JPH08251902A - Step motor - Google Patents

Abstract

PURPOSE: To obtain a stepping motor having a compact stator generating a maximum output without sacrifice of assembling performance by providing a second stator member being coupled with a first stator member in the vicinity of one end thereof to form a substantially U-shaped part. CONSTITUTION: First and second stator members 2, 3 are combined to have substantially U-shape with the end faces 2a, 3a facing the outer circumferential surface of a rotor 1. A coil 4 is made of a conductor wound around the part 2d of the first stator member 2. A bobbin 5, made of an insulating material, is interposed between the coil 4 and the first stator member 2. Third and fourth stator members 6, 7 are combined to have substantially U-shape with the end faces 6a, 7a facing the outer circumferential surface of a rotor 1. A coil 8 is made of a conductor wound around the part 6a of the third stator member 6. A bobbin 9, made of an insulating material, is interposed between the coil 8 and the third stator member 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step motor.

[0002]

2. Description of the Related Art It is well known that a stepper motor drives shutter blades of a camera or a photographing lens. As a step motor for compactly storing it in the lens barrel of the camera, for example, the type shown in FIG. 8 is disclosed in Japanese Utility Model Publication No. 63-113127 and Japanese Patent Publication No. 6-64281. The disclosed step motor is configured by arranging a rotor magnetized in the radial direction, a plurality of stators having a plurality of magnetic poles facing the outer circumference of the rotor, and a coil for exciting the stator in a substantially arc shape. .

Reference numeral 101 is a circular lens barrel base plate, and 102
Is a rotor rotatably attached to the lens barrel base plate 101. For example, as shown in FIG. 8, the rotor is divided into four in the circumferential direction and the S poles and N poles are alternately magnetized. 103 and 104 are stators, and magnetic poles 103a, 103b, 104a and 104b are formed so as to face the outer circumference of the rotor 102. Reference numerals 105 and 106 are coils for exciting the stators 103 and 104. The rotor is rotated by switching the energization of the coil.

[0004] The applicant has also filed Japanese Patent Application No. 4-163740.
In a step motor including a cylindrical rotor magnetized in the radial direction, a plurality of stators having a plurality of magnetic pole portions facing the outer circumference of the rotor, and a coil for exciting the stator, In the thickness direction (axial direction) of the cylindrical shape, a plurality of magnetized phases having different polarities are formed with respect to those adjacent to each other. A stepping motor is proposed which is arranged so as to face different layers in the axial direction.

[0005]

However, in both cases, the structure is such that the coil is inserted from the end face side facing the rotor of the stator, so the shape of the end face side facing the rotor of the stator must be the inner diameter of the coil. It must be smaller than the part, and the shape is limited, so that the optimum shape for maximizing the output of the motor cannot be obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a step motor which does not impair the assemblability, is compact, and has a stator shape that maximizes the output of the motor.

[0007]

In order to achieve the above object, according to the present invention, a stator member has a first stator member having one end portion having a sectional shape substantially the same as the inner diameter of the coil, and the first stator member. Connect near the one end of the stator member,
At least a second stator member that forms a substantially U-shaped portion together with the first stator member is featured.

In the above structure, the stator member can be a stator member in which the shape of the magnetic pole facing the rotor is not influenced by the coil assembling property. Further, the present invention is characterized in that the bobbin interposed between the stator member and the coil inner diameter portion is integrally provided with a holding means for holding the first stator member and the second stator member. With the above configuration, the first stator member and the second stator member can be unitized, and the step motor can be easily assembled.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

(Embodiment 1) FIGS. 1 to 4 show a step motor of Embodiment 1, and in these drawings,
Reference numeral 1 denotes a rotor which is composed of a permanent magnet rotatably attached to a ground plate (not shown), has an outer circumference divided into four, and has S poles and N poles alternately magnetized. Reference numeral 2 is a first stator member made of a soft magnetic material such as iron, and 3 is a second stator member made of a soft magnetic material such as iron. As shown in FIG. 1, the first stator member 2 and the second stator member 3 are combined to have a substantially U-shape, and end surfaces 2a and 3a thereof face the outer peripheral surface of the rotor 1. 4 is a coil consisting of a conductor wire
Is wound around a portion 2d of the stator member 2. Reference numeral 5 denotes a bobbin which is interposed between the coil 4 and the first stator member 2 and made of an insulating material.

Reference numeral 6 is a third stator member made of a soft magnetic material such as iron, and 7 is a fourth stator member made of a soft magnetic material such as iron. As shown in FIG. 1, the third stator member and the fourth stator member 7 are combined to have a substantially U-shape, and the end surfaces 6 a and 7 a face the outer peripheral surface of the rotor 1. Reference numeral 8 denotes a coil made of a conductive wire, which is wound around the portion 6d of the third stator member 6. 9 is the coil 8 and the third
The bobbin is made of an insulating material and is interposed between the stator members 6.

First stator member 2 and second stator member 3
The substantially U-shaped stator made of and the substantially U-shaped stator made of the third stator member 6 and the fourth stator member 7 are arranged such that their substantially U-shaped portions face each other through a predetermined space. The rotor 1 is arranged in the. FIG. 2 is a perspective view showing the relationship between the main components, and in the description that follows, the third stator member 6 will be referred to as the first stator member 2 and the third stator member 6 will be referred to as the fourth stator member 2.
Since the stator member 7 corresponds to the second stator member 6, the coil 8 corresponds to the coil 4, and the bobbin 9 corresponds to the bobbin 5, respectively, the first stator member 2, the second stator member 3, the coil 4, the bobbin 5, and the rotor 1 correspond to each other. Only the relationship will be explained. The portion 5a of the bobbin 5 is inserted into the inner diameter portion 4a of the coil 4.
The second stator member 3 is inserted from the side of the portion 3c into the hole 5d of the bobbin 5 having a shape similar to the portion 3d along the direction of the arrow A, the portion 3d is fitted into the hole 5d, and the direction other than the direction of the arrow A is indicated. The position of is defined.

Next, the first stator member 2 is inserted into the hole 5b of the bobbin 5 from the side of the portion 2b along the direction of arrow B.
The portion 2d of the first stator member 2 has a hole 5b in the bobbin 5,
It is similar to the inner diameter portion 4a of the coil 4, and the relative positions of the coil 4, the bobbin 5, and the first stator member are defined except for the direction of arrow B.

The portion 2b of the first stator member 2 enters the groove 3b of the second stator member 3 so that the first stator member 2 and the second stator member 3 are coupled to each other even in the magnetic magnetic path. The position of the second stator member 3 in the direction of arrow A (also in the opposite direction to A) is determined, and it serves as a stopper. on the other hand,
Since the portion 2c of the first stator member 2 is engaged with the claw portion 5c integrally provided on the bobbin 5 after being bent, the first stator member 2 is prevented from coming off in the direction opposite to the arrow B. The state at this time is shown in FIG.

In this way, the first stator member 2,
The second stator member 3, the bobbin 5, and the coil 4 are integrally assembled. Since the first stator member 2 can be incorporated into the coil 4 from the side of the portion 2b opposite to the magnetic pole portion 2a facing the outer circumference of the rotor, the shape of the magnetic pole portion 2a is a structure that is not restricted by the assemblability. This allows the magnetic pole portion to have a shape that maximizes the output of the motor.

FIG. 4 shows a first stator 2, a second stator 3,
It is a perspective view when the coil 4 and the bobbin 5 are assembled. Since it can be unitized in this way, subsequent assembly of the motor can be facilitated.

(Embodiment 2) FIGS. 5 to 7 show a second embodiment, and 10 is a rotor which is rotatably mounted on a ground plate (not shown) and is made of a permanent magnet. Is magnetized on the outer peripheral surface so as to be divided into two, and there is a magnetized layer divided into two layers in the axial direction of the rotor. Each magnetized layer has a polarity opposite to that of a portion adjacent to the circumferential direction, for example, the portion 10a and the portion 10b, and the upper and lower layers also have adjacent portions, for example, the portion 10c to the portion 10a. Have opposite polarities. That is, if the portion 10a is the S pole, the portion 10b is the N pole, and the portion 10b is the N pole.
c is an N pole, and the partial d pole is an S pole.

Reference numeral 11 denotes the upper layer portions 10a, 1 of the rotor 10.
Having a magnetic pole portion 11a located at a position facing the periphery of 0b,
A second stator member made of a soft magnetic material such as iron,
Reference numeral 12 is a first stator member made of a soft magnetic material such as iron, having a magnetic pole property 12a located at a position facing the lower layers 10c and 10d of the rotor 10, and 14 is a bobbin made of an insulating material. , 13 are coils made of conductive wires.

These relationships will be described with reference to FIG. A portion 14a of the bobbin 14 having an outer peripheral portion having a shape similar to that of the inner diameter portion 13a is inserted into the inner diameter portion 13a of the coil 13, and a hole 14b of the portion 14a further has a first stator member having a substantially similar sectional shape. 12 is inserted from the end face 12c side. The second stator member 11 is connected to the first stator member 12 in a magnetic magnetic path at the same time that the protrusion 11b is fitted into the hole 12b of the first stator member 12 from the direction of arrow c in FIG. To be done. Further, the 11c surface of the second stator member 11 contacts the surface of the first stator 12, and the first stator member 11 causes the arm 14 of the bobbin 14 to move.
After the d and 14f are once deflected, they are engaged with the claw portions 14e and 14g, and the convex portion 14c and the claw portions 14e and 14 of the bobbin 14 are engaged.
By being sandwiched between g and g, the unit is formed as shown in FIGS.

The first stator member 12 and the second stator member 11 form a substantially U-shaped stator, and the coil 13
Is for exciting these stators, and the coil 13
Arm 14 of the bobbin interposed between the first stator member 12 and the first stator member 12.
The d, 14f, the claw portions 14e, 14g, and the convex portion 14c constitute a holding means for holding the second stator member 11. 1
5 is a fourth stator member, and the second stator member 11
Further, 16 is a third stator member, 1st stator member 12 is a coil, 17 is a coil, 13 is a coil, 18 is a bobbin, and 18 is a bobbin.
Since it has the same structure, its explanation is omitted here.

According to the above-described structure, as in the first embodiment, the first stator member 12 has the coil 1 from the side of the portion 12c opposite to the magnetic pole portion 12a facing the outer circumference of the rotor.
3 can be incorporated into the magnetic pole portion 12a, the shape of the magnetic pole portion 12a is not restricted by the assembling property. This allows the magnetic pole portion to have a shape that maximizes the output of the motor. FIG. 7 is a sectional view of the first stator 12, the second stator 11, the coil 13, and the bobbin 14 when assembled. Since it can be unitized in this way, subsequent assembly of the motor can be facilitated.

[0022]

As described above, according to the present invention,
The shape of the magnetic pole portion is not restricted by the assembling property of the coil, and the output of the motor can be maximized. Further, since the stator member is divided and configured to be fixed and held by the bobbin, subsequent assembly of the motor can be facilitated.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is a perspective view of main components of the first embodiment.

FIG. 3 is a sectional view of the first embodiment during assembly.

FIG. 4 is an assembled perspective view of the first embodiment.

FIG. 5 is a perspective view of a second embodiment.

FIG. 6 is a perspective view of main parts of the second embodiment.

FIG. 7 is a sectional view of a second embodiment.

FIG. 8 is a plan view of a conventional example.

[Explanation of symbols]

 1 rotor 2 1st stator member 3 2nd stator member 4 coil 5 bobbin

Claims (8)

[Claims] 1. A conductor wire, two stator members made of a soft magnetic material having a substantially U-shaped portion around which the conductor wire is wound, and a permanent magnet arranged in a predetermined space between the two stator members. In the step motor, which is configured such that the center axis direction of the wound conductive wire is substantially toward the rotor, each of the stator members has a shape substantially the same as the inner diameter of the wound conductive wire. A first stator member having one end portion having a cross-sectional shape, connected to the first stator member in the vicinity of the one end portion, and having a shape that forms a substantially U-shaped portion by combining with the first stator member; Two
And a stator member of the step motor. 2. The step motor according to claim 1, further comprising a bobbin member made of an insulating material interposed between an inner diameter portion of the wound conductive wire and the first stator member, and the bobbin. A stepping motor, wherein the member comprises holding means for holding the connection between the first stator member and the second stator member. 3. The step motor according to claim 2, wherein the bobbin has a first portion that receives a main portion of the first stator member, and the main portion of the first stator member is received in the first portion. At this time, a second portion that elastically engages the end surface of the first stator member to perform a retaining function, and a second portion
A stepper motor having a third portion for receiving a portion of the stator member of. 4. The step motor of claim 3, wherein the first stator member is received in the first portion of the bobbin and the second stator member is received in the third member. The one stator member and the second stator member have engaging means at portions where they are connected to each other, and the engaging means prevent the second stator member from coming out of the third portion of the bobbin. A step motor characterized in that 5. A plurality of magnetizing layers, each of which has a cylindrical shape and which is equally divided in the circumferential direction and has different polarities which are alternately magnetized on the outer peripheral portion, are stacked in the axial direction of the cylinder, and are axially provided. With respect to the adjacent magnetized layers, the polarities of the magnetized portions of the magnetized layers are different from each other, and the first magnetized layers are arranged so as to face the outer peripheral portion of the rotor and to be different in the axial direction of the rotor. In a step motor comprising a substantially U-shaped stator having at least two magnetic pole portions, one magnetic pole portion and a second magnetic pole portion, and a coil for exciting the stator pressed into the inner diameter portion, the stator is A first stator member that is pushed into the inner diameter portion of the coil and has a cross-sectional shape that is substantially the same as the inner diameter of the coil toward at least one end;
And a second stator member that is connected near the one end of the stator member and has a shape that forms a substantially U-shaped portion together with the first stator member. 6. The step motor according to claim 5, further comprising a bobbin member made of an insulating material interposed between the coil inner diameter portion and the stator, wherein the bobbin member is the first stator member. A stepping motor comprising holding means for holding the connection with the second stator member. 7. The step motor according to claim 6, wherein the bobbin elastically sandwiches the first portion that receives the main portion of the first stator member and the second stator to perform a retaining function. A stepping motor having two parts. 8. The step motor according to claim 7, wherein the first stator member is received by the first portion of the bobbin and the second stator member is received by the second member. The one stator member and the second stator member have engaging means at portions where they are connected to each other, and the engaging means prevent the first stator member from coming out of the first portion of the bobbin. A step motor characterized in that