Aluminum frame

Abstract

To provide an aluminum frame capable of reducing manufacturing cost and shortening a manufacturing period in a state of maintaining strength by combining joining by an aluminum fixing metal fitting and a rivet and joining by fusion welding for joining of an aluminum angle material.SOLUTION: This aluminum frame is formed by combining a plurality of aluminum angle materials 1, and is formed by combining a rivet joining (first joining) part joined by an aluminum installing metal fitting 2 and a rivet 3 and a fusion welding joining (second joining) part joined by fusion welding for joining the aluminum angle materials 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an aluminum frame, and more particularly to an aluminum frame that can reduce manufacturing costs and shorten manufacturing time. [Background technology]

[0002] [Prior Art] Conventional aluminum frames that are installed inside vehicles and that carry electronic devices such as measuring instruments are made by combining aluminum angle bars and joining the joints by fusion welding.

[0003] Aluminum angle iron is a long material with an L-shaped cross section made by extruding aluminum. This aluminum angle iron is lightweight, strong, and has excellent corrosion resistance, and is widely used as a reinforcement and decorative material for machine parts, building materials, and structures.

[0004] Fusion welding of aluminum angle bars is a method of heating and melting aluminum to join them. Conventional aluminum frames are made strong and able to withstand vehicle vibrations by using fusion welding to create a one-piece structure.

[0005] However, welding aluminum angle iron is considered difficult for the following reasons. First, the melting point of aluminum is 660°C, which is lower than that of iron or copper, so the base material melts quickly, making welding difficult. Secondly, when aluminum surfaces come into contact with air, they form an oxide film, which has a high melting point and makes welding difficult. Thirdly, because aluminum has a high thermal conductivity, heat during welding tends to spread throughout the entire component, making it prone to distortion.

[0006] [Related Technology] Related prior art includes Japanese Patent Application Laid-Open No. 2011-014855 "Mounting structure for electronic device" (Patent Document 1) and Japanese Patent Application Laid-Open No. 2012-151330 "Communication device housing" (Patent Document 2).

[0007] Patent Document 1 discloses a structure in which base plates are attached to a base near the four corners of a housing to serve as fixing metal fittings, and are further fastened with screws. Patent Document 2 discloses a structure in which a housing can be assembled without welding and housing corner fittings are provided to fix two surfaces with rivets. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-014855 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-151330 Summary of the Invention [Problem to be solved by the invention]

[0009] However, with conventional aluminum frames, despite the difficulty of fusion welding aluminum, it was necessary to precisely join all of the aluminum angle bars using fusion welding, which resulted in problems such as high manufacturing costs and long manufacturing times.

[0010] Furthermore, with conventional aluminum frames, there is a risk of distortion occurring in the aluminum angle material when fusion welding is performed, which requires increased dimensional precision, resulting in a longer manufacturing period.

[0011] Incidentally, Patent Documents 1 and 2 do not describe a configuration in which aluminum angle bars are joined by combining joining with aluminum fixing metal fittings and rivets and fusion joining.

[0012] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an aluminum frame that can reduce manufacturing costs and shorten manufacturing time while maintaining strength by combining aluminum fixing metal fittings and rivet joining with fusion welding to join aluminum angle bars. [Means for solving the problem]

[0013] The present invention, which aims to solve the problems of the above-mentioned conventional examples, is an aluminum frame formed by combining multiple aluminum angle bars, and is characterized in that the aluminum angle bars are joined by a first joining portion that joins them with aluminum fixing brackets and rivets, and a second joining portion that joins them by fusion welding.

[0014] The present invention is characterized in that, in the aluminum frame, the number of first joint portions is greater than the number of second joint portions.

[0015] The present invention is characterized in that in the aluminum frame, the joints at the four corners of the bottom surface are second joints.

[0016] The present invention is characterized in that, in the above-mentioned aluminum frame, when the strength of the joining portion against the load caused by the mounted object and the load caused by vibration is equal to or less than a specific value, it is designated as a first joining portion, and when the strength exceeds the specific value, it is designated as a second joining portion.

[0017] The present invention is characterized in that, in the above-mentioned aluminum frame, the joining portion is determined as a first joining portion when a safety factor calculated by stress analysis when acceleration assuming vehicle vibration is applied based on a simulation model of the aluminum frame is used, and when the safety factor is equal to or greater than a specific set value, the joining portion is determined as a second joining portion, and when the safety factor is less than the specific set value, the joining portion is determined as a second joining portion.

[0018] The present invention is characterized in that in the aluminum frame, the specific set value of the safety factor is set to 1.3. [Effects of the Invention]

[0019] According to the present invention, an aluminum frame is formed by combining multiple aluminum angle bars, and the aluminum angle bars are joined by a first joint portion that is joined with an aluminum fixing bracket and rivet, and a second joint portion that is joined by fusion welding.This has the effect of reducing manufacturing costs and shortening manufacturing time while maintaining strength. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram of the frame. [Figure 2] FIG. [Figure 3] FIG. 1 is an enlarged view of a fusion welded joint. [Figure 4] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] An embodiment of the present invention will be described with reference to the drawings. [Outline of the embodiment] The aluminum frame (this frame) according to an embodiment of the present invention is formed by combining multiple aluminum angle bars, and the aluminum angle bars are joined by a first joint portion joined with an aluminum fixing bracket and rivet, and a second joint portion joined by fusion welding, thereby reducing manufacturing costs and shortening manufacturing time while maintaining strength.

[0022] [This frame: Figure 1] This frame will be described with reference to Figure 1. Figure 1 is a schematic diagram of this frame. As shown in Figure 1, this frame is formed by assembling multiple aluminum angle bars 1 vertically and horizontally, and combining the joints with rivet joints (first joints in the claims) using rivets 2 and mounting brackets (fixing brackets) 3, and fusion welded joints (second joints in the claims). The circular dotted line joint in FIG. 1 is the fusion welding point. In FIG. 1, for example, a frame with a height of approximately 1.6 m is assumed.

[0023] Furthermore, in this frame, it is desirable to increase the number of riveted joints (first joints) compared to the number of fusion welded joints (second joints), thereby further reducing manufacturing costs and shortening manufacturing time while maintaining strength.

[0024] In this frame, the joints at the four corners of the bottom surface may be fusion welded (second joints) to increase strength.

[0025] In this frame, when the strength of the joints against the loads caused by the loads on board and the loads caused by vibrations is below a specific value, they are riveted (first joint), and when the strength exceeds a specific value, they are fusion welded (second joint).

[0026] Specifically, a simulation model of an aluminum frame is generated, an expected load is mounted on the model and a simulation is performed, vibrations applied to the model are simulated, the strength against those loads is calculated, and the strength is compared with specific values ​​obtained by experiment or simulation. The strength may also be calculated by mounting the load on the model and performing a simulation in which vibrations are applied.

[0027] [Parts of this frame] Next, each part of this frame will be specifically described. [Aluminum angle material 1] The aluminum angle bar 1 is a long material with an L-shaped cross section manufactured by extruding aluminum. This frame is also made by combining aluminum flat bars (flat bars / rectangular bars). The aluminum angle material 1 or the aluminum flat bar is provided with an insertion hole for inserting a rivet 2 therein.

[0028] [Rivet 2] The rivet 2 is a mechanical fastener or connector used to firmly connect metals together. It is made of stainless steel, aluminum, or plastic, and is typically a blind rivet. Unlike screws and nuts, rivets join parts together using a special method called "crimping," and once they are fastened, they cannot be removed, providing a semi-permanent, strong fastening force.

[0029] The rivet 2 is inserted into the insertion hole of the aluminum angle bar 1 or aluminum flat bar and the insertion hole of the mounting bracket 3 described later, and crimps and joins the aluminum angle bar 1 etc. and the mounting bracket 3.

[0030] [Mounting bracket 3: Figure 2] The mounting hardware for this frame will be described with reference to Figure 2. Figure 2 is a schematic diagram of the mounting hardware. The mounting bracket (fixing bracket) 3 is attached so as to contact the inside of the aluminum angle bar 1 or aluminum flat bar in order to connect aluminum angle bar 1 to another aluminum angle bar 1 or to an aluminum flat bar.

[0031] Therefore, when connecting two aluminum flat bars, the mounting bracket 3 is L-shaped, and when connecting three aluminum angle bars 1, it is made of aluminum metal with an L-shaped cross section connected in the x, y, and z directions.

[0032] Figure 2 shows mounting brackets 3 connected in the x, y, and z directions, and Figure 2(a) has connecting portions 3a1, 3b1, and 3c1 that connect aluminum angle bars 1 together in a triangular shape, and an insertion hole 3d for inserting a rivet 2 is provided corresponding to the insertion hole of the aluminum angle bar 1.

[0033] 2(b) is provided with L-shaped connecting portions 3a2, 3b2, 3c2 so as to fit inside the aluminum angle material 1, and an insertion hole 3d for inserting a rivet 2 is provided corresponding to the insertion of the aluminum angle material 1. FIG. 2(a) shows a structure that is desirable for strengthening the connection portion of the aluminum angle bar 1, while FIG. 2(b) is suitable for a structure for pulling out wiring or a structure for providing rails or the like.

[0034] [Fusion welding joint: Figure 3] Next, the fusion welded joints of this frame will be described with reference to Fig. 3. Fig. 3 is an enlarged view of the fusion welded joints. As shown in Figure 3, fusion welding connects aluminum angle bars 1 together at fusion weld joints 10. The fusion welding itself is performed by using conventional technology to join the parts of aluminum angle bars 1 that come into contact with each other.

[0035] [Rivet joint: Figure 4] Next, the riveted joints of this frame will be described with reference to Fig. 4. Fig. 4 is an enlarged view of the riveted joints. The aluminum angle material 1 is placed so that the insertion hole of the rivet 2 is aligned with the insertion hole of the mounting metal 2, and the rivet 2 is inserted and pressed to fix it in place. Riveting is cheaper and easier to connect than fusion welding, and can shorten the manufacturing time.

[0036] [Main frame with safety factor] In the frame described above, the locations of riveted joints and fusion welded joints are determined based on strength, but the determination may also be made using a safety factor. Specifically, for this frame, a simulation model of the aluminum frame is generated for the joint portion, and a safety factor calculated by stress analysis when acceleration equivalent to vehicle vibration is applied based on that model is used. If the safety factor is equal to or greater than a specific set value, a riveted joint (first joint portion) is used, and if the safety factor is less than a specific set value, a fusion welded joint (second joint portion) is used.

[0037] The safety factor is a unitless quantity calculated using the following formula: Safety factor = (maximum force that can be applied to the material) / (maximum force that can actually be applied to the material) Here, "the maximum force that can be applied to a material" refers to the strength specific to the material, and if a force greater than this is applied to the material, the material will deform or break.

[0038] The strength here is determined by selecting the optimum value depending on the material and the characteristics you want to evaluate, such as proof stress, yield stress, fatigue strength, etc. In this case, the same type of force is also used for the "maximum force actually applied to the material."

[0039] When the safety factor exceeds 1, it can be determined that the actual force applied is smaller than the force that can be applied to the material, and it can be determined that the material can withstand the applied force. Conversely, if the safety factor is below "1", the material is determined to be deformed or destroyed, and the design is deemed inappropriate.

[0040] When designing, it is not enough to simply ensure that the safety factor exceeds 1; it is also necessary to design with a margin of strength so that the structure can withstand unexpected forces. For example, when designing products (vehicle-mounted equipment) that use this frame, the rule states that the safety factor must be 1.3 or higher.

[0041] However, these standards are based largely on experience, and manufacturers and designers may design with a higher safety factor at their discretion. In this case, the force to be judged is set as the yield stress, and the safety factor is calculated in conjunction with the applied stress. The yield stress here is not strictly speaking the same, but it is the force at which plastic deformation (deformation that does not return to its original shape even when the force is removed) begins, and if this is exceeded the deformation will not return to its original shape, so it is considered inappropriate as a design.

[0042] The safety factor is an index that can determine strength regardless of the type of material strength, making it easier to explain than defining it in terms of material strength. For example, if a product is subject to a pulling force, a safety factor using the tensile strength is used. This allows the evaluation criteria to be selected depending on the usage environment, making it widely applicable.

[0043] [Effects of the embodiment] This frame is formed by combining multiple aluminum angle bars 1, and the aluminum angle bars 1 are joined by a rivet joint (first joint) part that joins the aluminum mounting bracket 2 with a rivet 3, and a fusion weld joint (second joint) part that joins by fusion welding. This has the effect of reducing manufacturing costs and shortening manufacturing time while maintaining strength. [Industrial Applicability]

[0044] The present invention is suitable for aluminum frames that combine aluminum fixing brackets and rivet joining with fusion welding to join aluminum angle bars, thereby reducing manufacturing costs and shortening manufacturing time while maintaining strength. [Explanation of symbols]

[0045] 1...aluminum angle material, 2...rivet, 3...mounting bracket (fixing bracket), 3a1, 3b1, 3c1...connection part, 3a2, 3b2, 3c2...connection part, 3d...insertion hole, 10...fusion welding joint part

Claims

1. An aluminum frame formed by combining a plurality of aluminum angle members, This aluminum frame is characterized in that the aluminum angle bars are joined by a combination of a first joining portion that joins the aluminum fixing metal fittings with rivets and a second joining portion that joins the aluminum angle bars by fusion welding.

2. 2. The aluminum frame according to claim 1, wherein the number of the first joint portions is greater than the number of the second joint portions.

3. 2. The aluminum frame according to claim 1, wherein the second joints are formed at four corners of the bottom surface.

4. 2. The aluminum frame according to claim 1, wherein the joining portion is the first joining portion when the strength against the load caused by the mounted object and the load caused by vibration is equal to or less than a specific value, and is the second joining portion when the strength exceeds the specific value.

5. 2. The aluminum frame according to claim 1, characterized in that a safety factor calculated by stress analysis when acceleration assuming vehicle vibration is applied based on a simulation model of the aluminum frame is used for the joining portion, and if the safety factor is equal to or greater than a specific set value, the joining portion is the first joining portion, and if the safety factor is less than the specific set value, the joining portion is the second joining portion.

6. 6. The aluminum frame according to claim 5, wherein the specific set value of the safety factor is 1.3.

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