JP3672407B2 - Manufacturing method of frame-like structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for manufacturing a frame-like structure.
[0002]
[Prior art]
FIG. 16 is a perspective view of a typical frame-shaped structure. This frame-shaped structure 100 is an aluminum sash frame, and includes an upper frame 102 including a stepped portion 101, a lower frame 103, a left frame 104, and a right frame 105. Are combined in a mouth shape.
17A to 17C are manufacturing process diagrams of a conventional frame-like structure.
In (a), the long aluminum material is cut into a predetermined length to obtain the upper frame 102, the lower frame 103, the left frame 104, and the right frame 105. A long aluminum material having a fairly complicated cross-section (for example, a square cross-section including the stepped portion 101) can be easily manufactured by extrusion, and this may be used as a raw material.
In (b), the upper frame 102, the lower frame 103, the left frame 104, and the right frame 105 are combined into a mouth shape.
In (c), the frames are connected by welding. 106 (... indicates a plurality. The same applies hereinafter) is a bead.
[0003]
[Problems to be solved by the invention]
First, since the frames are connected to each other by welding, it is necessary to pay close attention not to cause welding defects such as pinholes or gas entrainment in the beads 106, and the cost increases because skilled workers are required. Strain and deformation are likely to occur due to welding heat, and advanced manufacturing techniques are required to maintain a good shape.
[0004]
The frame-like structure 100 has no problem as long as the overall shape is simple and the cross section is uniform, but is not suitable for the case where the cross-sectional shape changes from place to place.
Further, since the beads 106 are raised, post-processing such as smoothing with a grinder is essential, and a bead pattern remains even after grinding.
[0005]
[Means for Solving the Problems]
Since the present inventors are a cause of defects, the present inventors have conducted research to establish a technique for producing a frame-like structure without welding, and produce a frame-like structure having a complicated shape without welding. Succeeded.
Specifically, the method of claim 1 includes a step of cutting a round pipe made of aluminum alloy into a predetermined length, and a pipe end processing step of forming a male joint or female joint of a brazing joint at the end of the pipe. And a forming process in which the pipe is plastically processed to a shape approximate to the product shape by a vendor, a process in which the pipe is hooped by being connected to a male female joint, and a cavity that defines the outer peripheral surface of the product. The step of introducing the hoop material into the cavity of the blow mold, the step of heating the hoop material stored in the die to a temperature not lower than the softening point and lower than the melting point, and high pressure on the heated hollow hoop material. And a blow molding process in which a fluid is blown to expand and the outer peripheral surface is pressed against the outer peripheral surface of the cavity.
[0006]
Since welding is not required, there is no need to worry about welding defects, no need to process the bead, and the appearance shape is good.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The frame-like structure will be described using a vehicle door mounting frame 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 part 6 and a rear vertical frame part 7.
FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1. The front inclined frame 3 has a side surface 3a and a rear surface 3b which are straight surfaces, and has step portions 3e and 3f on the vehicle outer surface 3c and the front surface 3d.
3 is a cross-sectional view taken along line 3-3 of FIG. 1, 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. .
4 is a cross-sectional view taken along line 4-4 of FIG. 1, and the rear inclined frame portion 6 has tapered surfaces 6a and 6b and a step portion 6c.
FIG. 5 is a sectional view taken along line 5-5 in FIG. 1, and the rear vertical frame portion 7 has step portions 7c and 7d at the rear portion of the indoor surface 7a and at the front portion of the vehicle outer surface 7b.
Thus, the door mounting frame 1 has a different cross-sectional shape for each part.
[0008]
FIG. 6 is an explanatory view of a blow molding die according to the present invention. The blow molding die 10 includes a lower die 11 as a fixed die and an upper die 12 as a movable die, and a groove 13 and a rocket are formed in the lower die 11. Pins 14, 14 and upper mold 12 have grooves 15, pin receiving holes 16, 16 and blow pipe insertion holes 17, upper mold 12 is stacked on lower mold 11, and grooves 13 and 15 are combined to blow. A cavity is formed as a molding space for molding.
[0009]
FIG. 7 is a cross-sectional view of the cavity of the blow mold, and the figure is for obtaining the cross section of FIG. 2. The groove 15 of the upper mold 12 is overlapped with the groove 13 of the lower mold 11, and if necessary, Then, the required cavity 19 is formed by setting the standing mold 18. The contour of the cavity 19 matches the outer peripheral surface of the cross section of FIG. Although the shape of the cavity 19 is different for each place, the description is omitted.
[0010]
FIG. 8 is a principle diagram of the blow equipment and heating equipment according to the present invention. In the heating furnace 20, a heat insulating material 22 is lined on a furnace shell 21, heaters 23, 23 are attached to a furnace wall, and a pier 25, 25 and 25 and a temperature sensor 26 (for example, a thermocouple) are attached, a temperature signal of the temperature sensor 26 is received by the furnace temperature control unit 27, and the furnace temperature control unit 27 controls the temperature so that the furnace temperature becomes a predetermined value. Reference numeral 28 denotes a power supply control unit. The heating temperature is 480 to 550 ° C.
The blow equipment 30 includes a compressor 31, a pressure adjustment valve 32, a heat-resistant flexible tube 33, and the like, and supplies compressed air to the mold 10. In this example, the pressurizing medium is air, but if oxidation is disliked, an inert gas such as nitrogen gas is used, and the compressor 31 is changed to a gas cylinder.
[0011]
Next, a method for manufacturing the door mounting frame 1 using the equipment described above will be described.
FIGS. 9A to 9D are manufacturing process diagrams (previous term) of the door mounting frame according to the present invention.
{Cutting step} In (a), round pipes 41 and 42 having a predetermined length are cut out from a round Al-Mg aluminum alloy round pipe.
{Pipe end machining step} In step (b), male joints 41 a, 41 a are formed on both ends of the round pipe 41 by cutting. An enamel joint is a combination of a male joint and a female joint. The length of these male joints 41a and 41a is L1. In addition, female joints 42a and 42a of the bead joint are cut and formed at both ends of the round pipe 42. When the length of the female joints 42a and 42a is L2, L2 may be slightly larger than L1.
[0012]
{Forming Step} In step (c), the round pipes 41 and 42 are bent and formed two-dimensionally or three-dimensionally by a pipe bender (not shown).
{Hoop process} Next, the joints 41a and 41a are inserted into the female joints 42a and 42a. At this time, the fitting (fitting) of the bezel joint is preferably a somewhat tight stop fitting, and the clearance fitting is inappropriate.
In addition, the round pipes 41 and 42 are crushed by an unillustrated press to make an elliptical cross section if necessary.
In (d), a pressurizing pipe 43 is attached to an appropriate location on a forming material 45 formed by combining the round pipes 41 and 42.
[0013]
FIGS. 10A and 10B are manufacturing process diagrams (mid-term) of the door mounting frame according to the present invention.
(A) shows the state which inserted the both ends of the pipe by which the bending process and the ovalization process were carried out, and attached the pressurization pipe 43. FIG. The resulting forming material 45 exhibits a contour that is substantially the same as the product shape.
{Step of Injecting Hoop Material into Mold} (b), the forming material 45 is placed in the cavity 19 of the blow mold 10.
{Heating step} Heating to a temperature above the softening point (below the melting point) (temperature selected from the range of 480 to 550 ° C.) in the heating furnace 20 shown in FIG. .
[0014]
FIGS. 11A to 11F are manufacturing process diagrams (late stage) of the door mounting frame according to the present invention, that is, blow molding process explanatory views.
In (a), the forming material 45A formed into an ellipse is accommodated in the cavity 19 of the mold, and this is blown warm.
(B) shows the molded product W1 after blow molding (a part of the door mounting frame 1), and 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 this is warm blow molded.
(D) shows the 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 blown warm.
(F) shows the 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, it is ovalized or reduced in diameter.
[0015]
12 (a) to 12 (c) are detailed views (first embodiment) of the brazing joint according to the present invention.
The process of a junction part is demonstrated in detail during the said process.
In (a), the female joint 42a is fitted into the female joint 41a.
In (b), the round pipes 41 and 42 are set between the lower mold 11 and the upper mold 12. Next, the internal pressure p is applied.
In (c), the circular pipes 41 and 42 are expanded in diameter, and the joint 41a is tightly “crimped” on the female joint 42a.
[0016]
The door mounting frame 1 of FIG. 1 having the cross section of FIGS. 2 to 5 can be manufactured by the above warm blow molding.
[0017]
FIGS. 13A to 13C are detailed views (second embodiment) of the brazing joint according to the present invention.
This is a technique for improving the betel joint shown in FIG. 12, and is characterized in that a concave portion 42d is provided in the female joint 42c by boring.
In (a), the female joint 41a is fitted into the female joint 42c.
In (b), the round pipes 41 and 42 are set between the lower mold 11 and the upper mold 12. Next, the internal pressure p is applied. Then, a considerable portion of the outer peripheral surface of the male joint 41a bites into the recess 42d.
In (c), the diameter of the round pipes 41 and 42 is increased, and the joint 41a is firmly “caulked” by the female joint 42c.
[0018]
14 (a) to 14 (c) are detailed views (third embodiment) of the brazing joint according to the present invention.
Fig. 13 shows another improved technique for the brazing joint of Fig. 12.
The female joint 42e has a tapered hole, the male joint 41b has a taper with a node 41c, and the lower mold 11 and the upper mold 12 are provided with annular grooves 11a and 12a, respectively.
In (a), the female joint 41b is fitted into the female joint 42e.
In (b), the round pipes 41 and 42 are set between the lower mold 11 and the upper mold 12. Next, the internal pressure p is applied.
In (c), the diameters of the round pipes 41 and 42 are increased, and the wax joint is bent radially outward. As a result, the joint 41b of the female joint 42e is firmly “caulked”.
[0019]
FIGS. 15 (a) and 15 (b) are detailed views (fourth embodiment) of the bevel joint according to the present invention and show a further improvement technique for the betel joint of FIG.
The female joint 42e is a tapered hole, and the male joint 41b is tapered.
In (a), the female joint 41b is fitted into the female joint 42e.
In (b), the diameters of the round pipes 41 and 42 are increased, and the joint 41b is firmly caulked to the female joint 42e.
[0020]
In this embodiment, the door mounting frame has been described as an example. However, the frame-like structure of the present invention is not limited to this, and can be applied to a broad frame such as a vehicle frame, a building frame, or a decoration frame.
[0021]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
The method according to claim 1 includes a step of cutting a round pipe made of aluminum alloy into a predetermined length, a pipe end processing step of forming a male joint or female joint of a brazing joint at the end of the pipe, and a pipe bender. A forming process for plastic processing to a shape that approximates the product shape at a step, a process for forming a pipe by connecting it to a female joint, and a blow mold having a cavity that defines the outer peripheral surface of the product. The step of introducing the hoop material into the cavity, the step of heating the hoop material contained in the mold to a temperature above the softening point and below the melting point, and blowing the high-pressure fluid into the heated hollow hoop material for expansion. And a blow molding step of pressing the outer peripheral surface against the outer peripheral surface of the cavity.
[0022]
Since welding is not required, there is no need to worry about welding defects, no need to process the beads, and the appearance shape is good.
[Brief description of the drawings]
1 is an external view of a vehicle door frame manufactured by the method of the present invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. 1. FIG. 6 is an explanatory view of a blow molding die according to the present invention. FIG. 7 is a sectional view of a cavity of the blow molding die. ] Principle diagram of blow equipment and heating equipment according to the present invention [FIG. 9] Manufacturing process diagram of door mounting frame according to the present invention (previous term)
FIG. 10 is a manufacturing process diagram of a door mounting frame according to the present invention (mid-term)
FIG. 11 is a manufacturing process diagram of a door mounting frame according to the present invention (late stage).
FIG. 12 is a detailed view of a betel joint according to the present invention (first embodiment).
FIG. 13 is a detailed view of a betel joint according to the present invention (second embodiment).
FIG. 14 is a detailed view of a betel joint according to the present invention (third embodiment).
FIG. 15 is a detailed view of a betel joint according to the present invention (fourth embodiment).
FIG. 16 is a perspective view of a typical frame structure. FIG. 17 is a manufacturing process diagram of a conventional frame structure.
DESCRIPTION OF SYMBOLS 1 ... Frame-shaped structure (door attachment frame), 10 ... Blow molding die, 19 ... Cavity, 20 ... Heating furnace, 30 ... Blow equipment, 41, 42 ... Aluminum alloy round pipe (round pipe), 41a, 41b ... male joints, 42a, 42c, 42e ... female joints, 45 ... forming material.

Claims (1)

A process of cutting a round pipe made of an aluminum alloy into a predetermined length, a pipe end processing process for forming a male joint or female joint of an enamel joint at the end of the pipe, and the pipe approximated to the product shape by a vendor. Forming the plastic material into a shape; connecting the male joint to a female joint to make a pipe hoop; and placing the hoop material into the cavity of a blow mold having a cavity defining the outer peripheral surface of the product. A step of heating, a step of heating the hoop material contained in the mold to a temperature not lower than the softening point and lower than the melting point, and blowing the high-pressure fluid into the heated hollow hoop material to expand the outer peripheral surface. The manufacturing method of the frame-shaped structure which consists of a blow-molding process pressed against the outer peripheral surface.

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