JP4559765B2 - Magnet rotor forming method - Google Patents

Description

  The present invention relates to a magnet rotor insert molding method in an electromagnetic drive device used in a drive unit of various devices such as a camera and a mobile phone, and a magnet rotor using the same.

  2. Description of the Related Art Generally, an electromagnetic drive device used for a camera device or the like drives an operation function unit such as a shutter blade by rotating a cylindrical permanent magnet supported by a bearing so as to be rotatable by an exciting coil. Such a magnet rotor is composed of a rotating body magnetized on the NS pole, a central axis that rotatably supports the rotating body, and an operating arm that transmits rotational motion to the outside.

The following two methods are known for forming such a magnet rotor.
In the first method, a powder of a ferromagnetic material such as ferrite is formed into a hollow cylindrical shape by sintering, and separately from this, a rotating shaft and an operating arm are integrally formed by molding a synthetic resin, and then the ferromagnetic material is formed. In this method, a rotating shaft is inserted into the hollow, fixed with an adhesive, and magnetized on this integrated ferromagnetic body to manufacture a rotor structure. When this method is used, there is a merit that the magnetic material can be individually produced by the sintering process and the rotating shaft can be produced individually by the molding process, but there are many manufacturing processes, and there are disadvantages such as deterioration of the function due to leakage of the adhesive.

  The second method is to form a ferromagnetic powder material into a hollow cylindrical shape, insert the magnetic body into a molding die, inject a resin material, and integrally mold the central rotating shaft and the operating arm. It is. This method has the merit that the magnet, the rotating body, and the working arm can be molded at the same time and the molding process is relatively small. However, the magnetic pole direction magnetizing the ferromagnetic material and the direction of the working arm are accurately positioned. It is difficult to match. In other words, when the ferromagnetic material is loaded in a correct posture in the mold and the diameter of the magnet rotor is about 3 to 5 mm when the resin material is injected while maintaining its position, the mold and the magnetic material Alignment is difficult.

  Therefore, in Patent Document 1 (Japanese Patent Application Laid-Open No. 11-138553), a magnetic body is formed into a hollow cylinder using an anisotropic magnetic material, while an operating arm is formed at the same time as forming a mold using a nonmagnetic material. A magnetic field is generated in a direction perpendicular to the molded part. A method has been proposed in which the direction of the magnetic field and the easy magnetization axis of a magnetic material loaded therein are made to coincide with each other and injection molded, and then the rotor after injection molding is magnetized along the easy magnetization axis. When this method is used, the magnetic body is characterized in that it can maintain its posture along the direction of the magnetic field inside the injection mold and can be integrally molded with the working arm that is molded at the same time.

JP-A-11-138553

  In the conventional method known from the above-mentioned Patent Document 1 or the like, first, the magnetic material is limited to anisotropy, and an isotropic material cannot be used. In addition, if a columnar magnetic body is loaded at a significantly different angle between the magnetic field generated in the mold and the magnetization easy axis of the magnetic body, the magnetic pole direction of the magnetic body may deviate from the position (angle) of the operating arm. In particular, when the outer diameter of the magnetic body is configured to be 5 mm or less, it is difficult to load the mold while aligning the direction of the magnetic body to a certain extent, making it difficult to automate the work. Furthermore, a magnet embedded in order to generate a magnetic field in the mold cannot obtain the desired lines of magnetic force unless the NS poles are aligned correctly, but the magnetic body is difficult to process, and the magnetic body embedded in the mold is There is a risk that the position may be changed or damaged due to temperature change or impact during injection molding.

  Therefore, according to the present invention, when insert-molding a magnet rotor, the position of the transmission arm and the position of the ferromagnetic material can be accurately aligned in the mold, and there are few defects during molding, and the magnetic force to the mold is reduced. It provides a molding method that makes it easy to load the body, and at the same time, the rotary shaft and the transmission arm are integrally formed by insert molding on a hollow cylindrical ferromagnetic material. An object of the present invention is to provide a magnet rotor that can solve the problem that the rotational force generated in the ferromagnetic body due to idling due to a change with time is not transmitted to the transmission arm and that can reliably transmit the drive.

The present invention employs the following configuration in order to solve the above problems.
According to the first aspect of the present invention, the ferromagnetic material is formed into a hollow cylindrical shape, and after the magnetic material is loaded into a mold having at least one working arm molding portion, the resin material is injected to obtain the ferromagnetic material. A method of forming a magnet rotor that integrally molds an operating arm, wherein first, the peripheral surface of a hollow cylindrical ferromagnetic body is polarized and magnetized to at least two poles, and a shaft hole having a non-circular cross section is formed at the center. To form. The mold is made of a non-magnetic material, and a magnetic body insertion portion for rotatably loading the magnetic body, an operation arm formation portion for forming the operation arm, and a predetermined angular position with respect to the operation arm formation portion. And a positioning member made of a soft magnetic material disposed in the magnetic body insertion portion. Next, the ferromagnetic material is accommodated in the magnetic material insertion portion, and the ferromagnetic material is rotated and positioned at a predetermined angular position with the operating arm molding portion by suction of the positioning member, and in this state, the magnetic material is inserted. A magnet material is molded by injecting a resin material into the mold part. With this configuration, the above-described problem can be achieved.

  According to a second aspect of the present invention, the ferromagnetic body is polarized with NS2 poles on the peripheral side surface and magnetized, and the positioning member is composed of a pair of soft magnetic members opposed to the magnetic body insertion portion. Magnet rotors such as camera devices can be molded.

  According to a third aspect of the present invention, the ferromagnetic body and the transmission arm can be reliably integrated by forming the axial hole of the ferromagnetic body in a rectangular cross section.

  According to the fourth and fifth aspects of the present invention, the ferromagnetic material is formed by firing a magnetic powder such as neodymium by applying a magnetic field in a sintering mold, thereby strengthening the magnet by residual magnetism at the same time as forming an anisotropic magnet. It becomes possible to make magnetism around the outer periphery of the magnetic body.

  In the present invention, when inserting a hollow cylindrical ferromagnetic body polarized around at least two poles into a mold, a magnetic pole is attracted and held by a positioning member made of a soft magnetic material. Since the operation arm is integrally formed by injecting the resin material, the alignment between the direction of the operation arm and the magnetic pole of the ferromagnetic material is accurate and easy. In particular, when a ferromagnetic material is loaded into the magnetic body insertion part of the molding die, it is possible to load it using the shape of a non-circular shaft hole formed in the ferromagnetic material as a guide, and insertion of the ferromagnetic material into the molding die The operation, in particular, the operation of inserting a magnetic material having an extremely small outer diameter is easy.

  In addition, the magnet rotor after molding has a rotating shaft formed in a hollow shaft hole having a non-circular cross section, and a transmission arm is formed integrally with the rotating shaft. Since the non-circular cross section is fitted, the rotational force generated in the ferromagnetic material is reliably transmitted to the rotating shaft and the transmission arm. In particular, even if the expansion coefficient of the ferromagnet and the rotating shaft are different due to changes in the environmental temperature during use, since the non-circular shape is formed, looseness is less likely to occur and the rotation can be reliably transmitted to the transmission arm.

  The present invention will be described in detail based on the following preferred embodiments shown in the drawings. FIG. 1 is an exploded perspective view showing a configuration of a magnet rotor (hereinafter referred to as a rotor) according to the present invention, and FIG. 2 is a conceptual view showing a rotor mold and a perspective view. FIG. 3 is a plan view thereof.

  The configuration of the rotor will be described with reference to FIG. 1. The rotor 1 includes a magnet member 2, a rotating shaft member 3, and a transmission arm member 4. The magnet member 2 is composed of a circular cylindrical permanent magnet that is polarized by being polarized in a plurality of poles such as NS2 poles or 4 poles in the outer circumferential direction. The illustrated magnet member 2 is formed in a hollow cylindrical shape, a hollow shaft hole 2a having a rectangular cross section is provided at the center, and an upper end surface 2b and a lower end surface 2c are formed as flat surfaces. The rotary shaft member 3 is composed of upper and lower flanges 3a, 3b and a rotary shaft 3c. The upper and lower flanges 3a, 3b are in positions where they are joined to the upper end surface 2b and the lower end surface 2c of the magnet member 2, and the rotary shaft 3c is a hollow shaft hole. It is adapted to 2a.

  The transmission arm member 4 is formed of a transmission portion 4b connected to an arm portion 4a protruding outward in the radial direction of the magnet member 2, and a connecting portion 4c is formed at the tip of the transmission portion 4b to be fitted with a blade member described later. Yes. The magnet member 2, the rotary shaft member 3, and the transmission arm member 4 are integrally formed in the shape shown in FIG. 1 as follows. The magnet member 2 has a cylindrical shape and a rectangular cross section with a powder of a mixed material of samarium and cobalt, a material mainly composed of neodymium (NdFeB), a material mainly composed of ferrite, etc. Is filled into a firing mold having a shape that forms a hollow shaft hole.

  Next, when this sintering mold is heated and sintered, a sintered product having a shape shown as a magnet member 2 in FIG. 1 is formed. When sintered in a predetermined magnetic field during sintering, an anisotropic magnet is formed, and when sintered without applying a magnetic field, an isotropic magnet is formed. In the former anisotropic magnet, an easy magnetization axis is formed in the magnetic field direction XX, as shown in FIG. 4, and this easy magnetization axis forms a fixed positional relationship with the rectangular hollow shaft hole 2a. The rectangular hollow shaft hole 2a shown in the figure and the easy magnetization axis XX are in a relationship crossing the center of the square (XX line shown in the figure), and the easy magnetization axis XX can be determined at the position of the hollow shaft hole 2a. The anisotropic magnet has a residual magnetic field in the easy axis direction. On the other hand, an isotropic magnet that does not apply a magnetic field during sintering does not have an easy magnetization axis and does not have a residual magnetic field.

  In the ferromagnetic molded product formed as described above, the rotary shaft member 3 and the transmission arm member 4 are integrally formed by insert molding. In the present invention, the ferromagnetic material is magnetized and magnetized in the pre-process of the insert molding. The method is as follows: (a) When the sintered molded product is molded as an anisotropic magnet, the remanent magnetism (b) magnetized by the magnetic field during sintering is demagnetized when the sintered molded product is molded as an anisotropic magnet. A demagnetizing process is performed, and then a magnetic field having a predetermined strength is applied along the easy magnetization axis. At this stage, a final permanent magnet is generated. (C) When a sintered molded product is molded as an isotropic magnet, it is magnetized. By any one of these methods, the molded product has at least N-S2 poles polarized on the cylindrical peripheral side surface.

  The demagnetization treatment may be performed by applying a magnetic field in the opposite direction to the magnetic field applied during sintering to the sintered mold, and the magnetization is performed by applying a strong magnetic field to the sintered mold with a magnetizer. To make it magnetic. In this case, the direction of the magnetic pole to be applied is set at a constant angle with the rectangular shape of the hollow shaft hole 2a. Therefore, both the magnet member 2 is magnetized by a magnetizer, and the residual magnetism during sintering is in a predetermined direction with respect to the rectangular central shaft hole 2a, in the direction shown in FIG. Will be located.

  Next, the structure of the mold will be explained. Normally, the mold is divided into a fixed mold and a movable mold. The fixed mold and the movable mold are divided into a plurality of molds (nesting) according to the shape of the product to be molded. Divided. The illustrated one is divided into two parts according to the shape of the magnet rotor, and the magnet rotor 1 is formed in a plane shown in FIG. 5A, with the upper side being a fixed type and the lower side being a movable type. FIG. 5A shows the structure of the mold, 10 is a fixed mold, and 11 is a movable mold.

  The fixed mold 10 includes a shaft end forming portion 12 that forms one end of the rotating shaft 3c (upper end in FIG. 1), a flange 13a forming portion 13, a transmission arm member 4 forming portion 14, and a transmission portion 4b forming portion 15. A connecting portion 4c and a forming portion 16 are formed. The movable mold 11 is formed with a magnetic body insertion portion 17 into which the magnet member 2 is inserted. The movable mold 11 is formed with a forming portion 21 that forms the other end side flange 3b of the rotating shaft member 3 and a shaft end forming portion. Therefore, if the resin material is injected after the magnetic member 2 is loaded in the magnetic material insertion portion 17, the magnet rotor 1 shown in FIG. 1 is formed. In addition, 23 shown in the figure is an injection port formed in a fixed mold. 25 shown in the figure is an insertion hole of an extrusion rod for taking out a molded product.

  Therefore, in the present invention, the magnet member 2 molded as described above is loaded into the molding die (the fixed die 10 and the movable die 11), the resin material is injected, and the rotary shaft member 3 and the transmission arm member 4 are integrally molded. In this case, the following structure is adopted so that the angular positions of the transmission arm member 4 and the magnet member 2 can be easily aligned.

  First, as described above, the magnet member 2 is magnetized with the cylindrical peripheral side surface polarized to at least two poles. In the case of an anisotropic magnet, this magnetization may be the residual magnetism during sintering. And the said shaping | molding die forms the circumference | surroundings of the magnetic body insertion part 17 with a nonmagnetic material. In the illustrated example, the movable mold 11 and the fixed mold 10 are formed by cutting a stainless steel block material. With such a configuration, positioning members 26 and 27 made of a soft magnetic material are arranged around the magnetic body insertion portion 17 of the movable mold 11 as shown in FIG. Then, the magnet member 2 loaded in the magnetic body insertion portion 17 is attracted by the positioning members 26 and 27 so that the magnetic pole direction of the magnet member 2 and the direction of the positioning members 26 and 27 coincide.

  Therefore, in the illustrated example, a pair of positioning members made of a soft magnetic material such as iron are provided around the magnetic body insertion portion 17 at positions facing each other. The positioning members 26 and 27 are arranged at positions where the direction YY of the forming portion 14 of the transmission arm member 4 is orthogonal to the straight line XX where the pair of positioning members 26 and 27 are opposed. Therefore, the transmission arm member 4 is formed in a direction orthogonal to the magnetic pole direction XY of the magnet member 2.

  Further, the positioning members 26 and 27 are formed in a sharp shape (knife edge) as shown in FIG. 2, and their front end surfaces are opposed (opposed) to each other. This is a magnet member loaded in the magnetic material insertion portion 17. This is because consideration has been given so as not to be biased when 2 is attracted to the positioning member. When the tips of the positioning members 26 and 27 are formed in a sharp shape in this way, the cylindrical magnet member 2 is attracted to the sharpened portion, so that even if the positioning members 26 and 27 are attached with a slight deflection, the transmission arm member 4 and A positional relationship orthogonal to the magnetic poles of the magnet member 2 is obtained.

  Next, the manufacturing process of the magnet rotor will be described with reference to FIG. First, powder of a ferromagnetic material is filled in a sintered mold and fired in a magnetic field in a predetermined direction by applying a magnetic field to form an anisotropic magnet member, or heated and fired without applying a magnetic field. The magnet member is formed. At this time, the firing mold is cylindrical, and a non-circular, for example, rectangular shaft hole is formed in the center to form the magnet member 2 shown in FIG. When the magnet member 2 is formed anisotropically, the direction of the magnetic field (magnetization easy axis) FIG. 4X-X is set in a predetermined angular direction with respect to the shaft hole 2a. This direction is set to a direction in which the easy magnetization axis can be determined from the shape of the non-circular shaft hole 2a. Then, a magnetic field in the opposite direction along the easy magnetization axis is applied to demagnetize (demagnetize), or take out from the mold without demagnetization.

  Therefore, when the magnet member 2 is anisotropic and demagnetized, and is formed isotropic, it is magnetized in a predetermined direction. In this magnetizing process, the cylindrical magnet member 2 is magnetized to an appropriate number of poles, such as polarization magnetization or N-S4 poles, at least NS2 poles. The magnetization direction at this time is set so that the direction of the magnetic pole can be determined from the shape of the shaft hole 2a in a predetermined angular direction with respect to the central shaft hole 2a.

  Next, in the case shown in the drawing mold, the magnet member 2 is inserted into the magnetic body insertion portion 17 formed in the movable mold 11. This insertion is performed either automatically by an automatic inserter or by an operator. At this time, it is inserted so that the positional relationship between the non-circular hollow shaft hole 2a and the positioning members 26 and 27 is within a predetermined angle range.

  This will be explained with reference to FIG. 4. When the magnet member 2 is formed anisotropically, the easy axis of magnetization is aligned, and when it is formed isotropic, the magnetization direction is aligned with the XX direction shown in the figure. The forming portion 14 forming the transmission arm member 4 and the magnetic poles are orthogonal to each other.

  Therefore, the magnet member 2 is inserted into the magnetic body insertion portion 17 with respect to the positioning members 26 and 27 within a predetermined angle range, for example, 45 degrees, based on the shape of the hollow shaft hole 2a. That is, the insertion of the magnet member 2 into the magnetic body insertion portion 17 is inserted with reference to the positions of the positioning members 26 and 27, but the positions of the magnetic poles and the positioning members 26 and 27 are exactly aligned. There is no need to match.

  Thus, the magnetic member 2 inserted as a guide rotates in the magnetic material insertion portion 17 with the magnetic poles attracted to the positioning members 26 and 27, and the direction of the magnetic poles and the positioning members 26 and 27 completely coincide with each other. . That is, the movable mold 11 on which the magnetic body insertion portion 17 is formed is formed of a nonmagnetic member, and the positioning members 26 and 27 are formed of a soft magnetic material, so that the magnetized magnet member 2 is placed inside the magnetic body insertion portion 17. The direction of the magnetic pole rotates and the positioning members 26 and 27 coincide with each other and are held in that position.

  Next, the resin material is injected from the injection port 23 in a state where the magnet member 2 is held by the magnetic pole attracting action of the positioning members 26 and 27 provided in the mold as described above. The resin material may be appropriately selected from mechanical strength and environmental temperature change, but the illustrated material uses polyacetal resin.

  In this manner, insert molding of the magnet rotor is performed, and the magnet rotor 1 of FIG. 1 is taken out from the mold. Next, when the magnet member 2 is inserted in a state of having residual magnetism during firing without being anisotropically magnetized, the magnetizing process is performed as a final process.

  In the magnet rotor 1 formed in this process, the hollow cylindrical magnet member 2 and the rotary shaft 3c of the rotary shaft member 3 are formed in a non-circular cross section. Therefore, when it is formed in a rectangular shape as shown in the figure, the expansion and contraction of the rotating shaft 3c such as polyacetal resin is larger than that of a magnet member such as neodymium due to a normal temperature change. Since it contracts as shown by the chain line, the magnet member 2 and the rotating shaft 3c do not idle. Similar to the environmental temperature change, the change in shape after insert molding (sink during resin molding) is the same shape change.

  Next, an electromagnetic drive device using the above-described magnet rotor will be described. FIG. 6 shows a case where the present invention is adopted in a driving device for driving a shutter and a diaphragm device for a camera device. In FIG. 6, G02 is a coil frame, which is composed of two upper and lower bodies, has a magnet rotor G01 pivotally supported inside, and has a concave groove around which the conductive coil G03 is wound, and the conductive coil G03 is wound around it. It is something to turn around. G03 is a conductive coil, which is wound around the coil frame G02, and rotates the magnet rotor G01 as appropriate depending on the supply of drive current and the supply direction. G04 is a shielding yoke, which is mounted so as to wrap around the outer periphery of the coil frame G02 with the magnet rotor G01 pivotally supported on the inner side, and shields the external magnetic field to the magnet rotor G01. Is.

  As shown in FIG. 8, the shield yoke has a part of the outer periphery having a C-shaped cross section and a slit-like notch formed in part. The rotor always receives a rotational force at this notch, with the position where the line connecting the magnetic pole NS of the magnet rotor G01 intersects the notch as a stable point (neutral point). Therefore, when the apparatus power supply is turned off, the magnet rotor is held at a position where the magnetic pole coincides with the notch. With this configuration, a locking mechanism or the like is unnecessary, and the position of the magnet rotor can be easily controlled simply by cutting off the drive current and turning off the power.

  Next, a case where the shutter blades of the camera device are opened and closed using the above-described driving device will be described. The apparatus shown in FIG. 8 is configured as a unit in which a shutter blade E and a diaphragm blade C are incorporated into an apparatus substrate (hereinafter referred to as a base plate) F. The ground plate F is divided into a driving means H and a diaphragm blade C for the shutter blade E. An intermediate plate (partition plate) to be split, and B in the figure is a presser plate. This light quantity adjusting device has the following configuration and is incorporated in an imaging lens of an imaging device described later.

  The base plate F is formed by molding of resin or the like, and is configured in an appropriate shape to attach and support the shutter blade E, the diaphragm blade C, and the driving means H and G that open and close the blade members. An opening F01 coinciding with the photographing optical axis is formed in the base plate F, and this opening F01 has a larger diameter than an exposure opening D01 formed in an intermediate plate D described later. The base plate F is integrally formed with a pin-shaped stop blade support shaft F02 and a shutter blade support shaft F03, which rotatably support the shutter blade E and the stop blade C, respectively. Then, a shutter blade E is incorporated in the base plate F, and then an intermediate plate (partition plate) D, a diaphragm blade C thereon, and a pressing plate B are further superimposed thereon.

  The shutter blade E is rotatably supported by the shutter blade F03 and guided by a guide rib F06 formed on the base plate F so as to cover the opening F01 (closed position, hereinafter referred to as a closed position) and an open position retracted from the opening F01. It is supported movably between (open position, hereinafter referred to as open position). The shutter blade E has a long hole F05 in which a transmission pin H12 of a shutter driving means H, which will be described later, is engaged. The base plate F has a slit hole F05 that penetrates the transmission pin H12. The shutter blade member E appropriately blocks subject light received by the solid-state imaging device J such as a CCD that enters the front lens A and passes through the exposure opening formed in the intermediate plate D. A shutter for obtaining exposure, which is made of a sheet obtained by coating and vapor-depositing a black pigment on a polyester film, a tetron film, or the like. In the figure, E01 is a rotation center hole through which the shutter blade rotation center axis F03 of the base plate F passes, and is rotatably supported by the shutter blade rotation center axis F03. Reference numeral E02 denotes an operation slit hole through which the operation pin H12 of the shutter blade driving means H penetrates and swings the shutter blade member E around the rotation center hole E01.

  Further, the base plate F is integrally provided with stoppers F08 and F09 made of protrusions for restricting the movement of the shutter blade E supported so as to be freely opened and closed. The blade E contacts the stopper F09 at the closed position and contacts the stopper F08 at the open position. Abutting and further rotation is restricted. Accordingly, the stoppers F08 and F09 serve as regulating members that regulate the movement of the shutter blades E. Thus, the shutter blade E supported by the base plate F so as to be freely opened and closed is covered with an intermediate plate (partition plate) D. The intermediate plate D is supported by protrusions F10 and F11 formed integrally with the base plate F, and a gap in which the shutter blade E rotates is formed between the base plate F and the intermediate plate D. The shutter blade E is formed of a resin film, and this intermediate plate is also formed of a resin film such as the same material.

  The intermediate plate D is formed with an exposed opening D01 that coincides with the opening F01 of the base plate, and the illustrated one is formed with a diameter of 4 mm. The exposure opening D01 guides the maximum photographing light amount to a solid-state image pickup device of an image pickup apparatus to be described later when the shutter blade E is in an open state. As a result, even if strong light such as sunlight is sent to an image pickup device such as a CCD, there is no fear of burning, and this is a limit value obtained through experiments. The intermediate plate D is formed with a hole D02 through which the diaphragm blade support shaft F02 passes and a hole D03 through which the shutter blade support shaft F03 passes. Similarly, a slit D04 through which the operating pin G12 of the diaphragm blade drive means G passes and the shutter blade drive. A slit D05 through which the operating pin H12 of the means H passes is formed. Incidentally, D06 in the drawing is a retreat area when the diaphragm blade C and the shutter blade E are retreated from the exposure opening D01. The shutter blade E and the diaphragm blade C are respectively pivoted at a position that linearly opposes the posture that enters the exposure opening D01 and the posture that is located in the retreat area D06 with the exposure opening interposed therebetween. F03 is arranged. In the figure, D07 is a positioning concave groove hole and a pin F12 formed on the ground plane F is fitted, and D08 is a positioning hole and a pin F18 of the ground plane F is fitted.

  Next, the diaphragm blade C will be described. The diaphragm blade C for adjusting the amount of light from the exposure aperture D01 formed in the intermediate plate D to the solid-state image sensor J from the subject light incident from the front lens A of the imaging device described later. Is constructed as follows. The blade C formed by punching the resin film is provided with a diaphragm opening C03 having a diameter smaller than the exposure opening D01 of the intermediate plate D, and a rotation center hole C01 that engages with a support shaft F02 formed on the base plate and a diaphragm described later. A slit C02 that engages with the operating pin G12 of the blade driving means G is formed. An attachment reference hole C04 for attaching the ND filter described in FIG. 2 is provided in the vicinity of the aperture opening.

  Next, the presser plate B will be described. The presser plate B, which is formed of a metal plate substantially in the same shape as the base plate F, constitutes a unit by incorporating the shutter blade E and the aperture blade C described above between the base plate F. Yes. An opening B01 whose center coincides with the exposure opening D01 is formed in the pressing plate B, and the opening B01 is formed to have a diameter larger than that of the exposure opening D01. B02 is engaged with a support shaft F02 formed on the main plate, B03 is an escape hole that engages with the support shaft F03, and similarly, B04 is an escape hole through which the operating pin G12 of the diaphragm blade drive device moves, and B05 is This is a relief hole of the operating pin H12 of the shutter driving device. B07 is a stopper hole for the stopper F08, and B08 is a relief hole for the stopper F09.

  B09 and B10 in the figure are positioning holes, and the projections F12 and F13 formed on the main plate engage with each other. As a result, the base plate and the holding plate are aligned. Similarly, in the press plate B, several appropriately illustrated bent portions B11 are formed at six locations to form gaps between the base plate F, the intermediate plate D, and the press plate B. . Moreover, the latching recessed part B12 is provided in two places, and it fits with the nail | claws F14 and F15 formed in the ground plane F, and is integrated (fixed) with the ground plane. In addition, D08 in the figure is an escape hole for the intermediate plate positioning pin F13 of the ground plane F to penetrate through the positioning hole.

  The light amount adjusting device described above is incorporated in a lens barrel of a digital camera, a video camera, etc., and adjusts the amount of light such as a shutter that blocks the amount of light in the imaging optical path where light from the subject reaches the solid-state image sensor, or a diaphragm that adjusts the amount of light. I do. FIG. 9 shows an outline of the imaging apparatus, A is a front lens of the imaging lens, and I is a rear lens. An imaging lens usually composed of a plurality of lens arrays is incorporated in a lens barrel (not shown) so as to be movable along an imaging optical path (hereinafter referred to as an optical path) for focal position adjustment, and a drive motor is connected to the movable lens. ing. Its structure is well known and will be omitted.

  A driving circuit FM is connected to the motor of the focusing mechanism. A solid-state imaging device J is disposed on the imaging surface of the imaging lens. The solid-state imaging device has a number of photoelectric conversion elements arranged in accordance with the resolution, and electrically converts the formed subject image. For example, a device known as a CCD is composed of a charge layer that generates charge by light and a transfer layer that transfers the charge of the charge layer to the outside, and a CCD control circuit J01 is connected to the transfer layer. This CCD control circuit J01 incorporates a buffer memory for accumulating charges from the transfer layer, an amplifier circuit, and an A / D conversion circuit, and charges each pixel from the transfer layer to a buffer memory in accordance with a signal from a reference clock. Forward to. The light quantity adjusting device described above is unitized and incorporated between the front lens A and the rear lens I. A shutter drive shutter drive circuit SH is provided in the shutter drive means (drive meter) G, and an aperture drive means (drive meter) H is provided in the aperture drive means (drive meter) H. An aperture driving circuit IR is provided. These control circuits are connected to a CPU 100 that controls the entire camera apparatus, and each operation is controlled by the CPU 100. The CPU 100 is connected so that signals from the release switch SW2 and the power switch SW1 are transmitted. The operation will be described with reference to FIG.

  When the power switch of the camera is turned on (ST01), the CPU 100 supplies power to each drive component. For example, in a camera equipped with a display screen such as a liquid crystal, the backlight of the liquid crystal is turned on and display is possible, and the solid-state image sensor J also transfers the generated charge to the image processing circuit and sends it to the display screen. At this time, power is not supplied to the excitation coils H03 and G03 of the driving means H and G of the shutter blade E and the diaphragm blade C of the light amount adjusting device. (The same state as when the power switch SW1 is OFF). In this state, the shutter blade E is in the open position, the aperture blade C is in the retracted position, and the amount of light from the subject is imaged on the solid-state image sensor J and displayed on the display screen.

  Simultaneously with this apparatus power operation (ST01), the copy body image is displayed on the display screen and the monitor (ST02) is executed. Next, the user operates the mode selection switch to shoot in the state displayed on the monitor (moving image shooting mode) or to shoot in the still image state (still shooting mode) (ST03). When the still shooting mode (called single frame shooting mode) is selected, the user confirms the subject on the monitor display or from the viewfinder and executes the release operation. If the power switch SW01 is turned off without performing the release operation, all the operations are finished, the power supply is cut off, and the photographing is finished (ST04). In the release operation, the shutter button is first pressed halfway (ST05). In response to the signal, the CPU 100 drives the motor FM to execute a focusing operation and adjust the focus. At the same time, the CPU calculates an appropriate exposure amount from the received light amount of the CCD and determines whether or not to use the aperture blade. When the shutter button is fully depressed (ST06), the CPU issues an instruction signal for supplying power to the excitation coil G03 to the aperture driving circuit IR when using the aperture blade (small aperture imaging). In response to this signal, the diaphragm drive circuit IR supplies a predetermined current to the exciting coil G03, and the rotor rotates by the magnetic field generated in the coil G03. With this rotation of the rotor, the transmission pin G12 rotates the diaphragm blade C in the clockwise direction in FIG. 3 and moves from the two-dot chain line state to the one-dot chain line position, hits the stopper (diaphragm blade regulating means) F09, and a predetermined current is applied to the exciting coil G03. While being supplied, the blade C is maintained in this state (ST07). After the expected time for the operation of the diaphragm blade C, the CPU 100 issues a reset signal to the CCD control circuit J01. With this reset signal, the CCD control circuit J01 invalidates and resets the image data stored in the buffer memory (ST08). Exposure is started upon completion of the reset, and light from the subject is photoelectrically converted by the charge layer of the CCD.

  When a predetermined time (exposure time) obtained by calculation elapses, the CPU 100 issues a shutter closing instruction signal to the shutter driving circuit SH. The circuit SH obtains this signal and supplies a predetermined current to the excitation coil H03 of the shutter drive means (drive meter) H. The current generated in the coil H03 by supplying this current rotates the rotor and moves the shutter blade E from the open position to the closed position indicated by the dotted line. With this movement of the blades, the light from the subject is completely closed, and the exposure of the CCD is completed (ST09). The drive circuit SH continues to energize the coil H03 with a predetermined current even after the blades have moved to the closed position, and the generated magnetic field of the coil H03 applies a force that rotates the rotor counterclockwise. Accordingly, the blade E keeps the stationary state by hitting the stopper (shutter blade regulating means) F09 (ST10). At this time, even if an external force such as an impact is applied from the outside, the blade is held in the closed position.

  Next, the CPU 100 issues an exposure end signal to the CCD control circuit J01, and transfers the charge charged in the charge layer of the CCD to the image processing circuit via the transfer layer. This data transfer is performed in accordance with the scanning signal in the X and Y directions sequentially for the charge of each pixel of the CCD, and the control is performed based on the reference clock of the CCD control circuit. Therefore, the data transfer time is determined by the characteristics of the CCD and the control circuit. Therefore, the CPU 100 supplies a predetermined current to the exciting coil H03 for a preset time (at least longer than the data transfer time) based on the data transfer time. Then, the shutter blade E is held at the closed position, and external light does not reach the CCD during the data transfer process (ST11).

Next, when a predetermined set time has elapsed, the CPU 100 issues an operation end signal to the aperture driving circuit IR and the shutter driving circuit SH. With this signal, the diaphragm drive circuit IR supplies a reverse current to the exciting coil, and moves the blade C from the operating position to the retracted position (ST12). After this operation, the supply of current is cut off. Then, the blade E is attracted to the cut (slit) portion formed on the yoke by the rotor of the driving means by the magnetic force of the permanent magnet, and abuts against the stopper F08 and stops (ST13).
Similarly, the shutter drive circuit SH supplies a current in the reverse direction to the exciting coil H03, and moves the blade E from the dotted line closed position to the two-dot chain line open position (ST14). When the energization to the exciting coil H03 is cut off in this state, the rotor of the shutter driving means H is attracted to the slit portion formed in the yoke H04, and the blade E is held at the open position in a state where it abuts against the stopper F07. With this operation, the light amount adjusting device is in an initial state and is ready for the next photographing operation.

  The operation of the diaphragm blades and shutter blades has been described in the case where the current supplied to the exciting coil is opened and closed by reversing forward and backward. However, the operation is similar to a spring (close spring) that applies a retracting direction force to the diaphragm blades C. In the case where the shutter blade E is provided with a spring for applying a force in the opening direction, it is only necessary to turn off the supply power without applying a reverse current in ST12 and ST14. In this case, it is not necessary to provide a slit in the yoke of the drive meter to attract the magnet rotor in one direction. Other operations are the same as described above.

The disassembled perspective view which shows the structure of the magnet rotor of this invention. The perspective view which shows the structure of the shaping | molding die used for the shaping | molding method of the magnet rotor of this invention. Explanatory drawing which shows the plane of the shaping | molding die of FIG. Explanatory drawing which shows the direction of the magnetic field of an anisotropic magnet. The structure of the magnet rotor mold is shown, (a) is a central longitudinal sectional view (b) and a plan view is shown. The center longitudinal cross-sectional view of the electromagnetic drive device using the magnet rotor of FIG. Explanatory drawing which shows the process of the insert molding method of this invention. FIG. 7 is an exploded exploded perspective view of a shutter blade opening / closing device using the electromagnetic driving device of FIG. 6. Explanatory drawing of schematic structure of the camera apparatus using the apparatus of FIG. The operation | movement flowchart in the apparatus of FIG.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Magnet member 2a Hollow shaft hole 3 Rotary shaft member 3a, 3b Upper and lower flanges 3c Rotating shaft 4 Transmission arm member 4a Arm part 4b Transmission part 4c Connection part 10 Fixed type | mold 11 Movable type | mold 12 Shaft end formation part 13 Formation part 14 Formation part 17 Magnetic body insertion part 22 Shaft end formation part 23 Injection port 25 Insertion hole 26 Positioning member 27 Positioning member

Claims (5)

A magnet in which a ferromagnetic body is formed into a hollow cylindrical shape, and the magnetic body is loaded into a mold having at least one operating arm molding portion, and then a resin material is injected to integrally mold the ferromagnetic body and the operating arm. A method of forming a rotor,
The hollow cylindrical ferromagnet is formed such that the peripheral surface is polarized and magnetized to at least two poles, and has a non-circular axial hole in the center,
The molding die is formed of a non-magnetic material, and includes a magnetic body insertion portion for rotatably loading the magnetic body, an operating arm forming portion for molding the operating arm, and the magnetic arm at a predetermined angular position with respect to the operating arm forming portion. It consists of a positioning member made of a soft magnetic material arranged in the body insertion part,
The ferromagnetic body is accommodated in the magnetic body insertion portion, and the ferromagnetic body is rotated and positioned at a predetermined angular position with the operating arm molding portion by suction of the positioning member, and is held.
Next, a molding method of a magnet rotor, wherein a resin material is injected into the molding die.   2. The magnet according to claim 1, wherein the ferromagnetic body is polarized and magnetized with NS2 poles on a peripheral side surface, and the positioning member is composed of a pair of soft magnetic members facing each other to the magnetic body insertion portion. Rotor molding method.   The method for forming a magnet rotor according to claim 1, wherein the axial hole of the ferromagnetic body has a rectangular cross section.   2. The method of forming a magnet rotor according to claim 1, wherein the ferromagnetic body is formed by firing a magnetic powder such as neodymium by applying a magnetic field in a sintering mold.   5. The method of forming a magnet rotor according to claim 4, wherein the N-S magnetization of the ferromagnetic body forms a magnetic pole by a magnetic field during sintering.

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