JP4278818B2 - Webbing retractor and vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a webbing take-up device that tensions a webbing in the direction of occupant restraint when a vehicle is suddenly decelerated. In particular, when preventing webbing withdrawal, the webbing take-up allows the webbing withdrawal to absorb energy. Relates to the device.
[0002]
The present invention also relates to a vehicle provided with this webbing take-up device.
[0003]
[Prior art and problems to be solved by the invention]
In the webbing take-up device, the rotation of the spool (winding shaft) in the webbing take-out direction is locked when the vehicle suddenly decelerates, and the webbing take-out is prevented. As this lock mechanism, a lock means is arranged in the vicinity of the device frame on one end side of the spool, and the lock means is activated during sudden deceleration of the vehicle, thereby preventing the spool from rotating in the webbing pull-out direction. is there.
[0004]
In such a webbing take-up device, when the webbing is prevented from being pulled out, a predetermined amount of the webbing is allowed to be absorbed so as to absorb energy. As this energy absorption mechanism, for example, there is a structure in which a torsion bar is arranged coaxially with a spool. In general, the torsion bar is coupled to a lock base having one end connected to a spool and the other end connected to a lock means so as not to rotate relative to each other. Normally, the spool and the lock base rotate together via a torsion bar.However, when the rotation of the lock base in the webbing pull-out direction is prevented during sudden deceleration of the vehicle, the spool is moved to the lock base by the webbing tension. On the other hand, it rotates in the webbing pull-out direction. At this time, the torsion bar is twisted to absorb the energy, and a predetermined amount of rotation of the spool is allowed. Such absorbed energy is determined by the product of the load applied to the webbing (force limiter load) and the webbing withdrawal amount (spool rotation amount). In the webbing take-up device, the force limiter load and the allowable rotation amount of the spool (Torsion limit of torsion bar) is given.
[0005]
However, in such a conventional webbing take-up device, the force limiter load at the time of energy absorption is governed by the material property values and dimensions of the torsion bar. For example, the weight of the occupant, the physique, the vehicle speed at the time of collision, etc. are parameters. It was possible to take only a constant value regardless of the passenger's inertial energy such as the collision energy. Further, only a constant value can be given from the start to the end of energy absorption. That is, in the conventional webbing take-up device, it is not possible to select different force limiter loads either before the vehicle sudden deceleration or in the energy absorption process.
[0006]
By the way, if the force limiter load can be reduced (select a small force limiter load) after the spool has rotated by a predetermined amount in the energy absorption process, a large force limiter load is applied at the initial stage of the vehicle sudden deceleration to cause the spool rotation amount. By increasing the energy absorption amount per (webbing withdrawal amount), the webbing withdrawal amount (occupant movement amount) can be suppressed. On the other hand, after the predetermined energy absorption, the load (load) acting on the occupant can be reduced by reducing the force limiter load.
[0007]
In particular, in a vehicle equipped with an airbag device, it is possible to reduce the total load acting on the occupant by reducing the force limiter load immediately before the contact between the airbag and the occupant, thereby further reducing occupant injury. it can.
[0008]
Therefore, a webbing take-up device that can select different force limiter loads depending on the inertial energy of the occupant is considered, but in such a conventional webbing take-up device, in order to be able to change the force limiter load, for example, The structure is complex because it has multiple torsion bars and the energy absorption position is changed by changing the torsion bar or its combination that absorbs energy, or by combining the torsion bars of different diameters coaxially. It was.
[0009]
In consideration of such facts, the first object of the present invention is to obtain a webbing take-up device that has a simple structure and that can select different force limiter loads.
[0010]
A second object of the present invention is to provide a vehicle that includes the webbing take-up device and the airbag device described above, and that can reduce a load acting on an occupant.
[0011]
[Means for Solving the Problems]
In order to solve the first problem, a webbing take-up device according to the invention of claim 1 includes a cylindrical spool from which the webbing is taken up and pulled out, and is coaxial with the spool at one end side of the spool. A lock base provided so as to be rotatable relative to the lock base; and a lock means that is connected to the lock base and engages with the frame to prevent rotation of the lock base in the webbing pull-out direction when a predetermined acceleration is detected. The spool is provided coaxially with the spool, and one end is connected to the spool and the other end is connected to the lock base. Usually, the spool and the lock base are rotated together to form the lock. In the state where the rotation of the lock base in the webbing pull-out direction is prevented by the means, the spool is twisted by the webbing tension while the spool is A torsion bar that rotates relative to the webbing pull-out direction, a piston that can be engaged with the spool, a cylinder that is fixed to the frame and into which the piston is inserted, and a gas that is communicated with the cylinder and is contained in the cylinder. Gas supply means capable of supplying the gas, and when the vehicle suddenly decelerates, the gas supply device is operated, and the piston slides in the cylinder to forcibly rotate the spool to occupy the webbing A pretensioner mechanism that tensions in the restraining direction; ,in front Gas discharge means that can discharge the gas supplied to the cylinder When, With Tau Webbing take-up device The gas discharge means is arranged to be engageable with the hole provided in the cylinder, a cover member capable of closing the hole, and the cover member, and the hole can be opened and closed by moving the cover member And configured with It is characterized by that.
[0012]
In the webbing take-up device according to the first aspect, the spool and the lock base are connected to each other via a torsion bar, and these usually rotate integrally. Further, in the pretensioner mechanism, the piston and the spool are normally in a non-engaged state, and the piston does not become an obstacle to the rotation of the spool. For this reason, usually, the webbing can be freely taken out.
[0013]
When the vehicle suddenly decelerates, the gas supply device of the pretensioner mechanism is activated to supply gas into the cylinder. Due to the pressure of this gas, the piston slides while engaging with the spool, so that the spool is forcibly rotated in the webbing take-up direction, loosening of the webbing is removed, and the occupant is closely attached (pretensioner mechanism). Is finished).
[0014]
After the pretensioner mechanism is actuated, when a webbing tensile force due to the inertial energy of the occupant acts, the process proceeds to an energy absorption stage that allows a predetermined amount of webbing withdrawal.
[0015]
At this time, since the predetermined acceleration (deceleration) at the time of sudden deceleration of the vehicle has already been detected, the locking means is activated and engaged with the frame, and the rotation of the lock base in the webbing pull-out direction is prevented.
[0016]
Here, for example, when the vehicle suddenly decelerates at the time of a vehicle collision or the like, the weight of the occupant, the vehicle speed immediately before the sudden deceleration, the acceleration (deceleration), etc. are detected, and the force limiter load is changed according to the occupant's inertial energy When the inertia energy of the occupant is small, the gas discharge means is operated immediately after the pretensioner mechanism is operated, and the gas in the cylinder is discharged.
[0017]
At this time, the webbing tensile force accompanying the inertial movement of the occupant acts as a rotational force in the webbing pull-out direction on the torsion bar via the spool. Here, when the spool is rotated in the webbing pull-out direction, the piston is moved in the initial position return direction. However, since the gas in the cylinder is discharged, no resistance force is generated due to the movement of the piston.
[0018]
For this reason, while the torsion bar is twisted and the load acting on the webbing (occupant) is kept constant (only the torsion load of the torsion bar acts as a constant force limiter load), the spool moves in the webbing pull-out direction with respect to the lock base. The webbing is pulled out and the energy is absorbed.
[0019]
On the other hand, when the inertia energy of the occupant is large, the gas discharge means is not operated immediately after the pretensioner mechanism is operated. For this reason, a gas compression load or a load due to pressure loss due to gas leakage (a load given by the product of the pressure difference inside and outside the cylinder and the cross-sectional area of the piston) is generated as the piston moves in the initial position return direction.
[0020]
At this time, when the webbing tensile force is applied, in addition to the torsional load of the torsion bar described above, a load due to a gas compression load or a gas loss pressure loss acts on the webbing (occupant) as a force limiter load. That is, a force limiter load larger than the force limiter load obtained only by the torsion load of the torsion bar is obtained, and appropriate energy absorption is achieved by suppressing the webbing pull-out speed (spool rotation speed).
[0021]
Therefore, a different force limiter load can be selected depending on whether or not the gas discharge means is activated.
[0022]
Further, when the spool is rotated by a predetermined amount during the energy absorption process, the spool and the piston are disengaged (for example, the length of the piston that engages and moves with the spool corresponds to the allowable pulling amount of the webbing). If the inertial energy of the occupant is large and the gas discharging means is not operated, the force limiter load can be reduced in the energy absorption process. That is, until the spool rotates by a predetermined amount, the large force limiter load described above acts and primary energy absorption is achieved. On the other hand, when the spool is rotated by a predetermined amount, the engagement between the spool and the piston is released, so the webbing tensile force acts only as the rotational force of the torsion bar, and the load due to the compression loss of gas or the pressure loss of gas leakage The force limiter load is reduced by this amount. At this time, secondary energy absorption is performed while only the torsional load of the torsion bar acts as a force limiter load.
[0023]
Furthermore, if necessary, by operating the gas discharging means in the first energy absorption process, the force limiter load can be reduced at any time and the process can proceed to the second energy absorption process.
[0024]
Thus, in the webbing retractor according to the first aspect of the present invention, the structure is simple and different force limiter loads can be selected.
[0026]
Claims 1 In the described webbing take-up device, the piston is normally slid by the gas pressure when the cover member closes the hole provided in the cylinder when the pretensioner mechanism is operated. On the other hand, when the gas in the cylinder is discharged as necessary, the driving means moves the cover member to open the hole provided in the cylinder. Thereby, the gas in a cylinder is discharged | emitted reliably and a small force limiter load is selected.
[0027]
Thus, the claim 1 In the webbing take-up device described in 1), the structure is simpler, and different force limiter loads can be reliably selected.
[0028]
Claims 2 The webbing take-up device according to the invention of claim 1 In the webbing take-up device described above, the hole is provided in the cylinder body, the cover member is formed with a hole corresponding to the hole, and is disposed on the outer peripheral portion of the cylinder, and is rotatable relative to the cylinder. It is characterized by being a ring member.
[0029]
Claim 2 In the described webbing take-up device, when the pretensioner mechanism is operated, the ring member closes the hole provided in the cylinder body, so that the piston is normally slid by the gas pressure. On the other hand, when the gas in the cylinder is discharged as necessary, the driving means rotates the ring member on the outer periphery of the cylinder. As a result, when the position of the hole provided in the ring member coincides with the position of the hole provided in the cylinder, the hole provided in the cylinder is opened, and the gas in the cylinder is surely discharged so that a small force limiter load is applied. Is selected.
[0030]
Thus, the claim 2 In the webbing take-up device described in 1), the structure is much simpler, and different force limiter loads can be selected more reliably.
[0031]
And claims 3 The webbing take-up device according to the present invention is the first aspect. Or Claim 2 The webbing take-up device described above is characterized in that a small hole capable of discharging the gas in the cylinder is provided.
[0032]
Claim 3 In the described webbing take-up device, if the gas discharging means is not operated when energy is absorbed after the pretensioner mechanism is activated, if the webbing tensile force acts as a moving force of the piston via the spool, the gas remaining in the cylinder is removed. The piston is moved in the initial position return direction while reliably discharging from the small hole (releasing the gas pressure from the small hole). As a result, only a stable load (a load given by the product of the pressure difference inside and outside the cylinder and the cross-sectional area of the piston) due to the pressure loss due to gas discharge is not affected by the load due to the compression of gas that shows unstable behavior. Acts as a force limiter load.
[0033]
Thus, the claim 3 In the webbing take-up device described in 1), the structure is much simpler, and different force limiter loads can be selected more reliably.
[0034]
In order to solve the second problem, a claim is provided. 4 The vehicle according to the present invention is the first aspect. ~ Claim 3 A vehicle including the webbing take-up device according to any one of the above, and an airbag device, wherein the gas discharge means is operated immediately before contact between the airbag and an occupant.
[0035]
Claim 4 In the vehicle described above, the force limiter load is reduced by operating the gas discharge means immediately before the contact between the airbag and the occupant. Therefore, a large force limiter load is applied before the contact between the airbag and the occupant. Thus, the amount of energy absorbed per hour can be increased to suppress the webbing withdrawal amount (occupant movement amount). On the other hand, after the contact between the airbag and the occupant, the injury to the occupant can be further reduced by applying a smaller force limiter load to reduce the force acting on the human body from the outside.
[0036]
Thus, the claim 4 The described vehicle includes the webbing take-up device and the airbag device described above, and can reduce the load acting on the occupant.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0038]
FIG. 1 shows an overall configuration of a webbing take-up device 10 according to the present embodiment.
[0039]
The webbing take-up device 10 includes a frame 12. The frame 12 includes a pair of opposing leg pieces 12A and 12B, and a back piece 12C that connects the leg pieces, and is formed in a substantially U-shape. The back piece 12C extends downward, and its lower end is bolted to the vehicle body and fixed.
[0040]
Between the leg pieces 12A and 12B facing the frame 12, a cylindrical spool 14 whose axial direction is the opposite direction of the leg pieces 12A and 12B is provided. One end of a webbing 26 is locked to the spool 14, and the webbing 26 can be wound and pulled out of the spool 14 by the rotation of the spool 14.
[0041]
In the cylinder of the spool 14, a lock base 16 is disposed at the end on the leg piece 12A side. The lock base 16 is coaxially and rotatably supported by the spool 14 at the opening of the leg piece 12 </ b> A of the frame 12. The lock base 16 is connected to a lock plate 24 that constitutes a lock means. When an acceleration sensor (not shown) detects a predetermined acceleration (deceleration), the lock plate 24 is engaged with the frame 12 to rotate the lock base 16. Is configured to prevent.
[0042]
Further, the lock base 16 is inserted with a hexagonal portion of a torsion bar 20 disposed at an in-cylinder shaft center portion of the spool 14, and the lock base 16 always rotates integrally with the one-side hexagonal portion of the torsion bar 20. It is configured as follows.
[0043]
On the other hand, a sleeve 18 is disposed at the end of the spool 14 cylinder on the side of the leg piece 12B. The sleeve 18 is integrally connected to the spool 14 by fitting the spline-shaped teeth 20, and is supported coaxially and rotatably with the spool 14 at the opening of the leg piece 12 </ b> B. The distal end portion of the sleeve 18 protrudes outward from the leg piece, and a mainspring spring (not shown) is provided at the end of the protruding portion. As a result, the sleeve 18 is always urged to rotate in the direction of winding the webbing 34.
[0044]
Further, the sleeve 18 is connected to the lock base 16 by inserting the other end hexagonal portion of the torsion bar 20 described above. Thus, normally, the spool 14, the sleeve 18, the torsion bar 20, and the lock base 16 are configured to rotate integrally.
[0045]
The webbing take-up device 10 includes a pretensioner mechanism 30, and the pretensioner mechanism 30 includes a pinion 32. The pinion 32 is connected to the outer end of the spool 14 of the sleeve 18, and always rotates integrally with the spool 14 via the sleeve 18. For this reason, when the pinion 18 rotates, the spool 14 rotates and the webbing 26 can be wound or unwound.
[0046]
A cylinder 34 is fixed to the leg piece 12B. The cylinder 34 is formed in a cylindrical shape, and an upper end is opened near the pinion 32. A piston 38 is provided in the cylinder 34. The bottom portion of the piston 38 is formed in a disc shape, and is slidable in the cylinder 34. A seal holding part 42 is connected to the bottom of the piston 38, and an O-ring 44 for sealing between the inner wall of the cylinder 34 is fitted to the outer periphery of the seal holding part 42.
[0047]
On the other hand, a recess 36 is integrally formed at the bottom of the cylinder 34. The recess 36 is smaller in diameter than the cylinder inner diameter, and the cylinder 34 and the recess 36 are stepped. The O-ring 44 is engaged with the stepped portion so that the piston 38 does not bottom. The position at which the O-ring 44 engages with the stepped portion is the initial position of the piston 38.
[0048]
A gas supply device 46 is connected to the cylinder 34, and a control means 48 is connected to the gas supply device 46. Thus, at the time of sudden deceleration of the vehicle, the control means 48 operates the gas supply device 46, and the piston 38 is moved in the direction of arrow A in FIG.
[0049]
Further, as shown in FIG. 2, the cylinder 34 is provided with a hole 34A through the cylinder. A ring 50 is provided on the outer periphery of the cylinder 34. The ring 50 has a hole 50 </ b> A corresponding to the hole 34 </ b> A and is installed to be rotatable relative to the cylinder 34. Further, the driving means 52 is connected to the ring 50. The drive means 52 can rotate the ring 50 around the cylinder 34. Accordingly, the hole 34A is normally closed by the ring 50, and the gas in the cylinder can be discharged by aligning the positions of the hole 34A and the hole 50A when the driving means is operated.
[0050]
The driving means may be a linear motion actuator having a solenoid or a gas generator, or a rotational motion motor.
[0051]
On the other hand, a rack 40 is integrally provided at the tip of the piston 38. The rack 40 corresponds to the pinion 32 described above, and is normally positioned with a predetermined gap from the pinion 32 (disengaged). As a result, when the rack 40 slides in the cylinder 34 together with the piston 38 in the tip direction of the piston 38 (upward in FIG. 1), the rack 40 meshes with the pinion 32 so as to rotate the pinion 32 in the winding direction of the webbing 26. It has become.
[0052]
A small hole 38 </ b> A is provided at the bottom of the piston 38. The small hole 38A communicates with the inside and outside of the cylinder 34 and is configured to discharge the gas in the cylinder when the piston 38 moves. The size of the hole 38A is determined so as not to prevent the piston 38 from moving normally when the pretensioner mechanism 30 is operated.
[0053]
Next, the operation of the present embodiment will be described.
[0054]
In the webbing take-up device 10 configured as described above, since the spool 14 and the lock base 16 are connected by the torsion bar 20, they normally rotate together. Further, the rack 40 provided in the piston 38 is not engaged with the pinion 32, and the rack 40 does not become an obstacle to the rotation of the spool 14. For this reason, normally, the webbing 26 can be freely taken out.
[0055]
When the vehicle suddenly decelerates, first, the pretensioner mechanism 30 operates. That is, when the gas supply device 46 is operated, the piston 38 is slid in the tip direction by the pressure of the gas supplied into the cylinder 34, and the rack 40 moves while meshing with the pinion 32, so that the pinion 32 is wound by webbing. It is rotated in the taking direction. As a result, the spool 14 is forcibly rotated in the webbing take-up direction, the slack of the webbing 26 is removed, and the spool 14 is tightly attached to the occupant.
[0056]
After the pretensioner mechanism 30 is actuated, the process proceeds to an energy absorption stage that allows the webbing 26 to be pulled out by a predetermined amount.
[0057]
Here, a different force limiter load is selected in advance by a control means (not shown) or immediately before the vehicle suddenly decelerates. This selection is performed according to the occupant's inertial energy based on, for example, the occupant's physique and collision type, and therefore the operation will be described separately depending on the magnitude of the occupant's inertial energy.
[0058]
At this time, since the predetermined acceleration (deceleration) at the time of sudden deceleration of the vehicle is already detected when the pretensioner mechanism 30 is operated, the lock plate 24 is engaged with the frame 12 by the operation of the lock means, and the lock The rotation of the base 16 in the webbing pull-out direction is prevented.
(When the passenger's inertial energy is small)
For example, when the weight of the occupant is small or the vehicle speed immediately before sudden deceleration is low, the inertia energy of the occupant is small.
[0059]
In this case, immediately after the operation of the pretensioner mechanism 30 is completed, the ring 50 is rotated by the driving means 52, and the position of the hole 50A matches the position of the hole 34A (see FIG. 3B). Gas is exhausted.
[0060]
At this time, the webbing tensile force accompanying the inertial movement of the occupant acts as a rotational force in the webbing pull-out direction on the torsion bar 22 via the spool 14. On the other hand, when the spool 14 is rotated in the webbing pull-out direction, the piston 38 is moved in the initial position return direction via the pinion 32. However, since the gas in the cylinder 34 is discharged, the resistance accompanying the movement of the piston 38 is increased. No force is generated.
[0061]
As a result, the torsion bar 22 is twisted and the load acting on the webbing 26 (occupant) is kept constant as shown by the broken line in FIG. 4 (only the torsion load of the torsion bar 22 acts as a constant force limiter load). ) The spool 14 is rotated in the webbing pull-out direction with respect to the lock base 16 and the webbing 26 is pulled out, thereby absorbing energy.
(When the passenger's inertial energy is large)
On the other hand, for example, when the weight of the occupant is large or when the vehicle speed immediately before sudden deceleration is high, the inertia energy of the occupant is large. In this case, immediately after the pretensioner mechanism 30 is actuated, the gas discharge means is not actuated, and the hole 34A is kept closed by the ring 50 (see FIG. 3A).
[0062]
For this reason, when gas remains in the cylinder 34 and the webbing tensile force acts and the pinion 32 rotates in reverse via the spool 14 (after reaching the spool rotation amount C shown in FIG. 4), the cylinder 34 The piston 38 is moved to the initial position while reliably releasing the pressure of the remaining gas from the small hole 38A provided in the piston 38. As a result, while the piston 38 is moved to the initial position, a stable load (a load given by the product of the pressure difference between the inside and outside of the cylinder 34 and the cross-sectional area of the piston 38) due to the pressure loss accompanying the gas discharge is a force limiter. Acts as a load.
[0063]
Therefore, when the webbing tensile force acts, in addition to the torsional load of the torsion bar 22 described above, a load due to pressure loss due to gas discharge acts on the webbing (occupant) as a force limiter load. That is, a force limiter load (F2 in FIG. 4) larger than the force limiter load (F1 in FIG. 4) obtained only by the torsion load of the torsion bar 22 is obtained, and the webbing pull-out speed (spool rotation speed) is kept low. Primary energy absorption is performed (region A shown in FIG. 4).
[0064]
Further, when the spool 14 is further rotated (spool rotation amount D shown in FIG. 4) and the piston 38 is moved to the initial position, the engagement between the pinion 38 and the rack 40 is released, so that the webbing tensile force is applied to the torsion bar 22. Acts only as a rotational force. For this reason, as shown by the solid line in FIG. 4, the force limiter load is reduced by the amount of the load due to the pressure loss accompanying the gas discharge. Therefore, secondary energy absorption is performed while only the torsional load of the torsion bar 22 acts as a force limiter load (F1 in FIG. 4) (region B shown in FIG. 4).
[0065]
In addition, since the webbing withdrawal amount permitted at the time of energy absorption is larger than the webbing take-up amount by the pretensioner mechanism 30, a force limiter load characteristic indicated by a solid line in FIG. 4 is obtained.
[0066]
Further, if necessary, the ring 50 is rotated by the driving means 52 in the first energy absorption process so that the position of the hole 50A coincides with the position of the hole 34A. The force limiter load can be decreased as shown by the one-dot chain line in FIG. 4 at the time when the spool rotation amount X is shown), and the process can proceed to the second energy absorption process.
[0067]
In the webbing retractor 10 according to the present embodiment, the small hole 38A is provided in the piston 38, but the small hole may be provided in the cylinder. Moreover, it is good also as a structure which obtains the load by the pressure loss accompanying gas discharge | release by opening a part of hole 34A. In this case, the force limiter load at the time of primary energy absorption can be adjusted by adjusting the open area of the hole 34A. Further, a small hole may be provided in the ring 50 separately from the hole 50A, and the position of the small hole may be matched with the position of the hole 34A.
[0068]
Further, in the webbing take-up device 10 according to the present embodiment, the webbing take-up force by the pretensioner mechanism 30 is adjusted by opening a hole provided in the cylinder 34 before or during operation of the pretensioner mechanism 30. It is also possible to do. The webbing take-up force is adjusted by, for example, stopping the hole 50A provided in the ring 50 at a position slightly shifted from the position of the hole 34A provided in the cylinder 34, and adjusting the open area of the hole 34A. be able to. Further, as described above, a small hole is separately provided in the ring 50, and the webbing winding force can be adjusted by making the position of the small hole coincide with the position of the hole 34A.
[0069]
Thus, in the webbing take-up device 10 according to the present embodiment, the structure is simple and different force limiter loads can be selected.
[0070]
Moreover, the webbing retractor 10 according to the above-described embodiment can be applied to a vehicle including an airbag device.
[0071]
In this vehicle, it is desirable to include a sensor and a control means for detecting the positions of the occupant and the front surface of the airbag.
[0072]
In this case, after the pretensioner mechanism 30 is actuated, when the primary energy absorption is performed without opening the hole 34A, the sensor detects that it is just before the occupant and the airbag come into contact with each other. Then, the control means operates the drive means 52 and the ring 50 is rotated. Thus, when the position of the hole 50A coincides with the position of the hole 34A, the gas in the cylinder 34 is discharged, and the force limiter load is reduced by the load due to the pressure loss accompanying the gas discharge.
[0073]
Therefore, before the contact between the airbag and the occupant, a large force limiter load is applied to increase the energy absorption amount per rotation amount of the spool 14, thereby suppressing the webbing withdrawal amount (occupant movement amount). it can. On the other hand, after the contact between the airbag and the occupant, on the other hand, after the contact between the airbag and the occupant, the force limiter load is reduced, so the total load acting on the occupant is reduced and the degree of injury to the occupant is reduced. Can be reduced.
[0074]
As described above, a vehicle including the airbag device to which the webbing take-up device 10 according to the above embodiment is applied can reduce the load acting on the occupant.
[0075]
【The invention's effect】
As described above, the webbing take-up device according to the present invention has an excellent effect that the structure is simple and different force limiter loads can be selected.
[0076]
Furthermore, the vehicle according to the present invention includes the webbing take-up device and the airbag device described above, and has an excellent effect that the load acting on the occupant can be reduced.
[Brief description of the drawings]
FIG. 1A is a side view of a webbing take-up device according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view showing the overall configuration.
FIG. 2A is a perspective view showing a state before assembly of a cylinder and a ring constituting the webbing take-up device according to the embodiment of the present invention, and FIG. 2B is a closed state of a hole provided in the cylinder. (C) is a perspective view which shows the open state of the hole provided in the cylinder.
3A is a cross-sectional view showing a closed state of a hole provided in a cylinder of a pretensioner mechanism constituting the webbing take-up device according to the embodiment of the present invention, and FIG. 3B is provided in the cylinder. It is sectional drawing which shows the open state of a hole.
FIG. 4 is a diagram showing the relationship between the webbing tension (force limiter load) of the webbing take-up device according to the embodiment of the present invention and the amount of rotation of the spool in the webbing withdrawal direction.
[Explanation of symbols]
10 Webbing take-up device
12 frames
14 Spool
16 Lock base
18 sleeve
22 Torsion bar
24 Lock plate (locking means)
26 Webbing
30 Pretensioner mechanism
32 pinion
34 cylinders
34A hole (discharge means)
38 piston
38A small hole
40 racks
46 Gas supply device
50 ring (discharge means, cover member)
50A hole
52 Drive means (discharge means)

Claims (4)

A cylindrical spool on which the webbing is taken up and pulled out;
A lock base provided coaxially with the spool and rotatably relative to one end of the spool;
Lock means connected to the lock base and engaged with a frame to prevent rotation of the lock base in the webbing pull-out direction when a predetermined acceleration is detected;
The spool is provided coaxially with the spool, one end is connected to the spool and the other end is connected to the lock base. Usually, the spool and the lock base are rotated together, and the locking means A torsion bar that rotates the spool relative to the lock base in the webbing pull-out direction while being twisted by a webbing tensile force in the webbing pull-out direction rotation prevention state of the lock base by
A piston provided so as to be engageable with the spool; a cylinder fixed to the frame and having the piston inserted therein; and a gas supply means communicating with the cylinder and capable of supplying gas into the cylinder. A pretensioner mechanism that activates the gas supply device during a sudden deceleration of the vehicle, and forcibly rotates the spool by sliding the piston in the cylinder to tension the webbing in the occupant restraint direction;
Gas discharge means capable of discharging the gas supplied to the cylinder ;
In c Ebingu winding device provided with,
The gas discharging means;
A hole provided in the cylinder;
A cover member capable of closing the hole;
Drive means arranged to be engageable with the cover member and capable of opening and closing the hole by moving the cover member;
A webbing take-up device characterized by comprising: Providing the hole in the cylinder body;
A hole corresponding to the hole is formed in the cover member, and the cover member is disposed on the outer periphery of the cylinder, and is a ring member that can rotate relative to the cylinder.
Webbing retractor according to claim 1, wherein the this. Webbing retractor according to claim 1 or claim 2, wherein the gas in the cylinder provided with a drainable stoma. A vehicle comprising the webbing retractor according to any one of claims 1 to 3 and an airbag device,
A vehicle characterized in that the gas discharge means is actuated immediately before contact between an airbag and an occupant.

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