JPH106538A - Wire dot printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the welding strength of a wire with an armature and make the processing of the armature easy. SOLUTION: An end face pressing piece 37 being brought into contact with a rear end face 9a of a wire 9 and a rear end face 8b of an armature 8 and a metal reinforcing component 3b including a side face pressing piece 38 being brought into contact with both side faces 8C of the armature 8 and an encircling section 39 encircling the wire 9 in the three directions and formed integrally are provided, and the reinforcing component 36, the wire 9 and the armature 8 are bonded together by welding. The welding strength of the armature 8 with the wire 9 is enhanced by the arrangement. The processing of the armature 8 is easy as a channel for passing through the wire 9 or a through-hole is not required to be formed on the free end 8a side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a wire dot printer head.

[0002]

2. Description of the Related Art Conventionally, a plurality of cores around which a coil is wound are arranged in an annular shape, and an armature having a rear end portion of a wire welded thereto is supported on the end surface of each core so as to be able to undulate freely.
Displace the armature by exciting the coil,
There is a wire dot printer head in which a wire is projected toward a platen.

[0003] Here, a conventional connection structure between an armature and a wire will be described. FIG. 6 shows an example in which a wire 102 is brazed to a free end of an armature 101. FIG. 7 shows an example in which a wire 102 is brazed to a groove 103 formed at a free end of an armature 101. FIG.
A through hole 104 near the free end of the armature 101
In this example, a wire 102 is inserted into the through hole 104 and brazed.

[0004]

Here, the arrangement of the wires will be described with reference to FIG. In the figure, white circles indicate the arrangement of the rear ends of the wires welded to the free ends of the armature, and black circles indicate the arrangement of the front ends of the wires aligned by the wire guide. The dotted line shows the curved path of the wire. In such a wire arrangement, the armature is located outside the white circle. Therefore, since the wire bends in the longitudinal direction of the armature, the bending moment in the A and B directions acts on the wire 102 most, as shown in FIGS. Also, armature 101
Are arranged radially from the outside of the ring toward the center like petals, so that the armature 10
1 does not always match the bending direction of the wire 102 (see the dotted line in FIG. 3). In this case, bending moments in the C and D directions also act on the wire.

However, in the example shown in FIG. 6, since the wire 102 is supported by only one end of the armature 101, the wire 102 is weak against bending moments in the A, C, and D directions, and the brazed portion is easily peeled off. In the example shown in FIG. 7, since the wire 102 is supported by the three surfaces of the groove 103, the bending moment in the B, C, and D directions is strong, but the bending moment in the A direction is weak. In the example shown in FIG. 8, since the entire circumference of the wire 102 is supported by the inner surface of the through hole 104, the strength is strong, but the brazing work after inserting the wire 102 into the through hole 104 is difficult.

Further, when the armatures 101 are radially arranged, the arrangement interval on the free end side to which the wire 102 is welded becomes narrower, so that the shape of the armature 101 becomes thinner toward the free end side. Wire 10
When the groove 103 (FIG. 7) and the through hole 104 (FIG. 8) through which the groove 2 passes are formed, the wall thickness around the groove 103 and the through hole 104 becomes thin, and it is difficult to process the armature 101. Groove 103
When the width around the free end side of the armature 101 is increased when the thickness around the through hole 104 is allowed, the arrangement area of the armature 101 must be increased. As a result, the outer diameter of the wire dot printer head increases.

[0007]

According to a first aspect of the present invention, there is provided a wire dot printer head which presses an end surface of the armature on a rear end surface opposite to a printing direction of a wire and a rear end surface of the armature on an extended surface of the rear end surface. And a metal reinforcing member formed integrally with a surrounding portion surrounding the wire from three directions including side pressing pieces abutting on both side surfaces of the armature, the reinforcing member, the wire and The armature is connected by welding. Therefore, the wire is welded to the reinforcing member and the armature in a state where the entire circumference is supported by the free end of the armature and the surrounding portion of the reinforcing member, and the rear end face in the direction opposite to the printing direction is supported by the end face pressing piece. Is done.

According to a second aspect of the present invention, in the wire dot printer head according to the first aspect, an opposing interval between the opposing side pressing pieces is slightly smaller than a width dimension of the armature at a portion where the side pressing pieces abut. Specified at intervals. Therefore, when the armature is inserted between the side pressing pieces of the surrounding portion that surrounds the outer periphery of the wire from three sides, the relative position between the reinforcing member and the armature is determined by the holding force of the side pressing pieces, and the welding work is performed in that state. Can be performed.

According to a third aspect of the present invention, in the wire dot printer head according to the first or second aspect, the end surface pressing piece and the surrounding portion are formed by a narrow piece which contacts the wire with a narrow width facing the free end of the armature. They are continuously formed integrally at predetermined intervals. Therefore, in a portion where the strip of the reinforcing member and the free end of the armature are opposed to each other, the periphery of the wire is widely opened, so that the welding material easily enters between the strip and the wire, and between the wire and the armature. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, the overall structure of the wire dot printer head will be described with reference to FIGS. FIG. 4 is a vertical side view, and FIG. 5 is an exploded perspective view showing a mounting relationship of main parts. In the drawing, reference numeral 1 denotes a mounting member fixed to a carrier (not shown) of the printer, and 2 denotes a container-shaped front cover having one end opened. An armature guide 4 that contacts the bottom surface of the front cover 2 is integrally formed at one end of the wire guide 3 protruding from the bottom of the front cover 2. The armature guide 4 has a plurality of guide pins 5 and projections 4a for guiding both sides of the armature 8, and an armature spring 6 and a fulcrum holding spring 7 are provided inside and outside the guide pins 5. Arranged and held. A plurality of wires 9 fixed to the inner end of the armature 8 are slidably held by a plurality of guide chips 10 fixed to the wire guide 3. Further, a plurality of stopper receivers 11 are fitted into the armature guide 4. The armature 8 is inserted into the guide pin 5 while inserting the wire 9 through the guide chip 10 and between the protruding pieces 4a. The armature 8 is formed of the bottom surface of the front cover 2, the stopper receiver 11, and a non-magnetic material. An armature block 15 is formed by laminating the film 12 and the armature stopper 13 and connecting them with screws 14.

As shown in FIG. 5, the armature guide 4 has a plurality of notches 1 fitted with a stopper receiver 11.
6 are formed and a plurality of pins 17 are erected. A plurality of positioning holes 18 to be fitted with these pins 17 are formed in the front cover 2. Also,
The arrangement of the wires 9 is as described above with reference to FIG.

Next, a plurality of cores 20 each having the coil 19 mounted thereon and a yoke 21 are integrally formed.
Then, the yoke 21, the ring-shaped spacer 22, the substrate 23 to which the coil 19 is electrically connected, and the container-shaped housing 24 are stacked and connected by a plurality of screws 25 to form a yoke block 26. Are formed. The housing 24 includes a cylindrical wall 27 that extends along the arrangement direction of the coils 19 and surrounds the outside near the coils 19 and the periphery of the substrate 23, and a bottom wall 28 that extends along the back surface of the substrate 23.
And a plurality of fins 29 integrally formed of a metal material having high thermal conductivity.

A connector 30 connected to an external circuit is connected to the board 23. The yoke 21 has a cylindrical portion 21a facing the inside of the core 20 arranged in an annular shape, and a disk portion 21b forming the bottom of the cylindrical portion 21a. An opening 31 for projecting the connector 30 and a projection 32 projecting toward the yoke 21 are formed on the bottom wall 28 of the housing 24.
Are formed. A fitting hole 33 having the same size and shape as the protrusion 32 is formed in the substrate 23 and the spacer 22. The spacer 22 has an elongated hole 34 for drawing out the lead wire of the coil 19 and connecting it to the substrate 23. The contact surface 21c, which is the end surface of the disk portion 21b of the yoke 21, is in contact with the contact surface 32a, which is the end surface of the projection 32 of the housing 24, with a large area.

The armature block 15 and the yoke 21 are screwed into the yoke 21 by screwing a plurality of screws 35 passing through the mounting member 1, the front cover 2, the film 12, and the stopper receiver 11. Block 26 and the wire dot printer head P
H is completed. In this state, the inner surface of the armature 8 is opposed to the end surface of the core 20, and the cylindrical portion 21 a of the yoke 21 is pressed by the pressure of the fulcrum pressing spring 7.
Are supported via the film 12 so as to be able to undulate.

Next, the operation will be described. Coil 19
When the armature 8 is excited, the armature 8 is attracted to the end face of the core 20, and the wire 9 collides with the paper on the platen via an ink ribbon (not shown), thereby performing printing. When the power supply to the coil 19 is interrupted, the armature 8 returns by the urging force of the armature spring 6 and the return position is determined by the armature stopper 13.

Here, a connection structure between the armature 8 and the wire 9 will be described with reference to FIGS. The portion of the armature 8 facing the core 20 is widest and narrower toward the free end. The width of the free end is set to a value substantially equal to the diameter of the wire 9.

Then, the reinforcing member 36 formed of a metal plate, the armature 8 and the wire 9 are brazed (welded).
Have been. That is, the reinforcing member 36 includes a rear end surface 9a on the opposite side to the printing direction of the wire 9 and an end surface pressing piece 37 contacting the rear end surface 8b of the armature 8 on an extension of the rear end surface 9a, and both side surfaces of the armature 8. A surrounding portion 39 including a pair of side pressing pieces 38 abutting on the outer surface of the wire 9 in three directions, and a free end 8 of the armature 8
a small piece 4 which abuts on the wire 9 with a narrow width opposite to a.
0 are integrally provided. In this case, the end face pressing piece 37 and the surrounding portion 39 are arranged at a predetermined interval, but are continued by the strip 40. The distance between the pair of side pressing pieces 38 is set to be slightly smaller than the width of the armature 8 at the portion where the side pressing pieces 38 contact.

Armature 8, wire 9, and reinforcing member 36
When welding is performed, the wire 9 is passed through the surrounding portion 39 so that the rear end face 9 a is brought into contact with the end face pressing piece 37. Subsequently, while maintaining the state, the end face pressing piece 37 is moved to the armature 8.
The armature 8 is pushed between the pair of side pressing pieces 38 of the surrounding portion 39, and the wire 9 is sandwiched between the strip 40 and the free end 8a of the armature 8. In this state, the armature 8 is held by the pair of side surface pressing pieces 38, so that the relative position between the armature 8 and the reinforcing member 36 is stabilized without shifting. The wire 9 has a rear end face 9a.
Are aligned with the rear end face 8 b of the armature 8 by the end face pressing piece 37. Therefore, the armature 8, the wire 9, and the reinforcing member 36 can be connected by brazing while maintaining the relative positions accurately.

In this brazed state, the entire periphery of the wire 9 is supported by the free end 8a of the armature 8 and the surrounding portion 39 of the reinforcing member 36, and the rear end face 9a in the direction opposite to the printing direction is pressed against the end face. The armature 8 is supported by the piece 37 even if it is bent in any direction.
There is no departure from. Further, in a portion where the small piece 40 located between the end face pressing piece 37 and the surrounding portion 39 and the free end 8a of the armature 8 face each other, the periphery of the wire 9 is widely opened. Between wire 9
Between the armature 8 and the brazing material. Also in this respect, the brazing strength can be increased.

Further, the armature 8 does not need to form a groove or a through hole for passing the wire 9 on the side of the free end 8a, so that the processing is easy and the width can be reduced. Since the thickness of the side pressing pieces 38 that abut on both side surfaces of the armature 8 can be reduced, the armatures 8 can be arranged in a narrow space at high density, thereby contributing to downsizing of the wire dot printer head PH. be able to.

[0021]

According to the first aspect of the present invention, the rear end face opposite to the printing direction of the wire, the end face pressing piece which contacts the rear end face of the armature on the extension of the rear end face, and both sides of the armature A metal reinforcing member integrally formed with a surrounding portion surrounding the wire from three directions including a side pressing piece abutting on a surface, and the reinforcing member, the wire and the armature are joined by welding. Therefore, the wire can be supported on the entire circumference by the free end of the armature and the surrounding portion of the reinforcing member, and the reinforcing member is supported in a state where the rear end surface in the direction opposite to the printing direction is supported by the end surface pressing piece. And can be welded to armatures. Therefore, even if the wire is bent in all directions, the armature and the wire can be maintained in an extremely high connection state. Also, the armature is easy to process because it is not necessary to form a groove or a through hole for passing a wire on the free end side, the width can be reduced, and furthermore, a side pressing piece that contacts both side surfaces of the armature can be formed. Since the plate thickness can be reduced, the armature can be arranged at high density in a narrow space, which can contribute to downsizing of the wire dot printer head.

According to the second aspect of the present invention, the opposing interval between the opposing side pressing pieces is determined to be slightly smaller than the width of the armature at a portion where these side pressing pieces abut. When an armature is inserted between the side pressing pieces of the surrounding part that surrounds the outer circumference of the
Since the relative position between the reinforcing member and the armature is determined by the holding force of the side pressing piece, the armature, the wire, and the reinforcing member can be easily welded in a stable state in which the relative positions are accurately determined.

According to the third aspect of the present invention, the end face pressing piece and the surrounding portion are integrally connected to each other at a predetermined interval by a small piece which contacts the wire with a small width in opposition to the free end of the armature. Therefore, at the portion where the strip of the reinforcing member and the free end of the armature oppose each other, the periphery of the wire is widely opened, so that the welding material can easily enter between the reinforcing member and the wire, and between the wire and the armature. can do. Thereby, welding strength can be further increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joint structure between an armature and a wire according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a reinforcing member.

FIG. 3 is an explanatory diagram showing a positional relationship between a rear end portion and a front end portion of a wire.

FIG. 4 is a vertical sectional side view showing an internal structure of the wire dot printer head.

FIG. 5 is an exploded perspective view of the wire dot printer head.

FIG. 6 is a perspective view showing a conventional coupling structure between an armature and a wire.

FIG. 7 is a perspective view showing a conventional coupling structure between an armature and a wire.

FIG. 8 is a perspective view showing a conventional coupling structure between an armature and a wire.

[Explanation of symbols]

 HP wire dot printer head 8 armature 8a free end 8b rear end face 8c side face 9 wire 9a rear end face 19 coil 20 core 36 reinforcing member 37 end face pressing piece 38 side pressing piece 39 surrounding section 40 strip

Claims (3)

[Claims] 1. A plurality of cores, each of which is wound around a coil and arranged in an annular shape, and a plurality of armatures each having a free end to which a wire is welded are opposed to each other, and the armature is displaced by exciting the coil. A wire dot printer head configured to project the wire toward a platen, wherein a rear end surface of the wire opposite to the printing direction of the wire and an end surface that contacts the rear end surface of the armature on an extension of the rear end surface. A pressing member and a metal reinforcing member formed integrally with a surrounding portion surrounding the wire from three directions including a side pressing member abutting on both side surfaces of the armature are provided, and the reinforcing member and the wire are provided. The wire dot printer head is connected to the armature by welding. 2. The device according to claim 1, wherein an interval between the opposing side pressing pieces is set to be slightly smaller than a width dimension of the armature at a portion where the side pressing pieces abut. Wire dot printer head. 3. The end face pressing piece and the surrounding portion are integrally connected to each other at a predetermined interval by a narrow piece which is in contact with the wire with a narrow width facing the free end of the armature. Item 3. A wire dot printer head according to item 1 or 2.