JPS63153156A - Wire dot head - Google Patents

Abstract

PURPOSE:To realize wire driving having an excellent vibration damping performance against rebounding of wire and a high speed stability, by constructing such that a movable member is held at a non-operating position through a return spring and a stopper, and forming the stopper from complex material composed of rubber-like resilient material of different quality. CONSTITUTION:When power is fed to a coil 20, a movable member 26 and a plunger 27 are attracted to a core 18 so as to project a wire 15. when power is interrupted from the coil 20, the movable member 26 and the plunger 27 are reset to a non-operating position where they contact with a stopper 31 by means of a return spring 30. The stopper 31 is composed of inner and outer layers 36, 37 composed of rubber-like material having different quality. Consequently, the stopper 31 exhibits double-stage shock-absorbing performance when the movable member 26 collides against the stopper 31, thereby vibration damping performance against rebounding can be improved correspondingly resulting in stable motion of wire during high speed printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to the structure of a recording head (wire dot head) of a wire dot type recording apparatus.

[Prior art]

A wire dot type recording device is one type of recording device such as a printer or a facsimile machine.

This wire dot type recording device drives a plurality of wires (for example, 24 or 32 wires) to protrude based on a print data signal, and hits a sheet (recording medium such as paper) with the tip of the wire through an ink ribbon. This is an impact type recording device that forms dot patterns.

The recording head of this type of recording device, that is, the wire dot head, guides and holds a plurality of wires connected to a movable member operated by electromagnets so that they can protrude from the front end surface of the body, and each electromagnet is connected to a print data signal. The wire is configured to be actuated to drive a predetermined wire to protrude.

This wire dot hand is generally mounted on a carriage that scans along the sheet, and feeds the ink ribbon between the sheet and the ink ribbon at predetermined intervals based on print data signals in synchronization with the movement of the carriage. The movable member and the wire are configured to be driven by the movable member and the wire.

Each wire and movable member is held in a non-operating position by a return spring and a stopper, and when the corresponding electromagnet is energized, it is driven to protrude against the return spring, and when the energization is stopped, the return spring causes the stopper to move. It is returned to the non-operating position where it is pressed into contact.

[Problem that the invention seeks to solve]

Incidentally, as the stopper, a stopper made of a rubber-like elastic material has been proposed from the viewpoint of absorbing the impact when the dot wire returns to improve durability and reducing noise.

However, conventional stoppers were made of a relatively soft rubber-like elastic body with a single property (i.e., although they were excellent in shock absorption and noise reduction, their vibration damping ability was insufficient, and wire and There was a problem in that the speed at which the movable member rebounds after hitting the stopper is high (the rebound is large), so the behavior of each dot wire tends to become unstable, making high-speed printing difficult.

〔the purpose〕

An object of the present invention is to provide a wire dot head that can solve the problems of the prior art, has excellent vibration damping ability when the wire rebounds, and can realize stable wire drive even at high speeds.

[Means for achieving the goal]

The present invention provides a wire dot head in which a plurality of wires are driven to protrude by a plurality of movable members operated by electromagnets, each of the movable members is held in a non-operating position by a return spring and a stopper, and the stopper is By forming it from a composite made of rubber-like elastic material,
This aims to achieve the above objectives.

[Effect]

Since the stopper is formed of rubber-like elastic materials having different properties such as spring constant, repulsion coefficient, or hardness,
Nonlinear, two-stage shock absorption ability is obtained, and high vibration damping ability can be demonstrated by deceleration during rebound.

〔Example〕

The present invention will be specifically described below with reference to the drawings.

FIG. 4 illustrates a wire dot type recording device equipped with a wire dot head according to the present invention. In FIG. 4, a guide rail 3 is installed in front of and parallel to a platen 2 for puncturing a recording device medium (sheet) 1 such as paper or a thin plastic plate, and a carriage moves along this guide rail. A recording head (wire dot head) 5 is mounted on the recording head 4 .

Further, a ribbon cassette 6 for feeding an ink ribbon for transfer between the wire dot head 5 and the sheet 1 is replaceably mounted on the carriage 4.

During recording, the wire dot head 5 is driven based on the print data signal while the carriage 4 is driven to main scan the sheet l, and the wire dot head 5 is moved to the sheet and the wire dots.
An operation is performed to feed the ink ribbon between the two and the two cards.

FIG. 1 shows a wire dot head 5 according to an embodiment of the present invention.
FIG.

In FIG. 1, a tip guide 12 and an intermediate guide 13.1 are provided on a body 11 made of aluminum die-casting or the like.
A plurality of wires 15 (for example, 24 wires) are guided and supported by the wires 4 .

A housing-shaped yaw 16 made of a material with excellent magnetic properties such as silicon steel is attached to the rear side of the body 11, and is used to drive each of the plurality of wires 15 within the yoke 16. A plurality of electromagnets 17 are arranged in the circumferential direction.

Each electromagnet 17 includes a core 18 formed integrally with the yoke 16 and a coil 2 supported by a bobbin 19 surrounding the core.
It consists of 0.

Note that each coil 20 is energized via a terminal 22 from a flexible cable 21 attached to the end surface of the yoke 16.

A disk-shaped auxiliary yoke 23 made of a material with good magnetic properties such as silicon steel is attached to the rear side of the housing-shaped yoke 16. A metal hack cover 24 is attached.

Openings 25 are formed in the auxiliary yoke 23 to correspond to the cores 18 of the electromagnets 17, and a movable member 260 and plunger 27 protrude through these openings 25 to a position close to the cores 18.

The plunger 27 is fixed to a movable member 26 arranged on the back side of the auxiliary yoke 23.

Each movable member 26 forms an armature lever of the electromagnet 17, and is held by having its base fitted into a post 28 and pressed against the auxiliary yoke 23 by an armature pressing spring 29.

The proximal end of the wire 15 is connected to the distal end of each movable member 26 by caulking, soldering, or the like.

Further, each movable member 26 is moved to the core 1 by a return spring 30.
8 (downward in FIG. 1), and is positioned and supported by a stopper 31 at a non-operating position forming a predetermined gap with the core 18.

Each return spring 30 is held by a plastic subbody 32 fixed to the inner diameter of the auxiliary yoke 23.

On the other hand, the stopper 31 has a ring shape and is fixed to a damper member (eg, an inertial member made of Zn or the like having high vibration damping properties) held within the bank cover 24. In the illustrated example, this damper member 33 is a damper pressing spring 3.
It is held floating by 4.

Further, the other end of the armature pressing spring 29 is also connected to the damper member 33.

Each wire 15 is driven to protrude by driving (energizing) the corresponding electromagnet 17, and records a dot pattern on the sheet 1 via the ink ribbon 35.

That is, when the coil 20 is energized, a closed magnetic flux is formed through the core 18, the plunger 27, the auxiliary yoke 23, and the yoke 16 as shown by the chain double-dashed line Φ, and the magnetic force causes the movable member 26 and the plunger 27 to resist the return spring 30. The wire 15, which is attracted to the core 18 and coupled to the movable member 26, is driven to protrude.

When the coil 200 is de-energized, the magnetic force disappears, and the movable member 26 and the plunger 27 are returned by the return spring 30 to the non-operating position in which they abut the stopper 31.

Although the stopper 31 is made of a rubber-like elastic material in order to improve its shock absorbing ability, according to the present invention, it is made of a composite body made of different rubber-like elastic materials.

FIG. 2 illustrates the structure of the stopper 31, and the ring-shaped stopper 31 is composed of an inner layer (or lower layer) 36 and an outer layer (or upper layer) 37 having different properties.

For example, the inner layer 36 may have a high hardness (for example, 60 in JIS hardness).
The outer layer 37 is made of a rubber-like elastic material with a low hardness (
For example, it can be formed of a rubber-like elastic material with a JIS hardness of about 40).

In another embodiment, the inner layer 36 may be made of a soft elastic material and the outer layer 37 may be made of a hard elastic material.

Furthermore, the layers 36 and 37 made of different materials may include at least one layer of different hardness, an elastic material with a different spring constant, or an elastic material with a different coefficient of repulsion, which has a property that affects the rebound operation of the movable member 26 in the event of a collision. At least two elastic materials having different elastic properties can be employed.

During recording, the electromagnet 17 is driven at predetermined intervals and the wire 15 is repeatedly projected and retreated, and at this time the movable member 26 repeatedly collides with the stopper 31.

However, according to the present invention, since the stopper 31 is formed of a composite of rubber-like elastic materials 36 and 37 made of different materials,
When the movable member 26 collides with the stopper 31, the spring characteristics are non-linear and exhibit shock absorption in multiple stages (two stages in the case of two types), and the speed (i.e. amplitude) at the time of rebound is determined by the vehicle material. The vibration damping ability during rebound can be improved accordingly.

That is, if FIG. 3(A) shows the vibration behavior during rebound in the case of a conventional stopper made of a single rubber-like elastic material, as described above, the stopper 31 is made of a composite of rubber-like elastic materials made of different materials. The vibration behavior in the case of forming is as shown in FIG. 3(B).

According to the embodiments described above, the following effects could be obtained.

(1) The stopper 31 that regulates the return position of the wire 15 has a composite structure that combines rubber-like elastic bodies with different elastic behaviors such as spring constants, so the spring constant is nonlinear and suddenly increases midway through. can be made into spring characteristics,
As a result, the rebound speed when the movable member 26 returns to the non-operating position and collides with the stopper 31 can be reduced more rapidly than before (FIG. 3(B)), and even in high-speed printing, the movable member 26 and It is possible to prevent the wire 15 from bouncing back, stabilize the operation, and ensure stable recording operation.

(ii) Since the stopper 31 can be made of a rubber-like elastic material with a desired hardness, the same effects as in the case of conventional single material can be maintained in terms of shock absorption ability, noise prevention effect, and improved durability. .

In the illustrated embodiment, the stopper 31 is made of two types of materials 3.
6.37, but depending on the case, it can be made of three or more types of materials.

〔effect〕

As is clear from the above description, according to the present invention, it is possible to effectively reduce the rebound speed when the movable member repeatedly collides with the spacing during wire drive, and improve the vibration damping ability. , a wire dot head capable of stabilizing the movement of the wire even during high-speed printing is obtained.

[Brief Description of the Drawings] Fig. 1 is a longitudinal sectional view of a wire door head according to an embodiment of the present invention, Fig. 2 is a partially sectional perspective view of the stopper in Fig. 1, Fig. 3 (A), (B) is a graph illustrating the rebound characteristics of the stopper shown in FIG. 2 in comparison with that of a conventional stopper, and FIG. 4 is a perspective view of a main part of a wire dot type recording device using a wire dot head according to the present invention. . 15・−・−・−Wire, 17−・−・−・・−・
・Electromagnet, 26---Movable member, 30-
−−−−−−−−−One return spring, 31−−−−−・−・
-Stopper, 36.37-・----- Rubber-like elastic material made of different materials.

Claims (1)

[Claims] (1) In a wire dot head in which a plurality of wires are driven to protrude by a plurality of movable members operated by electromagnets, each of the movable members is held in a non-operating position by a return spring and a stopper, and the stopper is made of a different material. A wire dot head characterized in that it is formed of a composite body made of a rubber-like elastic material.