JP4757726B2 - Vehicle seat belt device - Google Patents

Description

  The present invention relates to a seat belt device for a vehicle. In particular, the present invention relates to a vehicle seat belt device having means for tightening webbing in an emergency.

  2. Description of the Related Art Generally, a vehicle seat belt device is provided with an ELR (Emergency Locking Retractor) that locks a webbing from a retractor so that it is difficult to lock when an acceleration of a certain value or more is applied to the vehicle. Further, as a vehicle seat belt device, there is a retractor in which a pretensioner, a road limiter, and the like are added to an ELR.

  The above-described pretensioner has a restraining function that restrains the occupant's body from moving forward by instantaneously winding up the webbing and taking looseness in the initial stage when an impact is applied to the vehicle. The road limiter has an energy absorption action (hereinafter referred to as EA: Energy Absorption action) that absorbs the kinetic energy of an occupant trying to move inertially by webbing. Various seat belt devices have been proposed in order to control the pretensioner and the road limiter to reduce the feeling of pressure in occupant restraint and to ensure safety.

As such a vehicle seat belt device, a vehicle seat belt device that can normally operate a conventional lock mechanism when an explosive pretensioner is operated has been invented (see, for example, Patent Document 1). . As another vehicle seat belt device, a vehicle seat belt device capable of stably operating a load limiter when an explosive pretensioner is operated has been invented (see, for example, Patent Document 2). .
JP 2002-326558 A JP 2003-191819 A

  In Patent Document 1 and Patent Document 2, rotation transmission to the spindle by the motor pretensioner is interrupted when the explosive pretensioner is activated. However, in the configurations according to Patent Document 1 and Patent Document 2, it is necessary to add a mechanism with components (for example, a solenoid) and members in order to cut off the power transmission of the drive system by the motor. Further, since a new mechanism is arranged so as to interrupt the conventional explosive pretensioner and the motor pretensioner, the assembly of the pretensioner becomes complicated and may cause a high cost. It is preferable that a conventional pretensioner can be used.

  For example, in a conventional vehicle seat belt device, the webbing is pulled out by the occupant moving forward after the explosive pretensioner is activated. That is, the spindle around which the webbing is wound rotates in the pulling direction. On the other hand, when the motor pretensioner is activated after the explosive pretensioner is activated, the clutch mechanism for preventing reverse rotation of the motor is engaged with the spindle in conjunction with the retracting operation of the motor, and the spindle is retracted. Further rotation may occur. When such a phenomenon occurs, an appropriate EA action cannot be exhibited, which is not preferable. There is also a problem that the load on the motor pretensioner connected to the spindle is large. These can be said to be the problems of the present invention.

  The present invention has been made in view of the above-described problems, and is a seat belt device that operates a motor pretensioner using an occupant's operation input as a trigger and also operates an explosive pretensioner at the time of a collision. An object of the present invention is to provide a vehicle seat belt device capable of exhibiting a good EA action.

  (1) First determination means for determining the possibility of a vehicle collision in response to a passenger's operation input; second determination means for detecting the collision of the vehicle; and the first determination means for detecting the collision of the vehicle. When the possibility is judged, a first pretensioner having a motor that rotates a spindle around which one end of the webbing is wound in the direction in which the webbing is pulled, and when the second judging means judges a collision, the explosive force of the explosive explodes the spindle. A vehicle seat belt device comprising: a second pretensioner that rotates in a direction in which the webbing is pulled in; and a control unit that disables the operation of the first pretensioner after the operation of the second pretensioner.

  Since the seat belt device according to the invention of (1) includes a control unit that disables the operation of the first pretensioner after the operation of the second pretensioner, the seatbelt device is EA after the operation of the second pretensioner. It can be excluded that the first pretensioner operates and inhibits the EA action while exerting the action. In addition, the seat belt device according to the invention of (1) is not a system based on the conventional prediction of a collision, and can cope with a sudden operation of an occupant, so that the robustness is improved. In addition, the occupant can be appropriately protected without using an expensive member such as a radar.

  (2) First determination means for determining the possibility of a vehicle collision in response to an occupant's operation input; second determination means for detecting the collision of the vehicle; and the first determination means for detecting the collision of the vehicle. When the possibility is judged, a first pretensioner having a motor that rotates a spindle around which one end of the webbing is wound in the direction in which the webbing is pulled, and when the second judging means judges a collision, the explosive force of the explosive explodes the spindle. The first pretensioner that rotates in the direction in which the webbing is pulled in, and the first pretensioner immediately before the second pretensioner operates based on the operation signal of the second determination means and / or the sensor signal arranged on the vehicle body. And a control unit for operating the vehicle.

  The seat belt device according to the invention of (2) operates the first pretensioner before the operation of the second pretensioner in the case where a collision occurs without being able to determine the possibility of a collision in addition to inputs of a brake, a sudden handle, etc. By doing so, it is possible to prevent the operation order from being always reversed. Therefore, even when a retractor having a precondition for the operation sequence is used, it can be operated appropriately.

  (3) When the motor rotates more than a predetermined driving force in the direction in which the spindle pulls the webbing against the force of the spindle rotating in the direction in which the spindle pulls out the webbing, the first pretensioner The vehicle seat belt device according to (1) or (2), further comprising a limiting mechanism that limits power transmission beyond the predetermined driving force to the spindle.

  The seat belt device according to the invention of (3) is a control unit that invalidates the operation of the first pretensioner after the operation of the second pretensioner, or the first pretensioner immediately before the operation of the second pretensioner by vehicle collision detection. Since the first pretensioner includes a limiting mechanism that limits power transmission beyond a predetermined driving force from the motor to the spindle, the inhibition of the EA action can be eliminated more reliably.

  (4) The limiting mechanism includes one intermediate gear in a gear train that transmits rotation from the motor to the spindle. The intermediate gear includes a first gear that transmits rotation from the motor, and the first gear. A second gear coupled coaxially with one gear and transmitting the rotation to the spindle; one or more elastic bodies for frictionally transmitting the first gear and the second gear with a predetermined friction force; The vehicle seat belt device according to (3).

  In the seat belt device according to the invention of (4), the intermediate gear incorporated in the first pretensioner is a limiting mechanism having a simple configuration of the first and second gears and one or more elastic bodies. Tensioners are available and no new mechanism needs to be placed. As the first pretensioner that drives the seat belt device with a motor, the assembly becomes easy and the factor of high cost can be eliminated.

  The seat belt device according to the present invention can eliminate the factor that hinders the EA action inherent in the seat belt device without changing the configuration. In addition, the seat belt device according to the invention is not a system based on the conventional prediction, and can cope with a sudden operation of the occupant, so that the robustness is improved. In addition, the occupant can be appropriately protected without using an expensive member such as a radar.

  Further, the seat belt device according to the present invention operates the first pretensioner before the second pretensioner is activated in the case where the collision occurs without being able to determine the possibility of the collision in addition to the input of the brake or the sudden handle. Thus, it is possible to always prevent the operation order from being reversed. Therefore, even when a retractor having a precondition for the operation sequence is used, it can be operated appropriately.

  Furthermore, the seat belt device according to the present invention includes a limiting mechanism in which the first pretensioner limits power transmission exceeding a predetermined driving force from the motor to the spindle, so that the inhibition of the EA action can be eliminated more reliably.

  The limiting mechanism according to the present invention is an intermediate gear having a simple configuration that can use the conventional first pretensioner, and eliminates the complexity and cost of assembly.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a functional block diagram showing an embodiment of a seat belt device according to the present invention. FIG. 2 is an exploded perspective view of the retractor of the seat belt device according to the embodiment. FIG. 3 is an exploded perspective view of the first pretensioner of the seat belt device according to the embodiment.

  FIG. 4 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment. FIG. 4 is a normal state diagram. FIG. 5 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment. FIG. 5 is a state change diagram of FIG. FIG. 6 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment. FIG. 6 is a state change diagram of FIG. FIG. 7 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment. FIG. 7 is a state change diagram of FIG.

  FIG. 8 is a configuration diagram of a gear train incorporated in the first pretensioner according to the embodiment, FIG. 8 (A) is a front view of the gear train, and FIG. 8 (B) is a longitudinal section of FIG. 8 (A). FIG. FIG. 9 is a front view of the gear train and is a state diagram in which a limiting mechanism that is an intermediate gear operates. FIG. 10 is a graph showing webbing tension and elapsed time at the time of collision. The vertical axis represents webbing tension, and the horizontal axis represents time. FIG. 11 is a system flowchart showing the operation of the seat belt device according to the embodiment.

  First, the overall configuration of the seat belt device according to the present invention will be described. In FIG. 1, the seat belt device 100 includes a webbing W and a retractor 10. The webbing W can be worn by an occupant P seated on the seat S. The retractor 10 restrains the occupant P by applying a predetermined tension to the webbing W.

  In FIG. 1, a seat belt device 100 includes a webbing W that can be worn by an occupant P seated on a seat S of a vehicle. One end of the webbing W is wound around the spindle 31 (see FIG. 2). The webbing W extending from the retractor 10 is folded back by a shoulder anchor w1 disposed in the vicinity of the shoulder of the occupant P and above the center pillar. The webbing W extending from the shoulder anchor w1 is inserted into the tongue plate w2, and the other end of the webbing W is locked by the anchor w3 below the center pillar. On the other hand, the seat S is provided with a buckle w4 in the vicinity of the waist of the occupant P, and the webbing W is put on by attaching the tongue plate w2 to the buckle w4.

  In FIG. 2, the retractor 10 is provided with a first pretensioner 1 having a motor M that can rotate in a direction in which the spindle 31 is pulled in the webbing W or in a direction in which the spindle 31 is pulled out. In FIG. 1, the control unit 12 that controls the operation of the motor M is interconnected with a second determination unit 13, a first determination unit 14, a display 17, and the like via an in-vehicle LAN.

  In FIG. 1, the 2nd determination means (for example, SRS unit) 13 will send an operation signal to the 2nd pretensioner 2 with which the retractor 10 is provided, if the detection signal from the sensor 15 is input.

  In FIG. 1, the first determination means (for example, VSA unit) 14 outputs a collision prediction signal based on the operation amount (for example, the brake operation, the state of the sudden steering) of the occupant P. The operation amount prediction unit 14 a that predicts the operation amount is included in the first determination unit 14. The control unit 12 sends an operation signal for operating the motor M provided in the first pretensioner 1 based on the collision prediction signal (see FIG. 2).

  In FIG. 1, the collision prediction unit 14b included in the first determination unit 14 is provided in a vehicle that detects the distance and relative speed to the preceding vehicle using a millimeter wave radar, for example, and determines that there is a possibility of a collision. In this case, a determination signal is sent, and the driver is warned with a warning by sound and display using the display 17.

  In FIG. 2, the retractor 10 includes a spindle 31 around which one end of the webbing W is wound, and a torsion bar 32 incorporated in the spindle 31, and the first pretensioner 1 mechanically transmits the rotational force driven by the motor M. Is transmitted to the spindle 31 by means. The first pretensioner 1 includes a clutch mechanism in which power to the spindle 31 is interrupted by forward / reverse rotation of the motor M, and forward / reverse rotation of the motor M is controlled by the control unit 12 (see FIG. 1). .

  In FIG. 1, first determination means 14 that determines the possibility of a vehicle collision in response to an occupant's operation input is connected to a plurality of sensor groups, and the first determination means is based on information from these sensor groups. When 14 determines the possibility of a vehicle collision, the motor M provided in the first pretensioner 1 rotates the spindle 31 around which the one end of the webbing W is wound in the direction in which the webbing W is drawn (see FIG. 2).

  In FIG. 2, the retractor 10 includes a second pretensioner 2. When the vehicle collides, the second pretensioner 2 rotates the spindle 31 in the direction in which the webbing W is drawn by the explosive force of the explosive. The second pretensioner 2 has a built-in mechanism for converting explosive force of gunpowder into rotational force, and transmits this rotational force to the spindle 31. Normally, the second pretensioner 2 is not connected to the spindle 31, but when the second determination means 13 detects a collision, the explosive explodes and the spindle 31 rotates.

  In FIG. 2, a first pretensioner 1 and a second pretensioner 2 are arranged on one side of a box-shaped base frame 4. An upper spring cover 5 u and a lower spring cover 5 d forming a set are provided on the side surface of the first pretensioner 1. A spiral spring 5s is disposed inside the upper spring cover 5u and the lower spring cover 5d. The outer peripheral end of the spiral spring 5s is fixed to the upper spring cover 5u, and the central end of the spiral spring 5s is fixed to the retainer 5r. The retainer 5r is rotatably connected to a central axis of a ratchet gear 1t of the first pretensioner 1 described later (see FIG. 3). The central axis of the ratchet gear 1t is detachably connected to a sleeve 33 provided at one end of the central axis of the spindle 31. Normally (when not in operation), the ratchet gear 1t is rotatable, so that the spiral spring 5s can urge the rotational force in the direction in which the spindle 31 pulls in the webbing W.

  In FIG. 2, a fitting recess (not shown) is provided inside the spindle 31, and one end of the torsion bar 32 is fitted in this fitting recess. The other end of the torsion bar 32 is fitted in a fitting recess 341 formed on one side surface of the tread head 34b. One side surface of the tread head 34b is rotatably connected to the spindle 31 by an EA stopper 34a. A locking element 34c is held in a recess formed on the other side surface of the tread head 34b. The posture of the locking element 34c is regulated by an omega-shaped omega spring 34d. The locking element 34c and the omega spring 34d are held in a sealable manner by a safety plate 34e. The safety plate 34e includes a steering wheel 35a, an internal coupling assembly 35b, and a bearing plate 35c. The bearing plate 35c is covered with a cover 35d.

  With such a configuration, both axes of the spindle 31 are supported by the upper spring cover 5u and the bearing plate 35c, and the webbing W can be taken up by the urging force of the spiral spring 5s. Further, the urging force of the spiral spring 5s gives a slight tension to the webbing W, and the spindle 31 having such a component is accommodated in the box-shaped base frame 4 (see FIG. 2).

  In FIG. 2, the mechanism is configured such that when a force that pulls out the webbing W suddenly is applied, the engaging claw of the locking element 34c housed in the tread head 34b jumps out. The engaging claw engages with the internal teeth 4g formed on the base frame 4 to constitute a lock mechanism 36 that prevents the tread head 34b from rotating. Specifically, when the acceleration of the vehicle exceeds a predetermined value, the engaging claw of the locking element 34c pops outward by the movement of the ball 36b and engages with the internal teeth 4g formed on the base frame 4. By doing so, the lock mechanism 36 is brought into a locked state. When the lock mechanism 36 is locked, the rotation of the torsion bar 32 is also stopped, and the spindle 31 is allowed to rotate only in response to the twist of the torsion bar 32. The webbing W rotates while receiving tension due to the torsional force of the torsion bar 32. That is, the EA action functions.

  In FIG. 2, the lever 35e and the WS spring 35f are interlocking members for coupling or separating the steering wheel 35a and the bearing plate 35c in conjunction with the internal coupling assembly 35b. Also, in FIG. 2, not all components are shown, and the mechanism is shown or described to the extent that can be understood by those skilled in the art.

  Next, the configuration and operation of the first pretensioner 1 will be described.

  In FIG. 2, the first pretensioner 1 has a pair of an upper gear case 1u and a lower gear case 1d, and the upper gear case 1u and the lower gear case 1d are combined to form a gear case 1ud. The gear case 1 ud is attached to one side surface of the base frame 4. Components to be described later are housed inside the gear case 1ud. A motor M is fixed on the lower gear case 1d side.

  In FIG. 3, the 1st gear g1 is attached to the rotating shaft of the motor M constituted by the motor elements m1 to m6, and the 1st gear g1 is transmitted to the final gear 1fg by intermediate gears g2 to g4. The motor M and the final gear 1fg are connected to form a gear train that serves as a speed reduction mechanism using the intermediate gears g2 to g4. Among the intermediate gears g <b> 2 to g <b> 4, the intermediate gear g <b> 3 constitutes a limiting mechanism that limits power transmission from the motor M to the spindle 31 over a predetermined driving force.

  In FIG. 8, the intermediate gear g3 serving as a limiting mechanism includes a first gear g31, a second gear g32, and a plurality of elastic bodies g33. The first gear g31 meshes with the intermediate gear g2, and the rotation is transmitted from the motor M. The second gear g32 meshes with the intermediate gear g4 and can transmit rotation to the spindle 31 (see FIG. 2). The second gear g32 is connected to the first gear g31 so as to be rotatable coaxially. The first gear g31 and the second gear g32 can be relatively rotated in the radial direction, but are connected so as not to easily move in the thrust direction.

  In FIG. 8, the elastic body g33 may be a leaf spring in the embodiment, and one end of the elastic body g33 is fixed to the shaft portion on which the tooth surface is not formed in the second gear g32, and the first gear g31 surrounding the shaft portion. Is pressed by the other end of the elastic body g33. One end of the elastic body g33 may be fixed to the inner periphery of the first gear g31 that surrounds the shaft portion, and the other end of the elastic body g33 may be pressed against the shaft portion. The plurality of elastic bodies g33 may include the first gear g31. And the second gear g32 are frictionally transmitted with a predetermined friction force. More specifically, an arc convex portion g331 formed at the other end of the elastic body g33 presses an arc concave portion g311 formed at the inner periphery of the first gear g31. When the rotational force exceeding the frictional force between the plurality of arc convex portions g331 and the plurality of arc concave portions g311 is applied to the first and second gears g31 and g32, the plurality of arc convex portions g331 are plural. Overcoming the circular arc recess g311, power transmission exceeding a predetermined driving force is limited. In FIG. 8, six elastic bodies g33 are arranged at equal intervals, but one or more elastic bodies g33 may be arranged in order to obtain a required frictional force. The arrangement number of g33 is determined.

  In FIG. 8 or FIG. 9, the axes of the first gear g1, the intermediate gears g2 to g4, and the final gear 1fg are arranged on a straight line so that the configuration and operation of the gear train can be understood. As shown in the embodiment, the axis centers of the intermediate gears g2 to g4 may be arranged to be the vertices of the triangle, and similarly, the axis centers of the intermediate gears g3 and g4 and the final gear 1fg are , May be arranged to be at the apexes of the triangle, and the gear train is accommodated in a compact manner.

  In FIG. 8, symbol T indicates clockwise rotation, and symbol NT indicates counterclockwise rotation. In the normal operation of the first pretensioner 1, when the 1st gear g1 rotates counterclockwise NT, the rotation is transmitted by the intermediate gears g2 to g4, the final gear 1fg rotates counterclockwise NT, and the spindle 31 is rotated. The webbing W can be rotated in the pulling direction (see FIGS. 1 and 2). When the first gear g1 rotates in the clockwise direction T, the rotation is transmitted by the intermediate gears g2 to g4, the final gear 1fg rotates in the clockwise direction T, and the connection between the final gear 1fg and the guide ring 1g is released by a mechanism described later. The That is, the mechanical transmission between the spindle 31 and the motor M is released (see FIG. 2).

  3 and 4, the final gear 1fg is formed in an annular shape, and a ring plate 1r is held so as to form a bottom surface in the annular shape. An Ω-shaped friction spring 1f is attached to the ring plate 1r. The guide ring 1g is held between the outer periphery of the friction spring 1f and the inner periphery of the final gear 1fg. Here, the guide ring 1g is arranged coaxially with the final gear 1fg. The guide ring 1g can be rotated relative to the final gear 1fg, but is held so as not to easily move in the thrust direction. Steps are provided on the inner circumference of the final gear 1fg and the outer circumference of the guide ring 1g, respectively, and the rotation angle of the guide ring 1g with respect to the final gear 1fg is defined by contacting the steps with each other.

  In FIG. 4, the friction spring 1f is attached to the ring plate 1r so that the outer periphery swells, and an elastic force is applied to the inner periphery of the guide ring 1g. When the final gear 1fg is rotated in one direction, the guide ring 1g is in sliding contact with the inner periphery of the final gear 1fg by friction transmission, and therefore follows the rotation of the final gear 1fg with a time delay. When the guide ring 1g rotates by a predetermined angle α, the final gear 1fg and the guide ring 1g rotate together (see FIG. 5). When the final gear 1fg is rotated in the other direction, the guide ring 1g is in sliding contact with the inner periphery of the final gear 1fg by friction transmission, and therefore follows the rotation of the final gear 1fg with a time delay (see FIG. 6). . When the guide ring 1g rotates by a predetermined angle β, the connection between the final gear 1fg and the guide ring 1g is released (see FIG. 6).

  4 and 5, the ratchet gear 1t is arranged so as to be surrounded by the guide ring 1g. A return spring (plate spring) 1s is provided on the other end side of the pawl 1p. The return spring 1s biases the pawl 1p so as to separate the pawl 1p from the ratchet gear 1t. When the final gear 1fg is rotated in one direction, the pawl 1p and the cam 1c approach each other, and one end of the cam 1c guides the pawl of the pawl 1p toward the ratchet gear 1t (see FIG. 4). Then, the pawl of the pawl 1p is engaged with the ratchet gear 1t, and the ratchet gear 1t is rotated in the same direction as the rotation direction of the final gear 1fg. That is, the spindle 31 is rotated in the direction in which the webbing W is drawn (see FIG. 5).

  As shown in FIG. 6, when the final gear 1fg is rotated in the other direction, the pawl 1p and the cam 1c are separated from each other, and one end of the cam 1c releases the pawl 1p with the ratchet gear 1t. To guide. Then, the claws are separated from the ratchet gear 1t, and the connection between the ratchet gear 1t and the final gear 1fg is released.

  In FIG. 4, the intermediate portion of the cam 1c is held by a guide ring 1g and a shear pin 1sp. Usually, the shear pin 1sp is rotatable together with the guide ring 1g. However, as shown in FIG. 5, when the pawl 1p has a pawl engaged with the ratchet gear 1t, if the ratchet gear 1t is rotated faster than the rotational speed of the final gear 1fg, that is, the second pre- When the tensioner 2 is actuated, the cam 1c is repelled in conjunction with the operation of the pawl 1p being repelled by the ratchet gear 1t, the shear pin 1sp is broken, and the cam 1c is displaced (see FIG. 7). That is, as long as the engagement with the spindle 31 is released and the motor M is not stopped, the final gear 1fg continues idling.

  As described above, when the second pretensioner 2 is operated while the first pretensioner 1 is operating, the first pretensioner 1 is engaged with the first pretensioner 1 and the spindle 31 by the rotational operation of the second pretensioner 2. Realizes a momentary disconnect mechanism that cancels the connection.

  The seat belt device according to the present invention is premised on that the first pretensioner is activated when the possibility of collision is determined, and the second pretensioner is activated when the collision is detected. For example, when the second pretensioner 2 is activated while the first pretensioner 1 is in operation, a momentary disconnection mechanism that releases the engagement of the first pretensioner 1 with the spindle 31 by the rotation of the second pretensioner 2 is provided. Provided. That is, the first pretensioner 1 is idled without the rotation of the motor M being transmitted to the spindle 31, and the first pretensioner 1 is not involved in the spindle 31 (see FIGS. 2 and 7).

  On the other hand, when a collision is reached without determining the possibility of a collision, for example, when a rear-end vehicle collides, the first pretensioner 1 does not operate and the second pretensioner is input by the sensor 15. 2 is activated. Furthermore, when the brake is stepped on immediately after the rear-end collision from the following vehicle, the first determination unit 14 satisfies the determination condition, and thus the first pretensioner 1 operates. At this time, when the operation of the gunpowder pretensioner is finished and the webbing W is pulled out by the movement of the occupant P, the spindle 31 rotates in the direction in which the webbing W is pulled out, that is, the EA action is performed. In spite of functioning, the first pretensioner 1 tries to rotate the spindle 31 in the direction in which the webbing W is drawn. That is, the EA action is inhibited.

  FIG. 10 is a graph showing the tension and elapsed time of the webbing W at the time of a collision, where the solid line indicates the second pretensioner 2 when the first pretensioner 1 is operated after the second pretensioner 2 is operated. Is activated (equivalent to a conventional explosive pretensioner).

  In FIG. 10, when only the second pretensioner 2 operates, when a collision occurs at time T0, the second determination means 13 detects the collision based on the signal from the sensor 15, and the second pretensioner at time T1. 2 is activated. The tension of the webbing W increases from time T2 when the occupant starts moving forward, and the tension of the webbing W reaches the maximum value at time T3 when the occupant moves forward. From time T3 to T4, a gentle energy absorption action, that is, an EA action is exhibited, and the tension of the webbing W eventually returns to a normal state. Thus, even if the 2nd pretensioner 2 act | operates without the 1st pretensioner 1 act | operating, EA effect | action is exhibited effectively.

  On the other hand, in FIG. 10, when the first pretensioner 1 is activated after the second pretensioner 2 is activated, if a collision occurs at time T 0, the second determination means 13 detects the collision based on the signal of the sensor 15. The second pretensioner 2 is activated at time T1. At time Tc after time T1, for example, when the amount of brake operation exceeds a predetermined value, the first determination means 14 determines the possibility of a collision and sends an operation signal to the control unit 12, and at time Td, the first The pretensioner 1 is activated. At this time, since the webbing W rotates in the pull-out direction due to the forward movement of the occupant P, the rotation of the spindle 31 in the pull-out direction is prevented by the operation of the motor M. For this reason, the maximum tension indicated by the time T3 is larger than the tension-time curve indicated by the broken line. That is, the EA action is inhibited.

  Therefore, in order to improve the phenomenon as described above, the seat belt device according to the invention is configured such that when the second pretensioner is operated without the first pretensioner being operated, the control unit is the motor of the first pretensioner. I decided to cancel the drive signal. That is, the control unit invalidates the operation of the first pretensioner after the operation of the second pretensioner.

  FIG. 11 is a system flowchart showing an improved operation procedure of such a seat belt apparatus. In FIG. 11, 1st and 2nd PT has shown 1st and 2nd pretensioner 1 * 2. First, it is determined whether the second pretensioner 2 is operating (step S101). In step S101, when the second pretensioner 2 is operating, the process proceeds to step S102. In step S102, it is determined whether the first pretensioner 1 is operating. If the first pretensioner 1 is operating in step S102, the drive of the motor M is stopped (step S103). And it returns to an initial state.

  If the first pretensioner 1 is not operating in step S102, the drive request for the motor M is ignored (step S104). That is, in step S104, the motor M drive signal is not transmitted even when the motor rotation request of the first pretensioner 1 is received. And it returns to an initial state. When the second pretensioner 2 is not operating in step S101, the process proceeds to step S105. In step S105, it is determined whether the operation of the first pretensioner 1 is requested. When the operation of the first pretensioner 1 is requested in step S105, the first pretensioner 1 is operated (step S106). Return to the initial state. If the operation of the first pretensioner 1 is not requested in step S105, the process returns to the initial state.

  As described above, the seat belt device according to the present invention can eliminate the factor that hinders the EA action inherent in the seat belt device by controlling without changing the configuration of the retractor. Therefore, the seatbelt device according to the present invention can give an appropriate restraining force to the occupant even when a collision occurs without determining the possibility of a collision. Further, the seat belt device according to the present invention is not a system based on the conventional prediction, but can cope with a sudden operation of the occupant, so that the robustness is improved. In addition, the occupant can be appropriately protected without using an expensive member such as a radar.

  Further, it is preferable that the first pretensioner operates before the second pretensioner operates. If the first and second pretensioners operate in this order, the rotation of the second pretensioner releases the engagement of the first pretensioner with the spindle, and the first pretensioner rotates the motor. The first pretensioner is not involved in the spindle without being transmitted. That is, the EA action functions effectively.

  Therefore, the seat belt device according to the invention of (2) operates the first pretensioner immediately before the second pretensioner operates based on the second determination means and / or the sensor disposed on the vehicle body.

  Specifically, the first determination means operates the first pretensioner when a predetermined state quantity (for example, acceleration) is detected, and the second state is detected when a state quantity exceeding the predetermined state quantity is detected. The determination means activates the second pretensioner. Alternatively, when the predetermined amount of state is detected, the second determination means forcibly operates the first pretensioner before operating the second pretensioner, and then operates the second pretensioner. According to this configuration, since the first pretensioner is in an operating state when the second pretensioner is operated, the drive transmission of the first pretensioner is appropriately cut off based on the above-described operating principle. Therefore, the EA action is not inhibited.

  As described above, the seat belt device according to (2) is determined in two stages by using a common signal source (when the second determination means satisfies the determination condition, the determination condition of the first determination means is always satisfied). (B) When the collision is determined, the first pretensioner may be forcibly operated in advance by the second determination unit regardless of the condition of the first determination unit. These configurations have the effect of eliminating the factors that inhibit the EA action when using a retractor with a defined operation sequence, and are conventionally used in the configuration (a). Even if the retractor provided with the explosive pretensioner is replaced by the retractor provided with the motor pretensioner, the retractor can be operated without any problem without a large control change. Therefore, the restraint performance can be further improved at a relatively low cost. In the configuration (b), since the motor is driven first in any case, the operation order can be ensured more reliably.

  The seat belt device according to the present invention further includes a control unit that disables the operation of the first pretensioner after the operation of the second pretensioner, or the operation of the second pretensioner by detecting the collision of the vehicle. In addition to the invention of (2) provided with a control unit for actuating the first pretensioner immediately before, the first pretensioner is provided with a limiting mechanism for limiting power transmission beyond a predetermined driving force from the motor to the spindle. Inhibition of action can be eliminated more reliably.

  FIG. 9 is a state diagram illustrating the action of the limiting mechanism that can more reliably eliminate such inhibition of EA action. In FIG. 9, the vehicle reaches a collision, and the kinetic energy of the occupant trying to move inertial is absorbed by the webbing W (see FIG. 1). That is, the EA action is functioning. In FIG. 9, pawls of the pawl 1p are locked to the ratchet gear 1t, and the webbing W is pulled out by the occupant trying to move inertial and the spindle 31 rotates, so that the final gear 1fg rotates (see FIG. 1 and FIG. 9). (See FIG. 2). The final gear 1fg rotates in the clockwise direction T, and rotates the second gear g32 in the clockwise direction T via the intermediate gear g4.

  As described above, for example, when the collision occurs without determining the possibility of the collision even though the EA action is functioning properly, the driving force from the motor M is driven by the spindle through the final gear 1fg. When transmitted to 31, EA action is inhibited (see FIG. 3). When the motor M rotates more than a predetermined driving force in the direction in which the spindle 31 pulls the webbing W against the force of the spindle 31 rotating in the direction in which the webbing W is pulled out, Since the first pretensioner 1 is provided with the intermediate gear g3 that serves as a limiting mechanism for limiting the power transmission beyond the predetermined driving force to the 31, the inhibition of the EA action can be more reliably eliminated (see FIGS. 1 and 3). .

  In FIG. 9, in response to the force that the final gear 1fg rotates the second gear g32 in the clockwise direction T via the intermediate gear g4, the first gear g1 moves the first gear g31 in the counterclockwise direction NT via the intermediate gear g2. When the rotating driving force is applied, the plurality of elastic bodies g33 slip beyond the frictional force with the second gear g32. That is, the first gear g31 and the second gear g32 are relatively rotated, and the unnecessary driving force of the motor M can be limited.

  As shown in FIG. 3 or FIG. 8, the present invention uses one intermediate gear in the gear train incorporated in the first pretensioner as the limiting mechanism. The limiting mechanism according to the present invention is simply constituted by the first and second gears and one or more elastic bodies. In this way, the conventional first pretensioner can be used, and there is no need to arrange a new mechanism. The first pretensioner that drives the seatbelt device with a motor is easy to assemble and can eliminate a factor of high cost.

It is a functional block diagram which shows one Embodiment of the seatbelt apparatus by this invention. It is a perspective exploded view of the retractor of the seat belt device according to the embodiment. FIG. 2 is a perspective exploded view of a first pretensioner of the seat belt device according to the embodiment. It is a principal part expansion longitudinal cross-section of the 1st pretensioner by the said embodiment, and is a normal state figure. 5 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment, and is a state change diagram of FIG. FIG. 6 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment, and is a state change diagram of FIG. 5. FIG. 6 is an enlarged vertical cross-sectional view of a main part of the first pretensioner according to the embodiment, and is a state change diagram of FIG. 5. It is a block diagram of the gear train integrated in the 1st pretensioner by the said embodiment, FIG. 8 (A) is a front view of the said gear train, FIG.8 (B) is a longitudinal cross-sectional view of FIG. 8 (A). It is a front view of the gear train, and is a state diagram in which a limiting mechanism that is an intermediate gear operates. It is the graph which showed the tension and elapsed time of webbing at the time of a collision. It is a system flowchart which shows operation | movement of the seatbelt apparatus by the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st pretensioner 2 2nd pretensioner 12 Control part 13 2nd determination means 14 1st determination means 31 Spindle 100 Seatbelt apparatus P Crew M Motor W Webbing

Claims (4)

First determination means for determining the possibility of a vehicle collision in response to an occupant's operation input;
Second determination means for detecting a collision of the vehicle;
A first pretensioner having a motor that rotates a spindle around which one end of the webbing is wound when the first determination unit determines the possibility of a collision of the vehicle in a direction in which the webbing is retracted;
A second pretensioner that rotates the spindle in a direction in which the webbing is pulled in by explosive force of explosives when the second determination means determines a collision;
A controller for disabling the operation of the first pretensioner after the operation of the second pretensioner ,
The controller ignores the drive request of the motor when the first pretensioner is not operating while the second pretensioner is operating, and the first pretensioner is operating while the second pretensioner is operating. A vehicle seat belt device that stops driving the motor when the motor is operating . First determination means for determining the possibility of a vehicle collision in response to an occupant's operation input;
Second determination means for detecting a collision of the vehicle;
A first pretensioner having a motor that rotates a spindle around which one end of the webbing is wound when the first determination unit determines the possibility of a collision of the vehicle in a direction in which the webbing is retracted;
A second pretensioner that rotates the spindle in a direction in which the webbing is pulled in by explosive force of explosives when the second determination means determines a collision;
Based on at least one of the actuation signals and arranged sensor signals to the body of the second determination means, and a control unit for the second pretensioner is activated always the first pretensioner immediately before actuation,
When the second pretensioner is activated while the first pretensioner is in operation, the first pretensioner is engaged with the first pretensioner and the spindle by the rotation of the spindle by the second pretensioner. A vehicle seat belt device having a momentary disconnection mechanism to be released .   The first pretensioner moves from the motor to the spindle when the motor rotates more than a predetermined driving force in the direction of pulling the webbing against the force of the spindle rotating in the direction of pulling out the webbing. The vehicle seat belt device according to claim 1, further comprising a limiting mechanism that limits power transmission beyond the predetermined driving force. The limiting mechanism is composed of one intermediate gear in a gear train that transmits rotation from the motor to the spindle,
The intermediate gear includes a first gear to which rotation is transmitted from the motor, a second gear that is rotatably connected coaxially with the first gear, and transmits rotation to the spindle, the first gear, and the first gear. The vehicle seat belt device according to claim 3, further comprising: one or more elastic bodies that frictionally transmit the two gears with a predetermined frictional force.

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