KR101040420B1

KR101040420B1 - Method of manufacturing wheel for heavy vehicle and wheel manufactured thereby

Info

Publication number: KR101040420B1
Application number: KR1020100130698A
Authority: KR
Inventors: 염진교
Original assignee: 염진교
Priority date: 2009-12-23
Filing date: 2010-12-20
Publication date: 2011-06-09

Abstract

PURPOSE: A method for manufacturing a wheel for a heavy vehicle and a wheel manufactured thereby are provided to simplify the manufacturing process of a wheel by manufacturing the wheel through spinning processing. CONSTITUTION: A method for manufacturing a wheel for a heavy vehicle is as follows. A rim manufactures a half-finished product for molding the rim using a heated rim processing member(111b) through vertical forging. The rim is molded in a circular forging machine to have a 15~25mm thickness through stamping processing. The molded wheel disk is cut. A wheel disk member with through holes is attached on a conical mold frame(112a) attached on the rotary shaft of a spinning machine.

Description

METHOD OF MANUFACTURING WHEEL FOR HEAVY VEHICLE AND WHEEL MANUFACTURED THEREBY}

The present invention is partly filed in Patent Application No. 10-2009-129711.

The present invention relates to a method for manufacturing a wheel for a commercial vehicle, and a wheel manufactured by the same, and more particularly, a rim on which an outer rubber tire is mounted on an outer circumferential surface thereof is forged to withstand the weight or load of a heavy commercial vehicle. The wheel disk is manufactured by an integrated structure, and the wheel disk is manufactured by spinning the wheel disk on the inner circumferential surface of the rim, which is manufactured and manufactured by spinning, to significantly improve the rigidity and durability of the wheel. wheel) The present invention relates to a method for manufacturing a wheel for a commercial vehicle that can simplify the manufacturing process, and to a wheel manufactured thereby.

In general, a wheel mounted on an automobile is composed of a rim on which a rubber tire is mounted, and a wheel disk on which the rim is coupled to a steering device of the vehicle.

As shown in FIG. 1, a general automobile wheel 1 includes a hollow cylindrical rim 10 having a predetermined diameter and a wheel disk 20 installed at both ends of the inner surface of the rim 10. A rubber tire (not shown) is attached to the outer circumferential surface of the rim 10.

In addition, one side of the rim 10, the wheel disk 20 in the air inlet 30 for injecting air to the rubber tire surrounding the outer circumferential surface of the rim 10 is attached to communicate with the outer peripheral surface of the central portion of the rim 10 ) Is formed to protrude to the side.

On the other hand, the automobile wheel 1 is produced by pressing both the rim 10 and the wheel disk 20, the rim 10 is press-formed into a planar member and then roll-molded to form a cylindrical member After the end is formed by joining and fixing by welding 40 or by long rolling the cross-sectional shape required by the rim 10 to the member, the member is cut to a predetermined length and the cut member is rolled into a cylindrical shape. Both ends are manufactured by the method of welding 40.

In addition, the wheel disk 20 attached to both sides of the rim 10 is a form in which the outside of the circular plate is bent a predetermined angle to one side, such a wheel disk 20 is also produced by the press working.

On the other hand, the rim 10 and the wheel disk 20 as described above may use some aluminum material, but usually uses a steel material (called a rolled steel for welding structure). Since aluminum wheels are more expensive than steel wheels, they are increasing the cost of production and increasing vehicle prices.

However, as described above, the conventional method of manufacturing a wheel by pressing and welding is possible in the case of a passenger car in which a relatively light body and a small load are applied. It is difficult to produce by the method.

The reason for this is that heavy commercial vehicles have a greater weight than passenger cars, and the weight of passengers or cargoes is greater, so the wheels must be made to have a larger bearing capacity to withstand the loads of vehicles and cargoes.

In the case of the rim 10 of a wheel 1 for a passenger car, if the thickness is about 9 mm (thickness between the inner and outer walls of the rim), the weight of the vehicle body or the bearing capacity to withstand the load pressure of the occupant can be secured. The rim of the wheel should be designed to be 15 ~ 25mm thick so that it can stably support the load pressure of the commercial vehicle.

However, according to the wheel manufacturing method by press working, forming a rim having a thickness of 15 to 25 mm has a very difficult problem with the current technology.

The reason for this is that in order to manufacture a rim having a thickness of about 15 to 25 mm, a steel plate (hereinafter referred to as a 'rim forming member') should not be made cylindrical, but a thick steel rim forming member is made cylindrical. Rolling is very difficult to implement in the current technology, and there is a problem in that the inner and outer surfaces of the rim must be cut for the rounding of the rim after molding.

In addition, even if it is assumed that the rim forming member having a thickness of 15 to 25mm rolled into a cylindrical shape, both ends of the rim forming member rolled into a cylindrical can only be connected by welding 40, so that the structure of the rim is not manufactured integrally and the wheel There is a disadvantage that the welded portion of the wheel can be damaged, which reduces the reliability of the wheel. That is, a problem that may cause a fatal accident in the vehicle while driving is potential, so the manufacturing method of the rim rather than the integrated structure is not preferable.

In addition, even in the case of wheel disks for commercial vehicles, the manufacturing process by press working is required to undergo hot rolling and trimming processing to improve moldability (processing the thickness of the rim forming member) before press working. There is a problem that the process is complex and the manufacturing cost increases a lot.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to manufacture a rim constituting the wheel for a commercial vehicle wheel and the manufacturing method of the rim of the wheel disc is produced integrally by forging By this, the durability to withstand the load pressure of heavy heavy vehicles can be secured, and the manufacture of wheel discs is made by spinning processing, and the wheel manufacturing method for heavy commercial vehicles that can simplify the working process according to the wheel manufacturing and its To provide a product.

The problem of the method for manufacturing a wheel for a commercial vehicle according to the object of the present invention,

In the method of manufacturing a wheel for a commercial vehicle,

(a) A semi-finished product for forming a rim having a cylindrical shape with a hole in the center of the rim processing member heated at 1150 ° C. to 1250 ° C. by vertical forging at a pressure of 210 kgf / cm 3 was manufactured. Forming a rim having a thickness of 15 to 25 mm by a force of a rotation speed of 65 to 56 rpm and a pressing force of 210 kgf / cm 3 through a forging machine;

(b) The wheel disk member, which is cut to a certain size and provided with a predetermined number of through-holes, is mounted in a conical shape attached to the rotating shaft of the spinning machine, and then the wheel disk member is rotated at a rotational speed of 650 rpm to 30 to 45 tons. Pressing the surface of the wheel disk member with a forming roller to which the pressure is applied to form the wheel disk member into a wheel disk in a shape such as that of a mandrel;

(c) the rim surface of the wheel disk member is processed to be combined with the inner circumferential surface of the rim, and then can be implemented by a manufacturing process consisting of welding the rim of the wheel disk member to the inner circumferential surface of the rim. have.

According to the method for manufacturing a wheel for a commercial vehicle according to the present invention, since the rim, which is one component of the wheel, is manufactured in a cylindrical shape integrally formed by forging, the wheel can not only enhance durability and rigidity of the wheel, but also there is no welding seam. There is no possibility of any potential defects such as bonding, ensuring reliability and safety. The wheel disc is manufactured by spinning, which eliminates the hot rolling and trimming processes as in conventional press molding. Since it is not required, because the wheel manufacturing process is simplified, the work efficiency can be improved, and the manufacturing cost can be greatly reduced.

1 is a perspective view illustrating an example of a typical passenger car wheel;
2a is a process diagram illustrating a manufacturing process of a rim according to the present invention;
Figure 2b is a cross-sectional view of the rim produced by the rim manufacturing process shown in Figure 2a,
Figure 3a is a process diagram illustrating a wheel disk manufacturing process according to the present invention,
3B is a cross-sectional view of the wheel manufactured by the wheel manufacturing process shown in FIG. 3A;
Figure 4 is a cross-sectional view of the wheel to complete the wheel by combining the rim and the wheel shown in Figures 2b and 3b.

Hereinafter, a method for manufacturing a wheel for a commercial vehicle according to the present invention and a wheel manufactured thereby will be described in detail with reference to the accompanying drawings.

A heavy commercial vehicle defined in the present invention means a freight vehicle or a heavy equipment vehicle having a weight of 8 tons or more, and the wheel for a heavy commercial vehicle means a tire wheel mounted on the aforementioned freight vehicle or heavy equipment vehicle.

Referring to Figure 4, Figure 4 illustrates a cross-sectional view of a wheel for a commercial vehicle according to the present invention, the wheel 100 for a commercial vehicle according to the present invention is a cylindrical rim 110 having a predetermined height and a hollow portion, The wheel disk 120 is coupled to the inner circumferential surface of the rim 110.

An air injection nozzle 130 for injecting air into the space between the rim 110 and the rubber tire is attached to the outer peripheral surface of the rim 110 so as to communicate with the outer peripheral surface of the central portion of the rim 110.

On the other hand, the rim 110 and the wheel disk 120 constituting the wheel for a commercial vehicle 100 according to the present invention are manufactured by forging and spinning processing, respectively, unlike the press working method, the first manufacturing of the rim 110 The process will be described with reference to FIGS. 2A and 2B.

As shown in (a) of Figure 2a is sufficiently heated so that the ingot 111a for producing a rim cut to a certain size to 1150 ~ 1250 ℃. The heating method of the rim manufacturing ingot 111a is not specified in the present invention, but in the present invention, an electric furnace is employed as the heating means.

In addition, the steel ingot 111a for rim manufacturing is made of C: 0.2%, P: 0.035% or less, Si: 0.55% or less, S: 0.035% or less, Mn: 1.60% or less, and the same Fe as the conventional rim material. It is okay to see.

The ingot 111a for rim manufacturing heated to 1150 to 1250 ° C. forms a hole in the center through a vertical forging machine (not shown in FIG. 2B) and has a height suitable for rim molding. Vertical forging is performed to produce a semi-finished product for rim processing (hereinafter referred to as "rim processing member 111b").

At this time, the rim member 111b is heated to 1150 ~ 1250 ℃ by applying a static or dynamic pressure to the metal in a good plastic flow state to refine the crystal grains and to uniform the structure and at the same time forming a continuous plate Unlike the rolling process to produce the cross section and the forging, individual products are made in the forging, and the metal flow and the grain structure can be adjusted, so that molded articles having high strength and toughness can be manufactured.

The rim forming member 111b, which is formed by the vertical forging machine, is placed in the mold 112a mounted on the mold forging machine 112, and the member is placed in the forging under the operating conditions of 210 kgf / cm3 or more and a rotational speed of 65 to 56 rpm. Pressing with a mounted roll mold 112b forms a rim 110 having a desired thickness as shown in FIG. 2B.

If the pressing force is less than 210kgf / cm3, not only the molding is not performed smoothly, but also the molding is delayed and an annular monolayer or a curved fine band may appear on the processed surface during the molding process. The same problem can be solved.

The rotation speed is for molding corresponding to the thickness of the rim (15-25 mm). For example, when forming a 25 mm rim with a constant thickness, the rotation speed is 65 rpm, and 56 rpm when forming a rim with a constant thickness of 15 mm. It can be molded by driving, but the present invention is because the manufacturing of the rim having a thickness of 15 ~ 25mm it is preferable to drive the rotational speed at 65rpm.

The above-mentioned vertical forging is a forging process that does not restrain the metal flow in a direction perpendicular to the direction of the pressing force when the workpiece is pressurized, and the forging is a processing method in which the flow of metal by compression is performed only within the mold. .

Therefore, as shown in FIG. 2B, the rim 110 formed by the forging described above can greatly improve the durability of the product because the structure is fine and the strength is larger than that of the rim after cutting or free forging. have.

In addition, the rim 110 manufactured by die forging not only has excellent mechanical and chemical properties such as rigidity, rigidity, toughness, etc., compared with the casting product, and also has excellent durability than the product by casting during lathe processing.

In addition, the forming method of the rim 110 by forging has a wide range of processing, and even a product having a complicated cross section that requires a lot of processes can be processed at once, and is formed while rotating, compared with other plastic processing. In particular, since the roundness is excellent and the point contact by roller processing, the surface of the product is very smooth and clean, and the processing chip does not occur, so it is very effective in improving the efficiency of the material.

In addition, since the mold can be processed only by the male mold (refer to (a) of FIG. 2A and the roll mold 112b of FIG. 2A), the mold manufacturing cost is low compared to the press, and consumables are very small, and thus the operating cost is small.

Since the rim 110 manufactured in accordance with the present invention integrally forms a cylindrical structure, there is no welding site (refer to reference numeral 40 in FIG. 1) that appears in the manufacture by a conventional press, thereby fundamentally preventing damage to the rim that may occur at the welding site. Since it can be solved, the safety or reliability of the wheel 100 can be secured clearly.

The rim 110 manufactured according to the present invention manufactured five rims having a thickness of 15 to 25 mm and tested five rims, and the tensile strength was 535.48 N / mm 2, the maximum load was 354.13 N / mm 2, and an average elongation of 33.4%. Could get

The above results show that there is no problem in forming the rim of a heavy-duty wheel with the properties exceeding the properties of the rim 110 currently used, that is, the tensile strength of 490 to 610 N / mm 2, the maximum load of 315 N / mm 2, and an elongation of 21% or more. In addition, even if there is no welding area, the thickness of the rim can be manufactured even by reducing the thickness, so it is possible to expect a side effect of reducing the manufacturing cost.

On the other hand, the wheel disk 120 of the wheel for a commercial vehicle 100 according to the present invention has a predetermined number of through holes (not shown) is formed on the surface, the outer circumferential surface by bending so as to partially contact with the rim 110 It has a curved surface. The present invention proposes a wheel disk manufacturing method by spinning in forming a wheel disk having the above shape.

The manufacturing process of the wheel disk 120 for a commercial vehicle according to the present invention will be described with reference to FIGS. 3A and 3B.

First, as shown in (a) and (b) of FIG. 3a, the steel plate (hereinafter referred to as the wheel disk member 120a) is prepared in a circular shape to a size suitable for forming the wheel disk, and then the prepared wheel disk After the member 120a is firmly mounted on a conical mold fixed to the rotation shaft 133 of the spinning machine 130, the molding is applied with a pressure of 30 to 45 tons while rotating the wheel disk member 120a at a rotational speed of 650 rpm. The wheel disk member 120a is pressed by the roller 131 to be shaped into the same shape as the shape of the mendrel 132 (Mendrel).

The roller disk member 120a is pressed against the surface of the wheel disk member 120a which is rotated as described above, and the wheel disk member 120a is pushed toward the mandrel 132 as shown in FIG. 120a is deformed in the shape of the mandrel 132. At this time, by forming the roller 131 is moved to the outside from the inside of the wheel disk member (120a) integrally to adjust the operating pressure to push the wheel disk member (120a) is shown in Figure 3b dome (Dome It is molded into a wheel disk 120 for a commercial vehicle having a shape such as).

In the present invention, when the rotational speed is less than 650rpm, the molding surface has a circular molding wrinkle or circular scratch and about 3.2 / 100 cracks at the periphery of the formed wheel disk, but when the rotational speed is above 650rpm, scratches and cracks are almost found. Not only is it possible to obtain wheel molded parts that are smooth and have a clean surface, without the need for separate machining such as cutting.

In the present invention, when the rotational speed is less than 650rpm, problems such as monolayer jungle phenomenon, monolayer crease or thickness unevenness occur on the surface of the workpiece, about 3.8 / 100, but when the rotational speed is above 650rpm, scratches and cracks are generated. Not only was this rarely found, but also a wheel-molded product with a rough surface was obtained.

For reference, the pressure of the forming roller 30 to 45 tons is a variable pressure range of the forming roller corresponding to the difference in molding thickness, the more the work piece is bent (the part where the inclined surface starts in the plane) during the forming operation The pressure range as described above is useful because the workpiece can be molded at a relatively high pressure, but can be molded at a relatively low pressure.

Spinning is a kind of plastic working, in which the wheel disk member 120a is fixed to the mandrel 132 and then the mandrel is rotated, and the surface of the wheel disk member is pressed by the forming roller 131 toward the mandrel 132. Since the wheel disk member can be molded into the same shape as the mandrel 132, and the thickness of the workpiece can be controlled, the present invention can simplify the manufacturing process because the hot rolling and trimming processes involved in press processing are not required. have.

Therefore, the spinning process in the manufacture of the wheel disk 120 according to an embodiment of the present invention is very useful for simplifying the manufacturing process of the wheel 100 for commercial vehicles according to the present invention and the effect that can greatly improve the work efficiency To provide.

The wheel disk 120 formed by the above-described process is a steel material composed of C: 0.2%, P: 0.04% or less, Si: 0.55% or less, S: 0.04% or less, Mn: 1.60% or less, and the remaining Fe. In this study, five wheel disks with 8.25 ~ 15mm thickness were fabricated and tested. Their average strength was 456 N / mm2, maximum load was 321N / mm2, and elongation was 43.0%.

The above grades are the physical properties of the wheel discs for commercial vehicles currently on sale, that is, the tensile strength is 440 N / mm 2, the maximum load is 275 N / mm 2, and the elongation is more than 22%. It was confirmed that the pass level.

As described above, the wheel 100 for a commercial vehicle according to the present invention welds the wheel disk 120 manufactured by spinning to the inner circumferential surface of the rim 110 manufactured as an integral cylindrical structure as shown in FIG. 4. 140) is completed.

Performance test results of the wheel for commercial vehicles completed according to the present invention are as follows.

Rubber tires were mounted on the finished wheel for the commercial vehicle, and the radial fatigue test was carried out on the tire surface under the pressure of 7,000kgf, the tightening torque of the wheel nut 55kgf.m, the rotational speed of 160rpm, and the rotational speed of 3.5 million times. As a result, the loosening of the fastening wheel 100 or cracking and deformation of the rim were not found at all, thereby satisfying all the test items.

In addition, the five wheel disks 120 were mounted on a bending tester and tested under conditions of 2500kgf.m, fastening torque of the wheel fastening nut 55kgf.m, and rotation speed 320rpm. The results satisfied all the inspection items such as expansion or deformation of the nut fastening hole and falling of the welded part of the wheel disc and the rim.

As described above, specific embodiments have been described in the detailed description of the present invention, but those skilled in the art will be able to practice various modifications and applications through preferred embodiments of the present invention. It will be appreciated that such modifications and applications are included in the claims defined below and in the true spirit of the present invention.

100: commercial vehicle wheel 110: rim
111a: Ingot for rim manufacturing 111b: Member for rim processing
112: mold forging machine 112a: mold
112b: roll mold 120: wheel disk
120a: wheel disk member 130: spinning machine
131: forming roller 132: mendrel

Claims

In the manufacturing method of the wheel for a commercial vehicle, which processes the rim surface of the formed wheel disk to have the same diameter as the inner circumferential surface of the rim, and then welds the rim of the wheel disk member to the inner circumferential surface of the rim,
The rim is manufactured by rim forming a semi-finished product having a cylindrical shape with a hole in the center by vertical forging with a rim processing member heated at 1150 ° C. to 1250 ° C. at a pressure of 210 kgf / cm 3, and then rotating in a circular forging machine. Forging is carried out at the speed of 56rpm and the working pressure of 210kgf / cm3 or more to form a rim with a thickness of 15 ~ 25mm,
The wheel disk is cut to a certain size, the wheel disk member provided with a predetermined number of through holes on the surface is mounted on a cone-shaped mold attached to the rotating shaft of the spinning machine, and then applied at a rotational speed of 650 rpm and a pressing force of 30 to 45 tons. A method for manufacturing a wheel for a commercial vehicle according to claim 1, wherein the wheel roller is formed into a wheel disk in a mandrel shape by pressing the molding roller onto the surface of the wheel disk member.

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A wheel for a commercial vehicle manufactured according to claim 1.