JPS61175052A - Wire dot head - Google Patents

Abstract

PURPOSE:To obtain a wire head of lesser heat quantity and also of lesser power consumption by adopting a structure in which a permanent magnet is set on a core. CONSTITUTION:A soft magnetic material 19 is fixed to the tip of a core 6 consisting of permanent magnet, and therefore, the magnetism of the core 6 forms a close loop in case where no current is applied to the coil 9 and an armature 5 is attracted against the force of a plate spring 3 toward the soft magnetic material 19 side. When making recording, current is flowed in the coil 9 in the direction of demagnetizing the core 6, whereupon a plate spring 3 is separated from the core 6 side and the wire goes forwards for printing. When current is applied to the coil 9, leakage magnetic flux occurs on the adjacent core 6' side, and the magnetic field occurs in the direction of attracting the armature 5'. Since the soft magnetic material 19' is fixed to the tip of the core 6, however, the magnetic resistance is greater and the attraction of the armature 5' is much smaller. Current flows in the coil 9' of the adjacent core 6', thus making the increase in current values necessary when demagnetizing the core 6' smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a wire dot head, and more particularly to a wire dot head used in a high-speed printer using a permanent magnet.

[Prior Art] A conventional wire dot head of this type is shown in FIGS. 1 to 4.

In FIG. 1, the symbol l indicates a ring-shaped permanent magnet. The lower surface of this permanent magnet 1 is fixed to a flat plate-shaped r yoke 7, and the ring-shaped middle yoke 2 is fixed to its upper surface. There is.

A plurality of leaf springs 3 are arranged radially on the upper side of the middle yoke 2 with spacers 10 interposed therebetween. Armatures 5 are arranged at the respective positions.

One wire 8 is fixed to each tip of the armature 5. As a result, the base portions of the wires 8 are arranged at equal angular intervals along the circumferential direction, but the tip portions of the wires 8 are arranged in the tip guide 11 which is narrowed into a truncated cone shape. They are guided along the inside, and are arranged, for example, in one vertical row at the tip of the tip guide 11.

On the other hand, the armature 5 at the tip of the leaf spring 3 is attached to the lower yoke 7.
A core 6 made of a permanent magnet is fixed in a state of l to l correspondence.

A coil 9 is wound around each core 6.

Based on the structure described above, the wire dot head performs the following operations.

That is, when no current is flowing through the coil 9 when the coil 9 is not in use, the magnetic flux generated from the permanent magnet 1 constitutes a magnetic circuit indicated by the solid line 15 in FIG.

The leaf spring 3 is attracted to the core 6 made of a permanent magnet together with the armature 5, and is in an elastically deformed state, and the tip of the wire 8 is in almost the same plane as the edge of the tip guide 11, and recording is not performed. do not have.

On the other hand, during recording, a current is passed through the coil 9 of the core 6 corresponding to the target wire 8. At this time, the 'IL current value is such that the magnetic force generated by the current flowing through the coil 9 cancels out the magnetic force of the core 6. It is a value.

When such a current is applied to the coil 9, the leaf spring 3 returns in a direction away from the core 6 due to its elasticity, and the wire 8 moves forward, recording dots on the recording paper via an ink ribbon (not shown). .

However, when a current is passed through the coil 9, a magnetic path is formed as shown by the broken line 16 in FIGS. 3 and 4, but as a result, as shown by the symbol 17 in FIG. A magnetic path will be formed.

As a result, the suction force of the armature 5 by the adjacent core 6' increases.

Therefore, in this state, if you try to generate a magnetic field in the direction of moving the leaf spring 3 away from the core 6' together with the armature 5 by passing a current through the coil 9 of the adjacent core 6', you will have to wave more current than usual. It disappears.

This extra current increases by 20 to 40% of the normal current, resulting in increased power consumption.

[Objective] The present invention has been made to eliminate the above-mentioned conventional drawbacks, and provides a wire dot head configured to operate a wire while significantly suppressing an increase in power consumption. The aim is to provide the following.

Embodiments] Hereinafter, details M11 of the present invention will be described based on embodiments shown in the drawings.

5 and 6 illustrate one embodiment of the present invention. In each figure, the same parts as in FIGS. 1 to 4 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In the wooden example, as shown in FIG. 5, the ring-shaped permanent magnet l fixed to the lower yoke 7 was removed, and a soft magnetic material 19 was fixed to the tip of the core 6 made of a permanent magnet.

When the coil 9 is not energized based on the above structure, the magnetic force of the core 6 made of a magnet forms a closed loop as shown by the reference numeral 20 in FIG. 6, and the armature 5
is attracted to the soft magnetic material 19 side against the elastic force of the leaf spring 3.

If it is desired to perform recording from this state, a current is applied to the coil 9 so as to generate a magnetic force in a direction that cancels the magnetic force of the core 6 made of a permanent magnet, as shown by a broken line 18. Then,
The leaf spring 3 separates from the core 6 side due to its own elasticity, and the wire moves forward to perform recording.

When the coil 9 is energized, leakage magnetic flux is generated on the adjacent core 6' side as indicated by the broken line 21 in FIG.

That is, this magnetic field is generated in a direction that attracts the armature 5', but in this embodiment, since the soft magnetic material 19' is fixed to the tip of the core 6, the magnetic resistance is large.
Compared to the conventional structure, the armature 5 due to this magnetic field
The attractive force of ' is extremely small, and only a small increase in the radio wave value is required when a current is applied to the coil 9' of the adjacent core 6' to cancel the magnetic force of the core 6' made of a permanent magnet.

Therefore, the increase in the armature's attractive force generated on adjacent cores is small, and the increase in power required to move the armature away from the core is small.

In this way, it is possible to operate the adjacent core side with less electric power than in the past, saving energy, generating less heat, and preventing overheating even when recording is performed for a long time.

[Effects] As is clear from the above description, according to the present invention, a core made of permanent magnets and a coil wound around this core are provided on the same circumference at a predetermined pitch on the common yoke-E, A wire dot head configured to be able to elastically deform and attract an armature to which a wire is attached via a spring, and to transmit radio waves to the coil to generate a magnetic field that cancels the magnetic field of the core made of a permanent magnet. Since a structure in which a permanent magnet material is arranged in the core is adopted, even when the armature is operated by simultaneously communicating with the coils of adjacent cores, the current flowing through the coils can be reduced, It is possible to obtain a wire dot head that consumes less power and generates less heat than conventional ones.

[Brief explanation of the drawing]

Figures 1 to 4 explain the conventional structure, with Figure 1 being a vertical sectional side view, Figure 2 being a plan view explaining the arrangement of the cores, and Figure 3 being a plan view explaining the arrangement of the cores.
FIG. 4 is an explanatory diagram showing the magnetic path in non-operation and in operation, FIG. 4 is an explanatory diagram of the developed state to explain the influence of the magnetic field on adjacent cores in operation, and FIGS. 5 and 6 are illustrations of the present invention. This is to explain one embodiment, and FIG. 5 is a vertical side view;
The sixth [Δ is an explanatory diagram showing the state of generation of a magnetic field. 2... Middle yoke 3... Leaf spring 4... Upper yoke 5... Armature 6... Core
7... Lower yoke 8... Wire 9.
Coil 11...Tip guide 19...Soft magnetic material Patent applicant: Canon Co., Ltd., -6,-1 Agent: Patent attorney Taku Kato 1")1 To-~, 4 Fig. 1 Fig. 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] Cores made of permanent magnets each wrapped with a coil are arranged at a predetermined pitch on the same circumference on a common yoke, and an armature to which the base end of the wire is fixed is attracted by elastically deforming a leaf spring, and the wire is In the wire dot head, a current is supplied to the coil so that when it is activated, a magnetic field is generated in a direction that cancels out the magnetic field of the core made of a permanent magnet.
A wire dot head characterized in that a permanent magnetic material is interposed in the core.