JP2004161109A - Vehicle energy absorbing structure - Google Patents

Abstract

Provided is an energy absorbing structure for a vehicle, which can reduce an impact force at the time of a collision with a simple structure, can easily perform repairs, and can reduce repair costs at a low cost.
An energy absorbing structure according to the present invention absorbs and reduces impact applied to a bumper provided at a front end or a rear end of a vehicle. The energy absorbing structure 1 uses a compression coil spring 2 having a hollow structure that expands and contracts in the front-rear direction of the vehicle. The compression coil spring 2 is held inside by a holder member 3. The holder member 3 has a spring tray member 5 for abutting the front and rear ends in the expansion and contraction direction of the compression coil spring 2, and has one end fixed to the spring tray member 5 and the other end slid with respect to the other spring tray member 5. And a slide guide 6 for allowing one spring receiving member 5 to approach or separate from the other spring receiving member 5.
[Selection] Fig. 6

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an energy absorbing structure for a vehicle, which is attached to a front end portion or a rear end portion of a vehicle such as an automobile, for example, to absorb and mitigate an impact due to a collision.
[0002]
[Prior art]
For example, vehicles such as automobiles are provided with impact mitigation devices at the front and rear of the vehicle for the purpose of mitigating an impact at the time of a collision due to a traffic accident, preventing damage to the vehicle, and ensuring passenger safety ( For example, see Patent Literature 1, Patent Literature 2, and Patent Literature 3).
[0003]
The vehicle impact mitigation device described in Patent Literature 1 includes a shock absorbing damper (shock absorber) between a bumper and a vehicle body frame, and includes a variable damping force mechanism that can change a damping force of the shock absorbing damper. The damping force of the shock absorbing damper can be adjusted by controlling the damping force variable mechanism based on information from a human body detecting means for detecting the presence of a human body.
[0004]
In this shock mitigation device, when the presence of a person at a predetermined distance in front of the vehicle is detected by the human body detection means, the damping force variable mechanism is controlled to reduce the damping force of the shock absorbing damper, thereby reducing the impact of the human body upon collision with the bumper. Relax.
[0005]
The movable bumper device for a vehicle described in Patent Document 2 has a coil spring and a shock absorber interposed between a bumper and a side member of a vehicle body so that the bumper can freely protrude from the vehicle body, and the vehicle can be connected to an obstacle. Collision prediction means for predicting the possibility of a collision based on the distance and the running state of the vehicle, and causing the bumper to protrude forward from the vehicle body or return to the original position according to a collision prediction signal from the collision prediction means Thereby, the impact force is reduced.
[0006]
According to this movable bumper device for a vehicle, the bumper can be protruded at an appropriate timing, so that the impact at the time of the collision can be mitigated to protect the opponent and to minimize the damage to the vehicle body. Safety can be improved.
[0007]
The vehicle bumper described in Patent Literature 3 divides a bumper into a plurality of parts, and a coil spring and an annular ring disposed outside the coil spring are provided between each of the divided bumpers and a support member fixed to a vehicle body. By arranging a spring assembly composed of the holder and the holder in a compressed state, the impact at the time of collision is absorbed and reduced by the spring assembly.
[0008]
According to this vehicle bumper, when an impact force acts on the bumper, the impact force is absorbed by the spring assembly, so that the impact force can be reduced. Further, according to this vehicle bumper, since the bumper is divided into a plurality of parts, even if a part of the bumper is damaged due to the collision, only the damaged bumper can be replaced.
[0009]
[Patent Document 1]
JP-A-10-109605 (pages 3 to 5, FIGS. 3 to 5)
[Patent Document 2]
JP-A-11-291845 (pages 2, 4, and 5; FIG. 1)
[Patent Document 3]
Japanese Patent Application Laid-Open No. 2002-2421 (Pages 2, 5, and 6, FIG. 2, FIG. 3, and FIG. 5)
[0010]
[Problems to be solved by the invention]
However, the shock mitigation device described in Patent Literature 1 controls the damping force variable mechanism based on a signal that detects the presence of a person so as to weaken the damping force of the shock absorbing damper. It is troublesome.
[0011]
Similarly, the vehicle movable bumper device described in Patent Literature 2 has a complicated structure, and the control for moving the bumper back and forth is troublesome, and the cost cannot be reduced.
[0012]
Although the vehicle bumper described in Patent Document 3 is not electronically controlled by a mechanical mechanism, the bumper is divided into a plurality of bumpers, and each of the divided bumpers is provided with a spring assembly for mitigating a collision. It is necessary, and the number of parts increases, so that cost reduction cannot be achieved. In particular, in this vehicle bumper, if a large impact is applied, the coil spring exceeds the elastic limit and it becomes difficult to absorb the impact in the plastic deformation region, so that the chassis frame may be damaged. There is.
[0013]
By the way, small cab-overs (types in which the driver's seat is entirely above the engine) or semi-cabovers (types in which the driver's seat is partially above the engine) are used to ensure safety in the event of a collision. In addition, the collision energy of the vehicle must be effectively absorbed in a short crash space in front of the vehicle.
[0014]
For this reason, this type of van or truck has been devised so that the chassis frame or floor under member is extended forward from the conventional front end position, so that the short crash space can be used up effectively. The frame has a projecting structure. On the other hand, in recent years, in order to reduce the repair cost in the event of a light collision, these vans and trucks are required to have a structure in which the configuration of the front bumper portion and the front frame portion is simple, easy to replace, and low in cost. .
[0015]
However, current cab-over and semi-cab type vans and trucks have a frame structure that protrudes up to the bumper, so the front end of the frame is inevitable even in a light collision, and it is not a serious collision that collided at high speed Nevertheless, it is necessary to repair the entire frame, and it is difficult to achieve both low cost and low repair cost at the time of a light collision.
[0016]
Therefore, the present invention has been made to solve the above-mentioned problems, and it is possible to alleviate the impact force at the time of collision with a simple structure, perform repair easily, and reduce the repair cost. The present invention provides a vehicle energy absorbing structure that can be used.
[0017]
[Means for Solving the Problems]
The present invention is an energy absorbing structure that absorbs and reduces shock applied to a bumper provided at a front end or a rear end of a vehicle, and has a hollow structure that expands and contracts in the vehicle front-rear direction between the vehicle and the bumper. A compression coil spring is arranged. Further, in the present invention, a holder member for housing the compression coil spring is provided so as to surround the compression coil spring.
[0018]
According to the present invention, when a light impact is applied to the bumper in a traffic accident or the like, the compression coil spring is elastically deformed to absorb and reduce the impact force. On the other hand, when a strong impact force is applied to the bumper, the compression coil spring has a hollow structure, so even if the compression coil spring exceeds the elastic limit and enters the plastic deformation region, it does not have a hollow structure. Since the plastic deformation state lasts longer than that of the coil spring, the impact force is absorbed and reduced by the plastic deformation of the compression coil spring.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. The present embodiment is an example in which the energy absorbing structure for a vehicle according to the present invention is applied to, for example, a small cabover or semi-cabover van or truck.
[0020]
"Configuration of Energy Absorbing Structure"
As shown in FIGS. 1 and 2, the energy absorbing structure 1 for a vehicle according to the present embodiment absorbs and reduces shock applied to a bumper provided at a front end or a rear end of the vehicle. It is composed of a coil spring 2 and a holder member 3 that houses the compression coil spring 2 so as to surround it.
[0021]
As shown in FIG. 3, for example, as shown in FIG. 3, the compression coil spring 2 is a coil spring having a hollow structure having a hollow portion 4 having a circular cross section inside, unlike a normal compression coil spring. That is, the compression coil spring 2 is used, which is formed by winding a round wire having a hollow inside into a coil shape. The compression coil spring 2 has a winding diameter, a pitch, a coil diameter, a pitch, and the like so that an impact force can be sufficiently absorbed and reduced in accordance with the weight and size of a vehicle to which the energy absorbing structure 1 is mounted. Wire diameter, spring constant, etc. are determined.
[0022]
As shown in FIGS. 1 and 2, the holder member 3 includes two spring holders 5 that are spring tray members and four slide guides 6 that are slide guide members attached to the spring holder 5. .
[0023]
The spring holder 5 includes a tray 7 for supporting the front and rear ends 2 a and 2 b in the direction of expansion and contraction of the compression coil spring 2 (the direction of arrow X in FIG. 2), and a wall 8 standing up around the outer periphery of the tray 7. And a so-called square shape.
[0024]
The receiving tray 7 is formed as a substantially rectangular flat steel plate with which the front and rear ends 2a and 2b of the compression coil spring 2 come into contact. The wall portion 8 is formed on each side of the rectangular receiving tray portion 7 so as to rise toward the compression coil spring 2, and guides the vicinity of the front and rear ends 2 a and 2 b of the compression coil spring 2. Prevent displacement. The wall portion 8 is formed with a screw hole 10 for attaching a slide guide 6 described later to the spring holder 5 by fastening means such as an attachment bolt 9.
[0025]
The slide guide 6 is formed as an elongated rectangular steel plate, and connects the spring holders 5 provided in contact with the front and rear ends 2a and 2b of the compression coil spring 2. A bolt insertion hole 11 for fixing the slide guide 6 to one spring holder 5 is formed at one end 6a of the slide guide 6. The mounting bolt 9 to be mounted on the screw hole 10 formed in the spring holder 5 is inserted into the bolt insertion hole 11.
[0026]
In the vicinity of the other end 6b of the slide guide 6, an elongated rectangular slide guide hole 12 is formed. The slide guide hole 12 is formed from the vicinity of the other end 6b of the slide guide 6 to almost the center position. The slide guide hole 12 may be formed from one end 6a of the slide guide 6 to the other end 6b. The mounting bolt 9 attached to the screw hole 10 formed in the spring holder 5 is loosely inserted into the slide guide hole 12.
[0027]
The energy absorbing structure 1 of the vehicle configured as described above is assembled as a unit component in which the compression coil spring 2 is housed in the holder member 3. The energy absorbing structure 1 assembled as a unit component is mounted between a bumper 14 provided at the front end of the cab overtrack 13 and a side frame 15 as shown in FIGS. 4 to 6.
[0028]
Specifically, the energy absorbing structure 1 is mounted on the distal ends of the side frames 15, 15 via a connecting member 16 that connects the distal ends of the side frames 15, 15. In order to mount the energy absorbing structure 1, the energy absorbing structure 1 is mounted in such a manner that the direction of expansion and contraction of the compression coil spring 2 is matched with the longitudinal direction of the side frames 15, 15 (vehicle longitudinal direction).
[0029]
That is, one spring holder 5 of the holder member 3 holding the compression coil spring 2 is fixed to the connecting member 16, and the other spring holder 5 is fixed to the bumper 14. For fixing the spring holder 5 to the connecting member 16 and the bumper 14, fastening means such as bolts and nuts may be used, or fixing means by welding or the like may be used.
[0030]
In the energy absorbing structure 1 mounted between the bumper 14 and the side frames 15, 15, a compressive force is slightly applied to the compression coil spring 2 in an initial state in order to suppress rattling of the compression coil spring 2. . In the normal traveling state of the cab-over track 13, the energy absorbing structure 1 holds the compression coil spring 2 by the holder member 3 without rattling, so that the vibration of the compression coil spring 2 is reduced. Can be suppressed.
[0031]
"Operation of energy absorbing structure during collision"
Next, the operation of the energy absorbing structure 1 when the cab-over truck 13 to which the energy absorbing structure 1 is mounted has a frontal collision with another vehicle due to a traffic accident or the like will be described.
[0032]
For example, when the cab-over truck 13 collides head-on with another vehicle at a low speed (hereinafter, this collision is referred to as a light collision), the energy absorbing structure 1 is moved from the initial state of FIG. ). That is, when the impact force F1 due to the collision acts on the bumper 14, this impact force (collision energy) F1 is transmitted to the compression coil spring 2, and the one slidable spring holder 5 is placed on the side frame 15, 15 side. It is pushed in against the urging force of the compression coil spring 2. Accordingly, the compression coil spring 2 is compressed so that its length is gradually shortened, and absorbs the impact force F1 by elastic deformation at the time of compression.
[0033]
As described above, if the impact force F1 is within a range not exceeding the elastic limit of the compression coil spring 2, the impact force F1 can be absorbed by the elastic deformation of the compression coil spring 2, so that the side frames 15, 15, etc. Can be prevented from being damaged. Further, since the holder member 3 holding the compression coil spring 2 is configured to be slidable in the direction of expansion and contraction of the compression coil spring 2, the spring holder 5 and the slide guide 6 are not deformed, and are compressed after collision. When the coil spring 2 recovers to the initial state, it returns to the original state (the initial state shown in FIG. 7A). Therefore, in the case of such a light collision, only the skin or the like of the bumper 14 can be scratched or dented, and the energy absorbing structure 1 and the side frames 15 and 15 are not damaged. Costs are minimal.
[0034]
On the other hand, when the cab-over track 13 collides with another vehicle at a high speed (hereinafter, this collision is referred to as a heavy collision), the energy absorbing structure 1 moves from the initial state of FIG. ). That is, when the impact force F2 due to the collision acts on the bumper 14, the impact force F2 is transmitted to the compression coil spring 2, and one of the slidable spring holders 5 is pushed into the side frames 15, 15. Since the impact force F2 due to the heavy collision cannot be cut off only by the elastic deformation of the compression coil spring 2, it is absorbed by the plastic deformation of the compression coil spring 2.
[0035]
That is, in the present embodiment, since the compression coil spring 2 has a hollow structure, the impact force F2 can be effectively absorbed by plastic deformation of the spring itself even after exceeding the elastic limit. This is because the compression coil spring 2 having a hollow structure (solid line A in FIG. 8) is a normal compression coil spring having no hollow structure (see FIG. 8). 8, the degree of plastic deformation after exceeding the elastic limit is much higher than that of the broken line B).
[0036]
That is, since the inside of the compression coil spring 2 having a hollow structure is hollow, the hollowed portion is crushed. In particular, since the load in the plastic deformation region has a layered structure for each spring pitch, an appropriate load is maintained for a long time. Therefore, the plastic deformation of the compression coil spring 2 effectively absorbs the impact force F2.
[0037]
In general, a compression coil spring that does not have a hollow structure has a crushing load after the elastic limit that rises rapidly and does not deform so much until a high load is maintained, so that not only the spring remains uncrushed, but also the impact force is reduced. F2 cannot be effectively absorbed, and an excessive load may damage the side frames 15, 15 holding the energy absorbing structure 1 at the rear end.
[0038]
In this regard, in the energy absorbing structure 1 according to the present embodiment, the slide guide 6 is deformed beyond the movable range. However, since the compression coil spring 2 having the hollow structure is used, an excessively high load can be effectively applied. It can be absorbed, and damage to the side frames 15, 15 can be prevented. Further, in the energy absorbing structure 1 according to the present embodiment, since the initial deformation characteristic is basically linear even with an excessive load, the deceleration generated at the initial stage of the collision is an accurate sine wave, so that the sensing of the occupant restraint system is performed. Such considerations can be easily obtained. In particular, for a vehicle having a short crash space, such as the cab-over truck 13, it is possible to effectively utilize the small space to absorb the impact force F2 at the time of the collision.
[0039]
9 and 10 show the state of the energy absorbing structure 1 after the heavy collision for reference. FIG. 9 is a view when the energy absorbing structure 1 of the present embodiment using the compression coil spring 2 having a hollow structure is mounted on a cab overtrack 13, and FIG. 10 uses a compression coil spring having no hollow structure. FIG. 2 is a diagram when the energy absorbing structure 1 is mounted on a cab-over track 13. In FIG. 9, since the compression coil spring 2 having a hollow structure is used, the energy absorption structure 1 is considerably crushed by effectively absorbing the impact force F2. Since the coil spring is used, the energy absorbing structure 1 is not sufficiently collapsed without sufficiently absorbing the impact force F2.
[0040]
Thus, according to the energy absorbing structure 1 of the present embodiment, the impact force is absorbed by the elastic deformation of the compression coil spring 2 during a light collision, and the plastic deformation of the hollow compression coil spring 2 itself during a heavy collision. Thereby, the impact force can be effectively absorbed, the front end of the cab over truck 13 to which the bumper 14 is attached can be prevented from being damaged, and the repair can be performed at a minimum necessary repair cost.
[0041]
As described above, the specific embodiments to which the present invention is applied have been described. However, the present invention is not limited to the above-described embodiments, and can be variously modified.
[0042]
For example, in the above embodiment, the energy absorbing structure according to the present invention is applied to a small cabover or semi-cabover van or truck. However, the energy absorbing structure according to the present invention is also applied to a vehicle having a monocoque (integrated structure) body. Can be attached. Even in a vehicle having a monocoque body, since a strength skeleton member called a member actually exists, the energy absorbing structure of the present invention can be mounted on the front end of the vehicle if there is a protruding portion such as a front side member.
[0043]
In the above-described embodiment, the energy absorbing structure 1 is mounted on the front end of the cab overtrack 13. However, the energy absorbing structure 1 of the present invention is mounted on the rear end of the cab overtrack 13. A similar effect can be obtained.
[0044]
【The invention's effect】
The present invention is implemented in the form described above, and has the following effects.
[0045]
According to the present invention, since a compression coil spring having a hollow structure is used, when a collision occurs in a traffic accident, if the collision is a light collision, the impact force is absorbed by elastic deformation of the compression coil spring, and In the case of a collision, the spring frame itself can be prevented from being damaged by absorbing the impact force by plastic deformation of the spring itself. Therefore, the impact force at the time of collision can be reduced with a simple structure. In addition, since the chassis frame is not damaged, repair can be easily performed, and repair costs can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of an energy absorbing structure of the present embodiment.
FIG. 2 is an exploded perspective view of the energy absorbing structure of the embodiment.
FIG. 3 is a perspective view of the compression coil spring having a hollow structure used in the energy absorbing structure of the present embodiment, which is partially cut away.
FIG. 4 is a perspective view of a cab-over-track showing a state before mounting the energy absorbing structure of the present embodiment.
FIG. 5 is a perspective view of a cab overtrack showing a state where the energy absorbing structure of the present embodiment is mounted.
FIG. 6 is an enlarged perspective view of a main part of a front end portion of a vehicle to which a bumper of the cab over truck shown in FIG. 5 is attached.
FIGS. 7A and 7B are diagrams illustrating an operation state of the energy absorbing structure when the cab-over truck collides with another vehicle in a head-on manner, where FIG. 7A is an initial state, FIG. ) Indicates the state at the time of a heavy collision.
FIG. 8 is a characteristic diagram showing a deformation amount of a compression coil spring with respect to a load.
FIG. 9 is a diagram showing a state in which the energy absorbing structure according to the present embodiment is crushed when the energy absorbing structure is mounted on a cab-over track and a heavy collision occurs.
FIG. 10 is a view showing a state in which the energy absorbing structure which is not a hollow structure is crushed when the energy absorbing structure is mounted on a cab-over track and a heavy collision occurs.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Energy absorption structure 2 Compression coil spring 3 Holder member 4 Cavity part 5 Spring holder 6 Slide guide 7 Receiving part 8 Wall part 12 Slide guide hole 13 Cab over track 14 Bumper 15 Side frame 16 Connection member

Claims (4)

An energy absorbing structure that absorbs and reduces shock applied to a bumper provided at a front end or a rear end of a vehicle,
An energy absorbing structure for a vehicle, comprising a compression coil spring having a hollow structure that expands and contracts in the vehicle front-rear direction between the vehicle and the bumper. An energy absorbing structure for a vehicle according to claim 1,
An energy absorbing structure for a vehicle, comprising: a holder member that houses the compression coil spring so as to surround the compression coil spring. An energy absorbing structure for a vehicle according to claim 2,
The holder member includes a spring tray member disposed at each of front and rear ends in the expansion and contraction direction of the compression coil spring, and one end portion fixed to one spring tray member and the other end slid with respect to the other spring tray member. An energy absorbing structure for a vehicle, comprising: a slide guide member that is freely attached and moves one spring tray member toward or away from the other spring tray member. An energy absorbing structure for a vehicle according to claim 3,
An energy absorbing structure for a vehicle, wherein one spring receiving member of the holder member is fixed to the bumper, and the other spring receiving member is fixed to a chassis frame of the vehicle.

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