JPH0346915Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) This invention is for a dot printer in which an armature is selectively driven by an electromagnet, and a printing wire connected to the armature is made to protrude to perform printing. This relates to the print head of the printer.

(Problems to be Solved by Prior Art and Ideas) Conventionally, in this type of print head, the end face of a cylindrical yoke member containing a plurality of electromagnets and the plane of a plate-shaped armature face parallel to each other. A large number of armatures were arranged, and the armatures were held down from behind by a lid member. Therefore, it is very troublesome to assemble the yoke member and the support member in a state where each armature correctly faces each electromagnet.

Structure of the device (means for solving the problem) This device was made to solve the above-mentioned problems, and has a front wall portion 3, an outer wall portion 4, and a plurality of cores 5, each of which has a front wall portion 3, an outer wall portion 4, and a plurality of cores 5. A first yoke member 1 provided with a plurality of electromagnets 12 by winding a coil 7 around the outer surface of a core 5, and a housing groove 22 disposed at the rear of the first yoke member 1 and facing each of the electromagnets 12. and a supporting member 16 provided with a shaft support 25 located outside of each of the housing grooves 22, and a support member 16 that is disposed in each of the housing grooves 22 so as to face the attraction surface 13 of the core 5 of the electromagnet 12, and is located front and rear. a rotatable armature 38; and a rotatable armature 38 fixed to the tip of each armature 38;
Printing wire 42 performs printing operation by rotational movement of
and a second yoke member comprising an annular peripheral wall portion 47 that joins to the rear end surface 14 of the outer wall portion 4 of the first yoke member 1 and a plurality of fitting grooves 48 arranged in a row in the peripheral wall portion 47.
yoke member 44.

(Function) Therefore, in the print head of this invention, the magnetic flux generated by the electromagnet 12 is transferred to the first yoke member 1.
from the outer wall portion 4 of the second yoke member 44 to the peripheral wall portion 4 of the second yoke member 44
7 into the armature 38 from its side. Therefore, even if the width of the armature 38 in the circumferential direction is reduced, a sufficient magnetic path can be secured, and the number of armatures 38, that is, the number of printed dots can be increased.

Furthermore, by manufacturing the outer wall portion 4 of the first yoke member 1 and the second yoke member 44 separately, the rear end surface 14 of the outer wall portion 4 of the first yoke member 1 and the adsorption surface of the core 5 can be 13 can be arranged on the same plane, and processing to uniformly align the suction surfaces 13 of each core 5 can be easily performed. Furthermore, by supporting the armature 38 in the radial housing groove 22 of the support member 16 and housing the support member 16 inside the second yoke member 44, the electromagnet 12 and the armature 38 are in a state of accurate correspondence. can be easily assembled.

(Example) Hereinafter, an example that embodies this invention will be described based on the drawings.

As shown in FIG. 1, the first yoke member 1 includes a circular front wall part 3 having an opening 2 in the center, an annular outer wall part 4 extending rearward from the outer peripheral edge of the front wall part 3, It is integrally constructed of a magnetic material such as iron and includes a plurality of cores 5 protruding from the rear surface of the front wall 3 at equal intervals along the inner surface of the outer wall 4. A bobbin 6 is inserted into each core 5, and a coil 7 is wound around the outer surface of the bobbin 6. The tip of the coil 7 is connected to a pair of terminal pins 8 protruding forward from the bobbin 6. and,
The core 5 and the coil 7 constitute an electromagnet 12, and the attracting surface 13 of each electromagnet 12, that is, the rear end surface of each core 5 is arranged on the same plane as the rear end surface 14 of the outer wall portion 4. Moreover, the first yoke member 1
A lead wire 10 is fixed to the front surface of the insulating plate 9 via an insulating plate 9, and the terminal pin 8 is connected to the lead wire 10. Note that the front surface of the lead wire 10 is covered with a protective rubber sheet 11.

As shown in FIGS. 1, 2, and 3, a support member 16 made of synthetic resin is disposed at the rear of the first yoke member 1. As shown in FIGS. The support member 16 includes a disk portion 17 that is joined to the rear side of the first yoke member 1, and a disk portion 17 that protrudes from the center of the front surface of the disk portion 17 and extends through the opening 2 of the front wall portion 3 of the first yoke member 1. It is integrally constructed with a nose portion 18 that protrudes forward. There are three wire guides 1 inside the nose part 18.
9, 20, and 21 are installed. A plurality of radially extending accommodation grooves 22 are formed in the disk portion 17,
A through hole 22 a is formed in each housing groove 22 at a position facing each electromagnet 12 . The disk portion 17 is located at a position corresponding to the inner end of each housing groove 22.
Accommodation holes 23 are formed in the rear side of the housing, and a compression spring 24 is housed in each accommodation hole 23. Further, a shaft support piece 25 is formed to protrude from the outer peripheral surface of the disk portion 17 at a position corresponding to the outer end of each housing groove 22, and a recess 26 is provided on the rear side surface of each shaft support piece 25.

As shown in FIGS. 3 and 5, a thin connecting plate 28 is installed between the outer surfaces of the pair of adjacent shaft support pieces 25 in the upper part of the disk part 17, and the inside of this connecting plate 28 has an upper insertion hole. 34. or,
The upper biaxial support pieces 25 protrude forward from the front surface of the disk portion 17 and constitute a pair of positioning protrusions 29, and these protrusions 29 are recessed in the rear end surface 14 of the outer wall portion 4 of the first yoke member 1. It is fitted into a pair of notches 30 provided therein. Furthermore, the second
As shown in FIGS. 4 and 5, between a pair of adjacent shaft support pieces 25 at positions 120 degrees apart clockwise and counterclockwise from the upper insertion hole 34,
Connecting plates 31 are installed so as to form a pair of side insertion holes 35 and 36, respectively. Each pair of shaft support pieces 25 on both sides protrude forward from the front surface of the disk portion 17 and serve as positioning protrusions 32, and each positioning protrusion 32 is formed on the rear surface of the lower end of the first yoke member 1 on both the left and right sides. It is fitted into the groove 33. And each of the positioning protrusions 29, 32
The support member 16 is unrotatably positioned with respect to the first yoke member 1 by fitting between the notch portion 30 and the groove 33 .

As shown in FIGS. 1, 2 and 3, the support member 1
An armature 38 made of a plate-like material is disposed in each of the housing grooves 22 of 6, with its thickness direction corresponding to the circumferential direction of the support member 16, and its width direction corresponding to the axial direction of the support member 16. Each is accommodated. The base end of each armature 38 is provided with the shaft support piece 2.
A protrusion 39 that fits into the recess 26 of No. 5 is formed, and the armature 38 can rotate back and forth around this protrusion 39. The forward protruding end surface 40 of each armature 38 faces the attraction surface 13 of each electromagnet 12 through the through hole 22a of the receiving groove 22. Further, the compression spring 24 is engaged with the front side surface of the tip end of each armature 38, and the armature 38 is always urged to rotate in a direction away from the suction surface 13 due to the spring force.

A printing wire 42 extending forward is fixed to the tip of each armature 38 at its rear end. Each printing wire 42 is connected to the nose portion 18
The movement is guided by each wire guide 19, 20, 21 inside. When the electromagnet 12 is selectively excited based on the print signal, the armature 38 facing the electromagnet 12 is attracted to the attraction surface 13 of the core 5 against the action of the compression spring 24. The printing wire 42 is the nose part 1
A printing operation is performed on printing paper on a platen (not shown) that protrudes from the front surface of the printer 8.

On the other hand, a second yoke member 44 is disposed at the rear of the first yoke member 1 with the support member 16 housed therein. As shown in FIGS. 1 and 3, this second yoke member 44 has an opening 4 in the center.
a circular rear wall section 46 with a circular rear wall section 46;
It is integrally formed of a magnetic material such as iron with an annular peripheral wall portion 47 that extends forward from the outer peripheral edge of the first yoke member 1 and joins with the rear end surface 14 of the outer wall portion 4 of the first yoke member 1 . Each shaft support piece 25 and each armature 38 as a protrusion of the support member 16 are provided on the peripheral wall portion 47.
A plurality of fitting grooves 48 are formed with cutouts into which the base end portions of the fitting grooves 48 are respectively fitted and positioned. Each fitting groove 4
The front end surfaces 50 of each of the comb-like yoke pieces 49 of the peripheral wall portion 47 formed by 8 are arranged on the same plane. Therefore, the first yoke member 1
In the state where the second yoke member 44 is joined to the outer wall portion 4 of the first yoke member 1,
The rear end surface 14, the attraction surface 13 of each electromagnet 12, and each yoke piece 49 in the second yoke member 44
The front end surfaces 50 of the two are arranged on the same plane.

As shown in FIG. 5, each of the yoke pieces 49a, 49b, and 49c located 120 degrees apart is inserted into the top insertion hole 34 and the side insertion hole of the support member 16, thereby connecting the support member 16 and the second yoke. Positioning with the member 44 is performed in the circumferential direction. Further, the yoke piece 4 fits into the upper insertion hole 34 of the support member 16.
9a is formed thinner than the other yoke pieces 49, so that the connecting plate 28 in the upper insertion hole 34 does not protrude to the outer surface of the second yoke member 44 in the assembled state. Furthermore, as shown in FIG. 3, a pair of square notch recesses 51 and a pair of semicircular positioning recesses 52 are provided on the circumferential surface of the opening 45 of the rear wall portion 46 of the second yoke member 44. each formed.

As shown in FIGS. 1 and 3, the second yoke member 4
A rear presser member 54 made of synthetic resin and formed into a disk shape is disposed at the rear of the housing 4 . A second yoke member 4 is provided on the front surface of the center portion of the rear holding member 54.
An annular projection 55 that fits into the opening 45 of each armature 38 is integrally formed, and the front surface thereof serves as a restriction surface 56 that restricts the rearward rotational position of each armature 38. Further, on the outer peripheral surface of the annular projection 55, a pair of projections 57 corresponding to both the notched recesses 51 of the second yoke member 44 are formed only at the tip of the annular projection 55, and also correspond to both the positioning recesses 52. A pair of semicircular protrusions 58 are provided to extend in the axial direction of the annular protrusion 55.

The annular projection 5 of the rear pressing member 54 is arranged so as to be connected to the front surface of the rear wall portion 46 of the second yoke member 44.
A thin annular retaining ring 60 is fitted onto the outer surface of the retaining ring 5 . A pair of locking spring pieces 61 and a pair of recesses 62 are provided on the inner peripheral edge of the retaining ring 60, respectively.
They are formed to face each other at 180 degrees.
Then, both the recesses 62 are fitted into the semicircular projection 58 of the annular projection 55, and both the locking spring pieces 61 are fitted into the projection 55.
By getting over 7 and locking them,
A retaining ring 60 is assembled and held within the second yoke member 44 to the rear presser member 54 . or,
A second yoke member 4 is attached to the outer peripheral edge of the retaining ring 60.
A plurality of spring protrusions 63 that fit into each of the fitting grooves 48 of 4.
are arranged in a row, and each armature 38 is pressed forward by the spring force of these spring protrusions 63,
The fitting between the projection 39 and the recess 26 of the shaft support piece 25 is maintained.

Further, on the front side of the retaining ring 60, a ring-shaped synthetic resin sheet 65 is fitted onto the annular projection 55 of the rear pressing member 54. A plurality of protrusions 66 corresponding to the spring protrusions 63 of the retaining ring 60 are arranged in rows on the outer peripheral edge of the synthetic resin sheet 65. Each protrusion 66 is attached to the retaining ring 6.
By being located between the spring protrusion 63 of 0 and the armature 38 and exerting a sliding action, the armature 38 can rotate smoothly.

As shown in FIGS. 2, 3, and 4, the first yoke member 1 and the second yoke member 44 are assembled together by an assembly member 68. As shown in FIGS. Assembly member 6
Reference numeral 8 indicates a central annular portion 69 and three leg portions 7 that protrude from the outer periphery of the annular portion 69 and are bent forward.
2 and a plurality of pressing pieces 70 that protrude from the center of the base end of each leg 72 to both sides in the circumferential direction of the annular portion 6 and are slightly bent forward, are integrally constituted by a leaf spring. A locking piece 71 is provided at the tip of each leg portion 72, and by fitting and locking the locking piece 71 into a locking recess 73 formed on the outer surface of the first yoke member 1, each of the pressing pieces 70 The first yoke member 1 and the second yoke member 44 are assembled and held together through the pressing action of. Note that three recesses 74 are formed on the outer peripheral surface of the rear presser member 74 in correspondence with each leg portion 72 of the assembly member 68. Further, as shown in FIG. 5, yoke pieces 49d, 49e, 49f of the second yoke member 44 corresponding to each leg 72
are formed thin so that the leg portions 72 do not protrude outward.

Next, the case of assembling the print head of this embodiment constructed as described above will be explained.

First, in FIG. 3, the semicircular projection 58 is aligned with the positioning recess 52, and the annular projection 55 of the rear holding member 54 is inserted into the opening 45 of the second yoke member 44. Next, each spring protrusion 63 is inserted into each fitting groove 48.
Attach the retaining ring 60 to the second yoke member 4.
4, and the locking spring piece 61 of the retaining ring 60 is locked to the projection 57 of the annular projection 55. In this way, the rear pressing member 54 and the retaining ring 60 are attached to the second yoke member 44 in a manner that cannot be separated. Subsequently, the synthetic resin sheet 65 is attached to the annular protrusion 55 with each protruding piece 66 aligned with each fitting groove 48 , and superimposed on the retaining ring 60 .

Next, the support member 16 with the armature 38 accommodated in each accommodation groove 22 is assembled to the second yoke member 44. In this case, if the upper insertion hole 34 and side insertion holes 35, 36 of the support member 16 are inserted into the three yoke pieces 49a, 49b, 49c of the second yoke member 44, as shown in FIG.
The support member 16 can be easily positioned in the circumferential direction with respect to the second yoke member 44. At this time, the second
The yoke member 44 and the support member 16 may be bonded to each other at their outer peripheral portions using an adhesive or the like. Subsequently, the support member 16 and the second yoke member 44 assembled in this way are assembled to the first yoke member 1. At this time, each positioning protrusion 29, 32 of the support member 16 is aligned with the first yoke member 1. If the support member 16 and the second yoke member 1 are fitted into the notch 30 and the groove 33 of the
The circumferential positioning of the yoke member 44 is automatically performed.

After the first yoke member 1, support member 16, and second yoke member 44 are integrated, the assembly member 68 is attached to them from the rear side, and each leg 7
The second locking piece 71 is locked in each locking recess 73 of the first yoke member 1. In this way, the first yoke member 1 and the second yoke member 44 housing the support member 16 can be reliably assembled by the spring force of the pressing piece 70 of the assembly member 68.

Effects of the invention As detailed above, in this invention, the magnetic flux generated by the electromagnet is introduced from the side surface of the armature from the outer wall of the first yoke member to the peripheral wall of the second yoke member. . For this reason,
Even if the width of the armature in the circumferential direction is reduced, a sufficient magnetic path can be secured, and the number of armatures, that is, the number of printed dots can be increased. In addition, by manufacturing the outer wall of the first yoke member 1 and the second yoke member separately, the rear end surface of the outer wall of the first yoke member and the suction surface of the core can be placed on the same plane. It is possible to easily align the suction surfaces of each core uniformly. Furthermore, the armature is supported in the radial accommodation groove of the support member,
By accommodating the support member inside the second yoke member, the electromagnet and the armature can be easily assembled in a state in which they correspond accurately.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of a printing head showing an embodiment of this invention, Fig. 2 is a partially cutaway rear view, Fig. 3 is an exploded perspective view of each part, and Fig. 4. is a side view showing the assembled state, and Fig. 5 is a side view showing the assembled state.
FIG. 3 is a front view showing a state in which the yoke member and the support member are assembled. In the figure, 1 is the first yoke member, 3 is the front wall, 4 is the outer wall, 5 is the core, 7 is the coil, 12 is the electromagnet, 13 is the adsorption surface, 14 is the rear end surface, 16 is the support member, and 22 is the 24 is a compression spring, 25 is a shaft support piece, 38 is an armature, 42 is a printing wire, 44 is a second yoke member, 47 is a peripheral wall portion, 4
8 is a fitting groove, 50 is a front end surface, 54 is a rear pressing member, 60 is a retaining ring, 65 is a synthetic resin sheet,
68 is an assembly member.

Claims (1)

[Claims for Utility Model Registration] 1. A substantially circular front wall 3, an annular outer wall 4 extending rearward from the outer periphery of the front wall 3, and a front wall extending along the inner surface of the outer wall 4. The first yoke member 1 has a plurality of cores 5 protruding from the rear surface of the portion 3 at equal intervals, and a plurality of electromagnets 12 are provided by winding a coil 7 around the outer surface of each core 5. and arranged at the rear of the first yoke member 1,
Accommodation grooves 22 extending radially at positions facing each of the electromagnets 12 and their accommodating grooves 22
a support member 16 having shaft supports 25 located outwardly from each other; and an attraction surface 13 of the core 5 of the electromagnet 12.
an armature 38 which is disposed in each housing groove 22 so as to face the armature 38 and whose base end is supported by the shaft support 25 and is rotatable back and forth;
A printing wire 42 that performs a printing operation by rotation of the armature 38 in conjunction with excitation of the electromagnet 12 and the support member 16 are housed therein, and are joined to the rear end surface 14 of the outer wall portion 4 of the first yoke member 1. Annular peripheral wall portion 47 and each armature 38
a second yoke member 44 having a plurality of fitting grooves 48 arranged in a peripheral wall portion 47 of the second yoke member so as to correspond to the positions of the second yoke member 44; 2. The support member 16 has a plurality of protrusions 25 on its outer periphery that fit into the fitting grooves 48 of the second yoke member 44. Utility model registration claim 1
Print head as described in section.