OA19451A - A frame assembly for a two wheeled vehicle. - Google Patents

Abstract

The present subject matter discloses a frame assembly (200) for a two wheeled vehicle (100) comprising a main tube (201) extending substantially rearwardly and downwardly from a head pipe (111), a free end of the main tube (201) comprising a swing arm pivot point (201c) to pivotally mount a swing arm (202), and a pair of right and left upper tubes (250) extending horizontally rearwards from a central portion of the main tube (201). A pair of right and left side tubes (260) extends upwardly rearward from the swing arm pivot point (201c), and said pair of right and left side tubes (260) extend till the rear end of the pair of right and left upper tubes (250) so that a rear portion of said pair of right and left upper tubes (250) experience negligible overhang. Further, a pair of right and left sheet gusset plate (210) is disposed between each of said pair of right and left upper tube (250) and each of said pair of right and left side tube (260) to support a rear suspension member (102). This improves strength and stiffness of the frame assembly consequently preventing the failure on the rear portion of said pair of right and left upper tubes (250).

Description

[00015] Various features and embodiments of the présent invention here will be discemible from the following further description thereof, set out hereunder. In the 5 ensuing exemplary embodiments, the vehicle is a straddle two wheeled vehicle.

However, it is contemplated that the disclosure in the présent invention may be applied to any two wheeled vehicle capable of accommodating the présent subject matter without defeating the spirit of the présent invention. The detailed explanation of the constitution of parts other than the présent invention which constitutes an essential part has been 10 omitted at suitable places.

[00016] A frame assembly is a core structure of a two wheeled vehicle. The frame assembly supports an internai combustion engine, providing the hinge points for both front and rear suspension members which is connected to the front and rear wheel respectively, and supports a rider and any pillion or luggage. The frame assembly also 15 supports a steering mechanism, smaller Systems like electronics, a fuel tank, and body panels. In a straddle type two wheeled vehicle, the frame assembly generally comprises a head pipe disposed in the front of the two wheeled vehicle, a main tube extending gradually downwards towards the rear portion and takes a gentle curve towards the bottom at the middle portion of the two wheeled vehicle, a down tube extends sharply >0 downwards from the head pipe, a pair of upper tubes extends horizontally rearward from the middle portion of the main tube, and a pair of side tubes extending from the free end of the main tube to join the pair of upper tubes a point located at predetermined distance from the starting of the pair of upper tubes. The IC engine is mounted between the ends of the down tube and the main tube and acts as a stressed member of the part of the 5 frame assembly. A swing arm is further pivotally attached to the end of the main tube to swingably support a rear wheel. The rear wheel is made swingable by loading it to a pair of rear suspension System mounted on the point where the upper tube and the side tube meet. A pillion handle mounting bracket is mounted across the pair of upper tubes at the rear end to support a pillion handle or a carrier to load goods and/or luggage. The pillion ~3 ~ handle mounting bracket is also used to mount a tail cover, rear fender, tail lamp, and also acts as a seat rest to support a seat assembly. Generally, the various components of the frame assembly are made of tubular Steel which provides suffïcient strength and stiffness.

[00017] Generally, for straddle type frame assembly, the pair of side tubes are connected to the pair of upper tubes at a point wherein the rear suspension is attached to the frame assembly to provide suffïcient support and load. Different parameters such as rider and pillion weight, load from the rear suspension décidé the stiffness and design of the frame assembly. Conventionally, the attachment of the pair of side tubes near the rear suspension point of the upper tube cannot support enough load on the rear portion of the upper tubes. The drawback is even more pronounced when a carrier is secured to the pillion support bracket configured to carry heavy loads when goods/luggage is loaded on the carrier. It is observed that, on repeated heavy loading on the carrier, the upper tubes of the frame assembly fails or deforms at the rear portion ofthe upper tube m close proximity to the beginning of the pillion support bracket. Hence, there is a need to improve the strength and stiffness of the frame assembly to prevent failure when subjected to heavy loads at the rear portion of the frame assembly. Further, the upper tube on which the fuel tank is mounted may interfère with the mounting of the fuel pump unit beneath the fuel tank. It is seen that, the fuel pump mounting bracket may foui or interfère with the pair of upper tubes on either side. Hence, complex design changes are required to modify the design of the pair of upper tubes. Furthermore, with an aim to enable better ground reach for a rider the height of the pair of upper tubes on which the seat assembly is mounted needs to be reduced.

[00018] Conventionally, in State of art to improve the stiffness and strength ofthe frame assembly when subjected to loading at the rear portion, the side tubes are extended beyond the rear suspension attachment point and attached to the upper tube further rearward beyond the rear suspension attachment point. However, such conventional frames hâve an inclined orientation of the side tube gradually tapering towards the upper tubes in order to triangularly support the upper tubes to increase ~4~ stiffness for the frame assembly. However, this design compromises on stiffness ofthe frame assembly when it is loaded on the extreme rear portion of the upper tube as the overhang of the upper tube after the point of attachment of side tube to the upper tube is more. Further during the attachment of the side tube to the upper tube in conventional State of art, the side tube is bashed to permit smooth attachment to the upper tube. This reduces the section modulus of the side tube reducing its stiffness and strength. Furthermore, the attachment of the side tube to the upper tube requires a large welding length and requires multiple welding passes for secured attachment. In cases where large loads are applied to the extreme rear of the upper tube, use of frame assembly in conventional state of art is insufficient and failure at the rear overhang portion can still occur. Another problem which arises is that, with this construction as described in prior art it is difficult to provide weld mounting brackets for mounting accessories such as carry box, saree guard etc. as to provide any such brackets needs larger size sheet métal brackets are needed which results in increase in cost weight and manufacturing difficulty. Also, the area around the rear suspension attachment point needs to be structurally strengthened as usage of rear suspension with higher spring rating may cause failure at that point. Hence, there is also a need to strengthen the area of rear suspension mounting without increasing weight, and cost.

[00019] Hence, it is the principal object of the présent subject matter is to provide a frame assembly wherein support is provided to the pair of upper tube to prevent failure at the rear portion of the pair of upper tubes near the pillion handle mounting bracket.

[00020] Another object of présent subject matter is to accommodate the fuel pump easily beneath the fuel tank so that it does not foui with the pair of upper tubes.

[00021] Another object ofthe présent subject matter is to facilitate the mounting of brackets to accommodate various vehicle accessories such as carry box, saree guard, lady pillion footrest, load carrier etc.

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[00022] Another objective of the présent subject matter is to reduce seat height from ground without modifying or reducing seat foam thickness to enable easier ground reach for a rider and better comfort while seating.

[00023] The présent invention describes a frame assembly comprising a head pipe, a main tube, a down tube and a pair of right and left upper tubes. The main tube extends substantially rearwardly and downwardly from the head pipe, said free end of the main tube comprising a swing arm pivot point to pivotally mount a swing arm to support a rear wheel. The down tube extends sharply rearwardly and downwardly from the head pipe and below said main tube, and an internai combustion engine is mounted between the free end of the down tube and the free end of the main tube. The pair of right and left upper tubes extends horizontally rearwards from a central portion of the main tube. The frame assembly further comprises a pair of right and left side tubes extending upwardly rearward from the swing arm pivot point, and said pair of right and left side tubes extending till the rear portion of the pair of right and left upper tubes to hâve a negligible overhang of rear portion of said pair of right and left upper tubes. Further, a pair of right and left Steel gusset plates are disposed between each of said pair of right and left upper tubes and each of said pair of right and left side tubes to support a rear suspension member joined at a rear suspension attachment point.

[00024] Along with the principal characteristic of the présent subject matter, a second characteristic of the présent subject matter describes the frame assembly wherein a pillion handle mounting bracket is attached to the rearmost portion of said pair of right and left upper tubes. Further, each of said pair of right and left side tubes is tubular in shape having circular cross section throughout its length and has its end welded directly on each of said pair of right and left upper tubes at a point beyond the beginning of the pillion handle mounting bracket, resulting in the increase of the section modulus at the joint.

[00025] Along with the principal characteristic of the présent subject matter, a third characteristic of the présent subject matter, wherein said pair of right and left side tubes

619451 hâve an inclined orientation till the rear suspension attachment point, and is parallel to said pair of right and left upper tubes beyond the rear suspension attachment point, thus enabling attachment of mounting brackets to mount accessories.

[00026] Along with the principal characteristic of the présent subject matter, a fourth characteristic of the présent subject matter, wherein said pair of right and left upper tubes comprises a stepped portion extending from the front end of said pair of right and left upper tubes till the rear suspension attachment point.

[00027] Along with the principal characteristic of the présent subject matter, a fifth characteristic of the présent subject matter, wherein an integrated lock is secured to the rear suspension attachment point, said integrated lock being elliptical in shape to enable a passenger to grip, and said integrated lock comprising a lever portion capable of being locked and unlocked to enable the locking of a helmet, and other luggage with hooks such as suitcase, goods in cover etc.

[00028] With the above design changes, the following advantages can be obtained such as higher stiffness of frame, weight saving, better ground reach, better strength of frame, lesser manufacturing difficulties, lesser seat height, higher seat comfort, higher induction volume, and higher ground clearance. The frame assembly construction is also not very complex.

[00029] The présent invention along with ail the accompanying embodiments and their other advantages would be described in greater detail in conjunction with the figures in the following paragraphs.

[00030] Fig. la. illustrâtes a side view of a saddle-ride type vehicle (100) colloquially called a motorcycle, in accordance with an embodiment of the présent subject matter. In an embodiment, the saddle-ride type vehicle (100) of the présent subject matter includes an internai combustion (IC) engine (101). The vehicle further includes a front wheel (110), a rear wheel (103), a frame assembly (200) (shown in Fig.2a), a fuel tank (107) and seat (106). The frame assembly (200) includes a head pipe ~7 ~ (111), a main tube (201) (shown in Fig.2a), a down tube (113), a pair of upper tubes (250) (shown in Fig.3) and a pair of side tubes (260) (shown in Fig.2a) extending from the free end ofthe main tube (201) and joining the rear portion ofthe pair of upper tubes and will be explained in detail later. The head pipe (111) supports a steering shaft (121) with two brackets — upper bracket (not shown) and lower bracket at the respective ends. Two telescopic front suspension (114) (only one shown) is attached to the lower bracket on which is supported the front wheel (110). The upper portion of the front wheel (110) is covered by a front fender (115) mounted to the lower portion of a front fork ofthe telescopic front suspension (114). A handlebar assembly (108) is fixed to upper bracket and can rotate to both sides. A headlamp assembly (109) is disposed in the front portion of the head pipe (111). The down tube (113) is disposed in front of an IC engine (101) and stretches slantingly downward from head pipe (111). A bracket (206) (shown in Fig.2a) is provided at the lower end of down tube (113) for supporting the IC engine (101) on the down tube (113) disposed on substantially front portion ofthe two wheeled vehicle. Main tube (201) is located above the IC engine (101) and stretches rearward from head pipe (111) and connects to the rear of the IC engine (101). The pair of upper tubes (250) is joined to the rear end of the main tube (201) and stretches rearward. The pair of upper tubes (250) are joined to the central portion of the main tube (201) and stretching rearward to support a seat assembly (106) disposed above. The free end ofthe main tube (201) comprises a rear engine mounting bracket (207) (shown in Fig.2a) pivotally supporting a swing arm (202) to swing vertically, and the rear wheel (103) is connected to rear end of the swing arm. Generally, two rear suspension members ( 102) (only one shown) are arranged between swing arm (202). A tail lamp assembly (104) is disposed on the rear end of the seat (106). A pillion handle (105) is also provided on the rear ofthe pair of upper tubes (250). Rear wheel (103) is arranged below seat assembly (106) and rotâtes by the driving force of the IC engine (101) transmitted through a chain drive (not shown) from the IC engine (101). A rear fender (122) is disposed above the rear wheel (122) and attached to the pair of upper tubes (250).

[00031] Fig. 1b. illustrâtes the side view of a two-wheeled vehicle having a carrier bracket (130) attached to the frame assembly (200) according to the embodiment of the ~8~ présent subject matter. The carrier bracket (130) is connected to the pair of upper tubes (250) on either side of the two wheeled vehicle and extends to be attached to the front portion of the pair of side tubes (260) on either side. The carrier bracket (130) aids in carrying heavy goods and luggage some to the excess of 200kg weight. The carrier bracket (130) facilitâtes the mounting of such luggage with multiple brackets and hooks. As highlighted in the previous paragraphe, the rear part of the frame assembly is subjected to loads exceeding 200 kgs, and there is a high probability of failure of the pair of upper tubes at the point of beginning of the pillion handle mounting région or carrier mounting région (at the pillion handle mounting bracket 220, shown in FIG.2a). The new frame assembly proposed in the présent subject matter addresses the above drawback.

[00032] Fig. 2a. illustrâtes an isométrie view of the frame assembly (200) as viewed from a rear direction and Fig. 2b. illustrâtes the isométrie view of the frame assembly as viewed from a front direction of the two wheeled vehicle according to the embodiment of the présent subject matter. The frame assembly (200) comprises a head pipe (111), a main tube (201), a down tube (113), a pair of upper tubes (250) and a pair of side tubes (260). The head pipe receives the steering shaft and supports the handlebar assembly, the front suspension system (114), the front wheel (110) and the front fender (115) and other éléments such as dashboard with instrument cluster (not shown). The main tube (201) extends rearwards and gradually downwards in an inclined manner from the head pipe (111) and further ahead in the middle région of the two wheeled vehicle, the main tube (201) curves downwards. Hence, the main tube (201) can be divided into two portions, a front portion (201a) which is substantially in an inclined manner extending rearwards, and a downward portion (201b) which curves downwards from the front portion (201a). The free end of the downward portion main tube (201) comprises of a swing arm pivot point (201c) to pivotally mount the swing arm (202) supporting the rear wheel (103). The free end also comprises a rear engine mounting bracket (207) to support the rear portion of the IC engine (101). The down tube (113) is integrally attached to the head pipe (111) at one end and extends sharply downwards towards the ground plane. The other end of the down tube (113) comprises a front engine mounting ~9~ bracket (206) to support the front portion of the IC engine (101). The down tube (113) not only connects the head tube (111) to other parts of the frame assembly but is also hollow to accommodate various wires and tubes (not shown) which connect the front part of the vehicle (100) to the rear. A gusset plate (209) connects angularly the joint of the main tube (201) and the down tube (113) to provide additional strength and stiffness to the frame assembly in general. A cross tube (208) connects the main tube (201) and the down tube (113) to provide additional stiffness and support. A pair of upper tubes viz. right upper tube (250R) and left upper tube (250L) is disposed rearwardly of the main tube (201) and extends horizontally rearwards from the central portion of the main tube (201) up to the vehicle tail lamp assembly. As seen in the Fig. 2a. and Fig. 2b. the pair of upper tubes join the main tube (201) at the central portion substantially at the portion of the beginning of the curve of the downward portion (201b). The right upper tube (250R) and the left upper tube (250L) include at least one pillion handle mounting bracket (220) to support the pillion handle (105) and/or the carrier (130). The pair of side tubes (260) is securely attached to the swing arm pivot point (201c) on the end of the main tube (201) and extends up to the rear portion of the pair of upper tubes and joined to the rear portion beyond the beginning of the pillion handle mounting bracket (220).

[00033] Fig. 3. illustrâtes the side view of the frame assembly according to the embodiment of the présent subject matter. As seen in the figure, the pair of side tubes (260) extend from the swing arm pivot point (201c) upwardly and rearwardly up to the rear suspension attachment point (211) to form an inclined shape. From the rear suspension attachment point (211), the pair of side tubes (260) extends further rearward parallel to the pair of upper tubes (250) till it joins the rear portion of the pair of upper tubes (250). This arrangement provides higher stiffness and strength to the rear of the frame assembly. Each of the pair of side tubes (260) takes a sharp curve upwards just before it joins the pair of upper tubes (250) at a point after the beginning of the pillion handle mounting bracket (220). The upper tube and side tube is connected to each other at the rear suspension attachment point by a sheet gusset plate (210) near the mid of upper tube (250) and side tube (260). It is at this location that the side tube (260) ~ 10 ~ transitions from an inclined orientation (261) to a parallel orientation (262) by forming a gentle curve. The sheet gusset plate (210) has a provision to weld the rear suspension member (102) on to it. This sheet gusset plate (210) connecting each of the pair of upper tube (250) and each of the pair of side tube (260) helps to improve the stiffness and strength of the frame assembly (200). As highlighted, the pair of upper tubes (250) extends from a mid of main tube (201) horizontally rearward till the end of the two wheeled vehicle. In another aspect of the présent subject matter, the front portion of the pair of upper tubes is stepped (see 251) from the front end of the pair of upper tubes till the rear suspension attachment point (211). This has advantages of accommodating fuel pump supporting structures on the fuel tank and also to support lower seat height. This réduction in seat height from ground level without any design change in the seat assembly including réduction in foam thickness. This enables better ground reach for the rider and also provides better comfort.

[00034] Fig. 4a. illustrâtes the rear view of the fuel tank of the two wheeled vehicle illustrating a prior art. A fuel pump unit (403) emerges from the base of the fuel tank (107) as shown in the figure. The fuel pump unit (403) has a fuel pump bracket extending widthwise and configured to secure the fuel pump unit (403) to the fuel tank through fasteners. But, in prior art it is observed that the fuel pump bracket fouis with pair of upper tubes (see 401) thus preventing the attachment of the fuel pump unit (403) and also prevent the accessibility of the fuel pump unit (403) during servicing. In order to address this drawback, the front portion of the pair of upper tubes is stepped (see 251 ) from the front end of the pair of upper tubes till the rear suspension attachment point (211). Fig. 4b. illustrâtes the rear view of the fuel tank unit (403) of the two wheeled vehicle according to the embodiment of the présent subject matter. Here it is observed that, on reducing the height of the front portion of the pair of upper tubes resulting in the formation of the stepped portion (251), it provides for enough space therein between the pair of upper tubes and bottom of the fuel tank (107) to attach the fuel pump bracket to the fuel tank (107) and hence secure the fuel pump unit (403) in position. Further, this facilitâtes easier accessibility of the fuel pump during servicing.

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[00035] Fig. 5 illustrâtes a close up view of the rear portion ofthe frame assembly (200) according to the embodiment of the présent subject matter. The pair of side tubes (260) is welded in close proximity to the end of the pair of upper tubes (250) after the point of beginning of the pillion handle mounting bracket (see 501). This reduces the overhang of the pair of upper tubes (250) beyond the point (501) where the side tube joins the upper tube. Further, as we can observe in the point of joining (501) that is a circular to circular attachment of the side tube (260). The end ofthe side tubes (260) are not bashed to make it fiat before attachment and the surface area of contact of the side tube (260) to the upper tube (250) is minimal (see 501). The arrangement increases the section modulus of the side tube (260) and hence capable of carrying more load and provides superior strength and stiffness. This also reduces the welding length and welding pass during attachment of side tube (260) to the upper tube (250) at the time of manufacture. This saves cost due to lesser welding and superior assembly. Furthermore, the side tube second section portion (262) is made parallel to the rear portion of the upper tube (252). This enables easy mounting of accessory mounting brackets (205). Hence, the parallel orientation of the second portion ofthe side tube (262) enables easy mounting of various vehicle accessories such as saree guard, foot rest, and electric components such as sensors, separate luggage holder, or a tank bag.

[00036] Fig. 6a. illustrâtes an integrated lock (600) mounted on the frame assembly at the rear suspension attachment point (211) and Fig. 6b. illustrâtes the isométrie view ofthe integrated lock (600) according to the embodiment of the présent subject matter. Generally, in two wheeled vehicles, a pillion handle can be provided in the side ofthe two wheeled vehicle projecting from below the seat assembly in addition to the pillion handle towards the rear portion of the pair of upper tubes. Further, a helmet lock is usually présent separately attached on the pillion handle or attached separately and disposed towards any one side. Further, a goods lock to affïx goods, lug gages and hang bags effectively from the side of the vehicle requires another hook member. Having separate components for each function will increase the accessories in the vehicle, cost of vehicle, weight and requires space for mounting each of pillion handle and helmet lock. Hence, another feature of the présent subject matter has the pillion handle and the ~

helmet lock integrated in one single unit. This single integrated helmet lock and pillion handle enables compact packaging of accessories in the two wheeled vehicle, reduces weight of the vehicle, it is cost effective and lesser parts are used. Further design changes such as making it a foldable unit enhancing the compactness. Hence, Fig. 6a. 5 illustrâtes an integrated helmet lock, suitcase lock and pillion handle attached at the rear suspension attachment point on either one or both sides of the two wheeled vehicle. Fig. 6b. illustrâtes an isométrie view of the integrated lock. The integrated lock (600) has a handle portion (602) elliptical in shape and said handle portion (602) has an attachment portion (604) at its base. The fastener member (212) which is used to secure the rear 10 suspension to the sheet gusset plate (210) is made slightly longer and aids in accommodating the attachment portion (604) of the integrated lock on the rear suspension attachment point (211). The handle portion (602) is made open able by a lever portion (601) connected to a lock member (603). The lever portion (601) is in opérable lap joint with the handle portion (602) and can be held in position (locked) or 15 movable pivaotably when it is unlocked. The lock member (603) is opérable by a key.

Hence, helmet, or any goods and luggage can be inserted through the gap in the handle portion when unlocked and can be locked in position. The shape of handle portion (602) and its location makes it convenient to function as a pillion handle grip for a pillion passenger.

[00037] Fig. 7. illustrâtes a second embodiment of the présent invention wherein the said pair of right and left tubes are parallel to said pair of right and left upper tubes. In this embodiment, the left and right Steel gusset plate can be modified in design to reduce its size, and the pillion handle mounting bracket (220) can be made bigger to provide greater support. This enhances load bearing capacity at the rear of the vehicle.

Claims (12)

1. A frame assembly (200) for a two wheeled vehicle (100) comprising:

a head pipe (111);

a main tube (201) extending substantially rearwardly and downwardly from the head pipe (111), a free end of the main tube (201) comprising a swing arm pivot point (201c) to pivotally mount a swing arm (202) to support a rear wheel (103) ofthe two wheeled vehicle (100);

a down tube (113) extending sharply rearwardly and downwardly from the head pipe (111) and below said main tube (201), with an internai combustion engine (101) mounted between a free end of the down tube (113) and the free end ofthe main tube (201);

a pair of right and left upper tubes (250) extending horizontally rearwards from a central portion of the main tube (201); and a pair of right and left side tubes (260) extending upwardly rearward from the swing arm pivot point (201c), and further extending till a rear portion ofthe pair of right and left upper tubes (250) so that a rear portion of said pair of right and left upper tubes (250) has negligible overhang.

2. The frame assembly (200) as claimed in claim 1, wherein said frame assembly (200) includes a pillion handle mounting bracket (220) attached to a rearmost portion of said pair of right and left upper tubes (250).

3. The frame assembly (200) as claimed in claim 1 wherein, each of said pair of right and left side tubes (260) is tubular in shape having circular cross section throughout its length and has its end welded directly on each of said pair of right and left upper tubes (250).

4. The frame assembly (200) as claimed in claim 3, wherein said pair of right and left side tubes (260) is welded on said pair of right and left upper tubes (250) at a point beyond the beginning of a pillion handle mounting bracket (220) of said vehicle.

5. The frame assembly (200) as claimed in claimed in claim 1, wherein said pair of right and left side tubes (260) hâve an inclined orientation till a rear suspension attachment point (211).

6. The frame assembly (200) as claimed in claim 5, wherein each side tube of said pair of right and left side tubes (260) extending beyond the rear suspension attachment point (211) till the rear portion of the pair of right and left upper tubes (250) is disposed parallel with respect to each other in the width direction.

7. The frame assembly (200) as claimed in claimed in claim 6, wherein said pair of right and left side tubes (260) extend parallel to said pair of right and left upper tubes (250) beyond the rear suspension attachment point (211).

8. The frame assembly (200) as claimed in claim 1, wherein said pair of right and left upper tubes (250) comprises a stepped portion (251) extending from a front end thereof till a rear suspension attachment point (211).

9. The frame assembly (200) as claimed in claim 8, wherein the rear suspension attachment point (211) provides support to an integrated lock (600), said integrated lock (600) being elliptical in shape to enable a passenger to grip.

10. The frame assembly (200) as claimed in claim 9, wherein said integrated lock (600) comprises a lever portion (601) capable of being locked and unlocked to enable the locking of a helmet and luggage with hooks.

11. The frame assembly (200) as claimed in claim 1, wherein said frame assembly (200) comprises a pair of right and left sheet gusset plates (210) disposed between each of said pair of right and left upper tubes (250) and each of said pair of right and left side tubes (260) to support a rear suspension member (102).

12. The frame assembly (200) as claimed in claim 11, wherein said pair of right and left sheet gusset plates (210) is provided at a rear suspension attachment point (211) on which said rear suspension member (102) is attached.