JP4282469B2 - Electromagnetic actuator - Google Patents

Description

  The present invention relates to an electromagnetic actuator capable of obtaining a rotational output from an intermediate portion.

Conventionally, various PM type stepping motors are known. A general PM type stepping motor includes a rotor made of a permanent magnet having a rotation shaft in the center, and an annular stator coil arranged around the rotor, and a pulse that is flowed sequentially through the stator coil. It is the structure which carries out step rotation in a predetermined direction with an electric current (patent document 1).
Japanese Patent Laid-Open No. 2001-275333 (FIG. 1)

  In such a conventional PM type stepping motor, pole teeth are formed so as to surround the outer periphery of the rotor, and therefore a mechanism for taking out the output from the outer periphery cannot be provided. Moreover, it is necessary to use a frame yoke (metal) on the outer periphery of the rotor, and the frame yoke and the case cannot be integrally formed of a plastic material or the like. Furthermore, since the output is at the end of the shaft, the conventional technology tends to cause a moment (shaking of the shaft). In addition, there is a problem that the inner length (comb tooth length) of the yoke is restricted by the inner diameter of the stator.

  An object of the present invention is to provide an electromagnetic actuator that can transmit an output from the middle and hardly cause shaft wobbling in view of the problems of the related art.

In order to solve such a problem, the present invention provides a cylindrical rotor magnet made of a permanent magnet having an annular end face magnetized by a plurality of magnetic poles, and a pair of stator coils arranged with the annular end face of the rotor magnet interposed therebetween. The rotor magnet includes a first rotor magnet facing the one stator coil and a second rotor magnet facing the other stator coil, and the rotor magnet is interposed between the first and second rotor magnets. A feature is that a gear for transmitting the rotation of the first and second rotor magnets to the outside is provided.

The pair of stator coils includes a first yoke having pole teeth extending in the iron core direction from the outer periphery, and a second yoke having pole teeth extending outward from the end of the iron core passing through the center of the stator coil. The pole teeth of the first yoke and the pole teeth of the second yoke are alternately arranged in the circumferential direction. The first stator coil and the second stator coil having such a configuration are arranged with the first and second rotor magnets interposed therebetween.

  The first and second stator coils are arranged at equal intervals so that the respective pole teeth are in the same phase with respect to the magnetic poles of the rotor magnets facing each other. The pole teeth and the pole teeth of the second stator coil are arranged with a half phase shift with respect to the magnetic poles of the opposing rotor magnet.

The first and second rotor magnets may be supported on a single shaft bar penetrating the pair of stator coils so as to be rotatable relative to the stator coils . The first and second rotor magnets may be pivotally supported with respect to the pair of stator coils.

  Further, at least one of the stator coils may include auxiliary magnetic poles at unequal intervals between the pole teeth provided at equal intervals.

  According to the electromagnetic actuator of the present invention, since the rotational force can be obtained from the rotor magnet disposed between the stator coils, it is possible to transmit the rotational force from the outer periphery of the intermediate rotor magnet, resulting in shaft shake. It becomes difficult. Furthermore, the pole teeth can be formed long in the radial direction.

  Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view showing a first embodiment of an electromagnetic actuator to which the present invention is applied, FIG. 2 is an exploded perspective view showing one stator portion of the same embodiment, and FIG. 3 is a rotor magnet of the same embodiment. 4A is a plan view of the electromagnetic actuator, FIG. 4B is a bottom view of the electromagnetic actuator, FIG. 5 is an end view of the electromagnetic actuator cut out, and FIG. FIG. 5 is a cross-sectional view showing the upper stator coil cut in the direction of arrow VIA-VIA in FIG. 4A and the lower stator coil cut in the direction of arrow VIB-VIB in FIG.

  The electromagnetic actuator includes a rotor magnet 30 sandwiched between a pair of first and second stator coils 10 and 20, and a first shaft rod 40 penetrating the first and second stator coils 10 and 20 and the rotor magnet 30. The first and second stator coils 10 and 20 are fixed, and the rotor magnet 30 is pivotally supported. In other words, in this embodiment, the intermediate rotor magnet 30 rotates relative to the first and second stator coils 10 and 20. The rotational force of the rotor magnet 30 is transmitted by a gear or the like formed on the outer peripheral surface of the rotor magnet 30.

  The first stator coil 10 includes a coil 11 wound around a cylindrical bobbin 12, a diametrical direction along one end surface of the coil 11, a bend along both outer peripheral surfaces, and an axial direction. A first yoke 13 having a substantially U-shape that extends and bends to hold the other end surface, a hollow iron core 14 that penetrates the hollow portion 12a of the bobbin 12, and an end portion of the iron core 14 that protrudes from the bobbin 12. A fixed second yoke 15 facing the rotor magnet 30 is provided.

  As for the 1st yoke 13, both the front-end | tip parts extended toward the center (iron core 14) of the 2nd yoke 15 so that the bobbin 12 may be held form pole tooth part 13a, 13b. The cylindrical iron core 14 integrally fixed to the center portion of the first yoke 13 has a hollow portion serving as a bearing hole 14 a, and the bearing hole 14 a passes through the first yoke 13. When the iron core 14 is fitted into the center hole 12a of the bobbin 1, the pole teeth 13a, 13b and the second yoke 15 are positioned in the orthogonal direction, and the pole teeth 13a, 13b of the first yoke 15 and the second yoke 15 are positioned. The pole teeth 15a and 15b are fixed so as to form 90 ° with respect to the rotation center. A predetermined air gap is ensured between the tip surfaces of the pole teeth 13 a and 13 b and the side surface of the second yoke 15.

  The second stator coil 20 has substantially the same structure as that of the first stator coil 10 and is disposed so as to face the first stator coil 10. In other words, the second stator coil 20 includes a coil 21 wound around a cylindrical bobbin 22, a diameter extending along one end surface of the coil 21, bending along both outer peripheral surfaces, and an axial direction. A first yoke 23 having a substantially U-shape, which is bent so as to further hold the other end face, and a hollow iron core 24 passing through the hollow portion 22a of the bobbin 22 and the other end face of the iron core 24 projecting from the other end face. The second yoke 25 fixed to the end facing the rotor magnet 30 is provided.

  As for the 1st yoke 13, both the front-end | tip parts extended toward the center (iron core 14) of the 2nd yoke 15 so that the bobbin 12 may be held form pole tooth part 13a, 13b. The cylindrical iron core 14 integrally fixed to the center portion of the first yoke 13 has a hollow portion serving as a bearing hole 14 a and penetrates the iron core 14 and the first yoke 13. When the iron core 14 is fitted into the center hole 12a of the bobbin 1, the pole teeth 13a, 13b and the second yoke 15 are positioned in the orthogonal direction, and the pole teeth 13a, 13b of the first yoke 13 and the second yoke 15 are positioned. The pole teeth 15a and 15b are fixed so that their centers form 90 ° with respect to the axis. A predetermined air gap is secured between the tip surfaces of the pole teeth 13 a and 13 b and the side surface of the second yoke 15.

  In the first and second coil rotors 10 and 20 described above, the first yokes 13 and 23, the iron cores 14 and 24, and the second yokes 15 and 25 are formed of a soft magnetic material. Then, when the first coil 11 is energized, the pole teeth 13a and 13b are excited to the same magnetic pole, and the pole teeth 15a and 15b are excited to multiple poles. Similarly, when the second coil 21 is energized, the pole teeth 23a and 23b are excited to the same magnetic pole, and the pole teeth 25a and 25b are excited to multiple poles.

  The rotor magnet 30 has a disk shape or a columnar shape with a shaft hole 31 formed in the center. Thus, the annular end face is magnetized by four magnetic poles, and there are four divided permanent magnet portions 33 in which SN poles appear alternately around the shaft hole 31 (see FIG. 3).

  A cylindrical bearing 33 having a shaft hole 33 a is fitted into the shaft hole 31 of the rotor magnet 30. Both ends of the bearing 33 slightly protrude from both annular end surfaces of the rotor magnet 30, and the annular end surfaces of the protruding portions are in sliding contact with the second yokes 15 and 25 of the first and second stator coils 10 and 20. Smooth relative rotation is maintained, and it acts as a spacer that forms a predetermined air gap between the rotor magnet 30 and the pole teeth 13a, 13b, 15a, 15b and the pole teeth 23a, 23b, 25a, 25b. .

  Although not shown, an external gear ring is fitted on the outer periphery of the rotor magnet 30. The rotation of the rotor magnet 30 is transmitted to the outside through this gear ring. The rotor magnet 30 can be equipped with a pulley or other rotation transmission means instead of the gear ring.

  The shaft rod 40 is inserted through the bearing hole 14a of the first stator coil 10, the shaft hole 33a of the rotor magnet 30, and the shaft hole 24a of the second stator coil 20. With respect to the shaft rod 40, the first stator coil 10 and the second stator coil 20 have one pole tooth part 13a, 13b, 15a, 15b and pole tooth part 23a, 23b, 25a, 25b in the axial direction. Fixed to the cylindrical case 50 in a state where the position around the axis is set so as to form an angle of 45 ° when projected and the position in the axial direction is set so that the rotor magnet 30 can freely rotate. Has been. The case 50 is provided with an opening 51 so that a part of the rotor magnet 30 is exposed (see FIG. 5). From this opening 51, the rotational force of the rotor magnet 30 can be transmitted to the outside by engaging a pinion gear or the like with the gear ring on the outer peripheral surface of the rotor magnet 30. The case 50 can be formed of plastic.

  The operation of the electromagnetic actuator shown in FIGS. 1 to 6 will be further described with reference to FIGS. FIG. 7 is a timing chart for energizing the first and second coils 11 and 21, and (0) to (4) in FIG. 8 are pole teeth of the rotor magnet 30 and the first and second stator coils 10 and 20. It is a figure which expands the part 13a, 13b, 15a, 15b, and the pole tooth part 23a, 23b, 25a, 25b linearly, and shows these phase relationships and a timing chart. In FIG. 7, pole teeth 13a, 13b, 15a and 15b are denoted by reference numerals A, A ', A and A', and pole teeth 13a, 13b, 15a and 15b are denoted by reference numerals B, B ', B and B'. It is represented as a magnetic pole with a mark.

"Step (0)"
In the non-energized state shown in FIG. 8 (0), the rotor magnet 30 has the magnetic poles S, N, S, N on the upper surface attracting the magnetic poles A, A ′, A, A ′, respectively, and the counter electrodes S, N on the lower surface. , S and N attract the magnetic poles B, B ′, B and B ′, respectively, and stop in a state where these attractive forces are in equilibrium. At this time, the magnetic poles A, A ′, A and A ′ are magnetized to S, N, S and N poles, respectively, and the magnetic poles B, B ′, B and B ′ of the second stator are N, S, N and S, respectively. Is magnetized. This state is defined as a first equilibrium state.

"Step (1)"
In this first equilibrium state, when the first and second stator coils 10, 20 are energized in the positive direction, the magnetic poles A, A ', A, A' are excited by the same magnetic poles. ', B, B' are excited by the reverse magnetic pole. Therefore, each of the magnetic poles B, B ′, B, B ′ attracts the magnetic pole on the left side of the rotor magnet 30, so that the rotor magnet 30 moves (rotates) in the right direction. Then, it stops in a state where the attractive forces by the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are balanced, that is, rotated by 45 ° from the initial position (FIG. 8 (1)). )). In this equilibrium state, the rotor magnet 30 receives an attractive force in the counterclockwise direction from the magnetic poles A, A ′, A, A ′, and receives an attractive force in the clockwise direction from the magnetic poles B, B ′, B, B ′. ing. Even if energization is interrupted in this state, this equilibrium state is maintained, and the rotor magnet 30 does not rotate. This equilibrium state is defined as a second equilibrium state.

"Step (2)"
In the second equilibrium state, the first stator coil 10 is reversely energized, and the second stator coil 20 is forward energized. Then, the magnetic poles A, A ′, A, A ′ are excited to the opposite magnetic poles, and the magnetic poles B, B ′, B, B ′ are excited to the same magnetic poles. Therefore, each of the magnetic poles A, A ′, A, A ′ attracts the magnetic pole on the left side, that is, the magnetic poles A, A ′, A, A ′, the magnetic poles B, B ′, B, B ′ are all the rotor magnet 30. Is attracted in the clockwise direction, so the rotor magnet 30 rotates clockwise. Thus, the magnetic field is stopped after being rotated 90 ° from the initial position where the attractive forces by the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are balanced (FIG. 8 (2)). . In this equilibrium state, the rotor magnet 30 receives an attractive force in the clockwise direction from the magnetic poles A, A ', A, A', and receives an attractive force in the counterclockwise direction from the magnetic poles B, B ', B, B'. ing. Even if energization is interrupted in this state, this equilibrium state is maintained, and the rotor magnet 30 does not rotate. This equilibrium state is defined as a third equilibrium state.

"Step (3)"
In the third equilibrium state, when the first and second stator coils 10, 20 are energized in the reverse positive direction, the magnetic poles A, A ', A, A' are excited to the same magnetic poles, and the magnetic poles B, B ', B and B 'are excited by the reverse magnetic pole. Therefore, each of the magnetic poles B, B ′, B, B ′ attracts the magnetic pole on the left side, that is, the magnetic poles A, A ′, A, A ′, the magnetic poles B, B ′, B, B ′ are all the rotor magnet 30. Is attracted in the clockwise direction, so that the rotor magnet 30 rotates in the right direction. Then, the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are stopped at a state where they are rotated by 135 ° from the initial position, which is the position where the attractive forces by the magnetic poles B, B ′, B, B ′ are balanced ( 3)). In this equilibrium state, the rotor magnet 30 receives an attractive force in the counterclockwise direction from the magnetic poles A, A ′, A, A ′, and receives an attractive force in the clockwise direction from the magnetic poles B, B ′, B, B ′. ing. Even if energization is interrupted in this state, this equilibrium state is maintained, and the rotor magnet 30 does not rotate. This state is defined as a fourth equilibrium state.

"Step (4)"
In this fourth equilibrium state, when the first stator coil 10 is forwardly energized and the second stator coil 20 is reversely energized, the magnetic poles A, A ′, A, A ′ are excited by the opposite magnetic poles, B, B ′, B, and B ′ are excited to the same magnetic pole. Therefore, each of the magnetic poles A, A ′, A, A ′ attracts the magnetic pole on the left side, that is, the magnetic poles A, A ′, A, A ′, the magnetic poles B, B ′, B, B ′ are all the rotor magnet 30. Is attracted in the clockwise direction, so the rotor magnet 30 rotates clockwise. Then, the magnetic field is stopped after 180 ° rotation from the initial position where the attractive forces by the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are balanced (FIG. 8 (4)). . In this equilibrium state, the rotor magnet 30 receives an attractive force in the clockwise direction from the magnetic poles A, A ', A, A', and receives an attractive force in the counterclockwise direction from the magnetic poles B, B ', B, B'. ing. Even if energization is interrupted in this state, this equilibrium state is maintained, and the rotor magnet 30 does not rotate. This equilibrium state is the same as the first equilibrium state.

  As described above, the equilibrium state in step (4) is the same as the first equilibrium state in step (0). Therefore, the rotor magnet 30 can be rotated stepwise in the right direction by a 45 ° step angle by repeating the energization processes of steps (1), (2), (3), and (4).

  It should be noted that the equilibrium state in which the rotor magnet 30 is stopped can be detected by a magnetic sensor. If energization is started in the order of the energization pattern based on the rotation direction from the step and the energization pattern corresponding to the detected equilibrium state, it can be rotated in either the left or right direction.

As described above, according to the first embodiment, the rotational force can be extracted from the magnet rotor 30 located in the middle between the first and second stator coils 10 and 20, so that the shaft shake hardly occurs. Furthermore, since the pole teeth of the first and second stator coils 10 and 20 are opposed to the magnet rotor 30 in the axial direction, the overall diameter can be reduced.

  In the first embodiment shown in FIGS. 1 to 6, the number of pole teeth of each of the stator coils 10 and 20 is the same as the number of magnetic poles of the magnet rotor 30. The number of pole teeth may be increased. As the number of magnetic poles increases, the rotation angle of one step becomes smaller. When the number of pole teeth of the stator coils 10 and 20 increases or the area increases, the rotational torque increases.

  Furthermore, in this embodiment, since the rotor magnet 30 can be formed long in the axial direction, the rotational torque can be increased by increasing the magnetic force without changing the diameter.

  Next, an embodiment in which the rotor magnet 130 is pivotally supported between the first and second stator coils 110 and 120 will be described with reference to FIGS. 9 to 11. 9A is a plan view of the electromagnetic actuator of the second embodiment, FIG. 9B is a bottom view thereof, FIG. 10 is a front view of the electromagnetic actuator partially cut away, and FIG. The upper first stator coil 110 is cut along the arrow XIA-XIA in FIG. 9A, and the lower second stator coil 120 is cut along the arrow XIB-XIB in FIG. 9B. FIG.

  The first stator coil 110 includes a coil 111 wound around a cylindrical bobbin 112, a diametrical direction along one end surface of the coil 111, a bend along both outer peripheral surfaces, and an axial direction. A first yoke 113 having a substantially U-shape that extends and bends so as to hold the other end face; an iron core 114 that penetrates the hollow portion of the bobbin 112; and a rotor magnet 130 that protrudes from the opposite end face of the iron core 114; A second yoke 115 is provided that is fixed to the opposite ends.

  As for the 1st yoke 113, both front-end | tip parts extended toward the axial center along the opposing side end surface form pole tooth parts 113a and 113b. A cylindrical iron core 114 that is integrally fixed to the central portion of the first yoke 113 passes through the first yoke 113, and a spherical contact portion 114a is formed at the protruding tip. When the iron core 114 is fitted into the center hole 112a of the bobbin 112, the pole teeth 113a and 113b and the second yoke 115 are positioned in the orthogonal direction, and the pole teeth 113a and 113b of the first yoke 113 and the second yoke 115 are positioned. The pole teeth 115a and 115b are fixed so that their centers form 90 ° with respect to the axis. A predetermined air gap is secured between the tip surfaces of the pole teeth 113 a and 113 b and the side surface of the second yoke 115.

  The second stator 120 has substantially the same structure as the first stator 110, and is disposed to face the first stator 110 with the rotor magnet 120 interposed therebetween. That is, both tip portions extending toward the axial center along the opposite side end surface form the pole tooth portions 123 a and 113 b, and the iron core 124 integrally fixed to the center portion of the first yoke 123 is the first yoke 123. A spherical abutting portion 124a is formed at the protruding tip portion. When the iron core 124 is fitted into the center hole 122a of the bobbin 121, the pole teeth 123a and 123b and the second yoke 125 are positioned in the orthogonal direction, and the pole teeth 123a and 123b of the first yoke 123 and the second yoke 125 are positioned. The pole teeth 125a and 125b are fixed so that their centers form 90 ° with respect to the axis. A predetermined air gap is secured between the tip surfaces of the pole tooth portions 123 a and 123 b and the side surface of the second yoke 115.

  In the first and second rotor coils 110 and 120 described above, the first yokes 113 and 123, the iron cores 114 and 124, and the second yokes 115 and 125 are formed of a soft magnetic material.

The rotor magnet 130 includes a disk-shaped first rotor magnet 131 and second rotor magnet 135 having a plurality of permanent magnet portions magnetized at equal intervals around the axis, and the first and second rotor magnets 131, A gear 133 fixed between 135 is provided. The first and second rotor magnets 131 and 135 and the gear 133 are fixed to a shaft 137 that passes through these shaft holes. The rotor magnets 131 and 135, like the rotor magnet 30, are not shown in detail, but have a disk shape or a columnar shape with a shaft hole formed in the center, and an annular end surface is magnetized by four magnetic poles. There are four divided permanent magnet parts in which SN poles appear alternately around. In each of the first and second rotor magnets 131 and 135, the magnetic poles appearing on the annular end faces exposed in opposite directions are projected in the axial direction and fixed in a state shifted from each other by half phase (or half pitch).

The pole teeth 113a, 113b, 115a, 115b and the pole teeth of the first and second stator coils 110, 120 are thus arranged by shifting the phases of the magnetic poles of the first and second rotor magnets 131, 135. The same effect as that obtained by shifting 123a, 123b, 125a, and 125b is obtained. That is, since the pole teeth 113a, 113b, 115a, 115b and the pole teeth 123a, 123b, 125a, 125b can be arranged so as to be projected in the axial direction and overlapped, the first and second rotor magnets 131, 135 can be positioned. It becomes easy.

  On both end surfaces of the shaft 137, concave bearing portions 137a and 137b having a radius slightly larger than the radius of the contact portions 114a and 124a are formed. These bearing portions 137a and 137b and the abutting portions 114a and 124a constitute a bearing that is pivotally supported by point contact at the apex passing through the respective shaft centers.

The first stator coil 110, the rotor magnet 130, and the second stator coil 120 support the bearing portions 137a and 137b of the shaft 117 with the contact portions 114a and 124a so that the rotor magnet 130 can freely rotate. In addition, the pole teeth 113a, 113b, 115a, 115b are fitted and fixed to the cylindrical outer cylinder 150 in a state where the pole teeth 123a, 123b, 125a, 125b are positioned so as to face each other with the rotor magnet 130 interposed therebetween. The The outer cylinder 150 is provided with an opening 151 that allows the gear 133 to mesh with an external gear.

  The energization control and the rotation operation in the second embodiment are shown in FIGS.

Each of the first and second rotor magnets 131 and 135 is fixed in a state where the magnetic poles exposed on the end faces are shifted from each other by a half phase and a half pitch.

FIG. 12 is a timing chart of energization to the first and second coils 111 and 121. (0) to (4) in FIG. 13 are the first rotor magnet 131, the second rotor magnet 135 , the first and second coils. It is a figure which shows the phase relationship and timing chart which expand | deploy linearly the pole tooth part 113a, 113b, 114a, 114b of the stator coil 110, 120, and the pole tooth part 124a, 124b, 125a, 125b. In FIG. 12, pole teeth 113a, 113b, 114a, 114b are denoted by reference numerals A, A ′, A, A ′, and pole teeth 124a, 124b, 125a, 125b are denoted by reference numerals B, B ′, B, B. It is represented as a magnetic pole with a '.

"Step (0)"
In the non-energized state shown in (0) of FIG. 12, the first and second rotor magnets 131 and 135 attract the magnetic poles A, A ′, A, and A ′ by the magnetic poles N, S, N, and S on the top surface, respectively. The counter electrodes S, N, S, and N on the lower surface attract the magnetic poles B, B ′, B, and B ′, respectively, and stop in a state where these attractive forces are balanced. At this time, the magnetic poles A, A ′, A and A ′ are magnetized to S, N, S and N poles, respectively, and the magnetic poles B, B ′, B and B ′ of the second stator are N, S, N and S, respectively. Is magnetized. This state is defined as a first equilibrium state.

"Step (1)"
In the first equilibrium state, when the first and second stator coils 110 and 120 are energized in the positive direction, the magnetic poles A, A ′, A and A ′ are excited to the same magnetic poles. B ', B, and B' are excited by the reverse magnetic pole. Therefore, the magnetic poles B, B ′, B, B ′ attract the magnetic poles on the left side of the first rotor magnet 131 and the second rotor magnet 135 , respectively, so both the first and second rotor magnets 131, 135 are directed to the right. Move (rotate). Then, it stops in a state where the attractive forces by the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are balanced, that is, rotated by 45 ° from the initial position (FIG. 13 (1)). )). In this equilibrium state, the first and second rotor magnets 131 and 135 receive a counterclockwise attractive force from the magnetic poles A, A ′, A, and A ′, and from the magnetic poles B, B ′, B, and B ′ to the right. Receiving suction force in the rotational direction. Even if energization is interrupted in this state, this equilibrium state is maintained, and the first and second rotor magnets 131 and 135 do not rotate. This equilibrium state is defined as a second equilibrium state.

"Step (2)"
In the second equilibrium state, the first stator coil 110 is reversely energized and the second stator coil 120 is forward energized. Then, the magnetic poles A, A ′, A, A ′ are excited to the opposite magnetic poles, and the magnetic poles B, B ′, B, B ′ are excited to the same magnetic poles. Therefore, each of the magnetic poles A, A ′, A, A ′ attracts the magnetic pole on the left side, that is, the magnetic poles A, A ′, A, A ′, the magnetic poles B, B ′, B, B ′ are all the first rotor. Since the magnet 131 and the second rotor magnet 135 are attracted in the clockwise direction, the first and second rotor magnets 131 and 135 rotate in the clockwise direction. Then, the magnetic field is stopped after 90 ° rotation from the initial position where the attractive forces by the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are balanced (FIG. 13 (2)). . In this equilibrium state, the first and second rotor magnets 131 and 135 receive the attractive force in the clockwise direction from the magnetic poles A, A ′, A, and A ′, and left from the magnetic poles B, B ′, B, and B ′. Receiving suction force in the rotational direction. Even if energization is interrupted in this state, this equilibrium state is maintained, and the first and second rotor magnets 131 and 135 do not rotate. This equilibrium state is defined as a third equilibrium state.

"Step (3)"
When the first and second stator coils 110 and 120 are energized in the reverse positive direction in the third equilibrium state, the magnetic poles A, A ′, A, and A ′ are excited to the same magnetic poles, and the magnetic poles B, B ′, B and B 'are excited by the reverse magnetic pole. Therefore, each of the magnetic poles B, B ′, B, B ′ attracts the magnetic pole on the left side, that is, the magnetic poles A, A ′, A, A ′, the magnetic poles B, B ′, B, B ′ are all the first, Since the second rotor magnets 131 and 135 are attracted in the right rotation direction, the first and second rotor magnets 131 and 135 rotate in the right direction. Then, the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are stopped at a state where they are rotated by 135 ° from the initial position, which is a position where the attractive forces by the magnetic poles B, B ′, B, B ′ are balanced (FIG. 3)). In this equilibrium state, the first and second rotor magnets 131 and 135 receive an attractive force in the counterclockwise direction from the magnetic poles A, A ′, A, and A ′, and to the right from the magnetic poles B, B ′, B, and B ′. Receiving suction force in the rotational direction. Even if energization is interrupted in this state, this equilibrium state is maintained, and the first and second rotor magnets 131 and 135 do not rotate. This state is defined as a fourth equilibrium state.

"Step (4)"
In this fourth equilibrium state, when the first stator coil 110 is forwardly energized and the second stator coil 120 is reversely energized, the magnetic poles A, A ′, A, A ′ are excited by the opposite magnetic poles, and the magnetic poles B, B ', B and B' are excited by the same magnetic pole. Therefore, each of the magnetic poles A, A ′, A, A ′ attracts the left magnetic pole, that is, the magnetic poles A, A ′, A, A ′, the magnetic poles B, B ′, B, B ′ are all the first, Since the second rotor magnets 131 and 135 are attracted in the clockwise direction, the first and second rotor magnets 131 and 135 rotate to the right. Then, the magnetic field is stopped after 180 ° rotation from the initial position where the attractive forces by the magnetic poles A, A ′, A, A ′ and the magnetic poles B, B ′, B, B ′ are balanced (FIG. 13 (4)). . In this equilibrium state, the first and second rotor magnets 131 and 135 receive the attractive force in the clockwise direction from the magnetic poles A, A ′, A, and A ′, and left from the magnetic poles B, B ′, B, and B ′. Receiving suction force in the rotational direction. Even if energization is interrupted in this state, this equilibrium state is maintained, and the first and second rotor magnets 131 and 135 do not rotate. This equilibrium state is the same as the first equilibrium state.

As described above, the equilibrium state in step (4) is the same as the first equilibrium state in step (0). Therefore, the first and second rotor magnets 131 and 135 are rotated stepwise by 45 ° in the right direction by repeating the energization processes in steps (1), (2), (3), and (4). be able to.

Note that the equilibrium state in which the first and second rotor magnets 131 and 135 are stopped can be detected by a magnetic sensor. If energization is started in the order of the energization pattern based on the rotation direction from the step and the energization pattern corresponding to the detected equilibrium state, it can be rotated in either the left or right direction.

As described above, according to the second embodiment, the rotational force can be extracted from the first and second rotor magnets 131 and 135 located between the first and second stator coils 110 and 120. It is hard to occur. Further, since the pole teeth of the first and second stator coils 110 and 120 are opposed to the first and second rotor magnets 131 and 135 in the axial direction, the overall diameter can be reduced.

In the second embodiment shown in FIG. 11, the number of pole teeth of each of the first and second stator coils 110 and 120 is the same as the number of magnetic poles of the first and second rotor magnets 131 and 135. The number of pole teeth of the first and second stator coils 110 and 120 may be increased in correspondence with the number of magnetic poles corresponding to the number of pole teeth. As the number of magnetic poles increases, the rotation angle of one step becomes smaller. As the number of pole teeth of each of the first and second stator coils 110 and 120 increases or the area increases, the rotational torque increases.

  Furthermore, in this embodiment, since the rotor magnet 30 can be formed long in the axial direction, the rotational torque can be increased by increasing the magnetic force without changing the diameter.

As described above, in the second embodiment, the rotor magnet is constituted by the two first and second rotor magnets 131 and 135 and the phases are arranged by being shifted by a half phase, so the first and second stator coils 30 are arranged. These magnetic pole portions can be arranged opposite to each other, and their position adjustment is facilitated. Further, since the gear is sandwiched between the first and second rotor magnets 131 and 135, the degree of freedom in the configuration of the gear is increased and the manufacture is facilitated.

  The pivot bearing that pivotally supports the rotor magnet 130 of the second embodiment may have a structure reverse to that of the bearing and the contact portion. Further, other bearing structures may be applied. The two-layer structure of the rotor magnet 130 of the second embodiment can also be applied to the first embodiment.

  The above is an embodiment in which the pole teeth are provided at equal intervals, but the electromagnetic actuator of the present invention can provide a part of the pole teeth at unequal intervals. A third embodiment in which part of the pole teeth is provided at unequal intervals will be described with reference to the operation timing and structure shown in FIGS.

  In the third embodiment, for example, in the first embodiment, the first yoke is removed from the first and second stator coils 10 and 20, and the second yoke is formed into a cross shape. It can be configured by forming one auxiliary yoke. That is, the four magnetic poles A formed at the tip of the cross-shaped yoke of the first stator coil, the four magnetic poles B formed at the tip of the cross-shaped yoke of the second stator coil, and the magnetic pole B One auxiliary magnetic pole B ′ formed at the tip of one yoke extending between the two. The magnetic poles A and B of each stator coil are provided at a central angle of 90 °, but the auxiliary magnetic pole B ′ has an angle of 0 ° <θ <45 ° and 45 ° when the central angle with respect to the adjacent magnetic pole B is θ. <Θ <90 °.

  On the other hand, in the magnet rotor, the number of magnetic poles of the magnet rotor 30 of the third embodiment is doubled to eight. That is, the number of magnetic poles is set to twice the number of pole teeth of one stator coil.

  The operation of the third embodiment will be described. In a non-energized state, it has stopped in the state of FIG. 15 (0). This stop position is defined as an initial position, step (0) with a rotation angle of 0 °. In the stopped state of step (0), each magnetic pole A of one stator coil is attracted to the N pole of the rotor magnet and magnetized to the S pole. On the other hand, each magnetic pole B and auxiliary magnetic pole B ′ of the other stator coil are attracted to the south pole of the rotor magnet and magnetized to the north pole. Here, the rotor magnet is in an equilibrium state and stopped by rotating in the traveling direction by an angle Δθ, compared to the case where there is no auxiliary magnetic pole B ′ due to the attractive force with respect to the auxiliary magnetic pole B ′. This stop state is defined as a first equilibrium state.

"Step (1)"
In the first equilibrium state, a current is passed through the first and second stator coils in the forward direction in which the magnetic poles A, B, and auxiliary magnetic pole B ′ are reversed. Then, the magnetic pole A, the magnetic pole B, and the auxiliary magnetic pole B ′ are excited to reverse the magnetic pole, and the magnetic pole A, the magnetic pole B, and the auxiliary magnetic pole B ′ whose magnetic poles are inverted are the adjacent magnetic poles on the right side that are the closest reverse magnetic poles of the rotor magnet. Therefore, the rotor magnet moves to the left (rotates counterclockwise) and stops in a state where the forces attracted by these magnetic poles are balanced (FIG. 15 (1)). That is, the rotor magnet rotates 45 ° to the left with respect to the first and second stator coils and stops in an equilibrium state. This stop state is defined as a second equilibrium state. Even if energization is interrupted in the second equilibrium state, the exciting action on the magnetic pole A, magnetic pole B, and auxiliary magnetic pole B ′ disappears, but the magnetic pole does not change, so the stopped state is maintained. This equilibrium state is defined as a second equilibrium state.

"Step (2)"
In this second equilibrium state, a current is passed through the first and second stator coils in the reverse direction. Then, the magnetic pole A, the magnetic pole B, and the auxiliary magnetic pole B ′ are excited in the direction in which the magnetic poles are reversed. The magnetic pole A, magnetic pole B, and auxiliary magnetic pole B ′ whose magnetic poles are reversed attract the magnetic pole nearest to the right of the rotor magnet, so the rotor magnet moves (rotates) in the left direction, and the force attracted by these magnetic poles is balanced. It stops in the state (FIG. 15 (2)). That is, the rotor magnet rotates 45 ° to the left with respect to the first and second stator coils and stops in an equilibrium state. This stop state is defined as a third equilibrium state. Even if energization is cut off in the third equilibrium state, the magnetic poles do not change because the excitation action on the magnetic pole A, magnetic pole B, and auxiliary magnetic pole B ′ disappears, and the stopped state is maintained.

  This third equilibrium state is the same state as the first equilibrium state. Therefore, thereafter, by repeating the energization of steps (1) and (2), the rotor magnet can be rotated stepwise by a 45 ° step angle. According to this embodiment, driving can be performed simply by switching the energization direction between forward and reverse, so that drive control is simple.

  In each of the above embodiments, the basic number of pole teeth of each stator coil is four, but it may be an even number of six or more poles. If the number of pole teeth is increased, driving with a smaller step angle becomes possible.

It is a perspective view showing a 1st embodiment of an electromagnetic actuator to which the present invention is applied. It is a perspective view which decomposes | disassembles and shows one stator part of the embodiment. It is a perspective view of the rotor magnet of the same embodiment. The electromagnetic actuator of 1st Embodiment is shown, (A) is a top view, (B) is a bottom view. It is sectional drawing which cuts and shows the outer cylinder of the same electromagnetic actuator. FIG. 6 is a cross-sectional view of the electromagnetic actuator, in which the upper stator coil is cut in the direction of the arrow VIA-VIA in FIG. 4 (A), and the lower stator coil is the arrow VIB- in FIG. 4 (B). It is sectional drawing cut | disconnected in the VIB direction. It is a figure which shows the electricity supply timing chart to the stator coil of the same electromagnetic actuator. It is a figure which expands the rotor magnet of the same electromagnetic actuator, and the pole tooth part of the 1st and 2nd stator in the shape of a straight line, and shows the phase relation and operation timing to (0) thru / or (4). The electromagnetic actuator of 2nd Embodiment is shown, (A) is a top view, (B) is the bottom view. It is the front view which cut and showed the outer cylinder of the electromagnetic actuator partially. FIG. 9 is a cross-sectional view of the electromagnetic actuator, with the upper stator coil cut in the direction of arrow XIA-XIA in FIG. 9A and the lower stator coil in the arrow XIB- of FIG. 9B. It is sectional drawing cut | disconnected in the XIB direction. It is a figure which shows the electricity supply timing chart to the stator coil of 2nd Embodiment. In the second embodiment, the first and second rotor magnets are fixed in a state where the magnetic poles exposed on the annular end faces exposed in the opposite directions are projected in the axial direction and are shifted from each other by half phase (or half pitch). It is a figure which shows the structure and operation | movement timing of a principal part. It is a figure which shows the electricity supply timing chart to the stator coil of 3rd Embodiment. It is a figure which shows the structure and operation | movement timing of the principal part of 3rd Embodiment which provided a part of pole tooth at unequal intervals.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st stator coil 11 coil 12 bobbin 12a hollow part 13 1st yoke 13a pole tooth part 13b pole tooth part 14 iron core 14a bearing hole 15 2nd yoke 15a pole tooth part 15b pole tooth part 20 2nd stator coil 21 coil 22 bobbin 22a hollow portion 23 first yoke 23a pole tooth portion 23b pole tooth portion 24 iron core 24a shaft hole 25 second yoke 25a pole tooth portion 25b pole tooth portion 30 rotor magnet 31 shaft hole 33 bearing 33a shaft hole 40 shaft rod 50 case 51 opening Part 110 First stator coil 111 Coil 112 Bobbin 112a Center hole 113 First yoke 113a Polar tooth part 113b Polar tooth part 114 Iron core 114a Contact part 115 Second yoke 115a Polar tooth part 115b Polar tooth part 117 Shaft 120 Second stator coil 121 Bobbin 122a Center hole 9
123 1st yoke 123a pole tooth part 123b pole tooth part 1
124 Iron core 124a Contact part 125 2nd yoke 125a pole tooth part 125b pole tooth part 1
130 rotor magnet 131 first rotor magnet 133 gear 135 second rotor magnet 137 shaft 137a bearing portion 137b bearing portion 150 case 151 opening

Claims (6)

A cylindrical rotor magnet composed of a permanent magnet whose annular end face is magnetized by a plurality of magnetic poles;
A pair of stator coils arranged across the annular end surface of the rotor magnet,
The rotor magnet includes a first rotor magnet facing the one stator coil, and a second rotor magnet facing the other stator coil,
An electromagnetic actuator comprising a gear for transmitting the rotation of the first and second rotor magnets to the outside between the first and second rotor magnets . The stator coil includes a first yoke having pole teeth extending in the iron core direction from the outer periphery, and a second yoke having pole teeth extending outward from an end portion of the iron core passing through the center of the stator coil, comprises a first stator coil and a second stator coil and the pole teeth of the first yoke pole teeth and the second yoke are arranged alternately in the circumferential direction, said first and second stator coils The electromagnetic actuator according to claim 1, wherein the electromagnetic actuator is disposed with the first and second rotor magnets interposed therebetween. The first and second stator coils are arranged at equal intervals so as to have the same phase with respect to the magnetic poles of the first and second rotor magnets , which are opposed to the respective pole teeth. 3. The electromagnetic actuator according to claim 2 , wherein the pole teeth of the first stator coil and the pole teeth of the second stator coil are arranged with a half phase shift with respect to the magnetic poles of the opposing rotor magnet. Said first, second rotor magnet, a single pintle extending through the pair of stator coils, one of the claims 1 to 3 are relatively rotatably supported to said pair of stator coils An electromagnetic actuator according to claim 1. The electromagnetic actuator according to any one of claims 1 to 3 , wherein the first and second rotor magnets are pivotally supported with respect to the pair of stator coils. Wherein at least one of the stator coils, or electromagnetic actuator of claims 1 to 5 is provided with an auxiliary pole teeth provided at unequal intervals between pole teeth provided in said regular intervals.

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