JP2007174795A - Electromagnetic actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic actuator which is equipped with a stator that can properly keep the interval between the two magnetic poles of a roughly U-shaped yoke. <P>SOLUTION: A rotor 8 is made of a permanent magnet which has a main body 8a, an arm 8b, and an output pin 8c, and the circumferential face of the main body 8a serves as a magnetic pole, and it is attached rotatably to a shaft 1c erected on a shutter bottom board 1. A yoke 9 engages its hole with the positioning pin 1d of the shutter bottom board 1, and it is whirl-stopped by projections 1e and 1f, and it opposes the magnetic poles at the tips of feet 9a and 9b to the magnetic pole of the rotor 8. A bobbin 11 fitted on the foot 9b has a coil 10 wound, and a bulge 11d is made, so that it can contact with the foot 9a, at a flange part 11c which is positioned on the magnetic pole side of the foot 9b. Therefore, in the manufacture process, it can keep the interval between the magnetic poles suitably even if the yoke 9 is deformed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a substantially U-shaped yoke having magnetic poles at the tip ends of two legs, and a bobbin around which a coil is wound is fitted to one of the legs, and the coil is energized. The present invention relates to an electromagnetic actuator that reciprocates a rotor having a permanent magnet.

  The stator is composed of a substantially U-shaped yoke having two legs, and a bobbin wound around a coil and fitted to one of the legs. The tip of each leg is a magnetic pole. As an example, there is known an electromagnetic actuator arranged so as to face the circumferential surface of a rotor having a permanent magnet. The following Patent Document 1 describes one having only one stator having such a configuration, and Patent Document 2 describes one having two stators. The electromagnetic actuator described in Patent Document 1 is used as a drive source for the shutter device, but the electromagnetic actuator having such a configuration can also be used as a drive source for a diaphragm device, a filter device, or the like. In addition, since it is easy to make the whole small and flat, it can also be used as a drive source for a camera lens built in an information terminal device such as a mobile phone or a personal computer. Further, in the case of the electromagnetic actuator described in Patent Document 2, it is used as a driving source for the diaphragm device, but the electromagnetic actuator having such a configuration can also be used as a driving source for a shutter device, a filter device, or the like. It is. Further, either configuration of the electromagnetic actuator can be used as a drive source for various small devices other than those related to the camera.

  By the way, since such an electromagnetic actuator is used as a driving source for various small devices, for example, the yoke is often 5 mm or less in length, 10 mm or less in width, and 1 mm or less in thickness. After punching with a press machine, it is manufactured through processes such as barreling and plating. However, since this type of electromagnetic actuator is a mass-produced product, the processing of these yokes is also performed for each lot. As a result, yokes collide with each other during transport between processes, during loading and unloading to processing equipment, during processing, etc., and finally a yoke with a predetermined shape cannot be obtained uniformly. It may end up. In that case, the most serious problem is that the distance between the magnetic pole portions provided at the tip portions of the two leg portions is changed beyond the allowable range. May also occur when assembling. Among such production problems, Patent Document 1 discloses that two magnetic pole portions provided on the yoke are assembled when a stator is assembled to the main body of the electromagnetic actuator (the substrate in Patent Document 1). The structure which can obtain | require the space | interval of is appropriately described is described.

JP 2004-95703 A JP-A-2005-107173

  The electromagnetic actuator described in the above-mentioned patent document 1 has a positioning projection formed on the main body of the electromagnetic actuator (substrate in patent document 1), and the yoke has two leg portions (patents) by the positioning projection. In the literature 1, the arm part) is elastically deformed and attached so as to widen the space between them. Therefore, as a matter of course, the positioning projections of the two flange portions provided on the bobbin push the two leg portions between the flange portion on the side of the magnetic pole portion of the yoke and the magnetic pole portion. ing. Therefore, in order to maintain the winding amount of the coil, if the bobbin is made to be the same size as the conventional one, the two legs of the yoke must be lengthened correspondingly, which is disadvantageous for downsizing. If the lengths of the two legs are made the same as before, there is a problem that the bobbin must be made small to reduce the amount of winding of the coil. Further, the configuration described in Patent Document 1 cannot solve the problem that when the bobbin is assembled to the yoke, the two magnetic pole portions may be deformed to be small.

  The present invention has been made to solve such problems, and the object of the present invention is to deform the two magnetic pole portions of the yoke so as to be small when the bobbin is assembled to the yoke. In addition, an electromagnetic actuator having a stator that can properly maintain a gap between two magnetic pole portions of a yoke without increasing the yoke or reducing the bobbin is provided. .

  In order to achieve the above object, an electromagnetic actuator of the present invention includes a rotor having a permanent magnet provided with a plurality of magnetic pole portions on a circumferential surface, and a substantially U-shaped two leg portion. A yoke having a tip portion as a magnetic pole portion and facing the circumferential surface, and two flange portions at both ends of a cylindrical portion around which a coil is wound, and the cylindrical shape of the two flange portions And a bobbin having a protruding portion that can come into contact with the other of the leg portions on a flange portion on the magnetic pole portion side of the yoke when the portion is fitted to one of the leg portions. .

  In that case, two yokes fitted with the bobbin may be arranged with the rotor in between. Further, the rotor is rotatably attached to at least one of the two plate-like members so that the rotor is parallel to the rotation axis of the rotor at a radial position of the rotation center. An output pin may be provided, and each of the portions that contact the two leg portions of the yoke and suppress the spread between the two magnetic poles of the yoke is at least one of the plate-like members. A plurality of them may be provided. Further, if one of the two plate-like members and the bobbin are manufactured by an integral molding process using a synthetic resin material, it is advantageous for downsizing and cost reduction.

  According to the electromagnetic actuator of the present invention, of the two flange portions formed on the bobbin, when the bobbin is fitted to one leg portion of the yoke, the flange portion on the side closer to the magnetic pole portion of the leg portion. Since the overhang portion is formed so as to be in contact with the other leg portion of the yoke, in the process of processing the parts of the yoke, even if the interval between the two leg portions is formed slightly smaller than the predetermined interval, When the bobbin is fitted, it is possible to keep a predetermined interval by the projecting portion as in the case of the configuration example described in Patent Document 1, and in addition to the configuration example described in Patent Document 1. There is no need to worry that the distance between the two leg portions of the yoke will be smaller than the predetermined distance during assembly such as when a bobbin is fitted to the yoke, and the yoke is enlarged. Or small bobbin There is an advantage that can be preferably ensured drive torque without.

  Embodiments of the present invention will be described with reference to the illustrated examples. As described above, the electromagnetic actuator of the present invention can be used as a driving source for various small products, but a representative example of such a small product is commercialized alone. There are various components built into cameras and cameras built into information terminal devices such as mobile phones and personal computers. Therefore, the embodiment is configured as a lens shutter device which is one of them. In the case of a lens shutter device, as is well known, a lens shutter device having the same configuration may be adopted for a silver salt film camera or a digital camera including a case where it is built in an information terminal device. However, the operation of the embodiment will be described in the case of being adopted in a digital camera.

FIG. 1 is a plan view of the embodiment showing the fully opened state (initial state) of the shutter blades, and FIG. 2 is a plan view of FIG. 1 viewed from the back side. 3 is a cross-sectional view showing the overlapping relationship of the constituent members in the embodiment in an easy-to-understand manner, and FIG. 4 is a view for comparing the main part of the embodiment with the conventional example. 4 (a) shows the case of the embodiment, and FIG. 4 (b) shows the case of the conventional example. Further, FIG. 5 is an external view of a mobile phone incorporating the shutter device of the embodiment, FIG. 5 (a) is a view from the subject side, and FIG. 5 (b) is a view from the photographer side. FIG.

  First, the configuration of the present embodiment will be described. The shutter base plate 1 is a relatively thick plate member made of synthetic resin, but the surface thereof is formed in a complicated shape on both sides, and in addition to a circular opening 1a for regulating the subject optical path, an arc shape is used. The long hole 1b is formed to be large. A synthetic resin frame plate 4 is attached to one surface of the shutter base plate 1 with two screws 2 and 3 at a predetermined interval to constitute an actuator chamber between them. In FIG. 1, the frame plate 4 and the screws 2 and 3 are indicated by a two-dot chain line in order to make the actuator chamber easier to see. A cover plate 5 is attached to the other surface of the shutter base plate 1 with two screws 6 and 7 at a predetermined interval, and a shutter chamber is formed between the two. The shutter base plate 1 is provided with a shaft 1c, a positioning pin 1d, and two projections 1e and 1f for position restriction on the surface on the actuator chamber side, and two shafts 1g on the surface on the shutter chamber side. , 1h, positioning pins 1i, and four stoppers 1j, 1k, 1m, 1n.

  In addition to the holes for mounting with the screws 2 and 3, the frame plate 4 has a long hole 4 a for inserting the tip of the positioning pin 1 d, a large rectangular cutout 4 b, A hole 4c for fitting the tip of the shaft 1c is formed, and two protrusions 4d and 4e having a circular cross-sectional shape are formed on the surface on the actuator chamber side. Further, the cover plate 5 has a shape similar to that of the shutter base plate 1, and has a diameter larger than that of the opening 1a at a position overlapping with the opening 1a in addition to the holes to be attached by the screws 6 and 7. A long hole 5b having a shape similar to that of the long hole 1b is provided at a position substantially overlapping with the long hole 1b. The cover plate 5 is also formed with holes 5c and 5d for inserting the ends of the shafts 1g and 1h and holes 5e for fitting the ends of the positioning pins 1i.

  In the actuator chamber, the rotor 8 is rotatably attached to the shaft 1c. The rotor 8 includes a cylindrical body 8a, an arm 8b projecting in the radial direction, and an output pin 8c formed at the tip of the arm 8b, all of which are permanent magnets. However, in FIG. 1, the boundary line of the magnetic pole of the main body 8a magnetized to two poles is indicated by a one-dot chain line. The output pin 8c is inserted into the blade chamber side from the long hole 1b, and the tip thereof is inserted into the long hole 5b. Although the rotor 8 of the present embodiment has such a configuration, the rotor of the present invention is not limited to such a configuration, and as is well known, the arm portion 8b and the output pin 8c described above. May be made of synthetic resin, or the main body portion 8a of the present embodiment may be a columnar shape and may be rotatably supported by both the shutter base plate 1 and the frame plate 4. . Further, as in the present embodiment, the arm portion 8b may not be provided, and the output pin 8c may be provided directly on the lower end surface of the main body portion 8a. Further, the output pin 8c is not provided, and it may be configured like a rotor described in Patent Document 2. In short, the rotor of the present invention only has to be formed by a plurality of magnetic poles of a permanent magnet on the circumferential surface of the main body.

  In the actuator chamber, a yoke 9 and a bobbin 11 around which a coil 10 is wound are disposed. Among them, the yoke 9 is substantially U-shaped as can be seen from FIG. 1, and the tip portions of the two leg portions 9a and 9b are magnetic pole portions. The bobbin 11 has a cylindrical portion 11a fitted to one leg portion 9b of the yoke 9, and two flange portions 11b and 11c formed at both ends of the cylindrical portion 11a. An overhang portion 11d is formed on the flange portion 11c on the part side so as to be in contact with the other leg portion 9a. As described above, the structure in which the bobbin 11 is fitted to the yoke 9 has a shape that the yoke 9 is easily deformed. Therefore, in the following, the problem and why the bobbin 11 of this embodiment has such a shape will be described.

  As described above, since the yoke 9 belongs to a so-called small part, after being punched from a thin plate with a press machine, barrel processing, plating processing, or the like is performed in units of several hundreds at a time. However, as can be seen from FIG. 1, since the yoke 9 has two elongated legs 9a and 9b, the legs 9a, 9b, etc. are brought into contact with each other during transportation or processing. 9b may be slightly deformed, and the distance between the magnetic poles at the tip, which is the most important part in the arrangement with the rotor 8, may be changed beyond the allowable range. In that case, the interval is often smaller than the interval is increased due to the shape.

  Thereafter, the tubular portion 11a of the bobbin 11 around which the coil 10 is wound is fitted into the leg portion 9b of the yoke 9, and the operator holds the yoke 9 on the finger of one hand. In order to carry out the operation quickly from one to the next by holding the bobbin 11 on the finger of the other hand, at least one of the leg portions 9a and 9b is deformed during handling of the yoke 9, It may change the interval. Also at this time, because of the shape of the yoke 9, the interval between the magnetic pole portions is often reduced.

  On the other hand, the bobbin 11 of the present embodiment has a protruding portion 11d formed on the flange portion 11c on the magnetic pole portion side of the leg portion 9b to be fitted. 9 can be corrected by pressing the leg portion 9a when the bobbin 11 is fitted even when the bobbin 11 is deformed so that the distance between the magnetic pole portions is reduced. Further, when performing the operation of fitting the cylindrical portion 11a of the bobbin 11 to the leg portion 9b of the yoke 9, the yoke 9 is deformed so that the interval between the magnetic pole portions is reduced immediately before the bobbin 11 is fitted. In this case, the overhang portion 11d is corrected by pushing the leg portion 9a in the same manner as described above, and after the bobbin 11 is fitted, the interval between the magnetic pole portions is small due to the presence of the overhang portion 11d. Since it cannot be, the operator's work becomes very easy.

  Further, Japanese Patent Application Laid-Open Publication No. 2004-151858 describes only that the interval between the magnetic pole portions, which is smaller than the predetermined interval, can be optimized when the yoke 9 is attached to the shutter base plate 1. Although the configuration is possible, the configuration of the present embodiment has an advantage more excellent than that with the miniaturization of the electromagnetic actuator. This will be described with reference to FIG. 4. FIG. 4 (a) is a plan view showing an essential part of the electromagnetic actuator of this embodiment shown in FIG. ) Shows the shape and arrangement of the yoke 9 and the rotor 8 exactly the same, and the winding diameter of the coil 10 is made the same for easy comparison with the present embodiment. As can be seen from this comparison, when the configuration described in Patent Document 1 is adopted, a protrusion 1x (positioning protrusion 13 in Patent Document 1) is formed on the shutter base plate 1, so that the bobbin 11 has to be reduced, the number of turns of the coil 10 is reduced, the driving torque is reduced and the rotor 8 cannot be suitably rotated, and conversely the size of the bobbin 11 Are the same, the lengths of the leg portions 9a and 9b of the yoke 9 must be increased, and the entire yoke 9 and eventually the electromagnetic actuator become larger. In the case of this embodiment, however, Must not.

  In the yoke 9 of the present embodiment in which the bobbin 11 is fitted in this manner, the hole formed in the common base of the two leg portions 9a and 9b is fitted to the positioning pin 1d, so that the shutter base plate 1 and is stopped by the two protrusions 1e and 1f. For this reason, although the possibility is extremely small, even if the yoke 9 is deformed so that the interval between the magnetic pole portions is increased, the projection 9 is appropriately corrected by these protrusions 1e and 1f. .

  After the yoke 9 is assembled to the shutter base plate 1 in this way, the frame plate 4 has the long holes 4a fitted to the positioning pins 1d and the holes 4c fitted to the shaft 1c. 3 is attached to the shutter base plate 1, but in the attached state, as shown in FIG. 3, the coil 10 and part of the bobbin 11 enter the notch 4 b, so that the shutter device is thin. Is possible. The two projections 4d and 4e of the frame plate 4 are provided to prevent the frame plate 4 from being bent, and the projection 4e is formed shorter than the projection 4d, and the longer one of the yoke 9 is provided. The tip of the leg portion 9 a is pressed against the shutter base plate 1. Therefore, even if the tip of the leg 9a is deformed to the frame plate 4 side, the deformation is corrected. Further, since the base side of the yoke 9 is pressed against the shutter base plate 1 by the frame plate 4, even if there is a deformation, it is corrected. In this embodiment, the frame plate 4 is not provided with a projection for pressing the tip of the leg portion 9b against the shutter base plate 1, but it is provided if necessary.

  Finally, the two shutter blades 12 and 13 arranged in the blade chamber will be described. The shutter blade 12 disposed on the shutter base plate 1 side is rotatably attached to the shaft 1g of the shutter base plate 1, and the output pin 8c of the rotor 8 is inserted into the long hole 12a. Further, the shutter blade 13 disposed on the cover plate 5 side is rotatably attached to the shaft 1h of the shutter base plate 1, and the output pin 8c of the rotor 8 is inserted into the elongated hole 13a. That is, the output pin 8c of the rotor 8 is inserted into both the long holes 12a and 13a formed in the shutter blades 12 and 13, and when the rotor 8 rotates counterclockwise in FIG. The shutter blades 12 and 13 rotate in opposite directions.

  Next, the operation of the present embodiment will be described. As described above, the shutter device of the present embodiment will be described in the case where it is adopted in a digital camera provided with a solid-state image sensor. FIGS. 1 and 2 show an initial state (shooting standby state) in which shooting is not performed even though the power of the camera is turned on. Therefore, in this state, since the shutter blades 12 and 13 have the opening 1a fully opened and the subject light strikes a solid-state image sensor (not shown), the photographer can observe the subject image on the monitor. It has become. Further, as is well known, at this time, the rotor 8 has a magnetic attractive force generated by the opposing relationship between the magnetic pole portions of the peripheral surface of the main body portion 8a and the magnetic pole portions of the leg portions 9a and 9b of the yoke 9, as shown in FIG. A force for rotating in the clockwise direction is applied. Therefore, the output pin 8c attempts to rotate the shutter blade 12 in the clockwise direction and the shutter blade 13 in the counterclockwise direction in FIG. 2, but the shutter blades 12 and 13 come into contact with the stoppers 1j and 1k. Therefore, this stop state is maintained.

  In such an initial state, when the photographer presses the release button, the charge accumulated in the solid-state image sensor is released by a signal from the exposure control circuit, and thereafter, accumulation of charge for photographing is newly started ( Exposure for shooting is started). When a predetermined time corresponding to the luminance of the subject elapses, the coil 10 is energized in the positive direction by a signal from the exposure control circuit, and the rotor 8 is rotated counterclockwise in FIG. Therefore, in FIG. 2, the output pin 8c rotates the shutter blade 12 counterclockwise and rotates the shutter blade 13 clockwise to perform the closing operation of the opening 1a. When the opening 1a is completely closed, the shutter blades 12 and 13 stop when the shutter blade 12 contacts the stopper 1n and the shutter blade 13 contacts the stopper 1m.

  When the closing operation of the shutter blades 12 and 13 is completed in this manner, the imaging information photoelectrically converted by the solid-state imaging device is transferred to the storage device. When the transfer is completed, the coil 10 is energized in the opposite direction. Therefore, the rotor 8 is rotated in the opposite direction, and the opening pin 1c is opened by rotating the shutter blade 12 clockwise by the output pin 8c and rotating the shutter blade 13 counterclockwise. To do. When the opening 1a is fully opened, the shutter blade 12 comes into contact with the stopper 1j and stops, and the shutter blade 13 comes into contact with the stopper 1k and stops. After that, when the coil 10 is de-energized, the initial state shown in FIGS. 1 and 2 is restored.

  As described above, the present embodiment is configured as a shutter device including the two shutter blades 12 and 13. However, since only one of the shutter blades can cover the opening 1a, Depending on the specifications, a shutter device having only one shutter blade may be provided. In addition, these shutter devices can be used as lens barrier devices for protecting the photographing lens. Further, in a shutter device having a single shutter blade, if the shutter blade is replaced with a diaphragm blade having a diaphragm opening having a diameter smaller than that of the opening 1a, a diaphragm device can be obtained. A filter device can be obtained by attaching an ND filter to the aperture opening.

  As described above, the electromagnetic actuator used in the present embodiment can be used not only as a driving source for various blade driving devices incorporated in a single camera product, but also as an information terminal device including a mobile phone, It can be used as a driving source for various blade driving devices and lens driving devices for cameras built in videophones, door phones, etc., and it can also be used as a driving source for devices other than cameras such as locking devices. Is possible. FIG. 5 is an external view when the shutter device of this embodiment is built in a mobile phone. FIG. 5 (a) is a view from the subject side, and FIG. 5 (b) is a photographer side. However, in order to make it easy to understand the state of arrangement of the built-in shutter device, some constituent members are indicated by broken lines and are indicated by reference numerals. As can be seen from this example, the electromagnetic actuator of the present invention is particularly suitable for miniaturization and thinning.

It is a top view of the Example which showed the shutter blade fully open state (initial state). It is the top view which looked at FIG. 1 from the back side. It is sectional drawing of the Example which showed clearly the overlapping relationship of the structural member. 4A and 4B are diagrams for comparing the main part of the embodiment with the conventional example, in which FIG. 4A is extracted from FIG. 1 and FIG. 4B shows the conventional example. It is. FIG. 5A is an external view of a mobile phone incorporating the shutter device of the embodiment, and FIG. 5A is a view seen from the subject side, and FIG. 5B is a view seen from the photographer side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a, 5a Opening part 1b, 4a, 5b, 13a, 13a Long hole 1c, 1g, 1h Shaft 1d, 1i Positioning pin 1e, 1f, 1x, 4d, 4e Protrusion 1j, 1k, 1m, 1n Stopper 2, 3, 6, 7 Screw 4 Frame plate 4b Notch 4c, 5c, 5d, 5e Hole 5 Cover plate 8 Rotor 8a Body 8b Arm 8c Output pin 9 Yoke 9a, 9b Leg 10 Coil 11 Bobbin 11a Tubular Part 11b, 11c Flange part 11d Overhang part 12, 13 Shutter blade

Claims (5)

  A rotor having a permanent magnet provided with a plurality of magnetic pole portions on a circumferential surface, and a substantially U-shaped, the tip portions of two leg portions are used as magnetic pole portions, and they are opposed to the circumferential surface. And a yoke having two flange portions at both ends of the cylindrical portion around which the coil is wound, and when the cylindrical portion is fitted to one of the leg portions of the two flange portions, the magnetic pole of the yoke An electromagnetic actuator comprising: a bobbin having a projecting portion that can come into contact with the other of the leg portions on a flange portion on a part side.   The electromagnetic actuator according to claim 1, wherein two yokes fitted with the bobbin are arranged with the rotor interposed therebetween.   The rotor is rotatably attached to at least one of the two plate-like members, and an output pin is arranged at a radial position of the rotation center so as to be parallel to the rotation axis of the rotor. The electromagnetic actuator according to claim 1, wherein the electromagnetic actuator is provided.   4. A plurality of portions are provided on at least one of the plate-like members, each of which is in contact with the two leg portions of the yoke and suppresses the spread between the two magnetic poles of the yoke. The electromagnetic actuator described in 1.   5. The electromagnetic actuator according to claim 3, wherein one of the plate-shaped members and the bobbin are manufactured by an integral molding process using a synthetic resin material.

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