JP3607114B2 - Webbing take-up device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a webbing take-up device that winds up an occupant-constrained webbing in a layered manner by an urging force.
[0002]
[Prior art]
Hereinafter, a conventional technique will be described with reference to FIGS.
[0003]
As shown in these drawings, a torsion shaft insertion hole 152 for inserting a torsion shaft 151 for a force limiter is formed in the shaft core portion of the spool 150 for winding the occupant restraining webbing in layers. . Further, a base lock mounting portion 154 having a larger diameter than that of the torsion shaft insertion hole 152 is formed on the same axial end. The base lock mounting portion 154 is mounted with a substantially cylindrical base lock 156 that forms part of locking means that prevents rotation of the spool 150 in the webbing pull-out direction during sudden deceleration of the vehicle.
[0004]
An annular groove 158 is formed at a predetermined position on the outer peripheral portion of the base lock 156 described above, and a corresponding through hole 160 is formed at a predetermined position on the inner peripheral portion of the base lock mounting portion 154 in the spool 150. Is formed. Conventionally, the base lock 156 is prevented from coming off from the spool 150 by inserting a single spring pin 162 having a substantially cylindrical shape and an open cross section into the concave groove 158 and the through hole 160.
[0005]
[Problems to be solved by the invention]
However, if a configuration in which the spring pin 162 is used to prevent it from coming off is used, a backlash occurs between the inner peripheral portion of the base lock mounting portion 154 and the outer peripheral portion of the base lock 156 of the spool 150, causing abnormal noise. For this reason, conventionally, grease 164 is applied between the inner peripheral portion of the base lock mounting portion 154 and the outer peripheral portion of the base lock 156 to prevent the generation of abnormal noise.
[0006]
As a method for avoiding the troublesome application of the grease 164, it is conceivable to press-fit the spring pin 162 to prevent the base lock 156 from coming off. However, it acts on one point where the press-fit load is biased with respect to the axis of the spool 150. Therefore, there is a disadvantage that the base lock 156 is inclined downward in FIG. 7 and the webbing winding property is lowered.
[0007]
In consideration of the above facts, the present invention has an object to provide a webbing take-up device that can prevent the generation of abnormal noise between the spool and the base member and can improve the webbing winding property. is there.
[0008]
[Means for Solving the Problems]
A webbing take-up device according to the present invention as set forth in claim 1 is mounted on a take-up shaft for taking up a webbing for restraining an occupant in a layered manner by an urging force, and a receiving recess formed at an end portion of the take-up shaft. And a substantially cylindrical base member that forms part of the locking means for locking the rotation of the winding shaft in the webbing pull-out direction when the vehicle suddenly decelerates, and the base member is mounted in the receiving recess of the winding shaft, And a retaining member press-fitted between the outer peripheral portion of the base member and the inner peripheral portion of the winding shaft and on both sides in the radial direction of the base member.
[0009]
According to the first aspect of the present invention, first, the substantially cylindrical base member is mounted in the receiving recess formed in the axial end of the winding shaft. In this state, there is a slight gap between the inner periphery of the receiving recess of the winding shaft and the outer periphery of the base member. Next, the retaining member is press-fitted between the inner peripheral portion of the receiving recess of the take-up shaft and the outer peripheral portion of the base member so as to sandwich the base member and on both sides in the radial direction of the base member. Thereby, the backlash between the inner peripheral part of the receiving recessed part of a winding shaft and the outer peripheral part of a base member is eliminated. Further, since the base member is equally spaced from the axis and receives the press-fitting load evenly at two locations facing each other in the radial direction, the base member does not tilt with respect to the axis of the winding shaft.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a webbing retractor 10 according to an embodiment of the present invention will be described with reference to FIGS.
[0011]
1-3, the principal part of the webbing take-up device 10 according to the present embodiment is depicted in a cross-sectional view, a front view, and a vertical cross-sectional view, respectively. As shown in these drawings, the webbing take-up device 10 includes a substantially U-shaped frame 12 in a plan view, and includes a first leg plate 14 and a second leg plate (not shown) extending in parallel with each other. Between them, a spool 16 as a “winding shaft” manufactured by die casting is rotatably supported.
[0012]
The spool 16 is disposed on the side of the first leg plate 14 (hereinafter referred to as the first leg plate 14) and a cylindrical spool shaft 16A that constitutes the shaft core portion, and a pair of flange portions that are formed in both ends of the spool shaft 16A. The flange portion is referred to as “first flange portion 16B”, and the flange portion disposed on the second leg plate side is referred to as “second flange portion 16C”). Yes.
[0013]
A torsion shaft insertion hole 18 for inserting a torsion shaft 20 that functions as a force limiter is formed in the shaft core portion of the spool shaft 16A. On the first flange portion 16B side of the torsion shaft insertion hole 18, a concave base lock receiving portion 22 having a larger diameter than the torsion shaft insertion hole 18 is formed coaxially. The base lock receiving portion 22 includes a concave body 22A that occupies most of the base lock, and a concave terminal portion 22B having a larger diameter than the concave body 22A.
[0014]
The base lock receiving portion 22 is mounted with a base lock 24 as a “base member” manufactured by die casting in the same manner as the spool 16. The base lock 24 is formed in a cylindrical shape with a hook, and has a base portion 24A fitted into the concave body 22A of the base lock receiving portion 22, a diameter larger than the base portion 24A, and a concave end portion of the base lock receiving portion 22. The intermediate portion 24B is fitted into 22B, and the holding portion 24C has a larger diameter than the intermediate portion 24B and is disposed in contact with the outer surface of the first flange portion 16B.
[0015]
Further, a hexagonal hole-like fitting hole 26 (see FIG. 3) is formed in a portion of the base lock 24 excluding the outer end of the shaft core portion. Further, the fitting hole 26 is formed at the outer end of the shaft core portion. A small hole (not shown) that is in communication with the shaft core portion and has a smaller diameter than that is formed.
[0016]
The above-described base lock 24 is a component that constitutes a part of a lock unit that instantaneously prevents (locks) rotation of the spool 16 in the webbing pull-out direction when the vehicle suddenly decelerates. In brief, the holding portion 24C of the base lock 24 is formed with a concave portion having a predetermined shape. A single lock plate (not shown) having a lock tooth formed on a part of the outer periphery is held in the recess. When the vehicle suddenly decelerates, an acceleration sensor (not shown) provided on the first leg plate 14 side of the frame 12 detects this, and rotation of the V gear (not shown) arranged adjacent to the base lock 24 in the webbing pull-out direction is performed. When blocked, the lock teeth of the lock plate are engaged with the ratchet teeth 28A of the internal tooth ratchet 28 formed on the first leg plate 14 of the frame 12. At this time, a reaction force when the lock teeth are engaged with the ratchet teeth 28 </ b> A acts on the base lock 24, and a portion opposite to the engagement portion is plastically deformed to the ratchet teeth 28 </ b> A of the internal tooth ratchet 28. The bite is engaged.
[0017]
A bolt-like torsion shaft 20 is inserted into the torsion shaft insertion hole 18 in the spool shaft 16A described above. A hexagonal portion similar to the head is formed on the tip end side of the torsion shaft 20, and this hexagonal portion is fitted into the fitting hole 26 of the base lock 24. In the fitted state, although not shown, the tip of the torsion shaft 20 passes through the small hole of the base lock 24, and the V gear is pivotally supported by the penetrating end so as to follow and rotate.
[0018]
A recess-shaped sleeve receiving portion (not shown) having a female spline formed on the inner peripheral portion is formed on the second flange portion side of the torsion shaft insertion hole 18, and the sleeve receiving portion is formed on the outer peripheral portion. A sleeve (not shown) in which a male spline is formed and a hexagonal hole-shaped fitting hole is formed in the shaft core portion is spline-fitted. The head portion (hexagonal portion) of the torsion shaft 20 is fitted into the fitting hole of the sleeve. Further, the spool shaft 16A and the base lock 24 are connected to each other in a state in which the spool shaft 16A is prevented from being detached by a stopper 34 described later. As described above, the torsion shaft 20 is integrated with the spool shaft 16A via the base lock 24 and the sleeve.
[0019]
Note that the inner end of an urging means (spring spring) for applying an urging force in the webbing take-up rotation direction to the spool 16 is locked to the sleeve via an adapter (not shown). The sleeve is an element of a pretensioner that instantaneously rotates the spool 16 in the webbing take-up direction when the vehicle suddenly decelerates.
[0020]
The above-described base locks 24 are connected to each other in a state in which the spool lock 16 is prevented from coming off from the spool shaft 16A. This is the main part of this embodiment, which will be described in detail below.
[0021]
A stopper insertion groove 30 into which a stopper 34 (to be described later) can be inserted is formed in the intermediate portion in the axial direction of the concave body 22A in the spool shaft 16A. The stopper insertion groove 30 is formed in an arcuate shape along the outer periphery of the spool shaft 16A and has a top mounting groove 30A whose cross-sectional shape is an inverted “convex” shape (detailed structure is shown in FIGS. 5A and 5B). ), And a pair of leg insertion grooves 30B (see FIG. 3) arranged perpendicular to the top mounting groove 30A and in parallel with each other. Correspondingly, an annular groove 32 is formed at a position facing the pair of leg insertion grooves 30B in the intermediate portion of the base lock 24 in the axial direction of the base 24A.
[0022]
The stopper insertion groove 30 and the annular groove 32 are inserted with a stopper 34 as a “prevention member” formed in a substantially U shape when viewed from the front, whereby the base lock 24 is connected to the base lock of the spool shaft 16A. The receiving part 22 is fixed in a state of being prevented from coming off.
[0023]
As shown in the detailed view of FIG. 4, the stopper 34 includes a top portion 34 </ b> A and a pair of legs 34 </ b> B that hang down in parallel from both sides of the top portion 34 </ b> A. A rib 36 having a predetermined width is integrally formed on the inner peripheral side of the portion extending from the top 34A to the leg 34B. Thereby, the cross-sectional shape of the top portion 34A of the stopper 34 is an inverted “convex” shape that is the same as the cross-sectional shape of the top portion mounting groove 30A formed in the spool shaft 16A. Moreover, the width direction dimension of the leg part 34B of the stopper 34 is set to be approximately the same as the groove width of the leg part insertion groove 30B and the annular groove 32. Further, the stopper 34 is made of a resin material or a spring material, and can be elastically deformed in a direction in which the pair of leg portions 34B approach and separate from each other.
[0024]
Next, the operation and effect of this embodiment will be described.
[0025]
First, the overall operation of the webbing take-up device 10 according to this embodiment will be briefly described.
[0026]
The occupant wears a tongue plate (not shown) inserted into the webbing, pulls out the webbing against the urging force of the mainspring spring, and engages the tongue plate with a buckle device (not shown), so that the occupant wears the webbing of the three-point seat belt device. It becomes a state. That is, a webbing from a shoulder anchor to a tongue plate (not shown) disposed on the center pillar is a shoulder side webbing, and a webbing from the tongue plate to the anchor plate fixed to the vehicle body floor is a lap side webbing.
[0027]
On the other hand, when the vehicle suddenly decelerates, a pretensioner (not shown) is operated to instantaneously rotate the spool 16 in the webbing take-up direction. At the same time, the acceleration sensor operates to prevent the V gear from rotating in the webbing pull-out direction. When rotation of the V gear in the webbing pull-out direction is prevented, the lock teeth of the lock plate held by the holding portion 24C of the base lock 24 are engaged with the ratchet teeth 28A of the internal ratchet 28 of the frame 12 and the base lock 24 It itself is plastically deformed and bites into and engages with the ratchet teeth 28A of the internal tooth ratchet 28. As a result, a locked state in which rotation of the spool 16 in the webbing pull-out direction is prevented via the base lock 24, the torsion shaft 20, and the sleeve is achieved. Further, when the webbing tension received from the occupant exceeds a predetermined value, the torsion shaft 20 undergoes plastic deformation due to torsion, allowing the webbing to be pulled out by a length corresponding to the plastic deformation amount, and depending on the plastic deformation amount. Only a certain amount of energy is absorbed. That is, the force limiter mechanism operates.
[0028]
Next, the procedure for assembling the base lock 24 to the spool shaft 16A using the stopper 34 will be described.
[0029]
First, the base lock 24 is inserted into the base lock receiving portion 22 formed in the shaft core portion of the spool shaft 16A. Next, the stopper 34 is inserted from the top mounting groove 30A side of the stopper insertion groove 30 of the spool shaft 16A. Specifically, the top 34A of the stopper 34 is fitted into the top mounting groove 30A, and the pair of legs 34B of the stopper 34 is paired with a pair of leg insertion grooves 30B formed on the spool shaft 16A and a base 24A of the base lock 24. Is inserted into the annular groove 32 formed in the outer peripheral portion of the outer peripheral portion.
[0030]
More specifically, as shown in FIG. 1, the leg portion 34B of the stopper 34 is disposed between one side surface 30C of the leg insertion groove 30B of the spool shaft 16A and one side surface 32A of the annular groove 32 of the base lock 24. Is press-fitted in the form of being pushed. As a result, the base lock 24 is pressed toward the axial center of the spool shaft 16A (in the direction of arrow A in FIG. 1), and there is no backlash in the axial direction between the base lock 24 and the spool shaft 16A. Further, the pair of leg portions 34B of the stopper 34 is press-fitted between the leg portion insertion groove 30B of the spool shaft 16A and the annular groove 32 of the base lock 24, that is, on both sides in the radial direction of the base portion 24A of the base lock 24. Accordingly, there is no backlash in the radial direction between the outer peripheral portion of the base portion 24A of the base lock 24 and the inner peripheral portion of the concave body 22A of the spool shaft 16A. As a result, the base lock 24 and the spool shaft 16A are connected to each other with no backlash in either the axial direction or the radial direction, and the base lock 24 is prevented from coming off from the spool shaft 16A. Thereby, according to this embodiment, generation | occurrence | production of the noise between the base lock 24 and the spool shaft 16A can be prevented.
[0031]
Furthermore, in the present embodiment, the stopper 34 is formed in a substantially U shape when viewed from the front. When the base lock 24 is fixed to the spool shaft 16A by the stopper 34, the base lock 24 is equidistant from the axis. In addition, the press-fitting load is equally received from the pair of leg portions 34B at two locations facing each other in the radial direction. Therefore, the base lock 24 does not tilt with respect to the axis of the spool shaft 16A. As a result, according to the present embodiment, the webbing wrapping property can be improved.
[0032]
In this embodiment, the stopper 34 having the substantially flat plate-like leg portion 34B is used. However, the present invention is not limited to this, and various stopper shapes can be adopted. For example, in the stopper 40 shown in FIG. 6A, the rib 42 is integrally formed at the intermediate portion in the width direction of the leg portion 40A. Further, in the stopper 44 shown in FIG. 6B, a long hole 46 is formed in the intermediate portion in the width direction of the leg portion 44A. Furthermore, in the stopper 48 shown in FIG. 6C, a concave groove 50 is formed in the intermediate portion in the width direction of the leg portion 48A. Furthermore, in the stopper 52 shown in FIG. 6D, a slit 54 is formed in the intermediate portion in the width direction of the leg portion 52A. In the stopper 40, by forming a groove into which the rib 42 is inserted on the annular groove 32 side of the base lock 24, it is possible to further enhance the retaining prevention effect and backlash preventing effect after press-fitting. Further, in the stoppers 44, 48, 52, a long hole 46, a concave groove 50, and a slit 54 (generally, elements that are grasped as “fragile portions” or “low-rigidity portions”) are respectively formed. Thus, the rigidity in the width direction of the leg portion 44A, the leg portion 48A, and the leg portion 52A can be reduced, so that the assembly workability can be improved.
[0033]
In the present embodiment, the present invention is applied to the webbing take-up device 10 having both the pretensioner and the force limiter. However, the present invention is not limited thereto, and the webbing winding having only one of the pretensioner and the force limiter is provided. The present invention can also be applied to a webbing take-up device that is not provided with any take-up device or any of a pretensioner and a force limiter.
[0034]
Furthermore, in this embodiment, the retaining member is configured by one component, but the present invention is not limited to this, and the component may be divided into two components.
[0035]
【The invention's effect】
As described above, the webbing take-up device according to the first aspect of the present invention has the outer periphery of the base member and the inner periphery of the take-up shaft in a state where the base member is mounted in the receiving recess of the take-up shaft. Since the retaining member is press-fitted between the base member and both sides of the base member in the radial direction, the backlash between the outer peripheral portion of the base member and the inner peripheral portion of the winding shaft can be eliminated, and the base It is possible to prevent the member from being inclined with respect to the axis of the winding shaft. As a result, the webbing take-up device according to the present invention has an excellent effect that it is possible to prevent the generation of noise between the spool and the base member and to improve the webbing winding property. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along line 1-1 of FIG. 3 showing a main part of a webbing take-up device according to the present embodiment.
FIG. 2 is a front view showing an assembled state of the spool and base lock shown in FIG. 1 in a state before press-fitting of a stopper.
3 is a longitudinal sectional view taken along line 3-3 of FIG. 1 showing the overall configuration of the webbing take-up device according to the present embodiment.
4 is a front view showing a detailed structure of the stopper shown in FIG. 2 and the like. FIG.
5A is an enlarged plan view of a main part of a spool to which the stopper shown in FIG. 4 is inserted; FIG. 5B is an enlarged main part taken along line (B)-(B) of FIG. It is a longitudinal cross-sectional view.
6 is a perspective view showing a modified example of the stopper shown in FIG. 2. FIG.
FIG. 7 is a partially cutaway front view showing a main part of a webbing take-up device according to a conventional example with a part cut away.
8 is a longitudinal section taken along line 8-8 of FIG. 7 showing the webbing take-up device shown in FIG. 7 in a side view.
[Explanation of symbols]
10 Webbing take-up device 16 Spool (winding shaft)
22 Base lock receiving part 24 Base lock (base member)
34 Stopper (Retaining member)
40 Stopper (Retaining member)
44 Stopper (Retaining member)
48 Stopper (Retaining member)
52 Stopper (Retention member)

Claims (1)

A winding shaft that winds up the occupant-constrained webbing in a layered manner by an urging force and a receiving recess formed at the end of the shaft core of the winding shaft are mounted in the webbing pull-out direction of the winding shaft during sudden deceleration of the vehicle. A substantially cylindrical base member constituting a part of the locking means for locking;
A retaining member press-fitted between the outer peripheral portion of the base member and the inner peripheral portion of the take-up shaft and on both sides in the radial direction of the take-up shaft in a state where the base member is mounted in the receiving recess of the take-up shaft; ,
Composed of,
A webbing take-up device characterized by that.

Images