OCCUPANT PROTECTION APPARATUS

An occupant protection apparatus to be applied to a vehicle includes a contact detector, a control processor, and a lifting mechanism. The contact detector detects frontal contact of the vehicle. The control processor includes a contact determination unit determining whether the frontal contact of the vehicle is underride contact based on a result of detecting by the contact detector. The lifting mechanism includes a lifting member and a lifting driver. The lifting member is disposed below a rear end part of a hood in a downward direction of the vehicle. The hood is disposed on a frontal part of the vehicle. The lifting driver transmits a driving force to the lifting member. When the contact determination unit determines that the frontal contact is the underride contact, the rear end part of the hood is lifted by the lifting mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Japanese Patent Application No. 2022-084886 filed on May 25, 2022, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The disclosure relates to an occupant protection apparatus.

Frontal contact of a vehicle includes underride contact. Upon underride contact, a vehicle slides underneath a contact body. For example, a collision determination device disclosed in Japanese Unexamined Patent Application Publication No. 2009-90816 determines whether frontal contact of a vehicle is underride contact. When determining that the frontal contact is underride contact, the collision determination device operates a passenger protection device such as a seatbelt device at an appropriate timing.

SUMMARY

An aspect of the disclosure provides an occupant protection apparatus to be applied to a vehicle. The occupant protection apparatus includes a contact detector, a control processor, and a lifting mechanism. The contact detector is configured to detect frontal contact of the vehicle. The control processor includes a contact determination unit configured to determine whether the frontal contact of the vehicle is underride contact based on a result of detecting by the contact detector. The lifting mechanism includes a lifting member and a lifting driver. The lifting member is disposed below a rear end part of a hood in a downward direction of the vehicle. The hood is disposed on a frontal part of the vehicle. The lifting driver is configured to transmit a driving force to the lifting member. When the contact determination unit determines that the frontal contact is the underride contact, the rear end part of the hood is lifted by the lifting mechanism.

An aspect of the disclosure provides an occupant protection apparatus to be applied to a vehicle. The occupant protection apparatus includes circuitry and a lifting mechanism. The circuitry is configured to detect frontal contact of the vehicle and determine whether the frontal contact of the vehicle is underride contact based on a result of detecting. The lifting mechanism includes a lifting member and a lifting driver. The lifting member is disposed below a rear end part of a hood in a downward direction of the vehicle. The hood is disposed on a frontal part of the vehicle. The lifting driver is configured to transmit a driving force to the lifting member. When the circuitry determines that the frontal contact is the underride contact, the rear end part of the hood is lifted by the lifting mechanism.

DETAILED DESCRIPTION

Upon underride contact, a vehicle slides underneath a contact body. A lap amount between the vehicle and the contact body is thus relatively small upon the underride contact. This can hinder contact energy generated upon the contact from being sufficiently absorbed, lowering performance to protect an occupant in the vehicle. It is therefore desired for a vehicle to have a structure that makes it possible to achieve superior performance to protect an occupant in the vehicle upon underride contact.

It is desirable to provide an occupant protection apparatus that makes it possible to achieve superior performance to protect an occupant in a vehicle upon underride contact.

An occupant protection apparatus10according to an example embodiment will now be described with reference to the accompanying drawings. Note that, in the drawings, an arrow UP indicates an upward direction of a vehicle (an automobile) V to which the occupant protection apparatus10is applied, an arrow FR indicates a frontward direction of the vehicle V, and an arrow RH indicates a righthand direction (one vehicle-width direction) of the vehicle V. Hereinafter, descriptions of directions are made based on the upward and downward directions (also referred to as a vertical direction), the frontward and rearward directions (also referred to as a longitudinal direction), and the right-hand and left-hand directions (also referred to as a vehicle-width direction) of the vehicle V unless otherwise stated.

As illustrated inFIGS.1to5, the occupant protection apparatus10may include a pair of right and left lifting mechanisms20, a pair of right and left anchor mechanisms40, and a pair of right and left sub-lifting actuators60. The lifting mechanisms20are configured to lift a rear end part of a hood80disposed on a frontal part of the vehicle V. The anchor mechanisms40may be configured to project from an underfloor90of the vehicle V in the downward direction and come into contact with the ground GR (i.e., to be lowered to a grounded position). The sub-lifting actuators60may be configured to lift a longitudinally intermediate part of the hood80. In the broad sense, the sub-lifting actuators60may serve as sub-lifting mechanisms. The occupant protection apparatus10further includes an electronic control unit (ECU)70. The ECU70may control operations of the lifting mechanisms20, the anchor mechanisms40, and the sub-lifting actuators60. In one embodiment, the ECU70may serve as a “control processor”. When the lifting mechanisms20and the sub-lifting actuators60are operated, the rear end part of the hood80may be lifted by the lifting mechanisms20and the sub-lifting actuators so that the head of an occupant P is hidden behind (covered with) the hood80as seen from in front of the vehicle V (seeFIG.5). In the following, the hood80is described in detail first, following which components of the occupant protection apparatus10are described in detail.

The hood80may have a substantially rectangular panel-like shape having a thickness in the vertical direction. The hood80may be disposed on the frontal part of the vehicle V so as to close an engine room91from above. The hood80may be provided with a pair of hood hinges82disposed below respective vehicle-width ends of the rear end part of the hood80. The hood hinges82may each include a hinge base82A and a hinge arm82B. The hinge base82A may have a substantially elongated plate-like shape having a thickness in the vertical direction and extending in the longitudinal direction. The hinge base82A may be disposed above a non-illustrated cowl constituting a framework of the vehicle V, and may be fastened and fixed to the cowl. The hinge arm82B may be disposed substantially in parallel to the hood80between the hinge base82A and the rear end part of the hood80, and may be fastened and fixed to the hood80. A rear end part of the hinge arm82B may be coupled to a rear end part of the hinge base82A so as to be rotatable about an axis extending in the vehicle-width direction. The rear end part of the hood80may be thereby coupled to the body of the vehicle V with the hood hinges82so as to be rotatable around an axis extending in the vehicle width direction. A striker84may be provided on a vehicle-width intermediate part of a frontal end part of the hood80. The striker84may project in the downward direction as illustrated inFIG.1, and a lower end of the striker84may be locked with a hood lock device86fixed to the body of the vehicle V. The hood80may be thereby kept at a closed position so as to close the engine room91.

The lifting mechanisms20may be disposed below the respective hood hinges82. The lifting mechanisms20may each include a lifter supporting member21, a lifter22, and a lifting driver24. In the broad sense, the lifter supporting member21may serve as a lifting supporting member. In one embodiment, the lifter may serve as a “lifting member”. The lifter supporting member21may have a pillar shape extending in a substantially vertical direction. The lifter supporting member21may be disposed inside a front pillar93of the vehicle V and fixed to the front pillar93. The lifter supporting member21may be curved into a substantially arc-shape that protrudes in the rearward direction in side view. For example, the lifter supporting member21may be curved into an arc-shape the center of which is located at a lower end of the striker84in side view.

The lifter22may have a substantially bottomed cylindrical shape that opens in the downward direction. Like the lifter supporting member21, the lifter22may be curved into a substantially arc-shape that protrudes in the rearward direction in side view. The lifter supporting member21may extend inside the lifter22. The lifter22may be coupled to the lifter supporting member21so as to be movable relative to the lifter supporting member21in the vertical direction (i.e., along a longitudinal length of the lifter supporting member21) and so as not to be movable relative to the lifter supporting member21in a circumferential direction of the lifter supporting member21. For example, when the lifting mechanism20is not operated, the lifter22may be located at an initial position as illustrated inFIGS.1and3. When the lifting mechanism20is operated, the lifter22may be located at a first lifted position as illustrated inFIG.4or a second lifted position as illustrated inFIG.5. Note that the first lifted position may be above the initial position, and the second lifted position may be above the first lifted position.

An upper end of the lifter22may be disposed below the hinge base82A and coupled to the hinge base82A with a ball joint23. The lifter22may thus be coupled to the rear end part of the hood80with the hood hinge82and the ball joint23. When the lifting mechanism20is operated, the fixed state of the hinge base82A to the body of the vehicle V may be released by a lifting force applied from the lifter22to the hinge base82A, so that the rear end part of the hood80is lifted together with the lifter22to a position corresponding to the first lifted position of the lifter22or a position corresponding to the second lifted position of the lifter22.

When the lifter22is lifted to the second lifted position, the rear end part of the hood80may be located at a vertical position where the rear end part of the hood overlaps with the head of the occupant P, as illustrated inFIG.5. Accordingly, when the lifter22is lifted to the second lifted position, the upper body of the occupant P may be hidden behind the hood80in front view. In the present example embodiment, when the lifter22is lifted to the second lifted position, the rear end part of the hood80may be lifted to a height substantially the same as that of an upper end of a windshield glass94of the vehicle V so that substantially the entire of the windshield glass94is hidden behind the hood80in front view. Note that, in the present example embodiment, the position of the head of the occupant P may be assumed to be the position of the head of a crash-test dummy seated in the driver's seat of the vehicle V. The crash-test dummy may be a human dummy representing a 50th percentile American male (AM50).

As to be described in detail later, when the lifter22is lifted to the first lifted position, the rear end part of the hood80may be located at a predetermined height to receive the head of a person (pedestrian) falling onto the hood80. That is, the height of the hood80at the position corresponding to the first lifted position of the lifter22may be determined to secure the performance to protect a person (pedestrian) falling onto the hood80.

As illustrated inFIG.3, the lifting driver24may include a lifting actuator and a driving power transmitter30. The lifting actuator25may include a pipe26having an elongated shape. The pipe26may be disposed in front of the lifter22and fixed to the body of the vehicle V. A micro-gas generator27(hereinafter referred to as a MGG27) may be provided at one end of the pipe26. In the broad sense, the MGG27may serve as a gas generator. When the MGG27is operated, gas generated by the MGG27may be supplied to inside the pipe26. The MGG27may be a two-stage gas generator configured to switch the level of a gas output between two levels, i.e., a low output level and a high output level. The MGG27may include two squibs, for example. When the MGG27is operated at the low output level, one of the squibs may be activated to burn an ignition agent. When the MGG27is operated at the high output level, the two squibs are both activated to burn the ignition agent. The MGG27may be electrically coupled to the ECU70to be described later so that an operation of the MGG27is controlled by the ECU70.

A piston28having a columnar shape may be disposed inside the pipe26in a movable manner. The piston28may be disposed closer to the other end of the pipe26than the MGG27is. Further, a plurality of balls29may be disposed inside the pipe26in a movable manner. The balls29may be disposed closer to the other end of the pipe26than the piston28is. Accordingly, when the gas generated by the MGG27is supplied to inside the pipe26, the piston28may be moved toward the other end of the pipe26by a gas pressure inside the pipe26, and may push the balls29. The balls29and the piston28may be thereby moved toward the other end of the pipe26.

The driving power transmitter30may be disposed between an upper end part of the lifter22and the pipe26. The driving power transmitter30may include a pinion31, a transmission gear32, and a rack33that is provided on the lifter22. The pinion31may be a two-stage gear that includes a first pinion gear31A and a second pinion gear31B. A part of the first pinion gear31A may be disposed inside the pipe26such that the first pinion gear31A engages with the balls29. The second pinion gear31B and the transmission gear32may be in mesh, and the transmission gear32may have a larger diameter than the second pinion gear31B. The rack33may extend on an outer circumference of the lifter22along a longitudinal length of the lifter22, and the transmission gear32and the rack33may be in mesh. Accordingly, when the MGG27is operated to move the balls29toward the other end of the pipe26, the pinion31and the transmission gear32may be rotated to raise the lifter22from the initial position. For example, the lifter22may be raised to the first lifted position when the MGG27is operated at the low output level, and to the second lifted position when the MGG27is operated at the high output level. Note that the pinion31and the transmission gear32may be rotatably supported by a non-illustrated gear holder fixed to the body of the vehicle V.

The lifting driver24may further include a lock mechanism34. The lock mechanism34may hold the lifter22raised to the first lifted position or the second lifted position. The lock mechanism34may include a lock member35that is rotatably coupled to a lower circumferential end of the lifter22. The lock member may be configured to engage with any of lock grooves36provided on the lifter supporting member21. When the lock member35engages with any of the lock grooves36, the lifter22is prevented from moving in the downward direction. The lock grooves36may be provided at respective positions corresponding to the initial position, the first lifted position, and the second lifted position of the lifter22. When the lifter22is raised to the first lifted position or the second lifted position, the lock member35may engage with the corresponding lock groove36. The lock member35may be urged by a non-illustrated urging member in a direction in which the lock member35is to engage with the lock groove36. While the lifter22is being raised, the lock member35may be caused to slide on the outer circumference of the lifter supporting member21by an urging force of the urging member.

As illustrated inFIGS.1and3, the anchor mechanisms40may be disposed below the respective lifting mechanisms20. The anchor mechanisms40may each include an anchor supporting member41, an anchor member42, and an anchor driver44. The anchor supporting member41may have a pillar shape extending in the vertical direction. The anchor supporting member41may be disposed inside the front pillar93of the vehicle V and fixed to the front pillar93. An upper end of the anchor supporting member41may be coupled to a lower end of the lifter supporting member21of the lifting mechanism20. That is, in the present example embodiment, the anchor supporting member41and the lifter supporting member21may be integrated with each other into a single member. Alternatively, the anchor supporting member41and the lifter supporting member21may be members separate from each other.

The anchor member42may have a substantially bottomed cylindrical shape that opens in the upward direction. The anchor supporting member41may extend inside the anchor member42. The anchor member42may be coupled to the anchor supporting member41so as to be movable relative to the anchor supporting member41in the vertical direction (i.e., along a longitudinal length of the anchor supporting member41) and so as not to be movable relative to the anchor supporting member41in a circumferential direction of the anchor supporting member41. For example, when the anchor mechanism40is not operated, the anchor member42may be located at an initial position as illustrated inFIGS.1and3. When the anchor member42is located at the initial position, the anchor member42may not project from the underfloor90of the vehicle V in the downward direction. When the anchor mechanism40is operated, the anchor member42may be lowered from the initial position to the grounded position as illustrated inFIG.5. When the anchor mechanism40is lowered to the grounded position, a lower end of the anchor member42may come into contact with the ground GR, that is, the lower end of the anchor member42may be grounded. Accordingly, the anchor mechanism40may apply a reaction force in the upward direction from the ground GR to the vehicle V. Note that the anchor member42located at the initial position may be held by a non-illustrated holding member.

The anchor driver44may have a configuration similar to that of the lifting driver24of the lifting mechanism20. For example, the anchor driver44may include an anchor actuator45and a driving power transmitter50. The anchor actuator45may include a pipe46having an elongated shape. The pipe46may be disposed in front of the anchor member42and fixed to the body of the vehicle V. A micro-gas generator47(hereinafter referred to as a MGG47) may be provided at one end of the pipe46. In the broad sense, the MGG47may serve as a gas generator. When the MGG47is operated, gas generated by the MGG47may be supplied to inside the pipe46. Unlike the MGG27of the lifting mechanism20, the MGG47may be a one-stage gas generator. The MGG47may be electrically coupled to the ECU70to be described later so that an operation of the MGG47is controlled by the ECU70.

A piston48having a cylindrical shape may be disposed inside the pipe46in a movable manner. The piston48may be disposed closer to the other end of the pipe46than the MGG47is. Further, a plurality of balls49may be disposed inside the pipe46in a movable manner. The balls49may be disposed closer to the other end of the pipe46than the piston48is.

The driving power transmitter50may include a pinion51, a transmission gear52, and a rack53that is provided on the anchor member42. The pinion51may be a two-stage gear that includes a first pinion gear51A and a second pinion gear51B. The first pinion gear51A may engage with the balls49. The second pinion gear51B and the transmission gear52may be in mesh, and the transmission gear52may have a larger diameter than the second pinion gear51B. The rack53may extend on an outer circumference of the anchor member42in the vertical direction, and the transmission gear52and the rack53may be in mesh.

Accordingly, when the MGG47is operated to move the balls49toward the other end of the pipe46, the pinion51and the transmission gear52may be rotated to lower the anchor member42from the initial position.

The anchor driver44may further include a lock mechanism54. The lock mechanism54may prevent the anchor member42lowered to the grounded position from moving in the upward direction. Like the lock mechanism34, the lock mechanism54may include a lock member55that is rotatably coupled to an upper circumferential end of the anchor member42. The lock member55may be configured to engage with any of lock grooves56provided on the anchor supporting member41. When the lock member55engages with any of the lock grooves56, the anchor member42is prevented from moving in the upward direction. The lock grooves56may be provided at respective positions corresponding to the initial position and the grounded position of the anchor member42. When the anchor member42is lowered to the grounded position, the lock member55may engage with the corresponding lock groove56. The anchor member42may be urged by a non-illustrated urging member in a direction in which the anchor member42is to engage with the lock groove56. While the anchor member42is being lowered, the lock member55may be caused to slide on the outer circumference of the anchor supporting member41by an urging force of the urging member.

As illustrated inFIG.1, the sub-lifting actuators60may be disposed below the respective vehicle-width ends of the longitudinally intermediate part of the hood80. The sub-lifting actuators60may each include a cylinder61, a micro-gas generator62(hereinafter referred to as a MGG62), and a piston rod63. In the broad sense, the MGG62may serve as a gas generator.

The cylinder61may have a cylindrical shape having an axis along a substantially vertical direction. The cylinder61may be fixed to the body of the vehicle V. For example, an upper part of the cylinder61may slightly incline in the forward direction in side view. The MGG62may be fit in a lower end of the cylinder61. When the MGG62is operated, gas generated by the MGG62may be supplied into the cylinder61. The MGG62may be electrically coupled to the ECU70to be described later so that an operation of the MGG62is controlled by the ECU70.

The piston rod63may extend along the axis of the cylinder61. A lower part of the piston rod63may be disposed inside the cylinder61in a movable manner. An upper end of the piston rod63may be disposed close to a lower side of the hood80. As to be described in detail later, the sub-lifting actuator60may be operated together with the lifting mechanism20to lift the hood80to the position corresponding to the second lifted position of the lifter22in cooperation with the lifting mechanism20.

As illustrated inFIG.2, the ECU70may be electrically coupled to the MGGs27,47, and62described above so that operations of the MGGs27,47, and62are controlled by the ECU70. Further, a first contact detection sensor71, second contact detection sensors72, and third contact detection sensors73may be electrically coupled to the ECU70. In one embodiment, the first contact detection sensor71, the second contact detection sensors72, and the third contact detection sensors73may each serve as a “contact detector”. The ECU70may determine whether to operate the MGGs27,47, and62based on detection signals outputted from these sensors.

The first contact detection sensor71may be disposed in front of a bumper beam96provided on a frontal end part of the vehicle V. The first contact detection sensor71may include a pressure tube71A and pressure sensors71B. The pressure tube71A may be an elongated hollow tube extending in the vehicle-width direction. The pressure sensors71B may be disposed at respective longitudinal ends of the pressure tube71A. When a contact body comes into contact with the frontal end part of the vehicle V, the pressure tube71A may be compressed, changing the pressure inside the pressure tube71A. The pressure sensor71B may then output a signal based on the change in the pressure inside the pressure tube71A to the ECU

The second contact detection sensors72may be disposed on respective frontal end portions of right and left front side frames97in pair. The pair of front side frames may be disposed on the frontal part of the vehicle V and extend in the longitudinal direction of the vehicle V. The second contact detection sensors72may each serve as an acceleration sensor that outputs a signal based an acceleration rate inputted to the vehicle V to the ECU70.

The third contact detection sensors73may include a stereo camera73A and millimeter-wave radars73B. The stereo camera73A may be disposed on an upper part of the windshield glass94at a position near a vehicle-width intermediate position. The stereo camera73A may capture an image of an environment in front of the vehicle V to detect a contact body in contact with the vehicle V, and may output measurement data including data on the image of the contact body to the ECU70. The stereo camera73A may measure, for example, a distance to the detected contact body and and a relative speed between the vehicle V and the contact body, and may output the measurement data to the ECU70. The millimeter-wave radars73B may be disposed on a bumper grill95that is disposed on the frontal end part of the vehicle V. The millimeter-wave radars73B may each measure a position of the contact body, a distance to the contact body, and a speed of the contact body, and may output the measured data to the ECU70.

The ECU70may include a contact determination unit70A. The contact determination unit70A may determine the type of frontal contact of the vehicle V based on a result of detection by the third contact detection sensors73. For example, the contact determination unit70A may determine whether the frontal contact of the vehicle V is underride contact, that is, whether the vehicle V has slid underneath the contact body. If it is determined by the contact determination unit70A that the frontal contact of the vehicle V is underride contact, the ECU70may cause the MGGs27of the lifting mechanisms20to operate at the high output level, and may cause the MGGs62of the sub-lifting actuators60to operate. Further, if it is determined that the frontal contact of the vehicle V is underride contact, the ECU70may cause one or both of the MGG47of the right anchor mechanism40and the MGG47of the left anchor mechanism40to operate based on results of detection outputted from the second contact detection sensors72after the lifting mechanisms and the sub-lifting actuators60are operated (i.e., after an elapse of a predetermined time from the start of operations of the MGGs27and62).

In contrast, if it is determined by the contact determination unit70A that the frontal contact of the vehicle V is not underride contact, the contact determination unit70A may determine whether the contact body in contact with the vehicle V is a person (pedestrian) based on the results of detection outputted from the first contact detection sensor71and the third contact detection sensors73. If it is determined that the contact body in contact with the vehicle V is a person, the ECU may cause the MGGs27to operate at the low output level to thereby cause the lifting mechanisms20to operate, that is, the ECU70may keep the sub-lifting actuators60and the anchor mechanisms40in non-operational states. In contrast, if it is determined that the contact body in contact with the vehicle V is a contact body other than a person, the ECU70may keep the MGGs27,47, and62in non-operational states, that is, the ECU70may keep the lifting mechanisms20, the anchor mechanisms40, and the sub-lifting actuators60in non-operational states.

Workings and Effects

Now, workings and effects of the present example embodiment are described.

While the lifting mechanisms20and the sub-lifting actuators60are in the non-operational states, the hood80may be located at the closed position so as to close the engine room91, as illustrated inFIG.1. While the anchor mechanisms are in the non-operational states, the anchor members42may be located so as not to project from the underfloor90of the vehicle V in the downward direction. Thereafter, if the contact determination unit70A of the ECU70detects frontal contact of the vehicle V other than underride contact based on the output signals from the first to third contact detection sensors71to73and determines that the contact body making frontal contact with the vehicle V is a person, the ECU70may cause the MGGs27of the lifting mechanisms20to operate at the low output level.

The lifting drivers24of the lifting mechanisms20may be thereby operated to raise the lifters22to the first lifted position as illustrated inFIG.4. For example, gas may be supplied from the MGG27to inside the pipe26, and the piston28may be moved toward the other end of the pipe26by the gas pressure inside the pipe26. The piston28may push the balls29to thereby move together with the balls29toward the other end of the pipe26. This may rotate the pinion31and the transmission gear32of the lifting mechanism20, raising the rack33in mesh with the transmission gear32. The lifter22may be thereby lifted from the initial position to the first lifted position, and the rear end part of the hood80may be lifted to the position corresponding to the first lifted position of the lifter22. For example, while being lifted, the rear end part of the hood80may rotate around the lower end of the striker84locked with the hood lock device86provided on the frontal end part of the hood80in side view. As a result, the person (pedestrian) falling onto the hood80upon the frontal contact may be received by the hood80lifted to the position corresponding to the first lifted position of the lifter22with a space formed below the rear end part of the hood80.

In contrast, if the contact determination unit70A of the ECU70detects underride contact of the vehicle V based on the output signals from the first to third contact detection sensors71to73, the ECU70may cause the MGGs27of the lifting mechanisms20to operate at the high output level and may cause the MGGs62of the sub-lifting actuators60to operate.

The lifting drivers24of the lifting mechanisms20may be thereby operated to raise the lifters22, as in the manner described above. At this time, the MGGs27may be operated at the high output level, and the lifters22may thus be lifted to the second lifted position as illustrated inFIG.5. Further, gas generated by the MGG62may be supplied to the cylinder61of the sub-lifting actuator60, and the piston rod63may be raised by the gas pressure inside the cylinder61, lifting the longitudinally intermediate part of the hood80. Accordingly, the rear end part of the hood80may be lifted to the position corresponding to the second lifted position of the lifter22by the lifting mechanisms20and the sub-lifting actuators60so that the windshield glass94is hidden behind the hood80in front view. The contact body (e.g., a contact body C illustrated inFIG.5) may be received by the hood80lifted to the position corresponding to the second lifted position of the lifter22to absorb contact energy applied to the vehicle V.

The contact determination unit70A of the ECU70may determine the position of contact between the contact body C and the vehicle V in the vehicle-width direction based on the output signals received from the second contact detection sensors72, and may cause, based on the result of the determination, the MGGs47of the anchor mechanisms40to operate. For example, when the contact body C comes into contact with a right part of the vehicle V, the MGG47of the right anchor mechanism40may be operated after the MGGs27and the MGGs62are operated. When the contact body C comes into contact with a left part of the vehicle V, the MGG47of the left anchor mechanism40may be operated after the MGGs27and the MGGs62are operated. That is, when the position of contact between the contact body C and the vehicle V is deviated from the vehicle-width intermediate part of the vehicle V, one of the MGGs47of the anchor mechanisms closer to the contact position with reference to the vehicle-width intermediate part of the vehicle V may be operated. When the contact body C comes into contact with a substantially intermediate part of the vehicle V in the vehicle-width direction, both of the MGG47of the right anchor mechanism40and the MGG47of the left anchor mechanism40may be operated after the MGGs27and the MGGs62are operated.

The anchor driver44of the anchor mechanism40may be thereby operated, and the anchor member42may be lowered from the initial position to project from the underfloor90of the vehicle V. For example, gas may be supplied from the MGG47to inside the pipe46, and the piston48may be moved toward the other end of the pipe46by the gas pressure inside the pipe46. The piston48may push the balls49to thereby move together with the balls49toward the other end of the pipe46. This may rotate the pinion51and the transmission gear52of the anchor mechanism40, lowering the rack53in mesh with transmission gear52. The anchor member42may be thereby lowered from the initial position, bringing the lower end of the anchor member42into contact with the ground GR. Accordingly, an reaction force may be applied in the upward direction from the ground GR to the anchor member42and the anchor supporting member41. The reaction force may be transmitted from the anchor supporting member41to the lifter22and the lifter supporting member21of the lifting mechanism20, and may be applied to the contact body C through the hood80.

As described above, the occupant protection apparatus10includes the lifting mechanisms20, and the lifting mechanisms20each include the lifter22and the lifting driver. The lifter22may be coupled to the rear end part of the hood80, and the lifting driver24is configured to apply a driving force to the lifter22. When the contact determination unit70A of the ECU70determines that the frontal contact of the vehicle V is underride contact, the ECU70may cause the lifting driver24to operate to raise the lifter22to the second lifted position, and the rear end part of the hood80may be lifted by the lifter22. When the lifter22is located at the second lifted position, the rear end part of the hood80may be located at the vertical position where the hood80overlaps with the head of the occupant P. Accordingly, when the vehicle V makes underride contact by sliding underneath the contact body C, the hood80may serve as a screen (seeFIG.5). Upon the underride contact, the contact body C is received by the hood80lifted to the position corresponding to the second lifted position of the lifter22, which prevents the contact body C from entering the cabin of the vehicle V. That is, upon the underride contact, the lap amount between the vehicle V and the contact body C is increased, and the contact energy generated upon the underride contact is absorbed by the hood80and the lifting mechanisms20. It is therefore possible to improve the performance to protect the occupant P upon underride contact.

According to the occupant protection apparatus10, when the contact determination unit70A of the ECU70determines that the contact body C making frontal contact with the vehicle V is a person (pedestrian), the ECU70may cause the MGGs27of the lifting mechanisms20to operate at the low output level so that the rear end part of the hood80is lifted by the lifters22to the position corresponding to the first lifted position of the lifter22. In contrast, when the contact determination unit70A of the ECU70determines that the frontal contact of the vehicle V is underride contact, the ECU70may cause the MGGs27of the lifting mechanisms20to operate at the high output level so that the rear end part of the hood80is lifted by the lifters22to the position corresponding to the second lifted position of the lifter22, as described above. In other words, the occupant protection apparatus10may be configured to lift the rear end part of the hood80to the two different lifted positions. This allows the hood80to serve differently depending on the types of the frontal contact. For example, upon underride contact, the hood may serve as a protection member that absorbs the contact energy generated upon the underride contact to protect the occupant P, whereas upon frontal contact with a person (pedestrian), the hood80may serve as a protection member that absorbs the contact energy generated upon the frontal contact to protect the person (pedestrian) falling onto the hood80. Accordingly, upon frontal contact of the vehicle V with a person (pedestrian), it is possible to protect the person falling onto the hood80using the occupant protection apparatus10that absorbs the contact energy generated upon the underride contact.

The anchor mechanisms40may be disposed below the respective lifting mechanisms20. The anchor mechanisms40may each include the anchor member42and the anchor driver44that applies a driving force to the anchor member42. Upon underride contact, the anchor driver44may be operated by the ECU70to cause the anchor member42to project from the underfloor90of the vehicle V in the downward direction and come into contact with the ground GR. Accordingly, a reaction force may be applied in the upward direction from the ground GR to the anchor mechanism40. The reaction force may be transmitted to the lifting mechanism20and applied to the contact body C through the rear end part of the hood80. Further, a contact load applied from the contact body C to the hood80may be transmitted from the lifting mechanism20and the anchor mechanism40to the ground GR. Accordingly, it is possible to effectively improve the performance to protect the occupant P.

After operating the MGGs27of the lifting mechanisms20, the ECU70may cause the MGGs47of the anchor mechanisms40to operate. Accordingly, it is possible to apply a reaction force from the hood80to the contact body C while stabilizing the state of the vehicle V upon underride contact. If the MGG s47of the anchor mechanisms40are operated before the MGGs27of the lifting mechanisms20are operated, wheels98of the vehicle V can leave the ground GR when the anchor members42come into contact with the ground GR. This can bring the vehicle V into an unstable state, making it difficult to apply an effective reaction force from the hood80to the contact body C. In contrast, in the present example embodiment, the MGGs47of the anchor mechanisms40may be operated after the MGGs27of the lifting mechanisms20are operated. Thus, at an early stage of the underride contact, the hood80lifted to the position corresponding to the second lifted position of the lifter22may come into contact with the contact body C to thereby apply a reaction force to the contact body C while the vehicle V is supported by the wheels98. At a later stage of the underride contact, the anchor mechanisms40may increase the reaction force to be applied to the contact body C. Accordingly, it is possible to apply the reaction force from the hood80to the contact body C while stabilizing the state of the vehicle V upon underride contact.

The MGG47of the right anchor mechanism40may be operated when the contact body C comes into contact with a right part of the vehicle V, whereas the MGG47of the left anchor mechanism40may be operated when the contact body C comes into contact with a left part of the vehicle V. In other words, when the position of contact between the contact body C and the vehicle V is deviated from the intermediate part of the vehicle V in the vehicle-width direction, one of the MGGs47of the anchor mechanisms40closer to the position of the contact in the vehicle width direction may be operated. When the contact body C comes into contact with a substantially intermediate part of the vehicle V in the vehicle-width direction, both of the MGG47of the right anchor mechanism40and the MGG47of the left anchor mechanism40may be operated. This makes it possible to effectively apply a reaction force to the contact body C. When the position of contact between the contact body C and the vehicle V is deviated from the vehicle-width intermediate part of the vehicle V in the vehicle width direction, a yawing behavior of the vehicle V may be caused by operating one of the MGGs47of the anchor mechanisms40closer to the contact position. The contact energy applied to the vehicle V may be thereby converted into the yawing behavior of the vehicle V. This suppresses a deformation of the vehicle V upon the underride contact.

Further, the sub-lifting actuators60may be disposed below the respective vehicle-width ends of the longitudinally intermediate part of the hood80. Upon underride contact, the ECU70may cause the sub-lifting actuators60to operate so that the hood80is lifted to the position corresponding to the second lifted position of the lifter22by the piston rods63of the sub-lifting actuators60. Accordingly, the longitudinally intermediate part of the hood80lifted to the position corresponding to the second lifted position of the lifter22is supported by the sub-lifting actuators60upon the underride contact. This makes it possible to improve the function of supporting the hood80upon the underride contact and transmit the contact load applied to the hood80upon the contact of the contact body C with the hood80to the vehicle body of the vehicle V in a distributed manner.

Further, the lifting driver24of the lifting mechanism20may include the lifting actuator25. The lifting actuator25may include the MGG27configured to be operated by the ECU70. This allows the lifting mechanism20to promptly operate to lift the lifter22to the first or second lifted position upon underride contact. Further, the lifting driver24of the lifting mechanism20may include the pinion31, the transmission gear32in mesh with the second pinion gear31B of the pinion31, and the rack33provided on the lifter22and being in mesh with the transmission gear32. The transmission gear32may have a larger diameter than the second pinion gear31B. Accordingly, the driving force of the lifting actuator25is amplified and transmitted to the lifter22. Accordingly, it is possible to lift the hood appropriately.

Although some embodiments of the disclosure have been described in the foregoing by way of example with reference to the accompanying drawings, the disclosure is by no means limited to the embodiments described above. It should be appreciated that modifications and alterations may be made by persons skilled in the art without departing from the scope as defined by the appended claims. The disclosure is intended to include such modifications and alterations in so far as they fall within the scope of the appended claims or the equivalents thereof. As used herein, the term “collision” may be used interchangeably with the term “contact”.