JPS5845085Y2 - Coil structure of ultra-small dot printer head - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a print head for a miniature dot printer, and in particular to a coil structure of a wire dot head having a clapper-type electromagnet with a suction section provided inside the end face of the electromagnetic coil that drives the print wire. .

Conventionally, in the case of a clapper-type electromagnet in which the suction part is constructed approximately in the middle of the coil as shown in FIG. 3, a certain inner diameter is required to ensure a space for the plunger 2 to operate.

When the bobbin 15 is used under such conditions, the overall size of the coil becomes large in order to secure the necessary coil volume, which is an obstacle to miniaturization.

Also, if you use a so-called bobbinless coil, which does not use a bobbin at all, the coil dimensions will be smaller by the thickness of the bobbin, but the coil assembly and insulation properties will be insufficient, resulting in lower reliability. Was.

The object of the present invention is to achieve a very compact and space efficient dot head by improving the coil structure compared to dot heads according to the prior art.

Another object of the present invention is to maintain the assemblability and insulation resistance of the drive coil and to ensure high reliability even in the coil structure of a very small dot head.

Based on this background, the present invention maximizes space efficiency even when the size of the dot head is made much more compact than conventional ones (for example, a 7-wire type has a diameter of 15 to 25 mm). This was done in an attempt to ensure insulation resistance without impairing assemblability and mass production, and will be explained in detail below with reference to the drawings.

FIG. 1 is a sectional view showing a specific example of the present invention, in which 1 is a frame having a plurality of coil core portions 1a on the circumference;
is a plunger that is selectively attracted to the attraction surface of the coil core portion 1a, and the other end is fixed to the actuating plate 3.

One end of the actuating plate 3 is connected to the plastic spring part 6 of the actuating plate guide 6.
A spacer 8 placed on the tip 6b of a and the yoke plate 7
It is sandwiched between and constitutes a rotation fulcrum A.

The spacer 8 is a spacer made of plastic disposed between the actuating plate 3 and the yoke plate 7. The other end of the actuating plate 3 engages with a wire button 10 fixed to the printed wire 9, and is pressed by a wire return spring 11. It is shifted in the non-printing direction,
It is positioned by the abutting portion 6C of the actuating plate guide.

In the specific example shown in FIG. 1, the coil core portion 1a extends to approximately the center of the coil, and the suction portion is formed approximately at the center of the coil.

4 is a drive coil, and 5 is a bobbin for the drive coil 4. As shown in detail in FIG. 2, a coil terminal terminal processing pin 15 is embedded in a part of the bobbin (only one is shown in the drawing).

Further, the bobbin 5 has only a coil core portion, and the plunger portion is bobbinless.

12 is a nose that holds the print wire 9; and a tip guide 13 that holds the print wire 9 and guides the printed end surface of the print wire. An intermediate guide 14 is installed to prevent the print wire from bending when driven.

Next, the printing operation shown in FIG. 1 will be explained.

When the drive coil 4 is excited in accordance with the printing command, the plunger 2 is attracted to the suction end surface of the coil core 1a.

Then, the actuating plate 3 to which the plunger 2 is fixed begins to rotate about the fulcrum A, driving the print wire engaged with the other end (tip) of the actuating plate 3, and printing energy is transmitted.

Printing is then performed by striking a recording medium (not shown).

When printing is completed, the print wire 9 is moved to the wire return spring 1.
1, it is positioned at the print standby position and the print cycle ends.

If we pay attention to the coil structure in FIG. 1, as mentioned above, the bobbin extends only up to the coil core portion 1a.

That is, the coil bobbin part is left in the part where insulation resistance is required and comes into contact with the coil core 1a part and a part of the frame.
By making the moving part of the plunger bobbinless,
The portion originally occupied by the thickness of the bobbin can be used as the moving portion of the plunger, and the overall size of the coil can be reduced.

Also, from the viewpoint of ease of assembly, as in the present invention, by leaving a part of the bobbin, the coil terminal end processing pin 15 can be easily removed.
It has the advantage of being able to provide a
The effects are significant when evaluated comprehensively in terms of mass productivity 5, ease of assembly, insulation resistance, etc.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a specific example of the present invention, and FIG. 2 is a detailed diagram of the coil structure. DESCRIPTION OF SYMBOLS 1... Frame, 1a... Coil core part, 2... Plunger, 3... Actuation plate, 4... Coil, 5... ...Bobbin, 6.
...Actuation plate guide, 9...Printed wire, 10...Button, 12...Nose body, 13...Tip guide, 3rd The figure shows a conventional coil structure.

Claims (1)

[Scope of utility model registration request] In the coil structure of the print head of a dot printer, which consists of a clapper-type electromagnet that has a suction section inside the coil end surface of the drive coil, a bobbin section is provided in the coil core section that constitutes the suction section, and a plunger that forms the suctioned section. The coil structure of the ultra-small dot printer head is characterized by its bobbin-less structure.