JPH0614407Y2 - Print magnet - Google Patents

Description

[Detailed Description of the Invention] [Outline] A recess for accumulating adhesive is formed on the inner peripheral surface of the coil bobbin of the printing magnet, and the adhesive injected into the recess enables the coil bobbin to be firmly fixed to the core in a short time. To do.

[Industrial application field]

The present invention relates to a print magnet used in a print belt type impact printer or the like.

As is well known, this type of printer has a configuration in which electric energy of a printing magnet driven by a printing signal is converted into mechanical energy by an armature and a printing hammer, and printing is performed on a sheet through an ink ribbon. The print magnet, however, has a structure in which a coil bobbin, in which a coil is wound around a core, is fixed.When the coil is energized by a print signal, the armature is attracted to the core, and when the coil is de-energized, the armature is separated from the core. It is something to do.

Therefore, the core is struck by the amateur every time printing is performed, and the coil bobbin needs to withstand the vibration accompanying the impact. If the coil bobbin moves due to weak coupling with the core, the upper surface of the bobbin comes into contact with the armature and the armature operation time becomes unstable, leading to printing failure.

[Conventional technology]

As a method of firmly attaching the coil bobbin to the core, conventionally, as shown in FIG. 2, a coil bobbin 2 is fitted to the core 1 and temporarily fixed, and then an epoxy-based adhesive is used around the joint with the core 1 on the upper surface of the bobbin 2. The method of applying the adhesive 3 in a manner of raising the adhesive 3 and fixing the core 1 and the coil bobbin 2 with the adhesive 3 has been adopted.

In addition, a method of applying an adhesive to the inner surface of the coil bobbin and the outer surface of the coil to join them together is possible, but since the mold release agent used when molding the coil bobbin adheres to the inner surface of the coil bobbin. Adhesion ability is low and it cannot be adopted.

[Problems to be solved by the invention]

However, in the conventional coil bobbin fixing method described above,
There were the following problems.

Since the adhesive 3 adheres to the amateur attraction surface of the core,
The adhesive must be removed in a later step.

Workability is poor due to the high viscosity of the adhesive.

It is difficult to control the amount of adhesive build-up to be constant. If the amount is small, the fixation between the core and the coil bobbin is weak, and if the amount is large, the adhesive removal work amount in the above item increases.

After the adhesive is applied, the process of drying (heating) and curing is performed in two steps.
Although repeated, the waiting time for the transition to the second stage is long because the curing time is long. It takes about 1.5 hours for this process and about 2 hours for the whole process, and the working time is very long.

It is an object of the present invention to provide a print magnet that can firmly and firmly connect the core and the coil bobbin in a simple and short time in view of the above conventional circumstances.

[Means for solving problems]

In the print magnet of the present invention, as shown in FIG. 1, a step portion 41 is formed on the inner surface of the coil bobbin 4 for accommodating the adhesive 5 having good permeability and quick drying property.

[Action]

The adhesive filled in the recess of the coil bobbin dries in a short time and solidifies on the core surface, and the solid body engages with the stepped portion of the recess of the coil bobbin to prevent the bobbin from slipping out. The core and the coil bobbin are firmly connected.

〔Example〕

FIG. 1 is a diagram showing the structure of an embodiment of the present invention. In the same figure, the coil bobbin 4 shown by cutting the center vertically is made of a non-magnetic material such as a resin mold as in the conventional case, A recess 41 is formed on about half of the inner peripheral surface on the opposite side. The concave portion 41 has a function of stopping the flow of the injected adhesive agent 5 and storing it, and a function of preventing the adhesive agent 5 from being caught. As the adhesive 5, an adhesive having good permeability and quick drying, for example, a cyanoacrylate adhesive is used.

The coil 2 is wound around the outer peripheral surface of such a coil bobbin 4, fitted into the core 1 and temporarily fixed. Then, the adhesive 5 is injected into the recess 41 of the coil bobbin 4 using the container 7 having a tapered spout. In this case, the adhesive does not build up on the upper surface of the bobbin. Therefore, it is never attached to the amateur suction surface of the core 1. The injected adhesive 5 adheres to the core and is dried and solidified in a short time. Coil bobbin 4
As described above, since the mold releasing agent is attached to the inner surface of the sheet, the adhesive agent 5 is hardly attached.

The adhesive 5 solidified on the core 1 is the recess 41 of the coil bobbin 4.
Therefore, the bobbin is engaged with the stepped portion a of the recess to prevent the bobbin from coming out of the core, that is, the coil bobbin 4 is immovably fixed to the core 1. The work up to this point is completed in a very short time of about 20 seconds.

Therefore, in such a magnet structure, the coil 2 is driven by the print signal, and even if the armature 6 is attracted to the core 1 and hits it, the coil bobbin 4 does not move due to the vibration at that time.

The shape of the recess 41 formed on the inner peripheral surface of the coil bobbin 4 is not limited to the simple shape as in the above-described embodiment, but may be an uneven shape.

[Effect of device]

As is clear from the above description, according to the print magnet of the present invention, the core and the coil bobbin can be firmly coupled with each other in a simple work and in a short time. therefore,
A print magnet with good print quality can be provided at low cost, which is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a print magnet according to the present invention by cutting a main portion thereof, and FIG. 2 is a view showing a conventional print magnet structure. In FIG. 1, 1 is a core, 2 is a coil, 4 is a coil bobbin, 5 is an adhesive, 6 is an amateur, 7 is an adhesive container, 41 is a concave portion, and a is a stepped portion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References: 60-77865 (JP, U): 60-109308 (JP, U): 58-148855 (JP, U): O. Richter. R. V. Phoss "Elements of Precision Instruments I" (Showa 39-10-20) Tokyo Book. P56 ~ 58

Claims (2)

[Scope of utility model registration request] 1. A print magnet comprising a resin-molded coil bobbin (4) wound with a coil driven by a print signal and fixed to a core (1), wherein the resin-molded coil bobbin (4) comprises: , A stepped recess (41) having an open upper end is provided in the upper part of the inner peripheral surface closely fitted to the core (1), and the stepped recess (41) is filled with an adhesive (5) to form the stepped recess (41). ) Inside the core (1) the adhesive adhered to the outer peripheral surface
A print magnet characterized in that the coil bobbin (4) is prevented from coming out by (5). 2. The printing magnet according to claim 1, wherein the adhesive (5) is made of a cyanoacrylate adhesive.