JPH03190751A - Wire dot printing head - Google Patents

Abstract

PURPOSE:To enhance the response and stability of wires by suppressing the unnecessary vibration of the wires by making it possible to guide the wires through the holes having diameters optimum to the respective wires by changing the diameters of the wire guide holes corresponding to the incident angles of the wires to the wire guides. CONSTITUTION:The wires 8 fixed to the leading end of a lever 19 are positioned so as to be opposed to the cores 12 arranged on the circumference of a frame 2 and arranged on a straight line on the surface of paper and, therefore, the incident angles of the wires 8 to wire guides are different. When the necessary min. diameters Da, Db of the wire guide holes of the wires 8a, 8b having different incident angles (a), (b) (a>b) are calculated, they become Da=d/sin(a)+t/tan(a) and Db=d/sin(b)+t/tau(b) (wherein d is the diameter of each of the wires 8 and t is the thickness of each of the wire guides).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire tod print head, and more particularly to the structure of a wire guide for a wire tod print head.

[Conventional technology]

The hole diameter of conventional wire guides was uniform regardless of the angle of the wire with respect to the wire guide.

[Problem to be solved by the invention]

However, if the hole diameter of the wire guide is made uniform regardless of the angle of the wire with respect to the wire guide (hereinafter referred to as the wire radiation angle) as in the past, the angle between the wire and the wire guide is the smallest, that is, the wire guide It is necessary to match the hole diameter of all wire guides to the largest hole diameter, and depending on the wire, the gap between the wire guide and the wire guide may be larger than necessary, causing unnecessary vibration in the wire during printing and causing poor response. There were drawbacks such as:

Additionally, in order to prevent the above-mentioned drawbacks, it is possible to drill the wire guide holes diagonally according to the angle of incidence of the wire, but such a method is technically difficult and costly compared to drilling vertical holes. There were other drawbacks, such as being expensive.

The present invention aims to solve these problems, and its purpose is to find the optimum diameter for each wire by changing the hole diameter of the wire guide according to the angle of incidence of the wire on the wire guide. Our goal is to provide a low-cost wire tod print head that guides the wire using the hole diameter, suppresses unnecessary vibrations of the wire, and has excellent responsiveness and stability.

[Means to solve the problem]

The wire tod print head of the present invention is characterized in that the hole diameter of the wire guide is changed depending on the angle of incidence of the wire onto the wire guide.

〔Example〕

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

FIG. 1 shows a cross-sectional view of an embodiment of the invention. As shown in FIG. 1, the wire tod print head is assembled by overlapping a nose 1, a frame 2, a yoke 3, a yoke 4, and a lever holder 5 with each other.

The nose 1 has a wire guide 6 and a wire guide 7.
and the wire guide 6 is attached to the wire 8.
are arranged in a straight line on the paper. A printed circuit board 10 is disposed between the nose 1 and the frame 2 with an insulating sheet 9 interposed therebetween.

A plurality of cores 12 are provided circumferentially on the frame 2, and a coil 17 is attached to each of these cores 12. A spring holder 15 is attached to the circumferential position of the core 12 with an intermediate guide B14 interposed therebetween.

The spring holder 15 is equipped with the same number of return springs 16 as the cores 12. Next, on the upper surface of the frame 2 is a yoke 3. A yoke 4 is attached, and this yoke 3. A lever 19 facing the core 12 is attached by a yoke 4. The wire 8 is fixed to the tips of these levers 19, and the return spring 1
6 in the return direction. The lever 19 holds the rotation fulcrum between the yoke 3 and the frame 2 by the fulcrum pressing spring 18.
It is supported in pressure contact with the corner formed by. Oil-impregnated member 11
is formed into a ring shape, and the lever 19 is sandwiched between the core 12
placed in a position opposite to. Further, a lever holder 5 is attached so as to be in contact with the upper surface of the spring holder 15, and a damper rubber 20 is attached to the center portion of this lever holder 5. The tip of the lever 19 is brought into contact with this damper rubber 20 with a damper spacer 21 interposed therebetween.

In the above-described mechanism, the coil 17 connected to the printed circuit board 10 is selectively energized according to the print signal, and the magnetic flux excited by the coil 17 causes a magnetic attraction force to work between the core 12 and the lever 19. As a result, the lever 19 is attracted to the core 12, and the wire 8 is guided by the intermediate guide 14 and the wire guide 6.degree. 7 and protrudes, applying an impact force to the recording paper to form dots and obtain the desired print.

Figure 2 shows a wire guide 6 which is a feature of the present invention.
．． 7 or a partially enlarged sectional view of the intermediate guide 14.

As mentioned above, the wire 8 fixed to the tip of the lever 19 is located on the frame 2 in a position opposite to the core 12 arranged on the circumference of the frame 20, and since they are lined up in a straight line on the paper, the wire guide of the wire 8 is The angle of incidence on each wire differs. Here the angle of incidence is a
, b (a>b), the required minimum wire guide hole diameters Da and Db of the wires 8a and 8b are calculated as follows: Da=d/s in (a)+t/lan (a)Db
=d/sin(b)+t/jan(b). Here, d is the wire diameter of the wire 8, and t is the thickness of the wire guide.

FIG. 3 shows a partially enlarged sectional view of a conventional wire guide, in which the diameter of the wire guide hole is made the same regardless of the angle of incidence of the wire. In such a method, the wire guide hole diameter needs to match the minimum wire angle of incidence (here b), and the minimum wire hole diameter is D=Db=d/sin (b)+t/jan (b) Therefore, for wires like wire 8a whose incident angle is larger than wire 8b'(a>b), an excessive gap X is created between wire 8a and the wire guide, and when wire 8a moves, wire 8a moves. Vibrations were generated in a direction perpendicular to the direction of the wire 8a, which was a factor impairing the responsiveness and stability of the wire 8a.

〔Effect of the invention〕

As described above, according to the present invention, by changing the hole diameter of the wire guide according to the angle of incidence of the wire on the wire guide, it is possible to guide the wire with the optimum hole diameter for each wire. This has the effect of suppressing unnecessary vibrations of the wire and providing a wire tod print head with excellent responsiveness and stability at a low cost.

7...Wire guide 8a, 8b...wire 2... Core 4...Intermediate guide 9...lever that's all

Claims (1)

[Claims] A wire dot print head characterized by changing the hole diameter of the wire guide depending on the angle of incidence of the wire on the wire guide.