JPS6251461A - Print head manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized in that a plurality of armature bodies, each having a printing wire fixed to its tip, press against a predetermined stopper member against the elastic force of an elastic member when inactive. When engaged, the print is held in a displaced state so that a predetermined elastic energy is stored in the elastic member, and when the print is activated, the holding is released and a printing operation is performed by the elastic energy. The present invention relates to a method of manufacturing a head, and particularly to a method of processing an armature body.

[Prior Art] Conventionally, as described in Japanese Patent Application No. 59-256251, a conventional method for manufacturing a print head of this type has been to maintain each armature in the same state as when it is not in operation, that is, with its own elasticity. The armature is held in a deformed state so that a predetermined elastic energy is stored against the force of the armature, and the engaging surface of each armature that engages with a predetermined stopper is surface-processed by electromagnetic processing. With this manufacturing method, the engaging surfaces of each armature are all formed on the same plane, so the elastic energy of each armature engaged with the stopper is the same when it is not in operation, and the printing pressure of the printing wire when it is in operation. became uniform.

[Problems to be Solved by the Invention] By the way, the engaging surface of each armature machined by electrical discharge machining has a rough surface, which causes the stopper that engages with the engaging surface to wear out, which shortens the life of the print head. decreased.

Furthermore, particles dissolved and removed during electrical discharge machining, ie, fine particles called electrical discharge splash, adhere to the side surface of the armature and the like. Since the attached discharge splash must be removed by a worker using a tool or the like, this work takes a long time, causing an increase in the manufacturing time of the print head. Furthermore,
This discharge splash enters between the engagement surface of the armature and the stopper due to the action of vibration and magnetic force when the print head is driven. As a result, the amount of wear on the stopper increased, further shortening the life of the print head.

[Object of the Invention] The present invention was made in order to solve the problems of the conventional print head manufacturing method, and its purpose is to improve the surface roughness of the engaging surface of the armature body and to reduce the discharge splash. It is an object of the present invention to provide a method for manufacturing a print head that can shorten the manufacturing time of the print head and improve the life of the print head by preventing the occurrence of the problem.

[Means for Solving the Problems] In order to solve the problems of the prior art, the present invention applies a pressing force to each armature body against the elastic force of an elastic member, so that each armature body A method is adopted in which the engagement surface of the armature body, which is held in the same state and engaged with a predetermined stopper member, is surface-processed by creep grinding.

[Function] In the present invention, the surface roughness of the engagement surface of the armature is improved by the above-mentioned means, and no discharge splash occurs, so the amount of wear of the stopper member that engages with the engagement surface is reduced; Improves print head life.

[Example] An example embodying the present invention will be described with reference to FIG.

As shown in FIG. 2, for example, the print head 10 manufactured in this embodiment has a frame 11 composed of a rear yoke 12 in the shape of a flat circular container and a front yoke 13 in the shape of a disk. A permanent magnet 14 and a spacer member 15 are interposed between the rear yoke 12 and the front yoke 13 to form an annular shape. Further, the guide body 1 has a large number of guide holes 16a arranged on the entire surface of the front yoke 13.
6 is installed.

Between the blocking yoke 13 and the spacer member 15, two gusset members 18 are screwed and arranged in a radial direction on substantially the same circumference at predetermined intervals. Each armature body 18 has a holder 19 whose base end is fixed between the front yoke 13 and the spacer member 15 with a screw 19a, and an armature with a wire arm 21 having a printing wire 22 brazed at its tip bonded. 20, and a torsion spring 23 which is brazed to the holder 19 and armature 20 and rotates the armature 20 in a direction perpendicular to its axis (left-right direction in FIG. 2) by elastic force.

A plurality of electromagnets 25 respectively corresponding to the armatures 20 have a core 26 which is protruded from the rear yoke 12 and whose tip forms a stopper member facing the engagement surface 20a of the corresponding armature 20, and a core 26 which is wound around the core 26. It is composed of an excitation coil 27 installed therein.

In such printheads, the permanent magnet 14 is always
, spacer member 15, holder 19, armature 20,
A magnetic path is formed by the core 26 and the rear yoke 12, and the armature 20 is connected to the core 26 by this magnetic path.
is adsorbed to the tip of the

As a result, the torsion spring 23 interposed between the holder 19 and the armature 20 is twisted to the left in FIG. 2, and elastic energy is stored.

Then, when a pulse voltage is applied to the excitation coil 27 of the electromagnet 25, the electromagnet 25 generates a magnetic force that cancels the magnetic force of the permanent magnet 14, and the armature 20 corresponding to this electromagnet 25 is activated by the elastic force stored in the torsion spring 23. It rotates to the right in Figure 2 due to the elastic force caused by the release of energy. The rotation of the armature 2Q causes the printing wire 22 to move to the right in FIG. 2 via the wire arm 22, thereby performing a printing operation.

FIG. 1 shows a front frame 13 of the print head 10;
Workpiece 3 consisting of guide body 16 and armature body 18
A cross-sectional view of a grinding machine jig with a 0 installed is shown. This jig main body 31 is formed into a cylindrical shape, and a protrusion 32 is provided on the upper inner surface thereof. This protrusion 3
2, the workpiece 30 is positioned such that the workpiece surface of the workpiece 30 inserted from below the jig main body 31 protrudes upward in FIG. 1 from the upper surface of the jig main body 31.

Further, two grooves 33 are provided on the inner surface of the jig main body 31 at positions facing each other, and a wire push-up plate 34 is inserted into the grooves 33 from below the jig main body 31. The wire push-up plate 34 has a rectangular plate shape, and through holes 35 are bored at both ends thereof. The wire push-up plate 34 is fixed to the jig main body 31 by a stepped screw 36 inserted through the through hole 35, and presses the printing wire 22 of the workpiece 30 upward in FIG. Maintain the same condition as when operating.

Further, the lower end of the jig main body 31 is fitted into a grinding chuck 37. This grinding chuck 37 is connected to a drive device (not shown) and is rotated at a low speed during grinding work.

A grinding wheel 40 is arranged to face the workpiece 30 mounted on the jig main body 31. This grinding wheel 40 is an elastic grinding wheel using an elastic binding material to bind abrasive grains, and its flat side 40a is designed to grind the engaging surface 20a of the armature 20, which is necessary for the processing surface. , are connected to a drive device (not shown). And grinding wheel 4
0 is rotated at high speed in the same direction as the grinding chuck 37 during grinding work.

Incidentally, the grinding process using the flat side surface 40a of the grinding wheel 40 is called creep grinding, and is a grinding method in which the grinding resistance applied to the workpiece 30 is extremely small.

Furthermore, in this embodiment, since the workpiece 30 and the grinding wheel 40 are rotated in the moving direction, the grinding resistance is further reduced.

Next, a method of processing the armature body 18 will be explained.

The front yoke 13 of the workpiece 30 is viewed from below the jig main body 31.
Insert until the circumferential part of the holder contacts the protrusion 32. Next, the wire push-up plate 34 is inserted along the groove 33 and fixed to the jig main body 31 with the step screw 36 inserted through the through hole 35. The printing wire 22 is moved by the jig main body 31 and the wire push-up plate 34.
is pushed upward in FIG. 1, and the armature body is held in the same state as when it is inactive. In this way, the jig main body 31 equipped with the workpiece 30 and the wire push-up plate 34 is fitted into the grinding chuck 37, while the grinding wheel 40 is placed at a position facing the grinding chuck 37.

When the grinding machine is turned on while maintaining this state, the grinding chuck 37 starts rotating at a low speed and the grinding wheel 40 starts rotating at a high speed in the same direction. Then, the grinding wheel 40 moves downward in FIG. 1 to grind the surface of the engagement surface 20a of the armature 20. This grinding process usually takes about 5 minutes.

After the grinding process is completed, the cutting powder generated during the process is blown away using air, and then the jig main body 31 is removed from the grinding chuck 37 and the workpiece 30 is taken out, thereby completing the process.

Each armature body 18 that has been ground in this way is moved to the core 2 by the wire push-up plate 34 in the same state as when it is not in operation.
Since the engagement surface 20a with the armature 6 is formed, the armature 2
When 0 is attracted to the core 26, each armature body 18 has the same elastic energy, and when a printing operation is performed, the printing pressure of the printing wire 22 becomes uniform.

In addition, the surface roughness of the engaging surface 20a formed by grinding is approximately 1/10 that of that formed by electrical discharge machining, so the amount of wear on the core that engages with the engaging surface 20a is reduced, and the print head Extends lifespan.

No electrical discharge splash occurs during grinding, but shavings from the grinding wheel are generated. However, this shavings can be blown away with air, eliminating the need for removal using a tool as in the case of discharge splash. As a result, the processing time can be reduced to about 1/10.

Effects of the Invention] As described in detail above, in the present invention, by creep-grinding the engaging surfaces of each armature body, the surface roughness of the engaging surfaces is improved and no discharge splash occurs.

Therefore, the amount of wear on the stopper member is reduced, and the life of the print head is increased.

Furthermore, since there is no need to remove discharge splash during the manufacturing process, manufacturing time can also be shortened.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the grinding jig, and FIG. 2 is a sectional view showing the print head in an inoperative state. In the figure, 18 is an armature body, 20a is an engagement surface, 22 is a printing wire, 23 is a torsion spring (elastic member), 26
is the core (stopper member).

Claims (1)

[Scope of Claims] A plurality of armature bodies (18) each having a printing wire (22) fixed to its tip are elastic members (22) when not in operation.
By being engaged with a predetermined stopper member (26) against the elastic force of 3), the elastic member (23) is held in a displaced state so that a predetermined elastic energy is stored, and when activated, In the method of manufacturing a print head configured to perform a printing operation by the elastic energy when the holding is released, a pressing force is applied to the armature body (18) against the elastic force of the elastic member (23). , armature body (18)
The armature body (1
8) A method for manufacturing a print head, characterized in that the engaging surface (20a) of item 8) is surface-treated by creep grinding.