JP3416625B2 - Low floor bus frame structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame structure of a low floor bus, and more particularly to a frame structure which can be reduced in weight and has excellent productivity. 2. Description of the Related Art In forming an intermediate frame for connecting a front support portion for supporting front wheels of a low floor bus and a rear support portion for supporting rear wheels, a center rail conventionally constituted by a square tube and a center rail are used. A lattice-shaped frame is formed by using a cross member having a cross section smaller than that of the center rail, and penetrating the cross member into a through hole provided in the center rail and welding and connecting the penetrating portion. However, when the cross section of the cross member is smaller than the cross section of the center rail, the upper surface of the center rail functions as a floor receiving portion, but the upper surface of the cross member does not function as a floor receiving portion. Would. For this reason, conventionally, a horizontal joist made of members extending in the vehicle width direction is attached to the upper surface of the center rail to constitute a receiving portion of the floor, so that the number of parts is increased and the weight and the number of manufacturing steps are increased. There was a defect. SUMMARY OF THE INVENTION [0004] The present invention has been made in view of the above-mentioned circumstances, and has been made to reduce the weight of the intermediate frame by improving the coupling structure between the cross member and the center rail constituting the intermediate frame. At the same time as improving productivity. [0005] In order to solve the above problems, the present invention provides an intermediate frame connecting a front support portion for supporting a front wheel and a rear support portion for supporting a rear wheel in a vehicle width direction. extending the frame structure of the low-floor bus constituted by the cross member and the longitudinal extending direction center rail, configured in square tube
And the center rails
Multiple cross members composed of square tubes with large surfaces
And the center rail end buttings are positioned and held.
It is equipped with a stiffener. And to the cross member
Penetrate the center rail through the through hole provided and fix it by welding
While configuring multiple partial frames,
Stiff at the end of the center rail fixed
Cover and position and hold the partial frames to each other.
Weld and fix the center rail and stiffener to secure the intermediate frame.
It is characterized in that the configuration was. An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic perspective view of an overall configuration showing one embodiment of a low floor bus frame structure according to the present invention, and FIG. 2 is an enlarged perspective view of a part of the frame structure shown in FIG. In these figures, an intermediate frame 3 connecting a front support portion 1 for supporting a front wheel (not shown) and a rear support portion 2 for supporting a rear wheel (not shown) includes a plurality of cross members 4 extending in the vehicle width direction. And a center rail 5 extending in the front-rear direction are connected in a grid pattern. When the intermediate frame 3 is assembled, the center rail 5 connects a plurality of square tubes in the front-rear direction, and connects a pair of upper and lower stiffeners 6 having a U-shaped cross section to each other. The parts are overlapped and positioned and then welded all around. The cross member 4 is formed of a square tube having a cross section larger than that of the center rail. Then, the center rail 5 is made to pass through the through-hole 7 formed in the cross member 4, and the penetrating portion is welded all around to form the intermediate frame 3 having a lattice shape as a whole. That is, the center rail 5 before joining is inserted into the through hole 7 of the cross member 4 in a skewered state, and the cross member 4 and the center rail 5 are welded and fixed to form a partial frame. The partial frames are arranged at predetermined positions in the front and rear directions, the ends of the center rails 5 are brought into contact with each other, the stiffeners 6 are put on each other, and the partial frames are positioned and held together. Constitutes the main part. When the cross member 4 and the center rail 5 are connected as described above, the center rail 5 is divided into a plurality of front and rear rails. Accordingly, the center rail 5 having a shorter length than the entire length of the intermediate frame 3 is penetrated through the cross member 4 and welded and fixed to form a partial frame. 5 can be combined to form an intermediate frame. For this reason, the intermediate frame 3 having a required length can be formed without using a long center rail. Even when the center rail 5 is pierced into the cross member 4 in a skewered state, it is exceptional. There is no difficulty. The intermediate frame 3 is formed by welding and fixing the cross member 4 having a cross section larger than that of the center rail 5 through the center rail 5, and furthermore, the upper surface of the cross member 5 extending to the full floor width. Is located above the upper surface of the center rail 5, it can function as a floor receiving portion as it is. Therefore, the horizontal joist, which has been essential in the past, is not always necessary, and the area of the floor receiving portion can be ensured only by providing the horizontal joist supplementarily as necessary in a portion where the space between the cross members 4 is large. Therefore, the number of parts and the weight of the intermediate frame 3 can be reduced, and at the same time, the productivity of the intermediate frame 3 can be increased. In the above-described embodiment, a pair of upper and lower stiffeners 6 having a U-shaped cross section are used to secure the workability of positioning the center rail to be joined and the joining strength . The shape is real
It is not limited to the embodiment. As is apparent from the above description, according to the present invention, an intermediate frame is formed by penetrating and welding a center rail formed of a square tube to a cross member formed of a square tube. Therefore, the receiving portion of the floor can be configured without using a horizontal joist as in the related art, so that the number of components and the weight of the intermediate frame can be reduced. Further, a plurality of partial frames are connected to form an intermediate
Because the frame is configured, the center rail, which is shorter than the total length of the intermediate frame, is welded through the cross member to form a partial frame, and then the center rail of each partial frame is joined. A frame is configured. Accordingly, even when the center rail is penetrated through the cross member, the workability is not deteriorated, and the productivity of the intermediate frame is improved in combination with the improvement of the positioning and welding workability due to the penetration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of an overall configuration showing one embodiment of a low floor bus frame structure according to the present invention. FIG. 2 is an enlarged perspective view of a part of the frame structure shown in FIG. [Description of Signs] 1 Front support section 2 Rear support section 3 Intermediate frame 4 Cross member 5 Center rail 6 Stiffener 7 Through hole

Claims (1)

(57) Patent Claims 1. A cross member 4 which extends the intermediate frame 3 in Kurumahaba direction to couple the side support portion 2 after which supports the rear wheel and the front support portion 1 for supporting the front wheel back and forth a frame structure of a low-floor bus constituted by a center rail 5 extending in the direction, angular
A plurality of center rails 5 composed of tubes;
A plurality of square tubes with a cross section larger than the terrain 5
The cross member 4 of the book and the end of the center rail 5
A stiffener 6 for positioning and holding the
The center rail 5 is passed through the through hole 7 provided in the member 4.
To form a plurality of partial frames.
End of center rail 5 penetrated and fixed to member 4
The stiffener 6 is placed over the part and the partial frames are positioned relative to each other.
And fix the center rail 5 and stiffener 6 by welding.
A low-floor bus frame structure characterized by comprising an intermediate frame .