JPH029969Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a wire dot type print head, and particularly to a print head assembly structure.

[Conventional technology]

In conventional wire dot type print heads, the front frame that has a guide section that slides the printing wire, the yoke member, and the back cover that regulates the stopping position of the armature are tightened using clamping means made of leaf springs. There are some assembled ones (for example, Japanese Patent Application Laid-Open No. 15371/1983, Japanese Utility Model Application No. 58-
Publication No. 117935).

[The problem that the idea attempts to solve]

In the conventional type, the back cover is held down by the spring force of the clamping means, so when many armatures hit the back cover after printing at the same time, the impact force resists the spring force of the clamping means and the back cover is held down. may rise and vibrate. As a result, the noise became louder, and when the armature was continuously driven, the timing became out of order, making it impossible to print clearly.

This invention solves these problems and also makes it easier to assemble the print head.

[Means to solve the problem]

The print head of this invention includes a yoke member 1 of a solenoid coil 2, an armature 4 disposed opposite to the yoke member 1, and a guide portion 6d for slidingly guiding a printing wire 7 driven by the armature 4. Front frame with 6
a base that abuts on the side opposite to the yoke member 1 in the front frame 6; a plurality of engagement arms 9b extending from the base along the side surfaces of the front frame 6 and the yoke member 1; and their respective engagement arms. A mounting body 9 consisting of an engagement hook 9c bent into a U-shape at the tip of the coupling arm 9b, and a mounting body 9 formed of an engagement hook 9c bent in a U-shape at the tip of the coupling arm 9b;
A locking body 8 is rotatably arranged in contact with the opposite side of the locking body 8, and has a plurality of claws 8b formed in a tapered shape that protrudes in the direction of rotation and has a tapered tip. A claw portion 8b is provided on the engaging hook 9c.
The front frame 6 and the yoke member 1 are tightened by engaging them and rotating the locking body 8.

[Effect]

With the above configuration, when the front frame 6 is stacked on the yoke member 1, the base of the mounting body 9 is brought into contact with the front frame 6, and the mounting body 9
The engaging arm 9b is arranged along the side surface of the front frame 6 and the yoke member 1. Then, the locking body 8 is brought into contact with the yoke member 1, and the claw portion 8b of the locking body 8 is engaged with the engagement hook 9c at the tip of the engagement arm 9b. . By rotating the locking body 8, the mounting body 9 can be drawn toward the locking body 8 by the tapered surface of the claw portion 8b, and the front frame 6 and the yoke member 1 can be tightened.

〔Example〕

FIG. 1 shows a partially cutaway side view of the print head, and the yoke member 1 includes an inner yoke 1b formed to protrude forward from the center of a disk-shaped base 1a, and as shown in FIGS. 3 and 4. The inner yoke 1b is composed of 24 outer yokes 1c protruding from the base 1a so as to be arranged annularly along the outer periphery of the inner yoke 1b. A stepped portion 1d is formed on the outer periphery of the tip of the inner yoke 1b, and a solenoid coil 2 is wound around each outer yoke 1c. Furthermore, three engaging grooves 1e are formed at equal intervals on the outer periphery of the base 1a of the yoke member 1.
The rear side portion (the side opposite to each of the yokes) is further cut out to form a locking step surface 1f. (below,
In FIG. 1, the right side will be described as the front and the left side as the rear. ) The armature holding member (hereinafter simply referred to as the holding member) 3 disposed on the front side of the yoke member 1 is molded from synthetic resin, and as shown in FIGS. 5 to 7, its annular outer peripheral frame is Twenty-four intermediate frame portions 3b are formed to protrude from the portion 3a toward the center. Each intermediate frame portion 3b is formed into a tapered shape, and the interval between each intermediate frame portion 3b is made equal to the width of the outer yoke 1c. The holding member 3 is disposed with respect to the yoke member 1 such that the spaces formed between the intermediate frame portions 3b face the outer yoke 1c.

The bridging frame portion 3c that bridges the tips of the intermediate frame portions 3b has a rear side projecting rearward and has an annular shape as a whole, and its inner circumferential surface fits into the stepped portion 1c of the inner yoke 1b. Further, the front side portion of the bridging frame portion 3c located between the intermediate frame portions 3b is formed to have an arcuate cross section as shown in FIG. 7, and serves as a swing fulcrum 3d for the armature described later. The outer peripheral frame portion 3
Three engagement grooves 3e facing the engagement groove 1e are formed on the outer periphery of a. armature 4
is disposed between each intermediate frame portion 3b of the holding member 3, and a fitting recess 4a formed on the rear side fits into the swinging fulcrum 3d and is supported to be swingable about the fulcrum 3d. Ru. As a result, 24 armatures 4 are arranged radially with both ends facing the inner yoke 1b and the outer yoke 1c. The surface on the inner end side facing the inner yoke 1b and the surface on the outer end side facing the outer yoke 1c are inclined with respect to each other as shown in FIG. I am doing it. and armature 4
is always held in a state in which the inner end is close to the inner yoke 1b (FIG. 1) by an elastic body, which will be described later. When the coil 2 is excited, the inner yoke 1b
The inner end surface facing the coil 2 is smaller than the outer end surface, and the magnetic flux generated in the coil 2 leaks to the outside before reaching the inner yoke 1b from the outer yoke 1c. As the magnetic flux of the yoke 1b decreases,
The outer end of the armature 4 is attracted to the outer yoke 1c as shown in FIG. 2, and swings counterclockwise.

The elastic body 5 disposed on the front side of the holding member 3 is molded from synthetic resin, and faces each of the armatures 4 from its annular base 5a toward the center, as shown in FIGS. 10 to 15. 24 ribs 5
b is formed to extend, and a fitting groove 5c having a U-shaped cross section is formed in the longitudinal direction on the front surface of the tip thereof.

A projecting piece 5d is provided on the rear side of the tip end of each of the ribs 5b, and is in contact with the front surface of the inner end of the opposing armature 4, respectively. And each protrusion 5d
The armature 4 is held between the base portion 5a and the swing fulcrum 3d as shown in FIG. coil 2
When the armature 4 swings based on the excitation, the rib 5b is bent forward by the inner end of the armature 4 against its elasticity, as shown in FIG.

Furthermore, three engagement grooves 5e are formed on the outer periphery of the base portion 5a of the elastic body 5 to face the engagement groove 3e.

The front frame 6 disposed on the front side of the elastic body 5 is molded from synthetic resin, and has 24 radially recessed grooves 6a on its rear surface, as shown in FIGS. 17 and 18. It is arranged to cover the elastic body 5 so as to face the rib 5b. or,
Three engagement grooves 6b are formed on the outer periphery of the front frame 6 and are opposed to the engagement groove 5e.

A guide member 6c is formed protruding from the center of the front surface of the front frame 6, and 24 guides are provided on the front surface of the guide member 6c corresponding to the number of armatures 4, that is, the number of printing wires 7 to be described later. A guide hole 6d is provided as a transparent part. As shown in FIG. 19, the 24 guide holes 6d are arranged so as to have an approximately diamond shape as a whole.

Each of the 24 printing wires 7 bent into an L shape has its base end 7a bent into a "U" shape, and the base end 7a is inserted into each groove 6 of the front frame 6.
The fitting grooves 5 of the elastic bodies 5 correspond to the base portions 7c which are fitted and fixed to the corresponding elastic bodies 5 and extend from the base end portions 7a toward the center to the bent portions 7b, respectively.
It is fitted into c. On the other hand, the tip end portion 7d of each printing frame 7 extending forward from the bent portion 7b penetrates the guide hole 6d and projects outward.

Each printing wire 7 is pushed forward through the rib 5b of the elastic body 5 based on the swinging of the corresponding armature 4, thereby being driven for printing, so as to perform 24×24 dot matrix printing. It's summery.

As shown in FIGS. 21 to 24, there are three locking bodies 8 disposed in contact with the rear side of the yoke member 1 on its outer periphery so as to face the engagement grooves 1e of the yoke member 1. A fitting recess 8a is formed. A claw portion 8 protruding in the circumferential direction is provided on one side wall of each fitting recess 8a.
b is formed, and the front surface of the claw portion 8b is flush with the front surface of the locking body 8, and the rear surface is formed in a tapered shape so that the tip is tapered as shown in FIG.

The mounting body 9 has its base connected to the front frame 6.
The guide member 6c of the frame 6 is disposed in contact with the front side thereof, and a rectangular through hole 9a is provided in the center of the base thereof through which the guide member 6c of the frame 6 protrudes. Further, three engagement arms 9b are formed on the outer periphery of the base and extend rearward while being engaged with the engagement grooves 1e, 3e, 5e, and 6b. Each engagement arm 9b has its tip
It is bent into a letter shape to form an engaging hook 9c, and the engaging hook 9c is engaged with the claw portion 8b of the locking body 8. Therefore, the attachment body 9 tightly secures the yoke member 1, the holding member 3, the elastic body 5, and the front frame 6 with the locking body 8.

In this embodiment, the printing wire 7
is bent into an L-shape, and the base end 7a of the printing wire 7 is fixed to the groove 6a formed in the front frame 6, and the tip 7d of the printing wire 7 is movably guided to the guide hole 6d. Then, the base 7c of the printing wire 7 receives the swinging motion of the armature 4 via the rib 5b of the elastic body 5, and drives the printing wire 7, thereby driving the tip 7d of the printing wire 7.
dot matrix printing is possible.

Therefore, in this embodiment, unlike conventional printing wires, there is no need to braze the base end to the armature. Also, the armature 4 is always in the first position due to the elastic return force of the elastic body 5 and the printing wire 7.
Since it is held as shown in the figure, there is no need to braze the leaf spring for return, which reduces many troublesome work steps.

Furthermore, since the base 7c of the printing wire 7 is pushed out to the armature 4 via the elastic piece 5d of the elastic body 5 made of synthetic resin, the armature 4 does not come into direct contact with the printing wire 7.
There is no fear that they will damage or wear out each other.

Further, in this embodiment, the outer yoke 1c around which the coil 2 is wound is arranged in a ring shape around the outer periphery of the inner yoke 1b, and the armatures 4 are arranged radially around the inner yoke 1b so as to face each other opposite to the outer yoke 1c. As a result, the assembly structure of the armature 4 can be made very compact, and the area occupied by the coil and the suction area of the armature can be made larger compared to the outer shape of the print head, and the suction force of the armature 4 can be increased. That is, the impact force of the printing wire 7 can be increased.

Furthermore, in this embodiment, the print head is assembled by stacking the locking body 8, the yoke member 1, the holding member 3 holding the armature 4, the elastic body 5, and the front frame 6, and then attaching the base of the mounting body 9. It comes into contact with the front frame 6, and the engaging hook 9c is inserted into the insertion part 8a of the locking body 8. Since the locking member 8 is simply rotated to engage the engagement hook 9c with the claw portion 8b, the print head assembly operation becomes extremely simple. Furthermore, since the front frame 6 is strongly tightened to the yoke member 1, the elastic body 5 does not lift the front frame 6 due to inertia when the armature 4 returns after printing, which is effective in reducing noise. Yes, and the printing operation will not become uncertain even during continuous printing. Moreover, at this time, the engagement arm 9b of the mounting body 9 is connected to the engagement groove 1 formed in the yoke member 1, the holding member 3, the elastic body 5, and the front frame 6.
e, 3e, 5e, and 6b, the respective members will not be displaced relative to each other due to vibration or the like during the printing operation, thereby preventing the printing operation from becoming impossible. Further, an engagement hook 9c formed on the engagement arm 9b of the mounting body 9
When the hook 9c and the claw portion 8b of the locking body 8 are engaged, simply rotating the locking body 8 will cause the engagement hook 9c and the claw portion 8
Since b is disengaged, the print head can be easily disassembled and maintenance work can be performed very easily.

Note that this invention is not limited to the above-described embodiment; for example, the printing wire 7 may be simply bent into an L shape as shown in FIG. Alternatively, the guide hole 6d may be formed in the front surface of the guide member 6c formed integrally with the front frame 6 in the above embodiment. Figure and 28th
As shown in the figure, a panel 10 having 24 guide holes 6d may be detachably attached to the front surface of the guide member 6c.

[Effect of idea]

As described in detail above, in this invention, the front frame and the yoke member are strongly tightened, so that when the armature returns after printing, the front frame is not lifted up due to inertia, and noise can be reduced. Moreover, even during continuous printing, the printing operation does not become uncertain, and furthermore, it is easy to assemble and exhibits excellent effects.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view of the print head, Fig. 2 is a sectional side view of the main part showing the operation of the armature,
3 and 4 are front views of the yoke member and
5 and 6 are front and rear views of the holding member, FIG. 7 is a sectional view taken along the A-A line in FIG. 5, and FIGS. 8 and 9 are front views of the armature. Figures 10 and 11 are front and rear views of the elastic body, Figures 12 to 14 are front views, rear views, and side sectional views of the ribs of the elastic body, and Figure 15 is the elastic body. 16 to 18 are a front view and rear view of the front frame, and a sectional view taken along the line A-A in FIG. 17; FIG. 19 is a front view showing the arrangement of guide holes; FIG. 20 is a side view of the printing wire,
Figures 21 to 23 are front views, rear views, and partially cutaway side views of the locking body, Figures 24 and 25 are front views and side views of the mounting body, and Figure 26 is another example of the printing wire. 27 and 28 are a front view and a side sectional view showing another example of the front frame. In the figure, 1 is a yoke member, 1b is an inner yoke, 1c is an outer yoke, 2 is a solenoid, 3 is an armature holding member, 3a is an outer peripheral frame part, 3b is an intermediate frame part, 3c is a bridging frame part, and 3d is a Swinging fulcrum, 4 is armature, 5 is elastic body, 5a is base, 5b is rib, 5c is elastic piece, 6 is front frame, 6a is fixing recess, 6d is guide hole, 7
is the printing wire, 7a is the base end, 7b is the bent part,
7c is a base, 7d is a tip, 8 is a locking body, 8b is a claw, 9 is a mounting body, and 9c is an engaging hook.

Claims (1)

[Claims for Utility Model Registration] A yoke member 1 of the solenoid coil 2, an armature 4 disposed opposite to the yoke member 1, and a guide portion 6d for slidingly guiding the printing wire 7 driven by the armature 4. a front frame 6 having: a base portion abutting the front frame 6 on a side opposite to the yoke member 1; and a plurality of engagement arms 9b extending from the base portion along side surfaces of the front frame 6 and the yoke member 1. , and a mounting body 9 consisting of an engagement hook 9c bent into a U-shape at the tip of each engagement arm 9b, and a mounting body 9 that is rotatable by abutting on the opposite side of the front frame 6 in the yoke member 1. and a locking body 8 having a plurality of tapered claws 8b that protrude in the rotating direction and have tapered tips, and the hooks 8b are engaged with the engagement hook 9c. 1. A print head characterized in that the front frame 6 and the yoke member 1 are tightened by rotating the locking body 8 in conjunction with each other.