JP3358470B2 - Truck cab structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a truck cab structure having a floor pan and a main sill.

[0002]

2. Description of the Related Art The cab structure of a truck is required to secure and improve occupant protection and safety. Therefore, various techniques have been used conventionally. For example, FIG.
As shown in the figure, the initial buckling load 31 is large with respect to the energy absorption curve 30 at the time of collision, and the energy absorption load 3 is large.
It is said that it is desirable to have a cab structure having a high efficiency such that 2 is substantially equal to the initial buckling load 31, that is, a cab structure having a small displacement at the time of collision and a large energy absorption.

[0003] The amount of energy absorption described in this specification indicates the energy obtained by integrating the load acting on the cab or the like in the event of a collision with the displacement of the cab. That is, the area of the portion indicated by hatching in FIG. 7 is shown.

As shown in FIG. 8, a typical truck cab structure has a floor pan 44 on which a seat 42 and a bed 43 are provided, and a floor pan 44 provided on a lower surface of the floor pan 44 so as to extend in the vehicle longitudinal direction. Main sill 45
It is configured with such as.

The floor pan 44 includes a central portion 46 located substantially at the center of the vehicle, two side portions 47 provided on the left and right sides of the central portion 46, and a central portion 46 and two side portions 47. A horizontal portion 48 provided on the rear side of the vehicle. As shown in FIG. 8, the central portion 46 is formed so as to have an upwardly convex portion 49 substantially at the center in the vehicle width direction due to limitations on the volume and height of the engine mounted on the vehicle. The side portions 47, 47 are seats 42, 4 for the occupants.
From the viewpoint of the installation of the vehicle 2 and securing the space for the occupants, etc., each has a step portion 50 whose height changes in the vehicle front-rear direction, and the front of the step portion 50 is one step lower than the convex portion 49 of the central portion 46. It is formed as follows. The horizontal part 4
Reference numeral 8 denotes a simplified bed 43 for the occupant, which is provided continuously at the rear end of the central portion 46 and the side portions 47, 47.

The main sill 45 is connected to the floor pan 4
4, a pair of parallel portions 51, which are fixed to the lower surfaces of the side portions 47, 47 from the front ends of the side portions 47, 47 to the horizontal portion 48.
A base portion 52 is provided at the rear end of the parallel portions 51 and 51 and fixed to the lower surface of the horizontal portion 48 of the floor pan 44 in the vehicle width direction. The parallel part 5
1, 51 are bent in order from the front side of the vehicle so as to have a first bent portion 53, a second bent portion 54, and a third bent portion 55 along the steps 50, 50 and the like of the floor pan 44. Is formed. Further, the main sill 45 is integrally provided with a connecting portion 56 for connecting the front ends of the parallel portions 51, 51 to each other.

The parallel portions 51, 51 and the base portion 52 are formed in a U-shape (hat shape) in view of weight reduction and securing of mechanical strength. FIGS. 9 and 10 show the results of analysis of the deformation state of the conventional cab structure 41 configured as described above at the time of collision by the finite element method performed using a computer or the like. The finite element method is one of the techniques for analyzing stress and deformation generated in a structure during a desired phenomenon, and is a complicated structure such as the cab structure 41 and has a large displacement such as a collision. It is a technique that has become possible to analyze phenomena due to recent advances in computers. In this analysis, the impact load at the time of the collision is modeled as stress due to the inertia of the carrier mainly caused by the deceleration of the vehicle body, and the main sill 45 and the floor are taken along the arrow T shown in FIGS. A load was applied to the rear end of the cab structure 41 composed of the pan 44 and the like.

FIG. 9 shows that the displacement of the cab structure 41 is the first displacement.
FIG. 10 shows a result obtained when the analysis is performed until the predetermined amount L1 is reached.
Shows the result when the displacement of the cab structure 41 is analyzed until the displacement reaches the second predetermined amount L2 larger than the first predetermined amount L1.

As a result of the stress (arrow T) simulating the load at the time of collision acting on the cab structure 41, FIGS.
When viewed from the side as shown in FIG.
5 mainly the second and third bent portions 5 of the parallel portions 51, 51.
The mode is bent at 4,55, and the floor pan 44 causes local buckling. 9 (A) and FIG.
As seen from above, as shown in (A), it became clear that mainly the second bent portion 54 of the parallel portion 51 of the main sill 45 was bent in the vehicle width direction and fell inside the vehicle.
In general, in a cab structure of a truck, the floor pan and the main sill bear 50% or more of the energy absorption acting on the entire vehicle at the time of a collision or the like.

[0010]

When the conventional cab structure 41 absorbs energy in the vehicle longitudinal direction,
Since the second bent portions 54, 54 of the parallel portions 51, 51 of the main sill 45 mainly fall in the vehicle width direction, they are easily deformed and the energy absorption load is reduced, and the energy absorption amount is lost. There was a tendency.

Accordingly, an object of the present invention is to provide a cab structure of a truck capable of further improving the collision safety by increasing the amount of energy absorption at the time of collision and reducing the deformation at the time of collision. It is in.

[0012]

According to a first aspect of the present invention, there is provided a truck cab structure having a step portion whose height changes in a longitudinal direction of a vehicle. And a pair of right and left parallel portions bent and formed to have a bent portion corresponding to the step portion of the floor pan while being closely attached to the lower surface of the floor pan and extending in the vehicle front-rear direction. and Meinshiru, e Bei and a connecting member provided along the vehicle width direction without being bonded between the bent portions of both parallel portions and fixed the lower surface of the floor pan, the parallel portions on both sides of the floor pan Along the steps
A first bent portion which is higher in order from the front side of the vehicle and a second bent portion.
A bent portion and a third bent portion are formed to be bent;
The main sill connects the front ends of the parallel parts to each other.
Formed between the connecting portion and the first bent portion of the two parallel portions.
Between the first connecting member and the second bent portion of the both parallel portions.
The formed second connecting member and the third bending portion of the two parallel portions are formed.
A third connecting member formed between the curved portions .

According to a second aspect of the present invention, there is provided a truck cab structure according to the first aspect, wherein the connecting member is made of a pipe material.

According to a third aspect of the present invention, there is provided the truck cab structure according to the second aspect, wherein the connecting member and the lower surface of the floor pan are not fixed to each other. I have.

According to a fourth aspect of the present invention, there is provided the truck cab structure according to the third aspect, wherein an upwardly convex portion is formed at an intermediate portion in the vehicle width direction of the floor pan. Further, the connecting member is characterized in that a step-shaped or arc-shaped portion that is convex upward is formed at a position corresponding to the convex portion of the floor pan.

As a result of taking the above measures, the following operation occurs. In the truck cab structure according to the first aspect, the phenomenon that the bent portion of the main sill falls down in the vehicle width direction at the time of a vehicle collision can be suppressed by the connecting member that connects the bent portions.

In the truck cab structure according to the second aspect, the strength of the connecting member can be easily increased by using a pipe member as the connecting member. According to the cab structure of a truck according to the third aspect, since the connecting member is hardly affected by the deformation of the floor pan at the time of a vehicle collision, the bent portion of the main sill falls down in the vehicle width direction even if the floor pan is deformed. The connection member can more surely suppress it.

The cab structure of the truck according to the fourth aspect is applicable to a truck equipped with a large engine.
Since the bent portions of the main sill can be reliably connected by the connecting member, it is possible to reliably suppress the phenomenon that the bent portion of the main sill falls down in the vehicle width direction at the time of a vehicle collision.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. A cab structure 1 of a truck shown in FIG. 1 has a main sill including a floor pan 4 on which a seat 2 and a bed 3 are provided, and a pair of parallel portions 11 provided on the lower surface of the floor pan 4 and extending in the vehicle front-rear direction. 5 and the parallel part 11 of the main sill 5,
11 are provided with connecting members 19, 20, 21 and the like.

The floor pan 4 has a central portion 6 located substantially at the center of the vehicle as in the conventional example (shown in FIG. 8), and both side portions 7, 7 provided on the left and right sides of the central portion 6 in the vehicle. A horizontal portion 8 is provided on the vehicle rear side of the central portion 6 and both side portions 7 and 7. The central portion 6 is formed so as to have an upwardly convex portion 9 substantially at the center in the vehicle width direction due to the limitation of the volume of the engine (not shown) mounted on the vehicle and the vehicle height. The both sides 7, 7 are seats 2, 2 for the occupants.
From the viewpoint of the installation of the vehicle and securing the space for the occupants, etc., each has a step portion 10 whose height changes in the vehicle front-rear direction, and the front of the vehicle drops one step lower than the projection 9 of the central portion 6 from this step portion 10. And is formed so as to be substantially horizontal to the central portion 6 at the rear end 7a. The horizontal portion 8 is provided at the rear end 6a of the central portion 6 and the rear ends 7a, 7a of the side portions 7, 7, and is provided with a simplified bed 3 for an occupant.

It should be noted that some vehicles have a relatively small engine mounted thereon. In this case, the central portion 6 of the floor pan 4 generally does not have the convex portion 9. is there.

The main sill 5 also has front ends 7 on both sides 7, 7 of the floor pan 4 as in the conventional example (shown in FIG. 8).
b, 7b, and a pair of parallel portions 11, which are fixed to the lower surfaces of the side portions 7, 7 by spot welding or the like over the horizontal portion 8.
And a base 12 connected to the rear ends 11a, 11a of the parallel portions 11, 11 and fixed to the lower surface of the horizontal portion 8 of the floor pan 4 by means such as spot welding over the vehicle width direction. Have. The parallel portions 11, 11 are in order from the vehicle front side, and the step portions 10,
10 and a second bent portion 14 along the
And a third bent portion 15. Further, the main sill 5 is connected to the parallel portions 11 and 11.
Are integrally provided with a connecting portion 16 for connecting the front ends 11b, 11b to each other.

The parallel portions 11, 11 and the base portion 12 are formed in a U-shape (hat shape) having both side walls 17a, 17a and a bottom wall 17b from the viewpoints of weight reduction and securing mechanical strength. Have been.

Further, the parallel portions 11,
11 between the first bent portions 13, 13.
9 are connected along the vehicle width direction and the second bent portion 1
A second connecting member 20 is connected between the fourth and the fourth along the vehicle width direction. A third connecting member 21 is connected between the third bent portions 15 along the vehicle width direction. These connecting members 19, 20, 21 are desirably formed of a rod-shaped pipe material or the like in view of simplicity in manufacturing and cost reduction, and a floor pan for increasing energy absorption load as much as possible when absorbing energy. Desirably, they are not fixed to each other. Further, if desired mechanical strength can be obtained, a material other than the pipe material may be used.

In the case where the center portion 6 of the floor pan 4 is formed to have the convex portion 9 in order to mount a relatively large engine on the vehicle, as shown in FIG. Step-like connecting member 2 projecting upward at a position corresponding to 9
As shown in FIG. 3, connection members 24 and 25 formed in an arc shape may be used.

As shown in FIG. 2, a first step-like
The second connecting members 22 and 23 are connected to the first bent portions 1 of the parallel portions 11 of the main sill 5 configured as described above.
The floor pan 4 (shown in FIG. 1) is connected between the third bent portion 13 and the second bent portion 14 along the vehicle width direction.
Steps 22a, 23 in the vehicle width direction along the convex portion 9 of the central portion 6
a.

As shown in FIG. 3, the first arc-shaped first
Similarly, the second connecting members 24 and 25 are also provided between the first bent portions 13 and 13 of the parallel portions 11 and 11 of the main sill 5 and the second connecting members 24 and 25.
Arcs 24 which are respectively connected between the bent portions 14 of the floor pan 4 along the vehicle width direction and which extend along the convex portions 9 of the central portion 6 of the floor pan 4.
a, 25a.

Each of the connecting members 22 and 23 formed in a step shape as shown in FIG. 2 and each of the connecting members 24 and 25 formed in an arc shape as shown in FIG.
Like 9, 20, 21 and the like, it is desirable to form with a pipe material or the like from the viewpoint of simplicity in manufacturing and cost reduction.
Moreover, it is desirable that the floor pan 4 should not be fixed to the floor pan 4 in order to increase the energy absorption load as much as possible during energy absorption. Further, if desired mechanical strength can be obtained, a material other than the pipe material may be used.

Each of the connecting members 22 and 23 formed in a step shape as described above or each of the connecting members 24 and 23 formed in an arc shape is used.
25, the parallel portions 11, 1 of the main sill 5 can be reliably ensured even in a vehicle using a relatively large engine.
The first and second bent portions 13 and 14 can be connected.

Hereinafter, a collision load application experiment performed to confirm the operation of the cab structure 1 of the truck of the above embodiment will be described with reference to FIGS. FIG. 4 is a view showing an experimental form, in which a cabin 26 of a truck to which main sills 5, 45 and the like are attached is installed on a moving body (not shown) having a moving rigid body 27 as shown in FIG. Under the conditions, the fixed barrier 28 was caused to collide in the direction of the arrow S, and the load acting on the cabin 26 and the like and the displacement of the main sills 5 and 45 were measured. FIG. 5 is a diagram showing the speed condition of the cabin 26 in the present experiment, and the speed condition is given a characteristic value based on actual measurement.

As shown in FIG. 6, in the results of this experiment,
First, the influence of each of the connecting members 19, 20, and 21 on the energy absorption of the main sill alone is examined. When the collision load acts on the main sill 45 alone (Comparative Example 1 in the drawing) of the conventional cab structure 41, the impact acts on the cabin 26 and the like. Immediately after the collision, the load reaches a peak (point P1 in the figure), and thereafter, the deformation progresses (the displacement increases) and the load (the energy absorption load) decreases significantly. This is similar to the analysis result shown in FIGS.
In the (initial buckling load), mainly the second and third bent portions 54, 55, etc. of the main sill 45 buckle and bend in the vehicle front-rear direction. This indicates that the vehicle has also fallen in the vehicle width direction. As described above, in Comparative Example 1, since the second bent portion 54 and the like of the main sill 45 mainly fell down in the vehicle width direction and were easily deformed, the energy absorption load tended to be reduced.

On the other hand, each of the bent portions 13 and 1 of the above embodiment
In the case of the main sill 5 alone (the present invention product 1 shown in the drawing) in which the connecting members 19, 20, and 21 are provided on the reference numerals 4 and 15, respectively, the initial buckling load (point P2 in the drawing) is higher than that of the comparative example 1 (the point shown in the drawing). It was confirmed that the energy absorption load at the evaluation point A (point Q2 in the figure) was about 4 times as large as that of the comparative example 1 (point Q1 in the figure), as well as an increase of about 20% as compared with P1). . This prevents the connecting members 19, 20, 21 from deforming (falling) in the vehicle width direction when the second and third bent portions 14, 15 of the main sill 5 buckle at the point P2 (initial buckling load). Therefore, even if the load increases and the displacement increases thereafter, each of the bent portions 13 and
Since the deformation (falling) of the vehicle 14 and 15 in the vehicle width direction is suppressed, it is considered that the energy absorption load increases accordingly.

Next, each connecting member 19, 20, 2 in the entire cab structure composed of the floor pan and the main sill.
1, the deformation (falling) of the bent portions 13, 14, 15 of the main sill 5 in the vehicle width direction is suppressed as described above, so that the cab structure 1 of the above embodiment (the present invention in the drawing) Article 2) has an initial buckling load (point P4 in the figure) increased by about 13% compared to the initial buckling load (point P3 in the figure) of the conventional cab structure 41 (comparative example 2 in the figure). At the same time, it was confirmed that the energy absorption load (point Q4 in the drawing) at the evaluation point A was increased by about 20% as compared with the conventional structure 41 (point Q3 in Comparative Example 2).

As a result, the effect of each of the connecting members 19, 20, and 21 on the amount of energy absorption obtained by integrating the load shown in the above-described product 2 of the present invention and Comparative Example 2 by displacement is examined. As shown by the curve M1, the structure 1 showed that the energy absorption at the evaluation point A increased by about 20% as compared with the conventional cab structure 41 (shown by the curve M2).

Further, when the displacement of the cab structures 1 and 41 caused by the collision under the same energy absorption amount, that is, under the same conditions (speed, mass, etc.) is compared, FIG. The curve M1 in the figure is different from the conventional cab structure 41 (curve M2 in the figure) in the evaluation point B.
It was confirmed that the displacement at was reduced by about 20%.

As described above, regarding the deformation of the main sill which affects the energy absorption amount of the cab structure in the truck, by connecting the bent portions of the main sill by the connecting member, the bent portion of the main sill in the vehicle width direction at the time of vehicle collision Of the vehicle is suppressed, and the vehicle is less likely to be deformed in the vehicle width direction. As a result, the initial buckling load of the bent portion of the main sill can be increased, and even if the deformation progresses, the energy absorption load can be maintained at a high load, so that the energy absorption amount of the cab structure is increased, and the deformation of the cab structure is improved. The amount (displacement) can also be reduced.

[0037]

According to the first aspect of the present invention, when a vehicle collision occurs ,
Second and third bending of the main sill at initial buckling load
Part a phenomenon that collapses in the vehicle width direction when buckled, can at suppressed by the first to third coupling member for coupling between the bent portions <br/>,
Maintains a high energy absorption load even as deformation progresses
Therefore, the energy absorption amount can be increased without increasing the deformation amount at the time of the vehicle collision. If the energy absorption of the cab structure is constant,
Since the amount of deformation of the cab structure can be reduced, it is possible to further improve the collision safety for the occupant. According to the invention, each connecting member is fixed to the lower surface of the floor pan.
The connecting member is not easily affected by the deformation of the floor pan in the event of a vehicle collision , so that even when the floor pan is deformed, the bent portion of the main sill falls down in the vehicle width direction. Can be suppressed. Also,
When the energy absorption amount of the cab structure is constant, the amount of deformation of the cab structure can be reduced, so that the collision safety for the occupant can be more reliably improved.

According to the second aspect of the invention, since the strength of the connecting member can be easily increased by using the connecting member as a pipe material, the phenomenon that the bent portion of the main sill falls down in the vehicle width direction can be more effectively suppressed. Therefore, it is possible to further increase the amount of energy absorption at the time of a vehicle collision. Also,
When the energy absorption amount of the cab structure is constant, the amount of deformation of the cab structure can be reduced, so that the collision safety for the occupant can be more effectively improved.

[0039]

According to the third aspect of the present invention, the connecting member can be provided between the bent portions of the main sill even in a truck equipped with a large engine, so that the bent portion of the main sill falls down in the vehicle width direction at the time of a vehicle collision. Can be reliably suppressed. As a result, even in a truck equipped with a large engine, it is possible to further increase the energy absorption amount without increasing the deformation amount at the time of a vehicle collision. The amount of structural deformation can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a cab structure of a truck showing one embodiment of the present invention.

FIG. 2 is a perspective view of a part of a cab structure showing a first modification of the connecting member according to the embodiment of the present invention.

FIG. 3 is a perspective view of a part of a cab structure showing a second modification of the connecting member according to the embodiment of the present invention.

FIG. 4 is a schematic view showing an experimental form of a collision load loading experiment.

FIG. 5 is a diagram showing conditions such as the speed of a collision load test.

FIG. 6 is a diagram showing energy absorption curves obtained in a collision load application experiment for the product of the present invention and a comparative example.

FIG. 7 is a diagram schematically showing an energy absorption curve of a cab structure of a truck.

FIG. 8 is an exploded perspective view showing a conventional truck cab structure.

FIG. 9 is a diagram showing a deformation state of a conventional cab structure of a truck when a collision load analysis is performed until the displacement reaches a first predetermined amount L1.

FIG. 10 is a diagram showing a deformation state of a conventional cab structure of a truck when a collision load analysis is performed until the displacement reaches a second predetermined amount L2 larger than the first predetermined amount L1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Truck cab structure 4 ... Floor pan 5 ... Main sill 10 ... Step part 11 ... Parallel part 13 ... First bent part 14 ... Second bent part 15 ... Third bent part 19 ... First connection member 20 ... second connection member 21 ... third connection member

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-262474 (JP, A) JP-A-8-310453 (JP, A) JP-A-7-149260 (JP, A) 42433 (JP, U) Japanese Utility Model 63-179281 (JP, U) Registered utility model 3002918 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62D 25/20 B62D 33/06

Claims (3)

(57) [Claims] 1. A floor pan bent and formed having a step portion whose height changes in the vehicle front-rear direction, and extending in the vehicle front-rear direction in close contact with the lower surface of the floor pan and being provided on the step portion of the floor pan. A main sill having a pair of left and right parallel portions bent and formed with corresponding bent portions; and connecting the bent portions of the both parallel portions and extending along the vehicle width direction without being fixed to the lower surface of the floor pan. The parallel part is provided along the steps on both sides of the floor pan.
A first bent portion which becomes higher in order from both front sides, and a second bent portion
And a third bent portion, wherein the main sill is formed between a connecting portion connecting front ends of the both parallel portions to each other and a first bent portion of the both parallel portions. The first connection
A second connection formed between the member and the second bent portion of the both parallel portions;
A third connection formed between the member and the third bent portion of the two parallel portions;
Cab structure of the track, characterized by comprising a member. 2. The cab structure of a truck according to claim 1, wherein said connecting member is made of a pipe material. 3. An upwardly projecting convex portion is formed at an intermediate portion of the floor pan in the vehicle width direction, and the connecting member has an upwardly projecting step at a position corresponding to the convex portion of the floor pan. The cab structure for a truck according to claim 1, wherein an arc-shaped portion is formed.