Joined body manufacturing method

Abstract

To provide a joined body manufacturing method that can prevent a sealer from expanding in random directions on a joined surface, in joining a cast product to a counterpart part with the sealer.SOLUTION: A joined body manufacturing method, which manufactures a joined body 10 of a cast product 12 and a counterpart part 14, comprises: a step of forming the cast product 12 using a metal mold constituted of a plurality of combined divided metal molds, which forms a protrusion part 18a on the cast product 12, on the basis of a gap between the plurality of divided metal molds; a step of placing a sealer 16 on the protrusion part 18a; and a step of pressing the counterpart part 14 against the cast product 12 while crushing the protrusion part 18a on which the sealer 16 is placed, so as to join the cast product 12 to the counterpart part 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a bonded body. [Background technology]

[0002] Various techniques have been proposed for casting, a type of molding process for machine parts. For example, there are techniques that are characterized by the process of forming the cast product, the mold itself used for casting, and the manufacturing method thereof.

[0003] Patent Document 1 discloses a mold apparatus that includes a mold body having a cavity for molding a molded product and a temperature control device that controls the temperature of the mold body. This mold apparatus can efficiently cool or heat by separating the parts of the mold body where the heat input is high or low from the other parts, so that it is possible to reproduce the desired mold temperature with a simple configuration and improve the wall thickness accuracy of the molded product. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-202442 Summary of the Invention [Problem to be solved by the invention]

[0005] There are cases where a casting is joined to a mating part. In particular, when it is desired to join the two parts airtightly, the two parts are pressed together with a sealer interposed between them. In this case, the sealer spreads radially within the joining surface of the two parts, regardless of the desired sealing direction. For this reason, a large amount of sealant may be required during joining.

[0006] Therefore, this specification provides a method for manufacturing a joined body that prevents the sealer from spreading in random directions on the joining surface when joining a casting and a mating part with a sealer. [Means for solving the problem]

[0007] The method for manufacturing a joined body disclosed in this specification is a method for manufacturing a joined body of a cast product and a mating part, and includes the steps of: molding the cast product using a mold that combines a plurality of split molds; providing a protrusion on the cast product based on the gap between the plurality of split molds; placing a sealer on the protrusion; and pressing the mating part against the cast product while crushing the protrusion with the sealer placed on it, thereby joining the cast product and the mating part.

[0008] According to the above configuration, the sealer can be prevented from spreading in random directions at the joining surface.

[0009] The plurality of split molds are designed based on predetermined locations for generating the protrusions.

[0010] According to the above configuration, by setting the dividing surface of the split mold at the location where the protrusion is desired to be provided, the position where the sealer is placed can be set more accurately.

[0011] The gaps are set by cutting the mating surfaces of the plurality of split molds to a predetermined depth.

[0012] According to the above configuration, it is easier to determine the location where the protrusion is to be provided and the size of the protrusion.

[0013] The protrusion has a thickness of 1 mm or less in a direction perpendicular to the surface pressed against the mating component.

[0014] According to the above configuration, the protrusions are easily crushed.

[0015] In addition, when the protrusion and the mating part are made of aluminum alloy, the thickness of the mating part is 3 mm or more.

[0016] According to the above configuration, even if the protrusion and the mating part are made of the same material, the protrusion is likely to be crushed due to the difference in thickness. [Effects of the Invention]

[0017] According to the method for manufacturing a joined body disclosed in this specification, when joining a casting and a mating part with a sealant, the sealant can be prevented from spreading in random directions at the joining surface. As a result, unnecessary consumption of the sealant can be suppressed. Furthermore, when the casting is fastened with a bolt, poor bolt fastening due to the sealant spreading at the fastening point can be avoided. [Brief explanation of the drawings]

[0018] [Figure 1] 1A to 1C are diagrams illustrating a method for manufacturing a bonded body according to an embodiment. [Figure 2] 2 is a diagram showing a comparative example in which the protrusion shown in FIG. 1 is not provided. FIG. [Figure 3] 1. FIG. 4 is a diagram showing another comparative example in which the protrusion shown in FIG. 1 is not provided. DETAILED DESCRIPTION OF THE INVENTION

[0019] The method for manufacturing a bonded body will be described below with reference to the drawings.

[0020] 1 is a diagram showing a method for manufacturing a bonded body according to an embodiment. Before describing this manufacturing method, the structure of a bonded body 10 will be described with reference to FIG.

[0021] FIG. 1 shows the manufacturing process of a joined body 10 made of a casting 12 and a mating part 14. The casting 12 shown in FIG. 1 is a conventional casting made of an aluminum alloy. In this example, the mating part 14 is also made of an aluminum alloy, like the casting 12. As shown in FIG. 1, the casting 12 has a protrusion 18a. The protrusion 18a is set to be very thin so that it will be crushed during the manufacturing of the joined body 10, which will be described later. Specifically, the thickness of the protrusion 18a in a direction perpendicular to the surface pressed against the mating part 14 is 1 mm or less. On the other hand, the mating part 14 needs to be thick enough to crush the protrusion 18a, so it is set to be 3 mm or more. Due to its thinness, the protrusion 18a is pressed against the mating part 14 and crushed, and then smoothed by the surface of the mating part 14. The joined body 10 shown in FIG. 1 is used, for example, in a vehicle body (specifically, a side sill, a wheelhouse, etc.). The shape of the joined body 10 is not particularly limited.

[0022] Next, with reference to FIG. 1 , a method for manufacturing a joined body 10 is described. First, a casting 12 is molded using a mold comprising multiple assembled split dies. The split dies are designed based on predetermined locations for generating protrusions 18a (described later). Next, protrusions 18a are formed on the casting 12 based on the gaps between the multiple split dies. This gap may be set by cutting the mating surfaces of the multiple split dies to a predetermined depth. Once the protrusions 18a are formed, a sealant 16 is applied to prevent the intrusion or leakage of liquids or gases (i.e., the sealant 16 is placed on the protrusions 18a). If the sealant 16 cannot seal the casting 12 and the mating part 14, for example, rainwater may get in, causing rust on the vehicle body, which can lead to structural damage. Therefore, when joining the joined body 10, the mating part 14 is pressed against the sealant 16 applied to the casting 12 to eliminate any gaps. In this example, the mating part 14 is pressed against the casting 12 while crushing the protrusion 18a, thereby joining the casting 12 and the mating part 14. Note that the sealer 16 is shown in light grey in Figure 1, but this is also the case in Figures 2 and 3, which will be described later.

[0023] In FIG. 1 , the left side of the white arrow labeled “Joined” in the center of FIG. 1 shows the state before joining of the casting 12 and the mating component 14, and the right side of the arrow labeled “Joined” shows the state after joining of the casting 12 and the mating component 14. In the method for manufacturing a joined body according to the embodiment shown in FIG. 1 , when joining the joined body 10, the protrusion 18a is sandwiched and crushed at the joining surfaces of the casting 12 and the mating component 14, so that the sealant 16 does not spread randomly at the joining surfaces. The spreading direction of the sealant 16 is indicated by the black arrow in FIG. 1 . That is, although the casting 12 has low flatness, the crushed protrusion 18a is sandwiched between the casting 12 and the mating component 14, so that the surface of the protrusion 18a facing the mating component 14 (hereinafter referred to as the “line end surface of the protrusion 18a”) is leveled against the surface of the mating component 14, thereby sealing the two components. In other words, the protrusions 18a function as dikes to prevent leakage of the sealant 16 during joining. As a result, the structure of the joined body 10 shown in Fig. 1 can suppress the sealant 16 from spreading in random directions and also control its downward spread, thereby avoiding unnecessary consumption of the sealant 16 and bolt fastening failures.

[0024] Next, a comparative example of the method for manufacturing a joined body according to the embodiment will be described with reference to Figures 2 and 3. In Figures 2 and 3, the same components as those in Figure 1 are designated by the same reference numerals, and their description will be omitted where appropriate. Figure 2 is a diagram showing a comparative example in which the protrusion shown in Figure 1 is not included. As in Figure 1, the left side of the white arrow labeled "Joined" in the center of Figure 2 shows the state before joining of the casting 12 and the mating part 14, and the right side of the arrow labeled "Joined" shows the state after joining of the casting 12 and the mating part 14.

[0025] As shown in FIG. 2, a sealer 16 is applied to a portion of one surface of the casting 12 that faces the mating part 14. Here, as shown in the diagram of the joined state in FIG. 2, the sealer 16 spreads in the vertical direction at the joining surface between the casting 12 and the mating part 14. In FIG. 2, the direction in which the sealer 16 spreads is indicated by a black arrow. That is, with the structure of the joined body 10 shown in FIG. 2, the sealer 16 cannot be prevented from spreading in the vertical direction, and spreads randomly. This is due to the low flatness inherent to castings. Therefore, a larger amount of sealer 16 than is required for sealing, and in some cases even a larger amount, may be applied to the application surface of the casting 12.

[0026] Furthermore, spreading of the sealant 16 beyond the necessary area can cause problems other than the unnecessary consumption of the sealant 16. For example, spreading of the sealant 16 to areas where the sealant 16 is fastened by a bolt can cause poor bolt fastening. Therefore, for example, another configuration of the joined body 10 is shown in FIG. 3. FIG. 3 is a diagram showing another comparative example in which the protrusion shown in FIG. 1 is not included. In other words, FIG. 3 is a diagram showing one method for addressing the problems of the joined body manufacturing method shown in FIG. 2. Note that in FIG. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and their description will be omitted. Also, as in FIGS. 1 and 2, the left side of the white arrow labeled "Joined" in the center of FIG. 3 indicates the state before joining between the casting 12 and the mating part 14, and the right side of the arrow labeled "Joined" indicates the state after joining between the casting 12 and the mating part 14. A protrusion 18b is provided on a portion of one surface of the casting 12 facing the mating part 14. The sealant 16 is placed on the protrusion 18b. That is, in the method shown in FIG. 3 , when the joined body 10 is joined, the protrusion 18b is sandwiched between the joining surfaces of the casting 12 and the mating part 14, so that the sealer 16 spreads only upward beyond the protrusion 18b, but not downward. The direction in which the sealer 16 spreads in this desired configuration is indicated by the black arrow in FIG. 3 . However, in reality, because the casting 12 has low flatness, it is difficult to achieve close contact between the surface of the protrusion 18b facing the mating part 14 (hereinafter referred to as the "end surface of the protrusion 18b") and the surface of the mating part 14. That is, because it is difficult to shape the end surface of the protrusion 18b so that it is even with the surface of the mating part 14, a gap occurs between the end surface of the protrusion 18b and the surface of the mating part 14. In this case, as shown in the joined state in FIG. 3 , the sealer 16 leaks out from the gap and partially spreads downward. In other words, with the structure of the joint 10 shown in Figure 3, although the spread of the sealer 16 in random directions can be somewhat suppressed, the downward spread cannot be controlled, and the problems of unnecessary consumption of the sealer 16 and poor bolt fastening cannot be solved.

[0027] As described above, compared to the comparative example of the bonded body manufacturing method shown in FIGS. 2 and 3 , the bonded body manufacturing method according to the embodiment shown in FIG. 1 can be configured to prevent the sealer from spreading in random directions at the bonded surface. The bonded body manufacturing method according to the embodiment can also eliminate the need for a burr removal process. Generally, when molding a casting using a mold in which split molds are combined, burrs are generated due to misalignment between the split molds that contact each other at the bonded surface. In this case, a separate process is considered to suppress the generation of burrs at the bonded surface, or a process for removing the burrs that do occur is added. However, in this example, the burrs are intentionally generated at predetermined locations as protrusions 18a, making use of the burrs themselves and avoiding the addition of unnecessary processes.

[0028] The above description is merely an example, and the method for manufacturing a joined body disclosed in this specification may be any method in which a mating part is pressed against a casting while crushing a protrusion provided on the casting with a sealer placed thereon, thereby joining the casting and the mating part. Therefore, other configurations may be changed as appropriate.

[0029] For example, in the embodiment, the mating part is described as being made of an aluminum alloy, similar to the casting, but the material of the mating part is not particularly limited. For example, if the mating part is made of iron, sufficient force can be applied to crush the protrusion made of aluminum alloy, so the dimensions of the mating part are not limited.

[0030] In the embodiment, a split mold is used because the position where the sealer is placed can be set more accurately by setting the split surface of the split mold at the location where the protrusion is desired. Also, since using a large mold (for example, a mold that is 1 m square) increases costs, a split mold is used to reduce costs. In other words, the shape and size of the split mold are not particularly limited as long as the location where the protrusion is to be generated can be set at the target location. [Explanation of symbols]

[0031] 10 joint body, 12 casting, 14 mating part, 16 sealer, 18a, 18b protrusions.

Claims

1. A method for manufacturing a joined body of a casting and a mating part, comprising the steps of: a step of molding the casting using a mold in which a plurality of split molds are combined, and a step of providing protrusions on the casting based on gaps between the plurality of split molds; placing a sealer on the protrusion; a step of pressing the mating part against the casting while crushing the protrusion with the sealer placed thereon, thereby joining the casting and the mating part; A method for manufacturing a bonded body comprising the steps of:

2. the plurality of split molds are designed based on predetermined locations for generating the protrusions; 2. The method for manufacturing a bonded body according to claim 1.

3. The gap is set by cutting mating surfaces of the plurality of split molds to a predetermined depth.

2. The method for manufacturing a bonded body according to claim 1.

4. The protrusion has a thickness of 1 mm or less in a direction perpendicular to the surface pressed against the mating component.

2. The method for manufacturing a bonded body according to claim 1.

5. When the protrusion and the mating part are made of aluminum alloy, the thickness of the mating part is 3 mm or more.

5. The method for manufacturing a bonded body according to claim 4.

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