JP4856411B2 - Suspension link - Google Patents

Description

  The present invention relates to a suspension link used in a suspension device for suspending a vehicle body such as an automobile on wheels.

  FIG. 11A is a perspective view of a multilink type rear suspension of an automobile, and FIG. 11B is an exploded view of the rear suspension. As the suspension link, a front upper link 21, a rear upper link 22, a front I-type lower link 23, and a toe control I-type link 25 are used.

  The suspension link described above is generally formed using an iron-based material because sufficient reliability and strength can be ensured even when manufactured using a joint and the price is relatively low. In recent years, suspension links have been made lighter in response to improvements in fuel economy due to vehicle weight reduction and improved ride comfort by reducing unsprung weight, and light metal materials such as aluminum alloys have begun to be adopted.

Conventional suspension links made of an aluminum alloy include those shown in Patent Documents 1-6. In this case, the suspension link is formed by joining multiple members that can freely create a certain shape, or the suspension link is formed by extrusion to ensure reliability and strength.
JP-A-10-272911 Japanese Patent Application Laid-Open No. 11-78455 Japanese Patent Laid-Open No. 11-90576 JP 2000-225821 A JP 2001-334813 A JP 2002-103044 A

  However, in a structure in which a suspension link is formed by joining multiple members, arc welding typified by general MIG and TIG welding, and friction stir welding (see, for example, Patent Document 5) or upset welding (see, for example, Patent Document 5) For example, refer to Patent Document 6), and there is mechanical fastening (for example, refer to Patent Document 2), but it is necessary to design in consideration of stress concentration due to abrupt shape change due to joining and deterioration of mechanical properties due to joining, It was necessary to increase the thickness, that is, increase the mass. In addition, the number of parts and joining costs increase with joining, and in addition, a great amount of internal defect inspection is required to ensure the reliability and strength of joining, resulting in an increase in work processes and manufacturing costs. .

  In addition, in an integrally extruded product of a joint portion at both ends and a portion connecting the joint portions at both ends (see, for example, Patent Documents 1 and 3), the portion connecting the joint portions at both ends is solid or It becomes an almost truss shape. The solid and truss shape that can be manufactured by extrusion molding for the rigidity and strength that can be raised as the performance of the suspension link must have extra performance, and is not suitable for weight reduction and material cost reduction. There is. Further, in general, suspension links are often used in an elongated shape, and the overall length is large. Therefore, when this is manufactured by extrusion molding, a very large extrusion equipment is required, resulting in an increase in manufacturing cost. In Patent Document 1, a device that reduces the extruded rough shape and does not increase the extrusion equipment is raised. However, it is easy to require a large manufacturing cost for plastic processing after extrusion to obtain a predetermined overall length. Conceivable.

  Moreover, in the structure which has a through-hole in the terminal of the extrusion molded product of a fixed cross section and uses the through-hole as a coupling | bond part (for example, refer patent document 4), it is extrusion-formed over the full length with the external size of a coupling | bond part. Therefore, since the site | part which has connected the coupling | bond part of both ends also becomes the same external shape size and the same cross section as a coupling | bond part, there exists a problem that it is not suitable for weight reduction and reduction of material cost.

  Therefore, the present invention has been made in the background of the above circumstances, and while ensuring sufficient reliability and strength while avoiding an increase in work process and cost, the connecting portion and the connecting portion at both ends are connected. It is a technical problem to provide a suspension link that can be reduced in weight by setting the external size, thickness, and cross-section of each part so that it is the minimum necessary for performance at the connected part.

In order to solve the above technical problem, the present invention is an I-type link member made of an aluminum alloy, and has coupling portions (111, 112) for coupling other members to both ends, and the coupling portions ( 111, 112) are connected by a connection portion (113) having a hollow closed cross section, and the thickness of the connection portion (113) is greater in the longitudinal center (533) than in the vicinity of the joint portions (531, 532) at both ends. The suspension link is characterized in that it is thicker and the joint portions (111, 112) and the connection portion (113) at both ends are integrally formed.
More specifically, a type I link members made of aluminum alloy, and a pipe-shaped connecting portion made of forged or extruded steel, of the connection portion and integral with the ends of both sides of the connection portion, the other member Each of the connecting portions is gradually changed with the cross-sectional thickness of the central portion in the longitudinal direction being thicker than the cross-sectional thickness of the end portions on both sides. At least one of the connecting portions is changed so that the thickness gradually increases from the connecting portion to the connecting portion, so that stress concentration on the connecting portion is suppressed, and the connecting portions on both sides are suppressed . The external size is different from the external size of the connecting portion by matching with other members connected to the connecting portion .

  According to the suspension link of the present invention, since the joint portions (111, 112) at both ends made of aluminum are connected by the connection portion (113) having the hollow closed cross section, the suspension link has high strength and rigidity and is lightweight. . In addition, since the joint portions (111, 112) and the connection portion (113) at both ends are integrally formed, consideration is given to stress concentration due to a sudden shape change caused by a multi-member joint or the like, and deterioration of mechanical properties due to joining. The design (increased wall thickness, that is, increased mass) becomes unnecessary, and the weight can be reduced while having high reliability. As a result, it is possible to reduce the unsprung weight, and it is possible to improve fuel consumption and ride comfort by reducing the vehicle weight. Furthermore, since it has high reliability, it is possible to improve durability with little progress of strength decrease due to long-term fatigue and the like.

  Further, the thickness (533) of the connecting portion (113) at the substantially central portion between the joint portions (111, 112) at both ends is equal to the thickness (531) of the hollow cross section near the joint portions (111, 112) at both ends. 532), it is thicker, so that sufficient rigidity is imparted to the central portion where the most deflection occurs when receiving the axially compressed force from the joints (111, 112) at both ends. , Operational stability can be improved.

The thickness (153) at the center in the longitudinal direction of the connecting portion (113) is desirably different from at least the maximum thickness (152) of the coupling portion (112) at one end. In order to satisfy different requirements required for the coupling portion (112) and the connection portion (113) by changing the thickness between the coupling portion (112) and the connection portion (113) at one end in this way. A suspension link can be formed with a combination of minimum wall thicknesses required for individual parts, and further weight reduction can be achieved.

It is desirable that the outer size at the center of the coupling portions (111, 112) at both ends and the outer size of the connection portion (113) are different from each other. Thereby, the shape of the attachment part of a member couple | bonded with a coupling | bond part (111,112), for example, a suspension member or an axle (13), can be made into the optimal dimension according to each required performance, noise, a vibration, etc. While making it possible to make fine adjustments for suppression, the external size of the connection portion (113) of the suspension link is kept small, which leads to further improvement in riding comfort while being lightweight.

At least one end of the coupling part (112) is a part where the thickness gradually changes from the connection part (113), and it is desirable that the thick part is formed by pressing or forging. As a result, the connecting portion (113) can be formed by a closed forging or extrusion molding that has been conventionally used to form a hollow closed cross-section whose thickness has changed, and the connecting portion (112) can also be formed. The shape of the coupling portion (112) can be formed by manufacturing by plastic working such as press working conventionally used. As a result, each shape of the suspension link has a different shape, thickness, and cross-section, making it difficult to manufacture. It became possible to form.

  According to the present invention, since the light-weight aluminum alloy is formed in a cross-sectional shape in which the thickness is partially thinned, the material used is greatly reduced and lightened, and the optimal cross-sectional shape for each part Therefore, it is possible to reduce the weight while ensuring sufficient strength.

  In addition, after forming the connection part and the joint part where the pipe-like hollow part extends from the one-end joint part by closed forging or extrusion molding, the joint part of the terminal having a hollow section is subjected to plastic working such as press working. Since it can be formed by molding into the shape of the joint portion, it can be manufactured only by combining conventional methods, and the cost for introducing a new new method is not required, and the manufacturing cost can be suppressed.

  Therefore, it is possible to reduce the weight while ensuring sufficient strength and reliability while avoiding an increase in work man-hours and costs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Embodiment 1 FIGS. 1 to 4 are views showing a first embodiment of a vehicle suspension link according to the present invention, and FIG. 1 is a perspective view of the suspension link. FIG. 2 shows a plan view and a front view of the suspension link, as well as cross sections AA to E-E. 3 and 4 show the manufacturing method of this embodiment.

  As shown in FIG. 1, the suspension link is an I-type link member that includes a coupling portion 111 and a coupling portion 112 at both end portions, and is configured by a connection portion 113 that connects the coupling portions (111, 112) at both ends. is there. FIG. 1 shows two perspective views (on the plane side and the bottom side) that are opposite viewpoints (the same applies to FIGS. 5, 7, and 9 of Examples 2 to 4). The coupling portion 111, the coupling portion 112, and the connection portion 113 are integrally molded products that are integrally molded without welding or joining. Other members, for example, a suspension member and an attachment portion of the axle 13 are coupled to the coupling portions (111, 112).

  Further, as can be seen from the cross-sectional view shown in FIG. 2, the suspension link connecting portion 3 has a hollow closed cross-section as shown in the partial cross-sectional views CC, DD, and EE. Is formed. FIG. 2 includes a plan view of a suspension link and a longitudinal sectional view (cross sectional view AA), a front view, a longitudinal sectional view (cross sectional view BB), and a transverse sectional view (cross sectional views CC and D). -D, EE). Further, the thickness 151 of the coupling portion 111 and the thickness 152 of the coupling portion 112 are different from the thickness 153 of the connection portion 113, respectively, and the coupling portion 111, The coupling portion 112 and the connection portion 113 are formed so that the shape and thickness change smoothly, and stress concentration is also suppressed.

Further, the central portion of the connecting portion 113 existing between the connecting portion 111 and the connecting portion 112 has a thickness 533 in a partial cross-sectional view CC, and the connection in the vicinity of the connecting portions (111, 112) at both ends. The thickness is larger than the thickness 532 of the partial cross-sectional view DD of the portion 113 and the thickness 531 of the partial cross-sectional view EE. Further, the wall thickness 153 of the connecting portion 113 in the longitudinal direction is different from at least the maximum wall thickness 152 of the coupling 112 portion at one end .

  As can be seen from FIGS. 1 and 2, the outer size of the coupling portion 111 and the outer size of the coupling portion 112 are different from each other in the outer size of the connection portion 113 having a hollow cross section. The coupling portion 111 is a suspension member. The mounting and connecting portion 112 has a shape that is optimal for the required performance in mounting to the axle 13. The connection portion 113 has a minimum shape that satisfies the strength and rigidity to reduce the weight.

  FIG. 3 shows a plan view and a longitudinal sectional view (cross-sectional view FF) thereof in the manufacturing process of the suspension link, and a front view and a longitudinal sectional view thereof (cross-sectional view GG). GG shows the molding process with a mold and a mandrel. In the suspension link according to the present embodiment, an aluminum alloy (2000 series, 6000 series, 7000 series, etc.) is first coupled with a connection section 113 having a pipe-shaped hollow portion extending from a coupling section 111 at one end as shown in FIG. The portion 112a is formed by closed forging or extrusion molding. Thereafter, as shown in FIG. 4 (a), the coupling portion 112a of the terminal having a hollow cross-section is formed as shown in FIG. 4 (b): notch, FIG. 4 (c): pipe expansion, FIG. 4 (d): trim, piercing. In this order, it is formed by forming into the shape of the coupling portion 112 by plastic working such as press working. That is, it is a manufacturing method that combines conventional methods, and the shape can be formed only by the conventional method in manufacturing.

  As shown in FIG. 3, the connecting portion 112 at one end is a portion 112a (152) where the thickness gradually changes from the connecting portion 113, and the thick portion 112a is pressed as shown in FIG. Alternatively, it is formed by forging.

  As described above, in the suspension link according to the present invention, the joint portions (111, 112) made of aluminum at both ends are connected by the connection portion 113 having a hollow cross section. is there. Since it is an integrated product with a smooth shape change, it is lightweight while having high reliability without stress concentration. Furthermore, the suspension link is formed by a combination of the minimum wall thicknesses required for each part, and sufficient rigidity is imparted. As a result, it is possible to reduce the unsprung weight, and it is possible to improve fuel efficiency and ride comfort by reducing vehicle weight. Furthermore, since it has high reliability, durability is improved with little progress of strength reduction due to fatigue due to long-term use.

  Second Embodiment FIGS. 5 and 6 are views showing a second embodiment of a vehicle suspension link according to the present invention. FIG. 5 is a perspective view of the suspension link. FIG. 6 shows a HH cross section and a II cross section as a plan view, a front view, and sectional views of the suspension link. In the second embodiment, the same configuration as that of the first embodiment described above is assigned with a code number obtained by adding 100 to the code number of the first embodiment, and detailed description thereof is omitted.

  The major difference between the second embodiment and the first embodiment is that the shape of the coupling portion 211 is the same as that of the coupling portion 212 as shown in FIGS.

  As described above, since the suspension link according to the second embodiment includes the same configuration as that of the first embodiment, the same effect can be obtained. The optimum shape of the coupling portion 211 can be set even when the suspension member is attached.

  [Embodiment 3] FIGS. 7 and 8 are views showing a third embodiment of a suspension link for a vehicle according to the present invention. FIG. 7 is a perspective view of the suspension link. FIG. 8 shows a JJ cross section and a KK cross section as a plan view, a front view, and cross-sectional views of the suspension link. In the figure, a two-dot chain line indicates a ball joint to be retrofitted. In the third embodiment, the same configuration as that of the first embodiment described above is assigned with a code number obtained by adding 200 to the code number of the first embodiment, and detailed description thereof is omitted.

  The major difference between the third embodiment and the first embodiment is that, as shown in FIGS. 7 and 8, a spherical joint is added to the inside in order to allow the ball joint to be assembled to the coupling portion 311. It is that you are.

  As described above, since the suspension link according to the third embodiment includes the same configuration as that of the first embodiment, the same effect can be obtained, and by changing the shape of the coupling portion 311, for example, a ball joint It is possible to set the optimum shape of the coupling portion 311 even in the demand of attaching the like.

  [Embodiment 4] FIGS. 9 and 10 are views showing a fourth embodiment of a suspension link for a vehicle according to the present invention. FIG. 9 is a perspective view of the suspension link. FIG. 10 shows cross sections MM to OO as a plan view, a front view, and sectional views of the suspension link. In the fourth embodiment, the same configuration as that of the first embodiment described above is provided with a code number obtained by adding 300 to the code number of the first embodiment, and detailed description thereof is omitted.

  A great difference between the fourth embodiment and the first embodiment is that, as shown in FIGS. 9 and 10, the connecting portion 412 is crushed and punched by plastic working such as press working, and the same as the connecting portion 411. It has a hole shape.

  As described above, since the suspension link according to the fourth embodiment includes the same configuration as that of the first embodiment, the same effect can be obtained and, for example, by changing the shape of the coupling portion 412, for example, a unique axle can be obtained. Even in the case of 13 attachment requests, it is possible to set the optimum coupling portion 411 shape.

  In the first, second, third, and fourth embodiments described above, the shape of the coupling portion 111 and the coupling portion 112 is changed so as to be optimal for a specific suspension member, axle 13, or ball joint. In addition, a suspension link constituted by a combination of the coupling portion 111 and the coupling portion 112 of the first, second, third, and fourth embodiments may be generated depending on the attachment request. Since the same structure is included, a similar effect can be obtained.

1 is a perspective view of a suspension link according to a first embodiment of the present invention. It is sectional drawing of the suspension link which concerns on 1st Example of this invention. It is a figure which shows the manufacture process of the suspension link which concerns on 1st Example of this invention. It is a perspective view which shows the formation process of the coupling | bond part of the suspension link which concerns on 1st Example of this invention. It is a perspective view of the suspension link which concerns on 2nd Example of this invention. It is sectional drawing of the suspension link which concerns on 2nd Example of this invention. It is a perspective view of the suspension link which concerns on 3rd Example of this invention. It is sectional drawing of the suspension link which concerns on 3rd Example of this invention. It is a perspective view of the suspension link which concerns on 4th Example of this invention. It is sectional drawing of the suspension link which concerns on 4th Example of this invention. It is a figure explaining the conventional suspension structure. FIG. 11A shows a suspension structure, and FIG. 11B shows an exploded part.

Explanation of symbols

13 ... Axle 21 ... Front I-shaped upper link 22 ... Rear I-shaped upper link 23 ... Front I-shaped lower link 24 ... Rear boat-shaped lower arm 25 ... Toe control I-shaped link 26 ... Compression coil spring 27 ... Shock absorber 111 ······················································································································ Thickness 531 Thickness 533 of the connecting portion in the wall thickness in the central portion of the connecting portion

Claims (2)

An I-type link member made of an aluminum alloy,
A pipe-like connection made of forging or extrusion; and
A of the connecting portion integrally to the end portions on both sides of the connecting portion, the coupling portion for coupling the other member respectively,
The connecting portion gradually changes in cross-sectional thickness at the center in the longitudinal direction to be thicker than the cross-sectional thickness at the ends on both sides,
Among the coupling portions on both sides, at least one of the coupling portions is changed so that the wall thickness gradually increases from the joint portion with the connection portion, so that the stress concentration on the joint portion is suppressed, and both sides The suspension link according to claim 1, wherein an outer size of the connecting portion is different from an outer size of the connecting portion by matching with another member connected to the connecting portion . After integrally forming one coupling part and connection part by closed forging or extrusion molding,
2. The method of manufacturing a suspension link according to claim 1, wherein the other connecting portion is formed by plastic working on the opposite side of the connecting portion from the one connecting portion.

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