JPS58177374A - Printing head - Google Patents

Abstract

PURPOSE:To enable to obtain high-speed printing performance and reliability, by a method wherein a spring member is provided substantially in parallel with a magnetically attracted surface of an attracted member, and a fulcrum for rotation of the attracted member is formed on a magnetic pole surface of a yoke, in an impact-type printer. CONSTITUTION:Before starting a printing operation, the attracted member 9 is attracted to magnetic pole surfaces 12A, 13A of the yoke by a permanent magnet 14, the spring member 10 accumulates strain energy by deviating, and the spring force is adjusted by a pressing-in member 19. When a printing current is passed through a coil 15, the magnetic force of the magnet 14 is canceled, the attracted member 9 is rotated around the fulcrum for rotation constituted of an angular part 13B of the magnetic pole surface 13B by the spring force, and a printing wire 4 prints a dot. The spring member 10 takes the shape of a flexure curve in the form of a cantilever, so that an excessively high stress is not exerted thereon. In addition, since the fulcrum for rotation is provided at the angular part 13B, the radius of rotation which is the distance from the angular part 13B to the wire 4 becomes shorter, thereby reducing the moment of inertia. Accordingly, high-speed printing performance can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is compatible with the print head of an impact type printer, and eliminates the strain energy of a spring member stored by the attraction force of a permanent magnet by canceling the attraction force of the permanent magnet by the magnetic flux of the electromagnet. The present invention relates to a print head of a cancel type printer that applies a suction member to the print head.

The print head of an impact printer generally biases a spring member using the attraction force of an electromagnet, stores strain energy in this spring member, and prints the distortion energy of the spring member by canceling the attraction force of the electromagnet. There is a type that acts as an operating force, a so-called electromagnet drive type, and a spring member is biased by the attraction force of a permanent magnet, and strain energy is stored in this spring member, and the attraction force of the permanent magnet due to the magnetic flux of the electromagnet is used. There is a so-called cancel type type in which the strain energy of a spring member acts as a printing operation force by ladle cutting.

The above-mentioned cancel type print head has been widely used in recent years because it has significant advantages over electric or magnetic drive type print heads.

In this type of print head, the print wire and the suction member provided therewith are made to fly by the strain energy accumulated by the deflection of the spring member.

That is, since the spring force of the spring member becomes the printing force of the instant printing wire, the magnitude of the spring force of the spring S material has a great influence on the printing quality.

However, in conventional print heads of this type, one end of the spring member is fixedly supported. For this reason, the spring force of this spring member must be adjusted by the magnetic flux cover of the permanent magnet or the excitation force of the electromagnet, and there is a problem in that it is very difficult to manage the adjustment. Furthermore, this type of print head is required to have high-speed printing performance and reliability.

The invention has been made based on the above-mentioned problems, and an object of the present invention is to provide a print head that can achieve high-speed printing performance and reliability, and is easy to adjust and manage.

In order to achieve the above object, the present invention provides a print head in which an attraction member is moved by magnetic attraction force, and strain energy obtained by biasing a spring member provided on the attraction member is used as an impact printing force. is provided on the suction member so as to be located in a plane substantially parallel to the magnetic attraction action surface of the suction member, and a rotation fulcrum of the suction member is provided on the magnetic pole surface of the yoke that forms a magnetic circuit with the suction member. and a means for adjusting the spring force of the spring member is engaged with the end of the spring member.Embodiments of the present invention will now be described with reference to the drawings.

1 and 2 show an embodiment of the print head of the present invention. As shown in these figures, the print head of the present invention has an outer frame structure including a guide frame 1, a head frame 2, and a water table plate 3. The guide 7 frame 1 includes five guides for the printing wire 4 and their center guide 5B. Outer plate 3
A companion protrusion 6 is formed on the outer chest to improve heat dissipation.

In a space defined by the head frame 2 and the book plate 3, a lever part 7 having a printing wire 4 and a driving mechanism 7A for the lever part 7 are provided. As shown in FIG. 2, a plurality of lever portions 7 are provided in the head frame 2 in a radial direction and in a circumferential direction. As shown in FIG. 3, this lever portion 7 is composed of a lever integral 81, a suction member 9, and a spring member IO. Lever integrated 8
has a printing wire 4 fixed to its tip. Suction member 9
is made of a magnetically permeable material, and has a lever unit 8 fixed to its casing 91 and a plate-shaped spring member 10 fixed to its shoulder. As shown in FIG. 3, the attachment portion of the spring member 1o to the attraction member 9 is designed to be substantially flush with the magnetic attraction surface 9A of the attraction member 9. Spring member 1
The end of the spring is provided with a hole 11t for receiving the spring force, as shown in FIG.

The structure of the drive mechanism 7A for this lever part 7 is as shown in FIG. A second yoke 13, a permanent magnet 14 arranged between these yokes 12 and 13, and a first
The coil 15 is provided on the yoke 12 of the yoke 12. The second yoke 13 has a magnetic pole surface 13A arranged close to the magnetic pole surface 12A of the first yoke 12. These magnetic pole faces 13A.

12A faces the suction member 9. First yoke 12, second yoke 13, permanent magnet 14. The attraction member 9 forms a magnetic circuit of a permanent magnet 14 and a coil 15. The permanent magnet 14 generates a magnetic flux that attracts the attraction member 9 toward the yoke. Coil 15 is L9 permanent magnet 14 in wJ magnet
It is designed to cancel the magnetic flux of

1st yoke 12. Second yoke 13. The permanent magnet 14 and the outer plate 3 are fixedly fastened to the head frame 2 by screws 16.

Normally, the lever part 7 has an attraction member 9 that is attached to the first yoke 12 and IP, 2 (D
The yaw 13(7)a [planes 12A and 13AK are disposed on the front surface of the yoke 12.13 by forming one layer of awns. The turning point of this lever portion 7 is constituted by a corner 13B of the magnetic pole surface 13 of the second yoke 13 that contacts the magnetic attraction surface 9A of the attraction member 9. A servo board 17 is provided on the surface of the second yoke 13 that faces the printing paper.

In order to prevent the lever part 7 from swinging when it rotates, the head frame 2 is provided with a lever guide 18 that guides the lever unit 8 of the lever part 7.

The means for adjusting the spring force of the spring member 10 includes a pushing member 19 screwed into the head frame 2. This pushing member 19 has a tapered portion 20 at its tip. The tapered portion 20 engages with a hole 11 provided at the end of the spring member 10, as shown in FIG. By pushing and pulling the pushing member 19, the spring member 10tl can be biased and its spring force can be adjusted.

Next, operation 1 of one embodiment of the print head of the present invention described above will be explained.

Before starting printing, the pulling member 9 is under the magnetic attraction force of the permanent magnet 14 as shown in FIG.

Magnetic pole surfaces 12 of the first yoke 12 and the second yoke 13
A, it is adsorbed to 13A. At this time, the spring member 10
is biased and stores distortion energy. The spring force associated with the cono-strain energy can be adjusted by pushing in and out of the pushing member 19.

Next, when current is applied to the coil 15, the magnetic flux of the permanent magnet 14 is canceled out, so that the attraction member 9 is rotated by the corner 13B of the magnetic pole face 13A due to the spring force of the spring member 10. It rotates around a dynamic fulcrum. Therefore, the printing wire 4 is guided tL by the kite 4 and center guide 5 of the guide frame 1, and its tip is struck by a granite through the ink ribbon and the printing paper. As a result, dots forming the character t are printed on the printing paper.

In the above-described printing operation, the spring member 1o is connected to the suction member 9
Since the cantilever exhibits a bow-shaped deflection curve between the connecting portion with the push-in member 19 and the retaining portion with the pushing member 19, no more stress than necessary is applied. Also.

As mentioned above, the rotational fulcrum of the lever part 7 is the corner 13B of the magnetic pole face 13, and the rotation radius of the lever part 70 is the length of the corner 13B and the printing wire 4, which is smaller than the conventional one. . As a result, the moment of inertia of the lever portion 7 becomes smaller, allowing higher speeds. Further, the pulling member 9 is pressed against the magnetic pole surface 13A of the second yoke 13 by the component of the attractive force by the permanent magnet 14 and the pressing force by the pushing member 19, and the rotational fulcrum thereof does not fluctuate much. Further, since the slippage at the engagement portion between the pushing member 19 and the spring member 10 is minute, the wear resistance properties thereof are also good.

In the above-mentioned embodiment, the lever portion 7 is held and the spring force y4 adjusting means is also used.

In the present invention, as shown in FIG.
It can also be applied to a type in which it is supported by a hinge mechanism 21 provided near the. In this case, the pushing member 1
The tip of the spring member 9 may be brought into contact with the end of the spring member 10. Furthermore, the spring member 10 can be provided so as to extend to the magnetic attraction surface 9A of the attraction member 9, as shown in FIGS. 5 and 6. Furthermore, forming a minute curved surface on the corner 13B of the magnetic surface 13A, which serves as a rotational fulcrum of the suction member 9, is also good in terms of wear resistance.

As described above, the present invention has advantages such as not only good high-speed printing performance and high reliability, but also easy management of spring force adjustment.

[Brief explanation of the drawing]

1 is a vertical side view showing an embodiment of the print head of the present invention, FIG. 2 is a front view showing a partial cross section of the print head of the non-invention shown in FIG. FIG. 4 is a perspective view of a part of the lever of the print head and its driving mechanism, and FIGS. 4 to 6 are perspective views showing other embodiments of the lever part and its driving mechanism used in the print head of the present invention. It is. 1...Guide frame% 2...Head frame%
3... Acta plate, 4... Printing wire, 7.
...Part of Renok. 7A... Drive mechanism, 8... Lever integrated, 9...
Suction member% 10...Spring member, 12...l! 1 yoke, 13...second yoke, 14...permanent magnet, 15...coil. ¥I2 Figure 43 Figure'! f'i4 Figure'''fJs figure

Claims (1)

[Claims] 1. In a print head in which an attraction member is moved by magnetic attraction force and the strain energy obtained by the bias of a spring member provided on the attraction member is used as an impact printing force, the spring member is moved by the attraction member. A rotation fulcrum of the attraction member is formed on a magnetic pole surface of a yoke that is provided on the attraction member so as to be positioned in a plane substantially parallel to the magnetic attraction action surface, and forms a magnetic circuit with the attraction member. . . 1 t% of the print head, wherein the end of the spring member is engaged with means for measuring the spring force of the spring member. 2. The print head according to claim 1, wherein the spring member is fixed to the suction member such that the attachment portion to the suction member is substantially flush with the magnetic attraction surface of the suction member. . 3. The printing system according to claim 1, wherein the spring member is provided extending from the magnetic attraction surface of the attraction member. 4. The rotation fulcrum of the attraction member is formed at a corner of the yoke magnetic pole surface that is in contact with the magnetic attraction surface of the attraction member, according to any one of claims 1 to 3. print head. 5. The print head according to claim 4, wherein the corner of the yoke magnetic pole surface constituting the rotational fulcrum of the pulling member has a minute curved surface.