KR960002908B1 - Process for manufacturing automobile wheel disk using high strength steel - Google Patents

Abstract

The method is for manufacturing the the wheel disk for automobile by drawing the high tensile steel. It comprises a step of flatening a workpiece with thickness of 3-5 mm via a multiple of rolls(2); a step of simultaneously blanking the workpiece into a disk shape, and drawing the workpiece by a slider of a 300-ton press; a step of drawing the disk by a 750-ton press to set the depth and the height of the disk; a step of burring the inner face of the shaft hole; and a step of forming a nut seat in the inner face of a bolt hole.

Description

Manufacturing method of automobile wheel disk using high strength steel

1A to 1F are manufacturing process diagrams for manufacturing a wheel disc for an automobile using high-strength steel according to the present invention.

2 is a front sectional view showing a wheel disk for an automobile using high tensile strength steel produced according to the present invention.

* Explanation of symbols for main parts of the drawings

1: disc material 2: roll

4: inner circumference 5: disk

6 bolt hole 7 shaft hole

8: nut seat

The present invention relates to a method for manufacturing a wheel disc for automobiles using high tensile steel, which will be described in more detail. The use of hard high tensile steel allows the manufacture of a wheel disc having excellent mechanical properties such as tensile strength and wear resistance. The second drawing process promotes smooth movement of the high tensile steel, and in particular, while the manufacturing process such as a number of drawing processes due to the use of the high tensile steel material is shortened, the surface is smooth and accurate roundness is used for automobiles. A disk manufacturing method.

BACKGROUND ART A generally known automotive wheel disk is a structural steel sheet having a tensile strength of about 38 kg / mm2 or more in a thin sheet state to complete a disk, and a rim for accommodating pneumatic tires is used for rolling. It is produced by the force of the wheel to the inner periphery of the rim is inserted into a custom fit tightly, and the combined edge of the inserted wheel and the rim to be fixed by welding.

Conventional automotive wheel disk manufacturing method associated with this technique is a plurality of blanking process for cutting into a disk shape using a structural structural steel for automobiles and a plurality of wheel disks to form a predetermined shape using a punch After forming the bolting and shaft hole center openings as a single punch tool set, while forming the wheel disk by forming the unevenness with rounded periphery on the hole which is the bolt installation part of the disk, the cylindrical disk is made. It is to be assembled to fit the inside of the rim (Rim) produced by the rolling process, and to join the fixed edge of the assembled disk and the rim by welding to complete the product.

Conventional automotive wheel disk manufactured by the above method is formed by the tensile strength of the automotive structural steel itself, which is the material of the disk is 38kg / ㎜ or more, it is relatively through the process such as drawing and piercing On the other hand, the mechanical properties such as the tensile strength are relatively weak, and the thickness of the disk body must be made thick (about 5-6 mm), thereby increasing the amount of mold in the material drawing process. There is a disadvantage that the weight is added, the weight of the disk becomes heavy.

In addition, when manufacturing the disk, there were various problems such as failure of assembly due to the failure of the periphery of the perforated metal during the processing of the bolted hole and the shaft hole in the drawn material of the disk, which is not smoothly processed.

The present invention is to improve the conventional conditions and various problems as described above, the purpose of which is a wheel disk having excellent mechanical properties such as tensile strength and abrasion resistance by using a high tensile force formed with a tensile strength of 55㎏ / ㎠ or more To facilitate the fabrication of the high-strength steel through the first and second draw process by maintaining the proper drawing pressure according to the use of the high-strength steel, and to reduce the weight of the disk itself. The present invention provides a method for manufacturing a wheel disc for automobiles using high-strength steel with a smooth surface and smooth product dimensions and roundness.

As a technical means for achieving the above object, the present invention provides a blanking process and a plurality of drawing to form a disk material by shearing the coil material by a shearing machine, and to form the disk material into a disk shape In the manufacturing method of the wheel disk for automobiles are manufactured by forming a blotto hole and a shaft hole in the center of the disk, the disk material is a high-strength steel material of 3-5mm thickness and flat through a plurality of rolls. The steps taken; A step of simultaneously performing a blanking process for forming the disk material into a disk shape and a first drawing process for arranging the inner circumferential surface of the disk to a predetermined depth as a slider of a press having a load of about 300 tons; Completion of the draw process of the disk in the second draw process to set the depth of the inner surface of the disk and the draw height of the disk by pressing the disk material of the first draw process is completed at a pressure of about 750 tons of commercial pressure ; A burring step of processing the inner surface of the shaft hole formed at the center of the inner circumferential surface of the disk into a flat surface; And a coining step of forming a nut seat on the inner surface of the bolt hole formed at the circumference of the inner circumferential surface of the disk.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A to 1F are manufacturing process diagrams for manufacturing automobile wheel disks using high tensile strength steel according to the present invention, and FIG. 2 is a front sectional view showing automotive wheel disks using high tension steel manufactured according to the present invention. That is, the high tensile steel material wound in the form of a coil of 3-5mm thickness is passed through a plurality of rolls (2) (2) (2) ... and flattened, and the disk material as described above is shearing machine. The disk material 1 is cut into a size of a wheel disk, for example, in the case of a general passenger car, and a rectangular disk material 1 is manufactured by cutting the disk material 1 to a size of 390 × 390 mm.

In this case, the reason for limiting the thickness of the disk material 1 to 3-5mm is that, when the thickness of the disk material 1 is 3mm or less, there is a risk of deformation due to the vehicle body load of a general passenger car, and when it is 5mm or more However, since the tensile strength of the high tensile strength steel is 55 kg / mm2 or more, if the thickness of the disk material is 3-5 mm, sufficient rigidity is maintained and there is no fear of deformation while the disk material thickness is 5 mm or more. This is due to the difficulty in drawing and the increase in the weight of the vehicle body.

Meanwhile, as described in FIG. 1B, the disk material 1 manufactured as described above is a crank press having a load of about 300 tons placed on a drawing die and processed into a circular wheel disk 5 shape. And a first drawing operation for drawing the inner peripheral surface 4 of the disk to a depth of 45 to 53 mm, preferably 48 to 52 mm.

At this time, the rounding (R) formed at the periphery of the drawing portion formed on the inner circumferential surface (4) is to be formed to R22mm.

The draw depth H is formed to be 48-52 mm, and the reason for the rounding R formed at the periphery thereof as R22 mm is that the material of the disk material 1 to be drawn is formed of high-strength steel, If the filling depth (H) is 48 mm or less, there is no problem in the drawing mold and the disk material. However, in order to form a constant drawing height of the disk 5, a number of drawing processes (3-4 times) are required. It is uneconomical because the line is extended, and when the drawing depth (H) is 52 mm or more, the metal material of the disc material 1 and the drawing die is not moved smoothly, causing deformation of cracks, and the like. This will cause breakage of the die.

In addition, the rounding (R) formed at the periphery of the drawing part has no deformation of the material at the time of R22mm, so that the most smooth drawing operation can be performed, and when R22mm or less, a crack is generated at the periphery.

Subsequently, in the disk material 1 in which the above-described primary drawing process is completed, the secondary drawing process is performed in a shape as shown in FIG. 1C.

The press has a load of about 750 tons during the second drawing operation, and the inner surface of the disk is set so that the drawing depth (h) of the inner side of the disk is set to 26-30 mm and the drawing height (L) is set to 80-83 mm. To complete.

Then, as shown in FIGS. 1d and e, the draw-off disk has a bolt hole piercing step of forming a bolt hole 6 around the inner circumferential surface of the disk to be coupled as a rim and a bolt. In addition, a burring process of bending the shaft hole 7 in the center of the inner circumferential surface of the disk to couple the axle of the vehicle is performed.

The shaft hole 7 preferably has a roundness of less than or equal to 1 because the balance of both axles must be maintained accurately when the axles are coupled.

As shown in FIG. 1F, the disk that has been processed as described above is subjected to a coining process in which a nut seat 8 is formed on the inner surface of the bolt hole 6 formed around the disk inner peripheral surface. The wheel disk 5 for a vehicle using high-strength steel as shown in FIG. 2 is completed.

The automobile wheel disk of the present invention manufactured by the method as described above, by using a hard high-tensile steel, it is possible to easily manufacture a lightweight wheel disk while excellent in mechanical properties such as tensile strength and wear resistance of the disk, as well as In order to facilitate the smooth movement of the high tensile strength steel through the first and second drawing processes, in particular, the manufacturing process can be shortened by reducing the number of drawing processes due to the use of high tensile steel materials, It is an excellent effect to manufacture a wheel disk for automotive precision and smooth surface.

Claims (4)

The coil material is formed by shearing the shearing machine 3 to form the disk material 1, and the blanking process and a plurality of drawing processes are performed to form the disk material 1 in a disk shape. In the method of manufacturing a wheel disc for an automobile in which a blotto hole 6 and a shaft hole 7 are formed in an inner circumferential surface 4 of a disc 5, the disc material 1 is made of high-strength steel having a thickness of 3-5 mm. Flattening through the plurality of rolls 2 as the material; A step of simultaneously performing a blanking process for forming the disk material 1 into a disk shape and a first drawing process for arranging the inner circumferential surface of the disk to a predetermined depth H as a slider of a press having a load of about 300 tons ; The disk material 1 of which the primary drawing process is completed is a press of a commercial pressure of about 750 tons as a second drawing process to set the inner depth of the disk (h) and the drawing height (L) of the disk. The drawing process of the disk is completed; A burring step of processing the inner surface of the shaft hole 7 formed in the center of the inner peripheral surface 4 of the disk 1 into a flat surface; And a coining step of forming a nut seat (8) on an inner surface of the bolt hole (6) formed around the inner peripheral surface (4) of the disk. The drawing depth H of the first drawing process is set to 45-53mm, and the rounding R formed around the drawing unit is set to R22mm. Method for manufacturing wheel disc for automobile using high strength steel. 2. The wheel disc for a vehicle according to claim 1, wherein the inner depth (h) and the drawing height (L) of the inner surface of the disk during the second drawing process step are set to 26-30 mm and 80-83 mm. Manufacturing method. According to claim 1, In the burring process for forming the shaft hole 7 in the center of the inner peripheral surface of the disk, the inner circumferential surface of the shaft hole 7 has a roundness (↗) of the automotive wheel using a high-tensile steel, characterized in that Disc manufacturing method.