WO2008117345A1

WO2008117345A1 - Linear motor and its control method

Info

Publication number: WO2008117345A1
Application number: PCT/JP2007/053984
Authority: WO
Inventors: Houng Joong Kim; Hitoshi Shibata
Original assignee: Hitachi, Ltd.
Priority date: 2007-02-23
Filing date: 2007-02-23
Publication date: 2008-10-02
Also published as: JPWO2008117345A1

Abstract

Device of a linear motor is made compact and is reduced in cost. The linear motor is configured to have nonmagnetic bodies (30) provided between a plurality of armature cores (20) each having a magnetic pole tooth constituting a closed magnetic path, and comprises a means for detecting the self inductance of the armature of each phase of the linear motor, a conversion means for converting the detection value of inductance into the phase angle of magnetic pole of the linear motor, and a control means for driving the linear motor using the phase angle of magnetic pole obtained from the magnetic pole phase angle conversion means. A linear motorin which the phase angle of magnetic pole is estimated with high precision without using a magnetic pole phase angle sensor can be provided.

Description

Specification

Linear motor and control method thereof Technical Field

The present invention relates to a linear motor, and more particularly to a linear motor that performs linear driving. Background art

Magnetic pole phase angle information (magnetic pole position information) is indispensable for driving linear motors, and in many cases, magnetic pole phase angle information is obtained using a magnetic pole phase angle sensor. However, a technology that does not require a magnetic pole phase angle sensor is being developed for the purpose of constraining the installation space of the magnetic pole phase angle sensor and reducing the cost. For example, in Japanese Laid-Open Patent Application No. 7-1 7 7 8 8 8 filed in Japan, the electrical angle (magnetic pole phase angle) of a motor is calculated by using the difference in the inductance and the inductance between phases for a rotary synchronous motor. A method for detecting and obtaining a correct magnetic pole phase angle even when the rotor is stopped is disclosed.

However, the magnetic pole phase angle estimation method as in Reference 1 above does not require a magnetic pole phase angle sensor, so that the device can be made compact and low in cost. However, on the other hand, the magnetic pole phase angle sensor can be realized. The resolution of magnetic pole position detection is inferior. Therefore, a method for estimating the magnetic pole phase angle with higher accuracy is required. Disclosure of the invention

An object of the present invention is to provide a linear motor having a function of estimating a magnetic pole phase angle with high accuracy without using a magnetic pole phase angle sensor.

In the linear motor according to the present invention, between the armature cores, the armature core Also has an armature phase in which a magnetic material having weak magnetism is arranged, and calculates the magnetic pole phase angle of the armature phase from the self-inductance detection value of the armature phase. It is characterized by driving the duck overnight.

Further, the linear motor of the present invention has an armature phase in which a non-magnetic material is disposed between a plurality of armature cores, and a magnetic pole phase angle of the armature phase from a self-inductance detection value of the armature phase. And the linear motor is driven in accordance with the magnetic pole phase angle. (Here, in the present invention, the non-magnetic material includes not only a material that does not have magnetism completely but also a weak magnetic material that has some magnetism.)

Brief Description of Drawings

FIG. 1 is an overall view showing the configuration of a linear motor control device according to the first embodiment. FIG. 2 is an overall view showing the configuration of the linear motor in the first embodiment.

FIG. 3 is a detailed view showing the configuration of the linear motor in the first embodiment.

FIG. 4 is a diagram showing a method for manufacturing an armature according to the first embodiment.

FIG. 5 is a diagram showing the output of the inductance detector in the linear motor of the first embodiment.

FIG. 6 shows an example of a conventional linear motor.

FIG. 7 is a diagram showing the output of the inductance detector in the conventional linear motor shown in FIG.

FIG. 8 is a graph showing the relationship between the deviation angle (load angle) of the initial magnetic pole phase angle of the linear motor in Example 1 and the generated thrust.

FIG. 9 is a diagram showing the structure of the armature in the second embodiment.

FIG. 10 is a diagram showing a configuration of an armature in the third embodiment.

FIG. 11 is a diagram showing a configuration of an armature in the fourth embodiment.

FIG. 12 is a diagram showing the structure of the armature in the fifth embodiment. FIG. 13 is a diagram showing the configuration of the armature and the mover in the sixth embodiment. FIG. 14 is a diagram showing the configuration of the armature and the mover in the seventh embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a linear motor control method according to an embodiment of the present invention will be described with reference to the drawings.

[Embodiment 1] FIG. 1 is an overall view showing a configuration of a linear motor control apparatus in Embodiment 1. FIG. Linear motor 1 0, Inductance detector 1 1, Movable position detector 1 2, Position controller 1 3, Speed controller 1 4, Current controller 1 5, Speed converter 1 6, Magnetic pole phase angle converter 17 is structured as shown in Fig. 1. Each operation is described below.

The mover position detector 1.2 detects the position of the mover of the linear motor and outputs the detected position information to the position controller 13 and the speed converter 16. Here, the position information detected by the mover position detector 12 is different from the magnetic pole phase angle information, but is the position information of the mover detected by reading the linear scale. The position controller 13 receives the position command and the position information from the mover position detector 12 and outputs a speed command. The speed converter 16 converts the position information detected by the position detector 12 into speed information and outputs this speed information to the speed controller 14. The speed controller 14 receives the speed command output from the position controller 13 and the speed information output from the speed converter 16, and outputs the current command to the current controller 15.

Next, the inductance detector 11 detects the self-inductance of the armature phase and outputs the detected inductance information to the magnetic pole phase angle converter 17. The magnetic pole phase angle converter 1 7 converts the inductance information received from the inductance detector into the magnetic pole phase angle information and sends it to the current controller 15. Outputs magnetic pole phase angle information. The current controller 15 receives the current command output from the speed controller 14 and the magnetic pole phase angle information output from the magnetic pole phase angle converter 17, and controls the current that flows to the linear motor 10. With such a configuration, it is possible to obtain information on the magnetic pole phase angle of the mover without using a magnetic pole phase angle sensor.

Next, the configuration of the linear motor will be described. FIG. 2 is an overall view showing the configuration of the linear motor in this embodiment. As shown in FIG. 2, the linear motor of this embodiment is composed of a mover 6 in which a plurality of permanent magnets 7 are arranged, and an armature 2 in which an armature coil 4 is wound around each armature phase. . Also, the magnetic pole pitch of the adjacent armature phases is (k · P + PZM) {(k = 0, 1, 2 · · ·), (M = 2, 3, 4 · · ·)} Each armature phase is arranged in series in the moving direction of the motor. Here, k is an arbitrary integer, and M is the number of phases of the armature. In this embodiment, the armature 2 is composed of three armature phases: U phase, V phase, and W phase.

FIG. 3 is a detailed view showing the configuration of the linear motor in this embodiment. As shown in FIG. 3, the armature is composed of an armature coil 4, a permanent magnet 7, and a plurality of magnetic pole teeth that constitute a closed magnetic circuit with a structure facing both the front and back surfaces of the permanent magnet. The armature 2 0 2 and the magnetic pole tooth 2 0 2 are arranged with a certain gap between them, and the armature 2 0 2 It is arranged so that it is located below the mover from the other side of the child. Further, the magnetic pole teeth 2 0 3 and the magnetic pole teeth 2 0 4 are arranged through a fixed gap, and the magnetic pole teeth 2 0 3 are positioned on the upper part of the mover from the other armature. 04 is arranged so as to be located from one end of the armature to the lower part of the mover.

By arranging the magnetic pole teeth in this way, the magnetic pole teeth 2 0 1 and the magnetic pole teeth 2 0 2 And a first opposing portion constituting a closed magnetic path and a second opposing portion constituting a closed magnetic path provided with magnetic pole teeth 20 3 and 2 4 are adjacent to each other and in opposite directions. Therefore, it is possible to simplify the manufacturing process and reduce the manufacturing cost by manufacturing a linear motor with a small number of armature coils.

Further, the plurality of armature cores 20 having the facing portions are arranged with the nonmagnetic material 30 interposed therebetween. By providing the non-magnetic material 30 between the armature cores 20 in this way, the magnetic circuit of the armature cores 20 constituting the closed magnetic circuit can be made independent. This has the effect of eliminating the leakage flux.

FIG. 4 is a diagram showing a method for manufacturing an armature in the present embodiment. As shown in FIG. 4, the armature is composed of a plurality of armature cores 20 having opposing portions and a plurality of nonmagnetic bodies 30. The armature cores 20 are arranged so that the directions of adjacent magnetic pole teeth are staggered, and a nonmagnetic material 30 is arranged between the armature cores 20. The plurality of armature cores 20 and the nonmagnetic body 30 arranged as described above are fixed integrally and wound with a common armature coil.

FIG. 5 is a diagram showing the output of the inductance detector 1 1 in the linear motor of this embodiment. The vertical axis in Fig. 5 represents the self-inductance of each armature phase, and the horizontal axis represents the magnetic pole phase angle. In this example, there are three armature phases. As can be seen from Fig. 5, the self-inductance signals of the V, υ, and W phases are sinusoidal signals with a phase difference of 60 degrees. Thus, the amplitude of each phase, U phase, and W phase self-inductance is about 40 [mH].

Here, the detailed operation of the magnetic pole phase angle converter 17 will be described with reference to FIG. The sine wave signals of self-inductances L u, L v, L w shown in Fig. 5 are input to the magnetic pole phase angle converter 17 to calculate the magnetic pole phase angle of the linear motor To do. The operation of this magnetic pole phase angle converter 17 is obtained, for example, by taking the analog values of the inductance signals of L u, L v and L w with the AZD converter of the microcomputer, and using the inverse trigonometric function calculation in the microcomputer.

The inverse depression function calculation may be performed using any of the inductance signals of L u, L V, and L w, but it is better to use two or more signals of L u, L V, and L w. In other words, when converting to a magnetic pole phase angle using one inductance signal, as can be seen from FIG. 5, four magnetic pole phase angle candidate values are found. Furthermore, if another inductance signal is used, it is possible to narrow down to two magnetic pole phase angle candidate values. The two magnetic pole phase angle candidate values have a relationship of 0 and 0 + 1 80 degrees.

Using the magnetic pole phase angle 0 estimated from the detected inductance value, a minute current is given to the current controller 15. At this time, confirm that the position detector 12 has changed several pulses, set the command current to 0 and stop the linear motor.

In the case of a linear motor, the thrust generated by the motor is reversed at Θ of 0 and 1800 degrees, and the force of the linear motor is reversed. Using a magnetic pole phase angle 0 estimated from the detected inductance value, when a small current is applied to the current controller 15, Θ or Θ + 180 degrees is determined from the direction in which the linear motor has moved. It is possible to calculate one magnetic pole phase angle by performing calculations in this way. In this embodiment, a linear motor composed of three armature phases of U phase, V phase, and W phase has been described. However, if the number of armature phases is three or more, the same method as described above is used. Thus, the magnetic pole phase angle can be calculated from the detected inductance value.

FIG. 6 shows an example of a conventional linear motor. As shown in Fig. 6, the armature coil is wound around each armature tooth, and the mover having a permanent magnet and the armature move relatively while being supported by a support mechanism with a certain gap. To do.

FIG. 7 is a diagram showing the output of the inductance detector in the conventional linear motor shown in FIG. The vertical axis in Fig. 7 represents the self-inductance of each armature phase, and the horizontal axis represents the magnetic pole phase angle. As can be seen from Fig. 7, the self-inductance signal of each phase of V phase, U phase and W phase becomes a sine wave signal with a phase difference of 60 degrees, and each self-inductance of V phase, U phase and W phase The amplitude of the evening is approximately 2.5 [m H].

The reason why the amplitude of the self-inductance in the conventional linear motor is smaller than the amplitude of the self-inductance in the linear motor of this embodiment is that the linear motor in this embodiment places the non-magnetic material 30 between the armature cores 20. Therefore, the magnetic circuit between the armature cores 20 constituting the closed magnetic circuit can be made independent, and the leakage flux between the adjacent armature cores is omitted. This is because a large difference in self-inductance with respect to the relative position of the magnet 30 appears.

FIG. 8 is a graph showing the relationship between the deviation angle (load angle) of the initial magnetic pole phase angle and the generated thrust in the linear motor of this embodiment. As can be seen from Fig. 8, by accurately detecting the initial magnetic pole phase angle, the thrust generated can be improved and the performance of the linear motor can be improved. Therefore, a highly accurate estimation method is required when estimating the initial magnetic pole phase angle as in the present invention.

Here, when the detection error of the self-inductance is 1 [m H], the detection error of the magnetic pole phase angle in the present embodiment and the conventional linear motor will be described with reference to FIGS. Make a comparison. In the linear motor of this embodiment, when the self-inductance detection error is 1 [m H], the error of the magnetic pole phase angle is about 10 [°] as shown in FIG. In contrast, the conventional As shown in Fig. 7, the error of the magnetic pole phase angle when the self-inductance detection error of 1 [m H] occurs in the linear motor is approximately 35 [°〗.

In this way, the amplitude of the self-inductance of the linear motor of this embodiment shown in FIG. 5 is shown in FIG. Since the amplitude of the self-inductance in the conventional linear motor is larger, the error of the magnetic pole phase angle when the error occurs in the detection of the self-inductance is a relatively small value. Therefore, the magnetic pole phase angle detection resolution is improved, and the magnetic pole phase angle can be detected with high accuracy.

That is, according to the present embodiment, it is possible to provide a linear motor that estimates a magnetic pole phase angle with high accuracy without having a magnetic pole phase angle sensor.

In this embodiment, the member having the permanent magnet is the mover and the armature is the stator. However, the member having the permanent magnet is the stator and the armature is the same as the mover. There is an effect. Further, in this embodiment, the armature has the non-magnetic body 30. However, instead of the non-magnetic body 30 of the present embodiment, a structure having a magnetic body that is weaker than the armature core 20 is used. Although the detection accuracy of the magnetic pole phase angle is inferior to the configuration with a non-magnetic material, the leakage accuracy of the magnetic pole phase angle can be increased because the leakage of magnetic flux is eliminated compared to the conventional linear motor shown in Fig. 6. It is.

[Example 2] In this example, another example different from Example 1 will be described. FIG. 9 is a diagram showing the structure of the armature in the present embodiment. The configuration and control method other than the armature shown in FIG. 9 of this embodiment are the same as those in the first embodiment.

As shown in FIG. 9, the armature in this embodiment is composed of an armature core 20 and a non-magnetic material 30. Furthermore, the armature core 20 is adjacent to the magnetic pole Teeth are arranged so that their directions are staggered, and nonmagnetic bodies 30 are arranged between the armature cores 20 and at both ends of the armature phase. In other words, the present embodiment has a configuration in which the nonmagnetic material 30 is disposed at both ends of the armature of the first embodiment.

With the configuration of the armature as in the present embodiment, for example, when a plurality of armature phases are arranged in series, the leakage magnetic flux between the armature cores 20 of adjacent armature phases can be omitted. It becomes possible. For this reason, it is possible to reduce the leakage magnetic flux as compared with the first embodiment, and for the same reason as described in the first embodiment, the magnetic pole phase angle can be detected with higher accuracy than the first embodiment. A linear motor without a phase angle sensor can be realized. In this embodiment, the member having the permanent magnet is the mover and the armature is the stator, but the member having the permanent magnet is the stator and the armature is the mover. The effect of. Further, in this embodiment, the armature has the non-magnetic body 30. However, instead of the non-magnetic body 30 of the present embodiment, a structure having a magnetic body that is weaker than the armature core 20 is used. Although the detection accuracy of the magnetic pole phase angle is inferior to that of the configuration including the non-magnetic material, the detection accuracy of the magnetic pole phase angle can be made higher than that of the conventional linear motor shown in FIG.

[Example 3] In this example, other examples will be described. FIG. 10 is a diagram showing the structure of the armature in the present embodiment. The configuration and control method other than the armature shown in FIG. 10 of this embodiment are the same as those of the first embodiment.

As shown in FIG. 10, the armature in this embodiment is composed of an armature core 20 and a nonmagnetic material 30. Furthermore, the armature cores 20 are arranged so that the directions of adjacent magnetic pole teeth are staggered, and a non-magnetic material that covers the side surfaces of the armature cores 20 in the arrangement direction between the armature cores 20. 30 is placed. 0

The non-magnetic body 30 of Example 1 does not block the armature tooth portion of the adjacent armature core, but the non-magnetic body 30 of this embodiment is about the armature tooth portion of the adjacent armature core. It has a structure that also blocks.

With the configuration of the armature as in this embodiment, the magnetic flux leaking between the armature teeth of adjacent armature cores can be omitted. Therefore, the leakage of magnetic flux can be reduced as compared with the first embodiment, and the magnetic pole phase angle can be detected with higher accuracy than the first embodiment for the same reason as described in the first embodiment. A linear motor having no magnetic pole phase angle sensor can be realized.

In this embodiment, the member having the permanent magnet is the mover and the armature is the stator. However, the member having the permanent magnet is the stator and the armature is the same as the mover. There is an effect. Further, in this embodiment, the armature has the non-magnetic body 30. However, instead of the non-magnetic body 30 of the present embodiment, a structure having a magnetic body that is weaker than the armature core 20 is used. Although the detection accuracy of the magnetic pole phase angle is inferior to the configuration provided with the nonmagnetic material, the detection accuracy of the magnetic pole phase angle can be made higher than that of the conventional linear motor shown in FIG.

[Example 4] In this example, other examples will be described. FIG. 11 is a diagram showing the structure of the armature in the present embodiment. The configuration and control method other than the armature shown in FIG. 11 of this embodiment are the same as those of the first embodiment.

As shown in FIG. 11, the armature in this embodiment is composed of an armature core 20 and a nonmagnetic material 30. Furthermore, the armature cores 20 are arranged so that the directions of adjacent magnetic pole teeth are staggered, and the arrangement direction of the armature cores 20 is between the armature cores 20 and between both ends of the armature phase. A non-magnetic material 30 is disposed to cover the side surface. The non-magnetic material 30 of Example 1 is an adjacent armature core. Although the armature tooth portion is not blocked, the nonmagnetic body 30 of the present embodiment is configured to block the armature tooth portion of the adjacent armature core. With the configuration of the armature as in the present embodiment, for example, when a plurality of armature phases are arranged in series, the leakage magnetic flux between the armature cores 20 of adjacent armature phases can be omitted. In addition, magnetic flux leaking between armature teeth of adjacent armature cores can be eliminated. Therefore, it is possible to reduce the leakage magnetic flux compared to the first embodiment, and for the same reason as described in the first embodiment, it is possible to detect the magnetic pole phase angle with higher accuracy than the first embodiment. A linear motor without a magnetic phase angle sensor can be realized. In this embodiment, the member having the permanent magnet is the mover and the armature is the stator. However, the member having the permanent magnet is the stator and the armature is the same as the mover. There is an effect. Further, in this embodiment, the armature has the non-magnetic body 30. However, instead of the non-magnetic body 30 of the present embodiment, a structure having a magnetic body that is weaker than the armature core 20 is used. Although the detection accuracy of the magnetic pole phase angle is inferior to that of the configuration including the non-magnetic material, the detection accuracy of the magnetic pole phase angle can be made higher than that of the conventional linear motor shown in FIG.

[Example 5] In this example, other examples will be described. FIG. 12 is a diagram showing the structure of the armature in the present embodiment. The configuration and control method other than the armature shown in FIG. 12 of the present embodiment are the same as those of the first embodiment.

As shown in FIG. 12, the armature in this embodiment is composed of a plurality of armature cores 20. Further, each armature core 20 is arranged so that the directions of adjacent magnetic pole teeth are staggered.

Due to the configuration of the armature as in this embodiment, the armature cores 20 face each other. 2

A closed magnetic circuit is formed between the armatures. Therefore, there is less magnetic flux leakage compared to the conventional linear motor as shown in Fig. 6. Therefore, for the same reason as described in Example 1, it has a magnetic pole phase angle sensor that can detect the magnetic pole phase angle with higher accuracy than the conventional linear motor shown in FIG. No linear motor can be realized.

In this embodiment, the member having the permanent magnet is the mover and the armature is the stator. However, the member having the permanent magnet is the stator and the armature is the same as the mover. There is an effect.

[Embodiment 6] In this embodiment, another embodiment will be described. FIG. 13 is a diagram showing the configuration of the armature and the mover in the present embodiment. The configuration and control method other than the armature and the mover shown in FIG. 13 of the present embodiment are the same as those of the first embodiment.

As shown in FIG. 13, the armature in this embodiment is composed of the armature cores 21, 2 2, the non-magnetic material 30, and the armature coil 4 wound around the armature cores 2 1, 2 2. Is done. Furthermore, the armature core 2 1 in which the armature coil 4 is wound in one direction of the mover 6 and the armature core 2 2 in which the armature coil 4 is wound in the other direction of the mover 6 are alternately arranged, A non-magnetic material 30 is disposed between the adjacent armature cores 2 1 and 2 2.

By providing the non-magnetic material 30 between the armature cores 2 1 and 2 2 as in this embodiment, the magnetic circuits of the armature cores 2 1 and 2 2 constituting the closed magnetic circuit can be made independent. This is effective in eliminating leakage magnetic flux between adjacent armature cores. Therefore, for the same reason as described in the first embodiment, it is possible to realize a linear motor that can detect a magnetic pole phase angle with high accuracy and does not have a magnetic pole phase angle sensor.

In this embodiment, the member having a permanent magnet is used as a mover, and the armature is fixed. Three

Although the stator is used, the same effect as in the present embodiment can be obtained by using a member having a permanent magnet as a stator and an armature as a mover. In this embodiment, the armature has the non-magnetic body 30. However, if the armature has a magnetic body weaker than the armature core instead of the non-magnetic body 30 of the present embodiment, the non-magnetic body 30 Although the detection accuracy of the magnetic pole phase angle is inferior to that of the configuration including the body, the detection accuracy of the magnetic pole phase angle can be made higher than that of the conventional linear motor shown in FIG.

[Example 7] In this example, other examples will be described. FIG. 14 is a diagram showing the configuration of the armature and the mover in the present embodiment. The configuration and control method other than the armature and the mover shown in FIG. 14 of the present embodiment are the same as those of the first embodiment.

As shown in FIG. 14, the armature in the present embodiment is composed of an armature core 20, a non-magnetic body 30, and an armature coil 4 wound around the armature core 20. One armature core 20 is wound around one armature core 20, and the armature core 20 is disposed in one direction of the mover 6. In addition, each armature core 20 is arranged with a nonmagnetic material 30 interposed therebetween.

By providing the non-magnetic material 30 between the armature cores 20 as in this embodiment, the magnetic circuit of the armature cores 20 constituting the closed magnetic circuit can be made independent, and the adjacent armatures This has the effect of eliminating leakage flux between cores. Therefore, for the same reason as described in the first embodiment, it is possible to realize a linear motor that does not have a magnetic pole phase angle sensor and can detect the magnetic pole phase angle with high accuracy.

In this embodiment, the member having the permanent magnet is the mover and the armature is the stator. However, the member having the permanent magnet is the stator and the armature is the same as the mover. There is an effect. In this embodiment, the armature has the nonmagnetic body 30. However, instead of the nonmagnetic body 30 of the present embodiment, the armature If the magnetic core is weaker than the core, the magnetic pole phase angle detection accuracy is inferior to that of the non-magnetic configuration. The accuracy can be increased. Industrial applicability

Conventional linear motors have a system configuration using magnetic pole phase angle detection means such as Hall ICs, but the present invention clearly detects the phase difference of the self-inductance and reduces the number of components. This is particularly effective for simple service systems.

Claims

The scope of the claims

1. a linear member having a primary side member having a plurality of permanent magnets arranged along the traveling direction, and a secondary side member having a plurality of armature cores having magnetic pole teeth opposed to both front and back surfaces of the permanent magnet In the motor, the secondary side member includes a plurality of armature cores wound with an armature coil, and a plurality of electric machines in which a magnetic material that is weaker than the armature core is disposed between the armature cores. And an inductance detection unit that detects the self-inductance of the armature phase, and a magnetic pole that calculates a magnetic pole phase angle of the armature phase from the self-inductance detection value detected by the inductance detection unit. A linear motor comprising: a phase angle calculation unit; and a control unit that drives the linear motor according to the magnetic pole phase angle calculated by the magnetic pole phase angle calculation unit.

2. The magnetic pole phase angle calculation unit according to claim 1, wherein the magnetic pole phase angle calculation unit includes a magnetic pole phase angle determination unit that determines a magnetic pole phase angle using operation direction information when the linear motor is operated by a minute distance. Linear Moru evening.

3. The magnetic pole phase angle calculation unit according to claim 1, wherein the magnetic pole phase angle calculation unit includes an inverse trigonometric function calculation unit that calculates a candidate value of the magnetic pole phase angle using an inverse trigonometric function calculation, and the linear motor is operated at a minute distance. And a magnetic pole phase angle determining unit that determines the magnetic pole phase angle using the operation direction information.

4. The magnetic body according to claim 1, wherein the magnetic body is magnetic flux leakage prevention means for preventing a magnetic flux generated by the armature core from leaking between adjacent armature cores when a current flows through the armature coil. There is a linear motor.

5. The linear motor according to claim 1, wherein the magnetic body is disposed on both front and rear side surfaces in the movable direction of the armature phase.

6. It has a first member having a magnetic body around which windings are wound, and the first member has a plurality of armature cores in which magnetic pole teeth are opposed to each other to form a closed magnetic circuit, 6

A linear motor in which a second member having a plurality of permanent magnets is disposed between magnetic pole teeth constituting the opposed portion, wherein the armature includes a non-magnetic material between the plurality of armature cores. An inductance detection unit that detects a self-inductance of the armature phase; and a magnetic pole phase that converts a self-inductance detection value detected by the inductance detection unit into a magnetic pole phase angle of the armature phase. A linear motor comprising: an angle conversion unit; and a control unit that drives the linear motor according to the magnetic pole phase angle converted by the magnetic pole phase angle conversion unit.

7. The magnetic pole phase angle conversion unit according to claim 6, wherein the magnetic pole phase angle conversion unit includes a magnetic pole phase angle determination unit that determines a magnetic pole phase angle using operation direction information when the linear motor is operated by a minute distance. Linearmo overnight.

8. The front magnetic pole phase angle conversion unit according to claim 6, wherein the front magnetic pole phase angle conversion unit uses an inverse trigonometric function calculation to calculate a magnetic pole phase angle candidate value; And a magnetic pole phase angle determining unit that determines the magnetic pole phase angle using the operation direction information.

9. The magnetic flux leakage preventing material according to claim 6, wherein the non-magnetic material is a magnetic flux leakage prevention material that reduces a magnetic flux leaking to the adjacent armature core when a magnetic flux generated in the armature core is driven when the linear motor is driven. A linear motor evening specializing in being.

10. The linear motor according to claim 6, wherein the non-magnetic material is disposed on both front and rear side surfaces in the movable direction of the armature phase.

1 1. A first member having a magnetic body around which windings are wound, a plurality of armature cores each having a magnetic pole tooth facing each other, and a magnetic pole tooth constituting the facing portion. In a linear motor control method in which a second member having a plurality of permanent magnets is disposed on the armature core, the first member includes a magnetic material that is less magnetic than the armature core and is adjacent to the armature core. The armature phase placed between Detecting the self-inductance of the armature phase, converting the self-inductance into a magnetic pole phase angle of the armature phase, and controlling the linear motor in accordance with the magnetic pole phase angle. Linear motor evening control method.

1 2. In Claim 11, when converting the self-inductance into the magnetic pole phase angle of the armature phase, the linear motor is operated for a minute distance, and the magnetic phase angle is obtained using the operation direction information of the minute distance operation. A linear motor control method characterized by determining

1 3. In claim 11, when converting the self-inductance into the magnetic pole phase angle of the armature phase, calculating a candidate value of the magnetic pole phase angle using inverse trigonometric function calculation, A linear motor control method, comprising: operating a linear motor by a minute distance; and determining a magnetic pole phase angle using operation direction information of the minute distance operation.

Summary The challenge is to reduce the size and cost of linear motor equipment. In order to solve this problem, a configuration in which a nonmagnetic body 30 is provided between a plurality of armature cores 20 having magnetic pole teeth constituting a closed magnetic circuit, and the armature self of each phase of the linear motor is provided. Detection means for detecting the inductance, conversion means for converting the detected inductance value into the magnetic pole phase angle of the linear motor, and control for driving the linear motor using the magnetic pole phase angle generated by the magnetic pole phase angle conversion means Means.

According to the present invention, it is possible to provide a linear motor that estimates a magnetic pole phase angle with high accuracy without using a magnetic pole phase angle sensor.