JP2003189581A - Step motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a magnetoresistance between a coil yoke and a polar tooth yoke to be reduced without increasing in size of an outer diameter of a stepping motor. <P>SOLUTION: The step motor comprises a permanent magnet block 29 relatively rotated to polar tooth yokes 34, 35 and 36 by changing an energization of a plurality of coil windings 33a, 33b of an electromagnetic coil block 32 in a predetermined pattern. A protrusion 50 protruding in a lateral direction is provided on the inside polar tooth yoke 35, and a recess 51 is provided on an end of a yoke coil 40 opposed to the protrusion 50. Thus, a magnetism is input or output between the yoke 40 and the yoke 35 at the protrusion 50 and the recess 51. Accordingly, as compared with the case in which the magnetism is input and output only at opposed surfaces perpendicularly crossed with an axial direction, the magnetoresistance is reduced in that corresponding to an increase in the opposed area. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step motor used as an actuator for rotation in various devices.

[0002]

2. Description of the Related Art Conventionally, as a PM type stepping motor, for example, one described in JP-A-7-39130 has been proposed.

In this step motor, an annular plate-shaped outer pole tooth yoke having a plurality of radially inward pole teeth and a disk-shaped inner pole tooth yoke having a plurality of radially outward pole teeth are provided. , An annular plate-shaped intermediate pole tooth yoke having a plurality of outward pole teeth and inward pole teeth is arranged, and a magnetic field is appropriately generated by a pair of electromagnetic coils in the tooth group of these pole tooth yokes. The permanent magnet block arranged so as to face the yoke is rotated. Specifically, the pole teeth on the opposite sides of the outer pole tooth yoke and the middle pole tooth yoke and the pole teeth on the opposite sides of the middle pole tooth yoke and the inner pole tooth yoke respectively form a pair, and the magnetic poles generated in these pole tooth pairs are set to both electromagnetic fields. The magnetic attraction repulsive force acting on the permanent magnet block is changed along the circumferential direction by appropriately changing the coil energization control. Each electromagnetic coil has a coil winding and a coil yoke. One end surface of the coil yoke in the axial direction faces each pole tooth yoke, and the magnetic flux generated by the electromagnetic coil is the corresponding pole from the end surface of the coil yoke. It flows into the tooth yoke.

[0004]

However, in the above-mentioned conventional step motor, one end face in the axial direction, which is the magnetic entry / exit portion of the coil yoke, and the corresponding pole tooth yoke are in a plane orthogonal to the axial direction. Because they face each other,
When the outer diameter of the motor is limited, it is not possible to sufficiently secure the facing area between them. Therefore, it is difficult to sufficiently reduce the resistance of the magnetic path including the coil yoke and the pole tooth yoke, and the loss of magnetic flux in the magnetic path must be increased. Therefore, in the case of the conventional step motor, the energizing current is inevitably large in order to secure a sufficient torque, which causes a problem that the power consumption is large.

Therefore, the present invention makes it possible to sufficiently reduce the magnetic resistance between the coil yoke and the pole tooth yoke without increasing the outer diameter of the motor, thereby achieving both miniaturization of the device and reduction in power consumption. An object of the present invention is to provide a step motor that can be achieved.

[0006]

As a means for solving the above-mentioned problems, the present invention provides an outer pole tooth yoke having a plurality of radially inward pole teeth and a plurality of radially outward pole teeth. An inner pole tooth yoke having an outer pole tooth yoke, an outer pole tooth yoke disposed between the outer pole tooth yoke and the inner pole tooth yoke, and a radially outward pole tooth positioned between adjacent pole teeth of the outer pole tooth yoke, and an inner pole tooth. An intermediate pole tooth yoke having radially inwardly facing pole teeth located between adjacent pole teeth of the yoke, and an electromagnetic coil block having a plurality of coil windings and a coil yoke facing the pole tooth yokes. A permanent magnet block rotatably provided so that the different magnetic poles are alternately arranged along the circumferential direction, and the magnetic pole surface faces the pole teeth of each pole tooth yoke. , For multiple coil windings of the electromagnetic coil block By varying the conductive in a predetermined pattern, in the step motor for relatively rotating the permanent magnet blocks with respect to the pole teeth yoke, of said pole teeth yokes, and at least one of the pole teeth yoke,
The coil yoke facing the pole tooth yoke is provided with one of a convex portion and a concave portion, one of which protrudes in the axial direction and the other of which corresponds to the depression. In the case of the present invention, since the magnetism is inputted and outputted between the coil yoke and the pole tooth yoke in the convex portion provided on one side and the concave portion provided on the other side, the magnetism is inputted and outputted only on the opposing surfaces orthogonal to the axial direction. Compared with the case, the magnetic resistance is reduced by the increase in the facing area.

It is desirable that the portion where the convex portion and the concave portion are provided is the inner pole tooth yoke and the end surface of the coil yoke that faces the pole tooth yoke. That is, since the inner pole tooth yoke has a small diameter, it is more difficult to secure the area of the end face as compared with the intermediate pole tooth yoke and the outer pole tooth yoke, but the inner pole tooth yoke and the coil facing the pole tooth yoke. By providing each of the convex portion and the concave portion on the end surface of the yoke, it is possible to easily reduce the magnetic resistance of that portion.

Further, at this time, it is desirable that the convex portion is provided on the inner pole tooth yoke side and the concave portion is provided on the end surface of the coil yoke. In this case, the convex portion of the inner pole tooth yoke enters into the concave portion of the coil yoke, but since the coil winding is not located in the area on the radial inside of the coil yoke, the dead space of this coil yoke is formed. Can be effectively used.

Further, the convex portion and the concave portion may be provided with an inclined surface which is inclined with respect to the axial direction. In this case, the change in shape of the outer surfaces of the convex portion and the concave portion becomes gradual, so that the magnetic flux flowing into the pole tooth yoke or the coil yoke is less likely to concentrate in a part, and the magnetic flux flows more smoothly.

Further, according to the present invention, a driven rotating body which is rotationally driven by a crankshaft of an internal combustion engine, and a camshaft or a separate member connected to the shaft, and a driven rotating body to which power is transmitted from the driving rotating body. A body, a radial guide provided on either one of the drive rotary body and the driven rotary body, and a side provided so as to be rotatable relative to the drive rotary body and the driven rotary body and facing the radial guide. Of the intermediate rotating body having a spiral guide on its surface, a movable guide portion displaceably guided and engaged with the radial guide and the spiral guide, and rotation of the other one of the drive rotating body and the driven rotating body. In a valve timing control device for an internal combustion engine, comprising a link that swingably connects the movable guide portion and a portion that is separated from the center, in the intermediate rotor, a drive rotor and It is suitable when used in the operation force imparting means for imparting a relative rotational operation force on the kinematic rotor. That is, since the step motor of the present invention can reduce the magnetic resistance between the coil yoke and the pole tooth yoke without increasing the outer diameter of the entire motor, the step motor can be used in a valve timing control device while suppressing an increase in power consumption. Can be stored compactly.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to the drawings.

In this embodiment, the step motor 4 according to the present invention is used in an actuator portion (operating force applying means) of a valve timing control device for an internal combustion engine.
As shown in FIG. 1, this valve timing control device includes an intake-side camshaft 1 rotatably supported by a cylinder head (not shown) of an internal combustion engine, and the camshaft 1.
A drive plate 3 having a timing sprocket 2 on its outer periphery, which is attached to the front end of the crankshaft so as to be rotatable relative to the crankshaft and is connected to a crankshaft (not shown) via a chain (not shown). Body), the front side of the drive plate 3 and the camshaft 1 (left side in FIG. 1)
And an assembly angle operating mechanism 5 for rotating the assembly angles of the both 3 and 1, and an assembly angle operating mechanism 5 arranged further forward of the assembly angle operating mechanism 5 for driving and operating the assembly angle. The step motor 4, the cylinder head (not shown) of the internal combustion engine, and the VTC cover 12 that is mounted over the front surface of the rocker cover and covers the assembly angle operation mechanism 5, the front surface of the step motor 4, and the peripheral area.
And are equipped with.

The drive plate 3 is formed in a disk shape having an insertion hole 6, and a lever shaft 10 (driven rotor) integrally connected to the front end portion of the cam shaft 1 is rotatable in the insertion hole 6 portion. It is assembled. Then, as shown in FIG. 2, three radial grooves 8 (radial guides) are formed on the front surface of the drive plate 3 (the surface opposite to the camshaft 1) so as to extend along the radial direction of the plate 3. Has been done.

Further, as shown in FIG. 1, the lever shaft 10 is integrally formed with three levers 9 radially protruding on the outer peripheral surface thereof, and is connected to the camshaft 1 by a bolt 13 penetrating the shaft center portion. ing. A base end of a link 14 is pivotally connected to each lever 9 of the lever shaft 10 by a pin 15, and a cylindrical boss 17 slidably engaged with each radial groove 8 is provided at a tip of each link 14. Are integrally formed.

Since each boss 17 is connected to the lever shaft 10 through the pivotal support of the link 14 and the lever 9 in a state of being engaged with the corresponding radial groove 8, the tip of the link 14 receives an external force. When received and displaced along the radial groove 8,
The drive plate 3 and the lever shaft 10 are relatively rotated by the action of the link 14 by a direction and an angle corresponding to the displacement of the boss 17.

A holding hole 18 is provided at the tip of each link 14 toward the boss 17 from the front side of the link body, and the holding hole 18 has a ball 19 and a substantially cylindrical retainer 20. A coil spring 21 for urging the retainer 20 forward is housed. The boss 17 and the ball 19 at the tip of the link 14 form a movable guide portion.

On the other hand, a substantially disk-shaped intermediate rotating body 23 is rotatably supported on the front side of the protruding position of the lever 9 of the lever shaft 10. A spiral groove 24 (spiral guide) having a semicircular cross section is formed on the rear surface of the intermediate rotating body 23, and the sphere 19 held at the tip of each link 14 is freely rollable in the spiral groove 24. Is engaged with. The spiral of the spiral groove 24 is formed so as to gradually reduce its diameter along the engine rotation direction R as shown in FIGS. 2 and 13 and 14. Therefore, the ball 19 of each link 14 is
When the intermediate rotating body 23 relatively rotates in the delay direction (deceleration direction) with respect to the drive plate 3 in the state of being engaged with 4, the tip end portion of the link 14 moves inward in the radial direction along the spiral shape of the spiral groove 24. Conversely, when the intermediate rotating body 23 relatively rotates in the advancing direction (acceleration direction), it moves outward in the radial direction.

The assembling angle operation mechanism 5 includes the radial groove 8, the boss 17, the ball 19, and the link 1 of the drive plate 3 described above.
4, the lever 9, the spiral groove 24 of the intermediate rotating body 23, and the like. In this assembly angle operation mechanism 5, when a relative rotational operation force with respect to the cam shaft 1 is input from the step motor 4 to the intermediate rotating body 23, the operation force passes through the spiral groove 24 and the engaging portion of the ball 19. The tip of the link 14 is displaced in the radial direction, and at this time, the relative rotational force is transmitted to the drive plate 3 and the cam shaft 1 by the action of the link 14 and the lever 9.

On the other hand, the step motor 4 includes a permanent magnet block 29 joined to the front side of the intermediate rotor 23 (the side opposite to the drive plate 3) and a yoke block 30 integrally connected to the lever shaft 10. , An electromagnetic coil block 32 mounted in the VTC cover 12, and the electromagnetic coil block 32 has a pair of coil windings 33a and 33b, which will be described later. Drive circuit (not shown) including pulse distribution circuit
It is connected to the. This drive circuit is controlled by a controller (not shown), which receives various input signals such as crank angle, cam angle, engine speed, and engine load, and drives control signals according to the operating state of the engine at any time. Output to the circuit.

As shown in FIG. 3, the permanent magnet block 29 has magnetic poles (N poles and S poles) extending in the radial direction on the surface facing the yoke block 30, and different magnetic poles in the circumferential direction. A plurality of magnets are magnetized so that they alternate along each other. Incidentally, FIG.
The magnetic poles of the middle permanent magnet block 29 are marked with N and S.

The yoke block 30 is shown in FIGS.
As shown in 0, the plurality of pole teeth 34 extending inward in the radial direction.
a substantially annular outer pole tooth yoke 34 having an a-shape, and a plurality of inner pole tooth yokes 35a arranged concentrically on the inner peripheral side of the outer pole tooth yoke 34 and extending radially outward. 35, the outer pole tooth yoke 34 and the inner pole tooth yoke 35, and the outward pole tooth 36a extending outward in the radial direction.
And an intermediate pole tooth yoke 36 having inward pole teeth 36b extending radially inward. Each of these yokes 3
4 to 36 are formed of a metal material having a high magnetic permeability and are coupled to each other by an insulating resin material so that the yoke block 30 as a whole has a substantially disc shape.

Outer pole tooth yoke 34 and intermediate pole tooth yoke 3
6, pole teeth 34a, 36a, and 36b, which extend to the opposite sides of the intermediate pole tooth yoke 36 and the inner pole tooth yoke 35, respectively.
35a form a pair with each other, and the pole teeth forming each pair (hereinafter, referred to as "outer pole tooth pair" and "inner pole tooth pair") are alternately arranged at equal pitches along the circumferential direction. It is arranged. The outer pole tooth pair and the inner pole tooth pair have a pole tooth of a quarter pitch angle in the circumferential direction when the pitch between the teeth of one pole tooth yoke 34 (35, 36) is one pitch angle. It is arranged so as to be offset. Further, each base portion 34 of the pole tooth yokes 34 to 36 is
The c, 35c, and 36c are formed in an annular shape and face the electromagnetic coil block 32, respectively.

As shown in FIG. 6, in the outer pole tooth yoke 34 and the intermediate pole tooth yoke 36, the end faces of the base portions 34c, 36c on the electromagnetic coil block 32 side are located on the same plane orthogonal to the axial direction. However, the inner pole tooth yoke 35 is
The base portion 35c is the base portion 34 of the other pole tooth yoke 34, 36.
c, 36c axially front side (electromagnetic coil block 3
2), and the protruding portion forms the convex portion 50 in the present invention. Incidentally, extending the base 35c of the inner pole tooth yoke 35 includes a thick cylindrical wall 35c ₁ that connects to the pole teeth 35a in the permanent magnet blocks 29 side, the end of the electromagnetic coil block 32 side of the thick cylindrical wall 35c ₁ It is composed of a thin disk wall 35c _{2 provided,} and as a whole is shown in FIG.
As shown in, the cross section is formed in a substantially L shape.

On the other hand, the electromagnetic coil block 32, as shown in FIGS. 1, 11, and 12, is a VT which is a non-rotating member.
A substantially disk-shaped coil yoke 40 locked to the C cover 12 in a state in which rotation is restricted, and a first coil yoke 40 concentrically housed in the coil yoke 40 while being wound around bobbins of different diameters. Coil winding 33a and second coil winding 33b
The end of the coil yoke 40 (the end opposite to the bottom surface of the VTC cover 12) faces the yoke block 30.

Specifically, annular magnetic inlets / outlets 37, 38, 39 having different diameters are concentrically arranged at the end of the coil yoke 40 on the side of the yoke block 30, and these magnetic inlets / outlets 37 are arranged. , 38, 39 are pole tooth yokes 34, 3
The annular base portions 34c, 36c, 35c of 6, 35 are opposed to each other via an air gap. Therefore,
When the coil windings 33a and 33b are excited and a magnetic field in a predetermined direction is generated, magnetic induction is generated in the corresponding pole teeth 34a, 36a, 36b and 35a of the yoke block 30 through the air gap, and the magnetic field is generated in that portion. Magnetic poles appear according to the direction of.

Here, of the magnetic entry / exit sections 37, 38, 39 of the coil yoke 40, the magnetic entry / exit section 39 located on the innermost side in the radial direction has a convex portion 50 of the inner pole tooth yoke 35.
The concave portion 51 is formed corresponding to the shape of the above. Therefore, in the inner pole tooth yoke 35 and the coil yoke 40, the tip end surface of the convex portion 50 faces the bottom surface of the concave portion 51, and the outer peripheral surface of the convex portion 50 faces the inner peripheral surface of the concave portion 51.

The magnetic fields generated by the coil windings 33a and 33b are sequentially switched in a predetermined pattern with respect to the pulse input of the drive circuit, whereby the permanent magnet block 2 is formed.
The pole teeth 34a, 36a, 36b, 3 facing the magnetic pole surface 9
The magnetic pole 5a moves along the circumferential direction by a quarter pitch. Therefore, the intermediate rotating body 23
Will follow the movement of the magnetic poles along the circumferential direction on the yoke block 30 at this time, and will rotate relative to the lever shaft 10.

In FIGS. 1 and 12, reference numeral 45 denotes a rubber elastic body which is attached to the back side of the coil yoke 30 and prevents looseness between the yoke 30 and the VTC cover 12.

Since this valve timing control device has the above-described structure, when the internal combustion engine is started or idled, the assembly angle of the drive plate 3 and the lever shaft 10 is set to the latest as shown in FIG. By maintaining the angle side, the rotation phase of the crankshaft and the camshaft 1 (the opening / closing timing of the engine valve) is set to the most retarded side, and the engine rotation can be stabilized and the fuel consumption can be improved.

Then, when the operation of the engine shifts to the normal operation from this state and a command to change the rotational phase to the most advanced side is issued from the controller (not shown) to the drive circuit of the step motor 4, the step The motor 4 changes the generated magnetic field in a predetermined pattern according to the command, and the permanent magnet block 2
9 is rotated together with the intermediate rotating body 23 to the maximum on the delay side. As a result, the tip of the link 14 engaged with the spiral groove 24 via the ball 19 is
The maximum displacement is made inward in the radial direction along the radial guide 8, and the assembly angle of the drive plate 3 and the lever shaft 10 is changed to the most advanced side. As a result, the rotation phases of the crankshaft and the camshaft 1 are changed to the most advanced side, and thereby the output of the engine is increased.

When a command is issued from the controller to change the rotational phase to the most retarded angle side from this state, the electromagnetic coil 32 changes the generated magnetic field in the reverse pattern to move the intermediate rotating body 23 to the advancing side. The link 14 which is relatively rotated to the maximum and is engaged with the spiral groove 24 via the ball 19.
As shown in FIG. 2, the distal end of the is maximally displaced radially outward along the radial guide 8. As a result, the link 14 relatively rotates the drive plate 3 and the lever shaft 10,
The rotation phase of the crankshaft and the camshaft 1 is changed to the most retarded angle side.

The rotation phases of the crankshaft and the camshaft 1 are not limited to the positions of the most advanced angle side and the most retarded angle side, but can be changed to any position by the control of the controller. As shown in FIG. 13, it is also possible to change to an intermediate position between the most retarded angle position and the most advanced angle position.

This valve timing control device has been described above.
Is used as the operating force applying means of this device.
The step motor 4 is a coil motor with an inner pole tooth yoke 35.
The ridge 40 faces the convex portion 50 and the concave portion 51 at a complicated portion.
Therefore, they face each other only on the plane orthogonal to the axial direction.
Compared with the case of doing so, the facing area is greatly expanded. Tsuma
In the case of this step motor 4, the end face (thin
Meat disk wall 36c₁End face) faces the bottom surface of the recess 51.
In addition to the above, the outer peripheral surface of the protrusion 50 (the thick cylindrical wall 36c ₂Out of
The peripheral surface) faces the inner peripheral surface of the recess 51.

Therefore, in the case of the step motor 4, the magnetic resistance between the inner pole tooth yoke 35 and the coil yoke 40 is surely lowered without increasing the outer diameter of the inner pole tooth yoke 35, and the loss of the magnetic flux in the magnetic path is reduced. Can be reduced. Therefore, in this motor 4, it is possible to achieve both miniaturization and low power consumption, which are important in a valve timing device for an internal combustion engine mounted on a vehicle.

Further, any one of the pole tooth yokes 34, 35, 36 of the yoke block 30 may be provided with a convex portion (in this case, a concave portion is provided at a corresponding portion of the coil yoke 40). .), The effect of reducing the magnetic resistance of that portion can be obtained. However, when the inner pole tooth yoke 35 is provided with the convex portion 50 as in the step motor 4 of this embodiment, in particular, Such an effect can be obtained.

That is, when there are three ring-shaped yokes of the inner pole tooth yoke 35, the intermediate pole tooth yoke 36, and the outer pole tooth yoke 34, due to the difference in circumference due to the difference in diameter,
It is more difficult to secure an area on a plane orthogonal to the axial direction as it is positioned on the inner side in the radial direction (the occupied radial direction width must be increased), but in the case of the step motor 4 of this embodiment, Since the convex portion 50 is provided on the pole tooth yoke 35 located on the innermost side in the radial direction and the facing area can be secured three-dimensionally with the concave portion 51, the aforementioned difficulty can be further reduced.

Therefore, the magnetic field appearing at the pole teeth 35a, 36b of the inner pole tooth yoke 35 and the intermediate pole tooth yoke 36 is further strengthened, and the torque exerted on the permanent magnet block 29 by the pole teeth 35a, 36b on the radially inner side and the radial direction are increased. Outer pole teeth 36a,
The torque exerted by the permanent magnet block 29 on the permanent magnet block 29 can be easily balanced, and the step motor 4 can be operated smoothly.

In contrast to this embodiment, the pole tooth yoke side 3
It is also possible to provide the concave portion 51 in 4, 25 and 36 and to provide the convex portion 50 projecting in the axial direction in the portion on the coil yoke 40 facing the concave portion, but in the inner pole tooth yoke 35 as in this embodiment. When the convex portion 50 is provided,
The dead space on the radially inner side of the coil yoke 40 where the coil windings 33a and 33b are not arranged can be effectively used. Therefore, with this configuration, it is possible to further reduce the size of the motor 4 as a whole and further improve the mountability of the valve timing control device on the vehicle.

Further, in the case of this embodiment, a thick cylindrical wall 35c ₁ is provided on the side of the base portion 35c of the inner pole tooth yoke 35 which is connected to the pole tooth 35a to secure a large cross-sectional area. Therefore, it is possible to avoid the problem that magnetic saturation occurs due to the magnetic flux from the tip end surface of the convex portion 50 and the magnetic flux from the outer peripheral surface simultaneously flowing in.

By the way, in the above-described embodiment, the convex portion 50 of the inner pole tooth yoke 35 is formed into a cylindrical surface along the axial direction so as to project. However, as shown in FIG.
It is also possible to make the concave portion 151 have a shape having an inclined surface 54 corresponding to the concave portion 151 while protruding with a tapered inclined surface 53 inclined with respect to the axial direction. In this case, since the magnetic flux entering from the tip end surface of the convex portion 151 and the magnetic flux entering from the inclined surface 53 gently join as shown by the arrow in the figure, the concentration of the magnetic flux on the pole tooth yoke 35 is unlikely to occur. Therefore, it becomes easier to generate a larger magnetic force. The flow of magnetic flux in the previous embodiment is shown by an arrow in FIG. 6 for comparison.

The embodiments of the present invention are not limited to those described above, and for example, the step motor may be applied to a device other than the valve timing control device of the internal combustion engine.

[0042]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the magnetic field between the coil yoke and the pole tooth yoke is provided by the convex portion provided on one of the coil yoke and the pole tooth yoke and the concave portion provided on the other. Therefore, the magnetic resistance is surely reduced as compared with the case where the magnetism enters and exits only on the facing surface orthogonal to the axial direction. Therefore, according to the present invention, the magnetic resistance between the coil yoke and the pole tooth yoke can be reduced without enlarging the outer diameter of the coil yoke or the pole tooth yoke. It is possible to achieve both.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 showing the same embodiment.

FIG. 3 is a front view of a permanent magnet block attached to the intermediate rotating body showing the embodiment.

FIG. 4 is a front view of the same embodiment, omitting illustration of a filling resin material of a yoke block.

FIG. 5 is a rear view of the same embodiment, in which illustration of a filling resin material of the yoke block is omitted.

FIG. 6 is a cross-sectional view taken along the line BB of FIG. 5 showing the same embodiment.

FIG. 7 is an enlarged perspective view of the front side of the yoke block showing the same embodiment.

FIG. 8 is an enlarged perspective view of the front side of the yoke block seen from another angle.

FIG. 9 is an enlarged perspective view of the rear side of the yoke block.

FIG. 10 is a partially enlarged front view of the yoke block showing the same embodiment.

FIG. 11 is a front view of an electromagnetic coil block showing the same embodiment.

FIG. 12 is a front view of an electromagnetic coil block showing the same embodiment.

FIG. 13 is a sectional view corresponding to FIG. 2, showing an operating state of the same embodiment.

FIG. 14 is a cross-sectional view corresponding to FIG. 2, showing another operating state of the same embodiment.

FIG. 15 is a cross-sectional view of a main part showing another embodiment of the present invention.

[Explanation of symbols]

1 ... Camshaft 3 ... Drive plate (drive rotor) 8 ... radial groove (radial guide) 10 ... Lever shaft (driven rotor) 14 ... Link 17 ... Boss (movable guide) 19 ... Sphere (movable guide) 23 ... Intermediate rotating body 24 ... spiral groove (spiral guide) 29 ... Permanent magnet block 32 ... Electromagnetic coil block 33a, 33b ... Coil winding 34 ... Outer pole tooth yoke 34a ... pole teeth 35 ... Inner pole tooth yoke 35a ... pole teeth 36 ... Intermediate pole tooth yoke 36a, 36b ... pole teeth 40 ... Coil yoke 50, 150 ... convex portion 51, 151 ... Recesses 53, 54 ... Inclined surface

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 7/14 H02K 7/14 Z (72) Inventor Yoshiyuki Kobayashi 1370 Atsugi, Kanagawa Prefecture Yu Corporation F-terms in NISSIA JEX (reference) 3G018 BA32 CA15 DA20 DA36 DA38 DA39 DA44 GA14 GA37 5H002 AA05 AA09 AB04 AC03 AE02 5H603 AA01 BB01 BB14 BB17 CA01 CA05 CB02 CC14 CD22 5H607 A0112 BB01 BB10 BB13 AFF12A22 BB01

Claims (5)

[Claims] 1. An outer pole tooth yoke having a plurality of radially inner pole teeth, an inner pole tooth yoke having a plurality of radially outer pole teeth, and an outer pole tooth yoke and an inner pole tooth yoke. Placed between
An intermediate pole tooth having radially outward pole teeth located between adjacent pole teeth of the outer pole tooth yoke and radially inward pole teeth located between adjacent pole teeth of the inner pole tooth yoke. An electromagnetic coil block having a yoke, a plurality of coil windings, and a coil yoke facing each pole tooth yoke, and different magnetic poles are magnetized so as to be alternately arranged along the circumferential direction, and the magnetic pole surface is A permanent magnet block rotatably provided so as to face the pole teeth of each of the pole tooth yokes, and the permanent magnets are changed by changing the energization of a plurality of coil windings of the electromagnetic coil block in a predetermined pattern. In a step motor that rotates a block relative to the pole tooth yoke, at least one pole tooth yoke of each of the pole tooth yokes and a coil yoke facing the pole tooth yoke, A step motor characterized in that one is provided with an axially protruding portion and the other is provided with one of a concave portion and a concave portion corresponding to the concave portion. 2. The step motor according to claim 1, wherein each of the convex portion and the concave portion is provided on an inner pole tooth yoke and an end surface of a coil yoke that faces the pole tooth yoke. 3. The step motor according to claim 2, wherein the inner pole tooth yoke is provided with a convex portion projecting to the coil yoke side, and a concave portion is provided on an end surface of the coil yoke facing the convex portion. 4. The inclined surface inclined to the axial direction is provided on each of the convex portion and the concave portion.
Step motor according to any one of 1. 5. A driven rotary body that is driven to rotate by a crankshaft of an internal combustion engine, and a driven rotary body that is composed of a camshaft or a separate member connected to the shaft, and that receives power from the drive rotary body, A radial guide provided on one of the drive rotating body and the driven rotating body,
An intermediate rotating body that is provided so as to be rotatable relative to the drive rotating body and the driven rotating body and has a spiral guide on a surface facing the radial guide, and is displaceable between the radial guide and the spiral guide. A movable guide portion that is guided and engaged with
A valve timing control device for an internal combustion engine, comprising: a link that oscillates between the movable guide portion and a portion of the other of the drive rotor and the driven rotor that is separated from the center of rotation, The step motor according to any one of claims 1 to 4, wherein the step motor is used as an operation force applying unit that applies a relative rotational operation force to the rotating body relative to the drive rotating body and the driven rotating body.