US20060214494A1 - Seat belt retractor - Google Patents
Seat belt retractor Download PDFInfo
- Publication number
- US20060214494A1 US20060214494A1 US10/543,893 US54389304A US2006214494A1 US 20060214494 A1 US20060214494 A1 US 20060214494A1 US 54389304 A US54389304 A US 54389304A US 2006214494 A1 US2006214494 A1 US 2006214494A1
- Authority
- US
- United States
- Prior art keywords
- take
- drum
- torsion bar
- plate body
- energy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/34—Belt retractors, e.g. reels
- B60R22/46—Reels with means to tension the belt in an emergency by forced winding up
- B60R22/4676—Reels with means to tension the belt in an emergency by forced winding up comprising energy-absorbing means operating between belt reel and retractor frame
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
- B60R2022/286—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices using deformation of material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
- B60R2022/286—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices using deformation of material
- B60R2022/287—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices using deformation of material of torsion rods or tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R22/00—Safety belts or body harnesses in vehicles
- B60R22/28—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices
- B60R2022/288—Safety belts or body harnesses in vehicles incorporating energy-absorbing devices with means to adjust or regulate the amount of energy to be absorbed
Definitions
- the present invention relates to a seatbelt retractor provided with an energy-absorbing means, which, in case of a vehicle emergency, restrains a webbing from being pulled out to restrain movements of vehicle occupant and absorbs an impact load acting on the vehicle occupant.
- JP 2001-301569A discloses a webbing take-up apparatus (seatbelt retractor) including a lock base (locking base) provided on one end of a cylindrical spool (take-up drum) which winds up webbing in a manner that a relative rotation with the spool is possible, a lock means which prevents a rotation of the lockbase in the direction of the webbing pulled out in case of a vehicle emergency, a torsion bar inserted into the spool, one end of which is coupled with the spool, the other end of which is coupled with the lock base, which generates a torsional deformation in a state where the lock means prevents a rotation of the lock base in the direction of the webbing pulled out, a wire, one end of which is fixed to the lock base
- the cutting position drifts depending on the tensile force of the webbing, namely, the pull-out speed of the wire being pulled out from the spool. Accordingly, the cutting is not performed at a constant position, and the resistance in the webbing pulled out is not stabilized, which is disadvantageous.
- an object of the present invention is to solve the above conventional problems.
- the first object of the invention is to make an energy-absorbing means which provides a resistive load capable of appropriately selecting the amount of the energy absorption, and to thereby halt the wire at a constant position and stabilize the resistance in the webbing pulled out.
- the second object is to make an energy-absorbing means which halts to provide the load, and to make it capable of freely adjusting the timing of halting, in a manner that it is able to perform an optimum energy absorption in correspondence with the physical make-up of vehicle occupant, scale of a vehicle collision, and time and so forth.
- the third object is to make an energy-absorbing members not generate excessive energy absorptions in switching the resistive loads, and to stabilize the provision of load by the energy-absorbing members, so that the vehicle occupant can easily be halted at specified positions.
- a seatbelt retractor comprises a take-up drum on which webbing is wound, a take-up shaft, one end of which is coupled with one end of the take-up drum in a manner that a relative rotation with the take-up drum is impossible, which is biased in the direction of the webbing taken up, an emergency lock mechanism which restrains a rotation in the direction of the webbing pulled out, a clutch mechanism located near the other end of the take-up shaft, a plate body provided close to a side on the other end of the take-up drum, which is provided on the other end of the take-up shaft through the clutch mechanism, and an energy-absorbing means located between the side of the take-up drum and the plate body, which provides a resistive load by mutually performing a relative rotation, wherein the clutch mechanism switches a first state where the plate body is provided on the other end of the take-up shaft in a manner that a relative rotation with the take-up shaft is impossible into a second state where the plate body is provided on the other end of
- a seatbelt retractor comprises a take-up drum on which webbing is wound, a torsion bar inserted through the take-up drum, one end of which is coupled with one end of the take-up drum in a manner that a relative rotation with the take-up drum is impossible, which is biased in the direction of the webbing taken up, an emergency lock mechanism located on the other end of the torsion bar, which restrains a rotation in the direction of the webbing pulled out, a lock actuating device which actuates the emergency lock mechanism in case of a vehicle emergency, a clutch mechanism located near the other end of the torsion bar, a plate body provided close to a side on the other end of the take-up drum, which is provided on the other end of the torsion bar through the clutch mechanism, and a second energy-absorbing means located between the side of the take-up drum and the plate body, which provides a resistive load by mutually performing a relative rotation, wherein the clutch mechanism switches a first state where the plate body
- the lock actuating device actuates the emergency lock mechanism in case of a vehicle emergency
- the other end of the take-up shaft or the torsion bar is restrained from rotating in the direction of the webbing pulled out, and the take-up drum is also restrained from rotating.
- the one end of the take-up shaft or the torsion bar 4 is coupled with the take-up drum being driven to rotate in a manner that a relative rotation is impossible, and the other end thereof is coupled with the emergency lock mechanism which has restrained the rotation in a manner that a relative rotation is impossible, therefore, the take-up shaft or the torsion bar, while generating a torsional deformation, rotates the take-up drum.
- the take-up shaft or the torsion bar (first energy-absorbing means) and the second energy-absorbing (EA) means are in operation.
- the clutch mechanism being put in operation through a clutch actuating mechanism at an arbitrary timing switches the plate body into the second state where the plate body is able to rotate relatively with the other end of the take-up drum or the torsion bar, and the clutch mechanism makes the take-up shaft or the torsion bar alone perform the energy absorption (EA).
- the provision of the resistive load is stopped without any contact with the energy-absorbing means (wire) being the second energy-absorbing means, excessive energy absorption is not generated in the switching, the provision of load becomes stabilized, and the vehicle occupant can easily be halted at specified positions.
- a seatbelt retractor is that, in the seatbelt retractor according to the second aspect of the invention, the clutch mechanism includes in a manner that a relative rotation with the emergency lock mechanism is impossible, at least one joint pawl pivoted to be turnable to a side of the plate body on the opposite side to the take-up drum, which comes in contact with the joint plate to turn outwardly, a release ring retained by a casing fixed on a side plate of a housing on the other end of the torsion bar to be movable in the axial direction while rotating, which is located on a periphery of the joint pawl; and a clutch release mechanism which actuates the release ring attached to the casing.
- the lock actuating device actuates the emergency lock mechanism
- the torsion bar and the second energy-absorbing (EA) means provide loads in practice
- the webbing is pulled and the take-up drum is rotated in the direction of the webbing pulled out.
- the plate body slightly rotates integrally with the take-up drum, so that a relative rotation is generated between the plate body and the joint plate coupled with the emergency lock mechanism to be impossible of a relative rotation, and the inner circumference of the joint pawl comes in contact with the joint plate, which presses the joint pawl outwardly.
- the joint pawl Since-the release ring is located on a periphery of the joint pawl, the joint pawl is restrained from expanding outwardly. As the clutch release mechanism actuates the operation, the release ring is made to move in the axial direction of the torsion bar while rotating, and is detached from the circumference of the joint pawl, and hence the joint pawl expands outwardly. Since the plate body is accordingly detached from the joint plate which has restrained the rotation of the plate body, the plate body rotates integrally with the take-up drum, the provision of the resistive load by the wire (energy-absorbing member) is halted, and only the energy absorption (EA) by the torsion bar is performed.
- EA energy absorption
- the plate body rotates integrally with the take-up drum in the normal use of the seatbelt retractor
- the emergency lock mechanism actuates the operation
- the plate body is put into the state where it cannot rotate integrally with the take-up drum
- the clutch release mechanism of the clutch mechanism actuates the operation
- the clutch mechanism can be easily installed.
- the load of the energy-absorbing means becomes zero without increasing, and the switching of the load can smoothly be performed.
- a seatbelt retractor is that, in the seatbelt retractor according to the third aspect of the invention, the clutch release mechanism includes a gas generator which generates gas in a cylinder attached to the casing at an arbitrary timing, and a piston pressed and driven by a gas pressure in the cylinder, which presses the circumference of the release ring to rotate the release ring.
- a seatbelt retractor is that, in the seatbelt retractor according to the fourth aspect of the invention, the release ring is provided with a contact on the circumference thereof, which comes in contact with the piston, and plural tapered parts located with a uniform spacing on the circumference thereof, and the casing which holds the release ring is provided with projections corresponding to the tapered parts of the release ring.
- the tapered parts provided on the circumference of the release ring are guided to the projections of the casing, and the release ring being rotated is made to move in the axial direction of the torsion bar.
- the tapered parts are located on the circumference of the release ring with a uniform spacing, it is possible to move the release ring in a state where the plane of the release ring is vertical to the axis.
- the piston driven by the gas pressure rotates the release ring in one breath, and it can release the joint pawl toward the circumference at once in defiance of the frictional resistance by contacts.
- the release ring Since the release ring is made to move in the state where the plane of the release ring is vertical to the longitudinal direction of the torsion bar, the contact of the joint pawl with the release ring is released at once, in the switching of the clutch, there is not any excessive load generated, except the load supplied by the second energy-absorbing means.
- a seatbelt retractor is that, in the seatbelt retractor according to any one of the first through the fifth aspects of the invention, the clutch mechanism is provided with a pawl holder which positions and supports the joint pawls, and the pawl holder is provided with ribs integrally formed thereon, which biases the joint pawls in the axial direction and will not return the joint pawls to the initial positions after operating the joint pawls.
- the positions of the joint pawls in the first state are maintained by biasing the springs.
- the outwardly expanded joint pawls are restrained from returning to the initial positions by the ribs of the pawl holder, and are retained at the positions where they are expanded. Further, the joint pawls retained there restrain the release ring from returning to the circumference of the joint pawls.
- a seatbelt retractor is that, in the seatbelt retractor according to any one of the second through the sixth aspects of the invention, the second energy-absorbing means includes a curved path provided on a side of the take-up drum on the other end of the torsion bar, and a wire, one end of which is fixed to a take-up part of the plate body, a substantially medium part of which is located in the curved groove.
- the joint pawls are biased by a spring force, if, in the normal use of the seatbelt retractor, the joint pawls are made to rotate together with the take-up drum and so forth, the joint pawls will be positioned at the specified positions, which stabilizes the operation of the joint pawls.
- the plate body prevents the joint pawls and the release ring from returning to specified positions in the first state where the plate body is provided on the other end of the take-up drum in a manner that a relative rotation is impossible from the second state where the plate body is provided on the other end of the take-up drum in a manner that a relative rotation is possible. Therefore, it is possible to stabilize a resistive load by the torsion bar without adding a load by the second energy-absorbing means.
- FIG. 1 is a front view of the whole seatbelt retractor according to the present invention.
- FIG. 2 is an exploded perspective view explaining the assembling of a housing, a take-up drum, a torsion bar, a locking base, a base stopper, and so forth of the seatbelt retractor illustrated in FIG. 1 ;
- FIG. 3 is an exploded perspective view explaining the assembling of the take-up drum, the plate assembly, a retainer, and a pawl holder;
- FIG. 4 is an exploded perspective view explaining the assembling of a plate assembly which is illustrated in FIG. 3 ;
- FIG. 5 is a side view of the plate assembly
- FIG. 6 is a front view partly in section of the plate assembly
- FIG. 7 is a partly enlarged front view in section illustrating another embodiment of the plate assembly
- FIG. 8 is a front view in section of an assembly in which the plate assembly and the take-up drum illustrated in FIG. 3 are assembled;
- FIG. 9 is a partly cutaway side view of the assembly illustrated in FIG. 8 ;
- FIG. 10 is a front view in section, in which the assembly illustrated in FIG. 8 is turned;
- FIG. 11 is a partly cutaway side view of the assembly illustrated in FIG. 10 ;
- FIG. 12 is an exploded perspective view explaining the assembling of a housing, a casing, and so forth, which are illustrated in FIG. 2 ;
- FIG. 13 is an exploded perspective view of a release ring, the casing, a piston, a gas generator, a gas generator holder, and so forth;
- FIG. 14 is an enlarged perspective view of the pawl holder
- FIG. 15 is an enlarged perspective view of a joint pawl
- FIG. 16 is a partly cutaway side view of a clutch mechanism before actuating the operation
- FIG. 17 is a plan view in section of the clutch mechanism illustrated in FIG. 16 ;
- FIG. 18 is a partly cutaway side view explaining a state where the clutch mechanism is engaged (first state);
- FIG. 19 is a plan view in section of the clutch mechanism illustrated in FIG. 18 ;
- FIG. 20 is a partly cutaway side view explaining a state where the clutch mechanism is released (second state);
- FIG. 21 is a plan view in section of the clutch mechanism illustrated in FIG. 20 ;
- FIG. 22 is an exploded perspective view explaining the assembling of the locking base, a lock clutch, a cover, and so forth;
- FIG. 23 is an exploded perspective view explaining the assembling of the torsion bar, the lock pawl, the locking base, and so forth;
- FIG. 24 is a diagram illustrating the relation between a tensile force acting on the webbing and the amount of the webbing pulled out.
- FIG. 1 is a front view of the whole seatbelt retractor according to the invention
- FIG. 2 is an exploded perspective view explaining the assembling of a take-up drum 2 , a connector 3 , a housing 9 , a torsion bar 4 , a locking base 5 , a base stopper 7 , and so forth which constitute the major part of the seatbelt retractor illustrated in FIG. 1 .
- the seatbelt retractor is provided with the substantially cylindrical take-up drum 2 on which webbing is wound.
- the torsion bar 4 is inserted through the center of the take-up drum 2 , and one end of the torsion bar 4 is coupled integrally with one end of the take-up drum 2 by means of the connector 3 , described later, and it is supported by a pair of side plates ( 9 b , 9 c ) to freely rotate.
- a spiral spring 19 ( FIG. 1 ) is mounted on the side plate 9 c , which constantly biases the take-up drum 2 to rotate in the take-up direction of the webbing, and the torsion bar 4 is biased to rotate in the take-up direction of the webbing.
- the seatbelt retractor in this embodiment has the structure which winds up slackness in the webbing by a gas pressure, and so forth in case of a vehicle emergency such as a collision, and restrains the movements of vehicle occupant by a pretensioner 15 ( FIG. 1 ) furnished on the side plate 9 c.
- the locking base 5 resembling a substantially disk-like shape is coupled integrally with the other end outside of the torsion bar 4 on the side of the side plate 9 b of the housing, and it constitutes an emergency lock mechanism which restrains a rotation in the direction of the webbing pulled out.
- a clutch mechanism located near the other end of the torsion bar 4 , while a second energy-absorbing means, described later, is located on the other end of the torsion bar 4 , close to the side on the other end of the take-up drum 2 , wherein the torsion bar 4 (first energy-absorbing means) and the second energy-absorbing means perform the absorption of impact energy in case of a vehicle emergency.
- the housing 9 is made from a metal plate by a press-molding in a manner the right and left side plates ( 9 b , 9 c ) rise up from both the sides of a back-plate fixed to the vehicle body, and the section of the housing forms a substantially U-letter.
- the base stopper 7 is to prevent the locking base 5 from coming off from the take-up drum 2 .
- the one end of the torsion bar 4 is engaged with a hole of the connector 3 having the same shape thereof, and the other end is coupled with the locking base 5 to be able to rotate integrally.
- the connector 3 is supported to freely rotate with the opening 9 d bored on the side plate 9 c of the housing 9 , and it is also engaged with a hexagonal engagement recess being formed on the one end of the take-up drum 2 to correspond with the external shape of the connector 3 , whereby the torsion bar 4 is capable of rotating integrally with the take-up drum 2 .
- the emergency lock mechanism actuates the operation and the other end of the torsion bar 4 is fixed, the one end of the torsion bar 4 will rotate integrally with the take-up drum 2 by the webbing being pulled out. That is, the torsion bar 4 is twisted by the rotational force of the take-up drum 2 , thus the energy of pulling out the webbing can be absorbed by the torsion resistance thereof.
- the torsion bar 4 functions as the first energy-absorbing means.
- FIG. 3 is an exploded perspective view explaining the assembling of a plate assembly 2 e .
- the plate assembly 2 e comprises a plate body 2 a , a spiral wire 2 b with plural winds, and a disk member 2 c having plural projections 2 q located circumferentially around a center hole.
- one end 2 g of the wire is fixed to the plate body 2 a , and the other end 2 h of the wire is suspended to the backside of the disk member 2 c (viewed from FIG. 3 ).
- FIG. 4 is an exploded perspective view illustrating the whole of the second energy-absorbing means.
- the plate assembly 2 e and the take-up drum 2 are attached with a retainer 2 d.
- FIG. 5 is a side view of the plate assembly 2 e
- FIG. 6 is a front view partly in section of the same, wherein the plate assembly 2 e is assembled with the plate body 2 a , the wire 2 b , and the disk member 2 c , as illustrated in FIG. 3 .
- a substantially circular receiving recess 2 f which constitutes a part of the second energy-absorbing means is formed on the side where the locking base is mounted on the take-up drum 2 , namely, on the end face of the left side in the drawing. Further, an engagement hole 2 k which receives a boss 5 c ( FIG. 2 ) of the locking base is formed on the center of the receiving recess 2 f .
- the engagement pins 14 to be engaged with the wire 2 b are formed at specified places on the periphery of the receiving recess 2 f positioned outside the engagement hole 2 k on the bottom face. And, the slopes 2 t ( FIG. 5 ) are formed at the specified places for engaging with the wire 2 b .
- three semi-circular engagement pins 14 are formed integrally to project from the bottom face of the receiving recess 2 f along the circumference thereof, wherein the wire 2 b is formed in spiral, and the circumference 2 i thereof ( FIG. 3 ) is formed in curvature, which conforms to the circular sliding face of the engagement pins 14 .
- FIG. 5 is a side view of the plate assembly 2 e in which the individual components illustrated in FIG. 3 are assembled.
- the disk member 2 c and the plate body 2 a are engaged integrally with each other in a state where the spiral wire 2 b is interposed between both. That is, the plate body 2 a and the disk member 2 c form a take-up part 2 m with a distance approximately equivalent to the diameter of the wire 2 b , and the disk member 2 c is coupled with the plate body 2 a in a manner that a relative rotation between both is impossible.
- the curved one end 2 g of the wire 2 b is placed and fixed in a curved groove 2 n ( FIG. 6 ) of the plate body 2 a.
- the wire 2 b having the one end thereof fixed to the plate body 2 a passes through the gap between the plate body 2 a and the disk member 2 c , and when the take-up drum 2 and the plate assembly 2 e perform a relative rotation, the wire 2 b reaches the upper face of the plate body 2 a being the take-up part 2 m.
- the disk member 2 c covers take-up part 2 m of the plate body 2 a and the one end 2 g of the wire 2 b in the assembly state.
- FIG. 6 is a front view which shows the internal structure of the plate assembly 2 e , part of which is sectioned.
- the curved groove 2 n is formed on the take-up part 2 m of the plate body 2 a by means of substantially semi-circular plural projections 2 p, and the one end 2 g of the wire 2 b is placed in the curved groove 2 n and is coupled therewith.
- the curvature radius of the curved groove 2 n is formed smaller than that of the curved path 2 j ( FIG. 4 ) of the take-up drum 2 .
- FIG. 7 illustrates another embodiment of the curved groove 2 n.
- the plural projections 2 p of the plate body 2 a at least one set of ribs 2 r facing to each other are formed between the projections 2 p forming the curved groove 2 n , and the gap between the ribs 2 r is made narrower than the diameter of the wire 2 b.
- FIG. 8 is a front view in section illustrating a state where the take-up drum 2 illustrated in FIG. 4 and the plate assembly 2 e are assembled
- FIG. 9 is a partly cutaway side view of the assembly illustrated in FIG. 8
- FIG. 10 is a front view in section, illustrating a state where the take-up drum 2 rotates to a certain degree after the emergency lock mechanism actuates the operation in the assembly illustrated in FIG. 8
- FIG. 11 is a partly cutaway side view in the same state.
- the second energy-absorbing means having the above construction is contained in a space delimited between the take-up drum 2 and the locking base 5 .
- the emergency lock mechanism actuates the operation, as the take-up drum 2 rotates, the wire 2 b illustrated in FIG. 8 and FIG. 9 is wound into the take-up part 2 m, as illustrated in FIG. 10 and FIG. 11 .
- the wire 2 b relatively moves between the disk member 2 c and the plate body 2 a , along the curved circumference 2 i projected from the circumferential face of the disk member 2 c , while sliding on the three semi-circular engagement pins 14 of the take-up drum 2 .
- the emergency lock mechanism actuates the operation, in case of a vehicle emergency such as a collision, the locking base 5 coupled with the other end of the torsion bar 4 is blocked in rotating in the direction of the webbing pulled out. And, when a rotational torque more than a predetermined value acts on the take-up drum 2 , due to the load acting on the webbing, the one end of the torsion bar 4 (first energy-absorbing means) actuates a torsional deformation.
- the take-up drum 2 rotates to a degree corresponding to the torsional deformation in the torsion bar 4 , and at the same time, the other end of the torsion bar 4 , which is fixed, rotates in the direction of the webbing pulled out, whereby the impact energy is absorbed. And, the actuation of the torsional deformation in the torsion bar 4 generates a relative rotation between the take-up drum 2 and the locking base 5 . The absorption of the impact energy by the second energy-absorbing means actuates based on this relative rotation.
- the plate body 2 a to which the one end 2 g of the wire 2 b is fixed is coupled with the locking base 5 , and it does not rotate, while since the engagement pins 14 formed integrally with the take-up drum 2 turn, the wire 2 b is pulled between the engagement pins 14 . That is, the wire 2 b slides between the engagement pins 14 while being positioned by the slopes 2 t, while being sequentially pulled to meander between the engagement pins 14 . At this moment, there generate a high sliding resistance and a bending resistance in the wire 2 b , and hence the sliding resistance and the bending resistance absorb the impact energy.
- both the torsion bar 4 (first energy-absorbing means) and the second energy-absorbing means operate as the energy-absorbing mechanism, and absorb the impact energy in case of a vehicle emergency.
- the clutch mechanism releases the engagement of the plate body 2 a with the locking base 5 of the emergency lock mechanism, and puts the plate body 2 a from the state of a relative rotation with the take-up drum 2 being possible into the state of a united rotation with the take-up drum 2 being possible with the locking base 5 detached.
- This clutch mechanism switches the first state where a relative rotation of the plate body 2 a with the other end of the torsion bar 4 is impossible into the second state where a relative rotation of the plate body 2 a with the other end of the torsion bar 4 is possible. It also comprises the clutch release mechanism which actuates the switching at an arbitrary timing after detecting a vehicle collision.
- the clutch mechanism comprises, as shown in FIG. 2 , a joint plate 5 b ( FIG. 23 ) coupled with the emergency lock mechanism in a manner that a relative rotation is impossible, and three joint pawls 12 being pivoted to be turnable on the opposite side of the take-up drum 2 to the plate body 2 a , which are in face contact with the joint plate 5 b to turn outward.
- the joint pawl 12 ( FIG. 15 ) is a bow-formed member, and a pin 12 b is formed on the one end thereof.
- the pin 12 b is pivoted on the opposite side of the take-up drum 2 to the plate body 2 a .
- the joint pawl 12 turns with the pin 12 b as the center.
- the joint pawl 12 has an inner projection 12 a ( FIG. 15 ) formed on the center of the inner wall, and a notch 12 c ( FIG. 15 ) formed on the other end inside.
- a pawl holder 13 (resin spring) ( FIG. 14 ) in a sectional concave and circular form is provided in order to position and support the joint pawls 12 .
- the pawl holder 13 is provided, on the circumference thereof in correspondence with the positions of the joint pawls 12 , with nail-formed parts 13 c each having ribs 13 a formed thereon. Inwardly slant slopes 13 b formed on the ribs 13 a and the nail-formed parts 13 c come into contact with the outer faces of the joint pawls 12 . This contact and the resin spring functions to bias the joint pawls 12 continuously toward the axial center.
- the plate body 2 a is provided with projections 2 s which restrain the joint pawls 12 from turning relative to the plate body 2 a immediately after the joint pawls 12 climb over the ribs 13 a of the pawl holder 13 , the joint pawls 12 are clamped by the rib backsides 13 d of the pawl holder and the projections 2 s of the plate body so that the joint pawls 12 are prevented from turning to the plate body 2 a.
- FIG. 12 is an exploded perspective view explaining the assembling of a release ring 8 , the housing 9 , a casing 10 , and so forth being the components for releasing the clutch.
- FIG. 14 is an enlarged exploded perspective view of the release ring 8 , the casing 10 , a piston 10 a , a gas generator 10 b , a gas generator holder 11 , and so forth, which are illustrated in FIG. 13 .
- the clutch release mechanism will be described with reference to FIG. 12 and FIG. 13 .
- the release ring 8 is mounted to be rotatable on the casing 10 fixed to the side plate 9 b of the housing on the other side of the torsion bar 4 ( FIG. 2 ), which is located on the circumferences of the joint pawls 12 .
- the clutch release mechanism is made up with the casing 10 , the gas generator 10 b which generates gas in a cylinder 10 e at an arbitrary timing after detecting a vehicle collision, and the piston 10 a , which is pressed and driven by the gas pressure in the cylinder, and presses the circumference of the release ring 8 to rotate the release ring 8 .
- the gas generator 10 b is attached to the casing 10 by the gas generator holder 11 .
- the release ring 8 is provided with a contact 8 b which comes in contact with the piston 10 a , and three tapered parts 8 a located with a uniform spacing on the circumference thereof.
- the casing 10 which holds the release ring 8 is provided with tapered projections 10 d corresponding to the tapered parts 8 a of the release ring 8 rotated.
- the piston 10 a pressed and driven by the gas pressure comes in contact with the contact 8 b formed on the circumference of the release ring 8 , and hence the release ring 8 rotates.
- the tapered parts 8 a of the release ring 8 are guided by the tapered projections 10 d of the casing, and the release ring 8 retreats toward the take-up drum 2 ( FIG. 2 ) and retreats from the circumferences of the joint pawls 12 ( FIG. 2 ).
- FIG. 16 through FIG. 21 are partly cutaway side views and plan views in section, which explain the operation of the clutch mechanism.
- the clutch mechanism switches the first state where a relative rotation of the plate body 2 a with the other end of the torsion bar 4 is impossible into the second state where a relative rotation of the plate body 2 a with the other end of the torsion bar 4 is possible.
- the joint pawls 12 are biased toward the axial center by the slopes 13 b ( FIG. 14 ) formed on the ribs 13 a of the pawl holder 13 .
- the three joint pawls 12 are fixed at the most inwardly convergent position, in non-contact with the inner circumference of the release ring 8 , and the inner projections 12 a of the joint pawls 12 are in contact with projections 5 d of the joint plate 5 b.
- an engagement tooth 6 b of a lock pawl 6 engages with the lock teeth 9 a ( FIG. 2 ) formed on the side plate 9 b of the housing, thus generating a relative rotation between the joint plate 5 b and the plate body 2 a which will continue to rotate.
- a relative rotation is generated between the joint pawls 12 and the projections 5 d of the joint plate, whereby the projections 5 d of the joint plate press the inner projections 12 a of the joint pawls 12 , so that the joint pawls 12 receive a force toward the circumference, and they are prone to expand outwardly.
- the joint pawls 12 When the force exceeds the biasing force of the pawl holder 13 , the joint pawls 12 come in contact with the inner-circumferential wall of the release ring 8 .
- the joint pawls 12 come in contact with the inner-circumferential wall of the release ring 8 and the outward expansion thereof is restrained, the locking base 5 and the plate body 2 a become integrated with each other, and a relative rotation is generated between the take-up drum 2 and the plate body 2 a , so that the wire 2 b is pulled and the second energy absorption is performed, in addition to the energy absorption by the torsion bar 4 .
- the piston 10 a ( FIG. 13 ) operates to rotate the release ring 8 , whereby the rotation of the release ring 8 guides the tapered parts 8 a of the release ring 8 to the tapered projections 10 d of the casing ( FIG. 13 ).
- the release ring 8 retreats toward the take-up drum 2 , and retreats from the circumferences of the joint pawls 12 at the same time.
- the joint pawls 12 come in face contact with the joint plate 5 b to expand outwardly, and become detached from the projections 5 d of the joint plate, whereby the plate body 2 a is released from the locking base 5 .
- FIG. 22 is an exploded perspective view explaining the assembling of the emergency lock mechanism, which is made up with the locking base 5 , a lock clutch 16 , a cover 18 , and so forth.
- FIG. 23 is an exploded perspective view explaining the assembling of the torsion bar 4 , the lock pawl 6 , the locking base 5 , and so forth.
- a spring receiving part 16 a is formed to project on one side of the lock clutch 16 , and the spring receiving part 16 a is engaged to be relatively movable with a play inside a spring containing part 5 a resembling a recessed-groove shape, which is formed on the locking base 5 .
- the spring receiving part 16 a is elastically biased in a specified direction by a return spring 17 made of a coil spring retained in the spring containing part 5 a , and the lock clutch 16 is made to rotate synchronously with the locking base 5 in a state of being biased in the direction of the webbing pulled out.
- the torsion bar 4 is inserted in a hole bored through the cylindrical boss 5 c, which is formed to project from the side of the locking base 5 in the direction of facing the take-up drum 2 , whereby, the torsion bar 4 is coupled with the locking base 5 to be rotatable integrally.
- the lock clutch 16 has a projected guide groove 16 c formed thereon, and into the guide groove 16 c, an interlocking pin 6 a formed on the lock pawl 6 ( FIG. 23 ) is slid and guided.
- the interlocking pin 6 a is made to be slid and guided into the projected guide groove 16 c by a relative rotation of the lock clutch 16 and the locking base 5 against the biasing force by the return spring 17 .
- This sliding and guiding of the interlocking pin 6 a makes it possible to freely project or retreat the engagement tooth 6 b of the lock pawl 6 from the circumference of the locking base 5 .
- the emergency lock mechanism is made up with the locking base 5 , the lock pawl 6 , the lock teeth 9 a ( FIG. 2 ) formed on the housing 9 , the lock clutch 16 , and so forth.
- a cover 18 is provided with a lock actuating mechanism which actuates the emergency lock mechanism in response to an abrupt pull-out of the webbing and an abrupt variation in the acceleration.
- the locking base 5 and the lock pawl 6 are attached with the joint plate 5 b.
- the engagement tooth 6 b is formed on a tip of the lock pawl 6 , and the lock pawl 6 is located to be slidable on the locking base 5 by the interlocking pin 6 a .
- the lock teeth 9 a with which the engagement tooth 6 b of the lock pawl 6 is able to engage are formed on the side plate 9 b of the housing 9 , and in case of a vehicle emergency, the engagement tooth 6 b of the lock pawl 6 is engaged with the lock teeth 9 a , and this engagement restrains the locking base 5 from rotating in the direction of the webbing pulled out.
- the second energy-absorbing means is contained in a space delimited by the take-up drum 2 and the locking base 5 , there is not a substantial size expansion in the axial direction of the seatbelt retractor to sacrifice the compactification, although the second energy-absorbing means is provided separately from the torsion bar 4 .
- the structures of the wire 2 b and the engagement pins 14 which constitute the second energy-absorbing means are equally simple, and the manufacturing process thereof is rather simple as well.
- FIG. 24 is a diagram illustrating the relation between a tensile force acting on the webbing and the amount of the webbing pulled out.
- the whole energy-absorbing load of the seatbelt retractor is the sum f 3 of an energy-absorbing load f 1 when the torsion bar 4 generates a torsional deformation and an energy-absorbing load f 2 by the second energy-absorbing means, as illustrated in FIG. 24 .
- the area of the energy absorption by the torsional deformation in the torsion bar 4 can be set freely independently.
- the area of the energy absorption by the second energy-absorbing means can be set to overlap a part of the area of the energy absorption by the torsional deformation in the torsion bar 4 , thereby securing a high energy-absorbing load equivalent to the sum of both the energy-absorbing loads, in the part of the area of the energy absorption by the torsional deformation in the torsion bar 4 .
- a low energy-absorbing load can be set only by the energy-absorbing function by the torsional deformation in the torsion bar 4 .
- the adjustment of the whole energy-absorbing load of the seatbelt retractor is related to various factors such that it is related not only to the modifications of the diameter and material of the torsion bar 4 , but also to the modifications of the size, shape, and material of the second energy-absorbing means.
- it is possible to realize a desired energy-absorbing load not depending on the modifications such as expansion of the diameter of the torsion bar 4 and modification of the material thereof, but by means of the design modification of the other remaining factors. That is, it is possible to easily set the energy-absorbing load high, without sacrificing the compactification of the seatbelt retractor by reducing the diameters of the torsion bar 4 and the take-up drum 2 .
- both the torsion bar 4 and the second energy-absorbing means can be modified, by adjusting the energy-absorbing load and adjusting the energy-absorbing area in both the means, it becomes possible to easily meet the demand for a specific energy characteristic based on differences of the vehicle structure, and also possible to flexibly meet various needs.
- the adjustment of the sliding resistance between the wire 2 b and the engagement pins 14 based on various factors such as a shape of the curved path, roughness of the contact faces of both, and size of the contact area and so forth.
- the adjustment of the sliding resistance is set based on various factors in this manner, for example, if a modification of part of the factors becomes difficult due to the restrictions of the dimensions, modifying the other factors will make it possible to adjust the sliding resistance comparably easily to an arbitrary value required.
- the seatbelt retractor of the invention is provided with the torsion bar 4 and the second energy-absorbing means, and also employs the clutch mechanism. Thereby, it is possible to appropriately select the amount of the energy absorption, by actuating both or only the torsion bar 4 at the actuating time of the energy absorption. And, after actuating the energy absorption by using both, in order to achieve an optimum energy absorption in correspondence with parameters such as physical make-up of vehicle occupant, scale of a vehicle collision, and time, it is possible to stop the provision of load by the second energy-absorbing means on the way, and to perform the energy absorption only by the torsion bar.
- the present invention is useful for a seatbelt retractor which absorbs an impact load acting on a vehicle occupant in case of a vehicle emergency such as a collision, and secures the vehicle occupant.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Automotive Seat Belt Assembly (AREA)
Abstract
A seatbelt retractor of the invention intends to stabilize the stopping position of a seatbelt, and to stabilize the resistance thereof. In order to absorb the energy acting on the seatbelt in case of a vehicle emergency, the seatbelt retractor includes a torsion bar 4 (first energy-absorbing means) being the rotational shaft of a take-up drum, a second energy-absorbing means utilizing the pulling of a wire, and a clutch mechanism which immediately switches a state where the first and second energy-absorbing means absorb the energy acting on the seatbelt in case of a vehicle emergency into a state where only the first energy-absorbing means absorbs the energy.
Description
- The present invention relates to a seatbelt retractor provided with an energy-absorbing means, which, in case of a vehicle emergency, restrains a webbing from being pulled out to restrain movements of vehicle occupant and absorbs an impact load acting on the vehicle occupant.
- There has been known in the seatbelt retractor which imposes a large resistive load on the seatbelt at the moment of a vehicle emergency and thereafter reduces the resistive load to achieve the security of vehicle occupant. There has been known, as an example, JP 2001-301569A which discloses a webbing take-up apparatus (seatbelt retractor) including a lock base (locking base) provided on one end of a cylindrical spool (take-up drum) which winds up webbing in a manner that a relative rotation with the spool is possible, a lock means which prevents a rotation of the lockbase in the direction of the webbing pulled out in case of a vehicle emergency, a torsion bar inserted into the spool, one end of which is coupled with the spool, the other end of which is coupled with the lock base, which generates a torsional deformation in a state where the lock means prevents a rotation of the lock base in the direction of the webbing pulled out, a wire, one end of which is fixed to the lock base, the other end and the medium part of which are inserted into the spool, which is pulled out from the spool when the spool rotates relatively with the lock base, and a cutting means capable of cutting the wire.
- In this webbing take-up apparatus, since the wire with the one end thereof fixed to the lock base is inserted into the spool (take-up drum), when a rotation of the lock base is prevented in case of a vehicle emergency, the torsional load in the torsion bar and the pulling load in the wire act on the webbing as a force limiting load. And, the wire is cut at an arbitrary timing, whereby the force limiting load is reduced to only the torsional load in the torsion bar.
- In the conventional webbing take-up apparatus, in the duration from the moment that the cutting means comes in contact with the wire pulled out from the spool (take-up drum) till the moment that the cutting means cuts the wire away, the resistance when the pulling load restrains a pull-out of the wire becomes larger than the resistance when the wire is pulled out. However, after the wire is cut away, the resistance by the wire completely disappears, and hence the difference of the tensile-force in a webbing increases in the duration. Accordingly, a vehicle occupant is restrained from moving forward at the actuation of cutting the wire, however the occupant is made to move forward abruptly after the wire is cut away, which creates the apprehension that the occupant do not stop at a specified-position. Further, since the wire is cut vertically to the pull-out direction, the cutting position drifts depending on the tensile force of the webbing, namely, the pull-out speed of the wire being pulled out from the spool. Accordingly, the cutting is not performed at a constant position, and the resistance in the webbing pulled out is not stabilized, which is disadvantageous.
- Therefore, an object of the present invention is to solve the above conventional problems.
- That is, the first object of the invention is to make an energy-absorbing means which provides a resistive load capable of appropriately selecting the amount of the energy absorption, and to thereby halt the wire at a constant position and stabilize the resistance in the webbing pulled out.
- The second object is to make an energy-absorbing means which halts to provide the load, and to make it capable of freely adjusting the timing of halting, in a manner that it is able to perform an optimum energy absorption in correspondence with the physical make-up of vehicle occupant, scale of a vehicle collision, and time and so forth.
- The third object is to make an energy-absorbing members not generate excessive energy absorptions in switching the resistive loads, and to stabilize the provision of load by the energy-absorbing members, so that the vehicle occupant can easily be halted at specified positions.
- 1. A seatbelt retractor according to a first aspect of the invention comprises a take-up drum on which webbing is wound, a take-up shaft, one end of which is coupled with one end of the take-up drum in a manner that a relative rotation with the take-up drum is impossible, which is biased in the direction of the webbing taken up, an emergency lock mechanism which restrains a rotation in the direction of the webbing pulled out, a clutch mechanism located near the other end of the take-up shaft, a plate body provided close to a side on the other end of the take-up drum, which is provided on the other end of the take-up shaft through the clutch mechanism, and an energy-absorbing means located between the side of the take-up drum and the plate body, which provides a resistive load by mutually performing a relative rotation, wherein the clutch mechanism switches a first state where the plate body is provided on the other end of the take-up shaft in a manner that a relative rotation with the take-up shaft is impossible into a second state where the plate body is provided on the other end of the take-up shaft in a manner that a relative rotation with the take-up shaft is possible, and the clutch mechanism includes a clutch release mechanism which actuates a switching at an arbitrary timing.
- 2. A seatbelt retractor according to a second aspect of the invention comprises a take-up drum on which webbing is wound, a torsion bar inserted through the take-up drum, one end of which is coupled with one end of the take-up drum in a manner that a relative rotation with the take-up drum is impossible, which is biased in the direction of the webbing taken up, an emergency lock mechanism located on the other end of the torsion bar, which restrains a rotation in the direction of the webbing pulled out, a lock actuating device which actuates the emergency lock mechanism in case of a vehicle emergency, a clutch mechanism located near the other end of the torsion bar, a plate body provided close to a side on the other end of the take-up drum, which is provided on the other end of the torsion bar through the clutch mechanism, and a second energy-absorbing means located between the side of the take-up drum and the plate body, which provides a resistive load by mutually performing a relative rotation, wherein the clutch mechanism switches a first state where the plate body is provided on the other end of the torsion bar in a manner that a relative rotation with the torsion bar is impossible into a second state where the plate body is provided on the other end of the torsion bar in a manner that a relative rotation with the torsion bar is possible, and the clutch mechanism includes a clutch release mechanism which actuates a switching at an arbitrary timing.
- In the seatbelt retractor according to the first aspect or the second aspect of the invention, as the lock actuating device actuates the emergency lock mechanism in case of a vehicle emergency, the other end of the take-up shaft or the torsion bar is restrained from rotating in the direction of the webbing pulled out, and the take-up drum is also restrained from rotating. At this moment, as the webbing is pulled out by a pull-out force more than a predetermined value, the one end of the take-up shaft or the
torsion bar 4 is coupled with the take-up drum being driven to rotate in a manner that a relative rotation is impossible, and the other end thereof is coupled with the emergency lock mechanism which has restrained the rotation in a manner that a relative rotation is impossible, therefore, the take-up shaft or the torsion bar, while generating a torsional deformation, rotates the take-up drum. At the same time, there generates a relative rotation between the take-up drum being rotating and the plate body of which relative rotation is disabled by the clutch mechanism on the other end of the take-up shaft or the torsion bar with the rotation restrained, and a resistive load is supplied by the second energy-absorbing (EA) means. - In the first state where a relative rotation of the plate body with the other end of the take-up shaft or the torsion bar is disabled by the clutch mechanism, the take-up shaft or the torsion bar (first energy-absorbing means) and the second energy-absorbing (EA) means are in operation. The clutch mechanism being put in operation through a clutch actuating mechanism at an arbitrary timing switches the plate body into the second state where the plate body is able to rotate relatively with the other end of the take-up drum or the torsion bar, and the clutch mechanism makes the take-up shaft or the torsion bar alone perform the energy absorption (EA).
- Thereby, it is possible to appropriately select the amount of the energy absorption, by actuating both of the take-up shaft or the torsion bar (first energy-absorbing means) and the second energy-absorbing means, or only the take-up shaft or the torsion bar at the actuating time of the energy absorption. And, after actuating the energy absorption by using both of the first and the second energy-absorbing means, in order to achieve an optimum energy absorption in correspondence with parameters such as physical make-up of vehicle occupant, scale of a vehicle collision, and time, it is possible to stop the provision of load by the second energy-absorbing means on the way, and to perform the energy absorption only by the take-up shaft or the torsion bar. Since the provision of the resistive load is stopped without any contact with the energy-absorbing means (wire) being the second energy-absorbing means, excessive energy absorption is not generated in the switching, the provision of load becomes stabilized, and the vehicle occupant can easily be halted at specified positions.
- 3. A seatbelt retractor according to a third aspect of the invention is that, in the seatbelt retractor according to the second aspect of the invention, the clutch mechanism includes in a manner that a relative rotation with the emergency lock mechanism is impossible, at least one joint pawl pivoted to be turnable to a side of the plate body on the opposite side to the take-up drum, which comes in contact with the joint plate to turn outwardly, a release ring retained by a casing fixed on a side plate of a housing on the other end of the torsion bar to be movable in the axial direction while rotating, which is located on a periphery of the joint pawl; and a clutch release mechanism which actuates the release ring attached to the casing.
- According to the third aspect of the invention, when the lock actuating device actuates the emergency lock mechanism, until the torsion bar and the second energy-absorbing (EA) means provide loads in practice, the webbing is pulled and the take-up drum is rotated in the direction of the webbing pulled out. At this moment, in the duration till rotating relatively with the take-up drum, the plate body slightly rotates integrally with the take-up drum, so that a relative rotation is generated between the plate body and the joint plate coupled with the emergency lock mechanism to be impossible of a relative rotation, and the inner circumference of the joint pawl comes in contact with the joint plate, which presses the joint pawl outwardly. Since-the release ring is located on a periphery of the joint pawl, the joint pawl is restrained from expanding outwardly. As the clutch release mechanism actuates the operation, the release ring is made to move in the axial direction of the torsion bar while rotating, and is detached from the circumference of the joint pawl, and hence the joint pawl expands outwardly. Since the plate body is accordingly detached from the joint plate which has restrained the rotation of the plate body, the plate body rotates integrally with the take-up drum, the provision of the resistive load by the wire (energy-absorbing member) is halted, and only the energy absorption (EA) by the torsion bar is performed.
- Although the plate body rotates integrally with the take-up drum in the normal use of the seatbelt retractor, when the emergency lock mechanism actuates the operation, the plate body is put into the state where it cannot rotate integrally with the take-up drum, while when the clutch release mechanism of the clutch mechanism actuates the operation, it is put into the state where it can rotate integrally with the take-up drum.
- Thus, according to the third aspect of the invention, if the setting of the clutch mechanism is performed in the assembling, the clutch mechanism can be easily installed.
- Further, when the clutch release mechanism actuates the operation, the operation is performed in the state where the clutch mechanism is restrained from rotating, and hence the operation by the clutch release mechanism is stabilized.
- Further, at the moment when the joint pawl expands outwardly, the load of the energy-absorbing means becomes zero without increasing, and the switching of the load can smoothly be performed.
- 4. A seatbelt retractor according to a fourth aspect of the invention is that, in the seatbelt retractor according to the third aspect of the invention, the clutch release mechanism includes a gas generator which generates gas in a cylinder attached to the casing at an arbitrary timing, and a piston pressed and driven by a gas pressure in the cylinder, which presses the circumference of the release ring to rotate the release ring.
- Thereby, the piston pressed and driven by the gas generator in the cylinder presses the circumference of the release ring and rotates the release ring, thus detaching the clutch.
- 5. A seatbelt retractor according to a fifth aspect of the invention is that, in the seatbelt retractor according to the fourth aspect of the invention, the release ring is provided with a contact on the circumference thereof, which comes in contact with the piston, and plural tapered parts located with a uniform spacing on the circumference thereof, and the casing which holds the release ring is provided with projections corresponding to the tapered parts of the release ring.
- Thereby, the tapered parts provided on the circumference of the release ring are guided to the projections of the casing, and the release ring being rotated is made to move in the axial direction of the torsion bar. At this moment, since the tapered parts are located on the circumference of the release ring with a uniform spacing, it is possible to move the release ring in a state where the plane of the release ring is vertical to the axis.
- According to the fourth and fifth aspects of the invention, although an outward force by the joint pawl acts on the inner circumference of the release ring, the piston driven by the gas pressure rotates the release ring in one breath, and it can release the joint pawl toward the circumference at once in defiance of the frictional resistance by contacts.
- Since the release ring is made to move in the state where the plane of the release ring is vertical to the longitudinal direction of the torsion bar, the contact of the joint pawl with the release ring is released at once, in the switching of the clutch, there is not any excessive load generated, except the load supplied by the second energy-absorbing means.
- 6. A seatbelt retractor according to a sixth aspect of the invention is that, in the seatbelt retractor according to any one of the first through the fifth aspects of the invention, the clutch mechanism is provided with a pawl holder which positions and supports the joint pawls, and the pawl holder is provided with ribs integrally formed thereon, which biases the joint pawls in the axial direction and will not return the joint pawls to the initial positions after operating the joint pawls.
- Thereby, the positions of the joint pawls in the first state are maintained by biasing the springs. The outwardly expanded joint pawls are restrained from returning to the initial positions by the ribs of the pawl holder, and are retained at the positions where they are expanded. Further, the joint pawls retained there restrain the release ring from returning to the circumference of the joint pawls.
- 7. A seatbelt retractor according to a seventh aspect of the invention is that, in the seatbelt retractor according to any one of the second through the sixth aspects of the invention, the second energy-absorbing means includes a curved path provided on a side of the take-up drum on the other end of the torsion bar, and a wire, one end of which is fixed to a take-up part of the plate body, a substantially medium part of which is located in the curved groove.
- Thereby, when the emergency lock mechanism actuates the operation, a tensile force acting on the webbing which exceeds a predetermined value generates a relative rotation between the take-up drum being rotating and the plate body on the other end of the torsion bar with the rotation restrained, and hence the take-up drum being rotating winds up the wire, one end of which is fixed to the take-up part of the plate body with the rotation restrained, into the take-up part of the plate body, while deforming the wire in the curved path at any time.
- According to the sixth and seventh aspects of the invention, since the joint pawls are biased by a spring force, if, in the normal use of the seatbelt retractor, the joint pawls are made to rotate together with the take-up drum and so forth, the joint pawls will be positioned at the specified positions, which stabilizes the operation of the joint pawls.
- The plate body prevents the joint pawls and the release ring from returning to specified positions in the first state where the plate body is provided on the other end of the take-up drum in a manner that a relative rotation is impossible from the second state where the plate body is provided on the other end of the take-up drum in a manner that a relative rotation is possible. Therefore, it is possible to stabilize a resistive load by the torsion bar without adding a load by the second energy-absorbing means.
- It is also possible to make the second energy-absorbing means at low cost with a simple structure, without using a member separately.
-
FIG. 1 is a front view of the whole seatbelt retractor according to the present invention; -
FIG. 2 is an exploded perspective view explaining the assembling of a housing, a take-up drum, a torsion bar, a locking base, a base stopper, and so forth of the seatbelt retractor illustrated inFIG. 1 ; -
FIG. 3 is an exploded perspective view explaining the assembling of the take-up drum, the plate assembly, a retainer, and a pawl holder; -
FIG. 4 is an exploded perspective view explaining the assembling of a plate assembly which is illustrated inFIG. 3 ; -
FIG. 5 is a side view of the plate assembly; -
FIG. 6 is a front view partly in section of the plate assembly; -
FIG. 7 is a partly enlarged front view in section illustrating another embodiment of the plate assembly; -
FIG. 8 is a front view in section of an assembly in which the plate assembly and the take-up drum illustrated inFIG. 3 are assembled; -
FIG. 9 is a partly cutaway side view of the assembly illustrated inFIG. 8 ; -
FIG. 10 is a front view in section, in which the assembly illustrated inFIG. 8 is turned; -
FIG. 11 is a partly cutaway side view of the assembly illustrated inFIG. 10 ; -
FIG. 12 is an exploded perspective view explaining the assembling of a housing, a casing, and so forth, which are illustrated inFIG. 2 ; -
FIG. 13 is an exploded perspective view of a release ring, the casing, a piston, a gas generator, a gas generator holder, and so forth; -
FIG. 14 is an enlarged perspective view of the pawl holder; -
FIG. 15 is an enlarged perspective view of a joint pawl; -
FIG. 16 is a partly cutaway side view of a clutch mechanism before actuating the operation; -
FIG. 17 is a plan view in section of the clutch mechanism illustrated inFIG. 16 ; -
FIG. 18 is a partly cutaway side view explaining a state where the clutch mechanism is engaged (first state); -
FIG. 19 is a plan view in section of the clutch mechanism illustrated inFIG. 18 ; -
FIG. 20 is a partly cutaway side view explaining a state where the clutch mechanism is released (second state); -
FIG. 21 is a plan view in section of the clutch mechanism illustrated inFIG. 20 ; -
FIG. 22 is an exploded perspective view explaining the assembling of the locking base, a lock clutch, a cover, and so forth; -
FIG. 23 is an exploded perspective view explaining the assembling of the torsion bar, the lock pawl, the locking base, and so forth; and -
FIG. 24 is a diagram illustrating the relation between a tensile force acting on the webbing and the amount of the webbing pulled out. - The preferred embodiment of the seatbelt retractor according to the present invention will be described in detail with reference to the accompanying drawings.
-
FIG. 1 is a front view of the whole seatbelt retractor according to the invention, andFIG. 2 is an exploded perspective view explaining the assembling of a take-up drum 2, aconnector 3, ahousing 9, atorsion bar 4, alocking base 5, abase stopper 7, and so forth which constitute the major part of the seatbelt retractor illustrated inFIG. 1 . - In
FIG. 2 , the seatbelt retractor is provided with the substantially cylindrical take-up drum 2 on which webbing is wound. Thetorsion bar 4 is inserted through the center of the take-up drum 2, and one end of thetorsion bar 4 is coupled integrally with one end of the take-up drum 2 by means of theconnector 3, described later, and it is supported by a pair of side plates (9 b, 9 c) to freely rotate. A spiral spring 19 (FIG. 1 ) is mounted on theside plate 9 c, which constantly biases the take-up drum 2 to rotate in the take-up direction of the webbing, and thetorsion bar 4 is biased to rotate in the take-up direction of the webbing. - Here, the seatbelt retractor in this embodiment has the structure which winds up slackness in the webbing by a gas pressure, and so forth in case of a vehicle emergency such as a collision, and restrains the movements of vehicle occupant by a pretensioner 15 (
FIG. 1 ) furnished on theside plate 9 c. - The locking
base 5 resembling a substantially disk-like shape is coupled integrally with the other end outside of thetorsion bar 4 on the side of theside plate 9 b of the housing, and it constitutes an emergency lock mechanism which restrains a rotation in the direction of the webbing pulled out. - A clutch mechanism, described later, is located near the other end of the
torsion bar 4, while a second energy-absorbing means, described later, is located on the other end of thetorsion bar 4, close to the side on the other end of the take-up drum 2, wherein the torsion bar 4 (first energy-absorbing means) and the second energy-absorbing means perform the absorption of impact energy in case of a vehicle emergency. - The
housing 9 is made from a metal plate by a press-molding in a manner the right and left side plates (9 b, 9 c) rise up from both the sides of a back-plate fixed to the vehicle body, and the section of the housing forms a substantially U-letter. - The
base stopper 7 is to prevent thelocking base 5 from coming off from the take-up drum 2. - First Energy-Absorbing Means
- Next, the first energy-absorbing means will be described.
- As shown in
FIG. 2 , the one end of thetorsion bar 4 is engaged with a hole of theconnector 3 having the same shape thereof, and the other end is coupled with thelocking base 5 to be able to rotate integrally. - The
connector 3 is supported to freely rotate with theopening 9 d bored on theside plate 9 c of thehousing 9, and it is also engaged with a hexagonal engagement recess being formed on the one end of the take-up drum 2 to correspond with the external shape of theconnector 3, whereby thetorsion bar 4 is capable of rotating integrally with the take-up drum 2. - Therefore, even if the emergency lock mechanism actuates the operation and the other end of the
torsion bar 4 is fixed, the one end of thetorsion bar 4 will rotate integrally with the take-up drum 2 by the webbing being pulled out. That is, thetorsion bar 4 is twisted by the rotational force of the take-up drum 2, thus the energy of pulling out the webbing can be absorbed by the torsion resistance thereof. - In this manner, the
torsion bar 4 functions as the first energy-absorbing means. - Second Energy-Absorbing Means
- Next, the second energy-absorbing means will be described with reference to
FIG. 3 throughFIG. 6 . -
FIG. 3 is an exploded perspective view explaining the assembling of aplate assembly 2 e. Theplate assembly 2 e comprises aplate body 2 a, aspiral wire 2 b with plural winds, and adisk member 2 c havingplural projections 2 q located circumferentially around a center hole. - In
FIG. 3 , oneend 2 g of the wire is fixed to theplate body 2 a, and theother end 2 h of the wire is suspended to the backside of thedisk member 2 c (viewed fromFIG. 3 ). -
FIG. 4 is an exploded perspective view illustrating the whole of the second energy-absorbing means. Theplate assembly 2 e and the take-up drum 2 are attached with aretainer 2 d. -
FIG. 5 is a side view of theplate assembly 2 e, andFIG. 6 is a front view partly in section of the same, wherein theplate assembly 2 e is assembled with theplate body 2 a, thewire 2 b, and thedisk member 2 c, as illustrated inFIG. 3 . - In
FIG. 4 , a substantiallycircular receiving recess 2 f which constitutes a part of the second energy-absorbing means is formed on the side where the locking base is mounted on the take-up drum 2, namely, on the end face of the left side in the drawing. Further, anengagement hole 2 k which receives aboss 5 c (FIG. 2 ) of the locking base is formed on the center of the receivingrecess 2 f. The engagement pins 14 to be engaged with thewire 2 b are formed at specified places on the periphery of the receivingrecess 2 f positioned outside theengagement hole 2 k on the bottom face. And, the slopes 2 t (FIG. 5 ) are formed at the specified places for engaging with thewire 2 b. In this case, three semi-circular engagement pins 14 are formed integrally to project from the bottom face of the receivingrecess 2 f along the circumference thereof, wherein thewire 2 b is formed in spiral, and thecircumference 2 i thereof (FIG. 3 ) is formed in curvature, which conforms to the circular sliding face of the engagement pins 14. -
FIG. 5 is a side view of theplate assembly 2 e in which the individual components illustrated inFIG. 3 are assembled. As illustrated in the drawing, thedisk member 2 c and theplate body 2 a are engaged integrally with each other in a state where thespiral wire 2 b is interposed between both. That is, theplate body 2 a and thedisk member 2 c form a take-uppart 2 m with a distance approximately equivalent to the diameter of thewire 2 b, and thedisk member 2 c is coupled with theplate body 2 a in a manner that a relative rotation between both is impossible. At this moment, the curved oneend 2 g of thewire 2 b is placed and fixed in acurved groove 2 n (FIG. 6 ) of theplate body 2 a. - Thus, the
wire 2 b having the one end thereof fixed to theplate body 2 a passes through the gap between theplate body 2 a and thedisk member 2 c, and when the take-up drum 2 and theplate assembly 2 e perform a relative rotation, thewire 2 b reaches the upper face of theplate body 2 a being the take-uppart 2 m. - The
disk member 2 c covers take-uppart 2 m of theplate body 2 a and the oneend 2 g of thewire 2 b in the assembly state. -
FIG. 6 is a front view which shows the internal structure of theplate assembly 2 e, part of which is sectioned. As illustrated in the drawing, thecurved groove 2 n is formed on the take-uppart 2 m of theplate body 2 a by means of substantially semi-circularplural projections 2 p, and the oneend 2 g of thewire 2 b is placed in thecurved groove 2 n and is coupled therewith. The curvature radius of thecurved groove 2 n is formed smaller than that of thecurved path 2 j (FIG. 4 ) of the take-up drum 2. -
FIG. 7 illustrates another embodiment of thecurved groove 2 n. In theplural projections 2 p of theplate body 2 a, at least one set ofribs 2 r facing to each other are formed between theprojections 2 p forming thecurved groove 2 n, and the gap between theribs 2 r is made narrower than the diameter of thewire 2 b. -
FIG. 8 is a front view in section illustrating a state where the take-up drum 2 illustrated inFIG. 4 and theplate assembly 2 e are assembled, andFIG. 9 is a partly cutaway side view of the assembly illustrated inFIG. 8 .FIG. 10 is a front view in section, illustrating a state where the take-up drum 2 rotates to a certain degree after the emergency lock mechanism actuates the operation in the assembly illustrated inFIG. 8 , andFIG. 11 is a partly cutaway side view in the same state. - The second energy-absorbing means having the above construction is contained in a space delimited between the take-
up drum 2 and thelocking base 5. After the emergency lock mechanism actuates the operation, as the take-up drum 2 rotates, thewire 2 b illustrated inFIG. 8 andFIG. 9 is wound into the take-uppart 2 m, as illustrated inFIG. 10 andFIG. 11 . - At this moment, the
wire 2 b relatively moves between thedisk member 2 c and theplate body 2 a, along thecurved circumference 2 i projected from the circumferential face of thedisk member 2 c, while sliding on the three semi-circular engagement pins 14 of the take-up drum 2. - When the emergency lock mechanism actuates the operation, in case of a vehicle emergency such as a collision, the locking
base 5 coupled with the other end of thetorsion bar 4 is blocked in rotating in the direction of the webbing pulled out. And, when a rotational torque more than a predetermined value acts on the take-up drum 2, due to the load acting on the webbing, the one end of the torsion bar 4 (first energy-absorbing means) actuates a torsional deformation. - Thereby, the take-
up drum 2 rotates to a degree corresponding to the torsional deformation in thetorsion bar 4, and at the same time, the other end of thetorsion bar 4, which is fixed, rotates in the direction of the webbing pulled out, whereby the impact energy is absorbed. And, the actuation of the torsional deformation in thetorsion bar 4 generates a relative rotation between the take-up drum 2 and thelocking base 5. The absorption of the impact energy by the second energy-absorbing means actuates based on this relative rotation. - While the take-
up drum 2 rotates relative to thelocking base 5, theplate body 2 a to which the oneend 2 g of thewire 2 b is fixed is coupled with thelocking base 5, and it does not rotate, while since the engagement pins 14 formed integrally with the take-up drum 2 turn, thewire 2 b is pulled between the engagement pins 14. That is, thewire 2 b slides between the engagement pins 14 while being positioned by the slopes 2 t, while being sequentially pulled to meander between the engagement pins 14. At this moment, there generate a high sliding resistance and a bending resistance in thewire 2 b, and hence the sliding resistance and the bending resistance absorb the impact energy. - That is, when the emergency lock mechanism actuates the operation in case of a vehicle emergency, and the load acting on the take-
up drum 2 in the direction of the webbing pulled out is increased more than a predetermined value, both the torsion bar 4 (first energy-absorbing means) and the second energy-absorbing means operate as the energy-absorbing mechanism, and absorb the impact energy in case of a vehicle emergency. - Clutch Mechanism
- Next, the clutch mechanism will be described which releases the engagement of the
plate body 2 a with thelocking base 5 of the emergency lock mechanism, and puts theplate body 2 a from the state of a relative rotation with the take-up drum 2 being possible into the state of a united rotation with the take-up drum 2 being possible with thelocking base 5 detached. - This clutch mechanism switches the first state where a relative rotation of the
plate body 2 a with the other end of thetorsion bar 4 is impossible into the second state where a relative rotation of theplate body 2 a with the other end of thetorsion bar 4 is possible. It also comprises the clutch release mechanism which actuates the switching at an arbitrary timing after detecting a vehicle collision. - The clutch mechanism comprises, as shown in
FIG. 2 , ajoint plate 5 b (FIG. 23 ) coupled with the emergency lock mechanism in a manner that a relative rotation is impossible, and threejoint pawls 12 being pivoted to be turnable on the opposite side of the take-up drum 2 to theplate body 2 a, which are in face contact with thejoint plate 5 b to turn outward. - The joint pawl 12 (
FIG. 15 ) is a bow-formed member, and apin 12 b is formed on the one end thereof. Thepin 12 b is pivoted on the opposite side of the take-up drum 2 to theplate body 2 a. Thejoint pawl 12 turns with thepin 12 b as the center. Further, thejoint pawl 12 has aninner projection 12 a (FIG. 15 ) formed on the center of the inner wall, and anotch 12 c (FIG. 15 ) formed on the other end inside. - A pawl holder 13 (resin spring) (
FIG. 14 ) in a sectional concave and circular form is provided in order to position and support thejoint pawls 12. Thepawl holder 13 is provided, on the circumference thereof in correspondence with the positions of thejoint pawls 12, with nail-formedparts 13 c each havingribs 13 a formed thereon. Inwardly slant slopes 13 b formed on theribs 13 a and the nail-formedparts 13 c come into contact with the outer faces of thejoint pawls 12. This contact and the resin spring functions to bias thejoint pawls 12 continuously toward the axial center. - Meanwhile, as the
joint pawls 12 turn outward against the elasticity of the resin spring and climb over theribs 13 a of thepawl holder 13, thepawl holder 13 is released from being pressed, the nail-formedparts 13 c return to the insides of thejoint pawls 12, andrib backsides 13 d of thepawl holder 13 come into contact withnotches 12 c of thejoint pawls 12. On the other hand, since theplate body 2 a is provided withprojections 2 s which restrain thejoint pawls 12 from turning relative to theplate body 2 a immediately after thejoint pawls 12 climb over theribs 13 a of thepawl holder 13, thejoint pawls 12 are clamped by therib backsides 13 d of the pawl holder and theprojections 2 s of the plate body so that thejoint pawls 12 are prevented from turning to theplate body 2 a. - Therefore, after the clutch is detached once, the clutch will not operate again.
- Clutch Release Mechanism
-
FIG. 12 is an exploded perspective view explaining the assembling of arelease ring 8, thehousing 9, acasing 10, and so forth being the components for releasing the clutch.FIG. 14 is an enlarged exploded perspective view of therelease ring 8, thecasing 10, apiston 10 a, agas generator 10 b, agas generator holder 11, and so forth, which are illustrated inFIG. 13 . - The clutch release mechanism will be described with reference to
FIG. 12 andFIG. 13 . Therelease ring 8 is mounted to be rotatable on thecasing 10 fixed to theside plate 9 b of the housing on the other side of the torsion bar 4 (FIG. 2 ), which is located on the circumferences of thejoint pawls 12. - As illustrated in
FIG. 12 andFIG. 13 , the clutch release mechanism is made up with thecasing 10, thegas generator 10 b which generates gas in acylinder 10 e at an arbitrary timing after detecting a vehicle collision, and thepiston 10 a, which is pressed and driven by the gas pressure in the cylinder, and presses the circumference of therelease ring 8 to rotate therelease ring 8. Thegas generator 10 b is attached to thecasing 10 by thegas generator holder 11. - The
release ring 8 is provided with acontact 8 b which comes in contact with thepiston 10 a, and three taperedparts 8 a located with a uniform spacing on the circumference thereof. On the other hand, thecasing 10 which holds therelease ring 8 is provided withtapered projections 10 d corresponding to the taperedparts 8 a of therelease ring 8 rotated. - In the operation, the
piston 10 a pressed and driven by the gas pressure comes in contact with thecontact 8 b formed on the circumference of therelease ring 8, and hence therelease ring 8 rotates. Thereby, the taperedparts 8 a of therelease ring 8 are guided by the taperedprojections 10 d of the casing, and therelease ring 8 retreats toward the take-up drum 2 (FIG. 2 ) and retreats from the circumferences of the joint pawls 12 (FIG. 2 ). - Next, the operation of the clutch mechanism will be described based on
FIG. 16 throughFIG. 21 . -
FIG. 16 throughFIG. 21 are partly cutaway side views and plan views in section, which explain the operation of the clutch mechanism. - In
FIG. 16 throughFIG. 21 , as already described, the clutch mechanism switches the first state where a relative rotation of theplate body 2 a with the other end of thetorsion bar 4 is impossible into the second state where a relative rotation of theplate body 2 a with the other end of thetorsion bar 4 is possible. - In the assembly state, the
joint pawls 12 are biased toward the axial center by theslopes 13 b (FIG. 14 ) formed on theribs 13 a of thepawl holder 13. The threejoint pawls 12 are fixed at the most inwardly convergent position, in non-contact with the inner circumference of therelease ring 8, and theinner projections 12 a of thejoint pawls 12 are in contact withprojections 5 d of thejoint plate 5 b. - Here, as the emergency lock mechanism actuates the operation, an
engagement tooth 6 b of a lock pawl 6 (FIG. 23 ) engages with thelock teeth 9 a (FIG. 2 ) formed on theside plate 9 b of the housing, thus generating a relative rotation between thejoint plate 5 b and theplate body 2 a which will continue to rotate. At this moment, a relative rotation is generated between thejoint pawls 12 and theprojections 5 d of the joint plate, whereby theprojections 5 d of the joint plate press theinner projections 12 a of thejoint pawls 12, so that thejoint pawls 12 receive a force toward the circumference, and they are prone to expand outwardly. - When the force exceeds the biasing force of the
pawl holder 13, thejoint pawls 12 come in contact with the inner-circumferential wall of therelease ring 8. When thejoint pawls 12 come in contact with the inner-circumferential wall of therelease ring 8 and the outward expansion thereof is restrained, the lockingbase 5 and theplate body 2 a become integrated with each other, and a relative rotation is generated between the take-up drum 2 and theplate body 2 a, so that thewire 2 b is pulled and the second energy absorption is performed, in addition to the energy absorption by thetorsion bar 4. - Next, as the clutch release mechanism actuates the operation in this state, the
piston 10 a (FIG. 13 ) operates to rotate therelease ring 8, whereby the rotation of therelease ring 8 guides the taperedparts 8 a of therelease ring 8 to the taperedprojections 10 d of the casing (FIG. 13 ). Thus, therelease ring 8 retreats toward the take-up drum 2, and retreats from the circumferences of thejoint pawls 12 at the same time. Thejoint pawls 12 come in face contact with thejoint plate 5 b to expand outwardly, and become detached from theprojections 5 d of the joint plate, whereby theplate body 2 a is released from the lockingbase 5. - That is, as the clutch mechanism actuates the operation to move the
release ring 8 in the axial direction, as illustrated inFIG. 20 andFIG. 21 , thejoint pawls 12 expand outward, and theprojections 5 d of the joint plate are completely detached from thejoint pawls 12, and hence the locked state where thelocking base 5 and theplate body 2 a are integrally fixed is released. In consequence, the pull-out motion of thewire 2 b is halted, and theplate body 2 a and the take-up drum 2 become rotatable integrally. However, since the take-up drum 2 and thelocking base 5 continue a relative rotation even in this case, thetorsion bar 4 alone continues the energy absorption. - Emergency Lock Mechanism
-
FIG. 22 is an exploded perspective view explaining the assembling of the emergency lock mechanism, which is made up with thelocking base 5, alock clutch 16, acover 18, and so forth.FIG. 23 is an exploded perspective view explaining the assembling of thetorsion bar 4, thelock pawl 6, the lockingbase 5, and so forth. - As a concrete construction of the emergency lock mechanism, various known ones may be adopted. As one example, as illustrated in
FIG. 22 andFIG. 23 , aspring receiving part 16 a is formed to project on one side of thelock clutch 16, and thespring receiving part 16 a is engaged to be relatively movable with a play inside aspring containing part 5 a resembling a recessed-groove shape, which is formed on thelocking base 5. - At this moment, the
spring receiving part 16 a is elastically biased in a specified direction by areturn spring 17 made of a coil spring retained in thespring containing part 5 a, and thelock clutch 16 is made to rotate synchronously with thelocking base 5 in a state of being biased in the direction of the webbing pulled out. - The
torsion bar 4 is inserted in a hole bored through thecylindrical boss 5 c, which is formed to project from the side of thelocking base 5 in the direction of facing the take-up drum 2, whereby, thetorsion bar 4 is coupled with thelocking base 5 to be rotatable integrally. - The
lock clutch 16 has a projectedguide groove 16 c formed thereon, and into theguide groove 16 c, an interlockingpin 6 a formed on the lock pawl 6 (FIG. 23 ) is slid and guided. The interlockingpin 6 a is made to be slid and guided into the projectedguide groove 16 c by a relative rotation of thelock clutch 16 and thelocking base 5 against the biasing force by thereturn spring 17. This sliding and guiding of the interlockingpin 6 a makes it possible to freely project or retreat theengagement tooth 6 b of thelock pawl 6 from the circumference of thelocking base 5. - The emergency lock mechanism is made up with the
locking base 5, thelock pawl 6, thelock teeth 9 a (FIG. 2 ) formed on thehousing 9, thelock clutch 16, and so forth. - In order to actuate the emergency lock mechanism, a
cover 18 is provided with a lock actuating mechanism which actuates the emergency lock mechanism in response to an abrupt pull-out of the webbing and an abrupt variation in the acceleration. - The locking
base 5 and thelock pawl 6 are attached with thejoint plate 5 b. - The
engagement tooth 6 b is formed on a tip of thelock pawl 6, and thelock pawl 6 is located to be slidable on thelocking base 5 by the interlockingpin 6 a. Thelock teeth 9 a with which theengagement tooth 6 b of thelock pawl 6 is able to engage are formed on theside plate 9 b of thehousing 9, and in case of a vehicle emergency, theengagement tooth 6 b of thelock pawl 6 is engaged with thelock teeth 9 a, and this engagement restrains thelocking base 5 from rotating in the direction of the webbing pulled out. - According to the invention thus described, since the second energy-absorbing means is contained in a space delimited by the take-
up drum 2 and thelocking base 5, there is not a substantial size expansion in the axial direction of the seatbelt retractor to sacrifice the compactification, although the second energy-absorbing means is provided separately from thetorsion bar 4. Further, the structures of thewire 2 b and the engagement pins 14 which constitute the second energy-absorbing means are equally simple, and the manufacturing process thereof is rather simple as well. -
FIG. 24 is a diagram illustrating the relation between a tensile force acting on the webbing and the amount of the webbing pulled out. - The whole energy-absorbing load of the seatbelt retractor is the sum f3 of an energy-absorbing load f1 when the
torsion bar 4 generates a torsional deformation and an energy-absorbing load f2 by the second energy-absorbing means, as illustrated inFIG. 24 . - In case of a high energy-absorbing load, the relation between both forms a curve O, A, B, D, F in case of a low energy-absorbing load, it forms a curve O, A, C, E by the switching by the clutch mechanism, and, in case of a medium energy-absorbing load, it forms a curve O, A, B, D, C, E.
- Further, with regard to the area of the energy absorption by the torsional deformation in the
torsion bar 4, the area of the energy absorption by the sliding resistance of the second energy-absorbing means can be set freely independently. - For example, the area of the energy absorption by the second energy-absorbing means can be set to overlap a part of the area of the energy absorption by the torsional deformation in the
torsion bar 4, thereby securing a high energy-absorbing load equivalent to the sum of both the energy-absorbing loads, in the part of the area of the energy absorption by the torsional deformation in thetorsion bar 4. In the area where both the energy-absorbing areas do not overlap each other, a low energy-absorbing load can be set only by the energy-absorbing function by the torsional deformation in thetorsion bar 4. Thus, it is possible to provide the energy-absorbing mechanism of the seatbelt retractor with such an energy-absorbing characteristic in which the energy-absorbing load varies during the operation. - Further, the adjustment of the whole energy-absorbing load of the seatbelt retractor is related to various factors such that it is related not only to the modifications of the diameter and material of the
torsion bar 4, but also to the modifications of the size, shape, and material of the second energy-absorbing means. For example, it is possible to realize a desired energy-absorbing load, not depending on the modifications such as expansion of the diameter of thetorsion bar 4 and modification of the material thereof, but by means of the design modification of the other remaining factors. That is, it is possible to easily set the energy-absorbing load high, without sacrificing the compactification of the seatbelt retractor by reducing the diameters of thetorsion bar 4 and the take-up drum 2. And, in case that the size and the material of both thetorsion bar 4 and the second energy-absorbing means can be modified, by adjusting the energy-absorbing load and adjusting the energy-absorbing area in both the means, it becomes possible to easily meet the demand for a specific energy characteristic based on differences of the vehicle structure, and also possible to flexibly meet various needs. - Meanwhile, it is preferable to set the adjustment of the sliding resistance between the
wire 2 b and the engagement pins 14 based on various factors such as a shape of the curved path, roughness of the contact faces of both, and size of the contact area and so forth. When the adjustment of the sliding resistance is set based on various factors in this manner, for example, if a modification of part of the factors becomes difficult due to the restrictions of the dimensions, modifying the other factors will make it possible to adjust the sliding resistance comparably easily to an arbitrary value required. - The seatbelt retractor of the invention is provided with the
torsion bar 4 and the second energy-absorbing means, and also employs the clutch mechanism. Thereby, it is possible to appropriately select the amount of the energy absorption, by actuating both or only thetorsion bar 4 at the actuating time of the energy absorption. And, after actuating the energy absorption by using both, in order to achieve an optimum energy absorption in correspondence with parameters such as physical make-up of vehicle occupant, scale of a vehicle collision, and time, it is possible to stop the provision of load by the second energy-absorbing means on the way, and to perform the energy absorption only by the torsion bar. - The present invention is useful for a seatbelt retractor which absorbs an impact load acting on a vehicle occupant in case of a vehicle emergency such as a collision, and secures the vehicle occupant.
Claims (7)
1. A seatbelt retractor comprises:
a take-up drum on which webbing is wound;
a take-up shaft, one end of which is coupled with one end of the take-up drum in a manner that a relative rotation with the take-up drum is impossible, which is biased in the direction of the webbing taken up;
an emergency lock mechanism which restrains a rotation in the direction of the webbing pulled out;
a clutch mechanism located near the other end of the take-up shaft;
a plate body provided close to a side on the other end of the take-up drum, which is provided on the other end of the take-up shaft through the clutch mechanism; and
an energy-absorbing means located between the side of the take-up drum and the plate body, which provides a resistive load by mutually performing a relative rotation;
wherein the clutch mechanism switches a first state where the plate body is provided on the other end of the take-up shaft in a manner that a relative rotation with the take-up shaft is impossible into a second state where the plate body is provided on the other end of the take-up shaft in a manner that a relative rotation with the take-up shaft is possible, and the clutch mechanism includes a clutch release mechanism which actuates a switching at an arbitrary timing.
2. A seatbelt retractor comprising:
a take-up drum on which webbing is wound;
a torsion bar inserted through the take-up drum, one end of which is coupled with one end of the take-up drum in a manner that a relative rotation with the take-up drum is impossible, which is biased in the direction of the webbing taken up;
an emergency lock mechanism located on the other end of the torsion bar, which restrains a rotation in the direction of the webbing pulled out;
a lock actuating device which actuates the emergency lock mechanism in case of a vehicle emergency;
a clutch mechanism located near the other end of the torsion bar;
a plate body provided close to a side on the other end of the take-up drum, which is provided on the other end of the torsion bar through the clutch mechanism; and
a second energy-absorbing means located between the side of the take-up drum and the plate body, which provides a resistive load by mutually performing a relative rotation;
wherein the clutch mechanism switches a first state where the plate body is provided on the other end of the torsion bar in a manner that a relative rotation with the torsion bar is impossible into a second state where the plate body is provided on the other end of the torsion bar in a manner that a relative rotation with the torsion bar is possible, and the clutch mechanism includes a clutch release mechanism which actuates a switching at an arbitrary timing.
3. A seatbelt retractor according to claim 2 , wherein the clutch mechanism includes:
a joint plate coupled with the emergency lock mechanism in a manner that a relative rotation with the emergency lock mechanism is impossible;
at least one joint pawl pivoted to be turnable to a side of the plate body on the opposite side to the take-up drum, which comes in contact with the joint plate to turn outwardly;
a release ring retained by a casing fixed on a side plate of a housing on the other end of the torsion bar to be movable in the axial direction while rotating, which is located on a periphery of the joint pawl; and
a clutch release mechanism which actuates the release ring attached to the casing.
4. A seatbelt retractor according to claim 3 , wherein the clutch release mechanism includes a gas generator which generates gas in a cylinder attached to the casing at an arbitrary timing, and a piston pressed and driven by a gas pressure in the cylinder, which presses the circumference of the release ring to rotate the release ring.
5. A seatbelt retractor according to claim 4 , wherein the release ring is provided with a contact on the circumference thereof, which comes in contact with the piston, and plural tapered parts located with a uniform spacing on the circumference thereof, and the casing which holds the release ring is provided with projections corresponding to the tapered parts of the release ring.
6. A seatbelt retractor according to claim 1 , wherein the clutch mechanism is provided with a pawl holder which positions and supports the joint pawls, and the pawl holder is provided with ribs integrally formed thereon, which biases the joint pawls in the axial direction and will not return the joint pawls to the initial positions after operating the joint pawls.
7. A seatbelt retractor according to claim 2 , wherein the second energy-absorbing means includes a curved path provided on a side of the take-up drum on the other end of the torsion bar, and a wire, one end of which is fixed to a take-up part of the plate body, a substantially medium part of which is located in the curved groove.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003024342A JP4166095B2 (en) | 2003-01-31 | 2003-01-31 | Seat belt retractor |
JP2003-024342 | 2003-01-31 | ||
PCT/JP2004/000793 WO2004067338A1 (en) | 2003-01-31 | 2004-01-29 | Seat belt retractor |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060214494A1 true US20060214494A1 (en) | 2006-09-28 |
Family
ID=32820761
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/543,893 Abandoned US20060214494A1 (en) | 2003-01-31 | 2004-01-29 | Seat belt retractor |
Country Status (6)
Country | Link |
---|---|
US (1) | US20060214494A1 (en) |
EP (1) | EP1600342B1 (en) |
JP (1) | JP4166095B2 (en) |
KR (1) | KR101105623B1 (en) |
DE (1) | DE602004005320T2 (en) |
WO (1) | WO2004067338A1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080073967A1 (en) * | 2006-08-30 | 2008-03-27 | Honda Motor Co., Ltd. | Seat belt retractor mounting system |
US20080203210A1 (en) * | 2007-02-28 | 2008-08-28 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing retractor |
CN107791998A (en) * | 2017-12-08 | 2018-03-13 | 沈阳金杯锦恒汽车安全***有限公司 | A kind of Webbing retractor mandrel component structure |
US20180086304A1 (en) * | 2015-04-24 | 2018-03-29 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing take-up device |
US10434976B2 (en) | 2018-02-27 | 2019-10-08 | Ford Global Technologies, Llc | Seatbelt assembly |
US10518740B2 (en) | 2018-02-27 | 2019-12-31 | Ford Global Technologies, Llc | Seatbelt assembly |
US10525929B2 (en) | 2018-02-27 | 2020-01-07 | Ford Global Technologies, Llc | Seatbelt assembly |
US10543806B2 (en) | 2018-02-27 | 2020-01-28 | Ford Global Technologies, Llc | Seatbelt assembly |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2400351B (en) * | 2003-04-09 | 2006-06-07 | Autoliv Dev | Improvements in or relating to a load limiting arrangement |
JP5078110B2 (en) * | 2006-06-15 | 2012-11-21 | タカタ株式会社 | Seat belt retractor and seat belt device provided with the same |
JP5323223B2 (en) * | 2012-03-16 | 2013-10-23 | タカタ株式会社 | Seat belt retractor and seat belt device provided with the same |
JP6306537B2 (en) * | 2015-05-29 | 2018-04-04 | 株式会社東海理化電機製作所 | Webbing take-up device |
Citations (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3666198A (en) * | 1969-07-12 | 1972-05-30 | Gen Motors Corp | Seat belt reel |
US4323205A (en) * | 1979-07-19 | 1982-04-06 | Nippon Soken, Inc. | Safety seat-belt retractor |
US5607118A (en) * | 1995-08-11 | 1997-03-04 | Alliedsignal Inc. | Retractor with adjustable load limiting levels |
JPH09202211A (en) * | 1996-01-24 | 1997-08-05 | Tokai Rika Co Ltd | Webbing take-up device |
US5823570A (en) * | 1996-10-10 | 1998-10-20 | Trw Vehicle Safety Systems Inc. | Seat belt retractor with energy management |
US5961060A (en) * | 1997-08-05 | 1999-10-05 | Daimler-Benz Aktiengesellschaft | Belt roller for a safety belt system of a passenger seat |
US5967442A (en) * | 1997-10-21 | 1999-10-19 | Trw Occupant Restraint Systems Gmbh | Force limiter for a seat belt restraint system |
US6206315B1 (en) * | 1998-06-04 | 2001-03-27 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Unit comprising at least two torsion bars for limiting the force in a belt retractor |
US6216972B1 (en) * | 1998-09-10 | 2001-04-17 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Device for force limitation in a vehicle occupant restraint system |
US6241172B1 (en) * | 1996-06-26 | 2001-06-05 | Autoliv Development Ab | Belt retractor with adjustable force-limiting device |
US20020017583A1 (en) * | 2000-05-02 | 2002-02-14 | Hideaki Yano | Seat belt retractor |
US20020070307A1 (en) * | 2000-12-08 | 2002-06-13 | Takata Corporation | Seat belt retractor |
US6416006B1 (en) * | 1998-12-07 | 2002-07-09 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Belt retractor for a vehicle safety belt |
DE20210812U1 (en) * | 2002-07-17 | 2002-11-21 | TRW Occupant Restraint Systems GmbH & Co. KG, 73553 Alfdorf | Belt retractor with force limiting function |
US6564895B1 (en) * | 1998-12-07 | 2003-05-20 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Belt retractor for a vehicle safety belt and method for actuating the belt retractor |
US6598822B2 (en) * | 2000-10-26 | 2003-07-29 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing retractor |
US6616081B1 (en) * | 1999-06-16 | 2003-09-09 | Autoliv Development Ab | Belt retractor with switchable force limiter |
US20030192975A1 (en) * | 2002-04-16 | 2003-10-16 | Palliser Martyn Neil | Seat belt retractor |
US20030192976A1 (en) * | 2002-04-16 | 2003-10-16 | Palliser Martyn Neil | Seat belt retractor with multi-level load limiting |
US6969022B2 (en) * | 2003-10-14 | 2005-11-29 | Key Safety Systems, Inc. | Seat belt retractor |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09286302A (en) * | 1996-04-23 | 1997-11-04 | Nippon Seiko Kk | Seat belt retractor |
JP4526631B2 (en) | 2000-01-24 | 2010-08-18 | オートリブ株式会社 | Seat belt device |
JP2001287621A (en) * | 2000-04-07 | 2001-10-16 | Tokai Rika Co Ltd | Device for winding webbing |
JP2001301569A (en) * | 2000-04-24 | 2001-10-31 | Tokai Rika Co Ltd | Webbing winding device and vehicle |
JP3723423B2 (en) * | 2000-05-31 | 2005-12-07 | エヌエスケー・オートリブ株式会社 | Seat belt device |
-
2003
- 2003-01-31 JP JP2003024342A patent/JP4166095B2/en not_active Expired - Fee Related
-
2004
- 2004-01-29 KR KR1020057013386A patent/KR101105623B1/en active IP Right Grant
- 2004-01-29 WO PCT/JP2004/000793 patent/WO2004067338A1/en active IP Right Grant
- 2004-01-29 EP EP04706290A patent/EP1600342B1/en not_active Expired - Fee Related
- 2004-01-29 US US10/543,893 patent/US20060214494A1/en not_active Abandoned
- 2004-01-29 DE DE602004005320T patent/DE602004005320T2/en not_active Expired - Lifetime
Patent Citations (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3666198A (en) * | 1969-07-12 | 1972-05-30 | Gen Motors Corp | Seat belt reel |
US4323205A (en) * | 1979-07-19 | 1982-04-06 | Nippon Soken, Inc. | Safety seat-belt retractor |
US5607118A (en) * | 1995-08-11 | 1997-03-04 | Alliedsignal Inc. | Retractor with adjustable load limiting levels |
JPH09202211A (en) * | 1996-01-24 | 1997-08-05 | Tokai Rika Co Ltd | Webbing take-up device |
US6241172B1 (en) * | 1996-06-26 | 2001-06-05 | Autoliv Development Ab | Belt retractor with adjustable force-limiting device |
US5823570A (en) * | 1996-10-10 | 1998-10-20 | Trw Vehicle Safety Systems Inc. | Seat belt retractor with energy management |
US5961060A (en) * | 1997-08-05 | 1999-10-05 | Daimler-Benz Aktiengesellschaft | Belt roller for a safety belt system of a passenger seat |
US5967442A (en) * | 1997-10-21 | 1999-10-19 | Trw Occupant Restraint Systems Gmbh | Force limiter for a seat belt restraint system |
US6206315B1 (en) * | 1998-06-04 | 2001-03-27 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Unit comprising at least two torsion bars for limiting the force in a belt retractor |
US6216972B1 (en) * | 1998-09-10 | 2001-04-17 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Device for force limitation in a vehicle occupant restraint system |
US6564895B1 (en) * | 1998-12-07 | 2003-05-20 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Belt retractor for a vehicle safety belt and method for actuating the belt retractor |
US6416006B1 (en) * | 1998-12-07 | 2002-07-09 | Trw Occupant Restraint Systems Gmbh & Co. Kg | Belt retractor for a vehicle safety belt |
US6616081B1 (en) * | 1999-06-16 | 2003-09-09 | Autoliv Development Ab | Belt retractor with switchable force limiter |
US20020017583A1 (en) * | 2000-05-02 | 2002-02-14 | Hideaki Yano | Seat belt retractor |
US6598822B2 (en) * | 2000-10-26 | 2003-07-29 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing retractor |
US20020070307A1 (en) * | 2000-12-08 | 2002-06-13 | Takata Corporation | Seat belt retractor |
US20030192975A1 (en) * | 2002-04-16 | 2003-10-16 | Palliser Martyn Neil | Seat belt retractor |
US20030192976A1 (en) * | 2002-04-16 | 2003-10-16 | Palliser Martyn Neil | Seat belt retractor with multi-level load limiting |
DE20210812U1 (en) * | 2002-07-17 | 2002-11-21 | TRW Occupant Restraint Systems GmbH & Co. KG, 73553 Alfdorf | Belt retractor with force limiting function |
US6969022B2 (en) * | 2003-10-14 | 2005-11-29 | Key Safety Systems, Inc. | Seat belt retractor |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080073967A1 (en) * | 2006-08-30 | 2008-03-27 | Honda Motor Co., Ltd. | Seat belt retractor mounting system |
US7497521B2 (en) * | 2006-08-30 | 2009-03-03 | Honda Motor Co., Ltd | Seat belt retractor mounting system |
US20080203210A1 (en) * | 2007-02-28 | 2008-08-28 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing retractor |
US20180086304A1 (en) * | 2015-04-24 | 2018-03-29 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing take-up device |
US10434978B2 (en) * | 2015-04-24 | 2019-10-08 | Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho | Webbing take-up device |
CN107791998A (en) * | 2017-12-08 | 2018-03-13 | 沈阳金杯锦恒汽车安全***有限公司 | A kind of Webbing retractor mandrel component structure |
US10434976B2 (en) | 2018-02-27 | 2019-10-08 | Ford Global Technologies, Llc | Seatbelt assembly |
US10518740B2 (en) | 2018-02-27 | 2019-12-31 | Ford Global Technologies, Llc | Seatbelt assembly |
US10525929B2 (en) | 2018-02-27 | 2020-01-07 | Ford Global Technologies, Llc | Seatbelt assembly |
US10543806B2 (en) | 2018-02-27 | 2020-01-28 | Ford Global Technologies, Llc | Seatbelt assembly |
Also Published As
Publication number | Publication date |
---|---|
EP1600342A1 (en) | 2005-11-30 |
WO2004067338A1 (en) | 2004-08-12 |
JP2004262262A (en) | 2004-09-24 |
DE602004005320D1 (en) | 2007-04-26 |
JP4166095B2 (en) | 2008-10-15 |
DE602004005320T2 (en) | 2007-12-20 |
EP1600342A4 (en) | 2006-02-15 |
EP1600342B1 (en) | 2007-03-14 |
KR20050091092A (en) | 2005-09-14 |
KR101105623B1 (en) | 2012-01-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7942361B2 (en) | Webbing retracting device | |
EP1600342B1 (en) | Seat belt retractor | |
US7753305B2 (en) | Seat belt retractor | |
JP4976241B2 (en) | Seat belt retractor and seat belt device using the same | |
US20110049283A1 (en) | Seatbelt retractor | |
EP2390148B1 (en) | Webbing retractor | |
US20060016926A1 (en) | Seat belt retractor and seat belt apparatus | |
US20080203808A1 (en) | Seat belt retractor and seat belt apparatus employing the same | |
JP2009061809A (en) | Seat belt retractor and seat belt device using the same | |
US20110057066A1 (en) | Seatbelt retractor | |
US20080203807A1 (en) | Seat belt retractor and seat belt apparatus employing the same | |
US9205773B2 (en) | Webbing take-up device | |
KR100620620B1 (en) | Pretensioner of retractor for a seat belt | |
WO2000013946A1 (en) | Pretensioner for seat belts | |
WO2013179978A1 (en) | Retractor for seat belt | |
US9738250B2 (en) | Seatbelt retractor | |
JPH07309203A (en) | Storage retractor of seatbelt web | |
JP2013049401A (en) | Webbing winder | |
WO2023112614A1 (en) | Webbing winding device | |
JP2006159982A (en) | Seat belt retractor | |
JP6739358B2 (en) | Webbing take-up device | |
KR200366953Y1 (en) | Pretensioner of retractor for a seat belt |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ASHIMORI INDUSTRY CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KATAYAMA, TAKAO;REEL/FRAME:017540/0373 Effective date: 20050610 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- AFTER EXAMINER'S ANSWER OR BOARD OF APPEALS DECISION |