Retractor and seat belt device

Abstract

To provide a retractor and a seat belt device which suppress wobbling (movement in right and left direction) of a guide member, and can improve drive performance of the retractor.SOLUTION: A retractor 1 includes a spool 2 for winding a webbing for restraining an occupant, a base frame 3 rotatably including the spool 2, and a pretensioner 4 for rotating the spool 2 at the time of emergency. The pretensioner 4 includes a power transmission device 42 for transmitting power to a ring gear 41 connected to the spool 2. The power transmission device 42 includes a power transmission member 42a for transmitting power to the ring gear 41, a cylindrical guide member 42b for guiding the power transmission member 42a to the ring gear 41, and a gas generator 42c for supplying operation gas to the inside of the guide member 42b. The base frame 3 includes a projection 37 for regulating the position of the guide member 42b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a retractor and a seat belt device, and more particularly to a retractor and a seat belt device suitable for a configuration including a pretensioner equipped with a power transmission member in the form of an elongated rod made of resin. [Background technology]

[0002] Vehicles such as automobiles are generally provided with a seat belt device for restraining an occupant in a seat having a seat portion on which the occupant sits and a backrest portion located behind the occupant. Such a seat belt device includes a webbing for restraining the occupant, a retractor for winding 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 engaging the tongue with the buckle. In addition, it is becoming common for the retractor to have a pretensioner that removes slack in the webbing in an emergency such as a vehicle collision.

[0003] Such pretensioners often include a power transmission device that includes a power transmission member that rotates a spool that winds up the webbing, a long, thin pipe-shaped pressure vessel (guide member) that guides the power transmission member, and a gas generator that applies a propulsive force to the power transmission member by supplying a working gas to the guide member (see, for example, Patent Document 1).

[0004] In recent years, as described in Patent Document 1, research and development has been conducted into the use of a thin, rod-shaped resin part as a power transmission member for a pretensioner. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-44901 Summary of the Invention [Problem to be solved by the invention]

[0006] The above-mentioned resin rod-shaped power transmission member rotates the spool while its rear end is inserted into the guide member, which has the problem that the guide member is prone to wobbling (moving left and right) depending on the behavior of the guide member.

[0007] The present invention was devised in consideration of such problems, and aims to provide a retractor and a seat belt device that can suppress the wobble (movement in the left-right direction) of the guide member and improve the driving performance of the retractor. [Means for solving the problem]

[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 contains the spool, and a pretensioner that rotates the spool in an emergency, wherein the pretensioner includes a power transmission device that transmits power to a ring gear connected to the spool, and the power transmission device includes a power transmission member that transmits power to the ring gear, a cylindrical guide member that guides the power transmission member to the ring gear, and a gas generator that supplies working gas inside the guide member, wherein the base frame has a convex portion that regulates the position of the guide member.

[0009] According to the present invention, in a retractor including a spool that winds up a webbing for restraining an occupant, a base frame that rotatably contains the spool, and a pretensioner that rotates the spool in an emergency, the pretensioner includes a power transmission device that transmits power to a ring gear connected to the spool, and the power transmission device includes a power transmission member that transmits power to the ring gear, a cylindrical guide member that guides the power transmission member to the ring gear, and a gas generator that supplies working gas inside the guide member, a fixing member for fixing the guide member to the base frame; and a fixing member formed on the base frame at a position separated from the fixing member. and a protrusion that regulates the position of the guide member.

[0010] The protrusion may be formed by a part of the side surface, or may be formed by a separate component disposed on the side surface.

[0013] The convex portion may be configured such that, in a cross section in which a part of the power transmission member is in contact with the guide member after the pretensioner is activated, a straight line connecting the center of the guide member and the center of the power transmission member passes closer to the second end face than a point of contact between the guide member and the convex portion.

[0014] The protrusions may be arranged in a dotted pattern, a line pattern, or a dotted line pattern.

[0015] The power transmission member may be made of resin and have a rod shape.

[0016] According to the present invention, there is also provided a seat belt device comprising a retractor having any of the above-described configurations. [Effects of the Invention]

[0017] According to the retractor and seat belt device of the present invention described above, by arranging a convex portion on the base frame that regulates the position of the guide member, it is possible to suppress the wobble (movement in the left-right direction) of the guide member when the pretensioner is activated, thereby improving the driving performance of the retractor. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a component exploded view showing a retractor according to an embodiment of the present invention. [Figure 2] FIG. 2 is a rear view showing the assembled state of the retractor shown in FIG. [Figure 3] 3A and 3B are partial cross-sectional views of the retractor, where (A) is a cross-sectional view taken along the line AA in FIG. 2, and (B) is a cross-sectional view taken along the line BB in FIG. [Figure 4]2A and 2B are cross-sectional views showing the operation of the pretensioner shown in FIG. 1, in which (A) shows the state before the start of operation, (B) shows the state when the power transmission member has reached the stopper pin, and (C) shows the state after the completion of operation. [Figure 5] 5A is a partial cross-sectional view showing the relationship between the power transmission member and the guide member, and FIG. 5B is a partial cross-sectional view showing the relationship between the power transmission member, the guide member, and the protrusion. [Figure 6] 10A to 10C are diagrams showing modified examples of the protrusion, where (A) shows a first modified example, (B) shows a second modified example, and (C) shows a third modified example. [Figure 7] 10A and 10B are diagrams showing modified examples of the protrusion, where FIG. 10A shows a fourth modified example, and FIG. 10B shows a fifth modified example. [Figure 8] FIG. 10 is a parts exploded view showing a modified example of the retractor. [Figure 9] 1 is an overall configuration diagram showing a seat belt device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 9. Fig. 1 is an exploded view of a retractor according to one embodiment of the present invention. Fig. 2 is a rear view showing the assembled state of the retractor shown in Fig. 1. Fig. 3 is a partial cross-sectional view of the retractor, where (A) is a cross-sectional view taken along the line AA in Fig. 2, and (B) is a cross-sectional view taken along the line BB in Fig. 2. In Fig. 3(A), for ease of explanation, the power transmission member 42a is shown shaded gray.

[0020] 1, a retractor 1 according to one embodiment of the present invention includes a spool 2 that winds up a webbing for restraining an occupant, a base frame 3 that rotatably houses the spool 2, and a pretensioner 4 that rotates the spool 2 in an emergency. Note that the webbing is not shown in FIG. 1.

[0021] The spool 2 is a winding drum that winds up the webbing, and is rotatably housed within a base frame 3 that forms the framework of the retractor 1. The base frame 3 has a first end face 31 and a second end face 32 that are arranged to face each other, and a side face 33 that connects these end faces. The base frame 3 may include a tie plate 34 that faces the side face 33 and is connected to the first end face 31 and the second end face 32. A bracket 35 for fixing the base frame 3 may be fixed to the side face 33.

[0022] Furthermore, for example, the spring unit 6 is disposed on the first end surface 31 side, and the pretensioner 4 and locking mechanism 5 are disposed on the second end surface 32 side. Note that the arrangement of the spring unit 6, pretensioner 4, locking mechanism 5, etc. is not limited to the configuration shown in the figure.

[0023] In addition, an opening 31a is formed in the first end surface 31 of the base frame 3, through which the shaft portion of the spool 2 is inserted, and an opening 32a having internal teeth that can engage with a pawl (not shown) of the locking mechanism 5 is formed in the second end surface 32 of the base frame 3.

[0024] Furthermore, a part of the pretensioner 4 (for example, a ring gear 41) is disposed inside the second end face 32 of the base frame 3. Furthermore, a locking mechanism 5 is disposed outside the second end face 32 of the base frame 3, and the locking mechanism 5 is housed in a retainer cover 51.

[0025] A vehicle sensor (not shown) that detects sudden deceleration or tilt of the vehicle body may be disposed in the recess 51a of the retainer cover 51. The vehicle sensor may have, for example, a spherical mass body and a sensor lever that swings due to movement of the mass body. The vehicle sensor may be fitted and fixed in a recess formed in the second end surface 32 of the base frame 3.

[0026] The spool 2 may have a cavity in the center, through which a torsion bar 21 that forms an axis is inserted. The torsion bar 21 has a first end connected to a locking base 52 of the locking mechanism 5 that is connected to an end of the spool 2, and a second end fixed to the spool 2 and connected to a spring core of the spring unit 6.

[0027] Therefore, the spool 2 is connected to the spring unit 6 via the locking base 52 and the torsion bar 21, and is biased in the direction of winding up the webbing by the spiral spring stored in the spring unit 6. Note that the means for applying a winding force to the spool 2 is not limited to the spring unit 6, and may be other means such as an electric motor.

[0028] The locking base 52 is provided with a pawl (not shown) that is arranged so as to be able to protrude from and retract into the side surface of the locking base 52. When the locking mechanism 5 is activated, the pawl protrudes from the side surface of the locking base 52 and engages with internal teeth formed in the opening 32a of the base frame 3, thereby restricting rotation of the locking base 52 in the webbing-unwinding direction.

[0029] Therefore, even if a load is applied in the webbing-pulling direction with the locking mechanism 5 activated, the spool 2 can be held in a non-rotating state until a load equal to or greater than a threshold value is applied to the torsion bar 21. When a load equal to or greater than the threshold value is applied to the torsion bar 21, the torsion bar 21 twists, causing the spool 2 to rotate relatively, and the webbing is pulled out.

[0030] The locking mechanism 5 also includes a locking gear 53 disposed adjacent to the locking base 52. The locking gear 53 includes a flywheel (not shown) disposed so as to be able to swing, and when the webbing is withdrawn faster than the normal speed, the flywheel swings and engages with internal teeth formed on the retainer cover 51. When the vehicle sensor is activated, the sensor lever engages with external teeth formed on the side surface of the locking gear 53.

[0031] In this way, the rotation of the lock gear 53 is restricted by the operation of the flywheel or vehicle sensor. When the rotation of the lock gear 53 is restricted, relative rotation occurs between the locking base 52 and the lock gear 53, and this relative rotation causes the pawl to protrude from the side surface of the locking base 52.

[0032] The locking mechanism 5 is not limited to the configuration shown in the figure, and various conventional configurations can be selected and used. Also, instead of the torsion bar 21, the spool 2 may be provided with a shock absorbing mechanism formed by combining a shaft with a wire-like or plate-like plastically deforming member.

[0033] The pretensioner 4 includes, for example, a ring gear 41 connected to the spool 2 and having engaging teeth on its outer periphery, a power transmission device 42 that transmits power to the ring gear 41, a pretensioner cover 43 that stores the ring gear 41, and a stopper pin 44 that restricts movement of the power transmission member 42a. Although not shown, the pretensioner 4 may also include a guide spacer within the pretensioner cover 43 that forms a movement space for the power transmission member 42a.

[0034] The ring gear 41 is disposed so as to be positioned in a space formed between the pretensioner cover 43 and the base frame 3 (second end surface 32). The ring gear 41 may also be referred to as a drive wheel or a rotating member.

[0035] The pretensioner cover 43 is disposed, for example, on the inside of the second end surface 32 of the base frame 3. The pretensioner cover 43 is fixed to the second end surface 32 of the base frame 3 together with the tip of the guide member 42b by, for example, a fixing member 45.

[0036] The stopper pin 44 is a component that regulates the position of the end point of the power transmission member 42a. The stopper pin 44 is disposed in a position close to the guide member 42b within the passage of the power transmission member 42a formed by the pretensioner cover 43. The stopper pin 44 is fixed, for example, by inserting it from the outside of the pretensioner cover 43 and crimping its end from the outside of the second end surface 32 of the base frame 3.

[0037] The power transmission device 42 includes, for example, a power transmission member 42a having a rod shape made of resin that transmits power to the ring gear 41, a cylindrical guide member 42b that guides the power transmission member 42a to the ring gear 41, a gas generator 42c that supplies working gas to the inside of the guide member 42b, a piston 42d arranged between the gas generator 42c and the power transmission member 42a, a sealing member 42e that seals the gap between the piston 42d and the guide member, an elastic body 42f arranged in front of the piston 42d, and a protective member 42g made of resin that protects the elastic body 42f.

[0038] Before being inserted into the guide member 42b, the power transmission member 42a is formed in a linear rod shape. For example, by press-fitting the power transmission member 42a into the guide member 42b from the tip side thereof, the power transmission member 42a is accommodated inside the guide member 42b in a state conforming to the shape of the guide member 42b, as shown in FIG. 1. The power transmission member 42a may have an expanded diameter portion 42w at its tip. The rear end of the power transmission member 42a (the end on the piston 42d side) may have a spherical shape. The rear end of the power transmission member 42a may also have a flat shape.

[0039] 1, the guide member 42b has a curved shape that passes over the upper part of the first end face 31, the upper part of the tie plate 34, and the upper part of the second end face 32, and is positioned along the inside of the corner 36 formed by the second end face 32 and the side face 33. The guide member 42b is made of a metal member because it is a component that constitutes the pressure vessel.

[0040] A guide member 42h may be disposed at the tip of the guide member 42b, which supports the power transmission member 42a when the power transmission member 42a starts to mesh with the ring gear 41. An opening 42i is formed at the tip of the guide member 42b, which releases the power transmission member 42a, guided by the guide member 42h, from the guide member 42b into a space formed by the pretensioner cover 43. The guide member 42b also includes a notch 42j that communicates from the tip of the guide member 42b to the opening 42i, and an insertion hole 42k that is formed below the opening 42i and through which a fixing member 45 is inserted.

[0041] Opening 42i is formed in guide member 42b at a position adjacent to guide member 42h, and constitutes an outlet for power transmission member 42a. Cutout 42j has the function of positioning guide member 42h in the circumferential direction, and a protrusion of guide member 42h is inserted into cutout 42j.

[0042] The guide member 42h has, for example, a generally cylindrical shape that can be inserted into the tip end of the guide member 42b, and a sliding surface 42m that guides the power transmission member 42a into the opening 42i is formed at an angle at the end on the insertion side. The sliding surface 42m may have a groove shape that curves along the outer shape of the power transmission member 42a. In addition, a notch 42n through which the fixing member 45 is inserted is formed at the bottom of the sliding surface 42m. The fixing member 45 is fixed from the outside of the second end face 32 of the base frame 3 by a push nut 45a or the like.

[0043] The guide member 42b may also include a restraining portion 42o that restrains movement of the piston 42d when the pretensioner 4 is activated. The restraining portion 42o is a portion that allows the power transmission member 42a to pass and stops the piston 42d within the guide member 42b. The restraining portion 42o is, for example, a throttle portion formed in a portion of the guide member 42b, and forms a protruding convex portion on the inside of the guide member 42b. The restraining portion 42o is formed, for example, by pressing a portion of the outer periphery of the guide member 42b. Note that the restraining portion 42o may also be formed by fixing a separate part, such as a pin, to the guide member 42b.

[0044] The gas generator 42c is a component that sprays working gas into the guide member 42b in an emergency such as a vehicle collision, thereby imparting a propulsive force to the power transmission member 42a. The gas generator 42c is connected to an ECU (electronic control unit) (not shown), and is controlled based on the measured values of an acceleration sensor, etc.

[0045] The piston 42d is a metal component including, for example, a head 42p having a substantially spherical shape and a substantially cylindrical body 42q formed behind the head 42p. A seal member 42e is disposed on the outer periphery of the body 42q. A spring 46 for biasing the piston 42d may be disposed behind the piston 42d between the piston 42d and the gas generator 42c. The configuration of the piston 42d is not limited to the configuration shown in the figure.

[0046] The head portion 42p has an outer diameter larger than the inner diameter of the restraint portion 42o. A first through hole 42r and a second through hole 42s that communicate with the spaces before and after the piston 42d are formed in the center of the head portion 42p (see FIG. 4(C)). The first through hole 42r has a smaller diameter than the second through hole 42s.

[0047] The first through-hole 42r is configured to be sealable by the rear end of a member (e.g., the power transmission member 42a) located in front of the piston 42d until the piston 42d reaches the restraint portion 42o. The amount of working gas released can be controlled by adjusting the diameter of the first through-hole 42r. The weight of the piston 42d can also be reduced by increasing the diameter of the second through-hole 42s.

[0048] The inner diameter of the body 42q is, for example, larger than the diameter of the second through-hole 42s. A plug 42t that controls the flow rate of the working gas flowing into the second through-hole 42s may be disposed in the body 42q. A groove is formed in the axial direction between the plug 42t and the body 42q, allowing the working gas to flow therethrough.

[0049] The seal member 42e is, for example, a substantially cylindrical elastomer part. The outer diameter of the seal member 42e is formed, for example, to be slightly larger than the inner diameter of the guide member 42b, and the seal member 42e is press-fitted into the guide member 42b. Therefore, the seal member 42e moves while maintaining contact with the inner surface of the guide member 42b due to the pressure of the working gas supplied from the gas generator 42c.

[0050] The elastic body 42f is, for example, an elastomer component formed in a generally cylindrical shape. The elastic body 42f is configured to closely contact the inner surface of the guide member 42b when attached. The elastic body 42f also has an elastic force that allows it to deform into a shape that allows it to pass through the restraint portion 42o when the pretensioner is activated.

[0051] By disposing such an elastic body 42f, the first through-hole 42r can be sealed by the elastic body 42f until the piston 42d collides with the restraint portion 42o. After the elastic body 42f passes through the restraint portion 42o, the working gas can be released from the first through-hole 42r, thereby reducing the kinetic energy of the piston 42d.

[0052] The protective member 42g is disposed between the elastic body 42f and the power transmission member 42a. The protective member 42g is made of, for example, the same material as the power transmission member 42a. The protective member 42g may be configured to be connectable to the elastic body 42f. Note that the configurations of the elastic body 42f and the protective member 42g are not limited to those shown in the drawings.

[0053] Here, the operation of the pretensioner 4 will be described with reference to Figures 4(A) to 4(C). Figure 4 is a cross-sectional view showing the operation of the pretensioner shown in Figure 1, where (A) shows the state before the start of operation, (B) shows the state when the power transmission member has reached the stopper pin, and (C) shows the state after the completion of operation. Note that in Figures 4(A) to 4(C), the power transmission member 42a is shown shaded gray for ease of explanation.

[0054] 4(A), before the pretensioner 4 is activated, the power transmission member 42a is housed in the guide member 42b. At this time, the tip end of the power transmission member 42a is inserted to a position facing the guide member 42h.

[0055] In the event of an emergency such as a vehicle collision, the pretensioner 4 is activated, and working gas is supplied from the gas generator 42c into the guide member 42b, causing the power transmission member 42a to be pushed out via the piston 42d and move along the guide member 42b. At this time, the tip of the power transmission member 42a collides with the sliding surface 42m of the guide member 42h, is deflected toward the opening 42i, moves along the sliding surface 42m, and is released toward the engaging teeth formed on the outer periphery of the ring gear 41.

[0056] The power transmission member 42a released from the guide member 42b collides with the engaging teeth of the ring gear 41, causing the ring gear 41 to rotate. Thereafter, the power transmission member 42a moves along the path formed by the pretensioner cover 43 while being plastically deformed by the engaging teeth of the ring gear 41.

[0057] As shown in Fig. 4(B), when the elastic body 42f reaches the restraint portion 42o while the movement of the power transmission member 42a is restricted by the stopper pin 44, the power transmission member 42a is compressed, and as shown in Fig. 4(C), the elastic body 42f passes through the restraint portion 42o, and the piston 42d collides with the restraint portion 42o and stops. After passing through the restraint portion 42o, the elastic body 42f is discharged into the space formed by the power transmission member 42a and the guide member 42b, having restored to almost its original shape.

[0058] Therefore, when the piston 42d is restrained, the working gas is not trapped within the guide member 42b, but is released to the outside from the through holes (first through hole 42r and second through hole 42s) of the piston 42d, thereby reducing the kinetic energy of the piston 42d.

[0059] As described above, the base frame 3 includes a first end face 31 disposed on the side where the ring gear 41 is not disposed, a second end face 32 disposed on the side where the ring gear 41 is disposed, and a side face 33 connecting the first end face 31 and the second end face 32. The tip of the guide member 42b is inserted into a corner 36 between the second end face 32 and the side face 33, and is fixed to the second end face by a fixing member 45.

[0060] This embodiment is characterized in that the base frame 3 includes a protrusion 37 that regulates the position of the guide member 42b. Specifically, the protrusion 37 is formed so as to protrude inward (the side facing the spool 2) of the side surface 33. Furthermore, the protrusion 37 is formed into a vertically elongated shape by pressing a portion of the side surface 33, for example, as shown in FIG. 2 . Furthermore, the protrusion 37 is formed near the upper portion of the side surface 33 so as to be spaced apart from the fixing member 45 that fixes the tip of the guide member 42b to the side surface 33.

[0061] 5A and 5B are explanatory diagrams of the convex portion, with (A) being a partial cross-sectional view showing the relationship between the power transmission member and the guide member, and (B) being a partial cross-sectional view showing the relationship between the power transmission member, the guide member, and the convex portion. For convenience of explanation, Fig. 5A shows only the partial cross-section shown in Fig. 3A, and includes the state of the power transmission member 42a after the pretensioner is activated. Fig. 5B is a partially enlarged view of Fig. 5A, and includes the cross-section of the power transmission member 42a.

[0062] 4(B) and 4(C), when the pretensioner 4 is activated, the power transmission member 42a passes through the pretensioner cover 43, and the tip (expanded diameter portion 42w) of the power transmission member 42a hits the stopper pin 44. At this time, the tip of the power transmission member 42a gets into between the second end surface 32 of the base frame 3 and the guide member 42b, as shown in FIG.

[0063] After the tip of the power transmission member 42a hits the stopper pin 44, an excessive load is generated on the power transmission member 42a in the direction of arrow P1 in the figure, and therefore the guide member 42b receives a load in the direction of arrow P2 in the figure, and a force is applied that moves the guide member 42b in the direction of arrow P2, causing the guide member 42b to wobble (move left and right). Note that in Figure 5(A), for ease of explanation, the position of the guide member 42b before it wobble (move left and right) is shown by a dotted line.

[0064] Therefore, in this embodiment, a convex portion 37 is formed on the side surface 33 to regulate the position of the guide member 42b, suppress the wobble (movement in the left-right direction) of the guide member 42b, and improve the driving performance of the retractor 1.

[0065] In order for the convex portion 37 to effectively restrict the wobble of the guide member 42b, for example, as shown in FIG. 5(B), the convex portion 37 is configured so that, in a cross section in which a part of the power transmission member 42a is in contact with the guide member 42b after the pretensioner 4 is activated, a straight line L connecting the center O1 of the guide member 42b and the center O2 of the power transmission member 42a passes closer to the second end face 32 than the contact point Q1 between the guide member 42b and the convex portion 37.

[0066] In other words, the position and height of the protrusion 37 are designed so that the straight line L passes through a contact point Q1 between the guide member 42b and the protrusion 37 and a contact point Q2 between the guide member 42b and the flat portion of the side surface 33.

[0067] Furthermore, since the wobble of the guide member 42b is based on the position where the tip of the guide member 42b is fixed to the second end face 32 by the fixing member 45, the wobble of the guide member 42b can be effectively suppressed by positioning the convex portion 37 as far away as possible from this base point (the position of the fixing member 45).

[0068] Next, modified examples of the protrusion 37 will be described with reference to Figs. 6(A) to 7(B). Fig. 6 shows modified examples of the protrusion, with (A) showing a first modified example, (B) showing a second modified example, and (C) showing a third modified example. Fig. 7 shows modified examples of the protrusion, with (A) showing a fourth modified example, and (B) showing a fifth modified example. Figs. 6(A) to 6(C) show partial rear views of the side surface 33, and Figs. 7(A) and 7(B) show partial cross-sectional views of the periphery of the protrusion 37.

[0069] As shown in Fig. 6(A) as a first modified example, the protrusions 37 may be dot-shaped. As shown in Fig. 6(B) as a second modified example, the protrusions 37 may be linear. As shown in Fig. 6(C) as a third modified example, the protrusions 37 may be dotted.

[0070] As in the fourth modified example shown in Fig. 7(A), the protrusion 37 may have a shape in which part of the inner surface of the side surface 33 is raised. Also, as in the fourth modified example shown in Fig. 7(A), the protrusion 37 may be formed by a separate part such as a rivet arranged on the side surface 33.

[0071] Next, a modified example of the retractor 1 will be described with reference to Fig. 8. Here, Fig. 8 is an exploded view of parts showing a modified example of the retractor.

[0072] The modified retractor 1 shown in Fig. 8 is of a type in which the amount of webbing wound when the pretensioner 4 is activated is less than that shown in Fig. 1. In the modified retractor 1 shown in Fig. 8, the length of the power transmission member 42a is formed to be shorter than that shown in Fig. 1. In addition, the path through which the power transmission member 42a passes, which is formed by the guide member 42b and the pretensioner cover 43, is also formed to be shorter than that shown in Fig. 1. As the other configurations are the same as those shown in Fig. 1, detailed description thereof will be omitted here.

[0073] As shown in Figures 1 and 8, by forming the convex portion 37, regardless of the amount of webbing taken up when the pretensioner 4 is activated, i.e., regardless of the length of the power transmission member 42a, the position of the guide member 42b is regulated and the wobbling (movement in the left-right direction) of the guide member 42b is suppressed, thereby improving the driving performance of the retractor 1.

[0074] Next, a seatbelt device according to one embodiment of the present invention will be described with reference to Fig. 9. Fig. 9 is an overall configuration diagram showing a seatbelt device according to one embodiment of the present invention. In Fig. 9, for the sake of convenience, components other than the seatbelt device are shown by dashed lines.

[0075] The seat belt device 100 according to this embodiment shown in FIG. 9 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, and a tongue 104 provided on the webbing W, and the retractor 1 has, for example, the configuration shown in FIG. 1.

[0076] Below, a brief description will be given of components other than the retractor 1. The seat S includes, for example, a seat S1 on which an occupant sits, a backrest S2 located behind the occupant, and a headrest S3 that supports the occupant's head. The retractor 1 is built into, for example, a B-pillar R of the vehicle body. In general, 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. In addition, the guide anchor 101 is often located on the B-pillar R. 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.

[0077] 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.

[0078] The above-described seat belt device 100 is a normal seat belt device for the front seats to which the retractor 1 according to the above-described embodiment is applied. Therefore, according to the seat belt device 100 according to the present embodiment, the position of the guide member 42b is restricted by the protrusion 37, and the wobbling (movement in the left-right direction) of the guide member 42b is suppressed, thereby improving the driving performance of the retractor 1.

[0079] The seat belt device 100 according to this embodiment is not limited to application to front seats, and can be easily applied to rear seats, for example, by omitting the guide anchor 101. The seat belt device 100 according to this embodiment can also be used in vehicles other than automobiles.

[0080] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0081] 1 Retractor 2 spools 3 Base Frame 4 Pretensioner 5 Locking mechanism 6 Spring unit 21 Torsion bar 31 First end surface 31a opening 32 Second end face 32a opening 33 Side 34 Thai Plate 35 Bracket 36 Corner 37 Convex part 41 Ring gear 42 Power transmission device 42a Power transmission member 42b Guide member 42c gas generator 42d piston 42e Sealing material 42f Elastic body 42g protective material 42h Guide member 42i opening 42j Notch 42k insertion hole 42m sliding surface 42n Notch 42o Restraint Section 42p head 42q Torso 42r First through hole 42s 2nd through hole 42t plug 42w expanded diameter part 43 Pretensioner cover 44 Stopper pin 45 Fixing member 45a push nut 46 Spring 51 Retainer cover 51a Recess 52 Rocking Base 53 Lock Gear 100 Seatbelt device 101 Guide Anchor 102 Belt anchor 103 Buckle 104 Tongs

Claims

1. a retractor including a spool that winds up a webbing for restraining an occupant, a base frame that rotatably houses the spool, and a pretensioner that rotates the spool in an emergency, wherein the pretensioner includes a power transmission device that transmits power to a ring gear connected to the spool, and the power transmission device includes a power transmission member that transmits power to the ring gear, a cylindrical guide member that guides the power transmission member to the ring gear, and a gas generator that supplies working gas into the guide member, a fixing member that fixes the guide member to the base frame; a protrusion formed on the base frame for regulating the position of the guide member at a position away from the fixed member, A retractor characterized by:

2. 2. The retractor according to claim 1, wherein the base frame comprises a first end face disposed on a side where the ring gear is not disposed, a second end face disposed on a side where the ring gear is disposed, and a side face connecting the first end face and the second end face, the guide member being configured to be inserted into a corner between the second end face and the side face, and the protrusion being formed to protrude inward from the side face.

3. The retractor according to claim 2, wherein the protrusion is formed by a part of the side surface, or by a separate component disposed on the side surface.

4. 3. The retractor according to claim 2, wherein the convex portion is configured such that, in a cross section in a state in which a part of the power transmission member is in contact with the guide member after the pretensioner is activated, a straight line connecting a center of the guide member and a center of the power transmission member passes closer to the second end face than a point of contact between the guide member and the convex portion.

5. The retractor according to claim 1 , wherein the protrusions are arranged in a dotted, linear, or dotted line pattern.

6. 2. The retractor according to claim 1, wherein the power transmission member is made of resin and has a rod shape.

7. A seat belt device comprising the retractor according to any one of claims 1 to 6.

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