JPH02882Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic drive device equipped with a magnet and an armature that can be attracted to and separated from each other, and particularly relates to improvements in the abutting portion thereof.

In general, in a magnetic drive device such as an electromagnet device, the magnet and armature must be reliably attracted and separated, and in particular, the attachment and detachment of the electromagnet device can control the operation of other mechanisms, such as the shutter of a camera, or other driven parts. For control, strong holding power and durability are required. In order to increase the holding force, the contact surface between the magnet and the armature must be made flat so that the contact between the contact surfaces is as good as possible. In this respect, it is sufficient to simply make electrical contact between the contacts that connect and separate, and a large contact force between the contacts is not required, and the magnitude of the holding force between the yoke and the armature is not necessarily important, such as relays, etc. Such a drive device is different from that.

For this reason, in conventional devices of this kind, the surfaces of the magnet and armature that are in contact with each other are plated with electroless nickel (so-called nickel plating) or plated with chrome to prevent rust and wear. , improving durability.

However, the former has the advantage that it is electroless and can adhere uniformly to the entire surface to form a flat adsorption surface, but on the other hand, since nickel is a magnetic material, if it is plated thickly, residual magnetism will occur in this coating. occurs and deteriorates the magnetism of the drive unit, i.e. “snaps”.
In addition, the plated coating is not necessarily pure nickel and contains some impurities, so after long-term use, these impurities stand out on the contact parts, become dirt, and reduce the magnetic force. There are certain drawbacks.

In the case of the latter, since chromium is non-magnetic, if it is deposited thickly, the magnetic permeability may deteriorate and the holding power may decrease.Also, since it is electrolytic plating, a lot of chromium adheres to the corners, causing flat adhesion. On the other hand, if the magnet and armature are made thinner, the mechanical strength against repeated contact between the magnet and the armature will be weakened, and if the thickness is uniform, the holding force may be reduced. It is difficult to adhere and causes unevenness, so it is not preferable in terms of rust prevention.

Furthermore, both processes are performed in liquid, and there is always a cleaning process, but even if the plated surface is cleaned, there will be some residual liquid, so organic matter cannot be completely wiped off the surface. When the attached organic matter is struck many times with the operation of the drive device,
This carbonizes and generates dirt, which makes the holding power of the magnet and armature unstable, causing deterioration of characteristics.
In any case, it cannot be said that the surface treatment is satisfactory.

An object of the present invention is to provide a magnetic drive device whose characteristics are less likely to deteriorate even after a large number of drive operations.

The present invention forms a compound film of nitride, carbide, or oxide on the surface of the magnet and armature by vapor phase plating such as sputtering method, vacuum evaporation method, ion plating method, plasma CVD method, etc.
In addition, by making the thickness of this compound film less than 1 μm, it is possible to eliminate the adhesion of dirt due to the cleaning process, improve wear resistance, and achieve the above object.

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a schematic structure of a magnetic drive device according to the present invention, and FIG. 2 shows an enlarged cross section of the main part thereof. In FIG. 1, a coil 2 is wound around a yoke 1 having a U-shape in plan to constitute an electromagnet 3, and an armature 4 made of a magnetic material such as iron is opposed to the electromagnet 3 so that it can be attracted and detached. There is. The armature 4 is supported at its center by an armature holder 6 via a drum-shaped shaft 5 so as to be rotatable and swingable in a direction perpendicular to the plane of the drawing. A stopper 7 is integrally installed on the armature holder 6, and a predetermined gap is formed between the stopper 7 and the armature 4, and the armature 4 is tightly attached to the end surface of the yoke 1 in this gap. A leaf spring 8 is interposed to bias the blade in the direction of the rotation. Further, a tension spring 9 is interposed between the armature holder 6 and the device main body (not shown), and the tension spring 9 causes the armature 4 to move away from the electromagnet 3 against the attractive force of the electromagnet 3. The armature 4 is separated from the electromagnet 3 when the coil 2 is de-energized. This movement of separating the armature 4 from the electromagnet 3 causes the driven part to
For example, the shutter mechanism of a camera is driven.

In FIG. 2, the surface of the yoke 1 and the surface of the armature 4 are made of metal nitride such as titanium nitride, chromium nitride, tungsten nitride, tantalum nitride, metal carbide such as titanium carbide or chromium carbide, or silicon oxide. , a compound film 10,1 made of an oxide such as tantalum oxide
1 is formed with a thickness of 0.1 to 0.2 μm. These compound films 10 and 11 are formed by sputtering method,
It is deposited by physical or chemical processes such as ion plating, vacuum evaporation, or plasma CVD, or by various vapor phase plating methods based on physical/chemical processes, and therefore does not use a liquid. It is evenly attached.

To explain the driving operation in such a configuration, when the coil 2 is energized, the yoke 1
The armature 4 is attracted to the end face of the drive device, and the drive device is in a closed state.

Next, when the coil 2 is de-energized, the magnetic force of the electromagnet 3 disappears, so the armature holder 6
is rotated clockwise in FIG. 1 by the biasing force of the tension spring 9 into an open state, and the shutter mechanism of the camera, which is a driven part, is driven via an operating member (not shown).

On the other hand, in order to change the open state to the closed state, a set mechanism (not shown), for example, a mechanism linked to the film winding mechanism of the camera, is used to move the armature holder 6 to the closed state.
This is done by returning the coil 2 to its old position and energizing the coil 2. This return operation charges the shutter mechanism of the camera with the driving force for the next time.

Thereafter, the driving operation is performed by repeating this operation.

According to this embodiment as described above, the yoke 1 constituting the electromagnet 3 and the armature 4, which is attached to and detached from the yoke 1 and which drives a driven part that requires a driving force greater than mere contact and separation, are connected. The surface is coated with a compound film 10 of nitride, carbide, and oxide.
11, the abrasion resistance is improved and the smoothness of the abutting surface can be maintained for a long period of time, and the durability can be significantly improved. In particular, the compound coating 10,
11 is formed in a liquid-free state by a vapor phase plating method such as a sputtering method without any cleaning process, so there is no possibility of organic matter adhering to the surface, and even after long-term use. There is no dirt on the contact surfaces between the electromagnet 3 and the armature 4, and from this point of view as well, durability can be improved. Furthermore, since there is no concentration control of the liquid, the control work can be made very easy.
Furthermore, since the compound coatings 10 and 11 formed by vapor phase plating have a uniform thickness, a flat adsorption surface can be formed and the holding power can be improved.

Experiments have shown that it has sufficient holding power, with no deformation such as abrasion or staining of the contact part, even after tens of thousands of driving operations, which is about 10 times that of the conventional method. It could be confirmed. In addition, compound coating 1
Regarding the thickness of 0,11, a range of 0.1 to less than 1 μm is appropriate; if it becomes thicker than this, the magnetic properties will deteriorate when a non-magnetic compound is used. Furthermore, as the metal compound, compounds of magnetic materials such as nickel can also be used, but adhesion is not good in sputtering methods due to the application of a magnetic field, so methods using non-magnetic materials have yielded good results. .

In addition, in implementation, the electromagnet 3 may be a permanent magnet, and in this case, the coil 2 is connected to the armature 4.
It acts not for adsorption but for desorption.

As described above, the present invention has the effect of providing a durable magnetic drive device with little deterioration in characteristics even after long-term use.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a schematic structure of an embodiment of a magnetic drive device according to the present invention, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 1... Yoke, 2... Coil, 3... Electromagnet,
4... Armature, 6... Armature holder, 9... Tension spring, 10, 11... Compound coating.

Claims (1)

[Scope of utility model registration request] In a magnetic drive device that includes a magnet and an armature that can be attached and detached from each other, and that drives a driven part that requires a driving force greater than mere contact and separation, the magnet and armature are brought into contact with each other by the attachment and detachment of the magnet and armature. A magnetic drive device characterized in that the surface thereof is provided with a nitride, carbide, or oxide compound film with a thickness of less than 1 μm.