KR100930908B1 - Manufacturing method of suspension arm for automobile rear suspension - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a suspension arm for a vehicle rear wheel suspension made of an aluminum alloy extruded material, and a suspension arm according thereto.

The method of the present invention includes the steps of manufacturing an aluminum alloy extruded shape member (11); Cutting the extruded shape member; Fixing the cut extruded shape member and bringing the mold into close contact; Pressing the bottom plate of the extruded shape to give a "c" shaped cross-sectional structure, and simultaneously forming connecting mounting portions at both ends; Punching a coil spring seating groove in an upper surface of the center of the bottom plate; Comprising a step of forming a hole through the outer surface of each one side wall mounting portion in the longitudinal direction.

The production method and the suspension arm of the present invention can improve the production productivity, it is possible to obtain the effect that can improve the fuel economy of the automobile.

Suspension Arm, Control Arm, Extrusion Profile, Automotive

Description

The manufacturing method of the suspension arm for the rear suspension of a car}

Figure 1 shows an embodiment of the suspension arm of the present invention,

  (A) is a perspective view,

  (B) is sectional drawing.

Figure 2 shows an embodiment of the present invention extrusion arm for producing a suspension arm,

  (A) is a perspective view,

  (B) is sectional drawing.

Figure 3 is a schematic diagram of one side end processing of the extruded shape member.

4 is a schematic view of the other end processing of the extruded shape member.

5 is a schematic view of the center mounting groove processing of the extruded shape member.

6 is a schematic view of a partial processing of each end hole formed in the extruded shape member.

7 is an overall processing schematic diagram of each end hole formed in the extruded shape member.

8 is a perspective view of a suspension arm after hole cutting and before cutting at both ends;

          ((Explanation of symbols for main part of drawing))

            11. Extrusion profile 11A. Bottom plate

            11B. Sidewall 11B1. Outer wall

            11B2. Inner wall

            H. Hole G. Seating groove

The present invention is to manufacture a suspension arm for a vehicle rear wheel suspension made of an aluminum alloy extruded material in order to improve the fuel efficiency of an automobile, to effectively reduce the impact or vibration with the road surface transmitted from a tire, and to improve the steering stability of the automobile. And a lower control arm accordingly.

As crude oil prices are expected to continue to rise in recent years and in the future, interest in energy savings is increasing, and the automotive sector is no exception.

Automobiles have evolved as a means of transportation, the most basic element of modern civilization, and modern civilization without automobiles cannot exist, but the emission of automobiles has a great influence on global warming and is the main cause of air pollution. Among them, various regulations are being implemented or in preparation for reducing automobile emissions.

Accordingly, car makers are developing automobiles using electricity, fuel cells, hydrogen, etc. as energy sources, or hybrid vehicles using fossil fuels and electricity in parallel, and some of them are currently on the market.

However, as described above, a vehicle with no pollution or a very small amount of vehicles still needs much time to become common. The most effective method as an intermediate step is the use efficiency of fuel consumed in driving with the reduction of carbon dioxide emission. It can be said that the weight of the car to increase the weight, the weight of the car can be made through the improvement of the vehicle body design technology and the development of lightweight materials to replace the steel (鋼).

In particular, research and development of materials that can replace steel have been made in various ways, and some of them have been tested, but compared with steel in terms of economics and rigidity, it is currently the most promising. In fact, the material used in mass production cars is aluminum alloy.

The aluminum alloy is only about one third the weight of steel, and has excellent specific strength, corrosion resistance, thermal conductivity, and the like, and the energy required for recycling is about 3% of the steel. Bars are superior to steel in both environmental and energy saving terms.

In addition, the development of alternative materials and the weight reduction of automobiles are important to the body design technology. Today's automobiles allow the design and development of parts at the same time, reduce assembly time, and reduce costs. In addition, a plurality of unit parts are assembled into one assembly, that is, a modular unit, and then a modular method of finally combining each assembly.

Therefore, the aluminum alloy of the chassis module, which is very important for the ride comfort and safety of the automobile and of the heavy weight among the various modules constituting the vehicle, is essential for the weight reduction of the vehicle. What should be done is the suspension system.

The suspension device is connected to the axle and the vehicle body, and absorbs vibration and shock of the road surface while driving to increase ride comfort and turning stability.The suspension device is connected in up and down directions to alleviate the shock transmitted from the road surface. It must be flexible and the connection in the horizontal direction must be strong enough to withstand the driving force, braking force and centrifugal force generated during the turn.

On the other hand, the suspension is classified into independent and integrated suspension, in particular, the suspension is applied to the independent suspension to control the movement of the wheel, also known as the control arm, also known as the control arm is located on the inside of the tire input from the road surface It is an important part that connects and supports wheels and braking devices to the car body so as to transfer the load to the car body, and lightweight should be made preferentially in order to improve the function and the corrosion resistance, but the conventional suspension arm is forged steel Since products, cast iron products, steel plate press products, and the like were used, further reduction in weight and function could not be achieved.

The present invention was devised to solve all the problems of the conventional steel suspension arm, that is, lack of corrosion resistance, improvement of function and light weight, and the like. In addition, the present invention provides a method for manufacturing a suspension arm for use in an automobile suspension device, in particular, a rear wheel suspension device, which can improve and improve vibration, energy absorption capability, and responsiveness.

The above object of the present invention is achieved by an aluminum alloy extruded shape member having a specific composition and having a substantially "c" shaped cross-sectional shape.

The suspension arm for a vehicle rear wheel suspension according to the present invention, also called a lower control arm, is manufactured by processing an extruded shape member having an upwardly open, substantially "c" shaped cross-sectional shape made of aluminum alloy, and not a hollow shape member. The technical feature is that it is manufactured from the shape of a double-walled upward open solid structure.

Since the suspension arm of the present invention as described above is manufactured by the processing of a hollow-free solid member manufactured by extrusion, as well as extrudability and moldability should be excellent, in order to satisfy these characteristics, the suspension of the present invention The arm is Si 0.95-1.05wt%, Mg 0.5-0.6wt%, Mn 0.5-0.6wt%, Fe 0.15-0.25wt%, Cr 0.13-0.18wt%, Cu 0.05wt% or less, Ti 0.03wt% or less, Zn is 0.05wt% or less, and other unavoidable components are individually 0.02wt% or less, the sum is 0.10wt% or less, and consists of an aluminum alloy composed of the balance of Al, in this way, limiting the content of the material component One reason is as follows.

Si is combined with Mg and precipitated as Mg ₂ Si by aging to influence the mechanical properties.Since combined with Mg, the remaining Si precipitates alone to improve mechanical properties and is effective for improving the fluidity of the melt. If the wt% is not reached, the desired strength cannot be obtained, and if it exceeds 1.05 wt%, not only the extrudability but also the surface quality of the extruded product is degraded.

Mg is a component that is precipitated with the Si and the compound to improve the mechanical properties, if the content is less than 0.5wt% Mg ₂ Si precipitate amount is insufficient to obtain the required strength, if exceeding 0.6wt% as a disadvantage to the extrusion flexible as in the case of over-Si as well as the risk of low intensity, the extrudable degradation by inhibiting the employment of an extra Mg Mg ₂ Si failed to form a Mg ₂ Si at the same time, the falling down of the productivity strength Will drop.

Mn improves the strength without deteriorating the corrosion resistance and is an effective component for grain refinement. If the content is less than 0.5wt%, Mn can obtain an effect of improving surface pick-up during extrusion by miniaturization of Mg ₂ Si. In addition, if the strength improvement effect due to miniaturization of the alloy structure is small and exceeds 0.6wt%, the transformation of the equilibrium α-AlFeSi phase into the non-equilibrium β-AlFeSi phase is promoted during the homogenization process, and thus the strength is increased. It tends to be lowered.

Fe is an ingredient that is effective in suppressing coarsening of recrystallized grains and miniaturizing crystal grains in casting.If it is less than 0.15wt%, Fe acts as an impurity, but the alloying effect is insignificant. It will also reduce the extrudability and productivity.

Cr inhibits the formation and growth of the recrystallized layer and forms a compound together with Al and Fe to distribute at the grain boundary, thereby inhibiting precipitation during aging and improving elongation. The content is 0.13wt%. If it does not reach, the recrystallization layer suppression effect is insignificant, the fatigue strength is lowered, and when it exceeds 0.18wt%, the extrudability is deteriorated.

Cu is a component that improves the flowability of the molten metal and improves the strength but lowers the corrosion resistance. When the content exceeds 0.05 wt%, Cu degrades the corrosion resistance, the weldability and the extrudability.

Ti is a component that is effective in refining particles, and when exceeding 0.03 wt%, the extrudability is reduced, and Zn is a component that improves corrosion resistance and mechanical properties, and when the content exceeds 0.05 wt%, Likewise, the extrudability is lowered.

In particular, the aluminum alloy of the present invention is improved in strength and extrudability and workability by adjusting the content of Si and Mn, which will be described below.

In order to accomplish the above object, by default, and the amount of precipitated and deposited in the form of Mg ₂ Si to be controlled with priority, it is In order that grain boundaries segregation at the same time that the amount of precipitation of the Mg ₂ Si to be adjusted to not more than 1.0wt% It should be suppressed, for this purpose it is to limit the content of Si and Mg to the above range.

Particularly, Mn plays a role of improving the strength and processability by minimizing the grain size and dispersing precipitate in the structure while minimizing segregation of Mg ₂ Si at the grain boundary during cooling after homogenizing the extruded material of the present invention. Rather, it promotes transformation of acicular β-AlFeSi into granular α-AlFeSi to improve the extrudability.

Further, by adding Mn together with Cr, these elements are efficiently dispersed in the structure, thereby preventing dislocation movement and recrystallization, thereby miniaturizing grains, thereby improving toughness and fatigue strength, as well as increasing temperature during extrusion. By suppressing the local melting phenomenon caused by the extrudeability.

Looking at the structure and the manufacturing method of the suspension arm of the present invention made of an aluminum alloy of the composition as described above as follows.

Figure 1 is a perspective view and a plan view of an embodiment of the present invention suspension arm, Figure 2 is a perspective view and a cross-sectional view of the extrusion member for producing the suspension arm, Figure 3 is a schematic view of one side end processing of the extrusion member, Figure 4 5 is a schematic view of the other end of the extruded shape, FIG. 5 is a schematic view of the center bottom seating groove of the extruded shape member, FIG. 6 is a partially processed schematic view of each end hole formed in the extruded shape material, and FIG. 8 is a perspective view of the suspension arm after hole processing and before cutting at both ends.

As shown, the suspension arm of the present invention is made of an extruded shape member, and the extruded shape member 11, which is the material, has a plate-shaped bottom plate 11A and both ends of the bottom plate 11A, respectively. Each side wall is a double wall structure, and each side wall 11B has an upper end portion of the outer wall after the outer wall 11B1 extends upright at each end in the width direction of the bottom plate. The inner wall 11B2 extends downward to the immediate side of the bottom plate 11A so as to be parallel to the outer wall 11B1 after being bent to form a quadrangle.

That is, the upper end of the outer wall 11B1 is firstly bent in the horizontal direction toward the outside and then bent upwardly and secondly in the vertical direction, and is further bent in the horizontal direction toward the inner side and then in the direction perpendicular to the bottom plate. The structure is bent downward to form the inner wall 11B2.

Therefore, the upper end portions of the inner and outer walls 11B2 and 11B1 have a width larger than the gap between the inner and outer walls by horizontal and vertical bending, and the outer surface is outside the outer wall outer surface while the inner surface is flush with the inner wall inner surface. A tubular body having a downwardly open rectangular cross section protruding from the body is integrally formed, thereby improving the rigidity of the extruded shape member, that is, the rigidity of the suspension arm.

The suspension arm manufactured from the extruded shape member of the double wall structure as described above,

Manufacturing an aluminum alloy member in which double walls are erected on each of both ends of the width direction of the bottom plate having an extrudate shape by extrusion;

Solution treating the extruded shape member;

Cutting the extruded shape to an appropriate length and shape;

Making the top surface of the cut extruded shape fixed, and simultaneously attaching the upper mold of the suspension arm internal shape to the inside of the center of the extruded shape;

Press the bottom of the width direction central part of the bottom plate longitudinal direction E1 of the extruded shape member upward so that the top surface of the bottom plate coincides with the height of the top surface of the extruded shape material. Forming a connection mounting portion with the sub-frame, having a downwardly open " c "

Press the bottom of the widthwise center portion of the bottom plate in the longitudinal direction of the other side end portion E2 of the extruded shape member upward so that the top surface of the bottom plate is less than the height of the top surface of the extruded shape member. Forming a connection mounting portion with the wheel shaft having a downwardly open “-” cross-sectional shape;

Separating the upper mold from the inside of the center of the extruded shape member each having the mounting portions formed at both ends, and forming a coil spring seating groove G for shock absorber on the upper surface of the center of the bottom plate by punching;

And through each of the holes H penetrating the outer surface of the other outer wall from the outer surface of each of the one outer wall of the longitudinal mounting portion.

In this case, the steps of forming the sub-frame connection mounting portion and the wheel shaft connection mounting portion, respectively, may be changed in order, or may be performed at the same time.

In addition, in the said process of manufacturing a suspension arm, the step which cuts the upper and lower ends of each end part of the shaping | molding process member shown in FIG. 8, and made it into the shape shown in FIG. 1 was abbreviate | omitted.

The solution treatment is a heat treatment for supersaturating the alloying elements of the heat treatment type alloy, and is performed at 500 to 550 ° C. for 20 to 60 minutes, and the temperature is advantageously high if possible, but exceeds the melting temperature, or Care should be taken because there is a possibility of non-equilibrium melting without reaching the melting temperature.

In addition, the suspension arm after the forming process after the solution treatment is subjected to an aging treatment, thereby imparting appropriate mechanical properties.

As described above, since the method of the present invention is manufactured using an extruded shape member, the productivity is improved, and the suspension arm of the present invention manufactured by such a method is subjected to vibration and impact in the up, down, left, and right directions. Since it has a high rigidity, not only the shock absorbing ability can be improved, but also the fuel efficiency is improved because it is lighter than the forced suspension arm.

Claims (5)

In the manufacturing method of the suspension arm constituting the vehicle rear wheel suspension, Through the mold of the extruder, sidewalls perpendicular to both ends of the flat bottom plate are integrally formed, and each side wall is bent inward from the upper end of the outer wall, and the bottom wall is parallel to the outer wall after being bent inward from the upper end of the outer wall. Extruding a cross-sectional shape aluminum alloy extruded shape member having a double-wall structure consisting of an inner wall extending apart from the plate; Solution treating the extruded shape member; Cutting the extruded shape member; Fixing an upper surface of the cut extruded shape member and bringing the upper mold into close contact with the center of the extruded shape member; Pressing the bottom of the width direction central portion of the bottom plate in one longitudinal direction of the extruded shape member upwards to give the bottom plate a "c" shaped cross-sectional structure of the bottom open, and at the same time, the double wall of both ends are in close contact with the width direction central side. Forming a connection mounting portion with the subframe and the wheel shaft, respectively; Separating the upper mold from the extruded shape members each having mounting portions formed at both ends, and forming a coil spring seating groove on the upper surface of the center of the bottom plate; And a step of penetrating through the outer surface of each of the one side outer wall of each of the longitudinal mounting portions to penetrate through the outer surface of the other outer wall, respectively. According to claim 1, wherein the outer wall upstanding at each end in the width direction of the bottom plate is bent in the downward vertical direction after the sequential bending in the horizontal direction toward the outside, the vertical direction upward, the horizontal direction toward the inside at the upper end portion thereof. The inner wall is formed by the manufacturing method of the suspension arm for automobile rear wheel suspension apparatus. The upper end of the inner and outer walls has a width larger than the gap between the inner and outer walls by horizontal and vertical bending, and the inner surface forms the same surface as the inner wall inner surface, according to any one of claims 1 and 2. A method of manufacturing a suspension arm for a vehicle rear wheel suspension according to claim 1, wherein a tubular body having a downwardly open rectangular cross section whose side is protruded outward from the outer wall is formed integrally. The method of claim 1, wherein the extruded shape member is Si 0.95-1.05wt%, Mg 0.5-0.6wt%, Mn 0.5-0.6wt%, Fe 0.15-0.25wt%, Cr 0.13-0.18wt%, Cu 0.05wt% Below 0.03 wt% Ti and below 0.05 wt% Zn, and other unavoidable components are individually below 0.02 wt%, the sum of which is 0.10 wt% or less, and the remainder is made of an aluminum alloy composed of Al. The manufacturing method of the suspension arm for automobile rear wheel suspension to be used. Prepared by the method of claim 1, Si 0.95-1.05wt%, Mg 0.5-0.6wt%, Mn 0.5-0.6wt%, Fe 0.15-0.25wt%, Cr 0.13-0.18wt%, Cu 0.05wt% or less , Ti 0.03wt% or less, Zn 0.05wt% or less, and other unavoidable components are individually 0.02wt% or less, the sum is 0.10wt% or less, and the aluminum alloy is composed of the balance of Al Method for producing a suspension arm for rear suspension.

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