WO2018092578A1 - Stator core and vr-type resolver provided with same - Google Patents

Abstract

This stator core (4) for a VR-type resolver (1) formed by stacking a plurality of core plates (7), has an annular yoke (8) and a plurality of teeth (9) that protrude from the yoke (8) toward the inside in the radial direction. A notch (10A) and a notch (10B) are formed as two feature portions having different shapes on the outer circumferential surface (8B) of the stator core (4). The angle (θ) [deg] formed between a straight line (11) that passes through the center (C) of the stator core (4) and the notch (10A), and a straight line (12) that passes through the center (C) of the stator core (4) and the notch (10B), satisfies the relationship 0 < θ < 180.

Description

Stator core and VR type resolver having the same

The present invention relates to a stator core for a VR (Variable Reluctance) type resolver and a VR type resolver including the same.

Generally, in order to suppress eddy current loss, a laminated core formed by punching a plurality of core plates from a rolled steel sheet and stacking the punched core plates is employed for the stator core. However, in the rolled steel sheet, a thickness deviation due to bending of a rolling roller used in the rolling process and a rolling magnetic anisotropy due to rolling remain. Therefore, when a plurality of punched core plates are stacked, the thickness deviation of each core plate and the rolling magnetic anisotropy accumulate, which adversely affects the dimensional accuracy and magnetic characteristics of the stator core. When such a stator core is used in a VR type resolver, the detection voltage does not become an accurate sine wave, so the rotation angle detection accuracy is poor.

On the other hand, for example, Patent Document 1 discloses a technique of rotating and laminating a plurality of punched core plates. Rotating lamination means that a plurality of punched core plates are rotated by mutually different angles and then laminated. According to this rotating lamination, the thickness deviation and rolling magnetic anisotropy of each core plate are averaged, and the dimensional accuracy and magnetic characteristics of the stator core can be improved, so that the detected voltage becomes an accurate sine wave. Therefore, the rotation angle detection accuracy is improved.

FIG. 9 of the present application shows a laminated iron core manufacturing apparatus disclosed in Patent Document 1. That is, when the steel plate 100 is conveyed onto the die 101 and the punch 102 is driven downward, the steel plate 100 is punched and the core plate 103 is formed. The punched core plate 103 is pushed into the squeeze ring 104 by the punch 102 and is caulked against the laminated iron core 106 held on the mounting table 105. Next, the hollow motor 107 is driven to rotate the laminated core 106 by a predetermined angle. Thereafter, punching by the punch 102 and rotation of the laminated core 106 by the hollow motor 107 are alternately repeated to form a laminated core 106 in which the core plate 103 is rotationally laminated.

JP 2011-156585 A

However, the apparatus for rotating and laminating the core plate is expensive because it has many moving parts and has a complicated structure, which increases the manufacturing cost of the stator core.

Therefore, an object of the present invention is to provide a technique for ensuring the rotational angle detection accuracy of a VR resolver at a low cost.

As a result of diligent research, the inventors of the present invention have found that the VR resolver can be obtained as long as the front and back sides and orientation of the stator core are laminated in the winding process without adopting rotational lamination when manufacturing the stator core. It has been found that the rotation angle detection accuracy can be secured at low cost. The reason is as follows. That is, in a plurality of stator cores manufactured on a single production line, the relationship between the front and back surfaces and the orientation when the stator cores are stacked and the directionality of the thickness deviation of the stator core and the rolling magnetic anisotropy is constant. Can be considered. Therefore, the number of turns of the detection coil is appropriately adjusted and determined for each tooth so that the required rotation angle detection accuracy can be obtained at the stator prototype stage. In the stator mass production stage, the determined number of turns is directly applied to the subsequent stator. When applied, the rotation angle detection accuracy of the subsequent stator is equivalent to the rotation angle detection accuracy of the prototyped stator. However, in order to apply the number of turns of the detection coil determined for each tooth in the trial production stage as it is to the subsequent stator in the mass production stage, it is necessary to grasp the front and back sides and the direction when the stator cores are stacked in the winding process. Therefore, the inventors of the present application have proposed the following stator core as a technical idea for grasping the front and back sides and the orientation of the stator core when they are stacked in the winding process.

That is, a stator core for a VR type resolver formed by laminating a plurality of core plates, the stator core having an annular yoke and a plurality of teeth projecting radially inward from the yoke, The outer peripheral surface is formed with two feature portions having at least one of a shape and a size, a straight line passing through the center of the stator core and one of the two feature portions, and the stator core An angle θ [deg.] Formed by the center and a straight line passing through the other of the two feature portions. ], A stator core satisfying 0 <θ <180 is provided.
Preferably, each of the two characteristic portions is formed on a straight line passing through the center of the stator core and any one of the plurality of teeth.
A stator core for a VR type resolver formed by laminating a plurality of core plates, the stator core having an annular yoke and a plurality of teeth projecting radially outward from the yoke. Two feature portions having at least one of a shape and a size different from each other are formed on the inner peripheral surface of the stator, a straight line passing through the center of the stator core and one of the two feature portions, and the stator core And an angle θ [deg.] Formed by a straight line passing through the other of the two feature portions. ], A stator core satisfying 0 <θ <180 is provided.
Preferably, each of the two characteristic portions is formed on a straight line passing through the center of the stator core and any one of the plurality of teeth.
Preferably, the two feature portions are both notches, or the two feature portions are both protrusions, or the two feature portions are notches and protrusions.
Preferably, the angle θ [deg. ] Satisfies 0 <θ <90.
Preferably, among all the core plates constituting the stator core, the thickest portions overlap each other in the stacking direction.
Preferably, a stator including the stator core, an insulator fixed to the stator core, and a plurality of coils respectively provided on a plurality of teeth of the stator core via the insulator, and rotatable with respect to the stator A VR resolver is provided.

According to the present invention, by confirming the two characteristic portions visually, it is possible to grasp the front and back sides and the direction when the stator core is laminated in the winding process. Therefore, the number of turns of the detection coil determined for each tooth in the trial production stage can be applied to the subsequent stator as it is in the mass production stage, so that the rotational angle detection accuracy of the VR resolver can be secured at low cost.

It is a perspective view of a VR type resolver in which illustration of a coil and a connecting wire is omitted. (First embodiment) It is the elements on larger scale of a stator. (First embodiment) It is a top view of a stator core. (First embodiment) It is a fragmentary top view of a stator core. (First embodiment) It is a fragmentary perspective view of a stator core. (First embodiment) It is a flowchart of the manufacturing method of a stator. (First embodiment) It is a fragmentary top view of a stator core. (Second Embodiment) It is a fragmentary top view of a stator core. (Third embodiment) It is the figure which simplified FIG. 1 of patent document 1. FIG.

(First embodiment)
The first embodiment will be described below with reference to FIGS.

FIG. 1 shows a VR resolver 1 for measuring a rotation angle and a rotation speed of a shaft of an electric motor or an internal combustion engine (not shown). The VR resolver 1 includes an annular stator 2 and a rotor 3 fixed to the shaft. The VR type resolver 1 of this embodiment is an inner rotor type in which the rotor 3 rotates inward in the radial direction of the stator 2.

(Rotor 3)
Concavities and convexities (not shown) are formed on the outer peripheral surface of the rotor 3, and the gap between the rotor 3 and the stator 2 changes periodically according to the rotation angle of the rotor 3.

(Stator 2)
As shown in FIGS. 1 and 2, the stator 2 includes a stator core 4, an insulator 5, a plurality of coils 6, and an external connection portion 30. FIG. 1 shows a rotation axis 2 </ b> C of the stator 2.

As shown in FIG. 2, the stator core 4 employs a laminated core formed by punching a plurality of core plates 7 from a rolled steel plate and laminating the punched core plates 7. In the present embodiment, the plurality of core plates 7 are not rotationally stacked. That is, the thickness deviation and rolling magnetic anisotropy of the plurality of core plates 7 constituting the stator core 4 are accumulated. Therefore, when the thickness distribution of the plurality of core plates 7 constituting the stator core 4 is measured, the thickest portions of the core plates 7 overlap each other in the stacking direction. In this embodiment, all the core plates 7 constituting the stator core 4 have the same shape.

3, the stator core 4 has an annular yoke 8 and a plurality of teeth 9. The yoke 8 has an inner peripheral surface 8A and an outer peripheral surface 8B. The plurality of teeth 9 are arranged at equal intervals in the circumferential direction and protrude from the inner circumferential surface 8 </ b> A of the yoke 8 inward in the radial direction.

The outer peripheral surface 8B of the yoke 8 is formed with a notch 10A and a notch 10B as two characteristic parts. The notch 10A and the notch 10B are formed apart from each other in the circumferential direction.

The notch 10A is formed on a straight line 11 passing through the center C of the stator core 4 and one tooth 9 in plan view. The teeth 9 positioned between the notch 10A and the center C of the stator core 4 are hereinafter referred to as teeth 9A. Similarly, the notch 10B is formed on a straight line 12 passing through the center C of the stator core 4 and the other one tooth 9 in plan view. The teeth 9 positioned between the notch 10B and the center C of the stator core 4 are hereinafter referred to as teeth 9B.

Then, an angle θ [deg.] Formed by a straight line 11 passing through the center C of the stator core 4 and the notch 10A and a straight line 12 passing through the center C of the stator core 4 and the notch 10B. ] Satisfies 0 <θ <180. Preferably, the angle θ [deg. ] Satisfies 0 <θ <90. In the present embodiment, the angle θ [deg. ] Is 45.

As shown in FIG. 4, the notch 10A and the notch 10B are formed in a rectangular shape in plan view. The cutout 10A and the cutout 10B have different shapes in plan view. In the present embodiment, the dimension in the radial direction of the notch 10A is equal to the dimension in the radial direction of the notch 10B, but the dimension in the circumferential direction of the notch 10A is smaller than the dimension in the circumferential direction of the notch 10B. Accordingly, the operator can visually distinguish the notch 10A and the notch 10B.

As shown in FIG. 5, the notch 10 </ b> A extends in parallel to the rotational axis 2 </ b> C of the stator 2 from the front surface 4 </ b> A to the back surface 4 </ b> B of the stator core 4. Accordingly, the notch 10 </ b> A is formed to extend straight with respect to the rotation axis 2 </ b> C of the stator 2. Similarly, the notch 10 </ b> B extends in parallel to the rotation axis 2 </ b> C of the stator 2 from the front surface 4 </ b> A to the back surface 4 </ b> B of the stator core 4. Therefore, the notch 10 </ b> B is formed to extend straight with respect to the rotation axis 2 </ b> C of the stator 2.

Referring back to FIG. 1, the insulator 5 is made of an insulating resin and is fixed to the stator core 4 by, for example, insert molding. The insulator 5 is mainly provided to prevent the plurality of coils 6 from coming into direct contact with the stator core 4.

As shown in FIG. 2, each coil 6 is wound around each tooth 9 via an insulator 5. Each coil 6 includes an excitation coil and a detection coil. The plurality of coils 6 are connected to each other by a plurality of crossover wires 13. That is, the plurality of coils 6 are connected by a crossover wire 13A that connects the excitation coils and a crossover wire 13B that connects the detection coils.

(External connection 30)
As shown in FIG. 1, the external connection unit 30 is used to input excitation signals from an external device, and to output detection signals generated by the stator 2 to the external device. Is the part that holds The external connection part 30 is comprised by the terminal block integrally formed with the insulator 5, and the several terminal pin hold | maintained at the terminal block.

The VR resolver 1 described above operates as follows. That is, as described above, irregularities (not shown) are formed on the outer peripheral surface of the rotor 3 so that the gap between the rotor 3 and the teeth 9 of the stator 2 changes periodically according to the rotation angle of the rotor 3. It has become. The excitation coil and the detection coil of the stator 2 are magnetically connected via the rotor 3. When an alternating current is passed through the excitation coil, an induced voltage is generated in the detection coil. Since the gap changes according to the rotation angle of the rotor 3, the magnetic resistance changes, and accordingly, the amplitude of the induced voltage changes according to the rotation angle of the rotor 3. The detection coil has two phases, and each is designed such that the induced voltage changes in a SIN shape and a COS shape with respect to the rotation angle of the rotor 3. Therefore, the rotation angle and the number of rotations of the rotor 3 are obtained from the ratio of the two-phase induced voltages.

(Manufacturing method of stator 2)
Next, a method for manufacturing the stator 2 will be described with reference to FIG.

Step S100: Punching and Laminating Step First, a plurality of core plates 7 are punched from a rolled steel sheet, and the plurality of punched core plates 7 are stacked. Specifically, the core plate 7 punched out from the rolled steel plate is accommodated in a stacking mold disposed immediately below the punch, and is caulked against the other core plate 7 previously accommodated. The stator core 4 is formed by repeating this punching and caulking a predetermined number of times.

Step S110: Injection Molding Process Next, an operator sets the stator core 4 in an injection mold. At this time, the operator recognizes the front and back and the direction when the stator core 4 is laminated by visually checking the notches 10A and 10B shown in FIG.

Here, if the surface 4A of the stator core 4 shown in FIG. 5 is a surface that is in contact with the punch when punched by the punch, the notch 10B is notched 10A when the operator holds the stator core 4. When viewed more clockwise, the surface 4A of the stator core 4 faces the operator. Therefore, the operator can set the stator core 4 in the injection mold so that the surface 4A of the stator core 4 faces upward. According to this, the stator core 4 can be set in the injection mold without causing burrs generated during punching to be caught on the inner surface of the injection mold.

Also, the operator sets the stator core 4 in the injection mold so that the notch 10A and the notch 10B of the stator core 4 are fitted to the pins provided in the injection mold.

Then, the terminal block of the insulator 5 and the external connection part 30 is formed by clamping the injection mold and injecting the molten resin into the injection mold. Thereby, the position of the external connection part 30 with respect to the front and back and the direction when the stator core 4 is laminated is maintained constant.

Step S120: Winding Step Next, an intermediate product in which the insulator 5 and the external connection portion 30 are provided on the stator core 4 is set in an automatic winding machine. At this time, the worker sets the intermediate product in the automatic winding machine so that the external connection portion 30 is in a predetermined posture at a predetermined position in the automatic winding machine. Then, the winding by the automatic winding machine is performed, so that the plurality of coils 6 are respectively formed on the plurality of teeth 9 of the stator core 4 via the insulator 5 to complete the stator 2.

In the trial production stage of the stator 2, the number of turns of the SIN side detection coil of the coil 6 for each tooth 9 so that the induced voltage of the SIN side detection coil and the induced voltage of the COS side detection coil have a sinusoidal distribution as much as possible. And the number of turns of the COS side detection coil is appropriately adjusted and determined.

On the other hand, in the mass production stage of the stator 2, the number of turns of the SIN side detection coil and the number of turns of the COS side detection coil determined for each tooth 9 in the trial production stage are applied to the subsequent stator 2 as they are. According to this, the relationship between the number of turns of the SIN-side detection coil and the number of COS-side detection coils for each tooth 9 and the thickness deviation of the stator core 4 and the direction of the rolling magnetic anisotropy is as follows. 2 and the subsequent stator 2 are the same. Therefore, the rotation angle detection accuracy equivalent to the rotation angle detection accuracy achieved in the prototype stage is also achieved in the subsequent stator 2.

The first embodiment described above has the following features.

For example, as shown in FIGS. 1 to 4, the stator core 4 for the VR resolver 1 formed by laminating a plurality of core plates 7 includes an annular yoke 8 and a plurality of protrusions projecting radially inward from the yoke 8. Teeth 9. On the outer peripheral surface 8B of the stator core 4, a notch 10A and a notch 10B are formed as two characteristic portions having different shapes. An angle θ [deg.] Formed by a straight line 11 passing through the center C of the stator core 4 and the notch 10A and a straight line 12 passing through the center C of the stator core 4 and the notch 10B. ] Satisfies 0 <θ <180. According to the above configuration, by confirming the notch 10A and the notch 10B with the eyes, it is possible to grasp the front and back and the direction when the stator core 4 is laminated in the winding process. Therefore, the number of turns of the coil 6 determined at the trial production stage for each tooth 9 can be applied as it is to the subsequent stator 2 in the mass production stage, and therefore, the rotation angle of the VR resolver 1 can be achieved without performing rotational lamination. Detection accuracy can be ensured at low cost.

For example, as shown in FIG. 3, in the first embodiment, two feature portions are formed on the outer peripheral surface 8 </ b> B of the stator core 4. If there are three or four characteristic portions, it takes a lot of time, though slightly, when the operator visually confirms the plurality of characteristic portions. On the other hand, if there is only one characteristic part, the front and back when the stator core 4 is laminated cannot be determined. Accordingly, it is considered essential that the number of feature portions is only two.

Further, for example, as shown in FIG. 4, in the first embodiment, the notch 10A and the notch 10B are different in shape, but instead, only the size may be different, the shape and Both sizes may be different.

For example, as shown in FIG. 3, the notch 10A is formed on a straight line 11 passing through the center C of the stator core 4 and the teeth 9A. The notch 10B is formed on a straight line 12 that passes through the center C of the stator core 4 and the teeth 9B. According to the above configuration, it is possible to suppress an increase in the magnetic resistance with respect to the magnetic flux formed in the yoke 8 due to the notches 10A and 10B, and the rotation angle detection accuracy of the VR resolver 1 is not adversely affected. .

Also, for example, as shown in FIG. 3, the angle θ [deg. ] Preferably satisfies 0 <θ <90. According to the above configuration, the notch 10A and the notch 10B are formed close to each other, so that it is easy to recognize at a glance at the same time.

In addition, among all the core plates 7 constituting the stator core 4, the thickest portions overlap each other in the stacking direction. The above configuration is most characterized by the fact that the stator core 4 of the present embodiment is not rotationally laminated.

For example, as shown in FIG. 1, the VR resolver 1 includes a stator core 4, an insulator 5 fixed to the stator core 4, and a plurality of coils provided on a plurality of teeth 9 of the stator core 4 via the insulator 5. 6 and a rotor 3 rotatable relative to the stator 2. According to the above configuration, the rotational angle detection accuracy of the VR resolver 1 can be ensured at low cost.

In this embodiment, when the intermediate product is set in the automatic winding machine, the intermediate product is set in the automatic winding machine so that the external connection portion 30 is in a predetermined posture at a predetermined position in the automatic winding machine. It was decided. However, instead of this, when the intermediate product is set in the automatic winding machine, the intermediate product is automatically wound so that the notch 10A and the notch 10B have a predetermined posture at a predetermined position in the automatic winding machine. It may be set in the machine.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. Hereinafter, the present embodiment will be described with a focus on differences from the first embodiment, and a duplicate description will be omitted.

As shown in FIG. 4, in the first embodiment, the outer peripheral surface 8 </ b> B of the stator core 4 is formed with notches 10 </ b> A and 10 </ b> B having different shapes as two characteristic portions.

However, instead of this, as shown in FIG. 7, in the present embodiment, the outer peripheral surface 8B of the stator core 4 is formed with protrusions 10C and protrusions 10D having different sizes as two characteristic portions. Even with the above configuration, the rotational angle detection accuracy of the VR resolver 1 can be secured at a low cost for the same reason as described in the first embodiment.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. Hereinafter, the present embodiment will be described with a focus on differences from the first embodiment, and a duplicate description will be omitted.

As shown in FIG. 4, in the first embodiment, the outer peripheral surface 8 </ b> B of the stator core 4 is formed with notches 10 </ b> A and 10 </ b> B having different shapes as two characteristic portions.

However, instead of this, as shown in FIG. 8, in the present embodiment, the outer peripheral surface 8B of the stator core 4 is formed with two protrusions 10E and a notch 10F. Even with the above configuration, the rotational angle detection accuracy of the VR resolver 1 can be secured at a low cost for the same reason as described in the first embodiment.

In the first to third embodiments, the so-called inner rotor type VR resolver 1 in which the plurality of teeth 9 protrude radially inward from the yoke 8 has been described. However, the VR resolver may adopt a so-called outer rotor type in which a plurality of teeth protrude radially outward from the yoke. In this case, the two characteristic portions are formed on the inner peripheral surface of the stator core.

This application claims priority based on Japanese Patent Application No. 2016-225750 filed on November 21, 2016, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 1 VR type resolver 2 Stator 2C Rotating axis 3 Rotor 4 Stator core 4A Front surface 4B Back surface 5 Insulator 6 Coil 7 Core plate 8 Yoke 8A Inner peripheral surface 8B Outer peripheral surface 9 Teeth 9A Teeth 9B Teeth 10A Notch (characteristic part)
10B Notch (characteristic part)
10C Protrusion (characteristic part)
10D protrusion (characteristic part)
10E Protrusion (characteristic part)
10F Notch (characteristic part)
11 Straight line 12 Straight line 13 Crossover line 13A Crossover line 13B Crossover line 30 External connection C Center θ Angle

Claims (8)

A stator core for a VR resolver formed by laminating a plurality of core plates,
An annular yoke,
A plurality of teeth projecting radially inward from the yoke;
Have
On the outer peripheral surface of the stator core, two characteristic portions different in at least one of shape and size are formed,
An angle θ [deg.] Formed by a straight line passing through the center of the stator core and one of the two characteristic portions and a straight line passing through the center of the stator core and the other of the two characteristic portions. ] Satisfies 0 <θ <180.
Stator core. The stator core according to claim 1,
Each of the two characteristic portions is formed on a straight line passing through the center of the stator core and any one of the plurality of teeth.
Stator core. A stator core for a VR resolver formed by laminating a plurality of core plates,
An annular yoke,
A plurality of teeth projecting radially outward from the yoke;
Have
On the inner peripheral surface of the stator core, two characteristic portions different in at least one of shape and size are formed,
An angle θ [deg.] Formed by a straight line passing through the center of the stator core and one of the two characteristic portions and a straight line passing through the center of the stator core and the other of the two characteristic portions. ] Satisfies 0 <θ <180.
Stator core. The stator core according to claim 3, wherein
Each of the two characteristic portions is formed on a straight line passing through the center of the stator core and any one of the plurality of teeth.
Stator core. A stator core according to any one of claims 1 to 4, wherein
The two feature parts are both notches,
Or
The two characteristic parts are both protrusions,
Or
The two characteristic parts are a notch and a protrusion,
Stator core. A stator core according to any one of claims 1 to 5, wherein
The angle θ [deg. ] Satisfies 0 <θ <90,
Stator core. A stator core according to any one of claims 1 to 6,
Between all the core plates constituting the stator core, the thickest portions overlap each other in the stacking direction,
Stator core. The stator core according to any one of claims 1 to 7, an insulator fixed to the stator core, and a plurality of coils respectively provided on a plurality of teeth of the stator core via the insulator. Including a stator,
A rotor rotatable with respect to the stator;
VR resolver provided with

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