JPH05123800A - Production of automotive member made of aluminum alloy - Google Patents

Abstract

PURPOSE:To maintain the sectional shape of an extrusion molded part at the time of secondary molding by previously applying the deformation quantity in an opposite direction allowing for the deformation quantity by the secondary molding to the part to be subjected to the secondary molding, then subjecting the part to be subjected to the secondary molding of the extrusion molded part to the secondary molding. CONSTITUTION:The deformation quantity D in the opposite direction allowing for the deformation quantity by the secondary molding is previously applied to the part to be subjected to the secondary molding of the extrusion molded part 1A at the time of extrusion molding of an aluminum alloy. The part to be subjected to the secondary molding of the extrusion molded part 1A is thereafter subjected to the secondary molding, such as bending. Consequently, the predeformation of the extrusion molded part is restored to the normal section shape at the time of the secondary molding. Then, the need for correction after the secondary molding is eliminated and the man-hours of production are decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an automobile member by subjecting an extrusion molded article made of an aluminum alloy to secondary molding such as bending.

[0002]

2. Description of the Related Art In recent years, in automobiles, the number of vehicle-mounted parts such as air conditioners, electronic control units and other functional parts has tended to increase due to improvement in safety and comfort, which hinders vehicle rigidity. It has been considered to use aluminum alloys to lighten the car body without inviting. In other words, aluminum alloy has an extremely lighter specific gravity than steel materials, so it is possible to increase the wall thickness.
This is because necessary and sufficient rigidity can be maintained.

Here, a method for manufacturing an automobile member such as a front pillar will be described with reference to FIGS.
First, a long extrusion molded article 1 having a predetermined length as shown in FIG. 8 is extrusion molded from an aluminum alloy billet. In this extrusion molded product 1, a flange 3 is integrally formed on the outer side of a cylindrical molded product body 2 along the extrusion direction of the molded product body 2. A flange forming angle θ between the flange 3 and the outer surface of the molded product body 2 is an acute angle. Next, the extrusion-molded product 1 extruded into a predetermined length is subjected to a bending process as a secondary molding as shown in FIGS. 9 and 10 to be an automobile member such as a front pillar. .. Specifically, as shown in FIG. 9, the secondary molding is performed by pulling both ends of the molded product main body 2 of the extruded product 1 so that the flange 3 of the extruded product 1 faces upward. The material clamps 11 and 12 are held by the material clamps 11 and 12, and the material clamps 11 and 12 are moved to both sides in the longitudinal direction of the extrusion-molded product 1 in accordance with an instruction from the controller 13 of the tensile molding machine 10.
Tensile force P such that stress above the yield point of the material is applied to
Give ₁ to the longitudinal direction. Then, while the tensile force P ₁ is being applied, the molding die 14 of the tensile molding machine 10 is driven to rise in accordance with an instruction from the controller 13 to apply a bending moment M to the extrusion molded product 1 as shown in FIG. By adding, the extrusion molded article 1 is bent along the processing surface 15 of the molding die 14 having a predetermined bending radius. As a result, the extruded product 1 becomes an automobile member such as a front pillar that is formed into a predetermined bending shape. Note that FIG.
In (A), L ₁ is a non-secondary molding target portion of the extrusion molded product 1, and L ₂ is a secondary molding target portion of the extrusion molded product 1.

[0004]

In the method of manufacturing an aluminum alloy automobile member described above, in the secondary forming target portion L ₂ which receives the bending moment M shown in FIG. The flange 3 is shown in FIG.
A deformation amount C as shown by a solid line is generated from a virtual line by receiving a force P ₂ for reducing the flange forming angle θ at the time of extrusion molding shown by a virtual line in (B). The deformation of the cross-sectional shape that occurs during the secondary molding requires a modification of the cross-sectional shape by a mechanical process using a press (not shown) or a manual process after the completion of the secondary molding, which increases the manufacturing man-hour and causes a cost increase. Becomes

In view of the above, the present invention has an object to maintain the cross-sectional shape of the extruded product during secondary forming such as bending, when the extruded product made of aluminum alloy is manufactured as an automobile member. ..

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, extrusion molding is performed on a portion to be subjected to secondary molding such as bending of an extrusion molded article made of an aluminum alloy while giving a preliminary deformation in the opposite direction in anticipation of deformation due to secondary molding. After that, secondary molding such as bending is performed on the secondary molding target portion of the extrusion molded product.

[0007]

In the secondary molding, the pre-deformation of the extruded product is restored so that it has a normal sectional shape.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings by attaching the same symbols to the same parts as those of the above-mentioned conventional example.

First Embodiment FIG. 1 shows an extrusion molding machine used in the first embodiment. The extrusion molding machine 20 shown in FIG. 1 is an extrusion molding machine in which an aluminum alloy billet 22 is extruded from a molding die 23 into a predetermined cross-sectional shape by an extrusion press 21 and a flange 3A is integrally formed on the outside of the molded product body 2. Mold product 1A. The extrusion-molded product 1A extruded from the molding die 23 is elongated while being held by a holding device 25 that moves along the guide rail 24 in the extrusion direction X of the extrusion-molded product 1A. Immediately after the extrusion molding machine 20 is extruded from the molding die 23, the extrusion molding machine 20 is subjected to a secondary molding target portion L ₂ such as bending of the flange 3A of the extrusion molding product 1A in a reverse direction in which deformation due to secondary molding is expected. A pre-deformation processing device 30 is provided to provide the pre-deformation. This preliminary deformation processing device 3
The controller 31 of 0 outputs an output signal corresponding to the detected extrusion pressure detected by the pressure sensor 32 provided in the extrusion press 21 (hereinafter referred to as the detected extrusion pressure),
It is provided in the vicinity of the downstream side in the extrusion direction of the molding die 23 by an output signal (hereinafter referred to as a detected extrusion speed) corresponding to the detected extrusion speed of the extrusion molded product 1A detected by the speed sensor 33 provided in the holding device 25. The hydraulic drive type machining tool 34 is driven and controlled, and by inputting the production plan data of the extrusion molded product 1A to the controller 31, the hydraulic supply path switching mechanism 36 for the actuator 35 of the machining tool 34 is operated. hand,
The working tool 34 is controlled to move forward and backward in a direction Y orthogonal to the extrusion direction X of the extrusion molded product 1A. In addition, reference numeral 40 in FIG. 1 is a restraint member that prevents the extrusion-molded product 1 </ b> A other than the portion where the preliminary deformation processing is performed from being deformed.

Therefore, in the first embodiment, the controller 31 of the pre-deformation processing device 30 is operated by the pressure sensor 32.
The hydraulic pressure supply passage switching mechanism 36 is operated based on the detected extrusion pressure input from the vehicle, the detected extrusion speed input from the speed sensor 33, and the production planning data previously input to the controller 31, and the hydraulic pressure supply passage switching mechanism 36 is operated. By supplying hydraulic oil from the hydraulic pressure supply source 37 to the forward movement port of the actuator 35 through 36 or by supplying hydraulic oil from the hydraulic pressure supply source 37 to the reverse movement port of the actuator 35, While controlling the movement direction, the machining tool 34 is moved forward and backward, and the deformation due to the secondary molding is expected in the secondary molding target portion L ₂ of the flange 3A of the extrusion molded product 1A extruded from the molding die 23. A preliminary deformation amount D in the direction is given. The pre-deformation amount D is the amount by which the flange 3A is restored to the predetermined flange forming angle θ by performing the bending process as the secondary forming, and as shown in FIG. 2, the secondary forming target portion L ₂
In the above, the central part of the bending process has a maximum value, and the minimum value is 0 at the boundary with the secondary molding non-target part L ₁ so that it is continuously changed along the extrusion direction X of the extrusion molded product 1A. There is.

Extruded product 1 thus obtained
In the case of A, as in the conventional case, both ends of the molding body 2 are held by the material clamps 11 and 12 of the stretch molding machine 10 (see FIG. 9), and the extrusion molded product 1A is subjected to stress equal to or higher than the yield point of the material. With the tensile force P _{1 applied} , the extrusion molded product 1 is made to follow the molding die 14 of the tensile molding machine 10.
By adding a bending moment M to A (see FIG.
(See (A)), the pre-deformation amount D of the flange 3A is recovered,
An automobile member such as a front pillar in which the flange forming angle in the secondary forming target portion L ₂ is almost the same as the flange forming angle θ in the non-secondary forming target portion L ₁ and the cross-sectional shape is maintained in the longitudinal direction. Can be obtained.

Experimental results of the first embodiment are shown in FIGS.
I will explain based on. FIG. 3 shows a front pillar that is bent after extrusion. In this front pillar, an extruded member 1B having a cross-sectional shape shown in FIG. 3 (B) has a bending radius 3 shown in FIG. 3 (A).
After bending at 00 mm, each measurement point G, H,
The amount of deformation at I, J, K, L, K ', J', I ', H', G'was measured. The extrusion molded member 1B includes a molded product body 2B and a flange 3B.

In this experiment, in order to know the comparison between the conventional example and the first embodiment, (1) without giving the pre-deformation amount D in the opposite direction to the flange 2B (D = 0), the extrusion molding member 1B Figure 4 shows the deformation amount (deformation amount after bending) C at each measurement point when the extrusion molding member 1B was bent, and (2) the flange 2B was prepared in the opposite direction. The maximum value of the deformation amount D is 0.5 times the maximum value of the deformation amount C after bending when the preliminary deformation amount D is not given, 1.
The amount of deformation at each measurement point when bending was performed by setting 3 types of 0 times and 1.5 times (the amount of deformation after bending) C '
5 is shown in FIG.
-L-K 'is the maximum value, and the measurement value is gradually changed from the maximum value to the minimum value 0 between the measurement points K-J-I-H and the measurement points K'-J'-I'-H'. It was set to 0 between the points H and G and between the measurement points H ′ and G ′.

Considering the experimental results shown in FIGS. 4 and 5, the maximum value of the preliminary deformation amount D is 1.0, which is the maximum value of the deformation amount C after bending when the preliminary deformation amount D is not given. It can be confirmed that a secondary molding member having a small cross-sectional shape deformation can be obtained by doubling it and gradually changing the preliminary deformation amount D from the maximum value to 0.

Second Embodiment FIG. 6 shows an extrusion molding machine 20 used in the second embodiment, in which a working tool 5 of a pre-deformation working apparatus 50 is used.
1 and the drive mechanism 52 of the processing tool 51. That is, the pre-deformation processing device 50 controls the rotation amount and the rotation direction of the pulse motor 53 of the drive mechanism 52 according to an instruction from the controller 31, and the rotational force of the pulse motor 53 is output from a plurality of gears of the drive mechanism 52. Is transmitted to the processing tool 51 via the reduction mechanism 54, and the processing tool 51 is rotationally moved in the circumferential direction of the extrusion molded product 1A in the vicinity of the downstream side in the extrusion direction of the extrusion molded product 1A of the molding die 23, thereby forming an extrusion molded product. On the secondary molding target portion L ₂ of 1A,
The same preliminary deformation as in the first embodiment is applied. Further, as shown in FIG. 7, the processing tool 51 is rotatably fitted on the bearing 56 of the support member 55. This processing tool 5
1 is formed with a processed groove 57 through which the flange 3A of the extrusion molded product 1A passes. A substantially semicircular relief groove 58 is formed at the bottom of the processed groove 57. The support member 5
The bearing 56 of No. 5 is formed in a cylindrical shape through which the pushing member 1A is inserted. An escape groove 59 through which the flange 3A passes is formed on the peripheral wall of the bearing member 56. Therefore, when the machining tool 51 rotates forward or backward in the arrow W direction shown in FIG. 7 about the bearing 56, the flange of the secondary molding target portion L ₂ of the extrusion molded product 1A extruded from the molding die 23. 3A is given a pre-deformation.

[0016]

As described above, according to the present invention, when the aluminum alloy is extrusion-molded, the extrusion molded article
Since the amount of deformation in the opposite direction, which allows for the amount of deformation due to secondary molding, is given to the part to be secondary molded, and then the secondary molding such as bending is performed on the part to be secondary molded of the extrusion molded product. At the time of the next molding, the pre-deformation of the extruded product is recovered so that the cross-sectional shape becomes normal. Therefore, 2
Since no modification is required after the subsequent molding, the number of manufacturing steps is reduced, and an aluminum alloy automobile member can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an extrusion molding machine used in a first embodiment of the present invention.

2A and 2B show an extrusion-molded product according to the first embodiment, in which FIG. 2A is a plan view and FIG. 2B is BB shown in FIG.
Sectional drawing which follows the line.

3A and 3B show front pillars used in the experiment of the first embodiment, where FIG. 3A is a plan view and FIG. 3B is a sectional view taken along line BB shown in FIG. 3A.

FIG. 4 is a measurement result diagram showing the amount of deformation of the flange after bending, which is used in the experiment of the first embodiment and when no preliminary deformation is applied.

FIG. 5 is a measurement result diagram showing the amount of deformation of the flange after bending when the preliminary deformation used in the experiment of the first example is given.

FIG. 6 is a configuration diagram showing an extrusion molding machine used in a second embodiment of the present invention.

7 is a cross-sectional view taken along the line BB shown in FIG.

FIG. 8 is a perspective view showing a conventional extruded product made of an aluminum alloy.

FIG. 9 is a bending process diagram showing a state in which a tensile force is applied to a conventional extruded product.

10A and 10B are views showing a state in which a bending moment is applied to a conventional extruded product, where FIG. 10A is a bending process drawing, and FIG. 10B is a sectional view taken along line BB shown in FIG. 10A.

[Explanation of symbols]

 1, 1A ... Extruded product 1B ... Extruded member 2, 2B ... Molded product body 3, 3A, 3B ... Flange 22 ... Aluminum alloy billet D ... Preliminary deformation amount

Claims (1)

[Claims] 1. Extrusion molding is performed after preliminarily deforming an extrusion-molded product made of an aluminum alloy in a direction such as bending of a product to be subjected to secondary deformation in anticipation of deformation due to secondary molding. A method for manufacturing an aluminum alloy automobile member, characterized in that secondary molding such as bending is performed on a secondary molding target portion of the product.