JP6516588B2 - Suspension arm and method of manufacturing the same - Google Patents

Description

  The present invention relates to, for example, a suspension arm provided in a suspension device of a car and a method of manufacturing the same.

  Generally, a suspension system of a motor vehicle is provided with a suspension arm for controlling the movement of a wheel during traveling. One end and the other end of the suspension arm are respectively connected to the vehicle body side member and the wheel side member (for example, Patent Documents 1 to 6).

  The suspension arm of Patent Document 1 includes an arm main body obtained by bending one metal plate into a cylindrical shape, and cylindrical members respectively provided on the vehicle body side end and the wheel side end of the arm main body. ing. A bush is attached to the cylindrical member.

  Further, the arm body of the suspension arm of Patent Document 2 is formed by pressing a steel plate, and is in the form of a substantially square cylindrical body including an upper surface, a lower surface, a front surface and a rear surface. On the lower surface of the arm body, an opening extending in the axial direction of the arm is formed at the center in the width direction, and a part of the arm body is opened by this opening. Cylindrical members for attaching a bush are respectively provided at the vehicle body side end and the wheel side end of the arm body.

  Further, the suspension arm of Patent Document 3 is configured by combining an upper half and a lower half made of a pressed plate material, and a bush is provided at one end and the other end of the lower half. A bush fitting hole to be fitted is formed by burring. The peripheral edge portion of the bush fitting hole is provided with a flange extending radially outward of the bush fitting hole.

  In addition, the suspension arm of Patent Document 4 is formed of a single metal plate, and the back plate extending in the axial direction of the arm and the winding in which the back plate is continuously bent on both sides in the width direction. And a bent portion. At one end and the other end, a bush fitting hole in which a bush is fitted is formed by burring. A bending flange formed to be folded back to the other end side is provided at one axial end of the bush fitting hole.

  In addition, the suspension arm of Patent Document 5 is formed of a single metal plate press-formed so that the cross section becomes a U-shape, and a bush is fitted in one end and the other end of the arm. The joint hole is formed by burring. As disclosed in FIG. 5 of Patent Document 3, the peripheral portion of the bush fitting hole extends radially outward of the bush fitting hole and then extends in the axial direction of the bush fitting hole, Thereafter, a flange bent so as to extend radially outward of the bush fitting hole is provided.

  Further, the suspension arm of Patent Document 6 is configured by combining a pair of pressed link arm halves, and has a cylindrical shape having no flange at one end and the other end of both halves. The bush fitting hole formed in each is provided.

JP, 2015-74319, A JP 2015-47996 A Unexamined-Japanese-Patent No. 2010-111226 JP, 2010-126095, A Japanese Patent Laid-Open No. 2000-16041 JP, 2002-192261, A

  By the way, although there are various structures of the suspension arm as described above, it can be divided into the pipe-shaped one of Patent Document 1 and the press-formed plate material of Patent Documents 2-6. In the case of using plate materials press-formed as in Patent Documents 2 to 6, the shape and size of the cross section can be changed relatively freely for each part of the suspension arm, so that the weight increase of the suspension arm can be suppressed. However, it is excellent in the point which can raise intensity and rigidity.

  Also, although bush fitting holes are required at both ends of the suspension arm, as in Patent Documents 1 and 2, when cylindrical members are provided at both ends of the arm main body, the number of parts is increased. Along with the increase, man-hours for welding the cylindrical member to the arm body are also required, resulting in an increase in cost. On the other hand, forming the bush fitting holes by burring as in Patent Documents 3 to 5 reduces the number of parts and the number of man-hours, which is advantageous in cost.

  That is, in order to obtain a lightweight, high-strength and high-rigidity suspension arm at low cost, the bush fitting hole is formed by pressing in the suspension arm made of a plate material press-molded as in Patent Documents 3 to 5 Is the preferred configuration.

  However, in patent document 3, the flange extended to the radial direction outward of a bush fitting hole is provided, and the protrusion amount of this flange is ensured 3 times or more of plate | board thickness. Further, in Patent Document 4, a bending flange is provided at the peripheral portion of the bush fitting hole, and this flange protrudes from the outer surface of the suspension arm by at least a plate thickness or more in consideration of spring back. Further, in Patent Document 5, a bending flange is provided at the peripheral portion of the bush fitting hole, and since this flange is in a bent shape, it protrudes largely from the outer surface of the suspension arm.

  In the case of providing a flange having a large amount of protrusion from the outer surface of the suspension arm as in Patent Documents 3 to 5, at least the thickness of the plate is projected as in the bending flange of Patent Document 4 as a minimum. It will When the entire suspension arm is enlarged, space efficiency is deteriorated in a state of being assembled to a vehicle, and in order to avoid interference between the flange and a counterpart part to which the suspension arm is attached, the mounting position of the suspension arm is oppositely It must be separated from the basic cross section of the part, and securing the rigidity of the mounting portion becomes an issue. In addition, in order to avoid interference with the flange, it is necessary to make the counterpart part into a shape which is greatly scooped, which causes a problem that the strength is reduced.

  Therefore, it is conceivable to eliminate the flange as in Patent Document 6, but if completely eliminated, it may be difficult to secure the strength in the vicinity of the bush.

  The present invention has been made in view of the foregoing points, and the object of the present invention is to provide a low-cost, high-strength and high-rigidity suspension arm at low cost, as well as excellent space saving. , And to reduce the decrease in strength of the other component.

  In order to achieve the above object, in the present invention, the radial separation dimension between the outer surface of the flange and the outer surface of the peripheral wall of the bush fitting hole is set equal to or less than the thickness of the peripheral wall.

The first invention is
A car body side bush fitting hole is formed at one end of which a bush attached to a car body side member is fitted, and is formed at the other end on a wheel side member. In a suspension arm having a wheel-side bush fitting hole in which a bush to be attached is formed,
The vehicle body side bush fitting hole and the wheel side bush fitting hole are formed by press processing,
The edge of the peripheral wall portion constituting the bush fitting hole of at least one of the vehicle body side bush fitting hole and the wheel side bush fitting hole protrudes radially outward of the one bush fitting hole The flanges formed on are integrally provided,
The radial separation dimension between the radial outer surface of the flange and the outer surface of the peripheral wall of the one bush fitting hole is set equal to or less than the thickness of the peripheral wall of the one bush fitting hole ,
The flange is formed in a plate shape extending in an axial direction of a peripheral wall portion of the one bush fitting hole .

  According to this configuration, since the suspension arm is formed of a pressed plate material, the strength and rigidity can be reduced while relatively increasing the shape and size of the cross section for each part of the arm to suppress the weight increase of the arm. It becomes possible to raise. Further, since the vehicle body side bush fitting hole and the wheel side bush fitting hole are formed by pressing, the number of parts can be reduced, the number of man-hours can be reduced, and the cost can be reduced.

  And since the flange was integrally provided in the peripheral wall part of the bush fitting hole, the intensity | strength of this peripheral wall part is ensured. Since the distance between the radial outer surface of the flange and the outer surface of the peripheral wall of the bush fitting hole is smaller than the thickness of the peripheral wall, the amount of protrusion of the flange from the outer surface of the suspension arm is sufficiently reduced. As a result, the space efficiency is improved in the state of being assembled to the vehicle. Furthermore, since the interference between the flange and the counterpart part can be avoided even if the attachment position of the suspension arm is not so far away from the basic cross section of the counterpart part to which the suspension arm is attached, the rigidity of the attachment part Sufficiently secured. In addition, since the interference with the flange is avoided even if the counterpart part is not formed into a large shape, the strength is sufficiently secured.

  Further, since the flange extends in the axial direction of the peripheral wall portion of the bush fitting hole, the amount of outward projection can be sufficiently reduced as compared with the case of providing the flange extending in the radial direction.

A second invention relates to the first invention,
The vehicle body side bush fitting hole and the wheel side bush fitting hole are formed by burring.

According to this configuration, the vehicle body side bush fitting hole and the wheel side bush fitting hole can be easily formed in the plate material .

In a third aspect of the present invention, in the first or second aspect ,
The vehicle body side bush fitting hole and the wheel side bush fitting hole are respectively formed at both end portions of the arm body,
The peripheral wall portion of the one bush fitting hole is formed to project from the arm body,
The flange extends in a direction opposite to a direction in which the peripheral wall protrudes from the arm body.

  According to this configuration, since the flange can be arranged to surround the outer surface of the bush fitted in the bush fitting hole, interference with other members is avoided.

The fourth invention is
A car body side bush fitting hole is formed by press working, which is made of a plate material pressed to have an arm shape elongated in a predetermined direction and a bush attached to a car body side member is fitted at one end portion. A wheel-side bush fitting hole to which a bush attached to the side member is fitted is formed by press processing, and at least one bush fitting hole of the vehicle-side bush fitting hole and the wheel-side bush fitting hole is formed. In a method of manufacturing a suspension arm in which a flange formed to project radially outward of one of the bush fitting holes is integrally provided at an edge portion of the peripheral wall portion,
After pressing a plate material to form a portion to be the above flange to obtain an intermediate molded product,
A burring process is performed inward of the portion to be the flange in the intermediate molded product to form a peripheral wall portion of the one bush fitting hole, and a radial outer surface of the flange and a peripheral wall of the one bush fitting hole The dimension of the radial separation from the outer surface of the portion is equal to or less than the thickness of the peripheral wall portion of the one bush fitting hole.

According to the first and fourth inventions, the vehicle-body-side bush fitting hole and the wheel-side bush fitting hole are formed by pressing in the suspension arm made of a pressed plate material, and the peripheral wall portion constituting the bush fitting hole A flange is integrally provided at the edge, and the radial separation dimension between the outer surface of the flange and the outer surface of the peripheral wall portion of the bush fitting hole is set equal to or less than the thickness of the peripheral wall portion. As a result, a lightweight, high-strength and high-rigidity suspension arm can be obtained at low cost, and a suspension arm excellent in space saving performance can be obtained, and further, a decrease in strength of the counterpart component is suppressed. be able to.

  Further, since the flange extends in the axial direction of the peripheral wall portion of the bush fitting hole, the amount of outward projection can be sufficiently reduced as compared with the case where the flange extending in the radial direction is provided.

According to the second aspect of the invention, since the vehicle body side bush fitting hole and the wheel side bush fitting hole are formed by burring, the bush fitting hole can be easily formed .

According to the third invention, the peripheral wall portion of one of the bush fitting holes is formed to project from the arm body, and the flange extends in the direction opposite to the direction in which the peripheral wall portion protrudes from the arm body. The flange can be arranged to surround the outer surface of the bush fitted in the bush fitting hole. This can prevent the flange from interfering with other members.

It is a perspective view showing the state where the suspension arm concerning the embodiment of the present invention was attached to the vehicle body side member. It is a bottom view of the suspension arm attached to the vehicle body side member. It is a front view of the suspension arm attached to the vehicle body side member. It is the IV-IV sectional view taken on the line in FIG. It is a top view of the material of a suspension arm. It is a top view of the intermediate molded article which passed through the 1st processing process. It is a top view of the intermediate molded article which passed through the 2nd processing process. It is a top view of the final product completed through the 3rd processing process. It is sectional drawing which shows the state which set the intermediate molded product to the metal mold | die which performs a 3rd process process. It is the FIG. 9 equivalent view which shows the state which the 3rd processing process completed.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of the preferred embodiments is merely illustrative in nature, and is not intended to limit the present invention, its applications, or its applications.

(Configuration of suspension arm)
FIG. 1 is a perspective view showing a state in which a suspension arm 1 according to an embodiment of the present invention is attached to a vehicle body side member. The suspension arm 1 is, for example, a member that constitutes a part of a rear suspension device (not shown) of an automobile, and is for controlling the movement of a wheel during traveling. As shown also in FIGS. 2 and 3, the suspension arm 1 is attached to the vehicle body in a posture extending in the vehicle width direction, and is swingable around the vehicle body side.

  In the description of this embodiment, the front side of the vehicle is simply referred to as the front, and the rear side of the vehicle is simply referred to as the rear.

  The suspension arm 1 is formed of a single plate material pressed so as to have an arm shape long in the vehicle width direction. Therefore, in this embodiment, the number of parts constituting the suspension arm 1 is one. The suspension arm 1 has an arm body 2 extending in the vehicle width direction. At one end (body end) of the arm body 2 of the suspension arm 1, as shown in FIG. 4, a vehicle-side bush fitting hole 11 is formed in which a vehicle-side bush 30 attached to the vehicle-side member 50 is fitted. It is done. As shown in FIG. 1, a wheel side bush in which a wheel side bush 40 attached to a wheel side member (not shown) is fitted to the other end (wheel side end) of the arm body 2 of the suspension arm 1 The fitting hole 21 is formed. The vehicle-body-side bush fitting hole 11 and the wheel-side bush fitting hole 21 are formed by press working, specifically, burring, which will be described later.

  The arm main body 2 is formed so that the entire body on the front side is expanded and the entire rear side is opened. Specifically, the arm body 2 has a front plate portion 3 positioned at a distal end in the bulging direction, an upper plate portion 4 extending rearward from an upper edge portion of the front plate portion 3, and a rear edge of the upper plate portion 4 A lower plate portion 6 extending upward from the lower edge portion of the front plate portion 3 as shown in FIG. 3 and a downward protrusion from a rear edge portion of the lower plate portion 6 as shown in FIG. 3 And the lower projecting plate 7. The front plate portion 3 is generally curved so that the vertically central portion is at the foremost position, the lower side, and the upper side. As shown in FIG. 1 and FIG. 3, the dimension in the vertical direction of the front plate portion 3 is set such that the longitudinal central portion is the shortest, the closer to the vehicle body side and the longer to the wheel side. As a result, the shape of the suspension arm 1 is such that the central portion in the longitudinal direction is thin, and the shape becomes thicker toward the vehicle side and the wheel side.

  Further, the upper plate portion 4 is slightly inclined so as to be positioned on the rear side. Furthermore, the lower plate portion 6 is slightly inclined so as to be positioned lower toward the rear side. Therefore, the cross section of the longitudinal middle portion of the arm body 2 is substantially hat-shaped and opened to the rear side.

  The upper protruding plate portion 5 and the lower protruding plate portion 7 function as a reinforcing portion that reinforces the arm body 2. The end portions of the upper protruding plate portion 5 and the lower protruding plate portion 7 on the vehicle body side are positioned closer to the wheel than the end portions of the arm main body 2 on the vehicle body side. Further, the wheel side end portions of the upper side projecting plate portion 5 and the lower side projecting plate portion 7 are positioned closer to the vehicle body than the wheel side end portions of the arm main body 2. Accordingly, the lengths of the upper side projecting plate portion 5 and the lower side projecting plate portion 7 become shorter than the length of the arm main body 2, and the upper side of the vehicle body side bush fitting hole 11 and the wheel side bush fitting hole 21 are formed on the upper side. The protruding plate portion 5 and the lower protruding plate portion 7 do not reach.

  Similarly, in the upper plate portion 4 and the lower plate portion 6, the length in the vehicle width direction is shorter than the length of the arm body 2, and the formation site of the vehicle body side bush fitting hole 11 and the wheel side bush fitting hole 21 The upper plate portion 4 and the lower plate portion 6 do not reach.

  As shown in FIG. 4, a vehicle body side peripheral wall 12 that constitutes a vehicle body side bush fitting hole 11 is formed at an end of the arm body 2 on the vehicle body side. As shown in FIG. 1, at the wheel-side end of the arm body 2, a wheel-side peripheral wall 22 that constitutes the wheel-side bush fitting hole 21 is formed. That is, the suspension arm 1 includes an arm body 2, a vehicle-side peripheral wall 12 and a wheel-side peripheral wall 22.

  The vehicle body side peripheral wall portion 12 is integrally provided to the arm body 2 and is formed so as to protrude forward from the front plate portion 3 of the arm body 2. The shape of the vehicle body side peripheral wall portion 12 is a cylindrical shape in which the axis extends in the front-rear direction. Further, the wheel side peripheral wall portion 22 is also integrally provided on the arm main body 2 and formed so as to project forward from the front plate portion 3 of the arm main body 2 and has an axial line extending in the longitudinal direction.

  The vehicle body side bush fitting hole 11 is fitted in a state where the vehicle body side bush 30 is inserted. The vehicle body side bush 30 includes a cylindrical metal pipe 31, a cylindrical rubber 32 provided so as to cover the outer surface of the metal pipe 31, and a cylindrical outer cylinder member 33 provided so as to cover the rubber 32. It consists of The outer cylinder member 33 is fitted in the vehicle body side bush fitting hole 11. The vehicle-body-side bush fitting hole 11 is positioned closer to one side than the axially central portion of the outer cylindrical member 33, that is, closer to the front side in FIG.

  At the rear edge portion of the vehicle body side peripheral wall portion 12, a vehicle body side flange 13 formed so as to project outward in the radial direction of the vehicle body side bush fitting hole 11 is integrally provided. The thickness of the vehicle body side flange 13 and the thickness of the vehicle body side peripheral wall portion 12 are set to be substantially the same. The vehicle body side flange 13 extends from the front plate portion 3 of the arm body 2 to the rear side, that is, in the axial direction of the vehicle body side bush fitting hole 11. Accordingly, the vehicle body side flange 13 extends in a direction opposite to the direction in which the vehicle body side peripheral wall portion 12 protrudes from the arm body 2.

  Further, the vehicle body side flange 13 has a plate shape extending so as to draw an arc along the vehicle body side peripheral wall portion 12. The vehicle body side peripheral wall 12 and the vehicle body side flange 13 are concentrically located. Both end portions in the circumferential direction of the vehicle body side flange 13 are located at the upper and lower portions of the arm main body 2 respectively, and are continuous with the vehicle body side end of the upper plate portion 4 and the vehicle body side end of the lower plate portion 6 ing.

  As shown in FIG. 4, the vehicle-body-side flange 13 has a diameter larger than that of the vehicle-body-side peripheral wall 12 because the vehicle-side flange 13 protrudes radially outward from the vehicle-side peripheral wall 12. That is, both the radial outer surface 13 a of the vehicle body side flange 13 and the outer surface 12 a of the vehicle body side peripheral wall 12 extend in the axial direction of the vehicle body side bush fitting hole 11. A radial separation dimension A between the radial outer surface 13 a of the vehicle body side flange 13 and the outer surface 12 a of the vehicle body peripheral wall 12 is set equal to or less than the thickness of the vehicle body peripheral wall 12. As a result, the amount of protrusion of the vehicle body side flange 13 from the vehicle body side peripheral wall portion 12 is equal to or less than the thickness of the vehicle body side peripheral wall portion 12, so the amount of protrusion of the vehicle body side flange 13 from the outer surface of the suspension arm 1 is sufficiently reduced. Can.

  Further, since the vehicle body side flange 13 projects from the vehicle body side peripheral wall portion 12, the dimension A is set between the radial inner surface 13 b of the vehicle body side flange 13 and the outer surface of the outer cylindrical member 33 of the vehicle body side bush 30. The same degree of clearance will be formed.

  On the other hand, as shown in FIG. 3, the wheel side bush fitting hole 21 is fitted with the wheel side bush 40 inserted. The wheel side bush 40 is constituted of a metal cylindrical pipe 41, a rubber 42, and an outer cylinder member 43, similarly to the vehicle body side bush 30, and the outer cylinder member 43 is a wheel side bush fitting hole 21. To fit.

  A wheel side flange 23 formed to project radially outward of the wheel side bush fitting hole 21 is integrally provided at the rear edge portion of the wheel side peripheral wall portion 22 similarly to the vehicle body side peripheral wall portion 12 ing. The wheel side flange 23 is the same as the vehicle body side peripheral wall portion 12 and thus the detailed description is omitted. Both end portions in the circumferential direction of the wheel side flange 23 are respectively located at the upper and lower portions of the arm body 2, and the end portion on the wheel side of the upper plate portion 4 and the end portion on the wheel side of the lower plate portion 6 It is continuous. Therefore, the reinforcing effect can be enhanced by continuously connecting the vehicle body side flange 13, the wheel side flange 23, the upper plate portion 4 and the lower plate portion 6 in an annular shape.

(Structure of vehicle body side members)
The vehicle body side member 50 is fixed to a vehicle body frame or the like (not shown), and as shown in FIG. 1, FIG. 2 and FIG. doing. That is, the vehicle body side member 50 includes the front wall 51 and the rear wall 52 both extending in the vertical direction, and the connecting plate 53 connecting the front wall 51 and the rear wall 52. The front wall 51 and the rear wall 52 are spaced in the front-rear direction, and the vehicle body side bush 30 is inserted between the front wall 51 and the rear wall 52. At an edge portion of the front wall portion 51, a front side projecting plate portion 51a which protrudes forward is formed. Further, at the edge of the rear wall portion 52, a rear side projecting plate portion 52a which protrudes backward is formed.

  As shown in FIG. 4, an insertion hole 51 b through which a bolt B for fastening the vehicle body side bush 30 is inserted is formed in the front wall portion 51. An insertion hole 52 b through which the bolt B is inserted is formed in the rear wall portion 52 so as to be concentric with the insertion hole 51 b of the front wall portion 51. The vehicle body side bush 30 is fastened to the vehicle body side member 50 by screwing a nut N on a bolt B inserted through the insertion hole 51 b of the front wall 51 and the insertion hole 52 b of the rear wall 52. Thereby, the suspension arm 1 is connected to the vehicle body side member 50 so as to be able to swing.

(Manufacturing method of suspension arm 1)
Next, a method of manufacturing the suspension arm 1 will be described. First, the material 100 shown in FIG. 5 is prepared. The material 100 is a plate material obtained by punching a steel plate. At both ends of the material 100, through holes 101 and 102 are formed which become pilot holes when the vehicle body side bush fitting hole 11 and the wheel side bush fitting hole 21 are to be described later.

  By pressing as a first processing step, a first intermediate formed product 110 as shown in FIG. 6 is obtained. In the first intermediate molded product 110, the front plate 3, upper plate 4, upper projecting plate 5, lower plate 6, lower projecting plate 7, vehicle side flange 13 and wheel side flange 23 of the arm main body 2 are It forms with a press die (not shown). At this time, the vehicle body side bush fitting hole 11 and the wheel side bush fitting hole 21, that is, the vehicle body side peripheral wall 12 and the wheel side peripheral wall 22 are not formed yet.

  Thereafter, the second intermediate molded product 120 as shown in FIG. 7 is obtained by trimming as a second processing step. In the second processing step, excess plate material on both side edges of the arm body 2 is cut off.

  Thereafter, burring is performed as a third processing step to obtain a suspension arm 1 as a final product as shown in FIG. In the third processing step, processing devices as shown in FIGS. 9 and 10 are used. The processing apparatus includes an upper die 200 and a lower die 300, and can be brought into contact with or separated from the lower die 300 by, for example, raising and lowering the upper die 200. FIGS. 9 and 10 show the case where the upper die 200 is lowered to be in the die closing state.

  In the upper mold 200, a first upper hole 201 and a second upper hole 202 extending in the vertical direction are formed spaced apart from each other. The distance between the first upper hole 201 and the second upper hole 202 corresponds to the distance between the vehicle-body-side flange 13 and the wheel-side flange 23 of the second intermediate molded product 120. At the lower part of the inner surface of the first upper side hole portion 201, a concave surface 201a formed so that the vehicle body side flange 13 is fitted from below is formed. The vehicle body side flange 13 fitted in the concave surface 201a is configured not to move upward at the time of burring. At a lower portion of the inner surface of the second upper hole portion 202, a concave surface 202a formed so that the wheel side flange 23 is fitted from below is formed. The wheel side flange 23 fitted to the concave surface 202a is configured not to move upward at the time of burring.

  Further, the lower mold 300 is provided with a first lower hole 301 and a second lower hole so that the lower mold 300 is positioned directly below and in communication with the first upper hole 201 and the second upper hole 202 of the upper mold 200, respectively. The part 302 is formed. In the first lower hole portion 301 and the second lower hole portion 302, a first cored bar 310 and a second cored bar 320 are disposed movably in the vertical direction. Under the first cored bar 310 and the second cored bar 320, as shown in FIG. 10, lifting and lowering devices 312 and 322 each comprising a fluid pressure cylinder or the like are disposed.

  At an upper portion of the first cored bar 310, a projection 311 inserted into the through hole 101 of the second intermediate molded product 120 is formed to project upward. Of the outer surfaces of the protrusions 311, the lower half 311a extends in the vertical direction, while the upper half 311b is formed such that the outer diameter decreases toward the upper end. The outer diameter of the lower half portion 311 a is set to be substantially equal to the inner diameter of the through hole 101 of the second intermediate molded product 120. The projection part 321 is formed also in the 2nd core metal 320, and similarly, it has the lower half part 321a extended to an up-down direction, and the tapered upper half part 321b.

  In the cross-sectional view shown in FIG. 9, the surface 201 b on the second upper hole 202 side of the inner surface of the first upper hole 201 of the upper mold 200 is the second lower hole in the first lower hole 301 of the lower mold 300. It is formed to be located closer to the second upper hole portion 202 than the surface 301 a on the portion 302 side. That is, the inner diameter of the first upper hole portion 201 of the upper mold 200 is set so as to allow the vehicle side peripheral wall portion 12 to be shaped so as to reach the inside of the first upper hole portion 201 at the time of burring.

  Similarly, the surface 202 b on the first upper hole 201 side of the inner surface of the second upper hole 202 of the upper mold 200 is the surface on the first lower hole 301 side of the second lower hole 302 of the lower mold 300. It is formed to be positioned closer to the first upper side hole 201 than 302a.

  In the third processing step, first, the upper mold 200 and the lower mold 300 are opened, and in this state, the second intermediate molded product 120 is placed on the upper surface of the lower mold 300, and then as shown in FIG. The upper mold 200 and the lower mold 300 are closed. At this time, the projection 311 of the first cored bar 310 is inserted into the through hole 101 of the second intermediate molded product 120, and the projection 321 of the second cored bar 320 is inserted into the through hole 102 of the second intermediate molded product 120. Keep it.

  Next, as shown in FIG. 10, the first cored bar 310 and the second cored bar 320 are raised by the lifting devices 312 and 322, and the lower hole of the second intermediate molded product 120 is shown by the first cored bar 310 (shown in FIG. The periphery of the through hole 101) is formed to extend upward, and the periphery of the lower hole (the through hole 102 shown in FIG. 9) of the second intermediate molded product 120 is formed to extend upward by the second core metal 320. As a result, the vehicle body side bush fitting hole 11 and the wheel side bush fitting hole 21, that is, the vehicle body side peripheral wall 12 and the wheel side peripheral wall 22 are formed, and the suspension arm 1 as shown in FIG. 8 is obtained.

  That is, in this embodiment, the material 100 is press-formed to form portions to be the vehicle body side flange 13 and the wheel side flange 23 to obtain the first intermediate molded product 110, and then trimming is performed to form the second intermediate molded product 120. Can be formed on the inner side of the portions of the second intermediate molded product 120 to be the vehicle body side flange 13 and the wheel side flange 23 to form the vehicle body side peripheral wall portion 12 and the wheel side peripheral wall portion 22. .

(Action effect)
As described above, since the suspension arm 1 is formed of a pressed plate, it is possible to relatively freely change the shape and size of the cross section for each portion of the suspension arm 1 while suppressing an increase in weight of the suspension arm 1 It is possible to increase the strength and rigidity.

  Further, since the vehicle body side bush fitting hole 11 and the wheel side bush fitting hole 21 are formed by burring, the number of parts can be reduced, the number of man-hours can be reduced, and the cost can be reduced.

  And since the vehicle body side flange 13 and the wheel side flange 23 were integrally provided in the vehicle body side surrounding wall part 12 and the wheel side surrounding wall part 22, the intensity | strength of this peripheral wall parts 12 and 22 is ensured. Since the radial separation dimension between the radial outer surfaces of the vehicle body side flange 13 and the wheel side flange 23 and the outer surfaces of the vehicle side peripheral wall 12 and the wheel side peripheral wall 22 is equal to or less than the thickness of the peripheral walls 12 and 22, the suspension The amount by which the flanges 13, 23 project from the outer surface of the arm 1 is sufficiently small. Thus, the space efficiency is improved in a state where the suspension arm 1 is assembled to the vehicle. Furthermore, interference between the vehicle body side flange 13 and the vehicle body side member 50 can be avoided even if the mounting position of the suspension arm 1 is not so far apart from the basic cross section of the vehicle body side member 50 to which the suspension arm 1 is attached. Therefore, sufficient rigidity of the mounting portion is ensured. In addition, since the interference with the vehicle body side flange 13 is avoided even if the vehicle body side member 50 is not formed into a large shape, the strength is sufficiently secured. Similarly, although not shown, interference between the wheel side member and the wheel side flange 23 is also avoided, so the space efficiency on the wheel side is also improved.

  In addition, although the case where the arm main body 2 is linear shape was demonstrated in the said embodiment, not only this but the arm main body 2 may be a curved shape.

  Moreover, although the said embodiment demonstrated the case where the vehicle body side flange 13 and the wheel side flange 23 were provided, you may provide not only this but only one of the vehicle body side flange 13 and the wheel side flange 23. FIG.

  The embodiments described above are merely illustrative in every respect and should not be construed as limiting. Furthermore, all variations and modifications that fall within the equivalent scope of the claims fall within the scope of the present invention.

  As described above, the suspension arm according to the present invention can be used, for example, as a component of a suspension device of a vehicle.

DESCRIPTION OF SYMBOLS 1 Suspension arm 2 Arm body 11 Body side bush fitting hole 12 Body side peripheral wall portion 13 Body side flange 21 Wheel side bush fitting hole 22 Wheel side peripheral wall portion 23 Wheel side flange 30 Body side bush 40 Wheel side bush 50 Body side member 110 first intermediate molded product 120 second intermediate molded product

Claims (4)

A car body side bush fitting hole is formed at one end of which a bush attached to a car body side member is fitted, and is formed at the other end on a wheel side member. In a suspension arm having a wheel-side bush fitting hole in which a bush to be attached is formed,
The vehicle body side bush fitting hole and the wheel side bush fitting hole are formed by press processing,
The edge of the peripheral wall portion constituting the bush fitting hole of at least one of the vehicle body side bush fitting hole and the wheel side bush fitting hole protrudes radially outward of the one bush fitting hole The flanges formed on are integrally provided,
The radial separation dimension between the radial outer surface of the flange and the outer surface of the peripheral wall of the one bush fitting hole is set equal to or less than the thickness of the peripheral wall of the one bush fitting hole ,
A suspension arm characterized in that the flange is formed in a plate shape extending in the axial direction of a peripheral wall portion of the one bush fitting hole . The suspension arm according to claim 1
A suspension arm characterized in that the vehicle body side bush fitting hole and the wheel side bush fitting hole are formed by burring. The suspension arm according to claim 1 or 2
The vehicle body side bush fitting hole and the wheel side bush fitting hole are respectively formed at both end portions of the arm body,
The peripheral wall portion of the one bush fitting hole is formed to project from the arm body,
A suspension arm characterized in that the flange extends in a direction opposite to a direction in which the peripheral wall protrudes from the arm body. A car body side bush fitting hole is formed by press working, which is made of a plate material pressed to have an arm shape elongated in a predetermined direction and a bush attached to a car body side member is fitted at one end portion. A wheel-side bush fitting hole to which a bush attached to the side member is fitted is formed by press processing, and at least one bush fitting hole of the vehicle-side bush fitting hole and the wheel-side bush fitting hole is formed. In a method of manufacturing a suspension arm in which a flange formed to project radially outward of one of the bush fitting holes is integrally provided at an edge portion of the peripheral wall portion,
After pressing a plate material to form a portion to be the above flange to obtain an intermediate molded product,
A burring process is performed inward of the portion to be the flange in the intermediate molded product to form a peripheral wall portion of the one bush fitting hole, and a radial outer surface of the flange and a peripheral wall of the one bush fitting hole A method of manufacturing a suspension arm, wherein a radial separation dimension of the outer surface of the portion is equal to or less than a thickness of a peripheral wall portion of the one bush fitting hole.

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