JPS6347632B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a wire drive member of a print head for a dot printer having a novel wire drive member.

In recent years, as the demand for printers as terminal devices has increased, dot printers have become popular due to their ability to print at high speed, high reliability, and wide versatility, and various print heads for dot printers have been proposed. has been done.

By the way, among print heads for dot printers of this type, those that use the so-called spring release printing method use a permanent magnet to bias a leaf spring with an armature that holds the base end of the print wire, and excite a degaussing coil corresponding to the print pattern. One type cancels the magnetic attraction force of a permanent magnet and releases the biasing force of a leaf spring to perform printing, and another type uses an electromagnet to bias a leaf spring with an armature without using a permanent magnet and de-energizes the magnet coil of the electromagnet. There is a method in which printing is performed by releasing the biasing force of the leaf spring.

However, in conventional print heads of this type, the wire drive member for driving the print wire is formed of a leaf spring, which not only increases the number of parts and processing steps, but also has low reliability.
Moreover, there is a problem that the printing head becomes larger. In other words, in the conventional manufacturing method of leaf springs, the spring pieces are formed radially by making a plurality of cuts in the radial direction of a disc made of spring material. This must be prepared and mounted on the spring piece. For this reason, breakage easily occurs at the welded or caulked parts used as attachment means, and the stiffness of each spring piece must be increased in order to have an armature, which hinders the miniaturization or high speed of the head. It was becoming.

The present invention solves these problems at once, and includes a wire drive member made of a magnetic material and having an effective thickness necessary for an armature, and a plurality of arms constituting a torsion spring obtained by dividing centripetally. By bending the tip of this arm part into a substantially L-shape and hardening the bent part or fixing a hard member and using it as a printed wire, manufacturing is easy and the number of parts and processing steps are reduced. The present invention provides a method for manufacturing a wire drive member for a print head for a dot printer, which is low in cost, highly reliable, and allows the print head to be made smaller or faster.

Hereinafter, the method and the like will be explained in detail using examples shown in the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a printing head manufactured by the manufacturing method according to the present invention. The yoke 1 constitutes a common magnetic path for other members to be described later. Reference numeral 2 denotes a core arranged annularly on the first yoke 1, and each core is provided with a demagnetizing coil 3, respectively. Reference numeral 4 indicates a permanent magnet, and reference numeral 5 indicates a spacer, which is formed by an annular plate having a thickness equal to the gap length between the core 2 and a wire driving member to be described later.

Reference numeral 6 denotes a wire drive member which is an essential part of the present invention. The first feature of this wire drive member 6 is that it is made of a magnetic material that can be heat treated, such as a carbon steel plate. The second feature is that, as shown in FIGS. 2a, b, and c, the arm part 6c, which forms a torsion spring, is integrally formed between the inner end 6a and the base end 6b, where the tip bent part forms the printed wire. At the point set,
The printed wire is hardened at a bent portion 6d extending substantially perpendicularly to the thickness direction of the inner end 6a, or a hard member 7 is attached to the bent portion 6d as shown in FIG.
It is formed by fixing.

FIG. 2 shows an example in which 24 wire drive members 6 are integrally formed. As shown in the figure, each wire drive member 6 has a plurality of cut grooves 8 and 9 in the radial direction, and both grooves 8 and 9. 9 and a cut groove 10 which is provided substantially in the circumferential direction so as to communicate with each other, and the whole is formed into a crank shape. In addition, each part of this whole formed in a crank shape, that is, the reference numeral 6e,
The parts designated 6c and 6b serve as armature, torsion spring and base, respectively. Therefore, the width b ₁ of the armature portion 6e, the width b ₂ of the arm portion (torsion spring portion) 6e, and the width b ₃ of the base portion 6b.
is formed so that b ₁ or b ₃ >b ₂ . Then, the thickness is determined as required for the armature.
It should be about 1.5 to 2.5 mm.

On the other hand, an inner end bent portion 6d of each wire driving member 6,
That is, the print wires are arranged in a circle for dot matrix printing. FIG. 3 is a schematic diagram in which n print wires 6d are arranged in a circular manner, and the direction of arrow C is the printing row direction, that is, the direction in which the printing head is fed and printing is performed, and the straight line perpendicular to arrow C is shown in FIG. Above, for example, if the printed wires projected in the direction of arrow C on line B-B are equally spaced, e.g.
If the distance from #1 to #26 is L, then L/n
on the A-A line.
#1, #n printed wires, other
#2, #3... Each printed wire of #25 is connected to A-
They are arranged alternately on the left and right with the A line at the center. for example,
If #2 printed wire is on the left, #3 printed wire is on the right, and similarly #4 is on the left.
#5 is arranged in a circular shape on the right side.

Next, a method of manufacturing the wire drive member 6 according to the present invention will be explained.

First, a blank 6A having approximately the same outer diameter as the wire drive member 6 is formed by precision punching a steel plate having a thickness necessary for the armature of the wire drive member 6 (FIG. 4a). Therefore, the outer surface of the blank 6A is smooth and finished with high precision.

After that, the blank 6A is subjected to a bending process and an ironing process using its outer surface as a reference surface.
A cylindrical projection 6B' as shown in FIG. 4b is formed at the center of the blank 6A. This cylindrical projection 6B'
The blank 6A in which the . By forming 8, 9, and 10, the aforementioned inner end 6a, substrate 6b, and arm portion 6c are formed. Then, the bent portion 6d of each inner end 6a is hardened by quenching or a hard member 7 is adhesively fixed to form a printed wire, thereby forming the wire driving member 6.

In FIG. 1, reference numeral 11 denotes a second yoke fixed on the annular fixing portion 6f of the wire drive member 6 with a screw 12, and this second yoke 11 has a radial groove 13 corresponding to each wire drive member 6. The wire driving member 6 is incorporated into the groove 13 so as to loosely fit into the groove 13, so that the radial portion 14 functions as a side magnetic path.

Next, the operation of the print head formed by such a manufacturing method will be explained. First, when the demagnetizing coil 3 is de-energized, the magnetic flux of the permanent magnet 4 passes through the spacer 5, the wire driving member 6, the second yoke 11, the core 2, and the first yoke 1, and due to the magnetic attraction force at this time, The arm portion 6c of the wire drive member 6 is elastically deformed in the torsional direction, and the wire drive member 6
is adsorbed to core 2. This state is shown in FIG. On the other hand, when the demagnetizing coil 3 corresponding to the printed pattern is excited, the magnetic field by the permanent magnet 4 is canceled out, and the magnetic attraction force is reduced or completely eliminated. Therefore, the wire drive member 6 is released from the suction force of the core 2 and is actuated by the multiple force of the arm portion 6c which had previously been elastically deformed, and the bent portion provided at the operating end of the wire drive member 6, that is, the printed wire 6d is 2 yoke 1
It is made to protrude outside from the radial part 14 of 1. In this manner, printing is performed at the tip of the print wire that is projected by the force of the spring.

Although the above operation has been described with respect to a print head equipped with a permanent magnet 4, the present invention is not limited to such a print head, but can also be applied to a print head that does not use a permanent magnet but is equipped with an electromagnet. That is,
In this case, the permanent magnet shown in FIG. 1 is configured as a third yoke, the wire driving member 6 is biased by excitation of the coil 3, and the printed wire 6d is projected onto the radial portion 14 by canceling the excitation. The structure shall be such that the

As explained above, the method for manufacturing a wire drive member for a print head according to the present invention includes providing an arm portion constituting a torsion spring on a wire drive member made of a magnetic material, and a bending portion extending in the thickness direction at the tip of the arm portion. By providing a section and hardening this bent section or fixing a hard member, the bent section can be used as a print wire, so unlike conventional devices, the print wire and armature cannot be welded or crimped. There is no need for fixing, which not only reduces the number of parts and the number of processing steps, but also eliminates breakage accidents because there are no connecting parts, resulting in a long life and improved reliability. Furthermore, since the arm portion of the wire drive member functions as a torsion spring, the stiffness can be set to be smaller than that of the conventional one using a leaf spring and armature, and the head can be made smaller and faster. Also,
Since each wire driving member is simultaneously formed from a single steel plate material, it can be manufactured uniformly and with high precision, and has many excellent effects such as being suitable for mass production.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of a print head manufactured by the manufacturing method according to the present invention, and FIG.
The figures show the wire drive member, A is a plan view, B is a side view, C is an enlarged view of the main part, Fig. 3 is a schematic diagram of the arrangement of printed wires, and Figs. FIG. 6... Wire drive member, 6a... Inner end, 6b...
...base end, 6c...arm part, 6d...bent part (printed wire), 6A...blank, 6B...cylindrical projection.

Claims (1)

[Claims] 1. A blank is formed by precision punching a steel plate material having a predetermined thickness, and a cylindrical protrusion is formed in the center of the blank by performing a bending process and ironing process using the outer peripheral surface as a reference plane. The blank on which the cylindrical protrusion is formed is sequentially hardened, primary tempered, and press-stained, and then a cut groove is formed in the blank that extends to the cylindrical protrusion, thereby forming an annular fixing part and one end of the annular fixing part. is continuous through the base, and a plurality of centripetally divided arms are formed, each having a continuous bent part at the other end, and the bent parts are then hardened or a hard member is bonded to the bent part. A method for manufacturing a wire drive member in a print head for a dot printer.