JP2926893B2 - Dot line printer cooling device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a dot line printer, and more particularly to a cooling device for a dot line printer in which hammer springs constituting a spring-charge type printing hammer are provided in two upper and lower stages. It is.

[Background of the Invention]

3 and 4 show an example of a conventional cooling device. This includes a plurality of hammer springs 8 provided at a predetermined pitch along the spar direction, a permanent magnet 9 extending along the spar direction, and a pole portion for attracting and holding the hammer springs 8 with a print pin mounted on the front surface of the free end. A cooling device for a so-called single-bank type dot line printer having a single-stage printing hammer assembly composed of a rear yoke 4 having a rear yoke 4 and an electromagnetic coil 1 for release provided near a pole portion of the rear yoke 4. Is mounted vertically to the electromagnetic coil 1, and the cooling air 3 is passed between the radiation fins 2 to cool the electromagnetic coil 1.

In order to increase the printing speed of the dot line printer, in the case of a so-called double bank type dot line printer in which the printing hammer assemblies are provided in two upper and lower stages, the upper and lower radiation fins 2 interfere with each other. Cannot be adopted. Therefore, the radiation fin as shown in FIG. 5 and FIG.
A cooling device has been proposed in which the cooling air is blown from the duct 5 to the adjacent portions of the upper and lower radiation fins 12 to attach the cooling fins 12 thereto. However, this cooling method has the following problems. That is, the cooling air 3 that has traveled straight between the two upper and lower radiation fins 12 is prevented from traveling straight by the hammer spring 8 and the paper 7 and is exhausted to the left and right in the girder direction.
At the point where the air flow branches right and left, the cooling air becomes stagnant, and the cooling efficiency deteriorates.

Further, the amount of heat generated by the electromagnetic coil 1 increases as the printing speed increases. However, if the surface area of the radiation fins 12 is increased to cope with this, the following problem occurs. That is, in order to increase the surface area, it is necessary to increase the height of each heat radiation fin 13 of the heat radiation fin 12, or to increase the number of heat radiation fins 13,
Since the cooling air 3 is narrowed down by the duct 5, the cooling air is not blown to the heat radiation fins 13 depending on the positional relationship with the duct 5, and a predetermined cooling effect cannot be obtained.

[Object of the invention]

The object of the present invention is to eliminate the above-mentioned disadvantages of the prior art,
An object of the present invention is to provide a cooling device that effectively cools the release electromagnetic coil and can be used in a high-speed dot line printer.

[Summary of the Invention]

According to the present invention, if a large number of heat radiation fins are provided extending from the bottom surface attached to the surface of the electromagnetic coil in a direction perpendicular to the beam direction, a gap opened at the free end side of the hammer spring is formed and reflected by the hammer spring or paper. The configuration of the radiation fin is devised so that the cooling air can pass through this gap to improve the cooling effect.

(Example of the invention)

The present invention will be described below with reference to FIGS. 1 and 2 showing embodiments. A fixed end of the hammer spring 8 having a print pin mounted on the front surface of the free end is attached to the yoke base 10 by a screw. The yoke base 10 extends along the girder direction together with the permanent magnet 9 placed behind it. The rear yoke 4 mounted on the permanent magnet 9 is inclined at a predetermined angle with respect to the hammer spring 8, and the release electromagnetic coil 1 is wound near a pole portion that attracts and holds the vicinity of the free end of the hammer spring 8.

The radiating fins 20 each having the tip of the bottom surface 21 attached to the surface of the electromagnetic coil 1 by, for example, bonding or the like, have a plurality of fins 23 extending in a direction perpendicular to the beam direction. The fin 23 is inclined rearward toward the fixed end of the hammer spring 8. In the figure, 6 is a platen, and 11 is a front yoke.

The gap formed between the plurality of heat radiation fins 23 opens toward the free end side of the hammer spring 8 and is located above and below the outlet of the duct 5 behind. When the duct 5 is inserted between the upper and lower radiation fins 2 as described above, the distance between the radiation fin 2 directly attached to the electromagnetic coil 1 and the duct 5 is shortened, and the cooling efficiency of the electromagnetic coil 1 is reduced. Is improved. Further, in the present invention, since a space through which the cooling air 3 from the duct 5 passes is formed between the upper and lower two heat radiation fins 23, the cooling air 3 sent from the duct 5 and the cooling air 3 are reflected from the radiation fins 2. As a result, interference with the discharged cooling air is eliminated, and the electromagnetic coil 1 can be efficiently cooled.

Therefore, the cooling air 3 blown out of the duct 5 passes through the space between the upper and lower radiation fins 20 and is reflected by the hammer spring 8 or the paper 7 as shown by the arrows. It passes and is discharged backward. As a result, the stagnation of the cooling air 3 as in the related art is eliminated, and the radiation fins 20 are efficiently cooled. As a result, the electromagnetic coil 1 is also efficiently cooled, so that the temperature rise of the electromagnetic coil 1 can be suppressed. it can. Further, since each heat radiation fin 23 of the cooling fin 20 is located on the electromagnetic coil 1 which is a heat source, the heat generated by the electromagnetic coil 1 can be surely dissipated by heat conduction. Become.

〔The invention's effect〕

According to the present invention, since the cooling air reflected by the hammer spring or the paper is discharged through the gap formed between the fins of the radiating fins, the electromagnetic coil can be efficiently cooled, and the electromagnetic coil can be efficiently cooled. Temperature rise can be reliably reduced and can be adopted as a cooling device for a high-speed dot line printer.

[Brief description of the drawings]

FIG. 1 is a partially sectional side view showing an embodiment of the present invention, and FIG.
FIG. 1 is a perspective view of a main part of FIG. 1, FIGS. 3 and 4 are cross-sectional views and perspective views showing an example of a conventional device, and FIGS. 5 and 6 are cross-sectional views showing another example of a conventional device. It is a perspective view. In the figure, 1 is an electromagnetic coil for release, 2, 12, and 20 are radiation fins, 3 is cooling air, 4 is a rear yoke, 5 is a duct, 7
Is a paper, 8 is a hammer spring, 9 is a permanent magnet, 10 is a yoke base, 21 is a bottom surface of a heat radiation fin, and 23 is a heat radiation fin.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-184151 (JP, A) JP-A-64-18645 (JP, A) JP-A-64-18646 (JP, A) 65251 (JP, U) Japanese Utility Model Showa 61-71461 (JP, U) Japanese Utility Model Showa 54-94414 (JP, U) Japanese Utility Model Showa 62-170234 (JP, U) (58) Field surveyed (Int. ⁶ , DB name) B41J 29/00 B41J 2/235

Claims (2)

(57) [Claims] 1. A plurality of yoke bases and permanent magnets extending in the direction of the spar, and one end attached to the yoke base and printing pins mounted on the front surface of the free end, and provided at a predetermined pitch in the direction of the spar. A hammer spring, a lower yoke having a lower portion mounted on the upper surface of the permanent magnet and having a pole portion facing the upper back surface of the hammer spring, and a rear yoke inclined at a predetermined angle with respect to the hammer spring, and near a pole portion of the rear yoke. A print hammer assembly composed of a wound release electromagnetic coil and a print hammer assembly are provided in two upper and lower stages so that respective print pins are close to each other, and at least two of these print hammer assemblies are arranged along the girder direction. In a dot line printer that reciprocates, drives the electromagnetic coil in the process of reciprocation, releases the hammer spring, and prints with the print pin. A radiation fin having a bottom surface attached to the surface of the electromagnetic coil along the inclination direction of the rear yoke and a plurality of radiation fins extending from the bottom surface in a direction perpendicular to the spar direction, in each of the upper and lower printing hammer assemblies. The bottom of each of the upper and lower radiating fins and the rear of the fins are inclined toward the fixed end of the hammer spring to provide a gap into which the cooling duct is inserted between the fins of the upper and lower fins. A cooling device for a dot line printer. 2. A cooling device for a dot line printer according to claim 1, wherein a space through which cooling air can pass is provided between the heat radiation fins of said upper and lower heat radiation fins.