JPH042053Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is applied to the print head of a dot line printer,
In particular, it relates to a print head that is smaller and lighter in weight.

[Prior art] Characters are printed on recording paper using a plurality of dots.
Dot printers that form numbers and other symbols are well known and have been widely used as printers for information processing devices in recent years because they can arbitrarily synthesize any character shape.

In order to increase the printing speed of this type of dot printer, the print head carrying the print wire is required to move at high speed in the row or column direction with respect to the platen and recording paper; The speed is naturally limited by the responsiveness of the electromagnetic actuator that drives the printing wire, etc., and in the past, in order to enable high-speed printing, multiple printing wires were arranged at equal intervals along the length of the platen. These printing wire groups are simultaneously driven based on corresponding printing commands, and such a printer is known as a dot line printer.

In such a dot line printer, it is preferable to align and arrange the printing wires to correspond to all the dots required for printing one line, but this arrangement does not ensure space for arranging the actually necessary number of electromagnetic actuators. It is not possible to do so, and it is also unfeasible from a cost standpoint.

For this purpose, a number of printing wires corresponding to the dot positions thinned out from the total number of dots required are arranged in a line, and frame wires carrying printing wires are driven back and forth only at empty dot positions between the printing wires. A device that performs pseudo simultaneous printing has been put into practical use and is well known as a shuttle printer.

A conventional shuttle type dot line printer has a structure in which a plurality of printing wires and electromagnetic actuators are aligned and fixed to a shuttle frame, as seen in, for example, Japanese Patent Laid-Open No. 131470/1983.

In this conventional device, the weight of the printing head is reduced by eliminating the permanent magnet that applies a biasing force to the printing wire in advance.As a result, the shuttle itself is also significantly lighter, and the well-known balancing weight when driving the shuttle is not required. An improved dot line printer is provided.

[Problems to be Solved by the Invention] However, in the conventional apparatus described above, the print heads arranged in alignment on the shuttle frame are each separated into an electromagnetic actuator part and a print spring part that supports the print wire, and these parts are separated from each other. This has a fixed structure, and as a result, there has been a problem in that the accuracy of the suction air, which has a large effect on the stamping period and the stamping force, is insufficient.

In addition, in the conventional device described above, machining holes to fit the electromagnets formed in the shuttle frame is expensive, and it is necessary to reduce the distance between the holes in order to increase printing speed. The question was whether it was possible.

The present invention was developed in view of the above-mentioned conventional problems. It efficiently dissipates heat from each printing head, thereby increasing the effective printing rate, and increasing the density of printing needles to achieve high speed printing. It is an object of the present invention to provide an improved print head for a dot line printer that enables printing and is inexpensive by making the shuttle frame suitable for mass production.

[Means for Solving the Problems] In order to achieve the above object, the present invention arranges a plurality of electromagnetic actuators in a reciprocating shuttle frame, and improves the heat dissipation efficiency of the structure of the frame and the electromagnetic actuators. is good,
It is characterized by having a shape or structure suitable for mass production. That is, in the present invention, the electromagnetic actuator positions and arranges the drive coil inside the shell by filling the shell with a high heat conductive material, thereby significantly improving the heat conduction between the coil and the shell, and also makes the shell into a rectangular shape. It fits almost perfectly into the fixing groove provided in the frame to improve heat conduction from the electromagnetic actuator shell to the frame, and reduces manufacturing costs and printing speed by reducing the spacing between the electromagnetic actuators. It is characterized by a marked improvement in

Furthermore, each electromagnetic actuator of the present invention has a printing spring integrally incorporated therein, making it possible to miniaturize the device and facilitate high-speed printing.

In the present invention, the above-mentioned shell fixing groove of the frame is made of a molded groove formed by drawing or extrusion, and there is an advantage that the frame can be manufactured at a low cost with a frame usually made of aluminum.

Therefore, according to the present invention, printing speed can be significantly increased by downsizing the device, improving heat dissipation characteristics, and increasing the density of printing needles, thereby improving the cost performance of the device. It becomes possible to improve.

[Embodiments] Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an overall schematic diagram of a print head according to the present invention applied to a shuttle type dot line printer, in which a recording paper 12 is wound and held on a platen 10, and the recording paper 12 is wound around the platen 10. In contrast, a shuttle frame 14 is supported so as to be reciprocating in the direction of arrow AB, and dot characters are formed on the recording paper 12 during this reciprocating drive. The shuttle frame 14 itself is lightweight and preferably made of aluminum, for example, and as described later, the shuttle frame 14 itself also serves as a heat sink that effectively releases heat generated from each print head.

Wire through holes 14a for receiving printing wires are aligned in the approximate center of the shuttle frame 14, and fixing grooves 14b and 14c provided on both sides of the wire through holes 14a are used to complete the printing head according to the present invention. The unit 16 is firmly fixed in the upside down position.

In the present invention, the fixing grooves 14b and 14c are suitable for holding the electromagnetic actuator 18 of the completed unit 16 while ensuring good thermal conductivity. The heat generated within the electromagnetic actuator 18 due to contact over a wide area can be effectively dissipated. This shuttle frame 14 is molded by drawing or extrusion, and the fixing grooves 14b and 14c are also obtained at the same time during this molding, making it possible to provide a frame structure that is inexpensive and highly accurate.

The completed unit 16 integrally includes an electromagnetic actuator 18 and a printing spring 22 carrying a printing wire 20, and in the state of the completed unit 16, the fixing and position adjustment of each part are completely performed.

As described later, the electromagnetic actuator 18 has a rectangular shell, and in the embodiment, a rectangular shell.
The fixing grooves 14b, 14c of No. 4 and the shell outer wall of each electromagnetic actuator 18 are brought into close contact, and a highly thermally conductive filler is interposed between the fixing grooves 14b, 14c and the shell outer wall to improve thermal conductivity. In addition to improving the electromagnetic actuator 18
Can be fixed with a rotation stopper. Therefore, it is also possible to omit the screw 30, which will be described later.

FIG. 2 shows the completed unit 16 fixedly held on the shuttle frame 14. A fixing screw 24 protruding from one end of the electromagnetic actuator 18 is passed through the through hole 14d of the shuttle frame 14, and the wire guide It is firmly fixed to the shuttle frame 14 with a fixing nut 28 with a plate 26 in between.

Further, the tail end of the printing spring 22 is fixed to the through hole 14e of the shuttle frame 14 with a screw 30, whereby the completed unit 16 is firmly fixed to the shuttle frame 14 in a non-rotating state. That will happen.

A catch seat 32 that engages with the wire through hole 14a of the shuttle frame 14 is caulked and fixed to the wire guide plate 26, and a wire bearing 34 is fixed to the catch seat 32.
The printing wire 20 is positioned in the correct position by the electromagnetic actuator 18, and the bearing 34 is positioned by the electromagnetic actuator 18.
The printing wire 20 is attached to the recording paper 12 while being supported by the recording paper 12.
Travel back and forth to.

As will be described later, the completed unit 16 itself has been assembled and positioned as a print head, but in order to correctly adjust the position of the tip of the print wire 20 while attached to the shuttle frame 14, an electromagnetic actuator 18 and an electromagnetic actuator 18 are required. It is preferable to insert a spacer 36 having an appropriate thickness between the fixing grooves 14c and 14b of the shuttle frame 14, thereby determining the final position of the printing wire 20.

The shuttle frame 14 effectively dissipates the heat generated by the plurality of completed units 16 arranged in a row, and in order to detect the temperature of the frame 14, the frame 14 has a frame 14 on at least one side, in the embodiment. Thermistor 38, 40 on both upper and lower sides
Temperature sensors such as the like are fixed, by means of which it is possible to control each electromagnetic coil so that it does not overheat.

Figure 3 shows the print head completed unit 1 mentioned above.
The detailed structure of 6 is shown.

In the present invention, in order to downsize the device and increase the driving efficiency of the printing wire 20, the electromagnetic actuator 18 forms a closed magnetic path type electromagnetic actuator, and for this purpose, a coil 42 is wound around the electromagnetic actuator 18. The core 44 is connected to the shell 46 and the yoke 48
It is confined in the space within the shell 46 in a substantially hermetically sealed state.

The fixing screw 24 is integrally formed on the core 44, and the coil 42 is attached to the core 42 while being wound around a bobbin 50.

As shown in FIG. 3, the shell 46 in this embodiment has a rectangular cross-sectional shape in the rectangular embodiment, and is processed by drawing. The square shaped shell 46 in such an embodiment
As shown in FIG. 1, when fixing to the fixing grooves 14b and 14c of the shuttle frame 14,
It is possible to set a large contact area between the outer surface of the shell and the shuttle frame 14, and heat conduction from the electromagnetic actuator 18 to the shuttle frame 14 is improved. Also, as shown in Figure 3,
Although the rectangular shell 46 creates more space than necessary between it and the coil 42 housed inside, in this embodiment, this space is filled with a highly thermally conductive filler 52 made of epoxy resin. Therefore, heat generated by the coil 42 is quickly transferred from the highly thermally conductive filler 52 to the shell 46, and good heat conduction from the shell 46 to the shuttle frame 14 described above is achieved.

[Effects of the invention] As explained above, according to the invention, a fixing groove is provided in a shuttle frame having good heat dissipation, such as aluminum molded by extrusion or drawing, and a rectangular electromagnetic actuator shell is inserted into the fixing groove. Furthermore, by filling the space between the coil and the shell in the electromagnetic actuator with a highly thermally conductive material, the heat generated by the coil can be effectively dissipated, and these printing heads can be made inexpensive and By increasing the density of printing needles, high-speed printing becomes possible.

Further, by improving the heat dissipation efficiency described above, the effective printing rate, which is the number of impressions per unit time, can be improved, making it possible to obtain a printing head that enables high-speed printing and has high cost performance.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing a print head according to the present invention installed in a shuttle-type dot line printer, Fig. 2 is a cross-sectional view of the main part of the assembled state in Fig. 1, and Fig. 3 is an illustration of an electromagnetic actuator. It is a sectional view of the main part. 14... Shuttle frame, 14b, 14c...
...Fixing groove, 16...Print head complete unit, 1
8... Electromagnetic actuator, 20... Printing wire, 22... Printing spring, 42... Coil, 44...
...Core, 46...Ciel, 48...York.

Claims (1)

[Scope of utility model registration request] In the printing head of a dot line printer, a plurality of electromagnetic actuators are arranged in a line on a reciprocating shuttle frame, and a printing wire is driven toward a platen by the driving force of an electromagnet that is excited and driven based on a printing command. The actuator includes a rectangular shell in which a core having a drive coil wound therein is fixed, and a yoke fixed to the shell so as to close an opening of the shell,
A printing spring is provided, one end of which is fixedly supported by a support tongue extending from the yoke, a printing wire is fixed to the tip thereof, and an armature is fixed at a position facing the core, and a printing spring is provided between the coil and the shell. The shuttle frame is filled with a highly thermally conductive material, and has a molded fixing groove into which the rectangular shell of each electromagnetic actuator is fitted, and when each shell is fitted into the fixing groove, the drive coil generates heat. A print head for a dot line printer characterized by rapid conduction dissipation from a high heat conductive material to a shell and frame.