JP5084623B2 - Vehicle body strength adjusting device - Google Patents

Description

  In the present invention, a crushing strength variable device that receives a collision load in the longitudinal direction of the vehicle body is disposed between the bumper beam and the vehicle body frame, and the crushing load of the crushing strength variable device is selected between a high load mode and a low load mode. The present invention relates to a vehicle body strength adjusting device for a vehicle that can be switched automatically.

  A bumper beam attached to the front end of the front side frame of an automobile is composed of a pair of front and rear beam members arranged in parallel to each other and a plurality of variable crushing strength devices arranged at predetermined intervals between both beam members. Is known from Patent Document 1 below.

The crushing strength variable device has three buckling plates made of shape memory alloy arranged adjacent to each other so as to buckle by the impact of a collision, and these buckling plates are integrally connected by two base members. And an actuator for switching to a state where they are separated from each other, and in the state where three buckling plates are integrally connected by two base members, the buckling strength is increased to increase the impact energy that can be absorbed, and In the state where the three buckling plates are separated from the two base members, the buckling strength is reduced to reduce the absorbable collision energy.
JP 2006-8106 A

  By the way, in the above-mentioned conventional one, when three buckling plates are integrally connected by two base plates (high load mode), the buckling plates are deformed so as to wave and buckle. In the state where the buckling plates are separated from the two base plates (low load mode), the buckling plates are deformed into a simple arc shape, but there is a difference in buckling, but the entire three buckling plates are buckled. It was difficult to bend and absorb the collision energy, and it was difficult to make a large difference in the absorption effect of the collision energy between the high load mode and the low load mode. In particular, when it is necessary to keep the injury to the collision partner as small as possible in the low load mode, it is required to collapse the variable crushing strength device with a smaller load.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a large difference in absorbable energy between the high load mode and the low load mode and to obtain an optimum energy absorption characteristic according to the collision partner.

In order to achieve the above object, according to the first aspect of the present invention, a crushing strength varying device that receives a collision load in the longitudinal direction of the vehicle body is disposed between the bumper beam and the vehicle body frame, and the crushing is performed. In a vehicle body strength adjusting device for a vehicle in which the crushing load of the strength varying device can be selectively switched between a high load mode and a low load mode, the crushing strength varying devices are arranged so as to face each other in the vehicle longitudinal direction. And at least a pair of buckling plates extending and buckling with a collision load acting between the bumper beam and the vehicle body frame, and a support member for rotatably supporting one end of the pair of buckling plates in the vehicle longitudinal direction When the actuator rod a male thread to be screwed to the support member internal thread formed on the formed at both ends, before and condition to restrain movement in the direction away from each other of said support member And a state that allows movement and a switchable locking mechanism by the actuator, in the high load mode, the restraining rotation of the actuator rod in the locking mechanism, said support member so as not to separate from each other the The buckling plate is restrained from falling outside, and in the low load mode, the lock mechanism allows the actuator rod to rotate, and the support member is separated from both ends of the actuator rod so that the buckling plate is outside. There is proposed a vehicle body strength adjusting device for a vehicle characterized in that the vehicle falls over .

According to the invention described in claim 2 , in addition to the configuration of claim 1 , the pair of first buckling plates and the pair of second buckling plates are arranged so as to form a substantially quadrangular prism. A vehicle body strength adjusting device for a vehicle is proposed.

According to the invention described in claim 3 , in addition to the configuration of claim 1 or claim 2 , the end portion of the buckling plate opposite to the support member is bent through the bent portion. In the low load mode, a vehicle body strength adjusting device for a vehicle is proposed in which the bent portion is plastically deformed.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, a vehicle body strength adjusting device for a vehicle is proposed in which a bead is formed on the buckling plate connected to the bent portion. Is done.

According to a fifth aspect of the invention, in addition to the configuration of the third or fourth aspect, a vehicle is characterized in that a strength adjusting hole is formed in the buckling plate in the vicinity of the bent portion. A vehicle body strength adjusting device is proposed.

According to a sixth aspect of the invention, in addition to the structure of any one of the first to fifth aspects, a reinforcing member is superimposed on the buckling plate. An intensity adjustment device is proposed.

According to the invention described in claim 7 , in addition to the configuration of any one of claims 1 to 6 , a box-shaped shock absorbing portion is provided at a position surrounded by the pair of buckling plates. A vehicle body strength adjusting device for a vehicle is provided.

The front side frame 12 of the embodiment corresponds to the vehicle body frame of the present invention, and the actuator storage box 16 of the embodiment corresponds to the shock absorbing portion of the present invention, and the first and second nut members of the embodiment. 21A and 21B correspond to the support member of the present invention, the first and second buckling plates 23A and 23B of the embodiment correspond to the buckling plate of the present invention, and the shape memory alloy 26 and the reinforcing plate of the embodiment. 34 corresponds to the reinforcing member of the present invention, the first and second actuator rods 42A and 42B of the embodiment correspond to the actuator rod of the present invention, and the solenoid 49 of the embodiment corresponds to the actuator of the present invention.

According to the configuration of the first aspect, the crushing strength varying device disposed between the bumper beam and the vehicle body frame is disposed so as to face each other and extends in the longitudinal direction of the vehicle body, and acts between the bumper beam and the vehicle body frame. At least a pair of buckling plates that can be buckled by a collision load, a support member that rotatably supports one end of the pair of buckling plates in the longitudinal direction of the vehicle body , and a female screw formed on the support member An actuator rod having male screws formed at both ends, and a lock mechanism that can switch between a state in which the movement of the support member in a direction away from each other and a state in which the support member is allowed to be permitted are provided by the actuator. restraining the rotation of the rod, the support member in the high load mode for restraining the inclination of the outer to the seat屈板not to away from each other, the seat屈板by collision load Buckling can increase the absorbable impact energy and allow, also allows rotation of the actuator rod in the locking mechanism, the low load mode the seat屈板collapses outwardly supporting member separated from both ends of the actuator rod Then, the impact energy that can be absorbed can be reduced by tilting the buckling plate without buckling with a collision load. As a result, it is possible to obtain a large difference in the absorbable energy between the high load mode and the low load mode, and to obtain an optimum energy absorption characteristic according to the collision partner .

According to the second aspect of the present invention, the pair of first buckling plates and the pair of second buckling plates are arranged so as to form a substantially quadrangular prism. Can be reliably absorbed.

According to the third aspect of the present invention, the end of the buckling plate on the side opposite to the support member is bent through the bent portion, and the bent portion is plastically deformed in the low load mode. The strength adjusting device can be crushed.

According to the fourth aspect of the present invention, since the bead connected to the bent portion is formed on the buckling plate, the load for plastic deformation of the bent portion can be finely adjusted only by changing the shape and size of the bead. .

According to the construction of claim 5 , since the strength adjusting hole is formed in the vicinity of the bent portion of the buckling plate, the load for plastic deformation of the bent portion can be finely adjusted only by changing the size and number of the strength adjusting holes. can do.

According to the configuration of the sixth aspect, since the reinforcing member is overlapped with the buckling plate, the amount of energy that can be absorbed by buckling the reinforcing member together with the buckling plate can be easily adjusted.

Moreover, according to the structure of Claim 7 , since the box-shaped impact-absorbing part was provided in the position surrounded by a pair of buckling plates, by buckling the box-shaped shock-absorbing part in addition to the buckling plate, The total amount of collision energy that can be absorbed can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 17 show a first embodiment of the present invention. FIG. 1 is a plan view of a front part of a vehicle body, FIG. 2 is an enlarged view of a part 2 in FIG. 1, and FIG. 4 is an exploded perspective view of the crushing strength varying device, FIG. 5 is a sectional view taken along line 5-5 in FIG. 2, FIG. 6 is a sectional view taken along line 6-6 in FIG. 7 is a cross-sectional view taken along line 8-8 of FIG. 5, FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 8, FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. FIG. 12 is an explanatory diagram of the operation in the high load mode, FIG. 13 is an explanatory diagram of the operation in the low load mode, FIG. 14 is a graph showing the axial force of the actuator shaft when locked and unlocked, and FIG. FIG. 16 is a graph showing the effect of the bead of the buckling plate, and FIG. 17 is a strength adjustment hole of the buckling plate. Is a graph showing the effect.

  As shown in FIG. 1, a bumper beam 11 disposed at the front of a vehicle body of a four-wheel vehicle is inclined toward the rear of the vehicle body from a body portion 11a extending linearly in the vehicle width direction and from both left and right ends of the body portion 11a. Left and right inclined portions 11b, 11b. Front ends of front side frames 12, 12 arranged in the front-rear direction on both sides of the vehicle body and left and right inclined portions 11 b, 11 b of the bumper beam 11 are connected by crushing strength variable devices 13, 13 that can change the crushing strength. The Since the left and right crushing strength varying devices 13 and 13 have substantially the same structure, the structure will be described below by taking the left crushing strength varying device 13 as an example.

  As shown in FIGS. 2 to 7, a square rear mounting plate 14 of the crushing strength varying device 13 is fixed by eight bolts 15 to an end plate 12 a that closes the front end opening of the front side frame 12 having a box cross section. The rear end of the rectangular frame-shaped actuator storage box 16 is fixed to the front surface of the rear mounting plate 14 with the bottom plate 17 interposed therebetween. Four pipe-shaped bearing portions 17a... Are formed along the four sides of the bottom plate 17 of the actuator storage box 16, and the upper and lower two bearing portions 17a, 17a facing each other are provided with hinge pins 18, 18. Two pin holes 19a, 19a at the rear end of the two first rear hinge plates 19A, 19A are pivotally supported, and hinge pins 18, 18 are mounted on the left and right bearing portions 17a, 17a facing each other. Two pin holes 19a, 19a at the rear ends of the two second rear hinge plates 19B, 19B are pivotally supported via the. The first and second rear hinge plates 19A, 19A; 19B, 19B are composed of strong thick plates, and both have similar shapes, but the longitudinal length of the first rear hinge plates 19A, 19A is long. This is slightly longer than the longitudinal length of the second rear hinge plates 19B, 19B.

  The first front hinge plates 20A, 20A paired with the first rear hinge plates 19A, 19A have two pin holes 20a, 20a at their rear ends, and the first rear hinge plates 19A, 19A Two pin holes 19b and 19b are provided at the front end. The first nut member 21A is fitted between the two pin holes 19b, 19b of the first rear hinge plate 19A, and is press-fitted into the pin holes 21a, 21a formed at both ends of the first nut member 21A. The hinge pins 22 and 22 are fitted into the pin holes 19b and 19b of the first rear hinge plate 19A and the pin holes 20a and 20a of the first front hinge plate 20A, respectively. As a result, the first front hinge plate 20A can be bent with respect to the first rear hinge plate 19A, and the first nut member 21A is against both the first rear hinge plate 19A and the first front hinge plate 20A. Relative rotation.

  Similarly, the second front hinge plates 20B, 20B paired with the second rear hinge plates 19B, 19B are provided with two pin holes 20a, 20a at the rear ends thereof, and the second rear hinge plates 19B, 19B. Is provided with two pin holes 19b, 19b at its front end. The second nut member 21B is fitted between the two pin holes 19b, 19b of the second rear hinge plate 19B, and is press-fitted into the pin holes 21a, 21a formed at both ends of the second nut member 21B. The hinge pins 22 and 22 are fitted into the pin holes 19b and 19b of the second rear hinge plate 19B and the pin holes 20a and 20a of the second front hinge plate 20B, respectively. Thus, the second front hinge plate 20B can be bent with respect to the second rear hinge plate 19B, and the second nut member 21B can be against both the second rear hinge plate 19B and the second front hinge plate 20B. Relative rotation.

  On the inner surface of each first front hinge plate 20A, a first buckling plate 23A having an L-shaped cross section and a rectangular reinforcing plate 34 are overlapped to form three bolts 24 ... and three weld nuts 25 ... It is fixed with. Further, on the inner surface of each second front hinge plate 20B, a second buckling plate 23B having an L-shaped cross section and a shape memory alloy 26 made of a thick plate are overlapped to form four bolts 27 ... and four nuts. 33... Of which the second front hinge plate 20B, the front second buckling plate 23B, and the shape memory alloy 26 are fastened together by two bolts 27, 27 and two nuts 33, 33. The four bolts 27 penetrate through four elongated holes 26a formed in the shape shape memory alloy 26.

  A flange 23a is bent and formed on the front surface of each first buckling plate 23A, and two strength adjusting holes 23b and 23b are formed in the vicinity of the bent portion 23d of the flange 23a. Each of the first buckling plates 23A is formed with a trapezoidal bead 23c that protrudes outward and widens toward the flange 23a. Similarly, a flange 23a is formed on the front surface of each second buckling plate 23B, and two strength adjusting holes 23b and 23b are formed in the vicinity of the bent portion 23d of the flange 23a. Each second buckling plate 23B is formed with a triangular bead 23c that protrudes outward and widens toward the flange 23a.

  Four stud bolts 29 are planted on a rectangular front mounting plate 28, and these stud bolts 29 are four flanges 23a of the first and second buckling plates 23A, 23A; 23B, 23B. ... and through the mounting bracket 30 having a U-shaped cross section, the nut 31 is fastened. The mounting bracket 30 is superimposed on the upper and lower walls of the inclined portion 11 b of the bumper beam 11 and fastened with bolts 32.

  Next, the structure of the lock mechanism 41 of the first and second nut members 21A, 21A; 21B, 21B will be described with reference to FIGS. 4 to 6 and FIGS. Since the lock mechanism 41 of the first nut members 21A and 21A and the lock mechanism 41 of the second nut members 21B and 21B have substantially the same structure, the lock mechanism 41 of one of the first nut members 21A and 21A is the same. The structure will be described.

  As apparent from FIGS. 4 to 6, the lock mechanism 41 includes a locked state in which the pair of first nut members 21 </ b> A and 21 </ b> A that are opposed to each other is held at a fixed distance, and the pair of first nut members 21 </ b> A and 21 </ b> A. It switches between unlocked states that can be separated from each other. Female screws 21b and 21b that are mutually reverse screws are formed in the center of the first nut members 21A and 21A, and male screws 42a and 42a that are mutually opposite screws formed at both ends of the first actuator rod 42A are the female screws. 21b and 21b are screwed shallowly. The pitches of the female screws 21b and 21b and the male screws 42a and 42a are formed coarse, and the sliding surfaces are coated with a low friction material such as fluorine or molybdenum, so that the pair of first nut members 21A and 21A are mutually connected. The first actuator rod 42A is automatically rotated by an external force received from the first nut members 21A and 21A when attempting to move in the direction of separation.

  The lock mechanism 41 includes a square cylindrical actuator housing 44, one end of which is fitted and held in a rectangular support hole 17b, 14a formed in the bottom plate 17 and the rear mounting plate 14 so as to be slidable back and forth. A lock gear 45 is fixed to the first actuator rod 42 </ b> A that passes through the actuator housing 44 in a rotatable manner, and a gear housing 46 that surrounds the outer periphery of the lock gear 45 is fixed inside the actuator housing 44.

  A pair of notches 46b and 46b are formed in an opening 46a provided in a part of the gear housing 46, and a pair of fulcrum protrusions 47a and 47a of a plate-like lock member 47 are swingable to the notches 46b and 46b. Engage with. An engaging portion 47b that can be engaged between the gear teeth of the lock gear 45 is integrally formed on one side with the fulcrum protrusions 47a and 47a interposed therebetween, and a coil spring 48 is interposed on the other side with the fulcrum protrusions 47a and 47a interposed therebetween. The output rod 49a of the solenoid 49 opposes. The engaging portion 47 b of the lock member 47 is biased in a direction to engage between the gear teeth of the lock gear 45 by the elastic force of the leaf spring 50, but the solenoid 49 is excited to lock the lock member via the coil spring 48. By pressing the other end side of 47, the lock member 47 can be swung around the fulcrum protrusions 47a and 47a, and the engaging portion 47b can be disengaged from between the gear teeth of the lock gear 45.

  Next, the operation of the first embodiment of the present invention having the above configuration will be described.

  Normally, the lock mechanism 41 of the variable crushing strength device 13 has its solenoid 49 demagnetized and the output rod 49a is retracted, so that the engaging portion 47b of the lock member 47 is locked by the elastic force of the leaf spring 50 to the lock gear 45. The first actuator rod 42A, which is fitted between the gear teeth and the opening 46a of the gear housing 46, and to which the lock gear 45 is fixed, is non-rotatably restrained. When the vehicle collides head-on in this state and a collision load is applied to the bumper beam 11 toward the rear of the vehicle body, the front mounting plate 28 and the rear mounting of the variable crushing strength device 13 disposed between the bumper beam 11 and the front side frame 12 are applied. The plate 14 is compressed in the front-rear direction.

  At this time, since the pair of first buckling plates 23A and 23A are arranged slightly inclined so that the front sides approach each other, the rear end side (first nut members 21A and 21A is caused by a collision load from the front. Side) will move away from each other. Then, since the pair of first nut members 21A and 21A connected to the rear ends of the pair of first buckling plates 23A and 23A also tends to be separated from each other, the female screws 21b and 21b made of the reverse screws are made of the reverse screws. The first actuator rod 42A screwed with the male screws 42a, 42a tries to rotate. As described above, since the rotation of the first actuator rod 42A is restricted by the lock mechanism 41, the pair of first nut members 21A. , 21A cannot move away from each other, and the crushing strength varying device 13 is in a high load mode capable of absorbing a large load.

  In the high load mode, the pair of first nut members 21A, 21A cannot move away from each other, and therefore, the crush sandwiched between the front side frame 12 by the collision load input from the bumper beam 11 When the strength varying device 13 is compressed in the front-rear direction, as shown in FIG. 12, the pair of first buckling plates 23A, 23A is curved outward together with the reinforcing plates 34, 34 superimposed on the inner surfaces thereof. It can buckle and absorb collision energy.

  As described above, the collision energy absorption due to the buckling of the pair of first buckling plates 23A and 23A has been described. However, the pair of the first buckling plates 23A and 23A disposed in a direction whose phase is shifted by 90 °. The second buckling plates 23B and 23B can also buckle so as to be bent outward by the same action and absorb the collision energy. The second buckling plates 23B and 23B are larger than the collision energy absorbed by the first buckling plates 23A and 23A because the shape memory alloys 26 and 26 superimposed on the inner surfaces thereof are integrally buckled. The collision energy can be absorbed. Since the shape memory alloys 26 and 26 have a high degree of freedom in setting the relationship of load against deformation, the absorption characteristics of collision energy can be arbitrarily set. The shape memory alloys 26 and 26 are brittle and easily broken, but are fixed to the second buckling plates 23B and 23B with bolts 27 through the long holes 26a. It is possible to prevent cracking by sliding in the range of the long holes 26a with respect to 23B and sufficiently exhibit the effect of absorbing the collision energy.

  When the collision load is extremely large, in addition to the first and second buckling plates 23A, 23A; 23B, 23B, the first and second rear hinge plates 19A, 19A; By also buckling 19B, the energy absorption effect is further enhanced. Further, the rectangular frame-shaped actuator housing 16 is also buckled by a collision load, and can contribute to absorption of collision energy. Furthermore, the actuator housing 16 also exhibits the function of preventing the first and second rear hinge plates 19A, 19A; 19B, 19B from falling over.

  In the high load mode described above, a relatively large tensile load and a relatively small rotational torque act on the first and second actuator rods 42A and 42B due to the collision load. Since the internal stress of the actuator rods 42A and 42B is canceled out, the first and second buckling plates 23A and 23A; 23B and 23B can be used if the lock mechanism 41 has sufficient strength to withstand a relatively small rotational torque. The buckling can be suppressed and buckled reliably. As a result, it is possible to reduce the cost by reducing the size and weight of the lock mechanism 41, and to enable placement in a narrow space. In addition, since the lock mechanism 41 that transmits only a relatively small rotational torque at the time of a collision is not easily damaged, if the deformation is within an allowable range even after the collision, the repeated function / performance can be satisfied, and the cost can be reduced. .

  On the other hand, when a collision that needs to reduce the impact is predicted from the external situation detected by the radar device or the TV camera mounted on the vehicle and the vehicle speed detected by the vehicle speed sensor, the solenoid 49 of the lock mechanism 41 is excited. Then, the output rod 49a moves forward and presses the other end of the lock member 47 via the coil spring 48, so that the lock member 47 swings around the fulcrum protrusions 47a and 47a and the gear teeth of the lock gear 45 Since the engaging portion 47b is disengaged from the gear housing 46, the first actuator rod 42A is released from the restraint and can freely rotate.

  As a result, as shown in FIG. 13, the first nut members 21A, 21A provided on the rear end side of the pair of first buckling plates 23A, 23A try to move away from each other by a collision load from the front. Then, since the first actuator rod 42A in which the male screws 42a and 42a made of the reverse screw are screwed to the female screws 21b and 21b made of the reverse screw is released, the first nut rod 21A, 21A is separated from both ends of the first actuator rod 42A. Then, the first rear hinge plates 19A and 19A, whose lower ends are pivotally supported by the bearing portions 17a and 17a by the hinge pins 18 and 18 and whose upper ends are pivotally supported by the hinge pins 22. Therefore, the first buckling plates 23A and 23A pivotally supported at the lower ends of the hinge pins 18 and 18 swing so as to fall outward without buckling. At this time, since the bent portion of the first buckling plates 23A and 23A bent at a substantially right angle is plastically deformed so as to be stretched, a slight energy absorption effect is exhibited. It becomes the low load mode that can absorb energy.

  As described above, the effect of absorbing the collision energy in the low load mode due to the pair of first buckling plates 23A and 23A falling down has been described. The direction in which the phase is shifted by 90 ° with respect to the pair of first buckling plates 23A and 23A. The pair of second buckling plates 23B and 23B arranged in the same manner can also fall to the outside by the same action and exhibit a collision energy absorbing effect in the low load mode. Even in the case of a collision in the high load mode, the first and second buckling plates 23A, 23A; 23B, 23B are plastically deformed so that the bent portions are stretched. Compared to the total amount of collision energy absorbed at the time of collision in the mode, the ratio is relatively small.

  In addition, the first and second rear hinge plates 19A, 19A; 19B, 19B fall to the outside at the time of collision in the low load mode, so that the first and second actuator rods 42A, 42B try to move rearward. Since 44 and 44 are manually fitted into the support holes 14A and 17b, the first and second actuator rods 42A and 42B can move rearward together with the actuator housings 44 and 44 without any trouble.

  Further, since the pair of first buckling plates 23A, 23A and the pair of second buckling plates 23B, 23B are arranged so as to form a quadrangular prism by shifting by 90 °, the collapsing strength varying device 13 is prevented from collapsing and colliding. Reliable absorption of energy can be made possible.

  FIG. 14 shows changes in the axial force of the first actuator rod 42A (or the second actuator rod 42B) with respect to the displacement (compression amount) in the front-rear direction of the crushing strength varying device 13 due to a collision load. The axial force increases as the displacement increases at the time (high load mode), whereas the axial force is maintained at zero regardless of the displacement when the lock mechanism 41 is unlocked (low load mode). You can see that

  FIG. 15 shows a change in the generated load of the crushing strength varying device 13 with respect to the displacement (compression amount) in the front-rear direction of the crushing strength varying device 13 due to a collision load, and the displacement is when the lock mechanism 41 is locked (high load mode). It can be seen that while the generated load increases with the increase in the load, when the lock mechanism 41 is unlocked (low load mode), the generated load is maintained at zero regardless of the increase in displacement. Even during unlocking, the first and second buckling plates 23A, 23A; 23B, 23B are plastically deformed so that the bent portions are stretched. A load is generated.

  FIG. 16 is a graph showing the effect of the beads 23c of the first and second buckling plates 23A, 23A; 23B, 23B, with respect to the displacement (compression amount) in the front-rear direction of the crushing strength varying device 13 due to a collision load. It is shown that the load having the beads 23c is larger than the load having no beads 23c. The reason is that if the first and second buckling plates 23A, 23A; 23B, 23B are simply bent, the bent portion 23d is easily extended and a load is not easily generated. By providing the bent portion 23d, it is considered that a load is likely to be generated because the bent portion 23d does not easily extend.

  The operation of the first and second buckling plates 23A, 23A; 23B, 23B having the beads 23c, will be described in more detail. As the first and second buckling plates 23A, 23A; 23B, 23B are bent. The parts on both sides of the beads 23c ... (parts where the beads 23c ... do not exist) are stretched and deformed, and then the parts of the beads 23c ... are compressed and buckled, whereby the first and second buckling plates 23A. , 23A; 23B, 23B can be generated with a larger load than when formed in a simple L shape.

  FIG. 17 is a graph showing the effect of the strength adjustment holes 23b formed in the flanges 23a of the first and second buckling plates 23A, 23A; 23B, 23B, before and after the crushing strength varying device 13 caused by a collision load. It is shown that the peak load with respect to the displacement (compression amount) in the direction is greatly reduced by providing the strength adjusting holes 23b.

  Therefore, by changing the shape, size, number, etc. of the beads 23c of the first and second buckling plates 23A, 23A; 23B, 23B, and the strength adjusting holes 23b, the energy at the time of the collision particularly in the low load mode. The absorption characteristics can be finely adjusted.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, the rotation of the first actuator rod 42A for connecting the pair of first nut members 21A, 21A is controlled by the lock mechanism 41, and the second for connecting the pair of second nut members 21B, 21B. Although the rotation of the actuator rod 42B is controlled by a separate lock mechanism 41, in the second embodiment, the two actuator rods 42A and 42B are interlocked with each other and controlled by only one lock mechanism 41. Is. That is, the worm 51 provided on the first actuator rod 42A connecting the first nut members 21A and 21A and the worm wheel 52 provided on the second actuator rod 42B connecting the second nut members 21B and 21B are mutually connected. The locking mechanism 41 is provided only on the first actuator rod 42A.

  Therefore, if the lock mechanism 41 restricts the rotation of the first actuator rod 42A in the high load mode, the rotation of the second actuator rod 42B interlocked via the worm 51 and the worm wheel 52 is also restricted, and the first and second The buckling plates 23A, 23A; 23B, 23B are both buckled and exhibit a large energy shock absorption effect.

  On the other hand, if the rotation of the first actuator rod 42A is allowed by the lock mechanism 41 in the low load mode, the first and second actuator rods 42A and 42B are both rotatable, and the pair of first nut members 21A and 21A. Since all the second nut members 21B and 21B are unconstrained, the first and second buckling plates 23A and 23A; 23B and 23B can be tilted without buckling, thereby reducing the crushing strength with a low load. 13 can be crushed.

  According to the second embodiment, it is possible to reduce the number of parts by reducing the number of lock mechanisms 41 to one.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the embodiment has described the crushing strength varying device 13 for the bumper beam 11 of the front bumper, but the present invention can also be applied to the crushing strength varying device 13 for the bumper beam of the rear bumper.

  In the embodiment, two pairs of the first buckling plates 23A and 23A and the second buckling plates 23B and 23B are provided, but only one pair may be provided.

  In the embodiment, the lock mechanism 41 is operated by the solenoid 49. However, the lock mechanism 41 can be operated by an inflator that generates high-pressure gas used in an airbag device or the like.

The top view of the vehicle body front part of the vehicle which concerns on 1st Embodiment 2 enlarged view of FIG. Perspective view of variable crushing strength device Exploded perspective view of variable crushing strength device Sectional view along line 5-5 in FIG. 6-6 sectional view of FIG. Sectional view along line 7-7 in FIG. 8-8 sectional view of FIG. Sectional view taken along line 9-9 in FIG. Sectional view taken along line 10-10 in FIG. Perspective view of locking mechanism Action diagram of high load mode Action diagram of low load mode Graph showing the axial force of the actuator shaft when locked and unlocked Graph showing the load generated by the variable crushing strength device when locked and unlocked Graph showing the effect of buckling plate beads Graph showing the effect of the strength adjustment hole of the buckling plate The figure corresponding to the said FIG. 6 based on 2nd Embodiment.

11 Bumper beam 12 Front side frame (body frame)
13 Crushing strength variable device 16 Actuator storage box (Shock absorber)
21A First nut member (support member)
21B Second nut member (support member)
21b female screw 23A first buckling plate (buckling plate)
23B Second buckling plate (buckling plate)
23b Strength adjustment hole 23c Bead 23d Bending part 26 Shape memory alloy (reinforcing member)
34 Reinforcement plate (reinforcement member)
41 Locking mechanism
42a male thread
42A first actuator rod (actuator rod)
42B second actuator rod (actuator rod)
49 Solenoid (actuator)

Claims (7)

Between the bumper beam (11) and the vehicle body frame (12), a crushing strength varying device (13) that receives a collision load in the longitudinal direction of the vehicle body to be crushed is disposed, and the crushing strength of the crushing strength varying device (13) is increased. In a vehicle body strength adjusting device that can be selectively switched between a load mode and a low load mode,
The crushing strength varying device (13)
At least a pair of buckling plates (23A, 23B) which are arranged so as to face each other and extend in the longitudinal direction of the vehicle body and can be buckled by a collision load acting between the bumper beam (11) and the vehicle body frame (12). When,
A support member (21A, 21B) that rotatably supports one end of the pair of buckling plates (23A, 23B) in the vehicle longitudinal direction;
Actuator rods (42A, 42B) having male screws (42a) screwed into the female screws (21b) formed on the support members (21A, 21B) at both ends;
Said supporting member (21A, 21B) each other and a state that allows the movement and state that restrains movement in the direction away an actuator switchable locking mechanism by (49) (41) to the,
In the high load mode, the lock mechanism (41) restrains the rotation of the actuator rods (42A, 42B) so that the support members (21A, 21B) are not separated from each other. , 23B) is restrained from falling outside ,
In the low load mode, the lock mechanism (41) allows the actuator rod (42A, 42B) to rotate, and the support member (21A, 21B) is separated from both ends of the actuator rod (42A, 42B). The vehicle body strength adjusting device for a vehicle, wherein the buckling plates (23A, 23B) are tilted outward . Wherein the one pair of first seat屈板and (23A) and a pair of second seat屈板(23B) are arranged substantially to form a rectangular prism body strength for a vehicle according to claim 1 Adjustment device. Before Symbol seat屈板(23A, 23B) said support members (21A, 21B) and the opposite end is bent through the bending portion (23d), the low-load mode the bent portion (23d) The vehicle body strength adjusting device for a vehicle according to claim 1 , wherein the vehicle body is plastically deformed. It said seat屈板(23A, 23B) leading to the front Symbol bent portion (23d), characterized in that the bead (23c) is formed, adjusting the rigidity of vehicle body apparatus for a vehicle according to claim 3. Characterized in that the seat屈板(23A, 23B) in the vicinity of the front Symbol bent portion (23d) to the intensity adjustment hole (23b) is formed, the rigidity of vehicle body of a vehicle according to claim 3 or claim 4 Adjustment device. Wherein the pre-Symbol seat屈板(23A, 23B) in the reinforcing member (26, 34) are superposed, adjusting the rigidity of vehicle body apparatus for a vehicle according to any one of claims 1 to 5. Characterized in that it comprises box-shaped impact absorbing portion (16) at a position surrounded by the front Symbol pair of seat屈板(23A, 23B), according to any one of claims 1 to 6 Vehicle body strength adjustment device.

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