JPH0667625B2 - Print wire drive for wire type dot printer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a drive device for a print wire in a wire type dot printer.

(Prior Art) In a wire type dot printer, since it is necessary to collectively arrange a required number of print wires in a limited space so that they can be driven, it is usually found in Japanese Patent Publication No. 58-35475. In addition, a structure is adopted in which a plurality of swingable drive plates forming a part of the magnetic path are radially arranged, and a print wire is fixedly attached to each of these tips.

However, in such a structure, the head is inevitably large and the inertia of the drive plate is large because the tip of the drive plate is thin in providing a cross-sectional area according to the magnetic flux density. There arises a problem that the response characteristic is deteriorated.

(Object) The present invention has been made in view of the above problems, and an object of the present invention is to form this portion as thin as possible by removing the tip of the drive plate from the path of the magnetic flux, and thus It is an object of the present invention to provide a new wire type dot printer which can achieve a more dense arrangement and a drastically downsized print head.

(Structure) That is, in order to achieve such an object, the present invention provides a plate-like member which is arranged in a direction orthogonal to the axial center of the head and which constitutes a part of a magnetic path, with a slit according to the magnetic pole of the coil core. And a plate-shaped print wire driving member in which magnetic pieces are laminated in the slits in a direction parallel to the magnetic flux of the coil core is arranged so as to be swingable in the axial direction of the head. Located in the wire drive.

Therefore, details of the present invention will be described below based on illustrated embodiments.

Each of the drawings shows an embodiment of the present invention. In the drawings, reference numeral 1 is a frame having a wire nose 2 at its tip, and the inner surface of the frame is made of a magnetic material positioned on a dowel 3 and is shallow. A bottom cylindrical core block 6 is integrally fixed. The core block 6 attracts a drive rod 15 described later together with a bottomed cylindrical yoke 10 and a disk-shaped side yoke 12, which will be described later. Twelve coils 7 are wound around the inner surface of the core rod 6. Of the bottomed cylindrical yoke 10 positioned by the cylindrical portion 4 projecting on the inner surface of the frame 1 on the end surface of the cylindrical portion 9 defining the outer periphery. The cylindrical end faces come into contact with each other, and a fixed gap is formed between the plate surface and the top of the core 8 by the cylindrical part, and the cylindrical block is assembled so as to form a magnetic flux circulation path. There is. Reference numeral 12 is a disk-shaped side yoke made of a magnetic material and similarly positioned by the tubular portion 4 of the frame 1 and laminated on the yoke 10, and as shown in FIG. Twelve radial slits provided on the plate surface with gaps that allow the drive plate 15 to swing.
11 and 13 are formed, and in the vicinity of the outer ends of these radial slits 13, lateral grooves 14 are formed in a cross shape,
The upper and lower sides of the lateral groove 14 are a bottomed cylindrical yoke 10 attached to the front and back surfaces of the side yoke 12, and a resin holding plate 20 described later.
The lateral groove 14 is formed as a pin 16 holding portion of the drive rod 15 by being surrounded by the respective surfaces.

By the way, the above-mentioned drive rod 15 has a print wire 17 fixed at its tip by swinging about a pin 16 as a fulcrum.
Of the drive rod 15 which is formed as thin as possible so as to reduce the inertia and is opposed to the core 8 as shown in FIG. Two ferromagnetic pieces 18, 18 are integrally attached to both sides of the part to be welded by welding a common pin 18a part inserted therethrough, and at the same time, a sufficient magnetic action area is secured. A spring that is configured to reduce the eddy current loss as much as possible by stacking, and is always interposed between the tubular portion 4 of the frame 1 and the drive rod 15.
Biased to the non-printing position by 19.

Although the basic structure of the printer head according to the present invention is exhausted by the above description, in this embodiment, the core block 6'positioned by the dowel 21 on the holding plate 20 and a part of the magnetic path are formed. A bottom cylindrical yoke 10 'and a disk-shaped side yoke 12', and a printed wire 1 at the tip.
A printer head assembly including twelve drive rods 15 'provided with 7'and a pressing plate 19' made of a resin material and the like is stacked on the pressing plate 20 and driven by the upper and lower printer head structures. For convenience, the 24 print wires 17 and 17 'are guided by the wire guide 23 provided in the wire nose 2 so that the sole surface
It is configured to project from 26.

In the figure, reference numeral 22 is a nose cover positioned and fixed by the dowels 5 on the frame 1, and 24 and 24 'are printed circuits interposed between the frame 1 and the core block 6 and between the holding plate 20 and the core block 6'. The base plate 25 is a tightening plate suspended from the upper surface of the pressing plate 20 'and the lower surface of the nose cover 21.

Next, the operation of the apparatus thus configured will be described.

When a current is applied to one or more drive coils 7 selected based on the print command signal, the flow of the magnetic flux from the core 8 is divided into two as shown in FIG. The closed magnetic circuit a (first part) which enters the inside from the pole piece surfaces of the radial grooves 11 and 13 formed in the yoke 12 and the bottomed cylindrical yoke 10 and returns to the core 8 via the core block 6 again (first
The magnetic flux flowing in the side yoke 12 and the cylindrical yoke 10 with a bottom is formed in the radial grooves 11 and 13 in accordance with this, and the ferromagnetic pieces 18 and 18 of the driving rod 15 which are close to each other here. Forming a detour b passing through the inside of. Therefore, the drive rod 15, which has been in the non-printing posture, that is, the rotation posture separated from the core 8 by the spring 19, first receives the magnetic flux flowing through the bypass b and is attracted to the core 8 side. As shown in (b), it is directly attracted by the magnetic flux from the core 8 and rotated counterclockwise in the figure, and the print wire 17 held at the tip is struck on the recording paper via an ink ribbon (not shown).

In the above-described embodiment, the driving rod 15 and the ferromagnetic pieces 18, 18 are fixed to each other by welding at the portion of the pin 18a inserted through them, but the insulating film is formed on the surface of these pieces 18, 18. In addition, the eddy current loss can be further reduced by fixing it to the drive rod 15 with an adhesive, and as shown in FIG. 5, the two ferromagnetic pieces 38, 38
If they are integrally formed so that they can be bent at the boundary, and the drive rod 35 is sandwiched between them to be integrally connected by the dowels 39, the assembling can be further facilitated.

(Effect) As described above, according to the present invention, the slit is formed on the plate-shaped member which is arranged in the direction orthogonal to the axis of the head and which constitutes a part of the magnetic path in accordance with the magnetic pole of the coil core. In addition, since the print wire driving member in which magnetic pieces are laminated in a direction parallel to the magnetic flux of the coil core is swingably arranged in this slit, the driving member is driven by the magnetic flux flowing in the plate thickness direction of the driving member. It is possible to suppress the loss due to the eddy current generated in the drive member of the print wire, thin the tip of the drive member to an allowable limit in terms of strength, and collect this part in the center of the head as much as possible. This allows the printer head to be significantly downsized while at the same time allowing the print wires to be guided to the tip of the nose without bending them. It is possible to reduce friction with the guide and reduce the mass of the tip end portion of the drive member as much as possible, thereby significantly improving the response characteristic.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an apparatus showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of a main part of the same apparatus, and FIG. 3 is an enlarged view of a drive rod. FIG. 4 is an exploded perspective view, FIGS. 4 (a) and 4 (b) are explanatory views showing the print driving operation, and FIG. 5 is a sectional view showing another embodiment of the drive rod. 1 …… frame, 6 …… core block 8 …… core, 10 …… bottomed cylindrical yoke 12 …… side yoke 15 …… driving rod, 17 …… print wire 18 …… ferromagnetic piece, 20 …… presser Board

Claims (1)

[Claims] 1. A head is disposed in a direction orthogonal to the axis of the head,
In addition, a plate-shaped printed wire drive in which a slit is formed on a plate-shaped member that constitutes a part of the magnetic path in accordance with the magnetic pole of the coil core, and a magnetic piece is laminated in the slit in a direction parallel to the magnetic flux of the coil core. A print wire driving device in a wire type dot printer, wherein a member is arranged so as to be swingable in the axial direction of the head.