JPH11324789A - Aluminum casting and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture an aluminum casting excellent in strength by integrally casting a joining metal sheet for joining and another aluminum casting. SOLUTION: Solder sheet 3a is previously mounted on a metal mold 13. After that, the metal mold 13 is brought into contact with a metal mold 11. Subsequently, molten aluminum is thrown in from a molten aluminum throw-in port 11 to fill a space formed by the metal molds 11, 13 with the molten aluminum by a plunger 11b. At this time, the solder sheet 3a is still mounted on the metal mold 13 and the molten aluminum is filled, so that the solder sheet 3a is integrally joined (insert) to the end face of the aluminum casting 3. A manufacturing method for a second aluminum casting is substantially similar to the method for the first aluminum casting 3. Subsequently, the corresponding joint faces of the respective aluminum castings are made face to face. In a heating furnace, the castings are heated and simultaneously fixed pressure is applied to the joint faces to join the castings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum casting and a method of manufacturing the same, and more particularly, to an aluminum casting formed by joining a plurality of members cast by die casting and a method of joining the same.

[0002]

2. Description of the Related Art Conventionally, an aluminum casting made of two members has been manufactured by the following method. That is, in Japanese Patent Application Laid-Open No. 9-2222047 by the present applicant, two aluminum castings are joined to each other via a zinc alloy solder layer,
A method of applying ultrasonic vibration to an aluminum casting at the time of this joining is disclosed.

The above conventional example will be described in detail with reference to FIG. Here, as an example, the manufacture of a cylinder block made of an aluminum casting will be described. First, a cooling water passage (water jacket) 109 is formed inside the cylinder block main body 103, and a sealing member 105 is joined to an upper portion of the cylinder block main body 103 to seal the cooling water passage 109. It is. At this time,
In advance, the cylinder block body 103 and the sealing member 105
Are machined to the joints 104a and 104b. This is for smoothing the surfaces of the cylinder block main body 103 and the sealing member 105 and for removing the oxide film on the surfaces.

Subsequently, the cylinder block main body 103 and the sealing member 105 are preheated to a predetermined temperature. And
A zinc alloy solder layer is coated on the machined surface subjected to the machining. The coating of the zinc alloy solder layer is performed while applying ultrasonic vibration to the cylinder block main body 103 and the sealing member 105. More specifically, each processing surface is immersed in a molten solder bath (not shown), and ultrasonic vibration is applied to the cylinder block main body 103 and the sealing member 105. The formation of these zinc alloy solder layers is performed separately for the cylinder block main body 103 and the sealing member 105.

Next, the joints 104a and 104b on which the zinc alloy solder layer is formed are brought into contact with each other so as to face each other. At this time, the positioning between the cylinder block main body 103 and the sealing member 105 is accurately performed. Then, the cylinder block main body 103 and the sealing member 10
5 and preheat. Then, the cylinder block body 103
Then, ultrasonic vibration is applied to the sealing member 105 and the cylinder block main body 103 and the sealing member 105 are joined. Depending on the size and properties of the members to be joined, after the two members are combined with each other, the members may be joined by heating both members while applying pressure to each other in a predetermined heating furnace.

[0006]

However, the above conventional example has the following disadvantages. That is, in the conventional example, prior to the zinc alloy solder layer on the processing surface,
It is necessary to preheat the cylinder block body and the sealing member. For this reason, there has been a problem that the strength of the aluminum casting constituting the cylinder block main body and the sealing member may be reduced by the preheating.

In addition to the above disadvantages, it takes a predetermined time to perform preheating while preventing a decrease in the strength of the cylinder block main body and the like. The inconvenience was caused.

[0008]

The object of the present invention is to improve the disadvantages of the prior art, and in particular, when manufacturing an aluminum casting having a complicated shape, an aluminum casting excellent in strength can be easily manufactured by joining a plurality of members. To provide a method that can be manufactured in
With that purpose.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an aluminum casting in which a joining metal sheet for joining with another aluminum casting is integrally cast. It has a configuration. And claim 2
In Nos. 4 to 4, the joining metal sheet is a solder sheet, an aluminum brazing alloy sheet or a brazing sheet. In this way, by pre-casting the joining metal sheet, it is possible to easily and firmly join another aluminum casting through the joining metal sheet.

According to the fifth aspect of the present invention, the first aluminum casting whose surface is integrally formed with the joining metal sheet is joined to the first aluminum casting via the joining metal sheet. An aluminum casting composed of the second aluminum casting is adopted.

Further, in the invention according to claim 6, a step of bringing a second aluminum casting into contact with a first aluminum casting having a surface integrally joined with a joining metal sheet via a solder sheet; A method of heating the contact surfaces of the aluminum castings that have come into contact with each other and then applying ultrasonic vibrations to the aluminum castings to join the aluminum castings are adopted.

By employing the above-described method, the joining metal sheet is firmly integrated with the aluminum casting at the stage of casting. And by joining with another aluminum casting through this joining metal sheet, a plurality of aluminum castings are joined and an aluminum casting with a complicated shape can be manufactured.

[0013]

An embodiment of the present invention will be described with reference to the drawings.

First, FIG. 1 shows a finished aluminum casting 1 manufactured by the manufacturing method according to the present invention, reference numeral 3 denotes a first aluminum casting, reference numeral 5 denotes a second aluminum casting, and reference numeral Reference numerals 3a and 5a denote a solder sheet as a bonding metal sheet, and reference numeral 7 denotes a bonding site by applying ultrasonic vibration.

First, as shown in FIG. 1, an aluminum casting 1 according to the present embodiment has a first
And a second aluminum casting 5 having a rectangular recess 10 facing the dome-shaped recess 9. Note that these shapes are merely examples, and are not particularly limited.

The first aluminum casting 3 and the second aluminum casting 5 are made of an aluminum (alloy) casting, and the joints of the first aluminum casting 3 and the second aluminum casting 5 are opposed to each other. Are shaped so that they can contact each other.

Hereinafter, this will be described in detail with reference to FIGS.
FIG. 4 is a diagram illustrating a process of manufacturing the first aluminum casting 3. First, FIG. 2 shows a first mold 11 and a second mold 13 for manufacturing the first aluminum casting 3 respectively. The first mold 11 has a predetermined rectangular recess 11c.
On the other hand, the second mold 13 has a predetermined dome-shaped protrusion 13 for forming the dome-shaped recess 9 described above.
a is formed. In addition, the first mold 11 has a molten aluminum inlet 11 for introducing molten aluminum into the mold.
a is formed. FIG. 2 shows the cross-sectional shape of each of the dies 11, 13, and the first aluminum casting 3 formed from these dies 11, 13 has a circular planar shape.

FIG. 3 is a perspective view showing the solder sheet 3a to be mounted on the second mold 13 in advance. The solder sheet 3a is formed in a ring shape and has an inner diameter of the second
Of the dome-shaped projection 13a of the metal mold 13. As a method for manufacturing the solder sheet 3a, a predetermined solder sheet material is rolled and formed into a predetermined shape in addition to a ring shape by press punching.
The material of the solder sheet 3a and the components of aluminum for aluminum casting will be described later.

Next, a specific manufacturing process will be described. As shown in FIG. 2, the solder sheet 3a is mounted on the second mold 13 in advance. After that, the second mold 13 is brought into contact with the first mold 11. Subsequently, as shown in FIG. 4, molten aluminum is introduced from the molten aluminum inlet 11a,
The space formed by the molds 11 and 13 is filled with molten aluminum by the plunger 11b. At this time, the molten aluminum is filled while the solder sheet 3a is mounted on the second mold 13, so that the aluminum casting 3
Solder sheet 3a is integrally joined to the end face of the mold (cast-in)
It will be in the state that was done. In the process of forming the aluminum casting 3, the boundary between the solder sheet 3a and the molten aluminum is firmly joined by the high-temperature molten aluminum.

FIG. 5 is a view showing the first aluminum casting 3 and the second aluminum casting 5 manufactured by the above-described steps. The method of manufacturing the second aluminum casting 5 is substantially the same as that of the first aluminum casting 3, and a description thereof will be omitted. It is not always necessary to join the solder sheets to both the first aluminum casting 3 and the second aluminum casting 5.

Next, a description will be given of a joining process of the first aluminum casting 3 and the second aluminum casting 5, which are manufactured separately, with reference to FIGS. That is, the corresponding joining surfaces 3b and 5b of the aluminum castings 3 and 5 face each other. At this time, the relative positioning of the first aluminum casting 3 and the second aluminum casting 5 can be performed accurately.
A predetermined positioning pin (not shown) on the first aluminum casting 3
And a concave portion (not shown) for a pin into which a positioning pin is inserted may be provided in the second aluminum casting 5. The positioning pins and the pin recesses may be formed at the stage of casting, or may be formed by machining after casting.

Next, the first aluminum casting 3 and the second aluminum casting 5 integrated with each other are actually joined. Prior to joining, the first aluminum casting 3 and the second aluminum casting 5
To preheat. A suitable preheating temperature is about 360 to 380 degrees. However, the preheating temperature needs to be appropriately selected depending on the material of the solder sheet 3a. still,
Various techniques can be considered for joining. Here, three types of joining methods will be described.

First, as a first joining method, FIG.
As shown in FIG. 5, heating is performed to a predetermined temperature in the heating furnace 35, and at the same time, a constant pressing force is applied to the joining surfaces 3b and 5b (see FIG. 5).
It is a joining method in addition to the above. A plurality of heaters 35a are provided in the heating furnace 15, and the electric power is supplied to the heaters 35a to heat the aluminum casting 1.
In addition, as an apparatus for heating, an electromagnetic heating furnace, a gas heating furnace, or the like may be used instead of using the normal heater 35a.

Various methods can be considered as the pressurizing means. In the present embodiment, the predetermined weight member 36 is described for convenience of description, but an air cylinder (not shown) having a heat-resistant structure may be used.

As a second bonding method, as shown in FIG. 7, a bonding method is performed while applying ultrasonic vibration. That is, the ultrasonic horn 37 is brought into contact with the aluminum casting 1 to apply ultrasonic vibration while applying a constant pressing force. By applying ultrasonic vibration after preheating, a part of the solder sheets 3a and 5a is melted, and the first aluminum casting 3 and the second aluminum casting 5 are joined. This method is suitable mainly for joining small aluminum castings.

In the joining method, the preheating step is omitted, and the aluminum casting 1 is directly heated by a gas burner or an electromagnetic heater (both not shown), and then joined by applying ultrasonic vibration. Good.

A third joining method is a joining method using a molten solder bath 19. For this, the aluminum casting 1 is immersed in the molten solder 15 in advance. Then, ultrasonic vibration is applied from a predetermined vibration plate 17 while the bonding surface is immersed in the molten solder 15. Specifically, the oscillation signal of the oscillator 27 is transmitted to the vibrator 25.
The ultrasonic vibration of the vibrator 25 is transmitted to the diaphragm 17 via the ultrasonic horn 23. Then, ultrasonic vibration is applied to the aluminum casting 1 carried on the vibration plate 17. At the joining surfaces 3b and 5b (see FIG. 5),
A part of the solder sheets 3a, 5a is melted, and the first aluminum casting 3 and the second aluminum casting 5 are joined to each other.

In the second and third joining methods, the joining conditions are as follows. That is,
The frequency of the ultrasonic vibration is about 20 [KHz], the output of the oscillator 27 is 150 to 1000 [W], and the application time of the ultrasonic vibration is about 3 to 10 [seconds].

FIG. 9 is a table showing the structure of the solder sheet used in the present invention. That is, the material is Zn-Al-based AH-Z95A or the like. Also, as the molding method,
In addition to the die casting method, press punching after rolling may be used. The solder sheet made of this material is Al-S
It is compatible with aluminum castings that are die cast from i-Cu based ADCs 12 and the like.

FIG. 9 shows a joining metal sheet.
It also describes the configuration of an aluminum alloy brazing sheet and a so-called brazing sheet instead of a solder sheet. As described above, various aluminum castings can be joined with high strength by using sheets for joining metals of different materials according to the material of the aluminum casting to be joined and the like.

Regarding the present invention, a comparison was made of the joining strength between the case of the conventional joining method and the case of the joining method of the present invention. The test pieces used in the test of the joining method of the present invention are as follows. That is, the solder sheet used for joining is
It is made of Zn-5% Al, and its thickness is 3 to 5 [mm].
Degree. On the other hand, the materials used in the production of aluminum castings are:
Al-Si-Cu-based ADC 12 or the like. In actual production of a test piece, as shown in FIG. 10, first, a solder sheet 63a is arranged at the bottom of a mold 61, and a molten aluminum (ADC12) 64 is filled thereon. At this time, the temperature of the molten aluminum 64 is about 740 degrees.

The molten aluminum 64 solidifies, and the solder sheet 63a is integrated with the aluminum casting 63. After the solder sheet 63a was thus integrated with the aluminum casting 63, a cylindrical test piece 65 having a diameter of 12 [mm] and a length of 40 [mm] was formed from the aluminum casting 63. At this time, the solder sheet 63a is left at the end of the test piece 65 as it is. Then, two test pieces 65 were prepared.

The two test pieces 65 are preheated in an electric furnace. The preheating temperature is about 250 degrees and the preheating time is about 30 minutes. Thereafter, the solder sheet 6 of these test pieces 65 is
One rod-shaped body was formed with the 3a side facing each other. In this state, the test piece 65 is placed on the ultrasonic horn and pressurized by an air cylinder. At the same time, the vicinity of the solder sheet 63a is heated with a gas burner (about 2 minutes),
Ultrasonic vibration was applied. At this time, as the joining conditions,
The pressure is about 30 [Kgf], the oscillator output of the ultrasonic vibration is 150 [W], and the application time of the ultrasonic vibration is about 5 seconds. Diameter 12 [mm] created by the above process
The test piece is finally processed into a test piece having a diameter of 8 [mm].
Then, a tensile test was performed. The results of the tensile test will be described later.

Next, production of a test piece by a conventional joining method will be outlined. As shown in FIG.
A test piece 74 made of the ADC 12 of 2 [mm] is prepared. Then, the test piece 74 is immersed in a molten solder bath 75 and preheated. At this time. The composition of the molten solder is Zn-5% A
l. The temperature of the molten solder is about 420 degrees, and the immersion time is about 2 (minutes).

Next, the test piece 74 is coated with solder. Specifically, the test piece 74 is placed on the vibration plate 67 in the molten solder bath 75, and ultrasonic vibration is applied. At this time, the oscillator output of the ultrasonic vibration is 150 [W], and the application time of the ultrasonic vibration is about 3 [seconds]. Through the above steps, the end face of the test piece 74 is subjected to the solder coating. Two test pieces are prepared.

As in the case of the joining method according to the present invention, the two test pieces 74 were made into one test piece with their solder-coated sides facing each other. Subsequent application of ultrasonic vibration and processing to a diameter of 8 [mm] are the same. And the tensile test was also performed on the test piece by the conventional joining method.

The results of the tensile test show that the test piece according to the conventional joining method broke with a force of 190 [MPa], whereas the test piece according to the joining method of the present invention 233 [MPa].
It reached and broke. That is, the strength is improved by about 40 [MPa] or more. In each of the test pieces, not the joint but the base material itself was broken. Therefore, in the joining method according to the present invention,
It is considered that the effect of the heat on the base material itself was suppressed by omitting the preheating once.

FIG. 12 is a flowchart illustrating the method for joining aluminum castings of the present invention.

In the above embodiment, the case where two aluminum castings are joined has been described. However, the present invention can also be applied to a case where three or more aluminum castings are joined. In particular, even when manufacturing a casting having a so-called undercut portion, by joining a plurality of aluminum castings without an undercut portion by the joining method of the present invention, a complicated aluminum casting can be easily manufactured. .

[0040]

As described above, even when a complex aluminum casting is manufactured by combining a plurality of aluminum castings, the aluminum casting can be joined via the joining metal sheet, thereby improving the manufacturing efficiency of the aluminum casting. Can be done.
In particular, even for a complicated aluminum casting having an undercut portion, a relatively simple aluminum casting is joined to each other to easily produce the intended complex aluminum casting without using a core or the like. The effect is excellent.

Further, in the case of applying the ultrasonic vibration, which is the conventional method, to perform solder coating, it was necessary to perform machining in advance, but according to the present invention, the machining process is completely unnecessary. Becomes In addition, there is no need to preheat the aluminum casting at the time of solder coating, and an excellent effect that the reduction in strength of the aluminum casting due to this preheating can be reliably suppressed is produced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an aluminum casting according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing a mold for manufacturing the first aluminum casting disclosed in FIG.

FIG. 3 is a perspective view showing a solder sheet as a joining metal sheet mounted on the second mold disclosed in FIG. 2;

FIG. 4 is a side sectional view showing a state in which a first aluminum casting is die-cast with the mold disclosed in FIG. 2;

FIG. 5 is a view showing a first aluminum casting and a second aluminum casting disclosed in FIG. 1, wherein FIG. 5 (A) shows a side sectional view and FIG. 5 (B) shows a bottom view.

FIG. 6 shows a first aluminum casting and a second aluminum casting according to the joining method of the present invention.
It is a side sectional view showing the state where aluminum casting of this is joined.

FIG. 7 is a side sectional view showing a state where a first aluminum casting and a second aluminum casting are joined by another joining method of the present invention.

FIG. 8 is a side sectional view showing a state in which a first aluminum casting and a second aluminum casting are joined by another joining method of the present invention.

FIG. 9 is a table showing characteristics of each of the joining metal sheets used in the present invention.

FIG. 10 is a view for explaining a process of manufacturing a test piece for verification of the present invention, and FIG. 10 (A) shows a casting process;
FIG. 10B shows a state where a test piece is manufactured from an aluminum casting.

FIG. 11 is a diagram illustrating a process of manufacturing a test piece for verification of the present invention, and FIG. 11 (A) shows a preheating process;
FIG. 11B shows a step of solder coating.

FIG. 12 is a flowchart showing steps of a method for manufacturing an aluminum casting of the present invention.

13A and 13B are side sectional views illustrating a conventional method for manufacturing an aluminum casting, in which FIG. 13A shows a state before joining of a sealing member, and FIG. 13B shows a state after joining. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aluminum casting 3 1st aluminum casting 3a Metal sheet for joining [1st solder sheet] 5 2nd aluminum casting 5a Metal sheet for joining [2nd solder sheet]

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B23K 1/19 B23K 1/19 A C22C 21/00 C22C 21/00 E

Claims (6)

[Claims] 1. An aluminum casting, wherein a joining metal sheet for joining with another aluminum casting is integrally cast. 2. The aluminum casting according to claim 1, wherein the joining metal sheet is a solder sheet. 3. The aluminum casting according to claim 1, wherein said joining metal sheet is an aluminum brazing alloy sheet. 4. The aluminum casting according to claim 1, wherein said joining metal sheet is a brazing sheet. 5. A first aluminum casting having a surface integrally joined with a joining metal sheet, and a second aluminum casting joined to the first aluminum casting via the joining metal sheet. An aluminum casting characterized by consisting of: 6. A step of bringing a second aluminum casting into contact with the first aluminum casting through which the metal sheet for joining is integrally cast on the surface thereof via the solder sheet, and contacting the aluminum castings with each other. A method of manufacturing an aluminum casting, comprising: a step of heating the contact surface of the aluminum casting; and thereafter, a step of applying ultrasonic vibration to the aluminum casting to join the aluminum castings.