JP6090180B2 - Shock absorption structure for vehicles - Google Patents

Description

  The present invention relates to an impact absorbing structure for a vehicle such as an automobile or other moving body, and more particularly, to a structure for absorbing energy of impact received by a structure such as a body when the moving body collides. .

  In a vehicle body or a main body (hereinafter simply referred to as “vehicle body”) of a vehicle such as an automobile or other moving body (hereinafter simply referred to as “vehicle etc.”), the vehicle or the like is an obstacle. Various structures are used in order to suppress the impact of a frontal collision from being transmitted to a passenger compartment or cab (occupant space) of a vehicle or the like. For example, in Patent Document 1, it is a tubular member disposed in front of a vehicle body or the like as an impact absorbing member, and a plurality of fragile portions, bead portions, and the like are adjusted in the position in the axial direction of the tubular structure. An impact-absorbing member that disposes and absorbs energy by buckling in the axial direction when receiving an impact in the axial direction of the tubular structure is disclosed. Further, Patent Document 2 discloses a structure in which a weak portion is provided in a side frame of a vehicle body to improve energy absorption capability. Further, in Patent Document 3, a weak portion is provided in the support structure of the engine of the vehicle so that the engine is moved forward by inertia when the vehicle collides, so that the collision energy can be offset by the inertia energy of the engine. A different configuration has been proposed. In addition, in the event of a vehicle collision, the unit or structural member mounted on the vehicle body is supported so that it can be moved or deformed forward by inertia, and the impact force is suppressed or reduced by the inertial force of the unit or structural member (Patent Document) 4-6) Various configurations have been proposed in which collision energy is transmitted to the rear of the passenger compartment or the cab in the event of a vehicle collision to ensure the safety of the passenger compartment or the cab (Patent Documents 7-11). Has been.

JP2012-218503 JP 2010-105537 A JP 2001-301646 A JP2008-1147 JP2007-2016901A Shokai 61-132107 JP 07-47842 A 4-115986 JP2010-241393 JP2010-6102 JP2011-195056

  As described above, in the structure that absorbs or reduces the appropriate collision energy in order to protect the passenger space at the time of the frontal collision of the vehicle etc., the conventional structure may require reinforcement with a somewhat complicated bone structure. Therefore, it has been difficult to reduce the weight of vehicles and the like. More specifically, in a vehicle body or the like, heavy components such as a power unit and a suspension device are appropriately arranged so as to optimize the center of gravity of the vehicle or the like. The vehicle or the like decelerates and stops while the fragile part of the structure of the vehicle body or the like in which the heavy part is interposed between the collision wall and the fixed point of the heavy part is selectively crushed. In that case, in particular, in order to prevent the occupant space from being crushed by the occupant space or a heavy component disposed behind the occupant space, a reinforcing beam structure is required for the heavy component. With regard to such a reinforced beam structure, in the conventional structure, generally, the support end of the reinforced beam is a curved beam laid on the front part of a vehicle or the like such as a front side member serving as a first transmission path of a collision load. Since the beam member is fixedly supported by the member and has a structure with bending and twisting, the structure of the support end of the reinforcing beam for protecting the passenger space is sufficient for the impact load. The structure is slightly complicated and relatively heavy so that drag can be obtained.

  Further, in the case of a vehicle that can have a relatively large space in the front part such as a vehicle body, for example, a vehicle such as an electric vehicle that uses an in-wheel motor as a drive source, it receives a front collision load for protecting the passenger space. Reinforced beam structure can be installed straight from the front of the vehicle body to the passenger space, but it is relatively light and there is no risk of crushing the passenger space, as in the case of a collision during mid- or low-speed driving. Considering that it is possible to absorb collision energy even in a collision, a weak part is provided on the front side member, or an easy crushing member is interposed between the front side member and the bumper reinforcement, As a structure capable of absorbing energy by crushing, a slightly complicated structure having a relatively large weight as described above is required.

  Furthermore, in the case of a configuration in which a weak part that is passively crushed by an impact force at the time of a collision is provided as an impact absorbing member, the manner of crushing differs depending on the input direction of the collision force, and the remaining crushing may occur. It is difficult to appropriately control the buckling mode in order to reduce the remaining crushing residue simply by adjusting the arrangement / size, etc., on the member of the fragile site to be passively crushed.

  Thus, one object of the present invention is an impact absorbing structure for a vehicle body such as a vehicle, which has a simpler configuration without significantly increasing the weight and more appropriately controls the buckling mode. It is to provide a new structure that can be done.

  Another object of the present invention is to provide a shock absorbing structure as described above, which has a higher protection performance for the passenger space and is relatively light.

  In solving the above problems, the inventor of the present invention does not simply passively generate crushing in the impact absorbing member, but actively applies force to the member to set the buckling mode. Inspired to control. As means capable of actively controlling and applying force to such a member, a linear deformation element whose size is changed by controlling application of current can be used. Such knowledge is used in the present invention.

  According to the present invention, the above-described problem is a shock absorber structure for a moving body, which extends in the longitudinal direction of the moving body and curves or bends the plate-like member in a direction substantially perpendicular to the longitudinal direction. And a plurality of strips whose length contracts when an electric current is applied, and are arranged at predetermined intervals in the longitudinal direction of the reinforcing body and intersect with the longitudinal direction of the reinforcing body. A band-like body fixed on the outer surface of the reinforcing body so as to extend along the direction, a first region of a part of the plurality of belt-like bodies, and a reinforcement facing the first region A first thin blade body inserted so as to extend along the longitudinal direction of the strip-shaped body with the cutting edge facing the region of the reinforcing body between the surface area of the body and a plurality of strip-shaped bodies The first region of the band different from the part of the band is the second region at a position offset in the circumferential direction and the first region. And a second thin blade inserted so as to extend along the longitudinal direction of the belt-like body with the cutting edge facing the region of the reinforcing body between the region of the reinforcing member and the surface region of the reinforcing body opposed to the region And a current control unit that applies a current to the band when a collision of the bodies is detected, and when the current is applied to the band and the band contracts, the reinforcing body that the cutting edges of the first and second thin blades face each other This is achieved by the shock absorbing structure in which the pressed region of the reinforcing body is weakened by pressing the surface region of the reinforcing member.

  In such a configuration, the “moving body” may be an arbitrary moving body such as a vehicle such as an automobile, a ship, an aircraft, or a micro mobility. The “reinforcing body” may typically be a member formed by molding a plate-like member into a substantially trapezoidal semi-cylindrical shape, and the axial direction of the semi-cylindrical shape is the bottom surface of the front part of the vehicle body or the like of the moving object It may be arranged so as to be substantially along the longitudinal direction of the vehicle body or the like. As described above, a plurality of “strip-shaped bodies” are arranged on the outer peripheral surface of the reinforcing body in the circumferential direction of the reinforcing body in the direction intersecting with the longitudinal direction (axial direction) of the reinforcing body. In a state of being fixed on the outer surface of the reinforcing body so as to extend along the longitudinal direction of the vehicle body and the like, and arranged at predetermined intervals in the longitudinal direction of the vehicle body, etc. In between, the “thin blade” is inserted with the cutting edge facing the surface of the reinforcing member. In addition, the insertion site of the thin blade is only a partial region of each strip, and the insertion site of the thin blade and the insertion site of other thin blades in some of the strips are different from each other. Preferably, they are inserted at different sites between adjacent strips. Each strip may be constituted by a linear deformation element whose length contracts when a current is applied. More specifically, for example, a wire made of a linear element that generates Joule heat by flowing an electric current and a shape memory alloy that contracts in length as the temperature rises as a band-like body that can shrink by application of such an electric current. A belt-like body combined with a strip-like element may be employed. In the above configuration, the “current control unit” is configured to apply a current to each of the belt-like bodies when a collision of the moving body is detected by an arbitrary method. Here, the detection of the collision of the moving body may be to detect the actual collision, but more preferably, the position and / or speed of the obstacle detected by the obstacle sensor, the GPS device, or the like. It may be prediction information such as the possibility of contact between the moving object and the obstacle estimated by using, for example, how long a collision will occur.

  In the operation of the above configuration, when it is detected that the moving body has collided with an obstacle while the moving body is traveling, first, a current is applied to the strip by the current control unit. . Then, since the length of the band-like body to which the current is applied contracts, each thin blade inserted between the band-like body and the reinforcing body presses the surface of the reinforcing body, Thereby, the surface area | region of the reinforcement body which the blade edge | tip of a thin blade body contacts will be weakened locally. In this state, when the collision force acts in the axial direction of the reinforcing body, the reinforcing body starts to be easily crushed from the locally weakened region, and the collision energy is efficiently absorbed.

  According to the above configuration, by appropriately adjusting the position on the reinforcing body where the belt-like body is disposed, the reinforcing body can be accurately and actively crushed and absorbed by collision energy in response to the inflow of collision energy. It becomes. In addition, since the region and the time period weakened by the contraction of the belt-like body can be controlled by appropriately selecting the belt-like body to which current is applied, the buckling mode can also be controlled. Furthermore, the reinforcing body and the belt-like body molded from the plate-like member do not occupy a large space and are relatively lightweight, so that an increase in weight due to the shock absorbing structure is kept low, and the passenger space is reduced. It is possible to absorb collision energy by crushing the reinforcing body so that the protection performance is higher. In addition, as described in the column of the following embodiment, the thin blades are arranged so that the positions are alternately arranged in the belt-like bodies arranged in parallel in the axial direction of the reinforcing body. It's okay. With this configuration, the reinforcing body is easily crushed in the axial direction in a wavy shape (for example, in the shape of a lantern), so that the remaining crushing can be reduced and the absorption of collision energy can be increased.

  In the embodiment, the shock absorbing structure may be incorporated as a front side portion of a straight beam structure penetrating rearward from a front edge of a vehicle body or the like of the moving body. The straight beam structure may be in contact with the side surface of the transverse beam crossing the front edge of the vehicle body or the like, and does not execute the weakening of the reinforcement body of the shock absorbing structure according to the present invention (when no current is applied to the belt-like body). The reinforcing body portion also has a strong rigid body property. Therefore, when the reinforcement body is not weakened, the impact load input given from the front edge of the vehicle body or the like is transmitted through the straight beam structure, and the passenger space is protected. In particular, when a heavy component is arranged behind the straight beam structure, the heavy component is fixed to the straight beam structure, and in the event of a collision, the inertial force of the heavy component becomes a drag force against the impact load input. That is, the straight beam structure may be configured such that its axial crushing strength exceeds the inertial force of the heavy component.

  Thus, according to the present invention described above, in the shock absorbing structure for a moving body, it is possible to actively adjust the weakened portion of the reinforcing body to be crushed at the time of collision. The remainder can be reduced, and the impact energy can be absorbed more efficiently. Moreover, since the shock absorbing structure of the present invention is simply configured to be arranged in a plurality of strips on the outer periphery of the reinforcing body, the structure is relatively simple and relatively lightweight, The occupant space can be protected more reliably without significantly increasing the weight of the vehicle body or the like.

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

FIG. 1A is a schematic perspective view of the bottom of a vehicle body to which the shock absorbing structure according to the present invention is applied, and FIG. 1B is a schematic enlarged view of a region where the shock absorbing structure is disposed. FIG. 2A is a schematic perspective view of the shock absorbing structure according to the present invention, and FIGS. 2B and 2C are views of the shock absorbing structure viewed from the direction of the arrow in FIG. It is typical sectional drawing. FIG. 2D is a schematic enlarged view of the belt-like body 11a and the reinforcing body 10 viewed from the direction of the arrow in FIG. FIG. 2E is a schematic perspective view for explaining a crushing mode of the reinforcing body of the shock absorbing structure. FIG. 3 is a schematic perspective view of the bottom of the vehicle body to which the shock absorbing structure is applied, and is a view for explaining a method of fixing heavy parts to a straight beam. It is. FIG. 4 is a diagram showing the configuration of the current control unit for the current applied to the band of the shock absorbing structure according to the present invention in the form of a control block.

DESCRIPTION OF SYMBOLS 1 ... Vehicle body bottom part 2FL-RR ... Wheel 3 ... Vehicle body floor 3a ... Vehicle body floor front part 4 ... Bumper reinforcement 5L, R ... Front side member 6 ... Tunnel (straight beam)
6a ... Fitting hole 7 ... Shock absorbing structure 8 ... Arbitrary heavy component 8a ... Flange 10 ... Reinforcing body 10a ... Flange 11a, b ... Strip-like body 12 ... Fastener 13a, b ... Thin blade 15 ... Electric resistance wire 16 ... Linear deformation element (shape memory alloy)

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

  Referring to FIG. 1, the shock absorbing structure 7 according to the present invention is, in the illustrated embodiment, a front part at a substantially central position on a floor 3 of a vehicle body 1 or the like of a vehicle 1 having left and right front and rear wheels 2FL to RR. It is applied to the front part of the straight beam 6 arranged to extend rearward from the side wall of the edge bumper reinforcement 4. The straight beam 6 may typically be a tunnel structure formed by fixing a structure in which a plate material is formed into a trapezoidal shape to a vehicle width central region on the floor 3 by welding or the like. Further, in the straight beam or tunnel 6, a heavy component 8 mounted on the vehicle, for example, a small auxiliary power generation engine disposed in an engine room in front of the vehicle, and a drive motor disposed in a space behind the vehicle. / Deceleration unit, battery, seat, etc. may be fixed. These heavy parts 8 may be typically fixed to the tunnel 6 by means such as bolt fastening, welding, etc., but the inertial force of the heavy parts 8 is more reliably applied to the tunnel when a vehicle or the like collides. 6, a stronger connection means may be employed between the heavy component 8 and the tunnel 6 so that the impact force can be offset. Specifically, as such means, for example, as illustrated in FIG. 3, a flange 8 a provided in the outer shell of the heavy component 8 is fitted into a fitting hole 6 a provided in the tunnel 6. You may be supposed to. Thereby, the outer shell of the heavy component 8 constitutes a part of the wall surface of the tunnel 6.

  A shock absorbing structure 7 according to the present invention comprising a reinforcing body 10 and strips 11 arranged around the reinforcing body 10 is typically a straight beam or tunnel 6 described above as illustrated in FIG. As a part of the tunnel 6, it may be incorporated in a portion that contacts the bumper reinforcement 4 at the leading edge. In the specific structure of the shock absorbing structure 7, as shown in FIG. 2A, a reinforcement formed by molding a plate material having substantially the same axial crushing strength as the tunnel 6 into a trapezoidal shape. On the outer periphery of the body 10, the strips 11 a and 11 b whose length contracts when an electric current is applied are fixed along the circumferential direction of the reinforcing body 10 intersecting the longitudinal direction of the reinforcing body 10 with a predetermined interval. Arranged. The reinforcing body 10 typically has substantially the same thickness and cross-sectional area as the tunnel 6, the front end abuts the bumper reinforcement 4 at the front edge, and the rear end aligns with the tunnel 6. You may arrange | position so that it may connect (FIG.1 (B)). Note that, for fastening between the rear side end and the tunnel 6, the flange 10 a may be disposed so as to contact the rear side end of the reinforcing body 10 and the front end of the tunnel 6 (FIG. 2A). ).

  More specifically, the strips 11a and 11b that contract in length when an electric current is applied are, as illustrated in FIG. 2D, linear shapes made of a shape memory alloy that contract in length as the temperature rises. A strip-shaped member composed of the deformation element 16 and a plurality of electric resistance wires 15 provided with an insulating film arranged at a predetermined density along the length direction on one side of the linear deformation element 16. It is. In the belt-like body of the present embodiment, when the temperature of the belt-like body reaches about 70 ° C. due to Joule heat generated by passing a current of about 1 A through the plurality of electric resistance wires 15, the length of the belt-like body is reached. The size of the band is adjusted so that the film shrinks by about 5%. The strips 11a and 11b are arranged so as to surround the periphery of the trapezoidal semi-cylindrical reinforcement as illustrated in FIGS. 2A to 2C. The floor 3a is fixed by fastening means such as bolts 12. A conductive wire (not shown) that is electrically connected to a drive circuit of an electric control unit for selectively applying a current is connected to both ends of each of the electric resistance wires 15.

  Further, between the strips 11a and 11b and the surface of the reinforcing body 10, the cutting edge s contacts the surface 10x of the reinforcing body 10 as shown in FIGS. 2 (A) to 2 (D). The thin blades 13a and 13b are inserted in contact with each other. The thin blade bodies 13 a and 13 b are preferably arranged at positions offset from each other in the circumferential direction of the reinforcing body 10. Specifically, as understood from FIG. 2A, the strips 11a and 11b are alternately arranged in the longitudinal direction of the reinforcing body 10, and the reinforcing body in the strip 11a. A thin blade body 13a may be inserted between the upper surface of 10 and a pair of thin blade bodies 13b may be inserted between both side surfaces of the reinforcing body 10 in the belt-shaped body 11b. As the thin blade body 13a, one having a length between L / 2 and L with respect to the upper surface of the circumferential width L of the reinforcing body 10 is selected. As the thin blade body 13b, the circumferential direction of the reinforcing body 10 is selected. A length between H / 2 and H may be selected for the side surface of the width H. Each thin blade body may be fixed to a corresponding strip-shaped body by fastening means such as a screw.

  According to the configuration including the reinforcing body 10, the strips 11a and 11b and the thin blades 13a and 13b, when a current is passed through the electric resistance wires 15 of the strips 11a and 11b, the shape memory alloy is generated by the generation of Joule heat. The temperature of the linear deformation element 16 made of the metal increases, and the length of the linear deformation element 16 contracts. When the strips 11a and 11b contract, the thin blades 13a and 13b locally press the reinforcing body surface regions 10x that abut each other. In this state, when a force (axial compressive load) is applied from the axial direction in the reinforcing body 10 in accordance with the theory of a thin cylinder that collapses into a lantern shape, the thin blade is used when the reinforcing body 10 buckles in a wave shape along the axial direction. The work pressed by the thin blade body (out-of-plane load) is further added to the portion pressed by the bodies 13a and 13b with respect to the axial compression load. As shown in FIG. 2, the pressed parts (E, F) of the thin blade body are buckled, that is, become weakened parts (plastic hinges), and begin to buckle. It can be crushed in a wave shape (in the shape of a lantern). In addition, since the contact part of a thin blade body influences the crushing state of the reinforcement body 10, about the arrangement space | interval of the strip | belt-shaped bodies 11a and 11b on the reinforcement body 10, and the insertion part of a thin blade body, the reinforcement body 10 previously. It is preferable that an appropriate sequence interval and site are determined by the axial compression fracture test. In addition, the strips 11a and 11b are loosened between the surface of the reinforcing body 10 with the thin blades 13a and 13b inserted with as little gap as possible so that the thin blades can be applied with an out-of-plane load as efficiently as possible. It is preferable to be fixed so as to be arranged in a state without any.

  Thus, in the shock absorbing structure 7 according to the present invention, the strength of the structure can be controlled by selectively applying the current to the strip 11 so that the reinforcing body 10 can be easily buckled. When the current application is not executed, the shock absorbing structure 7 acts together with the tunnel 6 as a part of a rigid straight beam. In the operation of the shock absorbing structure according to the present invention in a vehicle or the like, typically, when an obstacle collision is predicted during the traveling of the vehicle or the like, an electric current is applied to the strip 11. Is executed, and the reinforcing body 10 is easily buckled. The prediction of the collision of the obstacle and the control of the application of the current to the strip 11 may be executed by an electric control unit as schematically illustrated in FIG. First, the electric control unit receives information on the remaining estimated time (TTC) until the vehicle or the like comes into contact with an obstacle from an arbitrary collision prediction mechanism. The collision prediction mechanism is, for example, a detector (millimeter wave sensor (FMCW method), radar device, sonar device) for measuring the relative distance and relative speed with an obstacle (stopped object, preceding vehicle, etc.) ahead of the vehicle or the like. Etc.) using the detected value Ia obtained by the above-described method, in any manner, the processing for detecting the presence of an obstacle and detecting the relative distance / relative speed distance between the vehicle and the obstacle is executed. It may be a mechanism for calculating information of the remaining estimated time (TTC) until it touches the obstacle. In addition, as a collision prediction mechanism, you may utilize the GPS apparatus (car navigation system) which communicates with a GPS artificial satellite and acquires various information, such as the positional information on the own vehicle. When the electric control unit receives the prediction of the collision and the TTC information, the electric control unit applies the current to the band 11 based on the TTC information so that the band 11 contracts at the time when the collision occurs. Execute control. More specifically, when the TTC reaches the time (delay time δt) required from the start of application of current to the strip 11 to the load generation time due to contraction of the strip 11, the current to the strip 11 The application timing of the current may be controlled so that the reinforcing body 10 is in an easily buckled state at the time of collision. The delay time δt may be a value obtained experimentally or theoretically. When the electric control unit gives a current application control command to the drive circuit, the drive circuit causes the electric current to flow through each electric resistance line.

  Note that the control for making the reinforcing body 10 be easily buckled may be typically performed during a light / medium collision that does not cause the passenger space to be crushed by the impact of the collision. On the other hand, if the collision is expected to be a heavy collision that is expected to cause the occupant space to be crushed by the heavy components mounted by the impact, or the TTC is already below the delay time δt. In the case of high-speed collision, the reinforcing body 10 is used as a rigid straight beam structure integrated with the tunnel 6 to increase the axial crushing strength of the straight beam structure, rather than making the reinforcing body 10 easily buckled. Application of current to the strip 11 need not be performed.

  Thus, according to the shock absorbing structure 7 according to the present invention as described above, the reinforcing body 10 can be actively and selectively easily buckled with a simpler configuration without significantly increasing the weight. By doing so, it becomes possible to control the buckling mode more appropriately.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept.

Claims (1)

A shock absorbing structure for a moving body,
A reinforcing body that extends in the longitudinal direction of the moving body and curves or bends the plate-like member in a direction substantially perpendicular to the longitudinal direction;
A plurality of strips whose length contracts when an electric current is applied, arranged in the longitudinal direction of the reinforcing body at predetermined intervals, and in the circumferential direction of the reinforcing body intersecting the longitudinal direction of the reinforcing body A strip fixed on the outer surface of the reinforcing body so as to extend along,
A state in which the cutting edge faces the region of the reinforcing body between the first region of a part of the plurality of strips and the surface region of the reinforcing body facing the first region. A first thin blade inserted so as to extend along the longitudinal direction of the strip,
Of the plurality of strips, the first region of the strip other than the part of the strips is opposed to the second region at a position offset in the circumferential direction and the second region. A second thin blade body inserted so as to extend along the longitudinal direction of the belt-like body in a state where the blade edge faces the region of the reinforcement body between the surface area of the reinforcement body and
A current control unit that applies a current to the belt-like body when a collision of the moving body is detected;
When an electric current is applied to the belt-like body and the belt-like body contracts, the region where the reinforcement body is pressed is pressed by pressing the surface region of the reinforcement body where the cutting edges of the first and second thin blade bodies face each other. Shock absorbing structure to be weakened.

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