JPH01165454A - wire dot printer print head - Google Patents

Abstract

PURPOSE:To detect the overheating of a coil quickly and securely and thereby improve the use efficiency of a printing head by providing a pillar-like metal heat-conductive member constituted in such a manner that a solenoid comes into contact with the member in a device which prints dots by using a printing wire, and constituting a printing head for a wire dot printer. CONSTITUTION:A metallic thick circular tube 24 is fitted into the interior of solenoids 3 arranged in a circle, and the circular tube 24 and the solenoids 3 are fixed by adhesion. A thermister 18 is fitted into the circular tube 24 and the thermister 18 also is fixed inside the circular tube 24 by adhesion. Consequently, thermal resistance R between each solenoid 3 and the thermister 18 becomes uniform over all the solenoids 3 and reduces. Consequently, in a printing head 25, heat generated in the solenoid 3 propagates to the thermister quickly and a difference in the temperature between the solenoid 3 and the thermister 18 becomes small. Thus the overheating of the solenoid 3 can be detected quickly and securely. In addition, the use efficiency of the printing head 25 improves as a temperature set for monitoring a temperature to the solenoid 3 can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a print head for a wire dot printer in which dot printing is performed using a print wire fixed to the armature via a button driven by an armature using a solenoid. The present invention relates to a print head that can quickly and reliably detect overheating of a solenoid and improve the usage efficiency of the print head.

[Conventional technology]

FIG. 84 is a longitudinal cross-sectional view of a print head of a conventional wire dot printer, and FIG. 5 is a cross-sectional view taken along line AA in FIG. 4.

In FIGS. 4 and 5, ■ indicates a plurality of iron cores arranged in a circle and each having a wedge-shaped cross section, 2 indicates a coil wound around the iron core 1, and 3 indicates a coil and this coil. This is a solenoid consisting of an iron core L wound with .

4 are each driven by a solenoid 3. Each of these armatures 4 has one end fixed to the free end of a cantilever leaf spring 5, and each armature 4 has an armature opposed to each of the solenoids with a gap 22 interposed therebetween.
The base 6a of the printing wire 6 is fixed to the other end of each wire. Then, the plurality of iron cores 1 described above are
A ring-shaped permanent magnet 8 is attached to the inner surface of the bottom 7a of a bottomed cylindrical base 7 made of a magnetic material and having a circular through hole 7b in the bottom 7a. The yokes 9 and yokes 9 are stacked one after another and fixed with a ℃ adhesive. Furthermore, on the yoke 9, there is a spacer lO formed in a ring shape and a plate spring base Stt that supports the plate spring 5.

Internal gear-shaped yokes 12 and 2 are stacked on top of each other.

These spacer IO, base 11 and yoke 12 are connected to the circle 7 in yoke 9 and housing 14 by means of screws 13.
Lunge! 148, and in this case, the armature 4 is disposed with a gap between two adjacent internal teeth of the yoke 12.
There is.

Reference numeral 15 designates a plurality of wire guides fixed within the cylindrical body so that the tip 6b of the printing wire 6 projects from the other end of the cylindrical protrusion 14b to which the circular 7 flange 114a is attached at one end; The housing 14 is the 7-lunge IJ1 mentioned above.
4a and the protrusion 114b. 16 is coil 2
a circular terminal board provided with a terminal 17 for energizing;
18 is a specific one of the coils 2. A rod-shaped thermistor glued to the outside of a (i11 side), 19 is the terminal of the thermistor 18 provided on the terminal board 16,
so as to close the through hole 7b in the base bottom 7a.
, is fixed to the outer surface of the bottom portion 7a via a ring-shaped insulating plate 20 by means not shown in the figure.

Reference numeral 21 denotes a filler made of synthetic resin that is filled inside a bottomed cylinder formed by the magnet 8, the base 7, the terminal plate 16, and the insulating plate 20 as shown in the figure. It is also filled between the coil 2 and the coil 2.

In FIG. 4, the magnet 8 is magnetized in the direction of its axis, so when the solenoid 3 is not energized.

The magnetic flux Φ due to the magnet 8 is caused by the magnet, the yoke 9. Spacer 1
0. Base It, yoke 12. A gap between the internal teeth of the yoke and the armature 4, the armature 4, and the leaf spring 5. The air gap between the chain plate spring and the iron core 1 is 22%.The iron core 1 and the base 7 are successively connected to form a closed magnetic path 23, c1.As a result, the armature 4 is attracted to the iron core 1, and the plate spring 5 is bent. When the print head is to perform a printing operation, a predetermined solenoid 3 is energized via the terminal 17. Then, in this case, the closed magnetic circuit 23V to which the excited solenoid 3 belongs
Since the solenoid is configured so that the magnetic flux Φ at C decreases, the attraction force of the excited solenoid 3 to the armature 4 is weak.

The armature 4 is deflected and springs up by the spring force of the leaf spring 5 which has been heated to a temperature of 0.degree. C., and as a result, the tip 6b of the printing wire further protrudes from the housing protrusion 14b. therefore,
If the ink ribbon and paper are placed near the tip 6b of the printing wire, dots can be printed on the paper by the protrusion of the tip 6b. In the print head shown in FIG. 4, when the tip 6b of the print wire collides with the paper, the solenoid 3 described above is irradiated, so that the armature 4 is attracted to the iron core 1 again.

In FIG. 4, since the print head operates as described above, is the print head in printing operation? When printing, the coil 2 generates heat, and therefore, if the printing operation becomes intense, the coil 2 may be burnt out. The illustrated thermistor 18 is provided to constantly detect the temperature increase of the coil 2 (°C) and to take predetermined measures such as stopping the printing operation of the print head when the coil becomes overheated.

[Problem that the invention seeks to solve]

In FIG. 4, the temperature of the °C coil 2 is monitored as described above, but it is clear that the temperature of the coils 2 other than the coil 2a cannot be accurately detected. Therefore, by setting the set temperature Ts for temperature monitoring to a lower temperature Ts1, it is possible to ensure the safety of temperature monitoring in °C, but this lowers the maximum allowable temperature of the coil, making it more efficient to use the print head. decreases. Therefore, if the coil 2a to which the thermistor 18 is attached is the coil 2 that is most likely to operate, in this case the set temperature Ts is set to the coil 2.
Since it is only necessary to set ℃ for a, the set temperature value T at this time
S2 can be made higher than the Tst mentioned above, and C1 therefore improves the usage efficiency of the print head compared to the above case, but the coil 2, which is most likely to operate, may vary depending on the use of the print head, the type of printed characters, etc. It is normal for things to change in various ways.

In this case, there is a problem that it is difficult to select the coil 2a.

Therefore, the thermistor 18 is arranged at the center of the iron core l arranged in a circle as shown in FIG.
In addition to being extremely easy to install, temperature detection by the thermistor 18 is performed under the same conditions as the Venino coil 2, allowing temperature detection to be performed with relatively high accuracy when the temperature change of the coil 2 is slow. It turns out. However, in this case, since the filler 21 with low thermal conductivity is interposed over the entire relatively long distance between the thermistor 18 and the coil 2, it takes time for heat to be transferred from the coil 2 to the thermistor 18. In the past, there was a problem in that when the temperature of the coil 2 changed rapidly, the temperature detection by the thermistor 18 became inaccurate. In addition, since the filler 21 with low thermal conductivity is placed between the coil 2 and thermistor 18, a large temperature difference is likely to occur between the coil 2 and thermistor I8, and therefore the temperature monitoring settings described above are likely to occur. Since the temperature TS must be lowered, a print head in which the thermistor 18 is arranged as shown in FIG. 6 also has the problem that the usage efficiency of the print head is reduced.

An object of the present invention is to increase the thermal conductivity of the inclusion between the coil 2 and the thermistor 18, so that heat propagation between the coil and the thermistor is rapid and the coil 2
To make it possible to quickly and reliably detect overheating of a coil 2 by reducing the temperature difference between the coil 2 and a thermistor 18, and to improve the efficiency of one-time use of the print head. It is in.

[Means for solving problems]

According to the present invention, the above problems are solved.

The apparatus includes a plurality of circularly arranged solenoids, armatures driven by the solenoids and corresponding to each of the solenoids, and a printing wire fixed to each of the armatures.

In the apparatus for dot printing with the printing wire by driving the armature 1a with the solenoid, a temperature sensor is fitted into a sensor insertion hole provided along the axis of the dot, and all the A print head of a wire dot printer is constructed by providing a columnar metal heat conductive member having a K tA'Z structure so that the solenoid comes into contact with it.

[Function] With the above configuration, the temperature sensor and the valley solenoid will be in thermal contact with each other by thermal members such as gold iAH, which have high thermal conductivity, so the thermal temperature sensor and the solenoid will be in contact with each other. As a result of the rapid propagation of the opening and the small temperature difference between the two, overheating of the solenoid can be detected quickly and reliably.
Furthermore, in this case, the set temperature Ts for temperature monitoring of the solenoid can be increased, so that the usage efficiency of the print head is improved.

〔Example〕

FIG. 1 is a vertical cross-sectional view of the first embodiment of the present invention, and FIG.
In the B-BltT plane view in the figure. Figures 1 and 2
The major difference from FIGS. 4 to 6 is that a thick circular pipe 24 made of metal such as aluminum or copper is inserted into the inside of the solenoid 3 arranged in a circle. The thermistor 18 is fitted into the circular tube 24 and the thermistor 18 is also fixed within the circular tube 24 by a contact layer.

In FIG. 1, the filler 21 is also filled in the space between the iron core 1 and the coil 2, the space between the coil 2 and the base 7, and the space near the through hole 7b of the base. The filler 21 also fills the internal grooves of the metal circular tube 24. 25
1 is a print head of a wire dot printer consisting of the various parts shown in FIG.

In FIG. 1, since the print head 25 is configured as described above and the temperature is 0.degree. C., the thermal resistance R between each solenoid 3 and the thermistor 18 is uniform over all solenoids 3.
Moreover, it is clear that this thermal resistance Rb' - DEG C. is much smaller than the corresponding thermal resistance in FIG. Therefore, the odor c of the print head 25 is such that the heat generated in the solenoid 3 is quickly propagated to the thermistor 18, and as a result, the temperature difference between the solenoid 3 and the thermistor 18 is reduced. , it is possible to quickly and accurately detect overheating of the solenoid 3, and in this case, the set temperature for temperature monitoring of the solenoid 3 can be increased, so the efficiency of use of the printing pad 25 is improved. It turns out.

In FIG. 1, the lower end of the circular tube 24 is brought into contact with the terminal plate 16 made of electrically insulating material as shown in FIG. As a result, in order to prevent the solenoid 3 from overheating, the printing operation frequency of the ic li (solenoid) is severely restricted.

FIG. 3 is a longitudinal sectional view of a second embodiment of the invention.

The major difference between the figure and FIG. 1 is that a columnar gold interposer 26 corresponding to the metal circular tube 24 in FIG. 1 is arranged so as to be inscribed in a plurality of circularly arranged solenoids 3. A thick disc-shaped recess 27a is provided on the negative side, and a plurality of linear heat dissipating fins 27 are provided in parallel on the other side.
The heat dissipating member 27 provided with the base 7
In this case, by being glued to the outer surface of the bottom 7a of the
The interposer 26 is the terminal board at the bottom! 6 is brought into contact with the bottom surface of the recess 27a by a screw 28 and fixed at 0.degree. That's right, the thermistor 18 is the intervenor 26
On the upper surface side, the thermistor 18 is inserted into the sensor insertion hole 29 provided along the axis of the interposer 26.
The thermistor terminal 19 and the thermistor terminal 19 are connected to each other through a conductive hole 30 provided in the interposer 26 as shown in the figure.Also, in FIG. All of them are filled with the filler 21 at ℃.

In FIG. 3, C indicates that the print head is constructed as described above and has a temperature of 10° C. According to such a print head, the overheating of the solenoid 3 can be prevented in the same way as in the print head 25 shown in FIG. Although it is clear that detection can be done quickly and reliably, and that the efficiency of print head usage can also be improved.

Furthermore, in FIG. 3, the heat generated by the solenoid 3 is easily propagated from the portion of the interposer 26 penetrating through the insulating plate 20 and the terminal plate 16 to the heat radiating member 27.
Because the heat is dissipated dynamically.

The printing operation frequency of the solenoid can be made higher than that in the printing head 25, and the usage efficiency of the print head can be further improved than that of the print head 250.

In FIGS. 1 and 3, C represents the metal tube 24 and the interposer 2.
6 were configured as described above.

Each of these is a column-shaped structure in which a thermistor 18 as a temperature sensor is connected to a sensor insertion hole provided along the axis of the shaft, and a solenoid 3 of °C is in contact with the side pressure. It can be said that it is a heat conductive member made of gold. Further, in each of the above-described embodiments, the temperature sensor 18 is used as a temperature sensor, but in the present invention, the temperature sensor is not limited to a thermistor, but may be a temperature sensor based on a different operating principle. f [It is a detector, and the temperature is not a problem.

Further, each of the above-mentioned embodiments is a spring-release type print head in which printing is performed by the spring force of the leaf spring 5 by energizing the solenoid 3, but the present invention is based on the energized solenoid. It is obvious that the present invention can also be applied to an electromagnetic print head in which the print wire is magnetically driven.

〔Effect of the invention〕

As described above, in the present invention, C includes a plurality of solenoids arranged in a circle, armchairs corresponding to each of the solenoids driven by the solenoid, and a print fixed to each of the armatures. A temperature sensor is fitted into a sensor insertion hole provided along the axis of the odor C, which is provided with a temperature sensor wire, and a temperature sensor is inserted into a sensor insertion hole provided along the axis of the temperature sensor. In addition, a column-shaped metal heat conductive part was provided on the side surface so that all the solenoids were in contact with each other, thereby constructing a print head for a °C wire dot printer.

Therefore, with the above configuration, the temperature sensor and each solenoid will be thermally connected by a metal heat conductive member with a high thermal conductivity, so the temperature sensor and each solenoid will be thermally connected. As a result, the heat propagation between the two is rapid and the temperature difference between the two is small. 1. The present invention has the following advantages: it is possible to quickly and reliably detect solenoid overheating, and the reliability of solenoid overheat monitoring is improved. effective. Also.

In this case, the set temperature Ts for temperature monitoring for the solenoid
The present invention has the effect of improving the usage efficiency of the print head because it can increase the print head.

[Brief explanation of the drawing]

1 and 3 are longitudinal cross-sectional views of a first embodiment and a second embodiment of the present invention, respectively, and FIG. 2 is a line BB in FIG. 1.
4 is a longitudinal sectional view of a print head of a conventional wire dot printer, FIG. 5 is a sectional view taken along line A-A in FIG. 4, and FIG. FIG. 2 is a sectional view of a main part of a print head of a wire dot printer. 3... Solenoid, 4... Armature, 6... Printing wire, 18... Thermistor, 24... Metal circular tube. 25...Print head, 26...Interposer, 29...Sensor insertion hole. Itching 1 Sticky note 2 Figure 1 3 Sticky note 5Illi

Claims (1)

[Claims] A plurality of solenoids arranged in a circle, an armature corresponding to each of the solenoids driven by the solenoid, and a printing wire fixed to each of the armatures, the armature being driven by the solenoid. The temperature sensor is inserted into a sensor insertion hole provided substantially along the axis, and all of the solenoids are in contact with the side surface. A print head for a wire dot printer, characterized in that it is provided with a columnar metal heat conductive member.