JPH0225421B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) This invention relates to an improvement in a printing wire for a dot printer used in a computer terminal processing machine, a word processor, or the like. (Prior Art) Conventionally, impact printers and non-impact printers have been known as printers for computer terminal processing machines, word processors, and the like. Among these, impact printers are currently widely used because they have advantages over non-impact printers, such as lower cost, higher reliability, and the ability to make multiple copies at the same time. There are also types of impact printers that use specific type, and wire dot printers that do not use type and instead form characters using multiple dots. Of these, wire dot printers use specific types. Because of this, it is widely used in Japanese word processors that require a large number of characters. Furthermore, wire dot printers include wire dot type printers that print when driven by a magnet, shuttle type printers that cut prints when driven by a magnet, and the like. For example, as shown in FIG. 3, this wire dot type printer has a plurality of armatures 1... arranged in a head case, and each armature 1...
... has one end supported in a cantilever manner by the core 2 (or head case), and is constantly biased by a reset spring 3 so that the other end is separated from the core 2 by a certain amount. A printing wire (pin) 4 is fixed to the other end of the armature 1 by brazing or the like,
The printing wires 4 are slidably guided and supported by guides 5, 5'. A coil 6 is wound around the core 2, and the core 2 and the coil 6 constitute an electromagnet, and by passing current through the coil 6, the biasing force of the reset spring 3 is overcome. The armature 1... is drawn into the core 2. Therefore, this printer connects the armature 1 to the core 2 by energizing the coil 6 (electromagnet).
can be suctioned to print on the printing paper 8 on the platen 7 via the ribbon 9 by the printing wires 4 . Further, as shown in Fig. 4, the shuttle type printer is equipped with a plurality of armatures 1 in the head case, and each armature 1 has one end attached to the core 2 (or head case) and the other end of the spring 3'. The core 2 is supported at a constant distance from the core 2. On the opposite side of the core 2 of the armature 1, a printing wire (pin) 4 is fixed by brazing or the like, and the printing wire 4 is slidably guided and supported by guides 5, 5'. A coil 6 is wound around the core 2,
The core 2 and the coil 6 constitute an electromagnet, and by applying current to the coil 6, the armatures 1 are attracted to the core 2. Therefore, in this type of printer, the armature 1... is attracted to the core 2 by energizing the coil 6 (electromagnet), and by cutting off the energization, the printing wire 4... is drawn by using the restoring force of the spring 3'. Then, printing can be performed on the printing paper 8 on the platen 7 via the ink ribbon 9. As described above, the printing wire 4 of such a wire dot printer is pressed toward the platen 7 via the armature 1 by attraction or release of the electromagnet, so the tip is struck and the printing on the ink ribbon 9, etc. Print paper 8 while sliding on the medium
Since images are to be formed on the printing wire, printing wires are required to have wear resistance and impact resistance, and various materials have been developed over the years, such as cemented carbide, powdered high-speed steel, pure tungsten, and cobalt alloys. , and used. (Problem to be Solved by the Invention) However, conventionally known printing wire materials, such as cemented carbide, are strong against slipping and abrasion, but are brittle, so they are weak against bending moments and breakage occurs. easy. Moreover, it is expensive and has a high specific gravity (specific gravity 14.0), which causes problems such as high energy consumption and high running costs when dotting. In addition, although pure tungsten is relatively inexpensive, it has a higher specific gravity than cemented carbide (specific gravity 19.2).
Relatively high-speed printing is possible with around 7 or 9 wires, but in order to print complicated characters like kanji, around 24 or 36 wires are required. For example, it was practically unusable as a printer for a Japanese word processor. Furthermore, powdered high-speed steel (specific gravity 8.15) or cobalt-based alloy (specific gravity 8.3) is more expensive than pure tungsten, but cheaper than cemented carbide, and has a lower specific gravity. Therefore, for example, the printing speed of a 24-wire printer made of powdered high-speed steel is approximately 40 to 80 characters per kanji only.
Since it is possible to print at a high speed of approximately 120 to 240 characters/second in the case of seconds and kana, it is currently the mainstream printing wire for printers with a large number of wires, such as 24 or 36 wires. However, in the case of powdered HSS or cobalt-based alloy, when soldering with silver solder, etc. when joining the head parts (armature), the soldering temperature (approx.
(700 to 800℃), it undergoes a phase transformation and becomes brittle, making it difficult to use brazing, which has the highest strength and stability, and has no choice but to use mechanical joining methods such as caulking. , the joints with the head parts are likely to come off. As described above, none of the materials satisfactorily satisfies all the functions required for printing wires, such as abrasion resistance, impact resistance, brazing properties, price, and weight. Furthermore, most automatic devices are used to assemble the printing wire and armature. If the assembly is carried out automatically, weak printing wires may bend, causing errors in clamping the printing wire moving device, etc., and productivity is significantly hindered. Moreover, when a weak material is printed through the guide 5, it cannot withstand the printing pressure and bends, causing the guide 5 to catch and lose its function. It is an object of the present invention to provide a printing wire material that is sufficiently resistant to automatic assembly. (Means for Solving the Problems) The present inventor has discovered that the stiffness of the printing wire is determined by the hardness and
We discovered that it depends on the proportionality limit and Young's modulus, and found means to improve these factors. Specifically, Bitkers hardness (HV200g)
300 or more, the proportional limit by tensile test is 60Kg/
^mm2 or more, Young's modulus by cantilever bending test is 25000
By setting the weight to Kg/mm ² or more, a printed wire that can withstand automatic assembly can be obtained. More specifically, in order to make the Vickers hardness, proportional limit, and Young's modulus equal to or higher than the above values, in the present invention, cobalt is added from 0.05% to 5% by weight.
%, and La, Ce, Nd, Gd, Yb,
Th, Ho, Er, Li, Na, K, Rb, Cs, Be,
Mg, Ca, Ba, Ra, Sc, Y, Hf, Ta, W, Re,
Os, Ir, Ti, V, Cr, Fe, Ni, Cu, Zn, Al,
Si, Ga, Ge, In, Sn, Tl, Pb, Zr, Nb, Ru,
Rh, Pd, Cd, Bi or their oxides, carbides,
A sintered ingot having a composition of 0.05 to 5% by weight of one or more of forodides or nitrides, with the remainder being molybdenum, is preferably formed by hot drawing. has a hardness of 300 or more in microbits (HV200g),
Moreover, the proportional limit was 60Kg/mm ² by tensile test.
In addition, the Young's modulus in the cantilever bending test is 25,000 Kg/mm ² or more, making it possible to obtain a printing wire that has wear resistance, impact resistance, and solderability as a printing wire, and is lightweight and inexpensive. It is meant to be. (Example) Cobalt (Co) is a lightweight and inexpensive material that has the necessary abrasion resistance, impact resistance, and brazing properties as a material for printing wires for wire dot printers.
Focusing on molybdenum alloys doped with various amounts of doping and doping with one or more of various metals or metal oxides, carbides, oxides, or nitrides, they were processed under various processing conditions.
Molybdenum alloys doped with 5% or more Co and 0.5% or more of the various elements mentioned above are brittle and have poor wire workability, so they cannot be processed into wire rods. Therefore, if the diameter is 0.2φ, the weight ratio is 0.04%, 0.05%, 0.1
%, 2.0%, 3.0%, 4.0%, 5.0% Co, and doped with 0.05% or more of cobalt, ZrO ₂
A doped molybdenum powder with an average particle size of 4 μm to which 1.0% was added was press-molded at a pressure of 3 tons/cm ² and then sintered in a hydrogen furnace at 1800° C. for 10 hours to produce a sintered ingot. This sintered ingot costs 1000~
Perform hot rolling at a temperature of 1400℃, perform intermediate strain relief heat treatment once or twice, and finish to 3mmφ500
1 or 2 by hot drawing at a temperature of ~1000℃
Perform intermediate strain relief heat treatment. This molybdenum alloy wire was prepared and incorporated into the 24 wire dot type printer shown in FIG. 3 above, and a dot printing test of 200 million times was conducted. This test result is the first
As shown in the table and FIG. Note that the diameter of the molybdenum alloy wire was 0.2 mmφ.

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[Table] The amount of wear shown in Table 1 was determined by measuring the amount of wear at the tip of the printing wire in micrometers, the impact resistance was determined by determining the presence or absence of folding or bending after the test, and the specific gravity was determined by an underwater method. After brazing, a commercially available silver solder was used to braze at 845°C, and then the armature 1 was fixed to the clamp C as shown in FIG. 2 and a 90 degree bending test was performed. The proportional limit is the value of stress at the elastic limit measured by a tensile tester. Young's modulus was determined by a cantilever support bending test using an Amsler universal testing machine as shown in FIG. From the above test results, wear resistance is 1%
It was observed that there is a correlation with ZrO ₂ and Co content. Furthermore, Co content is 0.05% without ZrO ₂
When the wear amount is less than 80 μm, there are some cases where the wear amount exceeds 80 μm, and it was also recognized that these have a low proportional limit of 45 Kg/mm ² and a low Young's modulus of 20000 Kg/mm ² or less.
Similarly, in terms of impact resistance, this material is soft;
Although no bending occurred, there were cases where bending occurred when the Co content was less than 0.05%, similar to wear. From the above results, it has ZrO ₂ 1% and Co0.05%~5
The proportional limit is 60Kg for molybdenum alloy wire with %
/ ^mm2 or more, Bitkers hardness (HV200g) is 300
In addition, it was possible to obtain a strength with a Young's modulus of 25000 Kg/mm ² or more, and it was demonstrated that it can be sufficiently used as a printing wire for a wire dot printer. Although omitted in the paper, other metals or oxides,
A molybdenum alloy containing carbides, forodides, and nitrides in a weight ratio of 0.05 to 5.0% was also sufficiently usable as a printing wire. Furthermore, in the same manner as in the above-mentioned example, in the case of containing other metal elements or alloys of their oxides, carbides, borides, and nitrides, the wear rate μm and Young's modulus at 200 million dots were determined. (×10 ³ Kgf/
mm ² ), similar results were obtained as shown in the table below. Table 2 shows molybdenum with 1% Co and 1% of each metal element.
Table 3 shows that when a sintered ingot doped with molybdenum with 1% of Co and 1% of oxides with each metal element is hot drawn, The table shows the case where a sintered ingot in which molybdenum is doped with 1% Co and 1% carbide with each metal element is hot drawn. When a doped sintered ingot is hot drawn, Table 6 shows the following when a sintered ingot doped with molybdenum doped with 1% Co and 1% nitride with each metal element is hot drawn. There is. In addition, metal elements and oxides, carbides, borides,
and nitride, molybdenum doped with 1% Co, 0.5% Ta, 0.5% ZrO ₂ ,
Total of La ₂ C ₃ 0.5%, KB ₆ 0.5%, Ni ₃ N 0.5%
For 2.5% (excluding Ci) doped 0.2φ wire,
Its characteristics include a wear amount of 23 μm and a Young's modulus of 34×10 ³
It was Kgf/ ^mm2 . However, the doping weight percentage of each oxide, carbide, boride, and nitride compound mentioned above is not the weight ratio of the compound itself, but the weight ratio of each element contained in the compound. The percentage by weight of each alloying element contained in For example, 1% ZrO ₂ means that molybdenum contains 1% Zr by weight.

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【table】 [Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between wear amount and Co content containing 1% ZrO ₂ in this invention, Figure 2 is a schematic diagram of a test to judge the brazing properties of this invention, and Figure 3
4 and 4 are schematic diagrams of a known wire dot printer. FIG. 5 is a schematic diagram of the method for measuring Young's modulus of the present invention.

Claims (1)

[Claims] 1. A printing wire material used in a dot printer that contains 0.05 to 5% cobalt by weight and contains La, Ce, Nd, Gd, Yb, Th, Ho, Er, Li,
Na, K, Rb, Cs, Be, Mg, Ca, Ba, Ra,
Sc, Y, Hf, Ta, W, Re, Os, Ir, Ti, V,
Cr, Fe, Ni, Cu, Zn, Zn, Al, Si, Ga, Ge,
In, Sn, Tl, Pb, Zr, Nb, Ru, Rh, Pd, Cd,
Consisting of a sintered material containing 0.05 to 5% of either the metallic element Bi and an alloy of oxide, carbide, boride, or nitride of at least one of the metallic elements, and the balance being molybdenum. Printing wire material for dot printers featuring: