JP4270986B2 - Torsion beam suspension - Google Patents

Description

  In the present invention, both ends of a torsion beam extending in a substantially left-right direction of a vehicle body are connected to left and right trailing arms extending substantially in the front-rear direction of the vehicle body and swinging up and down, and wheels are attached to a spindle support plate welded to the left and right trailing arms. The present invention relates to a torsion beam suspension in which a spindle that supports the shaft is fixed.

  Such a torsion beam suspension is conventionally known as described in, for example, Patent Document 1 below. In this suspension, the trailing arm has a hollow pipe shape, so that it can be closed with a relatively low-cost production facility with good cross-sectional efficiency. A cross-sectional arm structure is obtained.

By the way, in this known one, in order to reduce the influence of welding heat distortion by separating the weld joint and the spindle mounting seating surface, a large bracket that projects upward is welded to the trailing arm, and the spindle is supported on this bracket. The plate is fixed. For this reason, the spindle axis and the main cross section of the trailing arm are greatly offset via the U-shaped bracket, and it is necessary to secure a sufficient thickness of the bracket to reliably support the load from the wheel. As a result, there is a problem that the weight is significantly increased.
JP 2000-94917 A

  Therefore, in order to eliminate the large bracket and solve the problem of the above-mentioned Patent Document 1, the rear end of the hollow pipe-shaped trailing arm is brought into contact with the plate-shaped spindle support plate as illustrated in FIG. It has already been proposed to directly weld and bolt the mounting flange integral with the spindle to this spindle support plate. With this, it is only possible to eliminate the heavy bracket and reduce the weight. Therefore, it is possible to make the axis of the spindle approach the main cross section of the trailing arm, which is advantageous in terms of strength.

  However, in the above proposal, since the welding connection between the trailing end of the trailing arm and the flat spindle support plate is made only at the abutting portion between the two, the strength and rigidity of the connection portion between them are sufficient. In order to ensure the welding, it is necessary to perform a welding process over the entire circumference (see (d) of FIG. 8). In this case, particularly in the welding portion on the vehicle front side, a large external input is applied to the main cross section of the trailing arm. Is important because it is necessary to communicate.

  On the other hand, the spindle support plate holds the axle side (spindle, back plate of the brake device, etc.) by bolt connection, so that the processing position of the tightened screw portion to which the bolt is tightened is set to the front and rear and the top and bottom of the spindle axis. The four locations need to be distributed in a well-balanced manner, but the tightening position is limited due to design restrictions related to space (arrangement of brake system, etc.). When trying to arrange the abutting position while avoiding the threading position, a pair of front and rear tightened screw portions are arranged outside the arm opening end surface, and the other pair of front and rear tightened screws The part is arranged inside the opening end face. In any case, since any of the four threaded parts are close to the butt weld, there is a deterioration in screw accuracy (thermal deformation) due to the influence of welding heat. Or, after welding, it is necessary to re-tap to ensure screw accuracy, and the pair of tightened screw parts on the other side of the upper and lower sides overhang outside the opening end face of the trailing arm. This also causes a decrease in the spindle support rigidity.

  Furthermore, because of the screw processing for fixing the spindle to the spindle support plate, the effective screw length necessary for the spindle tightening force must be ensured, and the plate thickness corresponding to the tightening force must be secured. Is required. In addition, since the spindle side mounting is a bolt connection, the spindle support plate is required to have a flat surface accuracy after welding, so that this plate is also sufficient from this point of view so as not to adversely affect the thermal strain of welding. It is necessary to use a plate thickness. As described above, the spindle support plate has a considerably thick plate structure. Therefore, if a product is to be supplied by press punching, a large special press processing facility is required, resulting in a significant cost increase and thermal forging. If it is going to supply a product by processing, it will increase processes, such as surface cutting, and will also increase cost.

  In addition, the present applicant has reduced the wall thickness of the spindle support plate to reduce the weight and suppress the occurrence of thermal strain caused by welding to solve the above-mentioned problem. Has been proposed to fix the plate by fitting and welding the bending flange formed on the outer periphery of the trailing end of the trailing arm to fix the plate (for example, see Japanese Patent Application No. 2002-199449). In the case of a pipe structure in which the rear half of the trailing arm extends in a straight line, the open end surface becomes a cut surface that obliquely intersects the arm axis. This makes it difficult to fit the outer periphery of the part. In order to mount the spindle, etc., it is necessary to fit all the four tightening screw parts distributed in the front and rear and upper and lower four positions with respect to the spindle axis inside the open end face of the rear end of the arm. The degree of freedom in selecting the position of the attached screw portion is narrowed.

  The present invention has been made in view of the above-mentioned circumstances, and an opening end surface of a trailing arm rear end that is formed in a hollow pipe shape and extends linearly in a substantially front-rear direction of the vehicle body is defined with respect to the arm axis. Butted and welded to the plate body of the spindle support plate as an obliquely intersecting cut surface, and four tightened screw parts for tightening the spindle etc. are attached to the plate body in the front and rear and top and bottom with respect to the spindle axis. The main object of the torsion beam suspension, which is provided at intervals, is to reduce the weight and cost by significantly reducing the thickness of the spindle support plate while solving the above problems of the conventional structure.

  In order to achieve the above object, the invention of claim 1 is characterized in that the left and right trailing arms, which are formed in a hollow pipe shape and linearly extend substantially in the front-rear direction of the vehicle body and swing up and down, To connect both ends of the torsion beam extending in the left-right direction, and to form the open end surface of the rear end of each left and right trailing arm as a cut surface that obliquely intersects the arm axis, and to support the spindle for wheel axle support The end face of the opening is abutted and welded to the plate body of the spindle support plate, and the plate body has four bolts for fixing the spindle or a wheel-related component arranged integrally therewith to the plate body. Four tightening screw parts to be tightened respectively are provided at a distance from each other in the front-rear and top-bottom directions with respect to the spindle axis. In the torsion beam suspension in which at least two of the upper and lower tightened screw portions are located outside the opening end surface of the trailing arm, the front end portion of the plate body has upper and lower A front-side bending flange that extends vertically over substantially the entire area in the direction, and a rear-side bending flange that extends vertically over substantially the entire area in the up-down direction of the rear end are integrally provided at the rear end of the plate body. The front bending flange extends forward along the outer surface of the trailing end of the trailing arm, and at least its front edge is welded to the outer surface of the trailing end; It is characterized by being welded by engaging with an end edge portion.

  According to a second aspect of the present invention, in addition to the feature of the first aspect of the invention, the front bending flange is welded in contact with the outer surface, upper surface, and lower surface of the trailing arm rear end. It is formed in a substantially U-shaped cross section from the front flange part, upper flange part, and lower flange part that are integrally formed with each other, and the upper flange and lower flange are at least on the upper and lower tightened screw parts on the front side. Correspondingly, an upper bending flange and a lower bending flange which are integrally connected to the upper edge and the lower edge of the plate main body, respectively, are integrally continuous.

  According to a third aspect of the present invention, in addition to the features of the first or second aspect of the present invention, the four tightening screw portions are projected and welded to the plate body, respectively, before and after the spindle axis. Each of the nuts is composed of four nuts arranged vertically at intervals.

  According to a fourth aspect of the invention, in addition to the features of the third aspect of the invention, at the rear end portions of the left and right trailing arms, at least one upper and lower front and rear nuts whose outer end surfaces are located outside thereof are provided. A tube forming part that bulges at least in the upper and lower directions is formed so as to pass through or in the vicinity of the connecting line connecting the axes of the nuts before and after the nut while escaping.

  According to a fifth aspect of the present invention, in addition to the features of the third or fourth aspect of the invention, the nut between the opening end surface of the left and right trailing arms and the plate body is outside the opening end surface. It welds along the circumferential direction of this opening end surface except at least the area | region corresponding to.

  According to a sixth aspect of the present invention, in addition to the feature of any of the first to fifth aspects, the rear bending flange is closely attached to a chamfered portion formed at a rear end portion of the opening end surface of the trailing arm. The rear edge of the chamfered portion is welded to the rear bending flange.

  The invention of claim 7 is characterized in that, in addition to the features of any of the inventions of claims 1 to 6, a spindle is press-fitted into a spindle support hole formed in the plate body by burring.

  In addition to the features of the invention of claim 7, the invention of claim 8 is characterized in that the tip of the spindle press-fitted from the spindle support hole into the trailing arm penetrates the trailing arm and protrudes to the outside. The protrusion is welded to the trailing arm.

  As described above, according to the invention of each claim, the front end of the plate body of the spindle support plate has a front bending flange extending vertically over substantially the entire vertical direction of the front end, and the rear end of the plate body. The rear bending flange extending vertically up and down substantially over the entire area of the rear end of the rear end portion is integrally connected to the portion, and the front bending flange extends forward along the outer surface of the trailing end of the trailing arm. And at least its front edge is welded to the outer surface of the rear end, and the rear bending flange engages and is welded to the rear edge of the trailing arm, thereby forming a thin spindle support plate. However, the rigidity of the front and rear end portions of the plate body, particularly the support rigidity of the front and rear tightening screw portions (nuts) on the outer side of the arm opening end surface can be increased, and the arm rear end is welded. Can be thermal deformation of the plate body in a heat distortion is effectively suppressed before and after the bending flanges, to ensure flatness after welding required for mounting the spindle and the like. In particular, the front bending flange is extended forward along the outer surface of the trailing end of the trailing arm and its front edge is welded to the outer surface of the arm, so that the spindle support plate is positioned as far as possible in front of the spindle axis. Since it becomes possible to weld with the trailing arm, not only the influence of the above-mentioned thermal strain can be eliminated, but also the load transmission efficiency from the spindle support plate to the trailing arm is improved and the load burden of the welded part is reduced, The durability is improved and the strength is increased.

  In particular, according to the invention of claim 2, the front bending flange is welded in contact with the outer side, upper side, and lower side of the trailing end of the trailing arm, respectively, and is welded. Since the front part is formed in a substantially U-shaped cross section, the rear end part of the arm is stably held by the front side bending flange, and the front side bending flange, the trailing arm, The moment span on the joint can be expanded both front and rear and up and down, so that the supporting stress generated in each welded portion can be reduced, and the durability and strength can be further improved. Moreover, the upper flange and the lower flange are respectively an upper bending flange and a lower bending flange that are integrally connected to the upper edge and the lower edge of the plate main body corresponding to at least two upper and lower tightening screw portions on the front side, respectively. Since each of them is continuously integrated, the bending rigidity of the plate body is further increased, and the support rigidity for the front and rear tightening screw portions on the outer side of the arm opening end face is further enhanced.

  Further, in particular, according to the invention of claim 3, each of the tightened screw portions is projection welded to the plate body, and is provided with four nuts lined up with each other at the front and rear and top and bottom with respect to the spindle axis. Since the plate body can be made thinner as described above, each nut can be fixed to the plate body easily and accurately by projection welding, and the plate body is not specially machined. However, it is possible to secure a sufficient screw length and to save costs.

  In particular, according to the invention of claim 4, the rear end portion of the trailing arm connects the axial lines of the front and rear nuts while the opening end surface escapes at least the front and rear nuts located on the outer side. Since the expanded pipe forming portion that swells at least in the upper and lower direction is formed so as to pass on or near the connecting line, the latter half of the arm is a straight pipe shape, and the molding process is relatively easy. Combined, the rear end of the arm can be expanded without difficulty while avoiding interference with the nut, and this expansion effect improves the support efficiency of the transmission load in the vertical direction from the spindle support plate to the trailing arm. The support rigidity in the vertical direction (support rigidity in the camber direction) can be improved.

  In particular, according to the invention of claim 5, a space between the opening end surface of the trailing end of the trailing arm and the plate main body is provided in a circumferential direction of the opening end surface except at least a region corresponding to a nut outside the opening end surface. Because it is welded along the plate body, it has a great influence on the flatness accuracy after welding necessary for mounting the spindle etc. on the plate body. We can abolish the welding near the outer nut and cause collapse due to heat shrinkage after cooling after welding. Can be effectively prevented, and the plane accuracy can be sufficiently secured.

  In particular, according to the invention of claim 6, the rear bending flange is in close contact with the chamfered portion formed at the rear end portion of the opening end surface of the trailing arm, and the rear end edge of the chamfered portion is the rear bending flange. Since it is welded, the welding between the rear bending flange and the arm rear end edge can be performed without difficulty.

  In particular, according to the invention of claim 7, since the spindle support plate is thinned, it is possible to form a spindle support hole in the spindle support plate by burring. As a result, the mounting flange is integrated with the spindle. Without being formed and fixed to the spindle support plate, the spindle can be fixed by being press-fitted into the spindle support hole formed by burring, and the weight of the spindle can be reduced by the amount of the mounting flange.

  In particular, according to the invention of claim 8, since the tip of the spindle that is press-fitted from the spindle support hole and penetrates the trailing arm to the outside is welded to the trailing arm, the influence of the heat of the welding is exerted on the spindle support plate. Without this, the spindle can be firmly fixed to the trailing arm.

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

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a plan view of a left half portion of a torsion beam type suspension, and FIG. 2 is an enlarged view of FIG. 3 is an enlarged sectional view taken along line 3-3 in FIG. 2, FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 3, and FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. FIG. 6 is a diagram corresponding to FIG. 2 showing the second embodiment, and FIG. 7 is a diagram corresponding to FIG. 3 showing the third embodiment.

  First, the first embodiment will be described. FIG. 1 is a plan view of the left half of a torsion beam suspension for a rear wheel of an automobile, and the right half has a symmetrical structure with respect to the longitudinal center line of the vehicle body. This torsion beam type suspension includes a pair of left and right trailing arms 10 extending substantially in the front-rear direction of the vehicle body, and a torsion beam 11 extending substantially in the left-right direction of the vehicle body and integrally connecting the left and right trailing arms 10. The gusset G that increases the coupling strength between the end of the torsion beam 11 and the intermediate portion of the trailing arm 10 is welded.

  A cylindrical trailing arm support portion 12 is welded to the front end of each trailing arm 10 and swings up and down on the vehicle body via a rubber bush joint (not shown) housed in the trailing arm support portion 12. It is supported freely. A rear wheel W is rotatably supported by a spindle 14 fixed to a spindle support plate 13 welded to a rear outer end of each trailing arm 10, and the intermediate portion of the trailing arm 10 and the gusset G span between them. A spring seat 15 is provided which is coupled to support the lower end of the suspension spring.

  The trailing arm 10 is entirely formed of a hollow metal pipe, the front end portion thereof is slightly squeezed and welded to the trailing arm support portion 12, and the remaining portion (ie, the main portion) is the front end portion. It extends straight to the rear end at an angle with the axis. An opening end surface 10a having a closed cross section at the rear end of the trailing arm 10 is formed as a substantially vertical cut surface that obliquely intersects the arm axis and extends in the longitudinal direction of the vehicle body. The opening end surface 10a is a spindle. It is welded to the back surface of the support plate 13 and welded. In the present invention, instead of the seamless pipe structure as shown in the illustrated example, a hollow pipe-shaped member in which the outer peripheries of the upper half and the lower half obtained by press-molding a metal plate are integrated with each other by welding is used. The arm 10 may be formed.

  Next, the spindle support plate 13 and the joining structure between the trailing arm 10 and the spindle support plate 13 will be described with reference to FIGS.

  The spindle support plate 13 has a plate body 13M having a substantially rectangular shape larger than the opening end surface 10a so that the back surface thereof comes into contact with the opening end surface 10a at the trailing end of the trailing arm. The front surface (left side surface in FIG. 3) of the plate body 13M is a flat mounting seat surface for the spindle 14, and four bolts B for fixing the spindle 14 to the plate body 13M are provided on the rear surface. Nuts Nfu, Nfd, Nru, and Nrd as tightened screw portions to be tightened respectively are provided with respect to the spindle axis L at a distance from each other before and after and vertically. Of these four nuts, the upper and lower two nuts Nfu and Nru are located outside the opening end surface 10a, and the lower and lower two nuts Nfd and Nrd are located inside the opening end surface 10a, respectively. Each nut Nfu, Nfd, Nru, Nrd is fixed to the plate body 13M by projection welding w2.

  The front end of the plate main body 13M has a front bending flange 13F that extends vertically over the substantially entire area between the upper and lower ends of the front end and is bent toward the inner side of the vehicle body. The rear bending flanges 13 </ b> R that extend up and down over substantially the entire area between the upper and lower ends of the rear end portion and are bent toward the inner side of the vehicle body are integrally connected to each other. The front bending flange 13F extends to the front side along the rear end outer surface of the trailing arm 10, the front end edge is welded to the rear end outer surface, and the rear bending flange 13R is The ring arm 10 is engaged with the rear end edge of the ring arm 10 and welded w4.

  In particular, in the illustrated example, the front bending flange 13F abuts the rear end of the trailing arm 10 so as to hold the rear end of the trailing arm 10, the front flange 13Ff, the upper flange 13Fu, and the lower The flange portions 13Fd are integrated with each other to form a substantially U-shaped cross section. The front flange portion 13Ff has a leading edge (that is, a front end edge) welded to the outer side surface of the arm rear end portion, and the upper flange portion 13Fu has a front end edge and an inner end edge on the upper side surface of the arm rear end portion. The lower flange portion 13Fd is welded w3 ″ at the front end edge and the inner end edge thereof to the lower surface of the arm rear end portion.

  Further, an upper bending flange 13U and a lower bending flange 13D, which are respectively bent toward the vehicle body inner side corresponding to the two upper and lower nuts Nfu and Nfd, are integrally formed on the upper and lower edges of the plate body 13M. The front end sides of the upper bending flange 13U and the lower bending flange 13D are integrally connected to the upper flange portion 13Fu and the lower flange portion 13Fd, respectively.

  Further, in the upper half of the trailing end of each trailing arm 10, two nuts Nfu and Nru are arranged around the top of the opening end face 10a at the rear end of the arm (ie, outside the opening end face 10a). While escaping so as to wrap around in the direction, a tube forming portion 10s that swells upward is formed so as to pass over or near the connecting line connecting the axes of the nuts Nfu and Nru. This pipe expansion forming part 10s is simultaneously formed in the step of forming the relief shape for the two nuts Nfu and Nru. In this case, since the trailing arm 10 has a straight pipe structure, the pipe expansion forming part 10s. Is formed relatively easily.

  Thus, according to the special arrangement of the tube expansion forming portion 10s, the support efficiency of the transmission load in the vertical direction from the spindle support plate 13 to the trailing arm 10 is improved, and the support rigidity in the vertical direction (support in the camber direction). Rigidity) can be improved.

  Further, a space between the opening end surface 10a at the rear end of the trailing arm 10 and the plate body 13M corresponds to at least the upper and rear two nuts Nfu and Nru (in the illustrated example, the front end region and the rear end portion). Except for (region), welding w1 is performed along the circumferential direction of the opening end face 10a. Thereby, in the plate body 13M, the welding in the vicinity of the nuts Nfu and Nru having the most influence on the planar accuracy after welding necessary for the spindle mounting can be abolished, and the occurrence of the collapse due to the heat shrinkage at the time of cooling after the welding is effective. Therefore, the plane accuracy can be sufficiently secured.

  The rear bending flange 13R is in close contact with a chamfered portion 10ar formed at the rear end of the opening end surface 10a at the rear end of the trailing arm 10, and the rear end edge of the chamfered portion 10ar is connected to the rear bending flange 13R. Welding w4. By forming such a chamfered portion 10ar on the opening end surface 10a at the rear end of the arm, the welding w4 between the rear bending flange 13R and the trailing end edge of the trailing arm 10 can be performed reasonably and accurately.

  Further, a spindle support hole 13h penetrating the inside and the outside of the plate body 13M is formed at a substantially central portion through which the spindle axis L passes. On the other hand, the spindle 14 includes a substantially rectangular mounting flange 14a formed on the outer periphery of the intermediate portion in the longitudinal direction, and a large diameter portion 14b penetrating and integrated therewith. It is fitted and supported in the support hole 13h. The spindle 14 is fixed to the spindle support plate 13 by four bolts B that pass through bolt holes provided at the four corners of the mounting flange 14a and are screwed into the nuts Nfu, Nfd, Nru, and Nrd. The spindle support hole 13h can be formed by burring as in a third embodiment to be described later.

  According to the structure of the first embodiment described above, the front bending flange 13F and the rear bending flange 13R extending in a wide range above and below the front end portion and the rear end portion of the plate body 13M of the spindle support plate 13 are connected to each other. The front bending flange 13F extends to the front side along the rear end outer surface of the trailing arm 10, the front end edge is welded to the rear end outer surface, and the rear bending flange 13R is The trailing edge of the trailing arm 10 is engaged and welded w4. Thus, even if the spindle support plate 13 is press-molded from a thin metal plate, the rigidity of the front end portion and the rear end portion of the plate body 13M, particularly the front and rear tightened screw portions (nuts Nfu on the outer side of the arm opening end face 10a). , Nru), the thermal deformation of the plate main body 13M due to thermal strain when welding the rear end of the arm is effectively suppressed by the front and rear bending flanges 13F, 13R, and the spindle 14 The planar accuracy after welding necessary for mounting can be ensured.

  In particular, since the front bending flange 13M extends forward along the outer surface of the rear end of the arm and the front end edge thereof is welded to the outer surface of the arm w3, the spindle support plate is located at a position sufficiently far ahead of the spindle axis L. 13 can be welded to the trailing arm 10, which not only eliminates the influence of the aforementioned thermal distortion, but also improves the load transmission efficiency from the spindle support plate 13 to the trailing arm 10. The load on the portion w3 is reduced, and the durability is improved and the strength is increased.

  Further, as shown in the illustrated example, the front bending flange 13F is in contact with the outer side surface, the upper side surface, and the lower side surface of the rear end portion of the arm, respectively, and is welded w3, w3 ′, w3 ″ to the front flange portion 13Ff and the upper flange portion 13Fu. The lower flange portion 13Fd is integrated and formed in a substantially U-shaped cross section, so that the rear end portion of the arm is stably held by the front bending flange 13F. The moment span on the joint between the front bending flange 13F and the trailing arm 10 can be expanded both in the front and rear direction and in the vertical direction, so that the supporting stress generated in each welded portion can be reduced, thereby further improving the durability and increasing the strength.

  Moreover, in the illustrated example, the upper flange portion 13Fu and the lower flange portion 13Fd of the front bending flange 13F are respectively provided on the upper and lower edges of the plate body 13M in correspondence with the two upper and lower nuts Nfu and Nfd, respectively. Since each of the bending flange 13U and the lower bending flange 13D is continuous integrally, the bending rigidity of the plate main body 13M is further increased, and the front and rear tightened screw portions (nuts Nfu, Nru) on the outer side of the arm opening end surface 10a are increased. Support rigidity is further strengthened.

  Since the spindle support plate 13 can be thinned as described above, the nuts Nfu, Nfd, Nru, and Nrd can be easily and accurately fixed to the plate body 13M by the projection welding w2, and the plate body 13M. Even if the screw itself is not specially machined, a sufficient screw length can be secured, and cost can be saved.

  Further, since the spindle support plate 13 is directly fixed to the rear end portion of the trailing arm 10 without using a large bracket, the amount of offset between the spindle axis L and the main cross section of the trailing arm 10 is reduced. The rigidity of the assembly of the arm 10 and the spindle 14 can be increased.

  FIG. 6 shows a second embodiment of the present invention. In this embodiment, the upper bending flange 13U and the lower bending flange 13D, which are integrally formed on the upper edge and the lower edge of the plate body 13M, respectively, are only in regions corresponding to the upper and lower two nuts Nfu and Nfd, respectively. However, it is different from the first embodiment in that it is formed long over substantially the entire length of the plate body 13M, and the other configuration is basically the same as the configuration of the first embodiment.

  Thus, also in the second embodiment, the same effect as that of the first embodiment is achieved, and the upper bending flange 13U and the lower bending flange 13D are formed in a wide range, so that the bending rigidity of the plate body 13M is increased. Is further strengthened.

  FIG. 7 shows a third embodiment of the present invention. In this embodiment, bolts B that are screwed into nuts Nfu, Nfd, Nru, and Nrd as four tightening screw portions provided at a distance from each other in the front-rear direction and the vertical direction with respect to the spindle axis L, Rather than being used to fasten the spindle 14 to the outer surface of the spindle support plate 13 as in the previous embodiment, the brake device back plate (not shown) is fastened to the outer surface of the spindle support plate 13. This back plate corresponds to the wheel-related component of the present invention.

  In the third embodiment, a spindle support hole 13h is formed by burring in a substantially central portion of the plate body 13M, and the large diameter portion 14b of the spindle 14 is press-fitted into the spindle support hole 13h. An annular protrusion 14a 'on the outer periphery of the spindle 14 is defined by engaging with the outer surface of the plate body 13M. The tapered small diameter portion 14c of the spindle 14 connected to the large diameter portion 14b passes through the opening 10k formed in the rear end inner wall of the trailing arm 10 from the inside to the outside, and is fixed by welding w5.

  Thus, in the third embodiment, basically the same function and effect as in the previous embodiment can be achieved.

  Since the spindle support plate 13 can be thinned as described above, the spindle support hole 13h can be formed by burring as in this embodiment. This is because if the spindle support plate 13 is thick, the expansion rate of the material becomes large during burring and cracking is likely to occur. Accordingly, the spindle 14 can be press-fitted and fixed to the spindle support hole 13h formed by burring in the spindle support plate 13 without integrally providing the spindle 14 with a mounting flange. Thus, the flange 14a) of the second embodiment can be eliminated to contribute to weight reduction.

  Further, since the tip of the spindle 14 press-fitted into the spindle support hole 13h is fixed by welding w5 through the opening 10k of the trailing arm 10 from the inside to the outside, the spindle 14 is attached to the trailing arm 10 and the spindle support plate 13. The rigidity can be greatly increased, which can contribute to the improvement of the toe rigidity and the camber rigidity of the suspension. Further, since the portion of the weld w5 is sufficiently separated from the spindle support plate 13, there is no possibility that the heat causes thermal distortion of the spindle support plate 13.

  As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.

  For example, in the embodiment, among the nuts Nfu, Nfd, Nru, and Nrd as four tightening screw portions provided at intervals in the front and rear and top and bottom with respect to the spindle axis L, the top and bottom two Although the nuts Nfu and Nru are positioned outside the opening end surface 10a at the trailing end of the trailing arm 10 and the two front and rear nuts Nfd and Nrd are positioned inside the opening end surface 10a, respectively, in the present invention, The upper and lower two nuts Nfu and Nru may be positioned inside the opening end surface 10a and the lower and lower two nuts Nfd and Nrd may be positioned outside the opening end surface 10a, respectively, upside down. In the present invention, at least three nuts (tightened screw portions) including at least two upper and lower nuts Nfu, Nru (or at least two lower front and rear nuts Nfd, Nrd) are positioned outside the opening end surface 10a. You may make it make it.

The top view of the left half part of the torsion beam type suspension which concerns on 1st Example 2 enlarged view of FIG. 3-3 enlarged sectional view of FIG. 4-4 enlarged sectional view of FIG. FIG. 5 is an enlarged sectional view taken along line 5-5. FIG. 2 correspondence diagram showing the second embodiment FIG. 3 corresponding diagram showing the third embodiment. Exploded view of main part showing conventional example and its b, c, d arrow view

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Trailing arm 10a Open end surface 10ar Chamfering part 10s Tube expansion forming part 11 Torsion beam 13 Spindle support plate 13D Lower side bending flange 13F Front side bending flange 13Ff Front side flange part 13Fd Lower flange part 13Fu Upper flange part 13h Spindle support hole 13M Plate main body 13R Rear side bending flange 13U Upper side bending flange 14 Spindle B Bolt L Spindle axis Nfu, Nfd, Nru, Nrd Nut as screw part to be tightened W Wheel w1-w5 Welding

Claims (8)

Both ends of the torsion beam (11) extending in the substantially left-right direction of the vehicle body are formed on the left and right trailing arms (10) formed in the shape of a hollow pipe and extending in a straight line in the substantially longitudinal direction of the vehicle body and swinging up and down. A spindle (14) that supports the wheel (W) while connecting and forming an open end surface (10a) at the rear end of each of the left and right trailing arms (10) as a cut surface obliquely intersecting the arm axis. The opening end face (10a) is abutted and welded (w1) to the plate body (13M) of the spindle support plate (13) for supporting the spindle, and the plate body (13M) is integrated with the spindle (14) or the same. Four bolts (N) to which four bolts (B) for fixing the wheel-related parts to be installed to the plate body (13M) are respectively fastened u, Nfd, Nru, Nrd) are spaced from each other on the spindle axis (L) in the front-rear and up-down directions, and at least two of the tightened screw portions at the front and rear are tightened. In the torsion beam type suspension in which the screw part (Nfu, Nru) is located outside the opening end face (10a),
The front end of the plate body (13M) has a front bending flange (13F) extending vertically over substantially the entire vertical direction of the front end, and the rear end of the plate body (13M) has a rear end. Rear bending flanges (13R) extending up and down over substantially the entire vertical direction of each part are integrally provided,
The front bending flange (13F) extends forward along the rear end outer surface of the trailing arm (10), and at least its front end edge is welded (w3) to the rear end outer surface.
The rear bending flange (13R) is engaged with the rear end edge of the trailing arm (10) and welded (w4). The front bending flange (13F) is welded (w3, w3 ′, w3 ″) in contact with the outer surface, upper surface, and lower surface of the trailing end of the trailing arm (10) and is integrally formed with each other. The front flange portion (13Ff), the upper flange portion (13Fu), and the lower flange portion (13Fd) are formed in a substantially U-shaped cross section,
The upper flange portion (13Fu) and the lower flange portion (13Fd) correspond to at least the upper and lower two tightened screw portions (Nfu, Nfd) on the upper and lower edges of the plate body (13M). 2. The torsion beam suspension according to claim 1, wherein the torsion beam suspension is integrally connected to an upper bending flange and a lower bending flange respectively connected integrally.   The four tightening screw portions are projection-welded (w2) to the plate body (13M), and are arranged to be spaced apart from each other in the front-rear direction and the vertical direction with respect to the spindle axis (L). The torsion beam suspension according to claim 1 or 2, characterized in that each of the suspensions comprises (Nfu, Nfd, Nru, Nrd).   At the rear end of each of the left and right trailing arms (10), the opening end face (10a) escapes at least one of the front and rear nuts (Nfu, Nru) positioned on the outer side of the opening end face (10a). The torsion beam according to claim 3, wherein a tube-forming part (10 s) that swells at least in one of the upper and lower sides is formed so as to pass on or in the vicinity of a connecting line connecting the axes of Nru). Suspension.   Between the opening end surface (10a) at the rear end of each of the left and right trailing arms (10) and the plate body (13M), there is a region corresponding to the nuts (Nfu, Nru) outside the opening end surface (10a). The torsion beam suspension according to claim 3 or 4, characterized in that, at least, the welding is performed (w1) along the circumferential direction of the opening end face (10a).   The rear bending flange (13R) is in close contact with a chamfered portion (10ar) formed at a rear end portion of the opening end surface (10a) of the trailing arm (10), and a rear end of the chamfered portion (10ar). The torsion beam suspension according to any one of claims 1 to 5, characterized in that the edge is welded (w4) to the rear bending flange (13R).   The torsion beam suspension according to any one of claims 1 to 6, wherein the spindle (14) is press-fitted into a spindle support hole (13h) formed by burring in the plate body (13M). The tip of the spindle (14) press-fitted into the trailing arm (10) from the spindle support hole (13h) penetrates the trailing arm (10) and protrudes to the outside. The torsion beam suspension according to claim 7, wherein the suspension is welded (10) to (10).

Images