Patent Description:
A vehicular suspension system is an apparatus which connects a wheel to a vehicular body. The vehicular suspension system includes a spring which absorbs vibration or impact transmitted from a road surface to a vehicular body, a shock absorber which adjusts an action of the spring, and a suspension arm or suspension link which controls an operation of the wheel.

By way of example, types of suspension systems for controlling the operation of a vehicular wheel include a swing arm type, a wishbone type, a McPherson strut type or the like. A suspension system using a wishbone type control includes a suspension arm (lower control arm) which connects a knuckle fastened to a vehicular wheel to a vehicular body. That is, one end of the suspension arm is connected to a cross member or a subframe which constitutes the vehicular body, while the other end of the suspension arm is connected to the knuckle via a ball joint. With this configuration, the suspension arm allows the vehicular wheel to be supported by the vehicular body, and appropriately controls the toe-in of the vehicular wheel in accordance with the running status of a vehicle, thereby improving the straight running performance and the steering stability of the vehicle.

The suspension arm has been manufactured in a casting type method and a press type method. Specifically, according to the casting type method, the suspension arm is manufactured by being molded by pouring molten steel or molten aluminum into a metal mold and then solidifying the molten steel or aluminum. Further, according to the press type method, the suspension arm is manufactured by fabricating an upper plate and a lower plate from a steel plate made of a steel material by a press, and welding the upper plate and the lower plate.

In the suspension arm manufacturing method, the suspension arm is fabricated from a steel casting, or the upper and lower plates are fabricated from a steel material by a press method and the upper and lower plates are welded thereafter. The foregoing methods are problematic since the weight of the suspension arm is heavy due to the characteristics of steel, a lot of manufacturing processes are required, and rigidity weakness and deformation may occur due to the welding of the steel plates. <CIT> discloses a vehicular hybrid suspension arm, comprising a suspension arm body made of a steel material, wherein a non-metal body is attached to said steel material.

Various embodiments of the present disclosure propose a vehicular hybrid suspension arm made of a composite material to solve the problems of the steel-made suspension arm and to achieve weight reduction.

Further, various embodiments of the present disclosure increase the rigidity of a vehicular hybrid suspension arm, prevents the strength decrease caused by the injection weld line of a plastic molding, and reduces the possibility of corrosion.

According to the present invention, a vehicular hybrid suspension arm as defined in claim <NUM> is provided to solve the above problems and achieve the above effects. The dependent claims show some examples of such a vehicular hybrid suspension arm, which may also be as follows.

The coupling portion may include a flange structure. The flange structure may include: a coupling flange formed to be bent inward in a width direction of the suspension arm body; and a fixing portion which is a portion of the insert molding and into which the coupling flange is inserted.

The reinforcement structure includes a reinforcement member which is inserted into and fixed to the suspension arm body and is in contact with the insert molding.

The reinforcement member may be disposed in a cross-sectional direction of the suspension arm body, and the insert molding may surround the reinforcement member.

At least one hole may be formed in the reinforcement member, and the insert molding may extend through the hole.

The reinforcement member may be disposed in a direction parallel to the suspension arm body, and a portion of the insert molding may be inserted into and coupled to the reinforcement member.

A distal end of the reinforcement member may be formed to be bent inward in a width direction of the reinforcement member.

The coupling portion may include a button structure. The button structure may include: one or more holes formed in the suspension arm body; and one or more buttons which are formed from the insert molding and are inserted into and fill in the one or more holes. The buttons may be enlarged up to peripheral edges of the one or more holes.

The suspension arm body may include two leg portions.

A bush coupling protrusion portion having a pipe shape may be integrally formed with one of the two leg portions, and the insert molding may be inserted into and coupled to the bush coupling protrusion portion.

The insert molding may be coupled to the other of the two leg portions by injection, and a ball joint may be inserted into and integrally coupled to a coupling leading end portion of the insert molding by injection.

The reinforcement member may have a plate shape.

The reinforcement member may include at least two plates connected to each other.

At least a portion of the reinforcement member may have a bent shape.

At least a portion of the reinforcement member may be embedded by the insert molding.

The suspension arm body may include an upper surface and a side surface extending from the upper surface. One surface of the reinforcement member may be in contact with the upper surface of the suspension arm body, and the other surface of the reinforcement member may be in contact with the side surface of the suspension arm body.

The suspension arm body may include two leg portions integrally formed with each other. A ball joint may be coupled to a leading end portion of one of the two leg portions, and a bush hole may be formed at a leading end portion of the other of the two leg portions.

The reinforcement member may be disposed to extend over a portion of one of the two leg portions and a portion of the other of the two leg portions.

The insert molding may include a reinforcement rib formed in at least a portion of at least one of the two leg portions.

According to one embodiment of the present disclosure, the suspension arm body made of a steel material is provided at the outer side, while the insert molding is disposed at the inner side. Thus, the section modulus of the steel-made suspension arm body can be sufficiently ensured, thereby increasing the rigidity.

Further, unnecessary portions that do not affect the rigidity are removed from the insert molding. Thus, the weld line of an injected article is reduced and the occurrence of cracks in the insert molding is suppressed as far as possible, thereby increasing rigidity and improving durability.

Further, due to the reduction in weight and the increase in rigidity in the hybrid-type suspension arm, the ride quality and the steering stability of the vehicle can be improved.

The embodiments shown in <FIG> and <FIG> do not form part of the invention, but represent examples, which are useful for understanding the claimed invention.

Embodiments of the present disclosure are illustrated for the purpose of explaining the technical idea of the present disclosure.

All technical and scientific terms used in the present disclosure have the meaning generally understood by those of ordinary skill in the art to which the present disclosure pertains, unless otherwise defined. All terms used in the present disclosure are chosen for the purpose of more clearly describing the present disclosure and are not chosen to limit the scope of rights according to the present disclosure.

As used in the present disclosure, expressions such as "comprising", "including", "having", and the like are to be understood as open-ended terms having the possibility of encompassing other embodiments, unless otherwise mentioned in the phrase or sentence containing such expressions.

The singular form described in the present disclosure may include a plural meaning, unless otherwise mentioned. This applies equally to the singular form recited in the claims.

In the present disclosure, where it is mentioned in the present disclosure that one element is "connected" to another element, it is to be understood that said one element may be directly connected to said another element, or may be connected to said another element via a new additional element.

Hereinafter, descriptions are made as to embodiments of the present disclosure with reference to the accompanying drawings. In the accompanying drawings, the same or corresponding elements are denoted by the same reference numerals. In the following descriptions of the embodiments, descriptions of the same or corresponding elements may be omitted. However, even if the descriptions of elements are omitted, it is not intended that such elements are not included in a certain embodiment.

<FIG> is a perspective view of a vehicular hybrid suspension arm <NUM> manufactured by a manufacturing method according to the present disclosure, and <FIG> is an exploded perspective view of the suspension arm <NUM> shown in <FIG>.

The vehicular hybrid suspension arm <NUM> may include a suspension arm body <NUM> which can be fabricated from a high tensile steel plate for a vehicle through a general press method.

The suspension arm body <NUM> may have a shape such as, for example, a U-like shape. The U-shaped suspension arm body <NUM> may be used as, for example, an upper control arm of a suspension system, but is not necessarily limited thereto.

The suspension arm body <NUM> may include two leg portions <NUM> and a joint portion <NUM> integrally connecting the two leg portions <NUM>. A bush pipe <NUM> may be coupled to each of leading end portions of the two leg portions <NUM> by welding, and a ball joint pipe <NUM> may be coupled to a leading end portion of the joint portion <NUM> by welding.

Specifically, a generally semi-cylindrical coupling hole is formed at the leading end portion of the joint portion <NUM>, and each of the pipes <NUM>, <NUM> is disposed to fit into the coupling hole. Each of the pipes <NUM>, <NUM> and the coupling hole may be coupled together by welding.

The ball joint pipe <NUM> may be located in a central portion between the bush pipes <NUM>. The bush pipes <NUM> may be disposed to be opened in the horizontal direction, while the ball joint pipe <NUM> may be disposed to be opened in the vertical direction.

Bushes <NUM> may be force-fitted into the respective two bush pipes <NUM>. The respective bushes <NUM> may be fastened to a vehicular body with a bolt or the like.

A ball joint <NUM> may be force-fitted into the ball joint pipe <NUM>. The specific structure of the ball joint <NUM> is shown in <FIG> and <FIG>.

The ball joint <NUM> may include: a ball stud <NUM>; a ball bearing <NUM> which surrounds and rotatably supports the ball stud; a dust cover <NUM> which surrounds the ball stud <NUM> to prevent intrusion of foreign matter; a ring clip <NUM> for assembling the dust cover <NUM> to the ball stud <NUM>; and a protector <NUM> covered on the ball stud <NUM> from the opposite side of the ball bearing <NUM>.

A large-diameter hole <NUM> having a relatively large diameter may be formed through the joint portion <NUM>. A plurality of middle-diameter holes <NUM> and a plurality of small-diameter holes <NUM> may be disposed in each leg portion <NUM> with predetermined spacings along a longitudinal direction of the leg portion. The diameter increases in the order of the small-diameter hole <NUM>, the middle-diameter hole <NUM> and the large-diameter hole <NUM>. The middle-diameter holes <NUM> may be disposed between the small-diameter holes <NUM>. The number of the middle-diameter holes <NUM> and the small-diameter holes <NUM> may be appropriately adjusted as needed.

An insert molding <NUM> may be coupled to the suspension arm body <NUM>.

The insert molding <NUM> may have a shape approximately similar to that of the suspension arm body <NUM>. That is, the insert molding <NUM> may include two leg portions <NUM> and a joint portion <NUM> interconnecting the two leg portions <NUM>. A large-diameter hole <NUM> may be formed through the joint portion <NUM>.

An edge of the large-diameter hole <NUM> of the joint portion <NUM> is formed with a large-diameter coupling rim <NUM> which is enlarged in a thickness direction and a radial direction. The large-diameter coupling rim <NUM> is formed such that, when the insert molding <NUM> is injected, the large-diameter coupling rim <NUM> is disposed along a peripheral edge of the large-diameter hole <NUM> of the suspension arm body <NUM>. Thus, the large-diameter coupling rim <NUM> increases a coupling force between the suspension arm body <NUM> and the insert molding such that the insert molding <NUM> inserted into the suspension arm body <NUM> is not separated from the suspension arm body <NUM>.

A plurality of buttons <NUM> may be formed in each of the leg portions <NUM> of the insert molding <NUM> at predetermined spacings along a longitudinal direction.

When the insert molding <NUM> is injected, the respective buttons <NUM> may be inserted into the small-diameter holes <NUM>, which are formed in each leg portion <NUM> of the suspension arm body <NUM>, to fill in the small-diameter holes <NUM>. When injection-molding the insert molding, the respective buttons <NUM> may be formed to have a size radially enlarged up to peripheral edges of the small-diameter holes <NUM>. The respective buttons <NUM> may increase the coupling force between the suspension arm body <NUM> and the insert molding <NUM>.

Further, when the insert molding <NUM> is injected, a middle-diameter coupling rim <NUM>, which is formed between the two buttons <NUM>, may be formed to be radially enlarged up to a peripheral edge of each of the middle-diameter holes <NUM> formed in each leg portion <NUM> of the suspension arm body <NUM>. Thus, the middle-diameter coupling rim <NUM> may increase the coupling force between the suspension arm body <NUM> and the insert molding <NUM>.

<FIG> is a rear view of the vehicular hybrid suspension arm <NUM> manufactured by the manufacturing method, and <FIG> is a sectional view taken along a line A-A in <FIG>.

One or more reinforcement ribs <NUM> having a generally lattice-patterned shape may be protrudingly formed in the insert molding <NUM> integrally with the insert molding <NUM>. The shape of such reinforcement ribs <NUM> may be determined by using a computer optimum design program so that a weight of the insert molding <NUM> can be minimized.

Referring to <FIG>, the suspension arm body <NUM> may include two coupling flanges <NUM> which are bent inward in a width direction of the suspension arm body. Each of the coupling flanges <NUM> may have a shape that is bent inward from a lateral distal end portion of each leg portion <NUM>.

The two coupling flanges <NUM> are formed to face each other. When the insert molding <NUM> is injected, the coupling flanges <NUM> are inserted into the inside of the insert molding <NUM>, i.e., the fixing portions 20a which are a portion of the insert molding <NUM>, and to which the coupling flanges <NUM> are inserted.

According to the above-described structure, an upper surface, a lower surface and a side surface of the coupling flanges <NUM> are supported by the fixing portions 20a. Therefore, there is no possibility that a gap occurs between the insert molding <NUM> and the coupling flanges <NUM>. Further, even if a crack occurs in the insert molding <NUM>, it is very unlikely that the insert molding <NUM> is separated from the suspension arm body <NUM>. Accordingly, the coupling force between the suspension arm body <NUM> and the insert molding <NUM> is increased.

<FIG> is a sectional view of the ball joint <NUM> of the vehicular hybrid suspension arm <NUM>.

Referring to <FIG>, as the insert molding <NUM> is injected in the state where the ball joint <NUM> is force-fitted into the ball joint pipe <NUM> of the suspension arm body <NUM>, the ball joint <NUM> may be integrally coupled to the ball joint pipe <NUM> by the insert molding <NUM>.

The insert molding <NUM> may surround the ball bearing <NUM> while also going between the ball bearing <NUM> and the ball joint pipe <NUM>. After the insert molding solidifies, the insert molding <NUM> may firmly fix the ball bearing <NUM> to the ball joint pipe <NUM>. The ball bearing <NUM> surrounds a spherical portion of the ball stud <NUM>. The dust cover <NUM> surrounds a stick portion of the ball stud <NUM> such that dust does not enter the ball bearing <NUM>.

<FIG> is an assembly view showing fabrication procedures of a manufacturing method (S100) of the vehicular hybrid suspension arm <NUM>. <FIG> is a flowchart of the manufacturing method (S100) of the vehicular hybrid suspension arm manufacturing method <NUM>.

Referring to <FIG> and <FIG>, according to the vehicular hybrid suspension arm manufacturing method, first, the ball stud <NUM> is fabricated by using a steel material (S110), and then the ball bearing <NUM> is fabricated by using plastic (S120), and thereafter the ball bearing <NUM> and the ball stud <NUM> are assembled by coupling the ball bearing <NUM> to the ball stud <NUM> (S130). At this time, to improve the performance of the ball bearing <NUM>, lubricant may be injected between the ball bearing <NUM> and the ball stud <NUM>.

Then, the suspension arm body <NUM> is fabricated by using a steel plate (S140), the pipes <NUM> and <NUM> are attached to the suspension arm body <NUM> by welding (S150), and the ball joint pipe <NUM> and the assembly of the ball stud <NUM> and the ball bearing <NUM> is assembled by force-fitting the assembly of the ball stud <NUM> and the ball bearing <NUM> into the ball joint pipe <NUM> (S160).

Subsequently, the suspension arm body <NUM> and the insert molding <NUM> are coupled to each other by inserting the suspension arm body <NUM> into a metal mold and injecting plastic resin (S170).

Then, the bush <NUM> and the bush pipe <NUM> are assembled by force-fitting the bush <NUM> into the bush pipe <NUM> (S180). The ball stud <NUM> is covered by the dust cover <NUM>, and the dust cover <NUM> is fixed by the ring clip <NUM> (S190), thereby completing the fabrication process of the suspension arm.

<FIG> is a perspective view of a vehicular hybrid suspension arm <NUM>. <FIG> is an exploded perspective view of the vehicular hybrid suspension arm <NUM> shown in <FIG>. <FIG> is a sectional view taken along a line B-B in <FIG> when the suspension arm is assembled.

Referring to <FIG>, the vehicular hybrid suspension arm <NUM> may be applied to a lower control arm. The lower control arm may have, for example, a λ-like shape.

The vehicular hybrid suspension arm <NUM> may include a suspension arm body <NUM>. The suspension arm body <NUM> may be fabricated from a high tensile steel plate for a vehicle through a press method. An insert molding <NUM> may be integrally coupled to the inside of the suspension arm body <NUM> by injection.

The suspension arm body <NUM> may include two leg portions <NUM>, <NUM> which are integrally connected to each other. A bush coupling protrusion portion <NUM> having a pipe shape may be integrally formed with one of the leg portions <NUM>. An insert molding <NUM> may be inserted into and coupled to the bush coupling protrusion portion <NUM>. A bush (not shown) may be coupled to the bush coupling protrusion portion <NUM> and may be mounted on a vehicular body.

The bush coupling protrusion portion <NUM> may have a tubular shape with a hollow interior. The insert molding <NUM> may include a filling rod 316a that may be inserted into an empty space of the bush coupling protrusion portion <NUM>. When the insert molding <NUM> is injected, the filling rod 316a may be formed while filling in the empty space of the bush coupling protrusion portion <NUM>.

The empty space of the bush coupling protrusion portion <NUM> may be completely filled with the filling rod 316a. Therefore, when compared with a case where the bush coupling protrusion portion is made of only steel, the bush coupling protrusion <NUM> may be reduced in weight and may be improved in bending and torsional strength.

The insert molding <NUM> may be coupled to the other of the leg portions <NUM> by injection. A ball joint <NUM> may be inserted into a coupling leading end portion of the insert molding <NUM> of the other leg portion <NUM> and may be integrally coupled to the coupling end by injection.

A large-diameter hole <NUM> is formed in a central portion of the λ-shaped suspension arm body <NUM>. The large diameter hole <NUM> may be disposed between the bush coupling protrusion portion <NUM> and the ball joint <NUM> and may be formed on one side surface of the suspension arm body <NUM>. A bush (not shown) may be force-fitted into and coupled to the large-diameter hole <NUM>.

To increase the coupling performance between the suspension arm body <NUM> and the insert molding <NUM>, one or more middle-diameter holes <NUM> may be formed in the suspension arm body <NUM>. Further, one or more buttons <NUM> may be formed in the insert molding <NUM> in such a manner that the buttons <NUM> fill in the middle-diameter holes <NUM> and are radially enlarged up to peripheral edges of the middle-diameter holes <NUM>.

One or more small-diameter holes <NUM> may be formed in the suspension arm body <NUM> and one or more small-diameter coupling rims <NUM> may be formed in the insert molding <NUM> so as to be radially enlarged up to peripheral edges of the small-diameter holes <NUM>.

The suspension arm body <NUM> may be formed with a recess portion <NUM> which is recessed throughout upper surfaces of the two leg portions <NUM>, <NUM>. The recess portion <NUM> may be formed in a separate form on the upper surfaces of the two leg portions <NUM>, <NUM>, or may be formed on only one leg portion. The recess portion <NUM> may increase the rigidity of the suspension arm body <NUM> itself. Further, at least one small-diameter hole <NUM> may be formed in the recess portion <NUM>.

The insert molding <NUM> is inserted between a portion bent by the recess portion <NUM> and the side surfaces of the two leg portions <NUM>, <NUM>. During a cooling process, the insert molding <NUM> is contracted, and the insert molding <NUM> may exert a force which tightens the above-mentioned bent portion. Therefore, the coupling force between the insert molding <NUM> and the suspension arm body <NUM> can increase.

The above-described structure related to the recess portion <NUM> may also be applied to the hybrid suspension arm <NUM> described above and a hybrid suspension arm <NUM> to be described below.

Referring to <FIG>, the suspension arm body <NUM> may be formed with two coupling flanges <NUM> which are bent inward in a width direction of the suspension arm body. The two coupling flanges <NUM> may be formed to face each other. Thus, when the insert molding <NUM> is injected, the two coupling flanges <NUM> may be inserted into the insert molding <NUM> in such a manner that the two coupling flanges are stuck into the inside of the insert molding. Therefore, the coupling force between the suspension arm body <NUM> and the insert molding <NUM> can be increased.

<FIG> is a perspective view of a vehicular hybrid suspension arm <NUM>. <FIG> is an exploded perspective view of the vehicular hybrid suspension arm <NUM> shown in <FIG>. <FIG> is a sectional view taken along a line C-C in <FIG>.

Referring to <FIG>, the vehicular hybrid suspension arm <NUM> may be applied to a lower control arm.

The vehicular hybrid suspension arm <NUM> may include a suspension arm body <NUM> and an insert molding <NUM>. The suspension arm body <NUM> can be fabricated from a high tensile steel plate for a vehicle through a press method. The insert molding <NUM> may be formed in the inner side of the suspension arm body <NUM> by injection and may be integrally coupled to the suspension arm body <NUM>.

The suspension arm body <NUM> may include two leg portions <NUM>, <NUM>. The insert molding <NUM> may be coupled to one leg portion <NUM> by injection. The ball joint <NUM> may be inserted into a coupling leading end portion of the insert molding <NUM> and may be integrally coupled to the coupling end by injection. A large-diameter bush coupling hole <NUM> is formed in a leading end portion of the other leg portion <NUM>. A bush (not shown) may be force-fitted into and coupled to the large-diameter bush coupling hole <NUM>.

A bush pipe <NUM> may be integrally coupled to a corner where the two leg portions <NUM>, <NUM> meet. Substantially, the bush pipe <NUM> may be disposed between the ball joint <NUM> and the large-diameter bush coupling hole <NUM>.

To increase the coupling performance between the suspension arm body <NUM> and the insert molding <NUM>, a middle-diameter hole <NUM> may be formed in an upper surface of the suspension arm body <NUM>, and the middle-diameter hole <NUM> may be located adjacent to a middle section when an entire length of the suspension arm body is trisected. A middle-diameter hole flange <NUM>, which is bent toward the inside of the insert molding <NUM>, may be formed in the upper surface of the suspension arm body <NUM>.

The insert molding <NUM> may include a flange cover portion <NUM> which surrounds such a middle-diameter hole flange <NUM>. When the insert molding <NUM> is injected, the flange cover portion <NUM> may be enlarged from an end of the middle-diameter hole flange <NUM> until the flange cover portion covers a portion of the upper portion of the suspension arm body <NUM>. Thus, the flange cover portion <NUM> surrounds the middle-diameter hole flange <NUM>, thereby increasing the coupling performance between the insert molding <NUM> and the suspension arm body <NUM>.

Further, to increase the coupling performance between the suspension arm body <NUM> and the insert molding <NUM>, one or more small-diameter holes <NUM> may be formed through the two leg portions <NUM>, <NUM>. One or more buttons <NUM> may be formed in the insert molding <NUM> in such a manner that the buttons fill in one or more small-diameter holes <NUM> and are radially enlarged up to peripheral edges of the small-diameter holes <NUM>.

As shown in <FIG>, two coupling flanges <NUM>, which are bent inward in a width direction of the suspension arm body <NUM>, may be formed in the suspension arm body <NUM>. The two coupling flanges <NUM> may be formed to face each other. When the insert molding <NUM> is injected, the two coupling flanges <NUM> may be inserted into the insert molding <NUM> in such a manner that the two coupling flanges <NUM> are stuck into the inside of the insert molding <NUM>, thereby increasing the coupling force between the suspension arm body <NUM> and the insert molding <NUM>.

To prevent separation between the suspension arm body and the insert molding, the above-described vehicular hybrid suspension arm <NUM>, <NUM>, <NUM> includes a coupling portion in which the suspension arm body and a portion of the insert molding intersect with each other.

For example, the coupling portion includes a reinforcement structure and further may include a flange structure, a button structure, or the like. However, the coupling portion is not limited to the aforementioned structure. Any structure may be applied as long as it is capable of increasing the coupling force between the suspension arm body and the insert molding.

The flange structure, the button structure and the reinforcement structure may be overlappingly applied to the vehicular hybrid suspension arm <NUM>, <NUM>, <NUM>. That is, there may be provided an embodiment of the vehicular hybrid suspension arm <NUM>, <NUM>, <NUM> to which the flange structure and the button structure are applied, an embodiment of the vehicular hybrid suspension arm <NUM>, <NUM>, <NUM> to which the flange structure and the reinforcement structure are applied, an embodiment of the vehicular hybrid suspension arm <NUM>, <NUM>, <NUM> to which the button structure and the reinforcement structure are applied, or an embodiment of the vehicular hybrid suspension arm <NUM>, <NUM>, <NUM> to which all of the flange structure, the button structure and the reinforcement structure are applied.

Detailed descriptions have been made as to the flange structure including the coupling flanges <NUM>, <NUM>, <NUM> and the button structure including the buttons <NUM>, <NUM>, <NUM> with reference to <FIG>. Hereinafter, descriptions are made as to the reinforcement structure with reference to <FIG>.

<FIG> is a bottom view of the suspension arm body <NUM> provided with a reinforcement member <NUM>. <FIG> is a bottom view of the vehicular hybrid suspension arm <NUM> provided with the reinforcement member <NUM>. <FIG> is a sectional view taken along a line A-A' in <FIG>, and <FIG> is a sectional view taken along a line B-B' in <FIG>. The suspension arm body <NUM> shown in <FIG> may have the same shape as the upper arm shown in <FIG>.

Referring to <FIG> and <FIG>, at least one reinforcement member <NUM> may be inserted into a C-shaped space formed by the suspension arm body <NUM> and may be welded and coupled to both inner side surfaces of the suspension arm body <NUM>.

The reinforcement member <NUM> may be made of the same metal material as the suspension arm body <NUM> and may be made of, for example, a steel material. Further, to reduce the weight of the reinforcement member <NUM>, the reinforcement member <NUM> may be made of aluminum.

The reinforcement member <NUM> may have a plate shape. At least a portion of the reinforcement member <NUM> may be embedded by the insert molding <NUM>. The insert molding <NUM> may surround the reinforcement member <NUM>.

The reinforcement member <NUM> may be disposed in a cross-sectional direction of the leg portion of the suspension arm body <NUM>. For example, three reinforcement members <NUM> may be provided for each leg. The reinforcement members <NUM> may be provided not only in a direction perpendicular to the longitudinal direction of the leg portion, but also in a direction oblique to the longitudinal direction of the leg portion.

Referring to <FIG>, an upper end of the reinforcement member <NUM> may not be coupled to an inner upper surface of the suspension arm body <NUM>. A space having a certain size may be provided between the upper end of the reinforcement member <NUM> and the inner upper surface of the suspension arm body <NUM>. The insert molding <NUM> may extend between the inner upper surface of the suspension arm body <NUM> and the upper surface of the reinforcement member <NUM>.

At least one hole <NUM> may be formed in the reinforcement member <NUM>. The insert molding <NUM> may extend through the hole <NUM>.

Referring to <FIG>, it can be ascertained that the reinforcement member <NUM> is inserted into the inside of insert molding <NUM> due to the formation of the hole <NUM>. Thus, the insert molding <NUM> and the reinforcement member <NUM> may be disposed so as to intersect with each other. Therefore, the overall rigidity of the reinforcement member <NUM> and the hybrid arm <NUM> can be increased, and the coupling force between the suspension arm body <NUM> and the insert molding <NUM> can be increased.

<FIG> is a sectional view of the vehicular hybrid suspension arm <NUM> provided with another reinforcement member <NUM>.

The reinforcement member <NUM> may have a configuration separated into two pieces, and may have a shape similar to the leg portion of the suspension arm body <NUM> as a whole. The reinforcement member <NUM> may include at least two plates connected to each other, and at least a part of the reinforcement member <NUM> may have a bent shape.

The reinforcement member <NUM> may be disposed along the longitudinal direction of the leg portion. That is, the reinforcement member <NUM> may have a configuration similar to a configuration in which the leg portions of the suspension arm body <NUM> are disposed doubly.

An upper surface and a side surface of the reinforcement member <NUM> may be disposed in a direction parallel to the upper surface and the side surface of the suspension arm body <NUM>. Unlike the reinforcement member <NUM>, the upper surface of the reinforcement member <NUM> may be coupled to the inner upper surface of the suspension arm body <NUM> by welding, and the insert molding may be inserted into a space between the upper surfaces of the separate pieces of the reinforcement member <NUM>.

Further, unlike the reinforcement member <NUM>, the upper surface of the reinforcement member <NUM> may be spaced such that a space exists between the upper surface of the reinforcement member <NUM> and the inner upper surface of the suspension arm body <NUM>. Therefore, the insert molding may not be inserted into such a space.

The reinforcement member <NUM> may have the aforementioned flange structure in order to increase the coupling force with the insert molding <NUM>. Thus, a lower distal end of the reinforcement member <NUM> may be formed to be bent inward in a width direction of the reinforcement member <NUM>. Further, unlike the reinforcement member <NUM>, the end portion of the suspension arm body <NUM> may not be formed to be bent inward in the width direction.

<FIG> is a sectional view of the vehicular hybrid suspension arm <NUM> provided with a further reinforcement member <NUM>.

Unlike the reinforcement member <NUM>, the reinforcement member <NUM> may have a one-piece structure without being divided into two pieces. The inner upper surface of the suspension arm body <NUM> and an upper surface of the reinforcement member <NUM> are spaced apart from each other by a predetermined distance, forming a space therebetween. The insert molding <NUM> is not inserted into such a space. Thus, the cross section of the suspension arm body <NUM> may have a quadrilateral cross-sectional structure, and the rigidity of the suspension arm body <NUM> can be increased.

The reinforcement member <NUM> may have a flange structure to improve the coupling force with the insert molding <NUM>. Thus, a lower distal end of the reinforcement member <NUM> may be formed to be bent inward in a width direction of the reinforcement member <NUM>. Further, unlike the reinforcement member <NUM>, the end portion of the suspension arm body <NUM> may not be formed to be bent inward in the width direction.

In case where the above-described reinforcement member <NUM> and the above-described reinforcement member <NUM> are disposed in the hybrid suspension arm <NUM>, <NUM> shown in <FIG>, the reinforcement member <NUM>, <NUM> may be disposed to extend over a portion of one of the two leg portions and a portion of the other of the two leg portions.

Hereinafter, descriptions are made as to a configuration for improving a contact ratio between the ball stud <NUM> and the ball bearing <NUM> in the ball joint <NUM> shown in <FIG> and <FIG>.

<FIG> is a perspective view showing a configuration in which grooves <NUM>, <NUM> are applied to the ball bearing <NUM> shown in <FIG>. A longitudinal groove <NUM> or a transverse groove <NUM> may be formed on an inner spherical surface of the ball bearing <NUM>.

Due to the presence of such a groove <NUM>, <NUM>, lubricant or grease fills in the groove <NUM>, <NUM>, and thus, when the ball stud <NUM> moves, such grease can better distribute on the spherical surface of the ball of the ball stud <NUM>. Therefore, the ball portion of the ball stud <NUM> and the inner spherical surface of the ball bearing <NUM> can be brought into more smooth contact with each other.

<FIG> is a perspective view showing a configuration in which slots <NUM> are applied to the ball bearing <NUM> shown in <FIG>.

The slots <NUM> may be disposed along an upper cutting line of the ball bearing <NUM>. The slots <NUM> can reduce the pressure applied to the inner spherical surface of the ball bearing <NUM> in a movement direction of the ball stud <NUM> during the movement of the ball stud <NUM>, thereby improving the overall contact ratio between the ball bearing <NUM> and the ball stud <NUM>.

<FIG> shows experimental data for selecting an appropriate number of the holes which are formed in the vehicular hybrid suspension arms <NUM>, <NUM>, <NUM> according to various embodiments.

It is necessary to select an appropriate number of the small-diameter holes or the middle-diameter holes in the above-described vehicular hybrid suspension arms <NUM>, <NUM>, <NUM>. In contrast, as for the large-diameter hole, only one large-diameter hole exits, and therefore, it is unnecessary to select the number of the large-diameter hole.

In the test conditions shown at the right side, case (a) corresponds to the case where the number of the holes is largest, case (b) has the number of the holes smaller than case (a), and case (c) corresponds to the case where the number of the holes is smallest.

Referring to the graph shown at the left side, the more the number of the buttons is, the more the bonding effect with the insert molding and the strength reinforcement effect can be improved. However, in case the buttons exist beyond the number within an appropriate range, the strength reinforcement effect may be reduced. Accordingly, it can be ascertained that the unconditionally large number of the buttons does not guarantee the maximum synergistic effect.

In the case of the U-shaped vehicular hybrid suspension arm <NUM> used as an upper control arm, it is preferable that two to four middle-diameter holes <NUM> and two to four small-diameter holes <NUM> are disposed in each leg as shown in <FIG>,.

Claim 1:
A vehicular hybrid suspension arm (<NUM>, <NUM>, <NUM>), comprising a suspension arm body (<NUM>, <NUM>, <NUM>) made of a steel material; and an insert molding (<NUM>, <NUM>, <NUM>) inserted into and coupled to the suspension arm body (<NUM>, <NUM>, <NUM>), the vehicular hybrid suspension arm (<NUM>, <NUM>, <NUM>) being characterized in that:
the vehicular hybrid suspension arm (<NUM>, <NUM>, <NUM>) comprises a coupling portion in which the suspension arm body (<NUM>, <NUM>, <NUM>) and a portion of the insert molding (<NUM>, <NUM>, <NUM>) intersect with each other to prevent separation between the suspension arm body and the insert molding,
the coupling portion includes a reinforcement structure,
the reinforcement structure includes a reinforcement member (<NUM>) which is inserted into and fixed to the suspension arm body (<NUM>, <NUM>, <NUM>) and is in contact with the insert molding (<NUM>, <NUM>, <NUM>),
the reinforcement member (<NUM>) is fixed to the suspension arm body (<NUM>, <NUM>, <NUM>) such that an upper surface of the reinforcement member (<NUM>) is spaced from the suspension arm body (<NUM>, <NUM>, <NUM>) to form a space therebetween, wherein the insert molding (<NUM>) is not inserted into said space.