JP2009067066A - Shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shock absorbing device capable of coping with a wide range of collision situations. <P>SOLUTION: In an internal space of a crash box 20, a gas generator 30 is stored. The gas generator 30 generates high pressure gas by burning powder and supplies the generated high pressure gas to the internal space of the crash box 20. When the shock in a collision is large to a certain extent, the powder is burned at the gas generator 30 and the internal space of the crash box 20 is pressurized to enhance strength of the crash box 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an impact absorbing device that is attached to a vehicle body and absorbs energy transmitted to the vehicle body at the time of a vehicle collision.

Conventionally, a vehicle such as an automobile has been provided with an impact absorbing member such as a crash box in order to suppress damage to the vehicle body at the time of a collision. For example, as disclosed in Patent Document 1, this type of shock absorbing member is a metal member formed in a box shape or a cylindrical shape, and is installed between a vehicle body body and a bumper of a vehicle. . When the vehicle collides, the shock absorbing member undergoes plastic deformation under the load accompanying the collision, and absorbs the energy of the collision by plastic deformation. As a result, the impact force acting on the vehicle body at the time of a vehicle collision is alleviated, and damage to the vehicle body is avoided or alleviated.
JP 2007-030725 A

  As described above, the impact absorbing member absorbs collision energy by plastic deformation. On the other hand, the strength of the shock absorbing member is determined by the material and shape of the shock absorbing member and cannot be adjusted after the shock absorbing member is installed in the vehicle. For this reason, if the strength is set high in order to increase the energy that can be absorbed by the shock absorbing member, the amount of deformation of the shock absorbing member is small when the vehicle speed at the time of the collision is low, and the impact of the collision cannot be sufficiently absorbed. If the strength of the impact absorbing member is set low, the impact absorbing member is completely deformed before the energy of the collision is sufficiently absorbed when the vehicle speed at the time of the collision is high. As described above, the conventional shock absorbing member has a problem that the strength cannot be adjusted after the shock absorbing member is installed in the vehicle, so that it cannot cope with a wide range of collision situations.

  This invention is made | formed in view of this point, The objective is to provide the impact-absorbing device which can respond to a wide collision condition.

  A first invention includes an impact absorbing member (20) provided in a vehicle (10), and an impact that relaxes energy transmitted to the vehicle body by plastic deformation of the impact absorbing member (20) when the vehicle (10) collides. Targeting absorbers. The impact absorbing member (20) is formed in a hollow container shape, and adjusts the pressure in the internal space of the impact absorbing member (20) according to the magnitude of impact received by the vehicle (10) at the time of collision. Pressure adjusting means is provided.

  In the first invention, the impact absorbing member (20) is formed in a hollow container shape. The internal pressure of the impact absorbing member (20) (that is, the pressure in its internal space) is adjusted by the pressure adjusting means according to the magnitude of the impact received by the vehicle (10) at the time of collision. The shock absorbing member (20) is configured so that a gas such as air can be enclosed in the internal space thereof. When the same amount of energy acts on the shock absorbing member (20) due to the collision of the vehicle (10), the amount of deformation of the shock absorbing member (20) decreases as the internal pressure increases, and increases as the internal pressure decreases. . That is, the strength of the shock absorbing member (20) increases as the internal pressure increases, and decreases as the internal pressure decreases. Therefore, the pressure adjusting means adjusts the magnitude of the impact caused by the collision of the vehicle (10) so that the strength of the impact absorbing member (20) becomes a value commensurate with the magnitude of the impact caused by the collision of the vehicle (10). Accordingly, the internal pressure of the shock absorbing member (20) is adjusted.

  In a second aspect based on the first aspect, the pressure adjusting means is configured to be capable of executing a pressurizing operation for increasing the pressure in the internal space of the shock absorbing member (20) when the vehicle (10) collides. Is.

  In the second invention, the pressure adjusting means is configured to be capable of performing a pressurizing operation. When the pressure adjusting means performs a pressurizing operation at the time of the collision of the vehicle (10), the internal pressure of the shock absorbing member (20) increases, and the strength of the shock absorbing member (20) increases.

  In a third aspect based on the second aspect, the pressure adjusting means includes a sensor (41) for measuring a physical quantity representing the magnitude of impact received by the vehicle (10) at the time of a collision, and the sensor (41) The pressurizing operation is performed when the measured physical quantity value exceeds a predetermined reference value.

  In the third invention, the pressure adjusting means includes a sensor (41) that measures a physical quantity (for example, acceleration) indicating the magnitude of the impact of the collision, and when the measured physical quantity is equal to or greater than a reference value, the shock absorbing member ( 20) Increase the internal pressure. That is, when the impact energy cannot be absorbed by the shock absorbing member (20) without increasing the internal pressure of the shock absorbing member (20), the internal pressure of the shock absorbing member (20) is increased to increase the shock absorbing member (20 ) To increase the amount of energy that can be absorbed by the impact absorbing member (20).

  According to a fourth invention, in the second or third invention, the pressure adjusting means supplies gas to the internal space of the shock absorbing member (20) to thereby reduce the internal space of the shock absorbing member (20). The operation for increasing the pressure is configured as a pressurizing operation.

  In the fourth invention, the pressure adjusting means during the pressurizing operation supplies gas to the internal space of the shock absorbing member (20) in order to increase the internal pressure of the shock absorbing member (20).

  In a fifth aspect based on the second or third aspect, the pressure adjusting means includes a gas generating section (30, 31, 32) for generating a high-pressure gas by reacting a gas generating agent. The operation of increasing the pressure in the internal space of the impact absorbing member (20) using the high-pressure gas generated in the sections (30, 31, 32) is performed as the pressurizing operation.

  In 5th invention, a gas generation part (30,31,32) is provided in a pressure control means. The gas generator (30, 31, 32) generates a high-pressure gas by reacting the gas generating agent. The pressure adjusting means during the pressurizing operation increases the internal pressure of the shock absorbing member (20) using the high-pressure gas generated in the gas generating section (30, 31, 32).

  In a sixth aspect based on the second or third aspect, the pressure adjusting means determines the amount of pressure increase in the internal space of the shock absorbing member (20) due to the pressurizing operation when the vehicle (10) It is comprised so that adjustment is possible according to the magnitude | size of the impact which a receives.

  In the sixth aspect of the invention, the increase in the internal pressure of the impact absorbing member (20) due to the pressurizing operation of the pressure adjusting means is adjusted according to the magnitude of the impact received by the vehicle (10) during the collision.

  In a seventh aspect based on the first aspect, the pressure adjusting means communicates the internal space of the shock absorbing member (20) with the outside of the shock absorbing member (20) when the vehicle (10) collides. The operation is configured to be executable.

  In the seventh invention, the pressure adjusting means is configured to be able to execute the communication operation. When the pressure adjusting means performs the communication operation at the time of the collision of the vehicle (10), gas flows out of the internal space along with the deformation of the impact absorbing member (20), and the impact absorbing member (20) is easily deformed. That is, when the pressure adjusting means performs the communication operation, the strength of the shock absorbing member (20) is reduced.

  In an eighth aspect based on the seventh aspect, the pressure adjusting means includes a sensor (41) for measuring a physical quantity representing a magnitude of impact received by the vehicle (10) at the time of a collision, and the sensor (41) The communication operation is performed when the measured physical quantity value is not less than a predetermined lower limit value and not more than a predetermined upper limit value.

  In the eighth invention, the pressure adjusting means includes a sensor (41) that measures a physical quantity (for example, acceleration or the like) indicating the magnitude of impact of the collision. When the measured physical quantity falls within a predetermined range, the pressure adjusting means causes the internal space of the shock absorbing member (20) to communicate with the outside. In other words, if the shock absorbing member (20) is not sufficiently deformed while the gas is sealed in the internal space of the shock absorbing member (20), the shock absorbing member (20) is connected to the outside to absorb the shock. By reducing the strength of the member (20), the load transmitted from the shock absorbing member (20) to the vehicle body is reduced.

  According to a ninth invention, in the seventh invention, the shock absorbing member (20) has a pressure in its internal space set in advance to a value higher than the atmospheric pressure, and the pressure adjusting means performs the communication operation. By doing so, the pressure in the internal space is reduced.

  In the ninth invention, the internal pressure of the shock absorbing member (20) is set in advance to a value higher than the atmospheric pressure. When the pressure adjusting means performs the communication operation, the internal pressure of the shock absorbing member (20) is reduced to atmospheric pressure, and the strength of the shock absorbing member (20) is reduced.

  In the shock absorbing device of the present invention, the pressure of the shock absorbing member (20) is adjusted by the pressure adjusting means, so that the strength of the shock absorbing member (20) is adjusted according to the magnitude of the shock at the time of the vehicle (10) collision. Can be adjusted. Therefore, according to the present invention, the strength of the impact absorbing member (20) can be changed after the impact absorbing member (20) is attached to the vehicle body, and the impact is absorbed according to the magnitude of the impact at the time of actual collision. By adjusting the strength of the member (20), it is possible to deal with a wide range of collision situations.

  In the second and third inventions, the pressure adjusting means can execute the pressurizing operation. And in 3rd invention, when the magnitude | size of the impact which a vehicle (10) receives at the time of a collision becomes a certain level or more, a pressure adjustment means will perform a pressurization operation, and will raise the intensity | strength of an impact-absorbing member (20). Therefore, in these inventions, the strength of the shock absorbing member (20) can be adjusted depending on whether or not the pressure adjusting means performs a pressurizing operation.

  In the said 5th invention, the high pressure gas used in order to raise the internal pressure of an impact-absorbing member (20) is generated by making a gas generating agent react. For this reason, for example, compared with the case where the tank etc. for storing the high pressure gas for raising the internal pressure of an impact-absorbing member (20) are provided, size reduction of an impact-absorbing device can be achieved.

  In the sixth aspect of the invention, the increase range of the internal pressure of the shock absorbing member (20) at the time of the collision of the vehicle (10) is adjusted. For this reason, the intensity | strength of an impact-absorbing member (20) can be adjusted in a wider range, and the width | variety of the collision condition which an impact-absorbing apparatus can respond can be expanded.

  In the seventh and eighth inventions, the pressure adjusting means can execute the communication operation. And in 8th invention, when the magnitude | size of the impact which a vehicle (10) receives at the time of a collision becomes in a predetermined range, a pressure adjustment means will perform a communication operation and will reduce the intensity | strength of an impact-absorbing member (20). Therefore, in these inventions, the strength of the shock absorbing member (20) can be adjusted depending on whether or not the pressure adjusting means performs the communication operation.

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

Embodiment 1 of the Invention
A first embodiment of the present invention will be described. In this embodiment, a crash box (20) and a control unit (40), which will be described later, constitute an impact absorbing device, and the control unit (40) constitutes a pressure adjusting means together with a gas generator (30), which will be described later. .

  As shown in FIG. 1, a front member (12) extending toward the front end of the vehicle body (11) is provided on the vehicle body (11) of an automobile (10) that is a vehicle. As shown in FIG. 2, one front member (12) is provided on each of the right and left sides of the automobile (10). Although not shown, an engine is arranged between the left and right front members (12).

  A crash box (20) is attached to the front end face of each front member (12). The crash box (20) is a metal member formed in a hollow container shape, and constitutes an impact absorbing member that is plastically deformed at the time of collision and absorbs the energy of the collision. The crash box (20) has a substantially enclosed space inside. A bumper frame (13) extending in the width direction of the automobile (10) is attached to the front end of each crash box (20). A bumper (14) is attached to the front surface of the bumper frame (13).

  As shown in FIG. 3A, a gas generator (30), which is a gas generator, is accommodated in the internal space of the crash box (20). Although not shown, the gas generator (30) is filled with explosives which are gas generating agents. The gas generator (30) is configured to generate a high-temperature and high-pressure gas by burning the charged explosive and supply the generated gas to the internal space of the crash box (20).

  The automobile (10) is provided with a control unit (40) (see FIG. 2). The control unit (40) includes an acceleration sensor (41) that measures the acceleration of the automobile (10). The acceleration of the automobile (10) measured by the acceleration sensor (41) is a physical quantity representing the magnitude of impact received by the automobile (10) at the time of a collision. Moreover, the gas generator (30) of each crash box (20) is electrically connected to the control unit (40).

When the automobile (10) collides, the automobile (10) decelerates more rapidly than when braking is performed during normal driving. Further, it can be determined that the greater the deceleration rate (ie, negative acceleration) of the automobile (10), the greater the impact associated with the collision. Therefore, the control unit (40), when the measured value G deceleration rate obtained by the acceleration sensor (41) becomes ₁ or more predetermined reference value G, a relatively large impact associated to it an automobile (10) collides And an ignition signal is output to the gas generator (30). The control unit (40) performs an operation of outputting an ignition signal to the gas generator (30) as a pressurizing operation.

  When explosives explode in the gas generator (30), the internal pressure of the crash box (20) rises significantly and momentarily. The gas pressure in the crash box (20) acts to push the crash box (20) outward. That is, the gas pressure in the crash box (20) also acts in the direction to cancel the load acting on the crash box (20) due to the collision. Therefore, if the load acting on the crash box (20) has the same magnitude and direction, the higher the internal pressure of the crash box (20), the smaller the deformation of the crash box (20). The energy of the impact that can be absorbed is increased.

  The operation of the shock absorber when the automobile (10) collides will be described.

  When the automobile (10) collides, the load generated along with it is transmitted to each crash box (20) via the bumper frame (13). When a load is applied to the front end of the crash box (20), the crash box (20) is plastically deformed so as to be crushed from the front. The crash box (20) absorbs collision energy by plastic deformation and reduces the load transmitted to the front member (12).

  When the car (10) collides, the control unit (40) determines whether to explode the explosives in the gas generator (30).

When the measured value G of the deceleration rate obtained by the acceleration sensor (41) is greater than or equal to a predetermined reference value G ₁ (G ₁ ≦ G), the control unit (40) causes the automobile (10) to collide with it. It is determined that the impact is relatively large, and an ignition signal is output to the gas generator (30). The gas generator (30) receives a signal from the control unit (40), explodes the explosive, and supplies the high-temperature and high-pressure gas generated thereby to the interior space of the crash box (20) (FIG. 3C). See). As a result, the internal pressure of the crash box (20) increases instantaneously, and the strength of the crash box (20) increases.

  Thus, when the automobile (10) collides and the impact associated therewith is relatively large (for example, when the vehicle speed at the time of the collision is high), the strength of the crash box (20) increases, and the crash box (20) Increases the amount of energy that can be absorbed. As a result, the crash box (20) absorbs relatively large collision energy by plastic deformation, and the load transmitted to the front member (12) is reliably reduced.

On the other hand, when the measured value G deceleration rate obtained by the acceleration sensor (41) is less than the predetermined reference value G ₁ (G <G _1), the control unit (40) is an automobile (10) has collided Even if there is a collision, it is determined that the impact caused by the collision is relatively small, and no ignition signal is output to the gas generator (30) (see FIG. 3B). For this reason, the strength of the crash box (20) does not change, and the deformation amount of the crash box (20) is ensured even if the collision energy is relatively small. Therefore, the crash box (20) is greatly plastically deformed even if the collision energy is not so large, and the load transmitted to the front member (12) is reliably reduced.

  In the crash box (20) of the present embodiment, the internal space does not need to be completely airtight. As described above, since the gas generator (30) generates gas by causing explosives to explode, a large amount of high-pressure gas can be instantaneously generated. For this reason, even if there is a hole in the crash box (20) that communicates the inside and outside of the crash box (20), if the hole is sufficiently small, the internal pressure of the crash box (20) can be increased sufficiently. It is possible to keep the internal pressure of the crash box (20) high as long as it is a short time until (10) collides and stops. Therefore, it is sufficient for the crash box (20) to have an airtightness enough to keep the internal pressure of the crash box (20) high from the start to the end of the collision. The inside and outside need not be completely shut off.

-Effect of Embodiment 1-
In the impact absorbing device of the present embodiment, the control unit (40) adjusts the internal pressure of the crash box (20) to adjust the strength of the crash box (20) according to the magnitude of the impact at the time of vehicle collision. be able to. Specifically, in this shock absorbing device, the strength of the crash box (20) can be changed in two stages, that is, when the explosive of the gas generator (30) is exploded and when it is not exploded. Therefore, according to the present embodiment, the strength of the crash box (20) can be changed after the crash box (20) is attached to the automobile (10), and according to the magnitude of impact at the time of actual collision. By adjusting the strength of the crash box (20), it is possible to deal with a wide range of collision situations.

  Further, in the impact absorbing device of the present embodiment, when the magnitude of impact received by the automobile (10) during a collision exceeds a certain level, the control unit (40) performs a pressurizing operation to increase the strength of the crash box (20). . Therefore, according to this embodiment, the strength of the crash box (20) can be adjusted depending on whether or not the control unit (40) performs the pressurizing operation.

  In the impact absorbing device of the present embodiment, the high-pressure gas used to increase the internal pressure of the crash box (20) is generated by exploding explosives. For this reason, the strength of the crash box (20) can be increased by instantaneously increasing the internal pressure of the crash box (20).

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. The impact absorbing device of the present embodiment is obtained by changing the configurations of the crash box (20) and the control unit (40) in the impact absorbing device of the first embodiment. Here, the difference between the crash box (20) and the control unit (40) of the present embodiment from that of the first embodiment will be described.

  As shown in FIG. 4A, the crush box (20) of the present embodiment is provided with a sealing valve (35) instead of the gas generator (30). In this embodiment, this sealing valve (35) constitutes a pressure adjusting means together with the control unit (40).

  The sealing valve (35) includes a main body member (36) and a sealing member (38). The main body member (36) is provided so as to penetrate the side wall portion of the crash box (20). Further, a through hole (37) is formed in the main body member (36). One end of the through hole (37) opens into the internal space of the crash box (20), and the other end opens into the external space of the crash box (20). The sealing member (38) is a small piece formed in a columnar shape, and is fitted in the through hole (37). The through hole (37) of the main body member (36) is closed by the sealing member (38).

  Although not shown, explosives are embedded in the sealing valve (35). And this sealing valve (35) is comprised so that the sealing member (38) can be instantaneously extracted from a through-hole (37) using the explosive force of an explosive. The sealing valve (35) of each crash box (20) is electrically connected to the control unit (40).

The control unit (40) of the present embodiment includes an acceleration sensor (41) as in the first embodiment. As described above, when the automobile (10) collides, the automobile (10) decelerates more rapidly than when braking is performed during normal driving. Further, it can be determined that the greater the deceleration rate (ie, negative acceleration) of the automobile (10), the greater the impact associated with the collision. Therefore, the control unit (40), when the measured value G deceleration rate obtained by the acceleration sensor (41) becomes a predetermined upper limit value G ₃ below a predetermined lower limit value G ₂ or more (G ₂ ≦ G ≦ G ₃ ), The automobile (10) has collided but the impact associated therewith is judged not to be so great, and an ignition signal is output to the sealing valve (35). The control unit (40) performs an operation of outputting an ignition signal to the gas generator (30) as a communication operation.

  In the crash box (20) of the present embodiment, the internal space is a completely sealed space. In the crash box (20), the internal space is filled with a gas such as air, and the internal pressure is a value higher than the atmospheric pressure in advance. When the explosive explodes at the sealing valve (35) and the sealing member (38) comes out of the through hole (37) of the main body member (36), the gas enclosed in the internal space of the crash box (20) Flows out through the through hole (37), and the internal pressure of the crash box (20) decreases.

  As described above, if the magnitude and direction of the load acting on the crash box (20) are the same, the higher the internal pressure of the crash box (20), the smaller the deformation amount of the crash box (20). ) The energy of collision that can be absorbed is increased. Therefore, when the internal pressure of the crash box (20) is lowered, the amount of deformation of the crash box (20) at the time of collision increases, and the crash box (20) is sufficiently deformed even if the energy of the collision is relatively small. .

  When the car (10) collides, the control unit (40) determines whether to explode the explosives in the gas generator (30).

When the measured value G of the deceleration rate obtained by the acceleration sensor (41) is not less than the lower limit G _{2 and not} more than the upper limit G ₃ (G ₂ ≦ G ≦ G ₃ ), the control unit (40) Is determined to have a relatively small impact, and an ignition signal is output to the sealing valve (35) (see FIG. 3B). In the sealing valve (35), the explosive explodes in response to a signal from the control unit (40), the sealing member (38) is removed from the through hole (37), and the through hole (37) is in a communication state. As a result, the internal pressure of the crash box (20) decreases instantaneously, and the strength of the crash box (20) decreases.

  Thus, when the automobile (10) has collided but the impact associated therewith is not so great (for example, when the vehicle speed at the time of the collision is not so high), the sealing valve (35) is generated by a signal from the control unit (40). ) Is removed from the through hole (37). Therefore, the crash box (20) is greatly plastically deformed even if the collision energy is not so large, and the load transmitted to the front member (12) is reliably reduced.

If the measured value G of the deceleration rate obtained by the acceleration sensor (41) exceeds the upper limit G ₃ (G ₃ <G), the control unit (40) will collide with the car (10) and the impact will be compared. The ignition signal is not output to the sealing valve (35). In this case, the through hole (37) of the sealing valve (35) remains blocked by the sealing member (38) (see FIG. 4C), and the internal pressure of the crash box (20) is kept high. Be drunk. That is, the strength of the crash box (20) does not decrease. As a result, the crash box (20) absorbs relatively large collision energy by plastic deformation, and the load transmitted to the front member (12) is reliably reduced even when the collision energy is relatively large. Is done.

-Effect of Embodiment 2-
According to the present embodiment, the same effect as in the first embodiment can be obtained. That is, according to this embodiment, the strength of the crash box (20) can be changed in two stages, and the strength of the crash box (20) can be adjusted according to the magnitude of the impact at the time of actual collision. It is possible to deal with a wide range of collision situations.

-Modification of Embodiment 2-
In the crash box (20) of the present embodiment, the internal pressure in the initial state (the state before the collision shown in FIG. 4A) may be approximately equal to the atmospheric pressure.

  When the automobile (10) collides and the crash box (20) is deformed, the internal volume of the crash box (20) decreases. For this reason, if the through hole (37) is kept closed without exploding the explosive of the sealing valve (35), its internal pressure increases with the deformation of the crash box (20), and the crash box (20) Will gradually become difficult to deform. On the other hand, if the explosive of the sealing valve (35) is exploded to bring the through hole (37) into communication, the internal pressure of the crash box (20) will hardly increase even if the crash box (20) is deformed. Deformation is not hindered. Accordingly, even in this case, the strength of the crash box (20) can be changed in two steps depending on whether or not an ignition signal is input from the control unit (40) to the sealing valve (35).

<< Embodiment 3 of the Invention >>
Embodiment 3 of the present invention will be described. The impact absorbing device of the present embodiment is obtained by changing the configurations of the crash box (20) and the control unit (40) in the impact absorbing device of the first embodiment. Here, the difference between the crash box (20) and the control unit (40) of the present embodiment from that of the first embodiment will be described.

  As shown in FIG. 5A, in the crash box (20) of the present embodiment, a sealing valve (35) is provided in addition to the gas generator (30). In this embodiment, this sealing valve (35) constitutes a pressure adjusting means together with the control unit (40) and the gas generator (30).

  The sealing valve (35) is configured in the same manner as in the second embodiment. That is, the sealing valve (35) is provided so that the main body member (36) penetrates the side wall portion of the crash box (20), and the through hole (37) of the main body member (36) is provided with the sealing member ( 38), and the sealing member (38) can be instantaneously extracted from the through hole (37) using the explosive force of the explosive.

  Further, the crash box (20) of the present embodiment has an internal space that is a sealed space, as in the second embodiment. Note that the internal pressure of the crash box (20) may be pre-pressurized to be higher than the atmospheric pressure, or may be approximately the same as the atmospheric pressure without being pressurized.

  The control unit (40) of the present embodiment includes an acceleration sensor (41) as in the first embodiment. The control unit (40) is electrically connected to each of the gas generator (30) and the sealing valve (35) provided in each crash box (20). The control unit (40) performs a pressurizing operation for outputting an ignition signal to the gas generator (30) and a communication operation for outputting an ignition signal to the sealing valve (35). Configured to be executable.

Specifically, the control unit (40) stores three reference values G ₄ , G ₅ , G ₆ for the deceleration rate (negative acceleration) of the automobile (10). Then, the control unit (40) selectively performs a predetermined operation based on these three reference values G ₄ , G ₅ , G ₆ and the actual deceleration value G obtained by the acceleration sensor (41). To do.

If the actual measurement value G of the deceleration rate obtained by the acceleration sensor (41) is the reference value G ₄ below following (G <G _4), the control unit (40) is an automobile (10) is determined not to collide The ignition signal is not output to the gas generator (30) and the sealing valve (35).

When the measured value G of the deceleration rate obtained by the acceleration sensor (41) is greater than or equal to the reference value G _{4 and} less than the reference value G ₅ (G ₄ ≦ G <G ₅ ), the control unit (40) Determines that the impact is low, and outputs an ignition signal only to the sealing valve (35). In the sealing valve (35) of each crash box (20), the explosive explodes in response to a signal from the control unit (40), and the sealing member (38) is instantaneously removed from the through hole (37) (FIG. 5). (See (B)). Therefore, when the crash box (20) is deformed, the internal pressure of the crash box (20) becomes approximately equal to the atmospheric pressure. As a result, even if the collision energy is not so high, the crash box (20) is greatly plastically deformed, and the load transmitted to the front member (12) is reliably reduced.

If the actual measurement value G of the deceleration rate obtained by the acceleration sensor (41) is less than the reference value G ₆ with a reference value G ₅ or more (G ₅ ≦ G <G _6), the control unit (40) is an automobile (10) It is judged that the impact level is medium and the impact is medium, and no ignition signal is output to either the sealing valve (35) or the gas generator (30). In this case, the through hole (37) of the sealing valve (35) remains blocked by the sealing member (38) (see FIG. 5C), and the airtightness of the internal space of the crash box (20) Is preserved. For this reason, compared with the case where the sealing member (38) is extracted from the through hole (37) of the sealing valve (35), the strength of the crash box (20) is increased. Therefore, the energy accompanying the moderate collision is reliably absorbed by the crash box (20), and the load transmitted to the front member (12) is reliably reduced.

If the actual measurement value G of the deceleration rate obtained by the acceleration sensor (41) is equal to or larger than the reference value G ₆ (G ₆ ≦ G), the control unit (40), the degree of impact vehicle (10) collide is large The ignition signal is output only to the gas generator (30). The high-pressure gas generated by the explosive explosion of the gas generator (30) is supplied to the internal space of the crash box (20) (see FIG. 5D). For this reason, the internal pressure of the crash box (20) is instantaneously increased, and the strength of the crash box (20) is further increased compared to the case where neither the gas generator (30) nor the sealing valve (35) is operated. . Therefore, the large energy accompanying the collision is reliably absorbed by the crash box (20), and the load transmitted to the front member (12) is reliably reduced.

  Thus, in the impact absorbing device of the present embodiment, the strength of the crash box (20) can be changed in three stages. Therefore, according to this embodiment, it is possible to deal with a wider range of collision situations.

<< Other Embodiments >>
About the said embodiment, it is good also as following structures.

-First modification-
In each of Embodiments 1 and 3, a plurality of gas generators (31, 32) may be installed in the crash box (20). Here, the case where this modification is applied to the impact absorbing device of the first embodiment will be described.

  As shown in FIG. 6 (A), the first gas generator (31) and the second gas generator (32) are accommodated in the internal space of the crash box (20) of this modification. Each gas generator (31, 32) is configured in the same manner as in the first embodiment, and generates high-pressure gas by exploding explosives. The gas generation amount in each gas generator (31, 32) is set to the same value.

  The control unit (40) of the present embodiment includes an acceleration sensor (41) as in the first embodiment. The control unit (40) is electrically connected to each of the gas generators (31, 32) provided in two in each crash box (20). The control unit (40) outputs an ignition signal to only the first gas generator (31) and outputs an ignition signal to both gas generators (31, 32). And an operation to be executed.

Specifically, the control unit (40) stores two reference values G ₇ and G ₈ for the deceleration rate (negative acceleration) of the automobile (10). Then, the control unit (40) selectively performs a predetermined operation based on these two reference values G ₇ and G ₈ and the actual deceleration value G obtained by the acceleration sensor (41).

If the actual measurement value G of the deceleration rate obtained by the acceleration sensor (41) is less than the reference value G ₇ or more (G <G _7), the control unit (40) is an automobile (10) or does not collide, automobiles In (10), the collision is judged to be relatively small, but the ignition signal is not output to the first and second gas generators (31, 32). In this case, the internal pressure of the crash box (20) does not increase due to the explosion of the explosive, and the strength of the crash box (20) does not increase (see FIG. 6 (B)). As a result, even if the collision energy is not so high, the crash box (20) is greatly plastically deformed, and the load transmitted to the front member (12) is reliably reduced.

If less than the reference value G ₈ in actual value G of the reduction ratio obtained by the acceleration sensor (41) is the reference value G ₇ or more (G ₇ ≦ G <G _8), the control unit (40) is an automobile (10) And the impact is judged to be moderate, and an ignition signal is output only to the first gas generator (31). High pressure gas generated by the explosive explosion of the first gas generator (31) is supplied to the internal space of the crash box (20) (see FIG. 6C). For this reason, the internal pressure of the crash box (20) increases instantaneously, and the strength of the crash box (20) becomes higher than when both the gas generators (31, 32) do not operate. Therefore, medium energy associated with the collision is reliably absorbed by the crash box (20), and the load transmitted to the front member (12) is reliably reduced.

If the actual measurement value G of the deceleration rate obtained by the acceleration sensor (41) is equal to or larger than the reference value G ₈ (G ₈ ≦ G), the control unit (40), the degree of impact vehicle (10) collide is large It judges and outputs the signal for ignition with respect to both a 1st gas generator (31) and a 2nd gas generator (32). The high pressure gas generated by the explosion of the explosives in the two gas generators (31, 32) is supplied to the internal space of the crash box (20) (see FIG. 6D). For this reason, the internal pressure of the crash box (20) is instantaneously increased, and the strength of the crash box (20) is further increased as compared with the case where only the first gas generator (31) is operated. Therefore, the large energy accompanying the collision is reliably absorbed by the crash box (20), and the load transmitted to the front member (12) is reliably reduced.

  In the crash box (20) of this modification, it is selected whether to operate only the first gas generator (31) or to operate both the first gas generator (31) and the second gas generator (32). As a result, the rising width of the internal pressure of the crash box (20) can be adjusted in two stages. Therefore, according to this modification, the strength of the crash box (20) can be adjusted in two stages according to the degree of collision, and the range of collision situations that can be handled by the shock absorbing device can be widened.

  In the crash box (20) of this modification, the gas generation amount of the first gas generator (31) and the gas generation amount of the second gas generator (32) may be set to different values. In this case, the increase in the internal pressure of the crash box (20) when only the first gas generator (31) is operated, and the crash box (20 when only the second gas generator (32) is operated. ) Is different from the increase in internal pressure. That is, in this case, the increase range of the internal pressure of the crash box (20) can be adjusted in three stages.

-Second modification-
In each of the above embodiments, the internal space of the crash box (20) is a substantial or complete sealed space, but the crash box (20) itself does not need to have an airtight structure. For example, the airtightness of the internal space of the crash box (20) may be ensured by accommodating a bag-like member having airtightness in the internal space of the crash box (20).

  For example, when this modification is applied to the crash box (20) of the first embodiment, the bag-like member housed in the crash box (20) is connected to the gas generator (30), and the gas generator (30 ) Is supplied into the bag-like member. As a result, the bag-like member swells and comes into close contact with the inner wall of the crash box (20), and the strength of the crash box (20) increases.

  When this modification is applied to the crash box (20) of the second embodiment, a bag-like member is accommodated in the interior space of the crash box (20) with high-pressure gas filled therein. The In this state, the bag-like member is in close contact with the inner wall of the crash box (20). One end of the through hole (37) of the sealing valve (35) is connected to the bag-like member. When the sealing valve (35) is activated and the sealing member (38) is removed from the through hole (37), the gas enclosed in the bag-like member flows out through the through hole (37) and crashes. The strength of the box (20) decreases.

-Third modification-
In the gas generation part (30, 31, 32) of each of the above embodiments, the high-pressure gas is generated by the combustion of the explosive using the explosive as a gas generating agent. What is necessary is just to be able to generate high-pressure gas instantaneously (for example, chemical reaction, evaporation, sublimation, etc.), and is not limited to explosives.

-Fourth modification-
The control unit (40) of each of the above embodiments includes an acceleration sensor and uses the measured value (that is, acceleration) as a “physical quantity indicating the magnitude of impact received by the vehicle body (11) during a collision”. A physical quantity other than acceleration may be used as “physical quantity indicating the magnitude of impact received by the vehicle body (11) at the time of collision”.

  For example, the control unit (40) includes a force sensor that measures the magnitude of the load acting on the vehicle body (11) in the event of a collision. It may be configured to be used as a “physical quantity indicating the magnitude of the impact received by the”. When this modification is applied to the first embodiment, the control unit (40) of the first embodiment determines that the automobile (10) has collided when the measured value of the force sensor exceeds a predetermined reference value, and the gas An ignition signal is output to the generator (30).

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for an impact absorbing device that is attached to a vehicle body and absorbs energy transmitted to the vehicle body at the time of a vehicle collision.

It is a schematic side view which abbreviate | omits and shows the front part of a motor vehicle. It is a schematic plan view which illustrates only the principal part of the front part of a motor vehicle. It is a schematic sectional drawing which shows the longitudinal cross-section of the crash box of Embodiment 1, (A) shows the state before a collision, (B) shows the state where a gas generator does not operate after a collision, (C) shows The gas generator is activated after the collision. It is a schematic sectional drawing which shows the longitudinal cross-section of the crash box of Embodiment 2, (A) shows the state before a collision, (B) shows the state which the sealing valve act | operated after the collision, (C) is The state where the sealing valve does not operate after the collision is shown. It is a schematic sectional drawing which shows the longitudinal cross-section of the crush box of Embodiment 3, Comprising: (A) shows the state before a collision, (B) shows the state which only the sealing valve act | operated after the collision, (C) Shows a state where both the sealing valve and the gas generator are not operated after the collision, and (D) shows a state where only the gas generator is operated. It is a schematic sectional drawing which shows the longitudinal cross-section of the crush box of the 1st modification of other embodiment, (A) shows the state before a collision, (B) shows the state which both gas generators do not operate | move. (C) shows the state where only the first gas generator is activated after the collision, and (D) shows the state where both gas generators are activated.

Explanation of symbols

10 Automobile (vehicle)
20 Crash box (shock absorbing member)
30 Gas generator (gas generator)
31 First gas generator (gas generator)
32 Second gas generator (gas generator)
41 Accelerometer

Claims (9)

An impact absorbing device comprising an impact absorbing member (20) provided in a vehicle (10), wherein the impact absorbing member (20) relaxes energy transmitted to the vehicle body by plastic deformation when the vehicle (10) collides,
While the impact absorbing member (20) is formed in a hollow container shape,
An impact absorbing device comprising pressure adjusting means for adjusting the pressure in the internal space of the impact absorbing member (20) according to the magnitude of impact received by the vehicle (10) during a collision. In claim 1,
The shock absorbing device is characterized in that the pressure adjusting means is configured to be capable of executing a pressurizing operation for increasing the pressure in the internal space of the shock absorbing member (20) when the vehicle (10) collides. In claim 2,
The pressure adjusting means includes a sensor (41) that measures a physical quantity representing the magnitude of impact received by the vehicle (10) at the time of a collision, and when the value of the physical quantity measured by the sensor (41) exceeds a predetermined reference value. An impact absorbing device configured to perform the pressurizing operation. In claim 2 or 3,
The pressure adjusting means is configured to perform an operation of increasing the pressure in the internal space of the shock absorbing member (20) as a pressurizing operation by supplying gas to the internal space of the shock absorbing member (20). A shock absorbing device characterized by comprising: In claim 2 or 3,
The pressure adjusting means includes a gas generating part (30, 31, 32) for generating a high pressure gas by reacting a gas generating agent, and using the high pressure gas generated in the gas generating part (30, 31, 32). An impact absorbing device, wherein the operation of increasing the pressure in the internal space of the impact absorbing member (20) is performed as the pressurizing operation. In claim 2 or 3,
The pressure adjusting means is configured to be able to adjust the amount of pressure increase in the internal space of the shock absorbing member (20) due to the pressurizing operation according to the magnitude of the impact received by the vehicle (10) during a collision. A shock absorber characterized by that. In claim 1,
The pressure adjusting means is configured to be capable of executing a communication operation for communicating the internal space of the shock absorbing member (20) with the outside of the shock absorbing member (20) when the vehicle (10) collides. Shock absorber. In claim 7,
The pressure adjusting means includes a sensor (41) that measures a physical quantity representing the magnitude of impact received by the vehicle (10) at the time of a collision, and the physical quantity value measured by the sensor (41) is greater than or equal to a predetermined lower limit value. An impact absorbing device configured to perform the communication operation when the value is equal to or less than an upper limit value of the above. In claim 7,
The shock absorbing member (20) is set so that the pressure in the internal space is set to a value higher than the atmospheric pressure in advance, and the pressure in the internal space decreases as the pressure adjusting means performs the communication operation. An impact absorbing device characterized by being configured.

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