JPS6330264A - Dot printer head - Google Patents

Abstract

PURPOSE:To enhance an operation speed and material consumption efficiency, by a method wherein an armature is formed so as to have an inclined surface on a printing wire positioning side so that the surface thereof opposed to the end surface of a yoke has a shape almost the same as that of said end surface and the opposite side thereof becomes smaller than the opposed surface and an auxiliary yoke is formed so that the inner end thereof does not extend from the inner end of the opposite surface of the armature. CONSTITUTION:An armature 6 forms a parallelogram plate shape slightly thicker than an auxiliary yoke 4 and the base end thereof is fixed to the leading end of the leaf spring 5 fixed so as to be held between the auxiliary yoke 4 and a press plate 10 to arrange the armature in the armature housing part 4a of the auxiliary yoke 4 in a replaceable manner and a printing wire 7 is fixed to one end of the armature 6 through an arm 9. This armature 6 is formed so as to have an inclined surface on a side where the printing wire 7 positions so that the opposed surface 6a thereof opposed to the end surface of the inner leg piece 3a of the yoke has a shape almost the same as that of said end surface and the opposite surface 6b thereof positioned on the side opposite to the opposed surface 6a becomes smaller than the opposed surface 6a. The above-mentioned auxiliary yoke 4 is formed so that the inner end 4c thereof does not extend from the inner end of the opposite surface 6b of the armature. When the coil 2 is excited, the magnetic flux of the coil 2 is canceled by that of a permanent magnet 8 and, therefore, the armature 6 is released from attraction by spring force of a leaf spring 5 to allow the printing wire 7 to protrude and printing is applied to the paper 22 on a platen 21.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a dot printer head that performs printing by controlling the excitation of coils in a plurality of radially arranged magnetic paths and displacing an armature to which a printing wire is fixed. Regarding.

[Background Art] This type of dot printer head generally has an armature and its surrounding structure as shown in FIG. That is, the armature A has a parallelogram plate shape, and has substantially the same shape as the end face shape of the yoke B. on the other hand,
The auxiliary yoke C faces the three sides of the armature through small gaps, and its inner end extends to the vicinity where it coincides with the inner end of the armature A or yoke B.

D is a leaf spring that fixes armature A.

The flow of magnetic flux in this object is indicated by the bald line φ in Figures 5 and 6.
? It becomes like this. That is, although the base (outer part) of the auxiliary yoke C has a dense magnetic flux density, the tip part (inner 5-way part) 1
The old ones have become sparse. Also, substantially the same thing can be said for amateur A1. In other words, this device has a part that is not very important in the flow of magnetic flux, which increases the weight of the armature, which is a moving member, and obstructs high-speed operation, or wastes material and reduces costs. You are causing harm in seven ways.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide a dot printer head that can improve operating speed and material consumption efficiency.

[Disclosure of the Invention] The dot printer head of the present invention includes a coil, a yoke,
? An iR auxiliary yoke, a magnetic gap, etc. form one magnetic path, and a plurality of these magnetic paths are arranged radially in parallel, and an armature fixed to the tip of a leaf spring whose base end is fixed absorbs the magnetic field of each magnetic path. In a dot printer head that is displaceably disposed within an armature accommodating portion of an auxiliary yoke connected to the air gap, the armature has an opposing surface that faces the end surface of the yoke and has substantially the same shape as the end surface of the yoke, and an opposite surface that is located on the opposite side of the opposing surface. The auxiliary yoke is characterized in that the side on which the printing wire is located is an inclined surface so that the surface is smaller than the opposing surface, and the auxiliary yoke is formed so that its inner end does not extend beyond the inner end of the opposite surface of the 7-way gusset. This improved operating speed and material consumption efficiency.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4.

l is a dot printer head, and coil 2. York 3. Auxiliary yoke 4. Leaf spring 5. The main components such as the armature 6 and the printing wire 7 are located in the housing 1). It is housed within 12.

The yoke 3 has a cross-sectional shape consisting of the inner and outer leg pieces 3a, 3b and the connecting piece 3.
It has a U-shape at c, but overall, the connecting piece 3c
has a ring plate shape, and the outer leg piece 3b has a cylindrical shape and is integrally formed. There are a plurality of inner pieces 3a (il! usually 9 pieces or 24 pieces).
They are arranged radially at equal intervals, and are either integrally formed with the yoke 3 or press-fitted into the connecting piece 3c. The coil 2 is wound around each inner piece 3a4. A ring-shaped permanent magnet 8 is placed and fixed on the end surface of the outer leg piece 3b of the yoke 3.

The auxiliary yoke 4 is in the form of a ring plate with a width slightly narrower than that overlapping the outer and outer leg pieces 3a and 3b of the yoke 3.
b (permanent magnet 8 in this embodiment) in a superposed manner. Further, the auxiliary yoke 4 has an armature accommodating portion 4a for movably accommodating an armature 6, which will be described later, at a position corresponding to the inner inner piece 3a. This armature accommodating portion 4a is connected to the magnetic medium Bg between the yoke 3 and the auxiliary yoke 4,
The three surfaces forming this are magnetic pole surfaces 4b, 4b, and 4b through which magnetic flux is exchanged with the armature.

Therefore, the yoke 3 around which the coil 2 is wound and the auxiliary yoke 4
forms one magnetic path with a magnetic gap g interposed therebetween, and a plurality of these magnetic paths are arranged radially in parallel.

The armature 6 has a parallelogram plate shape that is slightly thicker than the auxiliary cork 4, and its base end is fixed to the tip of a leaf spring 5 which is clamped and fixed between the auxiliary yoke 4 and the presser plate 10, and is fixed to the armature accommodating part of the auxiliary yoke. 4a, and a printing wire 7 is fixed to one end via an arm 9. This armature 6 has a facing surface 6 facing the end surface of the inner grinding piece 3a of the yoke.
a has substantially the same shape as that, and the side on which the printing wire 7 is located is set as an inclined surface 6C so that the opposite surface 6b located on the opposite side to the facing surface 6a of the bracket is smaller than the facing surface 6a. Further, the auxiliary yoke 4 is formed so that its inner side #A4c does not extend beyond the inner end of the opposite surface 6b of the armature.

13 is a printed wiring board, 14 is a shunt yoke that short-circuits the permanent magnet 8, 15 is a printing wire guide, 21 is a platen, 22 is paper, and 23 is an ink ribbon.

In such a dot printer, when the coil 2 is not excited, the armature 6 is attracted to the end surface of the inner grinding piece 3a of the yoke by the magnetic flux of the permanent magnet 8 against the spring force of the leaf spring 5. When the coil 2 is excited, the magnetic flux of the coil 2 cancels out the magnetic flux of the permanent magnet 8, and the armature 6 is released from attraction by the spring force of the leaf spring 5, causing the printing wire 7 to protrude and Print on paper 22.

Focusing on the flow of magnetic flux in the permanent magnet 8 or coil 2 during this operation, as shown in FIGS. 2 to 4, the magnetic flux φ1 from the end surface of the inner piece 3a of the yoke passes through the magnetic gap g and then passes through the opposing surface 6a of the armature. and then φ2. The magnetic pole face 4b of the auxiliary yoke is separated into φ2 and φ3, and passes through the magnetic gap g.
Enter 4b, 4b.

In this case, since the aafi surface of the inner leg of the yoke and the opposing surface 6a of the armature have substantially the same shape (cross-sectional area), the magnetic efficiency therebetween is the best. In the armature 6, the part where the magnetic flux density was sparse in the conventional model is simply removed, so the magnetic efficiency does not decrease, and even in the auxiliary yoke 4, the magnetic flux density is similarly reduced. Since only the sparse portions are removed, the magnetic efficiency does not decrease, and the weight of the armature 6 is reduced, the operating speed is improved, and the material consumption efficiency is also improved.

In this embodiment, a polarized type having a permanent magnet has been described, but it is also applicable to a type without a permanent magnet. In addition, if the armature 6 has a margin of magnetic flux density and its thickness is the same as or thinner than the auxiliary yoke 4, a recess should be added to the auxiliary yoke to prevent the middle part of the leaf spring 5 from coming into contact with the upper surface of the auxiliary yoke. The plate spring 5 may be formed in an appropriate manner, or the leaf spring 5 may be bent.

[Effects of the Invention] The dot printer head of the present invention is a plate in which a coil, a yoke, an auxiliary yoke, a magnetic gap, etc. form one magnetic path, a plurality of magnetic paths are arranged radially in parallel, and the base end is fixed. In a dot printer head in which an armature fixed to the tip of a spring is displaceably disposed within an armature accommodating portion of an auxiliary yoke connected to the magnetic gap of each magnetic path, the armature has an opposing surface facing the end surface of the yoke that is substantially the same as that of the armature. The side on which the printing wire (17) is placed is an inclined surface so that the opposite surface located on the opposite side to the opposing surface is smaller than the opposing surface, and the inner end of the auxiliary yoke is Since the armature and auxiliary yoke are formed so that they do not extend beyond the inner end, the parts of the armature and auxiliary yoke where the magnetic flux density was sparse in conventional models are removed, which reduces the weight of the armature and improves operating speed. This also improves material consumption efficiency.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the present invention, and shows a side view including a partial cross section, Fig. 2 is a perspective view of the main part □, and Fig. 3 is an A-A in Fig. 1. 4 is a plan view of the main part, FIG. 5 is a perspective view of the main part of the conventional example, and FIG. 6 is a plan view of the main part. 1- Dot printer head, 2- Coil, 3- Yoke, 3a- Inner piece, 4- Auxiliary yoke, 4a+4a.
- Armature housing part, 4b - Magnetic pole surface, 4C... - Inner end, 5 - Leaf spring, 6 - Armature, 6 a - Opposing surface, 6b
- Opposite surface, 6C- Inclined surface, 7- Print wire, g.-- Magnetic gap. Patent applicant Matsushita Electric Works Co., Ltd. Agent Patent attorney Toshimaru Takemitsu (2 idiots) Figure 4/2 (to) k ■A Figure 6

Claims (1)

[Claims] (1) The yoke around which the coil is wound and the auxiliary yoke form one magnetic path with a magnetic gap in between, and multiple magnetic paths are arranged radially in parallel, and the base end is fixed at the tip of the leaf spring. In a dot printer head in which a fixed armature is displaceably disposed within an armature accommodating portion of an auxiliary yoke connected to the magnetic gap of each magnetic path, and a printing wire is fixed to the armature, the amphitheater is connected to the yoke. The auxiliary yoke has an opposing surface facing the end surface having substantially the same shape as the end surface, and an inclined surface on the side where the printing wire is located so that the opposing surface located on the opposite side of the opposing surface is smaller than the opposing surface. A dot printer head, characterized in that the inner end thereof is formed so as not to extend beyond the inner end of the opposite surface of the abutment.