JPH0465253A - Print head - Google Patents

Abstract

PURPOSE:To accurately position print wires, stabilize the printing action and obtain a high quality print by a method wherein pin bearing slots of a U-shaped pin holder are opened downward so as to made part of the peripheral surface of a pin protrude downward, and the protruding part of the pin is pressed on a side yoke. CONSTITUTION:A pin holder 12 is formed into a U-shape, and an end of pin 11 is fitted in a bearing slot on a side wall of the pin holder 12, the other end in a bearing slot on the other side wall, and the pin 11 is penetrates through an axle hole of an armature 10. A shank of the pin holder 12 is supported by an armature support 13, and the pin 11 is pressed down on the surface of a side yoke 9 by the elastic force of a pressure rubber 14. A coil is selectively energized so that the armature 10 is attracted and turned on the pin 11 by a magnet core. As a result, a print wire 2 is driven and a specified dot is printed by the tip of the wire 2. After printing, power supply to the coil is cut off, and the armature 10 is returned to the original position together with the wire 2 by a return spring.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a print head, and particularly to a print head for an impact-type dot matrix printer having an armature passing through a pin serving as the center of rotation at the fulcrum of rotation. .

[Conventional technology]

Conventionally, this type of print head has been designed by sandwiching the pin that passes through the armature and serves as the center of rotation by placing a pin receiving fitting and a pin holding fitting on side yokes provided on both sides of the armature. Many methods of holding and positioning are used.

[Problem to be solved by the invention]

The conventional print head described above uses a method in which the pin, which is the center of rotation of the armature, is held between multiple metal plates, so the distance from the side yoke to the pin and the position on the side yoke are The drawbacks are that it is difficult to achieve high accuracy, and printing operations tend to become unstable and print quality tends to deteriorate. Another drawback is that the pins tend to fall out of the armature when assembling the print head, making assembly complicated.

[Means to solve the problem]

The print head of the present invention has an armature that passes through a pin serving as the center of rotation at the fulcrum part of the rotation, and the rotation movement of the armature drives the printing wire to strike the printing surface,
In the print head of an impact-type dot matrix printer that performs printing, a holder that holds the pin by passing both sides of the pin that has passed through the armature through each of the circular holes that are opened at a portion of the circumference provided on each side wall. ingredients and
Pressure is applied through a side yoke that supports a pin protruding from each of the circular holes in both side walls of this holder and a support provided at a connecting portion of both side walls of the holder, and the pin is pressed against the side yoke. and a pressure member.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal half-sectional view of one embodiment of the present invention, and FIG.
3 is an exploded perspective view of FIG. 2; FIG. 3 is a detailed view of the holding portion of the armature shown in FIG. In FIG. 1, a head frame 1 with a cylindrical front part houses a plurality of printing wires 2 that reciprocate and guides 3, 4 to 7 that guide the printing wires 2. The drive unit that moves the yoke 8, the magnetic core 8a connected to the yoke 8, the coil 17 wound around the magnetic core 8a, the side yoke 9, the armature 10 to which the printing wire 2 is joined, and the rotation of the armature 10. The pin 11 that is the center of movement, the bottle holder 12 that holds the pin 11, the pressure rubber 14 that presses the pin 11 against the side yoke 9 by applying pressure to the support provided on the pin holder 12, and the pin holder 12. It is composed of an armature support 13 that directs the support provided on the tool 12, a return spring 15 that returns one end of the armature 10 to the initial position, and a stopper 16 provided with a stopper rubber lea that determines the initial position of one end of the armature 10. ing. The magnetic cores 8a connected to the yoke 8 are arranged in a circle, and an armature 10 is provided facing each of the magnetic cores 8a.

Next, referring to FIGS. 2 and 3, the armature 10
Proceeding with the explanation of the holding mechanism of the pin 11 which is the center of rotation, the pin holder 12 is formed into a U-shape with two side walls and a connecting part connecting the two side walls. A circular hole with a part of its periphery open is provided, and an armature 10 is disposed between both side walls, and a pin 11 is passed from the circular hole in the end face of one side wall through the rotation hole of the armature 10 to the other side. It is fitted into a circular hole in the end face of the side wall. Further, a support is provided at the connecting portion of the pin holder 12, and this support is supported by an armature support 13, and functions to press the pin 11 against the surface of the side yoke 9 by the elastic force of the pressure rubber 14. . To assemble the print head, attach the pin 11 to the armature 10 and pin holder 12 in advance.
is formed as an integral part.

In the above configuration, like the conventional print head, the fill 17 is selectively energized and the generated magnetic flux causes the magnetic core 8 to
a attracts the armature 10, the armature 10 rotates around the pin 11, and drives the printing wire 2,
Predetermined printing is performed by the tip of the printing wire 2. Also, after printing, the power to the fill 17 is cut off, and the armature 1
0 is returned to the initial position together with the printing wire 2 by the return spring 15.

〔Effect of the invention〕

As explained above, the present invention has the pin holding hole provided in the U-shaped pin holder at a position where a part of the inner peripheral surface of the pin protrudes, and the protruding part of the fitted pin is attached to the side yoke. Pressure contact facilitates accurate positioning, stabilizes printing operations, and provides a print head with high print quality. Furthermore, since the armature and the holder can be integrally formed in advance with a pin, the manufacturing process is also facilitated.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal half-sectional view of one embodiment of the present invention, and FIG.
3 is an exploded perspective view of FIG. 2; FIG. 3 is a detailed view of the holding portion of the armature shown in FIG. 1... Head frame, 2... Printing wire, 3, 4
~7...Guide, 8...Yoke, 8a...Magnetic core,
9... Side yoke, 10... Armature, 11
... Pin, 12... Pin holder, 13... Armature support, 14... Pressure rubber, 15...
・Return spring, 16...stopper, 16a・
... Stopper rubber, 17... Coil.

Claims (1)

[Claims] Printing with an impact-type dot matrix printer that has an armature that passes through a pin that serves as the center of rotation at the fulcrum of rotation, and the rotational movement of the armature drives the printing wire to strike the printing surface and print. In the head, a holder that holds the pin by passing the pin that has passed through the armature through each of the circular holes provided in each of the side walls and opening a part of the circumference, and an opening in the both side walls of this holder. a side yoke that supports a pin protruding from each of the circular holes; and a pressure member that applies pressure to press the pin against the side yoke through a support provided at a connecting portion of both side walls of the holder. Characteristic print head.