JPS6220860A - Hot dipping device - Google Patents

Abstract

PURPOSE:To stably form a hot dipping layer having a uniform compsn. and thickness by stirring a hot dipping bath and removing the excess plating bath of an extruded multi-hole tube made of Aluminum for heat exchange after a plating treatment then quickly cooling the tube in the stage of preheating said tube then continuously hot dipping an Al-Si or Zn brazing filler metal thereto. CONSTITUTION:A corrosion resistant improving material such as Zn is added to the Al-Si brazing filler metal or Al, etc., are added to the Zn brazing filler metal in order to decrease the m.p. thereof in the stage of hot dipping the Al-Si or Zn brazing filler metal onto the surface of the extruded multi-hole tube 20 made of Al or Al alloy for the heat exchanger. After the tube 20 is preheated to a prescribed temp. by a preheater 13, the tube is introduced into a hot dipping cell 1 and the hot dipping bath 2 is heated by a holding device 4 and is stirred by a stirrer 8 so that the melts of Al-Si and Zn or An and Al having different specific gravities have the uniform compsn. Such melts are hot dipped on the surface of the tube 20. After the excess plating bath is removed from the tube by a die 15, the tube is quickly cooled by a cooler 16 and a fan 17, by which the brazing filler metal having uniform compsn. is formed on the surface of the tube 20 to uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application 5'f) The present invention provides A
The present invention relates to a hot-dip plating apparatus suitable for hot-dip plating of Si-based, Zn-based brazing materials, etc.

(Prior art) Generally, aluminum or aluminum alloy materials are
The technique of applying a plating layer of a brazing material such as n-Si or Zn is highly prized in the production of extruded multi-hole tube material for aluminum heat exchangers, which is assembled by brazing, for example.

That is, in recent years, from the standpoint of energy saving and cost reduction, there has been a strong desire to reduce the weight of heat exchanger cores, and in order to meet this demand, thinning of the fins is being considered. However, the thickness of the fin made of praising sheet is 0.1
If the thickness is made thinner than 6 mm, brazing around 610'O will cause problems such as the fins becoming more likely to buckle at temperatures.

This occurs because during soldering, Si in the brazing material of the plating sheet diffuses into the core material and its strength decreases, and the absolute thickness of the core material becomes thinner, resulting in a decrease in strength. .

Therefore, by brazing the bare fins with an extruded multi-hole tube whose outer surface is melt-plated with a brazing material, we are able to prevent buckling of the fins and achieve thinner walls, thereby reducing the weight of the heat exchanger core. It was hoped to reduce costs.

Conventionally, long aluminum materials such as extruded multi-hole tubes for aluminum heat exchangers have been made into A9. - As an apparatus for performing hot-dip plating with a Si-based brazing material, a Zn-based brazing material, etc., a hot-dip plating apparatus that only allows the plating solution to pass through it continuously has been proposed and implemented.

(Problems to be Solved by the Invention) However, in conventional hot-dip plating equipment, when Zn, etc. is added to Humanities-5I brazing filler metal for the purpose of improving corrosion resistance, the content does not reach the target level until the content is about 2% by weight. A plating layer is obtained, but if it exceeds 5 in-%, Zn will sink to the bottom and separate.Also, even in Zn-based brazing filler metals, Al is added to lower the melting point, but its content When the amount exceeds 5% by weight, Al floats upward while Zn sinks to form a Zn layer. Therefore, it was difficult to obtain a plating layer with a uniform composition even if the aluminum material was passed through the plating solution in such a state. In addition, it has been difficult to plate a long extruded aluminum tube with a stable composition throughout the entire process from the start to the end of plating.

The present invention has been made in view of the above points, and in particular,
The purpose is to provide a hot-dip plating device that can obtain a plated layer with a uniform composition using a device that has a simple structure, and can also plate long objects continuously and stably for a long period of time. shall be.

(Means for Solving the Problems) The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, they have found that the objective can be achieved by a plating apparatus such as the method. That is, in the present invention, when continuously hot-dipping aluminum or aluminum alloy materials with Al-5i-based, Zn-based brazing filler metals, etc., a molten metal stirring device and a molten metal warming device are provided in the plating tank. The present invention provides a hot-dip plating apparatus with special features.

(Example) Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

1(A) and (B) are a longitudinal sectional view and a plan view thereof of a hot-dip plating apparatus, and in FIGS. 1(A) and (B), the symbol (A) indicates the hot-dip plating apparatus according to the present invention. The hot-dip plating system M (A) includes a preheating section (b) disposed upstream of the plating section (a), and a plating section (a).
) and a take-out processing section (C) disposed at the subsequent stage.

The plated part (a) has a draw-out hole (
A plating tank (1) in which 1a) and (1a) are drilled, and a molten metal (plating solution) (
2) is formed by the stirring device (3) and heat insulating device (4), and the -side L part of this plating tank (1) is for injecting the molten metal (2) into the plating 4PI (1). A pouring trough (5) is provided. The stirring device (3) is formed by integrally connecting a motor (7) and a propeller-shaped stirring section (8) via a connecting member (6), while the heat retaining device (4) is formed by a heater. (9) and the heater tube (10) arranged around this heater (9).
) is formed by. (11), (11) are draw-out holes (1a) provided on both sides of the plating tank (1), (
(12) is a receiving member for the molten metal (plating solution) (2) provided at the outer lower part of the plating tank (1), and a stopper inserted into the molten metal discharge hole (1b) provided at the lower part of the negative side of the plating tank (1). show.

The preheating section (b), which is disposed upstream of the plating section (a), processes the metal material to be plated, for example, as shown in FIG. 2, an extruded aluminum multi-hole tube (20 ); a plurality of roller members (14) supporting the extruded aluminum multi-hole tube (20) transferred within the preheating furnace (13);
It is formed by (14)...

-1- The extraction processing section (C) arranged after the plating processing section (a) is an ironing section arranged near the extraction hole (1a) drilled on the - side of the plating tank (1). Dice (1
5), a cooling device (16) provided at the rear of this ironing die (15) and a plurality of cooling machines (17), (
17)... and a carrier (18). The carrier (18) is guided by a carrier rail (18a) via support rollers (19), (19), . . . .

Next, a plating method using the hot-dip plating apparatus of the present invention will be explained.

Since the hot-dip plating apparatus (A) is constructed as described above, when using it, the extruded aluminum multi-hole tube (20) is moved between the roller members (14) and (1) as shown in FIG.
4) ......The aluminum extruded multi-hole tube ( 20) is heated to a predetermined temperature. Next, the extruded aluminum multi-hole tube (20) thus heated to a predetermined temperature passes through the plating tank (1) of the plating processing section (a) and is transferred to the take-out processing section (C). in this case,
Molten metal (plating solution) (2) is in the plating tank (1).
) is constantly poured through the pouring trough (5), and a part of it is discharged from the draw-out holes (1a), (1a) drilled on both sides of this plating tank (1), and is poured into the receiving member. (
11) and (11). Also,
The molten metal (plating solution) (2) in the plating tank (1) is stirred by a stirring device (3) consisting of a motor (7) and a stirring section (8) to obtain a homogeneous composition, and a heat retention device (
4°) to maintain a predetermined plating temperature. This makes it possible to apply a plating layer of uniform composition to the extruded aluminum multi-hole tube (20), and to perform stable plating work continuously for a long period of time. The extruded aluminum multi-hole tube (20) transferred to the removal processing section (c) is then pulled out from the plating tank (1) by the carrier (18). At this point, a large amount of molten brazing material has adhered to the surface of the extruded aluminum multi-hole tube (20), so after removing the excess brazing material with the ironing die (15), the cooling device (16) and the electric fan are removed. (
17), (17)... to rapidly solidify the molten brazing filler metal. As a result, a plating layer having a uniform composition and a thickness of 2 to 50 JLm can be obtained on the extruded aluminum multi-hole tube (20).

Next, FIGS. 3(a) and 3(b) show the plating processing section (a).
In the same figure showing the other side, this plating processing part (ao
) is formed by connecting a trough (30) provided at the top and a molten metal holding furnace (31) provided at the bottom with a stalk (30b). The trough (30) is provided with pull-out holes (30a) and (3Qa) on both sides, and a motor (32) and a propeller-shaped stirring part (33) are connected to the upper part via a connecting member (31). A stirring device f! is integrally connected. (34), a heat retention device (3) consisting of a heater (35) and a heater tube (36) arranged around the heater (35).
7) is formed. (38) and (38) indicate receiving members for the plating solution (39) provided at the outer lower part of the draw-out holes (30a) and (30a), while the molten metal holding furnace (
31) has an air introduction hole (40) formed in the upper part thereof, and a motor (42) and a propeller-shaped stirring part (43) are connected to the left and right sides of the air introduction hole (40) via connecting members (41).
A stirring device (44) consisting of a stirrer (44), and a heat retaining device (47) consisting of a heater (45) and a heater tube (46) arranged around the heater (45) are formed.

Then, air introduction holes (40) are provided in this molten metal holding furnace (31).
) and stoke the molten metal (48) to the stoke (30b).
The plating solution (39) is pushed up to the upper trough (30) through the
), and the plating layer can be applied by transferring the extruded aluminum multi-hole tube (20) through the plating solution (39) using the same means as described above. In this case, the stirring device (34), (
44), when adding 5% or more of Zn, etc. to A-5i brazing filler metal for the purpose of corrosion resistance 1-, A-mata and Zn will separate into two layers and the target alloy composition will not be achieved. Moreover, since air is forced into the molten metal holding furnace (31), it is of course formed completely sealed with the sealing material (49).

Although there is no particular restriction on the composition of the aluminum or aluminum alloy material as the material to be plated and the brazing material as the plating material to be hot-dipped thereon, typical examples are as follows.

For aluminum or aluminum alloy materials, JIS
Pure aluminum ram such as 1050.1100, 3003
．． 3203 etc. t7) Al-M n-based alloy, 505
An-Mg alloy such as 2, A-Mg-St alloy such as 6063.6N01, AJI-Zn-Mg such as 7003
Examples include materials made of alloys.

As the Al-Si brazing filler metal, St 6 to 13% by weight
, an alloy consisting of the balance An and unavoidable impurities, such as JIS
4043.4045.4047, etc., and alloys 5 to which Mg is added in an amount of 0.5 to 2% by weight, such as J
IS 4003.4004.4005 etc., and in some cases Zn, Sn, etc. are added to the above alloy to improve corrosion resistance.
A brazing filler metal containing 0.10 to 30% by weight of one or more types of In may also be used. This brazing material is used for plating tubes made of pure aluminum or Al-Mn, which have a high melting point.

The Zn-based brazing material is an alloy consisting of 90 to 99% by weight of Zn, the balance being An and inevitable impurities. This brazing material is used for all aluminum and aluminum alloys.

(Effects of the Invention) As mentioned above, the hot-dip plating apparatus according to the present invention coats aluminum or aluminum alloy materials with AQ-3t series, Zn
When continuously hot-dipping brazing filler metals such as
The plating tank is equipped with 7g of melt, a stirring device, and a molten metal heat retention device. Therefore, even brazing filler metal whose composition would separate into two layers in a state close to Mn in this plating bath can be mixed to a uniform composition, so that it can be mixed into a uniform composition on the parts to be plated such as aluminum or aluminum alloy materials. Plating with a uniform composition can be applied reliably and easily. In addition, even when long objects are continuously plated for a long time, the temperature of the molten metal is kept constant, so stable plating can be formed. Therefore, the apparatus of the present invention is very suitable as mass production equipment.

In addition, since the structure of the device itself is simple, it is easy to manufacture, inexpensive, and economical.

[Brief explanation of the drawing]

Figures 1 (A) and (B) are a vertical sectional view and a plan view of a hot-dip plating apparatus, and Figure 2 is a perspective view of an extruded aluminum multi-hole tube to be hot-dipped by the hot-dip plating apparatus according to the present invention. 3(A) and 3(B) are a longitudinal cross-sectional view and a plan view thereof showing the plating processing section on the other side. Code (A)...Hot-dip plating equipment (a)...
Plating processing section (b)... Preheating processing section (c)...
Removal processing section (1)...Plating tank (3)...
Stirring device (4)... Heat retention device (13)... Preheating furnace (15)... Ironing die (16)... Cooling device (2o)... Aluminum extruded multi-hole tube patent applicant Furukawa Aluminum Alloy Co., Ltd. Figure 2 2゜Figure 3 (A)

Claims (1)

[Claims] Al-Si on aluminum or aluminum alloy material
A hot-dip plating apparatus is characterized in that a molten metal stirring device and a molten metal warming device are disposed in a plating tank for continuously hot-dipping a brazing filler metal such as Zn-based or Zn-based brazing materials.