JP2007062675A - Suspension arm for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure easily the requisite rigidity strength of a transition part from a pushing pressure fitting part to the body of a plate arm by securing the section shape of the transition part sufficiently and meet the request for increasing the arm strength without increasing particularly the peripheral space of the bushing fitting part. <P>SOLUTION: The arm body 1 is equipped with a main plate 2 formed through press working, constituting the main part of the arm body, and provided at one end with a short cylindrical portion EB rigidly and continuously by means of a burring process and a reinforcing plate H overlaid on one of the oversurface and undersurface of the main plate 2 for reinforcing the main plate 2, and the reinforcing plate H has an eyeball shaped head part Ha formed ring-shapedly and laid coaxially with the short cylindrical portion EB and a tail part Hb extending consolidatedly from the eyeball shaped head part Ha along the longitudinal direction of the main plate 2 and is formed from a single plate thicker than the main plate 2, wherein at least the tail part Hb is welded to the main plate 2, and the bushing pressure fitting part P1 is formed from the inside circumferential surface of the eyeball shaped head part Ha and the inside circumferential surface of the short cylindrical portion EB. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a suspension arm for a vehicle, and more particularly, to a suspension arm provided with an arm main body and a bush press-fit portion provided at one end of the arm main body and capable of press-fitting a bush.

  As the suspension arm having the above structure, for example, the inner peripheral portions of the ring plate-like upper end plate and lower end plate integrally connected to the respective ends of the upper plate and the lower plate constituting the arm body face each other inwardly. It has already been proposed that a pair of upper and lower inner peripheral flanges are formed by burring, and the inner peripheral surfaces of these inner peripheral flanges are bush press-fit surfaces (see, for example, FIG. 4 of Patent Document 1 below).

In this proposal, the pair of upper and lower inner peripheral flanges are in contact with each other, and the outer peripheral portions of the upper end plate and the lower end plate are substantially along the inner peripheral flange. Each pair is bent inward and has a pair of upper and lower outer peripheral flanges that face each other with a gap between them, so that the bush press-fit part has sufficient rigidity and strength equivalent to the collar. In addition, since there is no welded portion between the upper and lower end plates, there is an advantage that a lapping margin for welding is unnecessary and the arm end shape can be miniaturized as much as possible.
JP 2002-337525 A

  However, in the structure proposed above, it is necessary to perform burring on both the upper end plate and the lower end plate that are respectively connected to one end of each of the upper plate and the lower plate that are press-molded. In many cases, the machining process becomes complicated, resulting in poor productivity and high machining costs.

  In addition, when there is a need to increase the strength of the suspension arm due to an increase in the horsepower of the car, an increase in the tire flatness, etc. Although it is necessary to increase the plate thickness of the upper plate and the lower plate, the increase in the plate thickness increases the weight and cost, and also increases the occupied space, which greatly restricts the freedom of layout. There is a fear.

  In general, the suspension arm strength conditions differ depending on the vehicle type variation (normal car, advanced car, sports type car), but the molds for molding the upper and lower plates are usually common, so the strength conditions It is difficult to cope with the setting of the corresponding plate thickness, which results in an increase in weight and cost for a normal vehicle.

  The present invention has been proposed in view of the above circumstances, and a part of the bush press-fit portion and the arm main body are integrated, or the burring process on the arm main body for constituting the bush press-fit portion is omitted. Another object of the present invention is to provide a vehicle suspension arm that can solve the conventional problems with a simple structure.

  In order to achieve the above object, the invention according to claim 1 is a vehicle suspension arm comprising an arm main body and a bush press-fit portion provided at one end of the arm main body and capable of press-fitting and fitting a bush. The main body is press-molded to form the main part of the arm body, and a main plate body in which a short cylindrical part is integrally connected by burring at one end, and the upper and lower surfaces of the main plate body are superposed to reinforce the main plate body And a reinforcing plate that is formed in an annular shape and is aligned with the short cylindrical portion on the same axis so as to be integrated along the longitudinal direction of the main plate body from the eyeball-shaped head. A tail portion extending to the main plate body, and at least the tail portion is welded to the main plate body, the inner peripheral surface of the eyeball-shaped head, and With the inner peripheral surface of the short cylindrical part Wherein the Mesh press-fitting portion is constituted.

  According to a second aspect of the present invention, there is provided a vehicle suspension arm including an arm main body and a bush press-fit portion provided at one end of the arm main body and capable of press-fitting and fitting a bush. The arm main body is press-molded. A main plate having a main part of the arm main body and integrally formed with one end formed in an annular shape at one end, and a reinforcing plate that is superposed on the upper and lower surfaces of the main plate to reinforce the main plate The reinforcing plate is formed in an annular shape and is integrally extended from the eyeball-shaped head portion along the longitudinal direction of the main plate body. The tail plate is formed of a plate material thicker than the main plate body, and at least the tail portion is welded to the main plate body, on the inner peripheral surface of the eyeball-shaped head, or the eyeball The inner peripheral surface of the head and the inner peripheral surface of the eyeball-shaped end In characterized in that the bush press-fitting portion is constituted.

  According to a third aspect of the present invention, there is provided a vehicle suspension arm including an arm main body and a bush press-fit portion provided at one end of the arm main body and capable of press-fitting and fitting a bush. A hollow frame made of a combined body of lower plate bodies, press-molded to form main parts, an eyeball-shaped head formed in an annular shape, and a tail that extends integrally from the eyeball-shaped head And at least a reinforcing plate that is inserted into and welded to a hollow portion at one end of the hollow frame body, and the reinforcing plate is formed of a plate material that is thicker than the upper and lower plate bodies. In addition, the bush press-fitting portion is configured by an inner peripheral surface of the eyeball-shaped head.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the arm main body has an eyeball-shaped head formed in an annular shape and a tail portion extending integrally from the eyeball-shaped head. The tail portion further includes a second reinforcing plate welded to the upper and lower surfaces of one end portion of the hollow frame, and the second reinforcing plate is formed of a plate material thicker than the upper and lower plate bodies. In addition, the bush press-fitting portion is formed on the inner peripheral surface of the eyeball-shaped head of the second reinforcing plate.

  According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the tail portion of one of the reinforcing plates is formed longer than the tail portion of the other reinforcing plate, and the length of the upper and lower plate bodies is longer. It is characterized by extending along the direction.

  According to a sixth aspect of the present invention, in addition to the structure of any one of the first to fifth aspects, the reinforcing plate is formed by stamping a single plate material with a press.

  According to a seventh aspect of the invention, in addition to the configuration of the first or second aspect, the reinforcing plate is positioned so as to position the reinforcing plate with respect to the main plate in cooperation with a positioning hole provided in the main plate. Protrusion or hole is formed.

  According to an eighth aspect of the present invention, in addition to the configuration of the third, fourth, or fifth aspect, the reinforcing plate includes a reinforcing plate for the hollow frame body in cooperation with a positioning hole provided in the upper or lower plate body. Positioning projections or holes for positioning are formed.

  In addition to the structure of claim 1, 2, or 3, the invention of claim 9 includes a ring portion that overlaps the eyeball-shaped head portion of the reinforcing plate, and a part on the base side of the tail portion. A local reinforcing plate made of a plate material integrally having only overlapping tongue pieces is coupled in a laminated state, and the bush press-fitting portion is also formed on the inner peripheral surface of the ring portion.

  In addition to the configuration of claim 4, the invention of claim 10 includes, in addition to the structure of claim 4, the second reinforcing plate only on a ring portion that overlaps the eyeball-shaped head portion of the second reinforcing plate and a part on the base side of the tail portion. A local reinforcing plate made of a plate material integrally having an overlapping tongue piece is joined in a laminated state, and the bush press-fitting portion is also formed on the inner peripheral surface of the ring portion.

  In addition to the structure of claim 9 or 10, the invention of claim 11 welds between the inner surface of the through-hole formed in the tongue piece and the tail portion where the tongue piece overlaps, Thus, the local reinforcing plate and the reinforcing plate are combined.

  According to the invention of claim 1, the arm main body is press-molded to form a main portion of the arm main body, and one end of the short cylindrical portion is integrally connected by burring at one end, and the upper and lower sides of the main plate body. A reinforcing plate that is superposed on one surface and reinforces the main plate body. The reinforcing plate is formed in an annular shape and is aligned with the short cylindrical portion on the same axis. A tail portion that extends integrally along the longitudinal direction of the main plate body, and is formed of a plate material thicker than the main plate body, and at least the tail portion is welded to the main plate body, Since the bush press-fit portion is configured by the inner peripheral surface of the head and the inner peripheral surface of the short cylindrical portion, a portion of the bush press-fit portion and the arm body can be seamlessly connected integrally. This is advantageous for improving the The cross-sectional shape of the transition part from the bush press-fit part to the plate arm body is sufficiently secured, and the necessary rigidity and strength of the transition part can be easily secured, and the burring process for forming the bush press-fit part is the main plate The process may be performed only on one end of the body, and the machining process can be simplified accordingly, which can contribute to the improvement of productivity and the reduction of the machining cost. In addition, if the suspension arm is required to be further strengthened due to an increase in the horsepower of the car, etc., it can be handled simply by increasing the thickness of the reinforcing plate without increasing the outer peripheral space of the bush press-fit part. In addition, even when the suspension arm strength condition varies depending on the vehicle type variation, it is possible to easily and at low cost by changing the thickness of the reinforcing plate. Furthermore, since the bush press-fit part is composed of the inner peripheral surface of the eyeball-shaped head of the reinforcing plate and the inner peripheral surface of the short cylindrical part of the burring of the arm body, it is possible to secure a sufficient holding load on the bush, It is possible to omit or reduce the welding location between the arm main body and the reinforcing plate around the portion.

  Further, according to the invention of claim 2, the arm main body is press-molded to form a main part of the arm main body, and a main plate body integrally formed with an eyeball-shaped end portion formed in an annular shape at one end; A reinforcing plate that is superposed on the upper and lower surfaces of the main plate body to reinforce the main plate body, and the reinforcing plate is formed in an annular shape and has an eyeball-shaped head lined coaxially with the eyeball-shaped end portion; A tail portion that extends integrally from the center of the eyeball in the longitudinal direction of the main plate body, and is formed of a plate material thicker than the main plate body, and at least the tail portion is welded to the main plate body Since the bush press-fit portion is constituted by the inner peripheral surface of the eyeball-shaped head, or by the inner peripheral surface of the eyeball-shaped head and the inner peripheral surface of the eyeball-shaped end portion, the reinforcing plate allows the bush press-fit portion to Ensure a sufficient cross-sectional shape of the transition part to the plate arm body, and ensure the necessary rigidity of the transition part. Strength can be secured easily, and burring processing to form the bush press-in part can be omitted while leaving an integral part of the arm body and bush press-in part, improving productivity and reducing processing costs. Can contribute. In addition, if the suspension arm is required to be further strengthened due to an increase in the horsepower of the car, etc., it can be handled simply by increasing the thickness of the reinforcing plate without increasing the outer peripheral space of the bush press-fit part. In addition, even when the strength condition of the suspension arm is different depending on the vehicle type variation, it is possible to easily and at low cost by changing the thickness of the reinforcing plate. In particular, when the bush press-fit portion is composed of the inner peripheral surface of the eyeball-shaped head portion of the reinforcing plate and the inner peripheral surface of the eyeball-shaped end portion, a sufficient holding load for the bush can be secured, and the arm around the press-fit portion can be secured. It is possible to omit or reduce the welding location between the main body and the reinforcing plate.

  According to the invention of claim 3, the arm main body is press-molded to form the main part of the arm main body, and further, the hollow frame body composed of the combined body of the lower plate bodies, and the centerpiece formed in an annular shape. And a reinforcing plate that has a tail portion that extends integrally from the eyeball-shaped head portion, and the tail portion is inserted into a hollow portion of one end portion of the hollow frame body and welded thereto, and is reinforced The plate is formed of a thicker plate material than the upper and lower plate bodies, and the bush press-fit portion is formed by the inner peripheral surface of the eyeball-shaped head. Ensuring a sufficient cross-sectional shape of the transition part, it is possible to easily secure the necessary rigidity and strength of the transition part, and it is possible to omit the burring process for forming the bush press-fit part, improving productivity and processing This can contribute to cost savings. In addition, if the suspension arm is required to be further strengthened due to an increase in the horsepower of the car, etc., it can be handled simply by increasing the thickness of the reinforcing plate without increasing the outer peripheral space of the bush press-fit part. In addition, even when the strength condition of the suspension arm is different depending on the vehicle type variation, it is possible to easily and at low cost by changing the thickness of the reinforcing plate.

  Further, according to the invention of claim 4, in addition to the structure of the invention of claim 3, the arm body includes an eyeball-shaped head formed in an annular shape and a tail portion extending integrally from the eyeball-shaped head. And a second reinforcing plate that is welded to the upper and lower surfaces of one end of the hollow frame body, and the second reinforcing plate is thicker than the upper and lower plate bodies. In addition, since the bush press-fitting portion is formed on the inner peripheral surface of the eyeball-shaped head of the second reinforcing plate, a sufficient holding load on the bush can be secured.

  Further, according to the invention of claim 5, in addition to the structure of the invention of claim 4, the tail portion of one reinforcing plate is formed longer than the tail portion of the other reinforcing plate, so that the upper and lower plates Since it extends along the longitudinal direction of the body, the long tail portion can increase the bonding strength between the one reinforcing plate and the hollow frame.

  Further, particularly according to the invention of claim 6, in addition to the configurations of the inventions of claims 1 to 5, the reinforcing plate is formed by stamping a single plate material with a press. Not only is the productivity of the reinforcing plate of the structure excellent, but the inner peripheral surface of the eyeball-shaped head that becomes the bush press-fit portion in the reinforcing plate can be easily formed by using the cut surface of the press punching, High inner diameter accuracy required for press-fitting can be easily realized at low cost.

  In particular, according to the invention of claim 7 or 8, the reinforcing plate is positioned with respect to the main plate body or the hollow plate body in cooperation with positioning holes provided in the main plate body or the upper or lower plate body. Since the positioning projections or holes to be formed are formed, the reinforcing plate can be positioned accurately and easily with a simple positioning structure even if the reinforcing plate is separated from the arm body.

  In particular, according to the invention of claim 9 or 10, the reinforcing plate or the second reinforcing plate includes a ring portion that overlaps the eyeball-shaped head portion thereof, and a tongue piece that overlaps only a part of the base portion side of the tail portion. Since the local reinforcement plate made of the plate material integrally having the structure is joined in a laminated state, and the bush press-fitting portion is also formed on the inner peripheral surface of the ring portion, the laminating effect of the local enhancement plate allows the tail meat in the reinforcement plate to be While suppressing the increase in thickness as much as possible (that is, reducing the weight of the reinforcing plate), the bush holding strength can be increased by effectively increasing the axial width of the bush press-fitting portion, and the entire cross section of the reinforcing plate and the local reinforcing plate is bushed. The thickness can be reduced gradually from the press-fit portion to the arm main body, and the arm main body can be smoothly transferred to the cross section.

  In particular, according to the invention of claim 11, the inner surface of the through hole formed in the tongue piece and the tail part where the tongue piece overlaps are welded, and the local reinforcing plate and the Since the connection with the reinforcing plate is made, the weight of the local reinforcing plate can be reduced while ensuring the necessary welding strength.

  Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings.

  In the accompanying drawings, FIG. 1 is a perspective view schematically showing a vehicle mounting state of an automobile suspension arm according to one embodiment of the present invention, FIG. 2 is a single perspective view of the suspension arm, and FIG. 3 is the suspension. 4 is a bottom plan view of the suspension arm (as viewed from the direction of arrow 4 in FIG. 2), FIG. 5 is an exploded perspective view of the suspension, and FIG. 6 is an enlarged view of line 6-6 in FIG. 7 is an enlarged sectional view taken along line 7-7 in FIG. 3, and FIG. 8 is an enlarged sectional view taken along line 8-8 in FIG. 9 is a view corresponding to FIG. 8 showing a modified example of the positioning structure of the reinforcing plate with respect to the arm body, FIG. 10 is a plan view showing a first modified example of the first bush press-fitting portion, and FIG. FIG. 12 is a plan view showing a second modification of the first bush press-fitting portion, FIG. 13 is a sectional view taken along line 13-13 in FIG. 12, and FIG. 14 is taken along line 14-14 in FIG. 15 is a plan view showing a third modification of the first bush press-fitting portion, FIG. 16 is a sectional view taken along the line 16-16 in FIG. 15, and FIG. 17 is an enlarged view taken along arrow 17 in FIG. 18 is an enlarged sectional view taken along line 18-18 in FIG. 17, and FIG. 19 is a sectional view taken along line 19-19 in FIG. Further, FIG. 20 is a partial perspective view showing a modified example of the winding forming structure of the bush support sleeve, FIG. 21 is a diagram corresponding to FIG. 17 showing a first modified example of the coupling structure of the bush support sleeve and the arm body, and FIG. 21 is a sectional view taken along the line 22-22 in FIG. 21, FIG. 23 is a view corresponding to FIG. 17 showing a second modified example of the coupling structure of the bush support sleeve and the arm body, and FIG. 24 is a sectional view taken along the line 24-24 in FIG. It is. Further, FIGS. 25 to 27 show another embodiment in which the local reinforcing structure for the reinforcing plate by adding the local reinforcing plate is applied to the third modification of the first bush press-fitting portion, and FIG. 15 is a cross-sectional view taken along line 26-26 of FIG. 25, and FIG. 27 is an exploded perspective view.

  As shown in FIG. 1, a knuckle N that rotatably supports a wheel W of a wheel has a lower portion connected by a lower arm A and an upper portion connected by an upper arm (not shown) to a vehicle body or a subframe (hereinafter simply referred to as a vehicle body). F) and is supported so as to be movable up and down. In addition, a damper D with a coil spring is interposed between the vehicle body F and the lower arm A in order to support the vehicle body weight and buffer the vertical movement of the knuckle N.

  The lower arm A is a so-called A-type arm and constitutes the suspension arm of the present invention. The lower arm LA has an outer end connected to a knuckle N via a ball joint BJ so as to be able to swing, and a first and second inner ends divided into two forks are a pair of front and rear rubber bushes. It is connected to the vehicle body F via B1, B2 and connecting pins J1, J2 penetrating them.

  2 to 5, the arm body 1 of the lower arm LA is a hollow frame in which an upper plate 2 and a lower plate 3 formed by pressing a steel plate are integrally coupled to each other. The body T is configured as a main portion, and an outer arm portion 1A extending in a substantially vehicle width direction (that is, a substantially left-right direction of the vehicle body) from an arm central portion toward an outer end portion, and a first from the central portion. A first inner arm portion 1B extending obliquely forward inward toward the inner end portion and a second inner arm portion 1C extending obliquely backward inward from the central portion toward the second inner end portion are provided. A first bush press-fit portion P1 for press-fitting and supporting the first rubber bush B1 on the inner periphery is provided at the front first inner end of the arm body 1, and a second rubber is provided at the rear second inner end. A second bush press-fit portion P2 for press-fitting and supporting the bush B2 on the inner periphery is connected to each other, and a support bracket 4 having a mounting hole for supporting the ball joint BJ is welded to the outer end of the arm body 1. Is done.

  The axis of the first bush press-fit portion P1 is set in a substantially vertical direction, and the second bush press-fit portion P2 is set in a substantially front-rear direction of the vehicle body. The second bush press-fit portion P2 is constituted by a cylindrical metal collar C in the illustrated example, and the outer peripheral portion of the collar C is disposed in each second inner side on the rear side of the upper plate body 2 and the lower plate body 3. Welded to the end.

  Each part (namely, the outer arm portion 1A and the first and second inner arm portions 1B and 1C) from the center of the arm body 1 has a transverse cross section that is longer than the upper wall in the illustrated example, and the front and rear side walls. Is formed in a generally trapezoidal shape spreading toward the bottom. That is, the upper plate body 2 is formed in a substantially U-shaped cross section with a substantially flat upper wall portion, and a front side wall portion and a rear side wall portion that hang downward from the front and rear ends thereof. The plate body 3 is formed in a flat plate shape so as to close the lower end opening of the upper plate body 2 and is abutted between the inner surfaces of the lower end portions of the front and rear side walls of the upper plate body 2 and welded. .

  Next, the structure of the first bush press-fit portion P1 in the lower arm LA will be described with reference to FIGS.

  The first inner arm portion 1B of the arm body 1 includes an upper plate body 2 as a main plate body which is a main portion of the inner arm portion 1B and is integrally connected with a short cylindrical portion EB at one end by burring. A lower plate pair 3 welded to the upper plate 2 to block the open lower surface thereof, and a reinforcing plate H made of a single plate material superposed and welded on the upper surface of the upper plate 2 to reinforce the upper plate 2 Prepare.

  The reinforcing plate H is formed in an annular shape and extends integrally with the eyeball-shaped head portion Ha aligned coaxially with the short cylindrical portion EB and along the longitudinal direction of the upper plate body 2 from the eyeball-shaped head portion Ha. It has a tail portion Hb to be brought out, and is formed by stamping a steel plate thicker than the upper and lower plate bodies 2 and 3 with a press. Then, at least the tail portion Hb of the reinforcing plate H is welded to the upper plate 2 over substantially the entire length thereof. The center of the reinforcing plate H and the short cylindrical portion EB of the upper plate 2 are not welded in the illustrated example, but may be welded as necessary.

  Thus, the first bush press-fit portion P1 is constituted by the inner peripheral surface of the press-shaped head portion Ha and the inner peripheral surface of the burring-processed short cylindrical portion EB. Accordingly, the outer peripheral collar B1c of the first rubber bush B1 is fitted and held on the inner peripheral surfaces by sequential press-fitting from one axial side (the upper side in the illustrated example).

  According to the structure of the first bush press-fit portion P1 as described above, since a portion of the press-fit portion P1 and the arm body 1 are connected seamlessly and integrally, it is advantageous in increasing the strength. In addition, by providing the reinforcing plate H with a long tail portion Hb along the longitudinal direction of the arm main body 1, a sufficient cross-sectional shape of the transition portion from the bush press-fit portion P1 to the plate arm main body 1 is secured. The required rigidity and strength of the transition portion can be easily secured. Moreover, since the burring process for forming the bush press-fit portion P1 only needs to be performed on one end of the main plate (upper plate 2), the machining process can be simplified and the productivity can be improved and the machining cost can be reduced. Savings are planned.

  In addition, when further improvement in strength is required for the lower arm LA due to an increase in the horsepower of the automobile, etc., the outer peripheral space of the bush press-fit portion P1 can be specially increased simply by increasing the thickness of the reinforcing plate H. In addition, even when the strength condition of the lower arm LA varies depending on the vehicle type variation, it is possible to easily and at low cost by changing the thickness of the reinforcing plate H. Further, since the first bush press-fit portion P1 is configured by the inner peripheral surface of the eyeball-shaped head portion Ha of the reinforcing plate H and the inner peripheral surface of the short cylindrical portion EP subjected to burring of the arm body 1, the first rubber bush A sufficient holding load for B1 can be ensured, and the welding location between the arm body 1 and the reinforcing plate H around the press-fit portion P1 can be omitted or reduced. In addition, since the reinforcing plate H is formed by stamping a single plate material with a press, the productivity of the reinforcing plate H having a separate structure from the arm body 1 is not only high, but also in the reinforcing plate H. The inner peripheral surface of the eyeball-shaped head portion Ha serving as the bush press-fitting portion P1 can be easily formed by using a cut surface of press punching, and high inner diameter accuracy required for bush press-fitting can be easily realized at low cost. .

  Further, in the portion of the tail portion Hb of the reinforcing plate H close to the eyeball-shaped head portion Ha, the reinforcing plate H is positioned with respect to the upper plate body 2 in cooperation with the positioning hole 2h provided in the upper plate body 2. Positioning projections Hi to be formed are formed. Therefore, even if the reinforcing plate H is separated from the arm body 1, the reinforcing plate H can be positioned accurately and easily with a simple positioning structure. In place of such positioning protrusions Hi, as shown in FIG. 9, a reinforcing plate H is provided with a positioning hole Ho, and a jig J that fits into the hole Ho and the positioning hole 2h of the upper plate 2 is used. Then, positioning may be performed.

  Next, a first modification of the first bush press-fit portion P1 in the lower arm LA will be described with reference to FIGS.

  In this modification, the arm main body 1 is press-molded to form a main portion of the arm main body 1 and an upper plate as a main plate body integrally formed with an eyeball-shaped end portion EP formed in an annular shape at one end. A body 2 and a reinforcing plate H that is superposed on the upper surface of the upper plate 2 and reinforces the upper plate 2. Further, in the illustrated example, an annular press is also applied to one end of the lower plate 3. The molded eyeball-shaped end portion EP ′ is integrally connected via the inclined connecting portion 3k and is superposed on the same axis as the eyeball-shaped end portion EP of the upper plate 2.

  And the reinforcement board H is formed in the annular | circular shape like the previous Example, and the eyeball-shaped head Ha which arranges coaxially with the said short cylindrical part, and follows the longitudinal direction of the upper plate body 2 from the eyeball-shaped head Ha. In this way, the steel plate is formed by stamping a steel plate thicker than the upper and lower plate bodies 2 and 3 with a press. Of the reinforcing plate H, at least the tail portion Hb is welded to the upper plate 2 over substantially the entire length thereof. The center of the reinforcing plate H and the short cylindrical portions EP and EP ′ of the upper and lower plate bodies 2 and 3 are not welded in the illustrated example. It may be welded accordingly.

  Then, the inner peripheral surface of the eyeball-shaped head portion Ha press-molded or the inner peripheral surface of the eyeball-shaped end portions EP and EP ′ press-molded in the same manner as the inner peripheral surface of the eyeball-shaped head portion Ha. 1 bush press-fit portion P1 is configured. Accordingly, the outer peripheral collar B1c of the first rubber bush B1 is fitted and held on the inner peripheral surfaces by sequential press-fitting from one axial side (the upper side in the illustrated example).

  Further, in the portion of the tail portion Hb of the reinforcing plate H close to the eyeball-shaped head portion Ha, the reinforcing plate H is positioned with respect to the upper plate body 2 in cooperation with the positioning hole 2h provided in the upper plate body 2. Positioning projections Hi to be performed or positioning holes similar to those in FIG. 9 are formed.

  Thus, also in this first modified example, basically the same operational effects as those of the previous embodiment can be obtained, and the bush press-fit portion P1 is obtained while leaving an integral structure portion of the arm body 1 and the bush press-fit portion P1. The burring process for the arm body 1 for forming can be omitted, and the productivity can be improved and the processing cost can be reduced.

  Next, a second modification of the first bush press-fit portion P1 in the lower arm LA will be described with reference to FIGS.

  In this modification, the arm body 1 is a main part of the arm body 1, and further includes a hollow frame T formed of a combination of the lower plate bodies 2 and 3, an eyeball-shaped head Ha formed in an annular shape, and A reinforcing plate H is provided which has a tail portion Hb extending integrally from the eyeball-shaped head portion Ha, and the tail portion Hb is inserted and welded into a hollow portion at one end of the hollow frame T. In the illustrated example, the tail portion Hb of the reinforcing plate H is fixed to the inner surface of the upper plate body 2 (that is, engaged with the inwardly curved portion of the upper wall portion of the upper plate body 2 and the left and right side wall portions. After being fixed, the upper plate 2 and the lower plate 3 are joined. And the 1st bush press-fit part P1 is comprised by the inner peripheral surface of the said eyeball-shaped head Ha, and the outer peripheral collar B1c of 1st rubber bush B1 is the axial direction from the axial direction one side (in the example of illustration upper side). Fit and hold by press-fitting.

  Further, in a vehicle that requires a large press-fitting holding load of the first bush press-fitting portion P1, such as a sports type vehicle, as shown by a chain line in FIGS. 12 to 14, an eyeball-shaped head Ha ′ formed in an annular shape. And a tail portion Hb ′ extending integrally from the eyeball-shaped head portion Ha ′, and the tail portion Hb ′ is welded to the upper surface of one end portion of the hollow frame T. 'May be further provided. In that case, the first bush press-fit portion P1 is formed by the inner peripheral surfaces of the eyeball-shaped heads Ha, Hb; Ha ′, Hb ′ of both the reinforcing plates H, H ′. Accordingly, the outer peripheral collar B1c of the first rubber bush B1 is fitted and held on the inner peripheral surfaces by sequential press-fitting from one axial side (the upper side in the illustrated example).

  And in this 2nd modification, the tail part Hb of one reinforcement board H inserted and welded in the inside of the hollow frame T is longer than the tail part Hb 'of the reinforcement board H' outside the hollow frame T. Although formed and extends along the longitudinal direction of the hollow frame T, the tail portion Hb ′ of the reinforcing plate H ′ outside the hollow frame T is connected to the hollow frame opposite to the second modification. What is formed longer than the tail part Hb of one reinforcing plate H to be inserted and welded inside T and extends along the longitudinal direction of the hollow frame T is the third shown in FIGS. It is a modification.

  Thus, in the second and third modified examples, basically the same effects as those of the previous embodiment can be obtained, and further, burring processing on the arm body 1 for forming the bush press-fit portion P1 can be omitted. As a result, productivity can be improved and processing costs can be reduced.

  Although not shown in the second and third modifications, the eyeball heads Ha and Ha of the tails Hb and Hb ′ of at least one of the reinforcing plates H and H ′ are the same as in the above-described embodiment. A positioning projection or hole for positioning the reinforcing plates H and H ′ with respect to the hollow frame T is formed in a portion close to ′ in cooperation with the positioning holes provided in the upper or lower plate bodies 2 and 3. Also good.

  Next, a connection structure between the lower arm LA and the damper D will be described with reference to FIGS.

A fork-like lower end portion 7 of the damper D straddling the arm main body 1 (outer arm portion 1A in the illustrated example) near the outer end serving as a damper support portion with a gap s _D therebetween, It is connected via a connecting pin J3 that extends horizontally in the front-rear direction of the vehicle body and a third rubber bush B3 that surrounds the pin J3. A substantially cylindrical bush support sleeve S for press-fitting and supporting the third rubber bush B3 in the intermediate portion 1d is attached to the intermediate portion 1d of the arm body 1. Further, a drive shaft 10 for driving the wheel or a protective boot PB covering the joint portion of the shaft 10 passes through the gap s _D , and the outer end of the shaft 10 is integrated with the wheel W of the wheel. Connected so as to rotate.

  The intermediate portion 1d extending in the vehicle width direction of the arm body 1 (outer arm portion 1A) has a transverse cross section lower than that of the upper wall (upper wall portion 2u of the upper plate 2) like the other portions of the arm body 1. The wall (lower plate 3) is long, and the front side wall (front side wall 2f of the upper plate 2) and the rear side wall (rear side wall 2r of the upper plate 2) are formed in a generally trapezoidal shape that spreads downward. The The front side wall portion 2f and the rear side wall portion 2r are formed with a pair of front and rear sleeve holes 2fh and 2rh for fitting the front and rear end portions of the bush support sleeve S, respectively. At both ends, welding margins Sf and Sr are provided to slightly protrude outward from the arm body 1 in order to weld the sleeve S and the arm body 1. Accordingly, the bush support sleeve S is formed in a substantially trapezoidal shape in a side view so as to ensure necessary welding margins Sf and Sr corresponding to the cross-sectional shape of the arm body 1.

  In this way, the cross-sectional shape of the intermediate portion 1d of the arm body (outer arm portion 1A) is formed in a generally trapezoidal shape in which the lower wall is longer than the upper wall and the front side wall and the rear side wall expand downward. Corresponding to the cross-sectional shape of the arm main body intermediate portion 1d, the bush support sleeve S is formed in a generally trapezoidal shape in a side view so as to secure welding margins Sf and Sr between the sleeve S and the arm main body 1. Therefore, a large input load in the vertical direction acting on the arm body 1 from the fork-like lower end 7 of the damper D via the sleeve S and the bush B3 and a large input load in the front-rear direction from the wheel W (brake reaction force). On the other hand, it is possible to design the arm intermediate portion 1d itself to have a sufficient width section efficiently in a limited space, and a sufficient strength can be secured even with the arm body 1 having a plate structure.

  Further, on the front and rear end surfaces Sef, Ser of the bush support sleeve S, the fork-like lower end 7 and the fork-like lower end 7 of the damper D as shown by a chain line in FIG. Concave-curved reliefs nf and nr are formed between the sleeves S so as to secure a necessary minimum clearance. As a result, even if the side surface of the sleeve has a trapezoidal shape corresponding to the cross-sectional shape of the arm body 1 as described above, the front and rear end surfaces Sef, Ser of the endlessly expanding sleeve interfere with the fork-like lower end 7 of the damper D. There is no fear of it.

  By the way, the bush support sleeve S is formed by winding in a cylindrical shape so as to connect one end edge portion Sa and the other end edge portion Sb of a plate-shaped sleeve material pressed in the illustrated example. The edge portion Sa and the other end edge portion Sb are butt welded. Therefore, even if the front and rear end surfaces Sef and Ser of the bush support sleeve S are diverging downward in a side view as described above and have the reliefs nf and nr, they have complicated line shapes. The complicated line form can be formed with high precision by simple press processing on the plate-shaped sleeve material, and the accuracy and efficiency of the processing process can be improved.

  Also, in the illustrated example, opposed recesses in the form of notched holes are formed between the opposing surfaces of the one end edge portion Sa and the other end edge portion Sb of the bush support sleeve S that face each other. As a result, a through-hole Sk straddling the facing surface is formed. The inner surface of the through hole Sk and the outer peripheral surface of the inner sleeve SI exposed through the through hole Sk are welded to increase the coupling strength between the sleeves S and SI, and the one end edge portion Sa and others. The coupling strength between the edge portions Sb can also be increased.

  Note that the method of winding the bush support sleeve S and connecting the edges Sa and Sb is not limited to the illustrated example. For example, the through holes Sk are omitted and the edges Sa and Sb The opposing surfaces may be butt welded over their entire area. Further, instead of the butt welding as described above, both end edges Sa and Sb of the plate-shaped sleeve material partially overlap each other in the sleeve radial direction as shown in FIG. May be. In this case, as shown in FIG. 20 (a), only the edge of the overlap portion may be simply welded, and further, one end that is outside the overlap portion as shown in FIG. 2 (b). The hole 10 may be formed in advance in the edge portion Sa, and the inner peripheral surface of the hole 10 and the other end edge portion Sb may be welded.

  Further, in the illustrated example, a simple cylindrical inner sleeve SI shorter than the sleeve S is fitted and welded to the inner peripheral surface of the bush support sleeve S, and the third bush B3 is connected via the inner sleeve SI. The bush support sleeve S is press-fitted and fitted. According to such a double structure of the sleeves S and SI, even if the side surface form of the bush support sleeve S is trapezoidal as described above, the inner sleeve SI is disposed only at a portion necessary for holding the bush (that is, Since a double-sleeve structure (which eliminates waste meat as much as possible) is obtained, it is possible to sufficiently increase the rigidity and strength of the sleeves S and SI while reducing the weight as a whole. In addition, the processing accuracy of the outer sleeve S can be relatively low with respect to the inner sleeve SI that directly holds the bush B3, so that the processing cost can be reduced accordingly.

  By the way, the pair of sleeve holes 2fh and 2rh are each formed in the shape of a notch with an open top in the illustrated example, and an opening provided in the arm body 1 (upper plate 2) so as to cross the upper wall thereof. Communicate with each other via O. As a result, it is possible to use a bush support sleeve S having a relatively large diameter such that part of the sleeve holes 2fh and 2rh protrudes, and the sleeve holes 2fh and 2rh and the opening O are formed by pressing, or By forming by combining press processing and plasma cut processing, etc., the processing operation becomes relatively easy and cost saving is achieved.

  Further, as shown in FIG. 17, the inner side surface of the opening O of the upper wall of the arm body 1 (upper plate 2) is related to forming the opening O by press working or plasma cutting. The surface is substantially orthogonal to the outer surface of the arm body 1. Therefore, when the outer peripheral surface of the bush support sleeve S is a simple cylindrical surface, a V-shaped gap that is relatively widened is formed between the inner surface of the opening O and the outer peripheral surface of the bush support sleeve S. This is disadvantageous in increasing the welding strength of the welded portion in the gap. However, in the present embodiment, a pair of protrusions St bulging outwardly in the radial direction of the sleeve S is formed on the peripheral wall of the bush support sleeve S corresponding to the inner surfaces facing each other of the opening O. , St ′ are formed along the generatrix direction of the sleeve S and spaced apart from each other in the circumferential direction, whereby the inner surface of the opening O and the bush support sleeve S (the ridge portion St) are formed. , St ′) can be reduced as much as possible, so that the weld strength of the welded portion in the gap can be effectively increased.

  As described above, the support bracket 4 capable of holding the wheel support ball joint BJ is joined to the outer end portion of the arm body 1 (outer arm portion 1A) along the longitudinal direction of the other end portion. In the illustrated example, the support bracket 4 includes an outer end-side eyeball-shaped head 4a capable of holding the ball joint BJ, and an inner-end-side tail extending from the eyeball-shaped head 4a along the longitudinal direction of the arm body 1. The part 4b is formed integrally. The upper edge portion of the tail portion 4b is provided on the upper wall portion 2u of the upper plate 2 and has one end fitted and welded to the slit portion 2us communicating with the opening O, while the tail portion 4b The lower edge portion is fitted and welded to a slit portion 3 s provided in the lower plate 3.

  Further, the inner end side of the tail portion 4b is formed in a fork shape which is divided into two forks up and down, and the upper end of the inner end is an engagement formed on one protruding portion St provided on the outer periphery of the bush support sleeve S. It is inserted and welded into the engagement hole Sh as a recess. Thus, by utilizing the protrusion St of the bush support sleeve S, the welding region of the support bracket 4 to the arm body 1 side can be extended, and the coupling strength of the support bracket 4 to the arm body 1 can be increased. Thus, the coupling strength of the bush support sleeve S is also increased.

  Next, with reference to FIGS. 21 and 22, a first modification of the coupling structure between the bush support sleeve S and the arm body 1 will be described. In this modified example, a pair of front and rear sleeve holes 2fh and 2rh provided in the front and rear side walls of the intermediate part 1d of the arm body 1 are formed in circular holes instead of notches, and the circular holes A bush support sleeve S having a circular cross section (and thus a pair of protrusions St and St ′ on the outer periphery of the sleeve is omitted) is fitted and welded to the sleeve holes 2fh and 2rh. An inner sleeve SI similar to the previous embodiment is fitted and welded to the peripheral surface. In this embodiment, the front and rear end surfaces Sef, Ser of the bush support sleeve S are formed in the same manner as in the previous embodiment.

  Next, with reference to FIG. 23 and FIG. 24, a second modification of the coupling structure between the bush support sleeve S and the arm body 1 will be described. In this modification, the inner sleeve SI is omitted from the structure of the first modification, and the third rubber bush B3 is directly press-fitted and held on the inner peripheral surface of the bush support sleeve S. The structure is simplified.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various small design change is possible.

  For example, in the above-described embodiment, the A-type lower arm LA is shown as the suspension arm. However, the present invention may be applied to an I-type arm or an upper arm other than the A-type.

  In the above embodiment, the upper plate 2 and the lower plate 3 constituting the arm body 1 are connected by welding. However, in the present invention, the upper plate 2 and the lower plate 3 are connected to each other. You may make it couple | bond by fixing means other than welding.

  In the above embodiment, the bush support sleeve S is manufactured by winding a plate material into a cylindrical shape. However, both ends of an endless circular tube material are machined into a predetermined shape to form the bush support sleeve S. May be produced.

  In the above embodiment, only the reinforcing plate H and only the reinforcing plate H and the second reinforcing plate H ′ are connected to the arm body 1 in order to form the first bush press-fit portion P1. In the present invention (inventions 9 to 11), the local reinforcing plate H that reinforces the peripheral portion of the first bush press-fit portion P1 on one or both of the reinforcing plate H and the second reinforcing plate H ′. ”May be combined in a laminated state, and an example in which the local reinforcing structure of the reinforcing plates H and H ′ by the local reinforcing plate H ″ is implemented in the third modification shown in FIGS. 15 and 16 is shown in FIGS. It shows in FIG. That is, the local reinforcing plate H ″ includes an annular ring portion Ha ″ that overlaps the eyeball-shaped head portions Ha and Ha ′ of the reinforcing plates H and H ′, and tail portions Hb and Hb ′ of the reinforcing plates H and H ′. Is formed of a press-formed steel plate integrally having a tongue piece Hb ″ that overlaps only a part of the base side of the steel plate, and is integrally joined to the reinforcing plates H and H ′ in a laminated state. The first bush press-fit portion P1 is also configured by the inner peripheral surface of the ring portion Ha ″ of the reinforcing plate H ″. The tongue piece Hb ″ is formed with a through-hole 100 penetrating in the vertical direction. The inner surface of the hole 100 and the tail portions Hb and Hb ′ where the tongue pieces Hb ″ are superposed are welded, and the local reinforcing plate H ″ and the reinforcing plates H and H ′ are joined by the welding. The

  Thus, in this embodiment, the increase in the thickness of the tail portions Hb and Hb ′ in the reinforcing plates H and H ′ is suppressed as much as possible by the effect of laminating the local reinforcing plates H ″ (that is, the weight of the reinforcing plates H and H ′ is reduced). The bush holding strength can be increased by effectively increasing the axial width of the bush press-fit portion P1, and the entire cross section of the reinforcing plates H, H ′ and the local reinforcing plate H ″ can be extended from the bush press-fit portion P1 to the arm. The thickness can be reduced gradually toward the main body 1 side and smoothly transferred to the cross section of the arm main body. Such a local reinforcing structure of the reinforcing plate H using the local reinforcing plate H ″ can be implemented in the embodiments shown in FIGS. 6 to 9 and the modified examples shown in FIGS.

The perspective view which shows simply the vehicle attachment state of the suspension arm for vehicles concerning one example of the present invention. Single perspective view of the suspension arm Single plan view of the suspension arm Single unit bottom view of the suspension arm (viewed in the direction of arrow 4 in FIG. 2) Exploded perspective view of the suspension 6-6 enlarged sectional view of FIG. FIG. 7 is an enlarged sectional view taken along line 7-7. FIG. 8 is an enlarged sectional view taken along line 8-8. FIG. 8 is a view corresponding to FIG. 8 showing a modification of the positioning structure of the reinforcing plate with respect to the arm body. The top view which shows the 1st modification of a 1st bush press-fit part 11-11 sectional view of FIG. The top view which shows the 2nd modification of a 1st bush press-fit part 13-13 sectional view of FIG. 14-14 sectional view of FIG. The top view which shows the 3rd modification of a 1st bush press-fit part 16-16 sectional view of FIG. 17 enlarged view of FIG. FIG. 17 is an enlarged sectional view taken along line 18-18. Sectional view taken along line 19-19 in FIG. Partial perspective view showing a modified example of the winding forming structure of the bush support sleeve FIG. 17 is a view corresponding to FIG. 17 showing a first modification of the coupling structure between the bush support sleeve and the arm body. Sectional view taken along line 22-22 in FIG. FIG. 17 is a view corresponding to FIG. 17 showing a second modified example of the coupling structure between the bush support sleeve and the arm body. 24-24 sectional view of FIG. FIG. 15 is a view corresponding to FIG. 15 showing another embodiment in which the local reinforcing structure for the reinforcing plate by adding the local reinforcing plate is applied to the third modification of the first bush press-fitting portion. 25 is a cross-sectional view taken along line 26-26 in FIG. Exploded perspective view of the other embodiment

Explanation of symbols

B1 1st rubber bush (bush)
EB Short cylindrical part EP Eye end H, H 'Reinforcement plate Ha, Ha' Eye head Hb, Hb 'Tail H "Local foot reinforcement Ha" Ring part Hb "Tongue piece LA Lower arm (suspension arm)
P1 1st bush press-fit part (bush press-fit part)
T Hollow frame 1 Arm body 2 Upper plate (main plate)
3 Lower plate body 100 Through hole

Claims (11)

In a vehicle suspension arm comprising an arm body (1) and a bush press-fit portion (P1) provided at one end of the arm body (1) and capable of press-fitting and fitting a bush (B1), the arm body (1 ) Is a press-molded main plate (2) having a main portion of the arm main body (1) and a short cylindrical portion (EB) integrally connected to one end by burring, and the main plate (2). And at least a reinforcing plate (H) that is superposed on the upper and lower surfaces to reinforce the main plate (2),
The reinforcing plate (H) is formed in an annular shape and is aligned with the short cylindrical portion (EB) on the same axis, and the main plate body (2) is connected to the main plate body (2) from the eye-shaped head portion (Ha). A tail portion (Hb) that extends integrally along the longitudinal direction, and is formed of a thicker plate material than the main plate (2), and at least the tail (Hb) is the main plate. Welded to (2),
The suspension arm for a vehicle, wherein the bush press-fit portion (P1) is configured by an inner peripheral surface of the eyeball-shaped head (Ha) and an inner peripheral surface of the short cylindrical portion (EB). In a vehicle suspension arm comprising an arm body (1) and a bush press-fit portion (P1) provided at one end of the arm body (1) and capable of press-fitting and fitting a bush (B1), the arm body (1 ) Is a main plate body (2) formed by pressing and forming a main portion of the arm body (1), and an end-shaped end portion (EP) formed in an annular shape at one end, and its main plate A reinforcing plate (H) that is superposed on the upper and lower surfaces of the body (2) to reinforce the main plate (2);
The reinforcing plate (H) is formed in an annular shape and has an eyeball-shaped head (Ha) aligned coaxially with the eyeball-shaped end (EP), and a main plate body (2) from the eyeball-shaped head (Ha). And a tail (Hb) that extends integrally along the longitudinal direction of the main plate (2), and is formed of a thicker plate material than the main plate (2), and at least the tail (Hb) is the main plate. Welded to the body (2),
The bush press-fit portion (P1) is formed on the inner peripheral surface of the eyeball-shaped head (Ha), or on the inner peripheral surface of the eyeball-shaped head (Ha) and the inner peripheral surface of the eyeball-shaped end (EP). A suspension arm for a vehicle, comprising: In a vehicle suspension arm comprising an arm body (1) and a bush press-fit portion (P1) provided at one end of the arm body (1) and capable of press-fitting and fitting a bush (B1), the arm body (1 ) Are each press-molded to form the main part of the arm body (1), and further, a hollow frame (T) composed of a combined body of the lower plate bodies (2, 3), and an eyeball formed in an annular shape. A head (Ha) and a tail (Hb) extending integrally from the eyeball-shaped head (Ha), the tail (Hb) being hollow at one end of the hollow frame (T) At least a reinforcing plate (H) to be inserted and welded to the part,
The reinforcing plate (H) is formed of a plate material thicker than the upper and lower plate bodies (2), and the bush press-fit portion (P1) is formed on the inner peripheral surface of the eyeball-shaped head (Ha). A suspension arm for a vehicle. The arm body (1) has an eyeball-shaped head (Ha ′) formed in an annular shape and a tail (Hb ′) extending integrally from the eyeball-shaped head (Ha ′), The tail portion (Hb ′) further includes a second reinforcing plate (H ′) welded to the upper and lower surfaces of one end of the hollow frame (T),
The second reinforcing plate (H ′) is formed of a thicker plate material than the upper and lower plate bodies (2, 3), and the eyeball-shaped head portion of the second reinforcing plate (H ′) ( The suspension arm for a vehicle according to claim 3, wherein the bush press-fitting portion (P1) is also formed on the inner peripheral surface of Ha ').   The tail (Hb, Hb ′) of one of the reinforcing plates (H, H ′) is longer than the tail (Hb ′, Hb) of the other reinforcing plate (H ′, H). The vehicle suspension arm according to claim 4, wherein the vehicle suspension arm extends along the longitudinal direction of the hollow frame (T).   The vehicle suspension arm according to any one of claims 1 to 5, wherein the reinforcing plate (H, H ') is formed by stamping a single plate material with a press.   The reinforcing plates (H, H ') are positioned with respect to the main plate (2) in cooperation with positioning holes (2h) provided in the main plate (2). The vehicle suspension arm according to claim 1, wherein positioning protrusions (Hi) or holes (Ho) to be performed are formed.   The reinforcing plate (H, H ′) is provided with a reinforcing plate (H, H ′) for the hollow frame (T) in cooperation with a positioning hole provided in the upper or lower plate (2, 3). The vehicle suspension arm according to claim 3, 4 or 5, wherein a positioning projection (Hi) or a hole (Ho) for positioning is formed.   The reinforcing plate (H) includes a ring portion (Ha ″) that overlaps the eyeball-shaped head portion (Ha) thereof and a tongue piece (Hb ″) that overlaps only a part of the base side of the tail portion (Hb). And a local reinforcing plate (H ″) made of a plate material integrally formed in a laminated state, and the bush press-fitting portion (P1) is formed on the inner peripheral surface of the ring portion (Ha ″). The vehicle suspension arm according to claim 1, 2 or 3.   The second reinforcing plate (H ′) overlaps only with a ring portion (Ha ″) that overlaps the eyeball-shaped head portion (Ha ′) of the second reinforcing plate (H ′) and a part of the base side of the tail portion (Hb ′). A local reinforcing plate (H ″) made of a plate material integrally having a tongue piece (Hb ″) is joined in a laminated state, and the bush press-fitting portion (P1) is also formed on the inner peripheral surface of the ring portion (Ha ″). The vehicle suspension arm according to claim 4, wherein:   Welding between the inner surface of the through hole (100) formed in the tongue piece (Hb ″) and the tail (Hb, Hb ′) where the tongue piece (Hb ″) overlaps, The vehicle suspension arm according to claim 9 or 10, characterized in that the local reinforcing plate (H ") and the reinforcing plate (H, H ') are coupled.

Images