JPS61231147A - Manufacture of semi-hard copper tube - Google Patents

Abstract

PURPOSE:To manufacture a semi-hard copper tube hardly causing variance of mechanical properties with high productivity in CONSTITUTION:The copper tube 1 finished to a thickness of the required product dimensions and to an outside diameter larger than.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a semi-rigid copper tube, and more particularly to a method for manufacturing a semi-rigid copper tube with less variation in mechanical properties.

[Prior Art 1] Conventionally, there are methods for refining copper tubes as described below, but each method has its own problems. That is, (1) A straight copper tube (approximately 1.1 times the outer diameter of the product) is spouted, annealed in a roller hearth type furnace, and then reduced in diameter (upward) by approximately 10% in a drawing die using a drawing machine. This method involves straightening with a drum-shaped roll, detecting flaws, and cleaning after up-cutting and chamfering.

This method has problems in that the yield is low and the process is long due to the generation of mouth and upward cutting waste for each copper tube and the occurrence of defects due to handling after annealing. In addition, since this method uses drawn lubricating oil, it is necessary to perform a cleaning treatment at the end of the process.

(2) A long copper tube wound into a coil (L eve
IWound Co11. It is called LWC copper tube. ) is annealed in a roller hearth type furnace, followed by upward drawing (drawing, straightening, flaw detection, cutting, chamfering) using a combined finishing machine, and then cleaning.

This method disturbs the process control in the manufacturing process because the finishing machine is used twice for winding the LWC copper pipe and semi-rigid finishing drawing. Furthermore, since drawn lubricating oil is used, cleaning treatment is required at the end of the process.

(3) A method of achieving a semi-hard finish by controlling annealing conditions may be considered, but in the case of deoxidized copper, it is difficult to establish this technology due to the P content, trace impurities contained in the copper, and variations in the roller nose furnace. It has not been established as a practical method.

In this way, in general, as in methods (1) and (2) explained above, after annealing, diameter reduction is performed using a drawing die using lubricant on the side to adjust the T91 mechanical properties to semi-hard. That is what is being done.

[Problem to be Solved by the Invention 1] The present invention was made as a result of intensive research by the present inventor in view of the various problems in the conventional semi-rigid copper tube manufacturing method as explained above. We have developed a method for manufacturing semi-rigid copper tubes with less variation in mechanical properties, improved yield, and high productivity.

[Means for Solving the Problems] The method for manufacturing a semi-hard copper tube according to the present invention is characterized by: straightening the copper tube wound into a coil shape and then continuously annealing it; Next, semi-hard diameter reduction rolling is performed, and further correction is performed.

The method for manufacturing a semi-rigid copper tube according to the present invention will be described in detail below.

The method for manufacturing a semi-rigid copper tube according to the present invention will be explained with reference to the schematic diagram shown in FIG.

1 is a copper tube wound into a coil (pull coil copper tube, LW
Contains C copper tubes. ), the wall thickness is finished according to the product dimensions, and the outer diameter is finished approximately 10% larger than the product dimensions. The outer diameter of this copper tube is determined by the mechanical properties (σ8,
δ, σ0. ．． ) in advance so as to obtain the desired characteristic values.

2 is a copper tube entrance guide and straightening device.

3 is a degreasing device.

4 is an eddy current testing coil.

Reference numeral 5 denotes an induction heater, which anneales the copper tube to reduce variations in quality in the longitudinal direction and make it uniform.

Reference numeral 6 denotes a grooved roll for feeding the copper tube to a cassette roller die that performs diameter reduction processing in the next step.

7 is a cassette roller die that performs diameter reduction processing without lubrication.

8 is a grooved roll for pulling out and straightening the copper pipe after diameter reduction.

9 is a defect marking device.

10 is a cutter.

Next, a method for manufacturing the semi-rigid copper tube of the present invention will be explained.

The copper tube is fed from the copper tube 1 wound into a film to the entry guide 2, and then the outer surface of the straightened copper tube is degreased by the degreaser 3, and then annealed by the induction heater 5. At step 11, the dispersion in thermal quality in the longitudinal direction of the copper tube is made uniform, and the copper tube is sent to a cassette roller die 7 by a groove-shaped roll 6.

In this cassette roller die 7, a semi-hard annealed copper tube can be obtained by reducing the diameter by 10% using a non-lubricating method.

Next, the diameter-reduced copper tube is pulled out and straightened using grooved rolls 8 arranged in a staggered manner.

The semi-rigid copper tube obtained in this way is cut into regular length semi-rigid copper tube products (5000 mm1), further cut into short products, wound into a coil, or made into LWC products. shipped by either.

In the method for manufacturing a semi-rigid copper tube according to the present invention, the tensile strength σB) is 25 to 33 kgf/mm2 according to the JIS standard.
However, according to the method for manufacturing semi-rigid copper tubes according to the present invention, the range of variation is 2 to 3 kgf/+nm2, which is extremely small, and the line speed is 180 kgf/+nm2.
m/+ain, conventional 4O-60a+/min
Productivity is significantly improved by 3 to 4 times compared to 1).
Moreover, the yield is extremely improved.

[Effect of the invention 1 As explained above, since the method for manufacturing a semi-rigid copper tube according to the present invention has the above-mentioned configuration, it is possible to perform integrated production from the coiled copper tube to the product. is possible,
In addition, the line speed is fast, so productivity is excellent, and
The range of variation in mechanical properties is extremely small, and since the diameter is reduced without lubrication, the degreasing step can be omitted.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a method for manufacturing a semi-rigid copper tube according to the present invention. 1. Copper tube wound into a coil, 2. Inlet side,
3. Degreasing device, 4. Flaw detection device, 5. Induction heater, 6. Groove roll, 7. Cassette roller die, 8. Groove roll, 9. Defect marking device, 10. cutter.

Claims (1)

[Claims] A method for manufacturing a semi-rigid copper tube, which comprises straightening a copper tube wound into a coil shape, successively annealing the tube, then performing semi-rigid diameter reduction rolling, and further straightening the tube.