JP2002192261A - Link arm for suspension of vehicle and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a link arm for suspension which has a pair of mounting holes at both end parts in the longitudinal direction while maintaining the rigidity of the arm main body and to contribute to improve space efficiency. SOLUTION: A manufacturing method for the link arm includes a process to form a pair of link arm half bodies Lh and Lh equipped with a first and a second end parts E1 and E2 in which the outer peripheries are formed in a cylindrical shape having no flange and the inner peripheries are mounting holes H1 and H2, and an intermediate arm part Mh in a channel shape of the transverse which extends so as to integrally connect between the first and second end parts E1 and E2 from a plate-like blank W by press machining, and a process to integrally joint the both intermediate arm parts Mh of the both link arm half bodies Lh and Lh so as to superpose back to back to constitute a roughly H shape cross-section by cooperating with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension link arm for a vehicle having a pair of mounting holes parallel to each other at both longitudinal ends, and a method of manufacturing the same.

[0002]

2. Description of the Related Art The link arm for suspension described above is
It is used to support the wheels in a multi-link type suspension of an automobile so as to be able to move up and down. Are fitted and supported.

Incidentally, a large load (mainly a longitudinal push-pull load) is constantly input to the suspension link arm due to unevenness of the road surface, turning of the vehicle, braking of wheels, and the like during traveling of the vehicle, and thus the link arm withstands the load. It is necessary to have sufficient rigidity only.

In order to satisfy this requirement, a link arm having a structure shown in FIGS. 9 to 11 has been conventionally manufactured and used.

For example, the one shown in FIG. 9 is obtained by press-forming a single plate-shaped blank, and the mounting holes at both ends are obtained by press-forming. The extruded product (link arm material) obtained by simultaneously molding the mounting holes at both ends and the rib holes at the intermediate arm portion with the extrusion molding is formed by appropriately cutting in the extrusion direction. It was done. Further, in FIG. 11, a flat pipe-shaped blank having a rectangular cross section is press-formed, and the mounting holes at both ends thereof are obtained by press-forming.

[0006]

However, in the structure shown in FIG. 9, flanges are continuously provided on both ends and the outer peripheral portions of the intermediate arm portion over the entire circumference, so that the entire arm becomes large. Since the intermediate arm is formed in a flat and simple channel shape, the cross-sectional shape of the intermediate arm must be enlarged (widened) in order to secure necessary bending strength, etc. There is a problem that a large installation space is required and space efficiency is poor.

[0007] Further, in the structure shown in FIG. 10, since the cross-section of the intermediate arm portion is a large square, a large installation space is required and the space efficiency is poor, and the intermediate arm portion is reinforced. There is also a problem that the rib waste increases.

Further, in the structure shown in FIG. 11, flanges are continuously provided on the outer end sides of the both ends, so that the arm becomes longer in the longitudinal direction.
Since the shape of the pipe blank before processing is followed as it is, the cross-sectional shape of the intermediate arm also becomes large (wide), and a large installation space is required for the entire link arm, resulting in poor space efficiency. There is.

The present invention has been made in view of the above circumstances, and has as its object to provide a small and highly rigid vehicle suspension link arm which solves the above-mentioned problems of the conventional structure, and a method of manufacturing the same.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, a first aspect of the present invention is directed to a vehicle suspension link arm having a pair of mounting holes having respective axes parallel to each other at both longitudinal ends. In the manufacturing method, first and second end portions each formed into a cylindrical shape having no flange on the outer periphery and having the inner periphery as the mounting hole, and the first and second ends thereof.
Forming a pair of link arm halves each having an intermediate arm portion having a channel-like cross section extending so as to integrally connect between the end portions by press working from a plate-shaped blank; The method according to claim 2, further comprising a step of superimposing and joining together the intermediate arm portions of the body so that they cooperate with each other to form a substantially H-shaped cross section. A suspension arm of a vehicle having a pair of mounting holes, each having a parallel axis, at both ends in the longitudinal direction, comprising a pair of press-formed link arm halves, each link arm half being A first and a second end formed in a cylindrical shape having no flange on the outer periphery and having the inner periphery as the mounting hole, and extending so as to integrally connect the first and the second end. And at least the intermediate arms of the two link arm halves are integrally joined to each other, and at least the central portions in the longitudinal direction of the two intermediate arms cooperate with each other. It is characterized in that it is formed so as to form a shaped cross section.

According to the above feature, the flanges at the first and second ends of each link arm half are eliminated to reduce the size of the link arm end. By forming a substantially H-shaped cross-section by joining them back-to-back as a channel, it is possible to reduce the size of the cross-section while securing the required rigidity of the intermediate arm. The installation space can be minimized.

According to a third aspect of the present invention, there is provided a method of manufacturing a suspension link arm for a vehicle, comprising a pair of mounting holes having respective axes parallel to each other at both ends in a longitudinal direction. A link arm material comprising first and second ends formed respectively and an intermediate arm extending to connect between the first and second ends is obtained by extrusion molding and cutting after the molding. A step of forming the mounting holes at the first and second ends during the extrusion molding, and forming a slot at the intermediate arm portion in the same direction as the mounting holes. At least a longitudinal center portion of a pair of side wall portions of the intermediate arm portion, which are arranged in parallel with each other with a long hole interposed therebetween, is pressurized so that both side walls cooperate with each other to form a substantially circular cross section or a substantially oval cross section. And a ring processing step. The invention also provides a vehicle suspension link arm having a pair of mounting holes, each having a parallel axis, at both ends in the longitudinal direction. First and second ends respectively formed in a cylindrical shape having no first and second ends, and an intermediate arm extending so as to connect between the first and second ends, and the first and second ends are provided. And a pair of extruded parts, each having a mounting hole formed in the intermediate arm portion and a long hole opening in the same direction as the mounting hole in the intermediate arm portion. Are formed by pressing at least both side ends of each side wall into an arc-shaped cross section so that at least the central portions in the longitudinal direction cooperate with each other to form a substantially circular cross section or a substantially oval cross section. It is characterized by a door.

According to the above feature, even if the entire link arm is formed by extrusion, the cross-section of the intermediate arm is substantially circular or substantially oval. Thus, the cross section can be reduced in size while securing the space, so that the installation space for the link arm can be minimized. In addition, the elimination of the reinforcing ribs from the intermediate arm reduces waste in the intermediate arm.

According to a fifth aspect of the present invention, there is provided a pair of mounting holes having respective axes parallel to each other at both ends in the longitudinal direction.
In a method for manufacturing a suspension link arm for a vehicle, a step of manufacturing cylindrical first and second collars whose inner periphery is the mounting hole, and a step of forming a longitudinally intermediate portion of a flat pipe material having a square cross section. A step of narrowing to a substantially H-shaped closed cross section narrower than the first and second ends by press working; and a pair of opposing pairs at the first and second ends of the pipe material by press working. Punching first and second circular holes in the flat end walls of the first and second end walls, respectively, and cutting each outer end of each of the end walls into a semicircular arc; and forming the pair of end walls of the first end. Inserting a first collar between the pair of end walls of the second end portion corresponding to the first circular hole and a second collar between the pair of end walls of the second end portion, respectively;
After insertion of the collars, both ends of the first collar are provided between the pair of end walls of the first end, and both ends of the second collar are provided between the pair of end walls of the second end. And a step of caulking each of the end walls by press burring so that radial flanges do not remain on each of the inner and outer peripheries of the end walls. A link arm for a vehicle suspension having a pair of parallel mounting holes at both ends in the longitudinal direction, a link arm main body formed by pressing a flat pipe material and integrally formed, and a cylinder having an inner circumference serving as the mounting hole. A first end having a first circular hole corresponding to the first collar in each of a pair of flat end walls facing each other; For two colors A second end having a second circular hole in each of a pair of flat end walls opposed to each other, and a first and a second H-shaped closed cross-section formed narrower than the first and second ends. An intermediate arm portion integrally connecting the second ends, wherein the first collar is between the pair of end walls of the first end, and the second collar is the second end of the second end. It is characterized by being caulked and fixed between the pair of end walls so that no radial flange remains on each inner periphery and each outer periphery of the end walls.

According to the above feature, in forming the link arm by press-forming the pipe-shaped blank, the press-formed product and the collar forming the mounting hole are caulked and connected, and the first and second link arms are formed. By eliminating the flange at the end, the size of the link arm end can be reduced. In addition, the intermediate arm of the link arm is the first
And, by press-forming so as to constrict to a substantially H-shaped closed cross section narrower than the second end, the cross section can be reduced in size while securing the required rigidity of the intermediate arm. Thereby, the installation space for the link arm can be reduced as much as possible.

According to a seventh aspect of the present invention, in addition to the features of the second, fourth or sixth aspect of the present invention, both ends of the intermediate arm portion have a cross-sectional shape as they approach the first and second ends. Are gradually widened, and are formed so as to be substantially along the tangential direction of the outer peripheral portions of the first and second end portions. According to the above feature, since each end of the intermediate arm has a larger cross section as approaching the first and second ends of the link arm, the rigidity of the end of the intermediate arm is effectively increased. However, space efficiency is improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on embodiments of the present invention illustrated in the accompanying drawings.

1 to 3 show a first embodiment of the present invention, and FIG. 1 is a front view of a link arm, and a cross-sectional view taken along line AA and BB of the link arm. FIGS. 2A and 2B are process explanatory views schematically showing the process of forming the link arm, and FIG. 3 is a perspective view schematically showing an example of using the link arm. FIG. 4 is a front view of a link arm according to a second embodiment of the present invention, and a sectional view taken along line AA and BB of FIG. 5, and FIG. 3 is a process explanatory view schematically showing the steps sequentially. FIG. 6 is a front view of a link arm according to a third embodiment of the present invention, a sectional view taken along line AA of FIG.
FIGS. 7 and 8 are cross-sectional views taken along the line B, and FIGS. 7 and 8 are process explanatory views sequentially and simply showing the first half of the process of forming the link arm according to the third embodiment.

First, a first embodiment will be described with reference to FIGS. In FIG. 3, the suspension link arm L has a pair of first and second mounting holes H1 and H2 whose axes are perpendicular to the arm longitudinal direction and parallel to each other at both ends in the longitudinal direction. In the example shown in the figure, an I-type link for supporting a wheel so as to be able to move up and down in a multi-link type suspension of an automobile is used.
Used as the upper or lower arm of the mold.

Each mounting hole H at both ends of the link arm L
1 and H2, through rubber bushes B1 and B2, respectively, mounting brackets BR1 and BR on the vehicle body side and the wheel side.
Fixed mounting shafts P1 and P2 are fitted and held on R2, respectively.
The ends E1 and E2 are connected to the vehicle-body-side and wheel-side mounting brackets BR1 and BR2 via rubber bushes B1 and B2 and mounting shafts P1 and P2, respectively, so as to be relatively rotatable.

Referring also to FIG. 1, the link arm L is constituted by a pair of press-formed link arm halves Lh, Lh. Each of the link arm halves Lh integrally connects the first and second ends E1 and E2 formed in a cylindrical shape having no flange on the outer periphery with the first and second ends E1 and E2. And an intermediate arm portion Mh extending linearly. The first ends E1 and E1 of the link arm halves Lh and Lh cooperate with each other to form one end of the link arm L, and the inner circumferences of the two link arms E1 and E1 are aligned on the same axis. The holes cooperate with each other to form the first mounting hole H1. The second ends E2 and E2 of the link arm halves Lh and Lh cooperate with each other to form the other end of the link arm L.
The inner peripheral holes aligned on the coaxial line of the two E2 and E2 cooperate with each other to form the second mounting hole H2.

The pair of link arm halves Lh, Lh
At least the intermediate arms Mh, Mh are integrally joined (in the example shown, spot welding w at a plurality of locations at intervals in the arm longitudinal direction), and the link arm L
Of the intermediate arm. In addition, at least the central portion in the longitudinal direction of the two intermediate arm portions Mh, Mh (most portions except for the vicinity of both ends in the longitudinal direction of both intermediate arm portions Mh, Mh in the illustrated example) cooperate with each other to form a substantially H-shaped cross section. It is formed as follows.

Also, both ends Mhe of each intermediate arm Mh
Has a cross-sectional shape that gradually widens as it approaches the first and second ends E1 and E2.
It is formed substantially along the tangential direction of the outer peripheral portion of E2. As a result, the intermediate arm Mh is connected to both ends Mhe.
Are the first and second ends E1, E2 of the link arm half Lh.
, The cross-section becomes larger as the distance approaches. Therefore, the space efficiency is improved while effectively increasing the rigidity of both end portions Mhe of the intermediate arm portion Mh.

Next, referring to FIG.
The molding step will be described. In this step, a pair of link arm halves each including first and second cylindrical end portions E1 and E2 and a channel-shaped intermediate arm portion Mh extending so as to integrally connect both end portions thereof. Multi-stage pressing step (a) for press-forming Lh, Lh from plate-shaped blank W
(D), and a joining step (e) of overlapping and integrating at least the intermediate arm portions Mh, Mh of both link arm halves Lh, Lh.

Further, the multi-stage pressing step includes a press blanking step (a) of forming a strip-shaped blank W having both ends in a semicircular shape by a primary press working, and a secondary forming of the strip-shaped blank W. Press-drawing step (b) for finishing the link arm half Lh to an approximate form by a simple press working, and further tertiary and quaternary pressing to the link arm half Lh obtained in the press-drawing step. It comprises a press trim and piercing step (c) and a press wrist step (d) for sequentially applying the final shape of the link arm half Lh.

In the press-drawing step (b), the first and second ends E1 and E2 are formed so that the inner peripheral walls thereof are attached to the mounting holes H1 and H2.
2, the flanges are formed into a cylindrical shape with a flange, and outward flanges f1 and f2 are provided at one end of the cylindrical first and second ends E1 and E2, and inward flanges are provided at the other end. f1 'and f2' are formed respectively.

The intermediate arm portion Mh for integrally connecting the first and second ends E1 and E2 has a flat central portion 1 in the width direction, and has a bead-shaped upright wall on both side ends of the central portion 1. Portions c, c are continuously provided and formed as a channel groove as a whole, and the depth of the groove gradually decreases toward both ends near both ends of the intermediate arm portion Mh. Further, outward flanges f ″, f ″ are respectively connected to the outer edges of the upright walls c, c.

The above-mentioned press trim and piercing step (c)
And in the press list step (d), the flanges f1, f2, f1 ',
f2 ', f ", and f" are sequentially cut, and at the end of the press wrist process, the first and second ends E1 and E2 are finished to have a flangeless cylindrical shape.

In the joining step (e), the intermediate arm portions Mh, Mh of both link arm halves Lh, Lh are
In order that the two cooperate with each other to form a substantially H-shaped cross section,
The flat central portions 1 and 1 in the width direction are overlapped back to back and joined (in the example shown, spot welding w at a plurality of locations).
I do.

The link arm L manufactured in each of the above steps is used as an I-type upper arm or lower arm of a multi-link type suspension in the illustrated example, and the wheel is pivotally movable up and down on the vehicle body via the arm L. Support.
In this case, since the displacement of the wheel side in the longitudinal direction of the vehicle body is regulated by a leading arm or a trailing arm (not shown), the load applied to the arm L between the wheel side and the vehicle body side during traveling of the vehicle is mainly , Double rubber bush B
It becomes a compressive or tensile load in the direction connecting 1 and B2.

In the link arm L, the flanges at the first and second ends E1 and E2 of the link arm halves Lh and the outer peripheral edges of the intermediate arm Mh are eliminated, so that the link arm L is eliminated. L can be reduced in size. Moreover, the intermediate arm portions Mh, Mh of the link arm halves Lh, Lh are each formed into a channel shape and joined back to back to form a substantially H-shaped cross-section, thereby ensuring the required rigidity of the intermediate arm portion Mh. However, the size of the cross section can be reduced. Accordingly, as a whole, the installation space of the link arm L can be made as small as possible, so that the space efficiency around the arm of the automobile is improved.

Next, a second embodiment of the present invention will be described with reference to FIGS. The link arm L of this embodiment has first cylindrical members each having no flange on the outer periphery.
And second ends E1 and E2, and first and second ends E thereof.
And an intermediate arm portion M extending linearly so as to connect between the first and second end portions E1 and E2. The first and second end portions E1 and E2 have first and second mounting holes H1 and H2, respectively. Is formed by an extruded product in which a long hole Hm which opens in the same direction as the mounting holes H1 and H2 and extends in the arm longitudinal direction is formed. In this extruded product, a pair of side walls S, S of the intermediate arm portion M, which are opposed to each other in parallel with each other across the elongated hole Hm, have at least central portions in the longitudinal direction (most portions except both ends Me in the illustrated example). In order to form a substantially circular cross section or a substantially elliptical cross section, at least both side end portions Sr, Sr of each side wall portion S are formed into a cross-sectional arc shape (in the illustrated example, each side wall portion S has a semi-circular shape). Press-formed). It is to be noted that the substantially elliptical cross section includes an oval cross section as well as an oval cross section.

Both ends Me of the intermediate arm portion M are
The cross-sectional shape gradually widens as approaching the second end portions E1 and E2, and is formed substantially along the tangential direction of the outer peripheral portions of the first and second end portions E1 and E2. As a result, the cross section of the intermediate arm portion M becomes larger as its both ends Me approach the first and second ends E1 and E2 of the link arm L. Therefore, the rigidity strength of both ends Me of the intermediate arm portion M is increased. The space efficiency is improved while effectively increasing the space efficiency.

Next, referring to FIG.
The molding step will be described. This molding process includes the first and second
Extruding and cutting step (f) in which a link arm material W 'composed of end portions E1 and E2 and an intermediate arm portion M extending so as to connect between both end portions E1 and E2 is extruded and obtained by cutting after forming. ), (G) and a pressing step (h) of press-forming a portion corresponding to the intermediate arm portion of the link arm material W '.

In the extrusion step (f), the mounting holes H1 and H2 are provided in the first and second ends E1 and E2, and the mounting holes H1 and H1 are provided in the intermediate arm M during the extrusion.
A mold is used in which the long holes Hm that open in the same direction as H2 are simultaneously formed. In the cutting step (g), the extruded product is subjected to a cutting process with a cut surface orthogonal to the extrusion direction, whereby a plurality of link arm materials W 'having the same shape are obtained.

In the pressing step (h), at least a central portion in the longitudinal direction of a pair of side wall portions S, S of the intermediate arm portion M of each link arm material W 'which are opposed to each other across the elongated hole Hm. Press curling process is performed on each of the two side walls S, S so that at least both side ends Sr, Sr of each of them.
Are formed in an arc shape (in the illustrated example, the entire side wall portion S is formed in a semicircular arc shape) so that the opposing edge portions are in close contact with each other, and thus the both side wall portions S, S cooperate with each other. To form a substantially circular cross section or a substantially oval cross section.
Note that the amount of press curling for the side walls S, S is gradually reduced near both ends of the intermediate arm portion M as approaching both ends, and the side walls S, S near both ends where no press curling is performed. And continue smoothly.

In the link arm L manufactured in each of the above steps, the cross section of the intermediate arm portion M is substantially circular or substantially elliptical even though the entire arm is formed by extrusion molding. Without the intermediate arm M
The cross-sectional size can be reduced while securing the required rigidity. As a result, the installation space for the link arm L can be reduced as much as possible, so that the space efficiency around the arm of the vehicle can be improved, and the reinforcing ribs can be eliminated from the intermediate arm portion M. Reduction is achieved.

Next, a third embodiment of the present invention will be described with reference to FIGS. The link arm L of this embodiment has a link arm main body Lm integrally formed by pressing a flat rectangular pipe member W ″ having a rectangular cross section, and a first inner circumference.
And first and second cylindrical first and second mounting holes H1 and H2.
It is composed of colors C1 and C2.

The link arm main body Lm has a first end E having a pair of flat end walls e1 and e1 opposed to each other.
1 and a pair of flat end walls e2 and e2
End E2, each having a first and second end E2
1, formed in a substantially H-shaped closed cross section narrower than E2,
And an intermediate arm portion M that integrally connects the second end portions E1 and E2. The first collar C1 is between a pair of opposed flat end walls e1 and e1 of a first end E1, and the second collar C2 is a pair of opposed flat ends of a second end E2. Fixing Xi, X between the walls e2 and e2 respectively
and the first and second end portions E
No radial flanges remain on the inner and outer peripheries of each end wall e1, e1, e2, e2 of E1, E2.

As in the previous embodiment, both ends Me of the intermediate arm portion M have a cross-sectional shape that gradually widens as approaching the first and second ends E1 and E2.
It is formed substantially along the tangential direction of the outer peripheral portion of the end portions E1 and E2.

Next, a process for forming the link arm L will be described with reference to FIGS. In this forming step, the cylindrical first and second collars C1 and C2 whose inner circumferences are the first and second mounting holes H1 and H2, respectively, and the flat rectangular pipe member W ″ having a predetermined length are separately formed. Step (i), and pressing both ends E1, E2 of the flat pipe member W ″ by pressing the middle part thereof while leaving both ends E1, E2 in the longitudinal direction unprocessed.
A first and second end portions E1 and E of the pipe material W ″ are formed by a press forming step (j) in which the intermediate arm portion M is formed by narrowing to a substantially H-shaped closed cross section narrower than that of the pipe member W ″.
2 each of a pair of opposed flat end walls e1, e
1; e2 and e2, first and second circular holes h1 and h2 are punched out, and their end walls e1, e1; e2
a press trim piercing step (k) for cutting the outer ends r1, r1; r2, r2 of e2 into semicircular arcs bulging outward, and a pair of opposing first ends E1 of the pipe material W ″. A first collar C1 is provided between the end walls e1 and e1 corresponding to the first circular hole h1, and a first collar C1 is provided between a pair of opposed end walls e2 and e2 of the second end E2 of the pipe material. 2
A color inserting step (1) for inserting the second collars C2 respectively corresponding to the circular holes h2;
In the inserted state, both ends of the first collar C1 are attached to a pair of opposed end walls e1, e1 of the first end E1, and a pair of opposed end walls e2, of the second end E2. The step e2 includes a press burring caulking step (see FIG. 6) of fixing both ends Xi and Xo of the second collar C2 by press burring.

In the press forming step (j),
A compressive load is applied to the pair of flat intermediate walls 2 and 2 at the longitudinal middle part of the pipe material W ″ having a flat rectangular cross section from both outer sides until the inner surfaces at the center in the width direction are in close contact with each other. A pair of small closed cross-sections are formed on both sides of the intermediate wall portions 2 and 2 with the contact portion therebetween, so that the intermediate arm portion M is as shown in the BB cross-sectional view of FIG. It becomes a substantially H-shaped cross section.

In the press burring crimping step, a pair of flat end walls e opposing each other at the first end E1.
1, e1 semicircular outer ends r1, r1 and a first circular hole h
1, the inner peripheral edge of the first collar C1 is plastically deformed so as to be in close contact with the outer peripheral side and the inner peripheral side of both ends of the first collar C1, respectively, so that the radial flange does not remain on the inner and outer peripheral sides of the first end E1. Then, the first collar C1 is caulked and fixed to the first end E1. Further, semicircular outer ends r2, r2 of a pair of flat end walls e2, e2 opposed to each other of the second end E2.
And the second circular holes h2 and h2 and the inner peripheral portion thereof are connected to the second collar C2.
The second collar C2 is plastically deformed so as to be in close contact with the outer periphery and the inner periphery of both ends of the second collar C2 so that no radial flange remains on the inner and outer periphery of the second end E2.
To the second end E2.

The end of the link arm L manufactured by the above-described steps can be reduced in size by eliminating the flanges at the first and second ends E1 and E2. Moreover, the intermediate arm portion M of the link arm L is. By press-forming so as to constrict to a substantially H-shaped closed cross section narrower than the first and second end portions E1 and E2, the intermediate arm portion M can maintain a required rigidity and a small cross-section. Can be achieved. As a result, the installation space of the link arm L can be reduced as a whole, and the space efficiency around the arm of the automobile can be improved.

Although the embodiment of the present invention has been described in detail, various design changes can be made in the present invention without departing from the gist of the present invention.

For example, in the first embodiment, each intermediate arm portion Mh is formed in a channel shape by integrating bead-shaped upright wall portions c, c at both ends of the flat intermediate wall portion 1. However, in the present invention, the upright wall may be formed in a simple flange shape instead of a bead shape. In the first embodiment, in order to prevent backlash. Double link arm half L
Although only the flat intermediate wall portions 1, 1 of the intermediate arm portions Mh, Mh among the opposing surfaces of h, Lh are tightly connected to each other, the present invention provides the two link arm halves Lh. , Lh may be in contact with or bonded to other portions or the entire surface of the opposing surfaces.

In the second embodiment, the intermediate arm M
, A pair of side walls S parallel to each other with the long hole Hm interposed therebetween.
At least both end portions Sr, Sr of S are formed into a cross-sectional arc shape by press curling, so that the opposed edge portions are brought into close contact with each other. In the present invention, the opposed edge portions are formed. You may make it mutually separate.

[0048]

As described above, according to the first and second aspects of the present invention, the flanges at the first and second ends of the pair of link arm halves press-formed from the plate-shaped blank are eliminated, so that the link arm ends are eliminated. The intermediate arms of both link arm halves are channel-shaped, and these are joined back to back to form a substantially H
By adopting a cross-sectional shape, the required cross-sectional size can be reduced while securing the required rigidity of the intermediate arm, so that the installation space for the link arm can be reduced as much as possible, and the periphery of the link arm can be reduced. Can be improved in space efficiency.

According to the third and fourth aspects of the present invention, even when the entire link arm is formed by extrusion, the intermediate arm is press-formed so as to have a substantially circular or substantially oval cross section. Without this, the required cross-sectional size can be reduced while securing the required rigidity of the intermediate arm, thereby minimizing the installation space for the link arm and improving the space efficiency around the link arm. Can be contributed to. In addition, the elimination of the reinforcing ribs in the intermediate arm portion can reduce waste and contribute to a reduction in arm weight.

According to the fifth and sixth aspects of the present invention, when the link arm is press-formed from the pipe-shaped blank, the flange at the first and second ends of the link arm is eliminated to reduce the size of the arm end. It is possible,
Moreover, the intermediate arm portion of the link arm is press-molded so as to be narrowed to a relatively narrow, substantially H-shaped closed cross section, so that the required cross-sectional size can be reduced while securing the required rigidity of the intermediate arm portion. Therefore, the installation space for the link arm can be reduced as a whole, which can contribute to an improvement in space efficiency around the arm.

According to the seventh aspect of the present invention, since the cross section of each end of the intermediate arm portion becomes larger as approaching the first and second ends of the link arm, the end portion of the intermediate arm portion is enlarged. Space efficiency is improved while effectively increasing rigidity.

[Brief description of the drawings]

FIG. 1 is a front view showing a link arm according to a first embodiment of the present invention, and a sectional view taken along line AA and a line BB thereof.

FIG. 2 is a process explanatory view sequentially and simply showing a process of forming a link arm according to the first embodiment.

FIG. 3 is a perspective view schematically showing a use example of the link arm according to the first embodiment.

FIG. 4 is a front view showing a link arm according to a second embodiment of the present invention, and a sectional view taken along line AA and BB of the link arm.

FIG. 5 is a process explanatory view schematically sequentially illustrating a process of forming a link arm according to a second embodiment.

FIG. 6 is a front view showing a link arm according to a third embodiment of the present invention, and a sectional view taken along line AA and a line BB thereof.

FIG. 7 is a process explanatory view sequentially and simply showing the first half process of forming the link arm according to the third embodiment.

FIG. 8 is a process explanatory view schematically sequentially illustrating the second half of the process of forming the link arm according to the third embodiment.

FIG. 9 is a front view showing an example of a conventional link arm, and its AA and BB sectional views.

FIG. 10 is a front view showing another example of a conventional link arm, and its AA and BB sectional views.

FIG. 11 is a front view showing still another example of a conventional link arm, and its AA and BB sectional views.

[Explanation of symbols]

 B1, B2 Rubber bush C1, C2 First, second collar E1, E2 First, second end e1, e2 End wall H1, H2 Mounting hole Hm Long hole h1, h2 First, second circular hole L link Arm Lh Link arm half Lm Link arm main body M Intermediate arm Mh Intermediate arm r1, r2 Semicircular outer end S Side wall Sr Side end W Plate blank W 'Link arm material W ″ Pipe blank

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B21D 28/00 B21D 28/00 A 28/24 28/24 Z 28/28 28/28 39/00 39 / 00 D 53/88 53/88 Z B60G 7/00 B60G 7/00

Claims (7)

[Claims] 1. A pair of mounting holes (H) whose respective axes are parallel to each other.
(1) and (H2) at both ends in the longitudinal direction, respectively, in a method of manufacturing a link arm for suspension of a vehicle, the link arms are formed in a cylindrical shape having no flange on the outer periphery, and the inner periphery is the mounting hole (H1, H2). First and second ends (E1, E2) and the first and second ends (E1, E2).
2) A pair of link arm halves (Lh, Lh) each having an intermediate arm portion (Mh) having a channel-like cross section extending so as to integrally connect between them, is pressed by a plate blank (W). The forming step and the intermediate arm portions (Mh) of the two link arm halves (Lh, Lh) are overlapped back to back to form a substantially H-shaped cross section in cooperation with each other to form an integrated body. And a method of manufacturing a link arm for a suspension of a vehicle. 2. A pair of mounting holes (H) having respective axes parallel to each other.
1, H2) at both ends in the longitudinal direction, each of which has a pair of press-formed link arm halves (Lh, Lh). Lh) are first and second end portions (E1, E2) each formed in a cylindrical shape having no flange on the outer periphery and having the inner periphery as the mounting holes (H1, H2), and the first and second ends thereof. 2 ends (E1, E
2) An intermediate arm portion (M
h), and both link arm halves (Lh,
Lh), at least the intermediate arms (Mh) are integrally joined to each other, and at least the longitudinal central portions of the two intermediate arms (Mh) cooperate with each other to form a substantially H-shaped cross section. A link arm for suspension of a vehicle, characterized in that the link arm is used. 3. A pair of mounting holes (H) having respective axes parallel to each other.
1, H2) at both ends in the longitudinal direction of the link arm for a vehicle suspension, wherein the first and second ends (E1, E2) are respectively formed in a cylindrical shape having no flange on the outer periphery. , A link arm material (W ') comprising an intermediate arm portion (M) extending to connect between the first and second end portions (E1, E2) by extrusion molding and cutting after the molding. During the extrusion, the mounting holes (H1, H2) are formed in the first and second ends (E1, E2), and the mounting holes (H1, H2) are formed in the intermediate arm (M). Slot (H
m), and at least the central portion in the longitudinal direction of a pair of side wall portions (S, S) of the intermediate arm portion (M) which are parallel to each other across the long hole (Hm). Press-curling each side wall (S, S) so as to form a substantially circular cross section or a substantially oval cross section in cooperation with each other. Production method. 4. A pair of mounting holes (H) whose respective axes are parallel to each other.
1, H2) at both ends in the longitudinal direction of the suspension link arm for a vehicle, the first and second cylinder arms each having a cylindrical shape having no flange on the outer periphery.
End (E1, E2) and its first and second ends (E1, E2).
E2) and an intermediate arm portion (M) extending to connect between the first and second ends (E1, E2), the mounting holes (H1, H2) and the intermediate arm portion (M). M), an elongated hole (H) opening in the same direction as the mounting holes (H1, H2).
m) is formed of an extruded product, and a pair of side walls (S, S) of the intermediate arm (M), which are arranged in parallel with each other across the elongated hole (Hm), have at least a central portion in the longitudinal direction. At least both side ends (Sr, Sr) of each side wall (S) are each press-formed into an arc-shaped cross section so that the parts cooperate with each other to form a substantially circular cross section or a substantially oval cross section. Characteristic, link arm for vehicle suspension. 5. A pair of mounting holes (H) whose respective axes are parallel to each other.
(H1, H2) at both ends in the longitudinal direction, the first and second cylindrical collars (C1, C2) each having an inner periphery serving as the mounting hole (H1, H2). ), And pressing a middle portion in the longitudinal direction of a flat pipe material (W ″) having a rectangular cross section by press working, thereby forming a substantially H-shaped portion narrower than the first and second end portions (E1, E2). The first and second ends (E) of the pipe material (W ″) are formed by a process of constricting to a closed cross section of a shape and pressing.
1, E2), a pair of flat end walls (e1, e1, e2, e2) facing each other have first and second circular holes (h).
, H2), and the outer ends (r1, r1, r2) of the end walls (e1, e1, e2, e2).
, R2) in a semicircular arc shape, and a first circular hole (h1) corresponding to a first circular hole (h1) between the pair of end walls (e1, e1) of the first end (E1). Color (C1)
And the pair of end walls (e) of the second end (E2).
2, e2) between the second circular holes (h2) corresponding to the second circular holes (h2), and after inserting the collars (C1, C2), the first end (E2).
1) Both ends of the first collar (C1) between the pair of end walls (e1, e1) and between the pair of end walls (e2, e2) of the second end (E2). Both ends of the second collar (C2) are press-burred to fix them by caulking (Xi, Xi, Xi, E2) so that radial flanges do not remain on the inner circumference and the outer circumference of the end walls (e1, e1, e2, e2).
Xo). A method for manufacturing a link arm for suspension of a vehicle, comprising the step of: 6. A pair of mounting holes (H) whose respective axes are parallel to each other.
1, H2) at both ends in the longitudinal direction, a link arm for a vehicle suspension (Lm) formed by pressing a flat pipe material (W ″) and integrally forming the link arm main body (Lm). The link arm main body (Lm) is composed of cylindrical first and second collars (C1, C2) serving as mounting holes (H1, H2), and the first circular hole corresponding to the first collar (C1). A first end (E1) having a pair of flat end walls (e1, e1) facing each other (h1) and a second circular hole (h2) corresponding to the second collar (C2) are opposed to each other. A pair of flat end walls (e2, e
2), and a first and second end (E2) having a substantially H-shaped closed cross section narrower than the first and second ends (E1, E2). E1, E2) and an intermediate arm portion (M) for integrally connecting between the pair of end walls (e1, e1) of the first end (E1). In addition, the second collar (C1) is provided between the pair of end walls (e2, e2) of the second end E2, respectively, at the inner periphery and at each of the end walls (e1, e1, e2, e2). A link arm for suspension of a vehicle, wherein the link arm is fixed by caulking (Xi, Xo) so that a radial flange does not remain on each outer periphery. 7. Both ends (Mhe, Me) of the intermediate arm (Mh, M) are respectively connected to the first and second ends (E1, E1).
The cross-sectional shape gradually widens as approaching 2),
The link arm according to claim 2, 4 or 6, wherein the link arm is formed substantially along a tangential direction of an outer peripheral portion of the first and second end portions (E1, E2).