JP2011050225A - Linear motor and linear motor drive system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motor capable of easy and more highly accurate positioning, and to provide a linear motor drive system. <P>SOLUTION: The linear motor 1 in which a stator 10 and a mover 20 relatively move to each other includes a position detecting magnet unit 25 provided on the mover, having magnets 25n, 25s with magnetic poles different in the relative movement direction and alternately arranged, and detecting the position of the mover, a position detecting sensor 16 for detecting the magnets of the position detecting magnet unit which relatively move and detecting the position, and a gate sensor 36 for detecting the magnets of the position detecting magnet unit which relatively move. When the gate sensor detects the position detecting magnet unit, the position detecting sensor is disposed at the position of superimposing the position detecting magnet unit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear motor used for driving a carriage of a transfer device, and more particularly to a linear motor whose position is detected by a magnet and a linear motor driving system including a motor driving device that controls the linear motor.

  Linear motors for high positioning accuracy in feedback control are used in linear motors used in the fields of in-machine transfer devices, component transfer devices, and the like. However, with respect to the setting of the linear scale, the setting accuracy is strictly required, and when the mover has a long stroke, the length of the linear scale becomes longer and the cost increases. In addition, in the case of an optical linear encoder, the environmental resistance particularly against dust and dirt is not sufficient. Therefore, a linear motor that does not require setting as a magnetic linear encoder, is inexpensive, and has high environmental resistance has been proposed.

  For example, in Patent Document 1, a permanent magnet is configured to use both a magnetic field part of a linear motor and a magnetic scale part that is a detected body of a magnetic linear encoder, and the pitch interval of the permanent magnets is the same as that of the magnetic scale part. A linear motor device provided to have a scale pitch is disclosed.

JP 2004-56892 A

  By the way, the linear motor generally has a structure in which the mover moves on one stator. However, if the conveying path becomes long, problems such as an increase in equipment cost occur. A method has been proposed.

  However, the technique of Patent Document 1 cannot be said to be a linear motor that fully considers the distributed arrangement of stators, such as when the mover straddles between stators. In particular, when the mover moves between the stators, there is a region where the magnetic sensor cannot detect the driving magnet that also serves as the magnetic scale. It is necessary to perform highly accurate positioning in consideration of this case.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a linear motor and a linear motor driving system capable of simple and more accurate positioning.

  In order to solve the above-described problem, the invention according to claim 1 is a linear motor in which a stator and a mover move relative to each other, and is provided in the stator or the mover. Magnets of different magnetic poles are alternately arranged in the direction, and the position detection magnet unit for detecting the position of the mover and the magnet of the position detection magnet unit that moves relative to each other are detected to detect the position. A position detecting sensor for detecting the position detecting magnet portion, and a position detecting sensor for detecting the position detecting magnet portion. The sensor for use is disposed at a position overlapping the position detecting magnet section.

  According to a second aspect of the present invention, in the linear motor according to the first aspect, the gate sensor detects a magnetic pole of the position detecting magnet unit.

  According to a third aspect of the present invention, in the linear motor according to the second aspect, when the position detecting magnet unit and the gate sensor approach, the gate sensor is connected to the position detecting magnet unit. A magnetic pole identical to the magnetic pole of the leading magnet is detected, and the position detection sensor is disposed between the position detection magnet section and the gate sensor.

  According to a fourth aspect of the present invention, in the linear motor according to the second aspect, when the position detecting magnet unit and the gate sensor approach each other, the gate sensor is connected to the position detecting magnet unit. A magnetic pole different from the magnetic pole of the leading magnet is detected, and the magnetic pole is arranged between the position detecting magnet section and the position detecting sensor.

  The invention according to claim 5 is the linear motor according to any one of claims 1 to 4, wherein the plurality of gate sensors are arranged in the direction of the relative motion. And

  According to a sixth aspect of the present invention, in the linear motor according to any one of the first to third aspects, when the gate sensor detects the position detecting magnet portion, the position detecting sensor. It is further characterized by further comprising a gate portion for outputting the above signal.

  The invention according to claim 7 is the linear motor according to any one of claims 1 to 6, wherein the position detecting magnet section is a driving magnet for driving the movable element. It is characterized by.

  The invention described in claim 8 is characterized in that, in the linear motor according to any one of claims 1 to 7, a motor drive device for controlling the linear motor is provided.

  According to the present invention, a linear motor in which a stator and a mover move relative to each other, provided on the stator or mover, magnets of different magnetic poles arranged alternately in the direction of relative movement, A position detecting magnet for detecting a position, a position detecting sensor for detecting a magnet by detecting a magnet of the position detecting magnet for relative movement, and a magnet for a position detecting magnet for relative movement. And a gate sensor for detecting the position detection magnet portion. When the gate sensor detects the position detection magnet portion, the position detection sensor is disposed at a position overlapping the position detection magnet portion, so that the mover is moved between the stators. When the mover moves into the detection area of the position detection sensor, the disturbance of the output of the position detection sensor that occurs when the mover enters the detection area of the position detection sensor Because can remove, it is possible to provide a linear motor and a linear motor driving system capable of more accurate positioning with simple.

It is a block diagram which shows an example of schematic structure of the drive system of the linear motor which concerns on 1st Embodiment of this invention. It is a top view which shows typically an example of the stator of FIG. 1, and a needle | mover. It is a perspective view which shows typically an example of the stator and movable element of the linear motor of FIG. It is a block diagram which shows an example of a structure of the motor control apparatus of FIG. FIG. 2 is a diagram showing a magnetic sensor constituting the position detection sensor of FIG. 1 ((A) is a plan view showing the shape of a ferromagnetic thin film metal of the magnetic sensor, and (B) is an equivalent circuit diagram). 6 is a graph showing a sine wave signal and a cosine wave signal output from the magnetic sensor of FIG. 5. It is a block diagram which shows an example of schematic structure of the drive system of the linear motor without a sensor for gates. It is a schematic diagram which shows the output of the sensor for position detection of FIG. 1, and the sensor for gates. (A) to (E) are schematic views showing an operation example of the gate sensor in the relative movement of the stator and the mover in FIG. 3. (A) to (D) are schematic views showing an operation example of the gate sensor in the relative movement of the stator and the mover in FIG. 3. (A) to (E) are schematic views showing an operation example of the gate sensor in the relative movement of the stator and the mover in FIG. 3. (A) to (D) are schematic views showing an operation example of the gate sensor in the relative movement of the stator and the mover in FIG. 3. (A) to (B) are schematic views showing an operation example of a gate sensor in the first modification of the linear motor of FIG. 3. (A) to (B) are schematic views showing an operation example of a gate sensor in a second modification of the linear motor of FIG. 3. (A) to (D) are schematic diagrams showing an operation example of a gate sensor in a third modification of the linear motor of FIG. 3. (A) to (D) are schematic diagrams illustrating an example of a schematic configuration of a linear motor according to a second embodiment of the present invention and an operation example of a gate sensor in relative movement of a stator and a mover. (A) to (E) are schematic diagrams showing an operation example of the gate sensor in the relative movement of the stator and the mover of the linear motor of FIG. It is a schematic diagram which shows an example of schematic structure of the linear motor which concerns on 3rd Embodiment of this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(First embodiment)
First, a schematic configuration and function of a drive system for a linear motor according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an example of a schematic configuration of a linear motor drive system according to the first embodiment of the present invention. FIG. 2 is a plan view schematically showing an example of the stator and the mover shown in FIG. FIG. 3 is a perspective view schematically showing an example of a stator and a mover of the linear motor of FIG.

  As shown in FIG. 1, the linear motor drive system includes a stator 10 and a mover 20 that move relative to each other by magnetic action, and a motor drive device (driver) that drives the motor of the linear motor 1 by supplying current. 40 and a host controller 50 that controls the motor drive device 40. In FIG. 1, the configuration viewed from the side surfaces of the stator 10 and the mover 20 is schematically shown.

  As shown in FIG. 1, the stator 10 is supplied with a three-phase alternating current from the motor drive device 40 and magnetically acts on the mover 20, and position detection for detecting the position of the mover 20. Based on the outputs of the sensor 16 (16L, 16R), the gate sensor 36 (36n, 36s) for controlling the output of the position detection sensor 16, and the output of the position detection sensor 16 and the gate sensor 36. A gate unit 37 (37L, 37R) for outputting a signal related to the position of the child 20; and a position information switcher 38 for switching signals from the gate units 37L, 37R installed on the left and right in the longitudinal direction of the coil unit 15. .

  As shown in FIG. 1, the mover 20 includes a table 21 on which parts and workpieces are placed, and driving magnets 25 n and 25 s installed on the lower surface of the table 21, and magnetically acts on the coil unit 15. And a driving magnet unit 25. And the needle | mover 20 functions as carriers, such as components and a workpiece | work.

  Next, as shown in FIG. 2 (A), the coil portion 15 of the stator 10 has three types: a U-phase coil 15u, a V-phase coil 15v, and a W-phase coil 15w. The coils 15u and 15v and the coil 15w are periodically arranged in the order of the U phase, the V phase, and the W phase in the longitudinal direction of the stator 10 (direction of relative motion).

  The position detection sensors 16 (16L, 16R) are magnetic sensors that detect the magnetic force of the magnets 25n, 25s of the drive magnet unit 25. Instead of the magnetic scale, the position of the mover 20 is detected by detecting N-pole magnets 25n and S-pole magnets 25s arranged alternately in the relative motion direction. Further, as shown in FIG. 2 (A) and FIG. 3, the drive magnet unit 25 of the mover 20 is installed on both sides of the stator 10 of the coil unit 15 in the longitudinal direction, and the coil is moved in the relative motion direction. Detection of entry into the unit 15 is performed. The position detection sensor 16 is provided in the stator 10 on the coil portion 15 side, and detects the position of the magnets 25n and 25s of the drive magnet portion 25. As described above, the drive magnet unit 25 is provided on the stator or the mover, and magnets having different magnetic poles are alternately arranged in the direction of relative motion, and an example of a position detection magnet unit for detecting the position of the mover. Function as.

  Next, as shown in FIG. 1, FIG. 2 (B), and FIG. 3, the driving magnet portion 25 has a length L <b> 1 in the longitudinal direction and a magnet 25 n that appears on the surface facing the stator 10. , And a magnet 25 s appearing on the surface of the S pole facing the stator 10. N-pole magnets 25n and S-pole magnets 25s are alternately arranged in the relative motion direction. In this way, a periodic structure is formed in which the magnets 25n and the magnets 25s are alternately arranged in the order of the N pole and the S pole in the direction of relative movement between the stator 10 and the mover 20. The driving magnet unit 25 magnetically acts on the coil unit 15 to generate a driving force of the mover 20. As described above, the driving magnet unit 25 is an example in which magnets having different magnetic poles are alternately arranged in the direction of relative motion.

  2 and 3, the length of the coil portion 15 in the longitudinal direction, that is, the distance in the longitudinal direction of the U-phase coil 15u and the W-phase coil 15w at both ends of the coil portion 15 is illustrated in FIG. This corresponds to the length of the coil portion 15 in the longitudinal direction. Similarly, the longitudinal length L1 of the drive magnet unit 25 in FIGS. 2 and 3 corresponds to the longitudinal length L1 of the drive magnet unit 25 illustrated in FIG.

  Next, the gate sensor 36 is a sensor formed from a Hall element or the like and capable of detecting a magnetic pole. The gate sensor 36n has an N pole detection Hall element that can detect the magnet 25n of the drive magnet unit 25, and the gate sensor 36s has an S pole detection Hall element that can detect the magnet 25s. As shown in FIG. 1, FIG. 2A, or FIG. 3, the gate sensor 36 n is installed outside the position detection sensor 16 </ b> L in the stator 10, and the gate sensor 36 s is installed in the stator 10. Are installed outside the position detection sensor 16R. In FIG. 1, whether the gate sensors 36n and 36s are installed on the left and right positions depends on the order in which the magnets 25n and 25s of the driving magnet unit 25 of the mover 20 are arranged. As shown in FIG. 1, in the driving magnet unit 25, when the magnet 25n is the left end in the figure and the magnet 25s is the right end in the figure, the gate sensor 36n is the left end in the figure, and the gate sensor 36s is in the figure. It becomes the right end. When the arrangement of the magnets 25n and 25s is reversed, the arrangement of the gate sensors 36n and 36s is also reversed.

  As described above, the gate sensor 36 is provided on the stator 10 on the coil unit 15 side and detects the magnets 25n and 25s of the driving magnet unit 25 that moves relative to each other. Further, when the gate sensor 36 detects the drive magnet unit 25 as an example of the position detection magnet unit in this way, the position detection sensor 16 is disposed at a position overlapping the drive magnet unit. The gate sensor 36 detects the magnetic pole of the magnet 25n or the magnet 25s of the driving magnet unit 25 as an example of the position detecting magnet unit.

  The gate unit 37 has an input terminal connected to the position detection sensor 16 and the gate sensor 36 and an output terminal connected to the position information switch 38. The gate unit 37 has a gate function of passing the signal of the position detection sensor 16 to the position information switch 38 in accordance with the signal from the gate sensor 36. As described above, the gate unit 37 outputs the signal of the position detection sensor 16 when the gate sensor 36 detects the gate magnet 35.

  Next, as shown in FIG. 1, when there are a plurality of input signals from the plurality of position detection sensors 16 that have passed through the gate unit 37, the position information switching unit 38 selects one of them and drives the motor. Output to the device 40. For example, the position information switch 38 outputs the latest input signal. The position information switch 38 outputs the input signal as it is when there is one input signal, and does not output it when there is no input signal.

  Next, as shown in FIG. 4, the motor drive device 40 includes a controller 41 that controls the current that flows to the stator 10 of the linear motor based on information from sensors and the like, and power from the power source 45 based on the controller 41. It has a power converter 42 for conversion, and a current sensor 43 for detecting the power that the power converter 42 is flowing to the stator 10.

  The controller 41 is connected to the current sensor 43, the host controller 50 through the control line 51, and the position information switcher 38 through the encoder cable 52.

  The controller 41 controls a power converter 42 such as a PWM inverter (PWM: Pulse Width Modulation) so that the mover 20 moves in accordance with a command value from the host controller 50, and finally the stator. The current supplied to the ten coil portions 15 is controlled. The control system of the controller 41 includes a position control loop that performs position control, a speed control loop that performs speed control, a current control loop that performs current control, and the like. Further, the controller 41 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory).

  The motor drive device 40 is controlled by a command value from the host controller 50 and supplies a current to the coil unit 15 of the stator 10 until reaching a position according to the command value of the host controller 50.

  As shown in FIGS. 1 and 4, the host controller 50 and each motor driving device 40 are connected by a control line 51. The motor driving device 40 and the position information switching unit 38 are connected by an encoder cable 52. The position detection sensor 16, the gate sensor 36, the gate unit 37, and the position information switcher 38 are connected by an encoder cable 52. The motor driving device 40 and the stator 10 are connected by a power cable 53.

  The host controller 50 sends a command value pulse signal to the motor drive device 40 through the control line 51. The motor drive device 40 that has received the command value from the host controller 50 compares the command value with the information from the position information switch 38, and when the driven mover 20 has not reached the target position, The current continues to flow through the cable 53. The host controller 50 outputs a command value to the motor drive device 40 in accordance with a preset work procedure.

  Next, the magnetic sensor constituting the position detection sensor 16 will be described with reference to the drawings.

  FIG. 5 is a diagram showing two sets of full-bridge magnetic sensors constituting the position detection sensor of FIG. 1 ((A) is a plan view showing the shape of the ferromagnetic thin film metal of the magnetic sensor, B) is an equivalent circuit diagram).

  The magnetic sensor of the position detection sensor 16 has a magnetoresistive element composed of a ferromagnetic thin film metal of an alloy mainly composed of a ferromagnetic metal such as Ni or Fe formed on Si or a glass substrate. . A magnetic sensor is called an AMR (Anisotropic-Magnetro-Resistance) sensor (anisotropic magnetoresistive element) because its resistance value changes in a specific magnetic field direction.

  As shown in FIG. 5, the magnetic sensor of the position detection sensor 16 is formed by forming two sets of full-bridge elements on a single substrate so as to be inclined by 45 ° with respect to each other in order to know the direction of movement. Yes. The outputs VoutA and VoutB obtained by the two sets of full bridge circuits are a cosine wave and a sine wave having a phase difference of 90 ° from each other, as shown in FIG. Since the magnets 25n and 25s are alternately arranged in the relative motion direction, the output of the position detection sensor 16 is a cosine wave and a sine wave. As described above, the position detection sensor 16 is based on the periodic structure of the driving magnet unit 25 of the mover 20, and the change in the direction of the magnetic field periodically generated by the relative motion is a sinusoidal signal having a phase difference of 90 ° and Output as cosine wave signal.

  Incidentally, as shown in FIG. 7, in the case of a linear motor without the gate sensor 26, when the mover 20 moves on the stator 10, the position detection sensor 16 reaches the drive magnet unit 25. As shown in FIG. 8, the shape of the cosine wave or sine wave of the output waveform Sc of the position detection sensor 16 is disturbed, making it difficult to detect the position with high accuracy. This is because when the magnetic field of the magnets 25n and 25s at the end of the driving magnet unit 25 is separated from the end of the driving magnet unit 25 in the relative motion direction, the magnetic field gradually attenuates, the edge effect of the magnets 25n and 25s, etc. This is probably because the magnetic fields of the magnets 25n and 25s are disturbed. In this way, in the transient state where the position detection sensor 16 approaches the drive magnet unit 25, the output waveform Sc of the position detection sensor 16 is disturbed, but the drive magnet unit 25 passes through the position detection sensor 16. In the stable state, the output waveform of the position detection sensor 16 is stable.

  In this embodiment, in order to remove the disturbance of the output of the position detection sensor 16, the output of the position detection sensor 16 is stable so that the output can be performed while the cosine wave and the sine wave with less disturbance are being output. As shown in FIGS. 1 to 3, a gate sensor 36 is provided. As shown in FIG. 8, an output signal Sg <b> 1 of the gate sensor 36 is output by the gate sensor 36 installed on the stator 10. Then, the gate unit 37 counts the number of times the gate sensor 36 is turned on by a counter circuit or the like, and passes the output of the position detection sensor 16 only during a certain count number. For example, the signal Sg2 is turned ON at the first rise of the output signal Sg1 of the gate sensor 36, and the signal Sg2 is turned OFF at the rise of the output signal Sg1 of the number of magnets 25n or 25s of the driving magnet unit 25. Like that.

  As shown in FIG. 8, the output waveform Sc of the position detection sensor 16 is between the distance Lmv between the magnets 25n and 25s at both ends of the driving magnet unit 25 and the length L1 of the driving magnet unit 25. stable. A portion where the output waveform Sc of the position detection sensor 16 is stable is taken out by a certain distance between the gate sensor 36 and the poles of the magnets 25n and 25s in the drive magnet unit 25.

  Next, the signal that has passed through the gate unit 37 is taken into a position detection circuit (not shown), and digital interpolation is applied to a sine wave signal and a cosine wave signal having a phase difference of 90 ° to obtain a high resolution phase. Converted to corner data.

  Then, the position detection circuit generates an A-phase encoder pulse signal (corresponding to a sine wave signal) and a B-phase encoder pulse signal (corresponding to a cosine wave signal) from the phase angle data, and generates a Z-phase pulse once per cycle. Generate a signal. The position signals of these A-phase encoder pulse signal, B-phase encoder pulse signal, and Z-phase pulse signal are input to the position information switch 38. As shown in FIG. 4, the motor drive device 40 controls the power converter 42 based on the position signals of these A-phase encoder pulse signal, B-phase encoder pulse signal, and Z-phase pulse signal.

  Next, an operation example of the linear motor 1 will be described with reference to FIGS.

  FIGS. 9A to 9E and FIGS. 10A to 10D are schematic views showing an operation example of the gate sensor in the relative movement of the stator and the mover in FIG. Is when moving from left to right in the figure. In addition, the table 21 of the needle | mover 20 is abbreviate | omitted in the figure. Further, the base portion of the stator 10 shown in FIGS. 2 to 4 is also omitted.

  As shown in FIG. 9A, the mover 20 moves, and the driving magnet unit 25 and the gate sensor 36n as an example of the position detecting magnet unit approach each other. The gate sensor 36n has a function of detecting a magnetic pole (N pole) different from the magnetic pole (S pole) of the leading magnet 25s in the driving magnet unit 25. As shown in FIG. 9A, the gate sensor 36n is disposed between the drive magnet unit 25 and the position detection sensor 16L. Thus, when the leading magnet 25s in the driving magnet unit 25 is different from the magnetic pole that can be detected by the gate sensor 36n with respect to the traveling direction of the mover 20, the gate sensor 36n is connected to the position detection sensor 16L. This is the configuration in the foreground.

  Next, as shown in FIG. 9B, when the leading portion of the moving direction of the driving magnet portion 25 of the mover 20 reaches the gate sensor 36n, the right S in the drawing of the driving magnet portion 25 in the figure. Since the pole magnet 25s is approaching and the output of the gate sensor 36n is “OFF”, the information from the position detection sensor 16L is blocked by the gate portion 37L and is not output to the motor drive device 40.

  Next, as shown in FIG. 9C, the driving magnet portion 25 of the mover 20 reaches the position detection sensor 16L, but the magnetic force of the S pole magnet 25s is still applied to the gate sensor 36n. Since the output of the gate sensor 36n is “OFF”, the information from the position detection sensor 16L is blocked by the gate portion 37L and is not output to the motor drive device 40.

  Next, as shown in FIG. 9D, when the driving magnet unit 25 of the mover 20 reaches the coil unit 15, the position detection sensor 16 </ b> L overlaps the driving magnet unit 25, The detection sensor 16L can detect a magnetic field with little disturbance. At this time, the N-pole magnet 25n adjacent to the S-pole magnet 25s at the right end of the drive magnet portion 25 in the drawing reaches the gate sensor 36n and enters the region where the magnetic force of the N-pole magnet 25n is applied, and then the gate. The output of the sensor 36n is turned “ON”. Then, the information of the position detection sensor 16L is output from the gate unit 37L through the position information switch 38 to the motor driving device 40, and position detection is started. The position of the position detection sensor 16L is the origin of the stator 10 for detecting the position of the mover 20.

  Next, as shown in FIG. 9 (E), the gate sensor 36n is placed in a region where the magnetic force of the second S-pole magnet 25s from the right of the driving magnet portion 25 of the mover 20 reaches. The output signal of the gate sensor 36n is OFF, but the count number in the gate portion 37L is less than the number of magnets 25n or 25s, so that the gate of the gate portion 37L remains open and the position detection sensor 16L Information is output from the gate unit 37L.

  As described above, in the linear motor according to the present embodiment, when the drive magnet unit 25 as an example of the position detection magnet unit and the gate sensor 36 approach each other, the gate sensor 36n is the leading magnet in the drive magnet unit 25. This is an example in which a magnetic pole different from the magnetic pole of 25 s is detected and disposed between the driving magnet unit 25 and the position detection sensor 16L. In the case of such different magnetic poles, the distance D1 between the gate sensor 36n and the position detection sensor 16L is shorter than the distance D2 between the adjacent magnets 25n and 25s.

  Next, the mover 20 moves on the stator 10, and as shown in FIG. 10A, the drive magnet unit 25 and the gate sensor 36s as an example of the position detection magnet unit approach each other. come. The gate sensor 36s has a function of detecting the same magnetic pole (S pole) as the magnetic pole (S pole) of the leading magnet 25s in the driving magnet unit 25. As shown in FIG. 10A, the position detection sensor 16R is disposed between the drive magnet unit 25 and the gate sensor 36s. As described above, when the leading magnet 25 s in the driving magnet unit 25 is the same as the magnetic pole that can be detected by the gate sensor 36 s with respect to the moving direction of the mover 20, the position detection sensor 16 </ b> R This is a configuration in front of the gate sensor 36s in the direction.

  Next, as shown in FIG. 10B, when the mover 20 further moves and the driving magnet portion 25 of the mover 20 reaches the position detection sensor 16R, the gate sensor 36s is driven. Since the magnet unit 25 is not approaching and the output of the gate sensor 36s is “OFF”, the information from the position detection sensor 16R is blocked by the gate unit 37R and is not output to the motor drive device 40.

  Next, as shown in FIG. 10C, the driving magnet portion 25 of the mover 20 reaches the gate sensor 36s, and the leading magnet 25s of the driving magnet portion 25 is the S pole. The output of the sensor 36 s is “ON”. At this time, the position detection sensor 16R overlaps the drive magnet unit 25, and the position detection sensor 16L can detect a magnetic field with little disturbance. Since the output of the gate sensor 36s is “ON”, the information of the position detection sensor 16R is input to the position information switch 38 from the gate portion 37R. At this time, the information from the position detection sensor 16L is blocked by the position information switch 38, the position detection sensor 16R is output to the motor drive device 40, and the position detection is performed based on the information from the position detection sensor 16R. Be started. The gate sensor 36n is in a region where the magnetic force of the magnet 25s reaches and the output signal is OFF, but the count number in the gate portion 37L is less than the number of the magnet 25n or the magnet 25s. Information on the position detection sensor 16L is output from the gate portion 37L while the gate is open.

  This position detection sensor 16R becomes a new origin in the stator 10, and detects the position of the mover 20. Note that the origin of the stator 10 may remain at the position of the position detection sensor 16L. In this case, since the distance between the position detection sensor 16L and the position detection sensor 16R is known in advance, this distance is added to the information from the position detection sensor 16R.

  Next, as shown in FIG. 10D, after the gate sensor 36s has entered the region where the magnetic force of the N-pole magnet 25n adjacent to the S-pole magnet 25s at the right end of the drive magnet portion 25 in the drawing is reached. The output signal of the gate sensor 36s is OFF, but the count number in the gate portion 37R is less than the number of magnets 25n or 25s, so that the gate of the gate portion 37R remains open and the position detection sensor 16R Information is output from the gate unit 37R. On the other hand, the gate sensor 36n is in a region where the magnetic force of the magnet 25n reaches, and the count number in the gate portion 37L is the number of magnets 25n or 25s. Therefore, the gate of the gate portion 37L is closed and position detection is performed. Information of the sensor 16L is blocked by the gate portion 37L.

  As described above, in the linear motor according to the present embodiment, when the driving magnet unit 25 as an example of the position detecting magnet unit and the gate sensor 36s approach each other, the gate sensor 36s is the leading magnet in the driving magnet unit 25. This is an example in which the same magnetic pole as the magnetic pole of 25s is detected, and the position detection sensor 16R is disposed between the driving magnet unit 25 and the gate sensor 36s.

  Next, an example of the operation of the gate sensor 36 when the mover 20 moves in the opposite direction will be described.

  FIGS. 11A to 11E and FIGS. 12A to 12D are schematic views showing an operation example of the gate sensor in the relative motion of the stator and the mover in FIG. Is moving from the right to the left in the figure, and is moving in the opposite direction to the case of FIGS.

  As shown in FIG. 11A, the mover 20 moves, and the driving magnet unit 25, which is an example of the position detecting magnet unit, and the gate sensor 36s approach each other. The gate sensor 36s has a function of detecting a magnetic pole (S pole) different from the magnetic pole (N pole) of the leading magnet 25n in the driving magnet unit 25. As shown in FIG. 11A, the gate sensor 36s is disposed between the drive magnet unit 25 and the position detection sensor 16R. As described above, when the leading magnet 25n in the driving magnet unit 25 is different from the magnetic pole that can be detected by the gate sensor 36s with respect to the traveling direction of the mover 20, the gate sensor 36s is connected to the position detection sensor 16R. This is the configuration in the foreground.

  Next, as shown in FIG. 11B, when the leading portion of the moving direction of the driving magnet portion 25 of the mover 20 reaches the gate sensor 36s, N at the left end of the driving magnet portion 25 in the figure. Since the pole magnet 25n is approaching and the output of the gate sensor 36s is “OFF”, the information from the position detection sensor 16R is blocked by the gate portion 37R and is not output to the motor drive device 40.

  Next, as shown in FIG. 11C, the driving magnet portion 25 of the mover 20 reaches the position detection sensor 16R, but the magnetic force of the N-pole magnet 25n is still applied to the gate sensor 36s. Since the output of the gate sensor 36s is “OFF”, the information from the position detection sensor 16R is blocked by the gate unit 37R and is not output to the motor drive device 40.

  Next, as shown in FIG. 11D, when the driving magnet unit 25 of the mover 20 reaches the coil unit 15, the position detection sensor 16 </ b> R overlaps the driving magnet unit 25, The detection sensor 16R can detect a magnetic field with little disturbance. At this time, the S-pole magnet 25s adjacent to the N-pole magnet 25n at the right end of the drive magnet portion 25 in the drawing reaches the gate sensor 36s and enters the region where the magnetic force of the S-pole magnet 25s is applied, and then the gate. The output of the sensor 36 s is “ON”. Then, the information of the position detection sensor 16R is output from the gate portion 37R to the motor driving device 40 through the position information switch 38, and position detection is started. The position of the position detection sensor 16R is the origin of the stator 10 for detecting the position of the mover 20.

  Next, as shown in FIG. 11E, after the gate sensor 36s has entered the region where the magnetic force of the second N-pole magnet 25n from the left of the driving magnet portion 25 of the mover 20 is reached. The output signal of the gate sensor 36s is OFF, but the count number in the gate portion 37R is less than the number of magnets 25n or 25s, so that the gate of the gate portion 37R remains open and the position detection sensor 16R Information is output from the gate unit 37R.

  As described above, in the linear motor of this embodiment, when the driving magnet unit 25 as an example of the position detecting magnet unit and the gate sensor 36 approach each other, the gate sensor 36 s is the leading magnet in the driving magnet unit 25. This is an example in which a magnetic pole different from the magnetic poles of 25n is detected and disposed between the driving magnet unit 25 and the position detection sensor 16R.

  Next, the mover 20 moves on the stator 10, and as shown in FIG. 12A, the drive magnet unit 25 and the gate sensor 36n as an example of the position detection magnet unit approach each other. come. The gate sensor 36n has a function of detecting the same magnetic pole (N pole) as the magnetic pole (N pole) of the leading magnet 25n in the driving magnet unit 25. As shown in FIG. 12A, the position detection sensor 16L is arranged between the drive magnet unit 25 and the gate sensor 36n. As described above, when the leading magnet 25n in the driving magnet unit 25 is the same as the magnetic pole that can be detected by the gate sensor 36n with respect to the moving direction of the mover 20, the position detection sensor 16L moves the mover 20 forward. This is a configuration in front of the gate sensor 36s in the direction.

  Next, as shown in FIG. 12B, when the mover 20 further moves and the drive magnet portion 25 of the mover 20 reaches the position detection sensor 16L, the gate sensor 36s is driven. Since the magnet unit 25 is not reached and the output of the gate sensor 36n is “OFF”, the information from the position detection sensor 16L is blocked by the gate unit 37L and is not output to the motor drive device 40.

Next, as shown in FIG. 12C, the driving magnet portion 25 of the mover 20 reaches the gate sensor 36n, and the top magnet 25n of the driving magnet portion 25 has an N pole, so that the gate The output of the sensor 36n is turned “ON”. At this time, the position detection sensor 16L overlaps the driving magnet unit 25, and the position detection sensor 16L can detect a magnetic field with less disturbance. Since the output of the gate sensor 36s is “ON”, the information of the position detection sensor 16R is input to the position information switch 38 from the gate portion 37R. At this time, the information from the position detection sensor 16L is blocked by the position information switch 38, the position detection sensor 16R is output to the motor drive device 40, and the position detection is performed based on the information from the position detection sensor 16R. Be started.
This position detection sensor 16L becomes a new origin in the stator 10, and detects the position of the mover 20.

  Next, as shown in FIG. 12D, after the gate sensor 36n enters the region where the magnetic force of the S pole magnet 25s adjacent to the N pole magnet 25n at the left end of the driving magnet portion 25 in the drawing reaches. The output signal of the gate sensor 36n is OFF, but the count number in the gate portion 37L is less than the number of magnets 25n or 25s, so that the gate of the gate portion 37L remains open and the position detection sensor 16L Information is output from the gate unit 37L. On the other hand, the gate sensor 36s is in a region where the magnetic force of the magnet 25s reaches, and the count number in the gate portion 37R is the number of magnets 25n or 25s, so the gate of the gate portion 37R is closed and position detection is performed. Information of the sensor 16R is blocked by the gate portion 37R.

  As described above, in the linear motor according to the present embodiment, when the drive magnet unit 25 as an example of the position detection magnet unit and the gate sensor 36n approach each other, the gate sensor 36n is the leading magnet in the drive magnet unit 25. This is an example in which the same magnetic pole as that of 25n is detected, and the position detection sensor 16L is disposed between the drive magnet unit 25 and the gate sensor 36n.

  Thus, according to the present embodiment, the stator 10 and the mover 20 are linear motors 1 that move relative to each other, and the magnets 25n and 25s that are provided on the mover 20 and have different magnetic poles in the direction of relative movement are provided. The position is determined by detecting the magnets 25n and 25s of the drive magnet unit 25 as an example of the position detection magnet unit that is arranged alternately and detecting the position of the mover 20 and the drive magnet unit 25 that relatively moves. A position detection sensor 16 for detection, and a gate sensor 36 for detecting the magnets 25n and 25s of the drive magnet unit 25 that moves relative to each other, and the gate sensor 36 is an example of driving of the position detection magnet unit. When detecting the magnet part 25 for position, the position detection sensor 16 overlaps the driving magnet part 25 as an example of the position detection magnet part. By arranging the movable element 20 at the position, the disturbance of the output of the position detection sensor 16 that occurs when the mover 20 enters the detection region of the position detection sensor 16 is removed based on the gate sensor 36. It is possible to provide a linear motor 1 capable of highly accurate positioning and a linear motor drive system.

  Further, when detecting the magnetic pole of the driving magnet unit 25 as an example of the position detecting magnet unit, the gate sensor 36 can more easily remove the disturbance in the output of the position detecting sensor 16.

  Further, when the driving magnet unit 25 as an example of the position detection magnet unit and the gate sensor 36 approach each other, the gate sensor 36 has the same magnetic pole as the magnetic poles of the leading magnets 25n and 25s in the driving magnet unit 25. When the position detection sensor 16 is disposed between the drive magnet unit 25 and the gate sensor 26, the drive magnet unit 25 and the gate sensor 36 are moved closer to each other when the drive magnet unit 25 and the gate sensor 36 approach each other. The position detection sensor 16 located between the gate sensor 36 first detects the drive magnet unit 25. However, since the output of the gate sensor 36 is not "ON", the transient position detection sensor 16 Output can be shut off. Then, after the position detection sensor 16 is overlapped with the drive magnet unit 25, the output of the gate detection sensor 36 is turned "ON", so that the output of the stable position detection sensor 16 can be obtained.

  Further, when the driving magnet unit 25 as an example of the position detecting magnet unit approaches the gate sensor 36, the gate sensor 36 detects a magnetic pole different from the magnetic poles of the leading magnets 25n and 25s in the driving magnet unit 25. When the drive magnet unit 25 and the position detection sensor 16 are disposed between the drive magnet unit 25 and the gate sensor 36, the drive magnet unit 25 and the position detection sensor 16 are arranged. When the gate sensor 36 between and the first magnet 25n, 25s of the driving magnet unit 25 does not detect the different magnetic poles, and the magnet 25n, 25s passes and detects the adjacent magnet 25n, 25s. Because the driving magnet 25 and the position detection sensor 16 overlap, a distorted waveform can be eliminated, and the stable state It is possible to obtain an output of the position detecting sensor 16.

  In addition, when the plurality of gate sensors 36 are arranged in the direction of relative movement, for example, when the mover 20 comes out of the stator 10 or when the mover 20 is shorter than the stator, the position is unstable. The output of the detection sensor 16 can be cut off, and the position can be detected with high accuracy.

  In addition, when the gate sensor 36 detects the drive magnet unit 25 as an example of the position detection magnet unit, when the gate sensor 37 further outputs a signal of the position detection sensor 16, only the gate unit 37 is provided. Thus, the output of the unstable position detection sensor 16 can be cut off without improving the motor driving device 40, and the position can be detected with high accuracy.

  As a first modification of the first embodiment, the coil portion 15B of the stator 10B may be longer than the driving magnet portion 25 of the mover 20 as shown in FIG. In this case, a position detection sensor 16M and a gate sensor 36s are further provided. Position detection sensors 16L, 16M, and 16R are installed at intervals equal to or shorter than the length of the mover 20. In the central portion of the stator 10B, a gate sensor 36s is installed next to the position detection sensor 16M in front of the movable element 20 in the traveling direction. Further, when the leading magnet 25s in the driving magnet unit 25 is the same as the magnetic pole that can be detected by the gate sensor 36s with respect to the moving direction of the mover 20, the position detection sensor 16M is in the moving direction of the mover 20. In FIG. 3, the configuration is in front of the gate sensor 36s. Here, the position information switching unit 38 outputs the latest input signal to the motor driving device 40 in response to the input signals from the position detection sensors 16L, 16M, and 16R.

  FIG. 13A corresponds to FIG. 10B, and FIG. 13B corresponds to FIG. 10C. FIG. 13A shows an example of the operation of the gate sensor 36 in the relative movement of the stator 12 and the mover 22. Since the operation can be almost explained by replacing the position detection sensor 16R in FIG. 10 with the position detection sensor 16M in FIG. 13, the description of the operation is omitted.

  As described above, when the linear motor according to the present modification approaches the driving magnet unit 25 as an example of the position detecting magnet unit and the gate sensor 36s at the center of the stator 10B, the gate sensor 36s This is an example in which the same magnetic pole as that of the leading magnet 25s in the driving magnet section 25 is detected, and the position detection sensor 16M is disposed between the driving magnet section 25 and the gate sensor 36s.

  In addition, when the plurality of gate sensors 36n and 36s are arranged in the direction of relative movement in this way, even when the mover 20 is shorter than the stator 10B as in this modification, the position detection is unstable. The output of the sensor 16 can be cut off, and the position can be detected with high accuracy.

  Further, as a second modification of the first embodiment, as shown in FIG. 14, instead of the gate sensor 36s installed at the center of the stator 10B in the first modification, a gate sensor 36n is replaced with the stator 10C. You may install in the center part. In the central portion of the stator 10C, the gate sensor 36n is disposed next to the position detection sensor 16M at the rear of the moving direction of the mover 20.

Further, when the leading magnet 25s in the driving magnet unit 25 is different from the magnetic pole that can be detected by the gate sensor 36s with respect to the traveling direction of the mover 20, the gate sensor 36n The configuration is in front of the position detection sensor 16M.

  FIG. 14 (A) corresponds to FIG. 9 (B), and FIG. 14 (B) corresponds to FIG. 9 (C), as an example of the operation of the gate sensor 36 in the relative movement of the stator 12 and the mover 22. Since the operation can be substantially explained by replacing the position detection sensor 16L in FIG. 9 with the position detection sensor 16M in FIG. 13, the description of the operation is omitted.

  As described above, in the linear motor of this modification, when the driving magnet unit 25 as an example of the position detection magnet unit and the gate sensor 36 approach each other, the gate sensor 36n is the leading magnet in the driving magnet unit 25. This is an example in which a magnetic pole different from the magnetic pole of 25 s is detected and disposed between the driving magnet unit 25 and the position detection sensor 16M.

  Furthermore, as shown in FIG. 15, as a third modification of the first embodiment, a plurality of stators 10 may be spaced and arranged. In addition, a motor drive device is installed for every stator 10, and a single host controller controls each motor drive device.

  FIG. 15 is a schematic diagram showing a schematic configuration of a distributed linear motor 1 </ b> C in which the stators 10 are distributed so that the mover 20 straddles between the stators 10. 15A to 15B are schematic diagrams illustrating an operation example of the gate sensor 36 when the mover 20 moves to the next stator 10.

  As shown in FIG. 15A, the position of the mover 20 is detected with the position detection sensor 16R in the stator 10 on the left side in the figure as the origin. Further, the mover 20 moves to the stator 10 on the left side in the figure, and the drive magnet part 25 as an example of the position detection magnet part and the gate sensor 36n of the stator 10 on the right side in the figure are approaching. The operations of the position detection sensor 16L and the gate sensor 36n in the stator 10 on the right side in the drawing correspond to FIG. 9A.

  Next, as shown in FIG. 15B, when the driving magnet portion 25 of the mover 20 reaches the coil portion 15 of the stator 10 on the right side in the drawing, the position detection sensor 16L detects the driving position. The position detection sensor 16L is in a state where it can detect a magnetic field with little disturbance. The operations of the position detection sensor 16L and the gate sensor 36n in the stator 10 on the right side in the drawing correspond to FIG. 9D. Then, the position detection of the mover 20 is started with the position of the position detection sensor 16L as the origin of the right stator 10.

  Then, until the state shown in FIG. 15C, the position of the mover 20 is detected in both stators 10, and the propulsive force is obtained from both stators 10 to move.

  Next, as shown in FIG. 15D, the gate sensor 36s of the stator 10 on the left side in the drawing is in a region where the magnetic force of the magnet 25s is applied, and the gate portion 37R of the stator 10 on the left side in the drawing. Is the number of magnets 25n or 25s, the gate of the gate portion 37R is closed, and the information of the position detection sensor 16R of the stator 10 on the left side in the figure is blocked by the gate portion 37R. Position detection in the left stator 10 ends.

  In the case of this modification, when the mover 20 moves from the stator 10 to the adjacent stator 10, the mover 20 can obtain a propulsive force from at least one of the adjacent stators 10 to control the speed. The position can be controlled accurately.

(Second Embodiment)
Next, a drive system for a linear motor according to a second embodiment of the present invention will be described. First, a schematic configuration of the drive system for the linear motor 2 according to the second embodiment will be described with reference to FIGS. 16 and 17. Note that the same or corresponding parts as those in the first embodiment will be described using only the same reference numerals and different configurations and operations. The same applies to other embodiments and modifications.

  FIGS. 16A to 16D and FIGS. 17A to 17E are examples of the schematic configuration of the linear motor according to the second embodiment of the present invention, and the relative motion of the stator and the mover. It is a schematic diagram which shows the operation example of the sensor for gates in.

  As shown in FIG. 16, the linear motor 2 of the present embodiment is different from the linear motor of the first embodiment in that the gate sensors 36 s and 36 n are positioned inside the position detection sensors 16 L and 16 R in the stator 12. It has the structure each installed in the both sides of the coil part 15. FIG.

  Next, an operation example of the gate sensor 36 in the relative movement of the stator 12 and the mover 20 will be described. In addition, it is a case where the needle | mover 20 is moving from the left to the right in the figure. Although the configurations are different, the operations of the position detection sensor 16 and the gate sensor 36 are as shown in FIG. 10 in the first embodiment in FIG. 16 and in FIG. 9 in the first embodiment in FIG. Correspond.

  The operations of the position detection sensor 16L and the gate sensor 36s shown in FIGS. 16A to 16D are shown in FIGS. 10A to 10D of the first embodiment, and FIGS. The operations of the position detection sensor 16R and the gate sensor 36n shown in FIG. 9 correspond to FIGS. 9A to 9E of the first embodiment.

  As described above, in this embodiment, when the gate sensor 36 detects the drive magnet unit 25 as an example of the position detection magnet unit, the position detection sensor 16 is disposed at a position overlapping the drive magnet unit 25. It is.

  In addition, as shown in FIG. 16, the linear motor of this embodiment is configured such that when the driving magnet unit 25 as an example of the position detecting magnet unit and the gate sensor 36s approach each other, the gate sensor 36s is connected to the driving magnet unit. 25, the same magnetic pole as the magnetic pole of the leading magnet 25s is detected, and the position detection sensor 16R is disposed between the driving magnet unit 25 and the gate sensor 36s.

Further, as shown in FIG. 17, the linear motor of this embodiment is configured such that when the drive magnet unit 25 as an example of the position detection magnet unit and the gate sensor 36 approach each other, the gate sensor 36n 25 is an example in which a magnetic pole different from the magnetic pole of the leading magnet 25s is detected and disposed between the driving magnet unit 25 and the position detection sensor 16L.
As described above, the present embodiment can provide the same effects as those of the first embodiment.

(Third embodiment)
Next, a linear motor drive system according to a third embodiment of the present invention will be described.
First, a schematic configuration according to the third embodiment will be described with reference to FIG.

  FIG. 18 is a schematic diagram illustrating an example of a schematic configuration of a linear motor according to the third embodiment of the present invention.

  As shown in FIG. 18, the linear motor 3 of the present embodiment has a configuration in which the stator 10 and the mover 20 in the linear motor 1 of the first embodiment are reversed. In the linear motor 3 of the present embodiment, a driving magnet unit 65 is installed on the upper surface of the base portion of the stator 60, and a coil unit 75 and a position detection sensor 76 (76L, 76R) and gate sensors 86 (86L, 86R). And the coil part 75 moves on the magnet part 65 for a drive.

  The operations of the position detection sensor 76 and the gate sensor 86 are the same as the operations of the position detection sensor 16 and the gate sensor 36 in the linear motor 1 of the first embodiment, and have the same effects. As described above, the drive magnet unit 65 is provided on the stator or the mover, and magnets having different magnetic poles are alternately arranged in the direction of relative motion, and an example of a position detection magnet unit for detecting the position of the mover. Function as. The position detection sensor 76 detects the position of the magnet of the driving magnet unit 65 that moves relative to the position detection sensor 76. The gate sensor 86 is provided on the mover 70 on the coil section 75 side and detects a magnet of the driving magnet section 65 that relatively moves.

  As described above, even when the stator 60 has the driving magnet unit 65 and the mover 70 has the coil unit 75, the gate sensor 86 can be applied, and this embodiment has the same effect. The same applies to the modification of the first embodiment and the linear motor of the second embodiment.

  Thus, the present embodiment is a linear motor 3 in which the stator 60 and the mover 70 move relative to each other, and are provided on the stator, and magnets 65n and 65s having different magnetic poles are alternately arranged in the direction of relative movement. Position detection for detecting the position by detecting the magnet of the driving magnet unit 85 as an example of the position detecting magnet unit for detecting the position of the mover 70 and the magnet for the position detecting magnet unit that relatively moves. Sensor 76 and a gate sensor 86 that detects the magnet of the position detecting magnet portion that moves relative to the position detecting magnet portion. When the gate sensor detects the position detecting magnet portion, the position detecting sensor is the position detecting magnet. It is an example of the linear motor characterized by being arrange | positioned in the position which overlaps with a part.

  The first to third embodiments are linear motors (1, 2, 3) in which the stator (10, 60) and the mover (20, 70) move relative to each other, and the stator or the mover. Magnets (25n, 25s) (65n, 65s) having different magnetic poles in the direction of relative motion are alternately arranged, and a drive magnet as an example of a position detection magnet unit for detecting the position of the mover The position detection sensors (16, 76) for detecting the position by detecting the magnets of the position detection magnet part (25, 65), the position detection magnet part for relative movement, and the magnet for the position detection magnet part for relative movement. Detecting gate sensors (36, 86), and when the gate sensor detects the driving magnet portion, the position detecting sensor is disposed at a position overlapping the driving magnet portion. It is an example linear motor according to claim.

  The motor driving device 40 may directly receive signals from the position detection sensors 16 and 76 and the gate sensors 36 and 86 and have the functions of the gate unit 37 and the position information switch 38.

  Further, a magnetic scale may be used as the position detecting magnet unit instead of the driving magnet unit.

  The present invention is not limited to the above embodiments. Each of the embodiments described above is an exemplification, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and has the same operational effects can be used. It is included in the technical scope of the present invention.

  1, 2, 3, 4: Linear motor 10, 10B, 12, 13, 60: Stator, 16, 16L, 16R, 16M, 76L, 76R: Position detection sensor 20, 22, 23, 70: Movable Child, 25, 65: driving magnet section, 25n, 25s: magnet, 36, 36n, 36s, 86n, 86s: gate sensor, 37: gate section, 40: motor driving device

Claims (8)

A linear motor in which a stator and a mover move relative to each other,
A magnet for position detection for detecting the position of the mover, provided on the stator or the mover, magnets of different magnetic poles are alternately arranged in the direction of the relative motion,
A position detection sensor for detecting the position of the magnet of the position detection magnet section that moves relative to the position detection sensor;
A gate sensor for detecting a magnet of the position detecting magnet portion that moves relative to the magnet;
A linear motor, wherein when the gate sensor detects the position detection magnet portion, the position detection sensor is disposed at a position overlapping the position detection magnet portion. The linear motor according to claim 1,
The linear motor according to claim 1, wherein the gate sensor detects a magnetic pole of the position detecting magnet unit. The linear motor according to claim 2,
When the position detection magnet unit and the gate sensor approach,
The gate sensor detects the same magnetic pole as the magnetic pole of the leading magnet in the position detecting magnet section,
The linear motor according to claim 1, wherein the position detection sensor is disposed between the position detection magnet section and the gate sensor. The linear motor according to claim 2,
When the position detection magnet unit and the gate sensor approach,
The gate sensor detects a magnetic pole different from the magnetic pole of the leading magnet in the position detection magnet section, and is arranged between the position detection magnet section and the position detection sensor. A linear motor. In the linear motor according to any one of claims 1 to 4,
A linear motor comprising a plurality of gate sensors arranged in the direction of relative movement. In the linear motor according to any one of claims 1 to 3,
A linear motor, further comprising a gate portion that outputs a signal of the position detection sensor when the gate sensor detects a position detection magnet portion. In the linear motor according to any one of claims 1 to 6,
The linear motor, wherein the position detecting magnet section is a driving magnet for driving the movable element.   The linear motor according to any one of claims 1 to 7, further comprising a motor driving device that controls the linear motor.

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