JPH0326553A - Printing hammer mechanism - Google Patents

Abstract

PURPOSE:To efficiently drive a printing hammer with low current without deteriorating an impact force and an attraction force by a method wherein a metal piece is mounted on a tip end of a laminated yoke, and a metal block is coated with a high-hardness and wear-resistant film. CONSTITUTION:On the tip end of a coil spool 17, a metal piece 10 made of a magnetic body having approximately the same size as the tip end area of a laminated yoke 15 is integrally molded by insert molding. The metal piece 10 is securely brought into close contact with the tip end of the laminated yoke 15 by a magnetic attraction force. Therefore, at the time of operation, a printing hammer 14 does not directly impact the laminated yoke 15 but through the metal piece 10. In this manner, even with the occurrence of uneven impact, a stress applied to the laminated yoke 15 is dispersed to become remarkably small. As a result, such a defect in a prior art as an overstress causes the tip end of the laminated yoke 15 to be deformed and opened is eliminated. In addition, the coating of a high-hardness and wear-resistant film (e.g. ceramics) to the metal piece 10 can remarkably extend the life of the laminated yoke 15 from a wear resistant standpoint.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing hammer mechanism for a printer, particularly a dot impact type matrix printer.

[Conventional technology]

FIG. 2 shows a conventionally proposed printing hammer mechanism, in which a permanent magnet l is sandwiched between yokes 2 and 3, and a coil spool 7 with a coil 6 wound around a laminated yoke 5 facing the printing hammer 4. has been inserted. The printing hammer 4 is a type of cantilever leaf spring, and a printing wire 8 for printing dots is attached to the free end of the leaf spring, and the other end is fixed to the yoke 3 by a plate 9. The printing hammer 4 is normally bent to the right by the attractive force of the permanent magnet 1 and is attracted to the tip of the laminated yoke 5 as shown in FIGS. 2(b) and 2(c). When current is applied to the permanent magnet 6 to erase the magnetic flux of the permanent magnet 1, the permanent magnet 1 is released from the laminated yoke 5, and uses the deflection energy stored in itself to fly out to the left and perform printing.

[Problem to be solved by the invention]

Such a conventional laminated yoke 5 is constructed by laminating a large number of thin magnetic materials and fixing them by caulking or using an adhesive.

Therefore, after the printing hammer 4 jumps out to the left and prints, it collides with the laminated yoke 5 again due to the attractive force of the permanent magnet 1 and the repulsive force during printing, and is attracted to the laminated yoke 5. Since the tip of the printing hammer 5 is deformed and the opening is opened, there is a drawback that it is impossible to maintain a constant amount of deflection of the printing hammer 4 to ensure appropriate impact force and suction force.

[Means to solve the problem]

In the present invention, by attaching a metal piece to the tip of a laminated yoke and coating the metal block with a highly hard and wear-resistant coating, the printing hammer can be efficiently driven with low current without deteriorating the impact force and suction force. To provide a printing hammer mechanism.

That is, according to the present invention, in a printing hammer mechanism that uses strain energy accumulated in a printing hammer bent by the attractive force of a permanent magnet or an electromagnet as printing energy,
A printing hammer mechanism is obtained in which a metal piece or a metal piece coated with a high hardness and wear-resistant coating is attached to the tip of a laminated yoke around which a coil is wound. [Example] Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
) is a front view, FIG. 1(b) is a side view, and FIG. 1(c) is a sectional view taken along line xx' in FIG. 1(a).

In FIG. 1, the permanent magnet 11 is sandwiched between yokes 12 and 13, and a coil spool 7 having a coil 16 wound thereon is inserted into the laminated yoke 15 facing the printing hammer 14. A metal piece 10 made of a ferromagnetic material having approximately the same size as the tip area of the laminated yoke 15 is integrally molded at the tip of the coil sbourg 17 by insert molding, and the metal piece lO is attached to the laminated yoke 15 by magnetic attraction. It is firmly attached to the tip.

Therefore, due to this structure, the printing hammer 14 does not directly hit the laminated yoke 15 during operation, but hits it through the metal piece 10, so even if uneven contact occurs, the stress applied to the laminated yoke 15 is dispersed. It will be extremely low.

As a result, the laminated yoke 1
The disadvantage that the tip of the yoke 5 is deformed and the mouth opens is eliminated, and the metal piece 10 is coated with a high hardness and wear-resistant coating (for example, ceramics).
The wear resistance life of No. 5 can be dramatically extended.

〔Effect of the invention〕

As explained above, the present invention prevents the deformation and wear of the laminated yoke by attaching a metal piece to the tip of the laminated yoke, and efficiently prints in one print with low power without deteriorating the impact force and suction force. It is possible to provide a printing hammer mechanism that can drive the printing hammer mechanism.

Ilesbourg, 8,18...Printing wire, 9,
19...Plate, lO...Metal piece.

Claims (1)

[Claims] A printing hammer mechanism that uses strain energy stored in a printing hammer that is bent by the attractive force of a permanent magnet or electromagnet as printing energy, and is characterized by a metal piece attached to the tip of a laminated yoke around which a coil is wound. Printing hammer mechanism.