JPH06283039A - Cable for anti-spattering welding robot - Google Patents

Abstract

PURPOSE:To obtain a cable for anti-spattering welding robot which has a flexibility and a bending resistance. CONSTITUTION:A flexible conductor is produced with a high strength copper alloy wire which includes three or four sorts of In, Sn, Pb, and Sb, at the total amount of them 0.02 to 0.15wt%, with each amount of them 0.006wt% or more, and copper at the remaining part essentially. The insulating core wires made by providing an insulating coverage to the above flexible conductor are twisted each other, and a shielding layer is provided to the periphery so as to make into a shielded core wire 6. The shielded core wires 6 are twisted each other, and a sheath 8 is provided to the periphery of the twisted core wires 6 by using a resin composite made by mixing and kneading a chlorinated polyethylene and an ethylene acetic acid vinyl copolymer in the scope 35/65 to 65/35 in the wt. ratio. This resin composite 8 exercises the antispattering property.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable for controlling a welding robot and having durability against spatter during welding.

[0002]

2. Description of the Related Art The characteristics required for a welding robot cable are as follows. (1) Flex resistance. (2) Good flexibility. (3) It has heat resistance. (4) Sufficient to withstand spatter generated during welding.

In order to satisfy each of the above required characteristics, various studies have been conducted so far, and the present applicant has so far realized a flexible, flexible and heat resistant robot cable. He proposed 19 cases such as Japanese Patent Application No. 3-71371.

However, when the heat-resistant cable is used as a welding robot cable, there is no problem with the temperature during welding, but the sheath may be damaged by spatter. If the sheath is damaged, the damage will grow due to repeated bending, which will accelerate the disconnection of the conductor and may cause the robot to run away.

Therefore, an object of the present invention is to secure spatter resistance while having flexibility and bending resistance.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a plurality of insulations in which a flexible conductor made of a copper alloy having the following composition of copper alloy (I) is provided with an insulation coating are provided. A resin in which core wires are twisted together to form a core, and chlorinated polyethylene (CPE) and ethylene vinyl acetate copolymer (EVA) are kneaded around the core in a weight ratio of 35/65 to 65/35. A cable for a welding robot having a sheath formed of the composition was used.

(I) Indium, tin, lead and antimony are contained in three or four kinds, and the total content is 0.02 to 0.15% by weight, and the content of each is 0. A copper alloy containing 0.006% by weight or more and the balance being substantially copper. The substantial copper portion of the copper alloy preferably has an oxygen content of about 0.0001 to 0.005% by weight. (See JP-A-61-52334).

[0008]

According to the present invention having the above-mentioned constitution, the resin composition having the above-mentioned composition improves the spatter resistance and can sufficiently meet the needs of users.

In the ratio of CPE and EVA, EVA
If the amount is large, the spatter resistance becomes poor, while if it is small, the flexibility and bending resistance become poor.

The copper alloy having the above composition (I) is
As described in JP-A-61-52334, etc.,
Excellent flex resistance. For example, in the fatigue characteristics, under the condition that the bending strain is 0.306%, the number of break bending of the copper alloy wire is about 1610,000 times, whereas that of the pure copper wire is about 4.3 times.
It is about 1/4 times, and under the condition that the bending strain is 0.22%, the above copper alloy wire: 31.5 million times or more, pure copper wire: about 1
1930,000 times and less than 1/260, bending strain 0.18%
Under the above conditions, the copper alloy wire is 62 million times or more, and the pure copper wire is about 218,000 times, which is about 1/280 or less. Therefore, the cable has more excellent bending resistance.

[0011]

EXAMPLE First, as shown in FIG. 3, 7 lines / 36 lines / 0.
On a 05 mm thick copper alloy aggregate stranded wire a of the above composition (I),
The following resin composition b was extrusion-molded to a thickness of 0.3 mm to obtain an insulating core wire P (a part of the wire is omitted in the figure).

The polyether or polycarbonate polyurethane elastomer and the vinylidene fluoride-based fluoroelastomer are contained in a weight ratio of 30/70 to 90/10.
Resin composition b obtained by kneading within the range of, and adding the crosslinking agents 1 to 9 PHR thereto.

Next, as shown in FIG. 2, each pair of the above-mentioned insulated core wires P are twisted together, and the press-wound tape layer 4 is wound around them.
After forming, strand diameter: 0.01mm, braid density: about 8
A shielding layer 5 is provided by braiding 0% tin-plated annealed copper wire, and a press-winding tape layer 4 is also formed on the shielding layer 5 to form a shielding core wire 6. The braid can also be made of copper alloy wire of each composition described above.

Further, as shown in FIG. 1, six of the shielding core wires 6 are twisted together with an interposer 7, and a press-winding tape layer 4 is formed thereon, and the composition shown in Table 1 (Examples) is formed around it. The sheath 8 of 1 to 3) was extrusion-molded and coated with a thickness of 1.1 mm to obtain a cable A (diameter: 10.5 mm) according to the present invention. On the other hand, as a comparative example, a cable A ′ including the sheath 8 having the composition shown in Table 1 was also manufactured. In Table 1, the sheath 8 was compounded with appropriate amounts of a stabilizer, an antioxidant, a flame retardant, a cross-linking agent and the like.

[0015]

[Table 1]

When each example and comparative example were exposed to the following sputter jet conditions, in each example, the jet distance: 220
Only in the area of mm, "small charring" was confirmed at the concentrated portion and "small spatter mark" was confirmed at the peripheral portion, and at other distances, "burning" and "marks" were not generated at all (○ in Table 1). .
On the other hand, in Comparative Example 1, not only in the concentrated portion but also in the peripheral portion, “burn” occurred (x in Table 1).

(Sputtering jet conditions) Cut grinder cutting Grinding stone type: P36AB, φ350-400 mm * If the grinding stone diameter is small, the spattering jet direction scatters, so the outer diameter is specified, jetting time: 30 seconds, jetting distance: 220 mm, 400 mm , 600 mm Injection direction: Horizontal Cutting material: Soft steel (SS41), φ40 mm round bar.

Further, the bending resistance test was carried out by the apparatus shown in FIG. 4 under the following conditions, and the number of reciprocations at which breakage of the twisted wire a occurred was determined. In the figure, 1 is a moving guide and 2 is a fixed guide. The results are shown in Table 1 and those less than 3 × 10 ⁵ times were regarded as defective.

(Bending conditions) Samples A and A'length 25 cm, moving length of moving guide 1 5.0 cm, amplitude speed 60 times / min, curvature r 1.5 cm.

Further, in the flexibility test, those which cannot be generally used as a robot cable are judged to be defective, which is shown in Table 1.

From the above test results, it can be understood that each example has spatter resistance, bending resistance, and flexibility and can be sufficiently used as a welding robot cable. By the way,
The characteristics of the sheath 8 in the composition of Example 2 were as follows.

Tensile property 100% modulus (Kg / cm ² ) about 46 Tensile strength (〃) 218〃 Elongation (%) 470〃 Electric property (20 ° C) Volume resistivity (Ω-cm) 1.5 × 10 ¹⁴ Dielectric constant (ε) 4.63 Dielectric loss tangent (tan δ) 4.5 × 10 ^-2 Dielectric breakdown strength (KV / mm) 18.5
.

In the embodiment, since the twisted core wires 6 are twisted together, the "insulated core wires" in the "claims" are the shield core wires 6. In each embodiment, the effect of the present invention can be obtained even if the insulating core wires P are twisted together to form a core.

[0024]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, it is possible to obtain a sputter-welding robot cable having sufficient flexibility and bending resistance.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a detailed cross-sectional view of the shielding core wire of the same embodiment.

FIG. 3 is a partially cut perspective view of an insulating core wire.

FIG. 4 is a schematic view of a bending resistance tester, in which (a) is a front view and (b) is a left side view.

[Explanation of symbols]

 4 Holding tape layer 5 Shielding layer 6 Shielding core wire 7 Interposition 8 Sheath (sheath) P Insulating core wire a Stranded wire (flexible conductor) b Resin composition (insulation coating) A cable

Claims (1)

[Claims] 1. A flexible conductor made of a copper alloy having the following composition is twisted together to form a core, and a chlorinated polyethylene and an ethylene vinyl acetate copolymer are wound around the core. And a weight ratio of 35/65 to 65/35 are kneaded in the resin composition, and a sheath is applied to the cable. Note Indium, tin, lead and antimony containing 3 or 4 kinds, and the total content thereof is 0.02 to 0.15% by weight.
And the content of each of them is 0.006% by weight or more,
A copper alloy whose balance consists essentially of copper.