JPH0436864B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a dot impact printing head of a spring charge type in which high-order vibration of the spring and wear of the spring fulcrum are reduced.

[Prior art]

Conventional spring charge type dot impact printing heads, for example, as shown in Japanese Patent Application No. 56-125160, have an armature and a yoke located closer to the core than the leaf spring, and the yoke shape is similar to the core without the yoke. The shape is approximately the same as the deflection curve of the leaf spring when it is attracted, thereby reducing high-order vibrations of the leaf spring.

However, making the shape of the yoke substantially in the shape of a deflection curve of a leaf spring has the drawback of increasing variations in structural characteristics. In addition, in order to suppress high-order vibrations, some structures have a rigid body such as a core that absorbs the reaction force applied to the armature at the time of impact, but this is done by keeping a part of the armature in constant contact with a rigid body such as the core. Because of this, the fulcrum portion of the leaf spring tends to wear out easily, resulting in a change in printing characteristics.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to prevent high-order vibrations of the leaf spring and to stabilize printing characteristics.

[Structure of the invention]

In order to achieve the above-mentioned object, the present invention includes forming a slit in a tongue portion above the groove of a leaf spring supported by a flat plate-like yoke in which a groove is formed, and a rear end portion of an armature that drives in the groove. When the cores are arranged opposite to each other and the armature is attracted by the core, a force couple consisting of the product of the length from the core suction point to the fixation point of the armature and the leaf spring and the armature suction force at the core suction point is generated by the plate spring. It is characterized by acting on a spring, deforming the leaf spring in a direction away from the flat yoke, and storing strain energy in the leaf spring.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

In the figure, 1 is a roughly annular base yoke;
A plurality of cores 2 are integrally formed protruding from the outer periphery in a right angle direction. 3 is an electromagnetic coil wound around the core 2; 4 is a substantially annular substrate connected to a lead wire of the electromagnetic coil 3; a hole 5 into which the core 2 is inserted is formed;

6 is an annular permanent magnet; 7 is a ring yoke laminated on the permanent magnet 6; 8 is a flat plate-like yoke having a circular shape and a constant thickness; the side of the armature 9 extends radially from approximately the center toward the outer circumference; A groove 10 serving as a magnetic path is provided, and the armature 9 is arranged so as to be movable within the groove 10.

Reference numeral 11 denotes a regular polygonal annular spacer having the same number of sides as the armatures 9, and is arranged between the ring yoke 7 and the flat yoke 8 to provide a gap between the armature 9 and the core 2. Reference numeral 12 denotes an annular leaf spring having a tongue piece 13 extending centripetally, and the tongue piece 13 is provided with a substantially H-shaped slit 14, and an armature 9 is fixed to the tip side in the middle thereof. .

The rear end of the armature 9 is arranged opposite to the end of the slit 14 of the leaf spring 12, and is also arranged opposite to the core 2.

15 is a dot wire attached to the tip of the armature 9, and the dot printed end of the tip is attached to the housing 16.
is guided by a guide section 17. 18 is a cover, 1
Reference numeral 9 denotes a crank spring that fixes each part of the dot impact printing head together.

Next, to explain the operation of the above structure, first, when the electromagnetic coil 3 is not energized, the armature 9 is attracted to the tip of the core 2 by the magnetic flux Φ _M of the permanent magnet 6, as shown in FIG. . That is, as shown in FIG. 5, the length from the fixed point of the tongue piece 13 of the leaf spring 12 and the armature 9 to the suction point of the core 2 and the armature 9 is r, and the length of the armature 9 at the suction point of the core 2 is r. If the attraction force is p, then the force couple pr acts on the tongue piece 13 of the leaf spring 12, causing the armature 9 to bend in the opposite direction to the direction in which it is attracted to the core 2, and is held in a state in which strain energy is stored. Ru. At this time, the tongue piece 13 of the leaf spring 12 is in a state of being evenly curved between the fixed point of the armature 9 and the suction point of the core 2.

Furthermore, when the electromagnetic coil 3 is energized, the permanent magnet 6
A magnetic flux Φ _C is generated which cancels the magnetic flux Φ _M of , and the armature 9 is rotated by the strain energy of the tongue piece 13 .
At this time, the tongue piece 13 of the leaf spring 12 always moves while sequentially contacting the surface of the disc-shaped yoke 8, so the high-order vibration of the leaf spring 12 is suppressed and the strain energy of the leaf spring 12 is efficiently transferred to the rotation of the armature 9. The dot wire 15 prints dots on a printing medium (not shown).

Although the serial dot printing head has been described in the above embodiment, it is also possible to arrange a plurality of electromagnetic mechanisms linearly in one or more rows and apply it to a line printer system.

〔Effect of the invention〕

As described above, according to the dot impact printing head according to the present invention, a slit is formed in the tongue portion above the groove of the plate spring supported by the flat plate-shaped yoke in which the groove is formed, and an armature is driven within the groove. Cores are arranged opposite to each other at the rear end, and when the core attracts the armature, it consists of the product of the length from the core suction point to the point where the armature and leaf spring are fixed and the armature suction force at the core suction point. The couple acts on the leaf spring, deforms the leaf spring in the direction away from the flat yoke, and stores strain energy in the leaf spring, so that the force is no longer applied to a single point on the leaf spring as in the conventional case, and the leaf spring becomes a fulcrum. This has the effect of eliminating changes in printing characteristics due to wear, and also has the effect of suppressing higher-order vibrations as a flat plate-like yoke that is easy to manufacture.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG.
3 is an exploded perspective view, FIG. 4 is a plan view of a leaf spring used in the present invention, FIG. 5 is a partial plan view of an armature portion showing an embodiment of the present invention, and FIG. The figure is a side sectional view illustrating the operation of the present invention. 2... Core, 3... Electromagnetic coil, 6... Permanent magnet, 8... Flat yoke, 9... Armature,
10... Groove, 12... Leaf spring, 13... Tongue piece, 1
4...Slit, 15...Dot wire.

Claims (1)

[Scope of Claims] 1. An armature having a dot wire at its tip is fixed to each of the tips of a plurality of tongues of a leaf spring, and with the tongues biased by the magnetic force of a permanent magnet, By selectively exciting a plurality of provided electromagnetic mechanisms,
In a spring charge type dot impact printing head that prints by canceling the magnetic flux of the permanent magnet and converting the strain energy accumulated by the leaf spring into printing energy, a leaf spring supported by a flat plate-like yoke with a groove formed therein. A slit is formed in the tongue piece above the groove, and a core is disposed opposite to the rear end of the armature that drives in the groove, and when the armature is attracted by this core, the armature and leaf spring are separated from the core suction point. A force couple consisting of the product of the length up to the fixation point and the armature suction force at the core suction point acts on the leaf spring, causing the leaf spring to deform in the direction away from the flat yoke, imparting strain energy to the leaf spring. A dot impact printing head that stores . 2. A dot impact printing head characterized by having a permanent magnet arranged in the center and a core around which an electromagnetic coil of an electromagnetic mechanism is wound.