Dissimilar material joint, welded part, and casting method

Abstract

To provide a dissimilar material joint, a welded part, and a casting method in which the cast material is exposed at a predetermined position without being affected by the dimensional accuracy of the cast material. [Solution] The dissimilar material joint according to this embodiment comprises a non-hollow cast material made of a first metal material and a cast material made of a second metal material. The cast material is exposed from the cast material at the joint and is bent toward the joint within the cast material in a cross section perpendicular to the surface of the joint.

Description

Technical Field

[0001] The present invention relates to a dissimilar material joined body, a welded part, and a casting-in method.

Background Art

[0002] Casting can manufacture parts as a single entity without combining multiple parts. Therefore, casting can reduce the joining locations between parts and can realize lightweight and high-rigidity parts without inflection points from the perspective of rigidity. Parts manufactured by casting are composed of a single metal, and when arranging dissimilar materials with different properties according to the joining or interference with peripheral parts, a method called casting-in is used.

[0003] Patent Document 1 describes a casting-in structure of a casting-in member made of a steel plate that is cast with the joining part side left when forming a die-cast part. The casting-in member has a tapered die abutting part, and when the casting-in die is clamped, it abuts on both sides and adheres closely. Note that die-casting is a casting method in which a material is poured into a mold at high speed and high pressure.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the invention described in Patent Document 1, the alignment of the casting-in position for a die-cast part can be corrected by the die clamping operation of the die-casting mold. However, in the invention described in Patent Document 1, when the dimensional variation of the casting-in member is large and it interferes with the die-casting mold, the position may not be corrected sufficiently. Also, in the invention described in Patent Document 1, when the deformation rigidity of the casting-in member is high, the casting-in member may inhibit die clamping.

[0006] In view of the above-mentioned problems, this disclosure provides a dissimilar material joint, a welded part, and a casting method in which the cast material is exposed at a predetermined position without being affected by the dimensional accuracy of the cast material. [Means for solving the problem]

[0007] A dissimilar material joint according to one aspect of the present disclosure comprises a non-hollow cast material made of a first metal material and a cast material made of a second metal material. The cast material is exposed from the cast material at the joint and is bent toward the joint within the cast material in a cross section perpendicular to the surface of the joint.

[0008] In the above-described dissimilar material joint, the material to be cast may have a surface that is flush with the surface of the cast material at the joint.

[0009] The above-described dissimilar material joint may be welded to a fastening member made of a first metal material at the joint, as a welded component.

[0010] A casting method according to one aspect of the present disclosure involves holding a non-hollow material to be cast, made of a first metal material, which has a protruding surface and is bent toward the protruding surface in a cross section perpendicular to the protruding surface, with the protruding surface in contact with a mold, and pouring molten metal made of a second metal material into the mold to cast the material to be cast.

[0011] The above casting method may also involve equipping the mold with magnets, which may hold the material to be cast in a state where its protruding surface is in contact with the mold. [Effects of the Invention]

[0012] According to this disclosure, it is possible to provide a dissimilar material joint, a welded part, and a casting method in which the cast material is exposed at a predetermined position without being affected by the dimensional accuracy of the cast material. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of a dissimilar material joint according to Embodiment 1. [Figure 2]This is a flowchart of the casting method according to Embodiment 1. [Figure 3] This is a schematic diagram of the casting method according to Embodiment 1. [Figure 4] This is a schematic diagram of a welded part according to Embodiment 2. [Figure 5] This is a schematic diagram of the casting method according to Embodiment 3. [Modes for carrying out the invention]

[0014] The present invention will be described below through embodiments of the invention, but the invention claimed is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means of solving the problem. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary.

[0015] <Embodiment 1> Embodiment 1 relates to a dissimilar material joint manufactured by a casting method called full casting. Full casting is a method of manufacturing a dissimilar material joint in which the material to be cast is joined within the casting by casting using a mold in which the material to be cast is placed. Here, the cast portion that covers the material to be cast is called the full casting material.

[0016] By casting, the material to be cast can be exposed at a predetermined location in the dissimilar material joint. This avoids joining dissimilar metals, which is difficult to achieve high joint strength in material bonding with surrounding parts, and allows the dissimilar material joint to be joined with the same type of metal. Furthermore, based on the interference situation with surrounding parts, the dissimilar material joint can acquire surface properties appropriate to its location.

[0017] Figure 1 is a schematic diagram of a dissimilar material joint 1 according to Embodiment 1. Figure 1 shows a cross-sectional view of the dissimilar material joint 1. The dissimilar material joint 1 comprises a material to be cast 10 and a cast material 11.

[0018] The cast-in material 10 is made of a first metal material and is not hollow. The first metal material is, for example, a steel material, an iron material, or an aluminum alloy. The cast-in material 10 is cast into the casting material 11 and is exposed on the surface of the dissimilar material joined body 1 at the joint 12. The cast-in material 10 is bent toward the joint 12 within the casting material 11 in a cross section perpendicular to the surface of the joint 12.

[0019] The casting material 11 is made of a second metal material. The second metal material is different from the first metal material. The second metal material is, for example, a light alloy material such as aluminum. When an aluminum alloy is used as the first metal material, the aluminum alloy of the second metal material has a different additive metal or additive ratio. The casting material 11 covers the cast-in material 10. The casting material 11 exposes the cast-in material 10 at the joint 12.

[0020] The joint 12 is a part where the cast-in material 10 is exposed on the surface of the dissimilar material joined body 1 instead of the casting material 11. According to this, the dissimilar material joined body 1 can have the physical properties of the first metal material different from the second metal material at the joint 12.

[0021] FIG. 2 is a flowchart of the casting method according to Embodiment 1. The casting method according to Embodiment 1 includes the steps of S11 and S12.

[0022] In step S11, the cast-in material 10 is held in a state where the protruding surface 101 contacts the mold 2. Here, the cast-in material 10 has a protruding surface 101, is processed into a shape bent toward the protruding surface 101 in a cross section perpendicular to the protruding surface 101, and is a non-hollow material made of a first metal material. The protruding surface 101 is a surface that is exposed from the casting material 11 at the joint 12 of the dissimilar material joined body 1 when cast. The shape of the protruding surface 101 is not particularly limited. The protruding surface 101 is, for example, circular or rectangular. Also, the cast-in material 10 may be in a corrugated plate shape, and the peak portions may be used as the protruding surface 101. The cast-in material 10 is formed, for example, by press working or casting. The cast-in material 10 may be formed by cutting.

[0023] The protruding surface 101 is held in contact with the mold 2, so that the molten metal does not cover the protruding surface 101 during casting, and the material to be cast 10 is exposed at the joint 12 of the dissimilar material joint 1. The material to be cast 10 is held, for example, by the fitting of a holding hole formed in the material to be cast 10 with a pin formed in the mold. The mold is, for example, a metal mold or a sand mold.

[0024] Figure 3 is a schematic diagram of the casting method according to Embodiment 1. Figure 3 shows the state in which the material to be cast 10 is held within the mold 2. The mold 2 comprises a movable mold 20 and a fixed mold 21. The movable mold 20 also includes a pin 201 for fixing the material to be cast 10.

[0025] The material to be cast 10 is placed inside the movable mold 20 using the robot hand 3. Here, the retaining hole (not shown) formed in the material to be cast 10 engages with the pin 201, and the material to be cast 10 is held with its protruding surface 101 in contact with the movable mold 20. After placing the material to be cast 10 inside the movable mold 20, the robot hand 3 moves outside the movable mold 20.

[0026] Here, the cast material 10 may have a retaining hole (not shown) formed after press working, which tends to reduce dimensional accuracy. This allows the cast material 10 to be held in a predetermined position without being affected by dimensional variations caused by press working. Alternatively, the diameter of the retaining hole (not shown) in the cast material 10 may be designed to be larger than the diameter of the pin 201. This allows the dissimilar material joint 1 to be manufactured without being affected by the dimensional accuracy of the cast material 10.

[0027] In step S12, molten metal made of the second metal material is poured into the mold 2 in which the material to be cast 10 is held. This forms a cast material 11 that covers the material to be cast 10. The protruding surface 101 of the material to be cast 10, which is held in contact with the mold 2, is not covered by the cast material 11 and forms a joint portion 12 that is exposed from the cast material 11.

[0028] Alternatively, the molten metal made from the second metal material may be poured from the inside of the protruding surface 101 of the material to be cast 10 so that the protruding surface 101 does not lift away from the movable mold 20. Furthermore, the material to be cast 10 may be cast without moving it, depending on how the molten metal made from the second metal material is poured. In this case, the pin 201 does not need to be formed.

[0029] Referring to Figure 3, after the robot hand 3 moves outside the movable mold 20, molten metal (not shown) made of the second metal material is poured into the movable mold 20. The movable mold 20, into which the molten metal has been poured, slides toward the fixed mold 21 as indicated by the arrow, pushing out the excess molten metal. The molten metal cools within the mold 2, forming a dissimilar material joint 1 in which the material to be cast 10 is covered with the casting material 11. Here, the protruding surface 101 of the material to be cast 10, which is held in contact with the movable mold 20, does not immerse itself in the molten metal and is exposed from the casting material 11, forming the joint 12.

[0030] As described above, the casting method including steps S11 and S12 produces a dissimilar material joint 1 in which the material to be cast 10 is exposed at a predetermined position. In the casting method according to this embodiment, there are few points of contact with the mold 2 other than the protruding surface 101 of the material to be cast 10 that contacts the mold 2. Therefore, the dissimilar material joint 1 can be manufactured without being affected by the dimensional accuracy of the material to be cast 10.

[0031] Furthermore, the cast-in material 10 only needs to have its protruding surface 101, which is exposed at the joint portion 12 of the dissimilar material joint 1, deburred. Therefore, the casting method according to this embodiment can reduce the number of steps required for the deburring process. In addition, since most of the cast-in material 10 is cast into the cast-in material 11, the contact area between the cast-in material 10 and the cast-in material 11 is large and the joint is strong. Therefore, the cast-in material 10 of the dissimilar material joint 1 is less susceptible to deformation due to tension or rotation.

[0032] Furthermore, the casting method according to this embodiment can also be applied to other casting methods such as die casting or giga casting. Here, die casting is a casting method that manufactures complex and precise parts by injecting material into a mold at high speed and high pressure. Giga casting is a casting method that is an evolution of die casting, used to cast large and complex vehicle parts and the like in one batch.

[0033] <Embodiment 2> Figure 4 is a schematic diagram of the welded part 4 according to Embodiment 2. Figure 4 shows a cross-sectional view of the welded part 4. The welded part 4 is a part in which a dissimilar material joint 1 and a fastening member 5 are joined. Note that the dissimilar material joint 1 shown in Figure 4 has partly the same configuration as the dissimilar material joint described with reference to Figure 1. Therefore, redundant explanations of the configuration of the dissimilar material joint 1 are omitted.

[0034] The cast material 10 of the dissimilar material joint 1 forms the same surface as the cast material 11 at the joint portion 12. This allows the dissimilar material joint 1 to have metal materials with different physical properties on the same surface. Therefore, the dissimilar material joint 1 according to this embodiment can reduce the process of processing the surface shape of the fastening member 5 for joining with the dissimilar material joint 1.

[0035] The dissimilar material joint 1 is joined to the fastening member 5 at the joint portion 12. Here, the cast material 10 exposed at the joint portion 12 of the dissimilar material joint 1 is made of the first metal material. The fastening member 5 is also made of the first metal material. Therefore, the dissimilar material joint 1 and the fastening member 5 are firmly joined together as they are made of the same type of metal. Here, the joining is a material joining such as welding.

[0036] According to this, the dissimilar material joint 1 is not affected by the dimensional accuracy of the cast material 10, and a welded part 4 can be formed by joining it with a fastening member 5 made of a different metal material than the cast material 11. Furthermore, the dissimilar material joint 1 and the fastening member 5 are joined without using mechanical joining, which reduces the weight of the parts involved in the joining process.

[0037] <Embodiment 3> Figure 5 is a schematic diagram of the casting method according to Embodiment 3. Figure 5 shows the state in which the material to be cast 10 is held within the mold 2. Note that the casting method shown in Figure 5 has some of the same configuration as the casting method described with reference to Figure 3. Therefore, redundant explanations will be omitted.

[0038] The movable mold 22 shown in Figure 5 has a magnet 222 on the back side of the position where the protruding surface 101 of the cast material 10 makes contact. The magnet 222 may be positioned at the position where the protruding surface 101 of the cast material 10 makes contact. The magnet 222 holds the protruding surface 101 of the cast material 10 in contact with the movable mold 22 by magnetic force. The magnet 222 is, for example, an electromagnet. The magnet 222 may also be a permanent magnet. Here, the pin 201 does not have to be formed.

[0039] Furthermore, as a measure against demagnetization in high-temperature environments, a cooling device may be installed near the magnet 222. Also, the magnet 222 is used for alignment and may be removed from the movable mold 22 before or during the injection of molten metal made of the second metal material.

[0040] According to this, the joint portion 12 in which the cast material 10 is exposed can be suitably positioned without being affected by the dimensional accuracy of the cast material 10.

[0041] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the fixed mold side may be provided with a pressing mechanism that presses the material to be cast against the movable mold. Alternatively, a pressing mechanism that penetrates the fixed mold and presses the material to be cast against the movable mold may be provided. [Explanation of symbols]

[0042] 1 Dissimilar material joint 2. Mold 3. Robot Hand 4 Welded parts 5 Fastening members 10 Cast material 11 Cast Iron Material 12 Joint 20, 22 Movable type 21 Fixed type 101 Projection surface 201 pins 222 Magnets

Claims

1. A non-hollow cast material made of a first metal material, A cast material made of a second metal material, Equipped with, The aforementioned cast material is, At the joint, it is exposed from the cast material, In a cross-section perpendicular to the surface of the joint, the cast material is bent toward the joint. Joined body of different materials.

2. The dissimilar material joint according to claim 1, wherein the material to be cast forms the same surface as the surface of the cast material at the joint.

3. A welded part in which a dissimilar material joint according to claim 1 or 2 is welded to a fastening member made of a first metal material at the joint.

4. A non-hollow cast material made of a first metal material, having a protruding surface and being bent toward the protruding surface in a cross section perpendicular to the protruding surface, is held in a state where the protruding surface is in contact with the mold. The molten metal made of the second metal material is poured into the mold and the material to be cast is cast inside. Casting method.

5. The mold is equipped with a magnet, The magnet holds the material to be cast in a state where the protruding surface is in contact with the mold. The casting method according to claim 4.

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