JPH01145159A - Printing head - Google Patents

Abstract

PURPOSE:To enhance not only the abrasion resistance of a revolving fulcrum but also printing quality by mounting a resin chip to the revolving fulcrum of the armature engaged with the hole of a side magnetic plate forming a side magnetic path and integrally forming a press piece, which is elastically brought into contact with the side surface near to the center of the side magnetic plate, to said chip. CONSTITUTION:An armature 1 consists of a revolving fulcrum part having a revolving fulcrum A and a leading end part having a successively tapered triangular shape and a wire 4 is integrally fixed to the leading end thereof in an orthogonal state. A resin chip 5 is engaged with the upper surface of the revolving fulcrum part and two press pieces 6 are formed on both sides of one end of the chip 5 so as to have inclined surfaces. The armature 1 is inserted in the hole of a side magnetic plate 8 forming a side magnetic path by electromagnetic force and the press pieces 6 of the chip 5 are elastically brought into contact with one side surface 8b of the side magnetic plate 8. A fulcrum press spring 9 as a fulcrum press plate presses the chip 5 from above at the projection 9a thereof.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a wire dot type print head.

BACKGROUND OF THE INVENTION Conventionally, in order to reduce the size, power consumption, and cost of a print head, the guide mechanism of the rotating fulcrum has become important, especially in the fulcrum type armature print head. According to Japanese Unexamined Patent Publication No. 53-140121, the structure of such a guide mechanism of the fulcrum part and its importance are explained.

Furthermore, in the case of Japanese Patent Application Laid-Open No. 58-166066, the rotation fulcrum portion of the armature rotates while being guided by a side magnetic plate. That is, when the armature rotates, the armature and the side magnetic plate slide against each other. For this reason, oil is applied to the fulcrum part of the armature as a lubricant for the sliding parts.

Problems to be Solved by the Invention However, when oil is applied in this way, the viscous resistance of the oil has a large negative effect on the impact force when the wire strikes the paper. Furthermore, the impact force of the wire is unstable due to fluctuations in the viscosity of the oil due to temperature, resulting in poor printing quality. Additionally, oil can cause debris such as ink scum and paper scum to adhere to the inside of the print head, interfering with the normal functioning of the device.

Means for Solving the Problems The present invention provides a resin chip attached to the rotation fulcrum of the armature that fits into the hole of the side magnetic plate forming the side magnetic path, and a resin chip attached to the rotary fulcrum part of the armature that is fitted into the hole of the side magnetic plate forming the side magnetic path. A pressing piece that resiliently abuts the side surface is integrally formed.

Function: Therefore, the pressure piece formed on the tip can absorb the force that is applied when the suction returns, so the rotation fulcrum of the armature will not shift or swing. It is possible to provide a print head that can withstand high-speed operation by further improving the wear resistance at the fulcrum, and it is also possible to stabilize the impact force of the wire because there is no need to apply oil as a lubricant to the rotation fulcrum. This makes it possible to improve printing quality.

Example An embodiment of the present invention will be described based on the drawings.

First, the constituent parts of the print head according to the present invention will be explained with reference to FIGS. 1 to 4. The armature 1 is made of metal, and includes a rotation fulcrum part 2 having a rotation fulcrum A, and a triangular tip part 3 that tapers sequentially from the rotation fulcrum part 2.
It consists of

A wire 4 is fixed to the tip of the tip portion 3 in a perpendicular state by means of brazing or the like and integrated therewith.

Further, a resin chip 5 is fitted into the rotation fulcrum portion 2 from the upper surface, and two pressing pieces 6 having an inclined surface 7 are formed on both sides of one end of the chip 5. There is.

In this way, the armature 1 in which the tip 5 is fitted to the rotation fulcrum part 2 and the wire 4 is fixed to the tip part 3 is inserted into a hole in the side magnetic plate 8 that forms a side magnetic path by electromagnetic force. 8a. At this time, one side 8b of this side magnetic plate 8
The pressing piece 6 of the tip 5 fitted to the rotation fulcrum part 2 is resiliently abutted on the pivot part 2, and
A fulcrum presser spring 9 serving as a fulcrum presser plate presses the chip 5 from above at its projection 9a.

Next, the overall configuration of the print head will be explained based on FIG. 5. The side magnetic plate 8 on which the armature 1 is guided is
In its lower part there is a nose 10, an electromagnetic device 11. It is integrated with the amateur guide 12, etc. First, the nose 10 regulates and guides the moving direction of the wire 4 with respect to printing paper (not shown). Furthermore, the electromagnetic device 11 is configured using a yoke 13 as a base. This yoke 13 has a circular concave storage space 13.
a, and an end surface 13b on the upper surface around it, and a through hole 13c of a predetermined diameter is formed at the center of the bottom inside the storage space 13a.
A plurality of cores 13d are formed at equal intervals around the core 3c in a protruding state.

Each of these cores 13d constitutes an electromagnet by inserting a coil bobbin 14 around which a coil 14a is wound. A printed circuit board 1 is provided on the lower surface of the yoke 13.
5 is provided, and a coil terminal 1 of the coil 14a is provided.
By soldering 4b, a drive power source (not shown) and the coil 14a are electrically connected.

Further, a biased magnetic thin plate 16 in which a large inner portion 16a is formed is provided between the yoke 13 and the side magnetic plate 8, so that magnetic flux can flow efficiently. Further, an antimagnetic film 17 is provided within the large interior 16a of the polarized magnetic thin plate 16. The amateur guide 1 is provided in the through hole 13c of the yoke 13.
2 is installed. This amateur guide 12 is formed with a guide groove 12a for regulating the movement of the distal end portion 3 of the armature 1 in a direction other than the rotating direction. A return spring 18 is held to bias the first return position.

Next, the fulcrum presser spring 9 is provided on the upper part of the side magnetic plate 8 on which the armature 1 is guided, and the protrusion 9a of the fulcrum presser spring 9 allows the rotation fulcrum of the armature 1 to 2 is pressed through the tip 5.

Further, a spacer 19 is provided on the upper part of the fulcrum presser spring 9,
A stop member 22 consisting of a stopper 20 and a cover plate 21 is provided. The stopper 20 is made of a viscoelastic material and is located at the return position of the armature 1 to determine the return position of the armature 1 and at the same time absorb collisions during return.

Next, each of the above-mentioned parts includes a pin formed on each of the nose 10, the yoke 13, the polarized magnetic thin plate 16, the side magnetic plate 8, the fulcrum presser spring 9, the spacer 19, and the cover plate 21. Holes 10a, 13e, 16b, 8c, 9b
, 19a, 21a from the nose 10 side, and a nut 23b is screwed onto the screw 23a of the pin 23 to tighten and integrate them.

In such a configuration, the rotation fulcrum portion 2 of the armature 1
The pressing piece 6 formed on the chip 5 which is fitted from the upper surface of the chip 5 is in a state of pressing one side surface 8b of the side magnetic plate 8.

Further, the armature 1 is pressed from its upper surface by the projection 9a of the fulcrum presser spring 9 via the tip 5. In this state, when a current flows through the coil 14a placed at the bottom of the armature 1 and a magnetic field is generated, the armature 1 is struck by the biasing force of the return spring 18 and rotates while being attracted downward; When it disappears, it returns to its original position due to the biasing force of the return spring 18.

That is, in such a suction return operation, at the time of attraction, the rotation fulcrum A of the armature 1 receives a force that moves toward the center due to the magnetized core 13d; Since a spring force is applied by the pressing piece 6, this spring force can absorb the component force acting toward the center, so that the rotation fulcrum A will not move.

As a result, the armature 1 rotates around the stationary rotation fulcrum A.

On the other hand, at the time of return, the pressing piece 6 returns to its original position in contact with the side surface 8b of the side magnetic plate 8, but at this time, the rotation fulcrum A remains stationary as shown in FIG. Return to position.

Therefore, no matter how many times the armature 1 repeats the suction return operation, the rotation fulcrum A does not move, so the wear resistance of the rotation fulcrum 2 can be improved. Since it is no longer necessary to coat the wire, the impact force of the wire can be stabilized, thereby improving printing quality.

Effects In the present invention, a resin chip is attached to the rotation fulcrum of the armature that fits into the hole of the side magnetic plate forming the side magnetic path, and this chip elastically hits the side surface of the side magnetic plate near the center. Because the contacting pressure pieces are integrally formed.

Since the pressure piece formed on the tip can absorb the force that acts upon return to suction, the pivot point of the armature will not shift or swing, and this will reduce the resistance of the pivot point. We are able to supply print heads that further improve abrasion resistance and can withstand high-speed operation.
Furthermore, since there is no need to apply oil as a lubricant to the rotational fulcrum, the impact force of the wire can be stabilized, thereby improving printing quality.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention, Fig. 2 is a longitudinal side view showing a part of its configuration, Fig. 3 is an explanatory diagram of the rotation fulcrum of the armature, and Fig. 4 is the overall configuration. FIG. 5 is an exploded perspective view showing the overall configuration. DESCRIPTION OF SYMBOLS 1... Amateur, 2... Rotation fulcrum part, 4... Wire, 5... Chip, 6... Pressing piece, 7... Inclined surface, 8... Side magnetic plate, 8a ...hole, 8b...side,
9...Fully point presser spring (fulcrum presser plate), 10...Nose, 11...Electromagnetic device, 12...Amateur guide, 12a...Guide groove, 18...Return spring,
22...stop member ALla, IjcL
A313 diagram, %u diagram

Claims (1)

[Claims] A plurality of armatures each having a wire at its tip, a nose that guides the movement of the wire, a guide groove that rotatably guides and holds the armature tip side, and a guide groove that is installed in the guide groove and that guides the armature. An armature guide including a return spring that biases in a return direction, an electromagnetic device that drives the wire by suctioning the armature, and a stop member that regulates the return position of the armature that is biased by the return spring. and a fulcrum holding plate that presses and supports the rotational fulcrum portion of the armature, the rotational fulcrum portion of the armature that fits into the hole of the side magnetic plate forming the side magnetic path is made of resin. A print head characterized in that a chip is attached, and a pressing piece is integrally formed on the chip to elastically abut a side surface near the center of the side magnetic plate.