JPH02125749A - Dot printer head - Google Patents

Abstract

PURPOSE:To perform the title device with ease by coupling a yoke and a supporting body in the vicinity of respective outer peripheries, and providing an armature stopper in abutment with an armature at the center of said yoke in a movable manner along a direction orthogonal to the arranging surface of a core and a plurality of adjusting screws in a rotatable manner. CONSTITUTION:A yoke block 1 has a plurality of cores 4 arranged in a loop in a circular yoke 3. An armature block 2 fixes an armature guide 9 which holds a plurality of armatures 8 in a supporting body 7 so that the armatures can freely stand up and down. An armature stopper 22 is provided at the central part of the yoke 3. When an adjusting screw 25 is tightened, the armature stopper 22 is brought into contact with a reference surface 29 of the supporting body 7 which surface coincides with an end face of the core 4. Therefore, if only the flatness of the surface of the armature stopper 22 at the side of the armature 8 is secured, the relative position of the armature stopper 22 to the armature 8 can be adjusted by a plurality of adjusting screws 25.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a dot printer head.

Conventional technology Conventionally, the stroke of the armature has been adjusted in a dot printer head in which printing is performed by operating an armature connected to a needle by the excitation action of an electromagnetic coil, and after printing, the armature is returned to contact with an armature stopper by a biasing force. Although there are some things that are not possible, it is necessary to improve the dimensional accuracy of individual parts. For this reason, there is an invention described in Japanese Patent Publication No. 55-500160, as shown in FIG. 4, which allows the stroke of the armature to be adjusted. That is, an electromagnetic coil 102 is wound around a plurality of cores 101 arranged annularly in a yoke 100,
A support body 105 is provided which supports a plurality of armatures 103 with an elastic body 104 and holds them in an up and down manner. The yoke 100 has a fulcrum portion 1 that comes into contact with the armature 103.
06 is formed. Further, an armature stopper 108 fitted to the outer periphery of a boss 107 formed at the center of the support body 105 and a stopper holder 109 for holding this armature stopper 108 are provided. One end of this stopper holder 109 is fitted into a fitting part 110 formed on the yoke 100, and the stopper holder 109
An elastic washer 112 is interposed between the flange ill and the end face of the yoke 100, and a screw 113 passing through the stopper holder 109 is screwed into the boss 107 of the support 105. Further, a plurality of needles 114 are each urged by a spring 115 and are brought into contact with the tip of the armature 103.

Therefore, when the electromagnetic coil 102 is excited, the armature 103 is attracted to the core 101, and the needle 114 is struck by the armature 103 and collides with the platen. Thereafter, the armature 103 returns together with the needle 114 by the urging force of the spring 115, comes into contact with the armature stopper 108, and stops. Then, by tightening the screw 113, the stopper holder 109 presses the armature stopper 108, and when the screw 113 is loosened, the armature stopper 108 is retracted to the yoke 100 side together with the stopper holder 109, thereby adjusting the stroke of the armature 103. .

In order to adjust the stroke of the armature 103 that the invention seeks to solve, all the armatures 103 and the armature stopper 108 are
Conditions are required to make the relative position uniform. That is, the position of the axis between the fitting part 110 of the yoke lOO and the boss 107, the bending of the axis of the boss 107, and the stopper holder 1
If the parallelism between the outer circumferential surface fitted to the fitting portion 110 of 09 and the inner circumferential surface fitted to the boss 107 is out of alignment, the armature stopper 108 will tilt, and the strokes of each armature 103 will become uneven. In addition, the armature stopper 108
Variation in the thickness of the elastic washer 112 also causes variation in the stroke of the armature 103.

Moreover, the yoke 100 and the support body 1 are connected by a negative screw 113.
However, due to the tightening of this screw 113, it becomes difficult to balance the force with which the elastic body 104 presses the armature 103 against the fulcrum part 106 and the force with which the elastic washer 112 presses the armature stopper 108. The operation of 103 becomes unstable.

Furthermore, since the needles 114 are arranged around the outer periphery of the boss 107, although the tips of the needles 114 must be arranged close to each other, the arrangement diameter at the rear end becomes large, resulting in a large amount of bending. This allows needle 1
Friction between the needle guide 14 and the needle guide (not shown) increases and durability decreases. If the overall length of the needle 114 is shortened, the amount of bending of the needle 114 can be reduced, but the weight of the needle 114 increases, the operation speed of the needle 114, that is, the printing speed becomes slower, and the power consumption for driving the needle 114 is reduced. becomes larger. The overall structure of the dot printer head also becomes larger.

Means for Solving the Problems A yoke block is formed by winding an electromagnetic coil around a plurality of cores arranged in an annular manner on a yoke, and a plurality of armatures each having a needle connected to the tip are arranged opposite to the cores so as to be able to rise and fall freely. an armature block attached to a support body, the yoke and the support body are coupled near their outer peripheries, and an armature stopper abutting the armature is placed in the center of the yoke on the arrangement surface of the cores. an operating portion is formed on the support body or the yoke, the operating portion being connected to the outer circumferential portion of the armature stopper with an axis along the moving direction of the armature stopper and being exposed to the outside. A plurality of adjustment screws are rotatably provided.

The armature stopper can be moved forward and backward relative to the armature by operating the operation part exposed to the outside and turning a plurality of adjustment screws.This allows the stroke of the armature to be adjusted. Adjustment work can be done easily because it can be done regardless of whether it is connected to the support, and by connecting the yoke and the support near the outer periphery, the armature stopper can be positioned at the center of the yoke. This makes it possible to reduce the arrangement diameter at the rear end of the needle and the amount of bending of the needle, thereby preventing wear between the needle and the needle guide, and reducing the overall length of the needle and reducing its weight. This enables high-speed printing.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 3. ■ is a yoke block, and 2 is an armature block. The yoke block l is formed by arranging a plurality of cores 4 in an annular shape around an annular yoke 3, forming an annular fulcrum portion 5 located inside these cores 4, and attaching an electromagnetic coil 6 to each core 4. It is rolled. The armature block 2 has an armature guide 9 that holds a plurality of armatures 8 movable up and down on a support 7, and a nose portion 10 formed integrally with the second armature guide 9 has a plurality of needle guides 11, 12. .13 and a needle 14 fixed to the inner tip of the armature 8.
is slidably held by these needle guides 11, 12, and 13. The armature guide 9
A plurality of protrusions 16 are formed to protrude into the holes 15 formed in the armature 8, and balance springs 17 are positioned on the outer and inner circumferences of these protrusions 16 to press the armature 8. .18 is held. A balance spring 1 located above the fulcrum portion 5
The load on the balance spring 18 located on the inside is stronger than the load on the balance spring 7, and as a result, the rear end of the armature 8 is normally separated from the core 4. Furthermore, three mounting holes 19 are formed on the outer circumferential side of the support body 7 and are arranged at equal intervals, and screw holes 20 corresponding to these mounting holes 19 are formed on the outer circumferential side of the yoke 3. Mounting hole 19
The yoke 3 and the support body 7 are connected by screwing the mounting screw 21 inserted into the screw hole 20.

An armature stopper 22 is provided at the center of the yoke 3. This armature stopper 22 has a buffer material 24 made of fluororubber embedded in one surface of a substrate 23 made of aluminum and facing the armature 8. One surface of the substrate 23 on the armature 8 side is finished flat, and by baking fluororubber into the recesses formed on this finished surface, the substrate 23 and the buffer material 24 are positioned with their armature 8 side surfaces on the same plane. can be easily integrated. The support body 7 is formed with three through holes 26 arranged at equal intervals through which adjustment screws 25 screwed onto the outer circumference of the substrate 23 are inserted. An expanding recess 28 is formed to accommodate a spring 27. The heads 25a of these adjustment screws 25, which serve as operating portions, are exposed to the outside of the support body 7. Further, the joint surface of the yoke 3 to the support 7 and the end surface of the core 4 are finished on the same plane, and the support 7 and the armature guide 9 have a reference surface 29 facing the armature stopper 8 on the end surface of the core 4. It is located and formed on the same plane as.

In such a configuration, when a screwdriver is applied to the head ifr 25a and the adjustment screw 25 is tightened, the armature stopper 22 is brought to the reference surface 2 of the support body 7, which coincides with the end surface of the core 4.
Contact with 9. Based on this position, tighten the three adjustment screws 2.
5 is turned by the same angle in the direction of loosening, the armature stopper 22 receives the pressing force of the spring 27 and separates parallel to the reference surface 29, thereby setting the return position of the armature 8. The lower this return position is located in FIG. 1, the larger the gap between the rear end of the armature 8 and the end surface of the core 4 becomes, and the stroke of the armature 8 becomes larger accordingly.

Therefore, as long as the flatness of the surface of the armature stopper 22 on the armature 8 side is ensured, the plural adjustment screws 25
Armature stopper 2 for armature 8
The relative positions of the two can be adjusted. In this case, by once abutting the armature stopper 22 on the reference surface 29 of the support body 7, it can be positioned on the same plane as the end surface of the core 4, and by turning the adjustment screw 25 based on this position, the armature The stroke of 8 can be adjusted very easily. Since this adjustment can be performed regardless of the connection between the yoke 3 and the support body 7, the adjustment work can be performed even more easily. In addition, since the yoke 3 and the support body 7 are connected at the outer periphery by the mounting screw 21, the armature stopper 22 can be provided at the center of the yoke 3. This makes it possible to reduce the arrangement diameter of the rear end of the needle 14. The amount of bending of the needle 14 can be reduced, and therefore the needle 14 and the needle guide 11
, 12, 13, and the overall length of the needle 14 is shortened to reduce its weight. This makes it possible to perform high-speed printing and also to reduce the driving power of the electromagnetic coil 6.

Note that a plurality of adjustment screws are screwed into the yoke block 1, the tips of these adjustment screws are brought into contact with one surface of the armature stopper 22, and the surface of the armature stopper 22 on the armature 8 side is pressed by the spring 27, and the adjustment screws are tightened. When tightened, the armature stopper 22 is pressed against the reference surface 29 against the force of the spring 27, and when the adjustment screw is loosened, the armature stopper 22 is moved away from the reference surface 29 by the urging force of the spring 27. good.

Alternatively, the armature stopper 22 is biased from the yoke 3 side toward the reference surface 29 of the support body 7 by a spring,
The ends of the plural adjustment screws screwed into the yoke block 1 side are connected to the armature stopper 22 so that they can rotate freely while fixing their axial movement. When the adjustment screws are tightened, the armature stopper is moved to the reference plane by the biasing force of the spring. 29 side, and when the adjusting screw is loosened, the armature stopper 22 may be pulled in a direction away from the reference surface 29 by the adjusting screw moving backward.

Effects of the Invention Since the present invention is configured as described above, as long as the flatness of the armature side surface of the armature stopper is ensured, the armature can be adjusted relative to the armature by operating the operating section exposed to the outside and turning a plurality of adjustment screws. The relative position of the stopper can be adjusted, which allows the stroke of the armature to be adjusted, and this adjustment can be done regardless of the connection between the yoke and the support, making the adjustment work easier. In addition, by joining the yoke and the support near its outer periphery, the armature stopper can be provided at the center of the yoke, which reduces the arrangement diameter of the rear end of the needle and the amount of bending of the needle. Therefore, wear between the needle and the needle guide can be prevented, and the overall length of the needle can be shortened to reduce its weight.
This has effects such as enabling high-speed printing and reducing the driving power of the electromagnetic coil.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention,
Fig. 1 is a longitudinal side view, Fig. 2 is a plan view showing the yoke in a reduced size, Fig. 3 is a plan view showing the armature stopper in a reduced size, and Fig. 4 is a partial longitudinal side view showing a conventional example. be. DESCRIPTION OF SYMBOLS 1... Yoke block, 2... Armature block, 3... Yoke, 4... Core, 6... Support body,
8... Armature. 22... Armature stopper,... Buffer material, 25... Adjustment screw, 2... Electromagnetic coil, 7 14... Needle, 23... Board, 24 5a... Operating unit

Claims (1)

[Claims] 1. A yoke block formed by winding an electromagnetic coil around a plurality of cores arranged in an annular manner on a yoke, and a plurality of armatures each having a needle connected to the tip thereof, facing the core so as to be able to rise and fall freely. and an armature block attached to a support body, the yoke and the support body are coupled near their outer peripheries, and an armature stopper abutting the armature is provided at the center of the yoke, and the cores are aligned. an operating section that is movable along a direction perpendicular to the plane, is connected to the outer peripheral part of the armature stopper with an axis along the movement direction of the armature stopper on the support body or the yoke, and is exposed to the outside; 1. A dot printer head characterized in that a plurality of adjusting screws each having a shape formed thereon are rotatably provided. 2. The dot printer head according to claim 1, wherein a reference surface facing the armature stopper is formed on the support so as to be located on the same plane as an end surface of the core. 3. The dot printer head according to claim 1 or 2, wherein the armature stopper is formed by embedding a cushioning material facing the armature in one surface of the metal substrate.