JP2003199315A - Stepping motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide pole teeth of a pole teeth yoke having a sufficient length, without causing increase in the outside diameter. <P>SOLUTION: A permanent magnet block 29 is relatively rotated for pole teeth yokes 34 to 36, by changing poles of an outer pole teeth pair constituted of pole teeth 34a of the outer magnetic teeth yoke 34 and pole teeth 36a radially facing outward of the middle magnetic teeth yoke 36, and of an inner pole teeth pair constituted of pole teeth 36b radially facing inward of the middle magnetic teeth yoke 36 and pole teeth 35a of the inner magnetic teeth yoke 35. In the stepping motor, recessed parts 25 to 28, which open to a permanent magnet block 29 side, are formed at the positions where the pole teeth of the mating pole yoke orient, of base parts 34c to 36c of the pole teeth yokes 34 to 36. The recessed parts 25 to 28 can ensure sufficient distance between the annular base parts 34c to 36c and the mating pole teeth, thus increasing the length of the polarized teeth 34a, 35a, 36a, and 36b. <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.

This step motor includes an annular pole-shaped outer pole tooth yoke having a plurality of radially inward pole teeth and an annular plate inner pole tooth yoke having a plurality of radially outward pole teeth. , An annular pole-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 tooth yoke is rotated. Specifically, the pole teeth on the opposite sides of the outer pole tooth yoke and the intermediate pole tooth yoke, and the intermediate pole tooth yoke and the inner pole tooth yoke form the outer pole tooth pair and the inner pole tooth pair, respectively. The magnetic poles generated in the tooth pair are appropriately changed by controlling the energization of both electromagnetic coils, and thereby the magnetic attraction repulsive force acting on the permanent magnet block is changed along the circumferential direction.

Different magnetic poles are magnetized so as to alternate along the circumferential direction on the surface of the permanent magnet block on the side facing the pole teeth of the pole tooth yoke. Further, the pole teeth of each pole tooth yoke continuously extend in a plane shape in the radial direction from the annular base portion, and are arranged with a set insulating gap between adjacent pole teeth of the mating pole tooth yoke.

[0005]

However, in the above-mentioned conventional step motor, since each pole tooth yoke is continuously formed in a plane from the annular base portion to the pole tooth,
The extension length of each pole tooth is limited by the annular base of the mating pole tooth yoke. For this reason, the extension length of the pole tooth must be determined within a range in which the pole tooth and the base portion of the mating pole tooth yoke do not directly interfere with each other and magnetic flux does not leak from the pole tooth to the base portion of the mating pole tooth yoke. However, when the outer diameter of the outer pole tooth yoke is limited, the pole tooth length cannot be sufficiently secured.
Therefore, in the case of the conventional step motor, in order to increase the magnetic force acting on the permanent magnet block, the outer diameter of the entire motor must be increased, and it is difficult to achieve both the increase of the rotational torque and the downsizing of the device. It was

In view of the above, the present invention makes it possible to sufficiently secure the length of the pole teeth of the pole tooth yoke without increasing the outer diameter of the outer pole tooth yoke, thereby increasing the rotational torque and downsizing the device. The present invention is intended to provide a step motor that can achieve both of these.

[0007]

As a means for solving the above-mentioned problems, the present invention relates to an outer pole tooth yoke having a plurality of pole teeth extending radially inward from an annular base portion,
Between the inner pole tooth yoke, which is arranged on the inner peripheral side of the outer pole tooth yoke and has a plurality of pole teeth extending radially outward from the annular base, and between the outer pole tooth yoke and the inner pole tooth yoke. Pole teeth that are arranged and extend radially outward from the annular base portion and are located between adjacent pole teeth of the outer pole tooth yoke, and inner pole tooth yokes that extend radially inward from the same annular base portion. Intermediate pole tooth yokes having pole teeth positioned between adjacent pole teeth, an electromagnetic coil block having a plurality of coil windings for generating magnetic poles on each pole tooth yoke, and different magnetic poles in the circumferential direction. Are magnetized so that they are alternately arranged along
A permanent magnet block rotatably provided so that a magnetic pole surface faces the pole teeth of each of the pole tooth yokes, and the energization direction of a plurality of coil windings of the electromagnetic coil block is changed in a predetermined pattern. Thus, in a step motor that changes the magnetic poles generated in the pole teeth of each pole tooth yoke to rotate the permanent magnet block relative to the pole tooth yoke, at least one of the pole tooth yokes is a ring base. A concave portion opening to the permanent magnet block side is provided in the portion of the mating pole tooth yoke where the tips of the pole teeth are directed. In the case of the present invention, the pole teeth facing the concave portion of the pole tooth yoke can secure a sufficient distance from the annular base portion by the concave portion, so that the tip portion of the pole tooth corresponds to the base portion of the pole tooth yoke. There is no problem of direct interference with the magnetic pole or leakage of magnetic flux from the tip of the pole tooth to its base.

At this time, it is preferable that the root portion of the pole tooth is extended to the annular base portion by providing the concave portion, and the tips of the pole teeth of the mating pole tooth yokes are arranged in the concave portions of the annular base portion. By doing so, it becomes possible to secure a longer pole tooth length.

Further, the annular base of the intermediate pole tooth yoke is
The first concave portion and the second concave portion are provided so that the root portion of the radially outer pole tooth and the root portion of the radially inward pole tooth extend to the radial center of the annular base portion. First recess and second
It is preferable that the concave portions are communicated with each other at substantially the center in the radial direction of the annular base portion. In this case, the roots of the radially outward pole teeth and the radially inward pole teeth are secured to the maximum length in the annular base, and the radial lengths of the recesses that receive the pole tooth tips are also maximized. Secured.

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 has a structure with a small outer diameter, it can apply a reliable rotational operation force to the intermediate rotating body with a large magnetic force, so that it can be driven and rotated without sacrificing vehicle mountability. The rotation phases of the body and the driven rotating body can be changed accurately and reliably.

[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, a plurality of pole teeth 3 extending inward in the radial direction
4a ... and a substantially annular outer pole tooth yoke 34, and an inner pole tooth that is arranged concentrically on the inner circumferential side of the outer pole tooth yoke 34 and has a plurality of pole teeth 35a ... Yoke 35, outer pole tooth yoke 34 and inner pole tooth yoke 3
5 and a middle pole tooth yoke 36 having a plurality of pole teeth 36a extending outward in the radial direction and a plurality of pole teeth 36b extending inward in the radial direction. Each of the pole tooth yokes 34 to 36 is formed of a metal material having a high magnetic permeability and is 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 (hereinafter referred to as "outer pole tooth pair" and "inner pole tooth pair"), and the pole teeth 34a, 36a and 36b, 35a forming these pairs are circumferentially arranged. They are arranged alternately along the same pitch. Then, the pole teeth 34a, 36a, 3 of the outer pole tooth pair and the inner pole tooth pair
6b and 35a are adjacent pole teeth 34 of the pole tooth yoke 34.
When one pitch angle is set between a and 34a, 4 in the circumferential direction
It is arranged so as to be displaced by a 1-pitch angle. Also,
The base portions 34c, 35c, 36c that connect the adjacent pole teeth of each of the pole tooth yokes 34 to 36 are formed in an annular shape, and their axial end faces face the electromagnetic coil block 32, respectively.

Here, of the annular base portions 34c, 35c of the outer pole tooth yoke 34 and the inner pole tooth yoke 35, the permanent magnets are provided at the portions where the tips of the pole teeth 36a, 36b of the intermediate pole tooth yoke 36 are directed. A recess 25 that opens to the side of the block 29,
26 are formed respectively, and the roots of the pole teeth 34a, 35a are respectively formed into annular bases 34c, 3 by the recesses 25, 26.
It extends to 5c. The recess 25 on the outer pole tooth yoke 34 side is formed over the entire radial width of the annular base 34c.

Further, the annular base portion 3 of the intermediate pole tooth yoke 36
Reference numeral 6c denotes a first concave portion 27 that is open to the permanent magnet block 29 side at a position where the tips of the pole teeth 34a of the outer pole tooth yoke 34 point and a position where the tips of the pole teeth 35a of the inner pole tooth yoke 35 point. And second recesses 28 are formed respectively.
As shown in detail in FIGS. 5 and 9, the first recess 27 and the second recess 27
The recesses 28 are formed from the outer side and the inner side of the annular base portion 36c toward the substantially central portion in the radial direction, but the pole teeth 36a, 36b of the intermediate pole tooth yoke 36 are formed in the recesses 27, The root portion is extended by 28 to the substantially central portion in the radial direction of the base portion 36c. Further, since the first concave portion 27 and the second concave portion 28 are portions in which the pole teeth 34a, 35a of the outer pole tooth yoke 34 and the inner pole tooth yoke 35 are accommodated and arranged, respectively, the first concave portion 27, Recessed part 2
8, the pole teeth 36a and 36b are arranged along the circumferential direction with the order thereof shifted by a quarter pitch angle. The second recess 28 located on one circumferential side (right side in FIG. 5) of the first recess 27 is substantially central to the first recess 27 in the radial direction of the annular base portion 36c. It communicates in the range of a quarter pitch angle.

The pole teeth 36 of the intermediate pole tooth yoke 34 are
The tip ends of a and 36b extend to the vicinity of the recesses 25 and 26 of the outer pole tooth yoke 34 and the inner pole tooth yoke 35, respectively, and the pole teeth 34a of the outer pole tooth yoke 34 and the inner pole tooth yoke 35,
The tip of 35a is provided with the concave portions 27, 2
It is accommodated and arranged in 8.

On the other hand, as shown in FIG. 1, the electromagnetic coil block 32 has a substantially disk-shaped coil yoke 4 which is locked to the VTC cover 12 which is a non-rotating member in a state in which its rotation is restricted.
0, and a first coil winding 33a and a second coil winding 33b that are concentrically housed in the coil yoke 40 while being wound on bobbins of different diameters. Section (end opposite to bottom surface of VTC cover 12)
Are opposed to 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.

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. Therefore, the intermediate rotating body 23 follows the movement of the magnetic poles along the circumferential direction on the yoke block 30 at this time,
It 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, as shown in FIG. 2, the assembly angle of the drive plate 3 and the lever shaft 10 is set to the latest. 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 is executed. 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 rotation phase to the most retarded angle side from this state, the electromagnetic coil 32 changes the magnetic field generated in the reverse pattern to move the intermediate rotating body 23 to the advance 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 most advanced position and the most retarded position, 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.

The valve timing control device operates as described above, but the step motor 4 used as the operating force imparting means of the device includes the base portions 34c, 36c of the pole tooth yokes 34, 36, 35 of the yoke block 30. , 35c are formed with recesses 25, 27, 28, 26, and corresponding pole teeth 36a, 34a, 3 of the corresponding pole tooth yokes 36, 34, 35 are formed.
5a and 36b are arranged close to the recesses 25, 27, 28 and 26, or are arranged so as to be completely housed inside, so that the respective pole teeth 36a, 34a, 35a and 36 are arranged.
b and the base portions 36c, 3 of the mating pole tooth yokes 36, 34, 35
It is possible to secure a sufficiently long extension length of each pole tooth 34a, 35a, 36a, 36b without causing interference with 4c, 35c and leakage of magnetic flux. In the step motor 4, the outer pole teeth 34a, 35a, 36a,
Since the area of 36b can be increased, the motor 4
Permanent magnet block 2 without increasing the overall diameter
The magnetic force acting on 9 can be increased to increase the rotational torque.

In particular, in the case of this step motor 4,
The base portion 36c of the intermediate pole tooth yoke 36 is formed with a first recessed portion 27 extending from the outer side in the radial direction to the substantially central portion in the radial direction and a second recessed portion 28 extending from the inner side in the radial direction to the substantially central portion in the radial direction. Since the concave portions 27 and 28 of the base portion 36c communicate with each other substantially at the central portion in the radial direction of the base portion 36c, the base portions of the radially outward pole teeth 36a and the inward pole teeth 36b are maximized. It can be ensured on the side, and the maximum receiving length of the tip end portions of the pole teeth 34a, 35a of the mating pole tooth yokes 34, 35 can be secured. Therefore, in this case, the extended length of the pole teeth 34a, 36a, 36b, 35a can be secured to be larger, and the permanent magnet block 29 can be secured.
The magnetic force acting on can be efficiently increased.

Further, since the step motor 4 of this embodiment is used in the actuator portion (operating force applying means) of the valve timing control device of the internal combustion engine, the intermediate rotating body 29 can be provided without increasing the outer diameter of the device. It can be reliably rotated with a stable and large magnetic force. Therefore, the accuracy of valve timing control can be improved without causing a problem such as deterioration of vehicle mountability due to an increase in size of the device.

The embodiments of the present invention are not limited to those described above. For example, in the above embodiments, the outer pole tooth yokes, the inner pole tooth yokes, and the intermediate pole tooth yokes are all provided with concave portions at their bases. Although provided, a recess may be provided at the base of any one or two pole tooth yokes. Further, the application of the step motor is not limited to the valve timing control device but may be various other devices.

[0038]

As described above, according to the present invention, the annular base portion of the pole tooth yoke is provided with the concave portion at the portion of the base portion to which the tips of the pole teeth of the mating pole tooth yoke are directed. Since it is possible to secure a sufficient distance from the pole teeth of the yoke, it is possible to increase the extension length of the pole tooth yoke and increase the rotational torque without increasing the outer diameter of the outer pole tooth yoke. it can. Therefore, according to the present invention, it is possible to achieve both an increase in rotational torque and a reduction in size of the device.

[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 an enlarged 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.

[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) 25, 26 ... Recess 27 ... First recess (recess) 28 ... Second recess (recess) 29 ... Permanent magnet block 32 ... Electromagnetic coil block 33a, 33b ... Coil winding 34 ... Outer pole tooth yoke 34a ... pole teeth 34c ... base 35 ... Inner pole tooth yoke 35a ... pole teeth 35c ... base 36 ... Intermediate pole tooth yoke 36a, 36b ... pole teeth 36c ... base

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsunari Yoshida             1370 Onna, Atsugi, Kanagawa             Nissia Jex F term (reference) 3G018 BA32 CA15 DA36 DA38 DA39                       DA44 FA07 GA14

Claims (4)

[Claims] 1. An outer pole tooth yoke having a plurality of pole teeth extending inward in a radial direction from an annular base portion, an inner pole side of the outer pole tooth yoke, and a radial outward direction from the annular base portion. An inner pole tooth yoke having a plurality of pole teeth extending to, and arranged between the outer pole tooth yoke and the inner pole tooth yoke,
A pole tooth that extends radially outward from the annular base portion and is located between adjacent pole teeth of the outer pole tooth yoke and a pole tooth that extends radially inward from the same annular base portion and is adjacent to the inner pole tooth yoke An intermediate pole tooth yoke having pole teeth positioned between pole teeth, an electromagnetic coil block having a plurality of coil windings for generating magnetic poles in each pole tooth yoke, and different magnetic poles along the circumferential direction. A plurality of coil windings of the electromagnetic coil block, the permanent magnet blocks being magnetized so as to be alternately arranged and rotatably provided so that the magnetic pole surfaces face the pole teeth of the respective pole tooth yokes. A step motor for rotating the permanent magnet block relative to the pole tooth yoke by changing the magnetic poles generated in the pole teeth of each pole tooth yoke by changing the energization direction with respect to the wire in a predetermined pattern. Of at least one of the annular base portions is directed to the portion where the tips of the pole teeth of the mating pole tooth yoke are directed.
A step motor characterized in that a stepped opening is provided on the permanent magnet block side. 2. A root portion of a pole tooth is extended to an annular base portion by providing the recessed portion, and tips of pole teeth of a mating pole tooth yoke are arranged in the recessed portion of the annular base portion. The step motor according to claim 1. 3. An annular base portion of the intermediate pole tooth yoke has a root portion of a pole tooth radially outward and a root portion of a pole tooth radially inwardly extending to a substantially radial center portion of the annular base portion. First to do
3. The step motor according to claim 2, wherein the concave portion and the second concave portion are provided, and the first concave portion and the second concave portion communicate with each other substantially at the center in the radial direction of the annular base portion. 4. A driven rotating body that is rotationally driven by a crankshaft of an internal combustion engine, and a driven rotating body that is composed of a camshaft or a separate member coupled to the shaft, and that is driven by the drive rotating 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 3, wherein the step motor is used as an operation force applying unit that applies a relative rotational operation force to the rotating body with respect to the drive rotating body and the driven rotating body.