JP2635663B2 - Printer head - Google Patents

Description

The present invention is used for a print head of a dot printer,
The present invention relates to a core and a yoke forming a dot printing drive magnetic path.

[Conventional technology]

Conventionally, print heads in dot printers are classified into clapper type, ballistic type, spring charge type, and plunger type. However, although these are different in structure, they are all basically a kind of electric-mechanical conversion actuator by electromagnet.

FIG. 5 is a structural view of a typical spring-charged print head. The armature 6 is constantly attracted to the distal end surface of the core portion 1 of the yoke against the leaf spring 5 by the magnetic flux generated by the permanent magnet 4. Here, when an electric current is applied to the coil 10 wound around the core portion 1 to cancel the magnetic flux generated by the permanent magnet 4, the armature 6 vigorously moves from the distal end surface of the core 1 by the restoring force of the leaf spring 5 attached to the armature. This prints out on the print paper 9 via the ink ribbon 8 with the print wire 7 fixed to the leading end.

Conventionally, the shape of the yoke and the core is as shown in FIG.
It is a yoke-core type in which the yoke portion 2 and the core portion 1 are integrated, and the main material is silicon iron.

[Problems to be solved by the invention]

By the way, since the yoke core magnetically needs to have soft magnetic properties, silicon iron has been used. However, in the case of silicon iron, while the printing speed is increasing, the saturation magnetic flux density may be insufficient. For that purpose, it is conceivable to make the yoke core permender. However, in this case, there is a problem that if the yoke core is integrated, it becomes very expensive.

Further, the yoke core using silicon iron has a problem in that a very loud sound is produced during printing.

The present invention is to improve the magnetic and vibration damping characteristics of the yoke core and to reduce the cost of the printer head yoke. It is intended to provide a core.

[Means for solving the problem]

According to the present invention, in the dot printer head, the magnetic path of the dot printing drive system includes a circumferentially continuous yoke portion made of silicon iron and a core portion made of permender, and the core portion is formed in the yoke portion. A printer head which is fitted and joined in a through hole, and it is desirable that the joining be performed by press-fitting and using an adhesive together. In the present invention, the components of the core are expressed in terms of
Desirably, it is composed of 40 to 55%, V of 0.5 to 2.5%, W of 0.1 to 3%, C of 0.01 to 0.05% and the balance substantially of Fe.

According to the present invention, of the yoke cores, the cross-sectional area is limited, and the core portion having the highest magnetic flux density is replaced with the conventional yoke core.
By using a permender having a higher saturation magnetic flux density than silicon iron, which is a material of the core, it is possible to increase the magnetic flux or reduce the size, and at the same time, it is possible to improve the printing speed.

In addition, the present inventors have found that noise reduction can be achieved particularly by configuring the core portion with permenda. That is, as shown in FIG. 3, the permenda has a damping ability about 10 times as large as that of silicon iron, and thus is very effective in reducing noise.

Further, in the present invention, the yoke core having the core portion as a permender has an advantage that it can be manufactured at a lower cost without lowering the performance as compared with the integrated product by the permender, and can be manufactured with higher precision than the integrated product by casting. .

In particular, when the cross section of the core is an irregular cross section as shown in FIG. 1 (b), an extremely inexpensive and highly accurate core can be obtained by using an irregular drawn wire.

 Desirable components of the core are described below.

Co and V are the main elements constituting permender, and Co increases the magnetic flux density by forming an alloy with Fe. However, when it is less than 40% and exceeds 55%, the magnetic permeability is reduced.

V is known as an element that enhances the workability of the Fe—Co alloy. If it is less than 0.5%, there is no effect on the improvement of workability, and if it exceeds 2.5%, the permeability of the Permenda alloy will be reduced.
2.5%.

W and C have the effect of increasing the reversible magnetic permeability (μr), but the reason for setting C to 0.01 to 0.05 is that μ is smaller than 0.01 and coercive force becomes larger when it exceeds 0.05%. This is to lose the feature.

W shows a similar result to C, and at 0.1%, μr is small,
If it exceeds 3%, the holding power becomes large.

Further, even if the content of Si, Mn, and Al is 0.5% or less as a deoxidizing agent, it does not affect the feature of high reversible magnetic permeability (μr).

〔Example〕

 Hereinafter, the present invention will be described based on examples.

FIG. 1 shows an embodiment of the present invention, in which a is an overall sectional view, b is a detailed view of a core, and f is an overall plan view. First, a yoke 2 (having side walls 3) made of silicon iron and a core 1 made of permender are separately manufactured. Then, a hole into which the core can be inserted was provided in the yoke 2, and the core 1 having a root portion separately formed in a gradient from a deformed drawn wire was press-fitted and bonded together with an adhesive. In the present embodiment, the shape of the core 1 is an oval cross-sectional shape as shown in FIG. 2B, and a modified lead wire is used. However, the cross-sectional shape of the core is a tapered shape, a circle, a rectangle, etc. Is also good.
Further, as shown in FIG. 2, the side walls 3 of the yoke may be separately formed by a permender or the like, and joined by press-fitting or the like. In this embodiment, the method of press-fitting and joining was used.
The joining method may be a method of caulking from the fitted back side.

〔The invention's effect〕

According to the present invention, high-speed printing and low noise required for a printer head can be sufficiently satisfied. By separately forming the yoke and the core, which are conventionally integrated products, the above-mentioned required characteristics can be satisfied and a printer head can be supplied at low cost.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a yoke core according to the present invention.
(A) is a side view, (b) is a view showing a shape of a core, (c) is a view showing a plane shape of a yoke, FIG. 2 is an example of a case where a yoke side wall is press-fitted and joined, and FIG. FIG. 4 is a view showing the vibration damping characteristics of silicon iron, FIG. 4 is a view showing a conventional yoke core, and FIG. 5 is a view schematically showing a printer head. 1: Core, 2: Yoke, 3: Yoke side wall, 4: Permanent magnet, 5: Leaf spring, 6: Armature, 7: Wire, 8: Link ribbon, 9: Printing paper, 10: Coil

Claims (3)

(57) [Claims] In a dot printer head, a magnetic path of a dot printing drive system comprises a circumferentially continuous yoke portion made of silicon iron and a core portion made of permender, and the core portion is formed on the yoke portion. A printer head characterized by being fitted into and joined to a through hole. 2. The printer head according to claim 1, wherein the bonding is performed by press-fitting and using an adhesive together. 3. The printer head according to claim 1, wherein said core is made of a deformed drawn material.