JPH10193089A - Soldering method of inner surface of cylindrical part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a uniform and efficient solder layer in a cylindrical parts by elevating the level of the molten solder from the lower part of the cylindrical parts, filling the molten solder in the cylindrical parts, and applying the ultrasonic wave to the molten solder. SOLUTION: An Al alloy cylinder block 1 is fixed on a solder melting furnace 2 by an upper die 3 and lower dies 4, 5, 6. When the surface of the molten solder of the solder melting furnace 2 is pressed with the compressed air or the inert gas, the molten solder is filled inside a liner through a stoke 7. The pressure is preferably 0.01-0.05MPa, and the oxide film on the surface of the molten solder is less included. The liner is preheated to the solder melting point to prevent solidification of the solder. The ultrasonic wave is applied by an ultrasonic horn 8 immersed in the molten solder to form the solder layer. Adhesion of the solder to unnecessary parts can be prevented, and the consumption of the solder can be reduced, and the weight and cost of the parts can be reduced thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic soldering method for forming a solder layer on the inner surface of a cylindrical component such as an engine cylinder block.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a solder layer on the surface of an aluminum component, there is known an ultrasonic soldering method in which an ultrasonic film is applied to destroy an oxide film on the surface of the component and form a solder layer. ing. There are two typical methods for this ultrasonic soldering method. The first method is an immersion method, in which an aluminum component 102 is immersed in a molten solder bath 101 as shown in FIG.
Through which ultrasonic waves are applied to the solder bath 101 to form the solder layer 106. The second method is a method using a soldering iron, and as shown in FIG.
In this method, an ultrasonic wave is applied through an ultrasonic horn 110 of a tip using a soldering iron 109 to which an ultrasonic vibrator 108 is attached through a component 07 to form a solder layer 112 on the component surface 111.

[0003]

However, as shown in FIG. 6, two aluminum pipes 11 having different diameters are used.
3 and 114, the solder layer 11 is applied to the inner surface 115 of the large-diameter aluminum pipe 114 in advance.
7, or as shown in FIG. 7, a solder layer 120 is formed on the inner surface 118 of the aluminum cylinder liner 117 as a pretreatment for forming a thermal spray coating 119 for improving abrasion resistance. When soldering the inner surface of a cylindrical part, the conventional ultrasonic soldering method has the following problems.

1) In the immersion method, the solder layer 122 is formed even on an unnecessary portion such as the pipe outer peripheral surface 121 shown in FIG. Further, if masking is performed so that a solder layer is not formed at an unnecessary portion, the cost is increased. 2) With the method using the soldering iron 109, it is very difficult to form a solder layer uniformly and quickly on a curved surface such as the inner surface of a cylinder, and when the diameter of a cylindrical part is small, the soldering iron 109 is used. In some cases, it was not even possible.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for soldering an inner surface of a cylindrical component that uniformly and efficiently forms a solder layer on the inner surface of the cylindrical component.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned object, and the gist of the present invention is to fill a molten solder inside a cylindrical component and apply an ultrasonic wave to the molten solder. Thus, a solder layer is formed on the inner surface of the cylindrical component.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for soldering the inner surface of a cylindrical part according to the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an apparatus for forming a solder layer on the inner surface of a liner of an aluminum alloy cylinder block as a pretreatment for forming a thermal spray coating for improving abrasion resistance. The cylinder block 1 is fixed on a solder melting furnace 2 by an upper mold 3 and lower molds 4, 5, and 6. Opening and closing of the mold and cylinder block 1 by hydraulic cylinder etc. (not shown)
Can be fixed, and the sealing property of the mold is improved.

The solder used for forming the solder layer is Zn-A
Any of aluminum-based solder such as l-based, Sn-Zn-based, Cd-Sn-based, and Zn-Cd-based can be used. However, those containing Cd may cause pollution, and Sn-
The Zn system is inferior in strength and heat resistance. Therefore, for use in the cylinder block 1, a Zn-Al-based solder having excellent strength and heat resistance is desirable. The Zn-Al-based solder has an alloy composition of 95% Zn-5% Al and has a melting point of 3%.
At 82 ° C., the tensile strength is 200 MPa, which is excellent in heat resistance and mechanical properties. Further, since the solid solubility of Al in Zn is high, the alloying reaction between Zn and Al is apt to occur, and the adhesion of the solder layer to the Al surface is very high.

[0009] The solder is melted and held in a solder melting furnace 2 immediately below the mold. When a Zn-Al solder is used, the melting point is 382 ° C. ℃, more preferably 420 ℃ ±
It is preferable to dissolve and maintain at 5 ° C. If the temperature is lower than 400 ° C., the fluidity of the hot water is poor, and if the temperature is higher than 430 ° C., the solder is greatly consumed by oxidation.

When pressure is applied to the surface of the molten solder melted and held in the melting furnace by compressed air or an inert gas, the stalk 7 immersed in the molten solder is removed because the solder melting furnace 2 is closed. Then, the molten solder rises and the gaps on the inner surface of the liner are filled with the molten metal. At this time, the pressure applied to the molten solder is 0.01 to 0.05M.
Pa is preferable. When the pressure is in this range, the molten solder is gently filled without turbulent flow, and the oxide film on the surface of the molten solder is rarely involved. Then, in order to prevent the filled solder from solidifying on the inner surface of the liner before applying the ultrasonic wave, the liner is preheated to the same temperature as the solder melting temperature.
Further, the same effect can be obtained even if the molten metal level is raised by decompression, not by pressurization.

After the space is filled with solder, ultrasonic waves are applied to the molten solder from an ultrasonic horn 8 arranged in the liner and immersed in the molten solder. The frequency, output, and time of the applied ultrasonic waves vary slightly depending on factors such as the shape and size of the work,
It is preferable that the power is 0 kHz, the output is 100 to 4000 W, and the time is 1 to 10 seconds. If an ultrasonic wave is applied under these conditions, a good solder layer can be formed.

The ultrasonic horn 8 is preferably located at the center axis of the liner as shown in FIGS. 2 and 3 in order to form a uniform solder layer on the inner surface of the liner. As a result, the distance between the ultrasonic horn 8 and the liner becomes uniform, and the energy applied to the inner surface of the liner becomes uniform, so that the thickness of the solder layer becomes uniform. Further, since ultrasonic waves are applied directly to the molten solder, the output can be suppressed low. Even if ultrasonic waves are applied to the entire cylindrical part, a solder layer can be formed, but since ultrasonic waves are not applied directly to the molten solder, a larger ultrasonic output can be obtained compared to a case where a horn is arranged on the central axis. Required. Furthermore, since the work vibrates, the airtightness between the upper mold and the lower mold is not maintained, and there is a possibility that the molten solder leaks. Therefore, it is most preferable to arrange the ultrasonic horn 8 on the central axis of the cylindrical part.

Under the above conditions, the cavitation caused by applying ultrasonic waves to the molten solder destroys the oxide film on the surface of the liner of the cylinder block 1 made of Al, and a clean metal surface appears. And alloying occurs between them, and a strong solder layer is formed. The thickness of the solder layer can be controlled by the application time and output of the ultrasonic wave.
In the case where a solder layer is formed as a pretreatment for thermal spraying like the inner surface of the liner, the thickness is about 10 to 100 μm.

After the application of the ultrasonic wave to complete the formation of the solder layer, if the pressurization with air or an inert gas is released, the surplus molten solder filled is immediately returned to the melting furnace and again. It is heated and used for forming a solder layer.
By the above method, a solder layer having a uniform thickness can be efficiently formed on the inner surface of the liner of the cylinder block 1, and formation of a solder layer at an unnecessary portion can be prevented. A thermal spray coating is formed on the inner surface of the liner of the cylinder block 1 from above the solder layer in order to improve the wear resistance. However, since the solder layer exists under the thermal spray coating, the adhesion of the coating is improved.

Example A bore diameter is 100.0 mm and a stroke size is 82.0 mm.
mm, aluminum alloy casting AC4C (JIS
Standard) 42 cylinder block 1 of a single cylinder engine
After being preheated to 0 ° C., it was set in a mold of a soldering apparatus, and air pressure of 0.05 MPa was applied to the surface of the molten solder to fill voids in the cylinder block 1 with the molten solder. The solder used to form the solder layer has a melting point of 382 ° C
And a zinc solder AHZ9 having a composition of 95% Zn-5% Al
5A (JIS).

At the same time as the molten metal is filled, an ultrasonic horn 8 arranged coaxially with the center of the liner of the cylinder block 1 is applied to the molten metal. At this time, the frequency of the ultrasonic wave is 1
8.6 kHz, output 600 W, application time 5 seconds. Immediately after the application of the ultrasonic wave, the pressurization of the molten metal is stopped, so that the molten metal filled in the liner is returned to the solder melting furnace 2 through the stalk 7. Ultrasound 5
By applying for 2 seconds, a zinc solder layer having a uniform thickness of 100 μm was formed on the inner surface of the liner, and no solder layer was formed on any portion other than the inner surface of the liner.

Next, in order to improve abrasion resistance, a Fe—Cr coating was formed on the inner surface of the liner from above the solder layer by thermal spraying. Thermal spraying conditions were as follows: output 40 kw, supply current 850 A,
The driving gas (Ar) flow rate was 83 l / min, the powder supply gas (Ar) flow rate was 13 l / min, and the coating thickness was 200.
μm. The adhesion strength of the thermal spray coating was measured to be 50 MPa. As a comparative example, without the solder layer
The adhesion strength of the material sprayed under the same conditions as above was 25.
Since the pressure was MPa, it was found that the adhesion strength was improved by forming a solder layer as a base treatment for thermal spraying.

[0018]

As described above, according to the method for soldering the inner surface of a cylindrical part according to the present invention, the following advantages are obtained. (1) Since the molten metal is raised only on the inner surface of the cylindrical part and the void is filled with the solder, it is possible to prevent solder from adhering to unnecessary parts and reduce the amount of solder taken out. For this reason, cost reduction can be achieved in addition to weight reduction of parts. (2) Since ultrasonic waves are applied to the molten metal from the ultrasonic horn disposed on the central axis of the cylindrical component, a solder layer can be formed on the component with a uniform thickness. (3) The molten metal is raised from the lower side of the cylindrical part to fill the solder, the ultrasonic wave is applied, and the pressure is released, and then the excess molten metal is immediately discharged and returned to the melting furnace. Therefore, the soldering operation can be performed very efficiently.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an apparatus for soldering an inner surface of a cylindrical component according to the present invention.

FIG. 2 is a cross-sectional view taken along line II-II of FIG.

FIG. 3 is a longitudinal sectional view taken along line III-III in FIG. 2;

FIG. 4 is a schematic view showing a conventional ultrasonic soldering apparatus.

FIG. 5 is a schematic view showing a conventional ultrasonic soldering apparatus.

FIG. 6 is a longitudinal sectional view showing a state where two pipes having different diameters are fitted and joined.

FIG. 7 is a longitudinal sectional view showing a state in which thermal spraying is performed from above a solder layer on the inner surface of the cylindrical part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Solder melting furnace 3 Upper mold 4 Lower mold 5 Lower mold 6 Lower mold 7 Stoke 8 Ultrasonic horn

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C23C 2/32 C23C 2/32 F02F 1/00 F02F 1/00 C // C23C 2/06 C23C 2/06 (72) Inventor Kenji Miyai 300 Takatsukacho, Hamamatsu City, Shizuoka Prefecture Suzuki Co., Ltd.

Claims (3)

[Claims] 1. A cylindrical component is filled with a molten solder,
A method for soldering an inner surface of a cylindrical component, wherein a solder layer is formed on the inner surface of the cylindrical component by applying ultrasonic waves to the molten solder. 2. The method for soldering the inner surface of a cylindrical component according to claim 1, wherein the level of the molten solder is raised from below the cylindrical component to fill the interior of the cylindrical component with the molten solder. 3. The method for soldering an inner surface of a cylindrical part according to claim 1, wherein an ultrasonic horn is arranged on a central axis of the cylindrical part, and ultrasonic waves are applied by the ultrasonic horn.