JPS59194870A - Spring energy accumulating type dot printing head - Google Patents

Abstract

PURPOSE:To provide the titled head free from magnetic interference and reduced in the number of component parts, by a method wherein a movable part, a magnetic flux circle and a de-energizing coil for each printing wire unit are made to be independent from each other, and are fitted to a common yoke, in a spring energy accumulating type dot printing mechanism. CONSTITUTION:An armature 4 provided with the printing wire 5 is fitted to a leaf spring 3, and is attracted by the magnetic flux circle constituted of a permanent magnet 8, the first yoke 9 and a core 12. By canceling the magnetic flux by a coil 13, the wire 5 is protruded by a recoil force of the spring 3. The magnetic flux circle components 4, 10, 12 for each printing wire 5 are fitted to the second yoke which is common for them, magnetic interference between the circles is prevented from occurring, the number of component parts is reduced, and the head can be assembled in a compact form.

Description

[Detailed description of the invention] (Field of application of the invention) The present invention relates to a spring-loaded dot print head.

(Background of the Invention) A spring storage type dot print head biases a leaf spring using a permanent magnet, and excites a coil provided in a magnetic path of the permanent magnet to cancel the magnetic field of the permanent magnet. The biased leaf spring is released and the wire is driven by the leaf spring.

Such a print head includes a first yoke having a core, a coil disposed on the core, a permanent magnet attached to the first yoke, and a leaf spring to which one end of the permanent magnet is fixed. an armature fixed to the other end of the leaf spring corresponding to the core; a wire fixed to the armature; and a second yoke fixed on the leaf spring so as to magnetically couple with the armature. Consisting of By the way, a print head has a plurality of wires whose tips are arranged in a row, but in a conventional print head, as shown in Japanese Patent Laid-Open No. 52-49119, for example, It includes one core, one coil, one first yoke, one permanent magnet, and one second yoke. This has the disadvantage that the number of parts and the number of assembly steps increase, resulting in high costs.

Therefore, for example, JP-A-55-51569, JP-A-55-154178, and JP-A-56-37176
As shown in the publication, a first yoke with a plurality of cores, a plurality of coils, a permanent magnet, and a second yoke are connected to a plurality of wires.
It has been proposed that the yokes are each made of a single component and form a common magnetic path.

By the way, when the leaf spring is displaced and comes into contact with the core, it is preferable to absorb the mechanical impact without force, and it is preferable to have the leaf spring in close contact with the contact surface perpendicular to the flight direction of the armature to prevent wear and vibration. It has excellent magnetic efficiency. For this reason, it is necessary to cut the core into an inclined plane and rub it so that the leaf spring comes into close contact with the core. Also, JP-A-55-15417
There is a method that does not apply the ellipsoid plate spring, but the abutment surface is not perpendicular to the flight direction, so wear is high.

On the other hand, the arrangement of the core requires that the tips of the wires be aligned in a single line at the same time with high precision (to satisfy this condition, it is impossible to have a common magnetic path on the first yoke side as described above. Therefore, If the first yoke side is a common magnetic path, the leaf spring does not come into close contact with the core, so at the time of a collision (rebound occurs, the operation is unstable, and repeated collisions (this causes large wear and stroke fluctuations). As described above, it has the drawback that it is inferior in high speed and durability, and cannot obtain a high-performance print head.Furthermore, if the first yoke side is a common magnetic path, when a large number of wires are driven simultaneously. Due to the electromagnetic induction effect, magnetic interference occurs, which obstructs the flight of the wire and causes a decrease in print density.

As described above, all conventional print heads have advantages and disadvantages.

(Object of the Invention) An object of the present invention is to provide a high-performance spring-storage type drum 1 print head with a small number of parts and low cost.

(Embodiment of the Invention) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. A plurality of leaf springs 3 are arranged radially toward the center on the back surface of the second yoke 1 made of a single part with a second spacer 2 made of a single part interposed therebetween. An armature 4 is fixed to the front face of the inner side of each of the plurality of leaf springs 3, and one end of a wire 5 is fixed to each of these armatures 4. Further, a notch groove 1a is formed in the second yoke 1 so as to form a slight gap with the armature 4. A block 10 consisting of a first spacer 6, a magnet mounting plate 7, a permanent magnet 8, and a first yoke 9 is disposed on the fixed side of the back surface of the plurality of leaf springs 3, and the second spacer 2, the plurality of plates Spring 3, multiple blocks lO
are each fixed to the second yoke 1 by a screw 11. Each of the plurality of first yokes 9 has a core 12 disposed opposite to the back surface of the armature 4, and each of these cores 12ζ Coils 13 are attached, and each coil 13 is connected to an electronic circuit (not shown).Furthermore, a guide frame 14 is installed on the upper surface of the second yoke 1.
is fixed, and a wire guide 15 for guiding the wire 5 is attached to the tip ζ of this guide beam 14.

Therefore, the magnetic flux generated by the magnetomotive force ζ of the permanent magnet 8 is transmitted from the magnet mounting plate 7, the first spacer 6, the leaf spring 3, and the second spacer 2 to the second yoke 1 through the air gap from the second yoke 1. It passes through the armature 4, the plate spring 3, and the core 12 and the first yoke 9 through a gap from the plate spring 3. Therefore,
By energizing the coil 13ζ on and off, the core 12 generates a suction force that attracts the armature 7, and the leaf spring 3
The restoring force of 0 is used to print.

As mentioned above, since the second yoke 1 is made of a single component,
The number of parts and the number of assembly steps can be reduced compared to the case where the second yoke is made up of a plurality of parts. Furthermore, since other parts can be assembled using the second yoke 1 as a base, assembly is extremely easy.Also, the permanent magnet 8, the first yoke 9 with the core 12, and the coil 13 can be assembled into a single piece. Since one wire is provided for each of the wires 5 and the first yoke 9 side is configured to form an independent magnetic path, the end face of the core 12 can be easily cut into an inclined plane (this also prevents magnetic interference). However, there is no improvement in performance.

(Effects of the Invention) As is clear from the above description, the present invention [Accordingly, the second yoke is made of a single component as opposed to the plurality of wires, and the first yoke and the permanent magnet are made of a plurality of wires. Since they are provided independently and correspondingly to each other, the number of parts and assembly man-hours can be reduced and high performance can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the invention, and FIG. 2 is a plan view with the guide frame removed. 1... Second yoke, 3... Leaf spring, 4...
... Armature, 5... Wire, 8...
Permanent magnet, 9...first yoke, 12...
・Core, j3...Coil.

Claims (1)

[Claims] a first yoke having a core; a coil attached to the core; a permanent magnet attached to the first yoke; a leaf spring having one end fixed directly or indirectly to the upper part of the permanent magnet; an armature fixed to the other end of the leaf spring corresponding to the core; a wire fixed to the armature; and a wire fixed directly or indirectly onto the leaf spring so as to be magnetically coupled to the armature. In the spring storage type dot print head equipped with a second yoke, the second yoke is made of a single component for a plurality of wires, and the first yoke and the permanent magnet are each independent for a plurality of wires. A spring-loaded dot print head characterized by being provided with a spring-loaded dot print head.