JPH0994618A - Production of frame shaped structural body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply produce a frame shaped structural body by blow-forming an aluminum alloy round tube against that an aluminum sheet is press worked and welded in the conventional way. SOLUTION: A hoop shaped forming material 45 is made from an aluminum alloy round tube, the forming material 45 is loaded in a die 10, heated in a heating furnace 20 to the softening point or higher through a temp. below the melting point and subjected to blow-forming with a blowing equipment 30.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a technique for manufacturing a frame-like structure.

[0002]

2. Description of the Related Art FIG. 12 is a perspective view of a typical frame-shaped structure. The frame-shaped structure 100 is an aluminum sash frame and includes an upper frame 102 including a step portion 101, a lower frame 103, and a left frame. 1
04 and the right frame 105 are combined in a mouth shape. 13A to 13C are manufacturing process diagrams of a conventional frame-shaped structure. In (a), the long aluminum material is cut into a predetermined length to obtain an upper frame 102, a lower frame 103, a left frame 104, and a right frame 105. Since a long aluminum material having a considerably complicated cross section (for example, a square cross section including the step portion 101) can be easily manufactured by extrusion, it may be used as a material. In (b), the upper frame 102, the lower frame 103, the left frame 104, and the right frame 105 are combined in a mouth shape. In (c), the frames are connected by welding. Reference numerals 106... (Each denotes a plurality, the same applies hereinafter) are beads.

[0003]

The above-mentioned frame-like structure 100
There is no problem if the whole shape is simple and the cross section is uniform, but it is not suitable for the one whose cross sectional shape changes from place to place. Further, since the beads 106 are raised, post-treatment such as smoothing with a grinder is essential, and a bead pattern remains even after grinding.

By the way, the door mounting frame for mounting the vehicle door includes a curved portion, and many of them are three-dimensionally curved, and the cross-sectional shape changes from portion to portion. I can't handle it very much. Therefore,
A frame-shaped structure having a complicated shape must be formed by press molding.

[0005]

SUMMARY OF THE INVENTION The inventors of the present invention have studied aluminum alloys in the course of researching an alternative technique to a conventional technique for manufacturing a frame-like structure by combining materials pressed and bent from a flat plate and performing spot welding on the same. We succeeded in manufacturing a frame-shaped structure with a complicated shape using a round pipe made of material. Specifically, the method of claim 1 includes a step of cutting an aluminum alloy round pipe into a predetermined length, a forming step of plastically working the pipe to a shape close to a product shape by a bender, and a product. A step of introducing the forming material into the cavity of a blow molding die having a cavity defining the outer peripheral surface of the step, and a step of heating the forming material contained in the die to a temperature of a softening point or higher and a melting point or lower, A frame-shaped structure comprising a blow molding step in which a high-pressure fluid is blown into a heated hollow forming material to expand it and the outer peripheral surface is pressed against the outer peripheral surface of the cavity.

Since no welding is required, there is no need to treat the beads, and the appearance shape is good. Since no trimming is required, the yield is good and the cost can be reduced.

The invention of claim 2 is characterized in that a drawing process for reducing the diameter of the round pipe and / or a pressing process for making the round pipe oval is added to the above process. For a part where the cross-sectional area of the cavity is locally small, it is sufficient to reduce the diameter of the round pipe, make it oval, or make the diameter smaller and then make it oval, and manufacture a frame-shaped structure with more diverse cross-sections. can do.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. The frame-like structure will be described by taking a door mounting frame of a vehicle as an example. FIG. 1 is an external view of a door frame of a vehicle manufactured by the method of the present invention. The door mounting frame 1 includes an upper frame portion 2, a front inclined frame portion 3, a front vertical frame portion 4, a lower frame portion 5, and a rear inclined frame. It is a hollow annular body composed of a portion 6 and a rear vertical frame portion 7. FIG.
FIG. 2 is a sectional view taken along line 2-2 of FIG. 1. The front inclined frame portion 3 has a vehicle interior side surface 3 a and a rear surface 3 b which are straight surfaces, and
c and the front surface 3d have stepped portions 3e and 3f. FIG. 3 shows FIG.
3-3 is a cross-sectional view taken along line 3-3, and the lower frame portion 5 has a vertically long rectangular cross section, and has step portions 5c and 5d at the front portion of the vehicle interior side surface 5a and the rear portion of the vehicle outer surface 5b. FIG. 4 is a sectional view taken along line 4-4 of FIG. 1. The rear inclined frame 6 has tapered surfaces 6a and 6b and a step 6c. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 1. The rear vertical frame 7 has a stepped portion 7 at the rear of the interior surface 7a and at the front of the vehicle outer surface 7b.
c, 7d. Thus, the cross-sectional shape of the door mounting frame 1 differs from part to part.

FIG. 6 is an explanatory view of a blow mold according to the present invention. The blow mold 10 is a lower mold 1 as a fixed mold.
1 and an upper mold 12 as a movable mold. The lower mold 11 has a groove 13 and rocket pins 14 and 14, the upper mold 12 has a groove 15, pin receiving holes 16, 16 and a blow pipe insertion hole 17, The upper mold 12 is superimposed on the lower mold 11 and the groove 13 and the groove 15 are combined to form a cavity as a molding space for blow molding.

FIG. 7 is a cross-sectional view of the cavity of the blow mold, which is for obtaining the cross section of FIG. 2 described above. The groove 15 of the upper mold 12 is superimposed on the groove 13 of the lower mold 11. The necessary cavity 19 is formed by setting the placing die 18 as needed. The contour of the cavity 19 matches the outer peripheral surface of the cross section of FIG. Cavities 19 for each location
However, the description is omitted.

FIG. 8 is a diagram showing the principle of the blow equipment and the heating equipment according to the present invention.
And heaters 23, 23 attached to the furnace wall,
4 are provided with piers 25, 25, 25 and a temperature sensor 26 (for example, a thermocouple), a temperature signal of the temperature sensor 26 is received by a furnace temperature control unit 27, and the furnace temperature control unit 27 is controlled to a predetermined value. To control the temperature. Reference numeral 28 denotes a power supply control unit. The heating temperature is 480-550 ° C. The blow facility 30 includes a compressor 31, a pressure regulating valve 32, a heat-resistant flexible tube 33, and the like, and supplies compressed air to the mold 10. In this embodiment, the pressurized medium is air, but if oxidation is not desired, an inert gas such as nitrogen gas is used, and the compressor 31 is changed to a gas cylinder.

A method of manufacturing the door mounting frame 1 using the above-described equipment will be described below. 9 (a)-
(D) is a manufacturing process diagram (first half) of the door attachment frame according to the present invention. In (a), a predetermined length of aluminum alloy round pipe 41 is cut out from a fixed-length Al-Mg-based aluminum alloy round pipe. In (b), vendor 4
Bending at 2 (C) shows a step of turning the round pipe 41 into an elliptical cross-section pipe by pressing, and (d) shows a step of reducing the diameter of the round pipe 41 by drawing, and these steps are added as necessary.

FIGS. 10 (a) and 10 (b) are views (middle stage) of manufacturing steps of the door mounting frame according to the present invention. (A) shows a state in which both ends of a bent pipe are joined by welding, and a pressure pipe 43 is attached. 44 is a bead.
The obtained forming material 45 has substantially the same contour as the product shape. (B), the forming material 45
Is placed in the cavity 19 of the blow mold 10, heated in the heating furnace 20 shown in FIG. 8 to a temperature above the softening point (below the melting point) (a temperature selected from the range of 480 to 550 ° C.), and then heated. Blow molding is performed by sending pressurized fluid.

FIGS. 11 (a) to 11 (f) are manufacturing process diagrams (late stage) of the door mounting frame according to the present invention. In (a), an oval-shaped forming material 45A is housed in a cavity 19 of a mold, and this is subjected to warm blow molding. (B)
Is a molded product W1 after blow molding (part of the door mounting frame 1)
The outer peripheral surface of the molded product W1 is defined by the outer peripheral surface of the cavity 19 of the mold. Thus, the cross section shown in FIG. 2 can be formed. In (c), the forming material 45B is accommodated in the cavity 19 of the mold, and is subjected to warm blow molding. (D) shows a molded product W2 after blow molding, and the cross section shown in FIG. 5 can be molded. In (e), the forming material 45C is housed in the cavity 19 of the mold, and this is subjected to warm blow molding. (F) shows a molded product W3 after blow molding, and the cross section shown in FIG. 3 can be molded. As described above, when the aluminum alloy round pipe cannot be stored in the cavity as it is, the aluminum alloy round pipe is made elliptical or reduced in diameter.

2 to 5 by the above warm blow molding.
The door mounting frame 1 shown in FIG.

The order of the processing steps described with reference to FIGS. 9A to 9D can be changed. For example, (a) → (c) and / or
Or (d) → (b). Or, FIG.
(A) → (b) → FIG. 10 (a) → FIG. 9 (c), (d). Further, in this embodiment, the door mounting frame has been described as an example. However, the frame-shaped structure of the present invention is not limited to this, and can be applied to a frame in a broad sense such as a vehicle frame, a building frame, and a decorative frame.

[0017]

The present invention has the following effects due to the above configuration. According to a first aspect of the present invention, a step of cutting an aluminum alloy round pipe into a predetermined length, a forming step of plastically processing the pipe to a shape close to a product shape by a bender, and a cavity defining an outer peripheral surface of the product A step of introducing the forming material into the cavity of the blow molding die having a step of heating the forming material stored in the die to a temperature of the softening point or more and less than the melting point, and the heated hollow forming material. A frame-shaped structure is manufactured from a blow molding step in which a high-pressure fluid is blown into and expanded to press the outer peripheral surface against the outer peripheral surface of the cavity.
Since welding is not required, bead processing is not required and the appearance shape is improved. Also, since trimming is not required, the yield can be improved and the cost can be reduced.

According to a second aspect of the present invention, a drawing step for reducing the diameter of the round pipe and / or a pressing step for making the round pipe oval are added to the steps. For a part where the cross-sectional area of the cavity is locally small, it is sufficient to reduce the diameter of the round pipe, make it oval, or make the diameter smaller and then make it oval, and manufacture a frame-shaped structure with more diverse cross-sections. can do.

[Brief description of drawings]

FIG. 1 is an external view of a door frame of a vehicle manufactured by the method of the present invention.

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

FIG. 3 is a sectional view taken along line 3-3 of FIG.

4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is an explanatory view of a blow mold according to the present invention.

FIG. 7 is a sectional view of a cavity of a blow molding die.

FIG. 8 is a principle diagram of a blow facility and a heating facility according to the present invention.

FIG. 9 is a manufacturing process diagram (first half) of the door mounting frame according to the present invention.

FIG. 10 is a manufacturing process diagram of the door mounting frame according to the present invention (middle term).

FIG. 11 is a manufacturing process diagram of the door mounting frame according to the present invention (late stage).

FIG. 12 is a perspective view of a typical frame-shaped structure.

FIG. 13 is a manufacturing process diagram of a conventional frame-shaped structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Frame-shaped structure (door mounting frame), 10 ... Blow molding die, 19 ... Cavity, 20 ... Heating furnace, 30 ... Blow equipment, 41 ... Aluminum alloy round pipe, 42 ... Bender, 45 ... Forming material.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Minoru Moto 1-10-1 Shin-Sayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd.

Claims (2)

[Claims] 1. A step of cutting an aluminum alloy round pipe into a predetermined length, a forming step of plastically processing the pipe to a shape close to a product shape by a bender, and a cavity defining an outer peripheral surface of the product. A step of introducing the forming material into the cavity of the blow molding die having the step of: heating the forming material stored in the die to a temperature above the softening point and below the melting point, and a heated hollow forming material A method for manufacturing a frame-shaped structure comprising a blow molding step in which a high-pressure fluid is blown into and expanded to press the outer peripheral surface against the outer peripheral surface of the cavity. 2. The manufacturing of a frame-shaped structure according to claim 1, wherein a drawing step for reducing the diameter of the aluminum alloy round pipe and / or a pressing step for ellipticizing the round pipe are added to the steps. Method.