JPS61127363A - Drive coil device for wire dot head - Google Patents

Abstract

PURPOSE:To secure the insulation of a coil from cores by miniaturizing the size of a drive coil device by attaching a coil having a hole of a larger inside diameter than the outside diameter of core to a bobbin having a flat plate to be joined with the base of yoke and a lead wire holding cylinder. CONSTITUTION:A flat plate base face 12 is formed on one side of a yoke 4, many cores 13 are erected in parallel on the base face 12, and two through holes 14 are formed in the core 13. A bobbin 18 consists of a flat plate 19 to be joined with the base face 12, a hollow lead wire holding cylinder 21 to be inserted into the core hole 20 and the holes 12, and paired tongue-like thin insulating plate walls 22. The coil 23 has a hole 24 of larger inside diameter than the outside diameter of the core 13. A lead wire 25 is attached through the cylinder 21 to the bobbin 18. Since the hole 24 of the coil 23 is larger than the outside diameter of the core 13 in the attached state, the insulation between both can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a drive coil device for a wire dot head used in a dot printer or the like.

Conventional technology In general, in this type of device, the drive unit that drives the dot wire has a plurality of cores arranged around the inner periphery of a cylindrical yoke, and coils are wound around these cores. . Generally, a synthetic resin bobbin is used to provide insulation between the coil and the core.

In addition, there is also one in which the core is covered with a heat-shrinkable tube and a coil is wound around the outer periphery.

Problems to be Solved by the Invention A type of winding a coil around a bobbin and attaching it to a core has the advantage of ensuring insulation between the coil and the core, but the bobbin has a flange and is large. It is inevitable that the situation will change. Further, lead wires must be drawn out from this coil and extended to the printed wiring board, but there is a problem in that it is extremely difficult to insulate these lead wires.

In addition, the latter type mentioned above has the advantage of being able to be miniaturized, but it has poor workability due to the insulation treatment of the coil, and if a multi-pin head is used, the poor workability cannot be ignored. . Furthermore, there is no certainty regarding the insulation treatment of the lead wires.

It is unstable.

Means for Solving the Problem] The bobbin 18 to which the coil 23 is attached is formed by a flat plate portion 19 that is joined to the base surface 12 on which the core 13 is erected,
A lead wire guide part 21 in which the inner diameter of the coil 23 is made larger than the outer diameter of the core 13 and is attached to the flat plate part 19 of the bobbin 18, and the lead wire 25 is inserted into the bobbin 18.
is formed to penetrate the base surface 12.

Since the working coil 23 does not require a flanged bobbin, the overall size is reduced, and since the inner diameter of the coil 23 is larger than the outer diameter of the core 13, the insulation between the two is reliable. Also.

Since the lead wire 25 is insulated by the lead wire guide portion 21, there is no fear of dielectric breakdown in this portion and the device is stable.

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

First, the dot head 1 is assembled by stacking a nose 3 having a mounting portion 2, a yoke 4, an armature guide 5, and a cap 6 on top of each other.

A tip guide 7 and an intermediate guide 8 are attached to the nose 3, and the tip guide 7 has wires 9 arranged in a line. A printed wiring board Fi11 is disposed between the nose 3 and the yoke 4 with an insulating film 10 interposed therebetween.

The yoke 4 has a cylindrical shape, and a flat base surface 12 is formed on the negative surface thereof.

A large number of cores 13 are erected parallel to each other from this base surface 12 . Two through holes 14 are formed for each core 13 in the base surface 12 around these cores 13 . A spring receiver 16 is attached to the inner circumference of the core 13 with an intermediate guide 15 interposed therebetween. The same number of return springs 17 as the core 13 are attached to the spring receiver 16.

Next, a bobbin 18 is attached to each of the cores 13. This bobbin 18 includes a flat plate part 19 joined to the base surface 12, a core hole 20 formed in the flat plate part 19, and a hollow lead wire holding cylinder 21 inserted into the through hole 14.
and a pair of tongue-shaped insulating walls 22 that are thin and face each other. A coil 23 is attached to this bobbin 18,
This coil 23 has an insertion hole 24 having an inner diameter larger than the outer diameter of the core 13, and is attached to the bobbin 18 by passing its lead wire 25 through the lead wire holding cylinder 21. be.

Next, the armature guide 5 is attached to the upper surface of the yoke 4 with a residual magnetism prevention film 26 interposed therebetween.
An armature 27 facing the core 13 is attached by this armature guide 5. The wire 9 is fixed to the tips of these armatures 27, and is urged in the return direction by the return spring 17.

Also, a rubber ring 28 is attached to the outer end of the armature 27.
A cap 6 is attached with the cap 6 in contact with the cap 6, and a stopper 29 whose position can be freely adjusted is attached to the center of the cap 6. A damper 30 is attached to this stopper 29, and the tip of the armature 27 is brought into contact with this damper 3o with a film 31 interposed therebetween.

In such a configuration, the coil 23 connected to the printed wiring board 11 via the lead wire 25 is selectively energized according to the print signal. As a result, the armature 27 is attracted by the core 13, advances the wire 9, applies an impact force to the recording paper, and forms a dot.

In such a known device for operating the wire 9, the size of the core 13 and the coil 23, which serve as the driving portion, regulates the overall size.

Since the coil 23 is supported by the bobbin 18 formed by the flat plate part 19, its shape is small, and the insertion hole 24 does not fit into the core 13, especially when it is attached to the core 13.
The insulation between the two is reliable and stable because the outer diameter is larger than the outer diameter of the two. Therefore, there is no problem caused by making the device small.

Further, since the lead wire 25 is inserted into the lead wire holding cylinder 21 and passes through the through hole 14 of the yoke 4, it is completely insulated from the yoke 4, and no dielectric breakdown occurs.

Furthermore, from the viewpoint of assembly, the coil 23 can be easily attached because the lead wire 25 can be easily processed, and since the tip of the lead wire 25 is soldered to the printed wiring board 11, the coil 23 is not lifted up. The installation is stable.

Next, what is shown in FIGS. 7 to 9 are modified examples of the bobbin 18. First, in the bobbin 18 shown in FIG. 7, the direction of the tongue-shaped insulating wall 22 is changed from that shown in FIG. Further, in the one shown in FIG. 8, the insulating wall 22 has a thin cylindrical shape. Furthermore, the one shown in FIG. 9 eliminates the insulating wall 22 and the lead wire holding cylinder 2.
1 is not hollow, but instead has a groove 32 into which the lead wire 25 is fitted. This groove 32 is a lead wire guide section.

Effects of the Invention The present invention provides a plurality of cores that are erected from the base of the yoke as described above, and are inserted into the flat plate portion that is joined to the base and the through hole formed in the base. Since a coil having an insertion hole with an inner diameter larger than the outer diameter of the core is attached to a bobbin having a lead wire holding cylinder, the overall size can be reduced, and insulation from the core can be ensured. In particular, the insulation of the lead wire portion is reliable, and the installation of the coil is extremely easy.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is an exploded perspective view of a bobbin and a coil, FIG. 2 is an exploded perspective view showing the relationship with the core, and FIG. Fig. 4 is a partially cutaway perspective view showing the relationship between the bobbin and the printed wiring board, Fig. 4 is a horizontal sectional plan view of the dot head, and Fig. 5 is a partially cutaway part of the cap and a part with the armature removed. FIG. 6 is a partially exploded perspective view, and FIGS. 7 to 9 are perspective views showing modified examples of the bobbin. 4...Yoke, 11...Printed wiring board, 12.
... Base surface, 13 ... Core, 14 ... Through hole, 18.
...Bobbin, 19...Flat plate part, 20...Core hole, 2
1... Lead wire holding cylinder (lead wire guide part), 22...
・Insulating wall, 23... Coil, 24... Insertion hole, 25
...Lead wire, 32...Groove (lead wire guide part) Applicant Tokyo Electric Co., Ltd. - Figure 34 Figure 37 - Figure q Figure Z, I

Claims (1)

[Claims] 1. A plurality of cores are disposed on the inner periphery of a cylindrical yoke so as to stand up from the base surface, and a plurality of cores are provided around the core on the base surface and reach the printed wiring board. through-holes are formed, and a lead wire guide section to be inserted into these through-holes and a core hole into which the core is inserted are formed, and a bobbin is provided, which has a flat plate section joined to the base surface. A coil in which an insertion hole with an inner diameter larger than the outer diameter of the core is formed in the bobbin is joined to the flat plate part, and a lead wire drawn out from this coil is inserted and attached to the lead wire holding cylinder. Drive coil device for wire dot head. 2. A plurality of cores are arranged on the inner periphery of a cylindrical yoke so as to stand up from the base surface, and a plurality of through holes reaching the printed wiring board are formed around the cores on the base surface. , a flat plate part formed with a lead wire guide part inserted into these through holes, a core hole into which the core is inserted, and a thin plate-like insulating wall located around the core hole and joined to the base surface; A coil having an insertion hole having an inner diameter larger than an outer diameter of the core is formed in the bobbin and is connected to the flat plate portion while being fitted into the insulating wall, and the coil is pulled out from the coil. A drive coil device for a wire dot head, characterized in that a lead wire is inserted into and attached to the lead wire holding cylinder. 3. The drive coil device for a wire dot head according to claim 2, wherein the insulating wall is formed in the shape of a pair of opposing tongues.