KR20240010671A - Vehicle control arm and manufacturing method thereof - Google Patents

Abstract

The hybrid type control arm constituting the vehicle suspension system according to the present invention includes a metal plate to maintain basic rigidity; and a composite material made of plastic resin and glass fiber to cover the outer surface of the plate, wherein the plate includes a plate body and a ball joint welded on the plate body, and the control arm includes the ball within the mold. The composite is joined by injection molding in a state in which the jointed plate is inserted and includes a welded joint between the plate body and the ball joint, and pores formed through surface treatment are formed between the joint surface of the plate and the composite. It is characterized by increased bonding force through.

Description

Vehicle control arm and manufacturing method thereof}

The present invention relates to a control arm constituting a vehicle suspension system and a method of manufacturing the control arm. In order to maintain basic rigidity, a steel plate made of high-strength steel material is placed inside, and the outer surface of the steel plate is covered. The catalog is about control arm technology combined using composite materials containing plastic resin and glass fiber.

The suspension system, which prevents vibration of the vehicle body while driving, includes springs, shock absorbers, and stabilizers and plays a role in improving the vehicle's ride comfort and stability.

The control arm is a member that controls the movement of the vehicle wheels, and is attached to the body or axle using a ball joint, pillow ball, or rubber bush. Control arms include A-shaped A-arms and I-shaped I-arms, and most are made by compressing steel plates, but there are also cases where they are produced using forging. Among the types of control arms, the upper arm is a pair of upper and lower arms, and the upper arm is called the upper arm, and the lower arm is called the lower arm.

When assembling a vehicle, one side of the control arm is connected to the steering knuckle through a ball joint, and the other side is connected to the frame through an axle with a bush. The control arm with the above assembly structure is connected to the wheel when the vehicle is running. Durability is required as force is transmitted in multiple directions simultaneously.

Referring to the existing Korean Patent Publication No. 10-2004-0106110 (Control Arm Structure of Suspension System), it is a control arm structure of a suspension system that can reduce the weight of the control arm, connecting the axle and the vehicle body, and connecting the axle to the vehicle body and the road surface during driving. It provides technical details to improve riding comfort and turning stability by absorbing vibration and shock, but does not specifically disclose a method of providing a control arm with a reduced overall weight by adding plastic materials to the existing steel plate. There is a limit in that it does not exist.

(Patent Document 1) KR 10-2004-0106110 A

In the present invention, in order to maintain basic rigidity, a steel plate made of a high-strength steel plate and a ball joint welded on the steel plate are placed inside the mold, and the overall mold includes a ball joint socket welded on the steel plate. The purpose is to provide a control arm in a hybrid form using a composite material containing plastic resin and glass fiber to cover the control arm.

In addition, in the present invention, a steel plate made of a high-tensile steel plate material and a ball joint welded on the steel plate are placed in an insert format in a mold, and a composite material is formed at the joint between the steel plate and the ball joint and on the steel plate. The purpose is to provide a method of manufacturing by injection molding.

A hybrid type control arm constituting a vehicle suspension system according to one aspect of the present invention to achieve the above object includes a metal plate for maintaining basic rigidity; and a composite material made of plastic resin and glass fiber to cover the outer surface of the plate, wherein the plate includes a plate body and a ball joint welded on the plate body, and the control arm includes the ball within the mold. It is characterized in that the composite material is joined by injection molding in a state in which the jointed plate is inserted and a welded joint area is included between the plate body and the ball joint socket.

On the inner surface of the plate, a plurality of ribs are arranged in a lattice or curved shape through the composite material to prevent stress concentration.

The plate includes a plate body 110 forming the basic skeleton of the plate, plate wings 120 extending in a vertical direction from both edges of the plate body 110, and an inner surface of the plate body 110. A convexly formed plate core 130, a first bushing coupling portion 140 disposed on one end of the plate body 110, and a second bushing coupling portion disposed on a side of the plate body 110 ( 150), a ball joint socket coupling portion 160 disposed on the other end of the plate body 110, and a plurality of bushes 170 and 180 coupled to the first and second bushing coupling portions 140 and 150, respectively, and the ball It includes a ball joint 190 coupled to the joint socket coupling portion 160.

The plate body 110 has a plurality of weight reduction holes 111 formed to penetrate the upper and lower surfaces along the longitudinal direction of the plate body 110, and a plurality of weight reduction holes 111 between the plurality of weight reduction holes 111 and the plate core 130. It includes a composite coupling hole 113 formed in.

The composite material includes a main composite material 210 coupled to the upper and lower surfaces of the plate body 110, a sub composite material 220 that surrounds the plate wing 120 and is connected to the main composite material 210, and the main composite material ( 210) a first rib composite 240 having a structure that interconnects a pair of sub-composites 220 facing each other on the top, and any one of the first and second bushing coupling parts 140 and 150 and the pair of It includes a second rib composite material 250 having a structure that interconnects one of the sub composite materials 220.

The penetrated inner surfaces of the first and second bushing coupling portions 140 and 150 are exposed without the composite material applied thereto.

A method of manufacturing a control arm according to another aspect of the present invention to achieve the above object includes preparing a high-tensile steel plate to maintain basic rigidity; engaging the socket end of the ball joint on the plate; Performing insert injection by inserting the plate into a mold and supplying a composite material by injection molding, including a weld joint between the plate and the ball joint; And a step of combining bushes on a plurality of bushing coupling portions forming the plate, wherein the insert injection progress step includes adding a composite material made of plastic resin and glass fiber to cover the entire outer surface of the plate made of steel. They are combined and manufactured using a hybrid joining method.

The step of coupling the socket end of the ball joint on the plate welds a plurality of welding points between the socket end of the ball joint and the ball joint coupling portion of the plate or performs fillet welding.

The composite material is PA66 or POM+G/F.

The control arm constituting the vehicle suspension device according to the present invention as described above maintains basic rigidity by placing a steel plate made of high-strength steel plate inside, and at the same time, the steel plate is molded while including a welded ball joint socket. The overall weight is reduced by combining a composite material containing plastic resin and glass fiber with a hybrid method to completely cover the steel plate, including a ball joint socket welded on the steel plate, using an insert molding method while placed inside. It achieves weight reduction and enables a simple production method.

The present invention performs insert molding on the welded portion of a ball joint socket, eliminating the creation of holes for existing bolting joints and increasing the strength of the insert structure during injection molding, providing a manufacturing method that can be stably fixed to the mold. There is an advantage.

Welding points are performed at three or more points or fillet welding around the contact area.

The ball joint socket is welded on the inside of the steel plate on the movable side of the mold reference.

The present invention reduces manufacturing costs by eliminating the assembly process and removal of fastening parts such as bolts and nuts for combining a composite arm and a ball joint, while the mechanical strength of the nut fastening surface is weak compared to the steel nut material during bolting. It is difficult to prevent damage to the composite structure or maintain an appropriate tightening force to secure the ball joint in the product use environment, which can prevent the composite arm and ball joint from separating.

The present invention is designed to prevent stress concentration by arranging a plurality of ribs made of composite material in a lattice or curved shape on the inner surface of the steel plate in consideration of the vehicle load, and the location and quantity may change depending on the vehicle load. You can.

The present invention maintains the inner surface of the bushing joint without coating a separate composite material during the process of coupling the bushing to the bushing joint forming the steel plate. In other words, the part of the steel plate where the bushing is joined is coated and molded with a composite material so that the steel on the inner side is exposed.

Figure 1 shows an upper perspective view showing a control arm with a ball joint coupled to a metal plate according to an embodiment of the present invention.
Figure 2 shows a perspective view of the control arm of Figure 1 viewed from one side of the lower part.
Figure 3 shows an upper perspective view showing the control arm in a state in which composite materials are joined by injection molding, including the welded joint between the plate and the ball joint.
Figure 4 shows a perspective view of the control arm of Figure 3 as seen from one side of the lower part.
Figure 5 shows a perspective view of the ball joint and bush in Figure 4 in a separated state.
Figure 6 shows a method of manufacturing a control arm constituting a vehicle suspension system according to the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and to convey the scope of the invention to those skilled in the art. It is provided for complete information. In the drawings, like symbols refer to like elements.

When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

The control arm constituting the vehicle suspension system according to the present invention has a steel plate made of high-strength steel for automobiles inserted inside to maintain basic rigidity, and is made of plastic resin and glass fiber to cover the entire outer surface of the steel plate. It provides a hybrid-type structure surrounded by composite materials.

Hereinafter, a control arm constituting a vehicle suspension system according to an embodiment of the present invention will be described with reference to the drawings.

The control arm has a hybrid structure including a metal plate 100 to maintain basic rigidity and a composite material 200 made of plastic resin and glass fiber to cover the entire outer surface of the plate.

The control arm combines a composite material by injection molding with a plate inserted into a mold, and the bonding force between the plate and the composite material is increased through pores formed through surface treatment.

The plate is a hot-rolled high-strength steel plate (STEEL PLATE) for automobiles and adopts SAPH or SPFH.

The bushing joint welded on the plate may be STKM or S20C.

The composite material is implemented in the shape of multiple ribs on the inner surface of the plate, and is specifically arranged in a grid or curved shape to prevent stress concentration. That is, a plurality of ribs are arranged on the inner surface of the plate in consideration of the vehicle load, and the location and quantity of the arrangement may be changed depending on the vehicle load.

The composite material may be PA66 + GLASS FIBER or POM + GLASS FIBER.

The plate 100 includes a plate body 110 forming a basic skeleton, plate wings 120 extending in a vertical direction from both edges of the plate body 110, and a convex shape on the inner surface of the plate body 110. A plate core 130 formed, a first bushing coupling portion 140 disposed on one side of the plate body 110, a second bushing coupling portion 150 disposed on a side of the plate body 110, and a plate. A ball joint socket coupling portion 160 disposed on the other end of the body 110, a plurality of bushes 170 and 180 and a ball joint socket coupling portion 160 respectively coupled to the first and second bushing coupling portions 140 and 150. It includes a ball joint 190 coupled to the top.

In the present invention, the second bushing coupling portion 150 and the first bushing coupling portion 140 represent the area near the front bush and the area near the rear bush, respectively, and the plate core 130 represents the inner area between the front bush and the rear bush. indicates the protruding area.

The plate body 110 has a plurality of weight reduction holes 111 formed to penetrate the upper and lower surfaces of the plate body 110 along the longitudinal direction, and is formed between the plurality of weight reduction holes 111 and the plate core 130. It includes a composite coupling hole 113.

A plurality of weight reduction holes 111 are sequentially spaced apart from the ball joint socket coupling portion 160 on the plate body 110. Exemplarily, the plurality of weight reduction holes 111 are a first weight reduction hole 111a spaced apart from the ball joint socket coupling portion 160 by a first distance, and a second distance away from the first weight reduction hole 111a. a second weight reduction hole (111b), a third weight reduction hole (111c) spaced a third distance away from the second weight reduction hole (111b), and a fourth weight spaced apart from the third weight reduction hole (111c) by a fourth distance. It may include a reduction hole (111d). Here, the first to fourth distances may be the same or different.

As described above, the present invention implements a topology optimal design that creates a number of weight reduction holes to reduce weight.

Meanwhile, preferably, the diameter of the plurality of weight reduction holes 111 gradually increases from the first weight reduction hole 111a to the fourth weight reduction hole 111d. That is, the diameter of the weight reduction hole may gradually increase starting from the ball joint socket coupling portion 160 and moving toward the first bushing coupling portion 140.

The composite coupling hole 113 enables stable coupling of the composite material by completely filling the composite material bonded on both sides of the plate body 110. The composite coupling hole 113 is formed to be smaller than the diameter of any weight reduction hole among the plurality of weight reduction holes 111. In other words, the composite coupling hole 113 is not intended to reduce the weight of the plate body 110, but mainly serves the function of strengthening the binding of the coupling material through the plate core 130.

The composite material includes a main composite material 210 coupled to the upper and lower surfaces of the plate body 110, a sub composite material 220 that surrounds the plate wing 120 and is connected to the main composite material 210, and a main composite material 210. The first rib composite 240, which has a structure that interconnects a pair of facing sub-composites 220, one of the first and second bushing coupling parts 140 and 150, and one of the sub-composite materials 220. It includes a second rib composite 250 having a structure that interconnects the sub-composites, and a slimming molding portion 260 disposed between the fourth weight reduction hole 111d and the second bushing coupling portion 150.

The first rib composite 240 passes through a direct connection rib 241 and a plurality of weight reduction holes 111 that connect a pair of facing sub-composites 220 without passing through a plurality of weight reduction holes 111. It includes an indirect connection rib 243 that connects a pair of sub-composite materials 220 facing each other.

The second rib composite 250 includes a protruding rib 251 and a protruding rib ( 251) and a reinforcing rib 253 connecting any one of the sub-composites 220 facing each other.

The protruding rib 251 functions to separate the area of the plate body 110 from the first bushing coupling portion 140 to the fourth weight reduction hole 111d. That is, specifically, an area on the plate core 130 formed convexly on the inner surface of the plate body 110 is separated.

The reinforcing ribs have an overall zigzag shape, and the area where the reinforcing ribs 253 are located is formed larger among the areas between the sub-composites 220 on both opposing sides. That is, specifically, the structure may be such that the reinforcing rib 253 is located on one side of the protruding rib 251, and no separate rib exists on the other side.

The penetrated inner surfaces of the first and second bushing coupling portions 140 and 150 are exposed without the composite material applied thereto. The first and second bushing coupling portions 140 and 150 have cylindrical tubes welded together, and this enables coupling of a cylindrical bushing to the tube.

The ball joint socket coupling portion 160 corresponds to the end of the plate body 110 and enables coupling of the ball joint 190 equipped with a ball stud.

The seating groove 161 is formed in a semicircle-like depression on the central point of the end of the plate body 110. The ball joint 190 includes a socket 191 that surrounds a ball stud and a socket end 193 extending from the outer surface of the socket 191, and the socket end 193 is a ball joint socket coupling portion 160. ) are joined through welding.

When welding the socket end 193 to the ball joint socket coupling portion 160, three or more points of the socket end 193 must be welded, or the socket end 193 and the ball joint socket coupling portion 160 may be in contact. Fillet welding is performed along the area.

Here, the socket end 193 may be welded to the inside of the plate body 110. That is, welding is performed on the movable side of the mold base.

The socket end 193 of the ball joint 190 is welded and joined to the plate body 110 made of steel, and then the insert is injection-molded with the socket end 193 included.

As described above, by welding only a portion of the socket constituting the ball joint 190, the creation of holes for bolting between the ball joint and the plate body is eliminated, and at the same time, the strength of the insert structure is increased during injection molding, thereby stably forming the mold. There is a manufacturing advantage in that it can be fixed to.

Through this, the weight of the socket end 193 made of steel is reduced by removing coupling means such as bolts, and costs are reduced by eliminating fastening parts such as bolts and nuts, and compared to the steel that forms the nut fastening part during bolting. Prevents damage to relatively weak composite structures.

Surface treatment between the plate and the composite material is performed using the MPA method. The surface treatment may be a metal & plastics adhesion (MPA) technology, which improves the processing process of cases and interior parts that require slimming and lightweighting, and produces a plate by pressing the supplied plate material. Afterwards, three stages of MPA treatment are performed: degreasing, processing, and washing. This allows bosses or ribs to be formed directly on metal materials without using double-sided tape or bonds, and has excellent airtightness and waterproof performance, so it can replace aluminum welding, which is expected to improve productivity and reduce manufacturing costs by reducing the process.

Hereinafter, the manufacturing method of the control arm constituting the vehicle suspension system of the present invention will be described with reference to FIG. 6.

First, a high-strength steel plate is prepared to maintain basic rigidity.

A steel core plate is formed to form weight reduction holes and composite joining holes.

The socket of the ball joint is welded and joined on the ball joint coupling part forming the plate.

The plate is inserted and seated on the mold, including the welded joint between the plate and the ball joint socket, and the composite material is supplied by injection molding with the mold preheated to 120 to 150 degrees to perform insert injection.

Assemble the ball stud, plug, and boot in the above condition.

A plurality of bushes are respectively coupled to the plurality of bushing coupling portions forming the plate.

The insert injection process is performed using a hybrid bonding method by combining a composite material made of plastic resin and glass fiber to cover the entire outer surface of the plate made of steel.

As described above, the control arm constituting the vehicle suspension device according to the present invention maintains basic rigidity by placing a steel plate made of high-strength steel plate inside, and is performed by insert molding with the steel plate placed in a mold. By combining a composite material containing plastic resin and glass fiber with the outer surface of the steel plate in a hybrid method, the overall weight is reduced, making it lightweight, and enabling a simple production method.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

Claims (7)

Plate made of metal to maintain basic rigidity; and
In the hybrid type control arm including a composite material made of plastic resin and glass fiber to cover the outer surface of the plate,
The plate includes an inside of the plate body and a ball joint socket welded on the inside of the plate body,
The plate body 110 has a plurality of weight reduction holes 111 formed to penetrate the upper and lower surfaces along the longitudinal direction of the plate body 110, and a plurality of weight reduction holes 111 between the plurality of weight reduction holes 111 and the plate core 130. It includes a composite coupling hole 113 formed in,
The plurality of weight reduction holes 111 have a structure whose diameter gradually increases from the first weight reduction hole 111a to the fourth weight reduction hole 111d, and are disposed on the other end of the plate body 110. Starting from the ball joint socket coupling portion 160, the diameter of the weight reduction hole gradually increases toward the first bushing coupling portion 140 disposed on one side of the plate body 110,
The composite coupling hole 113 is formed to be smaller than the diameter of any weight reduction hole among the plurality of weight reduction holes 111, so that the composite material coupled to both sides of the plate body 110 completely fills the composite material. It enables stable combination of
The control arm is a form in which the composite material is combined by injection molding with a plate coupled to the ball joint socket inserted into the mold and a welded joint between the plate body and the ball joint socket.
A control arm that makes up the vehicle suspension system.
According to claim 1,
On the inner surface of the plate, a plurality of ribs are arranged in a grid or curved shape through the composite material to prevent stress concentration.
A control arm that makes up the vehicle suspension system.
According to claim 1,
The plate is,
Plate body 110 forming the basic skeleton of the plate, plate wings 120 extending in a vertical direction from both edges of the plate body 110, and convexly formed on the inner surface of the plate body 110 A plate core 130, a first bushing coupling portion 140 disposed on one side of the plate body 110, a second bushing coupling portion 150 disposed on a side of the plate body 110, A ball joint socket coupling portion 160 disposed on the other end of the plate body 110 and a plurality of bushes 170 and 180 respectively coupled to the first and second bushing coupling portions 140 and 150 and the ball joint socket coupling portion. Comprising a ball joint (190) coupled to (160),
A control arm that makes up the vehicle suspension system.
According to claim 1,
The composite material,
A main composite material 210 coupled to the upper and lower surfaces of the plate body 110,
A sub-composite material 220 that surrounds the plate wing 120 and is connected to the main composite material 210,
A first rib composite 240 having a structure that interconnects a pair of sub-composites 220 facing each other on the main composite 210, and
A second rib composite 250 having a structure that interconnects one of the first and second bushing coupling parts 140 and 150 and one of the pair of sub composites 220,
A control arm that makes up the vehicle suspension system.
According to claim 3,
The pierced inner surfaces of the first and second bushing coupling portions 140 and 150 are exposed without the composite material applied,
A control arm that makes up the vehicle suspension system.
According to claim 3,
The surface treatment carried out between the bonding surface of the plate and the composite material is carried out by the MPA method,
A control arm that makes up the vehicle suspension system.
In the method of manufacturing the control arm according to claim 1,
Preparing a high-strength steel plate to maintain basic rigidity;
welding the socket of the ball joint on the plate;
Performing insert injection by inserting the plate into a mold and supplying a composite material by injection molding, including a weld joint between the plate and the ball joint; and
Comprising: coupling bushes to each of the plurality of bushing coupling parts forming the plate,
Before injection forming, the mold is preheated to 120 to 150 degrees.
The insert injection process is performed by combining a composite material made of plastic resin and glass fiber to cover the entire outer surface of the plate made of steel, using a hybrid bonding method.
Manufacturing method of control arm.