JP4772691B2 - Seat belt device - Google Patents

Description

  The present invention relates to a seat belt device, and more particularly, to a seat belt device that prevents a tongue of a webbing in an unused state from falling off due to vibration or the like generated during actual traveling of a vehicle.

  As a conventional seat belt device, there is known a seat belt device in which an electric motor is operated when necessary to rotate a spindle to wind up a webbing and restrain an occupant to a seat (see, for example, Patent Document 1). ). Further, in the conventional seat belt device, a clutch is provided in the retractor. When the webbing is pulled out and mounted when the occupant gets on the clutch, the clutch is released, and normally the webbing pull-out resistance is reduced. Yes.

  Further, in the seat belt device provided with the retractor that winds the webbing by the winding spring, the winding force of the winding spring (10N to 15N as a drawing force), which has been set to be strong to some extent before, is very small in advance. The webbing can be easily pulled out by this setting, and the feeling of pressure from the webbing can be reduced during wearing.

However, in such a seat belt device, since the winding force of the winding spring is weak, it is difficult to completely store the webbing due to friction between the D-ring and the webbing and the weight of the tongue. In view of this, it has been devised that such a seat belt apparatus also performs a winding assist using a motor during storage. In this case, when the motor is driven to rotate in the winding direction, the clutch becomes in a state where power can be transmitted, and winding assistance is possible. When the storage is completed, the motor stops the winding assist and rotates in the direction opposite to the winding side, and this rotation makes the clutch unable to transmit power and returns to the original state, and the webbing is wound up. Only weak winding force by the spring is received.
JP 2001-163185 A

  By the way, vibration is generated during actual traveling of the vehicle, and this vibration is naturally applied to the seat belt device. At this time, a downward force due to the mass of the tongue is applied to the stored webbing in an unused state by vibration, and a force in the pulling direction acts on the webbing. In the case of a seat belt device having a certain degree of winding force, the tongue did not fall by itself even when vibration was applied to the tongue mass (about 70 g), but it was weak like the seat belt device described above. When a take-up spring with a take-up force is used, the pulling force is about 5N to 8N, so that the tongue may drop depending on strong vibration. When the tongue falls, the retracted webbing becomes loose, and a slight vibration may cause the tongue to collide with the interior parts of the vehicle and generate noise, which may cause discomfort or damage the interior parts.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seat belt device that prevents a tongue of a webbing in an unused state from falling off due to vibration or the like generated during actual traveling of the vehicle. There is to do.

The above object of the present invention is achieved by the following configurations.
(1) a spindle for winding a webbing;
A winding spring that is always connected to the spindle, and applies a winding force to the webbing that is set to such an extent that the slack of the webbing on the chest of the passenger is wound while the passenger is wearing the webbing;
A power generation unit that generates power for rotating the spindle in a desired direction,
When the power generating means generates the power to rotate the spindle in the webbing winding direction, the power generating means is in a power transmitting state capable of transmitting the power of the power generating means to the spindle. Power transmission means for making a power transmission impossible state in which the power of the power generation means cannot be transmitted to the spindle when power in a direction opposite to the power for rotating the power in the winding direction is generated;
Control means for driving and controlling the power generation means;
Webbing unused state detection means for detecting the unused state of the webbing;
A seat belt device comprising:
In a seat where it is detected that the webbing is not in use when the vehicle is actually running, the control means causes the power generation means to wind the webbing so that the power transmission means can be transmitted. The spindle is connected to the power generation means after the rotation in the winding direction, and drive control is performed so that the power transmission means maintains the power transmission possible state. Seat belt device.
(2) It further comprises webbing use predicting means for predicting the use of the webbing,
Wherein, when the use of the webbing is predicted, in order to the power transmitting means to the power transmission possible state, rotate the power generating means to said take-up direction opposite to the direction, the spindle is the power (1) The seat belt device according to (1), wherein the seat belt device is controlled to be separated from the generating means and controlled so that a winding force acts on the spindle by the winding spring .

  According to the seat belt device of the present invention, when the control means detects that the webbing is not in use, the control means controls the power generation means to rotate in the webbing take-up direction. The power transmission means maintains the power transmission possible state, and the webbing is difficult to be pulled out due to the power resistance of the power transmission means and the idling resistance of the power generation means, so that the tongue is dropped due to vibrations generated during actual running of the vehicle. Thus, it is possible to reliably prevent the occurrence of abnormal noise during traveling and damage to interior parts.

  Further, according to the seat belt device of the present invention, when the use of the webbing is predicted, the control means rotates the power generation means in the direction opposite to the winding direction so that the power transmission means cannot be transmitted. Therefore, the webbing can be easily pulled out during use.

1 is a block diagram of a seat belt device according to an embodiment of the present invention. It is sectional drawing of the clutch used for the seatbelt apparatus shown in FIG. FIG. 3 is an operation explanatory diagram of the clutch shown in FIG. 2. FIG. 3 is an operation explanatory diagram of the clutch shown in FIG. 2. FIG. 3 is an operation explanatory diagram of the clutch shown in FIG. 2. FIG. 3 is an operation explanatory diagram of the clutch shown in FIG. 2. It is a flowchart explaining operation | movement of the seatbelt apparatus shown in FIG. It is a flowchart explaining operation | movement of the seatbelt apparatus shown in FIG. It is the schematic of the vehicle body mounted state of the seatbelt apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Seat belt apparatus 11 Webbing 12 Spindle 15 Motor (power generation means)
16 Gear assembly (power transmission means)
17 Clutch (power transmission means)
18 Damper spring (power transmission means)
19 Rotary sensor 20 Controller (control means)
23 Door switch 24 Seat switch 25 Ignition switch

  Hereinafter, a seat belt device according to an embodiment of the present invention will be described in detail with reference to the drawings.

  1 is a block diagram of a seat belt device according to an embodiment of the present invention, FIG. 2 is a sectional view of a clutch used in the seat belt device shown in FIG. 1, and FIGS. 7, 7 and 8 are flow charts for explaining the operation of the seat belt apparatus shown in FIG. FIG. 9 is a schematic view of the seat belt device shown in FIG. 1 mounted on the vehicle body.

  As shown in FIG. 1, a seat belt device 10 according to an embodiment of the present invention includes a webbing 11, a spindle 12, a retractor 13, a winding spring 14, a motor 15, a gear assembly 16, a clutch 17, a damper spring 18, and a rotary sensor. 19 and the controller 20. In this embodiment, the motor 15 constitutes power generation means, the gear assembly 16, the clutch 17, and the damper spring 18 constitute power transmission means, and the controller 20 constitutes control means.

  In the retractor 13, a spindle 12 around which the webbing 11 is wound is accommodated rotatably. The winding spring 14 is always connected to the spindle 12 and applies a winding force to the webbing 11. The winding force of the winding spring 14 is set to be very weak, and is set to such an extent that the slack of the webbing 11 on the chest of the user can be wound up while the user is wearing the webbing 11. In the present embodiment, the webbing take-up force at the chest is set to 0.5N or more and 2N or less.

  Further, the spindle 12 is rotationally driven in the winding direction by the motor 15 via the power transmission means when necessary. The motor 15 is driven to rotate forward or reversely according to a forward or reverse current supplied from the controller 20, and transmits the power to the gear assembly 16. Here, the forward drive is a direction in which power for rotating the spindle 12 in the winding direction of the webbing 11 is generated, and the reverse drive is a direction in which power in the opposite direction to the power is generated.

  The gear assembly 16 is connected to the motor shaft 22 of the motor 15. The gear assembly 16 rotates as the motor shaft 22 rotates forward and backward, and the rotational power of the motor shaft 22 is decelerated (torque amplification) to the clutch 17. introduce.

  The clutch 17 transmits the power from the motor 15 to the spindle 12 via the damper spring 18 when the motor 15 rotates in the forward direction (power transmission possible state), while when the motor 15 reverses, Power is not transmitted (power transmission is impossible).

  The damper spring 18 prevents a sudden transmission of the driving force to the webbing 11 when the motor 15 is driven to wind down, reduces an impact on the user, and prevents a sense of incongruity. The configuration of the power transmission means will be described in detail below.

  The rotary sensor 19 is a rotation sensor that detects the rotation of the spindle 12 and generates an electrical signal such as a pulse signal, for example. Therefore, the controller 20 adds the number of pulses when the spindle 12 is rotated forward in the winding direction, and subtracts the number of pulses when the spindle 12 is rotated reversely in the pulling direction. The webbing 11 is converted into a winding / drawing amount (length). The addition / subtraction of the number of pulses may be reversed.

  The controller 20 includes a CPU, a ROM, a RAM, an input / output interface (I / F), a timer, and a motor driver, and drives and controls the motor 18 using these circuits. Here, a door switch 23, a seat switch 24, an ignition switch (IG switch) 25, and a buckle switch 26 are electrically connected to the controller 20.

  The door switch 23 is a detection switch that turns on when the door is open and turns off when the door is closed. Therefore, the controller 20 sets the door open flag by detecting the energization current when the door switch 23 is on, and sets the door close flag by not detecting the energization current when the door switch 23 is off. Stand up.

  The seat switch 24 is a contact type sensor such as a pressure switch, and turns on when the user is seated on the seat and turns off when the user is not seated on the seat. Therefore, the controller 20 sets a seated flag by detecting the energized current when the seat switch 24 is in the on state, and sets a flag without seating by not detecting the energized current when the seat switch 24 is in the off state. Stand up. The seat switch 24 may be configured to be reversed on and off.

  When the ignition switch 25 is turned on to start the engine, a current flows. When the engine is not started, no current flows. Therefore, the controller 20 sets a flag indicating that the engine is started when the ignition switch 25 is in the on state, and sets a flag indicating that the engine is not started when the ignition switch 25 is in the off state.

  The buckle switch 26 is turned on when the tongue is inserted into the buckle, and is turned off when the tongue is not inserted into the buckle. Therefore, the controller 20 sets a flag indicating that the seat belt is in use by detecting the energization current when the buckle switch 26 is in the on state, and does not detect the seat belt by not detecting the energization current when the buckle switch 26 is in the off state. Flag for use. These switches are conventionally known and will not be described in detail.

  As shown in FIG. 9, the seat belt device 10 is mounted in a vehicle body panel constituting a B-pillar in which a retractor 13 is disposed at the center of the vehicle body, and a base end portion of the webbing 11 is a spindle in the retractor 13. 12. The webbing 11 passes through a D-ring 53 that is fixed to an adjust through 52 that is attached to the B pillar so as to be movable up and down, and is drawn out into the vehicle interior. The webbing 11 has a tongue stopper 54 attached to the tip end side through which the tongue 50 is inserted, and the tip end portion is bound and fixed to the lap anchor 55. The tongue 50 is disposed so as to be movable between the D-ring 53 and the tongue stopper 54 along the webbing 11. When the webbing 11 is wound and stored in the retractor 13 when not in use, the tongue 50 is locked to the tongue stopper 54. Thus, it is held so as not to fall at a position close to the D ring 53 on the B pillar. The buckle 51 is installed on the vehicle interior side with the seat 56 sandwiched with respect to the retractor 13, and the occupant seated on the seat 56 is restrained by inserting and mounting the tongue 50.

  Next, the configuration of the power transmission means will be described with reference to FIGS. The final gear 38 of the gear assembly 16, the clutch 17, and the damper spring 18 are accommodated in a clutch housing 27 provided on the frame side of the retractor 13. The clutch 17 includes a joint 28, a friction spring 29, a clutch wheel 30, a latch plate 31, a ring 32, a pole 33, a return spring 34, and a rotor cam 35.

  The joint 28 is coupled concentrically with the spindle 12 and rotates integrally with the spindle 12. The friction spring 29 is formed in a ring shape, and the end portion is locked to the clutch housing 27 to slidably support the clutch wheel 30 disposed on the inner peripheral portion of the ring 32.

  The latch plate 31 has a tooth portion 39 formed on the outer peripheral portion, and is coupled to the joint 28 via the damper spring 18. That is, the damper spring 15, which is a torsion coil spring incorporated between the joint 28 and the latch plate 31, houses the coil portion in the joint 28, one end is the joint 28, and the other end is the latch plate 30. By locking, when the latch plate 31 rotates during the winding drive of the motor 15, a sudden transmission of the driving force to the webbing 11 is prevented.

  The pole 33 is swingably supported by a part of a ring 32 provided so as to be rotatable integrally with the inner peripheral portion of the final gear 38, and one end is on the end of the pole 33 and the other end is on the ring 32. Is always urged in a direction to be released from the latch plate 31 by a return spring 34 locked to a part of the return spring 34. The pole 33 swings toward the latch plate 31 along the cam surface 35a of the rotor cam 35 and engages with the tooth portion 39 of the latch plate 31 when the final gear 38 is rotated by the forward rotation of the motor 15. Therefore, the final gear 38 is connected to the spindle 12 via the latch plate 31.

  The rotor cam 35 is normally oscillated and fixed by a shear pin 40 (shown in FIG. 3), and includes a cam surface 35 a that comes into contact with the pole 33 when the pole 33 rotates together with the final gear 38. Further, when the pretensioner is operated, the rotor cam 35 swings around the shaft 41 due to the breakage of the shear pin 40 to retract the pole 33 from the latch plate 31 so that the clutch 17 is not operated.

  Next, the operation of the clutch 17 will be described with reference to FIGS. As shown in FIG. 3, when the winding is not performed by the motor 15, the spindle 33 can rotate in any direction because the pole 33 is not locked to the tooth portion 39 of the latch plate 31. Is in a state. As shown in FIG. 4, when the motor 15 starts to rotate normally by supplying current from the controller 20, the final gear 38 that is gear-coupled to the motor shaft 22 is rotated in the counterclockwise direction of FIG. Then, the pole 33 moves counterclockwise together with the ring 32, and the pole 33 starts to swing toward the latch plate 31 along the cam surface 35 a of the rotor cam 35 against the urging force of the return spring 34.

  As shown in FIG. 5, when the final gear 38 further rotates by the power of the motor 15, the pawl 33 is locked to the tooth portion 39 of the latch plate 31, so that the clutch 17 is engaged. Can be transmitted to the spindle 12. Since the rotational power of the latch plate 31 is transmitted to the spindle 12 via the damper spring 18, the webbing 11 is wound up. At this time, the rotor cam 35 and the clutch wheel 30 slide and rotate against the friction spring 29. The motor 15 stops driving when the webbing 11 has been wound up.

  As shown in FIG. 6, when the motor 15 is reversed by supplying current from the controller 20, the pole 33 is rotated together with the final gear 38 in the clockwise direction of FIG. 6. However, the rotor cam 35 and the clutch wheel 30 do not rotate while being urged by the friction spring 29. Since the pole 33 is separated from the rotor cam 35 and is swung in the direction away from the latch plate 31 by the return spring 34, the pole 33 is disengaged from the teeth 39 of the latch plate 31, the clutch 17 is released, and the motor 15 In this state, the power cannot be transmitted to the spindle 12 and the power cannot be transmitted.

  As shown in FIG. 2, a sensor housing 37 that houses the rotary sensor 19 and the magnetic plate 36 is attached to the outside of the clutch housing 27. The magnetic plate 36 is coupled to the distal end portion of the joint 28, and N poles and S poles, for example, are alternately magnetized in the circumferential direction on the outer peripheral portion. The rotary sensor 19 is assembled in a non-contact manner on the outer peripheral portion of the magnetic plate 36. When the magnetic plate 36 rotates together with the joint 28, the rotary sensor 19 generates a pulse signal proportional to the rotational speed of the joint 28. Output.

  Next, the operation of the seat belt device 10 will be described with reference to FIGS. The seat belt device 10 periodically executes the control operation shown in FIG. 7 and the control operation shown in FIG.

  As shown in FIG. 7, in the first control operation, first, it is detected whether or not the seat belt is in an unused state (S101). This is because the movement of the webbing 11 of the corresponding seat is in a stopped state and the door switch 23 based on the fact that the ignition switch 25 is turned off by the controller 20 and the rotary sensor 19 is not generating a pulse signal. When the door near the corresponding seat is in a closed state based on the fact that is in the off state, a flag indicating that the seat belt is not in use is set. Or when these conditions continue and predetermined time, for example, 5 minutes, for example, you may detect that a seatbelt is in an unused state. Alternatively, when the seat switch 24 is in an OFF state and it is determined that no occupant is seated in the corresponding seat, and the door is closed by the door switch 23 near the seat, the flag indicating that the seat belt is not used. You may stand up. Alternatively, a flag indicating that the seat belt is not used may be raised simply because the ignition switch 25 is turned off. In other words, the webbing unused state detecting means for detecting the unused state of the webbing 11 may be constituted by the ignition switch 25, the rotary sensor 19, and the door switch 23. The seat switch 24 and the door switch 23 or the ignition switch 25 may be used. However, various configurations are possible.

  When the seat belt is in use, the motor 15 is not driven and the process returns. On the other hand, when the flag indicating that the seat belt is not in use is established, current is supplied from the controller 20 to drive the motor 15 to the webbing take-up side (S102). The driving force here does not have to be so strong, and it is sufficient that the clutch 17 can be turned on. For example, the webbing 11 is wound up with a winding force of 10N.

  The webbing is wound by the winding drive by the motor 15, and when the storage is completed, the webbing 11 cannot be wound any more. Therefore, the rotary sensor 19 detects whether or not the movement of the webbing 11 is stopped (S103). ). At this time, the controller 20 adds the number of pulses obtained from the rotary sensor 19 and cuts off the current supply to the motor 15 when the numerical value reaches a value (for example, n) stored in the controller 20 in advance. It is turned off and the winding drive is stopped (S104). In this state, since the spindle 12 is connected not only to the winding force of the winding spring 14 but also to the motor drive system, the webbing 11 is difficult to pull out, and as a result, the tongue does not drop due to vibration or the like.

  Next, in the second control operation shown in FIG. 8, first, it is predicted whether or not the seat belt is likely to be used (S201). As a means for predicting here, for example, a flag is established in which the door near the corresponding seat is changed from the closed state to the open state when the door switch 23 is turned on from the off state in the same manner as described above. Or when the occupant is seated on the seat because the seat switch 24 is switched from the off state to the on state. At this time, if the flag that the use of the seat belt is not predicted is established, the motor drive is not performed and the process returns. That is, the webbing use predicting means for predicting the use of the webbing 11 may be the door switch 23 or the seat switch 24, and various configurations are possible.

  When the use of the seat belt is predicted, the motor 15 is driven to rotate in the direction opposite to the webbing take-up side by supplying current from the controller 20, so that the clutch 17 is released (S202). Thereafter, the drive is stopped (S203).

  As a result, the spindle 12 is disconnected from the motor drive system in terms of power, and only a weak winding force by the winding spring 14 is applied. Therefore, when pulling out the webbing 11, it can be pulled out with a weak force, and the user can easily perform the wearing operation of the seat belt. At this time, the rotation drive of the motor 15 is sufficient if the power and the drive time are such that the clutch can be released. For example, a voltage equivalent to the battery voltage is applied to the motor under a current limit of 3 A, and the time is about 200 ms. And

  Therefore, for example, when the occupant is seated in the driver's seat and the occupant is not seated in the passenger seat, the clutch 17 is released by predicting that the webbing 11 is used in the driver's seat, The spindle 12 is in a state where only a weak winding force is exerted by the winding spring 14. As a result, when the webbing 11 is pulled out, it can be pulled out with a weak force, and the occupant can easily mount the seat belt. On the other hand, in the passenger seat, since the unused state of the seat belt is detected, the webbing 11 is maintained while being wound up by the motor 15, and the clutch 17 remains in a state where power can be transmitted. Thereby, in addition to the weak winding spring 14, the webbing 11 is hardly pulled out by the power resistance of the clutch 17 and the idling resistance of the motor 15, and the tongue does not fall by itself.

  As described above, according to the seat belt device 10, when the controller 20 detects that the webbing 11 is not in use, the controller 20 drives and controls the motor 15 to rotate in the winding direction of the webbing 11. After the winding drive, the clutch 17 remains in a state where power can be transmitted, and the webbing 11 is not easily pulled out due to the power resistance of the clutch 17 and the idling resistance of the motor 15. Is surely prevented from falling off, and it is of high quality that does not cause abnormal noise during travel or damage to the interior parts.

  Further, according to the seat belt device 10, when the use of the webbing 11 is predicted, power in the direction opposite to that for rotating the motor 15 in the winding direction is generated so that the clutch 17 cannot transmit power. Therefore, the webbing 11 can be easily pulled out during use.

The present invention is not limited to the present embodiment, and modifications, improvements, etc. can be made as appropriate.
The structure of the clutch of this embodiment is an example, and the components and the like constituting it are not limited at all.
Further, an electronic key such as an immobilizer may be used to detect an unused state of webbing and predict use. In that case, when the electronic key goes out of the predetermined range around the vehicle, it is detected that the webbing is unused, and the webbing is used when it enters the range. It is only necessary to predict that.

  This application is based on a Japanese patent application filed on October 29, 2004 (Japanese Patent Application No. 2004-316030), the contents of which are incorporated herein by reference.

Claims (2)

A spindle for winding the webbing;
A winding spring that is always connected to the spindle, and applies a winding force to the webbing that is set to such an extent that the slack of the webbing on the chest of the passenger is wound while the passenger is wearing the webbing;
A power generation unit that generates power for rotating the spindle in a desired direction,
When the power generating means generates the power to rotate the spindle in the webbing winding direction, the power generating means is in a power transmitting state capable of transmitting the power of the power generating means to the spindle. Power transmission means for making a power transmission impossible state in which the power of the power generation means cannot be transmitted to the spindle when power in a direction opposite to the power for rotating the power in the winding direction is generated;
Control means for driving and controlling the power generation means;
Webbing unused state detection means for detecting the unused state of the webbing;
With
In a seat where it is detected that the webbing is not in use when the vehicle is actually running, the control means causes the power generation means to wind the webbing so that the power transmission means can be transmitted. The spindle is connected to the power generation means after the rotation in the winding direction, and drive control is performed so that the power transmission means maintains the power transmission possible state. Seat belt device. A webbing use predicting means for predicting the use of the webbing;
Wherein, when the use of the webbing is predicted, in order to the power transmitting means to the power transmission possible state, rotate the power generating means to said take-up direction opposite to the direction, the spindle is the power 2. The seat belt device according to claim 1, wherein the seat belt device is controlled so that a winding force is applied to the spindle by the winding spring .

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