Electromagnetic device

Abstract

In this electromagnetic device, a plurality of coil blocks in which coils equal in number to the number of phases are arranged in order in one direction are arranged in said one direction in a track part. In a moving body, permanent magnets constituting one or multiple electrical angle cycles are arranged in a direction corresponding to said one direction, and the end parts of the permanent magnets in a direction intersecting the arrangement direction of the permanent magnets are positioned opposite the end parts of the coils in a direction intersecting said one direction. As a result, in the electromagnetic device, by setting a d-axis current target value to a positive value when the coils are excited, step-out of the moving body with respect to the track part is suppressed due to attraction forces between the end parts of the coils and the end parts of the permanent magnets.

Description

electromagnetic device

[0001] The disclosed technology relates to electromagnetic devices.

[0002] JP 2021-507664 A discloses an electric motor including a long, thin, strip-like arrangement of densely arranged rod-shaped permanent magnets and a plate-shaped coil assembly consisting of an arrangement of flat coils arranged in the same direction as the permanent magnets.

[0003] In a conveyance device using a linear motor, for example, multiple coils are arranged on the track side, and when these coils are excited, an electromagnetic force is generated between the coils and permanent magnets arranged on the moving body facing the coils, causing the moving body to move in the direction of the coil arrangement by the electromagnetic force.

[0004] In such a conveying device, a loss of synchronization occurs, causing the moving body to shift in a direction intersecting the moving direction, resulting in movement problems (conveyance problems) of the moving body.To prevent this, it is possible to provide a guide means such as a guide for guiding the moving body in the moving direction while restricting movement of the moving body in the width direction.

[0005] However, when a guide means is provided, not only does the structure of the track become complicated, but there is also the problem that the guide means limits the range of movement of the moving body.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide an electromagnetic device that enables smooth movement of a moving body without providing a guide means or the like.

[0007] a field magnet section disposed on the movable body opposite the coils of the armature section, in which a plurality of permanent magnets are arranged in a direction corresponding to the one direction for one electrical angle cycle or multiple electrical angle cycles, and in which ends of the permanent magnets in a direction intersecting the arrangement direction face ends of the coils in a direction intersecting the arrangement direction; and a control section for setting a d-axis current target value and a q-axis current target value, thereby exciting each of the coils of each of the coil blocks in accordance with a drive voltage set based on the d-axis current target value and the q-axis current target value, and for setting a positive value for the d-axis current target value when the movable body is moved relative to the movable body.

[0008] In the electromagnetic device of the first aspect, a track portion to which a moving body faces extends in one direction, and the moving body is supported by a support portion so as to be movable along a moving plane including the one direction. An armature portion is provided on the track portion, and a field portion is provided on the moving body so as to face the armature portion.

[0009] The armature section is provided with coil blocks in which coils corresponding to the number of phases are arranged in one direction, and the plurality of coil blocks are arranged in one direction. The field section has a plurality of permanent magnets arranged in a direction corresponding to the one direction in which the coils are arranged, for one or more electrical cycles, and the ends of the permanent magnets in a direction intersecting the arrangement direction are opposed to the ends of the coils in a direction intersecting the arrangement direction.

[0010] The control unit excites each of the coils in each coil block according to the drive voltage set based on the d-axis current target value and the q-axis current target value, and moves the moving body relative to the track portion, by setting the d-axis current target value and the q-axis current target value.

[0011] Here, the control unit sets a positive value for the d-axis current target value. This causes an attractive force between the coil block and the array of permanent magnets for one electrical angle cycle. Furthermore, the end of the permanent magnets in a direction intersecting the array direction faces the end of the coils in a direction intersecting the array direction. Therefore, the attractive force between the coil and the permanent magnet generates a force that moves the end of the permanent magnet facing the end of the coil toward the center of the coil.

[0012] As a result, if the movable body shifts in a direction intersecting the coil arrangement direction, causing a misalignment between the end of the permanent magnet and the end of the coil, the movable body is moved by the force received by the permanent magnet, thereby suppressing the shift of the movable body. Therefore, the movable body is prevented from losing synchronization when moved along the track portion, and moves in a stable state. Furthermore, since the guide means is not required, the structure of the track portion can be simplified.

[0013] The electromagnetic device of the second aspect is the first aspect, wherein the field magnet portion has an integer of 3 or more divided into divisions, and the permanent magnets are arranged such that the magnetization direction is changed by an angle obtained by dividing one electrical angle cycle by the division number.

[0014] The electromagnetic device of a third aspect is the first or second aspect, wherein the field magnet portion has an array of permanent magnets whose magnetization direction is changed by an angle obtained by dividing one electrical angle cycle by a division number that is any one of integers obtained by adding 2 to a multiple of 3.

[0015] A fourth aspect of the electromagnetic device is any one of the first to third aspects, wherein the field magnet section includes a first magnet block in which the permanent magnets for one electrical angle cycle are arranged in a first direction corresponding to the one direction, and a second magnet block in which the permanent magnets for one electrical angle cycle are arranged in a second direction intersecting the first direction, the first magnet block and the second magnet block are adjacent to each other in the first direction and the second direction, the first magnet blocks and the second magnet blocks are adjacent to each other diagonally, the armature section includes, as the coil blocks, a first coil block in which the coils for the number of phases are arranged in the one direction, and a second coil block in which the coils for the number of phases are arranged in a direction intersecting the one direction, and the first coil block and the second coil block are arranged alternately in each of the one direction and the direction intersecting the one direction.

[0016] The electromagnetic device of the fifth aspect is any one of the first to fourth aspects, and is provided with a moving body detection unit for detecting whether the moving body is facing each of the coil blocks, and the control unit excites each of the coils of the coil block selected based on the detection result of the moving body detection unit.

[0017] The electromagnetic device of a sixth aspect is any one of the first to fifth aspects, wherein each of the coils is an air-core coil.

[0018] According to this aspect of the present invention, by setting the d-axis current target value to a positive value, an attractive force is generated between the permanent magnet and the coil, and when the center position of the permanent magnet deviates from the center position of the coil in the width direction, the center position of the permanent magnet is moved to the center position of the coil in the width direction. As a result, this aspect of the present invention has the effect of suppressing step-out of the movable body moving along the track portion, and allowing the movable body to move in a stable state.

[0019] 1 is a perspective view showing a main part of a conveying device according to a first embodiment; FIG. 2 is a plan view showing a schematic configuration of the conveying device; FIG. 3 is a front view showing an outline of the main part of the conveying device as viewed in the direction of travel; FIG. 4 is a side view showing an outline of the main part of the conveying device as viewed in the width direction; FIG. 5 is a block diagram showing a schematic configuration of a control unit; FIG. 6 is a block diagram showing a schematic configuration of an example of a magnetic pole position detection unit; FIG. 7 is a block diagram showing a schematic configuration of an example of a vector control controller; FIG. 8 is a block diagram showing a schematic configuration of an example of a coil excitation unit; FIG. 9 is a schematic view showing the relative position of a field magnet part and an armature part along the coil width direction as viewed in the direction of movement, showing a state in which their center lines overlap; FIG. 10 is a schematic view showing the relative position of a field magnet part and an armature part along the coil width direction as viewed in the direction of movement, showing a state in which the center line of the field magnet part is shifted to the right; FIG. 11 is a schematic view showing the relative position of a field magnet part and an armature part along the coil width direction as viewed in the direction of movement, showing a state in which the center line of the field magnet part is shifted to the left; 1 is a plan view schematically showing a track portion and a field portion, showing a state in which the center line of the field portion is inclined to the right with respect to the center line of the armature portion. FIG. 2 is a plan view showing the main parts of a conveying device according to a second embodiment. FIG. 3 is a plan view showing the basic configuration of a track portion according to the second embodiment. FIG. 4 is a plan view showing the main parts of a running portion according to the second embodiment. FIG. 5 is a plan view showing an example of a state in which the running portion is misaligned with respect to the track portion. FIG. 6 is a plan view showing another example of a state in which the running portion is misaligned with respect to the track portion. FIG. 7 is a plan view showing the main parts of a conveying device according to a third embodiment. FIG. 8 is a plan view showing the main parts of a running portion according to the third embodiment. FIG. 9 is a plan view showing an example of a state in which the running portion is misaligned with respect to the track portion.

[0020] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, "similar" refers to shapes, sizes, and functions that are identical or can be considered identical. For simplification (to avoid complexity), some similar components are omitted from the drawings. [First Embodiment] In the first embodiment, a conveying device (conveying system) 10 will be described as an example of an electromagnetic device according to the present disclosure. FIG. 1 shows a perspective view of the main components of the conveying device 10 according to the first embodiment, viewed obliquely from above. FIG. 2 shows a plan view of the main components of the conveying device 10 viewed from above. FIG. 3A shows a front view of the main components of the conveying device 10 viewed from one side along the direction of travel. FIG. 3B shows a side view of the main components of the conveying device 10 viewed from one side in the width direction.

[0021] 1 to 3, the conveying device 10 includes a track section 12, a traveling section 14 as a moving body, and a control section 50 (described below) that controls the traveling of the traveling section 14, and the conveying device 10 is configured as a two-dimensional linear motor. In the conveying device 10, the operation of the track section 12 is controlled by the control section 50, so that the traveling section 14 moves (proceeds) along the track formed by the track section 12. In the conveying device 10, an object to be conveyed (not shown) or the like is placed on the traveling section 14, and the object can be conveyed.

[0022] In the drawings, one side of the movement direction of the running unit 14 is indicated by an arrow Y, and one side of the device width direction, which is a direction intersecting the traveling direction, is indicated by an arrow X. The running unit 14 is movable in the direction of the arrow Y and in the direction opposite to the direction of the arrow Y, and the movement direction of the running unit 14 is the traveling direction of the running unit 14.

[0023] The raceway 12 includes a base 20, an armature section 22, and a raceway plate 24 that constitutes a support section. The base 20 and the raceway plate 24 are each strip-shaped with a required width, and in the raceway 12, the base 20 and the raceway plate 24 face each other vertically. In addition, a pair of support legs 26 with a rectangular cross section are attached to both ends of the base 20 in the width direction of the raceway 12, and the support legs 26 extend in the longitudinal direction of the base 20. In the raceway 12, the armature section 22 is disposed between the pair of support legs 26.

[0024] The track plate 24 is made of a non-magnetic and non-conductive material, and is formed as a thin plate capable of supporting the running section 14. The track plate 24 is divided into left and right halves of a required width at the middle of the width of the track section 12, and the divided track plates 24 are attached to the support legs 26 separately on the left and right. As a result, an opening of a required width formed between the pair of track plates 24 in the track section 12 extends along the base 20.

[0025] Although the conveying device 10 uses a track plate 24 that is divided into two parts, the track plate 24 may be made of a transparent acrylic plate or the like that is optically transparent. In this case, instead of dividing it into two parts, a single plate may be used as the track plate and placed across a pair of support legs 26.

[0026] A strip-shaped armature base 28 is disposed between the support legs 26 on the track portion 12, and extends along the longitudinal direction of the base 20. The armature base 28 has the armature portion 22 disposed on its upper surface.

[0027] The armature section 22 uses coil blocks 30 in the shape of a substantially rectangular block, and the armature section 22 has a plurality of coil blocks 30 arranged on an armature base 28 and aligned along the longitudinal direction (thrust generation direction) of the base 20. By arranging each of the coil blocks 30 on the armature base 28, both widthwise ends of each of the coil blocks 30 are located close to the lower surfaces of the track plates 24, and the widthwise intermediate portion is open upward from between the pair of track plates 24.

[0028] In the conveyance device 10, three-phase AC power is used as the power for running the traveling section 14. In the armature section 22, the coil block 30 is formed by three-phase coils (coil units) 32 (U-phase coil 32U, V-phase coil 32V, and W-phase coil 32W) serving as an armature. The coils 32 (32U, 32V, 32W) are air-core coils made of, for example, Litz wire.

[0029] The coil 32 has a generally rectangular block shape (it may also be generally oval or circular) when viewed from above, and has a required dimension Wc (width dimension) along the width direction of the base 20. In the coil block 30, the coils 32U, 32V, and 32W are arranged in this order along the longitudinal direction of the track portion 12. In the drawings, the center line Cc of the coil block 30 (coil 32) in the width direction is indicated by a dashed line.

[0030] The traveling section 14 includes a frame 34 serving as a moving body having a generally rectangular shape when viewed from above, and a field magnet section 36. The frame 34 is formed by a rectangular, flat bottom plate 34A and a generally rectangular frame body (outer frame) 34B erected from the peripheral edge of the bottom plate 34A, and the field magnet section 36 is disposed on the underside of the bottom plate 34A of the frame 34.

[0031] Furthermore, a plurality of casters 38 that form support parts are attached to the outer surface of the frame body 34B of the underframe 34, and the casters 38 are arranged so as to surround the field magnet part 36 (at the four outer corners of the field magnet part 36). The casters 38 are ball casters in which balls 38A are attached so as to be freely rotatable.

[0032] In the running section 14, the casters 38 of the underframe 34 correspond to each of the track plates 24, and the underframe 34 is disposed across the track plates 24 arranged in pairs on the track section 12, so that the balls 38A of the casters 38 come into contact with each of the track plates 24. As a result, in the running section 14, the upper surfaces of the track plates 24 form the track surfaces, and the underframe 34 is supported movably on the upper surfaces of the track plates 24 while straddling the pair of track plates 24, and the underframe 34 functions as a vehicle that moves on the track plates 24.

[0033] The field magnet section 36 uses a plurality of permanent magnets 40, each of which is substantially rectangular, and each permanent magnet 40 has a substantially rectangular cross section along a direction intersecting the longitudinal direction. The length Lm of each permanent magnet 40 along the longitudinal direction, which corresponds to the width direction of the coil 32, is the same as the width Wc of the coil 32 (Lm≈Wc). The longitudinal direction of each permanent magnet 40 corresponds to the width direction of the track section 12, and multiple permanent magnets 40 are arranged along the track direction of the traveling section 14 (the arrangement direction of the coil blocks 30 on the track section 12).

[0034] The field magnet section 36 forms a field magnet corresponding to one electrical angle cycle or multiple electrical angle cycles by arranging multiple permanent magnets 40. The field magnet section 36 may have a configuration in which north and south poles are alternately arranged downward (toward the raceway section 12) (SN array field magnet). It is also preferable that the field magnet section 36 has a Halbach array field magnet formed by a Halbach magnet arrangement. The magnetization direction of each permanent magnet 40 is from the south pole to the north pole within the permanent magnet 40, and the magnetization direction is indicated by an arrow within the permanent magnet 40 in FIG. 3B .

[0035] In the Halbach array field, the permanent magnets 40 are arranged in order, with the magnetization direction changed by an angle θm, which is obtained by dividing one electrical angle cycle by the division number m, where m is any one of integers (positive numbers) equal to or greater than three. As a result, in the Halbach array field, a stronger magnetic field is formed on one side of the direction intersecting the arrangement direction of the permanent magnets 40 than on the other side. Furthermore, in the Halbach array field, the magnetic flux density along the arrangement direction of the permanent magnets 40 (the movement direction of the traveling part 14) can be made sinusoidal, thereby suppressing torque ripple and thereby suppressing the occurrence of speed fluctuations, etc.

[0036] Furthermore, the number of divisions m of the Halbach array field magnet may be an integer equal to or greater than 3, and may be an integer obtained by adding 2 to a multiple of 3. This makes it possible to more effectively suppress harmonic components from being included in the change in magnetic flux density along the arrangement direction of the permanent magnets 40 in the Halbach array field magnet, thereby more effectively suppressing torque ripple.

[0037] A Halbach array field magnet in which the number of divisions m is 8 (m = 8 = 3 × 2 + 2) and the angle θm is 45° (θm = 45° = π / 4) is applied to the field magnet section 36 of the conveyance device 10. Eight permanent magnets 40 (40A to 40H) are arranged in the field magnet section 36 so as to generate a strong magnetic field on the lower side (the track section 12 side).

[0038] In the field magnet section 36, one magnet block 46 is formed by permanent magnets 40 (40A to 40H) corresponding to one electrical cycle, and the width dimension of the magnet block 46 is equal to the length dimension Lm of the permanent magnets 40. In the field magnet section 36, two magnet blocks 46 are formed by using 16 permanent magnets 40 (two permanent magnets 40A to 40H each), which corresponds to two electrical cycles. Note that the field magnet section 36 is not limited to covering two electrical cycles, and may also cover one electrical cycle, or three or more electrical cycles.

[0039] In the field magnet section 36 to which the Halbach array field magnet is applied, the permanent magnets 40 at both ends in the moving direction may have the same magnetization direction and a width dimension along the array direction that is half the width dimension of the other permanent magnets 40. As a result, in Figure 3A, the center line Cm of the field magnet section 36 and the center line of the traveling section 14 coincide with each other, making it easy to confirm the initial position of the magnetic poles.

[0040] Meanwhile, in the armature section 22 of the track section 12, a plurality of Hall sensors 42 constituting a magnetic pole position detection section and a plurality of optical sensors 44 constituting a moving body detection section are arranged in each of the coil blocks 30. The Hall sensors 42 may be Hall elements, and detect the strength of a magnetic field (magnetic flux density) by the Hall effect and output a signal (voltage signal) according to the detected magnetic flux density.

[0041] The Hall sensors 42 are provided for one set (corresponding to one electrical cycle) of coil blocks 30 at intervals of one electrical cycle or one-third of two electrical cycles (at intervals of 120° or 240° electrical degrees), i.e., at intervals that match the arrangement pitch of the coils 32. For this reason, one coil block 30 is provided with Hall sensors 42U, 42V, and 42W that correspond to the coils 32U, 32V, and 32W, respectively.

[0042] Hall sensors 42U, 42V, and 42W are disposed on the track portion 12 at the widthwise intermediate portion (near the center line Cc) and the travelwise intermediate portion of each of the coils 32U, 32V, and 32W. The Hall sensors 42 may be disposed at a required interval (every 120° or 240° electrical angle) corresponding to the coils 32U, 32V, and 32W. For example, on the track portion 12, the Hall sensor 42U may be disposed between the coil 32U and the coil 32W of another coil block 30 adjacent to the coil 32U, the Hall sensor 42V may be disposed between the coils 32V and 32U, and the Hall sensor 42W may be disposed between the coils 32W and 32V. The Hall sensors 42 may be disposed not only at the widthwise intermediate portion of the coils 32U but also at the widthwise end portions of the coils 32U and 32W, facing the permanent magnets 40 across the track plate 24.

[0043] The optical sensors 44 include a light-emitting portion and a light-receiving portion (both not shown). The optical sensors 44 are arranged at the same pitch as the coils 32, and detect the underframe 34 by using the light-receiving portion to detect light emitted from the light-emitting portion and reflected by the running section 14 (underframe 34). The armature section 22 uses optical sensors 44U, 44V, and 44W corresponding to the Hall sensors 42U, 42V, and 42W, respectively, and the optical sensors 44U, 44V, and 44W are arranged adjacent to the Hall sensors 42U, 42V, and 42W, respectively. This allows each of the optical sensors 44 to face the underframe 34 via an opening between a pair of track plates 24.

[0044] The position of the optical sensor 44 is not limited to the center of each coil 32. The optical sensor 44 only needs to be able to detect whether the underframe 34 faces at least each coil block 30. For example, one optical sensor 44 may be disposed for each coil block 30, or may be disposed between two coil blocks 30 adjacent to each other in the direction of movement of the traveling unit 14.

[0045] The conveyance device 10 is provided with a control unit 50, which controls the excitation of each coil 32 (32U, 32V, 32W) for each coil block 30 of the track unit 12, thereby controlling the travel of the traveling unit 14. Figure 4 is a block diagram showing a schematic configuration of the main parts of the control unit 50. Note that the control unit 50 functions in the same way for each coil block 30, and the following description will mainly focus on the operation for one coil block 30, for the sake of simplicity.

[0046] 4, the control unit 50 includes a travel controller 52 and a coil excitation unit 54, and the travel controller 52 includes a magnetic pole position calculation unit 56 and a vector control controller 58. The control unit 50 also includes current sensors 48 for detecting the current (excitation current) that flows when each coil 32 (32U, 32V, 32W) is excited. The current sensors 48 include a current sensor 48U disposed between the coil excitation unit 54 and the U-phase coil 32U, a current sensor 48V disposed between the coil excitation unit 54 and the V-phase coil 32V, and a current sensor 48W disposed between the coil excitation unit 54 and the W-phase coil 32W.

[0047] The travel controller 52 includes a microcomputer (not shown) in which a CPU, ROM, RAM, non-volatile storage, etc. are connected via a bus. In the travel controller 52, the CPU reads out the magnetic pole position calculation program and the vector control program stored in the ROM or storage, and executes them while expanding them into the RAM, thereby realizing the functions of the magnetic pole position calculation unit 56 and the vector control controller 58.

[0048] The magnetic pole position calculation unit 56 is connected to each of the Hall sensors 42 (42U, 42V, 42W) and optical sensors 44 (44U, 44V, 44W) that are arranged on each of the coil blocks 30 in the track portion 12. Note that in Fig. 4, for the sake of simplicity, the Hall sensors 42U, 42V, 42W and the optical sensors 44U, 44V, 44W are shown as being connected together, but the Hall sensors 42U, 42V, 42W and the optical sensors 44U, 44V, 44W are each individually connected to the magnetic pole position calculation unit 56 and the like.

[0049] The coil excitation unit 54 is connected to each of the optical sensors 44 (44U, 44V, 44W) and to a three-phase AC power supply 60. Also connected to the coil excitation unit 54 are the coils 32 (32U, 32V, 32V) of the coil blocks 30 arranged on the track portion 12.

[0050] The magnetic pole position calculation unit 56 detects the coil block 30 facing the field magnet portion 36 and the coil block 30 that is influenced by the magnetic force of the field magnet portion 36 based on the detection signals of the Hall sensors 42 (42U, 42V, 42W) and the optical sensors 44 (44U, 44V, 44W) of the coil blocks 30. Note that a coil block 30 that is influenced by the magnetic force of the field magnet portion 36 is a coil block 30 in which at least one of the coils 32U, 32V, 32W generates an electromotive force due to the magnetic force of the field magnet portion 36. In other words, a coil block 30 that is influenced by the magnetic force of the field magnet portion 36 is a coil block 30 in which a magnetic force is detected by one of the corresponding Hall sensors 42 (42U, 42V, 42W).

[0051] In addition, the magnetic pole position calculation unit 56 calculates the electrical angle θ indicating the position (relative position) of the magnetic pole (e.g., the N-pole permanent magnet 40A) of the field magnet unit 36 ​​relative to the coil block 30 based on the detection signals of each of the Hall sensors 42, and outputs the calculated electrical angle θ to the vector control controller 58.

[0052] The vector controller 58 controls the electric angle θ and the excitation current (current value) i of each phase detected by the current sensors 48 (48U, 48V, 48W). ｕ , i ｖ , iｗ Based on the above, a voltage command value (U-phase voltage command value v Ｕ ＊ , V-phase voltage command value v Ｖ ＊ , and the W-phase voltage command value v Ｗ ＊ ) and outputs it to the coil excitation unit 54.

[0053] The coil excitation unit 54 uses three-phase power supplied from a power supply 60 to generate a voltage command value v ｕ ＊ , v ｖ ＊ , v ｗ ＊ At this time, the coil excitation unit 54 controls the inverter based on the voltage command value v ｕ ＊ , v ｖ ＊ , v ｗ ＊ The coils 32 (32U, 32V, 32W) of the coil block 30 are excited to allow the frame 34 of the traveling section 14 to move relative to the coils 32 (32U, 32V, 32W), respectively.

[0054] Here, the operation of the control unit 50 in the conveying device 10 will be described with reference to the drawings. Fig. 5 shows a block diagram of the main components of the magnetic pole position calculation unit 56, Fig. 6 shows a block diagram of the main components of the vector control controller 58, and Fig. 7 shows a block diagram of the main components of the coil excitation unit 54.

[0055] 5, the magnetic pole position calculation unit 56 includes a plurality of output selectors 100, a plurality of output adjusters 102, a plurality of output calculators 104, and an electrical angle calculator 106. An output selector 100 corresponds to each of the optical sensors 44 aligned in the traveling direction (direction of arrow Y) of the underframe 34, and each output selector 100 is connected to the corresponding optical sensor 44 and the optical sensors 44 adjacent to the corresponding optical sensor 44 on the traveling direction side and on the opposite side to the traveling direction.

[0056] For example, the output selector 100 corresponding to the optical sensor 44V is connected to the optical sensors 44U and 44W as well as the optical sensor 44V. The output selector 100 corresponding to the optical sensor 44W is connected to the optical sensor 44U of the adjacent coil block 30 as well as the optical sensors 44V and 44W.

[0057] An output adjuster 102 is arranged corresponding to each output selector 100, and the output selector 100 outputs to the corresponding output adjuster 102 whether or not each (all) of the connected optical sensors 44 has detected the underframe 34. For example, when each of the optical sensors 44U, 44V, and 44W detects the underframe 34, the output selector 100 corresponding to the optical sensor 44V outputs a detection signal indicating that the underframe 34 has been detected (the underframe 34 is facing the coil block 30) to the output adjuster 102.

[0058] The output adjuster 102 is connected to the Hall sensors 42 (42U, 42V, 42W) corresponding to the output selector 100. When a detection signal of the underframe 34 is input from the output selector 100, the output adjuster 102 outputs a signal (voltage) corresponding to the output signal of the Hall sensor 42. The Hall sensor 42 outputs a signal (e.g., voltage) that is proportional to the magnetic flux density due to a reference magnetic pole (north pole, south pole) and varies between a negative maximum value and a positive maximum value. When outputting a voltage proportional to the output signal of the Hall sensor 42, the output adjuster 102 outputs 0 V if the output signal of the Hall sensor 42 indicates zero.

[0059] An output calculator 104 is provided for each phase (U-phase output calculator 104U, V-phase output calculator 104V, and W-phase output calculator 104W), and the output calculators 104U, 104V, and 104W for each phase are connected to a plurality of output adjusters 102 of the same phase. Each of the output calculators 104U, 104V, and 104W is also connected to an electrical angle calculator 106.

[0060] Each of the output calculators 104 (104U, 104V, 104W) outputs a voltage corresponding to the sum of the outputs of the output regulators 102 for each phase to the electrical angle calculator 106. That is, the output regulator 102U outputs a U-phase voltage Vha, the output regulator 102V outputs a V-phase voltage Vhb, and the output regulator 102W outputs a W-phase voltage Vhc.

[0061] The electrical angle calculator 106 calculates the electrical angle θ based on the voltages Vha, Vhb, and Vhc input from the output calculators 104U, 104V, and 104W, and outputs the electrical angle θ (an electrical angle signal indicating the electrical angle θ) to the vector control controller 58.

[0062] 6, the vector control controller 58 includes a speed target value generator 110, a speed controller 112, a current controller 114, a voltage converter 116, a current converter 118, and an integrating electrical angle differentiator 120. The vector control controller 58 also includes a d-axis current setter 122 as a setting unit. In the vector control controller 58, the d-axis current setter 122 sets a d-axis current target value i d_ref Set.

[0063] The integrated electrical angle differentiator 120 calculates the electrical angular velocity ω from the integrated electrical angle obtained by integrating the electrical angle θ input from the magnetic pole position calculation unit 56 (electrical angle calculator 106). es The speed target value generator 110 calculates a target value ω of the speed (travel speed) of the underframe 34, which is the object of travel control. ref The speed controller 112 generates an electrical angular speed ω es and the target speed ω ref Using the electrical angular velocity ω es The target value ω ref The q-axis current target value i q_ref Generate.

[0064] The current converter 118 is also connected to the current sensors 48U, 48V, and 48W, and receives the electrical angle θ output from the magnetic pole position calculation unit 56. The current converter 52 converts the excitation currents (current values) iu, iv, and iw of the U, V, and W phases input from the current sensors 48 based on the electrical angle θ, and outputs a d-axis current (current value) id and a q-axis current (current value) iq.

[0065] The current controller 114 calculates the q-axis current target value i q_ref , d-axis current target value i d_ref , the d-axis current id and the q-axis current iq are respectively set to the d-axis current target value i d_ref and the q-axis current target value i q_ref The d-axis voltage command value v ｄ ＊ and the q-axis voltage command value v ｑ ＊ Calculates and outputs.

[0066] The voltage converter 116 receives the electrical angle θ and the d-axis voltage command value v ｄ ＊ , and the q-axis voltage command value v ｑ ＊ The voltage converter 116 converts the voltage based on the electrical angle θ to obtain the d-axis voltage command value v ｄ ＊ and the q-axis voltage command value v ｑ ＊ is the voltage command value of each phase (the voltage command value v ｕ ＊ , V-phase voltage command value v ｖ ＊ and the W-phase voltage command value v ｗ ＊ ) and output to the coil excitation unit 54.

[0067] 7, the coil excitation unit 54 includes a plurality of excitation selectors 130 and a plurality of excitation devices 132, and the excitation selectors 130 and excitation devices 132 are provided for each coil 32 (32U, 32V, 32W) of the coil block 30. The excitation selectors 130 are connected to optical sensors 44 corresponding to the coils 32. For example, the excitation selector 130 is connected to an optical sensor 44U corresponding to the coil 32U, and an optical sensor 44V (or optical sensors 44V, 44W) adjacent to the optical sensor 44U in the traveling direction.

[0068] When at least one of the optical sensors 44 connected to the excitation selector 130 detects the frame 34, the excitation selector 130 outputs a detection signal to the corresponding excitation device 132 indicating that the frame 34 has been detected.

[0069] When a detection signal is input from the corresponding excitation selector 130, the excitation device 132 (132U, 132V, 132W) outputs the voltage command value v Ｕ ＊ , v Ｖ ＊ , v Ｗ ＊ The driving voltage (excitation voltage) V ｕ , V ｖ , V ｗ to the coils 32U, 32V, and 32W. As a result, in the transport device 10, in the coil block 30 that is affected by the magnetic force of the field magnet portion 36 of the underframe 34, the coils 32U, 32V, and 32W of each phase are excited, and the underframe 34 rotates at the target value ω ref It moves at a speed depending on the

[0070] When a signal indicating that the underframe 34 is no longer being detected (the underframe 34 that was previously detected is no longer being detected) is input from the excitation selector 130 to the excitation device 132, the excitation device 132 stops exciting the coils 32 of the corresponding phase. This allows the control unit 50 to excite only the coils 32 in the vicinity of the underframe 34, thereby reducing the power consumption required to excite the coils 32.

[0071] In the conveyance device 10 configured in this manner, the coil block 30 formed by arranging three-phase coils 32U, 32V, and 32W in one direction in the armature section 22 is further arranged in one direction. Furthermore, in the traveling section 14, permanent magnets 40 are arranged to form a field section 36. Therefore, by opposing the armature section 22 and the field section 36 so that the arrangement directions of the coils 32 and the permanent magnets 40 overlap, a propulsive force is generated in the frame 34 in the direction along the arrangement direction of the coils 32.

[0072] Furthermore, the electrical angle θ, which is information indicating the position of the N pole of the field magnet portion 36 relative to the coil block 30, is expressed as θ=(π / τ)·dm, where dm is the movement distance of the N pole and τ is the pole pitch. Therefore, by arranging the Hall sensors 42 at predetermined intervals, the electrical angle θ can be obtained from the output of the Hall sensors 42.

[0073] The vector control controller 58 obtains the d-axis current id and the q-axis current iq from the electrical angle θ calculated from the detection signals of the Hall sensors 42 (42U, 42V, 42W) and the excitation currents iu, iv, and iw of the respective phases, and the d-axis current id and the q-axis current iq are respectively set to the d-axis current target value i d_ref and the q-axis current target value i q_ref The d-axis voltage command value v ｄ ＊ and the q-axis voltage command value v ｑ ＊ and outputs the drive voltages Vu, Vv, and Vw for exciting the coils 32 of the respective phases.

[0074] In the transport device 10, the coils 32U, 32V, and 32W are excited by the drive voltages Vu, Vv, and Vw, causing the coils 32U, 32V, and 32W to generate a moving magnetic field, which applies a driving force to the field magnet portion 36, thereby moving the frame 34. At this time, in the transport device 10, the speed target value generator 110 generates a speed target value ω ref is set, and this target value ω ref to the q-axis current target value i q_ref is set, the underframe 34 reaches the target value ω ref It moves at a speed depending on the

[0075] On the other hand, in the control unit 50, a d-axis current setting unit 122 is arranged in the vector control controller 58, and the d-axis current target value i d_ref , and the q-axis current target value i q_ref The d-axis voltage command value v ｄ * , and the q-axis voltage command value v q * is set.

[0076] In vector control, the q-axis current target value i q_ref contributes to the thrust force on the underframe 34, and the d-axis current target value i d_ref influences the electromagnetic force between the coil block 30 (coils 32U, 32V, 32W) and the magnet block 46 (permanent magnets 40 (40A to 40H)).

[0077] 8A to 8C schematically show the coil block 30 (coil 32) of the armature section 22 and the magnet block 46 (permanent magnet 40) of the field section 36 as viewed from the direction of movement. Note that Fig. 8A shows a state in which the center line Cc of the coil block 30 and the center line Cm of the magnet block 46 overlap, Fig. 8B shows a state in which the center line Cm of the magnet block 46 is shifted to the right with respect to the center line Cc of the coil block 30, and Fig. 8C shows a state in which the center line Cm of the magnet block 46 is shifted to the left with respect to the center line Cc of the coil block 30.

[0078] In vector control, the q-axis current target value i q_ref When the value of i is negative, a driving force is generated to move the underframe 34 in one direction, and the q-axis current target value i q_ref When the q-axis current target value i q_ref The propulsive force increases as the value (absolute value) of increases.

[0079] In vector control, the d-axis current target value i d_ref affects the electromagnetic force (attraction and repulsion) generated between the coil block 30 (coil 32) and the magnet block 46 (permanent magnet 40), and the d-axis current target value i d_refis set to a negative value, a repulsive force is generated between the coil block 30 and the magnet block 46. In addition, the d-axis current target value i d_ref As the negative value of θ becomes larger, the repulsive force acting as an electromagnetic force generated between the coil block 30 and the magnet block 46 also becomes larger.

[0080] As a result, the d-axis current target value i d_ref is set to a negative value, the magnet block 46 can be levitated relative to the coil block 30. In the conveyance device 10, casters 38 are arranged on the frame 34, and the frame 34 is supported on the track plate 24 via the casters 38 so that it can be moved.

[0081] In response to this, the control unit 50 calculates the d-axis current target value i ｄ_ref is set to a positive value (a value greater than zero). As a result, as shown in Figures 8A to 8C, in the transport device 10, an electromagnetic force (attraction force) Fe is generated between the coil block 30 (coil 32) and the magnet block 46 (permanent magnet 40) as an attraction force that attracts the magnet block 46 to the coil block 30. Furthermore, in the transport device 10, a Halbach magnet arrangement is applied to the field magnet section 36, and in the transport device 10, a larger electromagnetic force Fe can be obtained compared to when an SN arrangement is applied to the field magnet.

[0082] As shown in FIG. 8A, at this time, the center line Cc of the coil block 30 and the center line Cm of the magnet block 46 overlap with each other, so that the electromagnetic force Fe acts on the magnet block 46 in a direction perpendicular to the magnet block 46 .

[0083] Furthermore, since the width dimension Wc of the coil 32 and the length dimension Lm of the permanent magnet 40, which are dimensions along the width direction of the track portion 12, are similar (substantially the same), the widthwise end of the magnet block 46 overlaps with the end of the coil block 30. Therefore, the right end of the magnet block 46 is subjected to a force F directed toward the center line Cm. ＣＲ acts, and force F ＣＲ The force F is directed in the opposite direction to the center line Cm at the left end. ＣＬ At this time, since the center line Cc and the center line Cm overlap, the force F ＣＬ and force F ＣＲ and are almost equal (F ＣＬ =FＣＲ ) Therefore, the frame 34 is moved while the coil block 30 and the magnet block 46 are held in a state in which their center lines Cc and Cm overlap each other.

[0084] On the other hand, as shown in FIG. 8B , when the underframe 34 is shifted to the right of the track portion 12 and the center line Cm is shifted to the right with respect to the center line Cc, the direction of the electromagnetic force Fe is tilted to the left. ＣＲ is the force F on the left ＣＬ becomes larger than (F ＣＬ <F ＣＲ Therefore, the magnet block 46 is subjected to a force F ＣＬ and force F ＣＲ A moving force Fm toward the left is generated with a strength corresponding to the difference between the center line Cm and the center line Cc. As a result, the magnet block 46 is moved leftward relative to the coil block 30, and the center line Cm is smoothly superimposed on the center line Cc.

[0085] 8C, when the frame 34 is shifted to the left of the track portion 12 and the center line Cm is shifted to the left with respect to the center line Cc, the direction of the electromagnetic force Fe is tilted to the left. ＣＬ is the force F on the right ＣＲ becomes larger than (F ＣＬ >F ＣＲ ) As a result, a moving force Fm toward the right is generated in the magnet block 46, and the magnet block 46 is moved to the right relative to the coil block 30, so that the center line Cm smoothly overlaps the center line Cc.

[0086] 9A shows a state in which the underframe 34 is shifted to the right with respect to the center line Cc. The underframe 34 has magnet blocks 46 arranged at the front and rear of the underframe 34 in the direction of movement. Therefore, a moving force Fm is generated in the front and rear of the underframe 34 in the direction of movement. As a result, the underframe 34 is efficiently moved so that the center line Cm overlaps the center line Cc.

[0087] 9B also shows a state in which the center line Cm of the underframe 34 is tilted to the right with respect to the center line Cc (a state in which a yaw angle is generated) due to, for example, rotation of the underframe 34. In this case, a moving force Fm toward the left is generated on the front side (the direction of travel) of the underframe 34, and a moving force Fm toward the right is generated on the rear side (the opposite side to the direction of travel). As a result, the underframe 34 is efficiently moved so that the center line Cm and the center line Cc overlap, and the tilt is corrected.

[0088] In this way, in the conveyance device 10, the underframe 34 is moved while the center line Cc of the coil blocks 30 of the track portion 12 and the center line Cm of the magnet blocks 46 of the underframe 34 are kept overlapping, thereby preventing loss of synchronization in the underframe 34 in the conveyance device 10. Therefore, in the conveyance device 10, the underframe 34 can be made to run (move) efficiently while preventing loss of synchronization and the like without providing a guide means such as a guide rail.

[0089] Furthermore, in the conveying device 10, since a guide means for the frame 34 such as a guide rail is not required, the configuration of the track section 12 can be simplified.

[0090] In the first embodiment, the underframe 34 is detected by the optical sensor 44. However, a Hall sensor 42 may be used as the moving body detection unit that detects the underframe 34. The Hall sensor 42 detects the magnetic flux density by the permanent magnet 40 of the field magnet unit 36 ​​arranged on the underframe 34, and by detecting the magnetic flux density using the Hall sensor 42, it is possible to detect whether the underframe 34 faces the corresponding coil block 30 (or coil 32), whether the underframe 34 is close to the corresponding coil block 30 (or coil 32), or whether the underframe 34 is far away.

[0091] When the Hall sensors 42 are used as the moving body detectors, the magnetic pole position calculator 56 may connect the Hall sensors 42 to each of the output selectors 100, and the output selectors 100 may detect the frame 34 from the magnetic flux density detected by each of the Hall sensors 42. Furthermore, the coil excitation unit 54 may connect the Hall sensors 42 to each of the excitation selectors 130, and the excitation selectors 130 may detect the frame 34 from the magnetic flux density detected by each of the Hall sensors 42. Furthermore, when the Hall sensors 42 are used, the track plate 24 does not need to be divided, and the structure of the track surface formed by the track plate 24 can be simplified.

[0092] In the first embodiment, the casters 38 that move freely on the track plate 24 are used as the support members. However, various configurations can be applied to the support members as long as they are configured to support the movable body movably on the track portion. For example, the support members may be configured with a bottom plate provided on the movable body side and an upper plate on the track portion with which the bottom plate slides. In this case, the bottom plate and the upper plate may each be made of a non-magnetic and non-conductive material and have low friction between them.

[0093] In the first embodiment, the track portion 12 has been described as having track plates 24 extending in one direction. However, the track portion may include an arc-shaped curved portion (a so-called curve). In this case, the track portion may have a plurality of coil blocks arranged along the curve (arc) of the curved portion. Furthermore, each of the plurality of coil blocks may be arranged so that its center line Cc is tangent to the center line of the curve at its arrangement position. This allows the moving body to move smoothly even in the curved portion without losing synchronization.

[0094] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Figures 10 to 13. Note that in the second embodiment, the same components and configurations as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and descriptions thereof will be omitted.

[0095] Fig. 10 shows a plan view of the main parts of a conveying device 70 as an electromagnetic device according to the second embodiment. As shown in Fig. 10, the conveying device 70 includes a track section 72 and a running section 74. Fig. 11A shows a plan view of the coil block 30 that constitutes the track section 72, and Fig. 11B shows a plan view of the main parts of the running section 74.

[0096] 10, the raceway portion 72 includes an armature portion 76 and a raceway plate 78. The armature portion 76 and the raceway plate 78 are applied to the second embodiment in place of the armature portion 22 and the raceway plate 24 of the first embodiment, respectively.

[0097] The raceway plate 78 is made of a non-magnetic and non-conductive material, such as a metal material such as a stainless steel plate or a resin material such as a plastic plate. The raceway plate 78 is a thin, generally rectangular plate capable of supporting the running portion 74, and forms a raceway surface that covers the armature portion 76. A transparent material can also be used for the raceway plate 78, and a transparent acrylic plate is used for the raceway plate 78.

[0098] The armature section 76 is provided with coil blocks 30. As shown in Fig. 11A, the coil blocks 30 are formed as a set of a coil block 30A in which coils 32U, 32V, and 32W are arranged in one direction, and a coil block 30B in which coils 32U, 32V, and 32W are arranged in a direction intersecting the one direction.

[0099] Hall sensors 42 (42U, 42V, 42W) are disposed on one widthwise end of the coil 32 in the coil blocks 30A, 30B. In the armature section 76, the coil blocks 30A and 30B are alternately arranged in one direction (arrow Y direction) and a direction intersecting the one direction (arrow X direction). As a result, in the armature section 76, the coil blocks 30A, 30B are arranged in a checkerboard pattern, and the center lines Cc of the coil blocks 30 (30A, 30B) form a grid pattern. In the conveying device 70, a transparent acrylic plate is used for the track plate 78, and the underframe 80 (described below) is detected by the optical sensor 44; however, the optical sensor 44 is omitted in the following description.

[0100] 11B, the running section 74 uses an underframe 80, and a field magnet section 82 is disposed on the underframe 80. The underframe 80 and the field magnet section 82 are applied to the second embodiment in place of the underframe 34 and the field magnet section 36 of the first embodiment.

[0101] The underframe 80 includes a frame body 84, and casters 38 (not shown in the second embodiment) are attached to required positions of the frame body 84. As a result, when the underframe 80 is placed on the track plate 78, the running unit 74 can freely move on the upper surface (track surface) of the track plate 78 via the casters 38.

[0102] The field magnet section 82 is disposed on the bottom surface of the frame body 84, and includes a plurality of magnet blocks 46. The magnet blocks 46 include a magnet block 46A in which the arrangement direction of the permanent magnets 40 is a first direction, and a magnet block 46B in which the arrangement direction of the permanent magnets 40 is a second direction that intersects with the first direction. In the field magnet section 82, one of the magnet blocks 46A, 46B is defined as the first magnet block, and the other as the second magnet block.

[0103] In the field magnet portion 82, the magnet blocks 46A and 46B are adjacent to each other in the first and second directions, and the magnet blocks 46A and 46B are adjacent to each other diagonally. In the magnet blocks 46A and 46B, the length Lm of each permanent magnet 40 is twice the width Wc of the coil 32.

[0104] 10, the magnet blocks 46A and 46B are each sized (area) to correspond to two coil blocks 30A and 30B. The magnet block 46A is configured so that both ends of the permanent magnet 40 in the length direction (direction of the length dimension Lm) can face both ends of the coil 32 in the width direction in the coil block 30A. The magnet block 46B is configured so that both ends of the permanent magnet 40 in the length direction can face one end of the coil 32 in the width direction in the coil block 30B.

[0105] The control unit 50 of the transport device 70 is capable of exciting the coils 32 of the coil blocks 30A and 30B for which the underframe 80 has been detected. At this time, the control unit 50 excites the coils 32 of the coil block 30A or the coil block 30B depending on the movement direction of the underframe 80. This allows the underframe 80 to move in both the direction indicated by the arrow Y and the direction indicated by the arrow X.

[0106] When the control unit 50 moves the underframe 80 in the direction of the arrow Y, it excites each of the coils 32 (32U, 32V, 32W) of the coil block 30A. As a result, a propulsive force is generated in each of the diagonally arranged magnet blocks 46A in the traveling unit 74. Furthermore, when the control unit 50 moves the underframe 80 in the direction of the arrow X, it excites each of the coils 32 (32U, 32V, 32W) of the coil block 30B. As a result, a propulsive force is generated in each of the diagonally arranged magnet blocks 46B in the traveling unit 74.

[0107] In this way, the magnet blocks 46A and the magnet blocks 46B are arranged diagonally relative to each other on the underframe 80. Therefore, in the underframe 80, similar thrust forces (similar in direction and magnitude) are generated in the magnet blocks 46A, causing them to move in the direction of arrow Y, and similar thrust forces are generated in the magnet blocks 46B, causing them to move in the direction of arrow X. As a result, the underframe 34 moves so that the center lines Cd are formed in a lattice pattern on the track portion 72 and follow any of the center lines Cc.

[0108] Here, the control unit 50 calculates the q-axis current target value i q_ref is set, and the d-axis current target value i d_ref is set to a positive value. Therefore, in the underframe 80, a force F , which directs the end of the permanent magnet 40 toward the center line Cc of the coil 32, is generated between the longitudinal end of the permanent magnet 40 of the magnet block 46A and the widthwise end of the coil 32 of the coil block 30A that faces this end. ＣＬ , F ＣＲ This force F ＣＬ , F ＣＲare balanced (different directions but the same strength), the frame 80 moves with the center line Cm of the magnet block 46A (the permanent magnet 40) overlapping the center line Cc of the corresponding coil block 30A (the coil 32).

[0109] On the other hand, Figure 12 shows a state in which the center line Cd is shifted to the right of the center line Cc when the underframe 80 is moved in the direction of the arrow Y, and Figure 13 shows a state in which the center line Cd is inclined with respect to the center line Cc when the underframe 80 is moved in the direction of the arrow Y.

[0110] 12, when the center line Cd of the frame 80 shifts to the left in the direction of movement of the center line Cc (for example, the direction of the arrow Y), the center line Cm of the magnet block 46A also shifts to the left with respect to the center line Cc of the excited coil block 30A. Therefore, each of the magnet blocks 46A that receives the electromagnetic force Fe from the excited coil block 30A is subjected to the force F ＣＬ、 F ＣＲ When subjected to force F ＣＲ More powerful than F ＣＬ becomes larger (F ＣＬ >F ＣＲ ).

[0111] As a result, in the underframe 80, each of the magnet blocks 46A receives the moving force Fm to the right in the traveling direction and is moved substantially in parallel to the right. As a result, the center line Cd of the underframe 80 overlaps with the center line Cc.

[0112] Furthermore, as shown in FIG. 13, when the center line Cd of the frame 80 tilts to the right in the traveling direction relative to the center line Cc, the center line Cm of the magnet block 46A also tilts to the right relative to the center line Cc of the excited coil block 30.

[0113] At this time, if the center line Cm of the magnet block 46A on the side in the moving direction of the underframe 80 is shifted to the right of the center line Cc of the opposing coil block 30A, the force F ＣＬ More powerful than F ＣＲ becomes larger (F ＣＬ <F ＣＲIn addition, if the center line Cm of the magnet block 46A on the opposite side to the moving direction of the underframe 80 is shifted to the left side of the center line Cc of the opposing coil block 30A, the force F ＣＲ More powerful than F ＣＬ becomes larger (F ＣＬ >F ＣＲ ).

[0114] As a result, the underframe 80 receives a leftward moving force Fm on the moving direction side and a rightward moving force Fm on the side opposite to the moving direction, causing the frame to rotate counterclockwise as a whole and causing the center line Cd to overlap the center line Cc.

[0115] In this way, in the conveying device 70, the center line Cm of the magnet block 46A or the center line Cm of the magnet block 46B of the frame 80 can be held at the center line Cc of the coil block 30A or the center line Cc of the coil block 30B, and the frame 80 can be moved.

[0116] As a result, in the conveyance device 70, the underframe 80 can be moved on the track plate 78 in the directions of arrow Y and arrow X by the electromagnetic forces generated between the coil blocks 30A, 30B and the magnet blocks 46A, 46B, without providing guide means such as guide rails that limit movement in directions intersecting the movement direction. Moreover, in the conveyance device 70, the structure of the track section 72 can be simplified without providing guides or the like on the track plate 78, and there are no obstacles, so the underframe 80 can be moved smoothly to any position on the track plate 78.

[0117] Furthermore, in the transport device 70, if the center line Cd of the underframe 80 is displaced or tilted in a direction intersecting the direction of movement with respect to the center line Cc, the displacement or tilt can be corrected by the electromagnetic force Fe generated between the coil blocks 30A, 30B and the magnet blocks 46A, 46B. This allows the transport device 70 to move the underframe 80 smoothly without causing loss of synchronization or the like.

[0118] In the conveying device 70, two magnet blocks 46A, 46B are provided in the field magnet section 82. However, it is sufficient that the first magnet blocks and second magnet blocks are arranged alternately in the first direction and the second direction, and the field magnet section may have three or more first magnet blocks and three or more second magnet blocks arranged in each of the first direction and the second direction. Also, the number of first magnet blocks and the number of second magnet blocks in the field magnet section may differ.

[0119] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to Figures 14 to 16. Note that in the third embodiment, the same components and configurations as those in the first or second embodiment are denoted by the same reference numerals as those in the first or second embodiment, and descriptions thereof will be omitted.

[0120] Fig. 14 shows a plan view of the main parts of a conveying device 90 as an electromagnetic device according to the third embodiment. As shown in Fig. 14, the conveying device 90 includes a track section 72 and a running section 92. Fig. 15 shows a plan view of the main parts of the running section 92.

[0121] 14 and 15 , a running section 92 includes an underframe 94, and a field section 96 is disposed on the underframe 94. The underframe 94 and the field section 96 are applied to the third embodiment in place of the underframe 80 and the field section 82 of the second embodiment.

[0122] The underframe 94 includes a frame body 98, and casters 38 (not shown in the third embodiment) are attached to the frame body 98 at required positions. As a result, when the underframe 94 is placed on the track plate 78, the running unit 92 can freely move on the upper surface (track surface) of the track plate 78 via the casters 38.

[0123] The field magnet portion 96 is arranged on the bottom surface of the frame body 98, and the field magnet portion 96 has a magnet block 46A and a magnet block 46B adjacent to it in each of the first and second directions, and the magnet blocks 46A and the magnet blocks 46B are arranged at an angle to each other.

[0124] In the field magnet portion 96, the space between the magnet block 46A and the magnet block 46B adjacent to each other in the first direction and the second direction is a non-placement space where no magnet block 46 is placed. As a result, in the frame 94, the space between the magnet block 46A and the magnet block 46B adjacent to each other in the first direction and the second direction is a non-placement space with a gap dimension D. A positive integer multiple of the width dimension Wc of the coil block 30 (coil 32) can be used as this gap dimension D.

[0125] The spacing dimension D may be an integer multiple of 0 or greater (0 corresponds to the field magnet portion 82 of the second embodiment), but in the field magnet portion 96, the spacing dimension D is set to the width dimension Wc of the coil block 30.

[0126] 14, in the field magnet portion 96, each of the magnet blocks 46A and 46B faces two of the coil blocks 30A and 30B, separated by one coil block 30. Furthermore, both ends of the magnet block 46A in the length direction (direction of the length dimension Lm) of the permanent magnet 40 can face one end of the coil 32 in the width direction of the coil 32 in the coil block 30A, and both ends of the magnet block 46B in the length direction (direction of the length dimension Lm) of the permanent magnet 40 can face one end of the coil 32 in the coil block 30B.

[0127] The control unit 50 of the transport device 90 excites the coils 32 of the coil blocks 30A and 30B for which the frame 80 is detected, thereby enabling the frame 94 to move in both the direction indicated by the arrow Y and the direction indicated by the arrow X.

[0128] Furthermore, the control unit 50 excites each of the coils 32 (32U, 32V, 32W) of the coil block 30A when moving the underframe 94 in the direction of the arrow Y, and excites each of the coils 32 (32U, 32V, 32W) of the coil block 30B when moving the underframe 94 in the direction of the arrow X. As a result, the underframe 94 is moved in the directions of the arrow Y and the arrow X on the running unit 92.

[0129] In the conveying device 90 configured in this manner, the control unit 50 controls the q-axis current target value i q_refand a d-axis current target value i for setting the d-axis current value id to a positive value. d_ref is set, and the q-axis current target value i q_ref and the d-axis current target value i d_ref As a result, the center line Cd of the frame 94 moves along the center line Cm of the magnet block 46A (the permanent magnet 40 thereof) or the center line Cm of the magnet block 46B.

[0130] At this time, in the transport device 10, when the center line Cd of the underframe 94 deviates to the right or left with respect to the center line Cc, a moving force Fm is generated in the magnet block 46A or the magnet block 46B in a direction that suppresses this deviation. As a result, in the transport device 90, the underframe 94 can be moved with the center line Cd of the underframe 94 overlapping the center line Cc of the coil block 30A or the coil block 30B.

[0131] 16 is a plan view showing a state in which the center line Cd of the underframe 94 is tilted to the left with respect to the center line Cc. As shown in Fig. 16, when the center line Cd of the underframe 94 is tilted to the left, for example, the magnet block 46A on the right side in the direction of arrow Y is shifted to the left relative to the opposing coil block 30A, and the magnet block 46A on the left side opposite the direction of arrow Y is shifted to the right relative to the opposing coil block 30A.

[0132] In this case, the magnet block 46A on the right side in the direction of the arrow Y receives a force F ＣＲ A force F ＣＲ Larger force F ＣＬ In addition, the magnet block 46A on the left side opposite to the direction of the arrow Y generates a force Fm in the direction of the arrow Y. ＣＲ A force F ＣＲ Smaller force F ＣＬ As a result, a moving force Fm toward the left is generated, which rotates the frame 94 clockwise and returns the center line Cd to the center line Cc.

[0133] In this way, the conveying device 90 also achieves the same effects as the conveying device 70. As a result, the conveying device 90 also can move the underframe 94 on the track plate 78 in the directions of arrow Y and arrow X by the electromagnetic force Fe generated between the coil blocks 30A, 30B and the magnet blocks 46A, 46B, without providing a guide means such as a guide rail that limits movement in a direction intersecting the movement direction. Therefore, the conveying device 90 also can smoothly move the underframe 94 on the track plate 78 in both the directions of arrow Y and arrow X without causing step-out or the like of the underframe 94.

[0134] In the first to third embodiments described above, three-phase power is used as the power source for exciting the coil 32. However, the power source is not limited to three-phase power, and may be two-phase power or four or more phase power. In these cases, one coil block may be formed by arranging coils equal to the number of phases.

[0135] As described above, the electromagnetic device according to the present disclosure can be modified in various ways. Furthermore, the periodic length of the magnetic poles in the magnet arrangement that forms the Halbach array field magnet only needs to be an integer (positive integer) multiple of one period of the magnetic poles, and there is no problem if it is three or more periods. Furthermore, while the permanent magnets that form the array field magnet (Halbach array field magnet) were previously magnetized so that the north pole on the side where the magnetic field of the Halbach array field magnet is stronger was positioned at the center of the field magnet, there is no problem if the permanent magnets were magnetized so that the north pole or south pole was positioned at any position in the field magnet.

[0136] As described above, the present disclosure includes the following aspects: <1> An electromagnetic device including: a track section extending in one direction; a movable body disposed opposite the track section and supported by a support section for freedom of movement along a moving plane including the one direction; an armature section in which a plurality of coil blocks, each having a number of coils corresponding to the number of phases arranged in order in the one direction, are arranged along the one direction on the track section; a field section disposed on the movable body opposite the coils of the armature section, in which a plurality of permanent magnets are arranged for one or more electrical cycles along a direction corresponding to the one direction, and in which ends of the permanent magnets in a direction intersecting the arrangement direction face ends of the coils in a direction intersecting the arrangement direction; and a control section in which a d-axis current target value and a q-axis current target value are set, thereby exciting each of the coils for each coil block in accordance with a drive voltage set based on the d-axis current target value and the q-axis current target value, and in which a positive value is set for the d-axis current target value when the movable body is moved relatively to the track section.

[0137] <2> The electromagnetic device of <1>, wherein the field magnet portion has an integer of 3 or more, and the permanent magnets are arranged such that the magnetization direction is changed by an angle obtained by dividing one electrical angle cycle by the division number.

[0138] <3> The electromagnetic device of <1> or <2>, wherein the field magnet portion has an array of permanent magnets whose magnetization direction is changed by an angle obtained by dividing one electrical angle cycle by a division number that is any one of integers obtained by adding 2 to a multiple of 3.

[0139] <4> The electromagnetic device of any one of <1> to <3>, wherein the field magnet section includes a first magnet block in which the permanent magnets for one electrical angle cycle are arranged in a first direction corresponding to the one direction, and a second magnet block in which the permanent magnets for one electrical angle cycle are arranged in a second direction intersecting the first direction, the first magnet block and the second magnet block being adjacent to each other in the first direction and the second direction, and the first magnet blocks and the second magnet blocks being adjacent to each other diagonally, and the armature section includes, as the coil blocks, a first coil block in which the coils for the number of phases are arranged in the one direction, and a second coil block in which the coils for the number of phases are arranged in a direction intersecting the one direction, and the first coil block and the second coil block are arranged alternately in each of the one direction and the direction intersecting the one direction.

[0140] <5> The electromagnetic device according to any one of <1> to <4>, further comprising a moving body detection unit for detecting whether or not the moving body faces each of the coil blocks, and the control unit excites each of the coils of the coil block selected based on a detection result of the moving body detection unit.

[0141] <6> The electromagnetic device according to any one of <1> to <5>, wherein each of the coils is an air-core coil.

[0142] The disclosure of Japanese Patent Application No. 2024-007085 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, or technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. A magnetic device comprising: an orbital portion extending along one direction; a moving body disposed opposite to the orbital portion and movably supported along a moving surface including the one direction by a support portion; an armature portion in which a plurality of coil blocks having a number of phases of coils arranged in order in the one direction are arranged along the one direction in the orbital portion; a field portion disposed on the moving body opposite to the coils of the armature portion, in which a plurality of permanent magnets are arranged in one or more electrical angle cycles along a direction corresponding to the one direction, and an end portion in a direction intersecting the arrangement direction of the permanent magnets faces an end portion in a direction intersecting the arrangement direction of the coils; and a control portion configured to excite each of the coils for each coil block according to a drive voltage set based on a d-axis current target value and a q-axis current target value, and when relatively moving the moving body with respect to the orbital portion, a positive value is set for the d-axis current target value.

2. The magnetic device according to claim 1, wherein the field portion includes permanent magnets whose magnetization directions are changed by an angle obtained by dividing one electrical angle cycle by an integer of 3 or more as a division number.

3. The magnetic device according to claim 1, wherein the field portion includes permanent magnets whose magnetization directions are changed by an angle obtained by dividing one electrical angle cycle by any one integer obtained by adding 2 to a multiple of 3 as a division number.

4. The magnetic device according to claim 1, wherein the field portion includes a first magnet block in which the permanent magnets for one electrical angle cycle are arranged in a first direction corresponding to the one direction, and a second magnet block in which the permanent magnets for one electrical angle cycle are arranged in a second direction intersecting the first direction, the first magnet block and the second magnet block are adjacent to each other in the first direction and the second direction, and the first magnet blocks and the second magnet blocks are diagonally adjacent to each other; the armature portion includes, as the coil blocks, a first coil block in which the coils for a number of phases are arranged in the one direction, and a second coil block in which the coils for a number of phases are arranged in a direction intersecting the one direction, and the first coil block and the second coil block are alternately arranged in each of the one direction and the direction intersecting the one direction.

5. The electromagnetic device according to claim 1, further comprising a moving body detection unit for detecting whether or not the moving body faces each of the coil blocks, wherein the control unit excites each of the coils of the coil block selected based on the detection result of the moving body detection unit.

6. The electromagnetic device according to claim 1, wherein each of the coils is an air-core coil.

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