JPS61199064A - Hot dip coating apparatus - Google Patents

Abstract

PURPOSE:To provide the titled apparatus by which dip coated wire having uniform coated thickness and stable quality is obtained, by providing a means for forming circulating flow of molten metal in a fixed direction, surrounding metallic wire or stripe to be dip coated. CONSTITUTION:In hot dip coating vessel 12 in which a core wire 2 supplied from a sending-out apparatus 1 is introduced into a molten metal 4 from a core wire supplying cap 10 through a pretreating vessel 3 and a stuck molten metal is controlled to a prescribed thickness by a die 5, then cooled by a cooling vessel 6 and the obtd. coated wire 8 is wound around a winder 7, a molten metal circulat or 9 is arranged to circulate the metal 4 in the same arrow direction as the sending direction at circumference of the wire 2 in a molten flow passage 11. Flow rate of the circulating flow is favorable to adjust to about the same as sending velocity of the wire 2. In this way, the wire 8 coated with uniform thickness can be obtd. stably.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a plating apparatus, particularly a hot-dip plating apparatus.

<Conventional technology> Manufacturing methods for plating materials can be roughly divided into hot-dip plating and electroplating.The former is relatively fast, uses simple equipment, and is suitable for forming a low-melting-point plating layer. However, on the other hand, there is a limit to the thickness of the plating layer, and it is difficult to form n-plating with good surface quality.

1-+
It is also capable of plating materials with high melting points.
However, the plating speed is slow and the manufacturing equipment is not economical in terms of plating bath costs.1 The surface hardness may be lower than that of hot-dip plated materials, which is a secondary problem when using plating materials. may also occur.

There has been a delay in the development of equipment that can produce stable products of uniform quality using hot-dip plating, which is more economical than electroplating.

(While the invention is trying to solve gJ points) The object of the invention is to provide a hot-dip plating device that eliminates the drawbacks of the prior art described above and that produces a plating material with good surface quality when performing H plating in the hot-dip plating method. Our goal is to provide the following.

Means for Solving the Problems> The present invention is characterized in that a wire or strip hot-dip plating S apparatus has a means for circulating molten metal flowing in a fixed direction around the metal wire or strip to be plated. The present invention provides a hot-dip plating apparatus that does the following.

<Configuration of the Invention> The configuration of the invention will be described in detail below using drawings showing preferred embodiments of the invention.

FIG. 2 is a schematic diagram showing a conventional hot-dip plating line.

The core wire 2 that has been pretreated in a predetermined pretreatment tank 3 enters the plating bath, passes through the hole in the die 5 with a plating layer of molten metal 4 on its surface, is pulled by an L force, and is wound. It is wound up by a winding machine 7. When the plating layer is relatively thick (approximately 5 pm or more), gravity, vibration,
Due to uneven cooling conditions, the plating layer tends to flow unevenly in the longitudinal and circumferential directions of the core wire on the surface of the core wire.
Local variations in plating thickness occur, and the smoothness of the surface condition is lost. In particular, as shown in FIG. 3, the molten metal 4 directly below the die 5 is susceptible to convection due to the speed of the wire to be plated 2, resulting in uneven plating due to die wobbling.

FIG. 1 shows an example of the configuration of the apparatus of the present invention, which improves the drawbacks of the conventional method.

The hot-dip plating apparatus 12 of the present invention includes core wire supply caps 10 and 4.
A molten metal wave path 11 that causes the core wire 2 supplied through the core wire supply mouth lO to run toward the center, and a die 5 that controls the plating amount of the molten metal plated on the core wire 2 by passing through the molten metal flow path 11. has.

As the core wire supply cap 10, any conventional cap can be used.

The molten metal flow path 11 forms a closed circulation path with the molten metal circulator 9, and the molten metal 4, which is given a laminar flow in the same direction as the running direction of the core wire 2 by the molten metal circulator 9, runs at a desired speed. . The traveling speed of the core wire 2 and the relative flow speed of the molten metal 4 can be variously selected by the molten metal circulator 9. In particular, it is preferable that the running speed of the core wire 2 and the flow speed of the molten metal 4 be the same.If the molten metal channel 11 is at least 5 times the diameter of the core wire, the cross section should be as narrow as possible, and the temperature should be controlled accurately. This makes it possible to thicken the wall with uniform thickness.

The molten metal circulator 9 can be a normal high-temperature metal pump or the like. Although not shown, the molten metal 4 can be supplied continuously or at regular intervals to replenish the molten metal 4 lost during plating so that a constant amount of molten metal always flows through the molten metal channel 11. do.

The dice 5 may be any conventional dice.

The length of the molten metal channel 11 is determined based on the diameter and material of the core wire 2 which is the material to be plated, and the type of the molten metal 4 which is the plating metal.
Thick coating can be achieved by optimally selecting the core wire running speed and molten metal temperature setting. The plating conditions are calculated theoretically in consideration of heat transfer, and are actually determined by making the following corrections through various experiments.

Although FIG. 1 shows a vertical hot-dip plating device in which the core wire 2 runs vertically, the core wire 2 can run in any direction, and if necessary, a horizontal hot-dip plating device can run horizontally. It may be.

In the plating process using the hot-dip plating apparatus of the present invention, the core wire 2 sent out from the sending out device t is wound up by the winder 7 and runs at a desired speed. A hot-dip plating device 12 is installed between the sending device 1 and the winding device 7 via a pretreatment tank 3, and a cooling tank 6 is installed adjacent to the die 5 of the hot-dip plating device 12.

The core wire 2 passes through a core wire supply mouthpiece 10 and is transferred to a molten metal circulation machine 9.
The wire passes through a molten metal fluid that is in a laminar flow state in a fixed direction, is squeezed into a predetermined size by a die 5, and is cooled by a cooling tank 6 immediately after the die to become a plated wire 8.

Example of implementation〉 Diameter 0.50m + wφc7) Mild steel wire was heated at 240±5℃ (7
) Hot-dip plating was performed using a Sn60%-Pb40% solder melting metal bath. Core wire running speed 50 cm/see,
The molten metal flow rate was 40 crs/sec, and the die diameter was 0. θ0■φ was used.

The obtained plated wire was changed to one with no uneven thickness and a smooth surface with a plating thickness of 0.025+sm.

<Effects of the Invention> Since the molten metal circulates in the hot-dip plating apparatus of the present invention, the temperature of the molten metal in contact with the wire to be plated becomes uniform, and the plating thickness becomes uniform.

You can replace the plated wire with stable quality.

In particular, when the molten metal runs at the same speed as the core wire, the metal around the core wire solidifies during that time, but the low-temperature core wire absorbs the heat, making it possible to build the material as thick as 0.030+wm.

In the conventional method, the high-temperature molten metal comes into contact with the core wire in a turbulent state, resulting in high temperatures and the upper limit for the plating thickness to be a few tiles.

In addition, by circulating the molten metal through a relatively narrow flow path,
Temperature control is possible with good responsiveness, making it easy to set thick walls and uniform conditions.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the hot-dip plating apparatus of the present invention. FIG. 2 is a sectional view of a conventional hot-dip plating line. FIG. 3 is a detailed view of the vicinity of the dice in FIG. 2. Explanation of symbols 1... Feeding device, 2... Core wire 3... Pretreatment tank, 4... Molten metal, 5... Dice 6... Cooling tank 7... Winding machine, 8... Plated wire 9... Molten metal bacteria 1; Machine, 10... Core wire supply mouthpiece, 11... Molten metal channel 12... Hot dip plating device, 13... Molten metal pair (Conventional example) Patent order: Nozomi Watanabe, agent for Hitachi Cable Co., Ltd. ? C FIG, 1 FIG, 2 FIG, 3

Claims (1)

[Claims] (1) A wire or strip hot-dip plating device characterized by having means for circulating molten metal flowing in a certain direction around the metal wire or strip to be plated.