JPH05116648A - Lower structure for open body car - Google Patents

Abstract

PURPOSE:To reduce the vibration of an open body car produced on the basis of a closed body car without lowering the basic performance and productivity of the closed body car. CONSTITUTION:A pair of side members 12 are provided at the body lower part of an open body car 10, and the front end parts of the side members 12 are respectively connected to the rear end parts 18A of a pair of front side members 18. A suspension cross member 20 is provided across the rear end parts 18A of this pair of front side members 18. The approximate center part in the body width direction of the suspension cross member 20 is connected to the part, opposed to the connecting part 28 of a front pillar lower part 24 to a locker 26, of the side member 12 by one removable brace 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substructure of an open body vehicle.

[0002]

2. Description of the Related Art Conventionally, since an open body vehicle does not have a roof portion, particularly a roof side rail, the rigidity of the vehicle body is lower than that of a vehicle body having a roof side rail, that is, a so-called closed body vehicle. For this reason, the torsional resonance frequency of the body is significantly lowered, and during normal traveling, the input from the suspension causes the upper body to vibrate left and right due to the torsional vibration peculiar to the body.

As a method of improving this, a method of reinforcing the rocker to improve the torsional rigidity of the rocker portion, and a lower part of each pillar and a floor or rocker are coupled with a gusset material to form a front pillar, a center pillar and a rear pillar. There are a method of preventing falling, a method of increasing the cross member to improve the torsional rigidity of the body, and the like. In addition, as a related technology, a new model bulletin 100
Bullet, published on June 22, 1991.

[0004]

However, although the substructures of these open body vehicles are effective when applied to the vehicle body dedicated to the open body vehicle, they are commonly used by general users and have various performance aspects. In case of applying to open body car called Targa and convertible, which is based on a closed body car with no problem, the open body car is most reasonably finished, and the open body car is the same as the base closed body car. The conditions for achieving the target performance without impairing productivity, weight, etc. are not sufficiently satisfied.

In view of the above facts, the present invention takes into consideration the above-mentioned facts without deteriorating the basic performance and productivity of a closed body vehicle.
It is an object of the present invention to obtain a substructure of an open body vehicle that can gradually reduce vibration of an open body vehicle produced based on a closed body vehicle.

[0006]

A lower structure for an open body vehicle according to claim 1 of the present invention comprises a pair of side members provided near both ends in the vehicle width direction and extending in the vehicle front-rear direction.
A pair of front side members whose rear end portions are connected to the pair of side members, and a suspension cross member that is erected on the rear portions of the pair of front side members,
A lower structure of an open body vehicle including: a pair of a pair of one end coupled to substantially the center of the suspension cross member in the vehicle width direction and the other end coupled to a position facing the lower part of the front pillar of the side member. It is characterized by having a reinforcing member.

[0007]

In the substructure of the open body vehicle according to the first aspect of the present invention, when the floor pan is about to be deformed in left and right opposite phases, the deformation serves as the center of rotation of the suspension cross member. That is, the other end of each of the pair of reinforcing members, one end of which is connected to the vehicle width direction substantially center of the suspension cross member in which front-rear reverse phase deformation does not occur, is connected to a position facing the lower part of the front pillar of the side member. There is. Therefore, when the floor pan is going to be deformed left and right in the opposite phase by the input from the suspension, the deformation of the floor pan can be gradually reduced by the pair of reinforcing members. Therefore, it is possible to prevent the torsional resonance frequency of the vehicle body from significantly lowering, and to gradually reduce the vibration of the open body vehicle due to the torsional deformation mode.

Further, according to the present invention, since only the open body vehicle is required to connect the suspension cross member and the side member with the reinforcing member in the assembling process,
It does not reduce the basic performance and productivity of the closed body car that is the base of the open body car.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lower structure of an open body vehicle according to the present invention will be described with reference to FIGS. In the figure, an arrow FR indicates a vehicle body front direction, an arrow UP indicates a vehicle body upward direction, and an arrow IN indicates a vehicle width direction inward direction.

As shown in FIG. 1, an open body vehicle 1
A pair of side members 12 extending in the front-rear direction of the vehicle body are provided near both ends of the vehicle body 0 in the vehicle width direction.

As shown in FIG. 3, the cross-sectional shape of these side members 12 as viewed from the front-rear direction of the vehicle body is a U-shaped cross-section with the opening facing upward in the vehicle body up-down direction. The upper end portion of the vehicle-width-direction outer vertical wall portion 12A is bent toward the vehicle-width-direction outer side to form a flange 12B, which is welded to the lower surface of the floor pan 14. Further, the upper end portion of the vehicle-width-direction inner vertical wall portion 12C is bent toward the vehicle-width direction inner side to form a flange 12D, and the flange 12D is welded to the lower surface of the floor pan 14. Therefore, the side member 12 and the floor pan 14 form a closed cross section 16 extending in the front-rear direction of the vehicle body.

As shown in FIG. 1, the front end portions of the pair of side members 12 have rear end portions 18A of the pair of front side members 18 provided with the front upper supports 13.
Are connected to each other. A suspension cross member 20 is installed on the rear end portions 18A of the pair of front side members 18.

As shown in FIG. 2, both end portions of the suspension cross member 20 in the vehicle width direction are connected to the rear end portions 18A of the pair of front side members 18, respectively.

As shown in FIG. 3, the cross-sectional shape of the suspension cross member 20 as viewed from the vehicle width direction is a U-shaped cross-section with the opening facing upward in the vertical direction of the vehicle body. An upper end portion of the vehicle front-rear direction front vertical wall portion 20A is bent toward the vehicle front-rear direction front side to form a flange 20B, and the flange 20B is welded to the lower surface of the floor pan 14. Further, the upper end portion of the rear vertical wall portion 20C of the vehicle body front-rear direction is bent toward the rear side of the vehicle body front-rear direction to form the flange 2
0D, this flange 20D is floor pan 1
4 is welded to the lower surface. Therefore, the suspension cross member 20 and the floor pan 14 form a closed cross section 22 extending in the vehicle width direction.

As shown in FIG. 1, in the lower portion of the vehicle body of the open body vehicle 10 of the present embodiment, there are formed a substantially central portion in the vehicle width direction of the suspension cross member 20, a lower front pillar 24 of the side member 12, and a rocker 26. A pair of braces 30 as a reinforcing member that connects the connecting portion 28 and the opposing portion is detachably provided.

As shown in FIG. 3, this brace 30 is made of an iron pipe having an outer diameter D of 20 mm and a plate thickness T of 1.6 mm, and both ends thereof are crushed to form flanges 30A, 30.
It is supposed to be B. A through hole 31 is formed in each of the flanges 30A and 30B at substantially the center thereof. On the other hand, the flange 30A is in contact with the bottom portion 12E of the side member 12, and the leg portion 32A of the bolt 32 inserted into the through hole 31 passes through the through hole 34 formed in the bottom portion 12E of the side member 12 to The weld nut 36 is welded to the upper surface of the bottom portion 12E of the member 12 and is screwed.

The other flange 30B is in contact with the bottom portion 20E of the suspension cross member 20, and the leg portion 32A of the bolt 32 inserted into the through hole 31 is bored in the bottom portion 20E of the suspension cross member 20. It passes through the through hole 38 and is screwed into a weld nut 36 welded to the upper surface of the bottom portion 20E of the suspension cross member 20. The flanges 30B of the left and right braces 30 are fastened together with bolts 32 and weld nuts 36 to the suspension cross member 20 at a substantially central portion in the vehicle width direction.

Next, the operation of this embodiment will be described. In the lower structure of the open-body vehicle of this embodiment, when the floor pan 14 is going to be deformed in the left-right direction (up-down direction in FIG. 5) in the front-rear reverse phase (direction of arrow A and arrow B in FIG. 5), this deformation occurs. 5 by the clockwise direction (direction of arrow C in FIG. 5) and the counterclockwise direction of FIG. 5 (direction by arrow D in FIG. 5) which is the center of rotation of the suspension cross member 20, that is, the front and rear opposite phases. Suspension cross member 2 that does not deform
The other end 30A of each of the left and right braces 30 whose one end 30B is connected to the center of the vehicle width direction of 0 is connected to a portion of the side member 12 that faces the connecting portion 28 between the lower front pillar 24 and the rocker 26. Has been done.

Therefore, when the floor pan 14 is going to be deformed in the left-right direction (up-down direction in FIG. 5) to the front-rear reverse phase by the input from the suspension, the floor-pan 14 is moved by the left and right braces 30. It is possible to gradually diminish the deformation of the left and right front and rear opposite phases. Therefore, it is possible to prevent the torsional resonance frequency of the vehicle body from significantly lowering, and to gradually reduce the vibration of the open body vehicle due to the torsional deformation mode.

Further, in the present embodiment, since only the open body vehicle is required to connect the suspension cross member 20 and the side member 12 with the left and right braces 30 in the assembling process, the closed body vehicle which is the base of the open body vehicle. It does not reduce the basic performance and productivity.

In this embodiment, the brace 30 has an outer diameter D.
Was made of an iron pipe with a thickness of 20 mm and a plate thickness T of 1.6 mm.
The material of the brace 30 is not limited to this, and other materials may be used. Further, in this embodiment, the brace 30 is fixed to the side member 12 and the suspension cross member 30 with the bolt 32 and the weld nut 36, respectively. There is no limitation, and other joining methods such as welding may be used. (Test Example) In the open body vehicle 10 having the brace 30 of the present embodiment shown in FIG. 1 and the open body vehicle of the comparative example having no brace, the left and right front upper supports 13 are subjected to vibrations in the opposite phases. The torsional resonance frequency and the left and right vibration levels at the upper ends of the left and right front pillars were measured, and the results are shown in FIG.

From these results, the open body vehicle 10 to which the brace 30 of this embodiment is attached has the torsional resonance frequency improved by 0.5 Hz and the horizontal vibration level is higher than that of the open body vehicle of the comparative example to which the brace is not attached. Was improved by 0.6 dB.

[0023]

According to the present invention, since the reinforcing cross member connects the substantially center of the suspension cross member in the vehicle width direction and the position of the side member facing the lower part of the front pillar, the basic performance and production of the closed body vehicle are improved. It has an excellent effect that it is possible to gradually reduce the vibration of the open body vehicle produced based on the closed body vehicle without deteriorating the property.

[Brief description of drawings]

FIG. 1 is a perspective view showing a lower structure of an open body vehicle according to an embodiment of the present invention as seen from a diagonally lower front side of a vehicle body.

FIG. 2 is a plan view showing a part of the lower structure of the open body vehicle according to the embodiment of the present invention as seen from below the vehicle body.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a side view showing a deformation mode of the open body vehicle.

FIG. 5 is a plan view showing a modification mode of the open body vehicle.

FIG. 6 is a graph showing a torsional resonance frequency and a horizontal vibration level of an open body vehicle.

[Explanation of symbols]

 10 Open Body Vehicle 12 Side Member 18 Front Side Member 20 Suspension Cross Member 24 Lower Front Pillar 30 Brace (Reinforcement Member)

Claims (1)

[Claims] 1. A pair of side members provided in the vicinity of both end portions in the vehicle width direction and extending in the vehicle front-rear direction, a pair of front side members having rear end portions connected to the pair of side members, and the pair of front sides. A lower structure of an open body vehicle including a suspension cross member erected on a rear portion of a member, wherein one end is coupled to a substantially center of the suspension cross member in a vehicle width direction and the other end is a front portion of the side member. An underbody structure for an open body vehicle, comprising a pair of reinforcing members connected to a position facing the lower part of the pillar.