JPS6190402A - Manufacture of yoke for dot printer and material for yoke - Google Patents

Abstract

PURPOSE:To obtain the good productivity with high accuracy by eliminating a mutually magnetic interference between yoke pieces by cutting a junction part of the yoke pieces after fixing them to a base plate with keeping the pieces conjuncted. CONSTITUTION:Yoke pieces 11 corresponding to each printing wire 7 include a pair of legs 23 and 13, and a linking part 14 for linking said legs with a basic end. The linking part 14 of the yoke pieces 11 of yoke material 40 which is formed by a precision investment casting by use of silicon steel is fixed to a base plate consisting of non-magnetic material by caulking and etc. Nextly an attaching plane 17 of the leg 13 of the yoke piece 11, a peripheral part 37, and a surface 48 of an extending part 47 are planed and polished so that these are present on one plane. As the yoke pieces 11 are conjuncted unitarily by a junction part 39, a surface treatment is easy and those are not detached from the base plate 15 during the treatment thereby improving a productivity and an accuracy in positioning. When the junction part 39 of the yoke material 40 and the extending part 41 are cut, the yoke pieces 11 are divided individually and the mutually magnetic interference can be prevented.

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a yoke used in a dot printer in which a printing wire is driven by electromagnetic force, and a yoke material used for manufacturing the yoke.

BACKGROUND ART Conventionally, yoke pieces for generating electromagnetic force in each printing wire used in a dot printer have been configured to be connected in the circumferential direction and left as an integral part. Therefore, in one case, one of the coils being wound is excited to drive the printing wire, and in the other case, in order to drive multiple printing wires, the coils corresponding to those printing wires are excited all at once. , the opening of the printing wire during operation and the printing speed are different, resulting in a problem that the quality of printing varies. this is,
Because the yoke pieces are connected in the circumferential direction, magnetic interference occurs between each yoke piece.

Another prior art approach to solving this problem involves manufacturing each yoke piece individually and mounting them on a base plate made of non-magnetic material. This makes it possible to eliminate magnetic interference between the yoke pieces. In such prior art, when the yoke pieces are individually fixed to the base plate by a method such as caulking, the fixing strength varies and the positioning accuracy of the yoke pieces decreases. Furthermore, after the yoke pieces have been installed on the base plate, when polishing them to make the height of all yoke pieces constant, the yoke pieces whose attachment strength to the base plate is weak may come off from the base plate. occurs.

Purpose An object of the present invention is to eliminate magnetic interference between yoke pieces;
Moreover, it is an object of the present invention to provide a method for manufacturing a yoke for a dot printer with high precision and excellent productivity, and a yoke material used in the manufacturing method.

Embodiment FIG. 1 is a sectional view of one embodiment of the present invention, and FIG.
FIG. 1 is a left side view of the dot printer shown in FIG. In the dot printer, a flat second housing 2 is fixed to a cap-shaped first housing 1, and a 7-piece 3 is fixed to this second housing 2.

FIG. 3 is an exploded perspective view of the vicinity of No.

The guide members 4, -,! l+t-6 is inserted. In these guide members 4.5.6, the printing wires 7 pass through a plurality of (ffi)
For example, 2441 guide holes 8, 9, and 10 are formed.

A yoke piece 11 individually corresponding to each printing wire 7 in the first housing 1 has a pair of legs, parts 12 and 13.
and a connection g1 connecting the base ends of these legs 12.13.
The vicinity of the connecting portion 14 of the yoke piece 11, including 4, is fixed to the base plate 15 made of a non-magnetic material such as aluminum 9 by a method such as caulking.

FIG. 4 is a plan view of the base plate 15.

FIG. 5 is a sectional view taken along the section line ■--■ in FIG. 4. A mounting hole 16 corresponding to each yoke piece 11 is formed in the base plate 15.
The connecting portion 14 of the yoke piece 11 is fitted.

Mounting surface 17 of the leg portion 13 on the radially outer side of the yoke piece 11
% A flat annular permanent magnet piece 18, a magnetic flux collecting plate 19 made of a ferromagnetic material and formed into a flat annular shape, and a flat annular magnetic plate made of a ferromagnetic material provided on the magnetic collecting plate 19. spacers 20 are arranged. An auxiliary yoke 21 is arranged on the spacer 20.

FIG. 6 is a plan view of a portion of the auxiliary yoke 21. FIG. Seven gussets 723 are arranged in the notches 11i22 formed at intervals in the circumferential direction in the auxiliary seek 21. 77-chi 723 is a leg that faces the magnetic pole surface 24 of the leg 12 on the radially inward side of the yoke piece 21, and has an internal screw hole 25 carved in the vicinity of the radially outer peripheral edge of the auxiliary yoke 22. A coil 26 is wound around the portion 12 . The permanent magnet piece 18 is magnetized in the kf and V directions of the leg portion 13, that is, in the left-right direction in FIG. A leaf spring 28 is arranged on the auxiliary yoke 21. This leaf spring 28 includes a spring [29] corresponding to each printing wire 7, and a mounting n3 that connects these spring parts 29.
As shown in FIG. 7, the armature 23 is fixed to the spring portion 29 including the armature 23 by spot welding or the like. An arm member 32 is brazed and fixed to this armature 23, and a printing wire 7 is brazed and attached 12i1 to the end of the arm member 32. The arm member 32 has through holes spaced apart from each other in its longitudinal direction to reduce weight and enable high-speed printing.

The mounting Hso of the leaf spring 28 comes into contact with the bone pressing member 33. The pin 34 is inserted through the hole 35 of the second housing 2, the pressing member 33, and the leaf spring 28, and is hinged to the inner L hole 25 of the auxiliary yoke 21.

FIG. 8 is a perspective view of a part of the seek material 40 showing a state in which the yoke pieces 11 are connected at intervals in the circumferential direction by the connecting portions 9, and FIG. 9 is a plan view of the yoke material 40. 10 is a sectional view taken along the cutting plane line XX in FIG. 9, and FIG. 11 is a bottom view of the yoke material 40. A process for fixing and manufacturing the yoke piece 11 to the base plate 15 will be described with reference to these drawings.

As a first step, first, the yoke material 40 is 3% by weight.
Precision 'v!' using silicon steel containing Si by the so-called lost wax method be left behind. The outer peripheral portion 37 of the yoke piece 11 is connected to the extension portion 81 on the radially outward side, and the extension portion 41 is connected to the connection portion 39. A rib 43 is formed along the direction in which the other legs 1113 extend on the radially outer surface 13p of the zero leg portion 13 with an opening 42 interposed between the yoke pieces 11 that are in S contact with each other. An internal threaded hole 44 is formed near the leg portion 13 in the connecting portion 14 of the nine-piece 11, which is useful for improving the strength when the lip 43 is press-fitted into the mounting hole 16 of the base plate 15. .

In step tjS2, as shown in FIGS. 12-13, the connecting portion 14 in the yoke piece 11 of the yoke collected material 40 is fixed to the base plate 15. For this fixing, the connecting portion 14 is press-fitted into the mounting hole 16 and caulked as described above.
A cross-sectional view taken along the cutting plane line x m-x and m in FIG. 2 is shown in FIG. 13, and FIG. 14 is a bottom view thereof. The yoke pieces 11 are integrally shaped 8. The yoke material 40 can be fixed to the base plate 15 all at once. Therefore, it is easy to equalize the caulking force when fixing the yoke piece 11 to the base plate 15, and the fixing strength can be improved. Further, each yoke piece 11 can be fixed to the base plate 15 in an accurate posture, and positioning accuracy can be improved.

In another embodiment, after the yoke material 40 is manufactured in the first step described above, the base plate 15 is manufactured in the f@2 step.
The yoke material 40 may be attached to a mold for forming the yoke material, and the base plate may be molded using synthetic resin with the base plate attached to the yoke material.

As a third step, the mounting surface 17 of the leg 13, the outer peripheral part 37, and the surface 48 of the extension part 47 of the yoke piece 11 are treated with a new agent or polished.
be in one plane. Since the yoke pieces 11 are integrally connected by the connecting parts 3 and 9, it is easy to process the surface 48 so that it lies within one plane, and the yoke pieces 11 can be easily removed from the base plate 15 during this process. There is no risk of it being put away, thus increasing productivity.

In the fourth step of the St manufacturing process, Figs. 15 to 17
Referring to the figure, the connecting portion 39 and the retaining portion 41 of the yoke material 40 are cut. FIG. 15 is a plan view showing the state in which the yoke material 40 is fixed to the base plate 15, and the first
6 is a sectional view taken along the section line XVI-XVI in FIG. 15, and FIG. 17 is a bottom view thereof. The shaded areas in FIGS. 15 and 17 indicate the portions to be cut and removed. In this way, each yoke piece 11 is individually separated, and mutual magnetic interference is prevented.

As a fifth step, as shown in FIGS. 18 to 20, the permanent magnet pieces 18 and the magnetic flux collecting plate 19 are fixed to the individual yoke pieces 11 using adhesive in common. In this way, the yoke piece 11, the base plate 15, the permanent magnet piece 18, and the magnetic flux collecting plate 19 constitute a yoke block 50. 1st
FIG. 8 is a plan view of this yoke block 50, and the 19th
The figure is a sectional view taken from the section line XI-XIX in FIG. 18, and FIG. 20 is a bottom view of the yoke block 50. As clearly shown in FIG. A positioning hole 51 into which a positioning pin fits is bored.

In addition, as another embodiment of the present invention, the permanent magnet piece 18 and the magnetic collector plate 19 are removed prior to the fourth step of cutting as described above.
The fifth step for fixing may be performed first.

As a sixth step, the surface 52 of the magnetic flux collecting plate 19 is polished so that it becomes one plane. On this surface 52 spacers 20 are arranged.

FIG. 21 is a needle view 1 of a part of a yoke piece 40a according to another embodiment of the present invention, and FIG. tA22 is a perspective view of a part of the yoke piece 40a shown in FIG. . This embodiment is similar to the previous embodiment, corresponding parts are indicated by the same reference numerals with the suffix a, and the yoke piece 11a has the following:
Leg portions 12a+13a and connecting portion 14m connecting them
The outer circumferential portion 37a is continuous with the 1# portion 13a. Reference mark in the thickness direction of this outer peripheral portion 37a! A connecting portion 3911 is formed over the thickness indicated by 1.

tPJ23 is a plan view of such a yoke piece 40m, and FIG. 24 is a cross section 1xxrv-XXIV of FIG. 23.
FIG. 25 is a sectional view of this yoke material 40.
FIG. As step 1a of the manufacturing process, the yoke material 40a shown in FIGS. 21 to 25 described above is
Prepare.

In step 2a, the yoke material 40a shown in FIGS. 21 to 25 is press-fitted into the base plate 15 and fixed by caulking. The plane in which the yoke material 40n and the base plate 15 are fixed in this way is shown in FIG. 26, and FIG.
28 is a sectional view as seen from (2), and FIG. 28 is a bottom view thereof. In this manner, the yoke pieces 11a are fixed to the base plate 15 while being interconnected by the connecting portions 39a.

In step 3a, the connecting portion 39a is cut with stone,
Further, the outer peripheral portion 37a is ground to obtain the state shown in FIGS. 29 to 31. FIG. 29 is a plan view showing the state after grinding, FIG. 30 is a sectional view taken along the section line XXX-XXX in FIG. 29'), and FIG. tA31 is a bottom view thereof. The amount of polishing is the thickness of the connecting part 39m! The amount is slightly larger than 1, thereby removing the connecting portion 39@ and making it possible for the surface 48m of the outer peripheral portion 37a to lie within one plane in each yoke piece 11m. Thereafter, the permanent magnet 18 and the magnetic collector plate 19 are attached as in the previous embodiment. A yoke block 50 having the following configuration is constructed.

Effects According to the present invention as described above, the yoke pieces are continuous in the circumferential direction via the connecting portions, and the yoke pieces are fixed to the base plate in a connected state, and then,
Since the connecting portions are removed, the yoke pieces do not cause magnetic interference with each other, so that the operating time and operating speed of the printing wire are constant, and printing quality can be improved. Since the yoke pieces are fixed to the base plate in a connected state, it is possible to stator each of the yoke pieces to the base plate with constant strength without variation, and the positioning accuracy of the yoke pieces is improved. Furthermore, the problem of the yoke pieces being individually separated from the base plate when the connecting portions are cut out can be avoided. In this way productivity is improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. tA2 is a left side view of the dot printer shown in FIG. A plan view, FIG. 5 is a sectional view taken along the cutting plane line ■-■ in FIG. 4, FIG. 6 is a plan view of a part of the auxiliary yoke 21, and FIG. FIG. 8 is a perspective view of a part of the yoke material 40, FIG. 9 is a plan view of the yoke material 40, and FIG. 11 is a bottom view of the yoke material 40, and FIG. 12 is a plan view showing the state in which the yoke material 40 is fixed to the base plate 15, PA1
Figure 3 is a cross-sectional view taken from the section line xw-xm in Figure 12;
14 is a bottom view of the yoke material 40 and base plate 15 shown in FIGS. 12 and 13, FIG. 15 is a plan view showing the cut portion 41 of the yoke material 40 fixed to the base plate 15, and FIG. Figure 16 is the 15th
A sectional view taken from the section line XVI-XVI in the figure, FIG. 17 is the yoke material 41 shown in FIG. PA15 and FIG. 16.
FIG. 18 is a plan view of the yoke block 50, FIG. 19 is a sectional view taken along the section line XIX-XIX in FIG. 18, and FIG. is a bottom view of the yoke block 50, FIG. 21 is a perspective view of a portion of a yoke 40a according to another embodiment of the present invention, and FIG. 22 is a view of the yoke material 4 shown in FIG.
23 is a plan view of 40g of yoke material, FIG. 24 is a cross-sectional view taken from the cutting plane line xxrv-xx■ of ttS23 diagram, and FIG. 25 is a yoke collection material. 40m bottom view, FIG. 26 is a plan view showing the state in which the seek material 40a is fixed to the base plate 15, FIG. 27 is a sectional view taken from the cut plane ixx■-xX■ in FIG. 26,
Fig. 28 is a bottom view of the yoke material 40m shown in Figs. 26 and 27 fixed to the base plate 15, and Fig. 29 shows the yoke material 40m fixed to the base plate 15 and the joint portion 39m is ground. A plan view showing the state in which the
31 is a sectional view taken from x-xxx, where the yoke piece 11a in FIGS. 29 and 30 is the base plate 15
FIG.

Claims (2)

[Claims] (1) Prepare a yoke material in which yoke pieces including a plurality of legs and connecting parts that connect the proximal ends of these legs are connected via connecting parts at intervals in the circumferential direction, and this yoke piece A method for manufacturing a yoke for a dot printer, comprising: fixing the connecting portion to a positioning base plate; and then cutting off the connecting portion. (2) For manufacturing a yoke for fixing a yoke piece to a base plate at intervals in the circumferential direction, the yoke piece includes a plurality of legs and a connection part that connects the proximal ends of these legs. A yoke material for a dot printer, characterized in that the yoke material is constructed by connecting a plurality of yoke pieces in the circumferential direction at joints to be cut out.