CN209927881U - Rotation speed detector - Google Patents
Rotation speed detector Download PDFInfo
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- CN209927881U CN209927881U CN201790000489.XU CN201790000489U CN209927881U CN 209927881 U CN209927881 U CN 209927881U CN 201790000489 U CN201790000489 U CN 201790000489U CN 209927881 U CN209927881 U CN 209927881U
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Abstract
The rotation speed detector (200) is characterized by comprising a disk-shaped magnet (5) arranged on a shaft (4) and more than 3 power generation parts (71, 72, 73) composed of magnetic wires and pickup coils, wherein each of the more than 3 power generation parts (71, 72, 73) is arranged on each of a plurality of sides forming a virtual polygon (10), and the polygon (10) is arranged on the end face side of the magnet (5). Accordingly, the rotation speed detector (200) achieves the effect of suppressing imbalance of the amount of power generation and realizing miniaturization.
Description
Technical Field
The utility model relates to a rotational speed detector (rotational speed detector) of rotational speed of detection rotator.
Background
[ Prior art documents ]
[ patent document ]
Patent document 1: international publication No. 2016/056122
SUMMERY OF THE UTILITY MODEL
[ problem to be solved by the utility model ]
In the encoder disclosed in patent document 1, since it is necessary to arrange 4 magnets so that magnetic fields do not interfere with each other, there is a problem in that the entire volume of the encoder increases.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotation speed detector that can be miniaturized.
[ technical means for solving problems ]
In order to solve the above-described problems, the present invention provides a rotation speed detector including a disk-shaped magnet provided on a shaft (draft), and 3 or more power generation units each including a magnetic wire and a pickup coil, wherein each of the power generation units is disposed on each of a plurality of sides of a virtual polygon disposed on an end surface side of the magnet, and at least one vertex of the polygon when the 3 or more power generation units are viewed from a plan view of the magnet is inscribed in a virtual circle having a diameter equal to that of the magnet.
In addition, the rotation speed detector of the present invention is characterized in that the polygon is an equilateral triangle or an isosceles triangle, and all vertexes of the equilateral triangle or the isosceles triangle are inscribed in the imaginary circle.
In addition, the rotation speed detector of the present invention is characterized in that the polygon is an equilateral triangle or an isosceles triangle, and the plurality of vertices of the equilateral triangle or the isosceles triangle are inscribed in the imaginary circle.
In the rotation speed detector according to the present invention, the distance from the power generation unit disposed on the side closest to the center of the magnet among the 3 sides of the isosceles triangle to the magnet is shorter than the distance from the power generation unit disposed on the remaining sides to the magnet.
In addition, the rotation speed detector of the present invention is characterized in that the angle of the apex angle of the isosceles triangle is larger than the hysteresis angle of the rotation angle generated in the magnetic wire due to the difference in the rotation direction of the magnet.
In addition, the rotation speed detector according to the present invention is characterized in that the magnet wire is a polygon formed by bending 1 wire rod, and the pickup coil is provided on each of a plurality of sides of the polygonal magnet wire.
In addition, the rotation speed detector of the present invention is characterized in that a soft magnet is provided at the end of the magnetic wire.
In addition, the rotation speed detector according to the present invention is characterized in that the S-pole and the N-pole of the magnet are magnetized in the thickness direction of the magnet, respectively 1 pole.
[ Utility model effect ] is provided
The utility model relates to a rotational speed detector gains the effect that can realize the miniaturization.
Drawings
Fig. 1 is a sectional view of a motor (motor) having a rotation speed detector according to embodiment 1.
Fig. 2 is a perspective view of the rotation speed detector according to embodiment 1.
Fig. 3 is a plan view of the power generating unit group shown in fig. 2, viewed from above with respect to the magnet.
Fig. 4 is a graph showing a relationship between the amount of power generation and the length of the magnet wires in each of the 3 power generation units shown in fig. 3.
Fig. 5 is a configuration diagram of the rotation speed detector according to embodiment 2.
Fig. 6 is a diagram showing a state in which components other than the power generating unit group are mounted on the substrate in the rotation speed detector according to embodiment 2.
Fig. 7 is a diagram for explaining hysteresis (hysteresis) characteristics based on the magnet rotation direction in the rotation speed detector according to embodiment 2.
Fig. 8 is a configuration diagram of a rotation speed detector according to embodiment 3.
Fig. 9 is a diagram showing a state in which components other than the power generating unit group are mounted on the substrate in the rotation speed detector according to embodiment 3.
Fig. 10 is a configuration diagram of a rotation speed detector according to embodiment 4.
Fig. 11 is a diagram showing a state in which components other than the power generating unit group are mounted on the substrate in the rotation speed detector according to embodiment 4.
Fig. 12 is a perspective view of the rotation speed detector according to embodiment 5.
Fig. 13 is a side view of the rotation speed detector according to embodiment 5.
Fig. 14 is a perspective view of the rotation speed detector according to embodiment 6.
Fig. 15 is a configuration diagram of a rotation speed detector according to embodiment 7.
Fig. 16 is a diagram showing a modification of the rotation speed detector according to embodiment 7.
Fig. 17 is an enlarged view of the Ferrite Bead (Ferrite Bead) shown in fig. 16.
Detailed Description
Next, a rotation speed detector according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.
Fig. 1 is a cross-sectional view of a motor having a rotation speed detector according to embodiment 1. Fig. 2 is a perspective view of the rotation speed detector according to embodiment 1. The motor 100 shown in fig. 1 includes: a cylindrical frame 1; a stator 2 fixed to the inside of the frame 1; a rotor 3 disposed inside the stator 2; and a shaft 4 disposed at the center of the rotor 3. The shaft 4 is rotatably supported by the frame 1 by a bearing not shown.
Further, the motor 100 includes: a disk-shaped magnet 5 provided at an end 4a of the shaft 4 in the axial direction D1 of the central axis AX; a substrate 6 that is disposed so as to face the end face 5a of the magnet 5 in the axial direction D1 and is fixed to the inside of the frame 1; a power generating unit group 7 fixed to an end surface 6a of the substrate 6 on the opposite side to the magnet 5 side in the axial direction D1; a connector 8 fixed to an end surface 6a of the substrate 6; and a rotation speed detection circuit 9 fixed to the end surface 6a of the substrate 6. The disk shape includes not only a disk shape but also an annular shape in which a through hole is formed in the center of the magnet 5 in the radial direction D2.
The magnet 5 is fixed to the shaft 4 by adhesion, screw fixation, or press fitting, and rotates together with the shaft 4. The rotation speed detector 200 is composed of at least the shaft 4, the magnet 5, and the power generating unit group 7.
As shown in fig. 2, the power generation unit group 7 includes 3 power generation units 71, 72, and 73. In fig. 2, the substrate 6 shown in fig. 1 is not shown. The power generation section 71 is constituted by a magnetic wire 71a and a pickup coil 71b wound around the magnetic wire 71 a. The power generation section 72 is constituted by magnetic wires 72a and a pickup coil 72b wound around the magnetic wires 72 a. The power generation section 73 is composed of a magnetic wire 73a and a pickup coil 73b wound around the magnetic wire 73 a.
Each of the 3 power generation units 71, 72, and 73 generates a voltage pulse according to a large Barkhausen effect (large Barkhausen effect) with the rotation of the magnet 5. The wire diameters and lengths of the magnetic wires 71a, 72a, 73a are set and the number of turns of the pickup coils 71b, 72b, 73b is set so that the magnitudes of the voltage pulses generated by the respective 3 power generation sections 71, 72, 73, that is, the amounts of power generation are equal to each other.
The magnetization direction of the magnet 5 may be a direction perpendicular to the axial direction D1 of the central axis AX or a direction parallel to the axial direction D1 of the central axis AX, but in the magnet 5 according to embodiment 1, the S-pole and the N-pole are each magnetized in the axial direction D1, that is, in the thickness direction of the magnet 5. On one end surface 5a of the magnet 5 in the axial direction D1, the S-pole and the N-pole are aligned along the rotational direction of the magnet 5. On the end face 5b of the magnet 5 located on the opposite side of the end face 5a in the axial direction D1, a polarity different from the polarity of the end face 5a is arranged along the rotation direction of the magnet 5.
The voltage pulses generated by the respective power generation units 71, 72, 73 are input to the rotation speed detection circuit 9 via signal lines, not shown, connected to the pickup coils 71b, 72b, 73 b. The rotation speed detection circuit 9 detects the rotation speed of the rotor 3 from the voltage pulse, and stores the rotation speed information of the rotor 3 in a memory, not shown. The rotational speed information is transmitted to a host device not shown via the connector 8 and a signal line connected to the connector 8. The upper-level device generates a voltage command for driving the motor 100 using the rotation speed information.
Fig. 3 is a plan view of the power generating unit group shown in fig. 2, viewed from above with respect to the magnet. Fig. 3 shows an imaginary circle 5A having a diameter equal to that of the magnet 5 shown in fig. 2. As shown in fig. 3, each of the 3 power generation units 71, 72, and 73 is disposed on each of a plurality of sides of the virtual polygon 10. The polygon 10 is assumed in fig. 2 and 3 to be an equilateral triangle 30.
The equilateral triangle 30 is composed of 3 vertices 31 and 3 sides 32 connecting the two adjacent vertices 31 to each other. The lengths of the 3 sides 32 are equal to each other and the magnitudes of the angles θ 1 of the 3 interior angles 33 are equal to each other. The angle θ 1 of the 1 interior angle 33 is 60 °.
When the power generation unit group 7 is viewed in plan toward the magnet 5 shown in fig. 2, 3 vertices 31 of the equilateral triangle 30 are inscribed in the virtual circle 5A. Perpendicular bisectors of the three sides of the equilateral triangle 30 intersect at the central portion CP1, with equal distances from the central portion CP1 to each vertex 31. The position of the center portion CP2 of the equilateral triangle 30 coincides with the position of the center portion CP1 of the imaginary circle 5A. The positions of the center portion CP2 and the center portion CP1 coincide with the position of the central axis AX of the shaft 4 shown in fig. 1.
The magnetic wires 71a, 72a, 73a of each of the power generation sections 71, 72, 73 have a length shorter than that of the side 32, but it is preferable to increase the lengths of the magnetic wires 71a, 72a, 73a as much as possible so as to be connected to the virtual circle 5A. That is, the power generation sections 71, 72, 73 are preferably configured such that the ends of the magnet wires 71a, 72a, 73a are disposed near the vertices 31 of the equilateral triangle 30.
Fig. 4 is a graph showing a relationship between the amount of power generation and the length of the magnet wires in each of the 3 power generation units shown in fig. 3. The vertical axis of fig. 4 represents the power generation amount. When the radius of the imaginary circle 5A shown in fig. 3 is equal to the radius of the magnet 5 shown in fig. 2, the horizontal axis of fig. 4 represents the ratio of the magnetic wire length to the radius when the radius of the magnet 5 is 1. Specifically, "1" on the horizontal axis in fig. 4 indicates that the radius of the magnet 5 and the magnetic wire length are equal. As shown in fig. 4, when the magnetic wire length is equal to a value √ 3 times the radius R, the amount of power generation by each of the 3 power generation sections 71, 72, 73 reaches the maximum.
Further, when the end portions of the magnetic wires 71a, 72a, 73a extend to the outside of the imaginary circle 5A and the magnetic wire length is larger than a value √ 3 times the radius R, the magnetic wires 71a, 72a, 73a located outside the imaginary circle 5A do not contribute to power generation and the amount of power generation is reduced due to the resistance portion of the magnetic wires.
By disposing the end portions of the magnetic wires 71a, 72a, 73a at the positions of the respective vertices of the 3 vertices 31 inscribed in the virtual circle 5A, the amount of power generated by the respective power generation units of the power generation units 71, 72, 73 is maximized, thereby enabling the detection accuracy of the rotation speed to be improved.
In fig. 1, the power generation unit group 7, the connector 8, and the rotation speed detection circuit 9 are provided on the end surface 6a of the substrate 6 on the opposite side to the magnet 5 side, but the power generation unit group 7, the connector 8, and the rotation speed detection circuit 9 may be provided on the end surface 6b of the substrate 6 on the magnet side. One or a plurality of the power generating unit group 7, the connector 8, and the rotation speed detecting circuit 9 may be provided on the end surface 6a, and the remaining ones may be provided on the end surface 6 b. As shown in fig. 1, by providing all of the power generation unit group 7, the connector 8, and the rotation speed detection circuit 9 on one of the end surface 6a and the end surface 6b of the substrate 6, the width in the axial direction D1 of the entire power generation unit group 7, the connector 8, the rotation speed detection circuit 9, and the substrate 6 can be reduced, compared to the case where some of the power generation unit group 7, the connector 8, and the rotation speed detection circuit 9 are provided on the end surface 6a and the remaining portions are provided on the end surface 6b, and the motor 100 can be downsized.
Fig. 5 is a configuration diagram of the rotation speed detector according to embodiment 2. The rotation speed detector 200 shown in fig. 3 is different from the rotation speed detector 200A shown in fig. 5 in that the polygon 10 assumed in the rotation speed detector 200A is an isosceles triangle 30A. In the power generation unit group 7A shown in fig. 5, the magnet wires 71a and 72a have the same length, and the magnet wires 71a and 72a have a length longer than that of the magnet wire 73 a.
The isosceles triangle 30A is composed of 3 vertexes 31, a waist 32a, and a base 32b, wherein the waist 32a is two sides having equal length, and the base 32b is a side shorter than the waist 32 a. The angle θ 11 of the apex angle 33b formed by the two waists 32a is smaller than the angle θ 12 of the base angle 33a formed by the base 32b and the waist 32 a.
Perpendicular bisectors of three sides of the isosceles triangle 30A intersect at the central portion CP3, and the distances from the central portion CP3 to the respective vertices 31 are equal. The position of the center portion CP3 of the isosceles triangle 30A coincides with the position of the center portion CP1 of the imaginary circle 5A. The positions of the center portion CP3 and the center portion CP1 coincide with the position of the central axis AX of the shaft 4 shown in fig. 1.
The magnetic wires 71a, 72a are shorter than the waist 32a, but it is preferable to increase the lengths of the magnetic wires 71a, 72a as much as possible so as to be connected to the imaginary circle 5A. The length of the magnetic wire 73a is shorter than the length of the base 32b, but it is preferable to increase the length of the magnetic wire 73a as much as possible so as to be connected to the imaginary circle 5A. That is, the power generation sections 71, 72, 73 are preferably configured such that the end portions of the magnet wires 71a, 72a, 73a are disposed in the vicinity of the vertex 31 of the isosceles triangle 30A.
In the power generation unit group 7A shown in fig. 5, the magnetic wires 71a and 72a have the same length, and the magnetic wires 71a and 72a have a length longer than that of the magnetic wire 73a, but the power generation unit group 7A may be configured such that the magnetic wires 71a and 72a have a length shorter than that of the magnetic wire 73 a.
According to the rotation speed detector 200A of embodiment 2, the following effects can be obtained in addition to the same effects as those of embodiment 1. Fig. 6 is a diagram showing a state in which components other than the power generating unit group are mounted on the substrate in the rotation speed detector according to embodiment 2. For convenience of explanation, the substrate 6 shown in fig. 6 has the same size and shape as the imaginary circle 5A shown in fig. 5.
When the power generating unit group 7A is mounted on the substrate 6, the power generating unit group 7A needs to avoid interference with components such as the connector 8 and the rotation speed detecting circuit 9 mounted on the substrate 6. By disposing the power generation sections 71, 72, 73 on the three sides of the isosceles triangle 30A as the virtual polygon 10 as in embodiment 2, the area between the outer side of the isosceles triangle 30A and the outer peripheral portion of the substrate 6 can be enlarged as compared with embodiment 1, and the mounting space of the connector 8 can be secured.
However, when the power generation amounts of the power generation units 71 and 72 are equal to each other and the power generation amounts of the power generation units 71 and 72 are larger than the power generation amount of the power generation unit 73, it is preferable that the capacities of the capacitors charged (charged) with the voltage pulses in the rotation speed detection circuit 9 shown in fig. 1 be changed so that the voltage pulses from the 3 power generation units 71, 72, and 73 are not unbalanced (unbalances). Specifically, when the capacitors charged by the voltage pulses generated by the power generation units 71, 72, and 73 have capacities of C11, C12, and C13, the same charging voltage can be obtained if the capacitor capacity is set so that C11 > C12 > C13.
Fig. 7 is a diagram for explaining hysteresis characteristics based on the magnet rotation direction in the rotation speed detector according to embodiment 2. Fig. 7 shows only the power generation section 71 as an example. The upper side of fig. 7 shows the rotation angle θ 4 at which a voltage pulse is generated in the pickup coil 71b of the power generation section 71 when the magnet 5 rotates in the right-turn direction DR. The rotation angle θ 4 is an angle from the generation of a positive voltage pulse (+ V) to the detection of a voltage pulse of a predetermined value or more when the magnet 5 rotates in the right-turn direction DR. A rotation angle θ 5 at which a voltage pulse is generated in the pickup coil 71b of the power generation section 71 when the magnet 5 rotates in the left turn direction DL is shown in the lower side of fig. 7. The rotation angle θ 5 is an angle from the generation of a negative voltage pulse (-V) to the detection of a voltage pulse of a predetermined value or more when the magnet 5 rotates in the left rotation direction DL.
The rotation speed detector 200A has the following hysteresis characteristics: the position where the voltage pulse of a predetermined value or more is detected when the magnet 5 rotates in the right-turn direction DR is different from the position where the voltage pulse of a predetermined value or more is detected when the magnet 5 rotates in the left-turn direction DL. When the hysteresis angle corresponding to the difference between the rotation angle θ 4 and the rotation angle θ 5 is defined as Φ, the angle θ 11 at the vertex angle 33b shown in fig. 6 is preferably larger than the hysteresis angle Φ.
When the angle θ 11 of the apex angle 33b is made smaller than the hysteresis angle Φ, the voltage pulses of a certain value or more are generated at the same timing in the respective power generation units 71 and 72 shown in fig. 6, and therefore, the rotation detection accuracy may be lowered. By making the angle θ 11 of the apex angle 33b of the isosceles triangle 30A larger than the hysteresis angle Φ of the rotation angle generated in the magnet wires due to the difference in the rotation direction of the magnet 5, it is possible to reduce the imbalance of the amount of power generation due to the decrease in the apex angle 33b of the isosceles triangle 30A, and to suppress the decrease in the rotation detection accuracy.
Fig. 8 is a configuration diagram of a rotation speed detector according to embodiment 3. The rotation speed detector 200 shown in fig. 3 is different from the rotation speed detector 200B shown in fig. 8 in that only two vertices 31 out of 3 vertices 31 of the equilateral triangle 30 as the virtual polygon 10 are inscribed in the virtual circle 5A in the rotation speed detector 200B. That is, the position of the center portion CP2 of the equilateral triangle 30 is shifted from the position of the center portion CP1 of the imaginary circle 5A.
When the power generation sections 71, 72, and 73 cannot be arranged so that the 3 vertices 31 of the equilateral triangle 30 are inscribed in the virtual circle 5A because the size of the substrate 6 is limited, the outputs of the power generation sections 71, 72, and 73 can be equalized by moving the equilateral triangle 30 in the direction in which the perpendicular bisector of the three sides of the equilateral triangle 30 extends.
However, in the rotation speed detector 200B, the power generation amounts of the power generation sections 71 and 72 are different from the power generation amount of the power generation section 73, compared to embodiment 1, and the power generation amounts of the power generation sections 71 and 72 are equal to each other and lower than the power generation amount of the power generation section 73 in the arrangement example of fig. 8. Therefore, similarly to embodiment 2, it is preferable that the capacity of the capacitor charged by the voltage pulse in the rotation speed detection circuit 9 be changed so that the voltage pulses from the 3 power generation units 71, 72, and 73 are not unbalanced.
According to the rotation speed detector 200B of embodiment 3, the following effects can be obtained in addition to the same effects as those of embodiment 1. Fig. 9 is a diagram showing a state in which components other than the power generating unit group are mounted on the substrate in the rotation speed detector according to embodiment 3. By disposing the power generation sections 71, 72, 73 as in embodiment 3, the area between the outer side of the equilateral triangle 30 and the outer peripheral portion of the substrate 6 can be enlarged as compared with embodiment 1, and therefore, the mounting space of the connector 8 can be secured.
In embodiment 3, an example in which only two vertices 31 out of 3 vertices 31 of the equilateral triangle 30 are inscribed in the virtual circle 5A is described, but similar effects can be obtained even in a case where the power generation units 71, 72, 73 are installed so that only 1 vertex 31 out of 3 vertices 31 of the equilateral triangle 30 is inscribed in the virtual circle 5A.
Fig. 10 is a configuration diagram of a rotation speed detector according to embodiment 4. The rotation speed detector 200A shown in fig. 5 is different from the rotation speed detector 200C shown in fig. 10 in that only 1 vertex 31 out of 3 vertices 31 of an isosceles triangle 30A as the virtual polygon 10 is inscribed in the virtual circle 5A in the rotation speed detector 200C. That is, the position of the center portion CP3 of the isosceles triangle 30A is shifted from the position of the center portion CP1 of the imaginary circle 5A. In fig. 10, a vertex 31 where the two waists 32a of the medium-waisted triangle 30A intersect is inscribed in the imaginary circle 5A.
Even when the power generation sections 71, 72, 73 cannot be arranged so that the 3 vertices 31 of the isosceles triangle 30A are inscribed in the virtual circle 5A because the size of the substrate 6 is limited, the power generation sections 71, 72, 73 can be arranged by moving the isosceles triangle 30A in the direction in which the perpendicular bisector of the base 32b of the isosceles triangle 30A extends.
In the rotation speed detector 200C according to embodiment 4, similarly to embodiment 2, it is preferable that the capacity of the capacitor charged with the voltage pulse is changed so that the voltage pulses from the 3 power generation units 71, 72, and 73 are not unbalanced.
According to the rotation speed detector 200C according to embodiment 4, the following effects can be obtained in addition to the same effects as those of embodiment 2. Fig. 11 is a diagram showing a state in which components other than the power generating unit group are mounted on the substrate in the rotation speed detector according to embodiment 4. By disposing the power generation sections 71, 72, 73 as in embodiment 4, the area between the outer side of the isosceles triangle 30A and the outer peripheral portion of the substrate 6 can be enlarged as compared with embodiment 2, and therefore, the mounting space of the connector 8 can be secured.
Fig. 12 is a perspective view of the rotation speed detector according to embodiment 5. Fig. 13 is a side view of the rotation speed detector according to embodiment 5. The differences between rotation speed detector 200 according to embodiment 1 and rotation speed detector 200D according to embodiment 5 are as follows. That is, in the rotation speed detector 200D, the power generation units 71, 72, 73 are attached such that only 1 vertex 31 out of the 3 vertices 31 of the equilateral triangle 30 as the virtual polygon 10 is inscribed in the virtual circle 5A, and the distance L1 from the pickup coil 72b to the magnet 5 is shorter than the distance L2 from the pickup coils 71b, 73b to the magnet 5.
When the distances from the pickup coils 71b, 72b, 73b to the magnet 5 are changed, the amount of power generation is changed. When the position of the center portion CP2 of the equilateral triangle 30 is shifted from the position of the center portion CP1 of the magnet 5 as shown in fig. 12, the power generation amounts of the power generation units 71, 73 are equal to each other and larger than the power generation amount of the power generation unit 72, and an imbalance of 3 power generation amounts occurs.
By making the distance L1 from the pickup coil 72b of the power generation section 72 to the magnet 5 shorter than the distance L2 from the pickup coils 71b, 73b of the power generation sections 71, 73 to the magnet 5, it is possible to increase the amount of power generation by the power generation section 72 and equalize the amounts of power generation by 3 power generation sections, wherein the power generation section 72 is disposed on the side closest to the center CP1 of the magnet 5 among the 3 sides of the isosceles triangle, and the power generation sections 71, 73 are disposed on the remaining sides. Accordingly, balance adjustment based on the capacity of the capacitor charged using the voltage pulse is not required.
In embodiment 5, the distance L1 from the pickup coil 72b to the magnet 5 is shorter than the distance L2 from the pickup coils 71b and 73b to the magnet 5, but since the strength of the magnetic field differs depending on the position of the magnet 5, the distance from each of the pickup coils 71b, 72b, and 73b to the magnet 5 may be changed depending on the strength of the magnetic field, thereby maintaining the balance of 3 power generation amounts.
Fig. 14 is a perspective view of the rotation speed detector according to embodiment 6. In the revolution speed detector 200E according to embodiment 6, 1 magnet wire 74 is used instead of 3 magnet wires 71a, 72a, 73 a. The magnet wires 74 are formed in an equilateral triangle shape by bending two portions of 1 linear magnet wire. Pickup coils 71b, 72b, 73b are arranged on 3 sides of an equilateral triangle on a magnetic wire 74 formed in the shape of the equilateral triangle. Thereby, 3 power generation sections 71, 72, 73 are formed. Further, after 1 linear magnetic wire passes through the 3 pickup coils 71b, 72b, and 73b, the magnetic wire is bent at two positions, thereby obtaining 3 power generation sections 71, 72, and 73.
When 3 magnet wires 71a, 72a, 73a are cut out from an elongated magnet wire, a difference occurs in the magnetic characteristics of the 3 magnet wires 71a, 72a, 73a due to a variation in stress generated in the magnet wires at the time of cutting, and the amounts of power generation in the respective 3 power generation sections 71, 72, 73 are unbalanced.
In embodiment 6, the magnet wire has a polygonal shape formed by bending 1 wire rod, and the pickup coils 71b, 72b, and 73b are provided on each of a plurality of sides of the polygonal magnet wire. Since 3 power generation units 71, 72, and 73 can be configured by bending 1 magnetic wire, there is no variation in stress due to cutting, and imbalance in the amount of power generation in each of the 3 power generation units 71, 72, and 73 can be eliminated.
Embodiment 7.
Fig. 15 is a configuration diagram of a rotation speed detector according to embodiment 7. In the revolution speed detector 200F according to embodiment 7, ferrite beads 50 as soft magnetic bodies are provided at both ends of each of the magnetic wires 71a, 72a, and 73 a. The ferrite beads 50 are arranged in the vicinity of 3 vertices 31 of the equilateral triangle 30 constituting the virtual polygon 10. Preferably, the ferrite beads 50 have a higher permeability than the magnetic wires 71a, 72a, 73 a. Since the ferrite bead 50 is provided, the magnetic flux is linked to the ferrite bead 50 when the magnet 5 rotates, and the ferrite bead 50 itself is magnetized, the amount of power generation generated by each of the power generation units 71, 72, and 73 increases, and the detection accuracy of the rotational speed improves.
Fig. 16 is a diagram showing a modification of the rotation speed detector according to embodiment 7. Fig. 17 is an enlarged view of the ferrite bead shown in fig. 16. In the revolution speed detector 200F shown in fig. 15, ferrite beads 50 provided at both ends of each of the magnetic wires 71a, 72a, 73a are used, but in the revolution speed detector 200G shown in fig. 16, ferrite beads 51 connected to two adjacent magnetic wires are used. As shown in fig. 17, magnet wires 71a and 73a are connected to the ferrite bead 51. The magnetic wires 71a, 73a are fixed to the ferrite bead 51 so as not to contact each other. The use of the ferrite beads 51 can provide the same effects as those of the ferrite beads 50 shown in fig. 15, and the number of the ferrite beads 51 used can be reduced as compared with the case of using the ferrite beads 50, so that the manufacturing time of the rotation speed detector can be shortened.
The configuration described in the above embodiment is an example of the content of the present invention, and may be combined with other known techniques, and a part of the configuration may be omitted or modified without departing from the scope of the present invention.
Description of the reference numerals
1: a frame; 2: a stator; 3: a rotor; 4: a shaft; 4 a: an end portion; 5: a magnet; 5A: an imaginary circle; 5a, 5b, 6a, 6 b: an end face; 6: a substrate; 7. 7A: a power generation unit group; 8: a connector; 9: a rotation speed detection circuit; 10: an imaginary polygon; 30: an equilateral triangle; 30A: an isosceles triangle; 50. 51: ferrite beads; 71. 72, 73: a power generation unit; 71a, 72a, 73a, 74: a magnetic wire; 71b, 72b, 73 b: a pickup coil; 100: a motor; 200. 200A, 200B, 200C, 200D, 200E, 200F, 200G: and a rotation speed detector.
Claims (14)
1. A rotation speed detector is characterized in that a rotation speed detector is provided,
has a disk-shaped magnet provided on a shaft and 3 or more power generating sections composed of magnetic wires and pickup coils,
each of the power generating portions is disposed on each of a plurality of sides of a virtual polygon formed on the end face side of the magnet,
at least one vertex of the polygon, when the magnet is viewed from the side of the magnet in a plan view of 3 or more of the power generating sections, is inscribed in an imaginary circle having a diameter equal to that of the magnet.
2. A revolution speed detector according to claim 1,
the polygon is an equilateral triangle or an isosceles triangle,
all the vertexes of the equilateral triangle or isosceles triangle are inscribed in the imaginary circle.
3. A revolution speed detector according to claim 1,
the polygon is an equilateral triangle or an isosceles triangle,
a plurality of the vertices of the equilateral triangle or isosceles triangle are inscribed in the imaginary circle.
4. A rotation speed detector according to claim 3,
the distance from the power generating portion disposed on the side closest to the center of the magnet among the 3 sides of the isosceles triangle to the magnet is shorter than the distance from the power generating portion disposed on the remaining side to the magnet.
5. A rotation speed detector according to claim 3,
the angle of the apex angle of the isosceles triangle is greater than the hysteresis angle of the rotation angle generated in the magnet wire due to the difference in the rotation direction of the magnet.
6. A revolution speed detector according to claim 4,
the angle of the apex angle of the isosceles triangle is greater than the hysteresis angle of the rotation angle generated in the magnet wire due to the difference in the rotation direction of the magnet.
7. A revolution speed detector according to claim 1,
the magnet wire is in a polygon formed by bending 1 wire rod,
the pickup coils are disposed on each of a plurality of sides of the polygonal magnet wire.
8. A revolution speed detector according to claim 2,
the magnet wire is in a polygon formed by bending 1 wire rod,
the pickup coils are disposed on each of a plurality of sides of the polygonal magnet wire.
9. A rotation speed detector according to claim 3,
the magnet wire is in a polygon formed by bending 1 wire rod,
the pickup coils are disposed on each of a plurality of sides of the polygonal magnet wire.
10. A revolution speed detector according to claim 4,
the magnet wire is in a polygon formed by bending 1 wire rod,
the pickup coils are disposed on each of a plurality of sides of the polygonal magnet wire.
11. A revolution speed detector according to claim 5,
the magnet wire is in a polygon formed by bending 1 wire rod,
the pickup coils are disposed on each of a plurality of sides of the polygonal magnet wire.
12. A rotation speed detector according to claim 1, 2, 3, 4, 5 or 7,
a soft magnet is provided at the end of the magnet wire.
13. A rotation speed detector according to claim 1, 2, 3, 4, 5 or 7,
in the magnet, the S pole and the N pole are magnetized along the thickness direction of the magnet respectively by 1 pole.
14. A revolution speed detector according to claim 12,
in the magnet, the S pole and the N pole are magnetized along the thickness direction of the magnet respectively by 1 pole.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2017/011135 WO2018173106A1 (en) | 2017-03-21 | 2017-03-21 | Rotation speed detector |
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| Publication Number | Publication Date |
|---|---|
| CN209927881U true CN209927881U (en) | 2020-01-10 |
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| CN201790000489.XU Active CN209927881U (en) | 2017-03-21 | 2017-03-21 | Rotation speed detector |
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| JP (1) | JP6336232B1 (en) |
| CN (1) | CN209927881U (en) |
| WO (1) | WO2018173106A1 (en) |
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| WO2020250439A1 (en) * | 2019-06-14 | 2020-12-17 | 三菱電機株式会社 | Rotation speed detector |
| CN111273053B (en) * | 2020-01-22 | 2022-11-01 | 武汉船用机械有限责任公司 | Rotating speed measuring device for motor |
| JP7428524B2 (en) * | 2020-01-27 | 2024-02-06 | ヒロセ電機株式会社 | rotation detection device |
| CN115943558A (en) * | 2020-06-30 | 2023-04-07 | 日本电产株式会社 | Motor and position estimation method |
| WO2022153356A1 (en) | 2021-01-12 | 2022-07-21 | 三菱電機株式会社 | Power generation element, magnetic sensor, and encoder |
| JPWO2022249795A1 (en) | 2021-05-27 | 2022-12-01 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5530298A (en) * | 1993-09-03 | 1996-06-25 | Dresser Industries, Inc. | Solid-state pulse generator |
| JP6017323B2 (en) * | 2013-01-15 | 2016-10-26 | ヒロセ電機株式会社 | Rotation detector |
| US9664535B2 (en) * | 2013-02-22 | 2017-05-30 | Mitsubishi Electric Corporation | Rotation number detector |
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2017
- 2017-03-21 JP JP2018506359A patent/JP6336232B1/en active Active
- 2017-03-21 CN CN201790000489.XU patent/CN209927881U/en active Active
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| WO2018173106A1 (en) | 2018-09-27 |
| JPWO2018173106A1 (en) | 2019-03-28 |
| JP6336232B1 (en) | 2018-06-06 |
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