JPH09300672A - Wire dot printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the welding strength of a wire with an armature and make the welding work easier. SOLUTION: The width in the neighborhood of a free end of an armature 8 is set at the value almost equal or more to the diameter of a wire 9, and a closed-end channel 8d having clamping walls 8a and 8b clamping the rear end of the wire 9 on two faces in the direction crossing orthogonally the longitudinal direction of the armature 8 is formed on one face of the armature, and the rear end of the wire 8 is fitted on the channel 8d of the armature 8 and welded thereon. Even when the large bending moment along the longitudinal direction of the armature 8 is applied to the rear end of the wire 9, the rear end of the wire 9 is supported firmly by the clamping walls 8a and 8b by the arrangement. When the bending moment along the width direction of the armature 8 is applied to the rear end of the wire 9, the rear end of the wire 9 is supported securely by a welding material filled in the channel 8d. Both side ends of the channel 8d are opened to make the welding work in the channel 8d easier.

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.

Next, the contents described in JP-B-3-7510 are shown in FIGS. 9 (a) and 9 (b). According to this, a cut 106 is formed near the tip of the armature 105 made of a thin plate.
Is formed, and the rear end portion of the wire 102 is inserted into this cut 106 for brazing.

[0005]

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 only by one surface of the tip of the armature 101, it 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.
Since the entire circumference of 2 is supported, the strength is strong, but the hole 10
It is difficult to perform the brazing work after inserting the wire 102 into the wire 4.

The armature 1 shown in FIG.
Since the plate thickness of the tip of 05 is much smaller than the diameter of the wire 102, the wire 102 protrudes in the plate thickness direction of the armature 105 as shown in FIG.
It is difficult to fill the brazing material. Further, since it is difficult to secure the brazing area, the wire 10 for the armature 105 is
The brazing length of 2 must be increased. For this reason, the dimension in the printing operation direction at the tip of the armature 105 becomes large, and the wire dot printer head becomes thick.

[0008]

According to the present invention, the width of the armature near the free end is set to a value substantially equal to or larger than the diameter of the wire, and one surface near the free end of the armature has a longitudinal direction of the armature. A bottomed groove having a U-shaped cross-section with both ends open and having a holding wall for holding the rear end of the wire on two surfaces in the orthogonal direction is formed, and the rear end of the wire is The groove is fitted and welded. Therefore, even if a large bending moment along the longitudinal direction of the armature acts on the rear end portion of the wire, the wire can be firmly supported by the holding wall.
Even if a bending moment along the width direction of the armature acts on the rear end portion of the wire, the welding material filled in the groove can reliably support the wire. Further, since both ends of the groove in the width direction of the armature are open, the welding work in the groove becomes easy.

[0009]

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 is formed with a plurality of guide pins 5 and projecting pieces (not shown) for guiding both sides of the armature 8, and an armature spring 6 and a fulcrum pressing spring 7 are provided inside the guide pin 5. And is arranged and held on the outside. Also, armature 8
The plurality of wires 9 fixed to the inner end of the wire 9 are slidably held by the plurality of guide tips 10 fixed to the wire guide 3. Further, a plurality of stopper receivers 11 are fitted into the armature guide 4. Then, while inserting the wire 9 into the guide tip 10, the armature 8
Is inserted into the guide pin 5, and the bottom surface of the front cover 2, the stopper receiver 11, the film 12 made of a non-magnetic material, and the armature stopper 13 are laminated to form the screw 1
An armature block 15 is formed by connecting the armature blocks 4 together.

As shown in FIG. 5, the armature guide 4 has a plurality of notches 1 which are fitted with stopper stoppers 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 a coil 19 attached thereto 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.

Then, the plurality of screws 35 passing through the mounting member 1, the front cover 2, the film 12, and the stopper receiver 11 are screwed into the yoke 21, whereby the armature block 15 and the yoke. The block 26 is connected to 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, the connecting structure of the armature 8 and the wire 9 will be described with reference to FIGS. 1 and 2. The armature 8 has the widest portion facing the core 20 and the width becomes narrower toward the free end, but the width near the free end is set to a value substantially equal to or larger than the diameter of the wire 9. . And on one side near the free end of the armature 8,
A direction (C in FIGS. 1 and 2) orthogonal to the longitudinal direction of the armature 8 (directions A and B in FIGS. 1 and 2).
A holding wall 8 for holding the rear end of the wire 9 on two surfaces (D direction).
A bottomed groove 8d having a U-shaped cross section having a and 8b and a bottom surface 8c is formed. Both ends of the groove 8d in the width direction of the armature 8 (directions C and D in FIGS. 1 and 2) are open. The rear end of the wire 9 has a groove 8d.
And is brazed (welded).

In such a structure, since the groove 8d into which the rear end of the wire 9 is inserted is open at both side ends of the armature 8 in the width direction, it can be easily brazed and the groove 8d The brazing material (welding material) can be sufficiently filled. Further, the rear end of the wire 9 has a holding wall 8 of the groove 8d.
Since the a and 8b are in line contact with each other, the wire 9 can be brazed almost all around. In particular, since the wire 9 is supported by the holding walls 8a and 8b in a direction orthogonal to the longitudinal direction of the armature 8 (A and B directions), it can sufficiently withstand a large bending moment in the A and B directions. it can. Further, since the groove 8d is sufficiently filled with the brazing material, it is possible to sufficiently withstand the bending moment acting in the C and D directions.

Further, since the brazing material can be adhered to substantially the entire circumference of the rear end portion of the wire 9, the brazing length of the wire 9 to the armature 8 can be shortened.
That is, the length in the wire sliding direction at the tip of the armature 8 can be shortened. Therefore, it is possible to contribute to the thinning of the wire dot printer head PH.

[0018]

According to the present invention, the width of the armature near the free end is set to a value substantially equal to or larger than the diameter of the wire,
On one surface near the free end of the armature, there are two walls in a direction orthogonal to the longitudinal direction of the armature, and there is a holding wall for holding the rear end of the wire. Since the groove is formed and the rear end of the wire is fitted and welded to the groove of the armature, even if a large bending moment along the longitudinal direction of the armature acts on the rear end of the wire, The wire can be firmly supported by the holding wall. Further, even if a bending moment along the width direction of the armature acts on the rear end portion of the wire, the welding material filled in the groove can reliably support the wire. Furthermore, since both ends of the groove in the width direction of the armature are open, the welding operation in the groove can be easily performed and the welding material can be sufficiently filled in the groove.

[Brief description of 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 plan view showing a joint structure of an armature and a wire.

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.

9A and 9B are views showing a conventional joint structure of an armature and a wire, wherein FIG. 9A is a side view and FIG. 9B is a plan view.

[Explanation of symbols]

 HP Wire dot printer head 8 Armature 8a, 8b Holding wall 8d Groove 9 Wire 19 Coil 20 Core

Claims (1)

[Claims] 1. A plurality of cores each having a coil wound therein and arranged in an annular shape, and a plurality of armatures to which wires are welded at their free ends are arranged to face each other, and the coils are excited to displace the armatures. In the wire dot printer head configured to cause the wire to project toward the platen, the armature has a width in the vicinity of the free end set to a value substantially equal to or larger than the diameter of the wire, and in the vicinity of the free end of the armature. On one surface, a bottomed groove having a U-shaped cross-section with both ends open and having a holding wall that holds the rear end of the wire on two surfaces in a direction orthogonal to the longitudinal direction of the armature is formed, A wire dot printer head, wherein a rear end portion of the wire is fitted into the groove of the armature and welded.