JPH0544540U - Impact dot head - Google Patents

Abstract

(57) [Abstract] [Purpose] In an impact dot head, suppress printing defects and improve reliability. [Structure] Urea (urea) was used as a thickener as a component of the grease 24 injected into the grease injection part 24. [Effect] Even when the printing wire 7 is driven, the fluidization of the grease 24 does not occur, and the grease 24 stays in the printing wire 7.
Does not seep into the tip 26 of the. Therefore, the grease 24 is not transferred to the ink ribbon 20 and printing failure does not occur.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a print head for an impact dot matrix printer.

[0002]

[Prior Art]

 Generally, to prevent adverse effects on the operation of the print wire due to the ink of the ink ribbon, waste of ink ribbon base cloth, and paper dust entering the tip of the impact dot head, and to prevent sliding wear between the print wire and the tip guide. As shown in FIG. 6, the printing wire tip holding part of the impact dot head as proposed in Japanese Utility Model Laid-Open No. 2-99645, only paying attention to the lubricity, and generally using soap as a thickener. It is known that grease 24 is injected.

[0003]

[Problems to be solved by the device]

 However, in the prior art, when the printing wire 7 is driven, the soap fibers in the grease 24 around the printing wire are broken by the reciprocating motion of the printing wire 7, and the grease 24 is fluidized. Therefore, if the ink ribbon 20 is left attached for a long time after the printing wire 7 is driven, the fluidized portion of the grease 24 injected into the printing wire tip holding portion of the impact dot head will be along the printing wire 7. And flows out to the tip 26 of the printing wire. This is transferred to the ink ribbon 20, and as shown in FIG. 3, a portion 25 (hereinafter referred to as an oil transfer portion) to which the grease 24 is transferred is formed on the ink ribbon 20. As a result, even if the oil transfer section 25 is hit by the printing wire 7, the ink is not transferred from the ink ribbon 20 to the printing paper 21 and a partially missing printing result is obtained as shown in FIG. There was a problem that it could not be obtained. However, such a problem occurs less frequently in the case of a conventional impact printer having a structure in which the impact dot head 23 is horizontally mounted as shown in FIG.

As a recent trend of impact printers, performance capable of handling a wide variety of printing papers is demanded, and in order to meet the needs, printing papers are printed without deformation as much as possible, as shown in FIG. 5 (b). A printing mechanism of an impact printer in which the printing paper 21 is not wound around the platen 22 such as the horizontal insertion type printing paper of the printing paper or the printing paper front insertion type printer shown in FIG. 5C is adopted. In the horizontal direction insertion type impact printer shown in FIG. 5B, the impact dot head 23 is mounted vertically so that it can print on a horizontal plane. Further, in the front insertion type impact printer shown in FIG. 5C, the impact dot head 23 is obliquely attached. In the above-mentioned printing paper horizontal insertion type or printing paper front insertion type impact printer, the grease injected into the impact dot head 23 is easily transferred to the ink ribbon due to the influence of gravity, and therefore some characters are missing as shown in FIG. The frequency of occurrence of this phenomenon has rapidly increased, and printing defects associated with it have become a problem. Further, even in an impact dot printer having a conventional structure in which the impact dot head 23 is horizontally mounted, when the gap between the impact dot head 23 and the platen 22 is narrowed to improve the speed, the response of the impact dot head 23 is improved. However, the degree of adhesion between the impact dot head 23 and the ink ribbon 20 is increased, and the grease 24 is easily transferred to the ink ribbon 20. Therefore, even when the impact dot head 23 is mounted horizontally, the printing failure due to the transfer of the grease 24 to the ink ribbon 20 becomes a problem with the increase in speed.

The present invention was made in order to solve such a problem, and the purpose thereof is to prevent the grease from fluidizing even when the printing wire is driven, and to leave the printer for a long time after printing once. We are providing a high-reliability impact dot head that does not drop in the printed characters even when printed from.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the impact dot head of the present invention is arranged at the tip of the printing wire by driving a plurality of printing wires and applying an impact force to the paper through the ink ribbon to perform printing. In the impact dot head in which grease is applied to the guide, urea (urea) is used as a thickener for grease.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a front view of an impact dot head of the present invention, and FIG. 1B is a side view thereof. FIG. 2 is a cross-sectional view showing the AA cross section of FIG. The operation of the impact dot head 23 that performs a printing operation by causing the printing wire 7 to project using electromagnetic force will be described with reference to FIG. When the coil 16 connected to the printed wiring board 9 is selectively energized according to a print signal, a magnetic flux is generated in the magnetic circuit composed of the frame 2, the first yoke 3, the second yoke 4, and the lever 18, and the lever 18 moves in the direction of the arrow. It is sucked in the A direction. Therefore, the printing wire 7 engaged with the lever 18 projects in the direction A, hits the ink ribbon 20, the printing paper 21 and the platen 22 to form dots on the printing paper 21 to perform printing. After the printing is completed, the printing wire 7 returns to the standby position before the printing signal is sent by the impact repulsion force and the return spring 15. The printing wire 7 is guided and held by an intermediate guide 8 and a tip guide 10 fixed to the nose 1. The tip guide 10 constitutes a grease injection part in a state of being fixed to the nose 1 by the intermediate guide 8 and the nose 1 which are closest to the tip guide 10. Ink generated when the ink ribbon 20, the printing paper 21 is struck, ink ribbon base cloth waste, and paper dust enter the impact dot head 23 in the grease injection portion of the dot portion at the tip of the printing wire 7. In order to avoid the adverse effect on the operation of the printing wire 7 due to the above, the grease 24 using urea (urea) as a thickener is injected through the grease injection hole 5 provided in the tip guide 10. When urea is used as a thickener, the strength of the urea fiber is so high that the urea fiber around the printing wire 7 is not destroyed even when the printing wire 7 is driven. Therefore, the grease 24 does not fluidize, and the grease 24 does not seep to the ink ribbon 20 side along the printing wire 7. Therefore, in the impact printer configured as described above, even when printing is performed after the printing wire 7 is once driven and the ink ribbon 20 is attached and left for a long period of time, the grease is not transferred to the ink ribbon 20 and the characters are not printed. There is nothing missing. The environment in which the impact dot head 23 is used may be a low temperature condition or a high temperature condition due to the heat generated by the impact dot head 23 itself. Due to this temperature change, the viscosity of the grease 24 changes, and the viscous resistance change between the print wire and the grease changes the print power of the print wire 7, which may deteriorate print quality. Since the grease 24 having excellent temperature characteristics at high temperature and low temperature is used, the fluctuation of the printing force of the printing wire 7 due to the temperature change of the environment can be reduced. Further, since the urea fiber has high strength, it can maintain a good lubricating state for a long period of time.

[0009]

[Effect of the device]

 As described above, according to the present invention, since urea (urea) is used as a thickener for the grease injected into the holding portion of the printing wire tip of the impact dot head, urea (urea) is used even when the printing wire is driven. ) The fiber does not break, so the grease does not fluidize. Therefore, the grease does not leak to the tip of the printing wire and is not transferred to the ink ribbon, and a highly reliable impact dot head with no missing characters can be realized.

[Brief description of drawings]

FIG. 1 is a front view and a side view of an impact dot head showing an embodiment of the present invention.

FIG. 2 is a sectional view of an impact dot head showing an embodiment of the present invention.

FIG. 3 is a schematic view showing a state in which grease adheres to an ink ribbon showing a conventional example.

FIG. 4 is a schematic diagram showing a result of printing in a state where grease is attached to an ink ribbon showing a conventional example.

FIG. 5 is a side view showing a mounting position of an impact dot head.

FIG. 6 is a sectional view of the vicinity of a tip guide portion of an impact dot head showing a conventional example.

[Explanation of symbols] 1 nose 2 frame 3 first yoke 4 second yoke 5 grease injection hole 6 damper 7 printing wire 8 intermediate guide 9 printed wiring board 10 tip guide 15 return spring 16 coil 18 lever 20 ink ribbon 21 printing paper 22 Platen 23 Impact dot head 24 Grease 25 Oil transfer part Arrow A Print wire protruding direction

Claims (1)

[Scope of utility model registration request] 1. Printing is performed by driving a plurality of printing wires and applying an impact force to paper through an ink ribbon,
An impact dot head in which grease is applied to a guide portion arranged at the tip of the printing wire, wherein urea is used as a thickener for the grease.