JPH0736753Y2 - Print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] Regarding a print head for a wire dot printer, it is possible to perform high-speed and high-quality printing and to provide an inexpensive print head. One end is supported on the peripheral portion, the substantially central portion is attracted by the electromagnet formed on the base portion, and the armature that is rotationally driven about the support portion as a rotation center is a separate body from the armature, and A wire, one end of which contacts the other end of the armature and whose tip follows the stroke of the armature to advance and retreat from the print head body, a return means for urging the wire toward the armature side, and an armature for urging the armature in the direction of attraction Then, a leaf spring body that presses the center of rotation of the armature against the base portion and generates a rotational moment against the biasing force of the wire returning means. And a biasing means including

[Industrial application field]

The present invention relates to a print head for a wire dot printer.

The print head for a wire dot printer is designed to print by moving the armature to which the wire is attached by an electromagnet so that the wire tip advances and retreats from the main body of the print head. Since it is repeatedly loaded by high-speed driving, it needs to be firmly fixed so as not to be damaged, and the cost is increased due to the limitation of the material of the wire and the processing steps such as brazing.

Under these circumstances, there is a need for a printhead that assembles wires without sticking them to the armature.

[Conventional technology]

Conventionally, the wire 10 as shown in FIG.
There is a printhead that assembles without sticking to 20. Third
In the figure, a resin is molded on the base end portion 110 of the wire 10 and is in contact with the armature 20, and the electromagnet 30 is excited to attract the armature 20 to cause the wire 10 to move.
Print with 10 protruding. The clamp spring 40 urges the end of the armature 20 so that the fulcrum 210 of the armature 20 is pressed against the print head body 30, and the wire 10 is returned by the coil spring 50. .

[Problems to be solved by the device]

However, in the print head as described above, the wire 10 and the armature 20 are pressed against each other in the return direction by the coil spring 50, but the rotational moment F due to the attraction force of the electromagnet 30 rapidly increases according to the stroke of the armature 20. When colliding with 30, a large repulsive force acts on the armature 20. The armature 20 returns due to the repulsive force of the collision, but the wire 10 bends slightly, so the armature 20
Returns faster than the return of the wire 10 by the coil spring 50, the wire 10 and the armature 20 separate, and the wire 10 cannot accurately follow the stroke of the armature 20,
It has a defect that the print quality is not stable due to faint print.

The present invention has been made to solve the above-mentioned drawbacks, and in a print head in which the wire and the armature are not fixed to each other, the wire accurately follows the stroke of the armature even at high speed operation, and high quality printing is achieved. It is an object of the present invention to provide a print head capable of

[Means for Solving the Problems]

The present invention will be described with reference to FIG. 1 corresponding to an embodiment. A wire 1 is assembled so that a tip 12 of the wire 1 can be moved back and forth from a print head main body 4, and a base end 11 of the wire 1 is coiled on an armature 2. It is urged by the return means 5 composed of a spring to be in pressure contact. The armature 2 is oscillated by being attracted by the electromagnet 3 provided in the print head main body 4 with the end portion on the opposite side of the distal end portion 22 of the base end portion 11 of the wire 1 that is pressed against as the fulcrum portion 21. Then, on the back side of the armature 2, a biasing means 6 for biasing the armature 2 in the attraction direction of the electromagnet 3 is provided.

[Action]

Based on the above configuration, in the present invention, the wire 1 and the armature 2 are urged into pressure contact with each other by the returning means 5 and the urging means 6. The base end 11 of No. 1 does not come apart, and reliably moves back and forth to perform high-speed printing without blurring of printing.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the print head of the present invention is a wire 1 that is assembled in a print head body 4 so as to be able to move back and forth.
An armature 2 for pushing the wire 1 into contact with the base end 11 of the wire 1 and an electromagnet 3 for attracting and actuating the armature 2; The armature 2 is provided with a biasing means 6 made of a leaf spring on the back surface thereof.

The wire 1 is held by the print head body 4 so that its tip 12 can be moved back and forth from the guide 42 of the front surface portion 41 of the print head body 4, and its base end portion 11 is made of a resin having a spherical tip. Button 13 is integrally formed, and the button 13
The return means 5 composed of a compression coil spring is provided between the print head body 4 and the partition wall 43 of the print head body 4, and the wire 1 returns the return means 5.
It is urged in the retreat direction by.

The armature 2 is made of a steel member attracted by the electromagnet 3, and is provided with one end in contact with the base portion 44 of the print head 4. Then, the abutting end is formed in an inclined surface shape, and the corner of the inclined surface is a fulcrum portion.
It is rotatable as 21. The tip portion 22 on the opposite side of the fulcrum portion 21 is extended to a position where the base end portion 11 of the wire 1 comes into contact, and the spherical portion of the button 13 of the wire 1 is a plane portion of the tip portion 22 of the armature 2. Is in pressure contact with the point contact.

The electromagnet 3 is provided on the front side of the armature 2 so as to attract the main body portion 23 of the armature 2 to the core portion 31 of the armature 2 when it is excited. Armature 2 by means 5
And the electromagnet 3 are separated from each other.

And the rear wall portion 45 of the armature 2 and the print head body 4
An urging means 6 made of a leaf spring is provided between and, and the urging means 6 fixes the base plate portion 61 to the rear wall portion 45 and presses the spring piece 62 against the rear surface portion 24 of the armature 2. Since the press contact position is located closer to the tip side than the fulcrum part 21, the fulcrum part 21 is pressed against the base part 44, and the armature 2 is directed toward the front side of the print head, that is, in the same direction as the attraction direction of the electromagnet 3. I am biased. Of course, the rotational moment m acting on the armature 2 due to the urging force m
The position and spring strength of the wire 1 are set so as to be smaller than the rotational moment m in the returning direction due to the urging force of the returning means 5 of the wire 1.

FIG. 2 shows the rotation moment acting on the armature 2. The rotation moment F due to the attraction force of the electromagnet 3 is shown.
Has a large stroke and rapidly increases as it approaches the electromagnet 3. The rotation moment m by the urging means 6 acts in the same direction as the attraction force F of the electromagnet 3, and the rotation moment n by the return means 5 acts in the opposite direction to the attraction force F. The sum n + (-m) of the rotation moments of the urging means 6 and the returning means 5 is set so as not to exceed the magnitude of the rotation moment F due to the suction force. Therefore, when the electromagnet 3 is excited, the armature 2 is attracted to the electromagnet 3,
The armature 2 that collides with the electromagnet 3 receives a repulsive force in the returning direction, but the repulsive force is reduced due to resistance by the urging means 6, and the armature 2 does not separate from the wire 1.

[Effect of device]

As is clear from the above description, according to the print head of the present invention, the armature and the wire base end portion are surely pressed by the biasing means to perform the integrated operation, so that the print is not blurred. High-speed, high-quality printing is possible. Since the armature and the wire do not use a fixing means such as brazing, damage to the fixed portion does not pose a problem, wire fixing processing is not required, and assembly can be performed easily, thus reducing the manufacturing cost. be able to.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of a relationship between a stroke and a rotation moment of an armature, and FIG. 3 is a sectional view showing a conventional example. In FIG. 1, 1 is a wire, 11 is a base end part, 2 is an armature, 3 is an electromagnet, 4 is a print head main body, 5 is a returning means, and 6 is a biasing means.

Claims (1)

[Scope of utility model registration request] 1. An armature, one end of which is supported by a peripheral portion of a base portion of a print head, and whose substantially center portion is attracted by an electromagnet formed on the base portion, and which is rotationally driven about the bearing portion. A wire that is separate from the armature and has one end abutting the other end of the armature, the tip of which moves back and forth from the print head body following the stroke of the armature, and a return means that urges the wire toward the armature side. And an urging member composed of a leaf spring member for urging the armature in the attracting direction of the electromagnet, pressing the center of rotation of the armature against the base portion, and generating a rotational moment against the urging force of the wire returning means. A printhead having a means.