JPS5920681A - Print hammer driver - Google Patents

Abstract

PURPOSE:To elevate the printing speed with a lighter print hammer by forming a side magnetic path with side yokes surrounding the hammer in ?-shaped manner facing the hammer on the side opposite to yokes, eliminating a magnetic pole piece fastened on the print hammer. CONSTITUTION:Yokes 2 and 3 are arranged on both sides a magnet 1 sandwiching it and a yoke 5 is provided at the tip of the columnal yoke 2 to attract a print hammer 14. Further more, side yokes 19 are arranged surrounding the print hammer 14 like a letter of ? through a marginal gap with the base end thereof anchored on the fixed end of the print hammer 14 to form a side magnetic path. Thus, the print hammer 14 is attracted to the tip of the yoke 5 by a magnetic flux running to the yoke 3 via the hammer 14 from the tip of the yoke 5 and a magnetic flux running to the yoke 3 via the side yoke 9 passing through the hammer 14 from the tip of the yoke 5 and when released from the attraction, it performs a printing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high speed printing hammer drive used in printers, particularly dot impact type matrix printers.

A printing hammer drive device in a conventional dot impact type matrix printer or the like has been constructed as shown in FIGS. 1a and 1b in order to form a side magnetic path and increase the attractive force. That is, a permanent magnet 1 and a yoke 2 disposed on both sides of the permanent magnet 1 to sandwich the permanent magnet 1.
．． 3, a plate spring-like printing hammer 4 that stores printing energy and whose fixed end is fixed to one yoke 3, and a yoke that is provided at the tip of the other columnar yoke 2 and protrudes toward the middle part of the printing hammer 4. 5, a coil 6 wound around the yoke 5 to cancel the internal magnetic flux of the yoke 5, and a printing pin 7 provided perpendicularly to the free end side of the printing hammer 4 via a 7 flange for printing dots. A circular magnetic pole piece 8 is fixed to the side opposite to the yoke at the intermediate portion of the printing hammer that is attracted to the tip of the yoke 5, and a circular magnetic pole piece 8 is disposed substantially parallel to the printing hammer 4, and its base end is arranged substantially parallel to the printing hammer 4. A side yoke 9 fixed to the yoke 3 together with the fixed end, and a magnetic pole piece 8 of this side yoke 9
The device printing hammer 4, which is formed by a hole lO drilled at a position corresponding to the diameter of the magnetic pole piece 8 and having a slightly larger diameter than the magnetic pole piece 8, is inserted from the tip of the yoke 5 as indicated by the solid line arrow in FIGS. 1a and 1b. The main magnetic flux flowing through the printing hammer 4 to the yoke 3, the magnetic pole piece 8 fixed to the printing hammer 4 from the tip of the yoke 5 indicated by the chain arrow, and this magnetic pole piece 8.
9. A lateral yoke having a hole io into which the yoke is inserted. That is, it was attracted to the yoke 5 by the side magnetic flux flowing through the side magnetic path. Therefore, the magnetic pole piece 8 is moved by the printing hammer 4, which is a movable part.
As the printing hammer 4 is provided separately and the printing hammer 4 is made long, the mass of the printing hammer 4 increases, the natural frequency decreases, and the printing speed cannot be increased.

The present invention eliminates the magnetic pole piece fixed to the printing hammer, and forms a side magnetic path with a side yoke that faces the printing hammer and surrounds the printing hammer in a "U" shape with pressure on the opposite side of the yoke. Another object of the present invention is to reduce the overall mass of the printing hammer, thereby providing a printing hammer driving device with a high natural frequency and a high printing speed.

2a, 2b, and 2C, in the footboard embodiment, a magnet l made of a permanent magnet or an electromagnet, a yoke 2 with buttons on both sides arranged to sandwich the magnet l,
3, a yoke 5 protruding from the tip of the columnar yoke 2 toward the free end of the printing hammer 14 to attract the printing hammer 14, and a yoke 5 wound around the yoke 5 to cancel the magnetic flux inside the yoke 5. The configuration of the coil 6 and the side yoke 19, which is disposed parallel to the printing hammer 14 at about tl and whose base end is fixed to the yoke 3 together with the fixed end of the printing hammer 14, is different from that of a conventional printing hammer drive device. It has a similar configuration.

On the other hand, the side yoke 19 is arranged substantially parallel to the printing hammer, and its base end is fixed to the yoke 3 together with the fixed end of the printing hammer 14. The method of configuring the gap with the hammer 14 is different. In other words, the side plates are arranged so as to sandwich the printing hammer 14 in the shape of a leaf spring, face the yoke 5, and surround the front and side surfaces of the printing hammer 14 in a U-shape with a slight gap between them. The yoke 19 forms a side magnetic path.

Therefore, the printing hammer 14 receives the main magnetic flux shown by the solid line arrow in FIGS. 2a, 2b and 20, that is, the magnetic flux flowing from the tip of the yoke 5 to the yoke 3 via the printing hammer 14, and the magnetic flux shown by the chain line arrow. The side magnetic flux flowing in the side magnetic path shown, that is, the printing number 14 from the tip of the yoke 5
The magnetic flux flowing through the yoke 3 through the side yoke 9, which is arranged so as to surround the side surface of the printed normal marker 14 in a U-shape with a slight gap, and the magnetic flux K flowing into the yoke 5 causes the magnetic flux to flow to the tip of the yoke 5. It gets sucked in. At this time, the leaf spring-shaped printing press 14 is bent and becomes in a state in which strain energy is stored. This strain energy is released through the printing pin 17 and converted into printing energy when a current flows through the coil 6, the magnetic flux flowing inside the yoke 5 is canceled out, and the attraction of the printing printer 14 is released. Note that it is also possible to use a printing wire or the like instead of the printing pin.

As described above, since there is no need to attach a magnetic pole piece to the leaf spring-shaped printing hammer to form the side magnetic path, the weight of the printing hammer can be extremely lightened, and therefore the printing hammer has a high natural frequency and a high printing speed. It can be a drive device.

In addition, when designing a printing/single hammer drive device under conditions where the natural frequency of the printing hammer, that is, the printing speed is determined, the weight of the printing hammer is light, so the spring constant of the printing hammer can be lowered, so the magnetic circuit It has the advantage of being smaller in size and lower in current.

[Brief explanation of the drawing]

1a and 1b show a front view and a side view of a conventional printing/percentage meter drive device, and FIGS. 2a and 2b and 2
Figure C shows a front view, a side view, and a plan view of a printing printer drive device according to an embodiment of the present invention. l...Magnet, 2, 3, 5...Yoke,
4.14... Printing hammer, 6... Coil, 7.17... Printing pin, 8... Magnetic pole piece, 9.19... ...Side yoke, 10...
··hole. Ei 10L figure 1b figure Hoko 2C figure

Claims (1)

[Claims] In a printing hammer drive device that uses strain energy accumulated in a plate spring-shaped printing hammer that is deflected by the attractive force of a magnet as printing energy, the printing hammer is opposed to the printing hammer on the opposite yoke side, and is placed in a U-shape through a slight cap. A printing hammer driving device, wherein a side yoke is arranged to surround the printing hammer, and a side magnetic path is formed by a side yoke whose base end is fixed to a fixed end side of the printing hammer.