JPS6018813Y2 - plunger magnet - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to improvements in plunger magnets.

For example, a serial printer having a dage-type (petal-type) wheel is shown in FIG.

That is, the printing mechanism consists of a platen 1 and a carrier 2.

The platen 1 is rotatably mounted on a base (not shown).

The carrier 2 is controlled by a space motor 4 via a drive belt 3, and is controlled to reciprocate by sliding on a stay shaft 6 by a feed screw gear 5 parallel to the latin 1.

This carrier 2 has a print head mounted thereon by means of a bracket 7.

The print head is equipped with a dage-type type wheel 8 whose rotation is controlled by a rotation selection motor 9.

The type wheel 8 is driven in the direction of the platen 1 in synchronization with the movement of the carrier 2 to press the type, impacting the print paper via an ink ribbon (not shown), etc., and causing the print head to This is for printing letters, numbers, symbols, etc. in type on the dage-type type wheel 8.

Conventionally, a hammer magnet 10 that presses the dage type wheel 8 of this printer. That is, various plunger magnets have been proposed.

Figures 2a and 2b are examples of conventionally proposed plunger magnets for hammers.

This magnetic circuit consists of a stator 12 having a coil 11 and a plunger 13, as shown in FIG.

A magnetic circuit is formed by cutting out a part of the stator 12 of the magnetic circuit, and complementing the magnetic circuit with the movable piece of the plunger 13 in the cutout, and the magnetic flux 14
The movable piece of the plunger 13 is attracted by the flow.

Due to this suction, the slide shaft 15 of the plunger 13 slides against the support member 16 and moves in the direction of the arrow to the left, as shown in FIG. to print.

This pressing force is due to the attractive force of the magnetic flux of the hammer plunger magnet 10, and the force is generated by the magnetic flux passing through the rectangular cross section of the plunger 13 as shown in FIG.

However, this configuration has the disadvantage that there is a lot of magnetic flux leaking into the air, and the efficiency is extremely low.
It is unsuitable due to its large size.

FIG. 3 shows another embodiment, in which the movable piece is a plunger 13 with a circular cross section and a coil 11 wound around a stator 12.
As a result, the magnetic circuit is formed and the magnetic flux 14
The movable piece of the plunger 13 is attracted by the flow, and the slide shaft 15 of the plunger 13 is moved to the support member 16.1.
6 to the left in the direction of the arrow, and the hammer 17 at the tip presses the type on the type wheel 8 to print.
Similarly to the above, this attractive force is generated only by the magnetic flux passing through the portion marked with ■ in the circular cross section of the movable piece, and no force is generated in the portion marked with ■.

That is, like the conventional example, it has the disadvantage of poor efficiency.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, and includes a notch part in which a part of the stator perpendicular to the axis is cut out in an annular shape, and an annular movable piece that is fitted into the notch part. The annular movable piece is configured to move by excitation of the stator.

An embodiment of the plunger magnet according to the present invention will be described below with reference to the front view of FIG. 4 and the cross-sectional side view of FIG.

In the figure, the stator 18 includes a coil 19, a part of which is cut out in an annular shape.

A ring-shaped plunger 20, which is an annular movable piece, is fitted into the notch.

The plunger 20 is connected to the stator 18 via a compression spring 22 to the slide shaft 15 by a connecting member 21 .

The annular movable piece of the ring-shaped plunger 20 makes the flow of magnetic flux in the magnetic circuit a closed loop.

The plunger magnet of the present invention has a magnetic circuit formed by cutting out a part of the stator 18 and complementing the cutout with a ring-shaped plunger 20, which is an annular movable piece, as shown in FIG. 4a. The plunger 20 has a coupling member 2
1, the slide shaft 15 is inserted and coupled to the center of the stator 18, and the coupling member 21 is always guided by the rectangular plate 23 by the bias of the compression spring 22.

In the plunger magnet constructed in this way, as shown in FIG.

A flow of magnetic flux 14 is generated in the direction of the arrow by the closed loop of magnetic flux with the inner diameter ■.

'At this time, as shown in FIG. 4, the efficiency is good because suction force is generated by the outer diameter part (2) and inner diameter part (2) of the ring-shaped closed loop.

This strong suction force causes the movable piece of the ring-shaped plunger 20 to be suctioned in the direction of the left arrow.

The coupling member 21 of the plunger 20 is moved by the compression spring 22 so that the slide shaft 15 slides on the center of the stator 18 and moves in the direction of the arrow to the left, and the hammer 17 at the tip of the slide shaft 15 moves the type on the dage type wheel 8. Printed by pressing.

The number of prints is determined when the excitation of the coil 19 is released and the slide shaft 15 is attached to the guide plate 23 by the coupling member 21 due to the bias of the compression spring 22.
is guided, and the movable plunger 20 returns to its initial state.

Therefore, such a plunger magnet
The radius of the notch 8 can be made large, and the corresponding radius of the ring-shaped plunger 20 can also be made large, so that the stator 16 and the ring-shaped plunger 2 can be made large.
The length of the opposing portion of the zero magnetic path is increased, the attraction efficiency is improved, and a strong attraction force is obtained.

Therefore, the printing pressing force of the hammer 17 can be increased.

As explained above with reference to the embodiments, according to the plunger magnet according to the present invention, the magnetic circuit becomes a closed loop due to the flow of magnetic flux in the magnetic circuit between the circular stator and the ring-shaped plunger of the circular movable piece. Therefore, it is efficient because it generates a suction force with less leakage of magnetic flux.Printing is performed by pressing with the suction force of a strong plunger, which prevents the printing speed from decreasing and improves the print quality. Since it can be made compact, it has advantages such as cost reduction.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a serial printer having a dage type wheel, Fig. 2 is a rotation front view a1 and a sectional side view of a conventional plunger magnet, and Fig. 3 is a rotation front view of another conventional embodiment. Figure 4 is a front view a1 and a cross-sectional side view b1 of an embodiment of the plunger magnet of the present invention.
It shows. In the figure, 1... platen, 2...
Carrier, 4... Space motor, 5...
...Feed screw gear, 8.--Dage type wheel, 9..-station selection motor, 10.
...Hammer Makunetsu), 11.19...
Coil, 12, 18... Stator, 13, 20
...Plunger, 14...Magnetic flux flow, 15...Slide shaft, 17...Hammer, 21...Coupling member, 22. ...Indicates a compression spring.

Claims (1)

[Scope of utility model registration request] In a plunger magnet that constitutes a magnetic circuit by cutting out a part of a stator around which a coil is wound and complementing the cutout part as a movable piece, a part of the perpendicular part to the axis of the stator is cut out in an annular shape. 1. A plunger magnet comprising: a notch portion; and an annular movable piece fitted into the notch portion and moved by excitation of the stator.