MXPA00007875A - Vehicle frame member having a shock absorbing mounting portion and a method for making the same - Google Patents

Abstract

The present invention relates to a method for making a vehicle frame member having a shock absorbing mounting portion constructed and arranged to be mounted to a structural component within a motor vehicle. The method comprises hydroforming a tubular blank within a hydroforming die by supplying pressurized fluid to the hollow interior of the blank. A drawforming member is moved inwardly with respect to the cavity of the hydroforming die while the fluid is pressurized so that the drawforming member deforms a portion of the tubular wall inwardly to form a recessed portion having an annular side wall portion and a bottom wall portion. The formed tubular blank is then removed from the hydroforming die and a mounting structure (38) is disposed inside the recessed portion and the blank and mounting structure (38) are then disposed within an injection molding die. Molten shock absorbing material (14) is injected into the recessed portion so that the molten material (14) surrounds the mounting structure. The molten shock absorbing material is thereafter solidified. Preferably, a pair of such recessed portions are formed. The present invention also relates to a vehicle frame member to be joined to a structural component in shock absorbing relation.

Description

MEMBER OF VEHICLE CHASSIS THAT HAS A PORTION OF ABSORBING ASSEMBLY OF SHOCKS AND METHOD TO MANUFACTURE THE SAME FIELD OF THE INVENTION The present invention relates to a vehicle chassis member, having a shock absorber mounting portion and a method for manufacturing the same.

BACKGROUND OF THE INVENTION In order to provide a conventional vehicle chassis member with a shock absorber mounting portion, the chassis member is first formed in the desired configuration, by hydro forming, die cutting, or some other suitable method, and then forming a hole in the wall of the chassis member during a secondary punching or drilling operation. A cup-shaped bushing, comprising a cup-shaped exterior, which can be filled with solidified rubber or other suitable shock-absorbing material, is REF .: 122066 welds then or snaps into the hole. This conventional method is used instead of stretching with the outside, directly from the wall of the chassis member, due to space constraints within the preformed tubular member. Specifically, the formed with stretching of an integral cup-shaped wall, from the wall of the preformed tubular member, can not be achieved because the female die half, necessary for that formed with stretch, can not be removed after to finish the forming operation with stretching. The problem with this type of arrangement is that numerous stages must be performed to properly assemble the bushing, thereby increasing manufacturing time and costs. Also, the tolerances between the outside of the bushing and the hole formed in the wall must be maintained within a certain interval, to ensure that a failure does not occur as a result of the bushing coming out.

^^ ¡^^^^^ £? BRIEF DESCRIPTION OF THE INVENTION Therefore, it is an object of the present invention to provide a chassis member of a vehicle, with a shock absorber mounting portion, that is manufactured using fewer operations and components compared to the conventional method described above, and thereby achieving both manufacturing costs reduced. To achieve this objective, an aspect of the present invention provides a method for producing a chassis member of a motor vehicle, having a shock absorbing mounting portion. The method comprises placing a tubular blank in the mold cavity of a shaped or shaped die. The die has inner surfaces defining the mold cavity and a reciprocating, reciprocating member. White is hydroformed by supplying pressurized fluid to the inside of the target, to expand the target against the interior surfaces that define the mold cavity. The stretched forming member moves inwardly relative to the cavity, such that the stretched forming member deforms a portion of the tubular blank target to form a recessed portion in the target. The blank is removed from the hydroforming die and placed within the recessed portion, a mounting structure constructed and arranged to be joined with the aforementioned structural component of the motor vehicle. The tubular blank, with the mounting structure within the recessed portion, is then placed in an injection molding die. Shock absorbing material, melted, is injected into the cavity, in relation to the mounting structure, and subsequently solidifies. The method of the present invention provides a vehicle chassis member in which the tolerance problems between the shock absorber mounting structure and the tubular member are eliminated. In addition, the manufacturing time and the handling of tools associated with the formation of a separate, shock-absorbing mounting structure are ^? ^ saj &^^ 3tog * s also eliminate because the recessed portion is formed in the hydroforming die, and the shock absorbing material is injected directly into the recessed portion. In this way, the resulting chassis member is not only of superior quality, as compared to a chassis member produced through the conventional method, but the manufacturing cost of that chassis member is significantly reduced. Another aspect of the present invention provides a chassis member of a vehicle, for joining another structural component in a motor vehicle, in a shock absorbing relationship. The chassis member comprises a hydraulically formed tubular member, having a main portion of tubular wall, which surrounds a hollow interior and a recessed portion extending inwardly and inwardly hollow. The recessed portion is formed integrally with the main portion of the tubular wall. The mounting structure is placed within the appropriate portion and is constructed and arranged to allow the chassis member of a vehicle to be mounted to the structural component within the motor vehicle. The solidified shock absorbing material is placed within the recessed portion and surrounds the mounting structure, such that the mounting structure can be elastically mounted to the structural component mentioned above, in a manner that allows relative movement, limited, between the hydroformed tubular member and the mounting structure, and hence, between the hydroformed tubular member and the structural component. The chassis member of the present invention does not suffer from push-pull failures of the chassis member constructed in accordance with the conventional method described above, because the recessed portion is deformed from the tubular wall portion. , and the annular, side wall portion is integrally formed with the tubular wall portion. In this way, any push / pull out failure between the mounting portion of the chassis member of the present invention and the tubular wall portion will require that a shear be present between the lateral annular wall portion and the MÉ ^ ÉÍMICA-ii-tcHIca tubular wall. This secure relationship is superior to the soldier or pressure adjustment, conventional, provided by the conventional method.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an isometric view of a hydroformed vehicle chassis member with a bumper mounting portion constructed in accordance with the principles of the present invention. Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1; Figure 3 is a sectional view, longitudinal, of an embodiment of a hydroforming assembly, in accordance with the present invention, and showing the halves of the hydroforming die, upper and lower, coupled with a tubular target, hydraulic cylinders coupled with the opposite portions of the tubular target, and retracted members, upper and lower, for the formed with stretch; Figure 4 is a partial, schematic, cross-sectional view taken along line 4-4 of Figure 3, but showing the upper half of the hydroforming die in a raised or open position; Figure 5 is a view similar to that of Figure 4, but showing the hydroformed die halves, closed, and the tubular blank initially deformed to an oval shape; Figure 6 is a view similar to that of Figure 5, but showing the pressure of the internal fluid expanding the diameter of the tubular blank; Figure 7 is a view similar to that of Figure 6, but showing the stretched forming members of the hydroforming assembly generally moving inward towards one another; Figure 8 is a view similar to that of Figure 7, but showing the stretch formed, retracted members, and the halves of the hydroforming die, upper and lower, spaced apart to remove the hydroformed tubular target with stretch; Figure 9 is a cross-sectional view, showing the wall portions of the bottom, of the recessed portions of the tubular blank hydroformed with stretch, being punched by a punching tool; Figure 10 is a cross-sectional view showing the tubular blank hydroformed with stretch, placed in an injection molding die, and injected with a shock absorbing material such as a rubber compound.

DETAILED DESCRIPTION OF THE PREFERRED MODALITY OF THE INVENTION Figures 1 and 2 show a vehicle chassis member, hydroformed with stretch, indicated, generally, with the number 10, manufactured in accordance with the principles of the present invention. The hydroformed chassis member with draw 10 has an integral, shock absorbing mounting portion and comprises two main components: a tubular hydroformed blank with draw, indicated generally at 12 and a mounting portion, absorber of shock, indicated, in general, with 14. The tubular white member 12 has a metal tubular wall of rectangular, irregular, or somewhat oval cross-section. The tubular wall surrounding a hollow interior includes an upper wall portion 16, generally flat, and a lower wall portion 18, generally flat. The curved side wall portions 20 are continuous with the upper wall portion 16 and the lower wall portion 18. Referring to Figure 2, the upper wall portion 16 has a cup-shaped, upper, cup-shaped portion 42 formed therein with a side portion, annular, stretched, 39, formed in one piece with the upper wall portion 16 and a bottom wall portion 41 formed integrally with the side wall portion 39. lower wall portion 18 has a cup-shaped, lower, cup-shaped portion 44 formed therein with a stretched, annular, side wall portion 43 formed integrally with the lower wall portion 18 and a portion of bottom wall 47 formed integrally with the side wall portion 43. The bottom wall portion 41 of the upper recessed portion 42 has an annular sealing lip 22 which is sealingly coupled with the inner planar surface, ad lying, 45, of the bottom wall portion 47 of the opposite recessed portion 44. As will be seen later in the application, the annular sealing lip 22 provides an annular seal that partially defines a cavity to be filled with the material Shock absorber, melted. The shock absorber mounting portion 14 includes upper and lower discs 15 and 17, respectively, made of a suitable injection-molded shock absorbing material, such as rubber or other elastic material, permanently deformable. The upper disc 15 is positioned within the upper recessed portion 42, and includes a circular upper surface 24 and an upper annular rim 34 extending around the periphery of the upper surface 24. The lower disc 17 is positioned within the lower recessed portion 44 and includes a circular bottom surface 26, and a The annular rim of the bottom 36 extends around the periphery of the bottom surface 26. A mounting structure in the form of an internally threaded mounting sleeve 38 is inserted through a central hole 28. which extends through the center of the upper disk 15, through the bottom wall portions 41, 47 of each recessed portion 42, 44, and through the lower disk 17. The sleeve 38 receives a clamping bolt to secure the chassis member 10 of the vehicle in shock absorbent relationship with another member of the vehicle chassis or some other structural component that is within the motor vehicle. Specifically, it is contemplated that the sleeve 38 could serve as a mounting point for an engine cradle or a suspension arm. The sleeve 38 could also be joined with other members of the vehicle chassis or structural components within the vehicle, such as body components, chassis components, engine cradle components, etc. When the sleeve 38 is attached or assembled with a structural component within the motor vehicle, in shock absorber relationship, the rubber discs 15, 17 allow limited, relative movement between the sleeve 38 and the tubular member 12. As a result, limited, relative movement is allowed between the frame member 10 and the structural component, during operation of the vehicle, such that the forces are not transmitted directly to the tubular member 12. In effect, the rubber discs 15, 17 will absorb a portion of the forces. A plurality of circumferentially spaced openings or holes 30 are formed in the bottom wall portions 41, 47 of the upper and lower recessed portions 42, 44. The holes 30 are positioned in a concentric, concentric relation to the hole central 28 and within the annular seal formed between the annular seal lip 22 and the mating surface 45. Preferably, the holes 30 that are in the bottom wall portion 41 of the recessed portion 42, are each substantially aligned with the associated hole 30 which is in the bottom wall portion 47 of the recessed portion 44. The holes 30 provide a conduit for the molten shock absorbing material to pass between the recessed portions 42, 44 during the molding process by injection that will be described later in the application. The end, longitudinal portions of the mounting sleeve 38 protrude above the upper surface 24 and below the bottom surface 26. Figure 3 shows an assembly for hydroforming with stretching, indicated, generally, at 50, for the use in accordance with the principles of the present invention. The assembly 50 is used to form two separate tubular targets 12 for hydroforming with stretching, for two separate chassis members 10 of the vehicle. The hydroforming assembly 50 with stretching includes a hydroforming die with a hydroforming die top half, generally indicated at 52, and a hydroforming die half, lower, generally indicated at 54. Half upper of hydroforming die, includes a pair of upper hydroforming members, indicated at 56, and the lower hydroforming die half, 54, includes a pair of lower hydroforming members, indicated, generally, at 58. Preferably, the stretch formed members 56, 58 are hydraulically actuated, stretch formed piston cylinders, as shown. The upper die half 52 includes a large main metal block 60, and an upper mounting plate 62 fixedly secured to the upper part of the main block 60. A pair of upper cylinder compartments 64 are formed within the main upper block 60. and placed near their longitudinal ends. The stretched forming cylinders 56 are fixedly mounted on the mounting plate 62 and received within the compartments 64. The upper half of the hydroforming die 52 has an inner, lower surface, a concave portion 67 of which defines part from a die cavity 68 (see Figure 4). The lower half of hydroforming die 54 has an inner, upper surface, a concave portion 79 of which defines a portion of the cavity 68 of the die, in cooperation with the concave portion 67 of the upper, hydroformed die half. The cavity 68 is elongated and has a cross-sectional, irregular, oval or rectangular configuration. The upper half of the hydroforming die 52 is fixed by conventional means to a conventional alternative hydraulic press (not shown) positioned on top plate 62 of the upper die half 52 to perform opening and closing movements with respect to the lower half 54 of hydroforming die. The lower die half 54 includes parts corresponding to those of the upper die half 52, but inverted with respect to them. The lower die half 54 has a main block 54 similar to the main block 60 of the upper die half 52 and positioned below the upper die half 52. The main block 72 is mounted on a mounting plate 74 of the middle of lower die. Two compartments 76 of lower cylinder, are placed in the main block 72 of the lower die half, near the longitudinal ends of the block 72. The lower cylinder compartments 76 are disposed directly below the upper cylinder compartments 64, placed in the main block 60 of the upper die half. Lower members for stretch forming, in the form of hydraulically actuated stretching-forming cylinders 58, are fixedly mounted on the mounting plate 64 of the lower die and are positioned within the compartments 76. The lower half 54 of the die of hydroforming, is ensured through conventional means, to a conventional stationary press platform (not shown) of the hydraulic press. The size and configuration of the die cavity 68 are predetermined to define the shape of a desired tubular chassis member that is to be formed during the hydroforming process. As can be seen from the embodiment illustrated in FIGS. 4 and 5, the cavity 68 of the die has a somewhat oval cross section, which has a greater width than height. The height, in a central portion 80 of the cavity 68 of the die, while maintaining the oval shape, is smaller than one of the end, longitudinal portions of the cavity 68. Figure 3 represents the end portions of a pair of hydraulically actuated press cylinders 85, coupled with the opposite, longitudinal end portions of the tubular target T to seal the hollow interior thereof. Each end portion 85 of the press cylinder has a central hole 87. One of the holes 87 is sealed while the other is connected to a fluid integrator, such that a fluid for hydroforming, substantially incompressible, is sealed. It can be injected into the hollow interior of the tubular target T. The fluid inside the tubular target T is pressurized by the sensor, so that it expands the diameter of the tubular target T until the r configuration of the target T is adjustment to the interior surfaces 67, 79 defining the cavity 68 of the die. While the fluid is pressurized, the press cylinders 85 are forced longitudinally inwardly and towards each other, in order to cause the metallic material of the blank T to flow to maintain the thickness of the hydroformed target wall within ± 10% of the original wall thickness. The upper cylinders 56 for forming with stretching, each includes a hydraulic cylinder chamber 57 and a retractable and retractable piston rod 69. The bottom-formed cylinders 58 of stretching are positioned within the lower cylinder compartments 76 and each includes a hydraulic cylinder chamber 90 and a retractable and extensible piston rod 92. The piston rods 69, 92 move alternately with respect to the fixed cylinder chambers 52, under the controlled force of the hydraulic oil supplied under pressure to the chambers 57, 90 as will be appreciated by those skilled in the art. The piston rods 69 and 92 have cylindrical punching members 71 and 94, respectively, fixed to the distal end portions thereof. When the piston rods 69 and 92 are extended, the The stitch members 71 and 94 extend into the cavity 68 of the punch to perform a stretch forming function which is described below. Figures 4 to 10 illustrate, in general, the hydroforming process with stretching of the present invention. In Figure 4, the upper and lower stretch shaped punches 71, 94 are shown in their retracted positions, where the upper stretch forming punches 71 extend through holes 70 in the block. 60 of the upper die and inside the cavity 68 of the die and punches. of lower hydroforming 94 extend through the holes 82 that are in the main block 72 of the lower die and into the cavity 68 of the die, in opposite relation to the upper punches 71. The tubular target T is loaded in its position on the lower half of hydroforming die 54. E Fig. 5 the upper die half 52 of the hydroforming press, has been lowered onto the lower die half 54 by deforming the tubular blank T in an oval, irregular cross section configuration , along most of its longitudinal extension. The hydroforming press is kept closed under ex ret pressure. In Figure 6 the press cylinders 85 are sealingly coupled with the opposite end portions of the tubular target T of a hydroforming fluid F, substantially incompressible, is supplied to the hollow interior of the target T through the hole 87 in one of the press cylinders 85, the fluid F is pressurized to diffuse the wall of the target T outwardly and against the inner surfaces 67, 79 which define the cavity 68. The hydraulic pressure drives the cylinders 85 inwards and one towards the other, to maintain the wall thickness of the white wall T, as the wall expands diametrically. The upper and lower stretch shaped punches 71, 94 remain in their respective retracted positions and the blank wall T deforms over the slightly protruding, distal end portions 96, 98 of the stretch formed punches, upper and lower, 71, 94. Figure 7 illustrates the formed with stretching of the recessed, cup-shaped portions 42, 44. First, the internal fluid pressure is slightly reduced to a selected level, to allow movement of the White hydroformed T. The upper and lower stretch forming cylinders 57, 90 are pressurized to extend the piston rods 69, 92, upper and lower, inwardly and towards each other, such that the stretching shaped punches 71 , 94 push the generally opposite wall portions of the hydroformed tubular blank T, generally inwardly towards each other, to substantially equal the predetermined depths, so as to form the recessed portions 42, 44. The reduced pressure of the The internal fluid provides internal support to the tubular target T such that the recessed portions 42, 44 are located in the areas that are in contact with the stretching punches 71, 94. The surfaces of the punches 71, 94 should be sufficiently smooth, with rounded corners or edges to prevent punches 71, 94 from piercing or cutting the tubular target T. With the recessed portions 42, 44 formed with stretching as described above, the bottom wall portion 41, 47 of each recessed portion 42, 44 will be separated from the other. This is preferred so that the wall thicknesses of the bottom wall portions of the recessed portions 42, 44 are not thinned by compression between the punches 71 and 94. However, within the scope of the present invention is coupling the bottom wall portions 41, 47 together. White T has been hydroformed and formed with stretch, conveniently, now, in accordance with the principles of the present invention, while occupying the same position in the same piece of equipment. In Figure 8, the pressure of the internal fluid is released and the fluid is allowed to drain from the tubular blank T hydroformed with stretch. The upper stretch 57 rolls and the bottom stretch 90 cylinders are now pressurized in a manner that retracts the upper piston rods 69 and the lower piston rods 92 and the associated punches 71 and 94. The upper press cylinder moves upward to raise the upper die half 52 of the lower die half 54. The stretch-formed white T is then removed from the hydroformed assembly 50 with stretch and placed on support frames for move to the next operation. The tubular target T can be cut in half to form two substantially identical tubular members 12 which can be used individually in an injection molding operation, to form two separate vehicle chassis members 10, of the type illustrated in Figure 1. Tubular white T can also be molded by injection before cutting. Alternatively, the present invention contemplates that only one tubular member needs to be f o rma r s e and be formed with stretch at the same time. In that method, a shorter tubular blank T is used, and only an upper die cylinder 56 and a cylinder of J &L-lower die 58 will be used in the hydroforming assembly 50 with stretching. In Fig. 9 the tubular member 12 hydroformed with stretch, cut, is placed in a piercing assembly 98. The tubular member 12 is placed in a preset position, on the lower die 100, which is fixedly mounted to a pallet. press. A punching tool 102 which is mounted to a movable upper cylinder (not shown) of the press, moves in an alternating, generally vertical movement, and engages to start its downward stroke. Attached to the forward end of the punching tool 102 is a tubular, central, cutting or hole-forming member 104 having a sharp, circular cutting edge 105. Two or more circular, smaller, cutting or hole forming members 106 are formed in a single piece with the punching tool 102 and placed in a splice relationship or in adjacent relation on diametrically opposite sides of the central cutting member 104. The punching tool 102 is lowered and the edge ^^ c ^ j ^^^^^^^^ jggkg ^^ í ^ cutting shears the holes or openings substantially aligned in the center of the bottom wall portions 41, 47 of the recessed portions 42, 44. The tool punch 102 continues down until the smaller cutting members 106 come into contact with the bottom wall pressures 41, 47 of the recessed portions 42, 44 and form two or more pairs of holes substantially aligned on the opposite sides of the holes. alienated holes formed by the cutting edge 105. This results in a central hole 114 and two or more smaller holes 116 on opposite sides of the central hole 114 cut in the recessed portion 42 and a lower central hole 118 and two or more holes smaller 120 on the opposite sides of the hole 118 cut in the recessed portion 44. The cut-out pieces 122 punched out from the central holes 114, 118, and the punched pieces 124 of the smaller holes 116, 120 are pushed through the bottom of die 100 and ejected therefrom. The smaller holes 116, 120 form the holes mentioned above 30 in the finished product. The central holes 114 and 118 are part of the central hole 28 described above. The punching tool 102 continues its downward stroke to a predetermined depth. The punching tool 102 has a rim 123 forming an annular lip, spaced radially outwardly from the members of circular cuts 106. The rim forming lip 123 that operates with the lower die 100 to form an annular groove 124 in the wall portion from the bottom 41 of the recessed portion 42. The slot 124 forms the annular sealing lip 22 in the finished product and is brought into sealing contact with the bottom wall portion 47 of the recessed portion 44. This punching and seal formation the construction of the tubular member 12 of the vehicle chassis member 10 ends. After the punching tool 102 has reached its preset depth, the press cylinder and the punch 102 move up to the starting position and the tubular member, hydrophobic with stretch, perforated, 12, is removed from the lower die 100. Within the scope of the present invention is to form the annular seal between the bottom wall portions 41, 47 of the recessed portions 42, 44 during the hydroforming portion. To do so, one of the stretch forming punches 71, 94 would have a lip forming flange (not shown) and the other stretching forming punch 71, 94 would have a slot (not shown). Like the punching tool, the stretch forming punches 71, 94 press the bottom wall portions together, so that the flange and groove cooperate to form an annular sealing lip on one of the wall portions. from fund 41, 47. In Fig. 10, the perforated, hydroformed, tubular member 12 has been moved to an injection molding station where it is placed in an injection molding die 130. The mounting sleeve 38 (see Figs. Figures 1, 2) is inserted through the upper central hole 114 and the lower central hole 118 of the hydroformed tubular member 12. The lower longitudinal end portion of the mounting sleeve 38 is inserted above the rounded upper end of a bolt. of lower fixing core 136 in the lower half of injection molding die 132. The upper half of injection molding die 134 is then lowered onto the lower die half 132 of the molding press and the rounded bottom end of a upper clamping core bolt 138 is received within the upper longitudinal end portion of the mounting sleeve 38. A molten, shock absorbing material such As an R-compound of plastic or rubber, it is injected into the molding die 130 through a channel 140 and then forced under pressure through a tunnel gate 142 and into a mold cavity 144. The cavity 144 is defined by a surface 146 of the inner, upper, mold cavity and a surface 148 of the interior cavity of the lower mold and the interior surfaces of the upper and lower recessed portions 42, 44. Half of upper mold 134 and lower mold half 132 form a leak-proof seal around the recessed portions 42, 44 of the hydroformed tubular member 12 with stretch and the outer surface of the mounting sleeve 38. The material R of molten rubber, injected , passes from the upper recessed portion 42 through the one or more holes 116 that are in the bottom wall portion 41 of the recessed portion 42, then through the two or more lower holes 120 that are in the portion of the bottom wall 47 of the recessed portion 44 and towards the lower recessed portion 44. The molten shock absorbing material R is prevented from being forced towards the inner confines of the chipping member. the vehicle 12 by an annular sealing lip 22 provided by the previous operation illustrated in Figure 9. The upper die half 134 and the lower die half 132 remain in sealed engagement for a set time, to allow the injected material R heals or solidifies. The mold 130 is then opened and the finished hydroformed vehicle chassis member 10, with the integral shock absorber mounting portion, as shown in Figures 1 and 2, is removed from the molding tool 130. by injection. The crash absorber material R, cured or solidified rubber, filling the recessed portion 42, forms the upper disc 15, while the shock absorbing material that fills the recessed portion forms the lower disc 17. Because the portions of disc 15, 17n are integrally connected through the holes 116, 120, the discs 15, 17 are fixed to the tubular member 12. By using the invention described above the quality problems related to the adjustment between the common component separated from the mounting against shocks and the hydroformed tube and faults are greatly reduced by pushing outwards. There is also some reduction in the number of operations, thus reducing costs by tools and costs of the parties. In this way it can be seen that the objects of the present invention have been fully and effectively designed. It should be understood that the foregoing specific embodiment has been provided to illustrate the structural and functional principles of the present invention and is not intended to be limiting. On the contrary, the present invention intends to cover all the modifications, substitutions and alterations that are within the spirit and scope of the appended claims.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims (25)

1. A method for manufacturing a chassis member of a motor vehicle, having a shock absorber mounting portion, characterized in that it comprises: placing a tubular target in a mold cavity of a hydroforming die, the die having interior surfaces defining the cavity of the mold and a forming member, with reciprocating movement, which can move inwards and outwards with respect to that cavity; supplying a fluid of h i dr or formed, substantially incompressible, to the interior of the tubular target; pressurizing the fluid, so as to expand the tubular target against the interior surfaces defining the mold cavity, to provide the blank with a shape, generally defined by the interior surfaces; moving the stretching member inwardly with respect to the mold cavity so that the stretching forming member deforms a portion of the tubular target to form a recessed portion in that target; release the fluid pressure and remove the tubular target from the hydroforming die; placing a mounting structure within the recessed portion, the mounting structure is constructed and arranged to be joined with another structural component of the motor vehicle; placing the tubular target, with the mounting structure, inside the recessed portion in the injection molding die; injecting the impact absorbing material, molten, in such a way that the molten material substantially fills the cavity, in relation surrounding the mounting structure; and subsequently solidifying the melt absorbing material, to ensure the mounting structure in the cavity.

2. A method according to claim 1, characterized in that the hydroforming die has a pair of members "- ^" M-tf-- .- «• - ^^ of formed with stretching, which can move inwards with respect to the cavity, generally towards each other and outwards, with respect to the cavity, in generally withdrawing from each other and wherein the movement of the stretching member inwardly with respect to the cavity comprises moving both the forming members with stretching, inwardly, with respect to the cavity, generally one towards the another such that the stretched forming members deform generally opposite portions of the tubular target, inwardly and one toward the other and into the tubular target, to form a pair of hollow portions, generally opposite each of the which has an annular side wall portion and a bottom wall portion formed integrally with the annular side wall portion, the method is characterized in that it further comprises: forming an annular seal between the wall portions of the wall or; forming openings through each of the bottom wall portions into the annular seal, in order to communicate the * ._ * «. .-., ^ J ^ ^ ^ ^ ^ ^ - Ssfa-cupped portions before placing the blank and the mounting structure on the injection molding die; the mounting structure is placed inside both recessed portions; the tubular target is placed inside the injection molding die with the mounting structure inside both recessed portions, such that those inner surfaces of both recessed portions, the outer surface of the mounting structure, the inner surfaces of the die injection molding and the annular seal formed between the bottom wall portions, cooperate to form a receiving space of the shock absorbing, sealing material; the molten shock absorbing material is injected into the receiving space of the shock absorbing material such that the molten material flows through the openings formed in the bottom wall portions, surrounds the mounting structure and substantially fills the receiving space of the material; and the molten shock absorber material solidifies so that the solidified shock absorbing material within one of the recessed portions is integrally connected to the solidified shock absorbing material within the other recessed portions.

3. A method according to claim 1, characterized in that the expanded tubular target is removed from the hydroforming die before forming the annular seal.

4. A method according to claim 2, characterized in that both the formation of the annular seal and the formation of the openings is carried out by coupling a punching tool with the bottom wall portions of the recessed portions, such that ( a) the hole forming portions of that tool cut the bottom wall portions to form the openings and (b) a stamp forming portion of the tool forms an annular sealing lip on one of the bottom wall portions and force the annular seal lip to come into sealed engagement with the other of the bottom wall portions.

5. A method according to claim 1, wherein prior to delivery, the hollow interior of the tubular target is sealed by sealing the opposite longitudinal, end portions of the tubular target, the method is characterized in that it further comprises: pushing the end portions , opposite of the tubular target, inwards and towards each other while the fluid is pressurized, in order to maintain the wall thickness of the tubular target, within a predetermined interval of its original thickness, when the tubular target expands.

6. A method according to claim 5, characterized in that the opposite end portions of the tubular target are sealed by coupling a pair of hydraulically actuated cylinders in sealing relationship at the opposite end portions and wherein the opposite end portions are ^^^ fe ^^ ^^^ & j ^^^ feteSg pushed inward by the hydraulic cylinders drive inwards, with respect to the tubular target, as the tubular target expands, at least one of the cylinders Hydraulics has a hole for fluid supply through which the fluid is supplied to the hollow interior of the tubular target.

7. A method according to claim 1, wherein the fluid is pressurized to a maximum level of pressurization while the tubular target expands, the method is characterized in that it further comprises: reducing the fluid pressure to a selected pressure level, lower than the maximum pressure level, after expanding the tubular member and before forming the recessed portions.

8. A method according to claim 1, characterized in that the members formed by stretching are hydraulically actuated. _ ^ i? ~? , "^ _. < »" »** - ,.

9. A method according to claim 8, characterized in that each of the members formed by stretching, is a piston in general cylindrical and because the recessed portions are generally cylindrical.

10. A method according to claim 1, characterized in that the hydroforming die comprises first and second hydroforming die halves, cooperating.

11. A method according to claim 1, characterized in that the injection molding die comprises first and second cooperating injection molding halves.

12. A method according to claim 2, characterized in that the mounting structure is a tubular mounting member and in that the mounting structure is positioned within each of the generally opposite recessed portions by insertion of the tubular voltage member. , through one of the openings, before placing the tubular blank in the injection molding die.

13. A method according to claim 12, characterized in that the tubular mounting member is internally threaded.

14. A method according to claim 1, characterized in that the shock-absorbing material is rubber.

15. A method according to claim 1, characterized in that the tubular target is formed of steel.

16. A chassis member for a motor vehicle, which is to be attached to another structural component within the motor vehicle in a shock absorbing relationship, the chassis member comprises: a tubular member designed to have a wall portion; main tubular, surrounding a hollow interior and a recessed portion extending from the main tubular wall portion, inwardly and inwardly hollow, the recessed portion is integrally formed with the main tubular wall portion; a mounting structure positioned within the recessed portion and constructed and arranged to allow the chassis member to be mounted to the structural component within the motor vehicle; and a solidified shock absorbing material placed within the recessed portion and surrounding the mounting structure, such that the mounting structure can be elastically mounted to the aforementioned structural component in a manner that allows limited relative movement, between the hydroformed tubular member and the mounting structure and therefore between the hydroformed tubular member and the structural component, characterized in that the shock absorbing material is molded over the integrally formed recess portion.

17. A vehicle chassis member, according to claim 16, characterized in that the recessed portion comprises a pair of recessed portions, generally opposite, deformed inwardly from the tubular power portion and extending inwardly and inwardly hollowly. each of the recessed portions has an annular wall portion formed in one piece with the tubular wall portion and a bottom wall portion formed integrally with the side wall portion; each of the bottom wall portions has a plurality of holes formed therethrough, communicating with the recessed portions; the mounting structure is positioned within each of the recessed portions; the solidified shock absorbing material is placed within each of the recessed portions and surrounds the mounting structure, the solidified shock absorbing material placed within one of the recessed portions is integrally connected to the shock absorbing material placed in the other of the cupped portions, through the holes.

18. A vehicle chassis member, according to claim 17, characterized in that the holes on one of the bottom wall portions are substantially aligned with the holes on the other of the bottom wall portions.

19. A vehicle chassis member, according to claim 17, characterized in that the mounting structure is a tubular mounting member, inserted through an aligned pair of those holes, with opposite external portions of the tubular mounting members that are they extend outward from the recessed portions and the shock absorbing material placed within the recessed portions.

20. A vehicle chassis member, according to claim 19, ^ l, ^, »,., ... characterized in that the tubular mounting member is internally threaded.

21. A vehicle chassis member according to claim 17, characterized in that each of the recessed portions is generally cylindrical.

22. A vehicle chassis member according to claim 17, characterized in that the shock absorbing material is placed inside each of the recessed portions, putting the hydroformed tubular blank into an injection molding die, then injecting the absorbing material of shock, molten, within the recessed portions, such that the molten shock absorbing material flows through the holes formed in the bottom wall portions and subsequently solidifies the molten, shock absorbing material.

23. A vehicle chassis member according to claim 22, characterized in that the shock absorbing material is rubber.

24. A vehicle chassis member according to claim 17, characterized in that the recessed portions are formed while the tubular target is placed inside a hydroforming die, by moving a pair of formed members with stretching, 10 generally opposite inwardly and towards each other, while pressurized fluid is supplied to the hollow interior of the white t ubul ar.

25. A vehicle chassis member according to claim 16, characterized in that the hydroformed tubular target is made from steel material. twenty 25 SUMMARY OF THE INVENTION The present invention relates to a • method for manufacturing a 5-vehicle chassis member, having a shock absorber mounting portion, constructed and arranged to be mounted to a structural component within a motor vehicle. The method comprises hydroforming a tubular target within a 10 hydroforming die, supplying pressurized fluid to the hollow interior of the target. A stretched forming member moves inwardly with respect to the cavity of the hydroforming die, while the fluid is 15 pressurizes so that the stretched forming member deforms a portion of the tubular wall inwardly to form a recessed portion having a side wall portion. # voided and a portion of the back wall. He The formed tubular white is then removed from the hydroforming die and a mounting structure (38) is placed inside the recessed portion and the blank and the mounting structure (38) are then placed inside a blank. 25 injection molding. The absorbing material of At the same time, shocks, melt (14) is injected into the recessed portion so that the molten material (14) surrounds the mounting structure. The molten shock absorber material subsequently solidifies. Preferably, a pair of these recessed portions are formed. The present invention also relates to a vehicle chassis member for joining a structural component in a shock absorbing relationship.