JPH0635181B2 - Print head - Google Patents

Description

The present invention relates to a print head.

(Problems to be Solved by the Related Art) In a conventional print head, a coil is wound around a core piece that drives a drive arm that drives a printing element, and an iron core facing the drive arm is provided. In order to prevent wear of the drive arm, the printing element, the iron core, etc., an oil impregnation material is provided inside the print head to supply oil to the above-mentioned parts to be worn.

According to the above-mentioned conventional technique, the structure in which the oil is directly supplied to the contact portion of the drive arm and the iron core cannot effectively prevent the wear of the above-mentioned portion. Therefore, the characteristics of the print head may be deteriorated.

In order to solve this problem
Japanese Patent Publication discloses a print head having a hole provided in each of the contacting iron core and drive arm, and a lubricant is put in the hole to directly supply the lubricant to the contacting part of the iron core and drive arm. I am doing it. The hole of the iron core is formed with a depth that does not penetrate the iron core. However, according to this conventional technique, the impregnating material impregnated with the lubricant is not contained in the hole of the iron core, and the lubricant immediately flows out from the hole, and when the lubricant disappears, the driving arm, There is a problem in that the lubricant cannot be supplied to the contact portion of the iron core, and it is impossible to prevent the wear of the above portion for a long period of time.

It is an object of the present invention to directly supply oil to a contact portion of a drive arm and an iron core for a long period of time to effectively prevent wear.

(Means for Solving the Problems) In order to achieve the above object, the print head according to the present invention is
A drive arm for driving the printing element, an iron core around which a coil is wound and facing the drive arm, and a core piece for driving the drive arm, and a core piece provided to penetrate through the iron core in the axial direction thereof. It is provided with a certain hole, an oil impregnated material embedded in the hole, and a supply member for supplying oil from the outside of the core piece to the opening of the hole opposite to the drive arm.

(Operation) Since the oil is directly supplied from the oil-impregnated material to the contact portion of the drive arm and the iron core, abrasion of the above-mentioned portion is prevented, and the oil is supplied to the oil-impregnated material from the outside of the core piece by the supply member. Therefore, it is possible to prevent deterioration of the characteristics of the print head for a long period of time.

(Embodiment) An embodiment in which the present invention is applied to a spring charge type print head will be described below with reference to the drawings. As shown in the figure, a core piece 2 for driving a drive arm, which will be described later, is provided with an iron core 2a around which a coil 1 is wound, and a magnet 3 is provided on the front surface of a side wall of the core piece 2, and a magnet 3 is provided. A magnet plate 4 forming a common magnetic path is provided on the front surface of the. A yoke plate 5 is provided on the front surface of the magnet plate 4, a leaf spring 6 is provided on the front surface of the yoke plate 5, and a drive arm 7 is fixed to the back surface of the leaf spring 6. The printing element 8 is fixed to the tip of the. The iron core 2a faces the drive arm 7. A support plate 9 is provided on the front surface of the leaf spring 6,
A wire frame 10 is provided on the front surface of the support plate 9.
The support plate 9 supports the outer end portion of the leaf spring 6 via the yoke plate 5, and the leaf spring 6 can swing about the outer end portion as a fulcrum. A guide member 11 that guides the printing element 8 is provided at the tip of the wire frame 10.

A hole 2b penetrates through the iron core 2a in the axial direction, and pipes 12, 12 in which oil impregnated materials 13, 13 are inserted are embedded in the hole 2b. At the opening of the hole 2b on the back surface of the core piece, the oil impregnated material 1 is applied from the outside of the core piece 2.
Oil tank (supply member) for supplying oil to 3, 13
14, 14 are provided. An oil impregnation material 15 is provided in the central recess of the core piece 2, and a thermistor frame 17 is provided on the back surface of the oil impregnation material 15. The thermistor frame 17 detects the temperature of the coil 1. Is held by the thermistor 16. A flexible cable 18 for connecting the print head to a control circuit (not shown) is provided on the back surface of the core piece 2, and an end portion (not shown) of the coil 1 and a lead of the thermistor 16 are provided. Line 20 is connected. Further, the core piece 2 is provided with a radiation fin 19 for lowering the temperature of the print head during printing.

Next, the operation will be described. As shown in the figure, at the time of non-printing, the drive arm 7 is attracted to the iron core 2a via the magnetic flux of the magnet 3 as shown in 7a of the figure, and the leaf spring 6 has its own elastic force as shown in 6a of the figure. In the retracted position, and the printing element 8 is also in the retracted position as shown in FIG. 8a.

Next, at the time of printing, when the coil 1 is energized, the magnet 3
The magnetic flux is canceled out, and thereby the magnetic attraction of the drive arm 7 to the iron core 2a is released. Then leaf spring 6
Moves forward by its own elastic force as shown in FIG. 6b to move the print element 8 forward as shown in FIG. 8b, and dots are formed on the print medium (not shown).

The oil-impregnated materials 15 and 13 supply oil to a frictional portion such as a contact portion between the drive arm 7 and the iron core 2a or a sliding portion between the printing element 8 and the guide member 11, and the above-mentioned portion Wear is prevented.

In particular, the oil impregnating material 13 supplies oil directly to the portion where the drive arm 7 and the iron core 2a come into contact, wear of this portion is effectively prevented, and deterioration of the characteristics of the print head can be prevented. The oil tank 14 supplies the oil to the oil impregnating material 13 for a long period of time.

Further, the thermistor 16 detects the temperature of the coil 1 via the thermistor frame 17 and is useful for controlling the temperature of the print head.

The pipe 12 may be omitted, and the oil impregnated material 13 may be directly embedded in the iron core 2a.

The oil tank 14 may be provided at another place inside the print head, or may be provided outside the print head. Further, if the oil can be injected into the oil tank 14 from the outside of the print head, the oil can be secured in the print head for a longer period of time.

Further, the printing method of the print head is not limited to this embodiment, and for example, the oil impregnated material of the present invention can be used in a clapper type print head that does not use a permanent magnet.

Further, a yoke film (for improving the magnetic performance of the print head) is provided between the drive arm 7 and the iron core 2a.
It is also possible to apply it to a print head provided with, and in that case, the oil impregnating material 13 supplies oil to the portion where the yoke film and the iron core 2a are in contact, and wear of this portion is prevented.

(Effect) As described above, in the present invention, the oil-impregnated material is embedded in the hole penetrating the iron core, and the supply member that supplies oil from the outside of the core piece to the opening of the hole opposite to the drive arm. Is provided. Since the supply member can supply oil to the impregnated material from the outside of the core piece, even if the oil in the oil-impregnated material runs out, the supply member can supply oil to the oil-impregnated material from the outside of the core piece.
It is not necessary to disassemble the print head and supply the oil to the oil impregnation material, and the oil is supplied to the part where the drive arm and the iron core come into contact with each other for a long period of time. It can easily be prevented from falling for a long time.

[Brief description of drawings]

The drawing is a cross-sectional view showing an embodiment of a print head according to the present invention. 1 ... Coil, 2 ... Core piece, 2a ... Iron core, 2b ... Hole, 7 ... Drive arm, 8 ... Printing element, 13 ... Oil impregnated material, 14 ... Supply member.

Claims (1)

[Claims] 1. A drive arm for driving a printing element, a core piece around which a coil is wound and having an iron core facing the drive arm, and a core piece for driving the drive arm, and an axis center of the iron core. A hole provided so as to penetrate in the direction, an oil impregnated material embedded in the hole, and a supply member for supplying oil from the outside of the core piece to the opening of the hole opposite to the drive arm. And a print head.