JP2004161035A - Front part structure of cab-over vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively transmit with a simple structure load input in front collision with a vehicle having different car height to a chassis frame without imparting a bad influence to a crush mode of the chassis frame in front collision. <P>SOLUTION: The cab-over truck 1 is provided with the chassis frame 2; a cab 5 disposed on the chassis frame 2; and a cab mount bracket 7. The cab mount bracket 7 has a base part 8 and a stopper 9. The base part 8 is rotatably connected to the chassis frame 2 from a usual position where it stands at least approximately vertically to a tilt position forwardly inclined and fixed to a front end lower part of the cab 5 to support the cab 5 from below. The stopper 9 inhibit the rotation of the base part 8 from the usual position to a rear side. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a front structure of a cab-over type vehicle provided with a tilt mechanism for rotatably connecting a front end of a chassis frame and a lower front end of a cab.
[0002]
[Prior art]
In a freight truck (hereinafter referred to as a cab over truck) in which a driver's cab (hereinafter referred to as a cab) is installed at the front of the chassis frame and the driver's seating position is generally higher than the engine position, the front of a rigid wall (hereinafter referred to as a barrier) is provided. In the event of a collision, the front end of the chassis frame that abuts against the barrier is effectively deformed to absorb kinetic energy, secure a living space for the cab located above, and improve safety (for example, see Patent Document 1). ).
[0003]
The cab is supported and mounted on a chassis frame via two cab mounts at the front, rear, left and right corners of the cab so that the cab can be tilted around the two front cab mounts.
[0004]
In a small cabover truck, an engine and various accessories are mounted in a narrow space between chassis frames. For this reason, the shape of the chassis frame is curved such that the distance between the chassis frames increases from the front to the rear of the vehicle. The front half of the frame side member has a closed sectional structure in order to secure a cab living space at the time of a front barrier collision or the like. With such a closed cross-section structure, the bending load at the curved portion of the chassis frame increases, the deformation resistance increases, the frame deformation is suppressed, and a more excessive load input is absorbed.
[0005]
The actual situation of the accident of a small cab-over truck is that, in addition to the head-on collision equivalent to the above-described head-on barrier collision, there are many rear-end collisions between trucks.For example, the rear-end collision Load may be input toward the front cab mount bracket by grazing the upper surface of the chassis frame.
[0006]
In such a case, it is effective to increase the coupling strength between the front cab mount bracket and the chassis frame, efficiently transmit the load input to the front cab mount bracket to the chassis frame, and absorb the energy by bending the chassis frame up and down. It is.
[0007]
Also disclosed is a cab structure in which an upper shock absorbing damper is provided at the front end of the cab frame to minimize cab deformation when an input is applied from the front due to a vehicle collision, regardless of the height of obstacles. (For example, see Patent Document 2).
[0008]
[Patent Document 1]
JP-A-11-170940 [Patent Document 2]
Published Japanese Utility Model Application No. Hei 6-13988
[Problems to be solved by the invention]
However, in the structure described in Patent Document 1, the load input to the upper shock absorbing damper is input to the chassis frame via the cab frame, the cab hinge upper bracket, and the cab hinge lower bracket. For this reason, in order to efficiently transmit the load input to the chassis frame, the cab hinge upper bracket and the cab frame, as well as the hinge pin which is the connecting portion between the cab hinge upper bracket and the cab hinge lower bracket, and the cab hinge are used. It is necessary to increase the rigidity of a plurality of portions, such as a fastening portion between the lower bracket and the chassis frame, which leads to a complicated structure and a heavy weight.
[0010]
Here, with respect to the load input toward the cab hinge lower bracket, if the rigidity of the fastening portion between the cab hinge lower bracket and the chassis frame is increased, the input of the load is efficiently transmitted to the chassis frame to transfer energy. It is also possible to absorb.
[0011]
However, since the upper portion of the cab hinge lower bracket is formed in a curved surface, there is a possibility that a load may be released along the curved surface in response to a load from the front of the cab hinge lower bracket. When the load escapes, the load input to the cab hinge lower bracket decreases, and as a result, the energy absorption due to the deformation of the chassis frame decreases, which may lead to an increase in the amount of crush deformation of the cab.
[0012]
The present invention has been made in view of the above circumstances, has a simple structure, does not adversely affect the crush mode of the chassis frame at the time of a head-on collision, and provides a load input at the time of a front collision to a vehicle having a different vehicle height. It is an object of the present invention to provide a front structure of a cab-over type vehicle that can effectively transmit the vehicle to a chassis frame.
[0013]
[Means for Solving the Problems]
A front structure of a cab-over type vehicle according to the present invention includes a chassis frame, a cab arranged on the chassis frame, and a cab mount bracket. The cab mount bracket has a base and a stopper. The base is rotatably connected to the chassis frame at least from a normal position standing substantially vertically to a tilt position inclined forward, and is fixed to a lower portion of a front end of the cab to support the cab from below. The stop prevents rotation of the base backward from the normal position.
[0014]
In the above configuration, in the case of a frontal collision with the barrier, the front end of the chassis frame that abuts the barrier is effectively crushed and deformed to absorb kinetic energy. As a result, a living space for the cab located above is secured.
[0015]
If the difference between the vertical position of the frame and the subject vehicle is small at the time of collision with the preceding vehicle (the subject vehicle), the front end of the chassis frame is effectively crushed and deformed to reduce kinetic energy, as in the case of a frontal collision with the barrier. Absorb. As a result, a living space for the cab located above is secured.
[0016]
On the other hand, when the load is different from the rear-end collision vehicle and the load is input upward of the chassis frame due to the passing of the vertical position of the frame, the base of the cab mount bracket at the normal position is pushed backward by receiving the input of the load. . Here, the stopper prevents the rearward rotation of the base. In addition, the stopper prevents an excessive load input to the rotating shaft between the chassis frame and the cab mount bracket, thereby preventing the rotating shaft from breaking. As a result, the load is efficiently transmitted to the chassis frame, the energy can be reliably absorbed by bending the chassis frame up and down, and a living space for the cab is secured.
[0017]
The base of the cab mount bracket may extend in a normal position to near the cab front window.
[0018]
In the above configuration, since the base portion of the cab mount bracket is arranged in a wide range in the vertical direction, energy can be reliably absorbed even when the vehicle collides with a vehicle in which the vertical position of the frame is largely shifted.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
[0020]
FIG. 1 is a side view schematically showing a front structure of a small cab-over track according to the present embodiment, FIG. 2 is a front view of a main part of the structure of FIG. 1 viewed from the direction of arrow II, and FIG. FIG. 4 is a perspective view of a main part of FIG. 1, and FIG. 5 is a plan view of a main part of FIG.
[0021]
As shown in FIGS. 1 and 4, a pair of frame side members 3 and a frame cross member 4 as a chassis frame 2 are provided at a lower front portion of the cab over track 1. The pair of frame side members 3 are disposed on the left and right sides in the vehicle width direction along the vehicle front-rear direction, and the frame cross members 4 are disposed at the vehicle front end along the vehicle width direction. 3a are connected to each other.
[0022]
A driver's cab (hereinafter referred to as a cab) 5 is provided at a front portion of the chassis frame 2, and a driver's seating position is generally located above an engine 6 (shown in FIG. 6).
[0023]
One ends 7a of cab mount brackets 7 are rotatably connected to outer walls of front ends 3a of left and right frame side members 3, which are front ends of the chassis frame 2, respectively. Each cab mount bracket 7 includes a rectangular column-shaped base 8 extending linearly from one end 7a, and a stopper 9 protruding from the rear surface of the base 8. The rotation range of the cab mount bracket 7 with respect to the frame side member 3 is set so as to be movable from a normal position where the base 8 stands substantially vertically to a tilt position inclined forward. The stopper 9 abuts on the upper surface of the frame side member 3 to prevent the base 8 from rotating backward from the normal position. The length of the base 8 of the cab mount bracket 7 is set to extend to the vicinity of the lower edge of the front window 16 of the cab 5 at the normal position.
[0024]
As shown in FIGS. 2 and 3, the frame side member 3 has a substantially U-shaped cross section that opens to the inside of the vehicle width, and the side wall of the front end 3 a of the frame side member 3 has a rotation protruding outward in the vehicle width direction. The shaft 14 is fixed. One end 7 a of the cab mount bracket 7 is connected to the rotating shaft 14 via a bearing 15.
[0025]
As shown in FIGS. 1 and 2, the cab 5 includes a floor panel (not shown) and a pair of left and right cab floor rails 11. The cab floor rail 11 is fixed to the lower surface of the floor panel and supports the floor panel from below. The front end of each cab floor rail 11, which is the lower front end of the cab 5, is fixed on the inner surface of the base 8 of each cab mount bracket 7.
[0026]
As shown in FIG. 1, the rear portion of the cab 5 is fixed to the chassis frame 2 by a cabill lock mechanism 13 so as to be detachable. By releasing the cab lock mechanism 13, the cab 5 can be tilted upward about the rotation shaft 14. With such a tilt mechanism, the engine 6 and the like are exposed in a state where the cab 5 is tilted upward, and work such as inspection can be performed.
[0027]
As shown in FIGS. 4 and 5, since the engine 6 and various accessories are mounted in a narrow space between the frame side members 3, the left and right frame side members 3 are shaped from the front to the rear of the vehicle. It is curved so that the distance between the two increases. The front half of the frame side member 3 has a closed cross-sectional structure in order to secure a living space for the cab 5 in the event of a front barrier collision, which will be described later. With such a closed cross-sectional structure, the bending load at the curved portion of the frame side member 3 increases, the deformation resistance increases, the frame deformation is suppressed, and a more excessive load input is absorbed.
[0028]
Next, the operation of the present embodiment will be described.
[0029]
6 is a side view schematically showing a state before a front barrier collision, FIG. 7 is a side view schematically showing a state before a rear-end collision with a vehicle, FIG. 8 is an enlarged view of a main part of FIG. Is an enlarged view of a main part schematically showing a state after a collision with a vehicle ahead, FIG. 10 is a side view schematically showing a state after a collision with a vehicle ahead, and FIG. FIG. 12 is a side view schematically showing a state in which a vehicle having a structure to be compared has collided with a forward vehicle.
[0030]
As shown in FIG. 6, in the case of a frontal collision against a rigid wall (barrier) (frontal barrier collision), the front end 3a of the frame side member 3 abuts against the barrier 17, and the front end 3a is effectively crushed and deformed to move. Absorb energy. As a result, a living space for the cab 5 located above is secured.
[0031]
When the difference between the vertical position of the frame and the vehicle to be driven is small during a rear-end collision with the vehicle in front of the vehicle, the front end 3a of the frame side member 3 abuts the rear end of the chassis frame of the vehicle to be driven. As in the case of the front barrier collision, the front end 3a is effectively crushed and deformed to absorb kinetic energy. As a result, a living space for the cab 5 located above is secured.
[0032]
On the other hand, as shown in FIGS. 7 to 9, the cab-over truck (the rear-end vehicle) 1 collides with a vehicle (the rear-end vehicle) 20 having a different vehicle height, and the chassis frame of the rear-end vehicle 20 is moved due to the passing of the frame vertically. When the load 21 is located above the chassis frame 2 of the cab overtrack 1 and a collision load is input toward the cab mount bracket 7, the stopper 9 prevents the cab mount bracket 7 from rotating backward. In addition, since the stopper 9 suppresses excessive load input to the rotating shaft 14, breakage of the rotating shaft 14 is prevented. Thus, the load input to the cab mount bracket 7 is transmitted to the frame side member 3, and the energy is absorbed by the vertical bending of the frame side member 3 (chassis frame 2).
[0033]
On the other hand, for example, as shown in FIG. 11, a cab mount bracket 30 is fixed to the front end 3a of the frame side member 3 and extends upward, and the cab 5 is fixed to the base 31 to rotatably support the cab 5. 12, there is a possibility that the chassis frame 21 of the rear-end collision vehicle 20 may pass over the hinge portion 32 of the cab mount bracket 30, as shown in FIG. The transmission of the load to the member 3 and the absorption of energy due to the vertical bending of the chassis frame 2 are hardly performed, which may lead to an increase in the amount of deformation of the cab 5.
[0034]
As described above, according to the present embodiment, a load is input to the chassis frame 2 with a simple structure without adversely affecting the crush mode of the chassis frame 2 at the time of a head-on collision and at the time of a rear-end collision with a vehicle having a different vehicle height. It is possible to effectively communicate, and it is possible to achieve both the securing of the living space of the cab 5 at the time of a head-on collision and the securing of the living space of the cab 5 at the time of a rear-end collision.
[0035]
The base 8 of the cab mount bracket 7 extends to the vicinity of the front window 16 of the cab 5 at a normal position, and the base 8 of the cab mount bracket 7 is arranged in a wide range in the vertical direction. Therefore, energy can be reliably absorbed even when the vehicle collides with a vehicle in which the vertical displacement of the frame is large.
[0036]
Although the cab mount bracket 7 is fixed to the frame side member 3 in the above embodiment, it may be fixed to the frame cross member 4.
[0037]
【The invention's effect】
According to the present invention, with a simple structure, it does not adversely affect the crush mode of the chassis frame at the time of a head-on collision, and can effectively transmit the load input at the time of a rear-end collision to a vehicle having a different vehicle height, It is possible to achieve both the securing of the cab living space at the time of a frontal collision and the securing of the cab living space at the time of a rear-end collision with the vehicle.
[Brief description of the drawings]
FIG. 1 is a side view showing a front structure of a small cab-over track according to a first embodiment.
FIG. 2 is a front view of a main part of the front structure of FIG. 1 viewed from the direction of arrow II.
FIG. 3 is an enlarged view of a main part of FIG. 2;
FIG. 4 is a perspective view of a main part of FIG. 1;
FIG. 5 is a plan view of a main part of FIG. 1;
FIG. 6 is a side view schematically showing a state before a front barrier collision.
FIG. 7 is a side view schematically showing a state before a rear-end collision with a vehicle ahead.
FIG. 8 is an enlarged view of a main part of FIG. 7;
FIG. 9 is an enlarged view of a main part schematically showing a state after a rear-end collision with a vehicle ahead.
FIG. 10 is a side view schematically showing a state after a rear-end collision with a vehicle ahead.
FIG. 11 is a side view schematically showing a main part of a structure to be compared.
FIG. 12 is a side view schematically showing a state after a vehicle having a structure as a comparison target collides with a vehicle ahead.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cab-over track 2 Chassis frame 3 Frame side member 3a Front end of frame side member (front end of chassis frame)
4 Frame cross member 5 Cab 6 Engine 7 Cab mount bracket 8 Base 9 Stopper 11 Cab floor rail 14 Rotation axis

Claims (1)

Chassis frame,
A cab arranged on the chassis frame,
A base portion rotatably connected to the chassis frame at least from a normal position standing in a substantially vertical direction to a tilt position inclined forward and fixed to a lower portion of a front end of the cab to support the cab from below; and the normal position. A cab mount bracket having a stopper for preventing rotation of the base from behind,
A front structure of a cab-over type vehicle, comprising:

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