JPS61154950A - Printing head for wire dot printer - Google Patents

Abstract

PURPOSE:To prevent the lowering in printing quality by preventing the vibration of a wire, by guiding and supporting a wire and an armature by a single guide member. CONSTITUTION:An armature 25 is attracted to the leading end surface of core against the sporting force of a coil spring 28 by the magnetic force of a permanent magnet 22 but, when a coil 24 is excited, the magnetic force of the permanent magnet 22 is negated and the armature 25 is pressed to the direction spaced apart from the leading end surface of the core 23. A wire 26 is protruded to the outside from the slot 34 of a guide member 32 to perform printing operation. Because the wire 26 and the armature 25 are guided and supported by the single guide member 32, the clearance between the wire 26 and the slot 34 of the guide member 32 or the clearance between the armature 25 and the armature guide part 35 of the guide member 32 can be set min. regardless of the mounting position accuracy of the guide member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head for a wire dot printer, and more particularly, the present invention relates to a print head for a wire dot printer, and more particularly, to a print head having a single armature and a single dot printing wire provided at the tip of the armature. The present invention relates to an improvement in a print head equipped with a printhead.

[Prior art]

2. Description of the Related Art Conventionally, a wire dot printing method has been known that uses a print head having a single armature and a single dot printing wire provided at the tip of the print head. When this type of print head is used alone in a printer, the print head is installed so that it can reciprocate in the longitudinal direction of the platen over the entire width of one line of the print medium, but normally the print head is installed as shown in FIG. Shuttle 2 parallel to 1
A plurality of print heads 3 are arranged at regular intervals in the longitudinal direction of the print medium 4, and each print head 3 is configured to reciprocate together with the shuttle 2 within a section of one line width of the print medium 4.

5 and 6 illustrate a conventional open-circuit printhead structure having a single armature and a single wire as described above. Referring to these figures, the magnetic path forming member 6 that holds the permanent magnet 5 has an electromagnet core 7.
An excitation coil 8 is attached to the outer periphery of the core 7. The base end side of the armature 10, which has a dot printing wire 9 implanted at its tip, is arranged on one end of the magnetic path forming member 6. The base end side of the armature 10 has a pair of ears 11 that protrude to both sides, and the side surfaces of the ears 11 are the recesses of the armature guide 12 attached to the one end side of the magnetic path forming member 6. 13 is fitted. The wire 9 is guided and supported in a long hole 14 of a wire guide 14 attached to the other end of the magnetic path forming member 6.

The distal end side of the armature 10 is always biased by a coil spring 17 in a direction away from the core 7, that is, in a direction in which the wire 9 protrudes outward from the wire guide 14. As a result, the core 7 is attracted to the tip end surface of the core 7 against the force of the coil spring 17.

When the coil 8 is excited, the magnetic force of the electromagnet cancels the magnetic force of the permanent magnet 5, and as a result, the coil spring 17
The armature 10 is separated from the core 7 by the spring force, and at the same time, the wire 9 projects outside the wire guide 14. Fourth
Referring to the figure, the protruding wire 9 is connected to the ink ribbon 18.
Dot printing is performed on the print medium 4 on the platen 1 via the dot.

[Problem that the invention seeks to solve]

In the conventional wire dot printer print head described above, the armature guide 12 and the wire guide 1
Since the armature guide 12 and 4 are formed separately and positioned separately with respect to the magnetic path forming member 6,
Furthermore, when installing the wire guide 14, there is a risk that galling may occur between the wire and the wire guide or between the armature and the armature guide due to positional accuracy errors. For this reason, armature 10 and armature guide 1 are usually
2 and the recess 13, and
Measures have been taken to increase the clearance between the wire 9 and the hole 15 of the wire guide 14, but if the armature 10 or the armature guide 12 begins to wear out, the behavior of the armature 10 becomes unstable, and at the same time the wire 9 The behavior of the printer also becomes unstable, which causes the print quality to deteriorate.

[Means for solving problems]

As a means for solving the above problems, the present invention provides an excitation coil that is held in the core of an electromagnet provided in a magnetic path component, and a dot printing device that is attached to the tip of an armature that extends across the tip of the core. The base end side of the armature is placed on a support surface provided on one end side of the magnetic path forming member, and the tip of the armature is placed on the other end side of the magnetic path forming member. A spring is provided on one end side of the magnetic path component to urge the armature away from the tip of the core, and the armature is pulled toward the tip of the core against the force of the spring. A permanent magnet is installed for
In a print head for a wire dot printer, the wire printing operation is performed by separating the armature from the tip of the core by canceling the magnetic force of the permanent magnet by excitation of the coil,
A guide member having an elongated hole through which the wire passes and an armature guide portion that guides a side surface of the proximal end of the armature is attached to a support member provided on the other end side of the magnetic path forming member. To provide a print head for a wire dot printer.

[Effect]

According to the above means, since the wire and the armature are guided and supported by a single guide member, the mounting of the guide member is determined by the clearance between the wire and the elongated hole of the guide member and the clearance between the wire and the elongated hole of the guide member and the armature and the guide member, regardless of the positional accuracy. The clearance between the member and the armature guide portion can be set to a minimum. Therefore, it is possible to prevent the wire from wobbling and to prevent deterioration in print quality. Further, since the clearance between the wire and the elongated hole of the guide member can be reduced, it is possible to prevent the wire from swinging even if the armature or the armature guide portion of the guide member is worn out. Therefore, deterioration in printing quality due to wear of the armature etc. can be prevented.

C Example] An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIGS. 1 to 3, the print head for an open type wire dot printer is equipped with a base member 21 as a magnetic path forming member, and a permanent magnet 22 is fixedly attached to one end of the base member 21. ing. An electromagnetic core 23 is provided approximately at the center of the base member 21, and an excitation coil 24 is attached to the outer periphery of the core 23.

A dot printing wire 26 is implanted at the distal end of the armature 25 that extends across the distal end surface of the core 23. The base end side of the armature 25 is arranged on the support surface of a support base 27 fixedly provided on the permanent magnet 22.

A coil spring 28 is disposed on the other end side of the base member 2I to bias the tip of the armature 25 in a direction that separates it from the tip end surface of the core 23. The coil spring 28 is housed in a substantially cylindrical support member 29 fixed to the other end of the base member 21, and the support member 29 has an adjustment screw 30 for adjusting the spring force of the coil spring 28. are screwed together, and a lock nut 31 is screwed onto the adjustment screw 30.

A guide member 32 is provided on the support member 29 . Here, the support member 29 is provided with a surrounding portion 33 that surrounds the tip of the armature 25, and this surrounding portion 33
has an opening through which the armature 25 passes. The outer periphery of the surrounding part 33 is formed into a cylindrical shape, and the guide member 32 is rotatably fitted to the outer periphery of the surrounding part 33.

The guide member 32 is provided with an elongated hole 34 through which the wire 26 is passed, and an armature guide portion 35 that guides the side surface of the base end of the armature 25.

A pair of ears 36 are provided at the base end of the armature 25 and protrude from both sides, and the guide member 32
The armature guide portion 35 has recesses 37 that fit into the side surfaces of the ear portions 36, respectively.

A cover 38 is attached to the guide member 32.

The cover 38 restricts the amount of shift of the armature 25 on the base end side.

In the above embodiment, the armature 25 is a permanent magnet 22
The magnetic force of the core 2 resists the spring force of the coil spring 28.
However, when the coil 24 is excited, the magnetic force generated by the coil 24 cancels the magnetic force of the permanent magnet 22, and the armature 25 is separated from the tip surface of the core 23 by the force of the coil spring 28. pushed in the direction of

As a result, the wire 26 protrudes outward from the elongated hole 34 of the guide member 32 to perform a printing operation.

In the above embodiment, since the wire 26 and the armature 25 are guided and supported by the single guide member 32, the guide member 32 can be attached between the wire 26 and the elongated hole 34 of the guide member, regardless of positional accuracy. Clearance between the armature 25 and the armature guide part 3 of the guide member
5 can be set to a minimum. Therefore, it is possible to prevent the wire 26 from wobbling and to prevent deterioration in print quality.

Even if the clearance between the wire 26 and the elongated hole 34 of the guide member is reduced, the wire 26 is only in line contact with the elongated hole 34, so that wear of the wire 26 and the elongated hole 34 is unlikely to occur. Therefore, even if the ear portion 36 of the armature 25 or the armature guide portion 35 of the guide member is worn out, the wire 26 can be prevented from deflecting, and the print quality can be prevented from deteriorating due to wear of the armature and the like.

In the embodiment, the guide member 32 is rotatable around the surrounding portion 33 of the support member 29, so that the armature 25
When the armature 25 is driven while being displaced from the core 23, the guide member 32 follows the displacement of the armature 25, thereby preventing galling between the armature 25 and the guide member 32.

Although one embodiment has been described above, the present invention is not limited to the embodiment described above, and various changes can be made within the scope of the invention as set forth in the claims. For example, the guide member 32 may be fixed to the support member 29 so as not to rotate, and the guide member 32 may include a flange portion for regulating the amount of shift of the armature 25 on the base end side. Good too.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, since the wire and the armature are guided and supported by a single guide member, the guide member can be attached to the elongated hole of the wire and the guide member regardless of positional accuracy. The clearance between the armature and the armature guide portion of the guide member can be set to a minimum. Therefore, it is possible to prevent the wire from wobbling and to prevent deterioration in print quality. Further, since the clearance between the wire and the elongated hole of the guide member can be reduced, it is possible to prevent the wire from swinging even if the armature or the armature guide portion of the guide member is worn out. Therefore, deterioration in printing quality due to wear of the armature etc. can be prevented.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a print head for a wire dot printer showing an embodiment of the present invention, FIG. 2 is a plan view of essential parts of the print head shown in FIG. 1, and FIG. 3 is a view of the print head shown in FIG. 1. 4 is a perspective view of the main parts of a shuttle type printer having a plurality of print heads, FIG. 5 is a vertical cross-sectional view showing the structure of a conventional print head for wire dot printers, and FIG. FIG. 6 is a plan view of essential parts of the print head shown in FIG. 5; 21... Base member (magnetic path constituent member), 22... Permanent magnet, 23... Core, 24... Exciting coil, 25
... Armature, 26 ... Wire, 27 ... Support stand, 28 ... Coil spring, 29 ... Support member,
32... Guide member, 34... Elongated hole, 35... Armature guide portion. LJ (T)

Claims (1)

[Claims] 1. An excitation coil is held in the core of an electromagnet provided in a magnetic path forming member, and a wire for dot printing is planted in the tip of an armature that extends across the tip of the core, The proximal end side of the armature is arranged on a support surface provided on one end side of the magnetic path forming member, and the distal end side of the armature is placed on the other end side of the magnetic path forming member, and the distal end side of the armature is placed on a supporting surface provided on one end side of the magnetic path forming member. a spring biased in a direction away from the core; a permanent magnet provided on one end side of the magnetic path forming member for drawing the armature toward the tip end of the core against the force of the spring; In the print head for a wire dot printer, the wire printing operation is performed by separating the armature from the tip of the core by canceling the magnetic force of the permanent magnet by excitation of the coil, wherein the magnetic path configuration is A wire dot printer characterized in that a guide member having an elongated hole through which the wire is passed and an armature guide portion that guides a side surface of the proximal end of the armature is attached to a support member provided on the other end of the member. print head. 2. The supporting member has an enclosing part surrounding the tip of the armature, an opening through which the armature passes is formed in the enclosing part, and an outer periphery of the enclosing part is formed in a cylindrical shape; 2. The print head for a wire dot printer according to claim 1, wherein the guide member is rotatably fitted to the outer periphery of the surrounding portion.