JP2002083711A - Electromagnetic drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic drive having a plunger, which has a simple structure, is strong and can operate efficiently. SOLUTION: An electromagnetic drive 10 comprises a solenoid 1 (coil 11, bobbin 12) having a hollow cylindrical structure and a yoke 13 for holding a movable plunger (movable iron core 15) in the hollow cylinder. The electromagnetic drive 10 comprises, for example, a conical concave part (movable iron core head 15a), which is provided on an end face of the plunger, and a yoke (fixed iron core 13a1) having a conical concave part, which is opposed to the conical concave part and is formed on a coaxial line with respect to the center in the moving direction of the length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small electromagnetic drive device used for driving an electromagnetic valve, a shutter drive lever of a camera, and the like.

[0002]

2. Description of the Related Art A recent technology of an electromagnetic driving device that moves a movable portion called a plunger by a solenoid is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-307217. A fixed iron core (fixed iron core) is fixed to the yoke itself by caulking or the like. 5A and 5B showing this conventional electromagnetic drive device 100, as shown in the sectional view of FIG. 5A, a coil 101 is wound around a bobbin 102 into which a movable iron core 105 is inserted. A solenoid having a hollow cylindrical structure formed by turning is assembled to the yoke 103, and a power supply 106 is connected to the coil 101 to generate a magnetic field in the cylinder and move the movable iron core 105. Such a plunger (that is, the movable iron core 105) of the electromagnetic drive device 100 can be used as a drive source for opening and closing a shutter of a camera or the like, for example.

[0003] A coil 101 is wound around the outer periphery of a cylindrical bobbin shaft hole 102a opened at the center of the bobbin 102 at a fine pitch between a pair of bobbin side plates 102b erected on both wings. Since the iron core 105 is inserted into the hole 102a and moves in the long axis direction due to the generation of a magnetic force, a shutter driving member (not shown: shutter driving lever for engagement with a neck 105b formed on the head of the movable iron core 105) Etc.) is moved to release the shutter.

Here, an improvement has been made to generate as large a magnetic force as possible with a small electric power.
As shown in an enlarged view in FIG.
05a is processed into a substantially conical convex shape.
The fixed iron core 104 has a conical concave portion 104a corresponding to the shape of the movable iron core 105 and faces the movable iron core 105.
Is the other bobbin shaft hole 102a of the yoke 103
Built in.

When magnetized, the fixed iron core 104
The force F that tries to pull in 05a is larger than the gap M (FIG. 6: conventional example) when the planes face each other.
As shown in (b), the conical surfaces have larger opposing areas, and the gap m in the normal direction between the opposing surfaces is m = M.
sin θ, which is represented by M> m, and the magnetic resistance is also reduced. As a result, a strong power can be obtained.

[0006]

However, in the above-mentioned known structure, the fixed iron core 104 is interposed between the yoke 103 and the movable iron core 105. A gap is created between them, which becomes the resistance of magnetic flux (magnetoresistive). As a result,
The magnetic force generated in the yoke 103 is attenuated by the fixed iron core 104, and the movable iron core 105 does not transmit the original magnetic force, causing a loss. This is also caused by the fact that if a loop is formed in the magnetic circuit, an efficient result is obtained, but the loop is not formed due to the interposition of another member such as the fixed iron core 104.

Further, conventionally, since the fixed iron core 104 is formed as a separate component and fixed by caulking or the like, the number of components increases accordingly, and it has been difficult to reduce the cost.

Therefore, the yoke 103 and the movable iron core 10
5 (ie, the fixed iron core 104 and air at the contact surface of the member with the yoke, etc.), which is the main cause of the magnetoresistance, requires a new structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic drive device having a plunger which has a simple structure, is powerful and can operate efficiently.

[0010]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention takes the following measures. That is, it can be implemented with a structure that does not require a separate member, and
The present invention proposes an improved structure that eliminates electromagnetic loss by eliminating the interposition of another member.

According to a first aspect of the present invention, in an electromagnetic drive device having a yoke for holding a solenoid and a movable plunger, a conical recess provided on one end surface of the plunger;
An electromagnetic drive device including a yoke portion having a conical convex portion which is opposed to the conical concave portion of the plunger and formed coaxially with the center of the plunger is proposed.

According to a second aspect of the present invention, there is provided an electromagnetic drive device having a yoke for holding a solenoid and a movable plunger, wherein the conical convex portion provided on one end surface of the plunger, and the conical convex portion of the plunger is provided. And a yoke portion having a conical recess formed opposite to the portion and formed coaxially with the center thereof.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention will be described below in detail with reference to a plurality of embodiments. (First Embodiment) FIGS. 1 and 2 show an external view and a longitudinal sectional structure of an electromagnetic drive device 10 according to a first embodiment of the present invention in an assembly view and a sectional view, respectively.

The electromagnetic drive device 10 exemplified here has a solenoid 1 which forms a hollow cylindrical structure with a bobbin 12 having a coil 11, a plunger (that is, a movable iron core 15) movable in the hollow cylinder, and holds these. The yoke 13 is mainly configured.

The solenoid 1 has a bobbin 12 on which a coil 11 is wound, and the bobbin 12 is mounted through a movable iron core 15 serving as the plunger.
3 is mounted as shown by an arrow in FIG. 1 and integrally assembled.

A coil 11 is wound on the outer periphery of a cylindrical bobbin shaft hole 12a opened at the center of the bobbin 12 at a fine pitch between a pair of bobbin side plates 12b erected on both wings. Thereby form a solenoid structure that generates a magnetic field.

The above-described electromagnetic drive device 10 is a solenoid 1 in which a plunger (movable iron core 15) is slidably inserted.
After winding the coil 11 around the bobbin 12, the coil 11 is housed in the yoke 13 and assembled. A predetermined magnetic path that can move the movable iron core 15 by generating a magnetic field by passing an AC or DC current through the coil 11. It has a structure.

Accordingly, the movable iron core 15 inserted into the bobbin shaft hole 12a receives a magnetic force based on a well-known law of magnetism and moves in the long axis direction due to the generation of a magnetic field.
If a predetermined member that engages with the groove formed in b is connected, it can be used to move a desired portion.

Therefore, such a plunger of the electromagnetic driving device 10 can be used as a driving source for opening and closing a shutter of a camera or the like. For example, a shutter driving member (not shown:
If a shutter drive lever or the like is connected here, the drive member can be moved and the shutter can be opened when power is supplied. In that case, the end of the coil 11 is configured to be connected to a predetermined power supply (not shown) so as to be energized (ON) via a release button of a camera, for example.

One feature of the electromagnetic drive device 10 is that, as shown in FIG. 2, a conical recess is formed on one end surface of the plunger (movable iron core 15).
The yoke portion (core-facing portion) of the movable iron core 15 facing the conical concave portion has a conical convex portion formed coaxially with the center thereof.

More specifically, a fixed iron core 13a1 having a conical projection is formed near the center of a yoke side plate 13b erected on one side of the yoke 13. Then, a rod-shaped movable iron core 15 is inserted from the other iron core insertion opening 13 a 2 of the yoke 13 while approaching the bobbin 12 while penetrating the bobbin shaft hole 12 a. At this time, the fixed iron core 1
A conical concave portion facing each other and having the same taper angle as the convex portion of the fixed iron core portion 13a1 is formed in the movable iron core head 15a of the movable iron core 15.

The conical convex portion formed on the fixed iron core 13a1 is formed by, for example, protruding from the outside of the yoke by a press or the like. The fixed iron core 1 of the yoke 13
An air hole 13c is opened at the center of 3a1 to allow ventilation.

Another feature is that the gap W between the bobbin side plate 12b and the yoke side plate 13b on the left side in the drawing, which is generated when the solenoid 1 is mounted on the yoke 13 with the movable iron core 15 pivotally supported, Is provided as an "assembly margin" for
Here, a frame-shaped spacer 14 which is made of an elastic material and is slightly bent in the shape of a "ku" extends the above-mentioned "ku" portion inside the yoke side plate 13b to resist the elastic force. Inserted. The play of the solenoid 1 in the thrust direction is suppressed by the spacer 14. As a result, the assemblability of the solenoid 1 conventionally bonded and fixed can be improved.

As described above, in the electromagnetic drive device of the first embodiment, the magnetic resistance is conventionally caused by the fixed iron core formed of a separate member interposed between the yoke and the movable iron core. The following effects are obtained by improving the road structure. In order to avoid the generation of magnetic resistance, the fixed iron core is formed integrally with the yoke side plate instead of a separate member, so that the original magnetic force in the magnetic field can be prevented from being attenuated.

Moreover, in order to increase the facing area between the fixed iron core and the movable iron core, the combination of the fixed iron core and the movable iron core is combined with a combination of conical irregularities having the same taper angle. By forming the opposing surface, it is possible to increase the number of magnetic fluxes passing therethrough and to strengthen the magnetic force acting on the movable iron core (plunger).

Further, by interposing an elastic material in a gap provided as an assembling margin, it is possible to add a play removing structure that effectively utilizes an extra space. Thus, a plunger that has a relatively simple structure, has a strong driving force, and is driven electromagnetically efficiently can be realized.

(Second Embodiment) Next, an electromagnetic drive device 20 according to a second embodiment of the present invention will be described. FIG.
The electromagnetic drive device 20 illustrated in FIG. 4 and FIG. 4 has substantially the same appearance as the above-described electromagnetic drive device 10 of the first embodiment except for a part thereof, and constitutes the electromagnetic drive device 20. The partial shape of the component has different characteristics as described later (details will be described later). However, the electromagnetic effects are equivalent.

The main components constituting the electromagnetic drive device 20 include a solenoid 2 which forms a hollow cylindrical structure with a bobbin 22 having a coil 21, a plunger movable in the hollow cylinder (ie, a movable iron core 25), and The yoke 23 holds these.

The electromagnetic drive device 20 includes the coil 2 as described above.
The solenoid 2 having the bobbin 22 around which the coil 1 is wound is accommodated in the yoke 23, and an alternating current or a direct current is supplied to the coil 21 so that the movable iron core 25 can be driven in the long axis direction. Therefore, it can be used to move the shutter drive lever via a member that engages with a groove formed in the movable iron core neck 25b of the movable iron core 25.

One feature of the electromagnetic drive device 20 is that the fixed iron core (cone-shaped convex portion) 13a1 in the above-described electromagnetic drive device 10 and the movable iron core head (recess) 15a of the plunger have irregularities. In the shape relationship opposite to that of the combination. That is, a conical convex portion is formed on one end surface of the movable iron core 25 (the movable iron core head 25a), and the vicinity of the center of the yoke side plate facing the convex portion (the fixed iron core portion 23a).
1) is provided with a conical concave portion having the same taper angle.

Then, the rod-shaped movable iron core 25 approaches from the iron core insertion opening 23a2 opened in the other yoke side plate 23b while penetrating the hollow cylindrical portion of the solenoid 2, and faces the fixed iron core portion 23a1. Then, the configuration is such that the facing area between the concave portion and the convex portion becomes larger than before.

The conical concave portion formed in the fixed iron core portion 23a1 is formed by punching (from the inside of the yoke) or the like with a press machine or the like. Alternatively, it may be made by drawing. Further, an air hole 23c is opened at the center of the fixed iron core portion 23a1 of the yoke 23 in the same manner as described above to allow ventilation.

As another feature, the gap between the bobbin side plate 22b and the yoke side plate 23b on the left side in FIG. 4 which is generated when the solenoid 2 is mounted on the yoke 23 with the movable iron core 25 pivotally supported is "Assembly margin". And no inclusions are provided here. Instead, in order to suppress the play of the solenoid 2 in the thrust direction, the bobbin side plate 2 is used here.
A yoke hole 23e is provided on the longitudinal center line of the lower plate of the yoke 23 to fit in the bobbin projection 22e projecting downward from the bottom 2b.

As described above, the electromagnetic drive device 20 of the second embodiment is another example of implementing a magnetic path structure that eliminates the cause of the occurrence of magnetic resistance interposed between the yoke and the movable iron core. is there.

That is, the combination of the irregularities of the fixed iron core portion (conical concave portion) 23a1 having the opposite relationship to the electromagnetic drive device 10 and the movable iron core head portion (conical convex portion) 25a of the plunger. By carrying out, the same operation and effect as in the first embodiment can be expected. In addition, by adopting a structure in which the bobbin protrusion 22e is fitted into the yoke hole 23e without using an additional member, a play-reducing effect can be obtained without increasing the number of components.

(Modifications) The above embodiments may be modified as follows. For example, the tip of the movable iron core serving as a plunger and the fixed iron core on the yoke may have the same shape, a similar shape, more specifically, an opposed surface having the same taper angle and the like. If the facing area increases, it may be other than a cone. However, in order to increase the number of magnetic fluxes, a combination of a concave surface and a convex surface is preferable. However, for example, a pair of two surfaces formed in a similar shape by combining a large number of irregularities may be used.

Further, after the solenoid bobbin is assembled to the yoke, the gap used as an assembling margin may be changed to be as narrow as possible by bending the yoke side plate inward so as to suppress rattling. According to these modified embodiments, an effect equal to or more than that of the first or second embodiment can be expected. In addition, various modifications can be made without departing from the spirit of the present invention.

Although the embodiments have been described above, the present invention includes the following inventions. (1) In an electromagnetic drive device having a yoke for holding a solenoid and a movable plunger, a conical concave portion provided on one end surface of the plunger, and a conical concave portion of the plunger opposed to and coaxial with the center thereof. And a yoke portion having a conical convex portion having the same shape as the conical concave portion formed in the electromagnetic driving device.

(2) The conical convex portion of the yoke portion is formed by a diaphragm.
Of the electromagnetic drive device. (3) The electromagnetic drive device according to (1), wherein a hole for venting air is provided at a center of the conical convex portion of the yoke portion.

(4) A yoke for holding a solenoid,
In an electromagnetic drive device having a movable plunger, a conical convex portion provided on one end surface of the plunger, and the conical convex portion formed opposite to the conical convex portion of the plunger and formed coaxially with the center thereof. And a yoke portion having a conical recess having the same shape as the portion.

(5) The conical recess of the yoke portion is made by drawing.
2. The electromagnetic drive device according to item 1. (6) A hole for venting air is provided at the center of the conical recess of the yoke portion, (4).
2. The electromagnetic drive device according to item 1.

[0042]

According to the present invention, it is possible to provide an electromagnetic drive device having a plunger capable of operating powerfully and efficiently with a simple structure.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an electromagnetic drive device shown as a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an assembly structure of the electromagnetic drive device according to the first embodiment.

FIG. 3 is an assembled perspective view of an electromagnetic drive device shown as a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing an assembly structure of the electromagnetic drive device according to the second embodiment.

5 (a) and 5 (b) show a conventional electromagnetic drive device, FIG. 5 (a) is a cross-sectional view showing the cross-sectional structure and device configuration of this electromagnetic drive device, and FIG. FIG. 5 is an enlarged sectional view showing the movement of a movable iron core as a plunger with respect to a fixed iron core provided on the yoke side.

FIG. 6 is an enlarged sectional view showing a gap between a fixed iron core and a movable iron core facing each other.

[Explanation of symbols]

1, 2, ... solenoid (hollow cylindrical structure), 10 ... electromagnetic drive device (device of the first embodiment), 11 ... coil, 12 ...
Bobbin, 12a: bobbin shaft hole, 12b: bobbin side plate, 13: yoke, 13a1: fixed iron core (conical convex portion), 13a2: movable iron core insertion opening, 13b: yoke side plate, 13c: air hole, 14 ... Spacer (elastic material), 15: movable iron core (plunger), 15a: movable iron core head, 15b: movable iron core neck, 20: electromagnetic drive device (device of the second embodiment), 21: coil, 22 ... Bobbin, 22a: bobbin shaft hole, 22b: bobbin side plate,
22e: bobbin projection (for mounting), 23: yoke, 23
a1: fixed iron core (conical recess), 23a2: movable iron core insertion opening, 23b: yoke side plate, 23c: air hole,
23e: yoke hole (for bobbin fitting), 25: movable iron core (plunger), 25a: movable iron core head, 25b:
Movable iron neck.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 7/16 FF term (Reference) 2H081 BB16 CC34 3H106 DB02 DB12 DB23 DB32 GA10 GA15 5E048 AB01 AB07 AD04

Claims (2)

[Claims] 1. An electromagnetic drive device having a yoke for holding a solenoid and a movable plunger, wherein the conical recess provided on one end surface of the plunger, the conical recess of the plunger opposes the center thereof, And a yoke having a conical convex portion formed coaxially with the yoke. 2. An electromagnetic drive device having a yoke for holding a solenoid and a movable plunger, wherein the conical convex portion provided on one end surface of the plunger is opposed to the conical convex portion of the plunger; And a yoke having a conical recess formed coaxially with the center thereof.