JP3473793B2 - Dot line printer shuttle mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shuttle mechanism of a dot line printer which prints while reciprocating a hammer bank having a plurality of hammers for printing hammers using a linear motor.

[0002]

2. Description of the Related Art The structure of a conventional shuttle mechanism will be described with reference to FIG.

A hammer bank 1 in which a plurality of printing hammers are arranged is provided with a pair of left and right linear bushings 5 that also function as a support portion of the hammer bank 1 and one linear bushing 6 in the center. The hammer shift plate 10 is fixed to the hammer shift plate 10, and the hammer shift plate 10 is slidably supported by two guide shafts 12 which serve as guides for reciprocating the hammer bank 1 in the column direction. Further, the coil 2 which also serves as a balancer for preventing vibration of the hammer bank 1 is held by a coil shift plate 11 having at least three linear bushings 7, and the coil shift plate 11 is mounted on the guide shaft 12 above. It is supported so that it can reciprocate in the girder direction. The hammer shift plate 10 and the coil shift plate 11 are connected by at least one wire 22, and a pair of left and right pulleys 21 pivotally supported by a side block 20 operate on the two guide shafts 12 in opposite phases. And is fixed to a mechanical base (not shown) at points A and B of the side block 20.

[0004]

The problems of the conventional shuttle mechanism will be described in detail below.

First, the shuttle mechanism is a hammer bank 1
In order to smoothly perform a reciprocating motion in the digit direction to perform the printing operation, the pulley 21 connected by the hammer bank 1 and the wire 22 for the purpose of reducing the vibration of the entire shuttle mechanism.
The coil 2 also functions as a balancer that reciprocates in opposite phases via the. According to the prior art, there are two guide shafts 12 that serve as guides for reciprocating motion, and assembly accuracy between the guide shafts 12 is required. Further, since the hole of the side block 20 supporting the guide shaft 12 is a through hole, the workability when inserting the guide shaft 12 is also poor.

Secondly, the printing reaction force from the hammer bank 1 is transmitted to the linear bushing 5, the guide shaft 12, and the supporting portions of the left and right side blocks 20. If the supporting rigidity is insufficient, the hammer gap changes due to the action of the printing reaction force, and the print density is lowered, the dot position is disturbed, etc., and the print quality is greatly lowered. Due to the characteristics of the printing hammer, the allowable change in the gap is several tens of μm.

Thirdly, the shuttle mechanism is a hammer bank 1
Also, the reciprocating motion of the balancer causes acceleration in the girder direction to reach a maximum of 5 G or more, and vibration due to the acceleration causes displacement in the girder direction. In order to prevent this, it is necessary to increase the rigidity of the side block 20 that supports the printing reaction force, which results in a heavy and expensive mechanism.

An object of the present invention is to provide an inexpensive shuttle mechanism section having excellent maintainability without lowering the rigidity of the shuttle mechanism.

[0009]

The above-mentioned object is to provide a guide shaft 12 which serves as a guide for reciprocating motion of a hammer bank 1.
It is supported by a book and the other fulcrums are ball bearings (hereinafter referred to as "B.
This is achieved by setting B). Further, the deformation of the guide shaft 12 due to the printing reaction force causes the supporting point to be at least 3
Achieved by supporting above points. Further, it is achieved by forming a groove in the guide shaft 12 and forming one of the frame stands 25 supporting the guide shaft 12 as an open hole.

[0010]

The shuttle mechanism constructed as described above can provide a dot line printer which is easy to disassemble, assemble and maintain without degrading print quality.

[0011]

Embodiments of the present invention will be described with reference to FIGS.

In FIG. 1, a hammer bank 1 is fixed by a pair of linear bushings 5 which also serve as a supporting portion thereof,
There is a hammer shift plate 10 that is mounted so as to be slidable in a column direction on one guide shaft 12 and that holds the linear bushing 5 as a rotation stop of the hammer bank 1. The hammer shift plate 1
0 is a pair of B.I. It is sandwiched from above and below by B15 to prevent rotation and also have a sliding property. Further, the coil 2 for the linear motor, which is sandwiched by magnets (not shown) having different poles in the upper and lower sides and also serves as a balancer, is held by a coil shift plate 11 having a linear bushing 7,
It is mounted on the guide shaft 12 of the book. In addition, the coil shift plate 11 is provided on the linear bushing 7 near the apex of the isosceles triangle. The coil shift plate 11 is sandwiched at B16 from above and below to provide slidability. The hammer shift plate 10 and the coil shift plate 11 are connected to a belt 22 and at least
It is mounted for movement in opposite directions by a pair of supported pulleys 21. Guide shaft 12
Is supported by a frame stand 25 made of thin sheet metal. Further, in order to support the printing force from the hammer bank 1, a shaft guide 30 is provided at least at one position outside the stroke range of each linear bushing (in the case of one position, approximately in the center, and in the case of two or more positions, at equal intervals). There is. Due to this support, the guide shaft 1 as in the prior art
It is possible to have rigidity equal to or higher than that without supporting the stand with high rigidity such that both ends of 2 become fixed ends.

The frame stand 25 is provided with a protrusion 26 as shown in FIG. 2 in the vicinity of the guide shaft support portion, and is abutted against the surface of a mechanical base stay 27 (not shown) for fixing the shuttle mechanism. The shuttle mechanism is positioned in the printing direction. Further, the groove 28 provided on the mechanical base surface and the projection 26 are fitted to each other, so that the shuttle mechanism can be prevented from shaking in the direction of the girder and backlash, and the dot position deviation can be prevented.

A groove is provided at one end of the guide shaft 12, and the shaft fixing hole of the frame stand 25 on the groove side is an open hole having a width that allows the groove to pass, whereby the hammer shift plate 10, the coil shift plate 11, etc. are attached. It can be easily attached and detached while it is being held, and maintainability can be improved.

[0015]

According to the present invention, the support method for the printing force acting on the shuttle mechanism and the construction of each member are devised, so that the maintainability can be improved without lowering the printing quality and the cost is low. A dot line printer can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of a shuttle mechanism portion according to the present invention.

FIG. 2 is a detailed view of a protrusion of the frame stand in FIG.

FIG. 3 is a prior art shuttle mechanism section.

[Explanation of symbols]

1 is a hammer bank, 2 is a coil, 5, 6, and 7 are linear bushings, 10 is a hammer shift plate, 11 is a coil shift plate, 12 is a guide shaft, and 15 and 16 are B.I. B and 21 are pulleys, 22 is a belt, 25 is a frame stand, and 30 is a shaft guide.

Continuation of front page (72) Genichiro Kawamichi 1060 Takeda, Hitachinaka City, Hitachinaka City, Ibaraki Pref. Within Hitachi Koki Co., Ltd. (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/22 B41J 19/18 B41J 19 / 20

Claims (3)

(57) [Claims] 1. A hammer bank provided with a plurality of dot printing hammers and reciprocating in a digit direction, and a balancer reciprocating in a phase opposite to that of the hammer bank, through a linear bushing on a guide shaft. In a dot line printer that is slidably supported and has a shuttle mechanism that uses a linear motor as a drive source for a hammer bank and a balancer, the hammer bank and the balancer are arranged on a single guide shaft via a linear bushing. A shuttle mechanism for dot line printers that guides in a slidable direction. 2. A shuttle mechanism for a dot line printer according to claim 1, wherein the guide shaft is supported on the shuttle mechanism section at at least three points at both ends and substantially the central portion. 3. The guide shaft according to claim 1, wherein a circumferential groove is provided at one end of the guide shaft (so that the guide shaft can be detached with the hammer bank and the balancer attached by moving the guide shaft in the small amount girder direction during disassembly and assembly). And a frame stand near one end of the guide shaft is provided with an opening hole that engages with the circumferential groove of the guide shaft.