coil.
In response to a control signal from the servo control unit 21, the drive amplifier circuit 22 applies a current to the U-phase electromagnetic coil, V-phase electromagnetic coil, and W-phase electromagnetic coil.
As a result, the mover 2 moves relative to the stator 3.
The position due to the movement is detected by the position / magnetic pole information generation circuit 20 described above.

  The linear motor 1A described above can be applied to, for example, a conveyance device that requires positioning control.

As long as the A-phase and B-phase Hall elements 17A and 17B maintain a 90 ° phase and the distance D from the stator 3, the base member 4 can be provided at any position.
Preferably, in the linear motor 1A of the present embodiment, for example, as illustrated in FIG. 3, a pair of A is provided at the end of the moving range of the mover 2 (left end or right end in the example of FIG. 3). A phase Hall element 17A and a B phase Hall element 17B are provided. By comprising in this way, the position within the movement range of the needle | mover 2 is detectable.
Referring to FIGS. 2 and 3, it is only necessary to fix the sensor substrate 18 on which the phase A hall element 17 </ b> A and the phase B hall element 17 </ b> B are mounted on the base member 4 to the linear motor 1 </ b> A.

The linear motor 1A of the present embodiment is compared with the linear motor 1 described with reference to FIG.
The linear motor 1 of the present embodiment does not require the linear scale 5 and the linear scale head 6. That is, it is not necessary to provide an additional member for the mover 2.
As a result, the structure of the linear motor is simplified. In particular, since it is not necessary to perform a shielding process for making the linear scale 5 unaffected by the magnetic field of the permanent magnet (magnet) 10, the structure as a linear motor is simplified.
Since the linear scale 5 and the linear scale head 6 are not used, the price can be reduced.

In the linear motor 1 illustrated in FIG. 1, a Hall element is provided for every three coils in one stator 3. If a plurality of stators 3A, 3B, 3C are provided to facilitate the movement of the mover 2 and increase the propulsive force of the mover 2 as illustrated in FIG. The number of elements increases. As the number of Hall elements increases, the number of circuits for calculating position information from the detection signals also increases.
On the other hand, the present invention includes a position / magnetic pole information generation circuit 20 that generates position information and magnetic pole information from a pair of Hall elements and their detection signals without depending on the number of stators 3A, 3B, 3C. It is sufficient to provide one.

In the linear motor 1A of the first embodiment, the A-phase Hall element 17A and the B-phase Hall element 17B are mounted on the stator 3 with respect to the arrangement of the three Hall elements 7U, 7V, and 7W illustrated in FIG. It is provided at a position sensitive to the magnetic field of the permanent magnet (magnet) 10 of the mover 2 at a position away from the influence of the magnetic field of the three coils. Therefore, it is less affected by the magnetic fields of the U-phase electromagnetic coil, V-phase electromagnetic coil, and W-phase electromagnetic coil mounted on the stator 3. As a result, there is an advantage that it is not necessary to perform a shielding process against a magnetic field such as a U-phase electromagnetic coil, a V-phase electromagnetic coil, and a W-phase electromagnetic coil.

In the first embodiment, the case where the Hall element is used as the sensor for detecting the position of the mover 2 has been described. However, the positions of the S magnetic pole and the N magnetic pole mounted on the mover 2 are determined. As a sensor to detect, other small-sized magnetic sensitive elements sensitive to the magnetic field of the magnetic pole, for example, a magnetoresistive (MR) element can be used.
Similar to the Hall element, the MR element has a characteristic that the resistance changes according to the magnetic field. For example, if a voltage is applied to the MR element and a change in resistance of the MR element is detected as a change in voltage, the position of the mover 2 can be detected as in the above embodiment using the Hall element. .

  In the above, the magnet movable type linear motor has been exemplified, but the reverse configuration, that is, the movable portion having a plurality of pairs of magnetic poles arranged in the fixed portion and having a U-phase electromagnetic coil, a V-phase electromagnetic coil, and a W-phase electromagnetic coil. The same applies to the case of moving to a fixed portion where a plurality of pairs of magnetic poles are fixed.

Second Embodiment In the above-described embodiment, basically, the position of the mover 2 in the 90 ° angle range is detected, and the zone processing is performed as appropriate, so that the adjacent S magnetic pole and N magnetic pole An example in which the position of 360 ° and one period configured is detected has been described.

In the above-described embodiment, the initial absolute position of the mover 2 with respect to the base member 4 (or the stator 3 or the A-phase and B-phase Hall elements 17A and 17B) cannot be automatically detected. In particular, when the mover of the linear motor is rotated from a stopped state, it cannot be detected at which position the mover 2 is located.
In order to detect the initial position (absolute position) of the mover 2, for example, a position adjustment operation such as once moving the end of the mover 2 to the reset position or the initial position is required.

In the second embodiment, an example of a linear motor and a linear motor device capable of detecting the absolute position of the mover 2 will be described with respect to the above-described embodiment.
A linear motor and a linear motor device according to the second embodiment will be described with reference to FIGS.
FIG. 6 is a configuration diagram of the linear motor according to the second embodiment.
6A is a top plan view of the linear motor according to the second embodiment, FIG. 6B is a cross-sectional view of the linear motor, and FIG. 6C is a partially enlarged view of FIG. 6B. is there.
In the linear motor according to the second embodiment, in addition to the A-phase and B-phase Hall elements 17A and 17B as an example of the pair of first and second magnetically sensitive elements of the present invention, A third Hall element 19A and a fourth Hall element 19B are provided as an example of the fourth magnetically sensitive element.

The arrangement of a pair of S and N magnetic poles adjacent to the A-phase and B-phase Hall elements 17A and 17B is the same as that in the first embodiment.
The arrangement relationship between the U-phase electromagnetic coil, V-phase electromagnetic coil, and W-phase electromagnetic coil in the stator 3 fixed to the base member 4 via the pedestal 13 and a plurality of pairs of magnetic poles mounted on the mover 2 is also as follows. This is the same as the first embodiment.

As illustrated in FIG. 6 and FIG. 7, the third Hall element 19A and the fourth Hall element 19B are, for example, A phase and B phase Hall elements 17A and 17B that are spaced apart by Pa / 4. At the same time, it is fixed to the sensor substrate 18A, and is fixed to the base member 4 via the sensor substrate 18A.
For example, the intermediate position of the third and fourth Hall elements 19A and 19B and the intermediate position of the first and second Hall elements 17A and 17B are separated by (11 × Pa) / 8 , and the sensor substrate 18A It is being fixed to the base member 4 via.
The center position of the third Hall element 19A and the center position of the first Hall element 17A are separated from each other in the direction (direction ) of the fourth Hall element 19A by, for example, a pitch Pa corresponding to one magnetic pole. It is fixed to the base member 4 via the substrate 18A. Further , the center position of the fourth Hall element 19B and the center position of the first Hall element 17A are, for example, separated by (2 × Pa) and fixed to the base member 4 via the sensor substrate 18A. Yes.
The pitch (arrangement interval) between the third Hall element 19A and the fourth Hall element 19B is substantially equal to the pitch Pa of the pair of magnetic poles.
The third Hall element 19A and the fourth Hall element 19B do not have to be mounted on the sensor substrate 18A together with the A phase and B phase Hall elements 17A and 17B, but preferably the A phase, When mounted together with the B-phase Hall elements 17A and 17B, the above-mentioned distance can be accurately maintained, and assembly and manufacture are facilitated.

FIG. 8A is a waveform diagram of the A-phase and B-phase signals of the A-phase and B-phase Hall elements 17A and 17B when, for example, the mover 2 moves to the left in FIG. FIG. 8A is substantially the same as FIG.
8B and 8C are waveform diagrams of the detection signal HD1 of the third Hall element 19A and the detection signal HD2 of the fourth Hall element 19B. The detection signals HD1 and HD2 of the third and fourth Hall elements 19A and 19B are high-level signals according to the same zero-cross detection timing as the zero-cross (ZC) detection point of the third Hall element 19A.

To be precise, the detection signals HD1 and HD2 illustrated in FIGS. 8B and 8C are detected by the third and fourth Hall elements 19A and 19B. The A-phase and B-phase Hall elements 17A and 17B are detected. 9 is a logic signal that is set to a high level when a zero cross is detected in the position determination circuit 25 illustrated in FIG.
Alternatively, when the zero cross is detected in the third and fourth Hall elements 19A and 19B and the zero cross is made from “negative” to “positive”, the high level signals HD1 and HD2 can be output.
In the present embodiment, a case will be described in which the position determination circuit 25 detects the zero crossing of the detection signals of the third and fourth Hall elements 19A and 19B and generates high level signals HD1 and HD2.

  As illustrated in FIG. 9, the linear motor device according to the second embodiment has a position / magnetic pole information generation circuit 20, a position determination circuit 25, a servo control unit 21, a linear motor having the configuration illustrated in FIG. An amplification drive circuit 22 is configured.

  The position / magnetic pole information generation circuit 20 uses the method described above with reference to FIG. 3 and FIGS. 5A and 5B, and the A-phase and B-phase Hall elements 17A and 17B are spaced at intervals of (Pa / 4). When arranged, the position over one period is detected based on the range of 90 °.

FIG. 10 is a diagram showing a circuit configuration of the position determination circuit 25.
The position determination circuit 25 includes a logic signal generation circuit 251, an absolute position determination circuit 252, and an absolute position calculation circuit 253.

  The logic signal generation circuit 251 detects the zero cross of the detection signals detected by the third and fourth Hall elements 19A and 19B, and generates the logic signals HD1 and HD2 shown in FIGS. 8B and 8C.

The absolute position determination circuit 252 determines the absolute position of the mover 2 in accordance with the level state of the logic signals HD1 and HD2.
As illustrated in FIG. 11, the third and fourth Hall elements 19A and 19B are arranged at positions preceding the movement direction of the mover 2 with respect to the A-phase and B-phase Hall elements 17A and 17B. When set, the logic signals HD1 and HD2 change as follows according to the movement of the movable element 2.
(A) When the mover 2 is in a position not facing the third and fourth Hall elements 19A and 19B. The logic signals HD1 and HD2 are both at a low level.
(B) When the mover 2 moves to the right, the logic signal HD1 of the third Hall element 19A becomes high level.
(C) When the mover 2 further moves to the right, the logic signal HD2 of the fourth Hall element 19B also goes high.

The absolute position determination circuit 252 determines the positional relationship between the mover 2 and the A-phase and B-phase Hall elements 17A and 17B, the third and fourth Hall elements 19A and 19B from the combination of the level states of the logic signals HD1 and HD2. judge.
For example, in the case of the above (a), the A-phase and B-phase Hall elements 17A and 17B are positioned at a pair of magnetic poles at the right end.
In the case of (b) above, the A-phase and B-phase Hall elements 17A and 17B are located one magnetic pole away from the right.
As described above, the absolute position determination circuit 252 determines the positions of the A-phase and B-phase Hall elements 17A and 17B, and outputs them to the absolute position calculation circuit 253 as a result.

The absolute position calculation circuit 253 adds an absolute position adjustment signal based on the output signal of the absolute position determination circuit 252 to the position of one magnetic pole detected by the position / magnetic pole information generation circuit 20, that is, the position signal P within one cycle. To output an absolute position signal.
Since the pitch Pa of one magnetic pole is known in advance, the absolute position adjustment signal is “0” in the case of (a) above, and the position of 1 pitch Pa in the case of (b) above, that is, 1 The signal corresponds to the position corresponding to the period.

As described above, according to the second embodiment, the absolute position of the mover 2 in the initial state of the linear motor can be calculated.
In the second embodiment, in order to detect the initial position of the mover 2, the third and fourth Hall elements 19 </ b> A and 19 </ b> B are A-phase and B-phase Hall elements 17 </ b> A in the traveling direction of the mover 2. , 17B need to be located in front of.
For example, when the mover 2 is stopped, in order to know the initial values at both ends of the mover 2, the third and fourth Hall elements 19A are provided on both sides of the A-phase and B-phase Hall elements 17A and 17B. , 19B are desirably provided.

  In addition to the third Hall element 19A and the fourth Hall element 19B, if the fifth and sixth Hall elements are further arranged at an interval of 1 pitch Pa, the absolute position of the mover can be detected.

In the second embodiment described above, the case where the third Hall element 19A and the fourth Hall element 19B are provided has been described, but when the mover 2 is stopped in the end region in the initial state. The initial position of the mover 2 can also be detected by one third Hall element 19A.
On the other hand, when the mover 2 stops in a wide area, in addition to the third Hall element 19A, a fourth Hall element 19B or a plurality of Hall elements can be provided at intervals of 1 pitch Pa.
The Hall element is less expensive than the combination of the linear scale 5 and the linear scale head 6.

In the second embodiment, if the zero cross detection timing of the signal of the third Hall element 19A and the zero cross detection timing of the fourth Hall element 19B are used, the moving direction of the mover 2 may be detected. it can.
FIG. 10 shows a configuration in which a direction detection circuit 254 is added to the position determination circuit 25.

The operations of the servo control unit 21 and the amplification drive circuit 22 are the same as in the twelfth embodiment.
In addition, the second embodiment can be applied to those described in the first and second embodiments. For example, an MR element can be used as the magnetically sensitive element.

  The first and second embodiments described above are merely examples, and the present invention is not limited to the above-described embodiments, and various modifications can be made.

  DESCRIPTION OF SYMBOLS 1, 1A ... Linear motor, 2 ... Movable element, 3 ... Stator (U phase electromagnetic coil, V phase electromagnetic coil, W phase electromagnetic coil), 4 ... Base member, 5 ... Linear scale, 6 ... Linear scale head, 10 ... Magnet, 17A, 17B, A phase, B phase Hall element, 18 ... Sensor substrate, 20 ... Position / magnetic pole information generation circuit, 21 ... Servo control unit, 22 ... Amplification drive circuit, 25 ... Position determination circuit, 202 ... Direction Detection unit, 2031 ... Phase data calculation unit, 203 ... Position calculation unit, 205 ... Magnetic pole information generation unit, 251 ... Logic signal generation circuit, 252 ... Absolute position determination circuit, 253 ... Absolute position calculation circuit, 254 ... Direction detection circuit

Claims (7)

A linear motor,
A stator,
A mover disposed so as to be movable relative to the stator in a first axis direction which is a longitudinal direction of the linear motor and a moving direction of the mover;
Disposed adjacent alternately along the first axis direction, and a different first and second magnetic poles of the magnetization characteristics, the pole group,
Arranged apart from the magnetic pole group in a second axis direction orthogonal to the first axial direction, at a position sensitive to the magnetic field of the magnetic pole group, and spaced apart along the first axis direction; A pair of first and second magnetically sensitive elements;
At least a pair of third and third members disposed at positions that are separated from the magnetic pole group in the second axial direction, are sensitive to the magnetic field of the magnetic pole group, and are separated from each other along the first axial direction. A fourth magnetically sensitive element
Have
When the width of the arrangement of the pair of adjacent first magnetic poles and second magnetic poles is defined as one magnetic pole pitch , the first and second magnetic sensitive elements are a distance of 1/4 of the one magnetic pole pitch. the spaced apart are disposed, the third and fourth magnetic sensitive element is disposed spaced apart only the distance equal to the one magnetic pole pitch,
The first magnetic sensitive element and the third magnetic sensitive element are spaced apart by a distance equal to at least one magnetic pole pitch in the direction in which the fourth magnetic sensitive element is disposed. ,
Linear motor. The stator is fixed to a base member;
Said stator is disposed in parallel with three electromagnetic coils which current different in phase by 120 ° is applied along the first axis direction,
The movable element is provided with the magnetic pole group facing the electromagnetic coil and in the first axial direction ,
The first and second magnetic sensitive elements and the third and fourth magnetic sensitive elements are disposed on the base member so as to be spaced apart from each other at positions not sensitive to the magnetic field of the electromagnetic coil. Item 10. The linear motor according to Item 1. The stator is provided with the magnetic pole group ,
Three electromagnetic coils to which currents whose phases are shifted by 120 ° are applied to the mover are arranged in parallel along the first axis direction ,
The first and second magnetic sensitive elements, and the third and fourth magnetic sensitive elements are disposed at positions where the movable element is not sensitive to the magnetic field of the electromagnetic coil .
The linear motor according to claim 1. The first and second magnetic sensitive elements and the third and fourth magnetic sensitive elements each include a Hall element that is sensitive to the magnetic field of the magnetic pole group .
The linear motor in any one of Claims 1-3. The first and second magnetic sensitive elements and the third and fourth magnetic sensitive elements each include a magnetoresistive variable element that is sensitive to the magnetic field of the magnetic pole group .
The linear motor in any one of Claims 1-3. The linear motor according to any one of claims 1 to 5;
The mover is 1 if the time to move only pole pitch was 1 cycle, based on the detection signal of the first and second magnetically sensitive element, a first adjacent said pair of said one cycle A position information generating circuit for detecting a relative position of a magnetic pole, a second magnetic pole, and the first and second magnetically sensitive elements;
An absolute position information generation circuit that detects an absolute position of the mover relative to the stator from a relative position generated by the position information generation circuit based on detection signals of the third and fourth magnetically sensitive elements. Motor device. The absolute position detection signal output from the absolute position information generation circuit, and the magnet constituting the magnetic pole group mounted on the mover or the magnet constituting the magnetic pole group mounted on the stator A magnetic pole information generation circuit for generating magnetic pole information based on the positional relationship;
The linear motor device according to claim 6.

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