JPS6122962A - Dot printer head - Google Patents

Abstract

PURPOSE:To ensure the operation of printing of a printing wire by suspending a dot printer head while forming a clearance between the printing wire and an armature. CONSTITUTION:When a yoke 21 is not excited, an armature 30 is sucked and fixed to the pole surface 29a of a pole piece 29 by a permanent magnet 28. A clearance TR is formed between a contacting section 30a in the armature 30 and a head section 35 in a printing wire 33 at that time. When a coil 25 is conducted and the yoke 21 is excited, the armature 30 is brought to a state shown in a virtual line 101, and a tip section in the printing wire 33 conducts the operation printing. When the currents of the coil 25 are de-energized, the armature 30 is returned. A flange section 36 in a head section 34 is fastened elastically by an elastic body 42 in the printing wire 33 under the operation of return. Accordingly, the head section 34 in the printing wire 33 collides with the armature 30, thus preventing two-time striking operation due to the bounce of the head section 34.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a dot printer head that performs printing by driving an amatia by electromagnetic force and driving a printing wire by the displacement of the amatia. 6 is a sectional view of a portion of the dot printer head, and FIG. 6 is a diagram for explaining the operating state of the dot printer head of FIG. 5. FIG. Figure 4 and v
The prior art dot printer head will be explained using Figure J5. The dot printer head includes a plurality of holes 1 arranged at equal intervals in the circumferential direction. The yoke 1 has a substantially E-shaped shape, and has an inner leg portion 2 radially inward (right side in FIG. 5).
, a central leg 3 that is radially outward (to the left in FIG. 5) of the inner leg 2, and an outer leg 4 that is radially outward of the central leg 3. A coil 15 is provided around the central leg 3.

An upper yoke 5 is provided above the sweetener 1 in FIG.
This upper yoke 5 includes side yokes 6 which are respectively magnetically coupled to the outer legs 4 of each yoke 1 . A permanent magnet 7 is fixed to the lower surface of the upper yoke 5 in FIG. 5 with an adhesive or the like. On the lower surface of the permanent magnet 7 in FIG.
The magnetic pole pieces 8 are respectively fixed in correspondence with the above.

An amatia 9 is provided between the yoke 1 and the pole piece 8. One end of the amatia 9 comes into contact with the upper magnetic pole surface of the central leg 3 of the yoke 1 in FIG. 5, and the amathea 9 is provided so as to be able to be angularly displaced about this abutment part as a fulcrum. An adjustment spring 1O is provided near the other end of the amachia 9 to bias the amachia 9 downward in FIG. The print wire 11 driven by the amatia 9 includes a head 12 . A return spring 14 is provided between the guide member 13 through which the printing wire 11 is inserted and the head 12 of the printing wire 11, which urges the printing wire 11 upward in FIG.

When the yoke 1 is not energized, the magnetic flux from the permanent magnet 7 flows in the directions indicated by arrows A and B. At this time, the amachia 9 is attracted and fixed to the lower first magnetic pole surface 8a of the magnetic pole piece 8 in FIG. Further, the head 2 of the printing wire 11 is pressed upward in FIG. 5 by the spring force of the return spring 14, and is in contact with the lower surface of the amatia 9 in FIG.

When the coil 15 is energized and the yoke 1 is excited, the arrow C
, D, E and arrows C, F are generated. The magnetic flux flows indicated by arrows C, D, and E are
The flow of magnetic flux from the permanent magnet 7 is canceled out, and the attractive force acting on the amatia 9 by the permanent magnet 7 is extremely reduced.

Furthermore, the magnetic flux flows indicated by arrows C and F generate an attractive force against the amatia 9 due to the second magnetic pole orientation 2a of the inner leg portion 2 of the yoke 1. Amathia 9 is therefore medial leg 3
Using part #a as a fulcrum, angular displacement is made clockwise in Fig. 5. The amatia 9 angularly displaced in this way presses the head 12 of the printing wire 11 downward in FIG. 5, and in this way the printing operation is performed.

The current in the coil 15 is deenergized after a predetermined time has elapsed after the Amathia 9 starts its angular displacement.

When the angular displacement of the amatia 9 becomes maximum, the amathea 9 is in the state shown by the imaginary line 100.

Then, due to the attractive force of the permanent magnet 7, the amachia 9 returns to the state shown by the solid line in FIG.

As described above, the dot printer head continues the printing operation.

Here, when the amachia 9 performs the above-mentioned return operation, since the amachia 9 and the printing wire 11 return at a fast speed E, the amachia 9 and the head 12 of the printing wire 11 are fast in the returning operation. separated, and then the head 1
2 collides with Amathia 9. Due to the impact of this collision,
There is a problem in that the printing wire 11 bounces downward in FIG. 5 and performs unnecessary printing as shown in FIG. 6. When the spring force of the adjustment spring 10 in FIG. 5 is changed, Amathia 9's ability to return will also change. Figure 6 (2) - Figure 6 (
4) shows the state of displacement of the printing wire 11 when the spring force is 120 g, 140 g, and 160 g, respectively. As shown in FIG. 6, the above-described bounce of the printing wire 11 could be varied by changing the spring force of the adjustment spring 10, but could not be eliminated.

OBJECTS It is an object of the present invention to solve the above-mentioned technical problems and to provide an improved dot printer head with reliable printing wire operation.

Embodiment FIG. 1 shows a dot printer head 20 according to an embodiment of the present invention.
FIG. @Figure 2 is l! FIG. 2 is a plan view showing a partial cross section of the dot printer head 20, including a portion shown in FIG. FIG. 3 is an exploded perspective view of the vicinity of the stop member of the dot printer head 20. Figure 4 is Figure 9 for explaining the operating state of the dot printer head 20. 1st
The dot printer 20 will be explained using FIGS. Yokes 21 having a substantially E-shape are arranged at equal intervals along the circumferential direction of the axis H of the dot printer head.

The yoke 21 has an inner leg 22 that is radially inward with respect to the axis +11HK, and a central leg 2 that is radially outward from the inner leg 22.
3, and an outer leg 24 radially outward from the central leg 23.
including. A coil 25 is provided around the central leg 23.

An upper yoke 26 is provided above the yoke 21 in FIG. Upper yoke 26 includes a side yoke 27 that corresponds to each yoke 21 and is magnetically coupled to an outer leg of each yoke 26 .

An annular permanent magnet 28 is fixedly provided on the lower surface of the upper moon 26 in FIG. 2 with respect to the axis H. An annular magnetic pole piece 29 concentric with the permanent magnet 28 is fixedly provided on the lower surface of the permanent magnet 28 in FIG.

An amatia 30 is provided between the pole piece 29 and the yoke 21. One end of the amatia 3o is in contact with the first magnetic pole surface 23a of the central leg 23 of the yoke 21, and the corner end 30b is
It is provided as a fulcrum so that it can be angularly displaced. A cut surface of the amachia 3o taken by a plane parallel to the radial direction is as shown in the first figure, and a busy difference portion 30c is provided on the lower surface of the first figure. This stepped portion 30c is the corner end portion 30 of the amatia 3o.
When the angular displacement with b as the fulcrum exceeds a predetermined degree, the center leg 23 comes into contact with one end of the corner end 30b.
is released from the central leg 23.

At this time, the amachia 30 is angularly displaced using the aforesaid abutting portion of the stepped portion 30c as a fulcrum, but at the time of its return, as will be described later, the angular acceleration due to the attractive force from the permanent magnet 28 acting on the amachia 3o is This is larger than when the corner end 30b is used as the fulcrum. Therefore, even if the amount of angular displacement of the amachia 30 becomes large, the angular acceleration of the amachia 30 at the time of return can be increased as described above, so that the return time can be shortened.

The amatia 30 extends radially inwardly of the dot printer head 20 and is provided with an adjustment spring 31 for biasing the other end downwardly in FIG. The spring force of the adjustment spring 31 is regulated by the adjustment screw 32. The adjustment spring 31 comes into contact with the amatia 30 by its head 31aK, and the amacia 3o
is urged downward in FIG.

A printing wire 33 is provided in the circumferential direction of the axis @H corresponding to each amatia 30. A head 34 is provided at the base end of the printing wire 33 (the upper end in FIG. 2). A return spring 35 that urges the head 34 upward in FIG.
It is provided at the bottom of the figure.

The head portion 34 includes a convex portion 35 and seven rung portions 36 that are continuously provided at the base end of one convex portion 35 . dot printer 2
0, the convex portion 35 of the head 34 of the printing wire 33
is inserted into the through hole 38 of the stop member 37. In the head 34 that has been fitted with the through hole 3gK in this way, its 7 rungs 36 are
The stop member 37 is stopped by coming into contact with the edge of the through hole 38 of the stop member 37 to form a gap TR between the head 34 and the amatia 30. The stop member 37 will be explained with reference to FIG. 3. Stop member 3
7 includes a bottomed cylindrical storage section 39 in which a plurality of printing wires 33 are stored, and a seven-rung section 40 that is continuously provided at the lower end of the storage section 39 in FIG. The aforementioned through holes 38 are provided in the bottom portion 41 of the storage portion 39 in a number corresponding to the number of printing wires 33 at equal intervals along a substantially arcuate line.

The lower surface of the bottom portion 41 in FIG. 3 is provided with an elastic body 42 made of an elastic material such as rubber. The aforementioned through hole 38 is provided to penetrate this elastic body 42. The seventh rung section 40 is placed on the upper surface of the guide member 44 (see FIG. 2) in FIG.
5 by a screw (not shown) screwed into the guide member 44.
Fixed.

Between the guide member 44 and the head 34 of the printing wire 33,
Return spring 4 that urges the printing wire 33 upward in FIG.
6 is provided.

The printing wheel 33 has a guide member 440 and a guide hole 44a.

and the guide hole 47a1 of the guide member 47 and the main guide body 4
8 guide hole 48a1, each guide hole 49a, 50a, 51as of guide member 49°50.51, and main guide body 48
are inserted through the guide holes 48b in this order. The printing wire 33 inserted through the guide hole 48b projects below the dot printer head 20 in FIG. 2 and hits the paper 54 on the platen 53 via the ribbon 52. The printing operation is performed in this way.

The operating state of the dot printer rad 20 having the above configuration will be explained with reference to FIGS. 1 to 4. When the yoke 21 is not energized, the magnetic flux from the permanent magnet 28 flows in the directions indicated by arrows I and J, and the amatia 30 is connected to the magnetic pole piece 2.
The first magnetic pole surface 29aK of No. 9 is attracted and fixed. At this time, a gap TR having a predetermined width is provided between the radially inward abutment @ 30 a of the amatia 30 and the head 35 of the printing wire 33 as described above.

When the coil 25 is energized and the yoke 21 is excited, the magnetic flux generated from the yoke 21 is as shown by the arrow K.

L, M and the arrows flow in the direction indicated by N.

As shown by the arrow, the magnetic flux from the permanent magnet 2B is canceled by the magnetic flux in the L and N directions, and the permanent magnet 28
The suction force acting on the is deenergized. Also, as shown by the arrow, the magnetic flux in the N direction causes the amatia 30 to be moved to the inner leg 2 of the yoke 21.
An attractive force is generated to attract the second magnetic pole surface 22a of the second magnetic pole.

As described above, the amatia 30 is angularly displaced clockwise using the corner end 30b of the amacia 30 as a fulcrum, and becomes in the state shown by the imaginary line 101 in FIG.

At this time, the contact @ 30 a of the Amachia 300 collides with the head 34 of the printing wire 33 and further presses the head 34 and the printing wire 33 downward. The tip of the printing wire 33 (
(lower end in FIG. 2) is connected to the platen 5 via the ribbon 52.
The paper 54 on the paper 3 is struck, and the printing operation is performed in this manner.

Time tl (just before the displacement amount of the printing wire 33 becomes maximum
4), the current in coil 25 is deenergized. Therefore, the magnetic flux generated from the yoke 21 is eliminated, and the attraction force that attracts the amadea 30 toward the inner leg portion 22 is deenergized. Also, the above-mentioned attractive force to Amachia 3° generated by the permanent magnet 28 is generated again. Therefore, the amatia 30 is angularly displaced counterclockwise about the corner end 30b mentioned above as a fulcrum, and returns to the state shown by the solid line in FIG.

At this time, the speed at which the amachia 30 returns is determined by the speed at which the printing wire 3
3, the contact portion 30a of the amatia 30 returns away from the head 34 of the printing wire 33. In addition, the printing wire 33 under the return operation has the flange portion 36 of the head 34 elastically locked by the elastic body 42, and the empty MT between the head 34 of the printing wire 33 and the amatia 30.
R is formed and retained.

The printing operation continues by repeating the above series of operations. At this time, before the head 34 of the printing wire 33 collides with the amatia 30 during its return radius, it is stopped by the stop member 37 so as to pass one gap TR as described above. Further, the head 34 of the printing wire 33 is elastically locked by the elastic body 42 provided on the stop member 37 as described above. In this way, it was possible to prevent the head 34 of the printing wire 33 from colliding with the amatia 30 and causing a double-strike operation due to its rebound.

Effects According to the present invention as described above, since a gap is provided between the printing wire and the amatia when they are at rest, unnecessary movement of the printing wire due to collision between the printing wire and the amatia is eliminated. However, the printing operation of the printing wire could be made much more reliable.

[Brief explanation of drawings]

FIG. 1 shows a dot printer head 20 according to an embodiment of the present invention.
FIG. 2 is a plan view showing an 18-section cross section of the dot printer head 20 including the structure shown in FIG. 1, FIG. 3 is an exploded perspective view of the structure related to the stop member 37, and FIG. FIG. 5 is a cross-sectional view of a portion of the prior art dot printer head corresponding to FIG. This is a diagram for

Claims (1)

[Scope of Claim] A dot printer head in which the amatia is driven by electromagnetic force, and the head of the printing wire is displaced in the longitudinal direction of the printing wire by the displacement of the amatia. A dot printer head characterized in that a gap is formed between the head of the printing wire and the amatia when the head is at rest.