JP4432647B2 - Dot line printer - Google Patents

Description

  The present invention relates to a dot line printer that performs dot printing with a plurality of printing hammers arranged in the digit direction, and more particularly to a winding structure of an electromagnetic coil on a magnetic circuit configured in the printing hammer.

  A dot line printer is a typical printing device that performs dot printing.

  A dot line printer is a printer that performs printing by reciprocating a hammer mechanism portion in which a plurality of printing hammers for performing dot printing are arranged and mounted in the digit direction by a shuttle mechanism portion. The printing hammer has a configuration in which a printing pin is attached to the tip of the leaf spring. The printing hammer is driven by releasing the bending energy previously given to the leaf spring, and printing is performed via an ink ribbon impregnated with ink. It is a printer that prints dots on paper.

  Hereinafter, the configuration of the hammer mechanism in the conventional dot line printer will be described in detail.

  The hammer mechanism shown in FIG. 3 is called a spring charge method. A hammer spring 2 having a hammer pin 1 joined to the tip thereof is attached to the yoke base 5 together with the front yoke 6 with bolts 7 on a magnetic circuit formed by the comb yoke 3, the magnet 4, the yoke base 5, and the front yoke 6. .

  Usually, the tip of the hammer spring 2 is magnetically attracted to the comb yoke 3 by the magnet 4 with a predetermined amount of deflection. Then, by applying a pulse current in a direction to cancel the magnetic attractive force to the hammer coil 8 attached to the comb yoke 3, the bending of the hammer spring 2 is released, and the hammer pin 1 strikes the printing paper 11 via the ink ribbon 10. As a result, dot printing is performed. Eventually, the hammer pin 1 returns to the original attraction position with the recovery of the magnetic attraction force upon completion of cancellation of the magnetic attraction force by the pulse current.

  In order to obtain normal printing with a dot line printer, dot printing is performed on all the printing hammers arranged in multiple lines, starting with the hammering force and repeatability of the printing hammer, that is, starting the supply of pulse current to the hammer coil. It is necessary to keep the time until returning to the suction position within a predetermined range. In the impact type printer, the impact force is an important required performance because it is frequently used for multi-part printing (copy paper) used for form paper. When repeatability is shortened, the shuttle speed at which the printing hammer moves can be improved, that is, the printing speed can be improved.

  In recent years, there has been a demand for further improvement in cost performance of dot line printers, and for the hammer mechanism, it is required to increase the speed of the printing hammer, but there are changes in coil winding and power supply voltage. The method has a problem that it involves an increase in power consumption.

  For speeding up the printing hammer, the driving control method of the printing hammer is a multi-stage pulse in which the pulse current is divided into a plurality of pulses, and by optimizing the wire diameter and the number of turns of the coil winding, There is an example in which the responsiveness of a printing hammer is improved while reducing power consumption (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2002-172808

  An object of the present invention is to improve the responsiveness of a printing hammer without increasing power consumption in a dot line printer.

  In order to solve the above problems, in the present invention, a plurality of printing hammers provided with hammer springs having a hammer pin at the tip and arranged at a predetermined pitch, and magnetic attraction for holding the printing hammers at a non-printing position are provided. A magnet for generating a force, a comb yoke for holding the printing hammer in a non-printing position, and each printing hammer for driving the printing hammer, and a pulse current of a predetermined width is supplied to the magnet. In a dot line printer having a hammer mechanism portion comprising an electromagnetic coil for canceling a magnetic field, a shuttle mechanism portion for reciprocating the hammer mechanism portion in the digit direction, and a paper feed mechanism portion for feeding printing paper, the electromagnetic coil has a bobbin. Provided with a taper portion at a flange portion of the bobbin end portion, and windings are wound along the taper portion. Grayed and brought close to the magnetic attracting surface of the Komuyoku characterized by arranged.

  According to the present invention, it is possible to configure a printing hammer that efficiently cancels the magnetic flux when supplying current to the coil and releasing the bending of the hammer spring, so that the responsiveness of the printing hammer can be improved without increasing power consumption. It becomes.

  It is necessary to efficiently cancel the magnetic flux when supplying current to the coil and releasing the bending of the hammer spring. For this purpose, it is effective to intensively cancel the magnetic flux in the vicinity of the attracting surface between the hammer spring and the comb yoke and prevent the magnetic flux from entering from the adjacent comb yoke or the like. Therefore, it is desirable to arrange the coil winding closer to the adsorption surface of the hammer spring and the comb yoke.

  Therefore, with respect to the bobbin constituting the coil, a taper portion is provided at the collar portion of the bobbin end portion, and windings are wound over several layers along the taper portion so that the winding arrangement is magnetically attracted between the hammer spring and the comb yoke. By adopting a structure close to the surface and improving the magnetic flux cancellation efficiency, it is possible to improve the response of the printing hammer.

  FIG. 1 is a diagram showing a coil bobbin 21 and a winding 22 of a hammer coil 8 as an example of the present invention.

  As shown in the figure, a tapered portion 23 is provided at the end of the coil bobbin 21 on the suction surface side, and several windings 22 are wound along the tapered portion 23 in this example. Compared to the case, the winding 22 has a structure closer to the adsorption surface of the hammer spring 2 and the comb yoke 3.

  As a result, when supplying a pulse current to the hammer coil 8 to release the bending of the hammer spring 2, it becomes possible to cancel the magnetic flux intensively in the vicinity of the attracting surface between the hammer spring 2 and the comb yoke 3, and adjacent to each other. By preventing the magnetic flux from coming in from the comb yoke 3 or the like, the efficiency of magnetic flux cancellation is improved.

  FIG. 2 shows a graph of temporal changes in the coil current 31 and the striking force 32 after the pulse current is supplied to the hammer coil with the above configuration.

  It can be seen that the striking force waveform 32 according to the present invention is more efficient in magnetic flux cancellation than the striking force waveform 33 according to the prior art, and shortens the time until the striking force is maximized (about 20 μs in this example). . Accordingly, it is possible to improve the response of the printing hammer as compared with the prior art. Further, the hammer spring is released with high responsiveness, so that the striking force is improved.

  Moreover, regarding the angle which comprises the said taper part, if it is a structure which has a taper angle to some extent, it has the effect of this invention. More preferably, as shown in FIG. 4, the taper angle is preferably set to α = 60 ° at which the coil winding can be wound without a gap. In the present embodiment, the base width t of the bobbin collar portion needs to have a certain size in terms of bobbin manufacturing (resin molding restriction), and is preferably about 0.5 mm. Further, there is a relationship of t1 = t−h / tan α.

  As shown in FIG. 5, the actual winding state is as shown in FIG. 5 (2) in which a slight gap is generated between each electric wire from the ideal state FIG. Sometimes. Specifically, the distance between the centers of the electric wires may be about 1.2 times the ideal state.

In this case, β = 57 ° when b = 1.1a, β = 53 ° when b = 1.2a,
Accordingly, a preferable taper angle range is 53 ° to 60 °.

  By improving the response of the printing hammer, it is possible to increase the speed of the dot line printer, as well as to reduce the number of hammer pins required to achieve the set target printing speed. In addition, since the entire configuration of the drive circuit and the like can be achieved, cost performance can be improved.

It is the schematic which shows the structure of the printing hammer which becomes an example of this invention. It is a figure which shows a coil electric current waveform and a hammer impact force waveform. It is the schematic which shows the structure of the printing hammer of a prior art. It is explanatory drawing about the taper angle of the taper part of this invention. It is explanatory drawing about the winding state of an electric wire.

Explanation of symbols

1 is a hammer pin, 2 is a hammer spring, 3 is a comb yoke, 4 is a magnet, 5 is a yoke base, 6 is a front yoke, 7 is a bolt, 8 is a hammer coil, 9 is a platen, 10 is an ink ribbon, 11 is printing paper, 21 Is a coil bobbin, 22 is a winding, 23 is a taper portion, 31 is a coil current waveform, 32 is a striking force waveform according to the present invention, and 33 is a striking force waveform according to the prior art.

Claims (1)

A plurality of printing hammers provided with a hammer spring having a hammer pin at the tip and arranged at a predetermined pitch; a magnet that generates a magnetic attraction force to hold the printing hammer in a non-printing position; and the printing hammer A comb yoke that is held at a printing position, a hammer mechanism unit that is provided for each printing hammer to drive the printing hammer, and that includes an electromagnetic coil that is supplied with a pulse current of a predetermined width to cancel the magnetic field of the magnet; In a dot line printer having a shuttle mechanism for reciprocating the hammer mechanism in the digit direction and a paper feed mechanism for feeding print paper,
The electromagnetic coil includes a bobbin, and a taper portion is provided at a flange portion of the bobbin end portion, and a winding is wound along the taper portion. The winding is close to a magnetic adsorption surface between the hammer spring and the comb yoke. A dot line printer characterized by being arranged.

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