JP2588403Y2 - Print head for dot printer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head for a dot printer.

[0002]

2. Description of the Related Art On a solenoid base, a plurality of solenoids each composed of a core and a coil wound around the core are arranged along a circumferential direction, and along the solenoid, an armature is radially formed with its tip directed toward a center. The rear end of the armature facing the solenoid is engaged with the outer edge of the solenoid base to serve as a swing fulcrum of the armature. An abutting plunger is integrally provided on the side of the armature facing the solenoid, and a needle is provided on an end face of the armature in a center direction with its tip directed forward, and the armature is energized by energizing the solenoid. Suction-type dot printer printing that sucks into the core and moves the needle at the end of the armature forward to perform stamping Head is, for example, the real-Open No. 4-836
No. 41 and Japanese Utility Model Laid-Open No. 4-137847.

In this type of print head for a dot printer, the pivot point of the armature and the contact surface of the plunger of the armature with the core of the solenoid are located on the same plane or parallel to each other. When the armature is attracted to the core by applying power to the core, it is desirable that the armature comes into contact with the surface.However, due to the accuracy of parts, errors during assembly, or wear during use, all elements must be brought into complete contact. Is difficult, and for this reason, the end of the plunger part on the center direction side far from the swing fulcrum part comes into contact with the core first,
There is a possibility that the end of the plunger on the side closer to the swing fulcrum may hit the core first.

In the armature itself, the position of the center of gravity is often closer to the center of the plunger than the plunger, and when the plunger contacts the plunger, the plunger is closer to the swing fulcrum than the plunger. After the end of the plunger hits, the plunger returns after the end of the plunger on the center direction far from the pivot point hits.
Armature returns worse. For this reason, the responsiveness of the armature is poor, and for example, printing defects such as blurring of printing and the hooking of a ribbon by a needle are likely to occur.

[0005] In order to improve the return of the armature, it is conceivable to increase the holding force at the swing center. Since the balance is lost, the mobility of the armature deteriorates, and it is impossible to increase the holding force at the swing center.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to ensure that only the center of the plunger is brought into contact with the core when the armature is sucked by the solenoid during printing, and that the armature has a return response. It is an object of the present invention to provide a print head of a printer capable of improving performance.

[0007]

According to the present invention, there is provided a print head for a printer comprising a core and a coil wound around the core.
Number of solenoids and the previous time when aspirated by said solenoids
It has a plunger section that contacts the core, and
An armature swingably supported by the outer edge of the armature;
Connected forward to the front end face of the armature in the center direction
In order to solve the above-mentioned problem, the armature plunger portion is provided on the side of the armature facing the core. The distance between the contact surface that is on the same plane as the swing fulcrum portion of the armature to be in contact with the core and the rear side of the armature that is adjacent to the swing fulcrum side of the corresponding contact surface and is closer to the rear side of the armature becomes larger. And a slope having a slope.

[0008]

When one of the plurality of solenoids is energized, the armature corresponding to the energized solenoid pivots forward around the swing fulcrum by the attraction force of the solenoid, and the plunger moves. Is sucked into the core.

In the plunger portion, on the side facing the core, the rocking fulcrum side of the armature is inclined such that the distance from the core becomes larger toward the rear side than in the middle. The contact surface located on the same plane as the pivot point closer to the needle than the middle of the plunger always hits the core first, and the contact surface is near the position of the center of gravity of the armature. It does not fluctuate back and forth.

[0010]

[0011]

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic side sectional view of a print head for a dot printer according to the present invention.

The print head 1 is generally formed by superimposing a nose 12, a print head main body 2 provided with a solenoid base 11, an armature guide member 28, and a rear cover 29 from the front stamping surface side.

The solenoid base 11 of the print head body 2
Inside, a plurality of solenoids 10 each composed of a core 8 and a coil 9 wound around the core 8 are arranged on the circumference concentric with the solenoid base 11 toward the rear side of the print head 1. The print head body 2 and the solenoid base 11
Are provided with insertion holes 18 and 19, respectively, at the center.

On the front side of the print head main body 2, a cylindrical nose 12 projecting from the front center is superposed, and the nose 12 is formed.
Needle guides 20, 21, 22, 22
The needle guides 20 to 23 are provided with insertion holes 24, 25, and 26, respectively, and the needle guide 23 on the distal end side of the nose 4 is provided with a protrusion 27.

The needle 6 is provided for each of the plurality of solenoids 10, and the leading end of the needle 6 faces the projection 27 of the needle guide 23 on the tip side of the nose 12. Hole 18,
From the side of 19, the needle guides 20, 21, 22 are inserted through the insertion holes 24, 25, 26 of the needle guides 20, and are disposed so as to be able to protrude and retract from the projecting openings 27.

The armature 7 is provided inside an armature guide member 28 that is superposed behind the print head main body 2, and is disposed radially along the plurality of solenoids 10, with the tip of the armature 7 facing the center.

The armature 7 is provided with a protrusion 13 on the side of the armature 7 facing the outer surface of the solenoid 10, and the protrusion 13 is engaged with the outer end edge of the solenoid base 10 to swing the fulcrum of the armature 7. The plunger part 5 which comes into contact with the core 8 when the armature 7 is sucked by the solenoid 10 is provided integrally on the side of the armature 7 facing the core 8, and the end face in the center direction of the armature 7 is provided with a needle. 6 are provided at the rear end.

The plunger portion 5 has a contact surface 3 that contacts the core 8 closer to the needle 6 from the middle of the plunger portion 5 on the side facing the core 8 and a swinging armature 7 that is adjacent to the contact surface 3. An inclined surface 4 having a slope that increases the distance from the core 8 toward the moving fulcrum portion 14 is provided. The swing fulcrum 14 of the armature 7 and the contact surface 3 of the plunger 5 are located on the same plane. The inclination angle between the contact surface 3 and the slope 4 of the plunger part 5 is formed in a range of 30 'or more and 1 ° 30' or less.

Behind the armature guide member 28,
The rear cover 29 is superimposed, and on the front side of the rear cover 29, an armature spring 15 made of a plate spring that biases the swing fulcrum portion 14 of the armature 7 from the rear toward the swing fulcrum portion 14 is provided. For this reason, the armature 7 is supported so as to be able to swing in the front-rear direction of the print head 1 around the swing fulcrum 14. Further, an armature stopper 16 for regulating the retreat position of the armature 7 is provided at the center of the front side of the rear cover 29.

Further, a needle spring 17 provided in the print head main body 2 is in contact with the front side of the armature 7 near the needle 6, and the urging force of the needle spring 17 when the solenoid 10 is not energized. The armature 7 contacts the armature stopper 16 and the needle 6 is sunk into the nose 12. When the solenoid 3 is energized, the armature 7 corresponding thereto is sucked, the needle 6 advances, and the tip of the needle 6 projects from the projecting opening 27 at the tip of the nose 12 to print.

Next, the operation of the print head 1 will be described. When one of a plurality of solenoids 10 is energized, the armature 7 corresponding to the energized solenoid 10 is attracted by the attraction force generated by the excitation of the solenoid 10. The plunger portion 5 is pivotally moved forward about the swing fulcrum portion 14 against the urging force of the needle spring 17, and the plunger portion 5 is sucked by the core 8.

The plunger portion 5 has a slope 4 on the side facing the core 8, the slope of which is closer to the swing fulcrum portion 14 of the armature than in the middle so that the distance from the core 8 increases toward the rear side. Therefore, the contact surface 3 located on the same plane as the swing fulcrum portion 14 closer to the needle 6 than in the middle of the plunger portion 5 than the slope 4 always collides with the core 8 first, and the contact surface 3 Because it is near the position of the center of gravity of the armature 7,
Armature 7 is stable and does not fluctuate back and forth.

That is, the end of the plunger on the side closer to the swing fulcrum of the armature, which has occurred in the prior art, causes a contact with the core first, and then the armature is moved from the swing fulcrum. It is prevented that the end of the plunger part on the center direction side farther away hits.

As the armature 7 moves forward, the needle 6 at the tip of the armature 7 moves forward, the tip of the needle 6 protrudes from the projecting opening 27, and presses against the paper surface through a printing ribbon (not shown) to perform printing. At the same time, the needle spring 17 is
Is contracted by the movement of.

When the energization of the solenoid 10 is stopped and the excitation of the solenoid 10 is extinguished, the armature 7 rebounds to the rear cover 14 due to the returning force of the contracted needle spring 17, and the armature stopper 16
Stop colliding with.

At this time, the contact surface 3 of the plunger 5 collides with the core 8 first, and the armature 7 is stabilized, so that a response regarding the return of the armature 7 to the standby position is good.

Instead of providing the inclined surface 4 on the plunger portion 5 of the armature 7, the surface of the plunger portion 5 facing the core 8 is contacted with a contact surface located on the same plane as the swing fulcrum portion 14 as in the prior art. On the other hand, on the core 8 side, which is closer to the swing fulcrum part 14 side than the middle of the corresponding tangent face, a slope is provided having an inclination toward the swing fulcrum part 14 side, the distance from which to the corresponding tangent face increases. It is possible.

However, it is difficult to form an inclined surface on the core side by cutting or grinding, and the production of the core requires a polishing step for the contact surface if lost wax, metal injection, casting or the like is used. Therefore, it is more advantageous to provide a slope on the plunger side of the armature, since the production cost is significantly increased.

[0031]

According to the present invention, in a print head for a dot printer, an armature swinging fulcrum contacting the core is provided on the side of the armature plunger portion facing the core, at a position closer to the armature needle direction than in the middle thereof. And a contact surface which is on the same plane as the contact surface, and a slope which is adjacent to the swing fulcrum side of the contact surface and has a slope whose distance from the core increases toward the rear side of the armature. When the armature is pivotally moved forward about the swing fulcrum portion by the attraction force of the excitation of the armature and the plunger portion of the armature is attracted to the core, the armature is positioned at an intermediate position on the side of the plunger portion facing the core. Of the plunger is closer to the center of the plunger than to the slope because the side of the swing fulcrum closer to the rocking fulcrum is inclined so that the distance to the core increases toward the rear side. Situated in dollar side side of the swing fulcrum portion on the same plane as the contact surface always becomes possible to collide with the core first.

For this reason, as in the case where the contact point of the core of the armature plunger is a single plane, the end of the plunger on the side closer to the pivot point of the armature comes into contact with the core first. After that, it is prevented that the end of the plunger portion on the center direction side far from the swing fulcrum hits, and the contact surface of the armature is near the center of gravity of the armature at the time of stamping. Therefore, the armature is stabilized, and the responsiveness regarding the return of the armature to the standby position is improved.

Even when a non-magnetic thin film is adhered to the core surface, the armature has a slope on the plunger side, so that the armature does not come in contact with the armature, and the core does not contact the swing fulcrum. The height tolerance and the tolerance of the length of the plunger portion from the contact surface of the plunger portion to the rear surface facing the corresponding contact surface can be increased as compared with the conventional case, and also, rather than providing a slope on the core side, Since manufacturing can be facilitated, manufacturing costs are low.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view showing a print head of a printer according to an embodiment of the present invention, partially cut away;

[Description of Signs] 1 Printhead 2 Printhead body 3 Contact surface 4 Bevel 5 Plunger 6 Needle 7 Armature 8 Core 9 Coil 10 Solenoid 11 Solenoid base 12 Nose 13 Projection 14 Swing support 15 Armature spring 16 Armature stopper 17 Needle Spring 18 Insertion Hole 19 Insertion Hole 20 Needle Guide 21 Needle Guide 22 Needle Guide 23 Needle Guide 24 Insertion Hole 25 Insertion Hole 26 Insertion Hole 27 Projection Port 28 Armature Guide Member 29 Rear Cover

Claims (2)

(57) [Scope of request for utility model registration] 1. A core comprising a core and a coil wound around the core.
When a plurality of solenoids are sucked by the solenoids
Having a plunger portion abutting on the core, the solenoid
Armature swingably supported by the outer edge of the base
To the front end face in the center direction of the armature,
A print head for a dot printer, comprising a plurality of needles connected in series with each other , wherein the armature plunger portion abuts on the core, closer to the needle direction side of the armature than halfway toward the side facing the core. A contact surface which is on the same plane as the swing fulcrum portion of the armature, and has an inclination adjacent to the swing fulcrum side of the corresponding contact surface and toward the rear side of the armature so that the distance from the core increases. A print head for a dot printer, comprising a slope. 2. A print head for a dot printer according to claim 1, wherein an inclination angle between said contact surface of said plunger portion and said slope is in a range of 30 'or more and 1 ° 30' or less.