JPH045056A - Core for printing head - Google Patents

Abstract

PURPOSE:To obtain a core for a printing head capable of increasing a number of printed letters per unit time by a small heating value by a method wherein core piece parts divided into a plurality of pieces are laminated to be partially bonded, and gaps are provided to parts other than the bonded parts to form an air layer. CONSTITUTION:A plurality of core pieces 2 are fitted to a base frame 12 by laser welding, and respective magnetic eraser coils 21 is wound on peripheral surfaces of respective core pieces 2 to be arranged in a printing head 1. The core piece 2 is divided into core piece parts 3-5. The core piece parts 3-5 are laminated, are integrated by bonding to form a laminated core piece, and gaps 7 are provided to other parts excepting bonded parts 6. Since the gap 7 acts as an insulating layer and it is not required that surfaces of respective core piece parts 3-5 are especially treated by insulation and insulating materials are interposed, the core piece 2 for printing head which can be manufactured at low cost is obtained. With the dot printing head 1 using this core piece 2, eddy current loss is decreased steeply and a number of printed letters per unit time can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a core of a print head used in a serial printer or the like.

<Prior Art> FIG. 5 shows an example of a wire dot print head conventionally used in serial printers.

In the figure, this dot print head 10 includes a plurality of core pieces 11 attached to a base frame 12 by laser welding, a first yoke 13, a second yoke 14, and so on.
Third yoke 15. Permanent magnet 16. Magnetic spacer 17.
Bias plate spring 18, armature 19. wire 20
．． Demagnetizing coil 21 Rubber spacer 22. Substrate 23. Base frame 24. Tip guide 25. first guide 26,
Second guide 27. Cap28. It is composed of a clamp spring 29 and the like.

In this dot print head 10, the degaussing coil 2
When the permanent magnet 16 is not excited, the magnetic flux of the permanent magnet 16 is
Yoke 14. magnetic spacer 17, first yoke 13.
Armature 19. Core piece 11. third yoke 15
The armature 19 is attracted to the core piece 11 while biasing the bias plate spring 18 due to the magnetic attraction force generated by the soil removal. Note that FIG. 5 shows this state.

Next, when a current is applied to the degaussing coil 21 to excite it from this state, the magnetic flux of the degaussing coil 21 causes the permanent magnet 16 to
The magnetic flux is canceled out, and the bias plate spring 18, which has been attracted to the core piece 11 in a biased state, is released. Then,
The biased state of the bias leaf spring 18 is released, and the bias leaf spring 18 and one armature become in a horizontal state. As a result, the wire 20 fixed to the tip of the armature 19 is driven to protrude from the tip guide 25, and printing is performed on the medium.

Furthermore, when the demagnetizing coil 21 is deenergized again and becomes de-energized, the armature 19 moves to the bias plate spring 18.
is attracted to the core piece 11 without being biased.

Therefore, in this dot print head 10, by repeating this operation, predetermined prints are sequentially performed.

In this conventional dot print head 10, each core piece 11 is generally formed of one block material as shown in FIG.

<Problems to be Solved by the Invention> However, in recent years, there has been a demand for printers that can print at higher speeds, and printers in which each core piece 11 is formed of one block material, as in the conventional dot print head 10, are required. During the printing operation, the amount of heat generated increases due to magnetic interference, copper loss, iron loss, etc. Therefore, the temperature of the print head tends to rise. Additionally, in conventional printers, protection measures are usually provided to stop printing to protect the degaussing coil when this temperature exceeds an acceptable limit, so it is not possible to sufficiently increase the number of prints per unit time. The problem was that it couldn't be done.

Therefore, one method for reducing the amount of heat generated is to divide the core piece 11, which forms part of the electromagnet, into a plurality of core piece pieces and laminate them to reduce the eddy current loss. However, in order to stack the core piece pieces, it is necessary to interpose an insulating material between each core piece piece, or to apply insulation treatment to the surface of the core piece piece.
Both methods have the problem of increased costs.

The present invention has been made in view of the above problems, and its purpose is to provide a core for a print head that is inexpensive, generates less heat, and can increase the number of prints per unit time. .

Means for Solving the Problems> In order to achieve the above object, the core for a print head according to the present invention consists of stacking core piece parts divided into a plurality of parts and joining them partially, and It is made by providing gaps in the parts to form air layers.

Effect> According to this configuration, the air layer created in the gap formed between each core piece component functions as an insulating layer between each core piece component. In the past, even without special insulating treatment on the surface of each core piece component or intervening insulating material between each core piece component,
A core piece with insulation between each core piece component can be easily obtained.

<Example> Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 shows an embodiment of a dot print head to which a print head core according to the present invention is applied. In FIG. 1, the same reference numerals as in FIG. 5 indicate the same components as in FIG. The main difference between the dot print head of the present invention shown in FIG. 1 and the conventional dot print head shown in FIG. 5 lies in the structure of the core piece and the method of manufacturing it. Therefore, redundant explanation of the same items will be omitted, and only the different points will be explained below.

In FIG. 1, the core piece 2 is a base frame 12.
A plurality of core pieces 1 are laser welded to each other, and a degaussing coil 21 is wound around the outer periphery of each core piece 1. In this state, the core piece 1 is placed in the dot print head 1.

More specifically, the core piece 2 is shown in FIGS. 2 and 3.
Core piece parts 3, 4.5 as shown as single items in the figure.
It is divided into three piece parts. In addition, after laminating these core piece parts 3 and 45, some of these parts 6
are joined and integrated to form a laminated core piece. A gap 7 is provided in the other parts except for the joined part 6, and in this gap 7, an air layer is created between the core piece part 3 and the core piece part 4 and between the core piece part 4 and the core piece 5. It is in a state of being

Next, we will explain how to manufacture the core piece 2 formed by laminating the core piece parts 3.4.5 divided into a plurality of pieces.First, as shown in FIG. Those with approximately the same outer diameter outline are prepared. In addition, among these parts, a plurality of holes 8 (in this embodiment, five holes 8 for laser welding) are formed in advance on the surfaces of the two core piece parts 3 and 5 which are arranged opposite to each other with the core piece part 4 in between.
In contrast, the core piece component 4 is left without holes, and prior to joining,
The three core piece parts 3.4.5 are stacked one after another, and set in this stacked state on a jig (not shown).Next, when the laser tip is irradiated into the hole 8 by a laser welder, the core piece part 3 is stacked in the hole 8. Part 6 of .4.5 is melted out and bonded and fixed to each other. When welding this leather, part 6
By melting the core piece parts 3 and 4, and between the core piece parts 4 and 5.
A gap 8 serving as an air layer is formed between the core pieces 2 and 3 as shown in FIG. 3, and the core piece 2 shown in FIG. 2 is completed.

Therefore, in the core piece 2 formed by laminating the core piece parts 3, 45, an air layer is formed in the gap 7 created between each core piece part 3.4.5, and these air layers are formed between each core piece part 34.5. It will act as an insulating layer between the two. As a result, even if the core piece 2 is a laminated type, it is not necessary to insulate the surface of each core piece component 3, 4.5, or insert an insulating material between each core piece component 3, 4.5. Therefore, a core piece 2 for the print head that is easy to manufacture and inexpensive can be obtained.

As a result, in the dot print head 1 using this core piece 2, eddy current loss is significantly reduced and the number of prints per unit time can be increased. In addition, experimental results revealed that by using the core piece 2 of the present invention in the wire tod print head 1, the number of prints per unit time was improved by about 15 to 20 percent.

Although the present invention has been explained with reference to the above embodiment, it is of course not limited to this embodiment.
The number is not limited to five, and may be increased or decreased as necessary. Further, the present invention can be similarly applied to a core piece of a clapper type print head.

<Effect of the invention> As explained above, according to the print head core according to the invention, the air layer created in the gap formed between each core piece component functions as an insulating layer between each core piece component. Therefore, it is possible to easily create a core piece with insulation between each core piece part, without having to take any special measures to insulate the surface of each core piece part or insert an insulating material between each core piece part. can get. As a result, it can be expected that a print head that is inexpensive, generates less heat, and can increase the number of prints per unit time can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view showing an embodiment of a dot print head to which the print head core according to the present invention is applied; FIG. 2 is a perspective view of a single core piece of the dot print head shown in FIG. 1; The figure is an enlarged cross-sectional view taken along line A-A in Figure 2, Figure 4 is an exploded perspective view of the core piece shown in Figure 2, and Figure 5 is a vertical cross-sectional side view of an example of a conventional dot print head. FIG. 6 is a perspective view of a single core piece of the dot print head shown in FIG. 5. 1... Print head, 2... Core piece, 3.4.5
・ Core piece component, 6... Part of the joint, 7... Gap where an air layer is formed. Patent applicant Oki Electric Industry Co., Ltd. Agent
Patent attorney Kuninori Funahashi: #Investigation θJ application poor B report service F',,, 17-7: Ha Soba 1st plan is bad

Claims (1)

[Claims] A core for a print head characterized in that a plurality of divided core piece parts are laminated and partially joined, and a gap is provided in a part other than the joined part to form an air layer.