Retractor and seat belt device

Abstract

Provide are a retractor and a seat belt device which can improve the slidability of a pawl with a simple structure and extend the life of components. The retractor 1 comprises a spool 2, a base frame 3, and a lock mechanism 4. The lock mechanism 4 comprises: a pawl 42 which is held at a position spaced apart from the base frame 3 when not in operation, and is moved to engage with the base frame 3 when in operation; and a locking base 43 (pawl holding part) which maintains the orientation of the pawl 42. The locking base 43 (pawl holding part) comprises: a first holding surface 431 disposed on the side of the spool; and a second holding surface 432 disposed on the opposite side to the spool 2. The first holding surface 431 is configured as an inclined surface of which the entire surface is inclined so that a gap between the first holding surface 431 and the second holding surface 432 widens in the direction of movement of the pawl 42.

Description

Retractor and seat belt device

[0001] The present invention relates to a retractor and a seat belt device, and more particularly to a retractor and a seat belt device that can improve the life of parts.

[0002] Vehicles such as automobiles are generally provided with a seat belt device that restrains an occupant in a seat that has a seat portion on which the occupant sits and a backrest portion located behind the occupant. Such a seat belt device includes a webbing that restrains the occupant, a retractor that winds up the webbing, a buckle located on the side of the seat, and a tongue located on the webbing, and the occupant is restrained in 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 houses the spool, a spring unit that applies a winding force to the spool, a vehicle sensor that detects sudden deceleration of the vehicle, a locking mechanism that is activated by the vehicle sensor and restricts the rotation of the spool, and a pretensioner that removes slack from the webbing in an emergency such as a vehicle collision.

[0004] The locking mechanism generally includes a pawl that protrudes radially outward when activated to engage with a fixed part of the retractor and restrict rotation of the spool in the withdrawal direction.For example, Patent Document 1 discloses a webbing take-up device in which a suppressing portion is formed on the support means on the inclined portion side of the abutting portion, thereby reducing the abutment area of ​​the locking member with the suppressing portion and suppressing a decrease in smoothness when the locking member moves in the locking direction due to the locking member abutting against the suppressing portion.

[0005] JP 2018-111398 A

[0006] However, in the invention described in Patent Document 1, a contact portion and an inclined portion are formed on the sliding surface when the pawl rotates, and there is a possibility that a convex portion such as a burr may be formed at the boundary between the contact portion and the inclined portion during part manufacturing, which may affect the sliding properties of the pawl.In addition, there is also the problem that the part shape becomes complicated, which leads to an increase in the frequency of mold maintenance and the number of man-hours for dimensional inspection, and increases the manufacturing cost.

[0007] The present invention has been devised in view of the above problems, and has as its object to provide a retractor and a seat belt device that can improve the sliding properties of the pawl with a simple structure and can extend the life of the parts.

[0008] According to the present invention, there is provided a retractor including a spool that winds up webbing for restraining an occupant, a base frame that rotatably houses the spool, and a locking mechanism that restricts rotation of the spool, wherein the locking mechanism includes a pawl that is held in a position spaced apart from the base frame when the locking mechanism is not activated and that is moved to engage with the base frame when the locking mechanism is activated, and a pawl holding portion that holds the attitude of the pawl, wherein the pawl holding portion includes a first holding surface that is arranged on the spool side and a second holding surface that is arranged on the opposite side of the spool, and the first holding surface or the second holding surface is configured as an inclined surface whose entire surface is inclined so that the distance between the first holding surface and the second holding surface is wider on the side in the movement direction of the pawl.

[0009] The first holding surface or the second holding surface may be configured to be inclined radially around the rotation axis of the spool.

[0010] The first holding surface or the second holding surface may be configured to be inclined in one direction from the rotation axis of the spool.

[0011] The first holding surface or the second holding surface may be configured to be inclined radially around the rotation axis of the pawl.

[0012] The first holding surface or the second holding surface may be configured to be inclined in one direction from the rotation axis of the pawl.

[0013] The first holding surface or the second holding surface may be configured to be inclined in a tangential direction of a rotational orbit of the pawl.

[0014] The pawl holding portion may include a disk-shaped flange portion having the first holding surface, and the flange portion may have a flange thickness adjustment portion that adjusts the thickness between the portion where the first holding surface is formed and the other portion.

[0015] The pawl holding portion may be configured as a single component having the first holding surface and the second holding surface.

[0016] The pawl holding portion may be configured by two parts: a part having the first holding surface and a part having the second holding surface.

[0017] The pawl holding portion may be configured by a flange portion having the first holding surface and a shaft portion having the second holding surface.

[0018] According to the present invention, there is also provided a seat belt device comprising a retractor having any of the above-described configurations.

[0019] According to the retractor and seat belt device of the present invention described above, the first retaining surface or the second retaining surface is configured to be an inclined surface with an inclination on its entire surface so that the distance between the first retaining surface and the second retaining surface of the pawl retaining portion is wider in the direction of movement of the pawl. As a result, no unevenness is formed on the sliding surface that comes into contact when the pawl moves, and the pawl can slide smoothly.

[0020] Furthermore, by making the entire first holding surface or the second holding surface an inclined surface, the complexity of the part shape is suppressed, the frequency of mold maintenance and the number of steps required for dimensional inspection are reduced, and increases in manufacturing costs are suppressed.

[0021] Therefore, the retractor and seat belt device according to the present invention can improve the sliding properties of the pawl with a simple structure, thereby improving the life of the parts.

[0022] 1 is an exploded view of a part of a retractor according to a first embodiment of the present invention. It is an enlarged view of the pawl holder shown in FIG. 1, where (A) is a perspective view and (B) is an exploded view of a part. It is a cross-sectional view showing the behavior of the pawl, where (A) shows the state before the locking mechanism is activated and (B) shows the state after the locking mechanism is activated. It is an explanatory view of the pawl holder, where (A) is a plan view and (B) is a B-B cross-sectional view. It is a plan view showing the inclination direction of the first holding surface, where (A) shows a first example and (B) shows a second example. It is a plan view showing the inclination direction of the first holding surface, where (A) shows a third example, (B) shows a fourth example, and (C) shows a fifth example. It is a cross-sectional view showing modified examples of the pawl holder, where (A) shows a first modified example and (B) shows a second modified example. It is a side view showing a third modified example of the pawl holder. It is an explanatory view showing a retractor according to a second embodiment of the present invention, where (A) shows the state before the locking mechanism is activated and (B) shows the inclination direction of the first holding surface. 10A and 10B are explanatory diagrams showing a retractor according to a third embodiment of the present invention, in which (A) is a perspective view of a pawl holding portion, and (B) is an exploded view of the parts of the pawl holding portion.

[0023] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 11. FIG. 1 is an exploded view of a retractor according to a first embodiment of the present invention. FIG. 2 is an enlarged view of the pawl holding portion shown in FIG. 1, where (A) is a perspective view and (B) is an exploded view. FIG. 3 is a cross-sectional view showing the behavior of the pawl, where (A) shows the state before the locking mechanism is activated and (B) shows the state after the locking mechanism is activated. Note that in FIG. 1, the webbing is omitted for ease of explanation.

[0024] As shown in FIG. 1 , a retractor 1 according to a first embodiment of the present invention includes, for example, a spool 2 that winds up webbing for restraining an occupant, a base frame 3 that rotatably houses the spool 2, a locking mechanism 4 that restricts the rotation of the spool 2, a pretensioner 5 that removes slack in the webbing in an emergency such as a vehicle collision, a spring unit 6 that biases the spool 2 in the winding direction, and a retainer cover 7 that houses the locking mechanism 4.

[0025] The locking mechanism 4 also includes a locking gear 41 arranged coaxially with the spool 2 so as to be rotatable relative to the spool 2, a pawl 42 that is held at a position spaced apart from the base frame 3 when the locking mechanism 4 is not activated and that is moved to engage with the base frame 3 when the locking mechanism 4 is activated, a locking base 43 that constitutes a pawl holding section that holds the posture of the pawl 42, a flywheel 44 that is arranged on the locking gear 41 and moves the pawl 42 by the relative rotation between the spool 2 and the locking gear 41, and a vehicle sensor 45 that detects the inertial force generated in the vehicle body and regulates the rotation of the locking gear 41.

[0026] The spool 2 has a cavity in the center, through which a torsion bar 21 that defines an axis is inserted. The torsion bar 21 has an expanded diameter portion 21a fixed to the spool 2, a first end portion 21b connected to a spring core of the spring unit 6, and a second end portion 21c fixed to the locking base 43. Note that the torsion bar 21 is an example of an energy absorbing member that reduces the load on the occupant that occurs after the locking mechanism 4 is activated, and other configurations may also be used.

[0027] Therefore, the spool 2 is connected to the spring unit 6 via the torsion bar 21, and is biased in the direction of winding up the webbing by a spiral spring stored in the spring unit 6. Note that a push nut 22 may be disposed between the first end 21b of the torsion bar 21 and the spring core.

[0028] The torsion bar 21 is a component that can twist when a load equal to or greater than a predetermined threshold is applied, and functions as an energy absorbing member when the locking mechanism 4 is activated. If a load is applied in the webbing-unwinding direction when the locking mechanism 4 is activated, the torsion bar 21 holds the spool 2 in a non-rotating state until a load equal to or greater than the threshold is applied to the torsion bar 21, and when a load equal to or greater than the threshold is applied to the torsion bar 21, the torsion bar 21 twists, causing the spool 2 to rotate in the webbing-unwinding direction.

[0029] The base frame 3 is a frame structure having, for example, a generally rectangular U-shaped cross section, with a pair of wall members forming side surfaces formed at both ends of a wall member forming the back surface. Openings 31, 32 are formed in the pair of wall members forming the side surfaces, through which the end of the spool 2 (including the locking base 43) is inserted. Engagement teeth 33 that engage with the pawl 42 of the locking mechanism 4 are formed on the inner peripheral surface of the opening 32 of the base frame 3.

[0030] The pretensioner 5 includes, for example, a pipe 51 capable of releasing a mass body (not shown), a gas generator 52 arranged at the rear end of the pipe 51, a ring gear 53 that is rotated by the mass body released from the pipe 51 upon activation of the gas generator 52, and a bearing 54 arranged between the spool 2 and the ring gear 53.

[0031] The pretensioner 5 is disposed, for example, inside a wall member of the base frame 3 adjacent to the locking base 43. The tip of the pipe 51 is fixed to the base frame 3 by a pin 55. The pretensioner 5 may be disposed outside the wall member of the base frame 3 adjacent to the locking base 43, or may be disposed inside the spring unit 6.

[0032] The spring unit 6 is fixed to the side surface of the base frame 3 by a plurality of fasteners 61. The retainer cover 7 is fixed to the side surface of the base frame 3 by a plurality of fasteners 71. The arrangement of the locking mechanism 4, pretensioner 5, and spring unit 6 is not limited to that shown in the figure.

[0033] The locking mechanism 4 is a mechanism that restricts the withdrawal of the webbing in an emergency such as a vehicle collision. As described above, the locking mechanism 4 is made up of components such as the lock gear 41, the pawl 42, the locking base 43, the flywheel 44, and the vehicle sensor 45. Note that the locking mechanism 4 is not limited to the configuration shown in the figure.

[0034] The lock gear 41 includes, for example, a disk portion forming a flat surface disposed so as to face the locking base 43, an outer peripheral wall erected outward along the outer edge of the disk portion, and a central portion inserted through the axis of the locking base 43. Engagement teeth 41a that can engage with the sensor lever of the vehicle sensor 45 are formed on the outer peripheral surface of the outer peripheral wall.

[0035] A space for accommodating the flywheel 44 is formed inside the outer peripheral wall of the lock gear 41. For example, a guide groove 41b for guiding the protrusion 42c of the pawl 42 is formed in the disk portion of the lock gear 41.

[0036] The pawl 42 has a first end 42a rotatably disposed on a pin 43c disposed on the locking base 43, and a second end 42b configured to be rotatable around the first end 42a. The second end 42b has a protrusion 42c inserted into a guide groove 41b formed in the lock gear 41, and an engagement claw 42d that can engage with the engagement teeth 33 of the base frame 3.

[0037] When the lock gear 41 rotates relative to the spool 2 (locking base 43), the protrusion 42c moves along the guide groove 41b, and the engagement claw 42d is pushed out radially from the side surface of the locking base 43 and engages with the engagement teeth 33 of the base frame 3. This engagement locks the rotation of the spool 2, restricting the withdrawal of the webbing.

[0038] Although not shown, the pawl 42 is biased radially inward by a pawl spring so that the engaging claws 42d do not protrude radially outward from the side surface of the locking base 43 when the locking mechanism 4 is not in operation.

[0039] The locking base 43 is a component disposed at the end of the spool 2 opposite the spring unit 6. The locking base 43 includes, for example, a flange portion 43a that constitutes a pawl holding portion, and a shaft portion 43b to which the ring gear 53 and the bearing 54 are fixed. A recess is formed at the tip of the shaft portion 43b to which the torsion bar 21 is fixed.

[0040] The locking base 43 is inserted into the opening 32 of the base frame 3, and is disposed so that the outer periphery of the flange portion 43a faces the engaging teeth 33. The flange portion 43a of the locking base 43 has a thickness that allows the pawl 42 to be housed therein, and a housing portion that provides a space that can house the pawl 42 is formed on part of the outer periphery.

[0041] The flywheel 44 is a component that moves the pawl 42 by relative rotation between the spool 2 (locking base 43) and the lock gear 41. The configuration of the flywheel is well known, so a detailed description thereof will be omitted here.

[0042] The vehicle sensor 45 includes, for example, a spherical mass, a sensor lever that swings as the mass moves, and a sensor cover that houses the mass and the sensor lever. When the vehicle decelerates or tilts beyond a predetermined value, the balance of the mass is lost and the sensor lever is pushed upward, causing the tip of the sensor lever to engage with the lock gear 41, restricting the rotation of the lock gear 41.

[0043] As described above, the rotation of the lock gear 41 is restricted by the operation of the flywheel 44 or the vehicle sensor 45. When the rotation of the lock gear 41 is restricted, relative rotation occurs between the locking base 43 and the lock gear 41, and this relative rotation causes the pawl 42 to protrude from the side surface of the locking base 43.

[0044] 2(A) and 2(B), the flange portion 43a of the locking base 43 has a thickness sufficient to accommodate the pawl 42, and includes a first holding surface 431 disposed on the spool 2 side and a second holding surface 432 disposed on the opposite side of the spool 2. The first holding surface 431 is an inclined surface formed in a substantially fan shape along the outer periphery of the flange portion 43a. Note that, for ease of explanation, the pin 43c is not shown in FIG. 2(A).

[0045] The second holding surface 432 is formed by a canopy portion 43d formed near the first end 42a of the pawl 42 (around the pin 43c) so as to allow movement of the second end 42b of the pawl 42. The second holding surface 432 is formed inside the canopy portion 43d and is a flat surface facing the first holding surface 431.

[0046] As shown in Fig. 3(A), before the locking mechanism 4 is activated, the pawl 42 is held housed inside the flange portion 43a of the locking base 43. When relative rotation occurs between the locking base 43 and the lock gear 41, the pawl 42 rotates about the pin 43c, and the engaging claw 42d of the pawl 42 protrudes outward from the outer periphery of the flange portion 43a, as shown in Fig. 3(B).

[0047] 4A and 4B are explanatory diagrams of the pawl holding portion, where (A) is a plan view and (B) is a cross-sectional view taken along line B-B. In Fig. 4B, a surface that is approximately perpendicular to the rotation axis (pin 43c) of the pawl 42 and that contacts the first holding surface 431 is defined as a first surface 421, and a surface that is approximately perpendicular to the rotation axis (pin 43c) of the pawl 42 and that contacts the second holding surface 432 is defined as a second surface 422.

[0048] As shown in FIG. 3B, when the pawl 42 moves, the first surface 421 of the pawl 42 slides while contacting the first holding surface 431, and the second surface 422 of the pawl 42 slides while contacting the second holding surface 432.

[0049] In order to reduce sliding resistance when the pawl 42 moves, the first retaining surface 431 is configured as an inclined surface whose entire surface is inclined so that the distance between the first retaining surface 431 and the second retaining surface 432 is wider on the side in the direction of movement of the pawl.

[0050] As shown in Figure 4 (B), if the distance between the first retaining surface 431 and the second retaining surface 432 on the side closer to the rotation axis L of the locking base 43 is D1, and the distance between the first retaining surface 431 and the second retaining surface 432 on the side farther from the rotation axis L of the locking base 43 is D2, the first retaining surface 431 is inclined as a whole so that the relationship D2 > D1 is satisfied.

[0051] 4(B), if the inclination angle of the first holding surface 431 with respect to a plane perpendicular to the rotation axis L of the locking base 43 is θ, the inclination angle θ is set, for example, within a range of 0.5 to 1.5°. The lower limit of the inclination angle θ can be set, for example, to a value greater than the manufacturing tolerance. The upper limit of the inclination angle θ can be set, for example, based on the relationship with the strength (flange thickness) required for the portion forming the first holding surface 431.

[0052] As shown in Figures 5(A) to 6(C), there are several possible methods for inclining the first holding surface 431. Figure 5 is a plan view showing the inclination direction of the first holding surface, with (A) showing a first example and (B) showing a second example. Figure 6 is a plan view showing the inclination direction of the first holding surface, with (A) showing a third example, (B) showing a fourth example, and (C) showing a fifth example.

[0053] In each drawing, the arrows on the first holding surface are shown to indicate the direction of inclination for the sake of convenience. In addition, in the gradation shown in each drawing, darker areas indicate positions with higher inclination, and lighter areas indicate positions with lower inclination.

[0054] 5(A) is configured such that the first holding surface 431 is inclined radially around the rotation axis L of the spool 2 (locking base 43). The inclined surface that constitutes the first holding surface 431 in the first example is configured, for example, by a part of a conical surface with the rotation axis L as the central axis. Note that the inclined surface that constitutes the first holding surface 431 may also be configured by a part of a plane that intersects with the rotation axis L.

[0055] 5(B) is configured such that the first holding surface 431 is inclined in one direction from the rotation axis L of the spool 2 (locking base 43). The inclined surface that constitutes the first holding surface 431 of the second example is configured by, for example, a part of a plane that intersects with the rotation axis L.

[0056] As shown in the first and second examples described above, the inclined surface constituting the first retaining surface 431 can be formed by a part of a plane or curved surface expressed based on the rotation axis L of the spool 2 (locking base 43).

[0057] 6(A) is configured such that the first holding surface 431 is inclined radially around the rotation axis (pin 43c) of the pawl 42. The inclined surface that constitutes the first holding surface 431 of the third example is configured, for example, by a part of a conical surface with the rotation axis (pin 43c) as the central axis. Note that the inclined surface that constitutes the first holding surface 431 may also be configured by a part of a plane that intersects with the rotation axis (pin 43c).

[0058] 6(B) is configured such that the first holding surface 431 is inclined in one direction from the rotation axis (pin 43c) of the pawl 42. The inclined surface constituting the first holding surface 431 of the fourth example is configured, for example, by a part of a plane intersecting with the rotation axis (pin 43c).

[0059] 6(C) is configured such that the first holding surface 431 is inclined in the tangential direction of the rotational path R of the pawl 42. The rotational path R is set, for example, by the path of the tip of the engaging claw 42d of the pawl 42 centered on the rotation axis (pin 43c). Note that the rotational path R may also be set by the path of another portion of the pawl 42.

[0060] As shown in the third to fifth examples described above, the inclination of the first holding surface 431 can be formed, for example, by a portion of a plane or curved surface expressed based on the rotation axis (pin 43c) of the pawl 42.

[0061] The reference for the inclined surface is not limited to the rotation axis L of the spool 2 (locking base 43) or the pivot axis (pin 43c) of the pawl 42, but can be selected arbitrarily. Furthermore, the direction of the inclination is not limited to the directions shown in the first to fourth examples.

[0062] According to the retractor 1 of the first embodiment described above, the first holding surface 431 is configured to be an inclined surface with an inclined surface on its entire surface so that the distance between the first holding surface 431 and the second holding surface 432 of the pawl holding portion becomes wider in the direction of movement of the pawl 42. As a result, no unevenness is formed on the sliding surface that comes into contact when the pawl moves, and the pawl 42 can slide smoothly.

[0063] Furthermore, by making the entire first holding surface 431 an inclined surface, it is possible to prevent the part shape from becoming complicated, reduce the frequency of mold maintenance and the number of steps required for dimensional inspection, and prevent an increase in manufacturing costs. Therefore, with the retractor 1 according to the first embodiment, it is possible to improve the sliding properties of the pawl 42 with a simple structure and to improve the lifespan of the part.

[0064] Next, modified examples of the pawl holder will be described with reference to Figures 7(A) to 8. Figure 7 is a cross-sectional view showing modified examples of the pawl holder, where (A) is a first modified example and (B) is a second modified example. Figure 8 is a side view showing a third modified example of the pawl holder.

[0065] In the first embodiment described above, only the first holding surface 431 is configured to have an inclined surface with an inclined surface over the entire surface. In contrast, in the first modified example shown in Fig. 7(A), only the second holding surface 432 is configured to have an inclined surface with an inclined surface over the entire surface.

[0066] In this way, in order to make the distance between the first holding surface 431 and the second holding surface 432 of the pawl holding portion wider in the direction of movement of the pawl 42, it is possible to incline only one of the first holding surface 431 or the second holding surface 432.

[0067] Whether the first holding surface 431 or the second holding surface 432 is inclined can be changed, for example, for each product model, depending on conditions such as the shape and balance of the pawl holding portion (locking base 43), the shape and balance of the pawl 42, and the direction of the load applied when the pawl 42 moves.

[0068] 7B , both the first holding surface 431 and the second holding surface 432 may be configured to have an inclined surface with an inclination angle of 0.5°, for example, when the required inclination angle is 1.0°, the inclination angle of the first holding surface 431 can be set to 0.5°, and the inclination angle of the second holding surface 432 can be set to 0.5°.

[0069] In the pawl holding portion (locking base 43) described above, the first holding surface 431 side has stricter strength requirements than the second holding surface 432, so if the inclination angle is increased, it may be necessary to increase the thickness of the portion forming the first holding surface 431. Even in such a case, by forming an inclined surface on the second holding surface 432, it is possible to reduce the burden of the design conditions required for the portion where the first holding surface 431 is formed.

[0070] 8, a flange thickness adjusting portion 43e is formed on the flange portion 43a having the first holding surface 431, to adjust the thickness of the portion where the first holding surface 431 is formed and the remaining portion. Specifically, the flange thickness adjusting portion 43e is a portion where the thickness of the outer periphery of the portion of the flange portion 43a where the first holding surface 431 is not formed is removed.

[0071] The surface of the flange portion 43a on the first retaining surface 431 side may constitute a bearing sliding portion when the pretensioner 5 is activated, and in that case, it is preferable to equalize the sliding resistance of the flange portion 43a over all phases. As shown in the figure, by arranging the flange thickness adjusting portion 43e in a portion where the first retaining surface 431 is not formed, it is possible to equalize the sliding resistance of the flange portion 43a.

[0072] Next, a retractor 1 according to another embodiment of the present invention will be described with reference to FIGS. 9(A) to 10(B). Here, FIG. 9 is an explanatory diagram showing a retractor according to a second embodiment of the present invention, where (A) shows the state before the locking mechanism is activated, and (B) shows the inclination direction of the first holding surface. FIG. 10 is an explanatory diagram showing a retractor according to a third embodiment of the present invention, where (A) is a perspective view of the pawl holding portion, and (B) is an exploded view of the pawl holding portion. Note that components that are the same as those in the first embodiment described above are designated by the same reference numerals, and redundant explanations will be omitted.

[0073] 9(A) differs from the pawl 42 of the first embodiment in the configuration of the pawl 46. The pawl 46 of the second embodiment includes an engagement claw 46a that engages with the engagement teeth 33 of the base frame 3 when the locking mechanism 4 is activated, a tail portion 46b that is formed on the opposite side of the engagement claw 46a and extends so as to straddle the rotation axis of the spool 2 (locking base 43), and a protrusion 46c that is inserted into a guide groove formed in the lock gear 41.

[0074] A guide groove 43f is formed in the locking base 43 to accommodate the pawl 46 when the locking mechanism 4 is not in operation and to guide the movement of the pawl 46 when the locking mechanism 4 is in operation. The bottom of the guide groove 43f forms a first holding surface 431, and is formed as an inclined surface similar to the first embodiment described above.

[0075] 9(B) illustrates a case where the first holding surface 431 is configured to be inclined in one direction from the rotation axis of the spool 2 (locking base 43), but is not limited to this configuration. Also, although not illustrated, in the retractor 1 according to the second embodiment, an inclined surface may be formed only on the second holding surface, or inclined surfaces may be formed on both the first holding surface 431 and the second holding surface.

[0076] 10(A) and 10(B), a flange portion 43a having a first holding surface 431 and a shaft portion 43b having a second holding surface 432 are configured as separate parts. In the first embodiment shown in FIGS. 2(A) and 2(B), the pawl holding portion is configured as a single part, the locking base 43, having the first holding surface 431 and the second holding surface 432. However, as in the third embodiment, the pawl holding portion (locking base 43) may be configured by assembling multiple parts.

[0077] The flange portion 43a has an opening 43g in its center. The shaft portion 43b includes a main shaft portion 43h that is inserted into the opening 43g, and a plurality of protrusions 43i that are formed on the end of the main shaft portion 43h and fit into recesses in the flange portion 43a. One of the protrusions 43i forms a canopy portion 43d where a second holding surface 432 is formed.

[0078] In this way, by configuring the pawl holder using two parts, a part (e.g., flange 43a) having the first holding surface 431 and a part (e.g., shaft 43b) having the second holding surface 432, the flange 43a and the shaft 43b can be made of different materials depending on the required strength, thereby achieving a reduction in size and weight of the part. Furthermore, by configuring the first holding surface and the second holding surface as separate parts, the pawl holder can be formed simply by splitting the upper and lower molds, improving moldability.

[0079] For example, when the webbing is pulled out while the locking mechanism 4 is activated, torque is generated on the rotation shaft of the retractor 1. The portion (shaft portion 43b) that comes into contact with the pawl 42 and is subjected to a high load when this torque is generated can be manufactured from a high-strength material such as carbon steel, and the other portion (flange portion 43a) can be manufactured from a lightweight material such as aluminum die-cast.

[0080] Next, a seat belt device according to one embodiment of the present invention will be described with reference to Fig. 11. Fig. 11 is an overall configuration diagram showing a seat belt device according to one embodiment of the present invention. In Fig. 11, for the sake of convenience of explanation, components other than the seat belt device are shown by dashed lines.

[0081] The seat belt device 100 according to this embodiment shown in FIG. 11 includes a webbing W for restraining an 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 provided on the side of the seat S on which the occupant sits, and a tongue 104 provided on the webbing W, and the retractor 1 has, for example, the configuration shown in FIG. 1.

[0082] Below, we will briefly explain the components other than the retractor 1. The seat S includes, for example, a seat portion S1 on which an 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, a B-pillar (not shown) of the vehicle body.

[0083] Generally, the buckle 103 is often located on the side of the seat S1, and the belt anchor 102 is often located on the underside of the seat S1. The guide anchor 101 is often located on the B-pillar. One end of the webbing W is connected to the belt anchor 102, and the other end is connected to the retractor 1 via the guide anchor 101.

[0084] Therefore, when the tongue 104 is fitted into the buckle 103, the webbing W is pulled out from the retractor 1 while sliding through the insertion hole of the guide anchor 101. Furthermore, when an occupant fastens the seat belt or releases the seat belt when getting out of the vehicle, the spring unit 6 of the retractor 1 acts to retract the webbing W until a certain load is applied.

[0085] Although the above-described seat belt device 100 has been described as being applied to a seat S arranged in the front seat of a vehicle, the seat belt device 100 may also be applied to a seat S arranged in the rear seat. Furthermore, the seat belt device 100 may also be applied to a seat belt device used in a vehicle other than a car.

[0086] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0087] 1 Retractor, 2 Spool, 3 Base frame, 4 Lock mechanism, 5 Pretensioner, 6 Spring unit, 7 Retainer cover, 21 Torsion bar, 21a Expanded diameter portion, 21b First end, 21c Second end, 22 Push nut, 31, 32 Opening, 33 Engagement teeth, 41 Lock gear, 41a Engagement teeth, 41b Guide groove, 42 Pawl, 42a First end, 42b Second end, 42c Protrusion, 42d Engagement claw, 43 Locking base (pawl holding portion), 43a Flange portion, 43b Shaft portion, 43c Pin, 43d Eaves portion, 43e Flange thickness adjustment portion, 43f Guide groove, 43g Opening, 43h Main shaft portion, 43i Convex portion, 44 Flywheel, 45 Vehicle sensor, 46 Pawl, 46a Engagement claw, 46b Tail portion, 46c Protrusion portion, 51 Pipe, 52 Gas generator, 53 Ring gear, 54 Bearing, 55 Pin, 61, 71 Clasp, 100 Seat belt device, 101 Guide anchor, 102 Belt anchor, 103 Buckle, 104 Tongue, 421 First surface, 422 Second surface, 431 First holding surface, 432 Second holding surface

Claims

1. A retractor comprising a spool that winds up webbing for restraining an occupant, a base frame that rotatably houses the spool, and a locking mechanism that restricts rotation of the spool, wherein the locking mechanism comprises a pawl that is held in a position separated from the base frame when the locking mechanism is not activated and that is moved to engage with the base frame when the locking mechanism is activated, and a pawl holding portion that holds the attitude of the pawl, wherein the pawl holding portion comprises a first holding surface that is arranged on the spool side and a second holding surface that is arranged on the opposite side of the spool, and wherein the first holding surface or the second holding surface is configured as an inclined surface whose entire surface is inclined so that the distance between the first holding surface and the second holding surface is wider on the side in the direction of movement of the pawl.

2. The retractor according to claim 1, wherein the first retaining surface or the second retaining surface is configured to be inclined radially about the rotation axis of the spool.

3. The retractor according to claim 1, wherein the first retaining surface or the second retaining surface is configured to be inclined in one direction from the rotation axis of the spool.

4. The retractor according to claim 1, wherein the first holding surface or the second holding surface is configured to be inclined radially around the rotation axis of the pawl.

5. The retractor according to claim 1, wherein the first holding surface or the second holding surface is configured to be inclined in one direction from the rotation axis of the pawl.

6. The retractor according to claim 1, wherein the first holding surface or the second holding surface is configured to be inclined in a tangential direction of the rotational path of the pawl.

7. A retractor as described in claim 1, wherein the pawl holding portion includes a disk-shaped flange portion having the first holding surface, and the flange portion is provided with a flange thickness adjustment portion that adjusts the thickness between the portion where the first holding surface is formed and the other portion.

8. The retractor according to claim 1, wherein the pawl holding portion is formed by a single part having the first holding surface and the second holding surface.

9. A retractor according to claim 1, wherein the pawl holding portion is made up of two parts: a part having the first holding surface and a part having the second holding surface.

10. A retractor as described in claim 1, wherein the pawl holding portion is composed of a flange portion having the first holding surface and a shaft portion having the second holding surface.

11. A seat belt device comprising a retractor according to any one of claims 1 to 10.

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