JP2014015166A - Frame structure of low floor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frame structure of a low floor vehicle, capable of firmly connecting a rear frame with different breadth and height to a front frame with high rigidity.SOLUTION: A frame structure of a low floor vehicle is configured by coupling a relatively wide rear frame 2 with a front frame 1 while lowering a height thereof more than the front frame 1. In the frame structure, a rear end of each side member 1a of the front frame 1 is coupled with a front end of each side member 2a of the rear frame 2 via a gusset 3 of a box structure. Also, the rear ends of each side member 1a of the front frame 1 are coupled with each other by a rear cross member 12, and the front ends of each side member 2a of the rear frame 2 are coupled with each other by a front cross member 13.

Description

  The present invention relates to a frame structure for a low floor vehicle.

  In recent years, there has also been a shift to electric vehicles in the field of commercial vehicles such as small trucks, and the drive systems such as motors have been consolidated under the cab to change from conventional rear wheel drive to front wheel drive. It has been studied to reduce the frame behind the cab and expand the cargo bed volume by eliminating the need for a propeller shaft for transmitting driving force to the vehicle.

  When the power support that supports the drive system such as the motor including the front axle support structure is the front frame and the load support that supports the load bed is the rear frame, the width is required to secure a sufficient horn angle of the front wheels. The rear frame, which requires a large battery to be laid below the floor of the loading platform, is configured to be wider than the narrow front frame, and it is low to avoid interference with the drive train and suspension. For the front frame, which is difficult to be floored, a drive transmission system such as a propeller shaft is unnecessary, and a curved portion is provided on the side member so as to avoid the movable range of the rear axle at the periphery of the rear axle (for example, The rear frame that can be used (see Patent Document 1) can be lowered to lower the height.

  In addition, although the case where a small truck is converted into an electric vehicle is described here as a preferred example, even if it is not an electric vehicle, it is a great advantage that the frame can be lowered to expand the loading platform volume, Further, since the rear frame is configured to be wide, there is an advantage that the overall rigidity and roll rigidity of the frame can be enhanced. Therefore, the above-described frame structure is not necessarily applied only to an electric vehicle.

JP 2006-56445 A

  However, in the past, since it was a general design philosophy to have an integrated frame structure over the entire length of the vehicle, the entire structure of the frame was divided into a front frame and a rear frame, and the front frame On the other hand, a frame structure that can firmly connect rear frames having different widths and heights with high rigidity has not been proposed yet, and a proposal for such a frame structure is desired.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a frame structure for a low floor vehicle capable of firmly connecting a rear frame having a different width and height to the front frame with high rigidity.

  The present invention is a low-floor vehicle frame structure in which a rear frame that is relatively wide with respect to a front frame is connected to a lower frame than the front frame, and the rear end of each side member of the front frame And the front end of each side member of the rear frame are connected via a gusset having a box structure, the rear ends of the side members of the front frame are connected to each other by a rear cross member, and The front end portions of the side members of the rear frame are connected by a front cross member.

  Thus, when the rear frame having a relatively wide width is connected to the front frame at a lower height than the front frame, the difference between the width and the height of the front frame and the rear frame. It is possible to achieve a high-rigidity connection with the gusset's strong box structure while supplementing the gusset with the width and height of the gusset. Further improvement in rigidity can be achieved by forming a closed cross-sectional structure in which is closed in a square shape.

  Further, in the present invention, the upper portion of the gusset is fixed to the outer surface of the rear end portion of each side member of the front frame, and the front end portion of each side member of the rear frame is fixed to the lower portion of the gusset. The rear end of each side member of the rear frame is connected to the front end of each side member of the rear frame, and the front end is penetrated in the vehicle width direction together with the gusset by the front cross member of the rear frame and fixed. It is preferable to do.

  In this way, the front end of each side member of the rear frame is not only simply inserted into the lower part of the gusset and fixed through, but also the gusset is penetrated in the vehicle width direction by the front cross member of the rear frame. Since it is prevented from coming off like a bowl, a stronger connection between the front frame and the rear frame is achieved.

  According to the frame structure of the low floor vehicle of the present invention described above, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, while the difference between the width and the height of the front frame and the rear frame is compensated by the width and height of the gusset, the rigid box structure of the gusset allows In addition to achieving high connection, the upper rear cross member, the gussets on both sides, and the lower front cross member form a closed cross-sectional structure in which the cross section is squarely closed, thereby further improving the rigidity. Therefore, the rear frame having a different width and height with respect to the front frame can be firmly connected with high rigidity, which can greatly contribute to the practical use of the low floor vehicle.

  (II) According to the invention described in claim 1 of the present invention, the rear frame having different width and height can be firmly connected with high rigidity to the front frame, so that the design is changed according to the application. Further, by preparing a plurality of types of rear frames and changing the combination of the rear frames with respect to the common front frame, it is possible to easily make vehicles for various purposes.

  (III) According to the invention described in claim 2 of the present invention, the front end portion of each side member of the rear frame is fixed to the lower portion of the gusset, and the gusset is moved in the vehicle width direction by the front cross member of the rear frame. Since it can be penetrated and prevented from coming off in the form of a bowl, a stronger connection between the front frame and the rear frame can be achieved.

It is a perspective view which shows an example of the form which implements this invention. It is a top view of the frame structure of FIG. FIG. 3 is an arrow view in the III-III direction of FIG. 2. It is an arrow view of the IV-IV direction of FIG. It is a perspective view which expands and shows the principal part of FIG. It is a perspective view which shows the state before the assembly | attachment of a gusset. It is a perspective view which shows the assembly | attachment state of a gusset and a rear part frame. It is a perspective view which shows the assembly | attachment state of a gusset and a front cross member.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 8 show an example of an embodiment for carrying out the present invention, and exemplify a case where the invention is applied to a small truck converted into an electric vehicle. In the example shown here, the frame structure of the small truck is shown. However, the power support portion that supports a drive system such as a motor including the front axle support structure is divided into a front frame 1 and the load support portion that supports the load platform is divided into a rear frame 2.

  The rear frame 2 that requires a large battery to be laid below the floor surface of the cargo bed is configured to be wider than the front frame 1 that is configured to be narrow in order to ensure a sufficient angle of the front wheels. (Refer to Fig. 2) In addition, the rear frame 2, which does not require a drive transmission system such as a propeller shaft, is used to expand the cargo bed volume, in contrast to the front frame 1 where it is difficult to reduce the floor to avoid interference with the drive system and suspension. In order to achieve this, the floor is lowered and the height is lowered (see FIG. 3).

  Further, the rear end portion of each side member 1a of the front frame 1 and the front end portion of each side member 2a of the rear frame 2 are connected via a gusset 3, particularly in FIG. As shown, the gusset 3 has three front side surfaces 4, inner side surfaces 5, and rear side surfaces 6 standing up and forming vertical walls, and a lower opening in a space surrounded by the three vertical walls. A box structure in which a bottom surface 7 to be closed and a ceiling surface 8 to be closed at a position where the upper opening is lowered by one step is assembled.

  And the part above the ceiling surface 8 in the inner surface 5 of the said gusset 3 is being fixed to the rear end part outer side surface of each side member 1a of the front frame 1 by bolt fastening (FIG.1, FIG.3 and FIG. 5), the front end portion of each side member 2a of the rear frame 2 is penetrated through the through hole 9 of the rear side surface 6 and fixed to the lower portion of the gusset 3 protruding outward in the vehicle width direction by welding. (See FIG. 7).

  Here, through-holes 10 and 11 that open in the vehicle width direction are formed in the inner surface 5 of the gusset 3 below the ceiling surface 8 and the front end of each side member 2a of the rear frame 2, respectively. The front cross member 13 of the rear frame 2 passes through the front end portion of each side member in the vehicle width direction through the through holes 10 and 11 and is fixed by welding (see FIG. 8).

  The rear ends of the side members 1a of the front frame 1 are connected to each other by a rear cross member 12, and the front ends of the side members 2a of the rear frame 2 are connected to each other by a front cross member 13. The upper rear cross member 12, the gusset 3 on both sides, and the lower front cross member 13 form a closed cross-sectional structure with a square cross section (see FIGS. 1 and 4). ).

  Thus, when the rear frame 2 having a relatively wide width relative to the front frame 1 is connected to the front frame 1 at a lower height than the front frame 1, the width of the front frame 1 and the rear frame 2 is reduced. The height of the gusset 3 can be compensated by the width and height of the gusset 3 and the rigid box structure of the gusset 3 can be used to achieve a highly rigid connection, and the upper rear cross member 12 and the gusset 3 on both sides The rigidity can be further improved by forming a closed cross-sectional structure in which the cross section is squarely closed by the lower front cross member 13.

  Particularly in the present embodiment, the front end of each side member 2a of the rear frame 2 is not only simply inserted into the lower portion of the gusset 3 and fixed through, but the front cross member 13 of the rear frame 2 Since all three are penetrated in the vehicle width direction and are prevented from coming off like a bowl, a stronger connection between the front frame 1 and the rear frame 2 is achieved.

  Therefore, according to the above embodiment, a highly rigid connection is achieved by the strong box structure of the gusset 3 while compensating for the difference in width and height between the front frame 1 and the rear frame 2 with the width and height of the gusset 3. In addition, the upper rear cross member 12, the gussets 3 on both sides, and the lower front cross member 13 can form a closed cross-sectional structure in which the cross section is squarely closed, thereby further improving the rigidity. Further, the front end of each side member 2a of the rear frame 2 is fixed to the lower portion of the gusset 3, and the front cross member 13 of the rear frame 2 is passed through the gusset 3 in the vehicle width direction to prevent it from coming off like a bowl. The rear frame 2 having a different width and height from the front frame 1 can be firmly connected with high rigidity, contributing greatly to the practical application of low-floor vehicles. It can be.

  In addition, since it is possible to realize a strong connection between the front frame 1 and the rear frame 2 having different widths and heights with high rigidity, a plurality of types of rear frames 2 that have been modified according to the application are prepared. By changing the combination of the rear frame 2 with respect to the front frame 1, vehicles for various purposes can be easily made.

  The frame structure of the low-floor vehicle of the present invention is not limited to the above-described embodiment, and is not limited to application to a small truck that has been converted into an electric vehicle, and other ranges that do not depart from the gist of the present invention. Of course, various changes can be made.

1 Front frame 1a Side member 2 Rear frame 2a Side member 3 Gusset 12 Rear cross member 13 Front cross member

Claims (2)

  A frame structure of a low-floor vehicle in which a rear frame that is relatively wide with respect to a front frame is connected to a lower frame than the front frame, and includes a rear end portion and a rear portion of each side member of the front frame. The front end of each side member of the frame is connected via a gusset having a box structure, and the rear ends of the side members of the front frame are connected to each other by a rear cross member. A frame structure for a low floor vehicle, wherein the front end portions of the side members are connected by a front cross member.   The upper portion of the gusset is fixed to the outer surface of the rear end portion of each side member of the front frame, and the front end portion of each side member of the rear frame is fixed to the lower portion of the gusset so as to pass through each side member of the front frame. A rear end portion is connected to a front end portion of each side member of the rear frame, and the front end portion is penetrated in the vehicle width direction by the front cross member of the rear frame and fixed. Item 2. The frame structure of the low floor vehicle according to Item 1.

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