JPS60248359A - Electromagnet device for dot printer - Google Patents

Abstract

PURPOSE:To obtain the titled device which enables a high speed performance by attracting an armature to a tip surface of an upper magnetic pole piece against the spring force of a lead spring by a magnetic flux of a permanent magnet when a coil is not excited. CONSTITUTION:When a coil 9 is excited, a magnetic flux Y of the coil 9 flows in the opposite direction of a flux X of a permanent magnet 7, resulting in cancelling each other. The spring force of a leaf spring 10 is larger than the force of an upper magnetic pole piece 5 which attracts an armature 11, and the armature 11 moves downwards. At the same time the magnetic flux Y of the coil 9 splits to cause attraction of the armature 11 by a bottom magnetic pole piece 6 and the downward motion of the armature 11 is accelerated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an electromagnet device for a dot printer using a permanent magnet in a magnetic circuit.

[Background Art] The electromagnetic device of this type of dot printer is as shown in the first diagram.
A U-shaped yoke 8, an auxiliary yoke B joined to one end of the cork A, a permanent magnet C inserted in the middle of these magnetic paths, and a yoke A to cancel the magnetic attraction force of the permanent magnet C. A coil D is wound around the coil D, a leaf spring E whose base end is fixed to the yoke A or the auxiliary yoke B, and a printing wire G whose one end is fixed to the free end of the leaf spring E and the other end is connected via the arm F.
Amatia ■ located between both ends of yokes A and B while fixing the
], Amachia H is attracted to the end face of the yoke when the coil D is not energized, and when the coil D is energized, this attraction force weakens and is displaced by the spring force of the leaf spring E, and the printed character responds to this displacement operation. Generally, a wire G prints on paper on a platen via an ink ribbon J.

In this case, since the magnetic flux during excitation of the coil D acts only to offset the magnetic attraction force of the permanent magnet C, it is difficult to obtain a large margin for the operation force for attracting and releasing the Amachia H.

Therefore, as shown in FIG. is made into a swinging type, with its middle part serving as a swinging fulcrum on the other end of the yoke A, and one end on the side where the printing wire G is not fixed is positioned between both legs of the auxiliary yoke B°. Proposed. In this case, the amachia H' is attracted to the upper leg piece of the auxiliary yoke B' when the coil D is not energized, and the coil D
When the yoke is energized, this attraction force weakens and the yoke is displaced by the spring force of the slope spring E, and the magnetic flux of the coil D also flows between one end of the armature H' and the lower leg piece of the auxiliary yoke B', promoting the above-mentioned displacement. As a result, a large margin of operating force for adsorption and release of the Amachia H was obtained, and high speed performance was improved. However, in this case, friction and wear occur between the other end of the yoke A, which constitutes the swinging fulcrum, and the middle part of the armature H, which causes problems in operational stability and life.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to provide an electromagnetic device for a dot printer that can speed up the operation and improve the stability and life of the operation. is to provide.

[Disclosure of the Invention] (Example) The present invention will be described below based on FIGS. 3 and 4, which are shown as an example.

In the figure, the yoke (■) is made of a magnetic material and is formed into a U-shape having one leg 2 and the other leg 3.

Reference numeral 4 denotes a magnetic pole piece block in which vertically opposing magnetic pole pieces 5.6 made of magnetic material are successively arranged in a U-shape together with a connecting piece 8 in which a permanent magnet 7 is inserted. Note that when the connecting piece 8 is smaller than the permanent magnet 7, the permanent magnet 7 is used as the connecting piece. The lower magnetic pole piece 6 of the magnetic pole piece block 4 is joined to the end surface of one leg 2 of the yoke 1, and the open ends of both magnetic pole pieces 5.6 are located on the other leg 3 side of the yoke 1.

9 is a coil for canceling the magnetic attraction force of the permanent magnet 7, and is wound around one leg 2 of the yoke 1. 6 10 is a coil whose base end is fixed to the connecting piece 8 of the magnetic pole piece block 4 (in practice) In the example, it is a leaf spring that is clamped and fixed between the permanent magnet 7 and the connecting piece 8.

11 is an amatia made of magnetic material, and one end is a leaf spring 10.
The other end has a printing wire 13 fixed thereto via an arm 12. This amatia 11 has a movable gap gl between both magnetic pole pieces 5°6 of the magnetic pole piece block 4,
g2 and is close to the end surface of the other leg 3 of the yoke 1,
Moreover, when the coil 9 is not energized, it is positioned so as to be attracted to the upper magnetic pole piece 5 of the magnetic pole piece block 4 against the spring force of the leaf spring 10. In this embodiment, a separate magnetic pole piece 14 is magnetically coupled to the other leg 3 of the yoke 1 to form an end face of the leg. The magnetic pole piece 14 extends to the vicinity of both sides between the two magnetic pole pieces 5 and 6 of the magnetic pole piece block 4 while being slightly inclined, and grips both sides of the amatia 11 located between the two magnetic pole pieces 5 and 6. Concave portion 14 that matches the shape of Amathia 11
a is formed, and further a longitudinal groove 14b for the arm 12 is formed. Since such recesses 14a and vertical grooves 14b are arranged on both sides of the amacia 11 and arm 12 with appropriate gaps, they have the effect of preventing interference with their operations.

In such an electromagnetic device, when the coil 9 is not energized, the flow flows between the leg 2 and the lower magnetic pole piece 6, and the amatia 11 is attracted to the end face of the upper magnetic pole piece 5 against the spring force of the leaf spring 10. Ru.

When the coil 9 is energized from this state, the magnetic flux Y from the coil 9 flows in the opposite direction to the above-mentioned magnetic flux wins, and Amatia 11 moves downward. At the same time, the magnetic flux Y from the coil 9 is also divided into the magnetic path from one leg 2 to the other leg 3 to the magnetic pole piece 14 to the amatia 11 to the lower magnetic pole piece 6, so the lower magnetic pole piece 6 attracts the amatia 11. It works like this. This action promotes the downward displacement movement of the amatia 11, making the movement faster. In addition, if the dynamic punch force margin for adsorption and release of Amachia 11 is made to be the same as that of the conventional one, the coil 9
The excitation current can be reduced, resulting in lower power consumption.

However, with this lever, like the conventional one, Amachia 1
Since there is no swinging fulcrum that causes friction or wear during the first displacement operation, the stability of the operation and the lifespan can be improved.

A dot printer is constructed by arranging multiple sets (for example, nine sets) of such electromagnetic devices in parallel, and prints by controlling the excitation of a coil corresponding to the printing location to displace the amatia, that is, the printing wire. .

[Effects of the Invention] The electromagnetic device for a dot printer of the present invention has a U-shaped yoke and vertically opposing magnetic pole pieces that are connected in a U-shaped manner together with a connecting piece in which permanent saltpeter is inserted, and furthermore, the lower magnetic pole a magnetic pole piece block in which a piece is joined to an end face of one leg of the yoke, and the open ends of both pole pieces are located on the other leg side of the cork; A coil wound around a yoke, a handling spring whose base end is fixed to the connecting piece of the magnetic pole piece block, one end fixed to the free end of the leaf spring, and the other end fixing the printing wire via an arm. and has a movable gap between both magnetic pole pieces of the magnetic pole piece block, and is close to the end face of the other leg of the yoke, and resists the spring force of the leaf spring when the coil is not energized. Since the magnetic pole piece is made of an amatia located so as to be attracted to the upper magnetic pole piece of the magnetic pole piece block, the operation speed can be increased, and the stability of the operation and the life span can be improved.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing a conventional example, Fig. 2 is a longitudinal sectional view showing another conventional example, Fig. 3 is a perspective view showing an embodiment of the present invention, and Fig. 4 is a longitudinal sectional view thereof. be. 1-Coke, 4-Pole piece block, 5-Top pole piece, 6
- lower magnetic pole piece, 7 - permanent magnet, 8 series of ties, 9 - coil, 10 - leaf spring, 11 - amathia, 12 - arm, 13
- printing wire, 14 - pole piece; Patent applicant Matsushita Electric Works Co., Ltd. Patent attorney Toshimaru Takemitsu (and 2 others) Figure 1 Figure 2 Figure 5133

Claims (1)

[Claims] +1+ A U-shaped yoke and vertically opposing magnetic pole pieces are connected in a U-shape together with a connecting piece in which a permanent magnet is inserted.
Moreover, the lower magnetic pole piece is joined to the end face of one leg of the cork, and the open ends of both magnetic pole pieces are connected to the magnetic pole piece block located on the other leg side of the yoke, and the magnetic attraction force of the permanent magnet. a coil wound around the yoke for offset, a leaf spring whose base end is fixed to the connecting piece of the pole piece block, one end fixed to the free end of the leaf spring, and the other end connected via an arm. The printing wire is fixed and has a movable gap between both magnetic pole pieces of the magnetic pole piece block and is close to the end face of the other leg of the yoke, and when the coil is not energized, the spring force of the leaf spring is an electromagnetic device for a de-nod printer, comprising: an amatia positioned so as to be attracted to the upper magnetic pole piece of the magnetic pole piece block against the magnetic field;