Retractable and seat belt systems

Abstract

To provide a retractor and a seat belt device which can reduce the generation of vibration sound.SOLUTION: A retractor 1 according to one embodiment of the present invention includes a lock mechanism 4 which regulates rotation of a spool 2. The lock mechanism 4 comprises: a lock gear 41 which is coaxially arranged so as to be relatively rotatable with respect to the spool 2; and a flywheel 43 which is arranged in the lock gear 41 and moves a pawl 42 with the relative rotation of the spool 2 and the lock gear 41. The flywheel 43 includes a protrusion 43f which is arranged on the tip in the relative rotation direction R. The lock gear 41 includes a stopper 41i configured to tilt the posture of the flywheel 43 by being in contact with the protrusion 43f in the time of non-actuation of the flywheel 43 and release contact with the protrusion 43f in the time of actuation of the flywheel 43.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a retractor and a seatbelt device, and particularly to a retractor and a seatbelt device capable of reducing the generation of vibration noise. [Background Art]

[0002] Vehicles such as automobiles are generally provided with a seatbelt device that restrains an occupant to a seat including a waist portion on which the occupant sits and a backrest portion located on the back side of the occupant. Such a seatbelt device includes a webbing that restrains the occupant, a retractor that winds up the webbing, a buckle disposed on a side surface of the seat, and a tongue disposed on the webbing, and restrains the occupant to the seat by the webbing by fitting the tongue into the buckle.

[0003] Such a retractor often includes a spool that winds up the webbing, a base frame that rotatably accommodates the spool, a spring unit that applies a winding force to the spool, a vehicle sensor that detects sudden deceleration of the vehicle, a lock mechanism that is activated by the vehicle sensor to engage the spool with the base frame, and a pretensioner that removes slack in the webbing in an emergency such as a vehicle collision.

[0004] For example, Patent Document 1 discloses a part of a locking device provided with a control disk as a lock mechanism. An inertia mass body is disposed on the control disk so as to be pivotable about a pivot shaft. In the invention described in Patent Document 1, in order to reduce noise (vibration noise) generated by the inertia mass body, an L-shaped projection that abuts against an abutment surface formed on the outer edge of the inertia mass body is disposed. Note that the control disk may also be referred to as a lock gear, and the inertia mass body may also be referred to as a flywheel. [Related Art] [Patent Literature]

[0005] [Patent Document 1] Patent No. 5545910 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, as described in Patent Document 1, if the protrusion and the inertial mass (flywheel) are in contact, it will hinder the rotational motion of the inertial mass (flywheel), so it is necessary to set a gap of some degree. Consequently, this gap becomes a source of vibration noise.

[0007] This invention was conceived in view of the aforementioned problems, and aims to provide a retractor and seat belt device that can reduce the generation of vibration noise. [Means for solving the problem]

[0008] According to the present invention, a retractor is provided comprising a spool for winding webbing to restrain an occupant, a base frame for rotatably housing the spool, and a locking mechanism for restricting the rotation of the spool, wherein the locking mechanism comprises a locking gear coaxially arranged to be rotatable relative to the spool, a pawl arranged to be engageable with the base frame, a flywheel arranged on the locking gear for moving the pawl by relative rotation between the spool and the locking gear, and a hook spring for biasing the flywheel in the direction opposite to the relative rotation direction during operation, wherein the flywheel has a projection positioned at its tip in the relative rotation direction, and the locking gear has a stopper configured to contact the projection when not in operation to tilt the position of the flywheel, and to release contact with the projection when in operation.

[0009] The stopper may have a tapered surface in the portion that contacts the projection.

[0010] The stopper may have a support portion formed on the lock gear and a projection portion formed to be in contact with the upper part of the projection.

[0011] The projection may have a curved surface in the portion that contacts the stopper.

[0012] The flywheel may be configured to be supported at three points by the lock gear when not in operation.

[0013] The lock gear comprises a pivot shaft that rotatably supports the flywheel, a plurality of engaging claws arranged on the outer circumference of the pivot shaft, and a guide portion formed along the outer circumference of the root portion of the pivot shaft. The flywheel comprises a through hole through which the pivot shaft is inserted and an engaging hole for engaging the engaging claws. The flywheel may be configured to be supported by the stopper, the engaging claws, and the guide portion when not in operation.

[0014] The hook spring may be arranged such that, when not in operation, it biases the projection in a direction that contacts the stopper.

[0015] Furthermore, the present invention provides a seat belt device characterized by comprising a retractor having any of the above-described configurations. [Effects of the Invention]

[0016] According to the retractor and seat belt device of the present invention described above, when the flywheel is not operating, a projection formed on the flywheel and a stopper formed on the lock gear are brought into contact to tilt the position of the flywheel, thereby eliminating the gap in the flywheel required when the flywheel is operating, and reducing the generation of vibration noise in the retractor and seat belt device when not operating. [Brief explanation of the drawing]

[0017] [Figure 1]It is an exploded view of components showing a retractor according to an embodiment of the present invention. [Figure 2] It is a plan view showing a state where a flywheel is assembled to the lock gear shown in FIG. 1. [Figure 3] It is a cross-sectional view of the component shown in FIG. 2, where (A) is a cross-sectional view taken along line A-A, and (B) is a cross-sectional view taken along line B-B. [Figure 4] It is a cross-sectional view of the component shown in FIG. 2, where (A) is a cross-sectional view taken along line C-C, and (B) is a cross-sectional view taken along line D-D. [Figure 5] It is a plan view showing the behavior of the flywheel during operation. [Figure 6] It is an overall configuration diagram showing a seat belt device according to an embodiment of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to FIG. 1 to FIG. 6. Here, FIG. 1 is an exploded view of components showing a retractor according to an embodiment of the present invention. FIG. 2 is a plan view showing a state where a flywheel is assembled to the lock gear shown in FIG. 1. Note that, in FIG. 1, the illustration of webbing is omitted for convenience of explanation.

[0019] A retractor 1 according to an embodiment of the present invention includes, as shown in FIG. 1 and FIG. 2, a spool 2 that winds webbing for restraining an occupant, a base frame 3 that rotatably accommodates the spool 2, and a lock mechanism 4 that restricts rotation of the spool 2. The lock mechanism 4 includes: a lock gear 41 coaxially disposed to be relatively rotatable with respect to the spool 2; a pawl 42 disposed to be engageable with the base frame 3; a flywheel 43 disposed on the lock gear 41 and configured to move the pawl 42 by relative rotation between the spool 2 and the lock gear 41; a hook spring 44 that biases the flywheel 43 in a direction opposite to a relative rotation direction during operation; and a locking base 45 disposed between the spool 2 and the lock gear 41.

[0020] The spool 2 is a winding drum that winds up webbing. For example, one end of the spool 2 is rotatably supported by the spring unit 5, and the other end is connected to the locking base 45. The locking base 45 is rotatably supported by the retainer cover 6 via a cap 46 (bearing).

[0021] The spring unit 5 is a component that biases the spool 2 in the winding direction, and incorporates a spiral spring. The retainer cover 6 is a component that accommodates the lock mechanism 4 and the vehicle sensor 47. The spring unit 5 and the retainer cover 6 are directly or indirectly fixed to the base frame 3.

[0022] Further, the retractor 1 may be provided with a pretensioner 7 that removes slack in the webbing during an emergency such as a vehicle collision. For example, the pretensioner 7 includes a pipe 71 capable of ejecting a mass body, a gas generator 72 disposed at a rear end of the pipe 71, and a ring gear 73 rotated by the mass body ejected from the pipe 71 upon actuation of the gas generator 72.

[0023] The pretensioner 7 is, for example, disposed inside the base frame 3 adjacent to the locking base 45. The pretensioner may be disposed outside the base frame 3 adjacent to the locking base 45, or may be disposed inside the spring unit 5.

[0024] The base frame 3 is, for example, a frame structure having a substantially rectangular U-shaped cross-section, and a pair of side wall members are formed at both ends of a back wall member constituting the back surface. An opening through which an end portion of the spool 2 (including the locking base 45) is inserted is formed in the pair of side wall members, and engaging teeth 31 are formed on an inner circumferential surface of the opening. Further, a tie plate constituting a front surface may be connected to tips of the pair of side wall members.

[0025] The locking mechanism 4 is a mechanism that restricts the extension of the webbing in emergencies such as vehicle collisions. The locking mechanism 4 is composed of components such as a locking gear 41, a pawl 42, a flywheel 43, a locking base 45, a cap 46, and a vehicle sensor 47. Note that the locking mechanism 4 is not limited to the configuration shown in the illustration.

[0026] The locking base 45 is a substantially disc-shaped component connected to the end of the spool 2. The locking base 45 is inserted through an opening in the base frame 3 and positioned so that its outer circumference faces the engaging teeth 31. The locking base 45 has a thickness that allows it to accommodate the pawl 42, and a housing portion 45a is formed on a part of its outer circumference, providing a space for accommodating the pawl 42. The locking base 45 also has a shaft portion 45b that constitutes the rotation axis of the spool 2.

[0027] The vehicle sensor 47 includes, for example, a spherical mass body 47a, a sensor lever 47b that is oscillated by the movement of the mass body 47a, and a sensor cover 47c that houses the mass body 47a and the sensor lever 47b. When the vehicle body decelerates or tilts beyond a predetermined value, the balance of the mass body 47a is disrupted, the sensor lever 47b is pushed upward, the tip of the sensor lever 47b engages with the lock gear 41, and the rotation of the lock gear 41 is restricted.

[0028] When the lock gear 41 rotates relative to the spool 2 (locking base 45), the pin 42a of the pawl 42 moves along the guide groove 41d, and its tip is pushed radially out from the side of the locking base 45. The engaging claw formed on the tip engages with the engaging teeth 31 of the base frame 3. This engagement locks the rotation of the spool 2 and restricts the extension of the webbing. The pawl 42 is biased radially inward by a pawl spring (not shown) to prevent its tip (engaging claw) from protruding radially outward from the side of the locking base 45.

[0029] The lock gear 41 includes, for example, a disc portion 41a that forms a plane facing the locking base 45, an outer peripheral wall 41b that is erected outward along the outer edge of the disc portion 41a, and a central portion 41c that is inserted into the shaft portion 45b of the locking base 45. Engaging teeth 41g are formed on the outer peripheral surface of the outer peripheral wall 41b, which can engage with the sensor lever 47b of the vehicle sensor 47.

[0030] The disc portion 41a has a guide groove 41d for guiding the pin 42a of the pole 42, a pivot shaft 41e for pivotally supporting the flywheel 43, a plurality of engaging claws 41f arranged on the outer circumference of the pivot shaft 41e, and a guide portion 41h (see Figure 3) formed along the outer circumference of the base portion of the pivot shaft 41e. The flywheel 43 is positioned in the space formed by the disc portion 41a and the outer peripheral wall 41b. The surface of the disc portion 41a may also have a plurality of protrusions to identify the space for housing the flywheel 43.

[0031] The flywheel 43 has a curved or bent shape that allows it to be inserted into the space surrounded by the disc portion 41a, outer peripheral wall 41b, and central part 41c of the lock gear 41, and has a first end portion 43a located upstream in the relative rotation direction R and a second end portion 43b located downstream in the relative rotation direction R.

[0032] Furthermore, the flywheel 43 includes, for example, an insertion hole 43c formed in the middle of the first end 43a and the second end 43b and inserted through the pivot shaft 41e of the lock gear 41, a plurality of engagement holes 43d arranged along the outer circumference of the insertion hole 43c and engaging with the engagement claws 41f of the lock gear 41, and an annular protrusion 43e arranged along the guide portion 41h of the lock gear 41.

[0033] The engagement hole 43d is configured to restrict the axial movement of the engagement claw 41f when it engages with the engagement claw 41f, while allowing the rotational movement of the engagement claw 41f. Furthermore, the relative rotation amount of the flywheel 43 is restricted by the circumferential length of the engagement hole 43d. In addition, the relative rotation of the flywheel 43 can be stabilized by guiding the convex portion 43e to the guide portion 41h.

[0034] Furthermore, the flywheel 43 has a projection 43f positioned at its tip in the relative rotation direction R. The projection 43f is formed, for example, along the extending direction of the first end portion 43a. The projection 43f has a curved surface 43g on the side of the flywheel 43 opposite to the relative rotation direction R or on the side closer to the outer peripheral wall 41b of the lock gear 41.

[0035] The lock gear 41 has a stopper 41i configured to contact the projection 43f when the flywheel 43 is not operating, thereby tilting the position of the flywheel 43, and to release contact with the projection 43f when the flywheel 43 is operating.

[0036] Furthermore, the multiple engaging claws 41f include, for example, a first engaging claw 41j positioned on the first end 43a side of the flywheel 43, and a second engaging claw 41k positioned on the second end 43b side of the flywheel 43, with the pivot shaft 41e in between. Note that the engaging claws 41f may also include engaging claws other than the first engaging claw 41j and the second engaging claw 41k.

[0037] The flywheel 43 is formed such that, for example, its first end 43a and second end 43b are oriented in substantially perpendicular directions, and an insertion hole 43c is formed approximately at its center. The first engaging claw 41j and the second engaging claw 41k are arranged such that they face each other on an extension of the direction from the insertion hole 43c toward the second end 43b.

[0038] The hook spring 44 is inserted, for example, through a support shaft 44a (see Figure 3) formed between the flywheel 43 and the central part 41c. The support shaft 44a may be formed on the lock gear 41 side or on the flywheel 43 side. The hook spring 44 is also positioned so as to bias the projection 43f in a direction that contacts the stopper 41i when not in operation.

[0039] The configuration of the projection 43f of the flywheel 43 and the stopper 41i of the lock gear 41 will be explained with reference to Figures 3(A) to 4(B). Here, Figure 3 is a cross-sectional view of the part shown in Figure 2, where (A) is a cross-sectional view taken along arrow AA and (B) is a cross-sectional view taken along arrow BB. Figure 4 is a cross-sectional view of the part shown in Figure 2, where (A) is a cross-sectional view taken along arrow CC and (B) is a cross-sectional view taken along arrow DD.

[0040] As shown in Figure 3(A), the stopper 41i is formed in a hook shape, having a support portion 41m erected from the lock gear 41 and a projection 41n formed to be in contact with the upper part of the projection 43f. The lower surface of the projection 41n constitutes the surface that contacts the projection 43f, and has a tapered surface 41p in the portion that contacts the projection 43f.

[0041] Furthermore, the projection 43f may have a curved surface 43g in the portion that contacts the tapered surface 41p of the stopper 41i. The projection 43f shown in Figure 3(A) has an inclined surface on its upper side, but the projection 43f only needs to have a rounded curved surface 43g at least at its tip (the end opposite to the relative rotation direction R). The curved surface 43g is not limited to the illustrated shape as long as it is configured to move smoothly along the tapered surface 41p.

[0042] As shown in Figure 3(B), when the flywheel 43 is not operating, that is, when the projection 43f is pressed against the tapered surface 41p of the stopper 41i, the projection 43f sinks in so as to approach the disc portion 41a of the lock gear 41, and the position of the flywheel 43 is tilted by an angle α. At this time, a part of the convex portion 43e of the flywheel 43 (the portion on the side where the projection 43f is formed) is pressed against the guide portion 41h of the lock gear 41, forming a pivot point for the tilt of the flywheel 43.

[0043] As shown in Figure 2, the flywheel 43 can be distinguished into a Down side (right side in the figure) that approaches the disc portion 41a of the lock gear 41 and an Up side (left side in the figure) that moves away from the disc portion 41a of the lock gear 41, separated by a straight line L that passes through the contact point between the convex portion 43e and the guide portion 41h when not in operation. The first engaging claw 41j and the second engaging claw 41k may be arranged to face each other along the straight line L.

[0044] The cross-sectional view shown in Figure 4(A), taken along the CC arrow in Figure 2, illustrates a cross-section passing through the first engaging claw 41j. Similarly, the cross-sectional view shown in Figure 4(B), taken along the DD arrow in Figure 2, illustrates a cross-section passing through the second engaging claw 41k. As shown in Figures 4(A) and 4(B), when the flywheel 43 is not operating, that is, when the projection 43f is pressed against the tapered surface 41p of the stopper 41i, the surface of the flywheel 43 is pressed against the first engaging claw 41j and the second engaging claw 41k.

[0045] Therefore, when not in operation, the flywheel 43 is supported by the stopper 41i, the engaging claws 41f (first engaging claw 41j and second engaging claw 41k), and the guide portion 41h. In other words, the flywheel 43 is supported at three points by the lock gear 41, with the back surface of the flywheel 43 on the straight line L shown in Figure 2 (the point of contact between the convex portion 43e and the guide portion 41h) as a fulcrum, by one point on the down side surface of the straight line L (the point of contact between the projection 43f and the stopper 41i) and two points on the up side surface of the straight line L (the points of contact between the first engaging claw 41j and the second engaging claw 41k and the flywheel 43).

[0046] Here, Figure 5 is a plan view showing the behavior of the flywheel during operation. The flywheel 43 is configured to rotate relative to the flywheel in the relative rotation direction R when the webbing is faster than the normal pulling speed, so that its second end 43b engages with the internal teeth formed on the retainer cover 6.

[0047] At this time, as shown in Figure 5, the relative rotation of the flywheel 43 causes the projection 43f to move away from the stopper 41i, and the projection 43f moves along the tapered surface 41p of the stopper 41i, and finally the contact between the projection 43f and the stopper 41i is released.

[0048] As the flywheel 43 (projection 43f) rotates relative to the other object, the inclination angle α of the flywheel 43 gradually decreases, and becomes 0° when the contact between the projection 43f and the stopper 41i is released. In other words, the flywheel 43 quickly transitions to a position perpendicular to the pivot axis 41e during operation, allowing the flywheel 43 to rotate relative to the other object smoothly.

[0049] According to the retractor 1 of the present embodiment described above, when the flywheel 43 is not operating, the projection 43f formed on the flywheel 43 and the stopper 41i formed on the lock gear 41 come into contact, causing the attitude of the flywheel 43 to be tilted. This eliminates the gap in the flywheel 43 that is necessary when the flywheel 43 is operating, thereby reducing the generation of vibration noise from the retractor 1 when it is not operating.

[0050] Next, a seat belt device according to one embodiment of the present invention will be described with reference to Figure 6. Here, Figure 6 is an overall configuration diagram showing a seat belt device according to one embodiment of the present invention. In Figure 6, for the sake of explanation, components other than the seat belt device are shown with dashed lines.

[0051] The seat belt device 100 according to this embodiment, shown in Figure 6, comprises a webbing W for restraining the occupant, a retractor 1 for winding up the webbing W, a guide anchor 101 provided on the vehicle body side for guiding the webbing W, a belt anchor 102 for fixing the webbing W to the vehicle body side, a buckle 103 positioned on the side of the seat S on which the occupant sits, and a tongue 104 positioned on the webbing W. The retractor 1 has, for example, the configuration shown in Figure 1.

[0052] The components other than the retractor 1 will be briefly described below. The seat S includes, for example, a seat portion S1 on which the occupant sits, a backrest portion S2 located behind the occupant, and a headrest portion S3 that supports the occupant's head. The retractor 1 is built into, for example, the B-pillar P of the vehicle body.

[0053] In general, the buckle 103 is often positioned on the side of the seat portion S1, and the belt anchor 102 is often positioned on the underside of the seat portion S1. The guide anchor 101 is often positioned on the B pillar P. The webbing W is connected at one end to the belt anchor 102 and at the other end to the retractor 1 via the guide anchor 101.

[0054] Therefore, when the tongue 104 is fitted onto the buckle 103, the webbing W is pulled out of the retractor 1 while sliding through the insertion hole of the guide anchor 101. Also, when an occupant fastens their seat belt or when they unfasten their seat belt upon exiting the vehicle, the webbing W is retracted by the action of the spring unit 5 of the retractor 1 until a certain load is applied.

[0055] Although the seat belt device 100 described above is applied to a seat S located in the front seat of a vehicle, the seat belt device 100 may also be applied to a seat S located in the rear seat. Furthermore, the seat belt device 100 may also be applied to seat belt devices used in vehicles other than cars.

[0056] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0057] 1 Retractor 2 spools 3 Base frame 4. Locking mechanism 5 Spring Unit 6. Retainer Cover 7 Pretensioner 31 Engaging teeth 41 Rock Gear 41a Disc section 41b Peripheral wall 41c center 41d Guide groove 41e Swivel axis 41f Engaging claw 41g engaging teeth 41h Information Department 41i Stopper 41j First engaging claw 41k Second engaging claw 41m support section 41n Protrusion 41p Tapered surface 42 Paul 42a pin 43 Flywheel 43a First end 43b Second end 43c Through hole 43d Engagement hole 43e protrusion 43f protrusion 43g curved surface 44 Hook spring 44a Support shaft 45 Rocking Bass 45a Storage area 45b Shaft 46 caps 47 Vehicle Sensors 47a mass body 47b Sensor lever 47c Sensor Cover 71 pipes 72 Gas generators 73 Ring Gear 100 Seat belt device 101 Guide Anchor 102 Belt Anchor 103 Buckle 104 Tongs

Claims

1. A retractor comprising a spool for winding webbing to restrain the occupant, a base frame for rotatably housing the spool, and a locking mechanism for restricting the rotation of the spool, The locking mechanism comprises a locking gear coaxially arranged so as to be rotatable relative to the spool, a pawl arranged so as to be engageable with the base frame, a flywheel arranged on the locking gear that moves the pawl by the relative rotation between the spool and the locking gear, and a hook spring that biases the flywheel in the direction opposite to the relative rotation direction during operation. The flywheel has a projection positioned at the tip in the relative rotation direction, The lock gear has a stopper configured to contact the projection when not in operation, thereby tilting the position of the flywheel, and to release contact with the projection when in operation. A retractor characterized by the following features.

2. The retractor according to claim 1, wherein the stopper has a tapered surface in the portion that contacts the projection.

3. The retractor according to claim 1, wherein the stopper has a support portion erected from the lock gear and a projection portion formed to be in contact with the upper part of the projection.

4. The retractor according to claim 1, wherein the projection has a curved surface in the portion that contacts the stopper.

5. The retractor according to claim 1, wherein the flywheel is configured to be supported at three points by the lock gear when not in operation.

6. The retractor according to claim 1, wherein the lock gear comprises a pivot shaft that pivotably supports the flywheel, a plurality of engaging claws arranged on the outer circumference of the pivot shaft, and a guide portion formed along the outer circumference of the root portion of the pivot shaft, the flywheel comprises a through hole through which the pivot shaft is inserted and an engaging hole for engaging the engaging claws, and the flywheel is configured to be supported by the stopper, the engaging claws and the guide portion when not in operation.

7. The retractor according to claim 1, wherein the hook spring is arranged to bias the projection in a direction that contacts the stopper when not in operation.

8. A seat belt device characterized by comprising a retractor according to any one of claims 1 to 7.

Images